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.

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

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Lewis, S Rochelle; Ellison, Siobhan P; Dascanio, John J; Lindsay, David S; Gogal, Robert M; Werre, Stephen R; Surendran, Naveen; Breen, Meghan E; Heid, Bettina M; Andrews, Frank M; Buechner-Maxwell, Virginia A; Witonsky, Sharon G

2014-01-01

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.

Exposure to Sarcocystis spp. in horses from Spain determined by Western blot analysis using Sarcocystis neurona merozoites as heterologous antigen.

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Arias, M; Yeargan, M; Francisco, I; Dangoudoubiyam, S; Becerra, P; Francisco, R; Sánchez-Andrade, R; Paz-Silva, A; Howe, D K

2012-04-30

Horses serve as an intermediate host for several species of Sarcocystis, all of which utilize canids as the definitive host. Sarcocystis spp. infection and formation of latent sarcocysts in horses often appears to be subclinical, but morbidity can occur, especially when the parasite burden is large. A serological survey was conducted to determine the presence of antibodies against Sarcocystis spp. in seemingly healthy horses from the Galicia region of Spain. Western blot analyses using Sarcocystis neurona merozoites as heterologous antigen suggested greater than 80% seroprevalance of Sarcocystis spp. in a sample set of 138 horses. The serum samples were further tested with enzyme-linked immunosorbent assays (ELISAs) based on recombinant S. neurona-specific surface antigens (rSnSAGs). As expected for horses from the Eastern Hemisphere, less than 4% of the serum samples were positive when analyzed with either the rSnSAG2 or the rSnSAG4/3 ELISAs. An additional 246 horses were tested using the rSnSAG2 ELISA, which revealed that less than 3% of the 384 samples were seropositive. Collectively, the results of this serologic study suggested that a large proportion of horses from this region of Spain are exposed to Sarcocystis spp. Furthermore, the anti-Sarcocystis seroreactivity in these European horses could be clearly distinguished from anti-S. neurona antibodies using the rSnSAG2 and rSnSAG4/3 ELISAs. Copyright © 2011 Elsevier B.V. All rights reserved.

The identification of a sequence related to apicomplexan enolase from Sarcocystis neurona.

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Wilson, A P; Thelen, J J; Lakritz, J; Brown, C R; Marsh, A E

2004-11-01

Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by Sarcocystis neurona, an apicomplexan parasite. S. neurona is also associated with EPM-like diseases in marine and small mammals. The mechanisms of transmission and ability to infect a wide host range remain obscure; therefore, characterization of essential proteins may provide evolutionary information allowing the development of novel chemotherapeutics that target non-mammalian biochemical pathways. In the current study, two-dimensional electrophoresis and matrix-assisted laser desorption ionization-time of flight (MALDI-ToF) mass spectrometry were combined to characterize and identify an enolase protein from S. neurona based on peptide homology to the Toxoplasma gondii protein. Enolase is thought to be a vestigial, non-photosynthetic protein resulting from an evolutionary endosymbiosis event of an apicomplexan ancestor with green algae. Enolase has also been suggested to play a role in parasite stage conversion for T. gondii. Characterization of this protein in S. neurona and comparison to other protozoans indicate a biochemical similarity of S. neurona enolase to other tissue-cyst forming coccidians that cause encephalitis.

A genetically diverse but distinct North American population of Sarcocystis neurona includes an overrepresented clone described by 12 microsatellite alleles.

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Asmundsson, Ingrid M; Dubey, J P; Rosenthal, Benjamin M

2006-09-01

The population genetics and systematics of most coccidians remain poorly defined despite their impact on human and veterinary health. Non-recombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in the coccidian Toxoplasma gondii despite opportunities for sexual recombination. In order to determine whether this may be generally true for tissue-cyst forming coccidia, and to address evolutionary and taxonomic problems within the genus Sarcocystis, we characterized polymorphic microsatellite markers in Sarcocystis neurona, the major causative agent of equine protozoal myeloencephalitis (EPM). Bayesian statistical modeling, phylogenetic reconstruction based on genotypic chord distances, and analyses of linkage disequilibrium were employed to examine the population structure within S. neurona and closely related Sarcocystis falcatula isolates from North and South America. North American S. neurona were clearly differentiated from those of South America and also from isolates of S. falcatula. Although S. neurona is characterized by substantial allelic and genotypic diversity typical of interbreeding populations, one genotype occurs with significantly excessive frequency; thus, some degree of asexual propagation of S. neurona clones may naturally occur. Finally, S. neurona isolated from disparate North American localities and diverse hosts (opossums, a Southern sea otter, and horses) comprise a single genetic population. Isolates associated with clinical neurological disease bear no obvious distinction as measured by these presumably neutral genetic markers.

Antigenic evaluation of a recombinant baculovirus-expressed Sarcocystis neurona SAG1 antigen.

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Gupta, G D; Lakritz, J; Saville, W J; Livingston, R S; Dubey, J P; Middleton, J R; Marsh, A E

2004-10-01

Sarcocystis neurona is the primary parasite associated with equine protozoal myeloencephalitis (EPM). This is a commonly diagnosed neurological disorder in the Americas that infects the central nervous system of horses. Current serologic assays utilize culture-derived parasites as antigen. This method requires large numbers of parasites to be grown in culture, which is labor intensive and time consuming. Also, a culture-derived whole-parasite preparation contains conserved antigens that could cross-react with antibodies against other Sarcocystis species and members of Sarcocystidae such as Neospora spp., Hammondia spp., and Toxoplasma gondii. Therefore, there is a need to develop an improved method for the detection of S. neurona-specific antibodies. The sera of infected horses react strongly to surface antigen 1 (SnSAG1), an approximately 29-kDa protein, in immunoblot analysis, suggesting that it is an immunodominant antigen. The SnSAG1 gene of S. neurona was cloned, and recombinant S. neurona SAG1 protein (rSnSAG1-Bac) was expressed with the use of a baculovirus system. By immunoblot analysis, the rSnSAG1-Bac antigen detected antibodies to S. neurona from naturally infected and experimentally inoculated equids, cats, rabbit, mice, and skunk. This is the first report of a baculovirus-expressed recombinant S. neurona antigen being used to detect anti-S. neurona antibodies in a variety of host species.

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

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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. Recently, S. neurona has emerged as a common cause of mortality in marine mammals, especi...

Sarcocystis neurona manipulation using culture-derived merozoites for bradyzoite and sporocyst production.

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Chaney, Sarah B; Marsh, Antoinette E; Lewis, Stephanie; Carman, Michelle; Howe, Daniel K; Saville, William J; Reed, Stephen M

2017-04-30

Equine protozoal myeloencephalitis (EPM) remains a significant central nervous system disease of horses in the American continents. Sarcocystis neurona is considered the primary causative agent and its intermediate life stages are carried by a wide host-range including raccoons (Procyon lotor) in North America. S. neurona sarcocysts mature in raccoon skeletal muscle and can produce central nervous system disease in raccoons, mirroring the clinical presentation in horses. The study aimed to develop laboratory tools whereby the life cycle and various life stages of S. neurona could be better studied and manipulated using in vitro and in vivo systems and compare the biology of two independent isolates. This study utilized culture-derived parasites from S. neurona strains derived from a raccoon or from a horse to initiate raccoon infections. Raccoon tissues, including fresh and cryopreserved tissues, were used to establish opossum (Didelphis virginiana) infections, which then shed sporocyts with retained biological activity to cause encephalitis in mice. These results demonstrate that sarcocysts can be generated using in vitro-derived S. neurona merozoites, including an isolate originally derived from a naturally infected horse with clinical EPM. This study indicates the life cycle can be significantly manipulated in the laboratory without affecting subsequent stage development, allowing further purification of strains and artificial maintenance of the life cycle. Published by Elsevier B.V.

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.

Molecular typing of Sarcocystis neurona: current status and future trends.

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Elsheikha, Hany M; Mansfield, Linda S

2007-10-21

Sarcocystis neurona is an important protozoal pathogen because it causes the serious neurological disease equine protozoal myeloencephalitis (EPM). The capacity of this organism to cause a wide spectrum of neurological signs in horses and the broad geographic distribution of observed cases in the Americas drive the need for sensitive, reliable and rapid typing methods to characterize strains. Various molecular methods have been developed and used to diagnose EPM due to S. neurona, to identify S. neurona isolates and to determine the heterogeneity and evolutionary relatedness within this species and related Sarcocystis spp. These methods included sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immuno-fluorescent assay (IFA), slide agglutination test (SAT), SnSAG-specific ELISA, random amplified polymorphic DNA (RAPD), PCR-based restriction fragment length polymorphism (RFLP), amplified fragment length polymorphism (AFLP) fingerprinting, and sequence analysis of surface protein genes, ribosomal genes, microsatellite alleles and other molecular markers. Here, the utility of these molecular methods is reviewed and evaluated with respect to the need for molecular approaches that utilize well-characterized polymorphic, simple, independent, and stable genetic markers. These tools have the potential to add to knowledge of the genetic population structure of S. neurona and to provide new insights into the pathogenesis of EPM and S. neurona epidemiology. In particular, these methods provide new tools to address the hypothesis that particular genetic variants are associated with adverse clinical outcomes (severe pathotypes). The ultimate goal is to utilize them in future studies to improve treatment and prevention strategies.

Purification of Sarcocystis neurona sporocysts from opossum (Didelphis virginiana) using potassium bromide discontinuous density gradient centrifugation.

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Elsheikha, Hany M; Murphy, Alice J; Fitzgerald, Scott D; Mansfield, Linda S; Massey, Jeffrey P; Saeed, Mahdi A

2003-06-01

This report describes a new, inexpensive procedure for the rapid and efficient purification of Sarcocystis neurona sporocysts from opossum small intestine. S. neurona sporocysts were purified using a discontinuous potassium bromide density gradient. The procedure provides a source of sporocyst wall and sporozoites required for reliable biochemical characterization and for immunological studies directed at characterizing antigens responsible for immunological responses by the host. The examined isolates were identified as S. neurona using random amplified polymorphic DNA primers and restriction endonuclease digestion assays. This method allows the collection of large numbers of highly purified S. neurona sporocysts without loss of sporocyst viability as indicated by propidium iodide permeability and cell culture infectivity assays. In addition, this technique might also be used for sporocyst purification of other Sarcocystis spp.

Parasitemia in an immunocompetent horse experimentally challenged with Sarcocystis neurona sporocysts.

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Rossano, M G; Schott, H C; Murphy, A J; Kaneene, J B; Sellon, D C; Hines, M T; Hochstatter, T; Bell, J A; Mansfield, L S

2005-01-04

Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable S. neurona from the blood of immunocompetent horses. Horses used in this study received orally administered S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 28 days, followed by 1000/day for 56 days. On day 98 of the study, six yearling colts were selected for attempted culture of S. neurona from blood, two testing positive, two testing suspect and two testing negative for antibodies against S. neurona on day 84 of the study. Two 10 ml tubes with EDTA were filled from each horse by jugular venipuncture and the plasma fraction rich in mononuclear cells was pipetted onto confluent equine dermal cell cultures. The cultures were monitored weekly for parasite growth for 12 weeks. Merozoites grown from cultures were harvested and tested using S. neurona-specific PCR with RFLP to confirm species identity. PCR products were sequenced and compared to known strains of S. neurona. After 38 days of in vitro incubation, one cell culture from a horse testing positive for antibodies against S. neurona was positive for parasite growth while the five remaining cultures remained negative for parasite growth for all 12 weeks. The Sarcocystis isolate recovered from cell culture was confirmed to be S. neurona by PCR with RFLP. Gene sequence analysis revealed that the isolate was identical to the challenge strain SN-37R and differed from two known strains UCD1 and MIH1. To our knowledge this is the first report of parasitemia with S. neurona in an immunocompetent horse.

Dual Sarcocystis neurona and Toxoplasma gondii infection in a northern sea otter from Washington state, USA

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Lindsay, D.S.; Thomas, N.J.; Rosypal, A.C.; Dubey, J.P.

2001-01-01

Dual Sarcocystis neurona and Toxoplasma gondii infection was observed in a Northern sea otter from Washington, USA. The animal was found stranded, convulsed, and died shortly thereafter. Encephalitis caused by both S. neurona and T. gondii was demonstrated in histological sections of brain. Immunohistochemical examination of sections with S. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. PCR of brain tissue from the sea otter using primer pairs JNB33/JNB54 resulted in amplification of a 1100 bp product. This PCR product was cut in to 884 and 216 bp products by Dra I but was not cut by Hinf I indicating that it was S. neurona [J. Parasitol. 85 (1999) 221]. No PCR product was detected in the brain of a sea otter which had no lesions of encephalitis. Examination of brain sections using T. gondii specific antisera demonstrated tachyzoites and tissue cysts of T. gondii. The lesions induced by T. gondii suggested that the sea otter was suffering from reactivated toxoplasmosis. T. gondii was isolated in mice inoculated with brain tissue. A cat that was fed infected mouse brain tissue excreted T. gondii oocysts which were infective for mice. This is apparently the first report of dual S. neurona and T. gondii in a marine mammal.

Efficacy of decoquinate against Sarcocystis neurona in cell cultures.

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Lindsay, David S; Nazir, M Mudasser; Maqbool, Azhar; Ellison, Siobhan P; Strobl, Jeannine S

2013-09-01

Decoquinate is a quinolone anticoccidial approved for use in the prevention of intestinal coccidiosis in farm animals. This compound has good activity against Toxoplasma gondii and Neospora caninum in cell cultures. The drug acts on the parasites' mitochondria. The activity of decoquinate against developing merozoites of 2 isolates of Sarcocystis neurona was examined in cell culture. Merozoite production at 10 days was completely inhibited when decoquinate was used at 20 or 240 nM. The IC50 of decoquinate was 0.5 ± 0.09nM for the Sn6 isolate of S. neurona from a horse and 1.1 ± 0.6 nM for the SnOP15 isolate of S. neurona from an opossum. Levamisole was toxic at 5 μg/ml and no synergism was observed when decoquinate was combined with levamisole and tested against the Sn3YFP isolate of S. neurona. Decoquinate was cidal for developing schizonts of S. neurona at 240 nM. Copyright © 2013 Elsevier B.V. All rights reserved.

Genetic Variation among Isolates of Sarcocystis neurona, the Agent of Protozoal Myeloencephalitis, as Revealed by Amplified Fragment Length Polymorphism Markers

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Elsheikha, H. M.; Schott, H. C.; Mansfield, L. S.

2006-01-01

Sarcocystis neurona causes serious neurological disease in horses and other vertebrates in the Americas. Based on epidemiological data, this parasite has recently emerged. Here, the genetic diversity of Sarcocystis neurona was evaluated using the amplified fragment length polymorphism (AFLP) method. Fifteen S. neurona taxa from different regions collected over the last 10 years were used; six isolates were from clinically diseased horses, eight isolates were from wild-caught opossums (Didelph...

