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Sample records for sarcocystis neurona merozoites

  1. Sarcocyst Development in Raccoons (Procyon lotor) Inoculated with Different Strains of Sarcocystis neurona Culture-Derived Merozoites.

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    Dryburgh, E L; Marsh, A E; Dubey, J P; Howe, D K; Reed, S M; Bolten, K E; Pei, W; Saville, W J A

    2015-08-01

    Sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (EPM), a neurological disease in horses. Raccoon ( Procyon lotor ) is considered the most important intermediate host in the life cycle of S. neurona in the United States; S. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating EPM. The focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different host-derived strains of in vitro-cultivated S. neurona merozoites. Four raccoons were inoculated with strains derived from a raccoon, a sea otter, a cat, and a horse. Raccoon tissues were fed to laboratory-raised opossums ( Didelphis virginiana ), the definitive host of S. neurona . Intestinal scraping revealed sporocysts in opossums who received muscle tissue from raccoons inoculated with the raccoon-derived or the sea otter-derived isolates. These results demonstrate that sarcocysts can mature in raccoons inoculated with in vitro-derived S. neurona merozoites. In contrast, the horse and cat-derived isolates did not produce microscopically or biologically detected sarcocysts. Immunoblot analysis revealed both antigenic and antibody differences when testing the inoculated raccoons. Immunohistochemical staining indicated differences in staining between the merozoite and sarcocyst stages. The successful infections achieved in this study indicates that the life cycle can be manipulated in the laboratory without affecting subsequent stage development, thereby allowing further purification of strains and artificial maintenance of the life cycle.

  2. Sarcocystis neurona retinochoroiditis in a sea otter (Enhydra lutris kenyoni).

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    Dubey, J P; Thomas, N J

    2011-12-29

    Sarcocystis neurona is an important cause of fatal disease in sea otters in the USA. Encephalitis is the predominant lesion and parasites are confined to the central nervous system and muscles. Here we report retinochoroiditis in a sea otter (Enhydra lutris kenyoni) found dead on Copalis Beach, WA, USA. Salient lesions were confined to the brain and eye. Multifocal nonsuppurative meningoencephalitis was present in the cerebrum and cerebellum associated with S. neurona schizonts. The retina of one eye had a focus of inflammation that contained numerous S. neurona schizonts and merozoites. The focus extended from the retinal pigment epithelium inward through all layers of the retina, but inflammation was most concentrated at the inner surface of the tapetum and the outer retina. The inner and outer nuclear layers of the retina were disorganized and irregular at the site of inflammation. There was severe congestion and mild hemorrhage in the choroid, and mild hemorrhage into the vitreous body. Immunohistochemistry with S. neurona-specific polyclonal rabbit antibodies stained schizonts and merozoites. To our knowledge this is the first report of S. neurona-associated retinochoroiditis in any naturally infected animal. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Atypical fatal sarcocystosis associated with Sarcocystis neurona in a White-nosed coati (Nasua narica molaris).

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    Dubey, Jitender P; Trupkiewicz, John G; Verma, Shiv K; Mowery, Joseph D; Adedoyin, Gloria; Georoff, Tim; Grigg, Michael E

    2017-11-30

    The protozoan parasite Sarcocystis neurona is an important cause of disease in horses (equine protozoal myeloencephalitis, EPM) and marine mammals. Isolated reports of clinical EPM-like disease have been documented in a zebra, raccoon, domestic cat, domestic dog, ferret, skunk, mink, lynx, red panda and fisher. The predominant disease is encephalomyelitis associated with schizonts in neural tissues. Here, we report highly disseminated sarcocystosis, in many tissues of a captive White-nosed coati (Nasua narica molaris). The 14year old, neutered male coati was euthanized due to progressive weakness, lethargy, and inappetence. Schizonts, including free and intracellular merozoites were detected in many cell types, and differed morphologically from S. neurona schizonts in horses. Only a few sarcocysts were seen in skeletal muscle and the myocardium. Immunohistochemically, the protozoa reacted positively to S. neurona but not to Toxoplasma gondii antibodies. Severe inflammtory disease detected in the stomach, intestine, adrenal and thyroid glands, ciliary body of eye, and urinary bladder associated with schizonts in the coati has not been reported earlier in any host with EPM. Although, a few schizonts were found in the brain, encephalitis was minimal and not the cause of clinical signs. Multilocus PCR-DNA sequencing using DNA derived from the coati lung tissue identified an S. neurona infection using the 18S, 28S and ITS-1 markers, and a novel genotype using primer pairs against antigenic surface proteins (SnSAG3, SnSAG4, SnSAG1-5-6) and microsatellite markers (MS, SN7, SN9). Although the genotype was similar to the widely distributed Type VI strain, it possessed a novel allele at SnSAG5, and a different MS combination of repeats at SN7 and SN9. Whether this severe parasitism was related to the host or the parasite needs further investigation. Published by Elsevier B.V.

  4. Frequency of antibodies against Sarcocystis neurona and Neospora caninum in domestic cats in the state of Bahia, Brazil

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    Iris Daniela Santos de Meneses

    2014-12-01

    Full Text Available Sarcocystis neurona is the major agent of equine protozoal myeloencephalitis. It infects several mammalian species in the Americas, where the definitive hosts, marsupials of the genus Didelphis (D. virginiana and D. albiventris are found. Domestic cats are one of the confirmed intermediate hosts of the parasite; however, antibodies against S. neurona had never before been demonstrated in Brazilian cats. The aim of this study was to determine whether cats in Bahia, Brazil, are exposed to the parasite. A total of 272 feline serum samples (134 from feral and 138 from house cats were subjected to an indirect fluorescent antibody test using cultured merozoites of S. neurona as antigen. Positivity was detected in 4.0% (11/272 of the tested samples, with titers ranging from 25 to 800. The feline sera were also tested for antibodies against the protozoan Neospora caninum, with an observed antibody frequency of 2.9%. To the author's knowledge, this is the first study to report antibodies against S. neurona in Brazilian cats. We conclude that cats are exposed to the parasite in the region of this study. Further investigations are needed to confirm the role of cats in the transmission cycle of S. neurona in Brazil.

  5. Investigação de anticorpos contra Sarcocystis neurona e Sarcocystis cruzi em equinos

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    A. M. Antonello

    2015-10-01

    Full Text Available ABSTRACTSarcocystis neurona is the primary agent for Equine Protozoal Myeloencephalitis (EPM, important neurological disease characterized by behavior or muscular changes, that impairs animal performance and husbandry. Sarcocystis cruzi is a pathogen related to myositis in cattle. Although related the life cycles of the parasites are distinct. S. neurona has opossums (Didelphis spp. and S. cruzi, dogs as definitive hosts. However, S. neurona and S. cruzi may undergo cross-reactivity in serological tests, interfering on results of EPM ante-mortem diagnostic tests. In the present study, serology of 189 mares was performed by indirect immunofluorescence antibody test, using antigens of S. neurona and S. cruzi in order to assess the exposure degree of animals to antigens. Analyzing the results, it was observed that most of the animals (84.13% reacted with at least one protozoal species and the number of animals which showed antibodies against S. cruzi was greater than S. neurona (80.42% and 33.86%, respectively and a third of seropositive animals reacted to antigens of both species.

  6. Detection of antibodies against Sarcocystis neurona, neospora spp., and Toxoplasma gondii in horses from Costa Rica

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    Serum samples from 315 horses from Costa Rica, Central America were examined for the presence of antibodies against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii using the SnSAG2 ELISA, the NhSAG1 ELISA, and the modified agglutination test, respectively. Anti-S. neurona antibodies were f...

  7. Sarcocyst development in raccoons (Procyon lotor) inoculated with different strains of Sarcosytis neurona culture-derived merozoites

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    Sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (EPM), a neurological disease in horses. Raccoon (Procyon lotor) is considered the most important intermediate host in the life cycle of S. neurona in the USA; S. neurona sarcocysts do mature in raccoon...

  8. Differential Roles for Inner Membrane Complex Proteins across Toxoplasma gondii and Sarcocystis neurona Development.

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    Dubey, Rashmi; Harrison, Brooke; Dangoudoubiyam, Sriveny; Bandini, Giulia; Cheng, Katherine; Kosber, Aziz; Agop-Nersesian, Carolina; Howe, Daniel K; Samuelson, John; Ferguson, David J P; Gubbels, Marc-Jan

    2017-01-01

    The inner membrane complex (IMC) of apicomplexan parasites contains a network of intermediate filament-like proteins. The 14 alveolin domain-containing IMC proteins in Toxoplasma gondii fall into different groups defined by their distinct spatiotemporal dynamics during the internal budding process of tachyzoites. Here, we analyzed representatives of different IMC protein groups across all stages of the Toxoplasma life cycle and during Sarcocystis neurona asexual development. We found that across asexually dividing Toxoplasma stages, IMC7 is present exclusively in the mother's cytoskeleton, whereas IMC1 and IMC3 are both present in mother and daughter cytoskeletons (IMC3 is strongly enriched in daughter buds). In developing macro- and microgametocytes, IMC1 and -3 are absent, whereas IMC7 is lost in early microgametocytes but retained in macrogametocytes until late in their development. We found no roles for IMC proteins during meiosis and sporoblast formation. However, we observed that IMC1 and IMC3, but not IMC7, are present in sporozoites. Although the spatiotemporal pattern of IMC15 and IMC3 suggests orthologous functions in Sarcocystis, IMC7 may have functionally diverged in Sarcocystis merozoites. To functionally characterize IMC proteins, we knocked out IMC7, -12, -14, and -15 in Toxoplasma. IMC14 and -15 appear to be involved in switching between endodyogeny and endopolygeny. In addition, IMC7, -12, and -14, which are all recruited to the cytoskeleton outside cytokinesis, are critical for the structural integrity of extracellular tachyzoites. Altogether, stage- and development-specific roles for IMC proteins can be discerned, suggesting different niches for each IMC protein across the entire life cycle. IMPORTANCE The inner membrane complex (IMC) is a defining feature of apicomplexan parasites key to both their motility and unique cell division. To provide further insights into the IMC, we analyzed the dynamics and functions of representative alveolin domain

  9. Systems based analysis of the Sarcocystis neurona genome identifies pathways that contribute to a heteroxenous life cycle

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    Sarcocystis neurona is a member of the Coccidia, a clade of single-celled parasites of medical and veterinary importance including Eimeria, Sarcocystis, Neospora and Toxoplasma. Unlike Eimeria, a single host enteric pathogen, Sarcocystis, Neospora and Toxoplasma are two host parasites that infect an...

  10. An update on Sarcocystis neurona infections in animals and Equine Protozoal Myeloencephalitis (EPM)

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    Dubey, J. P.; Howe, D. K.; Furr, M.; Saville, W. J.; Marsh, A.E.; Reed, S. M.; Grigg, M. E.

    2015-01-01

    Equine protozoal myeloencephalitis (EPM) is a serious disease of horses, and its management continues to be a challenge for veterinarians. The protozoan Sarcocystis neurona is most commonly associated with EPM. S. neurona has emerged as a common cause of mortality in marine mammals, especially sea otters (Enhydra lutris). EPM-like illness has also been recorded in several other mammals, including domestic dogs and cats. This paper updates S. neurona and EPM information from the last 15 years on the advances regarding life cycle, molecular biology, epidemiology, clinical signs, diagnosis, treatment and control. PMID:25737052

  11. Prevalence of antibodies against Neospora spp. and Sarcocystis neurona in donkeys from northeastern Brazil

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    Solange Maria Gennari

    2016-03-01

    Full Text Available Abstract Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys of 333 sera tested by the indirect fluorescent antibody test (IFAT with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys of the samples tested by IFAT (cut-off ≥50 and 21% (69 donkeys by the direct agglutination test (SAT ≥50. The SAT and IFAT results for S. neurona showed a poor concordance (value of Kappa=0.051. This is the first report ofNeospora spp. antibodies in Brazilian donkeys and the first detection of antibodies against S. neurona in this animal species.

  12. Bobcat (Lynx rufus) as a new natural intermediate host for Sarcocystis neurona

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    The protozoan Sarcocystis neurona is an important cause of severe clinical disease of horses (called equine protozoal myeloencephalitis, EPM), marine mammals, companion animals, and several species of wildlife animals in the Americas. The Virginia opossum (Didelphis virginiana) is its definitive hos...

  13. Prevalence of antibodies to Sarcocystis neurona and Neospora hughesi in horses from Mexico

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    The risk of equine protozoal myeloencephalitis (EPM) to horses in Mexico has not been established. Serum samples from 495 horses in Durango State, Mexico were examined for the presence of antibodies to Sarcocystis neurona and Neospora hughesi using enzyme-linked immunosorbent assays (ELISAs) based o...

  14. Effects of Experimental Sarcocystis neurona-Induced Infection on Immunity in an Equine Model

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    S. Rochelle Lewis

    2014-01-01

    Full Text Available Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM, affecting 0.5–1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both.

  15. Systems-Based Analysis of the Sarcocystis neurona Genome Identifies Pathways That Contribute to a Heteroxenous Life Cycle

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    Blazejewski, Tomasz; Nursimulu, Nirvana; Pszenny, Viviana; Dangoudoubiyam, Sriveny; Namasivayam, Sivaranjani; Chiasson, Melissa A.; Chessman, Kyle; Tonkin, Michelle; Swapna, Lakshmipuram S.; Hung, Stacy S.; Bridgers, Joshua; Ricklefs, Stacy M.; Boulanger, Martin J.; Dubey, Jitender P.; Porcella, Stephen F.; Kissinger, Jessica C.; Howe, Daniel K.

    2015-01-01

    ABSTRACT Sarcocystis neurona is a member of the coccidia, a clade of single-celled parasites of medical and veterinary importance including Eimeria, Sarcocystis, Neospora, and Toxoplasma. Unlike Eimeria, a single-host enteric pathogen, Sarcocystis, Neospora, and Toxoplasma are two-host parasites that infect and produce infectious tissue cysts in a wide range of intermediate hosts. As a genus, Sarcocystis is one of the most successful protozoan parasites; all vertebrates, including birds, reptiles, fish, and mammals are hosts to at least one Sarcocystis species. Here we sequenced Sarcocystis neurona, the causal agent of fatal equine protozoal myeloencephalitis. The S. neurona genome is 127 Mbp, more than twice the size of other sequenced coccidian genomes. Comparative analyses identified conservation of the invasion machinery among the coccidia. However, many dense-granule and rhoptry kinase genes, responsible for altering host effector pathways in Toxoplasma and Neospora, are absent from S. neurona. Further, S. neurona has a divergent repertoire of SRS proteins, previously implicated in tissue cyst formation in Toxoplasma. Systems-based analyses identified a series of metabolic innovations, including the ability to exploit alternative sources of energy. Finally, we present an S. neurona model detailing conserved molecular innovations that promote the transition from a purely enteric lifestyle (Eimeria) to a heteroxenous parasite capable of infecting a wide range of intermediate hosts. PMID:25670772

  16. Ultrastructural and molecular confirmation of the development of Sarcocystis neurona tissue cysts in the central nervous system of southern sea otters (Enhydra lutris nereis).

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    Miller, M A; Barr, B C; Nordhausen, R; James, E R; Magargal, S L; Murray, M; Conrad, P A; Toy-Choutka, S; Jessup, D A; Grigg, M E

    2009-10-01

    In 2004, three wild sea otters were diagnosed with putative Sarcocystis neurona-associated meningoencephalitis by histopathology and immunohistochemistry. Schizonts, free merozoites and tissue cysts were observed in the brains of all three infected animals. Tissue cysts walls from sea otter 1 (SO1) stained positively using anti-S. neurona polyclonal antiserum. However, positive staining does not preclude infection by closely related or cross-reactive tissue cyst-forming coccidian parasites. Two immature tissue cysts in the brain of SO1 were examined using transmission electron microscopy. Ultrastructural features included cyst walls with thin villous projections up to 1 microm long with tapered ends and a distinctive, electron-dense outer lining layer composed of linearly-arranged, semi-circular structures with a "hobnailed" surface contour. Small numbers of microtubules extended down through the villi into the underlying granular layer. Metrocytes were short and plump with an anterior apical complex, 22 sub-pellicular microtubules, numerous free ribosomes and no rhoptries. Some metrocytes appeared to be dividing, with two adjacent nuclear profiles. Collectively these ultrastructural features were compatible with developing protozoal cysts and were similar to prior descriptions of S. neurona tissue cysts. Panspecific 18S rDNA primers were utilized to identify protozoa infecting the brains of these otters and DNA amplification and additional sequencing at the ITS1 locus confirmed that all three otters were infected with S. neurona. No other Sarcocystis spp. were detected in the brains or skeletal muscles of these animals by immunohistochemistry or PCR. We believe this is the first ultrastructural and molecular confirmation of the development of S. neurona tissue cysts in the CNS of any animal.

  17. A protozoal-associated epizootic impacting marine wildlife: Mass-mortality of southern sea otters ( Enhydra lutris nereis) due to Sarcocystis neurona infection

    National Research Council Canada - National Science Library

    Miller, Melissa A; Conrad, Patricia A; Harris, Michael; Hatfield, Brian; Langlois, Gregg; Jessup, David A; Magargal, Spencer L; Packham, Andrea E; Toy-Choutka, Sharon; Melli, Ann C; Murray, Michael A; Gulland, Frances M; Grigg, Michael E

    2010-01-01

    .... However, detailed postmortem examinations revealed lesions consistent with an infectious etiology, and further investigation confirmed the protozoan parasite Sarcocystis neurona as the underlying cause. Tissues from 94...

  18. Seroepidemiology of Sarcocystis neurona and Neospora hughesi infections in domestic donkeys (Equus asinus) in Durango, Mexico.

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    Alvarado-Esquivel, Cosme; Howe, Daniel K; Yeargan, Michelle R; Alvarado-Esquivel, Domingo; Alfredo Zamarripa-Barboza, José; Dubey, Jitender P

    2017-01-01

    There is currently no information regarding Sarcocystis neurona and Neospora hughesi infections in donkeys in Mexico. Here, we determined the presence of antibodies against S. neurona and N. hughesi in donkeys in the northern Mexican state of Durango. Serum samples of 239 domestic donkeys (Equus asinus) were assayed for S. neurona and N. hughesi antibodies using home-made enzyme-linked immunoassays; six (2.5%) of the 239 donkeys tested seropositive for S. neurona. The seroprevalence of S. neurona infection was comparable among donkeys regardless of their origin, health status, or sex. Multivariate analysis showed that seropositivity to S. neurona was associated with increased age (OR = 2.95; 95% CI: 1.11-7.82; p = 0.02). Antibodies to N. hughesi were found in two (0.8%) of the 239 donkeys. Both exposed donkeys were healthy, 3- and 6-year-old females. This is the first evidence of S. neurona and N. hughesi infections in donkeys in Mexico. © C. Alvarado-Esquivel et al., published by EDP Sciences, 2017.

  19. Seroepidemiology of Sarcocystis neurona and Neospora hughesi infections in domestic donkeys (Equus asinus in Durango, Mexico

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    Alvarado-Esquivel Cosme

    2017-01-01

    Full Text Available There is currently no information regarding Sarcocystis neurona and Neospora hughesi infections in donkeys in Mexico. Here, we determined the presence of antibodies against S. neurona and N. hughesi in donkeys in the northern Mexican state of Durango. Serum samples of 239 domestic donkeys (Equus asinus were assayed for S. neurona and N. hughesi antibodies using home-made enzyme-linked immunoassays; six (2.5% of the 239 donkeys tested seropositive for S. neurona. The seroprevalence of S. neurona infection was comparable among donkeys regardless of their origin, health status, or sex. Multivariate analysis showed that seropositivity to S. neurona was associated with increased age (OR = 2.95; 95% CI: 1.11–7.82; p = 0.02. Antibodies to N. hughesi were found in two (0.8% of the 239 donkeys. Both exposed donkeys were healthy, 3- and 6-year-old females. This is the first evidence of S. neurona and N. hughesi infections in donkeys in Mexico.

  20. Genome-Wide Identification and Evolutionary Analysis of Sarcocystis neurona Protein Kinases

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    Edwin K. Murungi

    2017-03-01

    Full Text Available The apicomplexan parasite Sarcocystis neurona causes equine protozoal myeloencephalitis (EPM, a degenerative neurological disease of horses. Due to its host range expansion, S. neurona is an emerging threat that requires close monitoring. In apicomplexans, protein kinases (PKs have been implicated in a myriad of critical functions, such as host cell invasion, cell cycle progression and host immune response evasion. Here, we used various bioinformatics methods to define the kinome of S. neurona and phylogenetic relatedness of its PKs to other apicomplexans. We identified 97 putative PKs clustering within the various eukaryotic kinase groups. Although containing the universally-conserved PKA (AGC group, S. neurona kinome was devoid of PKB and PKC. Moreover, the kinome contains the six-conserved apicomplexan CDPKs (CAMK group. Several OPK atypical kinases, including ROPKs 19A, 27, 30, 33, 35 and 37 were identified. Notably, S. neurona is devoid of the virulence-associated ROPKs 5, 6, 18 and 38, as well as the Alpha and RIO kinases. Two out of the three S. neurona CK1 enzymes had high sequence similarities to Toxoplasma gondii TgCK1-α and TgCK1-β and the Plasmodium PfCK1. Further experimental studies on the S. neurona putative PKs identified in this study are required to validate the functional roles of the PKs and to understand their involvement in mechanisms that regulate various cellular processes and host-parasite interactions. Given the essentiality of apicomplexan PKs in the survival of apicomplexans, the current study offers a platform for future development of novel therapeutics for EPM, for instance via application of PK inhibitors to block parasite invasion and development in their host.

  1. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozonn cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossum, Didelphis virginiana, from Southern Louisian

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    We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoan’s of veterinary importance (Neospora caninum, Sarcocystis neurona and Besnoitia darlingi) in a population of North American opossums (Didelphis...

  2. Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal

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    Selma Samiko Miyazaki Onuma

    2014-12-01

    Full Text Available Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9% showed seropositivity for T. gondii, eight (72.7% for S. neurona, and seven (63.6% for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars.

  3. Anti-Sarcocystis neurona immunostaining associated with equine protozoal myeloencephalitis in Brazil Imunomarcação de Sarcocystis neurona associada com um caso de mieloencefalite protozoária eqüina no Brasil

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    Tatiane Alves da Paixão

    2007-12-01

    Full Text Available A retrospective study (1942 to 2005 of histopathological lesions included samples of central nervous system (SNC from 203 animals in the Equidae family. A total of 42.4% of these samples had significant pathological changes, which were classified as inflammatory (62.8%, degenerative (25.6%, circulatory (10.5%, and neoplasic (1.1% lesions. Immunohistochemistry anti-Sarcocystis neurona antigens was performed in all the cases with inflammatory changes (54, of which one of the case of encephalitis resulted positive to immunostaining. Although evidence of EPM (Equine Protozoal Myeloencephalitis has been previously reported in Brazil, to the best of our knowledge, this is the first report in which characteristic EPM lesion was associated with anti-S. neurona immunostaining in Brazil.Em um estudo retrospectivo (de 1942 a 2005, amostras do sistema nervoso central de 203 eqüídeos foram avaliadas para a presença de alterações histológicas. Dessas amostras, 42,4% apresentaram alguma lesão histopatológica significativa, das quais foram classificadas como alterações inflamatórias (62,8%, degenerativas (25,6%, circulatórias (10,5% e neoplásicas (1,1%. Fragmentos de SNC dos 54 animais com alterações inflamatórias foram avaliados para detecção de antígenos de Sarocystis neurona pela técnica de imunoistoquímica, que foi positiva em um caso de encefalite em eqüino. Embora haja registros de MPE no Brasil, este é o primeiro caso confirmado imunoistoquimicamente.

  4. A novel Sarcocystis neurona genotype XIII is associated with severe encephalitis in an unexpectedly broad range of marine mammals from the northeastern Pacific Ocean

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    Barbosa, Lorraine; Johnson, Christine K.; Lambourn, Dyanna M.; Gibson, Amanda K.; Haman, Katherine H.; Huggins, Jessica L.; Sweeny, Amy R.; Sundar, Natarajan; Raverty, Stephen A.; Grigg, Michael E.

    2015-01-01

    Sarcocystis neurona is an important cause of protozoal encephalitis among marine mammals in the northeastern Pacific Ocean. To characterize the genetic type of S. neurona in this region, samples from 227 stranded marine mammals, most with clinical or pathological evidence of protozoal disease, were tested for the presence of coccidian parasites using a nested PCR assay. The frequency of S. neurona infection was 60% (136/227) among pinnipeds and cetaceans, including seven marine mammal species not previously known to be susceptible to infection by this parasite. Eight S. neurona fetal infections identified this coccidian parasite as capable of being transmitted transplacentally. Thirty-seven S. neurona-positive samples were multilocus sequence genotyped using three genetic markers: SnSAG1-5-6, SnSAG3 and SnSAG4. A novel genotype, referred to as Type XIII within the S. neurona population genetic structure, has emerged recently in the northeastern Pacific Ocean and is significantly associated with an increased severity of protozoal encephalitis and mortality among multiple stranded marine mammal species. PMID:25997588

  5. Self-mating in the definitive host potentiates clonal outbreaks of the apicomplexan parasites Sarcocystis neurona and Toxoplasma gondii.

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    Jered M Wendte

    2010-12-01

    Full Text Available Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. In contrast, selfing and other life history traits, such as asexual expansion of tissue-cysts by oral transmission among intermediate hosts, have been proposed to explain the genetic basis for the clonal population structure of T. gondii. In this study, we investigated the contributing roles self-mating and sexual recombination play in nature to maintain clonal population structures and produce or expand parasite clones capable of causing disease epidemics for two tissue encysting parasites. We applied high-resolution genotyping against strains isolated from a T. gondii waterborne outbreak that caused symptomatic disease in 155 immune-competent people in Brazil and a S. neurona outbreak that resulted in a mass mortality event in Southern sea otters. In both cases, a single, genetically distinct clone was found infecting outbreak-exposed individuals. Furthermore, the T. gondii outbreak clone was one of several apparently recombinant progeny recovered from the local environment. Since oocysts or sporocysts were the infectious form implicated in each outbreak, the expansion of the epidemic clone can be explained by self-mating. The results also show that out-crossing preceded selfing to produce the virulent T. gondii clone. For the tissue encysting coccidia, self-mating exists as a key adaptation potentiating the epidemic expansion and transmission of newly emerged parasite clones that can profoundly shape parasite population genetic structures or cause

  6. Seroepidemiology of Sarcocystis neurona, Toxoplasma gondii and Neospora spp. among horses in the south of the state of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Manoel Junqueira Maciel Ribeiro

    2016-01-01

    Full Text Available Abstract The present study used the indirect fluorescent antibody test (IFAT to determine the seroprevalence of Sarcocystis neurona, Toxoplasma gondii and Neospora spp., and evaluated the variables associated with these infections among 506 apparently healthy horses, reared in the south of the state of Minas Gerais, Brazil. This study was conducted between April 2012 and October 2013. Among the horses, the true prevalence of S. neurona was 26% (95% CI: 22.0-30.4%, T. gondii 19.9% (95% CI: 15.5-24.8% and Neospora spp. 23.9% (95% CI: 19.9-28.1%; and among the farms, 88.3% (95% CI: 74.4-91.6%, 71.6% (95% CI: 41-92.8% and 85% (95% CI: 70.7-96.1%, respectively. Regarding mixed infection, 17 horses (3.4% were seropositive for both S. neurona and T. gondii, 16 (3.2% for T. gondii and Neospora spp. and 14 (2.8% for S. neurona and Neospora spp. The associations between seropositivity and variables relating to the structure of the farm, management and health were analyzed using the logistic regression analysis, through the generalized estimating equations (GEE. The results suggest that the south of Minas Gerais is an enzootic area for S. neurona, T. gondii and Neospora spp. among horses, with prevalence of asymptomatic subclinical or chronic infections.

  7. Dual congenital transmission of Toxoplasma gondii and Sarcocystis neurona in a late-term aborted pup from a chronically infected southern sea otter (Enhydra lutris nereis).

    Science.gov (United States)

    Shapiro, Karen; Miller, Melissa A; Packham, Andrea E; Aguilar, Beatriz; Conrad, Patricia A; Vanwormer, Elizabeth; Murray, Michael J

    2016-03-01

    Toxoplasma gondii and Sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. Close monitoring of threatened southern sea otters (Enhydra lutris nereis) in California allowed for the diagnosis of dual transplacental transmission of T. gondii and S. neurona in a wild female otter that was chronically infected with both parasites. Congenital infection resulted in late-term abortion due to disseminated toxoplasmosis. Toxoplasma gondii and S. neurona DNA was amplified from placental tissue culture, as well as from fetal lung tissue. Molecular characterization of T. gondii revealed a Type X genotype in isolates derived from placenta and fetal brain, as well as in all tested fetal organs (brain, lung, spleen, liver and thymus). This report provides the first evidence for transplacental transmission of T. gondii in a chronically infected wild sea otter, and the first molecular and immunohistochemical confirmation of concurrent transplacental transmission of T. gondii and S. neurona in any species. Repeated fetal and/or neonatal losses in the sea otter dam also suggested that T. gondii has the potential to reduce fecundity in chronically infected marine mammals through parasite recrudescence and repeated fetal infection.

  8. A protozoal-associated epizootic impacting marine wildlife: mass-mortality of southern sea otters (Enhydra lutris nereis) due to Sarcocystis neurona infection.

    Science.gov (United States)

    Miller, Melissa A; Conrad, Patricia A; Harris, Michael; Hatfield, Brian; Langlois, Gregg; Jessup, David A; Magargal, Spencer L; Packham, Andrea E; Toy-Choutka, Sharon; Melli, Ann C; Murray, Michael A; Gulland, Frances M; Grigg, Michael E

    2010-09-20

    During April 2004, 40 sick and dead southern sea otters (Enhydra lutris nereis) were recovered over 18km of coastline near Morro Bay, California. This event represented the single largest monthly spike in mortality ever recorded during 30 years of southern sea otter stranding data collection. Because of the point-source nature of the event and clinical signs consistent with severe, acute neurological disease, exposure to a chemical or marine toxin was initially considered. However, detailed postmortem examinations revealed lesions consistent with an infectious etiology, and further investigation confirmed the protozoan parasite Sarcocystis neurona as the underlying cause. Tissues from 94% of examined otters were PCR-positive for S. neurona, based on DNA amplification and sequencing at the ITS-1 locus, and 100% of tested animals (n=14) had elevated IgM and IgG titers to S. neurona. Evidence to support the point-source character of this event include the striking spatial and temporal clustering of cases and detection of high concentrations of anti-S. neurona IgM in serum of stranded animals. Concurrent exposure to the marine biotoxin domoic acid may have enhanced susceptibility of affected otters to S. neurona and exacerbated the neurological signs exhibited by stranded animals. Other factors that may have contributed to the severity of this epizootic include a large rainstorm that preceded the event and an abundance of razor clams near local beaches, attracting numerous otters close to shore within the affected area. This is the first report of a localized epizootic in marine wildlife caused by apicomplexan protozoa.

  9. Intra-uterine exposure of horses to Sarcocystis spp. antigens

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    A.M. Antonello

    2016-04-01

    Full Text Available The aim of this study was to examine the intra-uterine exposure to Sarcocystis spp. antigens, determining the number of foals with detectable concentrations of antibodies against these agents in the serum, before colostrum ingestion and collect data about exposure of horses to the parasite. Serum samples were collected from 195 thoroughbred mares and their newborns in two farms from southern Brazil. Parasite specific antibody responses to Sarcocystis antigens were detected using the indirect immunofluorescent antibody test (IFAT and immunoblot analysis. In 84.1% (159/189 of the pregnant mares and in 7.4% (14/189 of foals we detected antibodies anti-Sarcocystis spp. by IFAT. All samples seropositive from foals were also positive in their respective mares. Serum samples of seropositive foals by IFAT, showed no reactivity on the immunoblot, having as antigens S. neurona merozoites. In conclusion, the intra-uterine exposure to Sarcocystis spp. antigens in horses was demonstrated, with occurrence not only in mares, but also in their foals, before colostrum ingestion these occurrences were reduced.

  10. Evaluation and comparison of an indirect fluorescent antibody test for detection of antibodies to Sarcocystis neurona, using serum and cerebrospinal fluid of naturally and experimentally infected, and vaccinated horses.

    Science.gov (United States)

    Duarte, Paulo C; Daft, Barbara M; Conrad, Patricia A; Packham, Andrea E; Saville, William J; MacKay, Robert J; Barr, Bradd C; Wilson, W David; Ng, Terry; Reed, Stephen M; Gardner, Ian A

    2004-04-01

    The objectives of this study were to evaluate the accuracy of the indirect fluorescent antibody test (IFAT) using serum and cerebrospinal fluid (CSF) of horses naturally and experimentally infected with Sarcocystis neurona, to assess the correlation between serum and CSF titers, and to determine the effect of S. neurona vaccination on the diagnosis of infection. Using receiver-operating characteristic analysis, the areas under the curve for the IFAT were 0.97 (serum) and 0.99 (CSF). Sensitivity and specificity were 83.3 and 96.9% (serum, cutoff 80) and 100 and 99% (CSF, cutoff 5), respectively. Titer-specific likelihood ratios (LRs) ranged from 0.03 to 187.8 for titers between <10 and 640. Median time to conversion was 22-26 days postinfection (DPI) (serum) and 30 DPI (CSF). The correlation between serum and CSF titers was moderately strong (r = 0.6) at 30 DPI. Percentage of vaccinated antibody-positive horses ranged from 0 to 95% between 0 and 112 days after the second vaccination. Thus, the IFAT was reliable and accurate using serum and CSF. Use of LRs potentially improves clinical decision making. Correlation between serum and CSF titers affects the joint accuracy of the IFAT; therefore, the ratio of serum to CSF titers has potential diagnostic value. The S. neurona vaccine could possibly interfere with equine protozoal myeloencephalitis diagnosis.

  11. A new trivalent SnSAG surface antigen chimera for efficient detection of antibodies against Sarcocystis neurona and diagnosis of equine protozoal myeloencephalitis.

    Science.gov (United States)

    Yeargan, Michelle; de Assis Rocha, Izabela; Morrow, Jennifer; Graves, Amy; Reed, Stephen M; Howe, Daniel K

    2015-05-01

    Enzyme-linked immunosorbent assays (ELISAs) based on the SnSAG surface antigens of Sarcocystis neurona provide reliable detection of infection by the parasite. Moreover, accurate serodiagnosis of equine protozoal myeloencephalitis (EPM) is achieved with the SnSAG ELISAs by measuring antibodies in serum and cerebrospinal fluid (CSF) to reveal active infection in the central nervous system. Two independent ELISAs based on recombinant (r)SnSAG2 or a chimeric fusion of SnSAG3 and SnSAG4 (rSnSAG4/3) are currently used together for EPM serodiagnosis to overcome varied antibody responses in different horses. To achieve reliable antibody detection with a single ELISA instead of 2 separate ELISAs, rSnSAG2 was fused with rSnSAG4/3 into a single trivalent protein, designated rSnSAG2/4/3. Paired serum and CSF from 163 horses were tested with all 3 ELISAs. When the consensus antibody titers obtained with the rSnSAG2 and rSnSAG4/3 ELISAs were compared to the single SAG2/4/3 ELISA titers, Spearman rank correlation coefficients of ρ = 0.74 and ρ = 0.90 were obtained for serum and CSF, respectively, indicating strong agreement between the tests. When the rSnSAG2 and rSnSAG4/3 consensus serum-to-CSF titer ratio was compared to the rSnSAG2/4/3 serum-to-CSF titer ratio, the Spearman correlation coefficient was ρ = 0.87, again signifying strong agreement. Importantly, comparing the diagnostic interpretation of the serum-to-CSF titer ratios yielded a Cohen kappa value of 0.77. These findings suggest that the single ELISA based on the trivalent rSnSAG2/4/3 will provide serologic and diagnostic results that are highly comparable to the consensus of the 2 independent ELISAs based on rSnSAG2 and rSnSAG4/3. © 2015 The Author(s).

  12. A review of Sarcocystis spp. shed by opossums (Didelphis spp. in Brazil

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    Samantha Yuri Oshiro Branco Valadas

    2016-08-01

    Full Text Available South American opossums are the definitive hosts of Sarcocystis neurona, Sarcocystis falcatula, Sarcocystis speeri and Sarcocystis lindsayi. The sporocysts of these species of Sarcocystis are morphologically similar and methods like infectivity and pathogenicity for intermediate hosts (immunodeficient mice and psittacine birds and molecular tools are used for identification. Opossums are synanthropic wild animals, and widely distributed in Brazilian territory. Previous studies have shown high environmental contamination with S. neurona sporocysts in several Brazilian regions. This paper reviews information on Sarcocystis spp. shed by various opossum species and its occurrence in Brazil.

  13. Detection of Sarcocystis spp. infection in bobcats (Lynx rufus).

    Science.gov (United States)

    Verma, S K; Calero-Bernal, R; Lovallo, M J; Sweeny, A R; Grigg, M E; Dubey, J P

    2015-09-15

    The protozoan Sarcocystis neurona is an important cause of severe clinical disease of horses (called equine protozoal myeloencephalitis, EPM), marine mammals, companion animals, and several species of wildlife animals in the Americas. The Virginia opossum (Didelphis virginiana) is its definitive host in the USA and other animals act as intermediate or aberrant hosts. Samples of tongue and heart from 35 bobcats hunted for fur and food from Mississippi State, USA in February, 2014 were used for the present study. Muscles were examined for Sarcocystis infection by microscopic examination of either unfixed muscle squash preparations or pepsin digests, by histopathology of fixed samples, and by molecular methods. Sarcocystis-like bradyzoites were found in digests of 14 hearts and 10 tongues of 35 bobcats. In histological sections, sarcocysts were found in 26 of 35 bobcats; all appeared relatively thin-walled similar to S. felis sarcocysts under light microscope at 1000× magnification. S. neurona-like sarcocysts having thickened villar tips were seen in unstained muscle squash of tongue of two bobcats and PCR-DNA sequencing identified them definitively as S. neurona-like parasites. DNA extracted from bradyzoites obtained from tongue and heart muscle digests was analyzed by PCR-DNA sequencing at the ITS1 locus. Results indicated the presence of S. neurona-like parasite in 26 of 35 samples. ITS1 sequences identical to S. dasypi were identified in 3 bobcats, 2 of which were also co-infected with S. neurona-like parasite. The high prevalence of sarcocysts in bobcat tissues suggested an efficient sylvatic cycle of Sarcocystis spp. in the remote regions of Mississippi State with the bobcat as a relevant intermediate host. Published by Elsevier B.V.

  14. Sarcocystis spp. Infection in two Red Panda Cubs (Ailurus fulgens).

    Science.gov (United States)

    Zoll, W M; Needle, D B; French, S J; Lim, A; Bolin, S; Langohr, I; Agnew, D

    2015-01-01

    Two neonatal male red panda (Ailurus fulgens) littermates were submitted for necropsy examination. One animal was found dead with no prior signs of illness; the other had a brief history of laboured breathing. Post-mortem examination revealed disseminated protozoal infection. To further characterize the causative agent, transmission electron microscopy (TEM), immunohistochemistry (IHC), polymerase chain reaction (PCR) and amplification and nucleic acid sequencing were performed. IHC was negative for Toxoplasma gondii and Neospora caninum, but was positive for a Sarcocystis spp. TEM of cardiac muscle and lung revealed numerous intracellular apicomplexan protozoa within parasitophorous vacuoles. PCR and nucleic acid sequencing of partial 18S rRNA and the internal transcribed spacer (ITS)-1 region confirmed a Sarcocystis spp. that shared 99% sequence homology to Sarcocystis neurona and Sarcocystis dasypi. This represents the first report of sarcocystosis in red pandas. The histopathological, immunohistochemical, molecular and ultrastructural findings are supportive of vertical transmission resulting in fatal disseminated disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Antibodies and Plasmodium falciparum merozoites

    NARCIS (Netherlands)

    Ramasamy, R; Ramasamy, M; Yasawardena, S

    There is considerable interest in using merozoite proteins in a vaccine against falciparum malaria. Observations that antibodies to merozoite surface proteins block invasion are a basis for optimism. This article draws attention to important and varied aspects of how antibodies to Plasmodium

  16. Las neuronas de la conciencia

    Directory of Open Access Journals (Sweden)

    Rodrigo Quian Quiroga

    2008-05-01

    Full Text Available El estudio de la conciencia ha sido descrito como uno de los grandes desafíos de la humanidad. Es por ello que los neurocientíficos se han dedicado a estudiar la percepción visual consciente de objetos. Un reciente estudio en humanos –implantados con electrodos intracraneales por motivos clínicos- mostró la presencia de neuronas que disparan exclusivamente cuando las imágenes son percibidas conscientemente.

  17. Ancient, globally distributed lineage of Sarcocystis from sporocysts of the Eastern rat snake (Pantherophis alleghaniensis) and its relation to neurological sequalae in intermediate hosts.

    Science.gov (United States)

    Verma, Shiv K; Lindsay, David S; Rosenthal, Benjamin M; Dubey, Jitender P

    2016-07-01

    There is an emerging concern that snakes are definitive hosts of certain species of Sarcocystis that cause muscular sarcocystosis in human and non-human primates. Other species of Sarcocystis are known to cycle among snakes and rodents, but have been poorly characterized in the USA and elsewhere. Although neurological sequalae are known for certain species of Sarcocystis, no such neurological symptoms are known to typify parasites that naturally cycle in rodents. Here, sporocysts of a species of Sarcocystis were found in the intestinal contents of a rat snake (Pantherophis alleghaniensis) from Maryland, USA. The sporocysts were orally infective for interferon gamma gene knockout (KO) mice, but not to Swiss Webster outbred mice. The KO mice developed neurological signs, and were necropsied between 33 and 52 days post-inoculation. Only schizonts/merozoites were found, and they were confined to the brain. The predominant lesion was meningoencephalitis characterized by perivascular cuffs, granulomas, and necrosis of the neuropil. The schizonts and merozoites were located in neuropil, and apparently extravascular. Brain homogenates from infected KO mice were infective to KO mice and CV-1 cell line. DNA extracted from the infected mouse brain, and infected cell cultures revealed the highest identity with Sarcocystis species that employ snakes as definitive hosts. This is the first report of Sarcocystis infection in the endangered rat snake (P. alleghaniensis) and the first report of neurological sarcocystosis in mice induced by feeding sporocysts from a snake. These data underscore the likelihood that parasites in this genus that employ snakes as their definitive hosts constitute an ancient, globally distributed monophyletic group. These data also raise the possibility that neurological sequalae may be more common in intermediate hosts of Sarcocystis spp. than has previously been appreciated.

  18. Neuronas espejo y el aprendizaje en anestesia

    OpenAIRE

    Bautista, Jhon; Navarro, José Ricardo

    2011-01-01

    Las neuronas espejo fueron descritas inicialmente en primates de la especie Macaca nemestrina hacia el año 1990 por el neurofisiólogo Giacomo Rizzolatti y su grupo de la Universidad de Parma, en Italia. Son neuronas motoras que activan cuando el individuo observa la acción concreta para la que están predeterminadas sin generar ningún tipo de actividad motora. En la actualidad se considera que estas neuronas participan en procesos de adaptación al entorno social ya que permiten no solamente co...

  19. Acute, fatal Sarcocystis calchasi-associated hepatitis in Roller pigeons (Columba livia f. dom.) at Philadelphia Zoo.

    Science.gov (United States)

    Trupkiewicz, J G; Calero-Bernal, R; Verma, S K; Mowery, J; Davison, S; Habecker, P; Georoff, T A; Ialeggio, D M; Dubey, J P

    2016-01-30

    Four Roller pigeons (Columba livia f. dom.) at the Philadelphia Zoo died suddenly. Necropsy examination revealed macroscopic hepatitis. Microscopically, the predominant lesions were in liver, characterized with necrosis and mixed cell inflammatory response. Sarcocystis calchasi-like schizonts and free merozoites were identified in liver. Transmission electron microscopy confirmed that schizonts were in hepatocytes. A few schizonts were in spleen. PCR using S. calchasi-specific primers confirmed the diagnosis. Neither lesions nor protozoa were found in brain and muscles. This is the first report of acute visceral S. calchasi-associated sarcocystosis in naturally infected avian hosts. Published by Elsevier B.V.

  20. Neuronas espejo y el aprendizaje en anestesia

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    Jhon Bautista

    2011-10-01

    Full Text Available Las neuronas espejo fueron descritas inicialmente en primates de la especie Macaca nemestrina hacia el año 1990 por el neurofisiólogo Giacomo Rizzolatti y su grupo de la Universidad de Parma, en Italia. Son neuronas motoras que activan cuando el individuo observa la acción concreta para la que están predeterminadas sin generar ningún tipo de actividad motora. En la actualidad se considera que estas neuronas participan en procesos de adaptación al entorno social ya que permiten no solamente comprender las acciones sino también las intenciones de otros individuos. Se les atribuye función en los procesos de aprendizaje simple a través de la observación y la imitación que pueden ser aprovechados en la enseñanza de la anestesiología.

  1. Molecular characterization of the ribosomal DNA unit of Sarcocystis singaporensis, Sarcocystis zamani and Sarcocystis zuoi from rodents in Thailand.

    Science.gov (United States)

    Watthanakaiwan, Vichan; Sukmak, Manakorn; Hamarit, Kriengsak; Kaolim, Nongnid; Wajjwalku, Worawidh; Muangkram, Yuttamol

    2017-08-18

    Sarcocystis species are heteroxenous cyst-forming coccidian protozoan parasites with a wide host range, including rodents. In this study, Sarcocystis spp. samples were isolated from Bandicota indica, Rattus argentiventer, R. tiomanicus and R. norvegicus across five provinces of Thailand. Two major groups of Sarcocystis cysts were determined in this study: large and small cysts. By sequence comparisons and phylogenetic analyses based on the partial sequences of 28S ribosomal DNA, the large cysts showed the highest identity value (99%) with the S. zamani in GenBank database. While the small cysts could be divided into 2 groups of Sarcocystis: S. singaporensis and presupposed S. zuoi. The further analysis on 18S rDNA supported that the 2 isolates (S2 and B6 no.2) were as identified as S. singaporensis shared a high sequence identity with the S. singaporensis in GenBank database and the unidentified Sarcocystis (4 isolates, i.e., B6 no.10, B6 no.12, B10 no.4 and B10 no.7) showed 96.3-99.5% identity to S. zuoi as well as high distinct identity from others Sarcocystis spp. (≤93%). The result indicated that these four samples should be S. zuoi. In this study, we provided complete sequence of internal transcribed spacer 1 (ITS1), 5.8S rDNA and internal transcribed spacer 2 (ITS2) of these three Sarcocystis species and our new primer set could be useful to study the evolution of Sarcocystis.

  2. Differential Roles for Inner Membrane Complex Proteins across Toxoplasma gondii and Sarcocystis neurona Development

    OpenAIRE

    Dubey, Rashmi; Harrison, Brooke; Dangoudoubiyam, Sriveny; Bandini, Giulia; Cheng, Katherine; Kosber, Aziz; Agop-Nersesian, Carolina; Daniel K Howe; Samuelson, John; Ferguson, David J.P.; Gubbels, Marc-Jan

    2017-01-01

    The inner membrane complex (IMC) is a defining feature of apicomplexan parasites key to both their motility and unique cell division. To provide further insights into the IMC, we analyzed the dynamics and functions of representative alveolin domain-containing IMC proteins across developmental stages. Our work shows universal but distinct roles for IMC1, -3, and -7 during Toxoplasma asexual division but more specialized functions for these proteins during gametogenesis. In addition, we find th...

  3. Aborto ovino associado com infecção por Sarcocystis sp Ovine abortion associated with Sarcocystis sp. infection

    Directory of Open Access Journals (Sweden)

    Caroline A. Pescador

    2007-10-01

    parasite consistent with Sarcocystis sp. were found in the endothelial cells and vascular endothelium in several organs. Many schizonts with merozoites arranged in a rosette-like pattern were observed in brain and kidney tissues. In sections stained with periodic acid-Schiff (PAS, the limiting membrane of some schizonts appeared to be weakly PAS-positive. Merozoites and nuclei were PAS-negative. Protozoa did not react immunohistochemically to the antibody anti-Toxoplasma gondii; however, cross-reactivity was observed with Neospora caninum antibody. These findings were consistent with the diagnosis of Sarcocystis sp.

  4. Indirect haemagglutination reaction with Sarcocystis dispersa antigen.

    Science.gov (United States)

    Cerva, L; Cerná, Z

    1982-01-01

    A description is given of the preparation of antigen from Sarcocystis dispersa cystozoites and the procedure of the indirect haemagglutination test (IHA). The antibodies against this antigen were detected in experimentally infected mice from day 20 p.i. (1: 640). In the following weeks the antibody titres reached the value of 1: 40,960. The sera of pigs, sheep and horses spontaneously infected with other Sarcocystis species reacted with this antigen in low titres only. The bovine sera gave negative reactions even in cases when Sarcocystis cysts were present in the muscles of the examined animals. A possible application of IHA for the research and diagnostic purposes is discussed.

  5. Sarcocystis schneideri n. sp. (Sarcocystidae) infecting the barber skink Eumeces schneideri schneideri (Scincidae) Daudin, 1802. A light and ultrastructural study.

    Science.gov (United States)

    Bashtar, Abdel-Rahman; Al Aal, Zain Abd; Maarouf, Wael; Morsy, Kareem; Al Quraishy, Saleh

    2014-06-01

    The current study provides the first record of infection with Sarcocystis species in the barber skink Eumeces schneideri schneideri (Scincidae) captured from the north region of Egypt around the cities of El-Hamam and Al-Dabaa, Mersa Matruh Governorate, Egypt. Morphology of the parasite cysts was described using light and transmission electron microscopy. Five out of 80 (6.25%) of the examined skinks were found to be infected. The infection was recorded firstly by light microscopy as spindle-shaped cysts embedded in the muscle tissue. The cysts were microscopic and measured 250-900 μm in length × 50-100 μm in width (mean, 575 × 75 μm). The validity of this species was confirmed by means of ultrastructural characteristics of the primary cyst wall (0.28 μm thick) which revealed the presence of irregularly shaped crowded and osmiophilic knob-like projections underlined by a thin layer of ground substance measuring 0.15-0.17 μm (mean, 0.16 μm). This layer consisted mainly of fine, dense homogenous granules enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. Several septa derived from the ground substance divided the cyst into compartments. The merozoites were banana-shaped and measured 3-5 μm in length and 1.5-2.5 in width with centrally or posteriorly located nuclei. The morphological and morphometric data obtained during study were compared with those recorded previously from organisms within the Scincidae family. It was observed that this parasite possessed some distinguishing characteristics from the comparable species, which should be considered as a new species of the Sarcocystis genus, and the proposed name was Sarcocystis schneideri n. sp. with new host and locality records in Egypt.

  6. Sarcocystis rommeli, n. sp. (Apicomplexa: Sarcocystidae) from cattle (Bos taurus) and its differentiation from Sarcocystis hominis

    Science.gov (United States)

    Cattle (Bos taurus) are intermediate hosts for three named species of Sarcocystis, S. cruzi, S. hirsuta, and S. hominis. Recently, a fourth species was identified and named S. sinensis. However, S. sinensis originally named a species of Sarcocystis in water buffalo (Bubalus bubalis) in China. Based ...

  7. Isolation, Culture and Cryopreservation of Sarcocystis species

    Science.gov (United States)

    More than 200 valid Sarcocystis species have been described in the parasitological literature. The developmental life cycle in the intermediate host and definitive host has only been described for a few species. The majority of species have been identified based solely on the presence of the sarcocy...

  8. LAS NEURONAS DEL SEPTUM LATERAL MODIFICAN LA ACTIVIDAD DE LAS NEURONAS DEL NUCLEO TUBEROMAMILAR DEL HIPOTALAMO

    OpenAIRE

    FARIAS RODRIGUEZ, PAULA ANDREA

    2012-01-01

    El septum lateral (SL), es un núcleo del cerebro anterior, que, procesa la información sensorial afectiva procedente del hipocampo y dirige sus respuestas, importantes para la supervivencia, hacia las zonas del hipotálamo importantes para la motivación, como lo es el núcleo tuberomamilar del hipotálamo (TMN). El TMN contiene las neuronas histaminérgicas en el cerebro, la cual relacionamos con la vigilia y alerta en conductas motivadas y así puede dirigir y reforzar el comportamiento. El TM...

  9. ACOPLAMIENTO EXCITATORIO E INHIBITORIO DE NEURONAS PULSANTES ACOPLADAS

    Directory of Open Access Journals (Sweden)

    Francis Armando Segovia Chaves

    2012-05-01

    Full Text Available La información es representada como patrones de actividad neuronal o pulsos, lo que crea una diferencia significante entre las redes neuronales pulsantes y las redes neuronales clásicas. Una característica diferente de las redes neuronales pulsantes es que la información es codificada en patrones de actividad neuronal y estas se comunican usando trenes de pulsos en lugar de valores individuales. Además, este tipo de redes neuronales pulsantes trabajan con una gran cantidad de neuronas donde se requiere grandes recursos computacionales para ser simuladas. En el presente trabajo se realiza un análisis teórico de las redes neuronales pulsantes,  para el caso de dos neuronas acopladas. Se logra obtener teóricamente las condiciones para acoplamiento excitatorio e inhibitorio en las neuronas.

  10. Implementación en hardware de neuronas electrónicas

    OpenAIRE

    Baonza Cubillo, Gonzalo

    2016-01-01

    Este proyecto se centra en la simulación e implementación de neuronas electrónicas, capaces de replicar el funcionamiento de neuronas biológicas en tiempo real. Este tipo de neuronas permiten validar las restricciones temporales de los modelos software para construir circuitos híbridos en los que neuronas vivas y neuronas artificiales interactúan bidireccionalmente. El diseño se basa en el modelo de Hindmarsh-Rose (HR) por su bajo grado de dimensionalidad y porque representa, fielmente, el co...

  11. Different Sarcocystis spp. are present in bovine eosinophilic myositis.

    Science.gov (United States)

    Vangeel, Lieve; Houf, Kurt; Geldhof, Peter; De Preter, Katleen; Vercruysse, Jozef; Ducatelle, Richard; Chiers, Koen

    2013-11-08

    It has been suggested that Sarcocystis species are associated with bovine eosinophilic myositis (BEM). To date, parasite identification in this myopathy has been based on morphological techniques. The aim of the present study was to use molecular techniques to identify Sarcocystis species inside lesions of BEM. Histologically, BEM lesions of 97 condemned carcasses were examined for the presence of Sarcocystis species. Intralesional and extralesional cysts were collected using laser capture microdissection and the species was determined with a PCR-based technique based on 18S rDNA. Intralesional sarcocysts or remnants were found in BEM lesions in 28% of the carcasses. The majority (82%) of intralesional Sarcocystis species were found to be S. hominis. However S. cruzi and S. hirsuta were also found, as well as an unidentified species. It can be concluded that Sarcocystis species present in lesions of BEM are not restricted to one species. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Genetic assemblage of Sarcocystis spp. in Malaysian snakes.

    Science.gov (United States)

    Lau, Yee Ling; Chang, Phooi Yee; Subramaniam, Vellayan; Ng, Yit Han; Mahmud, Rohela; Ahmad, Arine Fadzlun; Fong, Mun Yik

    2013-09-09

    Sarcocystis species are protozoan parasites with a wide host range including snakes. Although there were several reports of Sarcocytis species in snakes, their distribution and prevalence are still not fully explored. In this study, fecal specimens of several snake species in Malaysia were examined for the presence of Sarcocystis by PCR of 18S rDNA sequence. Microscopy examination of the fecal specimens for sporocysts was not carried as it was difficult to determine the species of the infecting Sarcocystis. Of the 28 snake fecal specimens, 7 were positive by PCR. BLASTn and phylogenetic analyses of the amplified 18S rDNA sequences revealed the snakes were infected with either S. nesbitti, S. singaporensis, S. zuoi or undefined Sarcocystis species. This study is the first to report Sarcocystis infection in a cobra, and S. nesbitti in a reticulated python.

  13. Sarcocystis jamaicensis n. sp., from Red-Tailed Hawks (Buteo jamaicensis) Definitive Host and IFN-γ Gene Knockout Mice as Experimental Intermediate Host.

    Science.gov (United States)

    Verma, S K; von Dohlen, A Rosypal; Mowery, J D; Scott, D; Rosenthal, B M; Dubey, J P; Lindsay, D S

    2017-10-01

    Here, we report a new species of Sarcocystis with red-tailed hawk (RTH, Buteo jamaicensis) as the natural definitive host and IFN-γ gene knockout (KO) mice as an experimental intermediate host in which sarcocysts form in muscle. Two RTHs submitted to the Carolina Raptor Center, Huntersville, North Carolina, were euthanized because they could not be rehabilitated and released. Fully sporulated 12.5 × 9.9-μm sized sporocysts were found in intestinal scrapings of both hawks. Sporocysts were orally fed to laboratory-reared outbred Swiss Webster mice (SW, Mus musculus) and also to KO mice. The sporocysts were infective for KO mice but not for SW mice. All SW mice remained asymptomatic, and neither schizonts nor sarcocysts were found in any SW mice euthanized on days 54, 77, 103 (n = 2) or 137 post-inoculation (PI). The KO mice developed neurological signs and were necropsied between 52 to 68 days PI. Schizonts/merozoites were found in all KO mice euthanized on days 52, 55 (n = 3), 59, 61 (n = 2), 66, and 68 PI and they were confined to the brain. The predominant lesion was meningoencephalitis characterized by perivascular cuffs, granulomas, and necrosis of the neural tissue. The schizonts/merozoites were located in neural tissue and were apparently extravascular. Brain homogenates from infected KO mice were infective to KO mice by subcutaneous inoculation and when seeded on to CV-1 cells. Microscopic sarcocysts were found in skeletal muscles of 5 of 8 KO mice euthanized between 55-61 days PI. Only a few sarcocysts were detected. Sarcocysts were microscopic, up to 3.5 mm long. When viewed with light microscopy, the sarcocyst wall appeared thin (<1 μm thick) and smooth. By transmission electron microscopy, the sarcocyst wall classified as "type 1j" (new designation). Molecular characterization using 18S rRNA, 28S rRNA, ITS-1, and cox1 genes revealed a close relationship with Sarcocystis microti and Sarcocystis glareoli; both species infect birds as definitive hosts

  14. Molecular evidence of Sarcocystis species in captive snakes in Japan.

    Science.gov (United States)

    Abe, Niichiro; Matsubara, Katsuki; Tamukai, Kenichi; Miwa, Yasutsugu; Takami, Kazutoshi

    2015-08-01

    Sarcocystis nesbitti, using snakes as the definitive host, is a causative agent of acute human muscular sarcocystosis in Malaysia. Therefore, it is important to explore the distribution and prevalence of S. nesbitti in snakes. Nevertheless, epizootiological information of S. nesbitti in snakes remains insufficient because few surveys have assessed Sarcocystis infection in snakes in endemic countries. In Japan, snakes are popular exotic pet animals that are imported from overseas, but the degree of Sarcocystis infection in them remains unclear. The possibility exists that muscular sarcocystosis by S. nesbitti occurs in contact with captive snakes in non-endemic countries. For a total of 125 snake faecal samples from 67 snake species collected at animal hospitals, pet shops and a zoo, this study investigated the presence of Sarcocystis using polymerase chain reaction (PCR) for the 18S ribosomal RNA gene (18S rDNA). Four (3.2%) faecal samples were positive by PCR. Phylogenetic analysis of the 18S rDNA sequences obtained from four amplification products revealed one isolate from a beauty snake (Elaphe taeniura), Sarcocystis zuoi, which uses rat snakes as the definitive host. The isolate from a Macklot's python (Liasis mackloti) was closely related with unidentified Sarcocystis sp. from reticulated pythons in Malaysia. The remaining two isolates from tree boas (Corallus spp.) were closely related with Sarcocystis lacertae, Sarcocystis gallotiae and unidentified Sarcocystis sp. from smooth snakes, Tenerife lizards and European shrews, respectively. This report is the first of a study examining the distribution of Sarcocystis species in captive snakes in Japan.

  15. Molecular differentiation of Sarcocystis buffalonis and Sarcocystis levinei in water buffaloes (Bubalus bubalis) from Sarcocystis hirsuta and Sarcocystis cruzi in cattle (Bos taurus).

    Science.gov (United States)

    Gjerde, Bjørn; Hilali, Mosaad; Abbas, Ibrahim E

    2016-06-01

    The purpose of the present study was to obtain sarcocysts of Sarcocystis buffalonis and Sarcocystis levinei from water buffaloes and characterize the isolates by molecular methods in order to determine whether the two species were genetically different from Sarcocystis hirsuta and Sarcocystis cruzi, respectively, from cattle, which had been characterized before. About 35 macroscopically visible (3-4 × 1-2 mm) and 20 barely visible (1-3 × 0.2 mm) sarcocysts were excised from the esophagus of 18 naturally infected and freshly slaughtered adult water buffaloes at three slaughterhouses in Egypt. Genomic DNA was extracted from the sarcocysts, and all isolates were first characterized at the mitochondrial cytochrome c oxidase subunit I gene (cox1) gene through PCR amplification and direct sequencing. Selected isolates were subsequently further characterized at the 18S and 28S ribosomal (r) RNA genes and the internal transcribed spacer 1 (ITS1) region of the nuclear rDNA unit by direct sequencing or cloning. Only six of the isolated macroscopic sarcocysts belonged to S. buffalonis, whereas the others belonged to Sarcocystis fusiformis. Twelve of the smaller cysts belonged to S. levinei and seven to Sarcocystis sinensis. The characterization of the sarcocysts of S. sinensis and some of the sarcocysts of S. fusiformis have been reported before. Fifteen additional sarcocyst isolates of S. fusiformis were characterized at cox1 in the present study and found to be identical or closely similar to previous isolates. At cox1, the sequence identity between the six isolates of S. buffalonis was 99.8-100 % (two haplotypes), whereas the identity between the 12 isolates of S. levinei was 99.0-100 % (10 haplotypes). The identity between cox1 sequences of S. buffalonis and S. hirsuta (n = 56) was 92.9-93.6 % (on average 93.4 %), and the identity between cox1 sequences of S. levinei and S. cruzi (n = 22) was 92.9-94.0 % (on average 93.5 %). The phylogenetic

  16. Sarcocystis arieticanis (Apicomplexa: Sarcocystidae) infecting the heart muscles of the domestic sheep, Ovis aries (Artiodactyla: Bovidae), from K. S. A. on the basis of light and electron microscopic data.

    Science.gov (United States)

    Al Quraishy, Saleh; Morsy, Kareem; Bashtar, Abdel-Rahman; Ghaffar, Fathy Abdel; Mehlhorn, Heinz

    2014-10-01

    In the present study, the heteroxenous life cycle of Sarcocystis species from three strains of the slaughtered sheep at Al-Azizia and Al-Saada abattoirs in Riyadh city, K.S.A., was studied. Muscle samples of the oesophagus, diaphragm, tongue, skeletal and heart muscles were examined. Varied natural infection rates in the muscles of the examined sheep strains were recorded as 83% in Niemy, 81.5% in Najdy and 90% in Sawakny sheep. Muscles of the diaphragm showed the highest infection level above all organs except Najdy sheep in which oesophagus has the highest rate. Also, the heart was the lowest infected organ (40% Niemy, 44% Najdy and 53% Sawakny). Microscopic sarcocysts of Sarcocystis arieticanis are easily identified in sections through the heart muscles of the domestic sheep Ovis aries (Artiodactyla: Bovidae). Cysts measured 38.5-64.4 μm (averaged 42.66 μm) in width and 62.4-173.6 μm (averaged 82.14 μm) in length. The validity of this species was confirmed by means of ultrastructural characteristics of the primary cyst wall (0.1-0.27 μm thick) which revealed the presence of irregularly shaped crowded and hairy-like projections underlined by a thin layer of ground substance. This layer consisted mainly of fine, dense homogenous granules enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. Several septa derived from the ground substance divided the cyst into compartments. The merozoites were banana-shaped and measured 12-16 μm in length with centrally or posteriorly located nuclei. Experimental infection of carnivores by feeding heavily infected sheep muscles revealed that the dog, Canis familiaris, is the only final host of the present Sarcocystis species. Gamogony, sporogonic stages and characteristics of sporulated oocysts were also investigated.

  17. Genetic assemblage of Sarcocystis spp. in Malaysian snakes

    OpenAIRE

    Lau, Yee Ling; Chang, Phooi Yee; Subramaniam, Vellayan; Ng, Yit Han; Mahmud, Rohela; Ahmad, Arine Fadzlun; Fong, Mun Yik

    2013-01-01

    Background Sarcocystis species are protozoan parasites with a wide host range including snakes. Although there were several reports of Sarcocytis species in snakes, their distribution and prevalence are still not fully explored. Methods In this study, fecal specimens of several snake species in Malaysia were examined for the presence of Sarcocystis by PCR of 18S rDNA sequence. Microscopy examination of the fecal specimens for sporocysts was not carried as it was difficult to determine the spe...

  18. Ultrastructure of Sarcocystis bertrami sarcocysts from naturally infected donkey (Equus asinus) from Egypt

    Science.gov (United States)

    There is considerable confusion concerning Sarcocystis species in equids. Little is known of Sarcocystis infections in donkeys (Equus asinus). Here we describe the structure of Sarcocystis bertrami-like from the donkey by light and transmission electron microscopy (LM, TEM). Nineteen sarcocysts fro...

  19. How malaria merozoites reduce the deformability of infected RBC

    Science.gov (United States)

    Hosseini, Majid; Feng, James

    2011-11-01

    This talk presents a three-dimensional particle-based model for the red blood cell (RBC), and uses it to explore the changes in the deformability of RBC due to presence of malaria parasite. The cell membrane is represented by a set of discrete particles connected by nonlinear springs that represent shear and bending elasticity. The cytoplasm and the external liquid are modeled as homogeneous Newtonian fluids, and discretized by particles as in standard smoothed-particle-hydrodynamics models. The merozoite is modeled as an aggregate of particles constrained to rigid-body motion. The fluid flow and membrane deformation are computed, via the particle motion, by a two-step explicit scheme, with model parameters determined from experiments. The stretching of healthy and infected RBC by optical tweezers has been simulated to investigate the contribution of rigid merozoites to the decrease in deformability. Department of Mathematics, University of British Columbia, Vancouver, BC V6T 1Z2, Canada.

  20. Immunization of cattle with recombinant Babesia bovis merozoite surface antigen-1.

    Science.gov (United States)

    Hines, S A; Palmer, G H; Jasmer, D P; Goff, W L; McElwain, T F

    1995-01-01

    Cattle immunized with a recombinant merozoite surface antigen-1 molecule (MSA-1) produced high-titered antibody that reacted with the surface of the parasite and neutralized merozoite infectivity in vitro. However, recombinant MSA-1 immunization did not confer protection against challenge with virulent Babesia bovis. These results indicate that antibody-mediated neutralization of merozoite infectivity in vitro, at least for MSA-1-specific antibody, does not reflect in vivo protective immunity to babesiosis.

  1. Molecular identification of a malaria merozoite surface sheddase.

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    Philippa K Harris

    2005-11-01

    Full Text Available Proteolytic shedding of surface proteins during invasion by apicomplexan parasites is a widespread phenomenon, thought to represent a mechanism by which the parasites disengage adhesin-receptor complexes in order to gain entry into their host cell. Erythrocyte invasion by merozoites of the malaria parasite Plasmodium falciparum requires the shedding of ectodomain components of two essential surface proteins, called MSP1 and AMA1. Both are released by the same merozoite surface "sheddase," but the molecular identity and mode of action of this protease is unknown. Here we identify it as PfSUB2, an integral membrane subtilisin-like protease (subtilase. We show that PfSUB2 is stored in apical secretory organelles called micronemes. Upon merozoite release it is secreted onto the parasite surface and translocates to its posterior pole in an actin-dependent manner, a trafficking pattern predicted of the sheddase. Subtilase propeptides are usually selective inhibitors of their cognate protease, and the PfSUB2 propeptide is no exception; we show that recombinant PfSUB2 propeptide binds specifically to mature parasite-derived PfSUB2 and is a potent, selective inhibitor of MSP1 and AMA1 shedding, directly establishing PfSUB2 as the sheddase. PfSUB2 is a new potential target for drugs designed to prevent erythrocyte invasion by the malaria parasite.

  2. Examination of Sarcocystis spp. of giant snakes from Australia and Southeast Asia confirms presence of a known pathogen - Sarcocystis nesbitti.

    Science.gov (United States)

    Wassermann, Marion; Raisch, Lisa; Lyons, Jessica Ann; Natusch, Daniel James Deans; Richter, Sarah; Wirth, Mareike; Preeprem, Piyarat; Khoprasert, Yuvaluk; Ginting, Sulaiman; Mackenstedt, Ute; Jäkel, Thomas

    2017-01-01

    We examined Sarcocystis spp. in giant snakes from the Indo-Australian Archipelago and Australia using a combination of morphological (size of sporocyst) and molecular analyses. We amplified by PCR nuclear 18S rDNA from single sporocysts in order to detect mixed infections and unequivocally assign the retrieved sequences to the corresponding parasite stage. Sarcocystis infection was generally high across the study area, with 78 (68%) of 115 examined pythons being infected by one or more Sarcocystis spp. Among 18 randomly chosen, sporocyst-positive samples (11 from Southeast Asia, 7 from Northern Australia) the only Sarcocystis species detected in Southeast Asian snakes was S. singaporensis (in reticulated pythons), which was absent from all Australian samples. We distinguished three different Sarcocystis spp. in the Australian sample set; two were excreted by scrub pythons and one by the spotted python. The sequence of the latter is an undescribed species phylogenetically related to S. lacertae. Of the two Sarcocystis species found in scrub pythons, one showed an 18S rRNA gene sequence similar to S. zamani, which is described from Australia for the first time. The second sequence was identical/similar to that of S. nesbitti, a known human pathogen that was held responsible for outbreaks of disease among tourists in Malaysia. The potential presence of S. nesbitti in Australia challenges the current hypothesis of a snake-primate life cycle, and would have implications for human health in the region. Further molecular and biological characterizations are required to confirm species identity and determine whether or not the Australian isolate has the same zoonotic potential as its Malaysian counterpart. Finally, the absence of S. nesbitti in samples from reticulated pythons (which were reported to be definitive hosts), coupled with our phylogenetic analyses, suggest that alternative snake hosts may be responsible for transmitting this parasite in Malaysia.