Penetration of equine leukocytes by merozoites of Sarcocystis neurona.

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Lindsay, David S; Mitchell, Sheila M; Yang, Jibing; Dubey, J P; Gogal, Robert M; Witonsky, Sharon G

2006-06-15

Horses are considered accidental hosts for Sarcocystis neurona and they often develop severe neurological disease when infected with this parasite. Schizont stages develop in the central nervous system (CNS) and cause the neurological lesions associated with equine protozoal myeloencephalitis. The present study was done to examine the ability of S. neurona merozoites to penetrate and develop in equine peripheral blood leukocytes. These infected host cells might serve as a possible transport mechanism into the CNS. S. neurona merozoites penetrated equine leukocytes within 5 min of co-culture. Infected leukocytes were usually monocytes. Infected leukocytes were present up to the final day of examination at 3 days. Up to three merozoites were present in an infected monocyte. No development to schizont stages was observed. All stages observed were in the host cell cytoplasm. We postulate that S. neurona merozoites may cross the blood brain barrier hidden inside leukocytes. Once inside the CNS these merozoites can egress and invade additional cells and cause encephalitis.

Prevalence of antibodies to Sarcocystis neurona in cats from Virginia and Pennsylvania.

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Hsu, Vasha; Grant, David C; Dubey, J P; Zajac, Anne M; Lindsay, David S

2010-08-01

Sarcocystis neurona is best known as the causative agent of equine protozoal myeloencephalitis of horses in the Americas. Domestic cats ( Felis domesticus ) were the first animals described as an intermediate host for S. neurona . However, S. neurona -associated encephalitis has also been reported in naturally infected cats in the United States. Thus, cats can be implicated in the life cycle of S. neurona as natural intermediate hosts. The present study examined the seroprevalence of IgG antibodies to merozoites of S. neurona in populations of domestic cats from Virginia and Pennsylvania. Overall, sera or plasma from 441 cats (Virginia = 232, Pennsylvania = 209) were tested by an indirect immunofluorescent assay at a 1ratio50 dilution. Antibodies to S. neurona were found in 32 (7%) of 441 cats. Of these, 22 (9%) of the 232 cats from Virginia and 10 (5%) of the 209 cats from Pennsylvania were seropositive for S. neurona .

Selective inhibition of Sarcocystis neurona calcium-dependent protein kinase 1 for equine protozoal myeloencephalitis therapy

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Sarcocystis neurona is the most frequent cause of Equine Protozoal Myeloencephalitis (EPM), a debilitating neurologic disease of horses that can be difficult to treat. We identified SnCDPK1, the S. neurona homologue of calcium dependent protein kinase 1 (CDPK1), a validated drug target in Toxoplasma...

Molecular genetic transfection of the coccidian parasite Sarcocystis neurona.

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Gaji, Rajshekhar Y; Zhang, Deqing; Breathnach, Cormac C; Vaishnava, Shipra; Striepen, Boris; Howe, Daniel K

2006-11-01

Sarcocystis neurona is an apicomplexan parasite that is the major cause of equine protozoal myeloencephalitis (EPM). The biology of this pathogen remains poorly understood in part due to unavailability of molecular genetic tools. Hence, with an objective to develop DNA transfection capabilities for S. neurona, the 5' flanking region of the SnSAG1 gene was isolated from a genomic library and used to construct expression plasmids. In transient assays, the reporter molecules beta-galactosidase (beta-gal) and yellow fluorescent protein (YFP) could be detected in electroporated S. neurona, thereby confirming the feasibility of transgene expression in this organism. Stable transformation of S. neurona was achieved using a mutant dihydrofolate reductase thymidylate synthase (DHFR-TS) gene of Toxoplasma gondii that confers resistance to pyrimethamine. This selection system was used to create transgenic S. neurona that stably express beta-gal and YFP. As shown in this study, these transgenic clones can be useful for analyzing growth rate of parasites in vitro and for assessing drug sensitivities. More importantly, the DNA transfection methods described herein should greatly facilitate studies examining intracellular parasitism by this important coccidian pathogen.

Effect of intermittent oral administration of ponazuril on experimental Sarcocystis neurona infection of horses.

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Mackay, Robert J; Tanhauser, Susan T; Gillis, Karen D; Mayhew, Ian G; Kennedy, Tom J

2008-03-01

To evaluate the effect of intermittent oral administration of ponazuril on immunoconversion against Sarcocystis neurona in horses inoculated intragastrically with S neurona sporocysts. 20 healthy horses that were seronegative for S neurona-specific IgG. 5 control horses were neither inoculated with sporocysts nor treated. Other horses (5 horses/group) each received 612,500 S neurona sporocysts via nasogastric tube (day 0) and were not treated or were administered ponazuril (20 mg/kg, PO) every 7 days (beginning on day 5) or every 14 days (beginning on day 12) for 12 weeks. Blood and CSF samples were collected on day - 1 and then every 14 days after challenge for western blot assessment of immunoconversion. Clinical signs of equine protozoal myeloencephalitis (EPM) were monitored, and tissues were examined histologically after euthanasia. Sera from all challenged horses yielded positive western blot results within 56 days. Immunoconversion in CSF was detected in only 2 of 5 horses that were treated weekly; all other challenged horses immunoconverted within 84 days. Weekly administration of ponazuril significantly reduced the antibody response against the S neurona 17-kd antigen in CSF. Neurologic signs consistent with EPM did not develop in any group; likewise, histologic examination of CNS tissue did not reveal protozoa or consistent degenerative or inflammatory changes. Administration of ponazuril every 7 days, but not every 14 days, significantly decreased intrathecal anti-S neurona antibody responses in horses inoculated with S neurona sporocysts. Protocols involving intermittent administration of ponazuril may have application in prevention of EPM.

Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California.

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Rejmanek, Daniel; Miller, Melissa A; Grigg, Michael E; Crosbie, Paul R; Conrad, Patricia A

2010-05-28

Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums. (c) 2010 Elsevier B.V. All rights reserved.

Prevalence of sarcocystis species sporocysts in wild-caught opossums (Didelphis virginiana).

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Dubey, J P

2000-08-01

Sarcocystis sporocysts were found in intestinal scrapings from 24 (54.5%) of 44 opossums (Didelphis virginiana). The number of sporocysts varied from a few (< 10,000) to 245 million. Sporocysts from 23 of 24 opossums were fed to captive budgerigars (Melopsittacus undulatas), and the inocula from 21 opossums were infective, indicating the presence of Sarcocystis falcatula. Sporocysts from 24 opossums were fed to gamma-interferon-knockout (KO) or nude mice; inocula from 14 opossums were infective to mice. Sarcocystis neurona was detected in tissues of KO mice by specific staining with anti-S. neurona antibodies, and the parasite was cultured in vitro from the brains of KO mice fed sporocysts from 8 opossums. Sarcocystis speeri was identified by specific staining with anti-S. speeri antibodies in tissues of KO mice fed inocula from 8 opossums; 3 opossums had mixed S. neurona and S. speeri infections. Thus, the prevalences of sporocysts of different species of Sarcocystis in opossums were: S. falcatula 21 of 44 (47.7%), S. neurona 8 of 44 (18.1%), and S. speeri 8 of 44 (18.1%) opossums. Sarcocystis neurona alone was found in 1 opossum, and S. speeri alone was found in 1 opossum. Mixed Sarcocystis infections were present in 21 opossums.

Parasitemia due to Sarcocystis neurona-like infection in a clinically ill domestic cat.

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Zitzer, Nina C; Marsh, Antoinette E; Burkhard, Mary Jo; Radin, M Judith; Wellman, Maxey L; Jugan, Maria; Parker, Valerie

2017-09-01

An 8-year-old, 6-kg, male neutered Domestic Shorthair cat was presented to The Ohio State University Veterinary Medical Center (OSU-VMC) for difficulty breathing. Physical examination and thoracic radiographs indicated pneumonia, a soft-tissue mass in the left caudal lung lobe, and diffuse pleural effusion. The effusion was classified as modified transudate. Rare extracellular elongated (~5-7 μm × 1-2 μm) zoites with a central round to oval-shaped purple to deep purple vesicular nucleus with coarsely stippled chromatin and light blue cytoplasm were seen on a peripheral blood smear. Serum IgG and IgM were positive for Sarcocystis sp. antibodies and negative for Toxoplasma gondii antibodies, suggesting that the infection was acute rather than a recrudescence of prior infection. This organism was most consistent with either Sarcocystis neurona or Sarcocystis dasypi based on DNA sequence analysis of PCR products using COC ssRNA, ITS-1, snSAG2, and JNB25/JD396 primer sets. This is the first report to visualize by light microscopy circulating Sarcocystis sp. merozoites in the peripheral blood of a domestic cat. Therefore, Sarcocystis should be considered as a differential diagnosis in cats with suspected systemic protozoal infection. © 2017 American Society for Veterinary Clinical Pathology.

Rhinitis and disseminated disease in a ferret (Mustela putorius furo) naturally infected with Sarcocystis neurona.

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Britton, Ann P; Dubey, J P; Rosenthal, Benjamin M

2010-04-19

Naturally occurring Sarcocystis neurona infection in a ferret (Mustela putorius furo) with rhinitis and disseminated disease are described for the first time. The ferret exhibited severe rhinitis with intra-lesional S. neurona merozoites and schizonts. Diagnosis was confirmed immunohistochemically by staining with S. neurona-specific antibodies, and by phylogenetic analyses of conserved and variable portions of nuclear ribosomal DNA. On the basis of intense schizogony in the nasal mucosa, we propose the possibility of an olfactory nerve pathway route of infection for S. neurona meningoencephalitis.

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, Jos?; 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. neu...

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

2015-04-15

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. Published by Elsevier B.V.

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.

Enzyme-linked immunosorbent assays for detection of equine antibodies specific to Sarcocystis neurona surface antigens.

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Hoane, Jessica S; Morrow, Jennifer K; Saville, William J; Dubey, J P; Granstrom, David E; Howe, Daniel K

2005-09-01

Sarcocystis neurona is the primary causative agent of equine protozoal myeloencephalitis (EPM), a common neurologic disease of horses in the Americas. We have developed a set of enzyme-linked immunosorbent assays (ELISAs) based on the four major surface antigens of S. neurona (SnSAGs) to analyze the equine antibody response to S. neurona. The SnSAG ELISAs were optimized and standardized with a sample set of 36 equine sera that had been characterized by Western blotting against total S. neurona parasite antigen, the current gold standard for S. neurona serology. The recombinant SnSAG2 (rSnSAG2) ELISA showed the highest sensitivity and specificity at 95.5% and 92.9%, respectively. In contrast, only 68.2% sensitivity and 71.4% specificity were achieved with the rSnSAG1 ELISA, indicating that this antigen may not be a reliable serological marker for analyzing antibodies against S. neurona in horses. Importantly, the ELISA antigens did not show cross-reactivity with antisera to Sarcocystis fayeri or Neospora hughesi, two other equine parasites. The accuracy and reliability exhibited by the SnSAG ELISAs suggest that these assays will be valuable tools for examining the equine immune response against S. neurona infection, which may help in understanding the pathobiology of this accidental parasite-host interaction. Moreover, with modification and further investigation, the SnSAG ELISAs have potential for use as immunodiagnostic tests to aid in the identification of horses affected by EPM.

Enzyme-Linked Immunosorbent Assays for Detection of Equine Antibodies Specific to Sarcocystis neurona Surface Antigens†

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Hoane, Jessica S.; Morrow, Jennifer K.; Saville, William J.; Dubey, J. P.; Granstrom, David E.; Howe, Daniel K.

2005-01-01

Sarcocystis neurona is the primary causative agent of equine protozoal myeloencephalitis (EPM), a common neurologic disease of horses in the Americas. We have developed a set of enzyme-linked immunosorbent assays (ELISAs) based on the four major surface antigens of S. neurona (SnSAGs) to analyze the equine antibody response to S. neurona. The SnSAG ELISAs were optimized and standardized with a sample set of 36 equine sera that had been characterized by Western blotting against total S. neurona parasite antigen, the current gold standard for S. neurona serology. The recombinant SnSAG2 (rSnSAG2) ELISA showed the highest sensitivity and specificity at 95.5% and 92.9%, respectively. In contrast, only 68.2% sensitivity and 71.4% specificity were achieved with the rSnSAG1 ELISA, indicating that this antigen may not be a reliable serological marker for analyzing antibodies against S. neurona in horses. Importantly, the ELISA antigens did not show cross-reactivity with antisera to Sarcocystis fayeri or Neospora hughesi, two other equine parasites. The accuracy and reliability exhibited by the SnSAG ELISAs suggest that these assays will be valuable tools for examining the equine immune response against S. neurona infection, which may help in understanding the pathobiology of this accidental parasite-host interaction. Moreover, with modification and further investigation, the SnSAG ELISAs have potential for use as immunodiagnostic tests to aid in the identification of horses affected by EPM. PMID:16148170

High-throughput screen of drug repurposing library identifies inhibitors of Sarcocystis neurona growth

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Gregory D. Bowden

2018-04-01

Full Text Available The apicomplexan parasite Sarcocystis neurona is the primary etiologic agent of equine protozoal myeloencephalitis (EPM, a serious neurologic disease of horses. Many horses in the U.S. are at risk of developing EPM; approximately 50% of all horses in the U.S. have been exposed to S. neurona and treatments for EPM are 60–70% effective. Advancement of treatment requires new technology to identify new drugs for EPM. To address this critical need, we developed, validated, and implemented a high-throughput screen to test 725 FDA-approved compounds from the NIH clinical collections library for anti-S. neurona activity. Our screen identified 18 compounds with confirmed inhibitory activity against S. neurona growth, including compounds active in the nM concentration range. Many identified inhibitory compounds have well-defined mechanisms of action, making them useful tools to study parasite biology in addition to being potential therapeutic agents. In comparing the activity of inhibitory compounds identified by our screen to that of other screens against other apicomplexan parasites, we found that most compounds (15/18; 83% have activity against one or more related apicomplexans. Interestingly, nearly half (44%; 8/18 of the inhibitory compounds have reported activity against dopamine receptors. We also found that dantrolene, a compound already formulated for horses with a peak plasma concentration of 37.8 ± 12.8 ng/ml after 500 mg dose, inhibits S. neurona parasites at low concentrations (0.065 μM [0.036–0.12; 95% CI] or 21.9 ng/ml [12.1–40.3; 95% CI]. These studies demonstrate the use of a new tool for discovering new chemotherapeutic agents for EPM and potentially providing new reagents to elucidate biologic pathways required for successful S. neurona infection. Keywords: Drug repurposing, High-throughput screen, Sarcocystis neurona, Equine protozoal myeloencephalitis

California mussels (Mytilus californianus) as sentinels for marine contamination with Sarcocystis neurona.