  3. Efectos de la reinervación de una nueva diana por neuronas centrales axotomizadas

    OpenAIRE

    Benítez Temiño, Beatriz

    2004-01-01

    Se realizó un estudio de los efectos de un implante de primordio cerebeloso como posible nueva diana para las neuronas internucleares (Ints) del núcleo motor ocular externo (NMOE) axotomizadas. Para ello, se seccionó el fascículo longitudinal medial, y en algunos casos, se añadió en el sitio de la lesión, tras la axotomía, un implante de primordio cerebeloso. Las neuronas sobrevivieron a la axotomía, pero perdieron el patrón de disparo cerebeloso. Las neuronas sobrevivieron a la axotomía, per...

  4. Sarcocystis masoni, n. sp. (Apicomplexa: Sarcocystidae), and redescription of Sarcocystis aucheniae from llama (Lama glama), guanaco (Lama guanicoe) and alpaca (Vicugna pacos)

    Science.gov (United States)

    There is considerable confusion concerning the species of Sarcocystis in South American camelids (SAC). Several species names have been used, however, proper descriptions are lacking. In the present paper we redescribe the macroscopic sarcocyst forming Sarcocystis aucheniae and describe and name the...

  5. Molecular characterization of Sarcocystis species from Polish roe deer based on ssu rRNA and cox1 sequence analysis.

    Science.gov (United States)

    Kolenda, Rafał; Ugorski, Maciej; Bednarski, Michał

    2014-08-01

    Sarcocysts from four Polish roe deer were collected and examined by light microscopy, small subunit ribosomal RNA (ssu rRNA), and the subunit I of cytochrome oxidase (cox1) sequence analysis. This resulted in identification of Sarcocystis gracilis, Sarcocystis oviformis, and Sarcocystis silva. However, we were unable to detect Sarcocystis capreolicanis, the fourth Sarcocystis species found previously in Norwegian roe deer. Polish sarcocysts isolated from various tissues differed in terms of their shape and size and were larger than the respective Norwegian isolates. Analysis of ssu rRNA gene revealed the lack of differences between Sarcocystis isolates belonging to one species and a very low degree of genetic diversity between Polish and Norwegian sarcocysts, ranging from 0.1% for Sarcocystis gracilis and Sarcocystis oviformis to 0.44% for Sarcocystis silva. Contrary to the results of the ssu rRNA analysis, small intraspecies differences in cox1 sequences were found among Polish Sarcocystis gracilis and Sarcocystis silva isolates. The comparison of Polish and Norwegian cox1 sequences representing the same Sarcocystis species revealed similar degree of sequence identity, namely 99.72% for Sarcocystis gracilis, 98.76% for Sarcocystis silva, and 99.85% for Sarcocystis oviformis. Phylogenetic reconstruction and genetic population analyses showed an unexpected high degree of identity between Polish and Norwegian isolates. Moreover, cox1 gene sequences turned out to be more accurate than ssu rRNA when used to reveal phylogenetic relationships among closely related species. The results of our study revealed that the same Sarcocystis species isolated from the same hosts living in different geographic regions show a very high level of genetic similarity.

  6. Histological identification of muscular sarcocystis: A report of two cases

    OpenAIRE

    Mani Makhija

    2012-01-01

    Sarcocystis is an apicomplexan protozoan belonging to same phylum as toxoplasma. The parasite encysts inside striated muscles of its intermediate host. Humans are accidental host infected by eating food or water contaminated with oocysts or sporocysts of an infected definitive host. The infection is increasing in Southeast Asia and may be overlooked in histological sections if one is not aware of the histomorphological features. The size and shape of the bradyzoites and the appearance of the ...

  7. Phylogenetic analysis of of Sarcocystis nesbitti (Coccidia: Sarcocystidae) suggests a snake as its probable definitive host

    Science.gov (United States)

    Sarcocystis nesbitti was first described by Mandour in 1969 from rhesus monkey muscle. Its definitive host remains unknown. 18SrRNA gene of Sarcocystis nesbitti was amplified, sequenced, and subjected to phylogenetic analysis. Among those congeners available for comparison, it shares closest affinit...

  8. Gliding motility of Babesia bovis merozoites visualized by time-lapse video microscopy.

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    Masahito Asada

    Full Text Available BACKGROUND: Babesia bovis is an apicomplexan intraerythrocytic protozoan parasite that induces babesiosis in cattle after transmission by ticks. During specific stages of the apicomplexan parasite lifecycle, such as the sporozoites of Plasmodium falciparum and tachyzoites of Toxoplasma gondii, host cells are targeted for invasion using a unique, active process termed "gliding motility". However, it is not thoroughly understood how the merozoites of B. bovis target and invade host red blood cells (RBCs, and gliding motility has so far not been observed in the parasite. METHODOLOGY/PRINCIPAL FINDINGS: Gliding motility of B. bovis merozoites was revealed by time-lapse video microscopy. The recorded images revealed that the process included egress of the merozoites from the infected RBC, gliding motility, and subsequent invasion into new RBCs. The gliding motility of B. bovis merozoites was similar to the helical gliding of Toxoplasma tachyzoites. The trails left by the merozoites were detected by indirect immunofluorescence assay using antiserum against B. bovis merozoite surface antigen 1. Inhibition of gliding motility by actin filament polymerization or depolymerization indicated that the gliding motility was driven by actomyosin dependent process. In addition, we revealed the timing of breakdown of the parasitophorous vacuole. Time-lapse image analysis of membrane-stained bovine RBCs showed formation and breakdown of the parasitophorous vacuole within ten minutes of invasion. CONCLUSIONS/SIGNIFICANCE: This is the first report of the gliding motility of B. bovis. Since merozoites of Plasmodium parasites do not glide on a substrate, the gliding motility of B. bovis merozoites is a notable finding.

  9. El sistema de neuronas espejo y el procesamiento facial de las emociones: El caso del miedo

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    Aníbal Monasterio Astobiza

    2013-08-01

    Full Text Available Desde su descubrimiento en la corteza ventral premotora, área F5, del cerebro del macaco, las neuronas espejo se han convertido en el santo grial de la neurociencia sirviendo de base neurofisiológica para la empatía, imitación, entendimiento de las acciones e intenciones, lenguaje... Estudios recientes sugieren que el sistema de neuronas espejo contribuye también a procesar información emocional, pero niegan que la amígdala, región por excelencia responsable de procesar cierto tipo de emociones, sea parte de tal sistema. Parece ser que el sistema de neuronas espejo se reorganiza funcionalmente para compensar daños en la amígdala en algunos pacientes.

  10. Exposure of the Plasmodium falciparum clonally variant STEVOR proteins on the merozoite surface

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    Meri Seppo

    2011-03-01

    Full Text Available Abstract Background Plasmodium falciparum merozoites are free invasive forms that invade host erythrocytes in iterative cycles in the presence of different arms of the immune system. Variant antigens are known to play a role in immune evasion and several gene families coding for variant antigens have been identified in P. falciparum. However, none of them have been reported to be expressed on the surface of merozoites. Methods Flow cytometry, immunofluorescence microscopy, and immunoblotting assays were performed to assess surface exposure, membrane association and stage specific expression of the STEVOR family of variants proteins, respectively. Results Using a polyclonal antibody (anti-PFL2610w with a broad specificity towards different STEVOR variants, the STEVOR proteins were identified on the surface of non-permeabilized/non-fixed merozoites in flow cytometry assays. Anti-PFL2610w antibody showed that several STEVORs were expressed in the trophozoite stage of the parasite but only one variant was integrated into the merozoite membrane. Moreover, this antibody failed to identify STEVORs on the surface of the parent schizont infected erythrocytes (IE although they were readily identified when schizont IE were permeabilized. Conclusions These data suggest for a role for STEVOR in immune evasion by P. falciparum merozoites to allow successful invasion of erythrocytes. Additionally, the expression of STEVORs in the schizont stage may only represent a step in the biogenesis process of the merozoite surface coat.

  11. Las neuronas espejo y su aplicación en la recuperación funcional

    OpenAIRE

    Pardo Bermejo, Marta

    2015-01-01

    Introducción: Las neuronas espejo son neuronas que se activan cuando observamos la ejecución de una acción o movimiento de otro individuo, permitiéndonos imitar mentalmente los movimientos de la otra persona, en esto se basa la terapia de la observación de la acción, que persigue las mejoras motrices. Un accidente cerebrovascular (ACV) sucede cuando el flujo de sangre a una parte del cerebro se detiene y el cerebro no puede recibir ni nutrientes ni oxígeno, provocando la muerte de células cer...

  12. El sistema de neuronas espejo y el procesamiento facial de las emociones: El caso del miedo

    OpenAIRE

    Aníbal Monasterio Astobiza; Jesús Ezquerro Martínez

    2013-01-01

    Desde su descubrimiento en la corteza ventral premotora, área F5, del cerebro del macaco, las neuronas espejo se han convertido en el santo grial de la neurociencia sirviendo de base neurofisiológica para la empatía, imitación, entendimiento de las acciones e intenciones, lenguaje... Estudios recientes sugieren que el sistema de neuronas espejo contribuye también a procesar información emocional, pero niegan que la amígdala, región por excelencia responsable de procesar cierto tipo de emocion...

  13. Modelado de un Sistema de Neuronas Espejo en un Agente Autónomo Artificial

    OpenAIRE

    David Castillo Arceo; Esaú Escobar; Jorge Hermosillo; Bruno Lara

    2013-01-01

    La presente investigación está basada en el importante trabajo interdisciplinario desarrollándose en las ciencias cognitivas y que estudia tópicos tales como Neuronas Espejo, Reconocimiento de Comportamientos, Imit a ción, y Robótica Cognitiva. Abordando una perspectiva anclada en la Teoría de la Simulación y basado en modelos computacionales sobre Sistemas de Neuronas Espejo se ha diseñado un sistema, implemen tado en un Agente Autónomo Artificial. Dicho sistema d...

  14. El sistema de neuronas espejo y el procesamiento facial de las emociones: El caso del miedo

    National Research Council Canada - National Science Library

    Aníbal Monasterio Astobiza; Jesús Ezquerro Martínez

    2013-01-01

    Desde su descubrimiento en la corteza ventral premotora, área F5, del cerebro del macaco, las neuronas espejo se han convertido en el santo grial de la neurociencia sirviendo de base neurofisiológica para la empatía...

  15. COMPARTIMENTACIÓN INTRACELULAR DEL ACETATO EN NEURONAS DURANTE LA PRELACTANCIA

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    B. Barrios-Socha

    2006-06-01

    Full Text Available En la transición a la vida extrauterina, el recién nacido sufre un período de ayuno (prelactancia que transcurre entre el cese de la nutrición placentaria y la instauración de la lactancia. El gasto de energía por las neuronas es tan alto en estas circunstancias, que la glucogenólisis es incapaz de restablecer los niveles de glucosa en la sangre. En consecuencia, durante la prelactancia debe haber otros sustratos energéticos y lipogénicos, que adicionalmente ayuden a mantener la síntesis de neurotransmisores.Este trabajo establece la importancia de acetato en el metabolismo oxidativo y del lipogénico en neuronas durante la prelactancia. Se determinaron las velocidades de oxidación y lipogénesis en cultivos quiescentes de neuronas fetales de rata incubadas con acetato (5 mM, [1- 14C]-acetato, [2- 14C]-acetato y [U- 14C]-acetato(200-300dpm/nmol Adicionalmente, se utilizaron inhibidores enzimáticos como el dicloroacetato(1 mM y el aminooxiacetato (5 mM, e inhibidores del transporte como el α-ciano-4-hidroxicinnamato(2 mM, butilmalonato (5 mM y 1,2,3-bencenotricarboxilato (5 mM.Los resultados en su conjunto indican que las neuronas pueden metabolizar acetato más como sustrato energético que lipogénico, lo que nos permite pensar que este sustrato puede llegar a ser más importante para ayudar a mantener el metabolismo oxidativo, favoreciendo el reciclaje de carbonos en la prelactancia.Adicionalmente, se evidenció con el uso de [1-14C]-acetato una alta actividad anaplerótica sobre todo cuando las neuronas requieren mantener los reservorios de oxalacetato y acetil-CoA para mantener la respiración. Estos resultados señalan a la acetil-CoA sintetasa (AceCS2 y la enzima málica (mME mitocondriales, como enzimas claves para mantener el funcionamiento de las neuronas en la prelactancia.Con el uso de [2-14C]-acetato, los resultados sugieren que las neuronas tienen un alto requerimiento de carbonos, principalmente para la síntesis de

  16. Sarcocystis fayeri in skeletal muscle of horses with neuromuscular disease.

    Science.gov (United States)

    Aleman, Monica; Shapiro, Karen; Sisó, Silvia; Williams, Diane C; Rejmanek, Daniel; Aguilar, Beatriz; Conrad, Patricia A

    2016-01-01

    Recent reports of Sarcocystis fayeri-induced toxicity in people consuming horse meat warrant investigation on the prevalence and molecular characterization of Sarcocystis spp. infection in horses. Sarcocysts in skeletal muscle of horses have been commonly regarded as an incidental finding. In this study, we investigated the prevalence of sarcocysts in skeletal muscle of horses with neuromuscular disease. Our findings indicated that S. fayeri infection was common in young mature horses with neuromuscular disease and could be associated with myopathic and neurogenic processes. The number of infected muscles and number of sarcocysts per muscle were significantly higher in diseased than in control horses. S. fayeri was predominantly found in low oxidative highly glycolytic myofibers. This pathogen had a high glycolytic metabolism. Common clinical signs of disease included muscle atrophy, weakness with or without apparent muscle pain, gait deficits, and dysphagia in horses with involvement of the tongue and esophagus. Horses with myositis were lethargic, apparently painful, stiff, and reluctant to move. Similar to humans, sarcocystosis and cardiomyopathy can occur in horses. This study did not establish causality but supported a possible association (8.9% of cases) with disease. The assumption of Sarcocysts spp. being an incidental finding in every case might be inaccurate. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The utility of Plasmodium berghei as a rodent model for anti-merozoite malaria vaccine assessment

    Science.gov (United States)

    Goodman, Anna L.; Forbes, Emily K.; Williams, Andrew R.; Douglas, Alexander D.; de Cassan, Simone C.; Bauza, Karolis; Biswas, Sumi; Dicks, Matthew D. J.; Llewellyn, David; Moore, Anne C.; Janse, Chris J.; Franke-Fayard, Blandine M.; Gilbert, Sarah C.; Hill, Adrian V. S.; Pleass, Richard J.; Draper, Simon J.

    2013-01-01

    Rodent malaria species Plasmodium yoelii and P. chabaudi have been widely used to validate vaccine approaches targeting blood-stage merozoite antigens. However, increasing data suggest the P. berghei rodent malaria may be able to circumvent vaccine-induced anti-merozoite responses. Here we confirm a failure to protect against P. berghei, despite successful antibody induction against leading merozoite antigens using protein-in-adjuvant or viral vectored vaccine delivery. No subunit vaccine approach showed efficacy in mice following immunization and challenge with the wild-type P. berghei strains ANKA or NK65, or against a chimeric parasite line encoding a merozoite antigen from P. falciparum. Protection was not improved in knockout mice lacking the inhibitory Fc receptor CD32b, nor against a Δsmac P. berghei parasite line with a non-sequestering phenotype. An improved understanding of the mechanisms responsible for protection, or failure of protection, against P. berghei merozoites could guide the development of an efficacious vaccine against P. falciparum. PMID:23609325

  18. Identity of Sarcocystis species of the water buffalo (Bubalus bubalis) and cattle (Bos taurus) and the suppression of Sarcocystis sinensis as a nomen nudum.

    Science.gov (United States)

    Dubey, J P; Fayer, R; Rosenthal, B M; Calero-Bernal, R; Uggla, A

    2014-09-15

    There are uncertainties concerning the identity and host species specificity of Sarcocystis species of the water buffalo (Bubalus bubalis) and cattle (Bos taurus). Currently, in cattle three species are recognized with known endogenous stages, viz.: S. cruzi (with canine definitive host), S. hirsuta (feline definitive host), and S. hominis (primate definitive host). Recently, a fourth Sarcocystis species with an unknown life cycle has been reported from cattle. In the water buffalo, four species of Sarcocystis have been described: S. fusiformis (feline definitive host), S. buffalonis (feline definitive host), S. levinei (canine definitive host), and S. dubeyi (definitive host unknown but not cat or dog). Besides, there are studies of Sarcocystis infections in buffalo and cattle from China with results that are difficult to interpret and validate. For example, some of the studies report transmission of Sarcocystis species between cattle and buffalo, but steps to preclude exogenous exposures were not reported. A species of the water buffalo, 'S. sinensis', was proposed at a Chinese national conference in 1990, and published as an abstract without figures and with no archived type specimens for verification. The International Code of Zoological Nomenclature Articles 9 and 10 state that "abstracts of articles, papers, posters, text of lectures, and similar material when issued primarily to participants at meetings, symposia, colloquia or congress does not constitute published work"; therefore, S. sinensis is a nomen nudum. Published by Elsevier B.V.

  19. Frecuencia de Sarcocystis sp. en perros pastores de asociaciones alpaqueras de Marangani, Cusco

    National Research Council Canada - National Science Library

    Choque M., Jose; Chavez V., Amanda; Pacheco P., Atilio; Leyva V., Victor; Panez L., Susan; Ticona S., Daniel

    2007-01-01

    El objetivo del estudio fue determinar la frecuencia de Sarcocystis sp. en perros pastores de asociaciones alpaqueras del distrito de Marangani, Cusco, durante las dos epocas del ano (seca y lluviosa...

  20. Tumour necrosis factor and interleukin-6 production induced by components associated with merozoite proteins of Plasmodium falciparum

    DEFF Research Database (Denmark)

    Jakobsen, P H; Moon, R; Ridley, R G

    1993-01-01

    P. falciparum merozoite antigens, merozoite surface protein-1 (MSP-1) and rhoptry associated protein-1 (RAP-1), were shown to be liberated into the supernatant of in vitro parasite cultures and to be included in the endotoxin-like exoantigen complex, previously designated Ag7. Material affinity p...

  1. First Molecular Identification of Sarcocystis ovicanis (Protozoa, Apicomplexa in the Brain of Sheep in Iran.

    Directory of Open Access Journals (Sweden)

    Mitra Salehi

    2014-06-01

    Full Text Available The objective of the present study was to survey the presence of Sarcocystis in sheep's brain in North Khorasan Province.In general, 80 samples of sheep's brain were collected from slaughtered sheep in slaughterhouses of North Khorasan Province. Tissue digestion method was used for observing bradyzoites in tissues. Histopathological processing tracing Sarcocystis and ensuing structural change in the brain tissue were conducted. PCR analysis was conducted on all the brain samples. Sequencing was done for one PCR product. Genotype was identified by Blast search and homology analysis.Sarcocystis spp. was found in one of the brain samples (1.25% using tissue digestion method. The presence of bradyzoite was also confirmed in the prepared histopathological sections. PCR analysis was positive in one of samples. Genotyping of one sample proved that Sarcocystis species was Sarcocystis ovicanis and the nucleotide sequence of this parasite was deposited in the GenBank database under accession number No.KF489431.Sarcocystis ovicanis can involve brain tissue of sheep and consequently causes clinical symptoms.

  2. Antigenicity and immunogenicity of Plasmodium vivax merozoite surface protein-3.

    Directory of Open Access Journals (Sweden)

    Amanda R Bitencourt

    Full Text Available A recent clinical trial in African children demonstrated the potential utility of merozoite surface protein (MSP-3 as a vaccine against Plasmodium falciparum malaria. The present study evaluated the use of Plasmodium vivax MSP-3 (PvMSP-3 as a target antigen in vaccine formulations against malaria caused by P. vivax. Recombinant proteins representing MSP-3α and MSP-3β of P. vivax were expressed as soluble histidine-tagged bacterial fusions. Antigenicity during natural infection was evaluated by detecting specific antibodies using sera from individuals living in endemic areas of Brazil. A large proportion of infected individuals presented IgG antibodies to PvMSP-3α (68.2% and at least 1 recombinant protein representing PvMSP-3β (79.1%. In spite of the large responder frequency, reactivity to both antigens was significantly lower than was observed for the immunodominant epitope present on the 19-kDa C-terminal region of PvMSP-1. Immunogenicity of the recombinant proteins was studied in mice in the absence or presence of different adjuvant formulations. PvMSP-3β, but not PvMSP-3α, induced a TLR4-independent humoral immune response in the absence of any adjuvant formulation. The immunogenicity of the recombinant antigens were also tested in formulations containing different adjuvants (Alum, Salmonella enterica flagellin, CpG, Quil A,TiterMax® and incomplete Freunds adjuvant and combinations of two adjuvants (Alum plus flagellin, and CpG plus flagellin. Recombinant PvMSP-3α and PvMSP-3β elicited higher antibody titers capable of recognizing P. vivax-infected erythrocytes harvested from malaria patients. Our results confirm that P. vivax MSP-3 antigens are immunogenic during natural infection, and the corresponding recombinant proteins may be useful in elucidating their vaccine potential.

  3. Examination of Sarcocystis spp. of giant snakes from Australia and Southeast Asia confirms presence of a known pathogen – Sarcocystis nesbitti

    Science.gov (United States)

    Wassermann, Marion; Raisch, Lisa; Lyons, Jessica Ann; Natusch, Daniel James Deans; Richter, Sarah; Wirth, Mareike; Preeprem, Piyarat; Khoprasert, Yuvaluk; Ginting, Sulaiman; Mackenstedt, Ute

    2017-01-01

    We examined Sarcocystis spp. in giant snakes from the Indo-Australian Archipelago and Australia using a combination of morphological (size of sporocyst) and molecular analyses. We amplified by PCR nuclear 18S rDNA from single sporocysts in order to detect mixed infections and unequivocally assign the retrieved sequences to the corresponding parasite stage. Sarcocystis infection was generally high across the study area, with 78 (68%) of 115 examined pythons being infected by one or more Sarcocystis spp. Among 18 randomly chosen, sporocyst-positive samples (11 from Southeast Asia, 7 from Northern Australia) the only Sarcocystis species detected in Southeast Asian snakes was S. singaporensis (in reticulated pythons), which was absent from all Australian samples. We distinguished three different Sarcocystis spp. in the Australian sample set; two were excreted by scrub pythons and one by the spotted python. The sequence of the latter is an undescribed species phylogenetically related to S. lacertae. Of the two Sarcocystis species found in scrub pythons, one showed an 18S rRNA gene sequence similar to S. zamani, which is described from Australia for the first time. The second sequence was identical/similar to that of S. nesbitti, a known human pathogen that was held responsible for outbreaks of disease among tourists in Malaysia. The potential presence of S. nesbitti in Australia challenges the current hypothesis of a snake-primate life cycle, and would have implications for human health in the region. Further molecular and biological characterizations are required to confirm species identity and determine whether or not the Australian isolate has the same zoonotic potential as its Malaysian counterpart. Finally, the absence of S. nesbitti in samples from reticulated pythons (which were reported to be definitive hosts), coupled with our phylogenetic analyses, suggest that alternative snake hosts may be responsible for transmitting this parasite in Malaysia. PMID:29131856

  4. Modelado de un Sistema de Neuronas Espejo en un Agente Autónomo Artificial

    Directory of Open Access Journals (Sweden)

    David Castillo Arceo

    2013-01-01

    Full Text Available La presente investigación está basada en el importante trabajo interdisciplinario desarrollándose en las ciencias cognitivas y que estudia tópicos tales como Neuronas Espejo, Reconocimiento de Comportamientos, Imit a ción, y Robótica Cognitiva. Abordando una perspectiva anclada en la Teoría de la Simulación y basado en modelos computacionales sobre Sistemas de Neuronas Espejo se ha diseñado un sistema, implemen tado en un Agente Autónomo Artificial. Dicho sistema deberá reconocer los movimientos de otro agente, basado en el aprendizaje de sus movimientos y las relaciones que surgen de éstos con la percepción del mundo. El diseño de este sistema se propone parta de dos supuestos: (1 El Sistemas de Neuronas Espejo visto como un acoplamiento de los Modelos Internos Inverso y Directo - siendo el segundo y su función de predictor lo que se hipotetiza es la función de las Neuronas Espejo - y (2 que la base para el re conocimiento de las conductas de otros está en la habilidad de los seres vivos de empatar en un lenguaje común las conductas propias, desarrolladas a lo largo de su experiencia, con las conductas ejercidas por otros. Presentamos un ejercicio donde nuestro Agente imita a otro para comprobar que el reconocimiento de las conductas de los otros es posible desde la perspectiva que se ha adoptado. Creemos que nuestro experimento es una prueba de concepto y presenta una base s ó lida para investigaciones futuras.

  5. NEURONAS ESPEJO Y EL APRENDIZAJE EN ANESTESIA Learning anaesthesia and mirror neurons

    Directory of Open Access Journals (Sweden)

    John Bautista

    2011-12-01

    Full Text Available Las neuronas espejo fueron descritas inicialmente en primates de la especie Macaca nemestrina hacia el año 1990 por el neurofisiólogo Giacomo Rizzolatti y su grupo de la Universidad de Parma, en Italia. Son neuronas motoras que activan cuando el individuo observa la acción concreta para la que están predeterminadas sin generar ningún tipo de actividad motora. En la actualidad se considera que estas neuronas participan en procesos de adaptación al entorno social ya que permiten no solamente comprender las acciones sino también las intenciones de otros individuos. Se les atribuye función en los procesos de aprendizaje simple a través de la observación y la imitación que pueden ser aprovechados en la enseñanza de la anestesiología.Mirror neurons were initially described in primates from the Macaca nemestrina species around 1990 by the neurophysiologist Giacomo Rizzolatti and his group from Parma University in Italy. They are motor neurons which become activated when an individual observes a concrete action for which they are predetermined without any type of motor activity being produced. It is currently considered that these neurons participate in adapting to the social setting since they lead to understanding other individuals' actions and intensions. A function has been ascribed to them regarding simple learning through observation and imitation which can be exploited in teaching anesthesiology.

  6. Fatal Sarcocystis canis-like hepatitis in an Indo-Pacific bottlenose dolphin (Tursiops aduncus) in Hong Kong

    Science.gov (United States)

    Unlike most species in the genus Sarcocystis, Sarcocystis canis has a broad intermediate host range. Its life cycle is incompletely known and most reports are from the USA. Here we report fatal hepatitis in a 4 year old male Indo-Pacific bottlenose dolphin (Tursiops aduncus) from Hong Kong associate...

  7. Molecular identification of Sarcocystis spp. helped to define the origin of green pythons (Morelia viridis) confiscated in Germany.

    Science.gov (United States)

    Moré, Gastón; Pantchev, Nikola; Herrmann, Daland C; Vrhovec, Majda Globokar; Öfner, Sabine; Conraths, Franz J; Schares, Gereon

    2014-04-01

    Sarcocystis spp. represent apicomplexan parasites. They usually have a heteroxenous life cycle. Around 200 species have been described, affecting a wide range of animals worldwide, including reptiles. In recent years, large numbers of reptiles have been imported into Europe as pets and, as a consequence, animal welfare and species protection issues emerged. A sample of pooled feces from four confiscated green pythons (Morelia viridis) containing Sarcocystis spp. sporocysts was investigated. These snakes were imported for the pet trade and declared as being captive-bred. Full length 18S rRNA genes were amplified, cloned into plasmids and sequenced. Two different Sarcocystis spp. sequences were identified and registered as Sarcocystis sp. from M. viridis in GenBank. Both showed a 95-97% sequence identity with the 18S rRNA gene of Sarcocystis singaporensis. Phylogenetic analysis positioned these sequences together with other Sarcocystis spp. from snakes and rodents as definitive and intermediate hosts (IH), respectively. Sequence data and also the results of clinical and parasitological examinations suggest that the snakes were definitive hosts for Sarcocystis spp. that circulate in wild IH. Thus, it seems unlikely that the infected snakes had been legally bred. Our research shows that information on the infection of snakes with Sarcocystis spp. may be used to assess compliance with regulations on the trade with wildlife species.

  8. Morphological and molecular characterization of four Sarcocystis spp., including Sarcocystis linearis n. sp., from roe deer (Capreolus capreolus) in Italy.

    Science.gov (United States)

    Gjerde, Bjørn; Giacomelli, Stefano; Bianchi, Alessandro; Bertoletti, Irene; Mondani, Hajime; Gibelli, Lucia Rita

    2017-04-01

    Fresh (frozen/thawed) muscle samples from four 2-12-year-old roe deer (Capreolus capreolus) from the Sondrio province in north-eastern Italy were examined under a dissecting microscope, and about 180 sarcocysts were isolated and identified to morphological type in wet mounts by light microscopy (LM). Seventy-seven of these sarcocysts were subsequently examined by molecular methods, comprising polymerase chain reaction (PCR) amplification and sequencing of the partial cytochrome c oxidase subunit I gene (cox1) of all isolates, as well as PCR amplification, cloning and sequencing of the complete18S ribosomal RNA (rRNA) gene of two isolates of each species found. By LM, three major sarcocyst types were recognised: spindle-shaped sarcocysts, 0.5-3 mm long, either with no clearly recognisable protrusions (thin-walled) or with finger-like protrusions (thick-walled); and slender, thread-like sarcocysts, 2-3 mm long, with hair-like protrusions. Sequencing of cox1 revealed that the sarcocysts belonged to four different species. Those with no visible protrusions either belonged to Sarcocystis gracilis (n = 24) or to a Sarcocystis taeniata-like species (n = 19), whereas those with finger- and hair-like protrusions belonged to Sarcocystis silva (n = 27) and Sarcocystis capreolicanis (n = 7), respectively. The 19 cox1 sequences of the S. taeniata-like species, comprising five haplotypes, differed from each other at 0-16 of 1038 nucleotide positions (98.5-100% identity). They differed from 25 previous cox1 sequences of S. taeniata from moose and sika deer (with 98.0-100% intraspecific identity), at 33-43 nucleotide positions (95.9-96.8% interspecific identity), and there were 20 fixed nucleotide differences between the two populations. In the phylogenetic analysis based on cox1 sequences, the two populations formed two separate monophyletic clusters. The S. taeniata-like species in roe deer was therefore considered to represent a separate species, which was named

  9. Sarcocystis cruzi (Apicomplexa: Sarcocystidae no cachorro-do-mato (Cerdocyon thous Sarcocystis cruzi (Apicomplexa: Sarcocystidae in the crab-eating fox (Cerdocyon thous

    Directory of Open Access Journals (Sweden)

    Janaina S. Rodrigues

    2008-11-01

    Full Text Available Esporocistos de Sarcocystis foram identificados nas amostras fecais de um cachorro-do-mato. Eles foram dados por via oral para um bezerro em aleitamento, sendo observados cistos com morfologia compatível com os de Sarcocystis cruzi na musculatura cardíaca e esquelética, três meses após a infecção. Musculatura cardíaca deste bezerro foi dada para um segundo cão doméstico livre de coccídios, que eliminou esporocistos compatíveis com os de Sarcocystis em suas fezes, tendo com períodos pré-patente e patente 11 e 12 dias após a infecção respectivamente. Para comparar a morfologia dos esporocistos e cistos, um segundo cão, também livre de coccídios, foi alimentado com musculatura cardíaca de um bovino infectando naturalmente e positivo para cistos de S. cruzi. Esporocistos compatíveis com os eliminados pelo primeiro cão foram encontrados nas fezes. Apesar dos esporocistos eliminados pelo cachorro-do-mato serem significativamente diferentes dos eliminados pelos cães infectados experimentalmente, pode se considerar com base na morfologia dos esporocistos, cistos e na transmissão biológica que a espécie encontrada nas fezes do cachorro-do-mato é Sarcocystis cruzi.Sporocysts of Sarcocystis were identified in feces samples of a crab-eating fox, and were orally given to a suckling calf; after 3 months of infection, sarcocysts morphologically similar to Sarcocystis cruzi were observed in cardiac and skeletal striated muscles. The cardiac muscles of this calf were orally given to a puppy free of coccidia, that shed sporocysts in its feces.with a prepatent and patent period of 11 and 12 days after infection, respectively. To compare the morphology of the sporocysts and cysts, a second puppy was fed on bovine cardiac muscles infected naturally, and sporocysts identical to those shed by the first dog were recovered from its feces. In spite of the significant difference between sporocysts found in the mucosa of the crab-eating fox and

  10. A recombinant surface protein of Babesia bovis elicits bovine antibodies that react with live merozoites.

    Science.gov (United States)

    Reduker, D W; Jasmer, D P; Goff, W L; Perryman, L E; Davis, W C; McGuire, T C

    1989-07-01

    Ten monoclonal antibodies (MoAbs) were generated against five surface-exposed proteins (16 kDa, 42 kDa, 44 kDa, 60 kDa, 225 kDa) on merozoites of Babesia bovis. A genomic library constructed in the lambda gt11 expression vector was screened with MoAbs in a plaque immunoassay for identification of clones expressing recombinant surface proteins. Two recombinant clones were identified (lambda Bo44-15 and lambda Bo44-16) that encoded a protein recognized by a MoAb specific for an epitope on the native 44-kDa surface protein. Southern blot analysis using radiolabeled Bo44-15 DNA (1.25 kb) against merozoite DNA and bovine leukocyte DNA confirmed the parasite-specificity of the cloned insert and revealed multiple bands of hybridization with merozoite DNA. Western blot analyses of lambda Bo44-15 lysogen preparations demonstrated that recombinant protein production in this clone was IPTG-induced and that the recombinant molecule was a beta-galactosidase fusion protein. Additionally, recombinant 44-kDa protein, purified by immunoaffinity chromatography, reacted with specific MoAb in Western blot assay indicating that the integrity of the epitope was retained during purification. Immune sera from calves immunized with purified recombinant Bo44-15 protein immunoprecipitated metabolically radiolabeled merozoite protein of 44 kDa indicating that antibody induced by recombinant Bo44-15 protein recognized native 44-kDa protein. Also, these sera reacted with the surface of live merozoites as evidenced by indirect immunofluorescence assay. Serum antibody titers determined by this assay had a wide range.

  11. Sarcocystis masoni, n. sp. (Apicomplexa: Sarcocystidae), and redescription of Sarcocystis aucheniae from llama (Lama glama), guanaco (Lama guanicoe) and alpaca (Vicugna pacos).

    Science.gov (United States)

    Moré, Gastón; Regensburger, Cristian; Gos, M Laura; Pardini, Lais; Verma, Shiv K; Ctibor, Juliana; Serrano-Martínez, Marcos Enrique; Dubey, Jitender P; Venturini, M Cecilia

    2016-04-01

    There is considerable confusion concerning the species of Sarcocystis in South American camelids (SAC). Several species names have been used; however, proper descriptions are lacking. In the present paper, we redescribe the macroscopic sarcocyst forming Sarcocystis aucheniae and describe and propose a new name, Sarcocystis masoni for the microscopic sarcocyst forming species. Muscles samples were obtained from llamas (Lama glama) and guanacos (Lama guanicoe) from Argentina and from alpacas (Vicugna pacos) and llamas from Peru. Individual sarcocysts were processed by optical and electron microscopy, and molecular studies. Microscopic sarcocysts of S. masoni were up to 800 µm long and 35-95 µm wide, the sarcocyst wall was 2·5-3·5 µm thick, and had conical to cylindrical villar protrusions (vp) with several microtubules. Each vp had 11 or more rows of knob-like projections. Seven 18S rRNA gene sequences obtained from sarcocysts revealed 95-96% identity with other Sarcocystis spp. sequences reported in the GenBank. Sarcocysts of S. aucheniae were macroscopic, up to 1·2 cm long and surrounded by a dense and laminar 50 µm thick secondary cyst wall. The sarcocyst wall was up to 10 µm thick, and had branched vp, appearing like cauliflower. Comparison of the 11 sequences obtained from individual macroscopic cysts evidenced a 98-99% of sequence homology with other S. aucheniae sequences. In conclusion, 2 morphologically and molecularly different Sarcocystis species, S. masoni (microscopic cysts) and S. aucheniae (macroscopic cysts), were identified affecting different SAC from Argentina and Peru.

  12. CAMBIOS EN LAS PROPIEDADES DEL RECEPTOR DE GLICINA DURANTE EL DESARROLLO DE NEURONAS ESPINALES EN CULTIVO. EFECTOS CELULARES DE LA ACTIVACION.

    OpenAIRE

    TAPIA AMARO, JUAN CARLOS; TAPIA AMARO, JUAN CARLOS

    2002-01-01

    Evidencia experimental sugiere que el neurotransmisor inhibitorio glicina puede regular el crecimiento neurítico de neuronas embrionarias. Para evaluar esta hipótesis se propuso: 1) determinar cómo la activación del receptor de glicina en neuronas inmadur 216p.

  13. Sarcocystis cruzi (Apicomplexa: Sarcocystidae) no cachorro-do-mato (Cerdocyon thous)

    OpenAIRE

    Rodrigues, Janaina S.; Gisele S. Meireles; Carvalho Filho, Paulo R.; Ribeiro, Carlos T.; Flausino, Walter; Lopes,Carlos Wilson G.

    2008-01-01

    Esporocistos de Sarcocystis foram identificados nas amostras fecais de um cachorro-do-mato. Eles foram dados por via oral para um bezerro em aleitamento, sendo observados cistos com morfologia compatível com os de Sarcocystis cruzi na musculatura cardíaca e esquelética, três meses após a infecção. Musculatura cardíaca deste bezerro foi dada para um segundo cão doméstico livre de coccídios, que eliminou esporocistos compatíveis com os de Sarcocystis em suas fezes, tendo com períodos pré-patent...

  14. Sarcocystis nesbitti infection in human skeletal muscle: possible transmission from snakes.

    Science.gov (United States)

    Lau, Yee Ling; Chang, Phooi Yee; Tan, Chong Tin; Fong, Mun Yik; Mahmud, Rohela; Wong, Kum Thong

    2014-02-01

    Sarcocystis nesbitti is an intracellular protozoan parasite found as sarcocysts within muscle fibers of intermediate hosts (monkey and baboon). The definitive host is suspected to be the snake. We report two cases from a larger cohort of 89 patients who had fever, headache, and generalized myalgia after a trip to Pangkor Island, Malaysia. Sarcocysts were detected in skeletal muscle biopsy specimens by light and electron microscopy from these two patients. DNA sequencing based on the 18S ribosomal DNA region identified the Sarcocystis species as S. nesbitti. We also identified S. nesbitti sequences in the stools of a snake (Naja naja). Phylogenetic analysis showed that these sequences form a cluster with most of the other known Sarcocystis species for which the snake is a definitive host. We believe these two patients were likely to have symptomatic acute muscular sarcocystosis after S. nesbitti infection that may have originated from snakes.

  15. First molecular detection and characterization of Hepatozoon and Sarcocystis spp. in field mice and voles from Japan.

    Science.gov (United States)

    Moustafa, Mohamed Abdallah Mohamed; Shimozuru, Michito; Mohamed, Wessam; Taylor, Kyle Rueben; Nakao, Ryo; Sashika, Mariko; Tsubota, Toshio

    2017-08-01

    Sarcocystis and Hepatozoon species are protozoan parasites that are frequently detected in domestic and wild animals. Rodents are considered common intermediate and paratenic hosts for several Sarcocystis and Hepatozoon species. Here, blood DNA samples from a total of six rodents, including one Myodes rutilus, one Myodes rufocanus, and four Apodemus speciosus, collected from Hokkaido, Japan, were shown by conventional PCR of the 18S ribosomal RNA (rRNA) gene to contain Sarcocystis and Hepatozoon DNA. Sequencing of the DNA detected one Sarcocystis sp. in the M. rufocanus sample and two different Hepatozoon spp. in the M. rutilus and A. speciosus samples. Phylogenetic analysis showed that the detected Sarcocystis sp. sequence grouped with GenBank Sarcocystis sequences from rodents, snakes, and raccoons from Japan and China. The 18S rRNA partial gene sequences of both detected Hepatozoon spp. clustered with GenBank Hepatozoon sequences from snakes, geckos and voles in Europe, Africa, and Asia. This study provides evidence that wild rodents have a role in the maintenance of Sarcocystis and Hepatozoon species on the island of Hokkaido.

  16. Virus de rabia en cultivos de neuronas sensoriales de ratón adulto

    Directory of Open Access Journals (Sweden)

    H. Hurtado

    2000-02-01

    Full Text Available Introducción: Las neuronas sensoriales de los ganglios de la raíz dorsal (GRD del ratón adulto, son un modelo interesante en el estudio de la infección in vitro por virus de rabia. Su importancia radica puesto que es una de las vías que tiene el virus para llegar a sistema nervioso central. El virus de la rabia usualmente entra por la mordedura de un animal infectado, inicialmente llega al músculo, replicándose localmente, pasa a terminales nerviosas adyacentes, sube a través del sistema nervioso periférico y llega a los ganglio de la raíz dorsal. Durante el transporte del virus no hay síntomas y la enfermedad sólo se inicia con la llegada del virus al sistema nervioso central, donde la replicación del virus es seguida por su transporte en sentido centrífugo, teniendo un particular e inexplicable tropismo por las glándulas salivares y lacrimales. Objetivo: Describir el proceso de infección del virus de la rabia en neuronas GRD. Metodología: Cultivos de neuronas de GRD de ratón adulto fueron inoculados con virus de rabia cepa CVS, siendo observada la ultraestructura en tiempos progresivos de infección desde 5 minutos hasta 60 horas. Los resultados obtenidos en los que no se observaron viriones, nos llevaron a hacer un marcaje con inmunoperoxidasas para evidenciar este proceso. Para corroborar los resultados obtenidos fue necesario comparar ultraestructuralmente y con la técnica de inmunoperoxidasas la infección en tejido cerebral de ratones adultos inoculados experimentalmente. Resultados: Este estudio nos permite afirmar que la producción de partículas virales en neuronas de ganglio de raíz dorsal de ratón adulto, cultivadas in vitro, e inoculadas con virus de rabia es escasa, comparada con la gran cantidad de antígeno viral observada en vesículas de 0,5 mm localizadas en el citoplasma de estas mismas células. Los resultados más importantes del estudio revelan que las neuronas sensoriales de ratón adulto son

  17. Sistema inteligente basado en computación evolutiva y redes de neuronas para juegos de bloques

    OpenAIRE

    Larrodera Arcega, Sergio

    2016-01-01

    El objetivo de esta tesis fin de máster es explorar la utilización de técnicas de computación evolutiva y redes de neuronas artificiales para el desarrollo de sistemas inteligentes que resuelvan el problema aproximar la estrategia óptima en un juego de bloques. Si bien estas ramas de la computación natural ya se han empleado anteriormente en dicho problema, las redes de neuronas artificiales no han conseguido resultados satisfactorios hasta el momento y tampoco se ha investigad...

  18. Differing rates of antibody acquisition to merozoite antigens in malaria: implications for immunity and surveillance.

    Science.gov (United States)

    McCallum, Fiona J; Persson, Kristina E M; Fowkes, Freya J I; Reiling, Linda; Mugyenyi, Cleopatra K; Richards, Jack S; Simpson, Julie A; Williams, Thomas N; Gilson, Paul R; Hodder, Anthony N; Sanders, Paul R; Anders, Robin F; Narum, David L; Chitnis, Chetan; Crabb, Brendan S; Marsh, Kevin; Beeson, James G

    2017-04-01

    Antibodies play a key role in acquired human immunity to Plasmodium falciparum (Pf) malaria and target merozoites to reduce or prevent blood-stage replication and the development of disease. Merozoites present a complex array of antigens to the immune system, and currently, there is only a partial understanding of the targets of protective antibodies and how responses to different antigens are acquired and boosted. We hypothesized that there would be differences in the rate of acquisition of antibodies to different antigens and how well they are boosted by infection, which impacts the acquisition of immunity. We examined responses to a range of merozoite antigens in 2 different cohorts of children and adults with different age structures and levels of malaria exposure. Overall, antibodies were associated with age, exposure, and active infection, and the repertoire of responses increased with age and active infection. However, rates of antibody acquisition varied between antigens and different regions within an antigen following exposure to malaria, supporting our hypothesis. Antigen-specific responses could be broadly classified into early response types in which antibodies were acquired early in childhood exposure and late response types that appear to require substantially more exposure for the development of substantial levels. We identified antigen-specific responses that were effectively boosted after recent infection, whereas other responses were not. These findings advance our understanding of the acquisition of human immunity to malaria and are relevant to the development of malaria vaccines targeting merozoite antigens and the selection of antigens for use in malaria surveillance. © Society for Leukocyte Biology.

  19. COMPARTIMENTACIÓN INTERCELULAR DEL ACETATO EN NEURONAS Y ASTROCITOS DURANTE LA PRELACTANCIA

    Directory of Open Access Journals (Sweden)

    J. Tovar-Franco

    2005-12-01

    Full Text Available Durante el período perinatal el cerebro utiliza sustratos alternativos a la glucosa para mantener su desarrollo, pues en este momento sus niveles están disminuidos. El acetato es metabolizado por las neuronas y los astrocitos durante la prelactancia. La utilización del acetato por estas células puede verse mejorada por lasreacciones fijadoras de CO2, algunas de las cuales participan en el mantenimiento de los intermediarios del TCA, que son reducidos por la producción y liberación de aminoácidos, suministrando los recursos para la producción de energía y sustratos que son compartimentados intercelularmente.Se estudió el efecto de la fijación de CO2 en procesos metabólicos intercelulares donde está involucrado el acetato. En incubaciones con neuronas y astrocitos de 7 y 14 días de cultivo, utilizando acetato (5 mM y [14C]-bicarbonato de sodio (10 µ Ci (500-1000 dpm/nmol, se determinó la incorporación en metabolitos marcados en células y en sustratos estables liberados al medio. Adicionalmente, se realizaron experimentos similares utilizando inhibidores como el aminooxiacetato (AOA, dicloroacetato (DCA, α-ciano-4-hidroxicinnamato (α-CN, butilmalonato (BM y bencenotricarboxílato (BT, cuantificando porcromatografía de capa delgada la concentración en el medio de incubación de alanina, aspartato, glutamato y glutamina.Los resultados indican que las neuronas tienen una menor capacidad para fijar carbonos en estructuras celulares, durante la prelactancia, pero utilizan mejor el acetato vía acetil-CoA mitocondrial (AceCS2 para la producción de energía y aminoácidos. En los astrocitos, estas reacciones favorecen la utilización del acetato vía citrato liasa y Acetil-CoA citosólica (AceCS1 para la producción de estructuras y sustratos utilizados por las neuronas, que para la producción de aminoácidos.

  20. COMPARTIMENTACIÓN INTERCELULAR DEL ACETATO EN NEURONAS Y ASTROCITOS DURANTE LA PRELACTANCIA

    OpenAIRE

    Tovar Franco, J.; Laboratorio de Neurobioquímica, Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá; Saavedra, F.; Laboratorio de Neurobioquímica, Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá

    2005-01-01

    Durante el período perinatal el cerebro utiliza sustratos alternativos a la glucosa para mantener su desarrollo, pues en este momento sus niveles están disminuidos. El acetato es metabolizado por las neuronas y los astrocitos durante la prelactancia. La utilización del acetato por estas células puede verse mejorada por las reacciones fijadoras de CO2, algunas de las cuales participan en el mantenimiento de los intermediarios del TCA, que son reducidos por la producción y liberación de aminoác...

  1. The resurrection of a species: Sarcocystis bovifelis Heydorn et al., 1975 is distinct from the current Sarcocystis hirsuta in cattle and morphologically indistinguishable from Sarcocystis sinensis in water buffaloes.

    Science.gov (United States)

    Gjerde, Bjørn

    2016-01-01

    In the mid-1970s, it was established through transmission experiments and ultrastructural studies of sarcocysts by transmission electron microscopy (TEM) that cattle was the intermediate host of three Sarcocystis spp. using dogs, cats and humans, respectively, as definitive hosts. The cat-transmitted species with microscopic sarcocysts was initially named Sarcocystis bovifelis, but it was soon renamed Sarcocystis hirsuta, since it was considered to be identical with a previously named species. In recent years, an apparently new species has been detected in cattle in several countries by molecular methods and TEM and found by both methods to be indistinguishable from Sarcocystis sinensis in water buffaloes. This species was recently named Sarcocystis rommeli. Beginning in August 2014, a thorough review of papers comprising TEM micrographs of thick-walled sarcocysts in cattle was made in order to determine whether S. sinensis-like sarcocysts had been reported previously under other designations. Surprisingly, the review showed that the species S. bovifelis Heydorn et al., 1975 as described from cattle in Germany was S. sinensis-like and that indistinguishable sarcocysts had also been found in cattle in New Zealand and Canada in the 1980s. However, in the New Zealand study, these small sarcocysts were erroneously thought to represent developmental stages of a species with ultrastructurally similar but macroscopic sarcocysts, since the macroscopic cysts were found to be infective for cats. Thus, in the late 1980s, the cat-transmitted S. bovifelis, after having been renamed S. hirsuta, was erroneously synonymised with a second cat-transmitted species in cattle and then slid into obscurity until recently being rediscovered as a S. sinensis-like species in cattle and then named S. rommeli. Following the erroneous synonymisation, the name S. hirsuta has consistently been used for a taxon with macroscopic sarcocysts, and this usage should be continued. The name S. bovifelis

  2. Sarcocystis heydorni, n. sp. (Apicomplexa: Protozoa) with cattle (Bos taurus) and human (Homo sapiens) cycle

    Science.gov (United States)

    Cattle (Bos taurus) are intermediate hosts for four species of Sarcocystis, S. cruzi, S. hirsuta, S. hominis, and S. rommeli. Of these four species, mature sarcocysts of S. cruzi are thin-walled (< 1µm) whereas S. hirsuta, S. hominis, and S. rommeli have thick walls (4 µm or more). Here we describe ...

  3. First molecular detection and characterization of Sarcocystis species in slaughtered cattle in North-West Tunisia.

    Science.gov (United States)

    Amairia, Safa; Amdouni, Yosra; Rjeibi, Mohamed Ridha; Rouatbi, Mariem; Awadi, Sofia; Gharbi, Mohamed

    2016-12-01

    Sarcocystis spp. is one of the most prevalent foodborne parasites infecting both animals and humans. Consumption of raw or undercooked infected meat is a risk factor of human intestinal sarcocystosis. The present study aimed to estimate the prevalence of Sarcocystis species infecting slaughtered Tunisian cattle in North-West Tunisia (Béja governorate). DNA was extracted from 150 beef meat samples and a PCR-restriction fragment length polymorphism was used for identification. The overall infection prevalence of Sarcocystis spp. was 38% (57/150). Two species were identified, namely S. hominis (25%; 39/150) and S. cruzi (12%; 18/150). For both species, the highest prevalence was in Thibar locality (52.9 and 17.6% for S. hominis and S. cruzi, respectively). The molecular prevalence of S. cruzi was significantly higher in animals aged between two and eight years (19.2%; 10/52). This is the first molecular identification of Sarcocystis species in Tunisian cattle. Further studies in both human and animal Tunisian populations are needed to rank this parasitic disease among others. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Sarcocystis arctica (Apicomplexa: Sarcocystidae): ultrastructural description and its new host record, the Alaskan wolf (Canis lupus

    Science.gov (United States)

    Sarcocystis sarcocysts are common in muscles of herbivores but are rare in muscles of carnivores. Here, we report sarcocysts in muscle of an Alaskan wolf (Canis lupus) from Alaska, USA for the first time. Sarcocysts extracted from tongue of the wolf were up to 900 µm long, slender, and appeared to h...

  5. Intramuscular inoculation of cattle with Sarcocystis antigen results in focal eosinophilic myositis.

    Science.gov (United States)

    Vangeel, L; Houf, K; Geldhof, P; Nollet, H; Vercruysse, J; Ducatelle, R; Chiers, K

    2012-02-10

    Bovine eosinophilic myositis (BEM) is a subclinical myopathy characterized by multifocal white to grey-green discolorations in skeletal muscles, heart, tongue and oesophagus. These lesions are found at slaughter or during meat cutting and result in considerable economic losses. The etiology and pathogenesis are unclear, although it has been suggested, that Sarcocystis species are involved. To elucidate their role, two calves were repeatedly injected intramuscularly with adjuvanted Sarcocystis antigen. The morphological changes at the injection sites in these calves were histologically and immunohistochemically compared to spontaneous lesions from 44 BEM condemned carcasses sampled in slaughterhouses. Experimental intramuscular injection of Sarcocystis antigen resulted in lesions at the injection sites that were similar to the lesions of natural cases of BEM. They were characterized by massive infiltration of eosinophilic granulocytes, reactive macrophages (MAC387(+) cells), T-cells (CD3(+)) and B-cells (CD20(+)). Both in the experimental and in the natural cases, COX-2 expression was present in endothelial cells adjacent to lesional areas. MHC class II(+) staining was found amongst others in muscle cells surrounding the lesion. These results show that Sarcocystis antigens can induce an inflammatory response in bovine muscle having the characteristics of natural BEM. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Study of Zoonotic Tissue Parasites (Hydatid Cyst, Fasciola, Dicrocoelium and Sarcocystis in Hamadan Abattoir

    Directory of Open Access Journals (Sweden)

    M. Fallah

    2010-10-01

    Full Text Available Introduction & Objectives: Zoonotic parasites are large groups of zoonoses among which the most important are hydatid cyst, liver trematodes and sarcocystis.These zoonoses are of considerable importance regarding both human health and economy. The objective of this study was to determine the prevalence of tissue zoonotic parasites and their epidemiologic status in Hamadan and to estimate the health and medical burden they impose on the society.Materials & Methods: In this cross sectional study, viscera (including liver, lung, kidney, heart,… and muscles of 2590 sheep, 420 cattle, and 490 goats were macroscopically inspected for hydatid cysts, liver flukes, cysticercus , and microscopically (for Sarcocystis in the Hamadan abattoir. The data were presented by descriptive tables and analyzed by 2 statistical test. Results: The infection rate for hydatid cyst, Fasciola, Dicrocoelium and Sarcocystis were found 12.3%, 4.9%, 6.5%, and 5.5% respectively. The high infection rates for hydatid cyst and Fasciola were found in cattle (16.2% and 9.5% and for Dicrocoelium and Sarcocystis were found in sheep (6.9%. Infection rate of lungs was higher (41.2% than liver (36.6% and liver and lung simultaneously were 22.2% in the infected animals. Infection to Sarcocystis and Cysticercus were not found in the cattle. Conclusion: This study indicated that infection rate of tissue zoonotic parasites are relatively high in the domestic animals of Hamadan , however, the rate is lower in comparison to the previous studies. These parasites had imposed considerable economic burden on the society through reduction in the dairy production and increased the risk of infection in the population as well. (Sci J Hamadan Univ Med Sci 2010;17(3: 5-12

  7. Phylogenetic relationships between Sarcocystis species from reindeer and other Sarcocystidae deduced from ssu rRNA gene sequences

    DEFF Research Database (Denmark)

    Dahlgren, S.S.; Oliveira, Rodrigo Gouveia; Gjerde, B.

    2008-01-01

    any effect on previously inferred phylogenetic relationships within the Sarcocystidae. The complete small subunit (ssu) rRNA gene sequences of all six Sarcocystis species from reindeer were used in the phylogenetic analyses along with ssu rRNA gene sequences of 85 other members of the Coccidea. Trees...... were constructed using Bayesian analysis and maximum likelihood estimations. All six Sarcocystis species from reindeer were placed together with other Sarcocystis species using an even-toed ungulate as their intermediate host. The three canine transmitted species, S. grueneri, S. rangi, S...... and S. tarandi are felines, and in Norway notably the lynx. The overall phylogeny of the Sarcocystidae did not change by the inclusion of the six Sarcocystis species from reindeer. This study suggests that phylogentic analysis can be a useful tool in the search for possible definitive hosts for those...

  8. Neuronas Espejo y Teoría de la Mente en la explicación de la empatía

    OpenAIRE

    García García, Emilio; González Marqués, Javier; Maestú Unturbe, Fernando

    2011-01-01

    La empatía es la capacidad de una persona para vivenciar los pensamientos y sentimientos de los otros, reaccionando adecuadamente. Diferenciamos en la empatía dos componentes: cognitivo y emocional. El componente cognitivo comprende los pensamientos y sentimientos del otro. El componente afectivo comparte el estado emocional de otra persona. Comentamos dos teorías para explicar la empatía: las neuronas espejo y la Teoría de la Mente. Las neuronas espejo son un tipo particular de neuronas que ...

  9. Surface epitope localization and gene structure of a Babesia bovis 44-kilodalton variable merozoite surface antigen.

    Science.gov (United States)

    Jasmer, D P; Reduker, D W; Hines, S A; Perryman, L E; McGuire, T C

    1992-10-01

    Variation of Babesia bovis merozoite surface antigens occurs among geographic strains of the parasite. In this and a concurrent report, we investigate this variation at the gene and protein level. Using a monoclonal antibody (mAb 23/70.174), B. bovis gene sequences were identified that encoded a surface epitope of a 44-kDa merozoite surface antigen (MSA-2). This epitope is variably expressed among geographic isolates of B. bovis. Here, we describe the MSA-2 protein gene sequence, localize this surface epitope to a repeated amino acid sequence, and investigate the genomic organization of the gene in B. bovis strains from Mexico and Australia. The predicted protein sequence had hydrophobic regions at its amino and carboxy termini consistent with a signal peptide and a membrane anchor via glycosylphosphatidyl inositol, respectively. The surface epitope recognized by mAb 23/70.174 was localized within a 24-amino acid sequence which is repeated twice in tandem. Six different EcoRI bands hybridized to the MSA-2 gene sequence with varying intensities in genomic Southern blots of the homologous strain. Two of these appear to be alleles of the MSA-2 gene. Whereas 5' and 3' sequences of the MSA-2 gene sequence were detected in an Australia strain of B. bovis, internal gene sequences encoding the surface epitope were not. The 3' sequences of the MSA-2 gene also had significant sequence similarity with the MSA-1 gene of the Mexico strain B. bovis and a gene from the previously described BabR locus. These data indicate that the MSA-2 protein gene belongs to the BabR locus which encodes variable merozoite surface antigens.

  10. A GBP 130 derived peptide from Plasmodium falciparum binds to human erythrocytes and inhibits merozoite invasion in vitro

    Directory of Open Access Journals (Sweden)

    Jorge E Suarez

    2000-08-01

    Full Text Available The malarial GBP 130 protein binds weakly to intact human erythrocytes; the binding sites seem to be located in the repeat region and this region's antibodies block the merozoite invasion. A peptide from this region (residues from 701 to 720 which binds to human erythrocytes was identified. This peptide named 2220 did not bind to sialic acid; the binding site on human erythrocyte was affected by treatment with trypsin but not by chymotrypsin. The peptide was able to inhibit Plasmodium falciparum merozoite invasion of erythrocytes. The residues F701, K703, L705, T706, E713 (FYKILTNTDPNDEVERDNAD were found to be critical for peptide binding to erythrocytes.

  11. De las neuronas espejo a la neuropolítica moral

    OpenAIRE

    Olson, Gary

    2012-01-01

    Este artículo presenta el descubrimiento del sistema de neuronas espejo, que muestran que los mecanismo neuronales revelan que los humanos estamos «cableados” para la empatía, con lo que la moralidad tendría así sus raíces en la biología. Se argumenta que esta base científica tenderá a influir la opinión pública contribuyendo a disolver nuestras creencias actuales que nos llevan a la destrucción recíproca. La pregunta pendiente, se señala,  es por qué no actúa la empatía a nivel social, formu...

  12. Factores tróficos en neuronas dopaminérgicas mesencefálicas

    Directory of Open Access Journals (Sweden)

    G. Pinzón

    1994-12-01

    Full Text Available Desde su descubrimiento, se ha postulado, y en algunos casos comprobado, que los factores tróficos juegan un papel importante en el desarrollo, mantenimiento y regeneración del sistema nervioso. El conocimiento y la manipulación de estas sustancias ha servido para: a formular nuevas teorías acerca de la etiología de varios desórdenes neurodebeneraivos y b desarrollar nuevas altemativas terapéuticas para estas entidades. En la presente revisión, resumimos los principales efectos de diferentes factores tróficos sobre las neuronas dopaminérgicas de la substantia nigra en desarrollo, cuya degeneración en el adulto ocasiona la mayoría de los síntomas observados en la enfermedad de Parkinson.

  13. Eosinophilic myositis resulted from Sarcocystis infection in prime marbled beef of Japanese black cattle

    Directory of Open Access Journals (Sweden)

    Tohru Kimura

    Full Text Available Partial changes of color (greenish to brownish were found in prime marbled beef of Japanese black cattle. The disseminated lesions of the skeletal muscles were histopathologically examined in relation to Sarcocystis infection. The lesions in the muscles showed granulomas with inflammatory cell infiltration. The sarcocysts had a distinct wall, which was radically striated by palisading villar protrusions. The sarcocyst wall was surrounded by degenerative eosinophils and necrotic muscle fibers. In conclusion, eosinophilic myositis in prime marbled beef of Japanese black cattle resulted from Sarcocystis spp. infection. The muscular lesions were characterized by the presence of granulomas and capsulated sarcocysts surrounded by numerous eosinophils. [Vet. World 2011; 4(11.000: 500-502

  14. Indirect haemagglutination reaction with antigen of Sarcocystis gigantea (Railliet, 1886) Ashford, 1977.

    Science.gov (United States)

    Cerva, L; Gut, J

    1983-01-01

    The water extract from cryolyzed whole muscle cysts of Sarcocystis gigantea from sheep, in spite of the high lectin content, is a suitable antigen for the detection of specific antibodies by means of indirect haemagglutination reaction (IHA). The agglutinating effect of lectin from parasitic cysts can be eliminated with a 0.5% concentration of lactose dissolved in all solutions used for IHA. In sera of slaughterhouse sheep, positive titres ranging from 1:80 to 1:1 280 were registered. Positive reactions in lower titres were observed also with antibodies against S. dispersa, S. cuniculi and Sarcocystis sp. from pigs. Sensibilized erythrocytes can be stored in refrigerator at least for 1 week.

  15. N-Terminal Plasmodium vivax Merozoite Surface Protein-1, a Potential Subunit for Malaria Vivax Vaccine

    Directory of Open Access Journals (Sweden)

    Fernanda G. Versiani

    2013-01-01

    Full Text Available The human malaria is widely distributed in the Middle East, Asia, the western Pacific, and Central and South America. Plasmodium vivax started to have the attention of many researchers since it is causing diseases to millions of people and several reports of severe malaria cases have been noticed in the last few years. The lack of in vitro cultures for P. vivax represents a major delay in developing a functional malaria vaccine. One of the major candidates to antimalarial vaccine is the merozoite surface protein-1 (MSP1, which is expressed abundantly on the merozoite surface and capable of activating the host protective immunity. Studies have shown that MSP-1 possesses highly immunogenic fragments, capable of generating immune response and protection in natural infection in endemic regions. This paper shows humoral immune response to different proteins of PvMSP1 and the statement of N-terminal to be added to the list of potential candidates for malaria vivax vaccine.

  16. In vivo assessment of rodent Plasmodium parasitemia and merozoite invasion by flow cytometry.

    Science.gov (United States)

    Lelliott, Patrick M; McMorran, Brendan J; Foote, Simon J; Burgio, Gaetan

    2015-04-05

    During blood stage infection, malaria parasites invade, mature, and replicate within red blood cells (RBCs). This results in a regular growth cycle and an exponential increase in the proportion of malaria infected RBCs, known as parasitemia. We describe a flow cytometry based protocol which utilizes a combination of the DNA dye Hoechst, and the mitochondrial membrane potential dye, JC-1, to identify RBCs which contain parasites and therefore the parasitemia, of in vivo blood samples from Plasmodium chabaudi adami DS infected mice. Using this approach, in combination with fluorescently conjugated antibodies, parasitized RBCs can be distinguished from leukocytes, RBC progenitors, and RBCs containing Howell-Jolly bodies (HJ-RBCs), with a limit of detection of 0.007% parasitemia. Additionally, we outline a method for the comparative assessment of merozoite invasion into two different RBC populations. In this assay RBCs, labeled with two distinct compounds identifiable by flow cytometry, are transfused into infected mice. The relative rate of invasion into the two populations can then be assessed by flow cytometry based on the proportion of parasitized RBCs in each population over time. This combined approach allows the accurate measurement of both parasitemia and merozoite invasion in an in vivo model of malaria infection.

  17. Necrotizing meningoencephalitis caused by Sarcocystis falcatula in bare-faced ibis (Phimosus infuscatus).

    Science.gov (United States)

    Konradt, Guilherme; Bianchi, Matheus Viezzer; Leite-Filho, Ronaldo Viana; da Silva, Bruna Zafalon; Soares, Rodrigo Martins; Pavarini, Saulo Petinatti; Driemeier, David

    2017-02-01

    The infection by S. falcatula is commonly associated with respiratory disease in captive psittacine birds, with a few case reports of this protozoan causing encephalitis in wild birds. We describe the clinical, pathological, and molecular aspects of an infection by S. falcatula in a bare-faced ibis (Phimosus infuscatus). Clinically, wing paralysis and mild motor incoordination were observed. At necropsy, the telencephalic cortex showed multifocal to coalescing yellowish soft areas. Histologically, multifocal to coalescent nonsuppurative necrotizing meningoencephalitis of telencephalic cortex, cerebellum, and brainstem was observed. Necrotic areas showed multiple protozoan organism characteristics of Sarcocystis sp. schizonts in the cytoplasm of endothelial cells or lying free in the neuropil. Partial genetic sequences of the gene encoding cytochrome b (CYTB), the gene encoding the beta subunit of RNA polymerase (RPOB) and the first internal transcribed spacer (ITS-1) from Sarcocystis sp. schizonts revealed that the parasite had ITS-1 sequences that were 100% identical to the homologous alleles from Sarcocystis sp. shed by Didelphis albiventris in Brazil. RPOB and CYTB sequences were 100% identical to homologous of S. falcatula available in Genbank. Thus, this is the first report of necrotizing meningoencephalitis caused by S. falcatula in bare-faced ibis (P. infuscatus).

  18. Variation in clinical and parasitological traits in Pietrain and Meishan pigs infected with Sarcocystis miescheriana.

    Science.gov (United States)

    Reiner, G; Eckert, J; Peischl, T; Bochert, S; Jäkel, T; Mackenstedt, U; Joachim, A; Daugschies, A; Geldermann, H

    2002-06-03

    Future prophylaxis needs new concepts, including natural disease resistance of hosts against infectious agents. Genomic approaches to detect and improve disease resistance in farm animals and the molecular mechanisms involved in host-parasite interactions depend to a high degree on the trait differences between founder breeds, i.e. on the animal model. The present study evaluates differences in susceptibility/resistance against Sarcocystis miescheriana in the European Pietrain (PI) and the Chinese Meishan (ME) pig breeds, based on 25 individuals, infected orally with 5x10(4) sporocysts of S. miescheriana. Significant differences appeared in clinical, serological, haematological and parasitological findings. The major discriminating period post infection (p.i.) was between days 42 and 45. Severity of signs was negatively correlated with specific immunoglobulin titres during the first 3 weeks p.i. and positively with the load of bradyzoites in muscle tissues of the pigs. Loads of bradyzoites in muscle tissues were 20 times higher in PI than in ME. Sarcocystis-specific differences between the two breeds were in the range of 1-2 standard deviations. The study lays the foundation for further experiments to analyse chromosomal regions, candidate genes, and thus the molecular basis of Sarcocystis susceptibility/resistance as a model for host-parasite interaction in protozoan infectious disease.

  19. DNA extraction methods and multiple sampling to improve molecular diagnosis of Sarcocystis spp. in cattle hearts.

    Science.gov (United States)

    Bräunig, Patrícia; Portella, Luiza Pires; Cezar, Alfredo Skrebsky; Libardoni, Felipe; Sangioni, Luis Antonio; Vogel, Fernanda Silveira Flores; Gonçalves, Paulo Bayard Dias

    2016-10-01

    Molecular detection of Sarcocystis spp. in tissue samples can be useful for experimental and diagnostic purposes. However, the parasite spreads unevenly through tissues, forming tissue cysts, and the cystic wall is an obstacle in DNA extraction protocols. Therefore, adequate sampling and effective disruption of the cysts are essential to improve the accuracy of DNA detection by PCR. The aims of this study were to evaluate the suitability of four protocols for DNA extraction from cysts of Sarcocystis spp. present in bovine myocardium samples or after their harvest in phosphate-buffered saline (PBS) solution as well as determine the effects of single or multiple sampling on the accuracy of molecular diagnosis of sarcocystosis in cattle hearts. Cysts and myocardium samples from nine bovine hearts were randomly distributed to four DNA extraction protocols: kit, kit with modification, DNAzol, and cetyl-trimethyl ammonium bromide (CTAB). Samples were submitted to DNA extraction and PCR as replicates of each heart (simplicate, duplicate, and triplicate), and the probability of a true positive diagnostic was calculated. Among the protocols tested, the kit with modification was determined to be the most suitable for DNA extraction from cysts in PBS solution (92.6 % of DNA detection by PCR); DNAzol resulted in higher DNA detection frequency from bovine myocardium samples (48.1 %). Multiple sampling improved the molecular diagnosis of Sarcocystis spp. infection in cattle hearts, increasing at 22.2 % the rate of true positive diagnostic.

  20. Ultrastructure of Sarcocystis bertrami sarcocysts from a naturally infected donkey (Equus asinus) from Egypt.

    Science.gov (United States)

    Dubey, J P; VAN Wilpe, E; Verma, S K; Hilali, M

    2016-01-01

    There is considerable confusion concerning Sarcocystis species in equids. Little is known of Sarcocystis infections in donkeys (Equus asinus). Here we describe the structure of Sarcocystis bertrami-like from the donkey by light microscopy (LM) and transmission electron microscopy (TEM). Nineteen sarcocysts from the tongue of a donkey from Egypt were studied both by LM and TEM. By LM, all sarcocysts had variably shaped and sized projections on the sarcocyst walls, giving it a thin-walled to thick-walled appearance, depending on individual sarcocyst and plane of section. By TEM, sarcocysts walls had villar protrusions (vp) of type 11. The sarcocyst wall had conical to slender vp, up to 6 µm long and 1 µm wide; the vp were folded over the sarcocyst wall. The total thickness of the sarcocyst wall with ground substance layer (gs) was 1-3 µm. The vp had microtubules (mt) that originated deeper in the gs and continued up to the tip. The apical part of the vp had electron dense granules. The mt were configured into 3 types: a tuft of electron dense mt1 extending the entire length of the vp with a tuft of medium electron dense mt2 appearing in parallel, and fine mt3 present only in the villar tips. The gs was mainly smooth with few indistinct granules. All sarcocysts were mature and contained metrocytes and bradyzoites. Bradyzoites were approximately 11-15 × 2-3 µm in size with typical organelles.