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Michaels, Lauren; Rejmanek, Daniel; Aguilar, Beatriz; Conrad, Patricia; Shapiro, Karen

2016-05-01

Sarcocystis neurona is a terrestrial parasite that can cause fatal encephalitis in the endangered Southern sea otter (Enhydra lutris nereis). To date, neither risk factors associated with marine contamination nor the route of S. neurona infection to marine mammals has been described. This study evaluated coastal S. neurona contamination using California mussels (Mytilus californianus) as sentinels for pathogen pollution. A field investigation was designed to test the hypotheses that (1) mussels can serve as sentinels for S. neurona contamination, and (2) S. neurona contamination in mussels would be highest during the rainy season and in mussels collected near freshwater. Initial validation of molecular assays through sporocyst spiking experiments revealed the ITS-1500 assay to be most sensitive for detection of S. neurona, consistently yielding parasite amplification at concentrations ⩾5 sporocysts/1 mL mussel haemolymph. Assays were then applied on 959 wild-caught mussels, with detection of S. neurona confirmed using sequence analysis in three mussels. Validated molecular assays for S. neurona detection in mussels provide a novel toolset for investigating marine contamination with this parasite, while confirmation of S. neurona in wild mussels suggests that uptake by invertebrates may serve as a route of transmission to susceptible marine animals.

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.

Sarcocystis neurona schizonts-associated encephalitis, chorioretinitis, and myositis in a two-month-old dog simulating toxoplasmosis, and presence of mature sarcocysts in muscles.

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Dubey, J P; Black, S S; Verma, S K; Calero-Bernal, R; Morris, E; Hanson, M A; Cooley, A J

2014-05-28

Sarcocystis neurona is an unusual species of the genus Sarcocystis. Opossums (Didelphis virginianus, D. albiventris) are the definitive hosts and several other species, including dogs, cats, marine mammals, and horses are intermediate or aberrant hosts. Sarcocysts are not known to form in aberrant hosts. Sarcocystis neurona causes fatal disease in horses (Equine Protozoal Myeloencephalitis, EPM). There are numerous reports of fatal EPM-like infections in other species, usually with central nervous system signs and associated with the schizont stage of S. neurona. Here, we report fatal disseminated S. neurona infection in a nine-week-old golden retriever dog from Mississippi, USA. Protozoal merozoites were identified in smears of the cerebrospinal fluid. Microscopically, lesions and protozoa were identified in eyes, tongue, heart, liver, intestines, nasal turbinates, skeletal muscle and brain, which reacted intensely with S. neurona polyclonal antibodies. Mature sarcocysts were seen in sections of muscles. These sarcocysts were ultrastructurally similar to those of S. neurona from experimentally infected animals. These data suggest that the dog is another intermediate host for S. neurona. Data suggest that the dog was transplacentally infected. Copyright © 2014 Elsevier B.V. All rights reserved.

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...

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

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Gennari, Solange Maria; Pena, Hilda Fátima de Jesus; Lindsay, David Scott; Lopes, Marcos Gomes; Soares, Herbert Sousa; Cabral, Aline Diniz; Vitaliano, Sérgio Netto; Amaku, Marcos

2016-01-01

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 of Neospora spp. antibodies in Brazilian donkeys and the first detection of antibodies against S. neurona in this animal species.

Daily feeding of diclazuril top dress pellets in foals reduces seroconversion to Sarcocystis neurona.

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Pusterla, Nicola; Packham, Andrea; Mackie, Sarah; Kass, Philip H; Hunyadi, Laszlo; Conrad, Patricia A

2015-11-01

Thirty-three foals from a farm with a high exposure rate to Sarcocystis neurona were assigned to either an untreated or a diclazuril-treated group. Treated foals received daily 0.5 mg/kg of diclazuril pellets from 1 to 12 months of age. Monthly blood was tested for IgG against S. neurona using the indirect fluorescent antibody test. Following ingestion of colostral antibodies to S. neurona, there was a steady and continuous decline in seroprevalence to S. neurona until foals from both groups reached weaning age. Thereafter, the untreated foal group showed a significant increase in monthly seroprevalence compared to the diclazuril-treated foal group. The difference in temporal seroprevalence could be explained by the successful reduction of S. neurona infection in foals receiving a daily low-dose diclazuril. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phylogenetic relationships of Sarcocystis neurona of horses and opossums to other cyst-forming coccidia deduced from SSU rRNA gene sequences.

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Elsheikha, Hany M; Lacher, David W; Mansfield, Linda S

2005-11-01

Phylogenetic analyses based on sequences of the nuclear-encoded small subunit rRNA (ssurRNA) gene were performed to examine the origin, phylogeny, and biogeographic relationships of Sarcocystis neurona isolates from opossums and horses from the State of Michigan, USA, in relation to other cyst-forming coccidia. A total of 31 taxa representing all recognized subfamilies and genera of Sarcocystidae were included in the analyses with clonal isolates of two opossum and two horse S. neurona. Phylogenies obtained by the four tree-building methods were consistent with the classical taxonomy based on morphological criteria. The "isosporid" coccidia Neospora, Toxoplasma, Besnoitia, Isospora lacking stieda bodies, and Hyaloklossia formed a sister group to the Sarcocystis spp. Sarcocystis species were divided into three main lineages; S. neurona isolates were located in the second lineage and clustered with S. mucosa, S. dispersa, S. lacertae, S. rodentifelis, S. muris, and Frenkelia spp. Alignment of S. neurona SSU rRNA gene sequences of Michigan opossum isolates (MIOP5, MIOP20) and a S. neurona Michigan horse isolate (MIH8) showed 100% identity. These Michigan isolates differed in 2/1085 bp (0.2%) from a Kentucky S. neurona horse isolate (SN5). Additionally, S. neurona isolates from horses and opossums were identical based on the ultrastructural features and PCR-RFLP analyses thus forming a phylogenetically indistinct group in these regions. These findings revealed the concordance between the morphological and molecular data and confirmed that S. neurona from opossums and horses originated from the same phylogenetic origin.

Risk of transplacental transmission of Sarcocystis neurona and Neospora hughesi in California horses.

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Duarte, Paulo C; Conrad, Patricia A; Barr, Bradd C; Wilson, W David; Ferraro, Gregory L; Packham, Andrea E; Carpenter, Tim E; Gardner, Ian A

2004-12-01

The study objective was to assess the risk of transplacental transmission of Sarcocystis neurona and Neospora hughesi in foals from 4 California farms during 3 foaling seasons. Serum of presuckle foals and serum and colostrum of periparturient mares were tested using indirect fluorescent antibody tests for S. neurona and N. hughesi. Serum antibody titers were neurona and N. hughesi in mares increased with age. Mares neurona and N. hughesi, respectively, than mares from California. The strength of association between positivity to either parasite and state of birth decreased as age increased. Mares positive for S. neurona and N. hughesi were 2.2 and 1.7 times more likely, respectively, to have a previous abortion than negative mares, adjusted for age and state of birth. The annual mortality rate for mares was 4%. The annual incidence rate of equine protozoal myeloencephalitis was 0.2%. In conclusion, there was no detectable risk of transplacental transmission of S. neurona and N. hughesi. Prevalence of antibodies against both parasites in mares increased with age.

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.

Antibody index and specific antibody quotient in horses after intragastric administration of Sarcocystis neurona sporocysts.

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Heskett, Katherine A; Mackay, Robert J

2008-03-01

To investigate the use of a specific antibody index (AI) that relates Sarcocystis neurona-specific IgG quotient (Q(SN)) to total IgG quotient (Q(IgG)) for the detection of the anti-S neurona antibody fraction of CNS origin in CSF samples obtained from horses after intragastric administration of S neurona sporocysts. 18 adult horses. 14 horses underwent intragastric inoculation (day 0) with S neurona sporocysts, and 4 horses remained unchallenged; blood and CSF samples were collected on days - 1 and 84. For purposes of another study, some challenged horses received intermittent administration of ponazuril (20 mg/kg, PO). Sarcocystis neurona-specific IgG concentrations in CSF (SN(CSF)) and plasma (SN(plasma)) were measured via a direct ELISA involving merozoite lysate antigen and reported as ELISA units (EUs; arbitrary units based on a nominal titer for undiluted immune plasma of 100,000 EUs/mL). Total IgG concentrations in CSF (IgG(CSF)) and plasma (IgG(plasma)) were quantified via a sandwich ELISA and a radial immunodiffusion assay, respectively; Q(SN), Q(IgG), and AI were calculated. Following sporocyst challenge, mean +/- SEM SN(CSF) and SN(plasma) increased significantly (from 8.8 +/- 1.0 EUs/mL to 270.0 +/- 112.7 EUs/mL and from 1,737 +/- 245 EUs/mL to 43,169 +/- 13,770 EUs/mL, respectively). Challenge did not affect total IgG concentration, Q(SN), Q(IgG), or AI. S neurona-specific IgG detected in CSF samples from sporocyst-challenged horses appeared to be extraneural in origin; thus, this experimental challenge may not reliably result in CNS infection. Calculation of a specific AI may have application to the diagnosis of S neurona-associated myeloencephalitis in horses.

Horses experimentally infected with Sarcocystis neurona develop altered immune responses in vitro.

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Witonsky, Sharon G; Ellison, Siobhan; Yang, Jibing; Gogal, Robert M; Lawler, Heather; Suzuki, Yasuhiro; Sriranganathan, Namalwar; Andrews, Frank; Ward, Daniel; Lindsay, David S

2008-10-01

Equine protozoal myeloencephalitis (EPM) due to Sarcocystis neurona infection is 1 of the most common neurologic diseases in horses in the United States. The mechanisms by which most horses resist disease, as well as the possible mechanisms by which the immune system may be suppressed in horses that develop EPM, are not known. Therefore, the objectives of this study were to determine whether horses experimentally infected with S. neurona developed suppressed immune responses. Thirteen horses that were negative for S. neurona antibodies in serum and cerebrospinal fluid (CSF) were randomly assigned to control (n = 5) or infected (n = 8) treatment groups. Neurologic exams and cerebrospinal fluid analyses were performed prior to, and following, S. neurona infection. Prior to, and at multiple time points following infection, immune parameters were determined. All 8 S. neurona-infected horses developed clinical signs consistent with EPM, and had S. neurona antibodies in the serum and CSF. Both infected and control horses had increased percentages (P < 0.05) of B cells at 28 days postinfection. Infected horses had significantly decreased (P < 0.05) proliferation responses as measured by thymidine incorporation to nonspecific mitogens phorbol myristate acetate (PMA) and ionomycin (I) as soon as 2 days postinfection.

Risk of postnatal exposure to Sarcocystis neurona and Neospora hughesi in horses.

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Duarte, Paulo C; Conrad, Patricia A; Wilson, W David; Ferraro, Gregory L; Packham, Andrea E; Bowers-Lepore, Jeanne; Carpenter, Tim E; Gardner, Ian A

2004-08-01

To estimate risk of exposure and age at first exposure to Sarcocystis neurona and Neospora hughesi and time to maternal antibody decay in foals. 484 Thoroughbred and Warmblood foals from 4 farms in California. Serum was collected before and after colostrum ingestion and at 3-month intervals thereafter. Samples were tested by use of the indirect fluorescent antibody test; cutoff titers were > or = 40 and > or = 160 for S neurona and N hughesi, respectively. Risk of exposure to S neurona and N hughesi during the study were 8.2% and 3.1%, respectively. Annual rate of exposure was 3.1% for S neurona and 1.7% for N hughesi. There was a significant difference in the risk of exposure to S neurona among farms but not in the risk of exposure to N hughesi. Median age at first exposure was 1.2 years for S neurona and 0.8 years for N hughesi. Highest prevalence of antibodies against S neurona and N hughesi was 6% and 2.1 %, respectively, at a mean age of 1.7 and 1.4 years, respectively. Median time to maternal antibody decay was 96 days for S neurona and 91 days for N hughesi. There were no clinical cases of equine protozoal myeloenchaphlitis (EPM). Exposure to S neurona and N hughesi was low in foals between birth and 2.5 years of age. Maternally acquired antibodies may cause false-positive results for 3 or 4 months after birth, and EPM was a rare clinical disease in horses < or = 2.5 years of age.

SARCOCYSTIS NEURONA-ASSOCIATED MENINGOENCEPHALITIS IN A PACIFIC WALRUS ( ODOBENDUS ROSMARUS DIVERGENS).

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Krol, Lana; Fravel, Vanessa; Procter, Diana G; Colegrove, Kathleen M

2017-12-01

A 21-yr-old intact male walrus ( Odobendus rosmarus divergens) presented with acute onset of shifting lameness, initially associated with breeding behaviors. Further clinical signs manifested, including muscle tremors, anorexia, hematuria, and coughing. Diagnostics were limited, as the animal would not offer behaviors for voluntary sample collection. Signs were addressed with anti-inflammatories, anticonvulsants, and antibiotics. The walrus developed cluster seizures and ultimately, respiratory and cardiac arrest. Postmortem lesions included meningoencephalitis with intra- and extracellular protozoal zoites and schizonts, as well as interstitial pneumonia with intraendothelial protozoa. Immunolabeling of the protozoal organisms revealed Sarcocystis neurona. Previous S. neurona infections in an odobenid have not been reported. Protozoal infection should be considered in all species of captive marine mammals with nonspecific orthopedic, neurological, and respiratory clinical signs.

Identification of a dithiol-dependent nucleoside triphosphate hydrolase in Sarcocystis neurona.

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Zhang, Deqing; Gaji, Rajshekhar Y; Howe, Daniel K

2006-09-01

A putative nucleoside triphosphate hydrolase (NTPase) gene was identified in a database of expressed sequence tags (ESTs) from the apicomplexan parasite Sarcocystis neurona. Analysis of culture-derived S. neurona merozoites demonstrated a dithiol-dependent NTPase activity, consistent with the presence of a homologue to the TgNTPases of Toxoplasma gondii. A complete cDNA was obtained for the S. neurona gene and the predicted amino acid sequence shared 38% identity with the two TgNTPase isoforms from T. gondii. Based on the obvious homology, the S. neurona protein was designated SnNTP1. The SnNTP1 cDNA encodes a polypeptide of 714 amino acids with a predicted 22-residue signal peptide and an estimated mature molecular mass of 70kDa. Southern blot analysis of the SnNTP1 locus revealed that the gene exists as a single copy in the S. neurona genome, unlike the multiple gene copies that have been observed in T. gondii and Neospora caninum. Analyses of the SnNTP1 protein demonstrated that it is soluble and secreted into the culture medium by extracellular merozoites. Surprisingly, indirect immunofluorescence analysis of intracellular S. neurona revealed apical localisation of SnNTP1 and temporal expression characteristics that are comparable with the microneme protein SnMIC10. The absence of SnNTP1 during much of endopolygeny implies that this protein does not serve a function during intracellular growth and development of S. neurona schizonts. Instead, SnNTP1 may play a role in events that occur during or proximal to merozoite egress from and/or invasion into cells.