  1. Identification of Heparin Modifications and Polysaccharide Inhibitors of Plasmodium falciparum Merozoite Invasion That Have Potential for Novel Drug Development.

    Science.gov (United States)

    Boyle, Michelle J; Skidmore, Mark; Dickerman, Benjamin; Cooper, Lynsay; Devlin, Anthony; Yates, Edwin; Horrocks, Paul; Freeman, Craig; Chai, Wengang; Beeson, James G

    2017-11-01

    Despite recent successful control efforts, malaria remains a leading global health burden. Alarmingly, resistance to current antimalarials is increasing and the development of new drug families is needed to maintain malaria control. Current antimalarials target the intraerythrocytic developmental stage of the Plasmodium falciparum life cycle. However, the invasive extracellular parasite form, the merozoite, is also an attractive target for drug development. We have previously demonstrated that heparin-like molecules, including those with low molecular weights and low anticoagulant activities, are potent and specific inhibitors of merozoite invasion and blood-stage replication. Here we tested a large panel of heparin-like molecules and sulfated polysaccharides together with various modified chemical forms for their inhibitory activity against P. falciparum merozoite invasion. We identified chemical modifications that improve inhibitory activity and identified several additional sulfated polysaccharides with strong inhibitory activity. These studies have important implications for the further development of heparin-like molecules as antimalarial drugs and for understanding merozoite invasion. Copyright © 2017 American Society for Microbiology.

  2. Hepatic sarcocystosis in a striped dolphin (Stenella coeruleoalba) from the Spanish Mediterranean coast.

    Science.gov (United States)

    Resendes, A R; Juan-Sallés, C; Almeria, S; Majó, N; Domingo, M; Dubey, J P

    2002-02-01

    Fatal hepatic sarcocystosis was diagnosed in a striped dolphin (Stenella coeruleoalba) from the northeastern Spanish Mediterranean coast based on pathologic findings and the microscopic and ultrastructural characteristics of the intralesional parasite. Main gross lesions were icterus, subcutaneous hemorrhages, and hepatic congestion. The most prominent microscopic lesions consisted of severe acute multifocal to coalescing necrotizing hepatitis with cholestasis and intralesional protozoa. There was severe chronic pancreatitis with generalized distension of pancreatic ducts by hyaline plugs and adult trematodes. Only asexual stages of the protozoa were found. The parasite in the liver divided by endopolygeny. Schizonts varied in shape and size. Mature schizonts had merozoites randomly arranged or budding peripherally around a central residual body. Schizonts were up to 22 microm long, and merozoites were up to 6 microm long. Ultrastructurally, merozoites lacked rhoptries. This parasite failed to react by immunohistochemistry with anti-Toxoplasma gondii, anti-Neospora caninum and anti-Sarcocystis neurona antibodies. The microscopic and ultrastructural morphologies of the parasite were consistent with Sarcocystis canis, so far described only from animals in the Unites States. The life cycle and source of S. canis are unknown. The present report of S. canis-like infection in a sea mammal from Spain indicates that the definitive host for this parasite also exists outside of the United States.

  3. Specific T-cell recognition of the merozoite proteins rhoptry-associated protein 1 and erythrocyte-binding antigen 1 of Plasmodium falciparum

    DEFF Research Database (Denmark)

    Jakobsen, P H; Hviid, L; Theander, T G

    1993-01-01

    The merozoite proteins merozoite surface protein 1 (MSP-1) and rhoptry-associated protein 1 (RAP-1) and synthetic peptides containing sequences of MSP-1, RAP-1, and erythrocyte-binding antigen 1, induced in vitro proliferative responses of lymphocytes collected from Ghanaian blood donors living...... by individuals living in an area with a high transmission rate of malaria. Most of the donor plasma samples tested contained immunoglobulin G (IgG) and IgM antibodies recognizing the merozoite proteins, while only a minority showed high IgG reactivity to the synthetic peptides....

  4. Experimentos con una protección basada en redes de neuronas artificiales

    Directory of Open Access Journals (Sweden)

    Orlys Ernesto Torres Breffe

    2011-10-01

    Full Text Available En este trabajo se muestran los resultados de los experimentos físicos realizados con una protección basada totalmente en Redes de Neuronas Artificiales para un transformador eléctrico a escala de laboratorio. Se demuestra que unas Redes de Neuronas Artificiales entrenadas, con datos provenientes de regímenes simulados matemáticamente, opera correctamente con señales de regímenes provenientes de casos reales, al menos a escala de laboratorio y con niveles reducidos de intensidad. Se describe la instalación experimental, tanto desde el puntode vista de hardware como software utilizando la tecnología de National Instrument. Se entrenan diferentes tipos de Redes Neuronales y todas aprendieron a proteger correctamente. Estos experimentos establecen las pautas para el desarrollo de Relés Electrónicos Inteligentes que no se ajustarían, al menos con datos y valores de difícil comprensión como los actuales relés, sino que se entrenarían una vez mediante la simulación matemática y la experiencia práctica los haría cada vez mejores. In this work is shown the results of the physical experiments done with a protection totally based in Artificial Neural Networks for an electric transformer of the laboratory scale. Its demonstrated that some Artificial Neural Networks trained with data coming from a mathematically simulated regimens, it operates correctly with signals coming fromreal cases, at least to laboratory scale and with reduced levels of intensity. The experimental installation is described, so much from the hardware and software point of view, using the technology of National Instrument. Different types of Artificial Neural Nets are trained and all learned how to protect correctly. These experiments establish the rules forthe development of Intelligent Electronic Relays that would not be adjusted, at least with complex data and values like the current relays, they will be trained once from the mathematically simulation and the

  5. Sarcocystis spp. in llamas (Lama glama) in Southern Bolivia: a cross sectional study of the prevalence, risk factors and loss in income caused by carcass downgrades.

    Science.gov (United States)

    Rooney, A L; Limon, G; Vides, H; Cortez, A; Guitian, J

    2014-10-01

    Llamas (Lama glama) are intermediate hosts of the protozoan parasite Sarcocystis spp. This parasite is described as causing economic losses in the production of llama meat in South America. The aim of this study was to estimate prevalence, identify risk factors and explore spatial patterns of Sarcocystis in llamas in an area of the Bolivian High Plateau including estimating financial losses due to carcass downgrades as a result of the presence of Sarcocystis cysts. Information was collected from a local abattoir between 2006 and 2011 on 1196 llamas. Sarcocystis status was determined at meat inspection where any carcasses with one or more visible cysts were deemed Sarcocystis positive. A high prevalence was found, estimated to vary between 23.4% (95% CI 16.6-30.1) in 2007 and 50.3% (95% CI 44.4-56.3) in 2011. Period prevalence between 2006 and 2011 was estimated at 34.1% (95% CI 31.4-36.8). Age, sex and type (analogous to breed) were identified as risk factors for Sarcocystis using a mixed-effects logistic regression model adjusting for clustering by community and owner. Llamas over 4.5 years of age had an increased odds of being Sarcocystis positive (OR 19.31, 95% CI 9.10-40.98) as well as females (OR 1.75, 95% CI 1.13-2.68) and long haired type llamas (OR 1.90, 95% CI 1.26-2.87). An interaction between age and sex was detected indicating that the increased odds of disease from the youngest age group to the 2.5-4.5 years group was much more pronounced in females than in males. Spatial patterns of Sarcocystis were explored at district level by means of Standardised Morbidity Ratios and some spatial heterogeneity was revealed. Estimates of financial loss due to the disease were calculated using the difference in price paid for Sarcocystis positive and negative meat. Loss due to Sarcocystis varied per year but could be up to 20% of the annual income generated through the abattoir by sale of meat. Overall this study shows a high prevalence of Sarcocystis in the study

  6. Genetic diversity of the merozoite surface protein-3 gene in Plasmodium falciparum populations in Thailand

    Directory of Open Access Journals (Sweden)

    Sittiporn Pattaradilokrat

    2016-10-01

    Full Text Available Abstract Background An effective malaria vaccine is an urgently needed tool to fight against human malaria, the most deadly parasitic disease of humans. One promising candidate is the merozoite surface protein-3 (MSP-3 of Plasmodium falciparum. This antigenic protein, encoded by the merozoite surface protein (msp-3 gene, is polymorphic and classified according to size into the two allelic types of K1 and 3D7. A recent study revealed that both the K1 and 3D7 alleles co-circulated within P. falciparum populations in Thailand, but the extent of the sequence diversity and variation within each allelic type remains largely unknown. Methods The msp-3 gene was sequenced from 59 P. falciparum samples collected from five endemic areas (Mae Hong Son, Kanchanaburi, Ranong, Trat and Ubon Ratchathani in Thailand and analysed for nucleotide sequence diversity, haplotype diversity and deduced amino acid sequence diversity. The gene was also subject to population genetic analysis (F st and neutrality tests (Tajima’s D, Fu and Li D* and Fu and Li’ F* tests to determine any signature of selection. Results The sequence analyses revealed eight unique DNA haplotypes and seven amino acid sequence variants, with a haplotype and nucleotide diversity of 0.828 and 0.049, respectively. Neutrality tests indicated that the polymorphism detected in the alanine heptad repeat region of MSP-3 was maintained by positive diversifying selection, suggesting its role as a potential target of protective immune responses and supporting its role as a vaccine candidate. Comparison of MSP-3 variants among parasite populations in Thailand, India and Nigeria also inferred a close genetic relationship between P. falciparum populations in Asia. Conclusion This study revealed the extent of the msp-3 gene diversity in P. falciparum in Thailand, providing the fundamental basis for the better design of future blood stage malaria vaccines against P. falciparum.

  7. Sarcocystis arctica (Apicomplexa: Sarcocystidae): ultrastructural description and its new host record, the Alaskan wolf (Canis lupus).

    Science.gov (United States)

    Calero-Bernal, Rafael; Cerqueira-Cézar, Camila K; Verma, Shiv Kumar; Mowery, Joseph; Carmena, David; Beckmen, Kimberlee; Dubey, Jitender P

    2016-07-01

    Sarcocystis sarcocysts are common in muscles of herbivores but are rare in muscles of carnivores. Here, we report sarcocysts in the muscles of a gray wolf (Canis lupus) from Alaska, USA, for the first time. Sarcocysts extracted from the tongue of the wolf were up to 900 μm long and slender and appeared to have a relatively thin wall by light microscope. By transmission electron microscopy, the sarcocyst wall most closely resembled "type 9c," and had a wavy parasitophorous vacuolar membrane folded as pleomorphic villar protrusions (vp), with anastomoses of tips. The vp and the ground substance (gs) layer were smooth without tubules or granules. The gs was up to 2.0 μm thick. The total width of the wall including vp and the gs was 3.5 μm. The vp were up to 1.5 μm long. Mature sarcocysts contained numerous bradyzoites and few metrocytes. The bradyzoites were 9.5 μm long and 1.5 μm wide, and contained all organelles found in Sarcocystis bradyzoites with at least two rhoptries. Molecular characterization showed the highest identity for 18S rRNA, 28S rRNA, ITS-1, and cox1 sequences of Sarcocystis arctica of the Arctic fox (Vulpes lagopus) from Norway. The ultrastructure of S. arctica from the fox is unknown. Here, we provide ultrastructure of S. arctica from the Alaskan wolf for the first time. The definitive host of S. arctica remains unknown.

  8. DESARROLLO DE ESTADIOS ASEXUALES DE Sarcocystis Aucheniae EN CULTIVO DE CÉLULAS.

    OpenAIRE

    Uzuriaga S, Milagros; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Sam T., Rosa; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Manchego S., Alberto; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Alvarado S., Arnaldo; Laboratorio de Patología Clínica, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima

    2012-01-01

    Cistozoitos obtenidos a partir de macroquistes de Sarcocystis aucheniae presentes en carne de alpacas con sarcocistiosis fueron inoculados en cultivo primario de células de cornete nasal de feto de alpaca (CNA) y en líneas de células establecidas de riñón de bovino (BHK) y de mono (VERO). Los cistozoitos ingresaron a todas las células, transformándose en grandes y pequeños esquizontes multinucleares o en estadios como quistes, produciendo gran cantidad de merozoitos, todos de posición perinuc...

  9. Immune response in rabbits to two sizes of cysts of sarcocystis aucheniae

    OpenAIRE

    Romero, Jaime; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima. Perú; Chávez V., Amanda; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Casas A., Eva; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima Perú.; Maturano H., Lenin; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima. Perú; Puray C., Nidia; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima. Perú; Chileno M., María; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima. Perú

    2012-01-01

    The aim of this study was to evaluate the immune response of small and large macrocysts of Sarcocystis auchenie using three protocols of inoculation. Alpaca meat samples with S. aucheniae were obtained from the slaughterhouse of Huancavelica, Peru. Cysts were collected and classified by size in large (>5 mm) and small (1-3 mm), obtaining 3.23 and 2.45 mg/ml respectively of antigenic protein by the Biuret method. Fifteen rabbits were immunized with 0.05 mg/kg of antigenic protein derived fr...

  10. Hojas de cálculo para la simulación de redes de neuronas artificiales (RNA)

    OpenAIRE

    Garcia, J.

    2002-01-01

    La utilización de Redes de Neuronas Artificiales (RNA) en problemas de predicción de series de tiempo, clasificación y reconocimiento de patrones ha aumentado considerablemente en los últimos años. Programas informáticos de matemáticas de propósito general tales como MATLAB, MATHCAD y aplicaciones estadísticas como SPSS y S-PLUS incorporan herramientas que permiten implementar RNAs. A esta oferta de software hay que añadir programas específicos como NeuralWare, EasyNN o Neuron. Desde un punto...

  11. Naturally acquired antibodies target the glutamate-rich protein on intact merozoites and predict protection against febrile malaria

    DEFF Research Database (Denmark)

    Kana, Ikhlaq Hussain; Adu, Bright; Tiendrebeogo, Régis Wendpayangde

    2017-01-01

    Background.: Plasmodium species antigens accessible at the time of merozoite release are likely targets of biologically functional antibodies. Methods.: Immunoglobulin G (IgG) antibodies against intact merozoites were quantified in the plasma of Ghanaian children from a longitudinal cohort using ...... support previous studies that found OP of merozoites to be associated with protection against malaria and further shows IgG3 and GLURP antibodies are key in the OP mechanism, thus giving further impetus for the development of malaria vaccines targeting GLURP....... a novel flow cytometry-based immunofluorescence assay. Functionality of these antibodies, as well as glutamate-rich protein (GLURP)-specific affinity-purified IgG from malaria hyperimmune Liberian adults, was assessed by the opsonic phagocytosis (OP) assay. Results.: Opsonic phagocytosis activity...... was strongly associated (hazard ratio [HR] = 0.46; 95% confidence interval [CI] = .30-.73; P = .0008) with protection against febrile malaria. Of the antimerozoite-specific antibodies, only IgG3 was significantly associated with both OP and protection (HR = 0.53; 95% CI = .34-.84; Pcorrected = .03) against...

  12. Enhancing blockade of Plasmodium falciparum erythrocyte invasion: assessing combinations of antibodies against PfRH5 and other merozoite antigens.

    Directory of Open Access Journals (Sweden)

    Andrew R Williams

    Full Text Available No vaccine has yet proven effective against the blood-stages of Plasmodium falciparum, which cause the symptoms and severe manifestations of malaria. We recently found that PfRH5, a P. falciparum-specific protein expressed in merozoites, is efficiently targeted by broadly-neutralizing, vaccine-induced antibodies. Here we show that antibodies against PfRH5 efficiently inhibit the in vitro growth of short-term-adapted parasite isolates from Cambodia, and that the EC(50 values of antigen-specific antibodies against PfRH5 are lower than those against PfAMA1. Since antibody responses elicited by multiple antigens are speculated to improve the efficacy of blood-stage vaccines, we conducted detailed assessments of parasite growth inhibition by antibodies against PfRH5 in combination with antibodies against seven other merozoite antigens. We found that antibodies against PfRH5 act synergistically with antibodies against certain other merozoite antigens, most notably with antibodies against other erythrocyte-binding antigens such as PfRH4, to inhibit the growth of a homologous P. falciparum clone. A combination of antibodies against PfRH4 and basigin, the erythrocyte receptor for PfRH5, also potently inhibited parasite growth. This methodology provides the first quantitative evidence that polyclonal vaccine-induced antibodies can act synergistically against P. falciparum antigens and should help to guide the rational development of future multi-antigen vaccines.

  13. Malaria parasite cGMP-dependent protein kinase regulates blood stage merozoite secretory organelle discharge and egress.

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    Christine R Collins

    2013-05-01

    Full Text Available The malaria parasite replicates within an intraerythrocytic parasitophorous vacuole (PV. Eventually, in a tightly regulated process called egress, proteins of the PV and intracellular merozoite surface are modified by an essential parasite serine protease called PfSUB1, whilst the enclosing PV and erythrocyte membranes rupture, releasing merozoites to invade fresh erythrocytes. Inhibition of the Plasmodium falciparum cGMP-dependent protein kinase (PfPKG prevents egress, but the underlying mechanism is unknown. Here we show that PfPKG activity is required for PfSUB1 discharge into the PV, as well as for release of distinct merozoite organelles called micronemes. Stimulation of PfPKG by inhibiting parasite phosphodiesterase activity induces premature PfSUB1 discharge and egress of developmentally immature, non-invasive parasites. Our findings identify the signalling pathway that regulates PfSUB1 function and egress, and raise the possibility of targeting PfPKG or parasite phosphodiesterases in therapeutic approaches to dysregulate critical protease-mediated steps in the parasite life cycle.

  14. Plasmodium falciparum merozoite invasion is inhibited by antibodies that target the PfRh2a and b binding domains.

    Directory of Open Access Journals (Sweden)

    Tony Triglia

    2011-06-01

    Full Text Available Plasmodium falciparum, the causative agent of the most severe form of malaria in humans invades erythrocytes using multiple ligand-receptor interactions. The P. falciparum reticulocyte binding-like homologue proteins (PfRh or PfRBL are important for entry of the invasive merozoite form of the parasite into red blood cells. We have analysed two members of this protein family, PfRh2a and PfRh2b, and show they undergo a complex series of proteolytic cleavage events before and during merozoite invasion. We show that PfRh2a undergoes a cleavage event in the transmembrane region during invasion consistent with activity of the membrane associated PfROM4 protease that would result in release of the ectodomain into the supernatant. We also show that PfRh2a and PfRh2b bind to red blood cells and have defined the erythrocyte-binding domain to a 15 kDa region at the N-terminus of each protein. Antibodies to this receptor-binding region block merozoite invasion demonstrating the important function of this domain. This region of PfRh2a and PfRh2b has potential in a combination vaccine with other erythrocyte binding ligands for induction of antibodies that would block a broad range of invasion pathways for P. falciparum into human erythrocytes.

  15. A Babesia bovis 225-kilodalton spherical-body protein: localization to the cytoplasmic face of infected erythrocytes after merozoite invasion.

    Science.gov (United States)

    Dowling, S C; Perryman, L E; Jasmer, D P

    1996-07-01

    A 225-kDa Babesia bovis protein occurs on the cytoplasmic side of infected-erythrocyte membranes. Here it is demonstrated that the 225-kDa protein localizes to spherical-body organelles of merozoites. Organelles consistent in size and shape with spherical bodies were isolated between 1.17 and 1.21 g/cm(3) in a sucrose density gradient. Organelles consistent with rhoptries and micronemes were also present in fractions from 1.17 to 1.19 g/cm(3). Antisera generated by immunizing mice with the fraction (1.20 to 1.21 g/cm(3)) most enriched for spherical bodies reacted predominantly with spherical bodies in B. bovis merozoites. A monoclonal antibody generated from this immunization (70/97.14) recognized an epitope that occurs in the repeat region of the 225-kDa protein (now referred to as SBP2). Monoclonal antibody 70/97.14 bound to merozoite spherical bodies, vesicles in infected-host cytoplasm, and the cytoplasmic face of the infected-erythrocyte membrane. These results indicate that spherical-body proteins become associated with the host membrane via transport through the erythrocyte cytoplasm after intracellular invasion.

  16. Protozoal Meningoencephalitis in Sea Otters (Enhydra lutris): a Histopathological and Immunohistochemical Study of Naturally Occuring Cases

    Science.gov (United States)

    Thomas, N.J.; Dubey, J.P.; Lindsay, D.S.; Cole, R.A.; Meteyer, C.U.

    2007-01-01

    Protozoal meningoencephalitis is considered to be an important cause of mortality in the California sea otter (Enhydra lutris). Thirty nine of 344 (11.3%) California (CA) and Washington state (WA) sea otters examined from 1985 to 2004 had histopathological evidence of significant protozoal meningoencephalitis. The aetiological agents and histopathological changes associated with these protozoal infections are described. The morphology of the actively multiplicative life stages of the organisms (tachyzoites for Toxoplasma gondii and merozoites for Sarcocystis neurona) and immunohistochemical labelling were used to identify infection with S. neurona (n=22, 56.4%), T. gondii (n=5, 12.8%) or dual infection with both organisms (n=12, 30.8%). Active S. neurona was present in all dual infections, while most had only the latent form of T. gondii. In S. neurona meningoencephalitis, multifocal to diffuse gliosis was widespread in grey matter and consistently present in the molecular layer of the cerebellum. In T. gondii meningoencephalitis, discrete foci of gliosis and malacia were more widely separated, sometimes incorporated pigment-laden macrophages and mineral, and were found predominantly in the cerebral cortex. Quiescent tissue cysts of T. gondii were considered to be incidental and not a cause of clinical disease and mortality. Protozoal meningoencephalitis was diagnosed more frequently in the expanding population of WA sea otters (10 of 31, 32.3%) than in the declining CA population (29 of 313, 9.3%). Among sea otters with protozoal meningoencephalitis, those that had displayed neurological signs prior to death had active S. neurona encephalitis, supporting the conclusion that S. neurona is the most significant protozoal pathogen in the central nervous system of sea otters.

  17. Avances en el desarrollo infantil temprano: desde neuronas hasta programas a gran escala

    Directory of Open Access Journals (Sweden)

    Rafael Pérez-Escamilla

    2017-03-01

    Full Text Available El desarrollo infantil temprano (DIT es la base del desarrollo económico y social de los países y de su capacidad de cumplir con los Objetivos de Desarrollo Sostenible (ODS. La gestación y los primeros 3 años de vida son fundamentales para que los niños tengan un desarrollo físico, psicosocial, emocional y cognitivo adecuado para el resto de sus vidas. La crianza y el cuidado cariñoso y sensible a las necesidades de los niños durante la gestación y la primera infancia son esenciales para el desarrollo de los billones de neuronas y trillones de sinapsis necesarias. El DIT requiere de acceso a buena nutrición y servicios de salud desde la gestación, crianza sensible de acuerdo a la etapa de desarrollo del niño, protección social y del bienestar del niño, y oportunidades de estimulación y aprendizaje temprano. Para mejorar el DIT a nivel nacional se recomiendan seis acciones con fuerte participación de la sociedad civil: expandir la voluntad política y financiamiento, crear un entorno de políticas favorables basadas en evidencia, construir capacidad con coordinación intersectorial, asegurar una gobernanza justa y transparente de los programas y servicios, aumentar apoyo a la investigación multidisciplinaria y promover el desarrollo de líderes. México ha logrado avances importantes en DIT bajo el liderazgo del Sector Salud, pero enfrenta retos significativos para implementar estas recomendaciones. La reciente creación de un marco nacional intersectorial favorable al DIT con apoyo de los organismos internacionales y la participación de la sociedad civil pueden ayudar a sobreponer estos retos.

  18. Massive Muscular Infection by a Sarcocystis Species in a South American Rattlesnake (Crotalus durissus terrificus).

    Science.gov (United States)

    Roberts, J F; Wellehan, J F X; Weisman, J L; Rush, M; Childress, A L; Lindsay, David S

    2015-06-01

    Massive numbers of sarcocysts of a previously undescribed species of Sarcocystis were observed in the skeletal muscles throughout the body of an adult, female South American rattlesnake (Crotalus durissus terrificus). Examination of tissue sections by light microscopy demonstrated that sarcocysts were present in 20 to 40% of muscle fibers from 5 sampled locations. Sarcocysts were not present in cardiac muscle, smooth muscle, or other organs. Sarcocysts were 0.05-0.15 mm wide, had variable length depending on the viewed orientation and size of the muscle fiber, and had a sarcocyst wall less than 1-μm thick. Sarcocysts were subdivided by septa and had central degeneration in older sarcocysts. Host induced secondary encapsulation or an inflammatory response was not present. By transmission electron microscopy (TEM), the sarcocyst wall was Type I, with a parasitophorous membrane of approximately 100 nanometers in width arranged in an undulating pattern and intermittently folded inward in a branching pattern. The sarcocysts contained metrocytes in different stages of development and mature bradyzoites. The nucleic acid sequence from a section of the 18S small subunit rRNA gene was most closely related to S. mucosa that uses marsupials as intermediate hosts and has an unknown definitive host. This is apparently the third report of muscular Sarcocystis infection in snakes and is the first to describe the ultrastructure of the sarcocysts and use sequencing methods to aid in identification.

  19. Sarcocystis and Its Complications in Camels (Camelus dromedarius) of Eastern Provinces of Iran

    Science.gov (United States)

    Valinezhad, Akbar; Ahmadi, Nasrollah

    2008-01-01

    The prevalence of Sarcocystis spp. was investigated by gross and histopathological examinations in 250 camels (Camelus dromedarius) slaughtered from 2002 to 2005 in the Mashhad Slaughterhouse, eastern Iran. Samples were taken from the diaphragm, heart, tongue, esophagus and masseter muscles for histopathological studies. No macroscopic sarcocysts were found in the samples at gross inspection. Sarcocysts were detected in 209 of 250 (83.6%) examined camels at histopathological level. The infection rate of the esophagus, heart, masseter muscles, diaphragm, and tongue was 58.8%, 48.0%, 46.8%, 41.6%, and 28.0%, respectively. There was no significant difference in the rate of infection between male (85.8%) and female (81.0%) camels. The tissue response to vital cysts was minimal; however, reaction to the degenerating cysts was severe and caused tissue damages resulting in hyperemia, hemorrhages, mononuclear cell infiltration, necrotic changes, and fibrosis. The wild and domestic carnivores especially dogs may be the final hosts of Sarcocystis spp. in this area. PMID:19127328

  20. A chimeric Plasmodium falciparum merozoite surface protein vaccine induces high titers of parasite growth inhibitory antibodies.

    Science.gov (United States)

    Alaro, James R; Partridge, Andrea; Miura, Kazutoyo; Diouf, Ababacar; Lopez, Ana M; Angov, Evelina; Long, Carole A; Burns, James M

    2013-10-01

    The C-terminal 19-kDa domain of Plasmodium falciparum merozoite surface protein 1 (PfMSP119) is an established target of protective antibodies. However, clinical trials of PfMSP142, a leading blood-stage vaccine candidate which contains the protective epitopes of PfMSP119, revealed suboptimal immunogenicity and efficacy. Based on proof-of-concept studies in the Plasmodium yoelii murine model, we produced a chimeric vaccine antigen containing recombinant PfMSP119 (rPfMSP119) fused to the N terminus of P. falciparum merozoite surface protein 8 that lacked its low-complexity Asn/Asp-rich domain, rPfMSP8 (ΔAsn/Asp). Immunization of mice with the chimeric rPfMSP1/8 vaccine elicited strong T cell responses to conserved epitopes associated with the rPfMSP8 (ΔAsn/Asp) fusion partner. While specific for PfMSP8, this T cell response was adequate to provide help for the production of high titers of antibodies to both PfMSP119 and rPfMSP8 (ΔAsn/Asp) components. This occurred with formulations adjuvanted with either Quil A or with Montanide ISA 720 plus CpG oligodeoxynucleotide (ODN) and was observed in both inbred and outbred strains of mice. PfMSP1/8-induced antibodies were highly reactive with two major alleles of PfMSP119 (FVO and 3D7). Of particular interest, immunization with PfMSP1/8 elicited higher titers of PfMSP119-specific antibodies than a combined formulation of rPfMSP142 and rPfMSP8 (ΔAsn/Asp). As a measure of functionality, PfMSP1/8-specific rabbit IgG was shown to potently inhibit the in vitro growth of blood-stage parasites of the FVO and 3D7 strains of P. falciparum. These data support the further testing and evaluation of this chimeric PfMSP1/8 antigen as a component of a multivalent vaccine for P. falciparum malaria.

  1. Limited variation in vaccine candidate Plasmodium falciparum Merozoite Surface Protein-6 over multiple transmission seasons

    Directory of Open Access Journals (Sweden)

    Branch OraLee H

    2010-05-01

    Full Text Available Abstract Background Plasmodium falciparum Merozoite Surface Protein-6 (PfMSP6 is a component of the complex proteinacious coat that surrounds P. falciparum merozoites. This location, and the presence of anti-PfMSP6 antibodies in P. falciparum-exposed individuals, makes PfMSP6 a potential blood stage vaccine target. However, genetic diversity has proven to be a major hurdle for vaccines targeting other blood stage P. falciparum antigens, and few endemic field studies assessing PfMSP6 gene diversity have been conducted. This study follows PfMSP6 diversity in the Peruvian Amazon from 2003 to 2006 and is the first longitudinal assessment of PfMSP6 sequence dynamics. Methods Parasite DNA was extracted from 506 distinct P. falciparum infections spanning the transmission seasons from 2003 to 2006 as part of the Malaria Immunology and Genetics in the Amazon (MIGIA cohort study near Iquitos, Peru. PfMSP6 was amplified from each sample using a nested PCR protocol, genotyped for allele class by agarose gel electrophoresis, and sequenced to detect diversity. Allele frequencies were analysed using JMP v.8.0.1.0 and correlated with clinical and epidemiological data collected as part of the MIGIA project. Results Both PfMSP6 allele classes, K1-like and 3D7-like, were detected at the study site, confirming that both are globally distributed. Allele frequencies varied significantly between transmission seasons, with 3D7-class alleles dominating and K1-class alleles nearly disappearing in 2005 and 2006. There was a significant association between allele class and village location (p-value = 0.0008, but no statistically significant association between allele class and age, sex, or symptom status. No intra-allele class sequence diversity was detected. Conclusions Both PfMSP6 allele classes are globally distributed, and this study shows that allele frequencies can fluctuate significantly between communities separated by only a few kilometres, and over time in the

  2. The relationship between anti-merozoite antibodies and incidence of Plasmodium falciparum malaria: A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Freya J I Fowkes

    2010-01-01

    Full Text Available BACKGROUND: One of the criteria to objectively prioritize merozoite antigens for malaria vaccine development is the demonstration that naturally acquired antibodies are associated with protection from malaria. However, published evidence of the protective effect of these antibodies is conflicting. METHODS AND FINDINGS: We performed a systematic review with meta-analysis of prospective cohort studies examining the association between anti-merozoite immunoglobin (Ig G responses and incidence of Plasmodium falciparum malaria. Two independent researchers searched six databases and identified 33 studies that met predefined inclusion and quality criteria, including a rigorous definition of symptomatic malaria. We found that only five studies were performed outside sub-Saharan Africa and that there was a deficiency in studies investigating antibodies to leading vaccine candidates merozoite surface protein (MSP-1(42 and erythrocyte binding antigen (EBA-175. Meta-analyses of most-studied antigens were conducted to obtain summary estimates of the association between antibodies and incidence of P. falciparum malaria. The largest effect was observed with IgG to MSP-3 C terminus and MSP-1(19 (responders versus nonresponders, 54%, 95% confidence interval [CI] [33%-68%] and 18% [4%-30%] relative reduction in risk, respectively and there was evidence of a dose-response relationship. A tendency towards protective risk ratios (RR<1 was also observed for individual study estimates for apical membrane antigen (AMA-1 and glutamate-rich protein (GLURP-R0. Pooled estimates showed limited evidence of a protective effect for antibodies to MSP-1 N-terminal regions or MSP-1-EGF (epidermal growth factor-like modules. There was no significant evidence for the protective effect for MSP-2 (responders versus nonresponders pooled RR, MSP-2(FC27 0.82, 95% CI 0.62-1.08, p = 0.16 and MSP-2(3D7 0.92, 95% CI 0.75-1.13, p = 0.43. Heterogeneity, in terms of clinical and methodological

  3. Analysis of Antibodies Directed against Merozoite Surface Protein 1 of the Human Malaria Parasite Plasmodium falciparum

    Science.gov (United States)

    Woehlbier, Ute; Epp, Christian; Kauth, Christian W.; Lutz, Rolf; Long, Carole A.; Coulibaly, Boubacar; Kouyaté, Bocar; Arevalo-Herrera, Myriam; Herrera, Sócrates; Bujard, Hermann

    2006-01-01

    The 190-kDa merozoite surface protein 1 (MSP-1) of Plasmodium falciparum, an essential component in the parasite's life cycle, is a primary candidate for a malaria vaccine. Rabbit antibodies elicited by the heterologously produced MSP-1 processing products p83, p30, p38, and p42, derived from strain 3D7, were analyzed for the potential to inhibit in vitro erythrocyte invasion by the parasite and parasite growth. Our data show that (i) epitopes recognized by antibodies, which inhibit parasite replication, are distributed throughout the entire MSP-1 molecule; (ii) when combined, antibodies specific for different regions of MSP-1 inhibit in a strictly additive manner; (iii) anti-MSP-1 antibodies interfere with erythrocyte invasion as well as with the intraerythrocytic growth of the parasite; and (iv) antibodies raised against MSP-1 of strain 3D7 strongly cross-inhibit replication of the heterologous strain FCB-1. Accordingly, anti-MSP-1 antibodies appear to be capable of interfering with parasite multiplication at more than one level. Since the overall immunogenicity profile of MSP-1 in rabbits closely resembles that found in sera of Aotus monkeys immunized with parasite-derived MSP-1 and of humans semi-immune to malaria from whom highly inhibiting antigen-specific antibodies were recovered, we consider the findings reported here to be relevant for the development of MSP-1-based vaccines against malaria. PMID:16428781

  4. Retracción a largo plazo del árbol dendrítico de neuronas piramidales córtico-faciales por lesiones periféricas del nervio facial

    OpenAIRE

    Diana Urrego; Alejandro Múnera; Julieta Troncoso

    2011-01-01

    Introducción. Poco se sabe sobre las modificaciones morfológicas de las neuronas de la corteza motora tras lesiones en nervios periféricos, y de la implicancia de dichos cambios en la recuperación funcional tras la lesión. Objetivo. Caracterizar en ratas el efecto de la lesión del nervio facial sobre la morfología de las neuronas piramidales de la capa V de la corteza motora primaria contralateral. Materiales y métodos. Se reconstruyeron neuronas piramidales teñidas con la técnica de...

  5. Prevalence of Sarcocystis infection in meat-producing animals in Mongolia.

    Science.gov (United States)

    Fukuyo, M; Battsetseg, G; Byambaa, B

    2002-09-01

    A survey of Sarcocystis infection was conducted in Mongolia between June 1998 and July 1999. Samples of muscle were taken from the diaphragm, heart, tongue, esophagus,and intercostal region of cattle, yak, hainag, sheep, horses, and camels. A muscle compress method was used to determine the prevalence of infection: cattle 90.0% (27/30), yak 93.3% (28/30), hainag 100% (30/30), sheep 96.9% (753/777), horses 75% (3/4) and camels 100% (5/5). Of the various muscles, heart was the most commonly infected in cattle (100%), yak (86.7%), and hainag (100%); tongue was most likly to be infected in sheep (100%) and horses (100%).

  6. Plasmodium vivax merozoite surface protein PvMSP-3 beta is radically polymorphic through mutation and large insertions and deletions.

    Science.gov (United States)

    Rayner, Julian C; Huber, Curtis S; Feldman, Dmitry; Ingravallo, Paul; Galinski, Mary R; Barnwell, John W

    2004-12-01

    Plasmodium vivax causes the majority of malaria outside of sub-Saharan Africa and is an important burden for affected countries. The recent spread of drug-resistant P. vivax strains in these countries has led to renewed pressure for the development of a P. vivax vaccine. The complex life cycle of P. vivax presents many potential vaccine targets, but among the most promising candidates are subunits of the surface coat that surrounds the merozoite, the parasite stage that infects erythrocytes and initiates much of the pathology of malaria. Although the genes for several constituents of the P. vivax surface coat have now been cloned and sequenced, little is known about the extent to which these proteins vary between populations, an important consideration in vaccine development. The merozoite surface protein MSP-3beta is a member of a family of related merozoite surface proteins, all of which contain a central alanine-rich domain that is predicted to form a coiled-coil tertiary structure. We have sequenced the PvMSP-3 beta gene from P. vivax isolates originating in Central and South America, Asia and the Pacific. In this first assessment of PvMSP-3 beta variation between populations, we discovered widespread and significant diversity, mostly within the alanine-rich central region. We observed frequent differences in PvMSP-3 beta gene size, caused by the insertion and/or deletion of several large sequence blocks, as well as numerous single nucleotide polymorphisms and smaller scale insertions and deletions. Despite this high level of sequence diversity, certain physical properties of the encoded protein are maintained, particularly the ability to form coiled-coil tertiary structures, suggesting that although PvMSP-3 beta varies widely, it is under functional constraints. The implications for PvMSP-3 beta function and vaccine development are discussed.

  7. Naturally acquired humoral and cellular immune responses to Plasmodium vivax merozoite surface protein 9 in Northwestern Amazon individuals

    OpenAIRE

    Lima-Junior, J.C.; Tran, T. M.; Meyer, E.V.S.; Singh, B; De-Simone, S.G.; Santos,F.; Daniel-Ribeiro,C. T.; Moreno, A.; Barnwell, J W; Galinski, M.R.; Oliveira-Ferreira, J

    2008-01-01

    Antibody and T-cell reactivities to Plasmodium vivax merozoite surface protein-9 (PvMSP9) were evaluated in a cross-sectional study of individuals naturally exposed to malaria infections living in Ribeirinha, a native riverine community and in Colina, a transmigrant community, Rondonia, Brazil. The antibody responses to PvMSP9-RIRII and PvMSP9-Nt domains in Ribeirinha were higher compared with Colina and correlated with age and time of malaria exposure. IgG2 was most prevalent for PvMSP9-RII ...

  8. A Library of Plasmodium vivax Recombinant Merozoite Proteins Reveals New Vaccine Candidates and Protein-Protein Interactions.

    Directory of Open Access Journals (Sweden)

    Jessica B Hostetler

    2015-12-01

    Full Text Available A vaccine targeting Plasmodium vivax will be an essential component of any comprehensive malaria elimination program, but major gaps in our understanding of P. vivax biology, including the protein-protein interactions that mediate merozoite invasion of reticulocytes, hinder the search for candidate antigens. Only one ligand-receptor interaction has been identified, that between P. vivax Duffy Binding Protein (PvDBP and the erythrocyte Duffy Antigen Receptor for Chemokines (DARC, and strain-specific immune responses to PvDBP make it a complex vaccine target. To broaden the repertoire of potential P. vivax merozoite-stage vaccine targets, we exploited a recent breakthrough in expressing full-length ectodomains of Plasmodium proteins in a functionally-active form in mammalian cells and initiated a large-scale study of P. vivax merozoite proteins that are potentially involved in reticulocyte binding and invasion.We selected 39 P. vivax proteins that are predicted to localize to the merozoite surface or invasive secretory organelles, some of which show homology to P. falciparum vaccine candidates. Of these, we were able to express 37 full-length protein ectodomains in a mammalian expression system, which has been previously used to express P. falciparum invasion ligands such as PfRH5. To establish whether the expressed proteins were correctly folded, we assessed whether they were recognized by antibodies from Cambodian patients with acute vivax malaria. IgG from these samples showed at least a two-fold change in reactivity over naïve controls in 27 of 34 antigens tested, and the majority showed heat-labile IgG immunoreactivity, suggesting the presence of conformation-sensitive epitopes and native tertiary protein structures. Using a method specifically designed to detect low-affinity, extracellular protein-protein interactions, we confirmed a predicted interaction between P. vivax 6-cysteine proteins P12 and P41, further suggesting that the proteins

  9. A SURVEY ON THE PRESENCE OF ANIMALS SLAUGHTERED IN SARCOCYSTIS IN PUGLIA AND BASILICATA AND CORRELATIION WITH THE NATIONAL WASTE

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    L.A. Carosielli

    2012-08-01

    Full Text Available A survey was conducted to verify the presence of Sarcocystis in muscle samples of sheep, goats, pigs, horses, cattle and buffalo, slaughtered in the province of Foggia, and Sarcocystis in histological samples of uretrhal muscles, during the histological monitoring of prostate on the occasion of National residue plan 2010. Seventy eight cattles aged between 5 and 24 months slaughtered in Puglia and Basilicata were tested, taken from animals of domestic or foreign born but farmed in Italy. Also taken pieces of masseter muscles, diaphragm, esophagus and heart to perform the microscopic survey. Macroscopically there were 6 cases positive in esophagi of sheep coming from Parco del Gargano and four cases from a herd of Manfredonia and Bovino (FG. In cattles microscopically positivity was 68% (53 positive including 9 with presence of three or more cystis in the microscopic field. The urethral muscles of cattle, included in monitoring residual plan, was interested by a very high positivity, less finding in horse (8 of 40 and pigs (18 of 98 even if animals come from small, rural and promiscuous farm, but not in sheep (44 of 54, goats (27 of 35 and buffalo (18 of 25. Is desirable, as well as epidemiological survey carried out by us, to educate the farmers on this zoonosic patology, proposing to estabilish a farm file where the farmer report the finding of sarcocystis together with other conditions found at the slaughterhouse.

  10. Characterisation of erythrocyte invasion by Babesia bovis merozoites efficiently released from their host cell after high-voltage pulsing.

    Science.gov (United States)

    Franssen, Frits F J; Gaffar, Fasila R; Yatsuda, Ana P; de Vries, Erik

    2003-04-01

    Apicomplexa are a phylum of obligate intracellular parasites critically dependent on invasion of a host cell. An in vitro assay for erythrocyte invasion by Babesia bovis was established, employing free merozoites obtained after the application of high-voltage to the parasitised erythrocytes. The invasion proceeds efficiently in phosphate-buffered saline solution without the requirement for any serum or medium components. The kinetics of invasion can be measured over a time span of 5-60 min after which invasion is completed at an average efficiency of 41%. The fast kinetics and high efficiency exceed those of most previously established apicomplexan invasion assays. The manipulation of intracellular calcium concentration inhibits invasion. Preincubation of merozoites at 37 degrees C also reduces invasion, possibly by the premature secretion of protein. Proteins that are shed into the environment during invasion were directly detectable by protein staining after 2-D gel electrophoresis. The limitations posed by the immunological detection of proteins released during in vitro invasion by other apicomplexan parasites can, therefore, be avoided by this method. A unique feature of the assay is the reversible uncoupling of invasion and intracellular development, the latter taking place only under serum-rich medium conditions. In addition, host cell attachment is uncoupled from invasion by cytochalasin B.

  11. Partial Sequence Analysis of Merozoite Surface Proteine-3α Gene in Plasmodium vivax Isolates from Malarious Areas of Iran

    Directory of Open Access Journals (Sweden)

    H Mirhendi

    2008-12-01

    Full Text Available Background: Approximately 85-90% of malaria infections in Iran are attributed to Plasmodium vivax, while little is known about the genetic of the parasite and its strain types in this region. This study was designed and performed for describing genetic characteristics of Plasmodium vivax population of Iran based on the merozoite surface protein-3α gene sequence. Methods: Through a descriptive study we analyzed partial P. vivax merozoite surface protein-3α gene sequences from 17 clinical P. vivax isolates collected from malarious areas of Iran. Genomic DNA was extracted by Q1Aamp® DNA blood mini kit, amplified through nested PCR for a partial nucleotide sequence of PvMSP-3 gene in P. vivax. PCR-amplified products were sequenced with an ABI Prism Perkin-Elmer 310 sequencer machine and the data were analyzed with clustal W software. Results: Analysis of PvMSP-3 gene sequences demonstrated extensive polymorphisms, but the sequence identity between isolates of same types was relatively high. We identified specific insertions and deletions for the types A, B and C variants of P. vivax in our isolates. In phylogenetic comparison of geographically separated isolates, there was not a significant geo­graphical branching of the parasite populations. Conclusion: The highly polymorphic nature of isolates suggests that more investigations of the PvMSP-3 gene are needed to explore its vaccine potential.

  12. Extensive polymorphism in the plasmodium vivax merozoite surface coat protein MSP-3alpha is limited to specific domains.

    Science.gov (United States)

    Rayner, J C; Corredor, V; Feldman, D; Ingravallo, P; Iderabdullah, F; Galinski, M R; Barnwell, J W

    2002-11-01

    Plasmodium merozoites are covered by a complex coat of surface proteins. Several of the Merozoite Surface Proteins (MSPs) that make up this coat have been proposed as vaccine candidates although some of the MSPs are known to be highly polymorphic. We present here the first survey and analysis of the polymorphism in the recently characterized P. vivax surface protein PvMSP-3alpha. Full length or partial sequences were obtained for the Pvmsp-3alpha gene from isolates originating in Central and South America, Asia and the Pacific. The Pvmsp-3alpha sequence is remarkably diverse, but this extensive diversity is largely restricted to certain domains of the encoded protein. An acidic C-terminal domain and a smaller hydrophilic N-terminus are relatively conserved, while a central domain containing coiled-coil heptad repeats is highly polymorphic and in some isolates of P. vivax is partially deleted. Unlike other MSPs, there is no evidence of allelic families of PvMSP-3alpha gene sequences, and no evidence that certain patterns of polymorphism group within isolates of similar geographical origin. The distribution and nature of polymorphism suggest that there are functional restrictions on mutations in this gene, and have implications for inclusion of PvMSP-3alpha as a candidate in a P. vivax vaccine.

  13. Sarcocystis calchasi sp. nov. of the domestic pigeon (Columba livia f. domestica) and the Northern goshawk (Accipiter gentilis): light and electron microscopical characteristics.

    Science.gov (United States)

    Olias, Philipp; Gruber, Achim D; Hafez, Hafez M; Heydorn, Alfred O; Mehlhorn, Heinz; Lierz, Michael

    2010-02-01

    A novel highly pathogenic Sarcocystis species has been shown to cycle between the Northern goshawk (Accipiter gentilis) as definitive host and the domestic pigeon (Columba livia f. domestica) as intermediate host. However, genetically based characteristics are only available from very few bird-infecting Sarcocystis species. We therefore further characterised morphological properties of this protozoan in both hosts. Using light and electron microscopy, oocysts and sporocysts as well as schizonts and sarcocysts were characterised and compared with available morphological features of previously reported Sarcocystis species of Northern goshawks, Columbidae and genetically closely related species of other avian hosts. Sporocysts shed from day 6 on after experimental infection by the Northern goshawk were of ovoid appearance (11.9 x 7.9 microm). Ultrastructurally, schizonts of all developmental stages were found in the liver, spleen and next to or in endothelial cells of various organs of domestic pigeons 7 to 12 days after experimental infection. The cyst wall surface of slender sarcocysts (1 to 2 mm in length and 20 to 50 microm in width) was smooth and lacked protrusions. Cystozoites were lancet-shaped and measured 7.5 x 1.5 microm in Giemsa stain smears. The morphological findings, when combined with data of experimental infection and genetic studies, convergently indicate that the recently discovered Sarcocystis species represents a new species. We therefore propose to name this parasite Sarcocystis calchasi species nova.

  14. Merozoite surface protein-1 genetic diversity in Plasmodium malariae and Plasmodium brasilianum from Brazil.

    Science.gov (United States)

    Guimarães, Lilian O; Wunderlich, Gerhard; Alves, João M P; Bueno, Marina G; Röhe, Fabio; Catão-Dias, José L; Neves, Amanda; Malafronte, Rosely S; Curado, Izilda; Domingues, Wilson; Kirchgatter, Karin

    2015-11-16

    The merozoite surface protein 1 (MSP1) gene encodes the major surface antigen of invasive forms of the Plasmodium erythrocytic stages and is considered a candidate vaccine antigen against malaria. Due to its polymorphisms, MSP1 is also useful for strain discrimination and consists of a good genetic marker. Sequence diversity in MSP1 has been analyzed in field isolates of three human parasites: P. falciparum, P. vivax, and P. ovale. However, the extent of variation in another human parasite, P. malariae, remains unknown. This parasite shows widespread, uneven distribution in tropical and subtropical regions throughout South America, Asia, and Africa. Interestingly, it is genetically indistinguishable from P. brasilianum, a parasite known to infect New World monkeys in Central and South America. Specific fragments (1 to 5) covering 60 % of the MSP1 gene (mainly the putatively polymorphic regions), were amplified by PCR in isolates of P. malariae and P. brasilianum from different geographic origin and hosts. Sequencing of the PCR-amplified products or cloned PCR fragments was performed and the sequences were used to construct a phylogenetic tree by the maximum likelihood method. Data were computed to give insights into the evolutionary and phylogenetic relationships of these parasites. Except for fragment 4, sequences from all other fragments consisted of unpublished sequences. The most polymorphic gene region was fragment 2, and in samples where this region lacks polymorphism, all other regions are also identical. The low variability of the P. malariae msp1 sequences of these isolates and the identification of the same haplotype in those collected many years apart at different locations is compatible with a low transmission rate. We also found greater diversity among P. brasilianum isolates compared with P. malariae ones. Lastly, the sequences were segregated according to their geographic origins and hosts, showing a strong genetic and geographic structure. Our data

  15. A longitudinal study of type-specific antibody responses to Plasmodium falciparum merozoite surface protein-1 in an area of unstable malaria in Sudan

    DEFF Research Database (Denmark)

    Cavanagh, D R; Elhassan, I M; Roper, C

    1998-01-01

    Merozoite surface protein-1 (MSP-1) of Plasmodium falciparum is a malaria vaccine candidate Ag. Immunity to MSP-1 has been implicated in protection against infection in animal models. However, MSP-1 is a polymorphic protein and its immune recognition by humans following infection is not well unde...

  16. EFECTO DE LA UTILIZACIÓN DE DIFERENTES SUSTRATOS COMPARTIMENTADOS POR NEURONAS Y ASTROCITOS, SOBRE LA CONCENTRACIÓN DE CALCIO EXTRA E INTRACELULAR

    Directory of Open Access Journals (Sweden)

    Elsa Guzmán de Aristizábal

    2003-06-01

    Full Text Available El mecanismo de intercambio de sustratos entre neuronas y astrocitos, no es claro y menos claro es, si los efectos metabólicos en las células receptoras, son resultado de señalización por calcio. Se plantea la posibilidad de que existan señales entre neuronas y astrocitos que relacionen su funcionamiento metabólico a través de las concentraciones de calcio. La concentración de calcio se midió por absorción atómica en el medio intra y extracelular de cultivos primarios de neuronas y astrocitos y posteriormente en el medio intra y extracelular después de una hora de incubación con lactato, glutamato, glutamina y acetato a concentraciones fisiológicas. Las comparaciones estadísticas se efectuaron con ANOVA y Duncan (p < 0.05. Se hicieron 3 replicaciones de cada experimento con 5 repeticiones. Los resultados permiten afirmar que al hacer incubaciones in vitro con los sustratos, se producen variaciones en las concentraciones de calcio extra é intracelular. El estrés metabólico puede estar influyendo en estas variaciones. Adicionalmente, se demuestra que los astrocitos son menos dependientes del calcio extracelular que las neuronas. Las variaciones del calcio intracelular pueden incrementar el metabolismo de estas células y acelerar el metabolismo mitocondrial. Se postula que cambios en la concentración de calcio afectan el metabolis-mo de células excitables en incubaciones in vitro usando diferentes sustratos.

  17. Prevalence of Sarcocystis spp. in meat-producing animals in Iraq.

    Science.gov (United States)

    Latif, B M; Al-Delemi, J K; Mohammed, B S; Al-Bayati, S M; Al-Amiry, A M

    1999-07-01

    The prevalence of Sarcocystis spp. infection was investigated in 605 sheep, 826 goats, 1080 cattle, 580 water buffaloes and 36 camels slaughtered from 1992 to 1996 in the Baghdad area (Iraq) using naked eye examination for macroscopic sarcocysts, and peptic digestion, muscle squash, squeezing methods and indirect fluorescent antibody test (IFAT) for microscopic types. The intestinal stages of the parasite were also studied in dogs experimentally fed with tissues containing microscopic cysts. The percentage prevalence of macroscopic cysts were 4.1, 33.6, 0.2, 15.6 and 0, and of the microscopic type, 97.0, 97.4, 97.8, 82.9 and 91.6 for the above-mentioned hosts, respectively. Among the different organs examined, macroscopic cysts were found to be highest in the oesophagus and the lowest in the heart. Peptic digestion method gave the highest rate (93.3%) followed by indirect fluorescent antibody test (IFAT) (88.6%), squeezing (81.3%), and muscle squash (81.2%). Each infected dog shed a total of about 150-200 million sporocysts. Histologically, developmental stages of the parasite were detected in the small intestinal mucosa of the dogs on Days 7 and 13 post-infection.

  18. Mapping of quantitative trait loci affecting resistance/susceptibility to Sarcocystis miescheriana in swine.

    Science.gov (United States)

    Reiner, Gerald; Kliemt, Damaris; Willems, Hermann; Berge, Thomas; Fischer, Reiner; Köhler, Florian; Hepp, Sabine; Hertrampf, Barbara; Daugschies, Arwid; Geldermann, Hermann; Mackenstedt, Ute; Zahner, Horst

    2007-05-01

    The outcome of infectious diseases in vertebrates is under genetic control at least to some extent. In swine, e.g., marked differences in resistance/susceptibility to Sarcocystis miescheriana have been shown between Chinese Meishan and European Pietrain pigs, and these differences are associated with high heritabilities. A first step toward the identification of genes and polymorphisms causal for these differences may be the mapping of quantitative trait loci (QTLs). Considering clinical, immunological, and parasitological traits in the above model system, this survey represents the first QTL study on parasite resistance in pigs. QTL mapping was performed in 139 F(2) pigs of a Meishan/Pietrain family infected with S. miescheriana. Fourteen genome-wide significant QTLs were mapped to several chromosomal areas. Among others, major QTLs were identified for bradyzoite numbers in skeletal muscles (F = 17.4; p < 0.001) and for S. miescheriana-specific plasma IgG(2) levels determined 42 days p.i. (F = 20.9; p < 0.001). The QTLs were mapped to different regions of chromosome 7, i.e., to the region of the major histocompatibility complex (bradyzoites) and to an immunoglobulin heavy chain cluster, respectively. These results provide evidence for a direct and causal role for gene variants within these gene clusters (cis-acting) in differences in resistance to S. miescheriana.

  19. EXPERIMENTOS CON UNA PROTECCION BASADA EN REDES DE NEURONAS ARTIFICIALES;EXPERIMENTS WITH A PROTECTION BASED ON ARTIFICIALS NEURONS NETWORKS

    Directory of Open Access Journals (Sweden)

    Orlys Ernesto - Torres Breffe y otros

    2011-11-01

    Full Text Available En este trabajo se muestran los resultados de los experimentos físicos realizados con una protección basadatotalmente en Redes de Neuronas Artificiales para un transformador eléctrico a escala de laboratorio. Se demuestraque unas Redes de Neuronas Artificiales entrenadas, con datos provenientes de regímenes simuladosmatemáticamente, opera correctamente con señales de regímenes provenientes de casos reales, al menos a escalade laboratorio y con niveles reducidos de intensidad. Se describe la instalación experimental, tanto desde el puntode vista de hardware como software utilizando la tecnología de National Instrument. Se entrenan diferentes tipos deRedes Neuronales y todas aprendieron a proteger correctamente. Estos experimentos establecen las pautas para eldesarrollo de Relés Electrónicos Inteligentes que no se ajustarían, al menos con datos y valores de difícilcomprensión como los actuales relés, sino que se entrenarían una vez mediante la simulación matemática y laexperiencia práctica los haría cada vez mejores.In this work is shown the results of the physical experiments done with a protection totally based in Artificial NeuralNetworks for an electric transformer of the laboratory scale. Its demonstrated that some Artificial Neural Networkstrained with data coming from a mathematically simulated regimens, it operates correctly with signals coming fromreal cases, at least to laboratory scale and with reduced levels of intensity. The experimental installation is described,so much from the hardware and software point of view, using the technology of National Instrument. Different typesof Artificial Neural Nets are trained and all learned how to protect correctly. These experiments establish the rules forthe development of Intelligent Electronic Relays that would not be adjusted, at least with complex data and valueslike the current relays, they will be trained once from the mathematically simulation and the practical

  20. A threshold concentration of anti-merozoite antibodies is required for protection from clinical episodes of malaria

    DEFF Research Database (Denmark)

    Murungi, Linda M; Kamuyu, Gathoni; Lowe, Brett

    2013-01-01

    Antibodies to selected Plasmodium falciparum merozoite antigens are often reported to be associated with protection from malaria in one epidemiological cohort, but not in another. Here, we sought to understand this paradox by exploring the hypothesis that a threshold concentration of antibodies...... is necessary for protection. We analyzed data from two independent cohorts along the Kenyan coast, one in which antibodies to AMA1, MSP-2 and MSP-3 were associated with protection from malaria (Chonyi) and another in which this association was not observed (Junju). We used a malaria reference reagent...... to standardize antibody measurements across both cohorts, and applied statistical methods to derive the threshold concentration of antibodies against each antigen that best correlated with a reduced risk of malaria (the protective threshold), in the Chonyi cohort. We then tested whether antibodies in Junju...

  1. EFECTOS TÓXICOS DEL CONTENIDO DE DOS TAMAÑOS DE QUISTES DE Sarcocystis aucheniae EN CONEJOS INOCULADOS EXPERIMENTALMENTE

    OpenAIRE

    Chileno M., María; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima-Perú.; Chávez V., Amanda; Laboratorio de Microbiología y Parasitología Veterinaria, Laboratorio de Histopatología, Embriología y Patología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Casas A., Eva; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima-Perú.; Chavera C., Alfonso; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima-Perú.; Puray C., Nidia; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima-Perú.

    2012-01-01

    El objetivo del estudio fue determinar los efectos tóxicos de dos tamaños de macroquistes de Sarcocystis aucheniae (>5 mm y 1-3 mm) en conejos inoculados experimentalmente, a través del tiempo de supervivencia, manifestaciones clínicas y alteraciones anatomopatológicas. Se colectaron macroquistes del cuello de alpacas procedentes del camal de Huancavelica. Las concentraciones de proteínas antigénicas para los macroquistes grandes y pequeños, medidas por el método de Biuret, fueron de 3.3 y...

  2. Morphological and molecular characterization of Sarcocystis arctica-like sarcocysts from the Arctic fox (Vulpes lagopus) from Alaska, USA

    Science.gov (United States)

    Cerqueira-Cézar, Camila K.; Thompson, Peter C.; Verma, Shiv K.; Mowery, Joseph; Calero-Bernal, Rafael; Antunes Murata, Fernando H.; Sinnett, David R.; Van Hemert, Caroline R.; Rosenthal, Benjamin M.; Dubey, Jitender P.

    2017-01-01

    The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of 56 foxes were examined for Sarcocystis infection using several methods. Sarcocystis bradyzoites were detected in pepsin digests of 13 (23.2%), and sarcocysts were found in histological sections stained with hematoxylin and eosin (HE) of 9 (16.0%). By light microscopy, sarcocysts were up to 4 mm long and up to 245 μm wide. In HE-stained sections, the sarcocyst wall appeared smooth and up to 1.5 μm thick without visible protrusions. By transmission electron microscopy, the sarcocyst wall had a wavy parasitophorous vacuolar membrane (pvm) folded as pleomorphic villar protrusions (vp), sometimes with anastomoses of villar tips. The vp and the ground substance (gs) layer were smooth and without microtubules. The gs was up to 2.0 μm thick. The total width of the wall including vp and the gs was up to 4.0 μm. The vp were up to 3.0 μm long and most closely resembled “type 9c.” All sarcocysts were mature and contained numerous 8.1 × 2.1 μm sized bradyzoites. Molecular characterization (at 18S rDNA, 28S rDNA, ITS-1, and cox1) showed the highest affinity for S. arctica of the Arctic fox (V. lagopus) from Norway. In the present investigation, we provide evidence that sarcocysts are common in tongues of Alaskan Arctic foxes suggesting that these carnivores are serving as intermediate hosts, and we also provide ultrastructure of S. arctica from the Arctic fox for the first time.

  3. In the United States, negligible rates of zoonotic sarcocystosis occur in feral swine that, by contrast, frequently harbor infections with Sarcocystis meischeriana, a related parasite contracted from dogs

    Science.gov (United States)

    Transmission of pathogens between domestic and wild life animals plays important role in epidemiology. Feral pig populations are increasing and expanding in the USA, and may constitute a risk to non-biosecure domestic pig facilities by serving as reservoirs for pathogens. We surveyed, for Sarcocysti...

  4. Cross-sectional survey in pig breeding farms in Hesse, Germany: seroprevalence and risk factors of infections with Toxoplasma gondii, Sarcocystis spp. and Neospora caninum in sows

    DEFF Research Database (Denmark)

    Damriyasa, I.M.; Bauer, C.; Edelhofer, R.

    2004-01-01

    A cross-sectional survey was performed to estimate the prevalences of antibodies to Toxoplasma gondii (ELISA, IFAT), Sarcocystis spp. (ELISA, using S. miescheriana as antigen) and Neospora caninum (ELISA, immunoblotting) in sows from breeding farms in southern Hesse, Germany. A total of 2041 plasma...

  5. Sarcocystis pantherophis, n. sp. from eastern rat snakes (Pantherophis alleghaniensis) definitive hosts and interferongamma gene knockout mice as experimental intermediate hosts

    Science.gov (United States)

    Here we report a new species, Sarcocystis pantherophisi with the Eastern rat snake (Pantherophis alleghaniensis) as natural definitive host and the interferon gamma gene knockout (KO) mouse as the experimental intermediate host. Sporocysts (n=15) from intestinal contents of the snake were 17.3 x 10....

  6. Occurrence of Sarcocystis spp. in opossums (Didelphis aurita and Didelphis albiventris in regions of the State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Renata Assis Casagrande

    2009-04-01

    Full Text Available O objetivo deste estudo foi de determinar a ocorrência de Sarcocystis spp. em D. albiventris e D. aurita em três regiões do Estado de São Paulo. Para tal, utilizou-se noventa e oito Didelphis mortos, sendo 66 D. aurita e 32 D. albiventris, e também 28 D. aurita e cinco D. albiventris vivos. O método de centrífugo-flutuação em solução de sacarose foi empregado para isolamento dos oocistos/esporocistos de Sarcocystis spp. do intestino delgado e das fezes. Encontrou-se Sarcocystis spp. no intestino delgado de 9,1% dos D. aurita (6/66, sendo que quatro destes também houve positividade nas fezes. Não houve diferença estatística significativa entre machos e fêmeas positivos (P= 0,522, e entre os positivos de diferentes origens do Estado de São Paulo (P= 0,627, quanto a ocorrência de Sarcocystis spp. Entretanto, houve diferença estatística significativa entre animais de vida livre e de cativeiro (P = 0.009, sendo que somente os de vida livre foram positivos. Entre adultos e filhotes positivos também houve diferença (P= 0,004, sendo os adultos mais parasitados que os filhotes. Das amostras provenientes dos 28 D. aurita vivos, encontrou-se Sarcocystis spp. em 7.1% (2/28 deles. Dos 32 D. albiventris, todos foram negativos para Sarcocystis spp. nas amostras de intestino delgado e fezes. Os cincos D. albiventris vivos também foram negativos. Sendo assim, pode-se observar que a ocorrência de Sarcocystis spp. em D. aurita e D. albiventris nestas três regiões do Estado de São Paulo é baixa para estas condições analisadas.

  7. Antibodies to the N-terminal block 2 of Plasmodium falciparum merozoite surface protein 1 are associated with protection against clinical malaria

    DEFF Research Database (Denmark)

    Cavanagh, David R; Dodoo, Daniel; Hviid, Lars

    2004-01-01

    This longitudinal prospective study shows that antibodies to the N-terminal block 2 region of the Plasmodium falciparum merozoite surface protein 1 (MSP-1) are associated with protection against clinical malaria in an area of stable but seasonal malaria transmission of Ghana. Antibodies to the bl....... falciparum and, thus, a promising new candidate for the development of a malaria vaccine.......This longitudinal prospective study shows that antibodies to the N-terminal block 2 region of the Plasmodium falciparum merozoite surface protein 1 (MSP-1) are associated with protection against clinical malaria in an area of stable but seasonal malaria transmission of Ghana. Antibodies...... to the block 2 region of MSP-1 were measured in a cohort of 280 children before the beginning of the major malaria transmission season. The cohort was then actively monitored for malaria, clinically and parasitologically, over a period of 17 months. Evidence is presented for an association between antibody...

  8. Morphologic identification of a new Sarcocystis sp. in the common moorhen (Gallinula chloropus ) (Aves: Gruiformes: Rallidae) from Brolos Lake, Egypt.

    Science.gov (United States)

    El-Morsey, Ahmed; El-Seify, Mahmoud; Desouky, Abdel-Razik Y; Abdel-Aziz, Mohamed M; Sakai, Hiroki; Yanai, Tokuma

    2014-01-01

    Sarcocystis species are among the most common and widespread protozoan parasites of mammals and birds. The current study provides the first record of infection with Sarcocystis species in the common moorhens from Brolos Lake, KafrElsheikh province, Egypt. Morphology of the parasite cysts was described using light and transmission electron microscopy. Out of 25 examined birds, sarcocysts were found in neck, thigh, and legs muscles of two birds. The cysts were microscopic and measured 150-650 μm in length×45-185 μm in width. Histologically, the sarcocyst wall appeared striated and characterized by the presence of radial spines. Ultrastructurally, it measured 2-4.5 μm in thickness and had irregularly shaped crowded finger-like villar protrusions that measured 1.5-4 μm in length and up to 0.4-2 μm in width with the presence of dense electron ground substance of 200-750 nm thick. Several septa derived from the ground substance were present and divided the cyst into compartments containing both bradyzoites and metrocytes. The bradyzoites were banana-shaped and measured 6-12 × 1-2 μm with centrally or posteriorly located nuclei. The ultrastructural features of the cyst wall belonged to type 10 cyst wall according the classification of Dubey et al. (1989) and Dubey and Odening (2001).

  9. Morphology, Molecular Characteristics, and Demonstration of a Definitive Host for Sarcocystis rommeli from Cattle (Bos taurus) in China.

    Science.gov (United States)

    Hu, J J; Huang, S; Wen, T; Esch, G W; Liang, Y; Li, H L

    2017-10-01

    Sarcocysts of Sarcocystis rommeli were found for the first time in 6 of 34 (17.6%) cattle (Bos taurus) in China. With light microscopy, sarcocysts of S. rommeli were up to 1,130 μm long, with a striated, 4-8-μm-thick cyst wall. Using transmission electron microscopy, the villar protrusions (vp) were 4.7-5.2 × 0.2-0.3 μm, and 0.3-0.5 μm apart from each other. The vp contained microtubules extending from the top of the vp to the middle of the ground substance layer (gsl). A BLAST search of the near full-length 18S rRNA and partial mitochondrial cox1 sequences of S. rommeli revealed 98.7% identity and 99.2% identity with sequences of Sarcocystis bovini in GenBank, respectively. Two domestic cats (Felis catus) fed sarcocysts of S. rommeli shed oocysts/sporocysts in their feces with a prepatent period of 14 to 15 days; the partial mitochondrial cox1 sequences of these oocysts/sporocysts shared the high identities, that is, 99.4% and 99.5%, with cox1 sequences of S. rommeli sarcocysts and S. bovini sarcocysts, respectively. This is the first demonstration of a definitive host for S. rommeli.

  10. Occurrence and first molecular characterization of Sarcocystis spp. in wild boars (Sus scrofa) and domestic pigs (Sus scrofa domesticus) in Romania: Public health significance of the isolates.

    Science.gov (United States)

    Imre, Kálmán; Sala, Claudia; Morar, Adriana; Imre, Mirela; Ciontu, Cătălin; Chisăliță, Ion; Dudu, Andreea; Matei, Marius; Dărăbuș, Gheorghe

    2017-03-01

    Domestic and wild pigs, as intermediate hosts, can harbor tissue cysts of three Sarcocystis species namely S. miescheriana, S. suihominis and S. porcifelis. Out of them, S. suihominis is zoonotic. Romania is a country with high consumption of raw and/or undercooked traditional pork products. This fact may greatly favor the acquiring of the zoonotic Sarcocystis infections by humans, as definitive host. Based on this consideration and in order to investigate the occurrence and public health significance of Sarcocystis spp. in two western counties (Caraş-Severin and Timiş) of Romania, a total of 165 heart samples from hunted wild boars (Sus scrofa, n=101) and home slaughtered domestic pigs (Sus scrofa domesticus, n=64) were screened using microscopic fresh examination and molecular methods. Microscopic examination revealed the presence of sarcocysts in 60.4% of wild boars, and 23.4% of domestic pigs. Genetic characterization of isolates through the PCR-RFLP procedure, targeting the 18S rRNA gene, was successfully achieved for all microscopically positive samples, indicating the presence of a single species, S. miescheriana, in both hosts. The identity of 13 selected S. miescheriana isolates was also confirmed through sequencing. The tested hosts older than 27 months were found to be significantly higher infected (p<0.05) with Sarcocystis than the 6 to ≤27months age group. Although the human infective S. suihominis has not been registered, for a more reliable epidemiological picture, further molecular studies enrolling a larger number of animals and diagnosis on human intestinal Sarcocystis infections are still necessary. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. A Survey on Sarcocystis Infection Rate in Slaughtered Cattle and Sheep by Macroscopic Inspection and Pepsin Digestion Methods in Hamadan Abattoir, Iran, 2014

    Directory of Open Access Journals (Sweden)

    F. Parandin

    2015-10-01

    Full Text Available Introduction & Objective: 130 heteroxenous species of sarcosytis with different life cycle and pathogenesis have been recognized. The pathogenic species for humans are S. hominis from cattle and S. suihominis from pig that humans are definitive and cattle and pig are intermedi-ate hosts. Some species of Sarcocystis can cause important economic loss and disease in livestock, and health issues in humans. The aim of this study was to determine the prevalence of Sarcocystis infection in slaughtered Cattle and sheep in Hamadan, west of Iran. Materials & Methods: In this cross sectional descriptive study a total of 324 cattle and 334 sheep carcasses were examined using naked eye inspection for macroscopic Sarcocysts, and digestion method, for microscopic types of parasite. Muscles from thigh, heart, tongue, esophagus, diaphragm and costal muscles were examined. All carcasses examined by naked eyes and tissues were minced and poured in digestion medium separately and sediment was examined microscopically. Results: The prevalence of microscopic Sarcocystis in cattle was detected in 100% and there was no macroscopic cyst in examined carcasses. However, the prevalence of microscopic Sarcocystis in the sheep was also 100% and the sarcocysts were found in the 48.34 % of esophagus and 29.49% of diaphragm muscles by naked eyes inspection. Conclusion: The digestion is found the most sensitive method for diagnosis of Sarcocystis. Al-though 100% of muscles were found infected but the majority of the cysts in the sheep and all in the cattle were as microcysts. That means, the meat should be cooked sufficiently irrespec-tive of meat inspection results. (Sci J Hamadan Univ Med Sci 2015; 22 (3: 210-216

  12. Erythrocyte invasion by Babesia bovis merozoites is inhibited by polyclonal antisera directed against peptides derived from a homologue of Plasmodium falciparum apical membrane antigen 1.

    Science.gov (United States)

    Gaffar, Fasila R; Yatsuda, Ana P; Franssen, Frits F J; de Vries, Erik

    2004-05-01

    Apical membrane antigen 1 (AMA-1) is a micronemal protein secreted to the surface of merozoites of Plasmodium species and Toxoplasma gondii tachyzoites in order to fulfill an essential but noncharacterized function in host cell invasion. Here we describe cloning and characterization of a Babesia bovis AMA-1 homologue designated BbAMA-1. The overall level of similarity of BbAMA-1 to P. falciparum AMA-1 was low (18%), but characteristic features like a transmembrane domain near the C terminus, a predicted short cytoplasmic C-terminal sequence with conserved sequence properties, and an extracellular domain containing 14 conserved cysteine residues putatively involved in disulfide bridge formation are typical of AMA-1. Rabbit polyclonal antisera were raised against three synthetic peptides derived from the N-terminal region and domains II and III of the putative extracellular domain and were shown to recognize specifically recombinant BbAMA-1 expressed in Escherichia coli. Immunofluorescence microscopy showed that there was labeling of the apical half of merozoites with these antisera. Preincubation of free merozoites with all three antisera reduced the efficiency of invasion of erythrocytes by a maximum of 65%. Antisera raised against the N-terminal peptide detected a 82-kDa protein on Western blots and a 69-kDa protein in the supernatant that was harvested after in vitro invasion, suggesting that proteolytic processing and secretion take place during or shortly after invasion. A combination of two-dimensional Western blotting and metabolic labeling allowing direct identification of spots reacting with the BbAMA-1 peptide antisera together with the very low silver staining intensity of these spots indicated that very low levels of BbAMA-1 are present in Babesia merozoites.

  13. Relationship between malaria incidence and IgG levels to Plasmodium falciparum merozoite antigens in Malian children: impact of hemoglobins S and C.

    Directory of Open Access Journals (Sweden)

    Kazutoyo Miura

    Full Text Available Heterozygous hemoglobin (Hb AS (sickle-cell trait and HbAC are hypothesized to protect against Plasmodium falciparum malaria in part by enhancing naturally-acquired immunity to this disease. To investigate this hypothesis, we compared antibody levels to four merozoite antigens from the P. falciparum 3D7 clone (apical membrane antigen 1, AMA1-3D7; merozoite surface protein 1, MSP1-3D7; 175 kDa erythrocyte-binding antigen, EBA175-3D7; and merozoite surface protein 2, MSP2-3D7 in a cohort of 103 HbAA, 73 HbAS and 30 HbAC children aged 3 to 11 years in a malaria-endemic area of Mali. In the 2009 transmission season we found that HbAS, but not HbAC, significantly reduced the risk of malaria compared to HbAA. IgG levels to MSP1 and MSP2 at the start of this transmission season inversely correlated with malaria incidence after adjusting for age and Hb type. However, HbAS children had significantly lower IgG levels to EBA175 and MSP2 compared to HbAA children. On the other hand, HbAC children had similar IgG levels to all four antigens. The parasite growth-inhibitory activity of purified IgG samples did not differ significantly by Hb type. Changes in antigen-specific IgG levels during the 2009 transmission and 2010 dry seasons also did not differ by Hb type, and none of these IgG levels dropped significantly during the dry season. These data suggest that sickle-cell trait does not reduce the risk of malaria by enhancing the acquisition of IgG responses to merozoite antigens.

  14. Analysis of Polymorphisms in the Merozoite Surface Protein-3a Gene and Two Microsatellite Loci in Sri Lankan Plasmodium vivax: Evidence of Population Substructure in Sri Lanka

    DEFF Research Database (Denmark)

    Schousboe, Mette L; Rajakaruna, Rupika S; Amerasinghe, Priyanie H

    2011-01-01

    Abstract. The geographical distribution of genetic variation in Plasmodium vivax samples (N = 386) from nine districts across Sri Lanka is described using three markers; the P. vivax merozoite surface protein-3a (Pvmsp-3a) gene, and the two microsatellites m1501 and m3502. At Pvmsp-3a, 11 alleles....... The results show evidence of high genetic diversity and possible population substructure of P. vivax populations in Sri Lanka....

  15. Adaptación y modificaciones de corta y larga duración en la actividad eléctrica de neuronas de la corteza cerebral in vitro.

    OpenAIRE

    Montoro Laseca, Rafael Jesús

    2017-01-01

    El sistema nervioso central lleva a cabo sus complejas funciones gracias a la actividad armónica de sus unidades básicas, las neuronas, que son células de una enorme sofisticación morfológica y funcional. Una neurona típica recibe decenas de miles de aferencias y es capaz de generar en cada instante la respuesta bioquímica y electrofisiológica adecuada que permite la transmisión a otras células de una información c...

  16. Neuronas Espejo: un nuevo camino dentro de las Neurociencias : Aportes y aplicaciones, en el área de la reeducación y la rehabilitación

    OpenAIRE

    Figueroa Cuadrado, Emiliano

    2013-01-01

    El presente trabajo, pretende sumergirse en el mundo de las Neuronas Espejo. Dichas neuronas fueron descubiertas por un equipo de Neurobiólogos Italianos, de la Universidad de Parma, en el año 1995. Es el ultimo "gran descubrimiento" que se ha hecho en el ámbito de las Neurociencias; tanto que hasta algunos especialistas han llegado a decir, que tal descubrimiento estaba llamado a desempeñar en las Neurociencias, un papel semejante al que había tenido en Biología, la decodificación de la e...

  17. Formation of the food vacuole in Plasmodium falciparum: a potential role for the 19 kDa fragment of merozoite surface protein 1 (MSP1(19.

    Directory of Open Access Journals (Sweden)

    Anton R Dluzewski

    2008-08-01

    Full Text Available Plasmodium falciparum Merozoite Surface Protein 1 (MSP1 is synthesized during schizogony as a 195-kDa precursor that is processed into four fragments on the parasite surface. Following a second proteolytic cleavage during merozoite invasion of the red blood cell, most of the protein is shed from the surface except for the C-terminal 19-kDa fragment (MSP1(19, which is still attached to the merozoite via its GPI-anchor. We have examined the fate of MSP1(19 during the parasite's subsequent intracellular development using immunochemical analysis of metabolically labeled MSP1(19, fluorescence imaging, and immuno-electronmicroscopy. Our data show that MSP1(19 remains intact and persists to the end of the intracellular cycle. This protein is the first marker for the biogenesis of the food vacuole; it is rapidly endocytosed into small vacuoles in the ring stage, which coalesce to form the single food vacuole containing hemozoin, and persists into the discarded residual body. The food vacuole is marked by the presence of both MSP1(19 and the chloroquine resistance transporter (CRT as components of the vacuolar membrane. Newly synthesized MSP1 is excluded from the vacuole. This behavior indicates that MSP1(19 does not simply follow a classical lysosome-like clearance pathway, instead, it may play a significant role in the biogenesis and function of the food vacuole throughout the intra-erythrocytic phase.

  18. David Hume y las neuronas espejo: una actualización de la teoría del sentimiento de empatía

    OpenAIRE

    Castro, Luis Adrián

    2013-01-01

    El objetivo de esta ponencia será dar cuenta del modo en que los avances producidos en el campo de la neurociencia vienen a sustentar la intuición humeana de la motivación moral arraigada en un sentimiento de empatía. A este fin se realizará un breve recorrido por los puntos fundamentales en la concepción moral de Hume y se expondrán algunos resultados obtenidos en el área neurocientífica respecto al descubrimiento de las neuronas espejo en los macacos, y la posterior investigación de la exis...

  19. “Características de la citoarquitectura de las neuronas piramidales de la corteza prefrontal luego de isquemia cerebral y tratamiento neuroprotector con melatonina, en ratas”.

    OpenAIRE

    García Chávez, Dafne Vanessa

    2012-01-01

    La isquemia cerebral global aguda desencadena fenómenos de daño celular que pueden dar lugar a la muerte de grupos neuronales vulnerables; tales como las neuronas piramidales del cuerno de Ammon y las de las capas III y V de la corteza cerebral. Estas estructuras cerebrales y sus relaciones morfológicas y funcionales son relevantes para la integración de las funciones cognoscitivas como el aprendizaje espacial y la memoria de trabajo espacial, por lo que las secuelas de la isqu...

  20. Regulación del ciclo vesicular sináptico por las quinasas dependientes de GMPc en neuronas grabulares de cerebelo

    OpenAIRE

    Collado Alsina, Marina Andrea

    2016-01-01

    La comunicación entre las neuronas ocurre en regiones anatómicamente identificables denominadas sinapsis. Existen dos tipos de transmisión sináptica, las sinapsis químicas y las eléctricas, aunque predominan las sinapsis químicas. En este tipo de sinapsis, la comunicación neuronal ocurre en zonas especializadas de los axones, denominados terminales sinápticos, los cuales almacenan en su interior pequeñas vesículas que contienen un neurotransmisor. Ante la llegada de un potencial de acción al ...

  1. Caracterización de los canales de la subfamilia TREK (K2P) en neuronas del ganglio cervical superior en cultivo

    OpenAIRE

    Cadaveira Mosquera, Alba

    2014-01-01

    En neuronas simpáticas del ganglio cervical superior (GCS) el potencial de reposo está controlado por un mecanismo complejo en el que intervienen varias corrientes voltaje dependientes, la bomba de Na+/K+ y una corriente de fuga principalmente de K+ cuyo sustrato molecular era desconocido. El descubrimiento en 1996 de los canales K2P y su participación en el mantenimiento del potencial de reposo en varios tipos celulares, los reveló como los principales candidatos para transportar la corrient...

  2. Age-related differences in naturally acquired T cell memory to Plasmodium falciparum merozoite surface protein 1.

    Directory of Open Access Journals (Sweden)

    Kiprotich Chelimo

    Full Text Available Naturally acquired immunity to Plasmodium falciparum malaria in malaria holoendemic areas is characterized by the gradual, age-related development of protection against high-density parasitemia and clinical malaria. Animal studies, and less commonly, observations of humans with malaria, suggest that T-cell responses are important in the development and maintenance of this immunity, which is mediated primarily by antibodies that slow repeated cycles of merozoites through erythrocytes. To advance our rather limited knowledge on human T-cell immunity to blood stage malaria infection, we evaluated CD4 and CD8 T-cell effector memory subset responses to the 42 kDa C-terminal fragment of Merozoite Surface Protein 1 (MSP1(42, a malaria vaccine candidate, by 49 healthy 0.5 to ≥18 year old residents of a holoendemic area in western Kenya. The proportion of individuals with peripheral blood mononuclear cell MSP1(42 driven IFN-γ ELISPOT responses increased from 20% (2/20 among 0.5-1 year old children to 90% (9/10 of adults ≥18 years (P = 0.01; parallel increases in the magnitude of IFN-γ responses were observed across all age groups (0.5, 1, 2, 5 and ≥18 years, P = 0.001. Less than 1% of total CD4 and CD8 T-cells from both children and adults produced IFN-γ in response to MSP1(42. However, adults had higher proportions of MSP1(42 driven IFN-γ secreting CD4 and CD8 effector memory (CD45RA(- CD62L(- T-cells than children (CD4: 50.9% vs. 28.8%, P = 0.036; CD8: 52.1% vs. 18.3%, respectively P = 0.009. In contrast, MSP1(42 driven IFN-γ secreting naïve-like, transitional (CD45RA(+ CD62L(+ CD4 and CD8 cells were the predominant T-cell subset among children with significantly fewer of these cells in adults (CD4: 34.9% vs. 5.1%, P = 0.002; CD8: 47.0% vs. 20.5%, respectively, P = 0.030. These data support the concept that meaningful age-related differences exist in the quality of T-cell immunity to malaria antigens such as MSP1.

  3. Expression and Evaluation of Recombinant Plasmodium knowlesi Merozoite Surface Protein-3 (MSP-3 for Detection of Human Malaria.

    Directory of Open Access Journals (Sweden)

    Jeremy Ryan De Silva

    Full Text Available Malaria remains a major health threat in many parts of the globe and causes high mortality and morbidity with 214 million cases of malaria occurring globally in 2015. Recent studies have outlined potential diagnostic markers and vaccine candidates one of which is the merozoite surface protein (MSP-3. In this study, novel recombinant Plasmodium knowlesi MSP-3 was cloned, expressed and purified in an Escherichia coli system. Subsequently, the recombinant protein was evaluated for its sensitivity and specificity. The recombinant pkMSP-3 protein reacted with sera from patients with P. knowlesi infection in both Western blot (61% and ELISA (100%. Specificity-wise, pkMSP-3 did not react with healthy donor sera in either assay and only reacted with a few non-malarial parasitic patient sera in the ELISA assay (3 of 49. In conclusion, sensitivity and specificity of pkMSP-3 was found to be high in the ELISA and Western Blot assay and thus utilising both assays in tandem would provide the best sero-diagnostic result for P. knowlesi infection.

  4. Genetic diversity of plasmodium vivax merozoite surface protein-3alpha (Pvmsp-3alpha) gene in Jhapa District of Nepal.

    Science.gov (United States)

    Adhikari, Madhav; Ranjitkar, Samir; Schousboe, Mette Leth; Alifrangis, Michael; Imwong, Mallika; Bhatta, Dwij Raj; Banjara, Megha Raj

    2012-03-01

    In Nepal, Plasmodium vivax accounts for approximately 80-90% of the malaria cases, but limited studies have been conducted on the genetic diversity of this parasite population. This study was carried out to determine the genetic diversity of P. vivax population sampled from subjects living in an endemic area of Jhapa District by analyzing the polymorphic merozoite surface protein-3alpha (Pvmsp-3alpha) gene by using PCR-restriction fragment length polymorphism. Three distinct genotypes were obtained from 96 samples; type A: 40 (71%), type B: 7 (13%), and type C: 9 (16%) which could be categorized into 13 allelic patterns: A1-A9, B1, B2, C1 and C2. These results indicated a high genetic diversity within the studied P. vivax population. As the transmission rate of malaria is low in Nepal, the diversity is most likely due to migration of people between the malaria endemic regions, either within the country or between Nepal and India. Similar prevalence of the three genotypes of Pvmsp-3alpha between the two countries likely supports the latter explanation.

  5. Isolation of tissue cysts of Toxoplasma, Isospora, Hammondia and Sarcocystis from camel (Camelus dromedarius) meat in Saudi Arabia.

    Science.gov (United States)

    Hilali, M; Fatani, A; al-Atiya, S

    1995-07-01

    Meat samples were collected from the oesophagus and tongue of 38 camels slaughtered at the main abattoir of Al-Ahsa city, Saudi Arabia. Five cats and three dogs, conventionally reared and coccidia-free, were caged individually in steel cages. Camel meat was pooled, minced and fed to four cats and two dogs. One cat and one dog were not fed meat and were kept as noninfected controls. Faecal samples from infected and control animals were examined daily for a period of 2 months after feeding the meat. Three cats fed camel meat passed in their faeces oocysts of Toxoplasma gondii, Isospora felis and Isospora rivolta. The fourth cat passed only T. gondii and I. felis oocysts. One of the dogs fed camel meat passed oocysts of Isospora canis, Hammondia heydorni and Sarcocystis cameli sporocysts. The second dog excreted only S. cameli sporocysts.

  6. Identification and discrimination of Toxoplasma gondii, Sarcocystis spp., Neospora spp., and Cryptosporidium spp. by righ-resolution melting analysis.

    Directory of Open Access Journals (Sweden)

    Hllytchaikra Ferraz Fehlberg

    Full Text Available The objective of this study was to standardize the high-resolution melting method for identification and discrimination of Toxoplasma gondii, Sarcocystis spp., Neospora spp., and Cryptosporidium spp. by amplification of 18S ribosomal DNA (rDNA using a single primer pair. The analyses were performed on individual reactions (containing DNA from a single species of a protozoan, on duplex reactions (containing DNA from two species of protozoa in each reaction, and on a multiplex reaction (containing DNA of four parasites in a single reaction. The proposed method allowed us to identify and discriminate the four species by analyzing the derivative, normalized, and difference melting curves, with high reproducibility among and within the experiments, as demonstrated by low coefficients of variation (less than 2.2% and 2.0%, respectively. This is the first study where this method is used for discrimination of these four species of protozoa in a single reaction.

  7. Mieloencefalite protozoária eqüina (Relato de caso.

    Directory of Open Access Journals (Sweden)

    R. C. Gonçalves

    2005-03-01

    Full Text Available RESUMO :O objetivo deste trabalho foi relatar um caso de mieloencefalite protozoária eqüina no Estado de São Paulo, Brasil. O diagnóstico se baseou nos sinais clínicos, no resultado positivo para anticorpos contra Sarcocystis neurona no soro e no líquor pela técnica de Western blot. Palavras chave: Mieloencefalite, Sarcocystis neurona, eqüinos. SUMMARY: The purpose of this work was to present a case of equine protozoal myeloencephalitis (EPM in the State of São Paulo, Brazil. The diagnosis was based on the clinical sings, the positive results of the serum and cerebrospinal fluid analysis (Western blot for antibodies against Sarcocystis neurona. Keywords: Myeloencephalitis, Sarcocystis neurona,

  8. Production, characterization, and immunogenicity of a secreted form of Plasmodium falciparum merozoite surface protein 4 produced in Bacillus subtilis.

    Science.gov (United States)

    Chittibabu, G; Ma, Charles; Netter, Hans J; Noronha, Santosh B; Coppel, Ross L

    2014-04-01

    Plasmodium falciparum is the causative agent of the most serious form of malaria. Although a combination of control measures has significantly limited malaria morbidity and mortality in the last few years, it is generally agreed that sustained control or even eradication will require additional tools including an effective malaria vaccine. Merozoite surface protein 4, MSP4, which is present during the asexual stage of P. falciparum, is a recognized target that would be useful in a subunit vaccine against blood stages of malaria. Falciparum malaria is most prevalent in developing countries, and this in turn leads to a requirement for safe, low-cost vaccines. We have attempted to utilize the nonpathogenic, gram-positive organism Bacillus subtilis to produce PfMSP4. PfMSP4 was secreted into the culture medium at a yield of 4.5 mg/L. Characterization studies including SDS-PAGE, mass spectrometry, and N-terminal sequencing indicated that the B. subtilis expression system secreted a full length PfMSP4 protein compared to a truncated version in Escherichia coli. Equivalent amounts of purified B. subtilis and E. coli-derived PfMSP4 were used for immunization studies, resulting in statistically significant higher mean titer values for the B. subtilis-derived immunogen. The mouse antibodies raised against B. subtilis produced PfMSP4 that were reactive to parasite proteins as evidenced by immunoblotting on parasite lysate and indirect immunofluorescence assays of fixed parasites. The B. subtilis expression system, in contrast to E. coli, expresses higher amounts of full length PfMSP4 products, decreased levels of aggregates, and allows the development of simplified downstream processing procedures.

  9. Polymorphism of Merozoite Surface Protein-3α Gene of Plasmo-dium vivax in Isolates of Iran

    Directory of Open Access Journals (Sweden)

    M Asmar

    2008-04-01

    Full Text Available Background: The worldwide distribution of P. vivax has expanded significantly and the number of reported cases has been on the rise. Approximately 88% of malaria cases in Iran are caused by Plasmodium vivax, and in order to management of the disease, understanding the population genetic structure of the parasite is necessary for designing and applying drugs and vaccines. Among many potential candidates, merozoite surface protein-3α gene (PvMSP-3α is promising target to develop an effective vaccine. This study was carried out to determine the variation of this gene, as a genetic marker, in Plasmodium vivax isolates in malarious areas of Iran. Methods: Diversity in PvMSP-3α gene was assessed in 85 Plasmodium vivax isolated from four southern and east-southern provinces of the country by PCR/RFLP method. Amplification was performed with two primer pair sets in a nested PCR format and the products were digested by the enzyme HhaI in RFLP method. Results: Based on the size of the PCR products, we observed three biotypes A (about 1900bp, B (about 1400bp and C (about 1100bp of PvMSP-3α gene. Biotype A was predominant. According to RFLP patterns, 10 allelic groups of the gene were observed, that, 7, 2 and 1 groups correspond to the biotype A, B and C, respectively. Mixed genotype and multiple infections were not seen. Conclusion: RFLP method with HhaI enzyme is a useful method for determining the polymorphism of biotype A of PvMSP-3agene.

  10. Antibodies directed against Merozoite Surface Protein-6 are induced by natural exposure to Plasmodium falciparum in a low transmission environment

    Science.gov (United States)

    Jordan, Stephen J.; Oliveira, Ana L.; Neal, Aaron T.; Hernandez, Jean N.; Branch, OraLee H.; Rayner, Julian C.

    2011-01-01

    SUMMARY Malaria caused by Plasmodium falciparum is a major cause of global infant mortality, and there is currently no licensed vaccine that provides protection against infection or disease. Several P. falciparum vaccine targets have undergone early testing, but many more candidates remain with little data to support their development. Plasmodium falciparum Merozoite Surface Protein 6 (PfMSP6) is a candidate of particular interest because it is a member of the PfMSP3 multi-gene family, raising the possibility that vaccine-induced immune responses could cross-react across multiple family members. However, few immunoepidemiological studies of PfMSP6 have been carried out to measure domain-specific anti-PfMSP6 responses. This study investigated anti-PfMSP6 responses in P. falciparum infected individuals from the Peruvian Amazon, using two different PfMSP6 N-terminal allele antigens and a single C-terminal domain antigen, and compared the responses with both PfMSP6 genotyping data and anti-PfMSP3 response data that had been previously generated for the same samples. Anti-PfMSP6 responses were detected despite the low transmission setting, but were less frequent and of considerably lower intensity than anti-PfMSP3 responses. There was a positive correlation between anti-PfMSP3 and PfMSP6 responses, suggesting that the possibility that PfMSP3 family antigens could induce cross-reactive responses requires further detailed investigation. PMID:21585398

  11. Genetic variations in merozoite surface antigen genes of Babesia bovis detected in Vietnamese cattle and water buffaloes.

    Science.gov (United States)

    Yokoyama, Naoaki; Sivakumar, Thillaiampalam; Tuvshintulga, Bumduuren; Hayashida, Kyoko; Igarashi, Ikuo; Inoue, Noboru; Long, Phung Thang; Lan, Dinh Thi Bich

    2015-03-01

    The genes that encode merozoite surface antigens (MSAs) in Babesia bovis are genetically diverse. In this study, we analyzed the genetic diversity of B. bovis MSA-1, MSA-2b, and MSA-2c genes in Vietnamese cattle and water buffaloes. Blood DNA samples from 258 cattle and 49 water buffaloes reared in the Thua Thien Hue province of Vietnam were screened with a B. bovis-specific diagnostic PCR assay. The B. bovis-positive DNA samples (23 cattle and 16 water buffaloes) were then subjected to PCR assays to amplify the MSA-1, MSA-2b, and MSA-2c genes. Sequencing analyses showed that the Vietnamese MSA-1 and MSA-2b sequences are genetically diverse, whereas MSA-2c is relatively conserved. The nucleotide identity values for these MSA gene sequences were similar in the cattle and water buffaloes. Consistent with the sequencing data, the Vietnamese MSA-1 and MSA-2b sequences were dispersed across several clades in the corresponding phylogenetic trees, whereas the MSA-2c sequences occurred in a single clade. Cattle- and water-buffalo-derived sequences also often clustered together on the phylogenetic trees. The Vietnamese MSA-1, MSA-2b, and MSA-2c sequences were then screened for recombination with automated methods. Of the seven recombination events detected, five and two were associated with the MSA-2b and MSA-2c recombinant sequences, respectively, whereas no MSA-1 recombinants were detected among the sequences analyzed. Recombination between the sequences derived from cattle and water buffaloes was very common, and the resultant recombinant sequences were found in both host animals. These data indicate that the genetic diversity of the MSA sequences does not differ between cattle and water buffaloes in Vietnam. They also suggest that recombination between the B. bovis MSA sequences in both cattle and water buffaloes might contribute to the genetic variation in these genes in Vietnam. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Sarcocystis pantherophisi n. sp., from Eastern Rat Snakes (Pantherophis alleghaniensis) as Definitive Hosts and Interferon Gamma Gene Knockout Mice as Experimental Intermediate Hosts.

    Science.gov (United States)

    Verma, S K; Lindsay, D S; Mowery, J D; Rosenthal, B M; Dubey, J P

    2017-10-01

    Here, we report a new species, Sarcocystis pantherophisi n. sp., with the Eastern rat snake (Pantherophis alleghaniensis) as natural definitive host and the interferon gamma gene knockout (KO) mouse as the experimental intermediate host. Sporocysts (n = 15) from intestinal contents of the snake were 10.8 × 8.9 μm. Sporocysts were orally infective to KO mice but not to laboratory-raised albino outbred house mice (Mus musculus). The interferon gamma KO mice developed schizont-associated neurological signs, and schizonts were cultivated in vitro from the brain. Mature sarcocysts were found in skeletal muscles of KO mice examined 41 days postinoculation (PI). Sarcocysts were slender, up to 70 μm wide and up to 3.5 mm long. By light microscopy, sarcocysts appeared thin-walled (parasites that have snake-rodent life cycles. The parasite in the present study was molecularly and biologically similar to a previously reported isolate (designated earlier as Sarcocystis sp. ex Pantherophis alleghaniensis) from P. alleghaniensis, and it was structurally different from other Sarcocystis species so far described.

  13. A Babesia bovis merozoite protein with a domain architecture highly similar to the thrombospondin-related anonymous protein (TRAP) present in Plasmodium sporozoites.

    Science.gov (United States)

    Gaffar, Fasila R; Yatsuda, Ana P; Franssen, Frits F J; de Vries, Erik

    2004-07-01

    Recognition and invasion of host cells is a key step in the life-cycle of all apicomplexan parasites. The thrombospondin-related anonymous protein (TRAP) of Plasmodium sporozoites is directly involved in both processes and shares conserved adhesive domains with micronemal transmembrane proteins of other apicomplexans. Here, we report the cloning and characterization of a Babesia bovis TRAP homologue (BbTRAP). It was predicted to be a type 1 transmembrane protein containing a von Willebrand Factor A domain (vWFA), a thrombospondin type 1 domain (TSP1), a conserved transmembrane region and a conserved cytoplasmic C-terminus, thus resembling the domain arrangement of Plasmodium TRAP. In contrast to Plasmodium TRAP, BbTRAP was shown to be present during the asexual erythrocytic cycle, being located mainly at the apical side of merozoites. Polyclonal rabbit antisera directed against synthetic peptides derived from the TSP1 domain or the C-terminal end of the ectodomain were shown to inhibit erythrocyte invasion in vitro. Both antisera recognized a 75 kDa protein in merozoite extracts as well as in a protein fraction that was secreted into the extracellular milieu during in vitro invasion of erythrocytes.

  14. Allelic Diversity at the Merozoite Surface Protein-1 (MSP-1 Locus in Natural Plasmodium falciparum Populations: a Brief Overview

    Directory of Open Access Journals (Sweden)

    Marcelo U Ferreira

    1998-09-01

    Full Text Available The merozoite surface protein-1 (MSP-1 locus of Plasmodium falciparum codes for a major asexual blood-stage antigen currently proposed as a major malaria vaccine candidate. The protein, however, shows extensive polymorphism, which may compromise its use in sub-unit vaccines. Here we compare the patterns of allelic diversity at the MSP-1 locus in wild isolates from three epidemiologically distinct malaria-endemic areas: the hypoendemic southwestern Brazilian Amazon (n = 54, the mesoendemic southern Vietnam (n = 238 and the holoendemic northern Tanzania (n = 79. Fragments of the variable blocks 2, 4a, 4b and 6 or 10 of this single-copy gene were amplified by the polymerase chain reaction, and 24 MSP-1 gene types were defined as unique combinations of allelic types in each variable block. Ten different MSP-1 types were identified in Brazil, 23 in Vietnam and 13 in Tanzania. The proportion of genetically mixed infections (isolates with parasites carrying more than one MSP-1 version ranged from 39% in Brazil to 44% in Vietnam and 60% in Tanzania. The vast majority (90% of the typed parasite populations from Brazil and Tanzania belonged to the same seven most frequent MSP-1 gene types. In contrast, these seven gene types corresponded to only 61% of the typed parasite populations from Vietnam. Non-random associations were found between allelic types in blocks 4a and 6 among Vietnamese isolates, the same pattern being observed in independent studies performed in 1994, 1995 and 1996. These results suggest that MSP-1 is under selective pressure in the local parasite population. Nevertheless, the finding that similar MSP-1 type frequencies were found in 1994 and 1996 argues against the prominence of short-term frequency-dependent immune selection of MSP-1 polymorphisms. Non-random associations between MSP-1 allelic types, however, were not detected among isolates from Brazil and Tanzania. A preliminary analysis of the distribution of MSP-1 gene types per

  15. Texto y figuras preparatorios del Capítulo 5 (Tomo I) de la Histología del Sistema Nervioso de Cajal: INDUCCIONES FISIOLÓGICAS DE LA MORFOLOGÍA Y CONEXIONES DE LAS NEURONAS.

    OpenAIRE

    Freire, Miguel

    2007-01-01

    INDUCCIONES FISIOLÓGICAS DE LA MORFOLOGÍA Y CONEXIONES DE LAS NEURONAS. Papel conductor de las expansiones protoplásmicas y del soma ; conductibilidad de todas las partes de la neurona. ─ Refutación de la teoría de Golgi sobre el oficio nutritivo de las expansiones dendríticas. ─ Teoría de la polarización dinámica. ─ Teoría de la polarización axípeta. ─ La avalancha de conducción. ─ Leyes de ahorro de espacio, de tiempo y de materia que rigen la morfología de las células y el curso y arranque...

  16. Levels of antibody to conserved parts of Plasmodium falciparum merozoite surface protein 1 in Ghanaian children are not associated with protection from clinical malaria

    DEFF Research Database (Denmark)

    Dodoo, D; Theander, T G; Kurtzhals, J A

    1999-01-01

    The 19-kDa conserved C-terminal part of the Plasmodium falciparum merozoite surface protein 1 (PfMSP119) is a malaria vaccine candidate antigen, and human antibody responses to PfMSP119 have been associated with protection against clinical malaria. In this longitudinal study carried out in an area...... malaria season in April and after the season in November. Using enzyme-linked immunosorbent assay, we measured antibody responses to recombinant gluthathione S-transferase-PfMSP119 fusion proteins corresponding to the Wellcome and MAD20 allelic variants in these samples. Prevalence of antibodies...... recognizing the Wellcome 19 construct containing both epidermal growth factor (EGF)-like motifs in Wellcome type PfMSP119 was about 30%. Prevalence of antibodies to constructs containing only the first EGF domain from either Wellcome or MAD20 type PfMSP119 was about 15%, whereas antibodies recognizing...

  17. The origin and diversification of the merozoite surface protein 3 (msp3) multi-gene family in Plasmodium vivax and related parasites.

    Science.gov (United States)

    Rice, Benjamin L; Acosta, Mónica M; Pacheco, M Andreína; Carlton, Jane M; Barnwell, John W; Escalante, Ananias A

    2014-09-01

    The genus Plasmodium is a diversified group of parasites with more than 200 known species that includes those causing malaria in humans. These parasites use numerous proteins in a complex process that allows them to invade the red blood cells of their vertebrate hosts. Many of those proteins are part of multi-gene families; one of which is the merozoite surface protein-3 (msp3) family. The msp3 multi-gene family is considered important in the two main human parasites, Plasmodium vivax and Plasmodium falciparum, as its paralogs are simultaneously expressed in the blood stage (merozoite) and are immunogenic. There are large differences among Plasmodium species in the number of paralogs in this family. Such differences have been previously explained, in part, as adaptations that allow the different Plasmodium species to invade their hosts. To investigate this, we characterized the array containing msp3 genes among several Plasmodium species, including P. falciparum and P. vivax. We first found no evidence indicating that the msp3 family of P. falciparum was homologous to that of P. vivax. Subsequently, by focusing on the diverse clade of nonhuman primate parasites to which P. vivax is closely related, where homology was evident, we found no evidence indicating that the interspecies variation in the number of paralogs was an adaptation related to changes in host range or host switches. Overall, we hypothesize that the evolution of the msp3 family in P. vivax is consistent with a model of multi-allelic diversifying selection where the paralogs may have functionally redundant roles in terms of increasing antigenic diversity. Thus, we suggest that the expressed MSP3 proteins could serve as "decoys", via antigenic diversity, during the critical process of invading the host red blood cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Babesia bovis merozoites invade human, ovine, equine, porcine and caprine erythrocytes by a sialic acid-dependent mechanism followed by developmental arrest after a single round of cell fission.

    Science.gov (United States)

    Gaffar, Fasila R; Franssen, Frits F J; de Vries, Erik

    2003-12-01

    Babesia bovis infections have only been observed in bovine species in contrast to Babesia divergens that also can infect humans, sheep and rodents. Using an in vitro assay that assesses invasion of erythrocytes by free merozoites after a 1-h incubation period, it was shown that specificity is not determined by host-specific interactions associated with invasion. Human erythrocytes were invaded more efficiently than bovine erythrocytes whereas erythrocytes of sheep, pigs and horses were invaded only slightly less efficiently. In contrast, goat erythrocytes were refractory to efficient invasion. Significant differences in invasion efficiency into erythrocytes from different individuals of the same species were observed. Erythrocytes from all species, except for goats, supported intracellular development of newly invaded merozoites and high numbers of duplicated parasites, located in a morphologically normal accole position, were present. Only in bovine erythrocytes did subsequent rounds of invasion, leading to increased parasitaemia, take place. This suggests that host specificity is determined by factors operating late in the erythrocytic stage of the B. bovis life cycle. Incubation of erythrocytes with neuraminidase prior to invasion led to a decrease in invasion efficiency of approximately 80%. This effect was observed for several species. The removal of either alpha(2-3)-linked or alpha(2-6)-linked sialic acid residues gave similar levels of reduction whereas simultaneous removal did not show an additive effect. Pre-incubation of merozoites with N-acetylneuraminyl-lactose decreased invasion efficiency by approximately 45% whereas addition just prior to invasion had no significant effect. The results demonstrate that invasion is dependent on the presence of sialic-acid containing membrane receptors on erythrocytes that interact with merozoite ligands that are probably already accessible during pre-incubation prior to invasion.

  19. Modulación de los canales de potasio K2P por proteínas G y vías de segundos mensajeros en neuronas simpáticas de ratón en cultivo

    OpenAIRE

    Rivas Ramirez, Paula

    2016-01-01

    Las neuronas son células excitables que responden a estímulos con cambios en el potencial de membrana en reposo. La generación y mantenimiento del potencial de membrana en reposo se explica como una conductancia constante llamada corriente de fuga compuesta principalmente por K+ y con una contribución menor de Cl- y Na+. Los canales K2P o de doble dominio de poro son canales de potasio de reciente descubrimiento implicados en el mantenimiento de este potencial de membrana. Esta familia de ...

  20. Participación de los receptores muscarínicos en el efecto del β - amiloide (25-35) sobre las neuronas piramidales de la región CA3 del hipocampo. Estudio Electrofisiológico

    OpenAIRE

    Sanabria Castro, Alfredo

    2011-01-01

    [ES] El objetivo general de esta Tesis Doctoral es estudiar el efecto del péptido β - amiloide (25 - 35) y sus mecanismos de acción en neuronas piramidales pertenecientes a la región CA3 del hipocampo de rata por medio de técnicas electrofisiológicas de registro intracelular. [EN] The overall objective of this Thesis is to study the effect of β peptide - amyloid (25 - 35) and their mechanisms of action in pyramidal neurons belonging to the region of rat hippocampal CA3 through electrophysi...

  1. Genetic diversity in the C-terminus of merozoite surface protein 1 among Plasmodium knowlesi isolates from Selangor and Sabah Borneo, Malaysia.

    Science.gov (United States)

    Yap, Nan Jiun; Goh, Xiang Ting; Koehler, Anson V; William, Timothy; Yeo, Tsin Wen; Vythilingam, Indra; Gasser, Robin B; Lim, Yvonne A L

    2017-10-01

    Plasmodium knowlesi, a malaria parasite of macaques, has emerged as an important parasite of humans. Despite the significance of P. knowlesi malaria in parts of Southeast Asia, very little is known about the genetic variation in this parasite. Our aim here was to explore sequence variation in a molecule called the 42kDa merozoite surface protein-1 (MSP-1), which is found on the surface of blood stages of Plasmodium spp. and plays a key role in erythrocyte invasion. Several studies of P. falciparum have reported that the C-terminus (a 42kDa fragment) of merozoite surface protein-1 (MSP-1 42 ; consisting of MSP-1 19 and MSP-1 33 ) is a potential candidate for a malaria vaccine. However, to date, no study has yet investigated the sequence diversity of the gene encoding P. knowlesi MSP-1 42 (comprising Pk-msp-1 19 and Pk-msp-1 33 ) among isolates in Malaysia. The present study explored this aspect. Twelve P. knowlesi isolates were collected from patients from hospitals in Selangor and Sabah Borneo, Malaysia, between 2012 and 2014. The Pk-msp-1 42 gene was amplified by PCR and directly sequenced. Haplotype diversity (Hd) and nucleotide diversity (л) were studied among the isolates. There was relatively high genetic variation among P. knowlesi isolates; overall Hd and л were 1±0.034 and 0.01132±0.00124, respectively. A total of nine different haplotypes related to amino acid alterations at 13 positions, and the Pk-MSP-1 19 sequence was found to be more conserved than Pk-msp-1 33 . We have found evidence for negative selection in Pk-msp- 42 as well as the 33kDa and 19kDa fragments by comparing the rate of non-synonymous versus synonymous substitutions. Future investigations should study large numbers of samples from disparate geographical locations to critically assess whether this molecule might be a potential vaccine target for P. knowlesi. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The Suitability of P. falciparum Merozoite Surface Proteins 1 and 2 as Genetic Markers for In Vivo Drug Trials in Yemen

    Science.gov (United States)

    Al-abd, Nazeh M.; Mahdy, Mohammed A. K.; Al-Mekhlafi, Abdulsalam M. Q.; Snounou, Georges; Abdul-Majid, Nazia B.; Al-Mekhlafi, Hesham M.; Fong, Mun Y.

    2013-01-01

    Background The accuracy of the conclusions from in vivo efficacy anti-malarial drug trials depends on distinguishing between recrudescences and re-infections which is accomplished by genotyping genes coding P. falciparum merozoite surface 1 (MSP1) and MSP2. However, the reliability of the PCR analysis depends on the genetic markers’ allelic diversity and variant frequency. In this study the genetic diversity of the genes coding for MSP1 and MSP2 was obtained for P. falciparum parasites circulating in Yemen. Methods Blood samples were collected from 511 patients with fever and screened for malaria parasites using Giemsa-stained blood films. A total 74 samples were infected with P. falciparum, and the genetic diversity was assessed by nested PCR targeting Pfmsp1 (Block2) and Pfmsp2 (block 3). Results Overall, 58%, 28% and 54% of the isolates harboured parasites of the Pfmsp1 K1, MAD20 and RO33 allelic families, and 55% and 89% harboured those of the Pfmsp2 FC27 and 3D7 allelic families, respectively. For both genetic makers, the multiplicity of the infection (MOI) was significantly higher in the isolates from the foothills/coastland areas as compared to those from the highland (PYemen Pfmsp1 should not be used for PCR correction of in vivo clinical trials outcomes, and that caution should be exercised when employing Pfmsp2. PMID:23861823

  3. Two Plasmodium falciparum genes express merozoite proteins that are related to Plasmodium vivax and Plasmodium yoelii adhesive proteins involved in host cell selection and invasion

    Science.gov (United States)

    Rayner, Julian C.; Galinski, Mary R.; Ingravallo, Paul; Barnwell, John W.

    2000-01-01

    Two related Plasmodium falciparum genes and their encoded proteins have been identified by comparative analyses with Plasmodium vivax reticulocyte binding protein 2 (PvRBP-2). The P. falciparum genes have a structure which suggests that they may be the result of an evolutionary duplication event, as they share more than 8 kb of closely related nucleotide sequence but then have quite divergent unique 3′ ends. Between these shared and unique regions is a complex set of repeats, the nature and number of which differs between the two genes, as well as between different P. falciparum strains. Both genes encode large hydrophilic proteins, which are concentrated at the invasive apical end of the merozoite and are predicted to be more than 350 kDa, with an N-terminal signal sequence and a single transmembrane domain near their C termini. Importantly, they also share gene structure and amino acid homology with the Plasmodium yoelii 235-kDa rhoptry protein family, which is also related to PvRBP-2. Together these Plasmodium proteins define an extended family of proteins that appear to function in erythrocyte selection and invasion. As such, they may prove to be essential components of malaria vaccine preparations. PMID:10920203

  4. Prevalence of Sarcocystis spp. in two subspecies of caribou (Rangifer tarandus) in Newfoundland and Labrador, and foxes (Vulpes vulpes), wolves (Canis lupus), and husky dogs (Canis familiaris) as potential definitive hosts.

    Science.gov (United States)

    Khan, R A; Evans, L

    2006-06-01

    A study was conducted to determine the prevalence and geographical distribution of Sarcocystis spp. infecting 2 subspecies of caribou (Rangifer tarandus) inhabiting Newfoundland and Labrador and its potential definitive hosts. Muscle samples of caribou were obtained, primarily from hunters, and feces of red foxes (Vulpes vulpes) and wolves (Canis lupus), from trappers, and Husky dogs (Canis familiaris), from owners. Histological sections of muscle and flotation methods for feces were used for parasitic detection. Sarcocystis sp. infected more than 50% of barren-ground caribou (R. t. tarandus) from 4 locations in Newfoundland, but it was significantly greater in the north, where 99% of woodland caribou (R. t. caribou) from Labrador harbored the infection. Sporocysts were observed in 27 of 32 red foxes from eastern and northern Newfoundland, whereas 15 of 15 wolves and 22 of the 38 Husky dogs were infected. Wolves and red foxes probably acquired the infection through scavenging, and Husky dogs, from meat they were fed.

  5. Cloning and Sequence Analysis of Recombinant Plasmodium vivax Merozoite Surface Protein 1 (PvMSP-142 kDa In pTZ57R/T Vector.

    Directory of Open Access Journals (Sweden)

    Hadi Mirahmadi

    2015-06-01

    Full Text Available Carboxy-terminal 42 kDa region of Plasmodium vivax merozoite surface protein-1 is considered as an important antigen in blood stage. Since, this region has been observed to be polymorphic among isolates of P. vivax, it is significant to survey on different regions of this antigen in various areas of the world.In the present study, the genetic diversity of cloned PvMSP-142 kDa gene from an Iranian patient is analyzed. Parasite DNA was extracted from a P. vivax - infected patient in Iran. The region of PvMSP-142 kDa was amplified by PCR, cloned into pTZ57R/T vector and then sequenced.Sequencing of cloned PvMSP-142 kDa gene clearly has a high degree of homology (95% with reference Sal-I sequence and also with the homogeneous sequences from some studied countries (97%. Thirty eight SNPs (single nucleotide polymorphism were identified in cloned PvMSP-142 kDa gene which the mutations had localized in the 33 kDa fragment (PvMSP-133 kDa, while there was nearly no variation in the 19 kDa fragment (PvMSP-119 kDa. 2 out of 38 mutations were found as to be novel haplotypes.High similarity of cloned PvMSP-142 kDa gene in comparison to reference sequence and other sequences could be beneficial as a remarkable molecular marker for serological diagnostic kits of P. vivax in malarious neighboring countries of Iran and around the world.

  6. Cloning and Sequence Analysis of Recombinant Plasmodium vivax Merozoite Surface Protein 1 (PvMSP-142 kDa) In pTZ57R/T Vector

    Science.gov (United States)

    MIRAHMADI, Hadi; SPOTIN, Adel; FALLAHI, Shirzad; TAGHIPOUR, Niloofar; TURKI, Habibollah; SEYYED TABAEI, Seyyed Javad

    2015-01-01

    Background: Carboxy-terminal 42 kDa region of Plasmodium vivax merozoite surface protein-1 is considered as an important antigen in blood stage. Since, this region has been observed to be polymorphic among isolates of P. vivax, it is significant to survey on different regions of this antigen in various areas of the world. Methods: In the present study, the genetic diversity of cloned PvMSP-142 kDa gene from an Iranian patient is analyzed. Parasite DNA was extracted from a P. vivax - infected patient in Iran. The region of PvMSP-142 kDa was amplified by PCR, cloned into pTZ57R/T vector and then sequenced. Results: Sequencing of cloned PvMSP-142 kDa gene clearly has a high degree of homology (95%) with reference Sal-I sequence and also with the homogeneous sequences from some studied countries (97%). Thirty eight SNPs (single nucleotide polymorphism) were identified in cloned PvMSP-142 kDa gene which the mutations had localized in the 33 kDa fragment (PvMSP-133 kDa), while there was nearly no variation in the 19 kDa fragment (PvMSP-119 kDa). 2 out of 38 mutations were found as to be novel haplotypes. Conclusion: High similarity of cloned PvMSP-142 kDa gene in comparison to reference sequence and other sequences could be beneficial as a remarkable molecular marker for serological diagnostic kits of P. vivax in malarious neighboring countries of Iran and around the world. PMID:26246817

  7. AFCo1, a meningococcal B-derived cochleate adjuvant, strongly enhances antibody and T-cell immunity against Plasmodium falciparum merozoite surface protein 4 and 5

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    Pérez Oliver

    2009-02-01

    Full Text Available Abstract Background Whilst a large number of malaria antigens are being tested as candidate malaria vaccines, a major barrier to the development of an effective vaccine is the lack of a suitable human adjuvant capable of inducing a strong and long lasting immune response. In this study, the ability of AFCo1, a potent T and B cell adjuvant based on cochleate structures derived from meningococcal B outer membrane proteoliposomes (MBOMP, to boost the immune response against two Plasmodium falciparum antigens, merozoite surface protein 4 (MSP4 and 5 (MSP5, was evaluated. Methods Complete Freund's adjuvant (CFA, which is able to confer protection against malaria in animal MSP4/5 vaccine challenge models, was used as positive control adjuvant. MSP4 and 5-specific IgG, delayed-type hypersensitivity (DTH, T-cell proliferation, and cytokine production were evaluated in parallel in mice immunized three times intramuscularly with MSP4 or MSP5 incorporated into AFCo1, synthetic cochleate structures, CFA or phosphate buffered saline. Results AFCo1 significantly enhanced the IgG and T-cell response against MSP4 and MSP5, with a potency equivalent to CFA, with the response being characterized by both IgG1 and IgG2a isotypes, increased interferon gamma production and a strong DTH response, consistent with the ability of AFCo1 to induce Th1-like immune responses. Conclusion Given the proven safety of MBOMP, which is already in use in a licensed human vaccine, AFCo1 could assist the development of human malaria vaccines that require a potent and safe adjuvant.

  8. Rabbit and human antibodies to a repeated amino acid sequence of a Plasmodium falciparum antigen, Pf 155, react with the native protein and inhibit merozoite invasion.

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    Berzins, K; Perlmann, H; Wåhlin, B; Carlsson, J; Wahlgren, M; Udomsangpetch, R; Björkman, A; Patarroyo, M E; Perlmann, P

    1986-02-01

    The Plasmodium falciparum-derived antigen of Mr 155,000 designated Pf 155, deposited in the membrane of infected erythrocytes, contains at least two blocks of tandemly repeated amino acid sequences. The peptide Glu-Glu-Asn-Val-Glu-His-Asp-Ala, which corresponds to a subunit of a C-terminally located repeat, was synthesized. Rabbits immunized with the octapeptide conjugated with either keyhole limpet hemocyanine or tetanus toxoid formed antibodies against the octapeptide. These antibodies reacted with Pf 155 as detected by immunoblotting or a modified immunofluorescence assay. Sera from humans exposed to P. falciparum also contained antibodies binding to the octapeptide in a dot-blot immunoassay. Their anti-octapeptide titers were correlated with their immunofluorescence titers in the assay detecting Pf 155 and other parasite antigens in the membrane of infected erythrocytes. Human octapeptide-reactive antibodies were isolated on an affinity column with the octapeptide conjugated to bovine serum albumin as ligand. These human antibodies reacted with Pf 155 in immunoblotting and strongly stained the surface of infected erythrocytes in the modified immunofluorescence assay. Approximately 20% of this immunofluorescence activity in a high-titered human serum could be recovered from the octapeptide column, indicating that a significant fraction of these anti-parasite antibodies react with epitopes associated with the octapeptide. Furthermore, the human octapeptide-reactive antibodies very efficiently inhibited merozoite reinvasion into erythrocytes in vitro. Similarly purified rabbit antibodies also significantly inhibited reinvasion. Our results suggest that the C-terminal segment of repeated peptides in Pf 155 is a major antigenic region of the molecule and may contain target sites for protective immunity in P. falciparum malaria.

  9. Immunogenicity of self-associated aggregates and chemically cross-linked conjugates of the 42 kDa Plasmodium falciparum merozoite surface protein-1.

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    Feng Qian

    Full Text Available Self-associated protein aggregates or cross-linked protein conjugates are, in general, more immunogenic than oligomeric or monomeric forms. In particular, the immunogenicity in mice of a recombinant malaria transmission blocking vaccine candidate, the ookinete specific Plasmodium falciparum 25 kDa protein (Pfs25, was increased more than 1000-fold when evaluated as a chemical cross-linked protein-protein conjugate as compared to a formulated monomer. Whether alternative approaches using protein complexes improve the immunogenicity of other recombinant malaria vaccine candidates is worth assessing. In this work, the immunogenicity of the recombinant 42 kDa processed form of the P. falciparum merozoite surface protein 1 (MSP1(42 was evaluated as a self-associated, non-covalent aggregate and as a chemical cross-linked protein-protein conjugate to ExoProtein A, which is a recombinant detoxified form of Pseudomonas aeruginosa exotoxin A. MSP1(42 conjugates were prepared and characterized biochemically and biophysically to determine their molar mass in solution and stoichiometry, when relevant. The immunogenicity of the MSP1(42 self-associated aggregates, cross-linked chemical conjugates and monomers were compared in BALB/c mice after adsorption to aluminum hydroxide adjuvant, and in one instance in association with the TLR9 agonist CPG7909 with an aluminum hydroxide formulation. Antibody titers were assessed by ELISA. Unlike observations made for Pfs25, no significant enhancement in MSP1(42 specific antibody titers was observed for any conjugate as compared to the formulated monomer or dimer, except for the addition of the TLR9 agonist CPG7909. Clearly, enhancing the immunogenicity of a recombinant protein vaccine candidate by the formation of protein complexes must be established on an empirical basis.

  10. Lineage-specific positive selection at the merozoite surface protein 1 (msp1 locus of Plasmodium vivax and related simian malaria parasites

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    Kawai Satoru

    2010-02-01

    Full Text Available Abstract Background The 200 kDa merozoite surface protein 1 (MSP-1 of malaria parasites, a strong vaccine candidate, plays a key role during erythrocyte invasion and is a target of host protective immune response. Plasmodium vivax, the most widespread human malaria parasite, is closely related to parasites that infect Asian Old World monkeys, and has been considered to have become a parasite of man by host switch from a macaque malaria parasite. Several Asian monkey parasites have a range of natural hosts. The same parasite species shows different disease manifestations among host species. This suggests that host immune responses to P. vivax-related malaria parasites greatly differ among host species (albeit other factors. It is thus tempting to invoke that a major immune target parasite protein such as MSP-1 underwent unique evolution, depending on parasite species that exhibit difference in host range and host specificity. Results We performed comparative phylogenetic and population genetic analyses of the gene encoding MSP-1 (msp1 from P. vivax and nine P. vivax-related simian malaria parasites. The inferred phylogenetic tree of msp1 significantly differed from that of the mitochondrial genome, with a striking displacement of P. vivax from a position close to P. cynomolgi in the mitochondrial genome tree to an outlier of Asian monkey parasites. Importantly, positive selection was inferred for two ancestral branches, one leading to P. inui and P. hylobati and the other leading to P. vivax, P. fieldi and P. cynomolgi. This ancestral positive selection was estimated to have occurred three to six million years ago, coinciding with the period of radiation of Asian macaques. Comparisons of msp1 polymorphisms between P. vivax, P. inui and P. cynomolgi revealed that while some positively selected amino acid sites or regions are shared by these parasites, amino acid changes greatly differ, suggesting that diversifying selection is acting species

  11. Genetic diversity in merozoite surface protein-1 and 2 among Plasmodium falciparum isolates from malarious districts of tribal dominant state of Jharkhand, India

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    Hussain, M M; Sohail, M; Kumar, R; Branch, O H; Adak, T; Raziuddin, M

    2011-01-01

    Introduction: The genetic make-up of malaria parasite is potent for understanding the parasite virulence, designing antimalarial vaccine and evaluating the impact of malaria control measures. There is a paucity of information on genetic structure of Plasmodium falciparum in Jharkhand, India where malaria is rampant and this study aimed to establish molecular characterization of P. falciparum field isolates from Jharkhand measured with two highly polymorphic genetic markers, i.e. the merozoite surface proteins (MSPs) 1 and 2. Methods: The genetic diversity of P. falciparum population from low transmission area, Ranchi, Bokaro and Hazaribagh and highly malarious area, Latehar and Palamau districts of Jharkhand were evaluated by polymerase chain reaction-sequencing analyzing msp-1 and msp-2 genes to explore the genetic structure of parasite from this understudied region. Results: A total of 134 P. falciparum isolates were analyzed by polymorphic regions of msp-1 and msp-2 and classified according to prevalence of allelic families. The majority of patients from all the five sites had mean monoclonal infections of 67.1 and 60.4% of P. falciparum for msp-1 and msp-2, respectively, whereas, mean multiple genotypes of 32.8 and 39.5% for msp-1 and msp-2, respectively. Interestingly, we observed higher multiclonal infection in low transmission area as compared to highly malarious area in the case of msp-1 genotypes, whereas in msp-2 higher multiclonal infection was observed in highly malarious area compared to low transmission area. The overall multiplicities of infection of msp-1 and msp-2 were 1.38 and 1.39, respectively. Conclusion: This is the first report on molecular characterization of P. falciparum field isolates from Jharkhand. The genetic diversity and allelic distribution found in this study is somewhat similar to other reports from India and Southeast Asian countries. However, P. falciparum infection can be highly complex and diverse in these disease

  12. Long-term clinical protection from falciparum malaria is strongly associated with IgG3 antibodies to merozoite surface protein 3.

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    Roussilhon, Christian; Oeuvray, Claude; Müller-Graf, Christine; Tall, Adama; Rogier, Christophe; Trape, Jean-François; Theisen, Michael; Balde, Aissatou; Pérignon, Jean-Louis; Druilhe, Pierre

    2007-11-13

    Surrogate markers of protective immunity to malaria in humans are needed to rationalize malaria vaccine discovery and development. In an effort to identify such markers, and thereby provide a clue to the complex equation malaria vaccine development is facing, we investigated the relationship between protection acquired through exposure in the field with naturally occurring immune responses (i.e., induced by the parasite) to molecules that are considered as valuable vaccine candidates. We analyzed, under comparative conditions, the antibody responses of each of six isotypes to five leading malaria vaccine candidates in relation to protection acquired by exposure to natural challenges in 217 of the 247 inhabitants of the African village of Dielmo, Senegal (96 children and 121 older adolescents and adults). The status of susceptibility or resistance to malaria was determined by active case detection performed daily by medical doctors over 6 y from a unique follow-up study of this village. Of the 30 immune responses measured, only one, antibodies of the IgG3 isotype directed to merozoite surface protein 3 (MSP3), was strongly associated with clinical protection against malaria in all age groups, i.e., independently of age. This immunological parameter had a higher statistical significance than the sickle cell trait, the strongest factor of protection known against Plasmodium falciparum. A single determination of antibody was significantly associated with the clinical outcome over six consecutive years in children submitted to massive natural parasite challenges by mosquitoes (over three parasite inoculations per week). Finally, the target epitopes of these antibodies were found to be fully conserved. Since anti-MSP3 IgG3 antibodies can naturally develop along with protection against P. falciparum infection in young children, our results provide the encouraging indication that these antibodies should be possible to elicit by vaccination early in life. Since these

  13. Long-term clinical protection from falciparum malaria is strongly associated with IgG3 antibodies to merozoite surface protein 3.

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    Christian Roussilhon

    2007-11-01

    Full Text Available BACKGROUND: Surrogate markers of protective immunity to malaria in humans are needed to rationalize malaria vaccine discovery and development. In an effort to identify such markers, and thereby provide a clue to the complex equation malaria vaccine development is facing, we investigated the relationship between protection acquired through exposure in the field with naturally occurring immune responses (i.e., induced by the parasite to molecules that are considered as valuable vaccine candidates. METHODS AND FINDINGS: We analyzed, under comparative conditions, the antibody responses of each of six isotypes to five leading malaria vaccine candidates in relation to protection acquired by exposure to natural challenges in 217 of the 247 inhabitants of the African village of Dielmo, Senegal (96 children and 121 older adolescents and adults. The status of susceptibility or resistance to malaria was determined by active case detection performed daily by medical doctors over 6 y from a unique follow-up study of this village. Of the 30 immune responses measured, only one, antibodies of the IgG3 isotype directed to merozoite surface protein 3 (MSP3, was strongly associated with clinical protection against malaria in all age groups, i.e., independently of age. This immunological parameter had a higher statistical significance than the sickle cell trait, the strongest factor of protection known against Plasmodium falciparum. A single determination of antibody was significantly associated with the clinical outcome over six consecutive years in children submitted to massive natural parasite challenges by mosquitoes (over three parasite inoculations per week. Finally, the target epitopes of these antibodies were found to be fully conserved. CONCLUSIONS: Since anti-MSP3 IgG3 antibodies can naturally develop along with protection against P. falciparum infection in young children, our results provide the encouraging indication that these antibodies should be

  14. Enolasa específica de neurona en dos recién nacidos con depresión ligera al nacer Neuron- specific Enolase in two newborns presenting with moderate depression at birth

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    Raisa Bu-Coifiu Fanego

    2009-03-01

    Full Text Available INTRODUCCIÓN. La enolasa específica de neurona es una isoenzima que se vierte al torrente sanguíneo después de un episodio de daño neuronal. En los procesos de hipoxia neonatal estos valores enzimáticos en suero suelen estar alterados. El objetivo del presente artículo fue estudiar la enolasa específica de neurona en suero de 2 recién nacidos con Apgar bajo y determinar si, en el seguimiento durante un año, dichos pacientes presentaban trastornos del desarrollo psicomotor. MÉTODOS. Se tomaron muestras de suero al momento del nacimiento y a las 72 h siguientes. Se determinaron los niveles de enolasa específica de neurona por un método inmunoenzimático de tipo ELISA. Cada muestra fue evaluada por el método de reacción en cadena de la polimerasa para citomegalovirus, en el Instituto de Inmunología de Wuersburg (Alemania. También se cuantificaron anticuerpos contra citomegalovirus de clase IgM e IgG, en el Laboratorio de Neuroquímica de la Universidad Georg August de Goettingen (Alemania. Se recogieron los datos clínicos de interés de cada recién nacido y al año se citaron a estos pacientes y se les realizó un examen físico para evaluar su neurodesarrollo. RESULTADOS. Las cifras de enolasa estuvieron incrementadas tanto al nacimiento como a las 72 h, con anticuerpos anticitomegalovirus de clase IgG que fueron transferidos de la madre a través de la placenta. No se encontró presencia de este virus en el momento del nacimiento. En el examen físico y neurológico realizado al año se constató que los niños evolucionaban satisfactoriamente hasta esa fecha. CONCLUSIONES. Se recomienda extender el estudio hasta los 3 años de vida y aumentar el número de pacientes estudiados, con énfasis en aquellos casos cuyo Apgar es menor de 5 a los 5 min del nacimiento.INTRODUCTION: Neuron-specific Enolase of is an isoenzyme present in blood stream after a neuronal damage episode. In processes of neonatal hypoxia, these enzymatic values

  15. On the morphological diagnostics and host specificity of the Sarcocystis species of some domesticated and wild bovini (cattle, banteng and bison).

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    Odening, K; Wesemeier, H H; Walter, G; Bockhardt, I

    1995-08-01

    Sarcocysts of Sarcocystis cruzi, S. hominis and S. hirsuta were described and compared by means of light (LM) and transmission electron microscopy (TEM) from cattle, bantengs (born in a zoo) and bisons (born in zoo). No morphological differences were observed in the three forms of sarcocysts from each of the three host species. The morphological criteria of the three species were discussed and, partly, newly defined. S. cruzi can easily be distinguished from the other two species. It shows 6-13 micron long hair-like villar protrusions in the freshly extracted sarcocyst, has large compartments often bump-like bulged out (by LM, in the fresh state), and a "thin cyst wall" ( < 1 micron; LM, histology). TEM investigation is not necessary in most cases. S. hominis and S. hirsuta: with a "thick, radially striated" and 2.5-9.0 micron high cyst wall (LM). S. hominis can be most reliably determined by means of TEM: the villar protrusions arise with a broad basis from the cyst surface, are finger-like in the outline and have microfilaments in the core. LM: the villar protrusions are broadly seated on the cyst surface, without optical interruption. Likewise, S. hirsuta can be determined most reliably by TEM (in some cases also in semithin sections): the villar protrusions are club- or bulb-shaped in the outline, with a stalklet at the base and with microfilaments and large osmiophilic granules in the interior. LM (best in the fresh state): the palisade of villar protrusions often shows a bright or dotted horizontal line in the middle and a basal line with dark dots, arranged like a string of pearls.

  16. A Reduced Risk of Infection with Plasmodium vivax and Clinical Protection against Malaria Are Associated with Antibodies against the N Terminus but Not the C Terminus of Merozoite Surface Protein 1†

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    Nogueira, Paulo Afonso; Piovesan Alves, Fabiana; Fernandez-Becerra, Carmen; Pein, Oliver; Rodrigues Santos, Neida; Pereira da Silva, Luiz Hildebrando; Plessman Camargo, Erney; del Portillo, Hernando A.

    2006-01-01

    Progress towards the development of a malaria vaccine against Plasmodium vivax, the most widely distributed human malaria parasite, will require a better understanding of the immune responses that confer clinical protection to patients in regions where malaria is endemic. The occurrence of clinical protection in P. vivax malaria in Brazil was first reported among residents of the riverine community of Portuchuelo, in Rondônia, western Amazon. We thus analyzed immune sera from this same human population to determine if naturally acquired humoral immune responses against the merozoite surface protein 1 of P. vivax, PvMSP1, could be associated with reduced risk of infection and/or clinical protection. Our results demonstrated that this association could be established with anti-PvMSP1 antibodies predominantly of the immunoglobulin G3 subclass directed against the N terminus but not against the C terminus, in spite of the latter being more immunogenic and capable of natural boosting. This is the first report of a prospective study of P. vivax malaria demonstrating an association of reduced risk of infection and clinical protection with antibodies against an antigen of this parasite. PMID:16622209

  17. Expressão heteróloga da EMA-2 (equi merozoite antigen de Theileria equi em Pichia pastoris com potencial utilização em imunobiológicos

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    Ana Muñoz Vianna

    2014-10-01

    Full Text Available A piroplasmose equina causada por Theileria equi acomete os equinos de forma endêmica no Brasil e em diversos outros países tropicais e subtropicais. Considerada uma das mais importantes doenças de equinos, causa danos à saúde animal e perdas econômicas. A proteína equi merozoite antigen (EMA-2 é uma das principais proteínas de superfície, expressa nos diversos estágios do ciclo do parasita, estimula resposta imune em animais infectados, tornando-se um possível candidato para utilização em diagnóstico. O gene EMA-2 foi clonado e expresso na levedura Pichia pastoris. A proteína EMA-2 recombinante (rEMA-2 foi caracterizada antigenicamente por Western Blot e por ELISA indireto, utilizando-se soro de equino positivo para theileriose. O resultado do ELISA demonstrou uma especificidade de 90,9% e sensibilidade de 83,3%, quando comparado ao padrão, sendo superior à imunofluorescência (80,6% de especificidade e 75,0% de sensibilidade, o que sugere que a rEMA-2 expressa em P. pastoris é um promissor antígeno para ser utilizado como ferramenta no imunodiagnóstico de theileriose equina

  18. Genetic Diversity of Polymorphic Vaccine Candidate Antigens (Apical Membrane Antigen-1, Merozoite Surface Protein-3, and Erythrocyte Binding Antigen-175) in Plasmodium falciparum Isolates from Western and Central Africa

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    Soulama, Issiaka; Bigoga, Jude D.; Ndiaye, Magatte; Bougouma, Edith C.; Quagraine, Josephine; Casimiro, Prisca N.; Stedman, Timothy T.; Sirima, Sodiomon B.

    2011-01-01

    The malaria vaccine candidate antigens erythrocyte binding antigen 175 (EBA-175), merozoite surface protein 3 (MSP-3), and apical membrane antigen (AMA-1) from Plasmodium falciparum isolates from countries in central and west Africa were assessed for allelic diversity. Samples were collected on filter paper from 600 P. falciparum-infected symptomatic patients in Cameroon, Republic of Congo, Burkina Faso, Ghana, and Senegal and screened for class-specific amplification fragments. Genetic diversity, assessed by mean heterozygosity, was comparable among countries. We detected a clinical increase in eba 175 F-allele frequency from west to east across the study region. No statistical difference in msp-3 allele distribution between countries was observed. The ama-1 3D7 alleles were present at a lower frequency in central Africa than in West Africa. We also detected little to no genetic differentiation among sampling locations. This finding indicates that, at least at the level of resolution offered by restriction fragment length polymorphism analysis, these antigens showed remarkable genetic homogeneity throughout the region sampled, perhaps caused by balancing selection to maintain a diverse array of antigen haplotyes. PMID:21292899

  19. Non increased neuron-specific enolase concentration in cerebrospinal fluid during first febrile seizures and a year follow-up in pediatric patients No incrementos en la concentración de enolasa específica de neurona en el líquido cefalorraquídeo durante el primer ataque febril y al año en pacientes pediátricos

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    ALBERTO J. DORTA-CONTRERAS

    1998-09-01

    Full Text Available Febrile seizures are the commonest acute neurological disorder of early childhood. Studies suggested that febrile seizures are previous acute events from a more serious neurological problem. Due to neuron-specific enolase is generally accepted as a marker for neuropathological processes in the brain, 16 pediatric patients were studied during their first seizures and a year after it. Neuron-specific enolase in cerebrospinal fluid and blood were analysed by an immune enzyme assay. Non pathological neuron-specific enolase values were obtained in both periods in the group of patients. There were no significative differences when paired series statistics test was performed with 95% of confidence. Neuron-specific enolase appears not to be a marker for febrile seizures because its concentration not be increased in cerebrospinal fluid in this group of patients.Los ataques febriles constituyen el trastorno neurológico agudo más común en la infancia temprana. Existen estudios que sugieren que los ataques febriles son eventos agudos previos a problemas neurológicos más severos. Debido a que la enolasa específica de neurona está aceptada generalmente como marcador de procesos neuropatológicos en el cerebro, se estudiaran 16 pacientes pediátricos durante su primer ataque y al año de este. La enolasa específica de neurona en el líquido cefalorraquídeo y sangre fue analizada por una prueba inmunoenzimática. No se obtuvieron valores patológicos de enolasa específica de neurona en ambos períodos en el grupo de pacientes. No hubo diferencias significativas al aplicar el test de series apareadas con un 95% de confianza. La enolasa específica de neurona parece no ser un marcador para ataques febriles porque su concentración no se incrementa en este grupo de pacientes.

  20. Human IgG subclass antibodies to the 19 kilodalton carboxy terminal fragment of Plasmodium falciparum merozoite surface protein 1 (MSP1(19)) and predominance of the MAD20 allelic type of MSP1 in Uganda.

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    Apio, B; Nalunkuma, A; Okello, D; Riley, E; Egwang, T G

    2000-04-01

    To determine the natural human humoral immune responses to the 19 kilodalton carboxy terminal fragment of Plasmodium falciparum merozoite surface protein 1 (MSP1(19)), a malaria candidate vaccine antigen and to determine the prevalence of MAD20 and K1 alleles of P. falciparum MSP1. Community based cross-sectional study. Atopi Parish, Apac District, Uganda, 1995. Three hundred and seventy four Ugandans between <1 and 70 years old provided serum samples. IgG subclass antibodies by ELISA; MAD20 and K1 allelic types of MSP1 by PCR. Both the prevalence and the mean concentration of serum IgG1, and to a lesser extent IgG3, antibodies increased with age. IgG2 or IgG4 antibodies were virtually nonexistent. The cross-reactivity between the 4 sequence variants (E-KNG, E-TSR, Q-KNG and Q-TSR) of MSP1(19) was confirmed; however, a minority of sera preferentially recognised the KNG but not the TSR variants. All 33 P. falciparum isolates from different parts of Uganda carried the E-TSR (Mad20) allelic type and 3 isolates were mixed infections with E-TSR (MAD20) and Q-KNG (K1) allelic types, confirming the rarity of the K1 allele in Uganda. There is a robust IgG1 antibody response to the malaria vaccine candidate antigen MSP1(19) which begins at an early age. Future cohort studies are necessary to estblish the impact of these antibodies on clinical immunity to malaria. The MAD20 allelic type of MSP1 id predominant in Ugandan P. falciparum isolates.