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.

Serological investigation of transplacental infection with Neospora hughesi and Sarcocystis neurona in broodmares.

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Pusterla, Nicola; Mackie, Sarah; Packham, Andrea; Conrad, Patricia A

2014-12-01

The aim of the present study was to investigate the likelihood of transplacental transmission of Neospora hughesi and Sarcocystis neurona in foals, born from seropositive mares. Three broodmares with persistent N. hughesi infection gave birth to eight healthy foals over a period of 7 years. These foals were seropositive to N. hughesi prior to colostrum ingestion, with titers ranging between 640 and 20,480, measured by indirect fluorescence antibody test (IFAT). Of 174 foals born at another farm to mares with a high seroprevalence to S. neurona, only one (with a pre-colostrum antibody titer of 80) tested seropositive. Transplacental transmission of N. hughesi seems to occur from latently infected mares to their foals, while this route of transmission does not seem to occur commonly for S. neurona. Copyright © 2014 Elsevier Ltd. All rights reserved.

Small sarcocysts can be a feature of experimental infections with Sarcocystis neurona merozoites.

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Marsh, Antoinette E; Chaney, Sarah B; Howe, Daniel K; Saville, William J; Reed, Stephen M

2017-10-15

Several reports indicate the presence of small tissue cysts associated with Sarcocystis neurona infections. Several failed attempts to develop tissue cysts in potential intermediate host using in vitro derived parasites originally isolated from horses with equine protozoal myeloencephalitis suggest that the experimental methods to achieve bradyzoites with those isolates was not possible. Those prior studies reported the lack of detectable sarcocysts based on histology and in vivo feeding trials. A recent report of successful production and detection of small sarcocysts triggered us to review archived tissues from earlier experimental infection studies. The retrospective review sought to determine if small sized sarcocysts were not detected due to their relatively smaller size and infrequency as compared to larger sized sarcocysts produced with other isolates in these experimental inoculation trials. Tissues from two prior in vivo inoculation studies, involving in vitro-produced parasites inoculated into laboratory-reared cats and raccoons, were re-examined by immunohistochemistry staining to more easily detect the tissue cysts. In the experimental cat study no small tissue cysts were seen, consistent with the original publication results. However, in the experimental raccoon study, one raccoon inoculated with an EPM-derived isolate, SN-UCD1, had small sarcocysts not reported in the original publication. This retrospective study suggests that much closer scrutiny of tissues, including the use of immunohistochemistry on tissue sections is required to detect the smaller S. neurona sarcocysts associated with the experimental inoculations of the isolates originally derived from horses with EPM. Published by Elsevier B.V.

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

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Murungi, Edwin K; Kariithi, Henry M

2017-03-21

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.

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.

In vitro efficacy of nitro- and halogeno-thiazolide/thiadiazolide derivatives against Sarcocystis neurona.

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Gargala, G; Le Goff, L; Ballet, J J; Favennec, L; Stachulski, A V; Rossignol, J F

2009-06-10

Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). The aim of this work was to document inhibitory activities of nitazoxanide (NTZ, [2-acetolyloxy-N-(5-nitro 2-thiazolyl) benzamide]) and new thiazolides/thiadiazolides on S. neurona in vitro development, and investigate their structure-activity relationships. S. neurona was grown in bovine turbinate cell cultures. At concentrations varying from 1.0 to 5.0mg/L, nitazoxanide and 21 of 32 second generation thiazolide/thiadiazolide agents exerted a > or =95% maximum inhibition on S. neurona development. Most active agents were either NO(2) or halogen substituted in position 5 of their thiazole moiety. In contrast, other 5-substitutions such as hydrogen, methyl, SO(2)CH(3), and CH(3) negatively impacted activity. Compared with derivatives with an acetylated benzene moiety, deacetylated compounds which most probably represent primary metabolites exhibited similar inhibitory activities. Present data provide the first evidence of in vitro inhibitory activities of nitazoxanide and new thiazolides/thiadiazolides on S. neurona development. Active halogeno-thiazolide/thiadiazolides may provide a valuable nitro-free alternative to nitazoxanide for EPM treatment depending on further evaluation of their in vivo activities.

Immune response to Sarcocystis neurona infection in naturally infected horses with equine protozoal myeloencephalitis.

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Yang, Jibing; Ellison, Siobhan; Gogal, Robert; Norton, Heather; Lindsay, David S; Andrews, Frank; Ward, Daniel; Witonsky, Sharon

2006-06-15

Equine protozoal myeloencephalitis (EPM) is one of the most common neurologic diseases of horses in the United States. The primary etiologic agent is Sarcocystis neurona. Currently, there is limited knowledge regarding the protective or pathophysiologic immune response to S. neurona infection or the subsequent development of EPM. The objectives of this study were to determine whether S. neurona infected horses with clinical signs of EPM had altered or suppressed immune responses compared to neurologically normal horses and if blood sample storage would influence these findings. Twenty clinically normal horses and 22 horses with EPM, diagnosed by the presence of S. neurona specific antibodies in the serum and/or cerebrospinal (CSF) and clinical signs, were evaluated for differences in the immune cell subsets and function. Our results demonstrated that naturally infected horses had significantly (Pneurona in horses, as well as to determine the mechanism associated with suppressed in vitro proliferation responses. Finally, overnight storage of blood samples appears to alter T lymphocyte phenotypes and viability among leukocytes.

Risk factors associated with the presence of Sarcocystis neurona sporocysts in opossums (Didelphis virginiana).

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Rickard, L G; Black, S S; Rashmir-Raven, A; Hurst, G; Dubey, J P

2001-12-13

Sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (EPM) in horse in the Americas. The only known definitive host for this parasite in the United States is the opossum (Didelphis virginiana); however, despite the importance of the disease, the epidemiology of the parasite in the definitive host is poorly understood. To begin addressing these data gaps, potential risk factors were evaluated for their association with the presence of sporocysts of S. neurona in opossums live-trapped in March 1999 and November 1999 to May 2000. Sporocysts of S. neurona were found in 19 of the 72 animals examined. Potential risk factors evaluated were locality, trap date, age, gender, the presence of young in the pouch of females, and body condition score. Variables that were associated with the presence of S. neurona sporocysts were used in logistic regression analysis. Of the factors examined, season and body condition score were associated with increased odds of an animal harboring sporocysts.

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.

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

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Yeargan, Michelle R; Alvarado-Esquivel, Cosme; Dubey, Jitender P; Howe, Daniel K

2013-01-01

Equine protozoal myeloencephalitis (EPM) is a debilitating disease of horses caused by Sarcocystis neurona and Neospora hughesi. Sera from 495 horses in Durango State, Mexico were tested for anti-protozoal antibodies using enzyme-linked immunosorbent assays (ELISAs) based on major surface antigens of these two parasites. Antibodies to S. neurona were detected in 240 (48.5%) of the 495 horse sera tested with the rSnSAG2/4/3 trivalent ELISA. Multivariate analysis showed that exposure to S. neurona was associated with age, feeding grains and crops, and small herd size. Antibodies to N. hughesi were found in 15 (3.0%) of the 495 horse sera tested with the rNhSAG1 ELISA and confirmed by Western blot of N. hughesi tachyzoite antigen. This is the first report of S. neurona and N. hughesi exposure in horses in Mexico, and it affirms that EPM should be in the differential diagnosis for horses exhibiting signs of neurologic disease in this country. © M.R. Yeargan et al., published by EDP Sciences, 2013.

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.

Genetic variation among isolates of Sarcocystis neurona, the agent of protozoal myeloencephalitis, as revealed by amplified fragment length polymorphism markers.

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Elsheikha, H M; Schott, H C; Mansfield, L S

2006-06-01

Sarcocystis neurona causes serious neurological disease in horses and other vertebrates in the Americas. Based on epidemiological data, this parasite has recently emerged. Here, the genetic diversity of Sarcocystis neurona was evaluated using the amplified fragment length polymorphism (AFLP) method. Fifteen S. neurona taxa from different regions collected over the last 10 years were used; six isolates were from clinically diseased horses, eight isolates were from wild-caught opossums (Didelphis virginiana), and one isolate was from a cowbird (Molothrus ater). Additionally, four outgroup taxa were also fingerprinted. Nine primer pairs were used to generate AFLP patterns, with a total number of amplified fragments ranging from 30 to 60, depending on the isolate and primers tested. Based on the presence/absence of amplified AFLP fragments and pairwise similarity values, all the S. neurona isolates tested were clustered in one monophyletic group. No significant correlation could be found between genomic similarity and host origin of the S. neurona isolates. AFLP revealed significant intraspecific genetic variations, and S. neurona appeared as a highly variable species. Furthermore, linkage disequilibrium analysis suggested that S. neurona populations within Michigan have an intermediate type of population structure that includes characteristics of both clonal and panamictic population structures. AFLP is a reliable molecular technique that has provided one of the most informative approaches to ascertain phylogenetic relationships in S. neurona and its closest relatives, allowing them to be clustered by relative similarity using band matching and unweighted pair group method with arithmetic mean analysis, which may be applicable to other related protozoal species.

Sarcocystis neurona-specific immunoglobulin G in the serum and cerebrospinal fluid of horses administered S neurona vaccine.

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Witonsky, Sharon; Morrow, Jennifer K; Leger, Clare; Dascanio, John; Buechner-Maxwell, Virginia; Palmer, Wally; Kline, Kristen; Cook, Anne

2004-01-01

A vaccine against Sarcocystis neurona, which induces equine protozoal myeloencephalitis (EPM), has received conditional licensure in the United States. A major concern is whether the immunoglobulin G (IgG) response elicited by the vaccine will compromise the use of Western blotting (WB) as a diagnostic tool in vaccinated horses with neurologic disease. Our goals were to determine if vaccination (1) causes seroconversion: (2) causes at least a transient increase in S neurona-specific IgG in the cerebrospinal fluid (CSF); and (3) induces an IgG response that can be differentiated from that induced by natural exposure. Horses included in the study (n = 29) were older than 6 months with no evidence of neurologic disease. The presence or absence of anti-S neurona antibodies in the serum of each horse was determined by WB analysis. Seropositive horses had CSF collected and submitted for cytology, CSF index, and WB analysis. The vaccine was administered to all the horses and boostered 3-4 weeks later. On day 14 after the 2nd administration, serum and CSF were collected and analyzed. Eighty-nine percent (8 of 9) of the initial seronegative horses seroconverted after vaccination, of which 57% (4 of 7) had anti-S neurona IgG in their CSE Eighty percent (16 of 20) of the seropositive horses had an increase in serum S neurona IgG after vaccination. Of the 6 of 20 horses that were initially seropositive/CSF negative, 2 were borderline positive for anti-S neurona IgG in the CSF, 2 tested positive, and 2 were excluded because the CSF sample had been contaminated by blood. There were no WB banding patterns that distinguished samples from horses that seroconverted due to vaccination versus natural exposure. Caution must be used in interpreting WB analysis from neurologic horses that have been recently vaccinated for EPM.

Has Sarcocystis neurona Dubey et al., 1991 (Sporozoa: Apicomplexa: Sarcocystidae) cospeciated with its intermediate hosts?

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Elsheikha, Hany M

2009-08-26

The question of how Sarcocystis neurona is able to overcome species barrier and adapt to new hosts is central to the understanding of both the evolutionary origin of S. neurona and the prediction of its field host range. Therefore, it is worth reviewing current knowledge on S. neurona host specificity. The available host range data for S. neurona are discussed in relation to a subject of evolutionary importance-specialist or generalist and its implications to understand the strategies of host adaptation. Current evidences demonstrate that a wide range of hosts exists for S. neurona. This parasite tends to be highly specific for its definitive host but much less so for its intermediate host (I.H.). The unique specificity of S. neurona for its definitive host may be mediated by a probable long coevolutionary relationship of the parasite and carnivores in a restricted ecological niche 'New World'. This might be taken as evidence that carnivores are the 'original' host group for S. neurona. Rather, the capacity of S. neurona to exploit an unusually large number of I.H. species probably indicates that S. neurona maintains non-specificity to its I.H. as an adaptive response to insure the survival of the parasite in areas in which the 'preferred' host is not available. This review concludes with the view that adaptation of S. neurona to a new host is a complex interplay that involves a large number of determinants.

Acute onset of encephalomyelitis with atypical lesions associated with dual infection of Sarcocystis neurona and Toxoplasma gondii in a dog.

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Gerhold, Richard; Newman, Shelley J; Grunenwald, Caroline M; Crews, Amanda; Hodshon, Amy; Su, Chunlei

2014-10-15

A two-year-old male, neutered, basset hound-beagle mix with progressive neurological impairment was examined postmortem. Grossly, the dog had multiple raised masses on the spinal cord between nerve roots. Microscopically, the dog had protozoal myeloencephalitis. Toxoplasma gondii and Sarcocystis neurona were detected in the CNS by immunohistochemistry and polymerase chain reaction (PCR). Sarcocysts in formalin-fixed muscle were negative for Sarcocystis by PCR. Banked serum was negative for T. gondii using the modified agglutination test, suggesting an acute case of T. gondii infection or immunosuppression; however, no predisposing immunosuppressive diseases, including canine distemper, were found. To the authors' knowledge, this is the first report of dual T. gondii and S. neurona infection in a dog. Published by Elsevier B.V.

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

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Onuma, Selma Samiko Miyazaki; Melo, Andréia Lima Tomé; Kantek, Daniel Luis Zanella; Crawshaw-Junior, Peter Gransden; Morato, Ronaldo Gonçalves; May-Júnior, Joares Adenílson; Pacheco, Thábata dos Anjos; Aguiar, Daniel Moura de

2014-01-01

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.

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.

Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California.

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Rejmanek, Daniel; Vanwormer, Elizabeth; Miller, Melissa A; Mazet, Jonna A K; Nichelason, Amy E; Melli, Ann C; Packham, Andrea E; Jessup, David A; Conrad, Patricia A

2009-12-03

Sarcocystis neurona, a protozoal parasite shed by opossums (Didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. Over the course of 3 years (fall 2005-summer 2008), opossums from central California were tested for infection with S. neurona. Of 288 opossums sampled, 17 (5.9%) were infected with S. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. Risk factors evaluated for association with S. neurona infection in opossums included: age, sex, location, season, presence of pouch young in females, concomitant infection, and sampling method (live-trapped or traffic-killed). Multivariate logistic regression analysis identified that opossums in the Central Valley were 9 times more likely to be infected than those near the coast (p=0.009). Similarly, opossum infection was 5 times more likely to be detected during the reproductive season (March-July; p=0.013). This first investigation of S. neurona infection prevalence and associated risk factors in opossums in the western United States can be used to develop management strategies aimed at reducing the incidence of S. neurona infections in susceptible hosts, including horses and threatened California sea otters (Enhydra lutris neries).