  1. Variation in the immune responses against Plasmodium falciparum merozoite surface protein-1 and apical membrane antigen-1 in children residing in the different epidemiological strata of malaria in Cameroon.

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    Kwenti, Tebit Emmanuel; Moye, Adzemye Linus; Wiylanyuy, Adzemye Basil; Njunda, Longdoh Anna; Nkuo-Akenji, Theresa

    2017-11-09

    Studies to assess the immune responses against malaria in Cameroonian children are limited. The purpose of this study was to assess the immune responses against Plasmodium falciparum merozoite surface protein-1 (MSP-119) and apical membrane antigen-1 (AMA-1) in children residing in the different epidemiological strata of malaria in Cameroon. In a cross-sectional survey performed between April and July 2015, 602 children between 2 and 15 years (mean ± SD = 5.7 ± 3.7), comprising 319 (53%) males were enrolled from five epidemiological strata of malaria in Cameroon including: the sudano-sahelian (SS) strata, the high inland plateau (HIP) strata, the south Cameroonian equatorial forest (SCEF) strata, the high western plateau (HWP) strata, and the coastal (C) strata. The children were screened for clinical malaria (defined by malaria parasitaemia ≥ 5000 parasites/µl plus axillary temperature ≥ 37.5 °C). Their antibody responses were measured against P. falciparum MSP-119 and AMA-1 vaccine candidate antigens using standard ELISA technique. A majority of the participants were IgG responders 72.1% (95% CI 68.3-75.6). The proportion of responders was higher in females (p = 0.002) and in children aged 10 years and above (p = 0.005). The proportion of responders was highest in Limbe (C strata) and lowest in Ngaoundere (HIP strata) (p strata: the highest levels observed in the C strata and the lowest in the HIP strata. Furthermore, malaria transmission in Cameroon could be categorized into two major groups based on the serological reaction of the children: the southern (comprising C and SCEF strata) and northern (comprising HWP, HIP and SS strata) groups. These findings may have significant implications in the design of future trials for evaluating malaria vaccine candidates in Cameroon.

  2. Poly(I:C) adjuvant strongly enhances parasite-inhibitory antibodies and Th1 response against Plasmodium falciparum merozoite surface protein-1 (42-kDa fragment) in BALB/c mice.

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    Mehrizi, Akram Abouie; Rezvani, Niloufar; Zakeri, Sedigheh; Gholami, Atefeh; Babaeekhou, Laleh

    Malaria vaccine development has been confronted with various challenges such as poor immunogenicity of malaria vaccine candidate antigens, which is considered as the main challenge. However, this problem can be managed using appropriate formulations of antigens and adjuvants. Poly(I:C) is a potent Th1 inducer and a human compatible adjuvant capable of stimulating both B- and T-cell immunity. Plasmodium falciparum merozoite surface protein 142 (PfMSP-142) is a promising vaccine candidate for blood stage of malaria that has faced several difficulties in clinical trials, mainly due to improper adjuvants. Therefore, in the current study, poly(I:C), as a potent Th1 inducer adjuvant, was evaluated to improve the immunogenicity of recombinant PfMSP-142, when compared to CFA/IFA, as reference adjuvant. Poly(I:C) produced high level and titers of anti-PfMSP-142 IgG antibodies in which was comparable to CFA/IFA adjuvant. In addition, PfMSP-142 formulated with poly(I:C) elicited a higher ratio of IFN-γ/IL-4 (23.9) and IgG2a/IgG1 (3.77) with more persistent, higher avidity, and titer of IgG2a relative to CFA/IFA, indicating a potent Th1 immune response. Poly(I:C) could also help to induce anti-PfMSP-142 antibodies with higher growth-inhibitory activity than CFA/IFA. Altogether, the results of the current study demonstrated that poly(I:C) is a potent adjuvant that can be appropriate for being used in PfMSP-142-based vaccine formulations.

  3. Results from tandem Phase 1 studies evaluating the safety, reactogenicity and immunogenicity of the vaccine candidate antigen Plasmodium falciparum FVO merozoite surface protein-1 (MSP142 administered intramuscularly with adjuvant system AS01

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    Otsyula Nekoye

    2013-01-01

    Full Text Available Abstract Background The development of an asexual blood stage vaccine against Plasmodium falciparum malaria based on the major merozoite surface protein-1 (MSP1 antigen is founded on the protective efficacy observed in preclinical studies and induction of invasion and growth inhibitory antibody responses. The 42 kDa C-terminus of MSP1 has been developed as the recombinant protein vaccine antigen, and the 3D7 allotype, formulated with the Adjuvant System AS02A, has been evaluated extensively in human clinical trials. In preclinical rabbit studies, the FVO allele of MSP142 has been shown to have improved immunogenicity over the 3D7 allele, in terms of antibody titres as well as growth inhibitory activity of antibodies against both the heterologous 3D7 and homologous FVO parasites. Methods Two Phase 1 clinical studies were conducted to examine the safety, reactogenicity and immunogenicity of the FVO allele of MSP142 in the adjuvant system AS01 administered intramuscularly at 0-, 1-, and 2-months: one in the USA and, after evaluation of safety data results, one in Western Kenya. The US study was an open-label, dose escalation study of 10 and 50 μg doses of MSP142 in 26 adults, while the Kenya study, evaluating 30 volunteers, was a double-blind, randomized study of only the 50 μg dose with a rabies vaccine comparator. Results In these studies it was demonstrated that this vaccine formulation has an acceptable safety profile and is immunogenic in malaria-naïve and malaria-experienced populations. High titres of anti-MSP1 antibodies were induced in both study populations, although there was a limited number of volunteers whose serum demonstrated significant inhibition of blood-stage parasites as measured by growth inhibition assay. In the US volunteers, the antibodies generated exhibited better cross-reactivity to heterologous MSP1 alleles than a MSP1-based vaccine (3D7 allele previously tested at both study sites. Conclusions Given that the primary

  4. Identification and characterization of the merozoite surface protein 1 (msp1) gene in a host-generalist avian malaria parasite, Plasmodium relictum (lineages SGS1 and GRW4) with the use of blood transcriptome.

    Science.gov (United States)

    Hellgren, Olof; Kutzer, Megan; Bensch, Staffan; Valkiūnas, Gediminas; Palinauskas, Vaidas

    2013-10-30

    The merozoite surface protein 1 (msp1) is one of the most studied vaccine candidate genes in mammalian Plasmodium spp. to have been used for investigations of epidemiology, population structures, and immunity to infections. However methodological difficulties have impeded the use of nuclear markers such as msp1 in Plasmodium parasites causing avian malaria. Data from an infection transcriptome of the host generalist avian malaria parasite Plasmodium relictum was used to identify and characterize the msp1 gene from two different isolates (mtDNA lineages SGS1 and GRW4). The aim was to investigate whether the msp1 gene in avian malaria species shares the properties of the msp1 gene in Plasmodium falciparum in terms of block variability, conserved anchor points and repeat motifs, and further to investigate the degree to which the gene might be informative in avian malaria parasites for population and epidemiological studies. Reads from 454 sequencing of birds infected with avian malaria was used to develop Sanger sequencing protocols for the msp1 gene of P. relictum. Genetic variability between variable and conserved blocks of the gene was compared within and between avian malaria parasite species, including P. falciparum. Genetic variability of the msp1 gene in P. relictum was compared with six other nuclear genes and the mtDNA gene cytochrome b. The msp1 gene of P. relictum shares the same general pattern of variable and conserved blocks as found in P. falciparum, although the variable blocks exhibited less variability than P. falciparum. The variation across the gene blocks in P. falciparum spanned from being as conserved as within species variation in P. relictum to being as variable as between the two avian malaria species (P. relictum and Plasmodium gallinaceum) in the variable blocks. In P. relictum the highly conserved p19 region of the peptide was identified, which included two epidermal growth factor-like domains and a fully conserved GPI anchor point. This

  5. Neuronas espejo, intersubjetividad y desarrollo temprano

    OpenAIRE

    Martínez, Mauricio Sebastián

    2009-01-01

    Clásicamente la capacidad que poseemos las personas, y algunos primates, para atribuir estados mentales (intenciones, deseos, creencias, etc.) se ha intentado explicar desde dos perspectivas. La primera de ellas, usualmente denominada inferencialista, asume que esta capacidad se basa en la capacidad de nuestro sistema cognitivo para realizar inferencias sobre los estados mentales propios y de las demás personas. La segunda, a la conocida como simulacionista, sostiene que nuestra capacidad par...

  6. Increased presence of T lymphocytes in central nervous system of EPM affected horses.

    Science.gov (United States)

    Scott, Patricia; Witonsky, Sharon; Robertson, John; Daft, Barbara

    2005-12-01

    Equine protozoal myeloencephalitis (EPM), caused by Sarcocystis neurona infection in the central nervous system (CNS), affects up to 1% of all horses during their lifetimes. Neither the protective immune response nor the immunopathology associated with the disease is well understood. To begin to clarify the pathogenesis of the disease, immunohistochemical staining for B and T lymphocytes was performed on spinal cord sections obtained from 17 horses, all of which were all positive for S. neurona based on immunohistochemical staining. Fifteen of the 17 horses included in the study were killed due to neurologic dysfunction; 2 of the 17 horses were killed because of fractures. All 17 horses had histologic changes consistent with S. neurona infection. A significantly greater number of T cells were seen in sections from S. neurona-infected versus control horses. Because this was a small descriptive study, we were not able to determine the mechanisms of enhanced T-cell recruitment in the sections from the S. neurona-infected horses.

  7. Inmunomarcación de neuronas dopaminérgicas en cortes flotantes de hipotálamo de rata: preservación alternativa del tejido nervioso antes del corte Immunohistochemical Studies Of Dopaminergic Neurons On Free Floating Sections: Alternative Cryopreservation Method Of Nervous Tissue Before Cutting

    Directory of Open Access Journals (Sweden)

    Valeria Cholich

    2008-07-01

    Full Text Available Se realizó un estudio inmunohistoquímico de la enzima tirosina hidroxilasa (marcador de neuronas dopaminérgicas en el hipotálamo de ratas Wistar machos adultas en cortes flotantes de muestras fijadas por perfusión. Debido a que el número de cerebros que se procesaron fue superior al número que pueden ser cortados inmediatamente, el material debió almacenarse congelando los cerebros enteros a -80ºC. Pero por un desperfecto técnico del equipo de refrigeración, las muestras debieron trasladarse a -20ºC resultando en el deterioro de las mismas. Ante este inconveniente, los sucesivos cerebros fueron almacenados en sacarosa al 30% p/v en buffer fosfato salino (PBS con 0,01% de azida sódica y mantenidos a 4ºC durante tiempos variables (de semanas a meses hasta ser congelados con gas clorofluorado y cortados. Estos cerebros no mostraron alteración en la estructura morfológica del tejido. Esta metodología de preservación aquí descrita sería una alternativa de elección válida para aquellos laboratorios que no cuenten con un equipo de refrigeración de -80ºC.In central nervous system histological studies, free-floating sections of perfusion-fixed samples are frequently used. Samples storage may be performed freezing either the entire brain at -80ºC or sections at -20ºC. When studying hypothalamic tyrosine hydroxylase enzyme (dopaminergic neurons marker by immunohistochemistry in adult male Wistar rats, entire brains were stored at -80ºC. Due to an abrupt freezer technical failure, samples should be thawed to -20ºC with the resulting samples damage. To avoid this situation, subsequent brains were stored in 30% sucrose in saline phosphate buffer (PBS with 0.01% sodium azide and kept at 4ºC for different periods (weeks to months until they were frozen with chlorofluorade gas and cut. These brains showed no morphological alterations of tissue structure. This preservation method appeared to be an alternative valid option to

  8. Temporal association between land-based runoff events and California sea otter (Enhydra lutris nereis) protozoal mortalities.

    Science.gov (United States)

    Shapiro, Karen; Miller, Melissa; Mazet, Jonna

    2012-04-01

    Toxoplasma gondii and Sarcocystis neurona have caused significant morbidity and mortality in threatened Southern sea otters (Enhydra lutris nereis) along the central California coast. Because only terrestrial animals are known to serve as definitive hosts for T. gondii and S. neurona, infections in otters suggest a land to sea flow of these protozoan pathogens. To better characterize the role of overland runoff in delivery of terrestrially derived fecal pathogens to the near shore, we assessed the temporal association between indicators of runoff and the timing of sea otter deaths due to T. gondii and S. neurona. Sea otter stranding records 1998-2004, from Monterey and Estero bays were reviewed and cases identified for which T. gondii or S. neurona were determined to be a primary or contributing cause of death. Precipitation and stream flow data from both study sites were used as indicators of land-based runoff. Logistic regression was applied to determine if a temporal association could be detected between protozoal mortalities and runoff indicators that occur in the 2 mo preceding mortality events. A significant association was found between S. neurona otter deaths at Estero Bay and increased stream flow that occurred 30-60 days prior to mortality events. At this site, the cause of otter mortality following increased river flows was 12 times more likely to be S. neurona infection compared with nonprotozoal causes of death. There were no significant associations between the timing of T. gondii otter deaths and indicators of overland runoff. Our results indicate that the association between overland runoff and otter mortalities is affected by geography as well as parasite type, and highlight the complex mechanisms that influence transmission of terrestrially derived pathogens to marine wildlife. Policy and management practices that aim to mitigate discharges of contaminated overland runoff can aid conservation efforts by reducing pathogen pollution of coastal

  9. Antibodies against Merozoite Surface Protein 1 and 2 in Sudanese ...

    African Journals Online (AJOL)

    Background: Malaria is a serious childhood disease causing high morbidity and mortality despite control measures. Immunological control against malaria was initiated early, and immunity acquired by children in endemic areas, which is age and exposure dependant, differs in different endemic settings. The objective of the ...

  10. Molecular phylogeny of Toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences

    Directory of Open Access Journals (Sweden)

    Michelle Klein Sercundes

    2016-03-01

    Full Text Available Abstract Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC and beta subunit of RNA polymerase (rpoB, and mitochondrial gene coding for cytochrome B (cytB were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula and Sarcocystis neurona were investigated, along with Neospora caninum, Neospora hughesi, Toxoplasma gondii (strains RH, CTG and PTG, Besnoitia akodoni, Hammondia hammondiand two genetically divergent lineages of Hammondia heydorni. The molecular analysis based on organellar genes did not clearly differentiate between N. caninum and N. hughesi, but the two lineages of H. heydorni were confirmed. Slight differences between the strains of S. falcatula and S. neurona were encountered in all markers. In conclusion, congruent phylogenies were inferred from the three different genes and they might be used for screening undescribed sarcocystid parasites in order to ascertain their phylogenetic relationships with organisms of the family Sarcocystidae. The evolutionary studies based on organelar genes confirm that the genusHammondia is paraphyletic. The primers used for amplification of clpC and rpoB were able to amplify genetic sequences of organisms of the genus Sarcocystisand organisms of the subfamily Toxoplasmatinae as well.

  11. Sensitivity and specificity of western blot testing of cerebrospinal fluid and serum for diagnosis of equine protozoal myeloencephalitis in horses with and without neurologic abnormalities.

    Science.gov (United States)

    Daft, Barbara M; Barr, Bradd C; Gardner, Ian A; Read, Deryck; Bell, William; Peyser, Karen G; Ardans, Alex; Kinde, Hailu; Morrow, Jennifer K

    2002-10-01

    To determine sensitivity and specificity of western blot testing (WBT) of CSF and serum for diagnosis of equine protozoal myeloencephalitis (EPM) in horses with and without neurologic abnormalities. Prospective investigation. 65 horses with and 169 horses without neurologic abnormalities. CSF and serum from horses submitted for necropsy were tested for Sarcocystis neurona-specific antibody with a WBT. Results of postmortem examination were used as the gold standard against which results of the WBT were compared. Sensitivity of WBT of CSF was 87% for horses with and 88% for horses without neurologic abnormalities. Specificity of WBT of CSF was 44% for horses with and 60% for horses without neurologic abnormalities. Regardless of whether horses did or did not have neurologic abnormalities, sensitivity and specificity of WBT of serum were not significantly different from values for WBT of CSF. Ninety-four horses without EPM had histologic evidence of slight CNS inflammation. The low specificity of WBT of CSF indicated that it is inappropriate to diagnose EPM on the basis of a positive test result alone because of the possibility of false-positive test results. The high sensitivity, however, means that a negative result is useful in ruling out EPM. There was no advantage in testing CSF versus serum in horses without neurologic abnormalities. Slight CNS inflammation was common in horses with and without S neurona-specific antibodies in the CSF and should not be considered an indication of CNS infection with S neurona.

  12. First report of cerebellar abiotrophy in an Arabian foal from Argentina

    Science.gov (United States)

    Sadaba, S.A.; Madariaga, G.J.; Botto, C.M. Corbi; Carino, M.H.; Zappa, M.E.; García, P. Peral; Olguín, S.A.; Massone, A.; Díaz, S.

    2016-01-01

    Evidence of cerebellar abiotrophy (CA) was found in a six-month-old Arabian filly with signs of incoordination, head tremor, wobbling, loss of balance and falling over, consistent with a cerebellar lesion. Normal hematology profile blood test and cerebrospinal fluid analysis excluded infectious encephalitis, and serological testing for Sarcocystis neurona was negative. The filly was euthanized. Postmortem X-ray radiography of the cervical cephalic region identified not abnormalities, discounting spinal trauma. The histopathological analysis of serial transverse cerebellar sections by electron microscopy revealed morphological characteristics of apoptotic cells with pyknotic nuclei and degenerate mitochondria, cytoplasmic condensation and areas with absence of Purkinje cells, matching with CA histopathological characteristics. The indirect DNA test for CA was positive in the filly, and DNA test confirmed the CA carrier state in the parents and the recessive inheritance of the disease. To our knowledge this is the first report of a CA case in Argentina. PMID:28116251

  13. First report of cerebellar abiotrophy in an Arabian foal from Argentina

    Directory of Open Access Journals (Sweden)

    S.A. Sadaba

    2016-12-01

    Full Text Available Evidence of cerebellar abiotrophy (CA was found in a six-month-old Arabian filly with signs of incoordination, head tremor, wobbling, loss of balance and falling over, consistent with a cerebellar lesion. Normal hematology profile blood test and cerebrospinal fluid analysis excluded infectious encephalitis, and serological testing for Sarcocystis neurona was negative. The filly was euthanized. Postmortem X-ray radiography of the cervical cephalic region identified not abnormalities, discounting spinal trauma. The histopathological analysis of serial transverse cerebellar sections by electron microscopy revealed morphological characteristics of apoptotic cells with pyknotic nuclei and degenerate mitochondria, cytoplasmic condensation and areas with absence of Purkinje cells, matching with CA histopathological characteristics. The indirect DNA test for CA was positive in the filly, and DNA test confirmed the CA carrier state in the parents and the recessive inheritance of the disease. To our knowledge this is the first report of a CA case in Argentina.

  14. Diagnóstico diferencial de trombose aortoilíaca e mieloencefalite protozoária equina: relato de caso Differential diagnosis between aorto-iliac thrombosis and equine protozoal myeloencephalitis: case report

    Directory of Open Access Journals (Sweden)

    P.B. Escodro

    2010-10-01

    Full Text Available Relata-se o caso de uma égua de atividade de polo, que apresentou inicialmente claudicação leve no membro posterior esquerdo, a qual evoluiu para ataxia e atrofia da musculatura glútea do lado esquerdo, com diagnóstico de trombose aortoilíaca (TAI. A paciente foi tratada com suspeita de mieloencefalite protozoária equina, devido à semelhança dos sinais clínicos com essa doença, porém o líquido cefalorraquidiano apresentou-se negativo para anticorpos anti-Sarcocystis neurona. A palpação transretal indicou uma massa na bifurcação aortoilíaca esquerda. Na avaliação ultrassonográfica, visualizou-se imagem hiperecoica aderida ao endotélio vascular, sugerindo TAI atingindo a estenose de 70% da luz arterial.The case of a mare used for polo is reported. The animal showed clinical signs of soft lameness of the hindlimb, evolving to ataxia and gluteal muscle atrophy, with aorto-iliac thrombosis (AIT. The patient was treated with the suspect of equine protozoal myeloencephalitis (EPM, due to the resemblance of clinical signs. Cerebrospinal fluid analysis was negative for antibodies against Sarcocystis neurona. The transrectal examination indicated a mass in the left aorto-iliac bifurcation. In the ultrasonographic evaluation, a hyperechoic image adhered to the vascular endothelium was observed, suggesting (AIT, occupying 70% of arterial lumen. The present article has the objective of pointing out the importance of the differential diagnosis between AIT and EPM in horses with ataxia in hindlimbs and muscular atrophy.

  15. Regulación de la dinámica mitocondrial en neuronas sometidas a excitotoxicidad

    OpenAIRE

    Martorell Riera, Alejandro

    2014-01-01

    Durante el ictus, los niveles elevados de glutamato extracelular, el principal neurotransmisor excitador en el sistema nervioso central, aumentan y se unen al receptor de NMDA promoviendo la excitotoxicidad. Esta situación genera que un flujo excesivo de Ca2+ pase a través del receptor de NMDA aumentando sus concentraciones intracelulares activando toda una serie de cascadas de señalización que pueden actuar directamente sobre las mitocondrias, promoviendo varios programas de mu...

  16. El sistema de neuronas espejo y su activación en movimientos coordinados complejos

    OpenAIRE

    Bonito Gadella, Juan Carlos

    2012-01-01

    INTRODUCCIÓN Durante la observación de los movimientos realizados por los demás, la información visual se integra con las representaciones motoras, somatosensoriales y los recuerdos cinestésicos correspondientes, así como con las representaciones de los objetivos internos, instrucciones y la preferencia en la realización del movimiento. Los procesos corticales subyacentes han sido evaluados en monos y en humanos a través de la neuroimagen. En conjunto, estos estudios apuntan a una "equival...

  17. Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system

    Science.gov (United States)

    Johnson, Christine K.; Tinker, M. Tim; Estes, James A.; Conrad, Patricia A.; Staedler, Michelle M.; Miller, Melissa A.; Jessup, David A.; Mazet, Jonna A.K.

    2014-01-01

    The processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. By combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (Enhydra lutris nereis) population growth: disease and resource limitation. This threatened population has struggled to recover despite protection, so we followed radio-tagged sea otters and evaluated infection with 2 disease-causing protozoal pathogens, Toxoplasma gondii and Sarcocystis neurona, to reveal risks that increased the likelihood of pathogen exposure. We identified patterns of pathogen infection that are linked to individual animal behavior, prey choice, and habitat use. We detected a high-risk spatial cluster of S. neurona infections in otters with home ranges in southern Monterey Bay and a coastal segment near San Simeon and Cambria where otters had high levels of infection with T. gondii. We found that otters feeding on abalone, which is the preferred prey in a resource-abundant marine ecosystem, had a very low risk of infection with either pathogen, whereas otters consuming small marine snails were more likely to be infected with T. gondii. Individual dietary specialization in sea otters is an adaptive mechanism for coping with limited food resources along central coastal California. High levels of infection with protozoal pathogens may be an adverse consequence of dietary specialization in this threatened species, with both depleted resources and disease working synergistically to limit recovery.

  18. Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system.

    Science.gov (United States)

    Johnson, Christine K; Tinker, Martin T; Estes, James A; Conrad, Patricia A; Staedler, Michelle; Miller, Melissa A; Jessup, David A; Mazet, Jonna A K

    2009-02-17

    The processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. By combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (Enhydra lutris nereis) population growth: disease and resource limitation. This threatened population has struggled to recover despite protection, so we followed radio-tagged sea otters and evaluated infection with 2 disease-causing protozoal pathogens, Toxoplasma gondii and Sarcocystis neurona, to reveal risks that increased the likelihood of pathogen exposure. We identified patterns of pathogen infection that are linked to individual animal behavior, prey choice, and habitat use. We detected a high-risk spatial cluster of S. neurona infections in otters with home ranges in southern Monterey Bay and a coastal segment near San Simeon and Cambria where otters had high levels of infection with T. gondii. We found that otters feeding on abalone, which is the preferred prey in a resource-abundant marine ecosystem, had a very low risk of infection with either pathogen, whereas otters consuming small marine snails were more likely to be infected with T. gondii. Individual dietary specialization in sea otters is an adaptive mechanism for coping with limited food resources along central coastal California. High levels of infection with protozoal pathogens may be an adverse consequence of dietary specialization in this threatened species, with both depleted resources and disease working synergistically to limit recovery.

  19. Detection and characterization of diverse coccidian protozoa shed by California sea lions

    Directory of Open Access Journals (Sweden)

    Yvette A. Girard

    2016-04-01

    Full Text Available Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris. California sea lions (Zalophus californianus, whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina. In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi diagnosed with protozoal disease in Oregon (USA. Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near

  20. Polyparasitism is associated with increased disease severity in Toxoplasma gondii-infected marine sentinel species.

    Directory of Open Access Journals (Sweden)

    Amanda K Gibson

    2011-05-01

    Full Text Available In 1995, one of the largest outbreaks of human toxoplasmosis occurred in the Pacific Northwest region of North America. Genetic typing identified a novel Toxoplasma gondii strain linked to the outbreak, in which a wide spectrum of human disease was observed. For this globally-distributed, water-borne zoonosis, strain type is one variable influencing disease, but the inability of strain type to consistently explain variations in disease severity suggests that parasite genotype alone does not determine the outcome of infection. We investigated polyparasitism (infection with multiple parasite species as a modulator of disease severity by examining the association of concomitant infection of T. gondii and the related parasite Sarcocystis neurona with protozoal disease in wild marine mammals from the Pacific Northwest. These hosts ostensibly serve as sentinels for the detection of terrestrial parasites implicated in water-borne epidemics of humans and wildlife in this endemic region. Marine mammals (151 stranded and 10 healthy individuals sampled over 6 years were assessed for protozoal infection using multi-locus PCR-DNA sequencing directly from host tissues. Genetic analyses uncovered a high prevalence and diversity of protozoa, with 147/161 (91% of our sampled population infected. From 2004 to 2009, the relative frequency of S. neurona infections increased dramatically, surpassing that of T. gondii. The majority of T. gondii infections were by genotypes bearing Type I lineage alleles, though strain genotype was not associated with disease severity. Significantly, polyparasitism with S. neurona and T. gondii was common (42% and was associated with higher mortality and more severe protozoal encephalitis. Our finding of widespread polyparasitism among marine mammals indicates pervasive contamination of waterways by zoonotic agents. Furthermore, the significant association of concomitant infection with mortality and protozoal encephalitis identifies

  1. Cytokine gene signatures in neural tissue of horses with equine protozoal myeloencephalitis or equine herpes type 1 myeloencephalopathy.

    Science.gov (United States)

    Pusterla, N; Wilson, W D; Conrad, P A; Barr, B C; Ferraro, G L; Daft, B M; Leutenegger, C M

    2006-09-09

    This study was designed to determine the relative levels of gene transcription of selected pathogens and cytokines in the brain and spinal cord of 12 horses with equine protozoal myeloencephalitis (EPM), 11 with equine herpesvirus type 1 (EHV-1) myeloencephalopathy, and 12 healthy control horses by applying a real time pcr to the formalin-fixed and paraffin-embedded tissues. Total rna was extracted from each tissue, transcribed to complementary dna (cDNA) and assayed for Sarcocystis neurona, Neospora hughesi, EHV-1, equine GAPDH (housekeeping gene), tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10 AND IL-12 p40. S neurona cdna was detected in the neural tissue from all 12 horses with EPM, and two of them also had amplifiable cDNA of N hughesi. The relative levels of transcription of protozoal cdna ranged from 1 to 461 times baseline (mean 123). All the horses with ehv-1 myeloencephalopathy had positive viral signals by PCR with relative levels of transcription ranging from 1 to 1618 times baseline (mean 275). All the control horses tested negative for S neurona, N hughesi and EHV-1 cdna. The cytokine profiles of each disease indicated a balance between pro- and anti-inflammatory markers. In the horses with epm the pro-inflammatory Th1 cytokines (IL-8, TNF-alpha and IFN-gamma) were commonly expressed but the anti-inflammatory Th2 cytokines (IL-4, IL-6 AND IL-10) were absent or rare. In the horses with ehv-1 the proinflammatory cytokine IL-8 was commonly expressed, but IL-10 and IFN-gamma were not, and TNF-alpha was rare. Tissue from the control horses expressed only the gene GAPDH.

  2. Detection and characterization of diverse coccidian protozoa shed by California sea lions.

    Science.gov (United States)

    Girard, Yvette A; Johnson, Christine K; Fritz, Heather M; Shapiro, Karen; Packham, Andrea E; Melli, Ann C; Carlson-Bremer, Daphne; Gulland, Frances M; Rejmanek, Daniel; Conrad, Patricia A

    2016-04-01

    Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina). In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi) diagnosed with protozoal disease in Oregon (USA). Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near-shore marine

  3. Invasion by P. falciparum Merozoites Suggests a Hierarchy of Molecular Interactions.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available Central to the pathology of malaria disease are the repeated cycles of parasite invasion and destruction of human erythrocytes. In Plasmodium falciparum, the most virulent species causing malaria, erythrocyte invasion involves several specific receptor-ligand interactions that direct the pathway used to invade the host cell, with parasites varying in their dependency on these different pathways. Gene disruption of a key invasion ligand in the 3D7 parasite strain, the P. falciparum reticulocyte binding-like homolog 2b (PfRh2b, resulted in the parasite invading via a novel pathway. Here, we show results that suggest the molecular basis for this novel pathway is not due to a molecular switch but is instead mediated by the redeployment of machinery already present in the parent parasite but masked by the dominant role of PfRh2b. This would suggest that interactions directing invasion are organized hierarchically, where silencing of dominant invasion ligands reveal underlying alternative pathways. This provides wild parasites with the ability to adapt to immune-mediated selection or polymorphism in erythrocyte receptors and has implications for the use of invasion-related molecules in candidate vaccines.

  4. Expression of a type B RIFIN in Plasmodium falciparum merozoites and gametes

    DEFF Research Database (Denmark)

    Mwakalinga, Steven B; Wang, Christian W; Bengtsson, Dominique C

    2012-01-01

    ABSTRACT: BACKGROUND: The ability of Plasmodium falciparum to undergo antigenic variation, by switching expression among protein variants encoded by multigene families, such as var, rif and stevor, is key to the survival of this parasite in the human host. The RIFIN protein family can be divided...

  5. Efectos toxicos del contenido de dos tamanos de quistes de Sarcocystis aucheniae en conejos inoculados experimentalmente

    National Research Council Canada - National Science Library

    Chileno M., Maria; Chavez V., Amanda; Casas A., Eva; Chavera C., Alfonso; Puray C., Nidia

    2011-01-01

    .... Se colectaron macroquistes del cuello de alpacas procedentes del camal de Huancavelica. Las concentraciones de proteinas antigenicas para los macroquistes grandes y pequenos, medidas por el metodo de Biuret, fueron de 3.3...

  6. Daño nuclear en neuronas de cerebros de pacientes con enfermedad de Alzheimer y otras demencias

    Directory of Open Access Journals (Sweden)

    Francisco Lopera

    2000-02-01

    Full Text Available

    Introducción: La enfermedad de Alzheimer (EA es una entidad neurodegenerativa y es la causa más común de demencia. Recientemente se reportó en Antioquia (Colombia un grupo familiar con una mutación puntual en el codon 280 de la Presenilina 1 denominada E280A (sustitución de un ácido glutámico por una alanina, la cual produce un incremento en el acúmulo de b-Amiloide (bA de 42-43 aminoácidos y una patología cerebral severa. Durante los últimos años se ha propuesto que la muerte celular es uno de los factores principales de pérdida neuronal en la EA. Hasta el presente no se ha establecido el tipo de muerte celular implicadas en la pérdida neuronal. Por lo tanto el objetivo de esta investigación es establecer el tipo de muerte celular que ocurre en la EA y otras demencias tales como la Demencia Fronto Temporal (DFT, Huntington y Demencia Cerebro Vascular, con base en los siguientes criterios: 1. Fragmentación del ADN. 2. Cambios morfológicos nucleares. 3. Cambios citoplasmáticos y 4. Expresión de ciertas proteínas asociadas a muerte celular. Los resultados de esta investigación permitirán establecer una correlación entre los parámetros morfológicos e histoquímicos antes mencionados, entre placas de bA y ovillos neurofibrilares en la EA y con ovillos neurofibrilares en la DFT adicionalmente. Este trabajo nos permitirá determinar si existe un mecanismo común de muerte celular en las enfermedades neurodegenerativas con demencia.

    Objetivo General: Contribuir a la caracterización de los procesos de muerte celular en cerebros de pacientes con enfermedades neurodegenerativas

    Objetivos específicos: - Estandarizar un estudio cualitativo in situ para evaluar procesos de muerte celular neuronal en micro-secciones histológicas de las regiones cerebrales frontal, temporal, parietal, hipocampo, occipital y cerebelo de pacientes con la enfermedad de Alzheimer y otras demencias. - Establecer una correlación patológica entre la proporción de núcleos fragmentados y la presencia de placas seniles bA y ovillos neurofibrilares. - Establecer la correlación entre la expresión de las proteínas asociadas a muerte celular como Bax, p53, NF-kB, Par 4 y la fragmentación del ADN.

    Materiales y Métodos

    Preparaciones Histológicas:

    Secciones de tejido de cerebros humanos post-mortem de las regiones seleccionadas provenientes de pacientes con demencia, serán fijadas en formaldehido buferizado y embebidos en bloques de parafina. Secciones de 5mm serán adheridos a láminas precargadas. La deparafinización e hidratación se realizará de acuerdo a procedimientos estandares de histología (Gavrieli et al.,1992.

    Técnica de marcaje Tunel y Thioflavina:

    Las secciones serán marcadas in situ para TUNEL (terminal transferasemediated dUTP-fluorecent nick labeling tecnique de acuerdo al método descrito por Gavrieli et al., 1992 y al protocolo Promega de 1998. Adicionalmente, las láminas serán marcadas con Thioflavina-S para evidenciar las placas seniles bA y ovillos neurofibrilares (Smale et al., 1995. La evaluación semicuantitativa tanto de núcleos Tunel+, como de placas seniles y ovillos se realizarán de acuerdo a Mirra et al. 1991 y Troncoso et al. 1996 respectivamente.

    Inmunohistoquímica:

    Las microsecciones del cerebro, se incubarán con los anticuerpos primarios anti-p53, anti-p65(NF-kB, anti-Bax, anti-Par-4. Luego serán incubadas con anticuerpos secundarios anticonejo IgG conjugados con biotina, e incubadas con el sustrato extravidina peroxidasa. La cuantificación se realizará semi cuantitativamente de acuerdo a:(- no coloración,(+ coloración débil, (++ coloración moderada, (+++ coloración intensa. Adicionalmente, un registro microfotográfico se realizará y los datos se tabularán en tablas.

  7. PARTICIPACION DE LOS TRANSPORTADORES DE MONOCARBOXILATOS EN EL MECANISMO SENSOR DE GLUCOSA BASADO EN UNA INTERACCION METABOLICA GLIA-NEURONA

    OpenAIRE

    CORTES CAMPOS, CHRISTIAN GONZALO; CORTES CAMPOS, CHRISTIAN GONZALO

    2011-01-01

    El control de los niveles de glucosa sistémica y la ingesta alimenticia son dos procesos estrechamente relacionados y altamente regulados, que involucran a órganos periféricos y al sistema nervioso central. Se ha establecido que regiones específicas del cerebro, el hipotálamo y el núcleo arqueado (NA), son capaces de detectar y responder a cambios en la concentración de glucosa, desencadenando respuestas neuroendocrinas que regulan la ingesta alimenticia. Sin embargo, los mecanismos cel...

  8. Capacidad anaplerótica de las neuronas y los astrocitos, utilizando lactato y acetato en condiciones perinatales

    Directory of Open Access Journals (Sweden)

    Angel Alexandro Criollo Rayo

    2005-03-01

    Full Text Available En la transición a la vida extrauterina, el niño recién nacido para por un período crítico de vulnerabilidad y ayuno (prelactancia que transcurre enrre el cese de la nutrición placentaria y la instauración de la lactancia.

  9. Nuevos modelos de redes de neuronas artificiales para simulación y control desistemas dinámicos

    OpenAIRE

    Galván León, Inés María

    2011-01-01

    Uno de los principales problemas en el campo de los procesos dinámicos es el control de su comportamiento, control que es necesario para que la evolución del proceso se lleve a cabo en una dirección y con una cierta dinámica deseada. Esto puede traducirse en mantener una condición estable, seguir una trayectoria especificada o alcanzar una determinada meta. Para ello es necesario incluir un sistema de control, el cual influye en la dinámica del proceso, regulando su comportamiento. La teoría...

  10. A novel Pfs38 protein complex on the surface of Plasmodium falciparum blood-stage merozoites

    DEFF Research Database (Denmark)

    Paul, Gourab; Deshmukh, Arunaditya; Kaur, Inderjeet

    2017-01-01

    BACKGROUND: The Plasmodium genome encodes for a number of 6-Cys proteins that contain a module of six cysteine residues forming three intramolecular disulphide bonds. These proteins have been well characterized at transmission as well as hepatic stages of the parasite life cycle. In the present s...

  11. Comparative testing of six antigen-based malaria vaccine candidates directed toward merozoite-stage Plasmodium falciparum

    DEFF Research Database (Denmark)

    Arnot, David E; Cavanagh, David R; Remarque, Edmond J

    2008-01-01

    Immunogenicity testing of Plasmodium falciparum antigens being considered as malaria vaccine candidates was undertaken in rabbits. The antigens compared were recombinant baculovirus MSP-1(19) and five Pichia pastoris candidates, including two versions of MSP-1(19), AMA-1 (domains I and II), AMA-1......G concentrations. The two P. pastoris-produced MSP-1(19)-induced IgGs conferred the lowest growth inhibition. Comparative analysis of immunogenicity of vaccine antigens can be used to prioritize candidates before moving to expensive GMP production and clinical testing. The assays used have given discriminating...

  12. Genetic diversity of plasmodium vivax merozoite surface protein-3alpha (Pvmsp-3alpha) gene in Jhapa District of Nepal

    DEFF Research Database (Denmark)

    Adhikari, Madhav; Ranjitkar, Samir; Schousboe, Mette Leth

    2012-01-01

    In Nepal, Plasmodium vivax accounts for approximately 80-90% of the malaria cases, but limited studies have been conducted on the genetic diversity of this parasite population. This study was carried out to determine the genetic diversity of P. vivax population sampled from subjects living...

  13. A 10-day toxicity study of toltrazuril 5% suspension in the horse.

    Science.gov (United States)

    Furr, M O; Quance, J; Kennedy, T

    2000-01-01

    Equine protozoal myeloencephalitis (EPM) is a serious disorder of the nervous system of horses caused by Sarcocystis neurona. Recently, toltrazuril has begun to be used for treatment of EPM. The purpose of this study was to evaluate the potential toxicity of toltrazuril in horses when administered at a dose of 50 mg/kg for 10 days. Five horses were given 50 mg/kg of toltrazuril once daily for 10 days by nasogastric tube. Complete blood cell counts, serum chemistry values, and coagulation panels were evaluated before and after treatment; then a full postmortem examination was completed on day 11. Results of the study show that only mild clinical signs (i.e., anorexia, weight loss, and colic in one of the five horses) were observed after treatment. Minimal changes were noted in the serum chemistry analysis (i.e., increased bilirubin and serum protein, mildly increased hematocrit and hemoglobin concentration, and mildly increased albumin). Renal medullary congestion was noted on gross postmortem examination; however, no microscopic changes due to compound administration were noted in the kidneys or other tissue. Results of this study suggest that administration of toltrazuril at 50 mg/kg (5x to 10x anticipated clinical dosage) for 10 days resulted in only mild clinical abnormalities.

  14. Diagnosis and isolation of Toxoplasma gondii in horses from Brazilian slaughterhouses.

    Science.gov (United States)

    Evers, Fernanda; Garcia, João Luis; Navarro, Italmar Teodorico; Zulpo, Dauton Luiz; Nino, Beatriz de Souza Lima; Ewald, Maria Paula de Carvalho; Pagliari, Sthefany; Almeida, Jonatas Campos de; Freire, Roberta Lemos

    2013-01-01

    This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed to T. gondii.

  15. Comparison of a serum indirect fluorescent antibody test with two Western blot tests for the diagnosis of equine protozoal myeloencephalitis.

    Science.gov (United States)

    Duarte, Paulo C; Daft, Barbara M; Conrad, Patricia A; Packham, Andrea E; Gardner, Ian A

    2003-01-01

    A serum indirect fluorescent antibody test (IFAT) was compared with a Western blot (WB) and a modified Western blot (mWB) for diagnosis of equine protozoal myeloencephalitis (EPM). Using receiver-operating characteristic (ROC) analysis, the area under the curve of the IFAT was greater than the areaunder the curves of the WB and the mWB (P = 0.025 and P = 0.044, respectively). There was no statistically significant difference between the areas under the curves of the WBs (P > 0.05). On the basis of an arbitrarily chosen cut-off titer for a positive test result of 1:80 for the IFAT and interpreting weak positive WB results as positive test results, the sensitivities and 95% confidence intervals (CI) of all 3 tests were identical and equal to 88.9% (51.8-99.7%). The specificities and 95% CIs of the IFAT, WB, and mWB test were 100% (91-100%), 87.2% (72.6-95.7%), and 69.2% (52.4-83%), respectively. The overall accuracy of the IFAT was shown to be better than that of the WBs and, therefore, the test has potential for use in the diagnosis of EPM caused by Sarcocystis neurona.

  16. Qualitative evaluation of selective tests for detection of Neospora hughesi antibodies in serum and cerebrospinal fluid of experimentally infected horses.

    Science.gov (United States)

    Packham, Andrea E; Conrad, Patricia A; Wilson, W David; Jeanes, Lisa V; Sverlow, Karen W; Gardner, Ian A; Daft, Barbara M; Marsh, Antoinette E; Blagburn, Byron L; Ferraro, Gregory L; Barr, Bradd C

    2002-12-01

    Neospora hughesi is a newly recognized protozoan pathogen in horses that causes a myeloencephalitis similar to Sarcocystis neurona. There are no validated serologic tests using the gold standard sera that are currently available to detect specific N. hughesi antibodies and, thus, no tests available to detect antemortem exposure or estimate seroprevalence in the horse. The objectives of the present study were to establish a bank of gold standard equine sera through experimental infections with N. hughesi and to assess several serologic tests for the detection of related protozoan antibodies. Seven horses were inoculated with N. hughesi tachyzoites, and 7 horses received uninfected cell culture material. The horses were monitored, and blood and cerebrospinal fluid were collected repeatedly over a 4-mo period. With the sera, 4 different serologic techniques were evaluated. including a whole-parasite lysate enzyme-linked immunosorbent assay (ELISA), a recombinant protein ELISA, a modified direct agglutination test, and an indirect fluorescent antibody test. Qualitative and quantitative evaluation of the results showed that the N. hughesi indirect fluorescent antibody test (IFAT) consistently discriminated between experimentally infected and noninfected horses, using a cutoff of 1:640. Sera from 3 naturally infected horses had titers >1:640. Cerebrospinal fluid in all but I infected horse had very low N. hughesi IFAT titers (<1:160), starting at postinoculation day 30.

  17. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff.

    Science.gov (United States)

    Miller, Melissa A; Byrne, Barbara A; Jang, Spencer S; Dodd, Erin M; Dorfmeier, Elene; Harris, Michael D; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A; Miller, Woutrina A

    2010-01-01

    Although protected for nearly a century, California's sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health.

  18. Survey of the large-animal diplomates of the American College of Veterinary Internal Medicine regarding knowledge and clinical use of polymerase chain reaction: implications for veterinary education.

    Science.gov (United States)

    Pusterla, Nicola; Mapes, Samantha; Leutenegger, Christian M

    2006-01-01

    A questionnaire was developed to document the knowledge base of large-animal diplomates of the American College of Veterinary Internal Medicine (ACVIM) regarding polymerase chain reaction (PCR) technology and to identify the common use of this technology in equine practice. Ninety-three of the 278 mailed questionnaires were returned, for an overall response rate of 33.4%. Ninety respondents (99%) reported being familiar with the general principles of nucleic acid probe technology; however, only 52 (57%) knew the difference between conventional (traditional) and real-time (second-generation) PCR. The majority of the respondents (88%) emphasized the need for continuing education on molecular diagnostics. Eighty-four (92%) of the respondents regularly use PCR (conventional and/or real-time) for the detection of equine pathogens, and 80 (88%) commonly submit their samples to university/state veterinary laboratories. Blood, nasal swabs, and feces are the three equine specimens most commonly submitted for PCR analysis of Streptococcus equi, Lawsonia intracellularis, Neorickettsia risticii, equine herpesvirus 1/4, Rhodococcus equi, Sarcocystis neurona, and equine influenza virus. Diplomates reported costs associated with molecular diagnostics and unreliability of PCR as the most common limitations of PCR. Didactic training in veterinary curricula and during continuing-education opportunities continues to be necessary to produce veterinarians who have an understanding of the clinical applications of molecular diagnostics.

  19. Extracción de conocimiento en bases de datos astronómicas mediante redes de neuronas artificiales: aplicaciones en la misión Gaia

    Science.gov (United States)

    Fustes Villadóniga, Diego

    2014-02-01

    In the so-called IT era, the capabilities of data acquisition systems have increased to such an extent that it has become difficult to store all the information they produce, and analyse it. This explosion of data has recently appeared in the field of Astronomy, where an increasing number of objects are being observed on a regular basis. An example of this is the upcoming Gaia mission, which will pick up multiple properties of a billion stars, whose information will have a volume of approximately a petabyte. The analysis of a similar amount of information inevitably requires the development of new data analysis methods to extract all the knowledge it contains. This thesis is devoted to the development of data analysis methods to be integrated in the Gaia pipeline, such that knowledge can be extracted from the data collected by the mission. In order to analyze the data from the Gaia mission, the European Space Agency organized the Data Processing and Analysis Consortium (DPAC) which is composed of hundreds of scientists and engineers. DPAC is divided into eight Coordination Units (CUs). This thesis is dedicated to algorithm development in CU8, which is responsible for source classification and astrophysical parameters (AP) estimation. Methods based on Artificial Neural Networks (ANNs) are developed to perform the tasks related to two different work packages in CU8: the GSP-Spec package (GWP-823), and the OA package (GWP-836). The GSP-Spec package is responsible for estimating stellar APs by means of the Radial Velocity Spectrograph (RVS) spectrum. This work presents the development of one of the GSP-Spec modules, which is based on the application of feed-forward ANNs. A methodology is described, based on the optimization of genetic algorithms and aimed at obtaining an optimal set of configuration parameters for the ANN in each case, depending on the signal to noise ratio (SNR) in the RVS spectrum and on the type of star to parameterize. Furthermore, in order to improve the AP estimates, wavelet signal processing techniques, applied to the RVS spectrum, are studied. Despite the effectiveness shown by ANNs in estimating APs, in principle they lack the ability to provide an uncertainty value on these estimates, making it impossible to determine their reliability. Because of this, a new architecture for the ANN is presented in which the inputs and outputs are reversed, so that the ANN estimates the RVS spectrum from the APs. Such an architecture is called Generative ANN (GANN) and is applied to the AP estimation of a set of simulated RVS spectra for the Gaia mission, where it is more effective than the conventional ANN model, in the case of faint stars with low SNR. Finally, the GANN can be applied for obtaining the posterior probability of each of the APs according to the RVS spectrum, allowing for their more complete analysis. Given the nature of the Gaia mission, which is the first astronomical mission that will observe, in an unbiased way, the entire sky up to magnitude 20, a large number of outliers are expected. The OA package in CU8 handles the processing of this type of objects, which are defined as those that could not be reliably classified by the methods in the upstream classification packages. OA methods are based on the unsupervised learning of all outliers. Such learning has two parts: clustering and dimensionality reduction. The Self-Organizing Map (SOM) algorithm is selected as a basis for this learning. Its effectiveness is demonstrated when it is applied, with an optimal configuration, to the Gaia simulations. Furthermore, the algorithm is applied to real outliers from the SDSS catalog. Since a subsequent identification of the clusters obtained by the SOM is necessary, two different methods of identification are applied. The first method is based on the similarity between the SOM prototypes and the Gaia simulations, and the second method is based on the recovery of stored classifications in the SIMBAD catalog by cross-matching celestial coordinates. Thanks to the visualization of the SOM planes, and to both

  20. La atorvastatina protege las neuronas gabérgicas y dopaminérgicas del sistema nigroestriatal en un modelo experimental de isquemia cerebral focal transitoria en ratas

    Directory of Open Access Journals (Sweden)

    Angélica María Sabogal

    2014-06-01

    Full Text Available Introducción. La isquemia cerebral es la tercera causa de muerte y la primera de discapacidad permanente en el mundo. La atorvastatina es un fármaco neuroprotector prometedor para el tratamiento de la apoplejía; sin embargo, su acción sobre las poblaciones neuronales del sistema nigroestriatal después de la isquemia aún se desconoce. Objetivo. Evaluar el efecto de la atorvastatina sobre poblaciones gabérgicas y dopaminérgicas en regiones exofocales en un modelo de oclusión transitoria de la arteria cerebral media. Materiales y métodos. Se utilizaron 28 ratas Wistar macho de ocho semanas de edad. Los ejemplares con isquemia simulada y los ejemplares sometidos a isquemia fueron tratados con atorvastatina (10 mg/kg y carboximetilcelulosa (placebo administrados por medio de sonda a las 6, 24, 48 y 72 horas después de la reperfusión. Se analizó la inmunorreacción de la descarboxilasa del ácido glutámico y de la tirosina hidroxilasa en el globo pálido, el putamen caudado y la sustancia negra. Resultados. Los datos confirmaron el daño neurológico y la pérdida celular en el putamen caudado. Se incrementó la inmunorreacción de la tirosina hidroxilasa en el globo pálido medial y la sustancia negra pars reticulata, disminuyendo la inmunorreacción de la descarboxilasa del ácido glutámico en el globo pálido lateral de los animales isquémicos tratados con placebo; sin embargo, el tratamiento con atorvastatina pudo revertirla, lo que logró una disminución significativa de la tirosina hidroxilasa en el globo pálido medial y la sustancia negra pars reticulata y aumentando los niveles de descarboxilasa del ácido glutámico en el globo pálido lateral. Conclusión. Nuestros datos sugieren que la atorvastatina en el tratamiento posterior a la isquemia ejerce neuroprotección en las zonas exofocales, modulando las poblaciones neuronales gabérgicas y dopaminérgicas del sistema nigroestriatal, lo que podría prevenir trastornos neurológicos.

  1. Las neuronas del estriado son la diana del efecto neurotrófico del ácido oleico sintetizado en la zona subventricular durante el desarrollo postnatal

    OpenAIRE

    Polo Hernández, Erica

    2011-01-01

    [ES] Esta tesis se basa en: 1.- Estudio de los niveles de ácido oleico libre en el cerebro durante el desarrollo postnatal. 2.- Estudio de la región o regiones del cerebro en las que se localiza la enzima limitante en la síntesis de ácido oleico, la estearil- CoA desaturasa-1, SCD-1. 3.- Estudio del papel que ejerce la estearil-CoA desaturasa-1 en el desarrollo postnatal del cerebro. [EN] This thesis is based on: 1 .- Study of free oleic acid levels in the brain during postna...

  2. Demostración del ingreso del virus de la rabia a la corteza cerebral a través de las neuronas piramidales de la capa V

    Directory of Open Access Journals (Sweden)

    Hernán J. Pimienta J.

    2005-03-01

    Full Text Available En condiciones naturales el virus de la rabia (VR penetra en la piel o los músculos, con la saliva unyectada por un animal infectado y entra en contacto con receptores localizados en el sistema nervioso periférico.

  3. Diseño automático de redes de neuronas artificiales para la predicción de series temporales

    OpenAIRE

    Peralta Donate, Juan

    2012-01-01

    El ser humano ha avanzado mucho, tecnológicamente hablando, en el último siglo. La sed por descubrir e innovar no tiene límites y cómo no, aplicar dichas innovaciones para nuestro provecho y bienestar general. Uno de los campos de investigación a los que se ha aplicado dicha innovación es la predicción. Al hablar de predicción, lo primero que nos puede venir a la cabeza son temas no tan científicos como la astrología o la lectura de manos, pero en realidad, diversos métodos estadísticos y mat...

  4. Human T-cell recognition of synthetic peptides representing conserved and variant sequences from the merozoite surface protein 2 of Plasmodium falciparum

    DEFF Research Database (Denmark)

    Theander, T G; Hviid, L; Dodoo, D

    1997-01-01

    . The findings are encouraging for the development of a vaccine based on these T-epitope containing regions of MSP2, as the peptides were broadly recognized suggesting that they can bind to diverse HLA alleles and also because they include conserved MSP2 sequences. Immunisation with a vaccine construct...

  5. Human recombinant antibodies against Plasmodium falciparum merozoite surface protein 3 cloned from peripheral blood leukocytes of individuals with immunity to malaria demonstrate antiparasitic properties

    DEFF Research Database (Denmark)

    Lundquist, Rasmus; Nielsen, Leif Kofoed; Jafarshad, Ali

    2006-01-01

    against MSP-3 residues 194 to 257 (MSP-3(194-257)) on the molecular level. mRNA from peripheral blood leukocytes from clinically immune individuals was used as a source of Fab (fragment antibody) genes. A Fab-phage display library was made, and three distinct antibodies designated RAM1, RAM2, and RAM3...

  6. Genetic diversity of Plasmodium falciparum merozoite surface protein-1 (block 2), glutamate-rich protein and sexual stage antigen Pfs25 from Chandigarh, North India.

    Science.gov (United States)

    Kaur, Hargobinder; Sehgal, Rakesh; Goyal, Kapil; Makkar, Nikita; Yadav, Richa; Bharti, Praveen K; Singh, Neeru; Sarmah, Nilanju P; Mohapatra, Pradyumna K; Mahanta, Jagadish; Bansal, Devendra; Sultan, Ali A; Kanwar, Jagat R

    2017-12-01

    To elucidate the genetic diversity of Plasmodium falciparum in residual transmission foci of northern India. Clinically suspected patients with malaria were screened for malaria infection by microscopy. 48 P. falciparum-infected patients were enrolled from tertiary care hospital in Chandigarh, India. Blood samples were collected from enrolled patients, genomic DNA extraction and nested PCR was performed for further species confirmation. Sanger sequencing was carried out using block 2 region of msp1, R2 region of glurp and pfs25-specific primers. Extensive diversity was found in msp1 alleles with predominantly RO33 alleles. Overall allelic prevalence was 55.8% for RO33, 39.5% for MAD20 and 4.7% for K1. Six variants were observed in MAD20, whereas no variant was found in RO33 and K1 alleles. A phylogenetic analysis of RO33 alleles indicated more similarity to South African isolates, whereas MAD20 alleles showed similarity with South-East Asian isolates. In glurp, extensive variation was observed with eleven different alleles based on the AAU repeats. However, pfs25 showed less diversity and was the most stable among the targeted genes. Our findings document the genetic diversity among circulating strains of P. falciparum in an area of India with low malaria transmission and could have implications for control strategies to reach the national goal of malaria elimination. © 2017 John Wiley & Sons Ltd.

  7. Plasmodium falciparum merozoite surface protein 1 - Glycosylation and localization to low-density, detergent-resistant membranes in the parasitized erythrocyte

    DEFF Research Database (Denmark)

    Hoessli, D.C.; Poincelet, M.; Gupta, Ramneek

    2003-01-01

    . Subcellular fractionation of parasitized erythrocytes in the late trophozoite/schizont stage reveals that GPI-anchored C-terminal fragments of MSP-1 are recovered in Triton X-100 resistant, low-density membrane fractions. Our results suggest that O -GlcNAc-modified MSP-1 N-terminal fragments tend to localize...... within the parasitophorous vacuolar membrane while GPI-anchored MSP-1 C-terminal fragments associate with low-density, Triton X-100 resistant membrane domains (rafts), redistribute in the parasitized erythrocyte and are eventually shed as membrane vesicles that also contain the endogenous, GPI-linked CD...

  8. Redes neuronales de propagación inversa

    OpenAIRE

    Jesús Alberto Delgado Rivera

    2007-01-01

    Presenta la red neuronal por capas, su algoritmo de aprendizaje y una aplicación. Para lograr este propósito se inicia con la neurona natural y su modelo entrada/salida denominado neurona artificial.

  9. Diagnosis and isolation of Toxoplasma gondii in horses from Brazilian slaughterhouses Diagnóstico e isolamento de Toxoplasma gondii em equídeos de frigoríficos brasileiros

    Directory of Open Access Journals (Sweden)

    Fernanda Evers

    Full Text Available This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64, and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6% by IFAT and in 14 (3.5% by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16, T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15% of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed to T. gondii.O objetivo do estudo foi investigar anticorpos anti-Toxoplasma gondii e isolar o parasita do cérebro de equídeos abatidos em matadouros-frigoríficos no Brasil. Colheram-se amostras de 398 cérebros e sangue de equídeos machos e fêmeas de idades variadas, provenientes de seis estados brasileiros. As amostras de soro foram avaliadas pelo teste de imunofluorescência indireta (IFI para T. gondii (ponto de corte ≥ 64, e os fragmentos de cérebros foram submetidos ao bioensaio em camundongos. Por meio da IFI, 46 (11,6% equídeos foram soropositivos. Pelo bioensaio em camundongos, 14 (3,5% cérebros de equídeos testados foram positivos. Em doze dos bioensaios, os camundongos foram positivos somente pela IFI (ponto

  10. SURVEY FOR INFECTIOUS DISEASE IN THE SOUTH AMERICAN FUR SEAL (ARCTOCEPHALUS AUSTRALIS) POPULATION AT PUNTA SAN JUAN, PERU.

    Science.gov (United States)

    Jankowski, Gwen; Adkesson, Michael J; Saliki, Jeremiah T; Cárdenas-Alayza, Susana; Majluf, Patricia

    2015-06-01

    The Peruvian population of the South American fur seal ( Arctocephalus australis ) is a distinct evolutionarily significant unit that is endangered. One of the largest rookeries for this species in Peru is located within the Punta San Juan marine protected area (15°22'S, 75°12'W). To better understand the current health status of this population, exposure to 10 pinniped pathogens was evaluated in adult female fur seals (n=29) via serology and polymerase chain reaction (PCR) techniques in November 2010. The results suggest this population is naïve to canine and phocine distemper viruses (serum neutralization test), five Leptospira interrogans serovars (microscopic agglutination test), and Brucella canis (card test). Indirect fluorescent antibody testing for Toxoplasma gondii , Neospora caninum , and Sarcocystis neurona was also uniformly negative. PCR testing of nasal swabs using previously described Mycoplasma spp. primers was positive in 37.9% (11/29) of samples. One animal was positive via card test for Brucella abortus , whereas 53.7% (15/28) were positive or suspect using a marine Brucella competitive enzyme-linked immunosorbent assay. Antibody to phocine herpesvirus-1 (PHV-1) was identified in 85.7% (24/28) of the sampled population by serum neutralization testing. Overall, exposure to Mycoplasma spp., Brucella spp., and PHV-1 was observed, but results demonstrated low to no exposure to many key pinniped pathogens. The expansion of human populations, agriculture, and industry along the Peruvian coast may lead to increased pathogen exposure from human, domestic, and wild animal sources. The naïve nature of this key population of South American fur seals raises concerns about potential risk for disease outbreaks.

  11. Chagas disease in a Texan horse with neurologic deficits.

    Science.gov (United States)

    Bryan, Laura K; Hamer, Sarah A; Shaw, Sarah; Curtis-Robles, Rachel; Auckland, Lisa D; Hodo, Carolyn L; Chaffin, Keith; Rech, Raquel R

    2016-01-30

    A 10-year-old Quarter Horse gelding presented to the Texas A&M University Veterinary Teaching Hospital with a six month-history of ataxia and lameness in the hind limbs. The horse was treated presumptively for equine protozoal myeloencephalitis (EPM) based on clinical signs but was ultimately euthanized after its condition worsened. Gross lesions were limited to a small area of reddening in the gray matter of the thoracic spinal cord. Histologically, trypanosome amastigotes morphologically similar to Trypanosoma cruzi, the agent of Chagas disease in humans and dogs, were sporadically detected within segments of the thoracic spinal cord surrounded by mild lymphoplasmacytic inflammation. Ancillary testing for Sarcocystis neurona, Neospora spp., Toxoplasma gondii and Leishmania spp. was negative. Conventional and real time polymerase chain reaction (PCR) of affected paraffin embedded spinal cord were positive for T. cruzi, and sequencing of the amplified T. cruzi satellite DNA PCR fragment from the horse was homologous with various clones of T. cruzi in GenBank. While canine Chagas disease cases have been widely reported in southern Texas, this is the first report of clinical T. cruzi infection in an equid with demonstrable amastigotes in the spinal cord. In contrast to previous instances of Chagas disease in the central nervous system (CNS) of dogs and humans, no inflammation or T. cruzi amastigotes were detected in the heart of the horse. Based on clinical signs, there is a potential for misdiagnosis of Chagas disease with other infectious diseases that affect the equine CNS. T. cruzi should be considered as a differential diagnosis in horses with neurologic clinical signs and histologic evidence of meningomyelitis that originate in areas where Chagas disease is present. The prevalence of T. cruzi in horses and the role of equids in the parasite life cycle require further study. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Pathogen exposure and blood chemistry in the Washington, USA population of northern sea otters (Enhydra lutris kenyoni).

    Science.gov (United States)

    White, C LeAnn; Schuler, Krysten L; Thomas, Nancy J; Webb, Julie L; Saliki, Jeremiah T; Ip, Hon S; Dubey, J P; Frame, Elizabeth R

    2013-10-01

    Northern sea otters (Enhydra lutris kenyoni) from Washington State, United States were evaluated in 2011 to determine health status and pathogen exposure. Antibodies to Brucella spp. (10%) and influenza A virus (23%) were detected for the first time in this population in 2011. Changes in clinical pathology values (serum chemistries), exposure to pathogens, and overall health of the population over the last decade were assessed by comparing 2011 data to the data collected on this population in 2001-2002. Several serum chemistry parameters were different between study years and sexes but were not clinically significant. The odds of canine distemper virus exposure were higher for otters sampled in 2001-2002 (80%) compared to 2011 (10%); likelihood of exposure significantly increased with age. Prevalence of exposure to Sarcocystis neurona was also higher in 2001-2002 (29%) than in 2011 (0%), but because testing methods varied between study years the results were not directly comparable. Exposure to Leptospira spp. was only observed in 2001-2002. Odds of Toxoplasma gondii exposure were higher for otters sampled in 2011 (97%) than otters in 2001-2002 (58%). Substantial levels of domoic acid (n = 2) and saxitoxin (n = 2) were found in urine or fecal samples from animals sampled in 2011. No evidence of calicivirus or Coxiella burnetii exposure in the Washington population of northern sea otters was found in either 2001-2002 or 2011. Changes in exposure status from 2001-2002 to 2011 suggest that the Washington sea otter population may be dealing with new disease threats (e.g., influenza) while also increasing their susceptibility to diseases that may be highly pathogenic in naïve individuals (e.g., canine distemper).

  13. Assessment of clinical pathology and pathogen exposure in sea otters (Enhydra lutris) bordering the threatened population in Alaska

    Science.gov (United States)

    Goldstein, T.; Gill, V.A.; Tuomi, Pamela A.; Monson, Daniel H.; Burdin, A.; Conrad, P.A.; Dunn, J.L.; Field, C.; Johnson, Chad; Jessup, David A.; Bodkin, J.; Doroff, A.M.

    2011-01-01

    Northern sea otter (Enhydra lutris kenyoni) abundance has decreased dramatically over portions of southwest Alaska, USA, since the mid-1980s, and this stock is currently listed as threatened under the Endangered Species Act. In contrast, adjacent populations in south central Alaska, USA, and Russia have been stable to increasing during the same period. Sea otters bordering the area classified in the recent decline were live-captured during 2004–2006 at Bering Island, Russia, and the Kodiak Archipelago, Alaska, USA, to evaluate differences in general health and current exposure status to marine and terrestrial pathogens. Although body condition was lower in animals captured at Bering Island, Russia, than it was at Kodiak, USA, clinical pathology values did not reveal differences in general health between the two regions. Low prevalences of antibodies (>5%) were found in Kodiak, USA, and on Bering Island, Russia, to Toxoplasma gondii, Sarcocystis neurona, and Leptospira interrogans. Exposure to phocine herpesvirus-1 was found in both Kodiak, USA (15.2%), and Bering Island, Russia (2.3%). Antibodies to Brucella spp. were found in 28% of the otters tested on Bering Island, Russia, compared with only 2.7% of the samples from Kodiak, USA. Prevalence of exposure to Phocine distemper virus (PDV) was 41% in Kodiak, USA, but 0% on Bering Island, Russia. Archived sera from southwest and south-central Alaska dating back to 1989 were negative for PDV, indicating exposure occurred in sea otters in Kodiak, USA, in recent years. Because PDV can be highly pathogenic in naïve and susceptible marine mammal populations, tissues should be examined to explore the contribution of this virus to otter deaths. Our results reveal an increase in exposure to pathogens in sea otters in Kodiak, Alaska, USA, since the 1990s.

  14. Envejecimiento Neuronal y Transporte de Ca2+ Intracelular

    OpenAIRE

    Hernando Pérez, Mª Elena

    2017-01-01

    El envejecimiento promueve pérdida cognitiva y susceptibilidad a enfermedades neurodegenerativas, lo que se ha relacionado con la dishomeostasis del Ca2+ intracelular. Para investigar esta hipótesis se utiliza el cultivo a largo plazo de neuronas de hipocampo de rata, modelo de envejecimiento neuronal in vitro. Mediante imagen de fluorescencia se han estudiado cambios en transporte de Ca2+ en neuronas a lo largo del envejecimiento in vitro. Las neuronas se han identificado mediante inmunofluo...

  15. Inhibición de la síntesis de neurotransmisor en neuronas dopaminérgicas de los ganglios basales. Localización celular del receptor H3 de histamina

    OpenAIRE

    González Sepúlveda, Marta

    2011-01-01

    En esta tesis se pretende aportar datos experimentales que ayuden a comprender las interacciones entre el sistema neuronal histaminérgico y otros sistemas de neurotransmisores presentes en los ganglios basales, particularmente el dopaminérgico. Dicho conocimiento podría ayudar a paliar patologías tales como la adicción a drogas de abuso, la esquizofrenia o la enfermedad de Parkinson. Al intentar estudiar efectos de ligandos de receptores sobre la síntesis de dopamina nos encont...

  16. El 17-?-estradiol frente a la muerte apoptótica en neuronas granulares de cerebelo: efectos sobre la supervivencia y modulación de la plasticidad neuronal

    OpenAIRE

    Miñano Molina, Alfredo Jesús

    2006-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada Durant el desenvolupament de les malalties neurodegeneratives les neurones moren. Una de les conseqüències més comuns del desenvolupament de malalties neurodegeneratives és l'activació en la majoria d'elles del programa de mort cel·lular, conegut com apoptosi. El coneixement exhaustiu d'aquest programa apoptòtic és clau per poder abordar estratègies terapèutiques que puguin aturar l'avanç d'aquestes malalties. L'apoptosi...

  17. Papel de las proteínas transportadoras de ácidos grasos (FABPs), en la señalización del efecto neurotrófico del ácido oleico en neuronas

    OpenAIRE

    Arroyo Martín, Ángel Alberto

    2012-01-01

    [ES]Los niveles de ácido oleico en cerebro aumentan muy significativamente durante el primer día después del nacimiento. De hecho, el ácido oleico se sintetiza por los astrocitos en respuesta a la albúmina, la cual está aumentada en la zona periventricular adyacente al ventrículo lateral desde el día 17 de desarrollo embrionario hasta el día 3 postnatal en el cerebro de la rata. El ácido oleico unido a la albúmina actúa como un factor neurotrófico, promoviendo la diferenciación neuronal media...

  18. Retracción a largo plazo del árbol dendrítico de neuronas piramidales córtico-faciales por lesiones periféricas del nervio facial

    Directory of Open Access Journals (Sweden)

    Diana Urrego

    2011-06-01

    Esta reorganización morfológica cortical persistente podría ser el sustrato fisiopatológico de algunas de las secuelas funcionales que se observan en los pacientes con parálisis facial periférica.

  19. ENSEÑANZA DE LAS CIENCIAS BIOLÓGICAS, DESDE UN ENFOQUE ANATÓMICO, FISIOLÓGICO Y BIOFÍSICO. LA NEURONA Y SUS RESPUESTAS ELÉCTRICAS COMO MODELO DE TRABAJO

    OpenAIRE

    Hugo Molina Arroyo; Montserrat Vázquez Balbuena

    2014-01-01

    A partir del año 2008, la Benemérita Universidad Autónoma de Puebla implementa el Modelo Universitario Minerva (MUM), modelo fundamentado en el humanismo crítico y el construccionismo sociocultural, apostando por la implementación de nuevas TIC‟s en los procesos de aprendizaje, investigación y gestión. En este sentido la Escuela de Biología llevó a cabo una restructuración en su programa de estudios lo que permite garantizar, en todo momento, que el estudiante comprenda desde un punto de vist...

  20. Arquitecturas axónicas y organización de las neuronas de proyección multiespecífica del tálamo. Estudio en el núcleo posterior del ratón.

    OpenAIRE

    Porrero Calzado, César

    2016-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Anatomía, Histología y Neurociencia. Fecha de lectura: 06-09-2016 Esta tesis tiene embargado el acceso al texto completo hasta el 06-03-2017

  1. Redes neuronales de propagación inversa

    Directory of Open Access Journals (Sweden)

    Jesús Alberto Delgado Rivera

    1992-05-01

    Full Text Available Este artículo presenta la red neuronal por capas, su algoritmo de aprendizaje y una aplicación. Para lograr este propósito se inicia con la neurona natural y su modelo Entrada/Salida denominado neurona artificial.

  2. Use of Monoclonal Antibodies to Study the Structural Basis of the Function of Nicotinic Acetylcholine Receptors on Electric Organ and Muscle and to Determine the Structure of Nicotinic Acetylcholine Receptors on Neurons

    Science.gov (United States)

    1989-09-30

    of chicken neurona .4receptor subunits. Sequences of al and a2 are from Net .Ot al. -l Sequences of a3 and a4 were determintl from clones described...Sucrose gradient analysis of neurona & nicotinic receptors was conducted as follows. Chicken ind rat brain receptors were extracted from crude

  3. Classical Conditioning of Hippocampal Theta Patterns in the Rat.

    Science.gov (United States)

    1976-08-01

    associated with changes in performance of learned tasks , 1,4,5, 8,9 there have been very few studies of neurona l plasticity of the hippocampus It self...rapid development of a conditioned hippocampal theta response to a visual sti mulus demonstrates tha t there is considerable neurona l plasticity in the

  4. Respuesta neuronal a la lesión selectiva de células diana en el mamífero adulto

    OpenAIRE

    Rodríguez de la Cruz, Rosa María

    1992-01-01

    Los objetivos del presente trabajo se resumen en los puntos siguientes: a) Elegir un sistema de proyección sobre su blanco neuronal altamente específico. Las neuronas internucleares del núcleo del motor ocular externo constituyeron un buen modelo para cubrir este objetivo. Estas neuronas proyectan extensivamente sobre las motoneuronas del recto interno, en el núcleo del motor ocular común contralateral. Sólo una proporción pequeña (30%) de las neuronas internucleares emiten colaterales hacia...

  5. Efecto de las neurotrofinas en cultivos primarios de ganglio espinal, normales e infectados con virus de la rabia

    OpenAIRE

    Hernán Hurtado; Orlando Acosta; Marlén Martínez; Castellanos, Jaime E.

    2000-01-01

    Los cultivos de ganglio espinal son utilizados para estudiar la interacción entre el virus de la rabia y las neuronas sensoriales presentes en ellos. Se conoce que in vivo, el virus utiliza estas neuronas como una de las puertas de entrada al Sistema Nervioso Central en donde posteriormente se produce una encefalopatía letal. La patología producida por el virus es debida a su marcado tropismo hacia las neurona...

  6. Identification of Novel Membrane Structures in Plasmodium falciparum Infected Erythrocytes

    Directory of Open Access Journals (Sweden)

    Clavijo Carlos A

    1998-01-01

    Full Text Available Little is known about the molecular mechanisms underlying the release of merozoites from malaria infected erythrocytes. In this study membranous structures present in the culture medium at the time of merozoite release have been characterized. Biochemical and ultrastructural evidence indicate that membranous structures consist of the infected erythrocyte membrane, the parasitophorous vacuolar membrane and a residual body containing electron dense material. These are subcellular compartments expected in a structure that arises as a consequence of merozoite release from the infected cell. Ultrastructural studies show that a novel structure extends from the former parasite compartment to the surface membrane. Since these membrane modifications are detected only after merozoites have been released from the infected erythrocyte, it is proposed that they might play a role in the release of merozoites from the host cell

  7. LA TIROSINA QUINASA C-ABL EN LA ENFERMEDAD DE ALZHEIMER: SU FUNCION EN LA MUERTE NEURONAL Y EN LAS ALTERACIONES DEL CITOESQUELETO.

    OpenAIRE

    CANCINO LOBOS, GONZALO IGNACIO; CANCINO LOBOS, GONZALO IGNACIO

    2009-01-01

    Los mecanismos por los cuales las neuronas mueren en las enfermedades neurodegenerativas son sólo parcialmente conocidos y pobremente entendidos. Se ha descrito que tanto el envejecimiento como las enfermedades neurodegenerativas se caracterizan por una m 158p.

  8. Why our brains cherish humanity: Mirror neurons and colamus humanitatem

    National Research Council Canada - National Science Library

    John R. Skoyles

    2009-01-01

    .... Un descubrimiento reciente de la neurociencia, el de las neuronas espejo, sostiene que el cerebro y la mente no son construidos ni funcionan alejados de lo que pasa en otros individuos. ¿Qué...

  9. Copying the development: mirror neurons in child development

    OpenAIRE

    Demian Arturo Herrera Morban; Nathalia Caridad Montero Cruz

    2016-01-01

    Resumen Desde la vida intrauterina nuestro cerebro está siendo expuesto a factores internos y externos que generan cambios epigenéticos que afectan las redes neuronales y por tanto modifican las propiedades de las neuronas espejo del infante en desarrollo. Consideramos que cambios en las neuronas espejo pueden jugar un papel en las patologías del neuro-desarrollo del infante donde no es observada una lesión estructural cerebral.

  10. Copying the development: mirror neurons in child development

    Directory of Open Access Journals (Sweden)

    Demian Arturo Herrera Morban

    2016-06-01

    Full Text Available Resumen Desde la vida intrauterina nuestro cerebro está siendo expuesto a factores internos y externos que generan cambios epigenéticos que afectan las redes neuronales y por tanto modifican las propiedades de las neuronas espejo del infante en desarrollo. Consideramos que cambios en las neuronas espejo pueden jugar un papel en las patologías del neuro-desarrollo del infante donde no es observada una lesión estructural cerebral.

  11. Circadian regulation of daily rhythms in orexinergic neurons in diurnal and nocturnal rodents

    Directory of Open Access Journals (Sweden)

    Gladys S. Martínez

    2009-01-01

    Full Text Available El trabajo que se presenta aquí se centra en la regulación diferencial que ejerce el sistema nervioso central sobre ritmos circadianos en una especie diurna, Arvicanthis niloticus, o rata Nile grass y una especie nocturna, Rattus norvegicus, o rata de laboratorio. En Nile grass, las neuronas que expresan orexina (ORX mostraron un ritmo endógeno diario en la expresión de Fos, ritmo que correlaciona con el ciclo de sueño y vigilia de esta especie y que es opuesto en comparación con el ritmo visto en ratas de laboratorio. En Nile grass las neuronas de ORX reciben proyecciones sustanciales desde neuronas del núcleo supraquiasmático (SCN que expresan el péptido vasoactivo intestinal (VIP. En contraste, en ratas de laboratorio se encontraron muy pocas fibras positivas para VIP adyacentes a neuronas de ORX. Esta diferencia entre especies sugiere un control directo por parte del SCN sobre neuronas que expresan ORX en Nile grass y una regulación más indirecta en ratas de laboratorio. Estos resultados son consistentes con la hipótesis según la cual las diferencias entre especies diurnas y nocturnas se deben a diferencias en las funciones de regiones que reciben eferencias del SCN tales como las neuronas de ORX y el hipotálamos dorsomedial (DMH

  12. Why our brains cherish humanity: Mirror neurons and colamus humanitatem

    Directory of Open Access Journals (Sweden)

    John R. Skoyles

    2009-11-01

    Full Text Available El sentido común dice que estamos aislados. Después de todo, nuestros cuerpos están separados físicamente. Pero la obra Colamus humanitatem de Séneca y la observación de que “ningún hombre es una isla”, que hizo John Donne, sugieren que no estamos ni completamente aislados ni separados. Un descubrimiento reciente de la neurociencia, el de las neuronas espejo, sostiene que el cerebro y la mente no son construidos ni funcionan alejados de lo que pasa en otros individuos. ¿Qué son las neuronas espejo? Son células cerebrales que procesan tanto lo que le pasa como lo que hace un individuo, y, por así decirlo, su “reflexión” percibida cuando esa misma cosa le pasa a, o es hecha por, otro individuo. Por lo tanto, las neuronas espejo se activan cuando una persona realiza una acción específica y cuando percibe la misma acción realizada por otro. El descubrimiento de las neuronas espejo indica que es preciso revisar radicalmente nuestras nociones sobre la naturaleza humana, ya que estas neuronas ofrecen un medio por el cual no concebimos estar tan separados como pensamos. A diferencia de otros simios, los humanos están adaptados a interactuar de forma similar no verbal, cuando están juntos. De manera particular, nuestras caras han evolucionado para mostrar movimientos ágiles y rápidos. Mientras esto usualmente explica cómo se logra la comunicación no verbal, una mejor descripción sería la comunicación no verbal  basada en las neuronas espejo. El autor sostiene que valoramos la humanidad, colamus humanitatem, porque las neuronas espejo y nuestra interfaz interpersonal adaptada de espejo desdibujan las fronteras que nos separan.

  13. Human IgG subclass antibodies to the 19 kilodalton carboxy ...

    African Journals Online (AJOL)

    Human IgG subclass antibodies to the 19 kilodalton carboxy terminal fragment of Plasmodium Falciparum merozoite surface protein 1 (MSP1 19 ) and predominance of the MAD20 allelic type of MSP1 in Uganda.

  14. Loading of erythrocyte membrane with pentacyclic triterpenes inhibits Plasmodium falciparum invasion

    DEFF Research Database (Denmark)

    Ziegler, Hanne L; Staalsø, Trine; Jaroszewski, Jerzy W

    2006-01-01

    Lupeol and betulinic acid inhibit the proliferation of Plasmodium falciparum parasites by inhibition of the invasion of merozoites into erythrocytes. This conclusion is based on experiments employing parasite cultures synchronized by magnetic cell sorting (MACS). Identical inhibitory effects were...

  15. Static and Microfluidic Live Imaging Studies of Plasmodium falciparum Invasion Phenotypes

    OpenAIRE

    Lin, Yen-Chun

    2018-01-01

    Severe malaria caused by $\\textit{Plasmodium falciparum}$ ($\\textit{P. falciparum}$) remains a leading cause of death in many low and middle income countries. The intraerythrocytic reproduction cycle of the parasite is responsible for all the symptoms and mortality of malaria. The merozoite, first invade a red blood cell (RBC) in the circulation, then grows, develops and multiplies within it by clonal division. Merozoite invasion is a complex process involving dynamic interactions between lig...

  16. Quantitation of Malaria Parasite-Erythrocyte Cell-Cell Interactions Using Optical Tweezers

    Science.gov (United States)

    Crick, Alex J.; Theron, Michel; Tiffert, Teresa; Lew, Virgilio L.; Cicuta, Pietro; Rayner, Julian C.

    2014-01-01

    Erythrocyte invasion by Plasmodium falciparum merozoites is an essential step for parasite survival and hence the pathogenesis of malaria. Invasion has been studied intensively, but our cellular understanding has been limited by the fact that it occurs very rapidly: invasion is generally complete within 1 min, and shortly thereafter the merozoites, at least in in vitro culture, lose their invasive capacity. The rapid nature of the process, and hence the narrow time window in which measurements can be taken, have limited the tools available to quantitate invasion. Here we employ optical tweezers to study individual invasion events for what we believe is the first time, showing that newly released P. falciparum merozoites, delivered via optical tweezers to a target erythrocyte, retain their ability to invade. Even spent merozoites, which had lost the ability to invade, retain the ability to adhere to erythrocytes, and furthermore can still induce transient local membrane deformations in the erythrocyte membrane. We use this technology to measure the strength of the adhesive force between merozoites and erythrocytes, and to probe the cellular mode of action of known invasion inhibitory treatments. These data add to our understanding of the erythrocyte-merozoite interactions that occur during invasion, and demonstrate the power of optical tweezers technologies in unraveling the blood-stage biology of malaria. PMID:25140419

  17. First report of human intestinal sarcocystosis in Cambodia.

    Science.gov (United States)

    Khieu, Virak; Marti, Hanspeter; Chhay, Saomony; Char, Meng Chuor; Muth, Sinuon; Odermatt, Peter

    2017-10-01

    Human intestinal sarcocystosis (HIS), caused by Sarcocystis species, is acquired by eating undercooked meat from sarcocyst-containing cattle (S. hominis, S. heydorni) and pigs (S. suihominis). We report on the detection of human intestinal Sarcocystis infections in a cross-sectional survey of Strongyloides stercoralis in early 2014, in Rovieng District, Preah Vihear Province, northern Cambodia. Among 1081 participants, 108 (10.0%) were diagnosed with Sarcocystis spp. oocysts in stool samples. Males had a significantly higher risk of infection than females (OR: 1.9, 95% CI: 1.3-2.9, p=0.001). None of the reported symptoms (abdominal discomfort, diarrhea, muscle pain and itching skin) occurring in the two weeks preceding the examinations were associated with a Sarcocystis infection. Many Sarcocystis cases were found among those who had participated in a wedding celebration and Chinese New Year festivities, where they had consumed raw or insufficiently cooked beef (83.3%) and pork (38.9%) based dishes. This report documents the first HIS cases in Cambodia. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. MODELANDO EL CRECIMIENTO DE NEURITAS

    Directory of Open Access Journals (Sweden)

    Oscar Ávila

    2007-01-01

    Full Text Available El funcionamiento adecuado del sistema nervioso de un organismo, aun desde su estado embrionario, requiere que las neuronas establezcan conexiones específicas con otras neuronas o tejidos. Dado que una red neuronal contiene un número inmenso de neuronas, encontrar el camino correcto para cada una de ellas es claramente un fenómeno complejo, en el que participan muchos procesos. En este artículo estudiamos el crecimiento de neuritas in vitro, y nos enfocamos en los efectos que tienen diversos factores químicos en el medio de cultivo. Construimos un modelo teórico para explicar las diferencias encontradas en medios químicos diferentes. Simulaciones numéricas reproducen las observaciones y permiten predecir la forma como actúan diversas substancias químicas en el crecimiento y la conexión de neuritas.

  19. Neuroprotección en un nuevo modelo de animal transgénico

    OpenAIRE

    Mejías Estévez, Rebeca María

    2006-01-01

    El objetivo general de este proyecto fue analizar en un modelo de parkinsonismo experimental en ratones, si el aumento del poder reductor de forma selectiva en las neuronas dopaminérgicas nigrostriatales (neuronas DNS9, mediante la sobre-expresión del enzima glucosa-6-fosfato deshidrogenada (G6PD), les confiere protección. Además nos interesó estudiar algunos aspectos relacionados con la regulación de la expresión de dicho enzima en células excitables. Los objetivos específicos de este tra...

  20. EFECTOS DE LA INHIBICION DEL COMPLEJO I SOBRE LA HOMEOSTASIS DEL HIERRO MITOCONDRIAL, IMPLICANCIAS EN LA ENFERMEDAD DE PARKINSON

    OpenAIRE

    MENA JIMENEZ, NATALIA PAZ

    2011-01-01

    La enfermedad de Parkinson (EP) es la enfermedad neurodegenerativa más común del movimiento, caracterizada por la degeneración de las neuronas dopaminérgicas de la sustancia nigra pars compacta (SNpc) y la presencia de cuerpos de Lewy en las neuronas remanentes. Entre los síntomas de la enfermedad se encuentran: rigidez muscular, temblor y una lentitud en los movimientos físicos (bradiquinesia). La prevalencia de la enfermedad es de 1% en la población mayor a 60 años de edad (de R...

  1. Why our brains cherish humanity: Mirror neurons and colamus humanitatem

    OpenAIRE

    Skoyles, John R.

    2009-01-01

    El sentido común dice que estamos aislados. Después de todo, nuestros cuerpos están separados físicamente. Pero la obra Colamus humanitatem de Séneca y la observación de que “ningún hombre es una isla”, que hizo John Donne, sugieren que no estamos ni completamente aislados ni separados. Un descubrimiento reciente de la neurociencia, el de las neuronas espejo, sostiene que el cerebro y la mente no son construidos ni funcionan alejados de lo que pasa en otros individuos. ¿Qué son las neuronas e...

  2. Potenciación de la liberación de glutamato por los receptores metabotrópicos de glutamato de tipo 7 y β-andrenérgicos

    OpenAIRE

    Ferrero López, José Javier

    2016-01-01

    La comunicación entre las neuronas es la base del funcionamiento cerebral y se establece por medio de uniones celulares altamente especializadas, denominadas sinapsis. En las sinapsis químicas, esta comunicación es mediada por la liberación de neurotransmisores desde el terminal presináptico, que da lugar a la despolarización de la neurona postsináptica. Los neurotransmisores son almacenados en vesículas sinápticas, que se organizan en torno a la denominada zona activa. Esta región de la memb...

  3. Activación de la neurogénesis en el hipocampo de ratón adulto por factores embrionarios

    OpenAIRE

    Rodríguez Sáez, Sandra

    2012-01-01

    En este trabajo se ha estudiado la importancia del fluido cerebroespinal embrionario (CSF-E) en la replicación y diferenciación de los precursores neurales, situados en la pared de los ventrículos laterales, hacia células de estirpe neuronal en el cerebro de ratón adulto, así como la migración de neuronas jóvenes hacia el hipocampo, uno de los nichos neurogénicos tipificados hasta la fecha, en el cerebro adulto. para ello, se han marcado las neuronas jóvenes en replicación con el marcador...

  4. Estudio de un modelo catecolaminérgico del sistema nervioso periférico y su relación con la enfermedad de parkinson y las disfunciones simpáticas derivadas.

    OpenAIRE

    Cano Jaimez, Mª Felicidad

    2007-01-01

    RESUMEN La enfermedad de Parkinson es una enfermedad neurodegenerativa caracterizada por desórdenes motores debido a la afectación del sistema nervioso central. En esta enfermedad, por un lado se pierden neuronas de la substantia nigra produciendo, en consecuencia, un déficit en dopamina a los núcleos que proyecta, y por otro lado, las neuronas que quedan pueden presentar los característicos cuerpos de Lewy. Además de la afectación central, el sistema nervioso periférico también está afect...

  5. Spinal cord injury: Role of endothelial differentiation gene family lysophosphatidic acid receptors

    OpenAIRE

    Santos Nogueira, Eva

    2015-01-01

    El daño tisular secundario que se produce tras una lesión de la médula espinal contribuye de manera significativa a las pérdidas funcionales que se observan pacientes que padecen este tipo de afectación. Aunque la regeneración axonal y la sustitución de las neuronas dañadas tras el traumatismo medular son objetivos importantes para reparar estas lesiones, el desarrollo de estrategias experimentales que tengan como meta evitar el daño secundario sobre axones, neuronas, mielina y las células gl...

  6. Procesamiento de la información propioceptiva en el núcleo cuneatus

    OpenAIRE

    Leiras González, Roberto

    2013-01-01

    Se estudiaron los mecanismos implicados en la transmisión de la información propioceptiva en el núcleo cuneatus medio-ventral (mvCN) de gatos anestesiados, utilizando técnicas estándar de registro extracelular combinadas con estimulación eléctrica y microiontoforesis. Se demostró, mediante registros dobles de neuronas del mvCN y del cuneatus rostro-ventral (rvCN), que la microestimulación en el rvCN induce un efecto dual sobre las neuronas de proyección del mvCN. El GABA y la glicina eliminar...

  7. El espejo de la acción y la encarnación de la cognición

    OpenAIRE

    Alberto A. Yorio

    2009-01-01

    En este trabajo se comentan algunas evidencias que sugieren que los “engramas motores” y el “patrón de inervación motora”·clásicamente postulados como mecanismos independientes de la codificación de las “praxias”, tienen una existencia real y son funciones complementarias de una misma red de neuronas (“neuronas espejo”), que se localiza en la circunvolución supramarginal ubicada en el lóbulo parietal inferior izquierdo, cuya lesión ocasiona el trastorno neuropsicológico conocido como “apraxia...

  8. Camel (Camelus dromedarius) and sheep (Ovis aries) meat as a source of dog infection with some coccidian parasites.

    Science.gov (United States)

    Hilali, M; Nassar, A M; el-Ghaysh, A

    1992-06-01

    Experimental infection of dogs with camel (Camelus dromedarius) meat resulted in infection of the dogs with Isospora canis, Hammondia heydorni and Sarcocystis cameli. The dogs fed sheep (Ovis aries) meat passed oocysts of Isospora canis, Isospora ohioensis and sporocyts of Sarcocystis spp. Extraintestinal stages were detected in the intestinal lymph node of a rabbit killed 4 days following inoculation with Isospora ohioensis oocysts. Dogs fed the rabbit (killed 4 days after inoculation with I. ohioensis) passed I. ohioensis oocysts in their faeces 8 days post-infection.

  9. Efecto de la infección por el virus de la rabia sobre la expresión de parvoalbúmina, calbindina y calretinina en la corteza cerebral de ratones.

    Directory of Open Access Journals (Sweden)

    Orlando Torres-Fernández

    2004-03-01

    Full Text Available Algunas manifestaciones clínicas de la rabia, así como los resultados de experimentos con cultivos celulares y animales de laboratorio han llevado a sugerir que el virus de la rabia afecta la neurotransmisión gabaérgica. En la corteza cerebral existen diferentes tipos de neuronas que sintetizan el neurotransmisor GABA. Éstas se pueden identificar con marcadores neuronales, entre los que se destacan tres proteínas ligadoras de calcio: la parvoalbúmina (PV, la calbindina (CB y la calretinina (CR. El virus de la rabia se disemina a través de la corteza cerebral pero se desconocen sus posibles efectos citopáticos sobre las neuronas gabaérgicas. Para evaluar el efecto de la rabia sobre estas neuronas, se estudió mediante inmunohistoquímica la expresión de PV, CB y CR en la corteza frontal de ratones normales y ratones infectados con virus 'calle' o virus 'fijo' de la rabia. La PV se expresó en neuronas multipolares dispersas regularmente entre las capas II y VI, y en botones sinápticos que bordeaban el soma de las neuronas piramidales. La inmunorreactividad a CB se manifestó en dos franjas corticales: la primera, en las capas supragranulares II y III en neuronas con somas redondeados e inmersos en un neuropilo intensamente marcado; la segunda, en las capas infragranulares V y VI en neuronas multipolares dispersas y rodeadas por un neuropilo menos reactivo. La CR se expresó en neuronas bipolares con somas fusiformes distribuidas en las seis capas corticales, pero concentradas principalmente en las capas II y III. Hubo una característica común en las muestras infectadas con los dos tipos de virus: la inmunotinción a PV fue más intensa que en las muestras normales. La infección derivada del virus 'calle' no causó alteraciones adicionales en la expresión de las tres proteínas. En contraste, la infección con virus 'fijo' produjo una reducción notable del número de neuronas CB+, así como de la inmunorreactividad a CB en el

  10. Vulnerabilidad selectiva neuronal: la rabia como modelo de estudio

    Directory of Open Access Journals (Sweden)

    Orlando Torres Fernández

    2005-03-01

    Full Text Available La vulnerabilidad selectiva neuronal puede ser definida, anatómicamente, por la vulnerabilidad diferencial de circuitos y neuroquímicamnete, por la vulnerabilidad de las neuronas que expresan firentes proteínas en partícular.

  11. Alteraciones del sistema nervioso central en la discapacidad intelectual: Síndromes

    OpenAIRE

    Grau Rubio, Claudia

    2010-01-01

    Se describen las alteraciones en el desarrollo del sistema nervioso central, las partes del encéfalo y sus funciones, el funcionamiento de las neuronas y sinapsis y sus repercusiones en algunos síndromes asociados a la discapacidad intelectual

  12. Modelos Computacionales para Optimizar el Aprendizaje y el Procesamiento de la Información en Sistemas Adaptativos: Redes Neurogliales Artificiales (RR.NG.AA)

    OpenAIRE

    Porto Pazos, Ana Belén

    2004-01-01

    Tesis del Departamento de Tecnologías de la Información y las Comunicaciones, Facultad de Informática, Universidade da Coruña, y del Grupo de Fisiología celular de astrocitos y neuronas, Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal (IC-CSIC)

  13. Neurale Netwerken en Radarsystemen (Neural Networks and Radar Systems)

    Science.gov (United States)

    1989-08-01

    en/of de vorn van de intagratiefunctie te veranderen. In de macste artificiale NN zien we beide vormen van lange-termijngebeugan toegepast worden...34problemen". Neuronaal onderzoek levert maar zeer karige aanwijzingen over do signaalverwerking. Een veelbeid van modellen over de celverking is in het

  14. Informe de personal de apoyo: Reynaldo, Mirta Beatriz (2014-2015) 

    OpenAIRE

    Reynaldo, Mirta Beatriz

    2015-01-01

    Proyectos de investigación en los cuales colabora: a) Estudios del efecto modulador de ghrelina y leptina sobre las neuronas neuropeptidérgicas delhipotálamo. b) Estudio del rol modulador del receptor de ghrelina sobre las conductas hiperfágicas agudas c) Estudio del circuito neuronal por el cual ghrelina regula aspectos hedónicos del apetito

  15. Peptides of the liver stage antigen-1 (LSA-1) of Plasmodium falciparum bind to human hepatocytes.

    Science.gov (United States)

    García, Javier E; Puentes, Alvaro; López, Ramsés; Vera, Ricardo; Suárez, Jorge; Rodríguez, Luis; Curtidor, Hernando; Ocampo, Marisol; Tovar, Diana; Forero, Martha; Bermudez, Adriana; Cortés, Jimena; Urquiza, Mauricio; Patarroyo, Manuel E

    2003-05-01

    Synthetic peptides from the liver stage antigen-1 (LSA-1) antigen sequence were used in HepG2 cell and erythrocyte binding assays to identify regions that could be involved in parasite invasion. LSA-1 protein peptides 20630 ((21)INGKIIKNSEKDEIIKSNLRY(40)), 20637 ((157)KEKLQGQQSDSEQERRAY(173)), 20638 ((174)KEKLQEQQSDLEQERLAY(190)) and 20639 (191KEKLQEQQSDLEQERRAY(207)) had high binding activity in HepG2 assays. Were located in immunogenic regions; peptide cell binding was saturable. Peptide 20630 bound specifically to 48kDa HepG2 membrane surface protein. LSA-1 peptides 20630 ((21)INGKIIKNSEKDEIIKSNLRY(40)) and 20633 ((81)DKELTMSNVKNVSQTNFKSLY(100)) showed specific erythrocyte binding activity and inhibited merozoite invasion of erythrocytes in vitro. A monkey serum prepared against LSA-1 20630 peptide analog (CGINGKNIKNAEKPMIIKSNLRGC) inhibited merozoite invasion in vitro. The data suggest LSA-1 "High Activity Binding Peptides" could play a possible role in hepatic cell invasion as well as merozoite invasion of erythrocytes.

  16. Comparación de tres técnicas de trazado retrógrado para la identificación del origen espinal del nervio ciático en ratón.

    Directory of Open Access Journals (Sweden)

    Myriam L. Velandia

    2002-12-01

    Full Text Available En el presente trabajo se compararon tres técnicas para la aplicación de dos tipos de trazadores retrógrados fluorescentes (Dil y Fluorogold, con el fin de identificar las neuronas motoras y sensoriales que contribuyen con fibras al nervio ciático en ratones adultos. Se ensayó la aplicación de cristales directamente en el nervio, la inyección intraneural y la impregnación del nervio seccionado usando una cámara de silicona. La localización específica de las neuronas motoras en la médula espinal y las neuronas sensoriales en los ganglios de la raíz dorsal que aportan al nervio ciático de ratón se logró aplicando el Fluorogold mediante una cámara en el cabo proximal de los nervios previamente seccionados. Al utilizar el trazador Dil, la misma técnica no permitió hacer la identificación específica de las neuronas. Se encontró que al nervio ciático de ratón podrían contribuir el ganglio de la raíz dorsal más rostrales que los informados para ratas. Estos resultados muestran que la metodología de aplicación de neurotrazadores en cápsula y la descalcificación de tejidos es útil para la localización de neuronas de ganglios de raíz dorsal y de la médula espinal que componen el nervio ciático de ratón adulto, lo que en el futuro permitirá obtener mayor información sobre la neuroanatomía básica del ratón.

  17. The camel (Camelus dromedarius) as an intermediate host for Hammondia heydorni.

    Science.gov (United States)

    Warrag, M; Hussein, H S

    1983-10-01

    Dogs fed raw camel meat containing two types of cysts shed unsporulated Hammondia heydorni oocysts and later sporulated Sarcocystis sporocysts in their feces, but were resistant to reinfection with the Hammondia cysts. Sporulated H. heydorni occysts did not induce an enteroepithelial cycle in dogs, but resulted in the formation of muscle cysts.

  18. Sporozoite and liver stage antigen Plasmodium falciparum peptides bind specifically to human hepatocytes.

    Science.gov (United States)

    Puentes, Alvaro; García, Javier; Vera, Ricardo; López, Ramsés; Suarez, Jorge; Rodríguez, Luis; Curtidor, Hernando; Ocampo, Marisol; Tovar, Diana; Forero, Martha; Bermudez, Adriana; Cortes, Jimena; Urquiza, Mauricio; Patarroyo, Manuel E

    2004-03-12

    Sporozoite and Liver Stage Antigen (SALSA) sequence synthetic peptides were used in HepG2 cell binding assays to identify regions involved in parasite invasion. SALSA 20608 ( 21IWASEKKDEKEASEQGEESHY40) and 20611 ( 64KKDDGTDKVQEKVLEKSPKY83) peptides were determined as having high binding activity in HepG2 cell assays, some of them were located in immunogenic regions. Immune-fluorescence antibody test with 24276 (20608 peptide analogue, CGIWSSMKMDEKMAAMQGEESHCG) showed sporozoite and merozoite reactivity. This data suggests SALSA high activity binding peptides' (HABPs) possible role in hepatic cell invasion and merozoite invasion of erythrocytes.

  19. [EFECTOS NEUROENDOCRINOS DE INSULINA, IGF-I Y LEPTINA SOBRE LA SECRECIÓN DE HORMONA LIBERADORA DE GONADOTROPINAS (GnRH

    Directory of Open Access Journals (Sweden)

    Ana Maria Rosales-Torres

    2011-10-01

    Full Text Available El balance energético del individuo determina en gran medida su eficiencia reproductiva. Bajo condiciones de balance negativo de energía, en la mayoría de los mamíferos, hay una reducción en la síntesis de hormona liberadora de gonadotropinas (GnRH, lo cual disminuye la actividad del eje hipotálamo-hipófisis-gónadas. Cuando el balance energético es revertido, el hipotálamo puede monitorear este cambio y restablecer la secreción de GnRH. La Insulina, el Factor de Crecimiento similar a la Insulina I (IGF-I y Leptina parecen ser los principales mensajeros que informan al hipotálamo sobre el estado energético del animal puesto que las concentraciones periféricas de estas hormonas en situaciones energéticas negativas o positivas, se han asociado con los cambios en la secreción de GnRH. En la presente revisión se muestra como IGF-I actúa directamente sobre neuronas secretoras de GnRH, afectando su síntesis, en tanto que insulina y leptina actúan sobre neuronas en el núcleo arcuato, las cuales hacen sinapsis con neuronas GnRH en el área preóptica medial. Sobre neuronas productoras de neuropéptido Y (NPY insulina y leptina reducen su expresión y por lo tanto el efecto negativo del NPY sobre neuronas GnRH. En cambio insulina y leptina estimulan la síntesis de péptido similar a la galanina (GLAP y propiomelanocortina (POMC. Tanto GALP como los metabolitos de POMC (hormona estimulante de melanocitos principalmente incrementan la síntesis de GnRH. Finalmente, la leptina, incrementa la expresión de kispeptina en neuronas del núcleo ARC. Kispeptina por su parte también tiene un efecto positivo sobre la síntesis y secreción de GnRH.

  20. East African Medical Journal - Vol 77, No 4 (2000)

    African Journals Online (AJOL)

    Human IgG subclass antibodies to the 19 kilodalton carboxy terminal fragment of Plasmodium Falciparum merozoite surface protein 1 (MSP119) and predominance of the MAD20 allelic type of MSP1 in Uganda · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. B Apio ...

  1. An outbreak of locally acquired Plasmodium vivax malaria among migrant workers in Oman

    DEFF Research Database (Denmark)

    Simon, Bruno; Sow, Fatimata; Al Mukhaini, Said K.

    2017-01-01

    ), and merozoite surface protein 3 (msp3) markers for genotyping of parasite DNA obtained by scrapping off the surface of smears, genetic diversity and phylogenetic analysis were performed. The study found that the samples had very low genetic diversity, a temperate genotype, and a high genetic distance, with most...

  2. Host-parasite interactions that guide red blood cell invasion by malaria parasites.

    Science.gov (United States)

    Paul, Aditya S; Egan, Elizabeth S; Duraisingh, Manoj T

    2015-05-01

    Malaria is caused by the infection and proliferation of parasites from the genus Plasmodium in red blood cells (RBCs). A free Plasmodium parasite, or merozoite, released from an infected RBC must invade another RBC host cell to sustain a blood-stage infection. Here, we review recent advances on RBC invasion by Plasmodium merozoites, focusing on specific molecular interactions between host and parasite. Recent work highlights the central role of host-parasite interactions at virtually every stage of RBC invasion by merozoites. Biophysical experiments have for the first time measured the strength of merozoite-RBC attachment during invasion. For P. falciparum, there have been many key insights regarding the invasion ligand PfRh5 in particular, including its influence on host species tropism, a co-crystal structure with its RBC receptor basigin, and its suitability as a vaccine target. For P. vivax, researchers identified the origin and emergence of the parasite from Africa, demonstrating a natural link to the Duffy-negative RBC variant in African populations. For the simian parasite P. knowlesi, zoonotic invasion into human cells is linked to RBC age, which has implications for parasitemia during an infection and thus malaria. New studies of the molecular and cellular mechanisms governing RBC invasion by Plasmodium parasites have shed light on various aspects of parasite biology and host cell tropism, and indicate opportunities for malaria control.

  3. RESEARCH ARTICLE Analysis of polymorphisms and selective ...

    Indian Academy of Sciences (India)

    2017-01-27

    Jan 27, 2017 ... The apical membrane antigen-1 (AMA-1) of Plasmodium spp. is a merozoite surface antigen that is essential for the recognition and invasion of erythrocytes. Polymorphisms occurring in this surface antigen will cause major obstacles in developing effective malaria vaccines based on AMA-1. The objective ...

  4. Analysis of polymorphisms and selective pressures on ama1gene in ...

    Indian Academy of Sciences (India)

    The apical membrane antigen-1 (AMA-1) of Plasmodium spp. is a merozoite surface antigen that is essential for the recognition and invasion of erythrocytes. Polymorphisms occurring in this surface antigen will cause major obstacles in developing effective malaria vaccines based on AMA-1. The objective of this study was ...

  5. Untitled

    African Journals Online (AJOL)

    energy-dependent, active process that requires the merozoite to contact, .... that antibodies directed against several sexual stage antigens are capable of preventing the development of infectious the. Anopheles mosquitoes, thereby suggesting that vaccines (TBV) might be an effective weapon sporozoites in salivary glands ...

  6. Evidence that the Malaria Parasite Plasmodium falciparum Putative Rhoptry Protein 2 Localizes to the Golgi Apparatus throughout the Erythrocytic Cycle.

    Science.gov (United States)

    Hallée, Stéphanie; Richard, Dave

    2015-01-01

    Invasion of a red blood cell by Plasmodium falciparum merozoites is an essential step in the malaria lifecycle. Several of the proteins involved in this process are stored in the apical complex of the merozoite, a structure containing secretory organelles that are released at specific times during invasion. The molecular players involved in erythrocyte invasion thus represent potential key targets for both therapeutic and vaccine-based strategies to block parasite development. In our quest to identify and characterize new effectors of invasion, we investigated the P. falciparum homologue of a P. berghei protein putatively localized to the rhoptries, the Putative rhoptry protein 2 (PbPRP2). We show that in P. falciparum, the protein colocalizes extensively with the Golgi apparatus across the asexual erythrocytic cycle. Furthermore, imaging of merozoites caught at different times during invasion show that PfPRP2 is not secreted during the process instead staying associated with the Golgi apparatus. Our evidence therefore suggests that PfPRP2 is a Golgi protein and that it is likely not a direct effector in the process of merozoite invasion.

  7. Genetic diversity of Plasmodium falciparum field isolates from south ...

    African Journals Online (AJOL)

    Conclusion: The allelic distributions however were similar to those previously reported in other endemic malaria countries. Future studies will be designed to include other malaria endemic regions of Nigeria such as the oil exploration regions. Keywords: Genetic diversity; Plasmodium; Merozoite surface protein, monoclonal ...

  8. Multiplicity of infections and level of recrudescence in Plasmodium ...

    African Journals Online (AJOL)

    Polymorphism and antigenic variation are important biological survival strategies of malaria parasites determining the episode, outcome and implications of treatment interventions. In P. falciparum, polymorphic antigens are associated with the asexual blood-stage; merozoite surface protein 2 (MSP2). The MSP2 genes ...

  9. Expression, Purification and Characterization of GMZ2'.10C, a Complex Disulphide-Bonded Fusion Protein Vaccine Candidate against the Asexual and Sexual Life-Stages of the Malaria-Causing Plasmodium falciparum Parasite

    NARCIS (Netherlands)

    Mistarz, U.H.; Singh, S.K; Nguyen, T.; Roeffen, W.; Lissau, C.; Madsen, S.M.; Vrang, A.; Tiendrebeogo, R.W.; Kana, I.H.; Sauerwein, R.W.; Theisen, M.; Rand, K.D.

    2017-01-01

    PURPOSE: Production and characterization of a chimeric fusion protein (GMZ2'.10C) which combines epitopes of key malaria parasite antigens: glutamate-rich protein (GLURP), merozoite surface protein 3 (MSP3), and the highly disulphide bonded Pfs48/45 (10C). GMZ2'.10C is a potential candidate for a

  10. Multiplicity of infections and level of recrudescence in Plasmodium ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-09-18

    Sep 18, 2006 ... Polymorphism and antigenic variation are important biological survival strategies of malaria parasites determining the episode, outcome and implications of treatment interventions. In P. falciparum, polymorphic antigens are associated with the asexual blood-stage; merozoite surface protein 2 (MSP2).

  11. Human IgG subclass antibodies to the 19 kilodalton carboxy ...

    African Journals Online (AJOL)

    Objective: To determine the natural human humoral immune responses to the 19 kilodalton carboxy terminal fragment of Plasmodium falciparum merozoite surface protein 1 (MSP119), a malaria candidate vaccine antigen and to determine the prevalence of MAD20 and K1 alleles of P. falciparum MSP1. Design: Community ...

  12. Download this PDF file

    African Journals Online (AJOL)

    De Don

    Plasmodiumfalciparum merozoite surface protein-1. 19. (MSP-1. 19. ) is a prime candidate for a blood-stage malaria vaccine. The presence ofigM against. Plasmodiumfalciparum has been linked to protection from malaria. This study intends to provide insight into the role of anti-MSP-1 19 IgM in malaria immunity in children.

  13. Besnoitiosis in rodents from Colorado. [Parasitic infestations

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, G E; Winsor, T F; Adee, R R

    1976-01-01

    Parasitic cysts of Besnoitia jellisoni (coccidia) were found in rodents (Peromyscus maniculatus and Spermophilus tridecemlineatus) trapped in Eastern Colorado. The parasite was associated with a granulomatous inflammatory reaction in the lungs of each rodent and was disseminated in several organs from one Peromyscus. The ultrastructural appearance of the merozoites and the cyst wall formed by the host cell were studied.

  14. Author Details

    African Journals Online (AJOL)

    Abdullah, S. Vol 4, No 4 (2009) - Articles Antibodies against Merozoite Surface Protein 1 and 2 in Sudanese children. Abstract. ISSN: 1858-5051. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use ...

  15. Oxidative stress and non-enzymic antioxidant status in hypertensive ...

    African Journals Online (AJOL)

    SERVER

    2007-07-18

    Jul 18, 2007 ... Comparison of immunity to malaria in Sudan and Indonesia. Crisis form versus merozoite-invasion inhibition. Proc. Natl. Acad. Sci. USA. 86: 922-925. Khosh F, Khosh K (2001). A natural approach to hypertension. Attern. Med.6: 596-600. Lawal SO, Falase AO (1988) The effect of hypertension on the heart ...

  16. Signatures of malaria vaccine efficacy in ageing murine immune memory

    NARCIS (Netherlands)

    Haussig, J.M.; Burgold, J.; Hafalla, J.C.; Matuschewski, K.; Kooij, T.W.A.

    2014-01-01

    Malaria transmission occurs by mosquito bite. Thereafter, Plasmodium sporozoites specifically invade the liver, where they develop into thousands of merozoites that initiate blood-stage infection and clinical malaria. The pre-erythrocytic phase of a Plasmodium infection is the target of experimental

  17. Anti-Plasmodium falciparum invasion ligand antibodies in a low malaria transmission region, Loreto, Peru

    DEFF Research Database (Denmark)

    Villasis, Elizabeth; Lopez-Perez, Mary; Torres, Katherine

    2012-01-01

    Background: Erythrocyte invasion by Plasmodium falciparum is a complex process that involves two families; Erythrocyte Binding-Like (EBL) and the Reticulocyte Binding-Like (PfRh) proteins. Antibodies that inhibit merozoite attachment and invasion are believed to be important in mediating naturall...

  18. Utilización del patrón de restricción del DNA codificante para el RNA Ribosomal de la subunidad pequeña para la caracterización de Apicomplexa

    Directory of Open Access Journals (Sweden)

    López Adelaida

    1996-12-01

    Full Text Available Los Apicomplexos constituyen un phylum de protozoarios que se caracterizan por ser parásitos obligados de una gran variedad de huéspedes vertebrados e invertebrados. Hoy en día hay fuertes polémicas en tomo a su clasificación taxonómica, sus relaciones filogenéticas, y los patrones de coevolución con sus hospederos. El gen que codifica para el ARN ribosomal de la subunidad pequeña (ARN-SURp se utiliza como marcador molecular para resolver estas inquietudes. A partir del ADN de las especies de la familia Sarcocystidae (Sarcocystis cruzi, Sarcocystis sp. de Didelphis marsupialis y Sarcocystis sp. de Columbina talpacoti y Toxoplasma gondii, y de especies de la familia Plasmodiidae (Plasmodium de Anolis chloris, P. simium, y P. falciparumi, se amplificó por PCR el gen que codifica para el ARN de la subunidad ribosomal pequeña (ARN- SURp usando los iniciadores P5-P3, 0009-2134 Y566R-567R. Se compararon
    los patrones de restricción Hind III, Eco RI, Sau 3AI y Alw 261 del DNA ribosomal. La prueba de riboprini mostró que además de discriminar entre familias permite caracterizar diferencias a nivel de género y especie.Apicomplexa is a Protozoa phylum in which all members are obliged parasites of a wide range of vertebrate and invertebrate hosts. There is an ongoing controversy on
    systematics, phylogenetic relationships and parasite - host coevolution patterns. The SSU ribosomal gen has been used as a molecular marker in order to solve these issues.
    From DNA of the species of the Sarcocystidae family (Sarcocystis cruzi, Sarcocystis sp. from Didelphis marsupialis, Sarcocystis sp. from Columbina talpacoti and Toxoplasma
    gondii, and from the species of the Plasmodiidae family (Plasmodium from Anolis ehloris, P. simium, and P. falciparum, the SSU ribosomal DNA fragemnt was
    amplified by PCR, using the pair of primers P5-P3, 0009-2134 and 566R-567R. Hind III, Eco RI, Sau 3AI and Alw 261 restriction pattems were compared

  19. ELECTRICITY DEMAND FORECASTING USING A SARIMAMULTIPLICATIVE SINGLE NEURON HYBRID MODEL

    Directory of Open Access Journals (Sweden)

    JUAN DAVID VELÁSQUEZ HENAO

    2013-01-01

    Full Text Available La combinación de modelos SARIMA y redes neuronales son una aproximación común para pronosticar series de tiempo no lineales. Mientras la metodología SARIMA es usada para capturar las componentes lineales en la serie de tiempo, las redes neuronales artifi ciales son aplicadas para pronosticar las no-linealidades remanentes en los residuos del modelo SARIMA. En este artículo, se propone un modelo simple no lineal para el pronóstico de series de tiempo obtenido por la combinación de un modelo SARIMA y una neurona simple multiplicativa que usa las mismas entradas del modelo SARIMA. Para evaluar la capacidad de la nueva aproximación, la demanda mensual de electricidad en el mercado de energía de Colombia es pronosticada y comparada con los modelos SARIMA y la neurona simple multiplicativa.

  20. Efectos del ácido oleico en la migración neuronal y en la formación de sinapsis

    OpenAIRE

    Tello Hernández, María de la Vega

    2008-01-01

    El ácido oleico, un ácido graso de 18 átomos de carbono, con un doble enlace en posición cis, actúa como un factor neurotrófico en neuronas en cultivo primario. Este efecto neurotrófico se caracteriza por un aumento en los niveles de expresión del las proteínas marcadoras de diferenciación neuronal GAP-43 y MAP-2, así como por una agrupación de las neuronas por sus somas, emitiendo de forma radial los axones. En trabajos previos comprobamos que existe un efecto sinérgico entre el ácido oleico...

  1. Caracterización y simulación de arborizaciones dentríticas con redes bayesianas incluyendo variables angulares

    OpenAIRE

    Rodríguez Luján, Luis

    2015-01-01

    El funcionamiento interno del cerebro es todavía hoy en día un misterio, siendo su comprensión uno de los principales desafíos a los que se enfrenta la ciencia moderna. El córtex cerebral es el área del cerebro donde tienen lugar los procesos cerebrales de más alto nivel, cómo la imaginación, el juicio o el pensamiento abstracto. Las neuronas piramidales, un tipo específico de neurona, suponen cerca del 80% de los cerca de los 10.000 millones de que componen el córtex cerebral,...

  2. Modulación serotoninérgica de un circuito sensoro-motor en la sanguijuela Hirudo medicinalis

    OpenAIRE

    Iscla, Irene

    2001-01-01

    El rol neuromodulador de la serotonina ha sido conservado a lo largo de la evolución y se ha observado en invertebrados y en vertebrados. Los invertebrados han sido utilizados como modelos de estudio de la modulación por serotonina, ya que la simpleza de sus sistemas nerviosos, permite correlacionar alteraciones comportamentales con modificaciones en los circuitos neuronales subyacentes a dichos comportamientos. La posibilidad de identificar inequívocamente a las neuronas serotoninérgicas, pe...

  3. Esclerosis lateral amiotrófica: ¿es el astrocito la célula primariamente dañada?

    Directory of Open Access Journals (Sweden)

    Roberto E. Sica

    2013-12-01

    Full Text Available La esclerosis lateral amiotrófica (ELA es considerada una enfermedad primaria de las motoneuronas. Ninguno de los procesos que conforman su patogenia ha probado ser su causa. Tampoco pudo demostrarse que factores ambientales la originen. Las neuronas mueren por apoptosis, hecho que abre la posibilidad de que ello sea debido a cambios en su ambiente, sin que constituyan el blanco directo de la noxa que ocasiona la enfermedad. El examen del medio que circunda a las motoneuronas encuentra a los astrocitos como responsables de su bienestar. Éstos son células plásticas, adaptan su función al tipo de neurona con la que se relacionan, cada población astrocitaria es única; si fuera afectada, las neuronas que le son dependientes padecerían. En el caso de las motoneuronas, esta circunstancia llevaría a la alteración de la producción astrocitaria de neurotransmisores y transportadores y a la carencia de nutrientes y factores tróficos que le suministran. Para explicar por qué en la ELA los síntomas se trasladan de un grupo muscular al vecino, observación correlacionada con lo que ocurre en las neuronas motoras corticales y espinales, la hipótesis aquí sostenida sugiere que el factor causante migra de un astrocito a otro, lesionándolos y privando a las motoneuronas del cuidado que le prodigan. También propone que una proteína del astrocito se pliega defectuosamente, transformándose en infecciosa e induciendo el plegamiento errado de sus similares normales, trasladándose entre los astrocitos protoplásmicos y a los astrocitos fibrosos que rodean la vía piramidal, utilizando para ello las sinapsis de hendidura.

  4. La difícil decisión de ventilación mecánica en esclerosis lateral amiotrófica: A propósito de dos casos

    Directory of Open Access Journals (Sweden)

    Jorge REY DE CASTRO MUJICA

    2006-10-01

    Full Text Available Esclerosis Lateral Amiotrófica (ELA es una enfermedad progresiva y debilitante, invariablemente fatal que afecta a las neuronas motoras, en la que las funciones cognitivas del paciente permanecen intactas y habitualmente en las fases avanzadas se presenta insuficiencia respiratoria ventilatoria requiriendo alguna modalidad de soporte ventilatorio. Dos casos con diagnóstico de ELA forma bulbar se beneficiaron de esta intervención terapéutica en nuestra ciudad.

  5. difusividad, masa, humedad, volumen y sólidos en yacón (Smallantus sonchifolius deshidratado osmóticamente

    Directory of Open Access Journals (Sweden)

    Julio Rojas Naccha

    2012-01-01

    Full Text Available Se evaluó la capacidad predictiva de la Red Neuronal Artificial (RNA en el efecto de la concentración (30,40, 50 y 60 % p/p y temperatura (30, 40 y 50°C de la solución de fructooligosacaridos (FOS en la masa,humedad, volumen y sólidos en cubos de yacón osmodeshidratados, y en el coeficiente de difusividad efectivamedia del agua, con y sin encogimiento. Se aplicó la RNA del tipoFeedforwardcon los algoritmos deentrenamientoBackpropagationy de ajuste de pesosLevenberg-Marquardt, usando la topología: error metade 10-5, tasa de aprendizaje de 0.01, coeficiente de momento de 0.5, 2 neuronas de entrada, 6 neuronas desalida, una capa oculta con 18 neuronas, 15 etapas de entrenamiento y funciones de transferencialogsig-purelin. El error promedio global por la RNA fue 3.44% y los coeficientes de correlación fueron mayores a0.9. No se encontraron diferencias significativas entre los valores experimentales con losvalores predichos porla RNA y con los valores predichos por un modelo estadístico de regresión polinomial de segundo orden (p >0.95.Palabras clave:Red Neuronal Artificial (RNA, difusividad efectiva, yacón, deshidratación osmótica

  6. IMPORTANT PROTOZOAN DISEASES OF ANIMALS IN INDONESIA (A REVIEW

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    Soeprapto Soekardono

    2012-09-01

    Full Text Available An account on important protozoan diseases mostiy with obvious clinical symptoms are emphasized and their current status reviewed. Those diseases are surra, trichomonosis in catde, babesiosis, anaplasmosis, theileriosis, leucocyto-zoonosis in chicken, and coccidiosis. Toxoplasmosis, histomonosis, chicken malaria, balantidiosis and diseases caused by Giardia, Haemoproteus and Sarcocystis are not reviewed because significant problems caused by these parasites considered important economically do not appear in Indonesia.

  7. Sarcocystinae: nomina dubia and available names.

    Science.gov (United States)

    Frenkel, J K; Heydorn, A O; Mehlhorn, H; Rommel, M

    1979-02-28

    Examination of the original descriptions of the species of Sarcocystis in cattle, sheep, and swine, and of isosporid oocysts shed sporulated by dogs, cats, man, and other carnivores, has shown that it is not possible in most instances to identify unambiguously recently recognized taxa. The original descriptions are insufficient, and because no type specimens exist, could apply to two or more of the presently recognized taxa. We consider the following nomina dubia: Sarcocystis hirsuta S. miescheriana S. tenella S. cruzi S. bertrami Isospora bigemina (S. bigemina) I. hominis (S. hominis) I. buteonis (Frenkelia buteonis) Because the former type species, Sarcocystis miescheriana, is an indeterminate nomen dubium, we are proposing S. muris as the new type species. Historically, it was the first species described clearly and unambiguously even in the light of present knowledge, and the stages of its life cycle are probably completely known; it was the second species to be named. Old and recent descriptions are reviewed, and definitions are proposed for the following taxa: S. bovifelis S. bovicanis S. bovihominis S. ovifelis S. ovicanis S. muris (type species) S. suihominis S. suicanis S. equicanis Frenkelia microti F. glareoli for which neotypes will be prepared and deposited with designated institutions and curators. A new subfamily, Cystoisosporinae, is created.

  8. Evaluation of two Neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis.

    Science.gov (United States)

    Lally, N C; Jenkins, M C; Dubey, J P

    1996-01-01

    Neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. Neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. The purpose of this study was to identify N. caninum cDNA clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. Two N. caninum tachyzoite cDNA clones expressing antigens that were recognized by serum from naturally and experimentally infected cattle were identified. The DNA sequences of these clones were determined, and the inserts were subcloned into the plasmid expression vector pTrcHisB. Both recombinant antigens, expressed as fusion proteins with a His6 tag, were purified on a nickel-chelating affinity column and evaluated in separate enzyme-linked immunosorbent assays (ELISAs). Both recombinant antigen ELISAs were capable of distinguishing between sera from Neospora-infected cows and sera from uninfected control cows. Furthermore, both assays were able to detect an antibody response in animals that were experimentally inoculated with N. caninum. Neither antigen showed evidence of cross-reactivity with serum from animals inoculated with the closely related parasites Toxoplasma gondii, Sarcocystis cruzi, Sarcocystis hominis, and Sarcocystis hirsuta. PMID:8705668

  9. Surrogate hosts: Hunting dogs and recolonizing grey wolves share their endoparasites

    Directory of Open Access Journals (Sweden)

    Ines Lesniak

    2017-12-01

    Full Text Available Understanding how closely related wildlife species and their domesticated counterparts exchange or share parasites, or replace each other in parasite life cycles, is of great interest to veterinary and human public health, and wildlife ecology. Grey wolves (Canis lupus host and spread endoparasites that can either directly infect canid conspecifics or their prey serving as intermediate hosts of indirectly transmitted species. The wolf recolonization of Central Europe represents an opportunity to study parasite transmission dynamics between wildlife and domestic species for cases when a definitive host returns after local extinction – a situation equivalent to a ‘removal experiment’.Here we investigate whether the re–appearance of wolves has increased parasite pressure on hunting dogs – a group of companion animals of particular interest as they have a similar diet to wolves and flush wolf habitats when hunting. We compared prevalence (P and species richness (SR of helminths and the protozoan Sarcocystis to determine whether they were higher in hunting dogs from wolf areas (ndogs = 49 than a control area (ndogs = 29 without wolves. Of particular interest were S. grueneri and S. taeniata, known as ‘wolf specialists’.Five helminth and 11 Sarcocystis species were identified, of which all helminths and eight Sarcocystis species were shared between dogs and wolves. Overall prevalence and species richness of helminths (P:38.5% vs. 24.1%; SRmean:0.4 vs. 0.3 species and Sarcocystis (P:63.3% vs. 65.5%, SRmean:2.1 vs. 1.8 species did not differ between study sites. However, hunting dogs were significantly more likely to be infected with S. grueneri in wolf areas (P:45.2% vs. 10.5%; p = 0.035. The findings suggest that wolves indirectly increase S. grueneri infection risk for hunting dogs since cervids are intermediate hosts and occasionally fed to dogs. Furthermore, a periodic anthelminthic

  10. Plasmodium falciparum normocyte binding protein (PfNBP-1) peptides bind specifically to human erythrocytes.

    Science.gov (United States)

    Valbuena, John Jairo; Vera, Ricardo; García, Javier; Puentes, Alvaro; Curtidor, Hernando; Ocampo, Marisol; Urquiza, Mauricio; Rivera, Zuly; Guzmán, Fanny; Torres, Elizabeth; Patarroyo, Manuel Elkin

    2003-07-01

    Plasmodium falciparum normocyte binding protein-1 (PfNBP-1), a Plasmodium vivax RBP-1 orthologue is expressed in the apical merozoite area. PfNBP-1 binds directly to human erythrocyte membrane in a sialic acid-dependent but trypsin-resistant way. Erythrocyte binding assays were done with synthetic peptides covering the sequence reported as PfNBP-1. Two specific erythrocyte high activity binding peptides were found: 101VFINDLDTYQYEYFYEWNQ(120), peptide 26332, and 181NTKETYLKELNKKKMLQNKK(200), peptide 26336. These two peptides' binding was saturable and presenting nanomolar affinity constants. The critical binding residues (those residues underlined and highlighted in bold) were determined by competition assays with glycine-scan analogue peptides. These peptides were able to block merozoite in vitro invasion of erythrocytes.

  11. Eimeria bovis infection modulates endothelial host cell cholesterol metabolism for successful replication

    OpenAIRE

    Hamid, Penny H.; Hirzmann, Joerg; Kerner, Katharina; Gimpl, Gerald; Lochnit, Guenter; Hermosilla, Carlos R.; Taubert, Anja

    2015-01-01

    During first merogony Eimeria bovis forms large macromeronts in endothelial host cells containing >120 000 merozoites I. During multiplication, large amounts of cholesterol are indispensable for the enormous offspring membrane production. Cholesterol auxotrophy was proven for other apicomplexan parasites. Consequently they scavenge cholesterol from their host cell apparently in a parasite-specific manner. We here analyzed the influence of E. bovis infection on endothelial host cell cholestero...

  12. Developmentally Regulated Ribosomal rDNA Genes in Plasmodium vivax: Biological Implications and Practical Applications

    Science.gov (United States)

    1994-08-10

    eucaryotic ribosome synthesis. Biochem Cell Bioi 69: 5-22. Lewin , B., ed . (1980). In Gene Expression-2. Wiley, New York. pp.563-564. Li, J . , Wirtz, R...sporozoite invades the Hver cells and initiates an exoerythrocytic schizogony. Over a period of 5-15 days depending on the parasite species, the sporozoite...phase, erythrocytic schizogony, starts when the released merozoites enter the bloodstream and invade the red blood cells . The parasites proceed

  13. A novel antibody-dependent cellular cytotoxicity mechanism involved in defense against malaria requires costimulation of monocytes FcgammaRII and FcgammaRIII

    DEFF Research Database (Denmark)

    Jafarshad, Ali; Dziegiel, Morten H; Lundquist, Rasmus

    2007-01-01

    Clinical experiments have shown that the Ab-dependent cell-mediated inhibition of Plasmodium falciparum is a major mechanism controlling malaria parasitemia and thereby symptoms. In this study, we demonstrate that a single merozoite per monocyte (MN) is sufficient to trigger optimal antiparasitic......-dependent cellular cytotoxicity and implies that all MN are not equally effective. These findings have both fundamental and practical implications, particularly for vaccine discovery....

  14. Distorting malaria peptide backbone structure to enable fitting into MHC class II molecules renders modified peptides immunogenic and protective.

    Science.gov (United States)

    Cifuentes, Gladys; Patarroyo, Manuel Elkin; Urquiza, Mauricio; Ramirez, Luis E; Reyes, Claudia; Rodriguez, Raul

    2003-05-22

    The conserved, nonantigenic, nonimmunogenic malaria Merozoite Surface Protein-2 peptide 1, having high affinity for red blood cells, was rendered immunogenic and protective in Aotus monkeys by specifically changing some critical residues. The NMR structure revealed a switch from classical type III' into distorted III' and III beta turns in the protective peptides. These changes may lead to a better fit into the Aotus MHC class II human HLA-DRbeta1 12 molecule equivalent, thus activating the immune system.

  15. Proteins involved in invasion of human red blood cells by malaria parasites

    Directory of Open Access Journals (Sweden)

    Ewa Jaśkiewicz

    2010-11-01

    Full Text Available Malaria is a disease caused by parasites of Plasmodium species. It is responsible for around 1-2 million deaths annually, mainly children under the age of 5. It occurs mainly in tropical and subtropical areas.Malaria is caused by five Plasmodium species:[i] P. falciparum, P. malariae, P. vivax, P. knowlesi[/i] and [i]P. ovale[/i]. Mosquitoes spread the disease by biting humans. The malaria parasite has two stages of development: the human stage and the mosquito stage. The first stage occurs in the human body and is divided into two phases: the liver phase and the blood phase.The invasion of erythrocytes by [i]Plasmodium[/i] merozoites is a multistep process of specific protein interactions between the parasite and red blood cell. The first step is the reversible merozoite attachment to the erythrocyte followed by its apical reorientation, then formation of an irreversible “tight” junction and finally entry into the red cell in a parasitophorous vacuole.The blood phase is supported by a number of proteins produced by the parasite. The merozoite surface GPI-anchored proteins (MSP-1, 2, 4, 5, 8 and 10 assist in the process of recognition of susceptible erythrocytes, apical membrane antigen (AMA-1 may be directly responsible for apical reorientation of the merozoite and apical proteins which function in tight junction formation. These ligands are members of two families: Duffy binding-like (DBL and reticulocyte binding-like (RBL proteins. In [i]Plasmodium[/i] [i]falciparum[/i] the DBL family includes: EBA-175, EBA-140 (BAEBL, EBA-181 (JESEBL, EBA-165 (PEBL and EBL-1 ligands.To date, no effective antimalarial vaccine has been developed, but there are several studies for this purpose. Therefore, it is crucial to understand the molecular basis of host cells invasion by parasites. Major efforts are focused on developing a multiantigenic and multiepitope vaccine preventing all steps of [i]Plasmodium[/i] invasion.

  16. Time-lapse imaging of red blood cell invasion by the rodent malaria parasite Plasmodium yoelii.

    Directory of Open Access Journals (Sweden)

    Kazuhide Yahata

    Full Text Available In order to propagate within the mammalian host, malaria parasites must invade red blood cells (RBCs. This process offers a window of opportunity in which to target the parasite with drugs or vaccines. However, most of the studies relating to RBC invasion have analyzed the molecular interactions of parasite proteins with host cells under static conditions, and the dynamics of these interactions remain largely unstudied. Time-lapse imaging of RBC invasion is a powerful technique to investigate cell invasion and has been reported for Plasmodium knowlesi and Plasmodium falciparum. However, experimental modification of genetic loci is laborious and time consuming for these species. We have established a system of time-lapse imaging for the rodent malaria parasite Plasmodium yoelii, for which modification of genetic loci is quicker and simpler. We compared the kinetics of RBC invasion by P. yoelii with that of P. falciparum and found that the overall kinetics during invasion were similar, with some exceptions. The most striking of these differences is that, following egress from the RBC, the shape of P. yoelii merozoites gradually changes from flat elongated ovals to spherical bodies, a process taking about 60 sec. During this period merozoites were able to attach to and deform the RBC membrane, but were not able to reorient and invade. We propose that this morphological change of P. yoelii merozoites may be related to the secretion or activation of invasion-related proteins. Thus the P. yoelii merozoite appears to be an excellent model to analyze the molecular dynamics of RBC invasion, particularly during the morphological transition phase, which could serve as an expanded window that cannot be observed in P. falciparum.

  17. The conserved clag multigene family of malaria parasites: essential roles in host-pathogen interaction.

    Science.gov (United States)

    Gupta, Ankit; Thiruvengadam, Girija; Desai, Sanjay A

    2015-01-01

    The clag multigene family is strictly conserved in malaria parasites, but absent from neighboring genera of protozoan parasites. Early research pointed to roles in merozoite invasion and infected cell cytoadherence, but more recent studies have implicated channel-mediated uptake of ions and nutrients from host plasma. Here, we review the current understanding of this gene family, which appears to be central to host-parasite interactions and an important therapeutic target. Published by Elsevier Ltd.

  18. [Proteins involved in invasion of human red blood cells by malaria parasites].

    Science.gov (United States)

    Jaśkiewicz, Ewa; Graczyk, Jakub; Rydzak, Joanna

    2010-11-30

    Malaria is a disease caused by parasites of Plasmodium species. It is responsible for around 1-2 million deaths annually, mainly children under the age of 5. It occurs mainly in tropical and subtropical areas. Malaria is caused by five Plasmodium species: P. falciparum, P. malariae, P. vivax, P. knowlesi and P. ovale. Mosquitoes spread the disease by biting humans. The malaria parasite has two stages of development: the human stage and the mosquito stage. The first stage occurs in the human body and is divided into two phases: the liver phase and the blood phase. The invasion of erythrocytes by Plasmodium merozoites is a multistep process of specific protein interactions between the parasite and red blood cell. The first step is the reversible merozoite attachment to the erythrocyte followed by its apical reorientation, then formation of an irreversible "tight" junction and finally entry into the red cell in a parasitophorous vacuole. The blood phase is supported by a number of proteins produced by the parasite. The merozoite surface GPI-anchored proteins (MSP-1, 2, 4, 5, 8 and 10) assist in the process of recognition of susceptible erythrocytes, apical membrane antigen (AMA-1) may be directly responsible for apical reorientation of the merozoite and apical proteins which function in tight junction formation. These ligands are members of two families: Duffy binding-like (DBL) and reticulocyte binding-like (RBL) proteins. In Plasmodium falciparum the DBL family includes: EBA-175, EBA-140 (BAEBL), EBA-181 (JESEBL), EBA-165 (PEBL) and EBL-1 ligands. To date, no effective antimalarial vaccine has been developed, but there are several studies for this purpose. Therefore, it is crucial to understand the molecular basis of host cells invasion by parasites. Major efforts are focused on developing a multiantigenic and multiepitope vaccine preventing all steps of Plasmodium invasion.

  19. Optimisation of Production of Immunogenic Malaria Surface Antigens in Plants

    OpenAIRE

    KARTIKA MAILLIKA SETYABUDI

    2017-01-01

    Vaccines against malaria could serve a useful purpose in malaria control, prevention and eradication efforts. P. falciparum merozoite surface proteins (MSP): MSP119, MSP4 and MSP5 are promising targets to establish a protective immune response against malaria. Plant-based expression system presents potential as a cost-effective, scalable and safe production platform. This study provides evidence of the feasibility of plants to produce immunogenic P. falciparum MSP119, MSP4, MSP5. The demonstr...

  20. Complement and Antibody-Mediated Enhancement of Erythrocyte Invasion by Plasmodium Falciparum

    Science.gov (United States)

    2016-04-01

    Keywords: Malaria Complement Red blood cells Merozoites CR11. Introduction Malaria , a mosquito-borne infectious disease caused by eukaryotic intracellular... malaria kills hundreds of thousands of people every year. A vaccine that blocks red blood cell (RBC) invasion has been an elusive goal. Although...to use complement to invade RBCs and, thus, hijack the complement system and evade the host immune response. 15. SUBJECT TERMS Malaria , complement

  1. Revealing the sequence and resulting cellular morphology of receptor-ligand interactions during Plasmodium falciparum invasion of erythrocytes.

    Directory of Open Access Journals (Sweden)

    Greta E Weiss

    2015-02-01

    Full Text Available During blood stage Plasmodium falciparum infection, merozoites invade uninfected erythrocytes via a complex, multistep process involving a series of distinct receptor-ligand binding events. Understanding each element in this process increases the potential to block the parasite's life cycle via drugs or vaccines. To investigate specific receptor-ligand interactions, they were systematically blocked using a combination of genetic deletion, enzymatic receptor cleavage and inhibition of binding via antibodies, peptides and small molecules, and the resulting temporal changes in invasion and morphological effects on erythrocytes were filmed using live cell imaging. Analysis of the videos have shown receptor-ligand interactions occur in the following sequence with the following cellular morphologies; 1 an early heparin-blockable interaction which weakly deforms the erythrocyte, 2 EBA and PfRh ligands which strongly deform the erythrocyte, a process dependant on the merozoite's actin-myosin motor, 3 a PfRh5-basigin binding step which results in a pore or opening between parasite and host through which it appears small molecules and possibly invasion components can flow and 4 an AMA1-RON2 interaction that mediates tight junction formation, which acts as an anchor point for internalization. In addition to enhancing general knowledge of apicomplexan biology, this work provides a rational basis to combine sequentially acting merozoite vaccine candidates in a single multi-receptor-blocking vaccine.

  2. Activated Brain Endothelial Cells Cross-Present Malaria Antigen.

    Science.gov (United States)

    Howland, Shanshan W; Poh, Chek Meng; Rénia, Laurent

    2015-06-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention.

  3. Activated Brain Endothelial Cells Cross-Present Malaria Antigen.

    Directory of Open Access Journals (Sweden)

    Shanshan W Howland

    2015-06-01

    Full Text Available In the murine model of cerebral malaria caused by P. berghei ANKA (PbA, parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention.

  4. Activated Brain Endothelial Cells Cross-Present Malaria Antigen

    Science.gov (United States)

    Howland, Shanshan W.; Poh, Chek Meng; Rénia, Laurent

    2015-01-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention. PMID:26046849

  5. Exploitation of a newly-identified entry pathway into the malaria parasite-infected erythrocyte to inhibit parasite egress.

    Science.gov (United States)

    Glushakova, Svetlana; Busse, Brad L; Garten, Matthias; Beck, Josh R; Fairhurst, Rick M; Goldberg, Daniel E; Zimmerberg, Joshua

    2017-09-25

    While many parasites develop within host cells to avoid antibody responses and to utilize host cytoplasmic resources, elaborate egress processes have evolved to minimize the time between escaping and invading the next cell. In human erythrocytes, malaria parasites perforate their enclosing erythrocyte membrane shortly before egress. Here, we show that these pores clearly function as an entry pathway into infected erythrocytes for compounds that inhibit parasite egress. The natural glycosaminoglycan heparin surprisingly inhibited malaria parasite egress, trapping merozoites within infected erythrocytes. Labeled heparin neither bound to nor translocated through the intact erythrocyte membrane during parasite development, but fluxed into erythrocytes at the last minute of the parasite lifecycle. This short encounter was sufficient to significantly inhibit parasite egress and dispersion. Heparin blocks egress by interacting with both the surface of intra-erythrocytic merozoites and the inner aspect of erythrocyte membranes, preventing the rupture of infected erythrocytes but not parasitophorous vacuoles, and independently interfering with merozoite disaggregation. Since this action of heparin recapitulates that of neutralizing antibodies, membrane perforation presents a brief opportunity for a new strategy to inhibit parasite egress and replication.

  6. Plasmodium falciparum Adhesins Play an Essential Role in Signalling and Activation of Invasion into Human Erythrocytes.

    Directory of Open Access Journals (Sweden)

    Wai-Hong Tham

    2015-12-01

    Full Text Available The most severe form of malaria in humans is caused by the protozoan parasite Plasmodium falciparum. The invasive form of malaria parasites is termed a merozoite and it employs an array of parasite proteins that bind to the host cell to mediate invasion. In Plasmodium falciparum, the erythrocyte binding-like (EBL and reticulocyte binding-like (Rh protein families are responsible for binding to specific erythrocyte receptors for invasion and mediating signalling events that initiate active entry of the malaria parasite. Here we have addressed the role of the cytoplasmic tails of these proteins in activating merozoite invasion after receptor engagement. We show that the cytoplasmic domains of these type 1 membrane proteins are phosphorylated in vitro. Depletion of PfCK2, a kinase implicated to phosphorylate these cytoplasmic tails, blocks P. falciparum invasion of red blood cells. We identify the crucial residues within the PfRh4 cytoplasmic domain that are required for successful parasite invasion. Live cell imaging of merozoites from these transgenic mutants show they attach but do not penetrate erythrocytes implying the PfRh4 cytoplasmic tail conveys signals important for the successful completion of the invasion process.