Selective inhibition of Sarcocystis neurona calcium-dependent protein kinase 1 for equine protozoal myeloencephalitis therapy.

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Ojo, Kayode K; Dangoudoubiyam, Sriveny; Verma, Shiv K; Scheele, Suzanne; DeRocher, Amy E; Yeargan, Michelle; Choi, Ryan; Smith, Tess R; Rivas, Kasey L; Hulverson, Matthew A; Barrett, Lynn K; Fan, Erkang; Maly, Dustin J; Parsons, Marilyn; Dubey, Jitender P; Howe, Daniel K; Van Voorhis, Wesley C

2016-12-01

Sarcocystis neurona is the most frequent cause of equine protozoal myeloencephalitis, a debilitating neurological disease of horses that can be difficult to treat. We identified SnCDPK1, the S. neurona homologue of calcium-dependent protein kinase 1 (CDPK1), a validated drug target in Toxoplasma gondii. SnCDPK1 shares the glycine "gatekeeper" residue of the well-characterized T. gondii enzyme, which allows the latter to be targeted by bumped kinase inhibitors. This study presents detailed molecular and phenotypic evidence that SnCDPK1 can be targeted for rational drug development. Recombinant SnCDPK1 was tested against four bumped kinase inhibitors shown to potently inhibit both T. gondii (Tg) CDPK1 and T. gondii tachyzoite growth. SnCDPK1 was inhibited by low nanomolar concentrations of these BKIs and S. neurona growth was inhibited at 40-120nM concentrations. Thermal shift assays confirmed these bumped kinase inhibitors bind CDPK1 in S. neurona cell lysates. Treatment with bumped kinase inhibitors before or after invasion suggests that bumped kinase inhibitors interfere with S. neurona mammalian host cell invasion in the 0.5-2.5μM range but interfere with intracellular division at 2.5μM. In vivo proof-of-concept experiments were performed in a murine model of S. neurona infection. The experimental infected groups treated for 30days with compound BKI-1553 (n=10 mice) had no signs of disease, while the infected control group had severe signs and symptoms of infection. Elevated antibody responses were found in 100% of control infected animals, but only 20% of BKI-1553 treated infected animals. Parasites were found in brain tissues of 100% of the control infected animals, but only in 10% of the BKI-1553 treated animals. The bumped kinase inhibitors used in these assays have been chemically optimized for potency, selectivity and pharmacokinetic properties, and hence are good candidates for treatment of equine protozoal myeloencephalitis. Copyright © 2016

Development and evaluation of a Sarcocystis neurona-specific IgM capture enzyme-linked immunosorbent assay.

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Murphy, J E; Marsh, A E; Reed, S M; Meadows, C; Bolten, K; Saville, W J A

2006-01-01

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses caused primarily by the protozoal parasite Sarcocystis neurona. Currently available antemortem diagnostic testing has low specificity. The hypothesis of this study was that serum and cerebrospinal fluid (CSF) of horses experimentally challenged with S neurona would have an increased S neurona-specific IgM (Sn-IgM) concentration after infection, as determined by an IgM capture enzyme linked immunoassay (ELISA). The ELISA was based on the S neurona low molecular weight protein SNUCD-1 antigen and the monoclonal antibody 2G5 labeled with horseradish peroxidase. The test was evaluated using serum and CSF from 12 horses experimentally infected with 1.5 million S neurona sporocysts and 16 horses experimentally infected with varying doses (100 to 100,000) of S neurona sporocysts, for which results of histopathologic examination of the central nervous system were available. For horses challenged with 1.5 million sporocysts, there was a significant increase in serum Sn-IgM concentrations compared with values before infection at weeks 2-6 after inoculation (P neurona, there were significant increases in serum Sn-IgM concentration at various points in time after inoculation, depending on the challenge dose (P < .01). In addition, there was a significant increase between the CSF Sn-IgM concentrations before and after inoculation (P < .0001). These results support further evaluation of the assay as a diagnostic test during the acute phase of EPM.

Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals

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Dubey, J.P.; Zarnke, R.; Thomas, N.J.; Wong, S.K.; Vanbonn, W.; Briggs, M.; Davis, J.W.; Ewing, R.; Mense, M.; Kwok, O.C.H.; Romand, S.; Thulliez, P.

2003-01-01

Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and S. canis are related protozoans that can cause mortality in many species of domestic and wild animals. Recently, T. gondii and S. neurona were recognized to cause encephalitis in marine mammals. As yet, there is no report of natural exposure of N. caninum in marine mammals. In the present study, antibodies to T. gondii and N. caninum were assayed in sera of several species of marine mammals. For T. gondii, sera were diluted 1:25, 1:50, and 1:500 and assayed in the T. gondii modified agglutination test (MAT). Antibodies (MAT a?Y1:25) to T. gondii were found in 89 of 115 (77%) dead, and 18 of 30 (60%) apparently healthy sea otters (Enhydra lutris), 51 of 311 (16%) Pacific harbor seals (Phoca vitulina), 19 of 45 (42%) sea lions (Zalophus californianus), 5 of 32 (16%) ringed seals (Phoca hispida), 4 of 8 (50%) bearded seals (Erignathus barbatus), 1 of 9 (11.1%) spotted seals (Phoca largha), 138 of 141 (98%) Atlantic bottlenose dolphins (Tursiops truncatus), and 3 of 53 (6%) walruses (Odobenus rosmarus). For N. caninum, sera were diluted 1:40, 1:80, 1:160, and 1:320 and examined with the Neospora agglutination test (NAT) using mouse-derived tachyzoites. NAT antibodies were found in 3 of 53 (6%) walruses, 28 of 145 (19%) sea otters, 11 of 311 (3.5%) harbor seals, 1 of 27 (3.7%) sea lions, 4 of 32 (12.5%) ringed seals, 1 of 8 (12.5%) bearded seals, and 43 of 47 (91%) bottlenose dolphins. To our knowledge, this is the first report of N. caninum antibodies in any marine mammal, and the first report of T. gondii antibodies in walruses and in ringed, bearded, spotted, and ribbon seals. Current information on T. gondii-like and Sarcocystis-like infections in marine mammals is reviewed. New cases of clinical S. canis and T. gondii infections are also reported in sea lions, and T. gondii infection in an Antillean manatee (Trichechus manatus manatus).

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).

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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.

Comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and/or Sarcocystis neurona.

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Pusterla, Nicola; Tamez-Trevino, Eva; White, Alexandria; Vangeem, Joshua; Packham, Andrea; Conrad, Patricia A; Kass, Philip

2014-05-01

Equine protozoal myeloencephalitis is a commonly diagnosed neurological disease of horses in North America and is caused by infection with Sarcocystis neurona or Neospora hughesi. The aim of this study was to compare prevalence factors among horses seropositive or seronegative to N. hughesi and/or S. neurona. A total of 3123 submissions were included in the study, with horses originating from 49 States. Thirty-eight animals from 21 States tested seropositive for N. hughesi only, 840 horses from 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range.

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Sundar, N; Asmundsson, I M; Thomas, N J; Samuel, M D; Dubey, J P; Rosenthal, B M

2008-03-25

Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

Sarcocystis neurona infections in raccoons (Procyon lotor): evidence for natural infection with sarcocysts, transmission of infection to opossums (Didelphis virginiana), and experimental induction of neurologic disease in raccoons.

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Dubey, J P; Saville, W J; Stanek, J F; Lindsay, D S; Rosenthal, B M; Oglesbee, M J; Rosypal, A C; Njoku, C J; Stich, R W; Kwok, O C; Shen, S K; Hamir, A N; Reed, S M

2001-10-24

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses in the Americas and Sarcocystis neurona is the most common etiologic agent. The distribution of S. neurona infections follows the geographical distributions of its definitive hosts, opossums (Didelphis virginiana, Didelphis albiventris). Recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of S. neurona. In the present report, raccoons (Procyon lotor) were identified as a natural intermediate host of S. neurona. Two laboratory-raised opossums were found to shed S. neurona-like sporocysts after ingesting tongues of naturally-infected raccoons. Interferon-gamma gene knockout (KO) mice fed raccoon-opossum-derived sporocysts developed neurologic signs. S. neurona was identified immunohistochemically in tissues of KO mice fed sporocysts and the parasite was isolated in cell cultures inoculated with infected KO mouse tissues. The DNA obtained from the tongue of a naturally-infected raccoon, brains of KO mice that had neurological signs, and from the organisms recovered in cell cultures inoculated with brains of neurologic KO mice, corresponded to that of S. neurona. Two raccoons fed mature S. neurona sarcocysts did not shed sporocysts in their feces, indicating raccoons are not likely to be its definitive host. Two raccoons fed sporocysts from opossum feces developed clinical illness and S. neurona-associated encephalomyelitis was found in raccoons killed 14 and 22 days after feeding sporocysts; schizonts and merozoites were seen in encephalitic lesions.

Cross-sectional study of serum antibodies against Sarcocystis neurona in cats tested for antibodies against Toxoplasma gondii.

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Rossano, Mary G; Murphy, Alice J; Vrable, Ruth A; Vanzo, Nicole E; Lewis, Stacy K; Sheline, Katherine D; Kaneene, John B; Mansfield, Linda S

2002-08-15

To determine apparent seroprevalence of antibodies against Sarcocystis neurona in a population of domestic cats previously tested for antibodies against Toxoplasma gondii. Cross-sectional study. Serum from 196 domestic cats. Banked serum samples submitted to the Michigan State University Animal Health Diagnostic Laboratory for T. gondii diagnostic testing were tested for antibodies against S. neurona by use of an indirect fluorescent antibody (IFA) test and a western blot test. Submission records were analyzed to determine descriptive statistics and test for associations between positive results of a test for S. neurona and other variables in the data set. 10 of 196 (5%) samples yielded positive results for antibodies against S. neurona by use of western blot analysis, whereas 27 samples yielded positive results by use of the IFA. No association was found between S. neurona western blot test results and T. gondii test results, age, sex, or the reason for T. gondii testing. The S. neurona IFA titer was positively and significantly associated with positive results of western blot analysis. Domestic cats are not likely to play a substantial role as intermediate hosts in the natural life cycle of S. neurona. Results indicate that natural infection of domestic cats may occur, and small animal practitioners should be aware of this fact when evaluating cats with neurologic disease. The S. neurona IFA test had lower specificity than western blot analysis.

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

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

2015-01-01

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 1000x 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 parasite. 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. dayspi 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. PMID:26138150

Prevalence of agglutinating antibodies to Sarcocystis neurona in skunks (Mephitis Mephitis), raccoons (Procyon lotor), and opossums (Didelphis Virginiana) from Connecticut.

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Mitchell, Sheila M; Richardson, Dennis J; Cheadle, M Andy; Zajac, Anne M; Lindsay, David S

2002-10-01

Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural cases of encephalitis caused by S. neurona have been reported in skunks (Mephitis mephitis) and raccoons (Procyon lotor). Opossums (Didelphis spp.) are the only known definitive host. Sera from 24 striped skunks, 12 raccoons, and 7 opossums (D. virginiana) from Connecticut were examined for agglutinating antibodies to S. neurona using the S. neurona agglutination test (SAT) employing formalin-fixed merozoites as antigen. The SAT was validated for skunk sera using pre- and postinfection serum samples from 2 experimentally infected skunks. Of the 24 (46%) skunks 11 were positive, and all 12 raccoons were positive for S. neurona antibodies. None of the 7 opossums was positive for antibodies to S. neurona. These results suggest that exposure to sporocysts of S. neurona by intermediate hosts is high in Connecticut. The absence of antibodies in opossums collected from the same areas is most likely because of the absence of systemic infection in the definitive host.

High-throughput screen of drug repurposing library identifies inhibitors of Sarcocystis neurona growth.

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Bowden, Gregory D; Land, Kirkwood M; O'Connor, Roberta M; Fritz, Heather M

2018-04-01

The apicomplexan parasite Sarcocystis neurona is the primary etiologic agent of equine protozoal myeloencephalitis (EPM), a serious neurologic disease of horses. Many horses in the U.S. are at risk of developing EPM; approximately 50% of all horses in the U.S. have been exposed to S. neurona and treatments for EPM are 60-70% effective. Advancement of treatment requires new technology to identify new drugs for EPM. To address this critical need, we developed, validated, and implemented a high-throughput screen to test 725 FDA-approved compounds from the NIH clinical collections library for anti-S. neurona activity. Our screen identified 18 compounds with confirmed inhibitory activity against S. neurona growth, including compounds active in the nM concentration range. Many identified inhibitory compounds have well-defined mechanisms of action, making them useful tools to study parasite biology in addition to being potential therapeutic agents. In comparing the activity of inhibitory compounds identified by our screen to that of other screens against other apicomplexan parasites, we found that most compounds (15/18; 83%) have activity against one or more related apicomplexans. Interestingly, nearly half (44%; 8/18) of the inhibitory compounds have reported activity against dopamine receptors. We also found that dantrolene, a compound already formulated for horses with a peak plasma concentration of 37.8 ± 12.8 ng/ml after 500 mg dose, inhibits S. neurona parasites at low concentrations (0.065 μM [0.036-0.12; 95% CI] or 21.9 ng/ml [12.1-40.3; 95% CI]). These studies demonstrate the use of a new tool for discovering new chemotherapeutic agents for EPM and potentially providing new reagents to elucidate biologic pathways required for successful S. neurona infection. Copyright © 2018. Published by Elsevier Ltd.

SnSAG5 is an alternative surface antigen of Sarcocystis neurona strains that is mutually exclusive to SnSAG1.

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Crowdus, Carolyn A; Marsh, Antoinette E; Saville, Willliam J; Lindsay, David S; Dubey, J P; Granstrom, David E; Howe, Daniel K

2008-11-25

Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host.

Limited genetic diversity among Sarcocystis neurona strains infecting southern sea otters precludes distinction between marine and terrestrial isolates.

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Wendte, J M; Miller, M A; Nandra, A K; Peat, S M; Crosbie, P R; Conrad, P A; Grigg, M E

2010-04-19

Sarcocystis neurona is an apicomplexan parasite identified as a cause of fatal neurological disease in the threatened southern sea otter (Enhydra lutris nereis). In an effort to characterize virulent S. neurona strains circulating in the marine ecosystem, this study developed a range of markers relevant for molecular genotyping. Highly conserved sequences within the 18S ribosomal gene array, the plastid-encoded RNA polymerase (RPOb) and the cytochrome c oxidase subunit 1 mitochondrial gene (CO1) were assessed for their ability to distinguish isolates at the genus and species level. For within-species comparisons, five surface antigens (SnSAG1-SnSAG5) and one high resolution microsatellite marker (Sn9) were developed as genotyping markers to evaluate intra-strain diversity. Molecular analysis at multiple loci revealed insufficient genetic diversity to distinguish terrestrial isolates from strains infecting marine mammals. Furthermore, SnSAG specific primers applied against DNA from the closely related species, Sarcocystis falcatula, lead to the discovery of highly similar orthologs to SnSAG2, 3, and 4, calling into question the specificity of diagnostic tests based on these antigens. The results of this study suggest a population genetic structure for S. neurona similar to that reported for the related parasite, Toxoplasma gondii, dominated by a limited number of successful genotypes. Published by Elsevier B.V.