  7. Mattesia weiseri sp. nov., a new neogregarine (Apicomplexa: Lipotrophidae) pathogen of the great spruce bark beetle, Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae).

    Science.gov (United States)

    Yaman, Mustafa; Radek, Renate

    2015-08-01

    A new neogregarine pathogen of the great spruce bark beetle, Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae), is described based on light microscopy and ultrastructural characteristics. The pathogen infects the fat body and the hemolymph of the beetle. The infection was nonsynchronous so that different developmental stages could be observed simultaneously in the hemolymph. All life stages from sporozoite to oocyst of the pathogen including micronuclear and macronuclear merozoites were detected. The sporozoites measured about 8.7 × 1.9 μm and trophozoites, 11.9 × 3.3 μm. Micronuclear merozoites seen in the hemolymph were motile, elongate, slightly broader at the anterior pole, and measured 18.4 × 2.0 μm. Macronuclear merozoites had a size of ca. 16.4 × 2.3 μm. Gametogamy results in the formation of two paired oocysts within a gametocyst. The lemon-shaped oocyst measured 10.9 × 6.1 μm and had a very thick wall (375-450 nm). All morphological and ultrastructural characteristics of the life cycle stages indicate that the described neogregarine in D. micans is clearly different from known Mattesia species infecting bark beetles, and from any other described Mattesia spp. Therefore, we create a new species, Mattesia weiseri sp. nov.

  8. Development of a recombinant indirect ELISA for the diagnosis of Theileria sp. (China) infection in small ruminants.

    Science.gov (United States)

    Miranda, J; Bakheit, M A; Liu, Z; Yin, H; Mu, Y; Guo, S; Beyer, D; Oliva, A; Ahmed, J S; Seitzer, U

    2006-05-01

    Theileria sp. (China) causes severe limitations on the development of the livestock industry in the north-west of China. An enzyme-linked immunosorbent assay (ELISA) based on merozoite homogenate of the parasite for diagnosis of infection has been established; however, cross-reactivity with other small ruminant-infecting piroplasms could not be excluded. Thus, a prerequisite for epidemiological surveys and diagnosis was the establishment of a recombinant protein-based ELISA. To this end, serum from Theileria sp. (China)-infected sheep was used to screen a Theileria lestoquardi expression library, resulting in the identification of a specifically reacting clone with a high identity to the heat shock protein 70 (HSP70) of Theileria parva and Theileria annulata and thus named TlHSP70. An HSP70 homologue was also confirmed to be expressed by Theileria sp. (China) merozoites (TcHSP70). A part of the TlHSP70 protein, found to be conserved in TcHSP70, was recombinantly expressed and used to establish an ELISA. A total of 260 field serum samples tested resulted in a sensitivity and specificity of 94.3 and 89.5%, respectively, in comparison with the merozoite homogenate ELISA. The potentials of the application of the test in epidemiological surveys to map out the prevalence of the disease and for routine diagnostics are described.

  9. Subpoblaciones neuronales presentes en cultivos primarios de ganglio espinal y su relación con la infección in vitro por virus de rabia

    Directory of Open Access Journals (Sweden)

    Hernán Hurtado

    2000-02-01

    Full Text Available

    El virus de la rabia presenta un fuerte tropismo neuronal y que produce una encefalitis generalmente letal. En un accidente rábico clásico, producido por la mordedura de un animal infectado, el virus es captado por terminaciones nerviosas motoras, autonómicas o sensoriales. Si es captado por estas últimas, el virus se transporta retrógradamente hacia los somas neuronales ubicados en los ganglios espinales y de ahí pasa hasta el Sistema Nervioso Central en donde ejerce su acción patógena. Por este motivo los cultivos de ganglio espinal son un modelo relevante para estudiar la interacción entre el virus de la rabia y las neuronas sensoriales presentes en ellos. En estos cultivos se encuentran dos tipos de células, neuronas y células no neuronales (fibroblastos y células de Schwann. Al inocular los cultivos con virus de rabia cepa CVS (Challenge Virus Standard, a pesar de que las células no neuronales son la mayoría, las que se infectan en mayor proporción son las neuronas, lo que confirma el marcado neurotropismo del virus. Adicionalmente a esto, dentro de la población neuronal, parece existir una subpoblación con mayor susceptibilidad hacia la infección por el virus. Para comprobar esta hipótesis, se caracterizaron las subpoblaciones neuronales presentes en estos cultivos utilizando un criterio morfológico (diámetro neuronal y uno bioquímico (presencia de neuropéptidos como marcadores de subpoblaciones en el ganglio. Se realizó una técnica de doble inmunocitoquímica para virus rábico y los neuropéptidos Sustancia P (SP, Neuropéptido Y (NPY, Galanina (GAL, Péptido Relacionado con el Gen de la Calcitonina (CGRP y Péptido Intestinal Vasoactivo (VIP, que clásicamente se usan para la definición de subpoblaciones. El análisis morfométrico demostró que en nuestros cultivos el 85% de las neuronas presentes son de pequeño diámetro (<25

  10. El síndrome de Kallmann. Correlación fenotipo-genotípica.

    OpenAIRE

    García Piñero, Alfonso José

    2015-01-01

    El Síndrome de Kallmann (SK) es una enfermedad genética del desarrollo, que asocia un hipogonadismo hipogonadotrópico (HH) congénito con pérdida total (anosmia) o parcial (hiposmia) del olfato. La alteración olfativa es secundaria a la aplasia o hipoplasia de las estructuras olfatorias (bulbos, tractos y surcos cerebrales olfatorios). El HH se debe a la deficiencia en la hormona liberadora de gonadotropinas hipotalámica (GnRH) como resultado del fallo en la migración de las neuronas productor...

  11. Remodelado del calcio intracelular y susceptibilidad a la muerte neuronal en el envejecimiento y en la enfermedad de Alzheimer

    OpenAIRE

    Calvo Rodríguez, María

    2015-01-01

    a presente tesis doctoral se ha centrado en el estudio de la dishomeostasis del Ca2+ intracelular en el envejecimiento y en la Enfermedad de Alzhéimer como base para el desarrollo de nuevas estrategias eficaces en la prevención y/o el tratamiento de esta enfermedad. Nuestros resultados sugieren que el remodelado del Ca2+ intracelular, y particularmente la mayor captación de Ca2+ por la mitocondria, contribuyen a la mayor susceptibilidad a la muerte celular que aparece en las neuronas de hi...

  12. Guía didáctica de estimulación congnitiva, afectiva y expresiva para niños/as de o a 5 años dirigida a las maestrías del área pre-escolar de la Fundación San José de la Comuna

    OpenAIRE

    Benítez Telles, Andrea; Cuadros Moreira, Liliana

    2005-01-01

    La estimulación aumenta la actividad del sistema nervioso, favorece las conexiones entre neuronas, y crea una red neuronal necesaria para el aprendizaje. En el ámbito mundial, la estimulación ha experimentado un crecimiento importante en el campo de la pedagogía y de la calidad de la educación. El reciente y relevante informe sobre Educación Infantil difundido por la Organización para la Cooperación Económica y el Desarrollo (O.E.C.D)1, explicita que después del acceso, aumentar la calidad...

  13. Herpesvirus Herpesvirus

    OpenAIRE

    A. Bascones-Martínez; X. Pousa-Castro

    2011-01-01

    El Herpesvirus (HSV) destaca por ser el principal responsable de un gran número de infecciones de la región orofacial, así como de la región genital. El virus del herpes simple es el prototipo de una gran familia de virus de doble cadena de ADN, los herpesviridiae, que causan una gran morbilidad en humanos. La infección en las células de la mucosa epitelial da lugar a una serie de signos clínicos y a la infección latente a nivel de las neuronas sensoriales. Durante la fase de infección produc...

  14. Importancia de la terapia física en la optimización de las manifestaciones incapacitantes y de la calidad de vida en pacientes con Esclerosis Lateral Amiotrófica: Revisión bibliográfica.

    OpenAIRE

    Olmo Treceño, Gema del

    2015-01-01

    La esclerosis lateral amiotrófica es la manifestación más frecuente de la enfermedad de la motoneurona. Se trata de una enfermedad neurodegenerativa, progresiva e incapacitante, caracterizada por la afectación de la primera y segunda neurona motora, con baja incidencia y prevalencia y escasa supervivencia. El tratamiento es sintomático, paliativo y multidisciplinar; el único medicamento que se prescribe es el riluzol, como tratamiento modificador de la acción del glutamato. ...

  15. Genetics and epigenetics in Parkinson´s disease

    OpenAIRE

    Navarro Sánchez, Luis

    2014-01-01

    La enfermedad de Parkinson (PD) es progresiva y neurodegenerativa. Se caracteriza clínicamente por bradiquinesia, temblor en reposo, rigidez e inestabilidad postural y anatomopatológicamente por degeneración nigral y por la presencia de numerosos cuerpos de Lewy en las neuronas supervivientes. Alrededor del 90% de los casos corresponden a formas esporádicas o idiopáticas de PD, de causa desconocida, mientras que el 10% restante, las denominadas formas familiares o monogénicas, son causados...

  16. Terapia génica neuroprotectora a largo plazo en un modelo de envejecimiento experimental

    OpenAIRE

    Schwerdt, J. I.; Hereñú, Claudia Beatriz; Camihort, Gisela; Luna, Georgina; Spinedi, Eduardo; Goya, Rodolfo Gustavo; Cónsole-Avegliano, Gloria Miriam

    2015-01-01

    El envejecimiento se asocia a una mayor incidencia de enfermedades neurodegenerativas (Parkinson, Alzheimer) que abren la posibilidad de aplicar terapia génica con factores neurotróficos. Los pacientes portadores de enfermedad de Parkinson presentan alteraciones funcionales en el eje hipotálamolactotropo. En la rata hembra, el envejecimiento trae aparejada una progresiva degeneración y pérdida de neuronas hipotalámicas tubero-infundibulares dopaminérgicas (TIDA) que ejercen un control tóni...

  17. Estudios para la caracterización de los procesos de dinámica mitocondrial en modelos experimentalesde enfermedades neurodegenerativas

    OpenAIRE

    Solesio Torregrosa, María Encarnación

    2013-01-01

    El objetivo principal de esta tesis es el estudio de los cambios en la fisión mitocondrial y en la mitofagia en modelos farmacológicos realizados en cultivos celulares de neuronas dopaminérgicas pertenecientes a la línea celular SH-SY5Y. Los citados modelos fueron creados por la adición de 6-OHDA, (en el caso de la Enfermedad de Parkinson), o de 3NP, (en el de la de Huntington). Ambos fármacos son conocidos agentes inductores de estas enfermedades, en diversos modelos animales y celulares. ...

  18. Estudio electrofisiológico de los efectos de compuestos marinos en canales iónicos dependientes de voltaje y plasticidad sináptica neuronal

    OpenAIRE

    Martín Vázquez, Víctor

    2015-01-01

    En el trabajo titulado Estudio electrofisiológico de los efectos de compuestos marinos en canales iónicos dependientes de voltaje y plasticidad sináptica neuronal, se describió el efecto de varios compuestos de la esponja marina Crambe crambe sobre canales iónicos dependientes de voltaje y se realizó un estudio comparativo del efecto de la ciguatoxina y la maitotoxina, toxinas involucradas en la patología de la ciguatera utilizando como modelo celular las neuronas corticales. Además, se descr...

  19. El cine como instrumento para una mejor comprensión humana

    OpenAIRE

    Astudillo, Wilson; Mendinueta, Carmen

    2008-01-01

    [ES] El cine es una poderosa herramienta cultural que permite conocer algunos elementos de la condición humana a través de la imagen y del sonido enriquecido con todas las bellas artes para tratar de impactar al intelecto y a la emoción. Procura llegar al espectador a través de la empatía por los personajes y la proyección de las experiencias propias con lo que se ve en la pantalla. Se revisa en este artículo la importancia de las neuronas espejo y de la empatía para que los espectadores se s...

  20. Teoría de la mente y esquizofrenia: aspectos conceptuales y evolutivos

    OpenAIRE

    Sánchez de las Matas, María Carmen

    2014-01-01

    El presente trabajo analiza diversas definiciones y clasificaciones de ciertos elementos y procesos que se suelen considerar como estructuras o funciones del “cerebro social”, por ejemplo, las neuronas espejo, la empatía afectiva y la teoría de la mente o metarrepresentación, en relación con el surgimiento de hipótesis evolutivas sobre los trastornos que, de manera aparentemente paradójica, suponen la supervivencia biológica en la especie de trastornos cerebrales antiempáticos, como el autism...

  1. Plasticidad del sistema nervioso

    Directory of Open Access Journals (Sweden)

    L. M. Garcia-Segura

    1976-06-01

    Full Text Available En este trabajo se revisan los conocimientos más recientes sobre el fenómeno de la plasticidad del sistéma nervioso, tanto a nivel morfológico como a nivel fisiológico y molecular. Se estudian los cambios morfólogicos y fisiológicos de las neuronas frente a la experiencia. Tambien se considera la adaptación molecular del sistéma nervioso a la información que recibe como la base de todo tipo de plasticidad.

  2. Mecanismos celulares y moleculares implicados en los cambios comportamentales inducidos durante la dependencia de morfina= Cellular and molecular mechanisms involved in morphine dependence-induced behavioral alterations /

    OpenAIRE

    Lasheras Ruiz, Carmen

    2013-01-01

    El objetivo del presente trabajo de investigación fue evaluar la metabolización de DA y NA en el NAc y los lugares específicos de fosforilación de la TH en el NAc, VTA, y NTS en ratones condicionados mediante preferencia de plaza a morfina; estudiar el papel del CRF1-R en los efectos reforzadores positivos de la morfina usando el paradigma de CPP; y examinar el impacto de la administración de morfina crónica y la abstinencia a la misma, en la expresión génica y la actividad en las neuronas or...

  3. Fisiología de la respuesta neuronal a la lesión del VI par craneal en el gato

    OpenAIRE

    Torres Ruiz, Blas

    1985-01-01

    La interrupción de una vía nerviosa provoca de una parte la imposibilidad del transporte de metabolitos entre el soma y el terminal nervioso y, de otra, la pérdida de funcionalidad en la misma. Esta interrupción origina así mismo la aparición de numerosas alteraciones bioquímicas, ultraestructurales, morfológicas, electrofisiológicas y neurofisiológicas, tanto en las neuronas afectadas como en aquellas conectadas sinápticamente a las mismas. Desde hace más de un siglo el examen de estas modif...

  4. Excitabilidad intrínseca y su plasticidad en el hipocampo de rata

    OpenAIRE

    Sánchez-Aguilera López, Alberto

    2016-01-01

    Durante las primeras semanas del desarrollo postnatal se producen cambios en las propiedades electrofisiológicas y morfológicas (Pokorny & Yamamoto 1981a; Pokorny & Yamamoto 1981b; Schwartzkroin & Kunkel 1982; Liao et al. 1999), así como en la conectividad sináptica (Hsia et al. 1998; Groc et al. 2003) de las neuronas piramidales de CA1. Además, aumenta el comportamiento exploratorio que depende de la actividad hipocampal en las ratas (Langston et al. 2010). La propagación de la información d...

  5. EFECTOS DE FLUOXETINA SOBRE LAS SINAPSIS EXITADORAS TELENCEFALICAS Y SOBRE MODELOS DE DEPRESION INDUCIDA POR ESTRES

    OpenAIRE

    AMPUERO LLANOS, ESTIBALIZ MARIELA; AMPUERO LLANOS; ESTIBALIZ MARIELA

    2012-01-01

    En la depresión mayor, la remisión de los síntomas depresivos mediante el uso de fármacos antidepresivos (FADs) requiere de la administración prolongada de éstos. El retardo necesario para observar el efecto terapéutico sugiere que necesariamente deben inducirse procesos neuroadaptativos de curso temporal lento. Diversos antecedentes muestran que en pacientes deprimidos y en modelos animales de esta enfermedad, que se basan en la exposición repetitiva a estrés, se alteran las neuronas y...

  6. Efecto de la infección por el virus de la rabia sobre la expresión de parvoalbúmina, calbindina y calretinina en la corteza cerebral de ratones.

    OpenAIRE

    Orlando Torres-Fernández; Gloria E. Yepes; Javier E. Gómez; Hernán J. Pimienta

    2004-01-01

    Algunas manifestaciones clínicas de la rabia, así como los resultados de experimentos con cultivos celulares y animales de laboratorio han llevado a sugerir que el virus de la rabia afecta la neurotransmisión gabaérgica. En la corteza cerebral existen diferentes tipos de neuronas que sintetizan el neurotransmisor GABA. Éstas se pueden identificar con marcadores neuronales, entre los que se destacan tres proteínas ligadoras de calcio: la parvoalbúmina (PV), la calbindina (CB) y la calretinina ...

  7. Efecto de la inhibición dual de GSK-3 y PDE-7 en un modelo murino de esclerosis lateral amiotrófica

    OpenAIRE

    Atencia Cibreiro, María Gabriela

    2016-01-01

    La Esclerosis Lateral Amiotrófica (ELA) es una enfermedad neurodegenerativa en la que mueren progresivamente las neuronas motoras de la corteza cerebral y la médula, con la consiguiente atrofia de los músculos inervados por ellas. Si bien últimamente han aparecido distintos modelos animales para el estudio de la ELA, los ratones que sobre-expresan el gen SOD1 humano con la mutación G93A, son los más utilizados. Estos son los animales que empleamos en nuestro estudio, en el cual evaluamos un i...

  8. POLIOMIELITIS PARALÍTICA. NUEVOS PROBLEMAS: EL SÍNDROME POSTPOLIO

    OpenAIRE

    Jesús Esteban

    2013-01-01

    En 1875 M Raymond describió la aparición de una atrofia y debilidad muscular progresiva en 3 individuos supervivientes de una poliomielitis aguda en la infancia. Jean-Martin Charcot, sugirió que la lesión inicial debía dejar a las neuronas de estos individuos más sensibles para desarrollar enfermedades medulares posteriores y que la nueva debilidad era consecuencia del sobreuso de los músculos afectos. En 1979, tras la publicación de la descripción realizada por un paciente de 57 años de las ...

  9. Papel de la melotonina en la enfermedad de Alzheimer y otras enfermedades neurodegenerativas

    OpenAIRE

    Sampedro Núñez, Eva

    2015-01-01

    Las enfermedades neurodegenerativas son enfermedades crónicas y progresivas caracterizadas por la destrucción selectiva de neuronas motoras, sensitivas y sistemas cognitivos. A pesar de que los mecanismos etiopatogénicos de muchas de ellas no se conocen con exactitud, el acúmulo de radicales libres y el consiguiente daño tisular son fenómenos fisiopatológicos comunes a todas ellas. En los últimos años, se han realizado muchos trabajos de investigación que demuestran que la melatonina posee pr...

  10. Esclerosis lateral amiotrófica: investigaciones en el modelo sod1g93a y correlaciones de interés clínico

    OpenAIRE

    Cejudo Guillen, Marta

    2016-01-01

    La esclerosis lateral amiotrófica (ELA) es una enfermedad neurodegenerativa, incurable y de carácter fatal en un plazo de 3-5 años desde su diagnóstico. Esta enfermedad se caracteriza por la degeneración progresiva de neuronas motoras. Actualmente se sabe que el sistema nervioso central (SNC) no representa una zona inmunológicamente privilegiada, de hecho cada vez cobra mayor importancia el papel que el sistema inmunitario pudiera tener en la fisiopatología asociada al curso de ciertas enferm...

  11. INTERACCION MOLECULAR DE LOS RECEPTORES CRH-R2 Y DA-D1 EN EL AREA TEGMENTAL VENTRAL DE RATA

    OpenAIRE

    ARAYA GUTIERREZ, KATHERINE ANGELICA

    2013-01-01

    La administración repetida de drogas de abuso genera cambios plásticos perdurables que se traducen en alteraciones en las propiedades funcionales de las neuronas del sistema mesocorticolímbico, como lo es la sensibilización de la liberación de glutamato en el área tegmental ventral (VTA) inducida por la administración repetida de cocaína, esto determina la recaída a la droga (Wang y cols. 2005). Dicha sensibilización estaría siendo modulada por la activación de receptores dopam...

  12. El FGF2 como regulador de la actividad mitogénica de precursores neurales en el nicho celular del cerebro embrionario de ratón

    OpenAIRE

    Lamus Molina, José Francisco

    2016-01-01

    A lo largo de la vida del individuo, las células precursoras neurales se encuentran alojadas en microentornos especializados conocidos como nichos germinales neurogénicos, que garantizan su mantenimiento y posibilitan la generación de nuevas neuronas, experimentando su momento de máxima actividad neurogénica durante el desarrollo. El fluido cerebroespinal embrionario (eCSF) ha sido identificado como uno de los elementos esenciales del nicho neurogénico del cerebro embrionario, contactando de ...

  13. Evaluación de la técnica quirúrgica de implantación de neuroestimulador a nivel del ganglio esfenopalatino para el tratamiento de las cefaleas crónicas refractarias

    OpenAIRE

    Ventura Martinez, Natalia

    2017-01-01

    - Estado actual del conocimiento El ganglio esfenopalatino (GEP), situado en la fosa pterigopalatina, es una estructura anatómica compleja que ha sido reconocida como la mayor agrupación de neuronas fuera de la cavidad craneana. No posee función sensitiva, sin embargo tiene gran relación y conexiones con múltiples ramas faciales y trigeminales, por lo que se cree que interviene en la génesis y mantenimiento de dolores faciales atípicos y cefaleas unilaterales de tipo autonómico trigeminal...

  14. Estudio, implementación y análisis de nuevos algoritmos de aprendizaje y nuevas medidas de tolerancia al ruido para redes funcionales y neuronales

    OpenAIRE

    Fontenla-Romero, Óscar

    2011-01-01

    [Resumen] Esta tesis doctoral está organizada en dos partes, En la primera parte de la memoria se presentan nuevos algoritmos para el aprendizaje de redes de neuronas artificiales con alimentación hacia delante. En primer lugar se presenta un nuevo método para el aprendizaje de redes de una capa que permite el entrenamiento de este tipo de sistemas empleando un sistema de ecuaciones lineales. El método propuesto obtiene siempre el óptimo global de la función de error y, además, presen...

  15. El sistema vomeronasal y su posible funcionalidad en larvas de anuros

    Directory of Open Access Journals (Sweden)

    Pozzi, Andrea Gabriela

    2012-12-01

    Full Text Available El sistema vomeronasal (SVN es un sistema olfatorio accesorio presente en la mayoría de los tetrápodos. Clásicamente se lo ha asociado con el paso de los vertebrados al ambiente terrestre; sin embargo las evidencias surgidas en los últimos años indican que el SVN apareció tempranamente en la evolución de los tetrápodos y sería funcional en ambientes acuáticos. Este sistema sensorial ha sido descripto en etapas larvales de anuros. Pero ¿es funcional el SVN en renacuajos? No existen experimentos en donde se evalúe la participación del SVN en la quimiodetección en renacuajos. Sin embargo, un número considerable de evidencias indican que este sistema sensorial podría ser funcional en larvas de anuros: 1 El órgano vomeronasal (OVN aparece durante el desarrollo embrionario y está presente durante toda la etapa larval. 2 El OVN contiene neuronas bipolares cuyos axones proyectan al bulbo olfatorio accesorio (BOA donde establecen conexiones sinápticas con neuronas telencefálicas. 3 Las neuronas del OVN expresan los receptores de membrana descriptos en tetrápodos, así como la proteína G involucrada en la señalización intracelular. 4 Los análisis de microscopía electrónica demuestran que el OVN posee neuronas con microvellosidades apicales como se describe para otros grupos y sus características ultraestructurales no se modifican durante la metamorfosis. Más aún, no hay diferencias en la ultraestructura de las conexiones sinápticas entre larvas y adultos a nivel del BOA. Los renacuajos presentan una gran cantidad de comportamientos mediados por quimiodetección. Conocer si el SVN participa en la detección de alguno/s de estos estímulos ayudaría no sólo a dilucidar aspectos relacionados con la comunicación química y el comportamiento en renacuajos sino también a comprender aspectos evolutivos de los sistemas quimiosensoriales en vertebrados.

  16. Acciones neuroprotectoras del estradiol y los receptores de estrógenos

    OpenAIRE

    García Segura, Luis Manuel

    2016-01-01

    El estradiol y la progesterona regulan el desarrollo y la función de los sistemas nerviosos central y periférico. Además, las hormonas ováricas, actuando a través de las células endoteliales, las células de glía y las neuronas, ejercen acciones neuroprotectoras en varios modelos animales de patología neural. Sin embargo, las implicaciones clínicas de las acciones neuroprotectoras de las hormonas ováricas en el hombre, son objeto de debate. Universidad de Málaga. Campus de...

  17. Neurociencias, educación y entorno sociocultural 1

    National Research Council Canada - National Science Library

    Hernando Barrios-Tao

    2016-01-01

    ..., de manera particular, a los factores del entorno sociocultural que influyen en el aprendizaje. La revisión se delimita con el marco temporal 2002-2014, mediante la búsqueda en bases de datos y sistemas internacionales que denotan la relación neurociencias, educación y entorno social. Factores como salud, ambiente vital, ejercicio físico y aspectos como plasticidad, madurez cerebral y neuronas espejo son relevantes para considerar el influjo del entorno sociocultural en la educación. Palabras clave Neurocie...

  18. Efecto de las neurotrofinas en cultivos primarios de ganglio espinal, normales e infectados con virus de la rabia

    Directory of Open Access Journals (Sweden)

    Hernán Hurtado

    2000-02-01

    Full Text Available

    Los cultivos de ganglio espinal son utilizados para estudiar la interacción entre el virus de la rabia y las neuronas sensoriales presentes en ellos. Se conoce que in vivo, el virus utiliza estas neuronas como una de las puertas de entrada al Sistema Nervioso Central en donde posteriormente se produce una encefalopatía letal. La patología producida por el virus es debida a su marcado tropismo hacia las neuronas, que depende a su vez de la unión entre el virus y receptores específicos en la membrana neuronal. Entre las moléculas que se han reportado como posibles receptores virales están el Receptor Nicotínico de Acetilcolina (RNACh, la Molécula de Adhesión Celular Neuronal (NCAM y el receptor de baja afinidad para las neurotrofinas (p75NTR. Se sabe que en cultivos de neuronas sensoriales adultas, las neurotrofinas pueden promover la regeneración neurítica y mantener los fenotipos neuronales. Además existe evidencia de que en líneas celulares el Nerve Growth Factor (NGF modifica la calidad y cantidad de RNACh y NCAM expresados, así en estos cultivos primarios (que expresan toda clase de receptores para neurotrofinas se pudieran estar presentando también tales cambios, que conlleven a modificaciones en la infección por el virus de rabia. De esta manera, el objetivo de este estudio, fue evaluar el efecto de las neurotrofinas sobre la regeneración neurítica y la supervivencia neuronal (en cultivos no infectados y sobre la proporción de células infectadas por virus de rabia. Para ello, los cultivos se trataron desde el inicio con NGF, Brain-Derived Neurotrophic Factor (BDNF y Neurotrophin-3 (NT-3 a tres diferentes concentraciones y algunos de ellos fueron infectados con virus de la rabia, cepa CVS (Challenge Virus Standard obtenido en cerebro de ratón. A los

  19. Papel de CPT1C en el control de la Homeostasis Energética

    OpenAIRE

    Pozo Ariza, Macarena

    2015-01-01

    En los últimos años se ha tratado de profundizar en el estudio de los mecanismos moleculares a nivel hipotalámico responsables de regular el balance energético. En la actualidad se conoce que el metabolismo de los ácidos grasos a nivel hipotalámico juega un papel muy importante en el control del apetito. Más concretamente, se ha descrito que los niveles de malonil-CoA o de aciles-CoA son reconocidos por las neuronas del hipotálamo como señales intracelulares del estado nutricional del orga...

  20. Desensibilización inducida por agonista del receptor TRPV1

    OpenAIRE

    Sanz Salvador, Lucía

    2014-01-01

    El receptor TRPV1 es un canal catiónico capaz de activarse por calor, pH ácido, voltaje y por diferentes sustancias químicas entre las que destacan los agonistas vanilloides capsaicina y resiniferatoxina. En las neuronas aferentes nociceptivas o nociceptores, donde se expresa de forma abundante, TRPV1 actúa como un sensor polimodal cuya actividad se controla por multitud de mecanismos reguladores capaces de causar su sensibilización o desensibilización. La estimulación prolongada por sus agon...

  1. Análisis genético y funcional de la frataxina y otras proteínas mitocrondriales relacionadas con ataxias cerebelosas.

    OpenAIRE

    González-Cabo, Pilar

    2005-01-01

    RESUMEN El déficit de frataxina es la causa principal de la ataxia de Friedreich, una enfermedad hereditaria neurodegenerativa que afecta a las neuronas sensitivas del ganglio dorsal y del tracto espinocerebelar. Desde que se describi¨® el gen responsable de la enfermedad y sobre todo gracias a la generaci¨®n de organismos modelos para su estudio, se han postulado diferentes funciones para la frataxina: homeostasis del hierro mitocondrial, almacenamiento del hierro, respuesta al estr¨¦s ox...

  2. Caracterización de las proyecciones aferentes y eferentes de la región parapiramidal bulbar papel en el control de las funciones vegetativas

    OpenAIRE

    Crego Pérez, Rocío

    2001-01-01

    La región parapiramidal interviene de forma activa en el control de las funciones vegetativas. Por un lado, forma parte de la red neuronal implicada en el control de la activación e inhibición de distintos órganos viscerales. Además, actúa como sensor o quimiorreceptor central informando de las condiciones ácido-básicas de su entorno a las neuronas que generan el ritmo respiratorio. El estudio de esta área quimiorreceptora, recientemente descrita, pretende conocer el papel de esta área en la ...

  3. Modulación sináptica del umbral de reclutamiento y de la frecuencia de potenciales de acción en las motoneuronas oculares

    OpenAIRE

    Torres Torrelo, Julio

    2014-01-01

    Tesis descargada desde TESEO Las neuronas reciben e integran las señales sinápticas, éstas pueden generar potenciales de acción como mecanismo para transmitir información. La función neuronal de entrada-salida se puede ajustar modificando el umbral de reclutamiento y la ganancia de la relación. Los estudios realizados en preparaciones de animal alerta han demostrado que las motoneuronas de los músculos extraoculares presentan una frecuencia de potenciales de acción fásico-tónica. Esta frec...

  4. Estudio del sistema kisspeptina y su papel en el inicio de la pubertad de la lubina europea (Dicentrarchus labrax): Efecto de la restricción calórica en machos

    OpenAIRE

    Escobar Aguirre, Sebastián

    2015-01-01

    [spa] En esta tesis doctoral se estudia el efecto de una dieta de restricción calórica de mantenimiento a largo plazo (14 meses), en machos de lubina prepúberes, sobre el inicio y desarrollo de la pubertad. Para ello se consideró el papel que los sistemas kisspeptina/GnRH juegan en el cerebro y la gónada de esta especie en términos reproductivos. Nuestros resultados evidencian que tanto las neuronas que expresan kiss1 y kiss2 como sus receptores se encuentran localizadas en zonas hipofisiotró...

  5. Identification of new biomarkers for phenotypical characterization in peripheral neuropathies

    OpenAIRE

    Seco Cervera, Marta

    2017-01-01

    Introducción Las neuropatías periféricas hereditarias son aquellas enfermedades que afectan al sistema nervioso periférico y cuya etiología reside en un desorden genético hereditario. La neurodegeneración que presentan este tipo de enfermedades se caracteriza por una pérdida progresiva de la función y/o estructura en las neuronas. En el caso de axonopatias el proceso empieza en los extremos distales de los axones largos seguido de una progresión hacia las partes más proximales. Este tipo ...

  6. Neurogénesis en la retina de mamíferos adultos

    OpenAIRE

    Martín Nieto, José; Angulo Jerez, Antonia; Martínez Navarrete, Gema Concepción; Cuenca Navarro, Nicolás

    2009-01-01

    En el cerebro de mamíferos adultos tiene lugar la formación de nuevas neuronas (neurogénesis) de forma limitada a partir de células madre neurales residentes en dos nichos discretos, localizados en el ventrículo lateral y el hipocampo. En la retina existe neurogénesis persistente durante toda la vida en peces y anfibios en la llamada zona marginal ciliar, localizada en la parte anterior del globo ocular. Esta capacidad se ha perdido esencialmente a lo largo de la evolución en mamíferos. No ob...

  7. Resúmenes de los trabajos sobre las Enfermedades Neuromusculares

    OpenAIRE

    Congreso Nacional de Neurología

    2010-01-01

    Las enfermedades neuromusculares constituyen un conjunto de afectaciones que afectan las neuronas motoras periférica, las vías motoras eferentes o los efectores (músculos esqueléticos). Sus manifestaciones clínicas son muy variadas y dependen de la causa y de los niveles de afectación. En este acápite se pueden encontrar los resúmenes de trabajos relacionados con el síndrome de Guillain Barre, polineuropatía diabética, Atrofia Muscular Espinal, Distrofia miotónica y otros todos presentados en...

  8. Alteraciones inducidas por administración neonatal de monosodio L-glutamato (MSG) y su remisión mediante la administración de N-acetil cisteína

    OpenAIRE

    Villagarcía, Hernán Gonzalo; Castro, María Cecilia; Gonzáles Arbelaez, Luisa; Schinella, Guillermo; Castrogiovanni, Daniel; Massa, María Laura; Spinedi, Eduardo; Francini, Flavio

    2017-01-01

    La administración neonatal de monosodio L-glutamato (MSG) a ratas genera daño a nivel de neuronas del núcleo arcuato hipotalámico, lo cual determina en la adultez anormalidades morfológicas, neuroendocrinas y del comportamiento, similares a las observadas en el Síndrome Metabólico (SM) humano. Por otro lado, se reconoce un rol patogénico clave del estrés oxidativo en numerosas enfermedades, incluido el mencionado SM. En consecuencia, el objetivo del presente trabajo fue evaluar los efectos de...

  9. Intracellular signaling pathways involved in L-DOPA-induced dyskinesias

    OpenAIRE

    Ruiz de Diego, Irene

    2016-01-01

    La enfermedad de Parkinson es una de las enfermedades neurodegenerativas más prevalentes en la actualidad. Se caracteriza por la muerte de las neuronas dopaminérgicas de la substantia nigra pars compacta, lo que conlleva la subsecuente depleción dopaminérgica a nivel estriatal. La L-DOPA constituye desde su descubrimiento a principio de la década de los sesenta el tratamiento de elección en la enfermedad de Parkinson, ya que es la terapia no invasiva más eficaz para combatir los síntomas de e...

  10. Efectos de la proteína SPARC sobre la maduración de las sinapsis autápticas colinérgicas

    OpenAIRE

    Albrecht, David

    2012-01-01

    [spa] Las sinapsis son un elemento clave para el funcionamiento del sistema nervioso y la formación de las sinapsis es un proceso decisivo a lo largo de la vida. El establecimiento de los contactos sinápticos ocurre tanto en el sistema nervioso en desarrollo como en el cerebro adulto. Durante todo este proceso las neuronas y las células gliales se encuentran íntimamente acopladas por todo el sistema nervioso. Las investigaciones de las últimas décadas han evidenciado que las células gliales p...

  11. Estudio de la conectividad de los circuitos neuronales del bulbo olfatorio de los primates. Comparación de individuos control con casos de Parkinson

    OpenAIRE

    Liberia Vayá, Teresa

    2015-01-01

    La enfermedad de Parkinson es una enfermedad neurodegenerativa multisistémica que afecta al sistema nervioso central y periférico. Caracterizada por la degeneración selectiva de la neuronas dopaminérgicas de la sustancia negra pars compacta (SNpc), se englobada dentro de las llamadas α-sinucleinopatías. El sello distintivo de esta patología es la propagación de agregados proteicos patológicos de α-sinucleína, en forma de cuerpos y neuritas de Lewy, a lo largo de todo el sistema nervioso. La s...

  12. Identificación y caracterización de la población total de las células ganglionares de la retina en rata : nuevos métodos de trazado, expresión de melanopsina y de factores de transcripción Brn3:estudio de la respuesta neuronal y microglial a la axotomía y efecto del envejecimiento en la retina

    OpenAIRE

    Nadal Nicolás, Francisco Manuel

    2015-01-01

    Introducción La retina es parte del sistema nervioso central (SNC) y se localiza en la cara interna del globo ocular. Su función principal es la fototransducción de las ondas electromagnéticas del espectro de la luz visible en energía eléctrica. Esta función es realizada por los fotorreceptores (conos y bastones). Tras su procesamiento, la información llega a las células ganglionares de retina (CGR). Las CGR son las únicas neuronas aferentes de la retina y transmiten la información visual ...

  13. Intuiciones, complejidad y vida cotidiana

    OpenAIRE

    Elizalde, Antonio

    2012-01-01

    Este ensayo busca indagar en cuestiones profundamente ancladas en nuestros imaginarios que nos dificultan resolver la paradoja inherente a todo quehacer educativo: el domesticar para liberar. Para ello incursiona en  la pretensión de controlar lo incontrolable, releva la importancia de lo trivial y sugiere incursionar por caminos no transitados recuperando el papel de las neuronas espejo y de la razón cordial. Se pregunta por quien enseña a quien en el mundo actual y si es posible una educaci...

  14. Characterization of brush cells of the cerebellum treated by prolonged exposure of the sample to isopropyl alcohol variant of argentic impregnation

    OpenAIRE

    Reyes Graterol, Elbert Oberto; García Oduber, Sogeilys Milagro; Laguna Campos, Edgar José; Salas Méndez, Mario Javier

    2014-01-01

    Las células cepillo son neuronas glutamatérgicas de la capa granular en la corteza cerebelosa que constan de 3 (tres) o más subtipos, caracterizados por fenotipos químicamente distintos, propiedades intrínsecas para formar sinapsis y patrones de descarga particulares. Dichas células no fueron identificadas por métodos de impregnación argéntica hasta 1994, cuando Mugnaini realiza su descripción. En este trabajo presentamos una variante de impregnación argéntica, en el cual las muestras son sum...

  15. Modulación de la neuritogénesis y de la conducta por hormonas tiroideas en ratas adultas

    OpenAIRE

    Montero-Pedrazuela, Ana

    2006-01-01

    Las alteraciones hormonales están implicadas en muchas patologías asociadas con la edad como las enfermedades neurodegenerativas y los trastornos psiquiátricos. En el adulto, las alteraciones del estado tiroideo cursan con frecuencia con cambios psicológicos y trastornos del estado del ánimo como la depresión. Se ha demostrado que en los mamíferos adultos, incluido el hombre, continúa generándose neuronas a partir de células madre en el giro dentado GD, de la formación del hipocampo. Las neur...

  16. Factores implicados en la regulación del desarrollo de las vías del dolor.

    OpenAIRE

    Valdés Sánchez, Teresa

    2015-01-01

    En el presente trabajo de tesis doctoral hemos querido investigar aspectos de la regulación de las neuronas sensoriales periféricas que participan en la detección del dolor y, para ello, hemos estudiado la contribución de la neurotrofina BDNF y de la metaloproteasa MT-5 al desarrollo y mantenimiento de esta población sensorial de indudable inetrés biomédico. Los aspectos más destacables de los hallazgos pueden resumirse en: 1) hemos identificado por primera vez la dependencia trófica postnata...

  17. Mecanismos de neurodegeneración inducidos por el líquido cefalorraquídeo en la esclerosis múltiple

    OpenAIRE

    Cid Sánchez, Cristina

    2004-01-01

    La esclerosis múltiple (EM) es la enfermedad desmielinizante más frecuente del sistema nervioso central (SNC) y una de las causas más comunes de discapacidad neurológica en adultos jóvenes. Tradicionalmente se han estudiado la inflamación y desmielinización como causas primarias de la enfermedad. En este trabajo se ha abordado el estudio de los mecanismos de neurodegeneración causada por la ausencia de remielinización y/o por un daño directo a las neuronas, dos aspectos de la enfermedad poco ...

  18. Propioceptores articulares y musculares

    OpenAIRE

    Vega, José A.

    1999-01-01

    La función de los mecanorreceptores de las articulaciones y músculos se considera asociada a la propiocepción. Sin embargo, existen evidencias de que la propiocepción no sólo depende del morfotipo de mecanorreceptor presente en dichos tejidos sino también de las propiedades de las neuronas sensitivas primarias y las fibras sensitivas asociadas a ellos, así como de su proyección sobre el asta posterior de la médula espinal. Este artículo resume las bases morfológicas de la propi...

  19. Changing the intrinsic growth capacity of motor and sensory neurons to promote axonal growth after injury the role of FGF2 in axonal regeneration /

    OpenAIRE

    Allodi, Ilary

    2012-01-01

    Les lesions dels nervis perifèrics provoquen paràlisis, anestèsia i pèrdua del control autonòmic de la zona afectada. Després de lesió, la part distal dels axons queda desconectat del soma i degenera, provocant la denervació dels òrgans diana. La degeneració walleriana crea un microambient favorable per al creixement axonal, alhora que la neurona canvia a un fenotip proregeneratiu. Malauradament, la manca d'especificitat de la regeneració, en termes de creixement motor i sensorial i reinnerva...

  20. Changing the Intrinsic Growth Capacity of motor and sensory neurons to promote axonal growth after injury

    OpenAIRE

    Allodi, Ilary

    2012-01-01

    Les lesions dels nervis perifèrics provoquen paràlisis, anestèsia i pèrdua del control autonòmic de la zona afectada. Després de lesió, la part distal dels axons queda desconectat del soma i degenera, provocant la denervació dels òrgans diana. La degeneració walleriana crea un microambient favorable per al creixement axonal, alhora que la neurona canvia a un fenotip proregeneratiu. Malauradament, la manca d’especificitat de la regeneració, en termes de creixement motor i sensor...

  1. Análisis de la capacidad vital forzada como indicador de inicio de ventilación no invasiva en enfermos con esclerosis lateral amiotrófica

    OpenAIRE

    Martínez González, Daniel

    2014-01-01

    La Esclerosis lateral amiotrófica (ELA) es una enfermedad neurodegenerativa de causa desconocida que se caracteriza por la pérdida de neuronas motoras en la médula espinal, el tronco cerebral y la corteza motora. Como consecuencia se produce un debilitamiento progresivo de los músculos de las extremidades, bulbares, torácicos y abdominales. La consecuencia directa de este hecho tiene repercusiones sobre la morbimortalidad en los pacientes con ELA. Ésta se constituye principalmente por problem...

  2. "La Medicina Nuclear" Temprana Historia y Reminiscencias temporales.

    OpenAIRE

    Efraim Otero Ruiz

    2003-01-01

    PALABRAS DEL AUTOR DURANTE LA PRESENTACIÓN DEL LIBRO.

    Presentación en la Sesión Conjunta con la Sociedad Colombiana de Historia de la Medicina.

     

    EI libro que he querido traer hoy ante ustedes se refiere ante todo al nacimiento y puesta en marcha de una especialidad, Por eso la carátula, brillantemente diseñada por mi amigo Mauricio Pérez y su esposa, parece al tiempo una descarga eléctrica o el acercamiento de dos neuronas o el n...

  3. Incidencia de la linfopenia en pacientes con Esclerosis Múltiple en tratamiento con Interferón beta

    OpenAIRE

    Castillo Ferrero, Raquel

    2017-01-01

    La Esclerosis Múltiple se trata de una enfermedad crónica del sistema nervioso central de la cual se desconoce su causa. Se caracteriza por inflamación, desmielinización y cicatrización del tejido nervioso. Desde un punto de vista patológico, se trata de una enfermedad autoinmune en la que se produce un ataque inmunológico a la vaina de mielina que recubre los axones de las neuronas del sistema nervioso central. Actualmente, existen fármacos capaces de modificar la evolución na...

  4. Mechanisms responsible of sensory afferent projections into the hindbrain

    OpenAIRE

    Zecca, Andrea

    2014-01-01

    Los animales perciben el mundo externo a través de los sistemas sensoriales. Estos consisten en: i) los receptores sensoriales que detectan estímulos externos; ii) las vías neuronales que transmiten la información sensorial al cerebro; y iii) las neuronas centrales organizadas en núcleos que procesan la información. Con el objetivo de estudiar la inervación selectiva de las regiones del rombencéfalo por las aferentes sensoriales, hemos mapado la representación topográfica de las proyecciones ...

  5. MODELO PARA SIMULAR LA HOMEÓSTASIS NEURONAL DURANTE UN INFLUJO INCREMENTADO DEL CALCIO A TRAVÉS DEL CANAL ASOCIADO AL RECEPTOR IONOTRÓPICO DE GLUTAMATO ACTIVADO POR N-METIL-D-ASPARTATO

    OpenAIRE

    Lareo, L.; Departamento de Nutrición Y Bioquímica Facultad de Ciencias Pontificia Universidad Javeriana, Bogotá; Albarracín, S.; Departamento de Nutrición Y Bioquímica Facultad de Ciencias Pontificia Universidad Javeriana, Bogotá

    2005-01-01

    Dada la importancia del receptor ionotrópico de glutamato activado por N-Metil-D-Aspartato en los procesos de aprendizaje y la formación de la memoria mediados por el transporte de calcio a través del canal asociado a dicho receptor resulta importante desarrollar modelos que permitan comprender la homeóstasis que le permite a la neurona manejar incrementos en el flujo de dicho catión sin llegar a desarrollar procesos necróticos ni apoptóticos. Este trabajo presenta una sencilla simulación de ...

  6. ¿Qué es la optogenética? Aplicaciones futuras a la práctica clínica

    OpenAIRE

    Barrientos Duque, Marta A.

    2016-01-01

    RESUMEN: La optogenética es una técnica, desarrollada recientemente, que permite el control a través de la luz de la actividad de neuronas definidas genéticamente. Las células son primero modificadas genéticamente para expresar unas determinadas proteínas fotosensibles (opsinas), que son canales ionicos, bombas protónicas, o receptores acoplados a proteínas G. Luego, las células genéticamente modificadas son iluminadas con luz de una determinada longitud de onda, activando o inhibiendo los ca...

  7. Surrogate hosts: Hunting dogs and recolonizing grey wolves share their endoparasites.

    Science.gov (United States)

    Lesniak, Ines; Franz, Mathias; Heckmann, Ilja; Greenwood, Alex D; Hofer, Heribert; Krone, Oliver

    2017-12-01

    Understanding how closely related wildlife species and their domesticated counterparts exchange or share parasites, or replace each other in parasite life cycles, is of great interest to veterinary and human public health, and wildlife ecology. Grey wolves ( Canis lupus ) host and spread endoparasites that can either directly infect canid conspecifics or their prey serving as intermediate hosts of indirectly transmitted species. The wolf recolonization of Central Europe represents an opportunity to study parasite transmission dynamics between wildlife and domestic species for cases when a definitive host returns after local extinction - a situation equivalent to a 'removal experiment'. Here we investigate whether the re-appearance of wolves has increased parasite pressure on hunting dogs - a group of companion animals of particular interest as they have a similar diet to wolves and flush wolf habitats when hunting. We compared prevalence (P) and species richness (SR) of helminths and the protozoan Sarcocystis to determine whether they were higher in hunting dogs from wolf areas (n dogs  = 49) than a control area (n dogs  = 29) without wolves. Of particular interest were S. grueneri and S. taeniata , known as 'wolf specialists'. Five helminth and 11 Sarcocystis species were identified, of which all helminths and eight Sarcocystis species were shared between dogs and wolves. Overall prevalence and species richness of helminths (P:38.5% vs . 24.1%; SR mean :0.4 vs. 0.3 species) and Sarcocystis (P:63.3% vs . 65.5%, SR mean :2.1 vs . 1.8 species) did not differ between study sites. However, hunting dogs were significantly more likely to be infected with S. grueneri in wolf areas (P:45.2% vs . 10.5%; p = 0.035). The findings suggest that wolves indirectly increase S. grueneri infection risk for hunting dogs since cervids are intermediate hosts and occasionally fed to dogs. Furthermore, a periodic anthelminthic treatment of hunting dogs may be an effective

  8. Alguns ectoparasitas e protozoários em bovinos da República da Guiné-Bissau

    OpenAIRE

    Fernanda ROSA; Crespo, Maria Virgínia; Travassos Dias, J. A.

    1998-01-01

    Os autores assinalam a presença de algumas espécies de ixodídeos (Amblyomma variegatum, Boophilus annulatus, B. geigy e Hyalomma sp.) localizados em diferentes regiões do corpo de bovinos autóctones da República da Guiné-Bissau, colhidos entre Novembro de 1990 e Março de 1991. A pesquisa de protozoários, efectuada principalmente em esfregaços de sangue revelou a presença de Anaplasma marginale, Theileria mutans, Babesia bigemina e Sarcocystis sp. Não foram encontradas lesões relacionada...

  9. APPLICATION OF MALARIA DETECTION OF DRAWING BLOOD CELLS USING MICROSCOPIC OpenCV

    Directory of Open Access Journals (Sweden)

    Antonius Herusutopo

    2011-10-01

    literature studies about computer division with OpenCV and data collection of microscopic of blood sample. Analysis method includes process, detection procedure and malaria diagnosis. While design method includes steps of detection implementation and diagnosis to the application program, coding and continued with evaluation.MalariaMalaria parasites in human have a life cycle that requires a human host and mosquito host. In the anopheles mosquito, plasmodium does sexual reproduction. In humans, these parasites asexual reproduction, starting in the liver cells (hepatocytes, then repeatedly in the red blood cells (erythrocytes.While an infected female anopheles mosquito is sucking human’s blood, at the same time the mosquito inserts its saliva that is to keep the capillary vessels, which is inhaled not forming a blood clots factor that causes the blood flow stops. At this time the parasite creates sporozoites to enter the blood flow and infect hepatocytes. For one until two weeks (depends on plasmodium species, each sporozoites creates schizont; a structure that contains thousands of merozoites. When schizont is mature, hepatocytes will rupture and release merozoites to blood flow.In plasmodium vivax and plasmodium ovale, sporozoites develops into hipnozoit; a form of plasmodium that in dorman phase during several months to years. When hipnozoit re-activate, they will evolve into schizont that will cause recurrent symptoms to the infected person.Next is the merozoites, which is released to the blood flow, will invade erythrocyte then they will grow and consume hemoglobin. In erythrocyte, half of merozoites will grow to another phase of asexual, which creates schizont filled with merozoites. When schizont is mature, the cell will rupture and merozoites will be released and invade erythrocyte.

  10. IL-17A regulates Eimeria tenella schizont maturation and migration in avian coccidiosis.

    Science.gov (United States)

    Del Cacho, Emilio; Gallego, Margarita; Lillehoj, Hyun Soon; Quílez, Joaquín; Lillehoj, Erik P; Ramo, Ana; Sánchez-Acedo, Caridad

    2014-02-26

    Although IL17A is associated with the immunological control of various infectious diseases, its role in host response to Eimeria infections is not well understood. In an effort to better dissect the role of IL17A in host-pathogen interactions in avian coccidiosis, a neutralizing antibody (Ab) to chicken IL17A was used to counteract IL17A bioactivity in vivo. Chickens infected with Eimeria tenella and treated intravenously with IL17A Ab, exhibited reduced intracellular schizont and merozoite development, diminished lesion score, compared with untreated controls. Immunohistological evaluation of cecal lesions in the parasitized tissues indicated reduced migration and maturation of second-generation schizonts and reduced lesions in lamina propria and submucosa. In contrast, untreated and infected chickens had epithelial cells harboring second-generation schizonts, which extend into the submucosa through muscularis mucosa disruptions, maturing into second generation merozoites. Furthermore, IL17A Ab treatment was associated with increased parameters of Th1 immunity (IL2- and IFNγ- producing cells), reduced levels of reactive oxygen species (ROS), and diminished levels of serum matrix metalloproteinase-9 (MMP-9). Finally, schizonts from untreated and infected chickens expressed S100, Wiskott-Aldrich syndrome protein family member 3 (WASF3), and heat shock protein-70 (HSP70) proteins as merozoites matured, whereas the expression of these proteins was absent in IL17A Ab-treated chickens. These results provide the first evidence that the administration of an IL17A neutralizing Ab to E. tenella-infected chickens inhibits the migration of parasitized epithelial cells, markedly reduces the production of ROS and MMP-9, and decreases cecal lesions, suggesting that IL17A might be a potential therapeutic target for coccidiosis control.

  11. Differing patterns of selection and geospatial genetic diversity within two leading Plasmodium vivax candidate vaccine antigens.

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    Christian M Parobek

    2014-04-01

    Full Text Available Although Plasmodium vivax is a leading cause of malaria around the world, only a handful of vivax antigens are being studied for vaccine development. Here, we investigated genetic signatures of selection and geospatial genetic diversity of two leading vivax vaccine antigens--Plasmodium vivax merozoite surface protein 1 (pvmsp-1 and Plasmodium vivax circumsporozoite protein (pvcsp. Using scalable next-generation sequencing, we deep-sequenced amplicons of the 42 kDa region of pvmsp-1 (n = 44 and the complete gene of pvcsp (n = 47 from Cambodian isolates. These sequences were then compared with global parasite populations obtained from GenBank. Using a combination of statistical and phylogenetic methods to assess for selection and population structure, we found strong evidence of balancing selection in the 42 kDa region of pvmsp-1, which varied significantly over the length of the gene, consistent with immune-mediated selection. In pvcsp, the highly variable central repeat region also showed patterns consistent with immune selection, which were lacking outside the repeat. The patterns of selection seen in both genes differed from their P. falciparum orthologs. In addition, we found that, similar to merozoite antigens from P. falciparum malaria, genetic diversity of pvmsp-1 sequences showed no geographic clustering, while the non-merozoite antigen, pvcsp, showed strong geographic clustering. These findings suggest that while immune selection may act on both vivax vaccine candidate antigens, the geographic distribution of genetic variability differs greatly between these two genes. The selective forces driving this diversification could lead to antigen escape and vaccine failure. Better understanding the geographic distribution of genetic variability in vaccine candidate antigens will be key to designing and implementing efficacious vaccines.

  12. Two functional reticulocyte binding-like (RBL) invasion ligands of zoonotic Plasmodium knowlesi exhibit differential adhesion to monkey and human erythrocytes.

    Science.gov (United States)

    Semenya, Amma A; Tran, Tuan M; Meyer, Esmeralda Vs; Barnwell, John W; Galinski, Mary R

    2012-07-06

    Plasmodium knowlesi is a monkey malaria species that is becoming a serious public health concern infecting hundreds and perhaps thousands of humans in Southeast Asia. Invasion of erythrocytes by merozoites entails a cascade of molecular interactions. One step involves the adhesion of Plasmodium reticulocyte binding-like (RBL) proteins. Plasmodium knowlesi merozoites express only two RBL invasion ligands, known as Normocyte Binding Proteins (PkNBPXa and PkNBPXb). Overlapping N-terminal regions of PkNBPXa and PkNBPXb were expressed in COS7 cells and tested for surface expression and adhesion to rhesus monkey erythrocytes. Subsequent tests to study specific receptor ligand interactions included adhesion to a panel of human and non-human primate erythrocytes, enzymatic treatment, and site directed mutagenesis. An N-terminal cysteine-rich region of PkNBPXb (PkNBPXb-II) exhibited specific adhesion to rhesus monkey erythrocytes. Mutation of four of five cysteines in PkNBPXb-II interfered with its surface expression on COS7 cells, suggesting disulphide bond conformation is critical for intracellular trafficking. Binding of PkNBPXb-II was abolished when rhesus erythrocytes were pre-treated with chymotrypsin, but not trypsin or neuraminidase. PkNBPXb-II also bound other Old World monkey species and gibbon erythrocytes. However, erythrocytes from other primate species including humans did not bind to PkNBPXb-II or native PkNBPXb. Importantly, unlike PkNBPXb, PkNBPXa bound human erythrocytes, and this binding was independent of the Duffy blood group determinant. The data reported here begins to clarify the functional domains of the P. knowlesi RBLs. A binding domain has been identified and characterized in PkNBPXb. Notably, this study demonstrates that unlike PkNBPXb, PkNBPXa can bind to human erythrocytes, suggesting that PkNBPXa may function as a ligand to enable the invasion of P. knowlesi merozoites into human cells.

  13. Two functional reticulocyte binding-like (RBL invasion ligands of zoonotic Plasmodium knowlesi exhibit differential adhesion to monkey and human erythrocytes

    Directory of Open Access Journals (Sweden)

    Semenya Amma A

    2012-07-01

    Full Text Available Abstract Background Plasmodium knowlesi is a monkey malaria species that is becoming a serious public health concern infecting hundreds and perhaps thousands of humans in Southeast Asia. Invasion of erythrocytes by merozoites entails a cascade of molecular interactions. One step involves the adhesion of Plasmodium reticulocyte binding-like (RBL proteins. Plasmodium knowlesi merozoites express only two RBL invasion ligands, known as Normocyte Binding Proteins (PkNBPXa and PkNBPXb. Methods Overlapping N-terminal regions of PkNBPXa and PkNBPXb were expressed in COS7 cells and tested for surface expression and adhesion to rhesus monkey erythrocytes. Subsequent tests to study specific receptor ligand interactions included adhesion to a panel of human and non-human primate erythrocytes, enzymatic treatment, and site directed mutagenesis. Results An N-terminal cysteine-rich region of PkNBPXb (PkNBPXb-II exhibited specific adhesion to rhesus monkey erythrocytes. Mutation of four of five cysteines in PkNBPXb-II interfered with its surface expression on COS7 cells, suggesting disulphide bond conformation is critical for intracellular trafficking. Binding of PkNBPXb-II was abolished when rhesus erythrocytes were pre-treated with chymotrypsin, but not trypsin or neuraminidase. PkNBPXb-II also bound other Old World monkey species and gibbon erythrocytes. However, erythrocytes from other primate species including humans did not bind to PkNBPXb-II or native PkNBPXb. Importantly, unlike PkNBPXb, PkNBPXa bound human erythrocytes, and this binding was independent of the Duffy blood group determinant. Conclusions The data reported here begins to clarify the functional domains of the P. knowlesi RBLs. A binding domain has been identified and characterized in PkNBPXb. Notably, this study demonstrates that unlike PkNBPXb, PkNBPXa can bind to human erythrocytes, suggesting that PkNBPXa may function as a ligand to enable the invasion of P. knowlesi merozoites into

  14. Fecal shedding of Toxocara canis and other parasites in foxes and coyotes on Prince Edward Island, Canada.

    Science.gov (United States)

    Wapenaar, Wendela; Barkema, Herman W; O'Handley, Ryan

    2013-04-01

    Knowledge of parasites shed by wild canids can assist in recognizing risk to human and domestic animal health. Our aim was to estimate the prevalence of patent infections with Toxocara canis and other parasites in foxes (Vulpes vulpes) and coyotes (Canis latrans) in Prince Edward Island, Canada. Identification of parasite species was based on microscopic examination of feces, with the use of a sucrose fecal flotation method. Sample collection was performed in winter on carcasses of 271 and 185 hunted or trapped foxes and coyotes, respectively. One or more parasite species were observed in 242 (89%) foxes and 128 (69%) coyotes. Toxocara canis, Uncinaria stenocephala, Capillaria spp., Mesocestoides, Taenidd spp., Alaria spp., Cryptocotyle lingua, Sarcocystis spp., Neospora caninum-like coccidia, and other coccidia were identified. A third of juvenile foxes were shedding T. canis and had a high prevalence of Capillaria spp., especially in juvenile foxes (69%). Taenidd eggs, Alaria spp. and Sarcocystis spp. were more common in coyotes (24, 18, and 9%, respectively) than foxes (8, 11, and 1%, respectively). Despite the limitations of fecal flotation to identify parasite species, the high prevalence of T. canis warrants the attention of public health professionals.

  15. Histopathological survey of protozoa, helminths and acarids of imported and local psittacine and passerine birds in Japan.

    Science.gov (United States)

    Tsai, S S; Hirai, K; Itakura, C

    1992-12-01

    A total of 534 psittacine and passerine birds consisting of 241 imported and 293 local birds were examined histologically. As a result, the following parasites were found: Giardia (86 cases), Knemido-coptes (26 cases), coccidia (10 cases), Ascaridia (6 cases), Cryptosporidium (5 cases), Sarcocystis (5 cases), tapeworm (4 cases), microfilaria (2 cases), Hexamita (1 case), and Spiroptera (1 case). High incidences of giardiasis and knemido-coptic infestation were detected in the local birds, but rarely in the imported birds. Giardial trophozoites were observed mainly in the duodenum of budgerigars (Melopsittacus undulatus). Knemidocoptic mites burrowed into the epidermis producing proliferative dermatitis in 25 budgerigars and 1 African Grey Parrot (Psittacus erithacus erithacus). This ectoparasite often infested the skin around the cloaca. Coccidiosis was seen only in the small intestines of the finch (Poephila gouldiae gouldiae), African Grey Parrot, Rainbow lory (Trichoglossus haematodus), Indian Ring-necked parakeet (Psittacula krameri manillensis) and peach-faced lovebird (Agapornis roseicollis). Two parrots (Amazona aestiva aestiva and Psittacus erithacus erithacus) and two budgerigars had intestinal cryptosporidiosis. Conjunctivitis associated with cryptosporidial infection was seen in a lovebird. Sarcocystis cysts containing crescent-shaped bradyzoites were found not only in the thigh and breast but also in the heart and cloacal muscles. Other organisms such as Ascaridia, tapeworm, microfilaria, Hexamita, and Spiroptera were clinically less significant. However, infections such as Giardia and Cryptosporidim might have zoonotic implications.

  16. Molecular assessment of apicomplexan parasites in the snake Psammophis from North Africa: do multiple parasite lineages reflect the final vertebrate host diet?

    Science.gov (United States)

    Tomé, Beatriz; Maia, João P M C; Harris, D James

    2013-10-01

    The Apicomplexa are intracellular pathogens of animals, with the Coccidia being the largest group. Among these are the hemogregarines, which include some of the most common hemoparasites found in reptiles. Several studies have reported a possible pattern of prey-predator transmission for some of these parasites. Snakes from the Mediterranean region have been found to be parasitized with Hepatozoon spp. similar to those in lacertids and gekkonids, supporting the prey-predator transmission hypothesis. Here we analyzed specimens of the saurophagous genus Psammophis from North Africa, an ecologically different region. Through molecular analysis of tissue samples we detected 3 different apicomplexan parasites: Caryospora, Sarcocystis, and Hepatozoon. Caryospora was detected in a Forskål's sand snake Psammophis schokari from Algeria, constituting the first time these parasites have been detected from a tissue sample through molecular screening. The obtained Sarcocystis phylogeny does not reflect the relationships of their final hosts, with the parasites identified from snakes forming at least 3 unrelated groups, indicating that it is still premature to predict definitive host based on the phylogeny of these parasites. Three unrelated lineages of Hepatozoon parasites were identified in Psammophis, each closely related to lineages previously identified from different lizard groups, on which these snakes feed. This once again indicates that diet might be a key element in transmission, at least for Hepatozoon species of saurophagous snakes.

  17. Coccidian parasites (Apicomplexa) from snakes in the southcentral and southwestern United States: new host and geographic records.

    Science.gov (United States)

    McAllister, C T; Upton, S J; Trauth, S E; Dixon, J R

    1995-02-01

    Four hundred thirty-five leptotyphlopid, colubrid, elapid, and viperid snakes were collected from various localities in Arkansas, New Mexico, Oklahoma, and Texas, and their feces were examined for coccidian parasites. Of these, 131 (30%) were passing oocysts or sporocysts of at least 1 coccidian; 88 (67%) of the infected snakes had only 1 species of coccidian when they were examined. Aquatic and semiaquatic snakes accounted for 48% of the infections, whereas strictly terrestrial snakes comprised the other 52%. There was more than a 2-fold difference in prevalence among these 2 groups as 63 of 129 (49%) of the aquatic and semiaquatic snakes versus 68 of 306 (22%) of the terrestrial snakes harbored coccidia. Most terrestrial snakes were infected by species of Caryospora and Sarcocystis that are either facultatively or obligatorily heteroxenous. The aquatic and semiaquatic species most often harbored eimerians. Attempts to transmit some of the Sarcocystis spp. experimentally from Crotalus atrox to Mus musculus, Peromyscus leucopus, Peromyscus maniculatus, or Microtus ochrogaster were unsuccessful. This report documents 27 new host and several distributional records for coccidians from snakes in the southcentral and southwestern United States.

  18. Expression, Purification and Characterization of GMZ2'.10C, a Complex Disulphide-Bonded Fusion Protein Vaccine Candidate against the Asexual and Sexual Life-Stages of the Malaria-Causing Plasmodium falciparum Parasite

    DEFF Research Database (Denmark)

    Mistarz, Ulrik H; Singh, Susheel K; Nguyen, Tam T T N

    2017-01-01

    PURPOSE: Production and characterization of a chimeric fusion protein (GMZ2'.10C) which combines epitopes of key malaria parasite antigens: glutamate-rich protein (GLURP), merozoite surface protein 3 (MSP3), and the highly disulphide bonded Pfs48/45 (10C). GMZ2'.10C is a potential candidate...... for a multi-stage malaria vaccine that targets both transmission and asexual life-cycle stages of the parasite. METHODS: GMZ2'.10C was produced in Lactococcus lactis and purified using either an immunoaffinity purification (IP) or a conventional purification (CP) method. Protein purity and stability...

  19. Study of humoral immune response in mammals immunized with Plasmodium falciparum antigenic preparations

    Directory of Open Access Journals (Sweden)

    Antonio B. Cruz Cubas

    1992-01-01

    Full Text Available Six Plasmodium falciparum protein fractions, isolated under reducing conditions, were used to immunize mice, rabbits and the squirrel monkey Saimiri sciureus. Five or seven subcutaneous injections of each antigenic preparation, in conjunction with Freund's complete or incomplete adjuvants, were administered. This led to the development of specific antibodies detected by IFAT, ELISA or immunobloting which inhibited merozoite reinvasion in in vitro P. falciparum cultures. This activity seems to be associated with rhoptry proteins contained in fractions Pf F2 and Pf F4.

  20. Humoral immune response to Plasmodium falciparum vaccine candidate GMZ2 and its components in populations naturally exposed to seasonal malaria in Ethiopia

    DEFF Research Database (Denmark)

    Mamo, Hassen; Esen, Meral; Ajua, Anthony

    2013-01-01

    to investigate the nature of humoral immune response to malaria in two ethnic groups in two endemic localities: Shewa Robit in north, and Boditi in south Ethiopia which are characterized by varying levels of malaria transmission and altitude. In a cross-sectional study, the study participants were diagnosed...... for malaria infection microscopically and by the rapid diagnostic test (RDT). Sera were tested by using enzyme-linked immunosorbent assay (ELISA) for total immunoglobulin (Ig) G against P. falciparum blood-stage vaccine candidate GMZ2 and its subunits (Glutamate-rich protein (GLURP-R0), merozoite surface...

  1. In vitro effect of chloroquine, mefloquine and quinine on human lymphocyte proliferative responses to malaria antigens and other antigens/mitogens

    DEFF Research Database (Denmark)

    Bygbjerg, I C; Theander, T G; Andersen, B J

    1986-01-01

    The effect of 3 antimalarial quinoline derivatives, chloroquine, mefloquine and quinine on human blood mononuclear cells in vitro was studied. High concentrations profoundly suppressed the proliferation of mitogen- and antigen-stimulated lymphocytes, as indicated by decreased 14C...... of pokeweed mitogen) and antigens studied, including P. falciparum merozoites. The drugs' potential adverse effect on the immune system is discussed.......-thymidine incorporation. On a weight base, the most potent drug was mefloquine. At clinically relevant doses, chloroquine and mefloquine did not affect the response to malaria antigens, but mefloquine decreased the response to phytohaemagglutinin; quinine suppressed the response to all mitogens (with the exception...

  2. Delineation of stage specific expression of Plasmodium falciparum EBA-175 by biologically functional region II monoclonal antibodies.

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    B Kim Lee Sim

    2011-04-01

    Full Text Available The malaria parasite Plasmodium falciparum EBA-175 binds its receptor sialic acids on glycophorin A when invading erythrocytes. The receptor-binding region (RII contains two cysteine-rich domains with similar cysteine motifs (F1 and F2. Functional relationships between F1 and F2 domains and characterization of EBA-175 were studied using specific monoclonal antibodies (mAbs against these domains.Five mAbs specific for F1 or F2 were generated. Three mAbs specific for F2 potently blocked binding of EBA-175 to erythrocytes, and merozoite invasion of erythrocytes (IC(50 10 to 100 µg/ml IgG in growth inhibition assays. A mAb specific for F1 blocked EBA-175 binding and merozoite invasion less effectively. The difference observed between the IC(50 of F1 and F2 mAbs was not due to differing association and disassociation rates as determined by surface plasmon resonance. Four of the mAbs recognized conformation-dependent epitopes within F1 or F2. Used in combination, F1 and F2 mAbs blocked the binding of native EBA-175 to erythrocytes and inhibited parasite invasion synergistically in vitro. MAb R217, the most potent, did not recognize sporozoites, 3-day hepatocyte stage parasites, nor rings, trophozoites, gametocytes, retorts, ookinetes, and oocysts but recognized 6-day hepatocyte stage parasites, and schizonts. Even though efficient at blocking binding to erythrocytes and inhibiting invasion into erythrocytes, MAb R217 did not inhibit sporozoite invasion and development in hepatocytes in vitro.The role of the F1 and F2 domains in erythrocyte invasion and binding was elucidated with mAbs. These mAbs interfere with native EBA-175 binding to erythrocyte in a synergistic fashion. The stage specific expression of EBA-175 showed that the primary focus of activity was the merozoite stage. A recombinant RII protein vaccine consisting of both F1 and F2 domains that could induce synergistic activity should be optimal for induction of antibody responses that

  3. Développement clinique d’un vaccin antipaludique de stade sanguin et diversité antigénique de Plasmodium Falciparum à Bandiagara, Mali

    OpenAIRE

    Théra, Mahamadou Ali

    2015-01-01

    An effective malaria vaccine will be a powerful tool in the fight against this scourge. The apical membrane antigen 1 of the merozoite, AMA1 is a protein essential to parasite biology and was associated with parasite growth inhibition in vitro. Anti-AMA1 antibodies have also been correlated with protection against clinical malaria in sero epidemiological studies in Africa. Expressed in Escherichia coli and in combination with the adjuvant AS02A, the AMA1 antigen derived from strain 3D7, const...