Testing the Sarcocystis neurona vaccine using an equine protozoal myeloencephalitis challenge model.

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Saville, William J A; Dubey, Jitender P; Marsh, Antoinette E; Reed, Stephen M; Keene, Robert O; Howe, Daniel K; Morrow, Jennifer; Workman, Jeffrey D

2017-11-30

Equine protozoal myeloencephalitis (EPM) is an important equine neurologic disorder, and treatments for the disease are often unrewarding. Prevention of the disease is the most important aspect for EPM, and a killed vaccine was previously developed for just that purpose. Evaluation of the vaccine had been hampered by lack of post vaccination challenge. The purpose of this study was to determine if the vaccine could prevent development of clinical signs after challenge with Sarcocystis neurona sporocysts in an equine challenge model. Seventy horses that were negative for antibodies to S. neurona and were neurologically normal were randomly assigned to vaccine or placebo groups and divided into short-term duration of immunity (study #1) and long-term duration of immunity (study #2) studies. S. neurona sporocysts used for the challenge were generated in the opossum/raccoon cycle isolate SN 37-R. Study #1 horses received an initial vaccination and a booster, and were challenged 34days post second vaccination. Study #2 horses received a vaccination and two boosters and were challenged 139days post third vaccination. All horses in study #1 developed neurologic signs (n=30) and there was no difference between the vaccinates and controls (P=0.7683). All but four horses in study #2 developed detectable neurologic deficits. The neurologic signs, although not statistically significant, were worse in the vaccinated horses (P=0.1559). In these two studies, vaccination with the S. neurona vaccine failed to prevent development of clinical neurologic deficits. Copyright © 2017 Elsevier B.V. All rights reserved.

Sarcocysts of an unidentified species of Sarcocystis in the sea otter (Enhydra lutris)

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Dubey, J.P.; Lindsay, D.S.; Rosenthal, B.M.; Thomas, N.J.

2003-01-01

The number of Sarcocystis species that infect sea otters (Enhydra lutris) is unknown. Sea otter tissues were recently shown to harbor sarcocysts of S. neurona and of unidentified species of Sarcocystis. Whereas sarcocysts of S. neurona have walls 1a??3 I?m thick with type 9 villar protrusions, ultrastructure of a distinct thin-walled sarcocyst (0.5a??0.7 I?m thick) lacking villar protrusions, but instead exhibiting minute type 1 undulations on the sarcocyst wall, is described in this report. Parasites characterized from a sea otter infection were inferred to be related to, but distinct from, other species belonging to Sarcocystis, based on sequencing and phylogenetic analysis of a portion of the beta subunit of the plastid-encoded RNA polymerase gene.

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

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Dangoudoubiyam, S; Oliveira, J B; Víquez, C; Gómez-García, A; González, O; Romero, J J; Kwok, O C H; Dubey, J P; Howe, D K

2011-06-01

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 by using the surface antigen (SAG) SnSAG2 enzyme-linked immunosorbent assay (ELISA), the NhSAG1 ELISA, and the modified agglutination test, respectively. Anti- S. neurona antibodies were found in 42.2% of the horses by using the SnSAG2 ELISA. Anti- Neospora spp. antibodies were found in only 3.5% of the horses by using the NhSAG1 ELISA, and only 1 of these horses was confirmed seropositive by Western blot. Antibodies to T. gondii were found in 34.0% of the horses tested, which is higher than in previous reports from North and South America. The finding of anti- S. neurona antibodies in horses from geographical areas where Didelphis marsupialis has wide distribution suggests that D. marsupialis is a potential definitive host for this parasite and a source of infection for these horses.

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.

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

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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.

Prevalence of antibodies to Neospora caninum, Sarcocystis neurona, and Toxoplasma gondii in wild horses from central Wyoming.

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Dubey, J P; Mitchell, S M; Morrow, J K; Rhyan, J C; Stewart, L M; Granstrom, D E; Romand, S; Thulliez, P; Saville, W J; Lindsay, D S

2003-08-01

Sarcocystis neurona, Neospora caninum, N. hughesi, and Toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. The source of infection for N. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for S. neurona, N. caninum, and T. gondii, respectively. Seroprevalence of these coccidians in 276 wild horses from central Wyoming outside the known range of the opossum (Didelphis virginiana) was determined. Antibodies to T. gondii were found only in 1 of 276 horses tested with the modified agglutination test using 1:25, 1:50, and 1:500 dilutions. Antibodies to N. caninum were found in 86 (31.1%) of the 276 horses tested with the Neospora agglutination test--the titers were 1:25 in 38 horses, 1:50 in 15, 1:100 in 9, 1:200 in 8, 1:400 in 4, 1:800 in 2, 1:1,600 in 2, 1:3,200 in 2, and 1:12,800 in 1. Antibodies to S. neurona were assessed with the serum immunoblot; of 276 horses tested, 18 had antibodies considered specific for S. neurona. Antibodies to S. neurona also were assessed with the S. neurona direct agglutination test (SAT). Thirty-nine of 265 horses tested had SAT antibodies--in titers of 1:50 in 26 horses and 1:100 in 13. The presence of S. neurona antibodies in horses in central Wyoming suggests that either there is cross-reactivity between S. neurona and some other infection or a definitive host other than opossum is the source of infection. In a retrospective study, S. neurona antibodies were not found by immunoblot in the sera of 243 horses from western Canada outside the range of D. virginiana.

Seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, GA, USA.

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Yabsley, Michael J; Jordan, Carly N; Mitchell, Sheila M; Norton, Terry M; Lindsay, David S

2007-03-15

In the current study, we determined the seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, Georgia. Serum samples were tested from 52 ring-tailed lemurs (Lemur catta), six blue-eyed black lemurs (Eulemur macaco flavifrons), and four black and white ruffed lemurs (Varecia variegata variegata) using an agglutination assay. Three ring-tailed lemurs (5.8%) were positive for T. gondii (titer of 1:50); one ring-tailed lemur (1.9%) and one black and white ruffed lemur (25%) were positive for S. neurona (titers of 1:1000); and one ring-tailed lemur (1.9%) was positive for E. cuniculi (titer of 1:400). All blue-eyed black lemurs were negative for antibodies to T. gondii, S. neurona, and E. cuniculi. This is the first detection of antibodies to T. gondii in ring-tailed lemurs and antibodies to S. neurona and E. cuniculi in any species of prosimian.

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

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Meneses, Iris Daniela Santos de; Andrade, Müller Ribeiro; Uzêda, Rosângela Soares; Bittencourt, Marta Vasconcelos; Lindsay, David Scott; Gondim, Luís Fernando Pita

2014-01-01

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.

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.

Investigation of SnSPR1, a novel and abundant surface protein of Sarcocystis neurona merozoites.

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Zhang, Deqing; Howe, Daniel K

2008-04-15

An expressed sequence tag (EST) sequencing project has produced over 15,000 partial cDNA sequences from the equine pathogen Sarcocystis neurona. While many of the sequences are clear homologues of previously characterized genes, a significant number of the S. neurona ESTs do not exhibit similarity to anything in the extensive sequence databases that have been generated. In an effort to characterize parasite proteins that are novel to S. neurona, a seemingly unique gene was selected for further investigation based on its abundant representation in the collection of ESTs and the predicted presence of a signal peptide and glycolipid anchor addition on the encoded protein. The gene was expressed in E. coli, and monospecific polyclonal antiserum against the recombinant protein was produced by immunization of a rabbit. Characterization of the native protein in S. neurona merozoites and schizonts revealed that it is a low molecular weight surface protein that is expressed throughout intracellular development of the parasite. The protein was designated Surface Protein 1 (SPR1) to reflect its display on the outer surface of merozoites and to distinguish it from the ubiquitous SAG/SRS surface antigens of the heteroxenous Coccidia. Interestingly, infection assays in the presence of the polyclonal antiserum suggested that SnSPR1 plays some role in attachment and/or invasion of host cells by S. neurona merozoites. The work described herein represents a general template for selecting and characterizing the various unidentified gene sequences that are plentiful in the EST databases for S. neurona and other apicomplexans. Furthermore, this study illustrates the value of investigating these novel sequences since it can offer new candidates for diagnostic or vaccine development while also providing greater insight into the biology of these parasites.

Evidence that antibodies against recombinant SnSAG1 of Sarcocystis neurona merozoites are involved in infection and immunity in equine protozoal myeloencephalitis.

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Ellison, Siobhan; Witonsky, Sharon

2009-07-01

Sarcocystis neurona is the principal etiologic agent of equine protozoal myeloencephalitis (EPM). An immunodominant protein of S. neurona, SnSAG-1, is expressed by the majority of S. neurona merozoites isolated from spinal tissues of horses diagnosed with EPM and may be a candidate for diagnostic tests and prophylaxis for EPM. Five horses were vaccinated with adjuvanted recombinant SnSAG1 (rSnSAG1) and 5 control (sham vaccinated) horses were vaccinated with adjuvant only. Serum was evaluated pre- and post-vaccination, prior to challenge, for antibodies against rSnSAG1 and inhibitory effects on the infectivity of S. neurona by an in vitro serum neutralization assay. The effect of vaccination with rSnSAG1 on in vivo infection by S. neurona was evaluated by challenging all the horses with S. neurona merozoites. Blinded daily examinations and 4 blinded neurological examinations were used to evaluate the presence of clinical signs of EPM. The 5 vaccinated horses developed serum and cerebrospinal fluid (CSF) titers of SnSAG1, detected by enzyme-linked immunosorbent assay (ELISA), post-vaccination. Post-vaccination serum from vaccinated horses was found to have an inhibitory effect on merozoites, demonstrated by in vitro bioassay. Following the challenge, the 5 control horses displayed clinical signs of EPM, including ataxia. While 4 of the 5 vaccinated horses did not become ataxic. One rSnSAG-1 vaccinated horse showed paresis in 1 limb with muscle atrophy. All horses showed mild, transient, cranial nerve deficits; however, disease did not progress to ataxia in rSnSAG-1 vaccinated horses. The study showed that vaccination with rSnSAG-1 produced antibodies in horses that neutralized merozoites when tested by in vitro culture and significantly reduced clinical signs demonstrated by in vivo challenge.

Prevalence of Sarcocystis species sporocysts in Northern Virginia opossums (Didelphis virginiana).

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Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

2004-08-01

A total of 206 Virginia opossums ( Didelphis virginiana) collected from the mid-Michigan region, United States, during a period extending from 1996 to 2002 were sampled for the presence of Sarcocystis spp sporocysts. All isolates were phenotypically identified as Sarcocystis spp and genotyped to the species level by PCR-based techniques. The overall prevalence of Sarcocystis spp in opossums was 18% (37/206). The prevalence of Sarcocystis spp differed significantly with age ( P<0.001) and adult opossums were more commonly infected (14.6%; 30/206) than juveniles (3.4%; 7/206). No significant difference in the prevalence of Sarcocystis spp infection was observed between male and female ( P<0.15). The highest prevalence was recorded during summer (9.2%; 19/206). PCR-RFLP analyses demonstrated the majority of Sarcocystis isolates to be S. neurona, with some animals co-infected with sporocysts of S. falcatula. Out of the 37 Sarcocystis-infected opossums, 23 (62%) had sporocysts of S. neurona only, four (11%) had sporocysts of S. falcatula only, and eight (22%) had a mixture of S. neurona and S. falcatula sporocysts. These findings indicate that mixed Sarcocystis infections in opossums are common. The propensity for Sarcocystis spp to co-exist in the opossum gut enhances dissemination and environmental contamination with these coccidia. Additionally, this increases the chance for sexual recombination between Sarcocystis spp, given the proclivity of these species to reproduce sexually at high numbers in the intestinal cells of their definitive host.

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...

Evidence that Surface Proteins Sn14 and Sn16 of Sarcocystis neurona Merozoites Are Involved in Infection and Immunity†

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Liang, Fang Ting; Granstrom, David E.; Zhao, Xiao Min; Timoney, John F.

1998-01-01

Sarcocystis neurona is the etiologic agent of equine protozoal myeloencephalitis (EPM). Based on an analysis of 25,000 equine serum and cerebrospinal fluid (CSF) samples, including samples from horses with neurologic signs typical of EPM or with histologically or parasitologically confirmed EPM, four major immunoblot band patterns have been identified. Twenty-three serum and CSF samples representing each of the four immunoblot patterns were selected from 220 samples from horses with neurologic signs resembling EPM and examined for inhibitory effects on the infectivity of S. neurona by an in vitro neutralization assay. A high correlation between immunoblot band pattern and neutralizing activity was detected. Two proteins, Sn14 and Sn16 (14 and 16 kDa, respectively), appeared to be important for in vitro infection. A combination of the results of surface protein labeling, immunoprecipitation, Western blotting, and trypsin digestion suggests that these molecules are surface proteins and may be useful components of a vaccine against S. neurona infection. Although S. neurona is an obligate intracellular parasite, it is potentially a target for specific antibodies which may lyse merozoites via complement or inhibit their attachment and penetration to host cells. PMID:9573058

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

2015-08-01

Sarcocystis neurona is an important cause of protozoal encephalitis among marine mammals in the northeastern Pacific Ocean. To characterise 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. Published by Elsevier Ltd.

Epidemiology of Sarcocystis neurona infections in domestic cats (Felis domesticus) and its association with equine protozoal myeloencephalitis (EPM) case farms and feral cats from a mobile spay and neuter clinic.

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Stanek, J F; Stich, R W; Dubey, J P; Reed, S M; Njoku, C J; Lindsay, D S; Schmall, L M; Johnson, G K; LaFave, B M; Saville, W J A

2003-11-28

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease in the horse most commonly caused by Sarcocystis neurona. The domestic cat (Felis domesticus) is an intermediate host for S. neurona. In the present study, nine farms, known to have prior clinically diagnosed cases of EPM and a resident cat population were identified and sampled accordingly. In addition to the farm cats sampled, samples were also collected from a mobile spay and neuter clinic. Overall, serum samples were collected in 2001 from 310 cats, with samples including barn, feral and inside/outside cats. Of these 310 samples, 35 were from nine horse farms. Horse serum samples were also collected and traps were set for opossums at each of the farms. The S. neurona direct agglutination test (SAT) was used for both the horse and cat serum samples (1:25 dilution). Fourteen of 35 (40%) cats sampled from horse farms had circulating S. neurona agglutinating antibodies. Twenty-seven of the 275 (10%) cats from the spay/neuter clinic also had detectable S. neurona antibodies. Overall, 115 of 123 (93%) horses tested positive for anti-S. neurona antibodies, with each farm having greater than a 75% exposure rate among sampled horses. Twenty-one opossums were trapped on seven of the nine farms. Eleven opossums had Sarcocystis sp. sporocysts, six of them were identified as S. neurona sporocysts based on bioassays in gamma-interferon gene knockout mice with each opossum representing a different farm. Demonstration of S. neurona agglutinating antibodies in domestic and feral cats corroborates previous research demonstrating feral cats to be naturally infected, and also suggests that cats can be frequently infected with S. neurona and serve as one of several natural intermediate hosts for S. neurona.

Sarcocystis speeri N. sp. (Protozoa: Sarcocystidae) from the opossum (Didelphis virginiana).

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Dubey, J P; Lindsay, D S

1999-10-01

The North American opossum (Didelphis virginiana) is host to at least 3 species of Sarcocystis: Sarcocystisfalcatula, Sarcocystis neurona, and a recently recognized Sarcocystis sp. A new name, Sarcocystis speeri, is proposed for the third unnamed Sarcocystis. Immunodeficient mice are an experimental intermediate host for S. speeri. Sarcocystis speeri sporocysts are 12-15 x 8-10 microm in size, and its schizonts are found in many organs of mice. Sarcocysts of S. speeri are found in skeletal muscles and they are up to 5 mm long and filiform. By light microscopy, the sarcocyst wall is thin (<1 microm thick); ultrastructurally, the cyst wall is up to 1.8 microm thick and has characteristic steeple-shaped villar protrusions surmounted by a spire. Sarcocystis speeri schizonts are morphologically and antigenically distinct from schizonts of S. neurona, and S. speeri sporocysts were not infective to budgerigars (Melopsittacus undulatus).

Strains of Sarcocystis neurona exhibit differences in their surface antigens, including the absence of the major surface antigen SnSAG1.

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Howe, Daniel K; Gaji, Rajshekhar Y; Marsh, Antoinette E; Patil, Bhagyashree A; Saville, William J; Lindsay, David S; Dubey, J P; Granstrom, David E

2008-05-01

A gene family of surface antigens is expressed by merozoites of Sarcocystis neurona, the primary cause of equine protozoal myeloencephalitis (EPM). These surface proteins, designated SnSAGs, are immunodominant and therefore excellent candidates for development of EPM diagnostics or vaccines. Prior work had identified an EPM isolate lacking the major surface antigen SnSAG1, thus suggesting there may be some diversity in the SnSAGs expressed by different S. neurona isolates. Therefore, a bioinformatic, molecular and immunological study was conducted to assess conservation of the SnSAGs. Examination of an expressed sequence tag (EST) database revealed several notable SnSAG polymorphisms. In particular, the EST information implied that the EPM strain SN4 lacked the major surface antigen SnSAG1. The absence of this surface antigen from the SN4 strain was confirmed by both Western blot and Southern blot. To evaluate SnSAG polymorphisms in the S. neurona population, 14 strains were examined by Western blots using monospecific polyclonal antibodies against the four described SnSAGs. The results of these analyses demonstrated that SnSAG2, SnSAG3, and SnSAG4 are present in all 14 S. neurona strains tested, although some variance in SnSAG4 was observed. Importantly, SnSAG1 was not detected in seven of the strains, which included isolates from four cases of EPM and a case of fatal meningoencephalitis in a sea otter. Genetic analyses by PCR using gene-specific primers confirmed the absence of the SnSAG1 locus in six of these seven strains. Collectively, the data indicated that there is heterogeneity in the surface antigen composition of different S. neurona isolates, which is an important consideration for development of serological tests and prospective vaccines for EPM. Furthermore, the diversity reported herein likely extends to other phenotypes, such as strain virulence, and may have implications for the phylogeny of the various Sarcocystis spp. that undergo sexual stages

Seroprevalences of anti-Sarcocystis neurona and anti-Neospora hughesi antibodies among healthy equids in the United States.

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James, Kaitlyn E; Smith, Woutrina A; Conrad, Patricia A; Packham, Andrea E; Guerrero, Leopoldo; Ng, Mitchell; Pusterla, Nicola

2017-06-01

OBJECTIVE To describe the general seroprevalence of anti-Sarcocystis neurona and anti-Neospora hughesi antibodies among healthy equids by use of indirect fluorescent antibody tests and determine potential risk factors for seropositivity. DESIGN Cross-sectional study. SAMPLE Whole blood samples collected from 5,250 equids (1 sample/animal) across 18 states in the United States during October 2013. PROCEDURES Information regarding potential risk factors (geographic region, breed, primary use, sex, and age) was collected along with the blood samples. For each equid, an indirect fluorescent antibody test was used to determine serum titers of antibody against each of the 2 protozoal parasites. Mixed-effects logistic regression models were created to determine ORs for seropositivity. RESULTS The overall seroprevalence of anti-S neurona and anti-N hughesi antibodies in the tested equids was 78% and 34%, respectively. Of the equids, 31% were seropositive and 18% were seronegative for antibodies against both parasites. Factors associated with equids being seropositive for anti-S neurona antibodies were residence in the South, warmblood breed, and age > 5 years. Seroprevalence of anti-N hughesi antibodies did not differ among equids in different states across the country, but warmblood breed and age > 5 years were associated with seropositivity. CONCLUSIONS AND CLINICAL RELEVANCE With regard to risk factors for S neurona and N hughesi exposure and antibody response among tested equids, older age was not unexpected; however, the influences of warmblood breed and geographic location on seropositivity for anti-S neurona antibody but not for anti-N hughesi antibody deserve further investigation.

Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana)

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Dubey, J.P.; Rosypal, A.C.; Rosenthal, B.M.; Thomas, N.J.; Lindsay, D.S.; Stanek, J.F.; Reed, S.M.; Saville, W.J.A.

2001-01-01

Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 I?m long, and the villar protrusions on the sarcocyst wall were up to 1.3 I?m long and up to 0.25 I?m wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana).

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Dubey, J R; Rosypal, A C; Rosenthal, B M; Thomas, N J; Lindsay, D S; Stanek, J F; Reed, S M; Saville, W J

2001-12-01

Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 microm long, and the villar protrusions on the sarcocyst wall were up to 1.3 microm long and up to 0.25 microm wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

Analysis of the Sarcocystis neurona microneme protein SnMIC10: protein characteristics and expression during intracellular development.

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Hoane, Jessica S; Carruthers, Vernon B; Striepen, Boris; Morrison, David P; Entzeroth, Rolf; Howe, Daniel K

2003-07-01

Sarcocystis neurona, an apicomplexan parasite, is the primary causative agent of equine protozoal myeloencephalitis. Like other members of the Apicomplexa, S. neurona zoites possess secretory organelles that contain proteins necessary for host cell invasion and intracellular survival. From a collection of S. neurona expressed sequence tags, we identified a sequence encoding a putative microneme protein based on similarity to Toxoplasma gondii MIC10 (TgMIC10). Pairwise sequence alignments of SnMIC10 to TgMIC10 and NcMIC10 from Neospora caninum revealed approximately 33% identity to both orthologues. The open reading frame of the S. neurona gene encodes a 255 amino acid protein with a predicted 39-residue signal peptide. Like TgMIC10 and NcMIC10, SnMIC10 is predicted to be hydrophilic, highly alpha-helical in structure, and devoid of identifiable adhesive domains. Antibodies raised against recombinant SnMIC10 recognised a protein band with an apparent molecular weight of 24 kDa in Western blots of S. neurona merozoites, consistent with the size predicted for SnMIC10. In vitro secretion assays demonstrated that this protein is secreted by extracellular merozoites in a temperature-dependent manner. Indirect immunofluorescence analysis of SnMIC10 showed a polar labelling pattern, which is consistent with the apical position of the micronemes, and immunoelectron microscopy provided definitive localisation of the protein to these secretory organelles. Further analysis of SnMIC10 in intracellular parasites revealed that expression of this protein is temporally regulated during endopolygeny, supporting the view that micronemes are only needed during host cell invasion. Collectively, the data indicate that SnMIC10 is a microneme protein that is part of the excreted/secreted antigen fraction of S. neurona. Identification and characterisation of additional S. neurona microneme antigens and comparisons to orthologues in other Apicomplexa could provide further insight into the

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.

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

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

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Wendte, Jered M; Miller, Melissa A; Lambourn, Dyanna M; Magargal, Spencer L; Jessup, David A; Grigg, Michael E

2010-12-23

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 devastating disease

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

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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.

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

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Ribeiro, Manoel Junqueira Maciel; Rosa, Marina Helena Figueredo; Bruhn, Fábio Raphael Pascoti; Garcia, Adriana de Mello; Rocha, Christiane Maria Barcellos Magalhães da; Guimarães, Antônio Marcos

2016-06-07

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.

Purine salvage in the apicomplexan Sarcocystis neurona, and generation of hypoxanthine-xanthine-guanine phosphoribosyltransferase-deficient clones for positive-negative selection of transgenic parasites.

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Dangoudoubiyam, Sriveny; Zhang, Zijing; Howe, Daniel K

2014-09-01

Sarcocystis neurona is an apicomplexan parasite that causes severe neurological disease in horses and marine mammals. The Apicomplexa are all obligate intracellular parasites that lack purine biosynthesis pathways and rely on the host cell for their purine requirements. Hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) and adenosine kinase (AK) are key enzymes that function in two complementary purine salvage pathways in apicomplexans. Bioinformatic searches of the S. neurona genome revealed genes encoding HXGPRT, AK and all of the major purine salvage enzymes except purine nucleoside phosphorylase. Wild-type S. neurona were able to grow in the presence of mycophenolic acid (MPA) but were inhibited by 6-thioxanthine (6-TX), suggesting that the pathways involving either HXGPRT or AK are functional in this parasite. Prior work with Toxoplasma gondii demonstrated the utility of HXGPRT as a positive-negative selection marker. To enable the use of HXGPRT in S. neurona, the SnHXGPRT gene sequence was determined and a gene-targeting plasmid was transfected into S. neurona. SnHXGPRT-deficient mutants were selected with 6-TX, and single-cell clones were obtained. These Sn∆HXG parasites were susceptible to MPA and could be complemented using the heterologous T. gondii HXGPRT gene. In summary, S. neurona possesses both purine salvage pathways described in apicomplexans, thus allowing the use of HXGPRT as a positive-negative drug selection marker in this parasite.

Sarcocystis neurona infection in gamma interferon gene knockout (KO) mice: comparative infectivity of sporocysts in two strains of KO mice, effect of trypsin digestion on merozoite viability, and infectivity of bradyzoites to KO mice and cell culture.

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Dubey, J P; Sundar, N; Kwok, O C H; Saville, W J A

2013-09-01

The protozoan Sarcocystis neurona is the primary cause of Equine Protozoal Myeloencephalitis (EPM). EPM or EPM-like illness has been reported in horses, sea otters, and several other mammals. The gamma interferon gene knockout (KO) mouse is often used as a model to study biology and discovery of new therapies against S. neurona because it is difficult to induce clinical EPM in other hosts, including horses. In the present study, infectivity of three life cycle stages (merozoites, bradyzoites, sporozoites) to KO mice and cell culture was studied. Two strains of KO mice (C57-black, and BALB/c-derived, referred here as black or white) were inoculated orally graded doses of S. neurona sporocysts; 12 sporocysts were infective to both strains of mice and all infected mice died or became ill within 70 days post-inoculation. Although there was no difference in infectivity of sporocysts to the two strains of KO mice, the disease was more severe in black mice. S. neurona bradyzoites were not infectious to KO mice and cell culture. S. neurona merozoites survived 120 min incubation in 0.25% trypsin, indicating that trypsin digestion can be used to recover S. neurona from tissues of acutely infected animals. Published by Elsevier B.V.

Diagnosis and treatment of Sarcocystis neurona-induced myositis in a free-ranging California sea lion.

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Carlson-Bremer, Daphne P; Gulland, Frances M D; Johnson, Christine K; Colegrove, Kathleen M; Van Bonn, William G

2012-02-01

An underweight, lethargic adult female California sea lion (Zalophus californianus) became stranded along the California shore and was captured and transported to a rehabilitation hospital for assessment and care. Initial physical assessment revealed the sea lion was lethargic and in poor body condition. Active myositis was diagnosed on the basis of concurrent elevations in activities of alanine aminotransferase and creatine kinase detected during serum biochemical analysis. Infection with Sarcocystis neurona was diagnosed after serologic titers increased 4-fold over a 3-week period. Diagnosis was confirmed on the basis of histopathologic findings, positive results on immunohistochemical staining, and results of quantitative PCR assay on biopsy specimens obtained from the diaphragm and muscles of the dorsal cervical region. Anticoccidial treatment was instituted with ponazuril (10 mg/kg [4.5 mg/lb], PO, q 24 h) and continued for 28 days. Prednisone (0.2 mg/kg [0.09 mg/lb], PO, q 12 h) was administered for 2 days and then every 24 hours for 5 days to treat associated inflammation. At the end of treatment, the sea lion was clinically normal, alanine aminotransferase and creatine kinase values were within reference limits, and antibody titers against S neurona had decreased 6-fold. The sea lion was released approximately 3 months after becoming stranded. S neurona-induced myositis was diagnosed in a free-ranging California sea lion. On the basis of the successful treatment and release of this sea lion, anticoccidial treatment should be considered for marine mammals in which protozoal disease is diagnosed.

Sporocyst size of isolates of Sarcocystis shed by the Virginia opossum (Didelphis virginiana).

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Cheadle, M A; Dame, J B; Greiner, E C

2001-02-26

The Virginia opossum (Didelphis virginiana) is a definitive host for multiple Sarcocystis species including Sarcocystis neurona, one of the causative agents of equine protozoal myeloencephalitis (EPM), a severe, neuromuscular disease of horses. Size and morphologic characteristics of isolates of Sarcocystis shed by the opossum were examined to determine if differences were useful in discriminating between the isolates and/or species. Collections of sporocysts from 17 opossums were molecularly characterized and measured using an ocular micrometer. The mean sporocyst size of isolates of S. neurona was 10.7 microm x 7.0 microm, Sarcocystis falcatula 11.0 microm x 7.1 microm, Sarcocystis speeri 12.2 microm x 8.8 microm, 1085-like isolate 10.9 microm x 6.8 microm, and 3344-like isolate 19.4 microm x 10.5 microm. The length and width of S. speeri were statistically different (p < 0.05) from the sporocysts of other types. The length of S. neurona and S. falcatula sporocysts were statistically different (p < 0.05) from each other and the width of S. falcatula and 1085 differed (p < 0.05). The fifth sporocyst type (3344) was observed, but due to pronounced morphological characteristics, statistical analysis was not performed. There was no consistent difference between the taxa based on internal structure of the sporocyst.

Effects of blood contamination of cerebrospinal fluid on results of indirect fluorescent antibody tests for detection of antibodies against Sarcocystis neurona and Neospora hughesi.