  4. A randomized controlled Phase Ib trial of the malaria vaccine candidate GMZ2 in African children

    DEFF Research Database (Denmark)

    Bélard, Sabine; Issifou, Saadou; Hounkpatin, Aurore B

    2011-01-01

    GMZ2 is a fusion protein of Plasmodium falciparum merozoite surface protein 3 (MSP3) and glutamate rich protein (GLURP) that mediates an immune response against the blood stage of the parasite. Two previous phase I clinical trials, one in naïve European adults and one in malaria-exposed Gabonese ...... adults showed that GMZ2 was well tolerated and immunogenic. Here, we present data on safety and immunogenicity of GMZ2 in one to five year old Gabonese children, a target population for future malaria vaccine efficacy trials....

  5. A novel antibody-dependent cellular cytotoxicity mechanism involved in defense against malaria requires costimulation of monocytes FcgammaRII and FcgammaRIII

    DEFF Research Database (Denmark)

    Jafarshad, Ali; Dziegiel, Morten Hanefeld; Lundquist, Rasmus

    2007-01-01

    activity. Using particulate Ag as pseudomerozoites, we show that only Ags, and no other parasite-derived factor, are required to trigger MN activation and that a single Ag is as potent as the complex combination of Ags constituting the merozoite surface. Moreover, we found that soluble Ags binding at least...... two Abs are as effective as the parasite at stimulating MN and that nonmalarial Ags are as efficient provided they are targeted by cytophilic Abs. Indeed, only cytophilic IgGs are potent and, in agreement with immunoepidemiological findings, IgG3 is superior to IgG1. Very low Ab concentrations (>700 p...

  6. The fine structure of the endogenous stages of Isospora hemidactyli carini, 1936 in the gecko Hemidactylus mabouia from North Brazil

    Directory of Open Access Journals (Sweden)

    Paperna I

    2000-01-01

    Full Text Available The ultrastructure is described of the meronts, microgamonts and young oocyst stages of Isospora hemidactyli of the gecko Hemidactylus mabouia from Belém, PA, north Brazil. The endogenous stages all develop in the nucleus of the gut epithelial cells. The nucleus remains intact up to the latest stages of the parasite's development, but degenerates by the time the oocyst appears. Merogonic division appears to be asynchronous, and some of the differentiated merozoites contained more than one nucleus. Microgamonts conform in structure with those of other eimeriids. Some of the type 2 wall-forming bodies disintegrate into smaller globules and ground substance of lower density.

  7. Alteraciones hipocampales y cambios cognitivos preceden al deposito de placas amiloides en un modelo murino de la enfermedad de Alzheimer

    Directory of Open Access Journals (Sweden)

    Juan Beauquis

    2014-08-01

    Full Text Available Existen múltiples evidencias de alteraciones neuronales y gliales en etapas avanzadas de la enfemedad de Alzheimer con abundantes depósitos cerebrales de beta amiloide, aunque hay pocos datos de cambios tempranos que podrían contribuir al desarrollo de la enfermedad. Evaluamos alteraciones morfológicas neuronales y gliales, y cambios cognitivos y emocionales tempranos en ratones transgénicos PDAPP-J20 (Tg, portadores del gen humano de APP (amyloid precursor protein mutado, a los 5 meses de edad, aún sin depósitos amiloides en el hipocampo y con niveles bajos de péptidos amiloides cerebrales. Mediante inmunohistoquímica para NeuN, los Tg presentaron menor número de neuronas piramidales y granulares en el hipocampo, junto con un menor volumen de la estructura, en comparación con los controles no transgénicos. La neurogénesis se encontró afectada, evidenciada por reducido número de neuronas DCX+ en el giro dentado. En la región CA3, hubo una menor densidad de sinaptofisina sugiriendo alteraciones sinápticas entre neuronas granulares y piramidales, sin cambios en la densidad de espinas dendríticas en CA1. Utilizando microscopía confocal, observamos una disminución del número de astrocitos GFAP+ con una reducción de la complejidad celular, sugiriendo atrofia glial. Se detectó un déficit cognitivo (reconocimiento de localización novedosa de un objeto y un aumento de la ansiedad (campo abierto en los Tg, con aumento en los núcleos c-Fos+ en amígdala, evidenciando el papel de la emocionalidad en los inicios de la enfermedad. El estudio de las alteraciones iniciales en la enfermedad amiloide podría contribuir al desarrollo de métodos de diagnóstico temprano y de terapéutica preventiva.

  8. The homeostasis of Plasmodium falciparum-infected red blood cells.

    Directory of Open Access Journals (Sweden)

    Jakob M A Mauritz

    2009-04-01

    Full Text Available The asexual reproduction cycle of Plasmodium falciparum, the parasite responsible for severe malaria, occurs within red blood cells. A merozoite invades a red cell in the circulation, develops and multiplies, and after about 48 hours ruptures the host cell, releasing 15-32 merozoites ready to invade new red blood cells. During this cycle, the parasite increases the host cell permeability so much that when similar permeabilization was simulated on uninfected red cells, lysis occurred before approximately 48 h. So how could infected cells, with a growing parasite inside, prevent lysis before the parasite has completed its developmental cycle? A mathematical model of the homeostasis of infected red cells suggested that it is the wasteful consumption of host cell hemoglobin that prevents early lysis by the progressive reduction in the colloid-osmotic pressure within the host (the colloid-osmotic hypothesis. However, two critical model predictions, that infected cells would swell to near prelytic sphericity and that the hemoglobin concentration would become progressively reduced, remained controversial. In this paper, we are able for the first time to correlate model predictions with recent experimental data in the literature and explore the fine details of the homeostasis of infected red blood cells during five model-defined periods of parasite development. The conclusions suggest that infected red cells do reach proximity to lytic rupture regardless of their actual volume, thus requiring a progressive reduction in their hemoglobin concentration to prevent premature lysis.

  9. Plasmodium berghei Δp52&p36 parasites develop independent of a parasitophorous vacuole membrane in Huh-7 liver cells.

    Directory of Open Access Journals (Sweden)

    Ivo H J Ploemen

    Full Text Available The proteins P52 and P36 are expressed in the sporozoite stage of the murine malaria parasite Plasmodium berghei. Δp52&p36 sporozoites lacking expression of both proteins are severely compromised in their capability to develop into liver stage parasites and abort development soon after invasion; presumably due to the absence of a parasitophorous vacuole membrane (PVM. However, a small proportion of P. berghei Δp52&p36 parasites is capable to fully mature in hepatocytes causing breakthrough blood stage infections. We have studied the maturation of replicating Δp52&p36 parasites in cultured Huh-7 hepatocytes. Approximately 50% of Δp52&p36 parasites developed inside the nucleus of the hepatocyte but did not complete maturation and failed to produce merosomes. In contrast cytosolic Δp52&p36 parasites were able to fully mature and produced infectious merozoites. These Δp52&p36 parasites developed into mature schizonts in the absence of an apparent parasitophorous vacuole membrane as shown by immunofluorescence and electron microscopy. Merozoites derived from these maturing Δp52&p36 liver stages were infectious for C57BL/6 mice.

  10. Plasmodium falciparum acid basic repeat antigen (ABRA) peptides: erythrocyte binding and biological activity.

    Science.gov (United States)

    Curtidor, H; Urquiza, M; Suarez, J E; Rodriguez, L E; Ocampo, M; Puentes, A; Garcia, J E; Vera, R; Lopéz, R; Ramirez, L E; Pinzon, M; Patarroyo, M E

    2001-08-14

    Non overlapping 20-mer peptides, covering the complete sequence of acid basic repeat antigen (ABRA) of Plasmodium falciparum, were synthesised and tested in binding assays to erythrocytes. Five peptides localised in the N-terminal region coded 2148 (121LQSHKKLIKALKKNIESYQN(140)), 2149 (141KKHLIYKNKSYNPLLLSCVK(160)), 2150 (161KMNMLKENVDYIQKNQNLFK(180)), 2152 (201YKSQGHKKETSQNQNENNDN(220)) and 2153 (221QKYQEVNDEDDVNDEEDTND(240)) specifically bind to erythrocytes. These peptides bind independently of the peptide and erythrocyte charge, with high affinity (Kd between 70 and 180 nM) and the hydrophobic interaction is important for this binding ( approximately 30% hydrophobic critical residues). These results allow us define a specific erythrocyte binding region (residues 121-240), which may bound to at least three different binding sites on erythrocytes. Peptide 2153 shares the underlined sequence 221QKYQEVNDEDDVNDEEDTND(240) with an earlier 18-mer peptide recognised by human exposed sera. Peptides number 2148 and 2149 in vitro inhibit erythrocyte invasion by merozoites. We found that 2149 peptide and some of its glycine analogues show specific haemolytic and/or antimicrobial activity. We discuss a possible role of ABRA or its regions in the merozoite invasion of erythrocyte.

  11. The blood-stage malaria antigen PfRH5 is susceptible to vaccine-inducible cross-strain neutralizing antibody.

    Science.gov (United States)

    Douglas, Alexander D; Williams, Andrew R; Illingworth, Joseph J; Kamuyu, Gathoni; Biswas, Sumi; Goodman, Anna L; Wyllie, David H; Crosnier, Cécile; Miura, Kazutoyo; Wright, Gavin J; Long, Carole A; Osier, Faith H; Marsh, Kevin; Turner, Alison V; Hill, Adrian V S; Draper, Simon J

    2011-12-20

    Current vaccine strategies against the asexual blood stage of Plasmodium falciparum are mostly focused on well-studied merozoite antigens that induce immune responses after natural exposure, but have yet to induce robust protection in any clinical trial. Here we compare human-compatible viral-vectored vaccines targeting ten different blood-stage antigens. We show that the full-length P. falciparum reticulocyte-binding protein homologue 5 (PfRH5) is highly susceptible to cross-strain neutralizing vaccine-induced antibodies, out-performing all other antigens delivered by the same vaccine platform. We find that, despite being susceptible to antibody, PfRH5 is unlikely to be under substantial immune selection pressure; there is minimal acquisition of anti-PfRH5 IgG antibodies in malaria-exposed Kenyans. These data challenge the widespread beliefs that any merozoite antigen that is highly susceptible to immune attack would be subject to significant levels of antigenic polymorphism, and that erythrocyte invasion by P. falciparum is a degenerate process involving a series of parallel redundant pathways.

  12. Subcellular location, phosphorylation and assembly into the motor complex of GAP45 during Plasmodium falciparum schizont development.

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    Mohd A Mohd Ridzuan

    Full Text Available An actomyosin motor complex assembled below the parasite's plasma membrane drives erythrocyte invasion by Plasmodium falciparum merozoites. The complex is comprised of several proteins including myosin (MyoA, myosin tail domain interacting protein (MTIP and glideosome associated proteins (GAP 45 and 50, and is anchored on the inner membrane complex (IMC, which underlies the plasmalemma. A ternary complex of MyoA, MTIP and GAP45 is formed that then associates with GAP50. We show that full length GAP45 labelled internally with GFP is assembled into the motor complex and transported to the developing IMC in early schizogony, where it accumulates during intracellular development until merozoite release. We show that GAP45 is phosphorylated by calcium dependent protein kinase 1 (CDPK1, and identify the modified serine residues. Replacing these serine residues with alanine or aspartate has no apparent effect on GAP45 assembly into the motor protein complex or its subcellular location in the parasite. The early assembly of the motor complex suggests that it has functions in addition to its role in erythrocyte invasion.

  13. Design and evaluation of antimalarial peptides derived from prediction of short linear motifs in proteins related to erythrocyte invasion.

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    Alessandra Bianchin

    Full Text Available The purpose of this study was to investigate the blood stage of the malaria causing parasite, Plasmodium falciparum, to predict potential protein interactions between the parasite merozoite and the host erythrocyte and design peptides that could interrupt these predicted interactions. We screened the P. falciparum and human proteomes for computationally predicted short linear motifs (SLiMs in cytoplasmic portions of transmembrane proteins that could play roles in the invasion of the erythrocyte by the merozoite, an essential step in malarial pathogenesis. We tested thirteen peptides predicted to contain SLiMs, twelve of them palmitoylated to enhance membrane targeting, and found three that blocked parasite growth in culture by inhibiting the initiation of new infections in erythrocytes. Scrambled peptides for two of the most promising peptides suggested that their activity may be reflective of amino acid properties, in particular, positive charge. However, one peptide showed effects which were stronger than those of scrambled peptides. This was derived from human red blood cell glycophorin-B. We concluded that proteome-wide computational screening of the intracellular regions of both host and pathogen adhesion proteins provides potential lead peptides for the development of anti-malarial compounds.

  14. Molecular Signaling Involved in Entry and Exit of Malaria Parasites from Host Erythrocytes.

    Science.gov (United States)

    Singh, Shailja; Chitnis, Chetan E

    2017-10-03

    During the blood stage, Plasmodium spp. merozoites invade host red blood cells (RBCs), multiply, exit, and reinvade uninfected RBCs in a continuing cycle that is responsible for all the clinical symptoms associated with malaria. Entry into (invasion) and exit from (egress) RBCs are highly regulated processes that are mediated by an array of parasite proteins with specific functional roles. Many of these parasite proteins are stored in specialized apical secretory vesicles, and their timely release is critical for successful invasion and egress. For example, the discharge of parasite protein ligands to the apical surface of merozoites is required for interaction with host receptors to mediate invasion, and the timely discharge of proteases and pore-forming proteins helps in permeabilization and dismantling of limiting membranes during egress. This review focuses on our understanding of the signaling mechanisms that regulate apical organelle secretion during host cell invasion and egress by malaria parasites. The review also explores how understanding key signaling mechanisms in the parasite can open opportunities to develop novel strategies to target Plasmodium parasites and eliminate malaria. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  15. Digestive vacuoles of Plasmodium falciparum are selectively phagocytosed by and impair killing function of polymorphonuclear leukocytes.

    Science.gov (United States)

    Dasari, Prasad; Reiss, Karina; Lingelbach, Klaus; Baumeister, Stefan; Lucius, Ralph; Udomsangpetch, Rachanee; Bhakdi, Sebastian Chakrit; Bhakdi, Sucharit

    2011-11-03

    Sequestration of parasitized erythrocytes and dysregulation of the coagulation and complement system are hallmarks of severe Plasmodium falciparum malaria. A link between these events emerged through the discovery that the parasite digestive vacuole (DV), which is released together with infective merozoites into the bloodstream, dually activates the intrinsic clotting and alternative complement pathway. Complement attack occurs exclusively on the membrane of the DVs, and the question followed whether DVs might be marked for uptake by polymorphonuclear granulocytes (PMNs). We report that DVs are indeed rapidly phagocytosed by PMNs after schizont rupture in active human serum. Uptake of malaria pigment requires an intact DV membrane and does not occur when the pigment is extracted from the organelle. Merozoites are not opsonized and escape phagocytosis in nonimmune serum. Antimalarial Abs mediate some uptake of the parasites, but to an extent that is not sufficient to markedly reduce reinvasion rates. Phagocytosis of DVs induces a vigorous respiratory burst that drives the cells into a state of functional exhaustion, blunting the production of reactive oxygen species (ROS) and microbicidal activity upon challenge with bacterial pathogens. Systemic overloading of PMNs with DVs may contribute to the enhanced susceptibility of patients with severe malaria toward invasive bacterial infections.

  16. Mechanisms of invasion from sporozoite and merozoíto of Plasmodium

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    Lilian M. Spencer

    2016-05-01

    Full Text Available Malaria or paludismo is caused in humans by four species of Plasmodium belonging to phylum Apicomplexa: ovale, malaria, vivax and falciparum, being the last, the responsible of the clinical complication and death in the vertebrate host. Plasmodium parasite possess a specialized secretory organelles called rhoptries, micronemes and dense granules that facilitate invasion of host cells. The sporozoite stage of Plasmodium travels through the different cells of vertebrate host until it reaches the hepatocyte and have been form the parasitophorous vacuole. The infected hepatocytes rupture, results in the releasing thousands of daughter merozoites that invade the erythrocytes with the formation of parasitophorous vacuole too. Several researchers suggest the gliding motility mechanism as the responsible of hepatocyte invasion. While, which the erythrocyte invasion process has been described as the result of tree steps: first contact, re-orientation and invasion. In this review the surface proteins of merozoites and esporozoites are pointed out as the most important factors for the molecular invasion mechanisms until the elaboration of the parasitophorous vacuole. These proteins that take part in these mechanisms are the possible candidates in the design of an anti-malaria vaccine.

  17. Hemoglobinopathic Erythrocytes Affect the Intraerythrocytic Multiplication of Plasmodium falciparum In Vitro

    Science.gov (United States)

    Glushakova, Svetlana; Balaban, Amanda; McQueen, Philip G.; Coutinho, Rosane; Miller, Jeffery L.; Nossal, Ralph; Fairhurst, Rick M.; Zimmerberg, Joshua

    2014-01-01

    Background. The mechanisms by which α-thalassemia and sickle cell traits confer protection from severe Plasmodium falciparum malaria are not yet fully elucidated. We hypothesized that hemoglobinopathic erythrocytes reduce the intraerythrocytic multiplication of P. falciparum, potentially delaying the development of life-threatening parasite densities until parasite clearing immunity is achieved. Methods. We developed a novel in vitro assay to quantify the number of merozoites released from an individual schizont, termed the “intraerythrocytic multiplication factor” (IMF). Results. P. falciparum (3D7 line) schizonts produce variable numbers of merozoites in all erythrocyte types tested, with median IMFs of 27, 27, 29, 23, and 23 in control, HbAS, HbSS, and α- and β-thalassemia trait erythrocytes, respectively. IMF correlated strongly (r2 = 0.97; P erythrocytes was confirmed using clinical parasite isolates with different IMFs. Mathematical modeling of the effect of IMF on malaria progression indicates that the lower IMF in thalassemia trait erythrocytes limits parasite density and anemia severity over the first 2 weeks of parasite replication. Conclusions. P. falciparum IMF, a parasite heritable virulence trait, correlates with erythrocyte indices and is reduced in thalassemia trait erythrocytes. Parasite IMF should be examined in other low-indices erythrocytes. PMID:24688070

  18. Revealing the Sequence and Resulting Cellular Morphology of Receptor-Ligand Interactions during Plasmodium falciparum Invasion of Erythrocytes

    Science.gov (United States)

    Weiss, Greta E.; Gilson, Paul R.; Taechalertpaisarn, Tana; Tham, Wai-Hong; de Jong, Nienke W. M.; Harvey, Katherine L.; Fowkes, Freya J. I.; Barlow, Paul N.; Rayner, Julian C.; Wright, Gavin J.; Cowman, Alan F.; Crabb, Brendan S.

    2015-01-01

    During blood stage Plasmodium falciparum infection, merozoites invade uninfected erythrocytes via a complex, multistep process involving a series of distinct receptor-ligand binding events. Understanding each element in this process increases the potential to block the parasite’s life cycle via drugs or vaccines. To investigate specific receptor-ligand interactions, they were systematically blocked using a combination of genetic deletion, enzymatic receptor cleavage and inhibition of binding via antibodies, peptides and small molecules, and the resulting temporal changes in invasion and morphological effects on erythrocytes were filmed using live cell imaging. Analysis of the videos have shown receptor-ligand interactions occur in the following sequence with the following cellular morphologies; 1) an early heparin-blockable interaction which weakly deforms the erythrocyte, 2) EBA and PfRh ligands which strongly deform the erythrocyte, a process dependant on the merozoite’s actin-myosin motor, 3) a PfRh5-basigin binding step which results in a pore or opening between parasite and host through which it appears small molecules and possibly invasion components can flow and 4) an AMA1–RON2 interaction that mediates tight junction formation, which acts as an anchor point for internalization. In addition to enhancing general knowledge of apicomplexan biology, this work provides a rational basis to combine sequentially acting merozoite vaccine candidates in a single multi-receptor-blocking vaccine. PMID:25723550

  19. Efectos neurobiológicos de la actividad física aeróbica sobre la depresión: propuesta de un modelo experimental en roedores

    OpenAIRE

    González Bauer, Natalia

    2013-01-01

    El proyecto de investigación que proponemos tiene como objetivo indagar los efectos neurobiológicos de la actividad física aeróbica en la disminución de los síntomas depresivos. Para ello, adherimos a los supuestos de la Psiconeuroinmunoendocrinología y a la hipótesis neurogénica de la depresión. Dicha hipótesis supone que la neurogénesis, “formación de nuevas neuronas en el cerebro” (Fernández, S., Trejo Pérez, Fernández, & Torres Aleman, 2009, pp. 84), se halla inhibida en el hipocampo ...

  20. Revisión bibliográfica: Utilidad clínica de las células madre

    OpenAIRE

    Tatiana Monge Jiménez; Cindy Montero Granados

    2008-01-01

    La sangre de cordón umbilical (SCU) es una de las fuentes más codiciadas para la obtención de células madre (CM) por la presencia de poblaciones de células embrionarias pluripotenciales. En SCU se ha encontrado CM capaces de originar diferentes tipos de células, como osteoblastos, condrocitos, miositos, adipositos, neuronas y células B. La SCU posee mayor cantidad de CM que la médula ósea y sangre periférica. En esta revisión bibliográfica se brinda un panorama actualizado en este tema y sus ...

  1. Terapia a través de la danza y el movimiento en mujeres con cáncer de mama: el impacto psicofísico del proceso empático

    OpenAIRE

    Blázquez, Alicia; Nierga, Judit; Javierre Garcés, Casimiro F.

    2011-01-01

    Objetivos: describir el proceso terapéutico y la posible influencia de las neuronas espejo en la empatía kinestésica empleando la terapia a través de la danza y el movimiento en el cáncer de mama. Método: se utilizó un estudio de caso. Una paciente diagnosticada con cáncer de mama desde hace dos años fue derivada al Departamento de Ciencias fisiológicas II de la Universidad de Barcelona. Ella asistió a una intervención con terapia a través de la danza y el movimiento durante 5 meses (1 hora s...

  2. Actualidad en termorregulación

    OpenAIRE

    López Dávila, Alfredo Jesús

    2014-01-01

    Esta revisión tiene como objetivo presentar avances recientes en la comprensión de los mecanismos fisiológicos de la termoregulación en mamíferos. Los termoreceptores cutáneos y profundos son neuronas polimodales que detectan estímulos dolorosos, mecánicos y químicos, además de los térmicos. La información detectada por los receptores es enviada por vías aferentes hasta la médula espinal, donde la información térmica es filtrada y subsecuentemente enviada a puntos de relevo en el mesencéfalo ...

  3. ESTRÉS PRENATAL Y SUS EFECTOS SOBRE EL NEURODESARROLLO

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    Dr. Rodrigo Díaz

    2016-07-01

    Full Text Available El desarrollo normal del sistema nervioso central (SNC se compone de varias etapas que son controladas e influenciadas por la interacción entre los genes y el ambiente. El genoma humano contiene entre 20.000-25.000 genes 1, a pesar de lo impresionante del número, es poco probable que puedan por sí solos controlar la organización de 100 billones de neuronas y trillones de sinapsis. La expresión normal de estos genes requiere de un ambiente propicio. Este ambiente puede influir de manera postnatal o prenatal. Es en este desarrollo prenatal en el que queremos centrarnos en este artículo, revisando las corrientes de investigación más recientes al respecto.

  4. ¿Sueños utópicos de libertad o cotidiana construcción colectiva?

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    Antonio Elizalde

    2010-05-01

    Full Text Available Recuperando el permanente debate en la historia humana sobre los límites de lo posible y de lo deseable, seplantea la proximidad de la reconstrucción del perfil bioquímico de los seres humanos mediante la tecno ciencia actualy los dilemas éticos y políticos a los cuales pronto nos veremos enfrentados, introduciendo una reflexión en torno alibertad como de autonomía, aprendizaje y praxis. Se destaca la opción abierta entre tecnologías “endosomáticas” y“exosomáticas”, relevando el papel de las neuronas espejo y de la cordura y la razón cordial. Finaliza este breve ensayodestacando el ejercicio de la ciudadanía como espacio para la construcción colectiva de libertad.

  5. PREDICCIÓN DE LA ESTRUCTURA Y CARACTERÍSTICAS BIOQUÍMICAS DE LA ACETATO TIOQUINASA

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    Jairo A. Tovart

    2001-12-01

    Full Text Available Las actividades de las enzimas implicadas en el metabolismo de los cuerpos cetónicos están presentes tanto en neuronas, como en astrocitos y en oligodendroglía. La utilización de cultivos primarios ha puesto de manifiesto que estos cuerpos cetónicos pueden ser metabolizados en estas células.La· acetato tioquinasa reportada en tejido neural total es una enzima que reduce significativamente el costo energético de la utilización del acetato y por lo tanto se propone como una ruta de elección en metabolismo de esta sustancia.Los datos de predicción para propiedades bioquímicas y estructurales de la enzima muestran una estructura estable, con segmentos conservados entre todas las secuencias existentes y una alta flexibilidad estructural, propia de la mayoría de la enzimas.

  6. ¿Prevalece un vínculo, objetivo, entre la percepción sensible y los conceptos?

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    Martha Dolores Delgado Wise

    2014-01-01

    Full Text Available La imposibilidad de alcanzar contenidos cognitivos por medio de la percepción sensible actualmente puede ser cuestionada. Se busca reconsiderar que el conocimiento obtenido por medio de la percepción sensible guarde contenidos de objetividad, expresables aún con los conceptos. Se señalan relaciones de correspondencia entre percepción sensible con lo dado y las posibilidades resguardadas en la simbolización. Dado que la conceptualización es la abstracción racional de dichas relaciones, se demuestra la existencia vinculatoria de tales relaciones. El conocimiento de las neuronas espejo confirma la existencia de tales relaciones objetivas de correspondencia. Ello pone en evidencia que el conocimiento tiene acceso parcial a la realidad misma y que tal conocimiento está lejos de una relatividad absoluta.

  7. En busca de un fundamento crítico y social de la moral desde una perspectiva neurocientífica

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    Edgar Straehle Porras

    2013-04-01

    Full Text Available En este artículo se realiza una aproximación a la moralidad desde una perspectiva neurológica que procura resaltar los aspectos prosociales del cerebro aunque también su inherente neuroplasticidad. Con esto se trata de recusar algunas de las frecuentes explicaciones que, de manera consciente o no, acaban por ofrecer un cuadro simplista y muchas veces determinista de la naturaleza humana. Asimismo se apela a un uso responsable y reflexivo de las neurociencias, enfatizando que el estudio del cerebro debe tener un carácter interdisciplinar. La neurología aporta un conocimiento que es muy provechoso para una exploración biológica de la ética, como es el caso de las neuronas espejo, cuya existencia revaloriza la importancia del otro, quizá también como uno de los ingredientes cruciales de la moral.  

  8. Impact of pharmacological and environmental manipulations on neuronal structural plasticity and dynamics

    OpenAIRE

    Pérez Rando, Marta

    2017-01-01

    El sistema nervioso de vertebrados es uno de los más estudiados, aunque peor comprendidos, del organismo de mamíferos. Desde que Ramón y Cajal postuló su teoría celular de este sistema (Ramón y Cajal 1909), la neurona se ha postulado como su unidad funcional. Sin embargo, durante las últimas décadas se ha revolucionado la visión que se tenía de éste. Una de las percepciones más asentadas era que, tras el desarrollo embrionario, el sistema nervioso se mantenía inmutable. Sin embargo, ahora sab...

  9. Acción del factor de crecimiento epidérmico sobre el desarrollo de las células estriatales cultivadas

    OpenAIRE

    Lázara Castillo; Orlando Castellano; Johanka Soto; Juan C. Rosillo; Karelys de la Cuétara

    1996-01-01

    En este trabajo se describe la acción del factor de crecimiento epidérmico (FCE) sobre las células del estriado embrionario en un sistema de cultivo disociado de neuronas y glías. El cultivo de células se preparó a partir de embriones de ratas de 16-17 días. En el sistema de cultivo empleado, la población celular fue cultivada durante 20-24 horas en un medio que contenía suero y, posteriormente, fue tratada con 20 ng/mL del FCE en un medio libre de suero. La eliminación del suero en este perí...

  10. La Conexión Homocisteína

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    Alfredo Jácome Roca

    2012-04-01

    Full Text Available Este aminoácido azufrado –involucrado en la transferencia de grupos metilos en el metabolismo celular-ha cobrando importancia desde hace algunas décadas por su relación con la arteriosclerosis, enfermedades cardiovascular y de Alzheimer, entre otras patologías. Se considera uno de los factores de riesgo emergentes, que tratan de cerrar la brecha del 40% de los casos coronarios no relacionados con los riesgos tradicionales conocidos. Tiene que ver con daño endotelial, incremento en estrés oxidativo,fallas en vasodilatación mediada por oxido nítrico y toxicidad mediada por β-amiloide, muerte de neuronas corticales y de sus circuitos.

  11. Péptido neuroprotector así como su uso en el tratamiento de enfermedades cerebrovasculares y otras patologías del SNC

    OpenAIRE

    Díaz-Guerra, Margarita; Sánchez Tejeda, Gonzalo; Gómez Vidaurre, Oscar

    2012-01-01

    La presente invención hace referencia a un péptido neuroprotector, caracterizado por comprender los 11 aminoácidos C-terminales de TrkB-T1 (residuos 466- 476) (SEQ ID NO: 1) y ser capaz de interferir y/o inhibir la unión entre TrkB-T1 y sus moléculas interaccionantes en una neurona y/o célula glial. Así mismo, en la presente invención se protege el uso de dicho péptido neuroprotector para prevenir y/o tratar el daño neuronal en mamíferos causado por una enf...

  12. La teoría del todo (2014, una mirada hacia los efectos de la Esclerosis Lateral Amiotrófica en la vida de Stephen Hawking/ The theory of everything (2014, a closer to the effects of Amiotrophic Lateral Sclerosis in the life of Stephen Hawking

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    Sofia Aguiñaga?Malanco et al.

    2017-03-01

    Full Text Available Stephen Hawking, autor de las teorías más fundamentales sobre el comportamiento de los agujeros negros, entreotras consideraciones sobre el tiempo y el espacio; padece de esclerosis lateral amiotrófica, la cual le fue diagnosticadadurante su último año en Oxford, tal y como se describe en la película La teoría del todo (2014 dirigida porJames Marsh y producida por Anthony McCarten. La esclerosis lateral amiotrófica (ELA o enfermedad de Lou Gehriges una alteración neurodegenerativa progresiva que ocasiona debilitamiento gradual de la musculatura voluntaria.Se caracteriza por una pérdida progresiva de la moto?neurona de la corteza motora, tronco del encéfalo y médulaespinal.

  13. La teoría del todo (2014, una mirada hacia los efectos de la Esclerosis Lateral Amiotrófica en la vida de Stephen Hawking

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    Sofía AGUIÑAGA MALANCO

    2017-06-01

    Full Text Available Stephen Hawking, autor de las teorías más fundamentales sobre el comportamiento de los agujeros negros, entreotras consideraciones sobre el tiempo y el espacio; padece de esclerosis lateral amiotrófica, la cual le fue diagnosticadadurante su último año en Oxford, tal y como se describe en la película La teoría del todo (2014 dirigida por James Marsh y producida por Anthony McCarten. La esclerosis lateral amiotrófica (ELA o enfermedad de Lou Gehrig es una alteración neurodegenerativa progresiva que ocasiona debilitamiento gradual de la musculatura voluntaria.Se caracteriza por una pérdida progresiva de la moto?neurona de la corteza motora, tronco del encéfalo y médulaespinal.

  14. MODELO PARA SIMULAR LA HOMEÓSTASIS NEURONAL DURANTE UN INFLUJO INCREMENTADO DEL CALCIO A TRAVÉS DEL CANAL ASOCIADO AL RECEPTOR IONOTRÓPICO DE GLUTAMATO ACTIVADO POR N-METIL-D-ASPARTATO

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    L. Lareo

    2005-12-01

    Full Text Available Dada la importancia del receptor ionotrópico de glutamato activado por N-Metil-D-Aspartato en los procesos de aprendizaje y la formación de la memoria mediados por el transporte de calcio a través del canal asociado a dicho receptor resulta importante desarrollar modelos que permitan comprender la homeóstasis que le permite a la neurona manejar incrementos en el flujo de dicho catión sin llegar a desarrollar procesos necróticos ni apoptóticos. Este trabajo presenta una sencilla simulación de parte de los procesos metabólicos asociados al receptor como un paso inicial para comprender los mecanismos subyacentes al aprendizaje y memoria.

  15. McGreevey, cuarenta años después

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    Salomón Kalmanovitz

    2015-12-01

    Full Text Available A raíz del lanzamiento de la segunda edición del libro Historia económica de Colombia 1843-1930 estuve recuperando memorias grabadas en neuronas escondidas. Le preparamos a William Paul McGreevey una emboscada intelectual en un seminario que se le organizó en Bogotá en julio de 1975, que por fuera de la ira que nos despertaba revelaba que su libro nos había conmocionado profundamente. Varios éramos marxistas, otros eran seguidores radicales de la Escuela francesa de los Anales, y los había que hacían algo de historia económica sin apoyarse en modelos ni en la econometría. Estaban los historiadores norteamericanos Frank Safford y David Bushnell, que tocaban temas económicos sin ser economistas.

  16. Predicción por redes neuronales artificiales de la calidad fisicoquímica de vinagre de melaza de caña por efecto de tiempo-temperatura de alimentación a evaporador-destilador flash

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    Víctor Vásquez V.

    2010-01-01

    Full Text Available Se predijo por Redes Neuronales Artificiales (RNA importantes características fisicoquímicas de vinagre de melaza: pH, densidad, acidez total, etanol, aldehídos totales y furfural; obtenidas mediante operaciones de evaporación flash y clarificación por destilación flash. Melaza fermentada por vía alcohólica y acética, fue alimentada a un evaporador flash a cuatro temperaturas (61, 66, 71 y 76 °C y tres tiempos (25, 35 y 45 min. La predicción se realizó con dos redes: RNA-A y RNA-B, ambas con buen desempeño. La RNA-A fue del tipo feedforward (FF, con algoritmos de entrenamiento Backpropagation (BP y ajuste de pesos Levenberg-Marquardt (LM, topología: 6 entradas (datos de las operaciones de evaporación-destilación flash, 7 salidas lineales (características fisicoquímicas, 9 neuronas tangente sigmoidales en 1 capa oculta, coeficiente de momento 0.5, tasa de aprendizaje 0.01, meta del error 0.0001 y 20 etapas de entrenamiento. La RNA-A mostró mejor desempeño que un modelo estadístico de primer orden. La RNA-B igualmente FF, con algoritmos BP y LM, topología: 2 entradas (datos de la evaporación flash, 7 salidas lineales (características fisicoquímicas, 84 neuronas logaritmo sigmoidales en 1 capa oculta, coeficiente de momento 0.5, tasa de aprendizaje 0.01, meta del error 0.0001 y 300 etapas de entrenamiento. La RNA-B mostró igual capacidad predictiva que un modelo estadístico de primer orden con interacción de términos.

  17. Receptores para el virus de la rabia

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    Jaime E. Castellanos

    2001-12-01

    Full Text Available El virus de la rabia causa una infección en el sistema nervioso que puede provocar la muerte. La patogenia y el neurotropismo de este virus han sido estudiados extensamente con el objeto de explicar el porque la letalidad de la enfermedad y proponer nuevas alternativas terapéuticas. El proceso de adsorción del virus a la célula bianco se considera un evento que define el neurotropismo del virus. Se piensa que debe existir una molécula en la superficie de las neuronas que une con alta afinidad al virus y da comienzo al proceso infeccioso. Durante los últimos años se han propuesto varias proteínas, carbohidratos y lipidos complejos, como receptores para el virus de rabia y se han hecho nuevas proposiciones de terapia antirreceptor. Además de los gangliósidos y fosfolípidos para los que se ha hallado evidencia sobre su participación en la adsorción del virus de la rabia, hay datos experimentales sobre la participación del receptor nicotinico de acetilcolina. la molécula de adhesión celular neural y el receptor de baja afinidad para neurotrofinas en la infección neurona1 En este articulo se hace una revisión de los datos que sustentan a cada una de las moléculas propuestas, se discuten sus implicaciones para la explicación del neurotropismo del virus de rabia y la exploración de nuevas terapias antivirales.

  18. Estimación de la resistencia del rotor de un motor asincrónico utilizando FPGA

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    Juan Carlos Jaimes J.

    2013-09-01

    Full Text Available En este trabajo se presenta la implementación de Redes Neuronales Artificiales en un dispositivo lógico programable como es una FPGA, la finalidad es desarrollar un modelo en Sysgen capaz de estimar la resistencia rotórica en motores de inducción. Para crear una neurona en Sysgen se debe partir del modelo estándar de una neurona artificial, la cual es, la sumatoria de los pesos menos el umbral, todo multiplicado por una función de activación, en este caso la función de activación utilizada fue Tansig para la capa oculta y Purelin para la capa de salida. La red neuronal utiliza datos decimales de entrada-salida, y la FPGA es digital, por lo tanto se diseñó en Sysgen un acondicionamiento capaz de manejar datos binarios en la tarjeta, para esto se utilizó un conversor Digital- Análogo, y se creó la manera de suprimir el número de pines utilizados en la FPGA, diseñando una etapa de registros que sirve para guardar el dato deseado y por ende enviarlo a una de las entradas de la red neuronal. La trama de datos se hace progresivamente cada registro sirve para guardar el valor decimal presente a la salida del conversor Digital-Análogo y cada vez que se cambie el dato se activa el registro correspondiente a la entrada de la red neuronal.

  19. Sobre Neuronatomía, Neurohistología e Historia

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    Jaime Fandiño-Franky

    2012-07-01

    Full Text Available En el trabajo titulado “Causas históricas que justificaron al cirugía de las epilepsias” se hacen varias afirmaciones entre las que se cuentan: 1. Franz Morell descubrió las neuronas internunciales 2. En la estimulación del nervio vago los impulsos llegan al núcleo del tracto solitario y de allí al tronco cerebral 3. Las estimulaciones corticales fueron realizadas por Harvey Cushing en 1009 lo que le permitió localizar el área motora y sensitiva. En oposición a estas notas, manifiesto lo que va en contra del consenso histórico en el campo por las siguientes sencillas razones: 1. Las interneuronas son neuronas cruciales de las redes cerebrales relacionadas con el control motor (4 y fueron descubiertas por Camillo Golgi, quién inventó la reacción oscura en 1873 y fue el descubridor de la fina estructura anatómica del sistema nervioso. Estas células que Golgi describió y descubrió, fueron entonces propuestas como prototipo de interneuronas (5. Camilo Golgi realizó este descubrimiento por finales del siglo XIX y Franz Morell realizó contribuciones hacia finales del siglo XX. 2. El núcleo del tracto solitario se ubica en el tronco encefálico y está constituido por aferentes axonicos de los nervios craneales facial, glosofaríngeo y vago (2. Por ubicación topográfica se circunscribe al bulbo raquídeo (3, por lo que estando en el tronco encefálico no pude dirigirse así mismo (es redundante. 3. Harvey Cushing no existía en 1009, él fue un eminente neurocirujano que vivió entre 1869 y 1939 (6.

  20. Frequency of parasites and Salmonella infection in captive maned-wolf, Chrysocyon brachyurus, kept in Zoos at the State of São Paulo, Brazil

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    Gilioli R.

    2000-01-01

    Full Text Available Thirty-one captive maned wolves (Chrysocyon brachyurus, Illiger 1815 from 11 Zoos at the State of São Paulo, Brazil, were screened to investigate the presence of parasites and Salmonella infection by parasitological diagnostic methods and fecal selective culture. The most frequent ecto and endoparasites found were Ctenocephalides felis (56.2%, Rhipicephalus sanguineus (12.5%, Ancylostoma caninum (45.1%, Strongyloides sp. (29.0%, Uncinaria stenocephala (3.2%, Capillaria sp. (3.2%, Entamoeba sp. (22.9%, Sarcocystis sp. (29.0%, Cryptosporidium sp. (19.3%, Eimeria sp. (19.3%, Giardia sp. (9.6% and Isospora sp. (3.2%. Four different serotypes of Salmonella were identified in six animals (25%. Only one infected animal showed clinical signs of diarrhea. The ability to harbor Salmonella spp. as normal nonpathogenic bacteria of the gastrointestinal tract may be a physiological adaptation of this specie.

  1. Human and animal invasive muscular sarcocystosis in Malaysia--recent cases, review and hypotheses.

    Science.gov (United States)

    Tappe, D; Abdullah, S; Heo, C C; Kannan Kutty, M; Latif, B

    2013-09-01

    Sarcocystosis, an unusual parasitic zoonotic disease, is caused by coccidian/ apicomplexan protozoa in humans and animals. The parasites usually develop in a heteroxenous predator-prey life-cycle involving final (carnivore) and intermediate (omnivore/herbivore) hosts. Besides the intestinal, non-invasive form of the disease in which humans and animals are the definitive hosts for certain Sarcocystis spp., the invasive form has come to recent attention. In the latter, humans and animals serve as intermediate host harbouring sarcocysts in their muscle tissue. Already in 1991 sarcocystosis was seen as a potential emerging food borne zoonosis in Malaysia, and in 2011 and 2012 the largest cluster of symptomatic human muscular sarcocystosis world-wide was reported from Tioman Island, Pahang state. In this review, we focus on invasive sarcocystosis in humans and animals in Malaysia, review the recorded cases and epidemiology, and present hypotheses.

  2. Fatal toxoplasmosis in a vinaceous Amazon parrot (Amazona vinacea).

    Science.gov (United States)

    Ferreira, Francisco Carlos; Donatti, Rogerio Venâncio; Marques, Marcus Vinícius Romero; Ecco, Roselene; Preis, Ingred Sales; Shivaprasad, H L; Vilela, Daniel Ambrózio da Rocha; Martins, Nelson Rodrigo da Silva

    2012-12-01

    Toxoplasmosis was diagnosed in a vinaceous Amazon parrot based on histopathology and immunohistochemistry. The bird was prostrate on the bottom of the cage and died. Necropsy revealed edema and congestion of the lungs, cloudy air sacs, and mild hepatomegaly. Histopathology revealed severe pulmonary congestion and edema and interstitial mononuclear cell inflammation associated with many cysts containing bradyzoites of Toxoplasma gondii scattered throughout. The heart had mild multifocal lymphocytic myocarditis and free tachyzoites in the muscle fibers, and the kidneys had mild interstitial nephritis and a few cysts containing bradyzoites of T. gondii. Immunohistochemistry was negative for Sarcocystis falcatula and Neospora caninum and confirmed the protozoa as T. gondii. This is the first description of T. gondii in an endangered species ofa Brazilian psittacine.

  3. Chlamydiosis in a red-tailed hawk (Buteo jamaicensis).

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    Mirandé, L A; Howerth, E W; Poston, R P

    1992-04-01

    A red-tailed hawk (Buteo jamaicensis) with signs of respiratory distress and diarrhea was captured in the Manchac Wildlife Management Area, Louisiana (USA) and died the following day. At necropsy, the carcass was emaciated and there were splenomegaly, and fibrinous pericarditis, airsacculitis, and perihepatitis. Microscopically, there were fibrinous pericarditis and airsacculitis, myocardial necrosis, necrotizing hepatitis, splenic necrosis with reticuloendothelial cell hyperplasia, interstitial pneumonia and focal pancreatic necrosis. Intracytoplasmic chlamydial inclusion bodies were noticed in macrophages in the fibrinous exudate covering air sac and pericardium, and in spleen, liver, heart, lung, and pancreas. Schizonts compatible with a Sarcocystis sp.-like protozoon were present in the walls of air capillaries in the lung. A Chlamydia sp.-like organism was isolated in embryonating chicken eggs and cell culture and identified as C. psittaci with immunofluorescent staining.

  4. Prevalence of Zoonotic and Other Intestinal Protozoan Parasites in Stray Cats (Felis domesticus of Kerman, South-East of Iran

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    Sakineh BEIGI

    2017-01-01

    Full Text Available Intestinal protozoan parasites constitute a major source of diseases for stray cats and have been recognized as important public health problems in several parts of the world. Considering the potential risk of stray cats for public health, present cross-sectional study was carried out to determine the type and frequency of protozoan parasites by faecal examination. A total of 100 stray cats were examined in Kerman city, Iran, Overall 67 cats (67% were infected with at least one protozoan parasite. The following parasites, with their respective prevalence, were found; Isospora felis 38%, Isospora rivolta 25%, Toxoplasma gondii 16%, Sarcocystis spp. 8%, Cryptosporidium spp. 7%, and Giardia sp. 5%. Based on our data, the sex of stray cats was not significantly associated with the prevalence of gastrointestinal protozoan parasites. The high infection rate of zoonotic intestinal protozoan parasites in stray cats is considered to be critical from the viewpoint of public health importance.We

  5. Prevalensi Infeksi Protozoa Saluran Pencernaan Pada Kucing Lokal (Felis catus Di Denpasar

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    Putu Titin Evi Sucitrayani

    2014-08-01

    Full Text Available Cat is one of the pets which many people love to looking after.  A lot of people looking after cat but so many of them don’t pay much attention to cats wealth, this makes them become stray cat. The most common gastrointestinal protozoa in cat is Giardia felis, Cryptosporadium felis, Sarcocystis spp, Hammondia hamondi, Toxoplasma gondii, and Isospora spp. The purpose of this research is to know the prevalence of gastrointestinal protozoa infection in local home cat and stray cat in Denpasar. This research used 80 samples of cat feces, 40 home cat feces and 40 stray cat feces. Samples examined using float concentration method, with saturated sodium chloride. From 80 examined samples, 25 samples (31,3 % infected with gastrointestinal protozoa. For home cat, from 40 examined samples 9 samples  (22,5%  infected with gastrointestinal protozoa, meanwhile from stray cat, 16 samples (40 %  infected from gastrointestinal protozoa.

  6. Endoparasites of American marten (Martes americana: Review of the literature and parasite survey of reintroduced American marten in Michigan

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    Maria C. Spriggs

    2016-12-01

    Full Text Available The American marten (Martes americana was reintroduced to both the Upper (UP and northern Lower Peninsula (NLP of Michigan during the 20th century. This is the first report of endoparasites of American marten from the NLP. Faeces from live-trapped American marten were examined for the presence of parasitic ova, and blood samples were obtained for haematocrit evaluation. The most prevalent parasites were Capillaria and Alaria species. Helminth parasites reported in American marten for the first time include Eucoleus boehmi, hookworm, and Hymenolepis and Strongyloides species. This is the first report of shedding of Sarcocystis species sporocysts in an American marten and identification of 2 coccidian parasites, Cystoisospora and Eimeria species. The pathologic and zoonotic potential of each parasite species is discussed, and previous reports of endoparasites of the American marten in North America are reviewed.

  7. Development of a biomolecular assay for postmortem diagnosis of Taenia saginata Cysticercosis.

    Science.gov (United States)

    Chiesa, Francesco; Dalmasso, Alessandra; Bellio, Alberto; Martinetti, Manuela; Gili, Stefano; Civera, Tiziana

    2010-10-01

    Bovine cysticercosis is caused by the larval stage of the human tapeworm Taenia saginata. According to European data on meat inspection, the prevalence ranges from 0.007% to 6.8%, but the real prevalence is considered to be at least 10 times higher. Laboratory confirmation of the etiological agent is based on gross, stereomicroscopic, and histological examination of submitted specimens. False identifications may occur, possibly because of death and degeneration of cysts, or because taeniid larvae and other tissue parasites, such as Sarcocystis spp., may cause similar macroscopic morphological lesions. Therefore, tests that can warrant sure identification of taeniid lesions and calcified cysts in the muscle are needed. The focus of our study was to develop a suitable postmortem test that could be applied on putative lesions by T. saginata cysticerci, as ambiguously diagnosed after routine meat inspection. In particular, we proposed a biomolecular assay targeting the mitochondrial cytochrome c oxidase subunit I gene (COI). For developing the polymerase chain reaction assay, viable cysts of Cysticercus bovis (n = 10) were used as positive reference samples, and those of Echinococcus granulosus (n = 3), Cysticercus tenuicollis (n = 3), and Sarcocystis spp. (n = 4) as reference negative controls. Further, to evaluate the applicability of the proposed assay, 171 samples of bovine muscular tissue, obtained from local slaughterhouses and containing lesions recognized as T. saginata cysticerci by macroscopic examination, were tested. The proposed test confirmed the diagnosis at postmortem inspection in 94.7% (162/171) of samples. In conclusion, the assay developed in this study, amplifying a short fragment from the mitochondrial gene COI, showed to be suitable for samples containing both viable and degenerating T. saginata cysticerci, yielding an unequivocal diagnosis.

  8. Survey of Dogs’ Parasites in Khorasan Razavi Province, Iran

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    GhR Razmi

    2009-12-01

    Full Text Available "nBackground: Dog is known to act as definitive host for some parasites that cause important diseases in man and animals. The aim of the present study was to determine the prevalence of Neospora caninum and other intestinal parasites in dogs in Khorasan Razavi Province, Iran. "nMethods: A cross-sectional study was done concerning frequency of N. canium and other in­testinal parasites in dogs in Mashhad area. Totally, 174 fecal samples from 89 farm dogs and 85 household dogs were collected from 2006 to 2007. Fecal samples were examined for de­tecting intestinal parasites by Mini Parasep®SF faecal parasite concentrator in Department of Parasitology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran "nResults: The overall prevalence of other intestinal parasites in farm dogs and household dogs were 29.21% and 14.11%, respectively. Seven parasites were found in farm dogs as follows: Toxocara canis 17.9%, Taenia sp. 10.1% , Strongyloides stercoralis 5.6%, Hammondia Neo­spora-like oocysts (HNLO 4.4% , Isospora sp. 7.8 %, Sarcocystis sp. 7.8 % and   Giardia sp. 1.1%  and four parasite in housed dogs:  Toxocara. 4.4%, Taenia sp. 3.3 % , Isospora sp. 2.3 % and  Sarcocystis sp. 4.7 %.  The fecal samples with HNLO were examined by N. caninum -specific PCR, and two of samples were positive for N. caninum. "nConclusion: The farm and household dogs are the source of some important zoonotic and non-zoonotic diseases in Iran .

  9. Microscopic and molecular characterization of Hepatozoon domerguei (Apicomplexa and Foleyella furcata (Nematoda in wild endemic reptiles from Madagascar

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    Maia João P.

    2014-01-01

    Full Text Available Madagascar is one of the world’s top twelve “megadiversity” hot spots hosting unique and threatened flora and fauna. Parasites are a major component of biodiversity but remain largely uncharacterized in wildlife. In this study we combine microscopic and molecular assessment of hemoparasites in endemic reptile species from Madagascar. We detected three distinct parasites: the apicomplexans Hepatozoon and Sarcocystis, and filarial nematodes. The prevalence and intensity of these apicomplexans were low overall, while microfilarial infections in chameleons were relatively high. We detected mixed infections of two Hepatozoon haplotypes in Madagascarophis colubrinus, and of Hepatozoon and microfilariae in a Furcifer sp. Phylogenetic analyses of Hepatozoon showed evidence of prey-predator transmission, with identical sequences found in the snakes M. colubrinus and Ithycyphus oursi, and their prey Furcifer sp. Based on previous studies regarding the life cycle of Hepatozoon domerguei Landau, Chabaud, Michel, and Brygoo, 1970 in these hosts and due to their morphological similarity, we propose that this Hepatozoon haplotype is Hepatozoon domerguei. Future studies, including the examination of invertebrate hosts, are needed to verify this preliminary taxonomic identification. A distinct hemogregarine haplotype was found in Oplurus sp., which displayed morphologically different gametocytes, some of which were apparently inside leukocytes. The Sarcocystis identified from Tracheloptychus petersi was identical to that reported in a North African snake, indicating that the same lineage is found in geographically distinct regions. By combining morphological and genetic information, Foleyella furcata (Linstow, 1899 filarial nematodes were identified in several Furcifer chameleons. This study provides insights into the distribution, diversity and host-parasite interactions of hemoparasites in wild reptile populations from Madagascar.

  10. Microscopic and molecular characterization of Hepatozoon domerguei (Apicomplexa) and Foleyella furcata (Nematoda) in wild endemic reptiles from Madagascar.

    Science.gov (United States)

    Maia, João P; Crottini, Angelica; Harris, David James

    2014-01-01

    Madagascar is one of the world's top twelve "megadiversity" hot spots hosting unique and threatened flora and fauna. Parasites are a major component of biodiversity but remain largely uncharacterized in wildlife. In this study we combine microscopic and molecular assessment of hemoparasites in endemic reptile species from Madagascar. We detected three distinct parasites: the apicomplexans Hepatozoon and Sarcocystis, and filarial nematodes. The prevalence and intensity of these apicomplexans were low overall, while microfilarial infections in chameleons were relatively high. We detected mixed infections of two Hepatozoon haplotypes in Madagascarophis colubrinus, and of Hepatozoon and microfilariae in a Furcifer sp. Phylogenetic analyses of Hepatozoon showed evidence of prey-predator transmission, with identical sequences found in the snakes M. colubrinus and Ithycyphus oursi, and their prey Furcifer sp. Based on previous studies regarding the life cycle of Hepatozoon domerguei Landau, Chabaud, Michel, and Brygoo, 1970 in these hosts and due to their morphological similarity, we propose that this Hepatozoon haplotype is Hepatozoon domerguei. Future studies, including the examination of invertebrate hosts, are needed to verify this preliminary taxonomic identification. A distinct hemogregarine haplotype was found in Oplurus sp., which displayed morphologically different gametocytes, some of which were apparently inside leukocytes. The Sarcocystis identified from Tracheloptychus petersi was identical to that reported in a North African snake, indicating that the same lineage is found in geographically distinct regions. By combining morphological and genetic information, Foleyella furcata (Linstow, 1899) filarial nematodes were identified in several Furcifer chameleons. This study provides insights into the distribution, diversity and host-parasite interactions of hemoparasites in wild reptile populations from Madagascar. © J.P. Maia et al., published by EDP Sciences

  11. Molecular Method Development to Identify Foodborne Sarcocystishominis in Raw Beef Commercial Hamburger

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    Bahador Hajimohammadi

    2014-11-01

    Full Text Available Background: Sarcocystisspp. is zoonotic parasitic pathogen endangering safety of meat and derived meat products such as hamburgers which is among the most popular fast foods worldwide. Objectives: The current study aimed to design a protocol for molecular identification of Sarcocystis hominis in commercial hamburgers using PCR-RFLP with target of 18S rRNA. Materials and Methods: A total of 25 raw commercial hamburger samples were randomly collected from supermarkets of Yazd city, Iran. Five mm slices from different parts of each sample were selected, well mixed, and then preserved in ethanol 70% at -20°C for the next steps. The genomic DNA was extracted using salting out method. Detection and identification of Sarcocystis isolates were performed using PCR RFLP. The 18s rRNA gene sequence was mined from GenBank and the specific primer pair was designed using Primer3 software. Restriction fragment length polymorphims (RFLP analysis was performed using BfaI and RsaI restriction enzymes. The digestion was analyzed, using agarose gel electrophoresis alongside 100base pair DNA ladder. Results: Among 25 commercial hamburger samples, 17 samples showed a PCR product around 900 bp which could detect Sarcocyst Spp. After RFLP with BfaI, the restriction fragments of 376 bp and 397 bp detected S. hominis or S. hirsuta and fragments of 184 bp, 371 bp and 382 bp detected S. cruzi. After RFLP with RsaI, the restriction fragments of 376 bp and 557 bp detected S. hirsuta and fragment of 926 bp, without any digestion, detected S. hominis. For verification, each species detected in samples was randomly selected and sent for sequencing and the results were analyzed with BLAST. Conclusions: In conclusion, the current study developed a practical technique to detect the prevalence of S. hominis in meat products such as hamburgers.

  12. Protection of aouts monkeys after immunization with recombinant antigens of Plasmodium falciparum

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    Burhard Enders

    1992-01-01

    Full Text Available The genus Aotus spp. (owl monkey is one of the WHO recommended experimental models for Plasmodium falciparum blood stage infection, especially relevant for vaccination studies with asexual blood stage antigens of this parasite. For several immunization trials with purified recombinant merozoite/schizont antigens, the susceptible Aouts kenotypes II, III, IV and VI were immunized with Escherichia coli derived fusion proteins containg partial sequences of the proteins MSAI (merozoite surface antigen I, SERP (serine-strech protein and HRPII (histidine alanine rich protein II as well as with a group of recombinant antigens obtained by an antiserum raised against a protective 41 kD protein band. The subcutaneous application (3x of the antigen preparations was carried out in intact animals followed by splenectomy prior to challange, in order to increase the susceptibility of the experimental hosts to the parasite. A partial sequence of HRPII, the combination of three different fusion proteins of the 41 kD group and mixture of two sequences of SERP in the presence of the modified Al(OH3 adjuvant conferred significant protection against a challange infection with P. falciparum blood stages (2-5 x 10 (elevado a sexta potência i. RBC. Monkey immunized with the MS2-fusion protein carrying the N-terminal part of the 195 kD precursor of the major merozoite surface antigens induced only marginal protection showing some correlation between antibody titer and degree of parasitaemia. Based on the protective capacity of these recombinant antigens we have expressed two hybrid proteins (MS2/SERP/HRPII and SERP/MSAI/HRPII in E. coli containing selected partial sequences of SERP, HRPII and MSAI. Antibodies raised against both hybrid proteins in rabbits and Aotus monkeys recognize the corresponding schizont polypeptides. In two independent immunization trials using 13 animals (age 7 months to 3 years we could show that immunization of Aotus monkeys with either of the

  13. Fitness components and natural selection: why are there different patterns on the emergence of drug resistance in Plasmodium falciparum and Plasmodium vivax?

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    Schneider Kristan A

    2013-01-01

    Full Text Available Abstract Background Considering the distinct biological characteristics of Plasmodium species is crucial for control and elimination efforts, in particular when facing the spread of drug resistance. Whereas the evolutionary fitness of all malarial species could be approximated by the probability of being taken by a mosquito and then infecting a new host, the actual steps in the malaria life cycle leading to a successful transmission event show differences among Plasmodium species. These “steps” are called fitness components. Differences in terms of fitness components may affect how selection imposed by interventions, e.g. drug treatments, differentially acts on each Plasmodium species. Thus, a successful malaria control or elimination programme should understand how differences in fitness components among different malaria species could affect adaptive evolution (e.g. the emergence of drug resistance. In this investigation, the interactions between some fitness components and natural selection are explored. Methods A population-genetic model is formulated that qualitatively explains how different fitness components (in particular gametocytogenesis and longevity of gametocytes affect selection acting on merozoites during the erythrocytic cycle. By comparing Plasmodium falciparum and Plasmodium vivax, the interplay of parasitaemia and gametocytaemia dynamics in determining fitness is modelled under circumstances that allow contrasting solely the differences between these two parasites in terms of their fitness components. Results By simulating fitness components, it is shown that selection acting on merozoites (e.g., on drug resistant mutations or malaria antigens is more efficient in P. falciparum than in P. vivax. These results could explain, at least in part, why resistance against drugs, such as chloroquine (CQ is highly prevalent in P. falciparum worldwide, while CQ is still a successful treatment for P. vivax despite its massive use

  14. Identification of Plasmodium falciparum reticulocyte binding protein homologue 5-interacting protein, PfRipr, as a highly conserved blood-stage malaria vaccine candidate.

    Science.gov (United States)

    Ntege, Edward H; Arisue, Nobuko; Ito, Daisuke; Hasegawa, Tomoyuki; Palacpac, Nirianne M Q; Egwang, Thomas G; Horii, Toshihiro; Takashima, Eizo; Tsuboi, Takafumi

    2016-11-04

    Genetic variability in Plasmodium falciparum malaria parasites hampers current malaria vaccine development efforts. Here, we hypothesize that to address the impact of genetic variability on vaccine efficacy in clinical trials, conserved antigen targets should be selected to achieve robust host immunity across multiple falciparum strains. Therefore, suitable vaccine antigens should be assessed for levels of polymorphism and genetic diversity. Using a total of one hundred and two clinical isolates from a region of high malaria transmission in Uganda, we analyzed extent of polymorphism and genetic diversity in four recently reported novel blood-stage malaria vaccine candidate proteins: Rh5 interacting protein (PfRipr), GPI anchored micronemal antigen (PfGAMA), rhoptry-associated leucine zipper-like protein 1 (PfRALP1) and Duffy binding-like merozoite surface protein 1 (PfMSPDBL1). In addition, utilizing the wheat germ cell-free system, we expressed recombinant proteins for the four candidates based on P. falciparum laboratory strain 3D7 sequences, immunized rabbits to obtain specific antibodies (Abs) and performed functional growth inhibition assay (GIA). The GIA activity of the raised Abs was demonstrated using both homologous 3D7 and heterologous FVO strains in vitro. Both pfripr and pfralp1 are less polymorphic but the latter is comparatively more diverse, with varied number of regions having insertions and deletions, asparagine and 6-mer repeats in the coding sequences. Pfgama and pfmspdbl1 are polymorphic and genetically diverse among the isolates with antibodies against the 3D7-based recombinant PfGAMA and PfMSPDBL1 inhibiting merozoite invasion only in the 3D7 but not FVO strain. Moreover, although Abs against the 3D7-based recombinant PfRipr and PfRALP1 proteins potently inhibited merozoite invasion of both 3D7 and FVO, the GIA activity of anti-PfRipr was much higher than that of anti-PfRALP1. Thus, PfRipr is regarded as a promising blood-stage vaccine

  15. A new species of plasmodiidae (Coccidia: Hemosporidia) from the blood of the skink Scincus hemprichii (Scincidae: Reptilia) in Saudi Arabia.

    Science.gov (United States)

    Amoudi, Mikky A; Alyousif, Mohamed S; Saifi, Muheet A; Alanazi, Abdullah D

    2015-05-01

    Fallisia arabica n. sp. was described from peripheral blood smears of the Skink lizard, Scincus hemprichii from Jazan Province in the southwest of Saudi Arabia. Schizogony and gametogony take place within neutrophils in the peripheral blood of the host. Mature schizont is rosette shaped 17.5 ± 4.1 × 17.0 ± 3.9 μm, with a L/W ratio of 1.03(1.02-1.05) μm and produces 24(18-26) merozoites. Young gametocytes are ellipsoidal, 5.5 ± 0.8 × 3.6 ± 0.5 μm, with a L/W of 1.53(1.44-1.61) μm. Mature macrogametocytes are ellipsoidal, 9.7 ± 1.2 × 7.8 ± 1.0 μm, with a L/W of 1.24(1.21-1.34) μm and microgametocytes are ellipsoidal, 7.0 ± 1.1 × 6.8 ± 0.9 μm. with a L/W of 1.03(1.01-1.10) μm. In comparison to the described Fallisia species, this new taxon has rosette schizonts and is larger than F. dominicensis, in Hispaniola, F. bipocrati, F. poecilopi, in Panama, F. thecadactyli in Venezuela, and F. effusa, F. simplex, F. modesta, in Brazil. F. arabica has fewer merozoites than F. effusa, F. poecilopi, F. thecadactyli and F. siamense in Thailand. This new species has more merozoites than F. dominicensis and F. modesta. All of these species belong to diverse saurian families (Agamidae, Gekkonidae, Polychrotidae, Scincidae and Teiidae) parasitize only thrombocytes or lymphocytes and some species parasitize immature erythroid cells and leucocytes.

  16. Selections, frameshift mutations, and copy number variation detected on the surf 4.1 gene in the western Kenyan Plasmodium falciparum population.

    Science.gov (United States)

    Gitaka, Jesse N; Takeda, Mika; Kimura, Masatsugu; Idris, Zulkarnain Md; Chan, Chim W; Kongere, James; Yahata, Kazuhide; Muregi, Francis W; Ichinose, Yoshio; Kaneko, Akira; Kaneko, Osamu

    2017-03-02

    Plasmodium falciparum SURFIN4.1 is a putative ligand expressed on the merozoite and likely on the infected red blood cell, whose gene was suggested to be under directional selection in the eastern Kenyan population, but under balancing selection in the Thai population. To understand this difference, surf 4.1 sequences of western Kenyan P. falciparum isolates were analysed. Frameshift mutations and copy number variation (CNV) were also examined for the parasites from western Kenya and Thailand. Positively significant departures from neutral expectations were detected on the surf 4.1 region encoding C-terminus of the variable region 2 (Var2) by 3 population-based tests in the western Kenyan population as similar in the Thai population, which was not covered by the previous analysis for eastern Kenyan population. Significant excess of non-synonymous substitutions per nonsynonymous site over synonymous substitutions per synonymous site was also detected in the Var2 region. Negatively significant departures from neutral expectations was detected on the region encoding Var1 C-terminus consistent to the previous observation in the eastern Kenyan population. Parasites possessing a frameshift mutation resulting a product without intracellular Trp-rich (WR) domains were 22/23 in western Kenya and 22/36 in Thailand. More than one copy of surf 4.1 gene was detected in western Kenya (4/24), but no CNV was found in Thailand (0/36). The authors infer that the high polymorphism of SURFIN4.1 Var2 C-terminus in both Kenyan and Thai populations were shaped-up by diversifying selection and maintained by balancing selection. These phenomena were most likely driven by immunological pressure. Whereas the SURFIN4.1 Var1 C-terminus is suggested to be under directional selection consistent to the previous report for the eastern Kenyan population. Most western Kenyan isolates possess a frameshift mutation that would limit the expression of SURFIN4.1 on the merozoite, but only 60% of Thai

  17. Changes in Serological Immunology Measures in UK and Kenyan Adults Post-Controlled Human Malaria Infection

    Directory of Open Access Journals (Sweden)

    Susanne Helena Hodgson

    2016-10-01

    Full Text Available Background: The timing of infection is closely determined in controlled human malaria infection (CHMI studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS (Pan African Clinical Trial Registry: PACTR20121100033272 was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated Plasmodium falciparum sporozoites administered by needle and syringe and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria. Methods: We describe detailed serological and functional immunological responses pre- and post-CHMI for participants in the KCS and compare these with those from malaria-naïve UK volunteers who also underwent CHMI (VAC049 (ClinicalTrials.gov NCT01465048 using PfSPZ Challenge. We assessed antibody responses to three key blood-stage merozoite antigens (merozoite surface protein 1 (MSP1, apical membrane protein 1 (AMA1 and reticulocyte-binding protein homolog 5 (RH5 and functional activity using two candidate measures of anti-merozoite immunity; the growth inhibition activity (GIA assay and the antibody-dependent respiratory burst activity (ADRB assay. Results: Clear serological differences were observed pre- and post-CHMI by ELISA between malaria-naïve UK volunteers in VAC049, and Kenyan volunteers who had prior malaria exposure. Antibodies to AMA1 and schizont extract correlated with parasite multiplication rate (PMR post-CHMI in KCS. Serum from volunteer 110 in KCS, who demonstrated a dramatically reduced PMR in vivo, had no in vitro GIA prior to CHMI but the highest level of ADRB activity. A significant difference in ADRB activity was seen between KCS volunteers with minimal and definite prior exposure to malaria and significant increases were seen in ADRB activity post-CHMI in Kenyan volunteers

  18. Response of Plasmodium falciparum to cotrimoxazole therapy: relationship with plasma drug concentrations and dihydrofolate reductase and dihydropteroate synthase genotypes

    DEFF Research Database (Denmark)

    Khalil, Insaf F; Rønn, Anita M; Alifrangis, Michael

    2005-01-01

    We assessed the efficacy of trimethoprim/sulfamethoxazole (TRM/SMX) in vivo in relation to the frequency of dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) alleles in 45 Sudanese malaria patients. Plasma levels of TRM, SMX, and acetylsulfamethoxazole (AcSMX) were measured before...... treatment and at days 3, 7, and 14 or upon recrudescence to ascertain drug absorption. Forty patients (89%) had an adequate clinical response, one patient (2%) had an early treatment failure response, while four patients (8%) showed late treatment failure responses. Genotyping of merozoite surface protein 1......, MSP-1, MSP-2, and glutamate-rich protein before treatment and upon recrudescence showed that all recurring parasites were recrudescences. The plasma levels of TRM, AcSMX, and SMX indicated adequate drug absorption in all patients. This suggests parasite resistance as a cause of treatment failure...

  19. An experimental vaccine cocktail for Plasmodium falciparum malaria.

    Science.gov (United States)

    Bathurst, I C; Gibson, H L; Kansopon, J; Hahm, B K; Green, K M; Chang, S P; Hui, G S; Siddiqui, W A; Inselburg, J; Millet, P

    1993-01-01

    Surface proteins from several different life-cycle stages of the malaria parasite Plasmodium falciparum were expressed at high levels in the yeast Saccharomyces cerevisiae. Purified proteins, both individually and in cocktails, were used to immunize mice and goats in conjunction with either Freund's adjuvant or a muramyl tripeptide-based adjuvant. Immune responses were measured by enzyme-linked immunosorbent assays and by the ability of antisera to inhibit (1) the invasion of hepatocytes by live sporozoites, (2) in vitro invasion of human erythrocytes by live merozoites, and (3) the development of oocytes in the mosquito vector. These results suggest that cocktails of different stage-specific antigens can provide the components necessary to block the development of the malaria parasite at multiple stages of its life cycle.

  20. Genetic complexity of Plasmodium falciparum in two ethnic groups of Burkina Faso with marked differences in susceptibility to malaria.

    Science.gov (United States)

    Paganotti, Giacomo M; Babiker, Hamza A; Modiano, David; Sirima, Bienvenu S; Verra, Federica; Konaté, Amadou; Ouedraogo, Andre L; Diarra, Amidou; Mackinnon, Margaret J; Coluzzi, Mario; Walliker, David

    2004-08-01

    We have characterized Plasmodium falciparum genotypes among the Mossi and Fulani sympatric ethnic groups in villages in Burkina Faso during the rainy season. Differences in clinical malaria presentation and in immune responses to malaria occur between the two groups. Asexual parasite rate, density, and gametocyte rate were higher among the Mossi than the Fulani. There was no difference in frequencies of alleles of the P. falciparum merozoite surface protein 1 (msp-1), msp-2, and glutamate-rich protein (glurp) genes among the parasites in each group. However, there were significant differences in the mean number of P. falciparum clones in the two populations, with there being more in the Mossi than in the Fulani. This effect was especially marked in older children. These differences can most probably be attributed to genetic differences in immune responsiveness to malaria between the two ethnic groups.