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Finno, Carrie J; Packham, Andrea E; David Wilson, W; Gardner, Ian A; Conrad, Patricia A; Pusterla, Nicola

2007-05-01

The purpose of this study was to determine the effect of blood contamination of cerebrospinal fluid (CSF) on the results of indirect fluorescent antibody tests (IFATs) for Sarcocystis neurona and Neospora hughesi. The in vitro study used antibody-negative CSF collected from non-neurologic horses immediately after euthanasia and blood samples from 40 healthy horses that had a range of IFAT antibody titers against S. neurona and N. hughesi. Serial dilutions of whole blood were made in seronegative CSF to generate blood-contaminated CSF with red blood cell (RBC) concentrations ranging from 10 to 100,000 RBCs/microl. The blood-contaminated CSF samples were then tested for antibodies against both pathogens using IFAT. Blood contamination of CSF had no detectable effect on IFAT results for S. neurona or N. hughesi at any serologic titer when the RBC concentration in CSF was or=5) for S. neurona and N. hughesi were detected only when the corresponding serum titers were >or=160 and >or=80, respectively. The IFAT performed on CSF is reliable for testing horses for equine protozoal myeloencephalitis caused by S. neurona or N. hughesi, even when blood contamination causes the RBC concentration in CSF to be up to 10,000 RBCs/microl.

Sarcocystis neurona merozoites express a family of immunogenic surface antigens that are orthologues of the Toxoplasma gondii surface antigens (SAGs) and SAG-related sequences.

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Howe, Daniel K; Gaji, Rajshekhar Y; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

2005-02-01

Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s).

Sarcocystis neurona Merozoites Express a Family of Immunogenic Surface Antigens That Are Orthologues of the Toxoplasma gondii Surface Antigens (SAGs) and SAG-Related Sequences†

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Howe, Daniel K.; Gaji, Rajshekhar Y.; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

2005-01-01

Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s). PMID:15664946

Prevalence of and risk factors associated with the presence of Sarcocystis neurona sporocysts in opossum (Didelphis virginiana) from Michigan: a retrospective study.

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Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

2004-11-10

From April 1996 to December 2002 the prevalence of Sarcocystis neurona sporocysts in North American opossum (Didelphis virginiana) in Southern Michigan was estimated. Sporocysts of S. neurona were found in intestinal scrapings from 31 (15%) of 206 examined opossum. The frequency of infection was higher in adult animals (26/206; 12.6%) and females (19/206; 9.2%) than in juveniles (5/206; 2.4%) and males (12/206; 5.8%). Also, prevalence of S. neurona sporocysts in opossums in relation to factors such as age, sex, season, body condition, presence of concomitant infection, and presence of young in the pouch of females was studied in detail over the course of the year, 2002. Univariate analyses identified the following factors as being associated with the presence of S. neurona sporocysts in opossums: (i) for age, adult (odd ratio [OR] = 2.074, P = 0.0005); (ii) for sex, female (OR = 7.016, P = 0.0119); (iii) for season, summer (OR = 7.917, P = 0.0032) and spring (OR = 4.071, P = 0.1063); (iv) for body condition, poor (OR = 3.50, P = 0.1200) and good (OR = 1.167, P = 0.8637); (v) for the presence of concomitant infection (OR = 23.056, P = 0001), and (vi) for the presence of young in the pouch of females (OR = 40.083, P = 0.0001). Multivariate logistic-regression analyses selected the following factors as being significantly associated with presence of S. neurona sporocysts in opossums: (i) for the presence of concomitant infection (OR = 8.722, P = 0.0160) and (ii) for the presence of young in the pouch of females (OR = 31.915, P = 0.0065). The prevalence of S. neurona sporocysts in D. virginiana suggests that this opossum may constitute an ample reservoir of infection to other animals in the northern United States.

The heptanucleotide motif GAGACGC is a key component of a cis-acting promoter element that is critical for SnSAG1 expression in Sarcocystis neurona.

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Gaji, Rajshekhar Y; Howe, Daniel K

2009-07-01

The apicomplexan parasite Sarcocystis neurona undergoes a complex process of intracellular development, during which many genes are temporally regulated. The described study was undertaken to begin identifying the basic promoter elements that control gene expression in S. neurona. Sequence analysis of the 5'-flanking region of five S. neurona genes revealed a conserved heptanucleotide motif GAGACGC that is similar to the WGAGACG motif described upstream of multiple genes in Toxoplasma gondii. The promoter region for the major surface antigen gene SnSAG1, which contains three heptanucleotide motifs within 135 bases of the transcription start site, was dissected by functional analysis using a dual luciferase reporter assay. These analyses revealed that a minimal promoter fragment containing all three motifs was sufficient to drive reporter molecule expression, with the presence and orientation of the 5'-most heptanucleotide motif being absolutely critical for promoter function. Further studies should help to identify additional sequence elements important for promoter function and for controlling gene expression during intracellular development by this apicomplexan pathogen.

The SnSAG merozoite surface antigens of Sarcocystis neurona are expressed differentially during the bradyzoite and sporozoite life cycle stages.

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Gautam, A; Dubey, J P; Saville, W J; Howe, D K

2011-12-29

Sarcocystis neurona is a two-host coccidian parasite whose complex life cycle progresses through multiple developmental stages differing at morphological and molecular levels. The S. neurona merozoite surface is covered by multiple, related glycosylphosphatidylinositol-linked proteins, which are orthologous to the surface antigen (SAG)/SAG1-related sequence (SRS) gene family of Toxoplasma gondii. Expression of the SAG/SRS proteins in T. gondii and another related parasite Neospora caninum is life-cycle stage specific and seems necessary for parasite transmission and persistence of infection. In the present study, the expression of S. neurona merozoite surface antigens (SnSAGs) was evaluated in the sporozoite and bradyzoite stages. Western blot analysis was used to compare SnSAG expression in merozoites versus sporozoites, while immunocytochemistry was performed to examine expression of the SnSAGs in merozoites versus bradyzoites. These analyses revealed that SnSAG2, SnSAG3 and SnSAG4 are expressed in sporozoites, while SnSAG5 was appeared to be downregulated in this life cycle stage. In S. neurona bradyzoites, it was found that SnSAG2, SnSAG3, SnSAG4 and SnSAG5 were either absent or expression was greatly reduced. As shown for T. gondii, stage-specific expression of the SnSAGs may be important for the parasite to progress through its developmental stages and complete its life cycle successfully. Thus, it is possible that the SAG switching mechanism by these parasites could be exploited as a point of intervention. As well, the alterations in surface antigen expression during different life cycle stages may need to be considered when designing prospective approaches for protective vaccination. Copyright © 2011 Elsevier B.V. All rights reserved.

Molecular characterization and development of Sarcocystis speeri sarcocysts in gamma interferon gene knockout mice.

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Dubey, J P; Verma, S K; Dunams, D; Calero-Bernal, R; Rosenthal, B M

2015-11-01

The North American opossum (Didelphis virginiana) is the definitive host for at least three named species of Sarcocystis: Sarcocystis falcatula, Sarcocystis neurona and Sarcocystis speeri. The South American opossums (Didelphis albiventris, Didelphis marsupialis and Didelphis aurita) are definitive hosts for S. falcatula and S. lindsayi. The sporocysts of these Sarcocystis species are similar morphologically. They are also not easily distinguished genetically because of the difficulties of DNA extraction from sporocysts and availability of distinguishing genetic markers. Some of these species can be distinguished by bioassay; S. neurona and S. speeri are infective to gamma interferon gene knockout (KO) mice, but not to budgerigars (Melopsittacus undulatus); whereas S. falcatula and S. lindsayi are infective to budgerigars but not to KO mice. The natural intermediate host of S. speeri is unknown. In the present study, development of sarcocysts of S. speeri in the KO mice is described. Sarcocysts were first seen at 12 days post-inoculation (p.i.), and they became macroscopic (up to 4 mm long) by 25 days p.i. The structure of the sarcocyst wall did not change from the time bradyzoites had formed at 50-220 days p.i. Sarcocysts contained unique villar protrusions, 'type 38'. The polymerase chain reaction amplifications and sequences analysis of three nuclear loci (18S rRNA, 28S rRNA and ITS1) and two mitochondrial loci (cox1 and cytb) of S. speeri isolate from an Argentinean opossum (D. albiventris) confirmed its membership among species of Sarcocystis and indicated an especially close relationship to another parasite in this genus that employs opossums as its definitive host, S. neurona. These results should be useful in finding natural intermediate host of S. speeri.

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

Prevalence of antibodies to Trypanosoma cruzi, Leishmania infantum, Encephalitozoon cuniculi, Sarcocystis neurona, and Neospora caninum in Capybara, Hydrochoerus hydrochaeris, from São Paulo State, Brazil.

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Valadas, Samantha; Gennari, Solange Maria; Yai, Lucia Eiko Oishi; Rosypal, Alexa C; Lindsay, David S

2010-06-01

Little is known about the importance of capybara, Hydrochoerus hydrochaeris, as reservoirs for parasites of zoonotic or veterinary importance. Sera from 63 capybaras, from 6 counties in the state of São Paulo, Brazil, were examined for antibodies to Trypanosoma cruzi, Leishmania infantum, Encephalitozoon cuniculi, Sarcocystis neurona, and Neospora caninum using an indirect immunofluorescent antibody test. Five (8%) of the 63 capybaras had antibodies to T. cruzi epimastigotes. None of the samples from capybara reacted positively with L. infantum promastigotes or with spores of E. cuniculi . Two (3%) of the serum samples were positive for antibodies to S. neurona merozoites, and 2 (3%) of the serum samples were positive for antibodies to N. caninum tachyzoites. A serum sample from 1 capybara was positive for antibodies to both T. cruzi and N. caninum. None of the remaining 62 samples reacted with more than 1 parasite.

MANAGEMENT OF ACUTE RENAL FAILURE WITH DELAYED HYPERCALCEMIA SECONDARY TO SARCOCYSTIS NEURONA-INDUCED MYOSITIS AND RHABDOMYOLYSIS IN A CALIFORNIA SEA LION (ZALOPHUS CALIFORNIANUS).

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Alexander, Amy B; Hanley, Christopher S; Duncan, Mary C; Ulmer, Kyle; Padilla, Luis R

2015-09-01

A 3-yr-old captive-born California sea lion (Zalophus californianus) developed Sarcocystis neurona-induced myositis and rhabdomyolysis that led to acute renal failure. The sea lion was successfully managed with fluid therapy, antiprotozoals, antibiotics, anti-inflammatories, antiemetics, gastroprotectants, and diuretics, but developed severe delayed hypercalcemia, a syndrome identified in humans after traumatic or exertion-induced rhabdomyolysis. Treatment with calcitonin was added to the management, and the individual recovered fully. The case emphasizes that animals with rhabdomyolysis-induced renal failure risk developing delayed hypercalcemia, which may be life threatening, and calcium levels should be closely monitored past the resolution of renal failure.

Characterization of Sarcocystis from four species of hawks from Georgia, USA.

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Yabsley, Michael J; Ellis, Angela E; Stallknecht, David E; Howerth, Elizabeth W

2009-02-01

During 2001 to 2004, 4 species of hawks (Buteo and Accipiter spp.) from Georgia were surveyed for Sarcocystis spp. infections by examining intestinal sections. In total, 159 of 238 (66.8%) hawks examined were infected with Sarcocystis spp. Samples from 10 birds were characterized by sequence analysis of a portion of the 18S rRNA gene (783 base pairs). Only 3 of the 10 sequences from the hawks were identical; the remainder differed by at least 1 nucleotide. Phylogenetic analysis failed to resolve the position of the hawk Sarcocystis species, but they were closely related several Sarcocystis species from raptors, rodents, and Sarcocystis neurona. The high genetic diversity of Sarcocystis suggests that more than 1 species infects these 4 hawk species; however, additional molecular or experimental work will be required to determine the speciation and diversity of parasites infecting these avian hosts. In addition to assisting with determining species richness of Sarcocystis in raptors, molecular analysis should be useful in the identification of potential intermediate hosts.

Experimental transmission of Sarcocystis speeri Dubey and Lindsay, 1999 from the South American opossum (Didelphis albiventris) to the North American opossum (Didelphis virginiana).

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Dubey, J P; Speer, C A; Bowman, D D; Horton, K M; Venturini, C; Venturini, L

2000-06-01

Sarcocystis speeri Dubey and Lindsay, 1999 from the South American opossum Didelphis albiventris was successfully transmitted to the North American opossum Didelphis virginiana. Sporocysts from a naturally infected D. albiventris from Argentina were fed to 2 gamma-interferon knockout (KO) mice. The mice were killed 64 and 71 days after sporocyst feeding (DAF). Muscles containing sarcocysts from the KO mouse killed 71 DAF were fed to a captive D. virginiana; this opossum shed sporocysts 11 days after ingesting sarcocysts. Sporocysts from D. virginiana were fed to 9 KO mice and 4 budgerigars (Melopsittacus undulatus). Schizonts, sarcocysts, or both of S. speeri were found in tissues of all 7 KO mice killed 29-85 DAF; 2 mice died 39 and 48 DAF were not necropsied. Sarcocystis stages were not found in tissues of the 4 budgerigars fed S. speeri sporocysts and killed 35 DAE These results indicate that S. speeri is distinct from Sarcocystis falcatula and Sarcocystis neurona, and that S. speeri is present in both D. albiventris and D. virginiana.

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

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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.

Improved detection of equine antibodies against Sarcocystis neurona using polyvalent ELISAs based on the parasite SnSAG surface antigens.

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Yeargan, Michelle R; Howe, Daniel K

2011-02-28

Equine protozoal myeloencephalitis (EPM) is a common neurologic disease of horses that is caused by the apicomplexan pathogen Sarcocystis neurona. To help improve serologic diagnosis of S. neurona infection, we have modified existing enzyme-linked immunosorbent assays (ELISAs) based on the immunogenic parasite surface antigens SnSAG2, SnSAG3, and SnSAG4 to make the assays polyvalent, thereby circumventing difficulties associated with parasite antigenic variants and diversity in equine immune responses. Two approaches were utilized to achieve polyvalence: (1) mixtures of the individual recombinant SnSAGs (rSnSAGs) were included in single ELISAs; (2) a collection of unique SnSAG chimeras that fused protein domains from different SnSAG surface antigens into a single recombinant protein were generated for use in the ELISAs. These new assays were assessed using a defined sample set of equine sera and cerebrospinal fluids (CSFs) that had been characterized by Western blot and/or were from confirmed EPM horses. While all of the polyvalent ELISAs performed relatively well, the highest sensitivity and specificity (100%/100%) were achieved with assays containing the rSnSAG4/2 chimera (Domain 1 of SnSAG4 fused to SnSAG2) or using a mixture of rSnSAG3 and rSnSAG4. The rSnSAG4 antigen alone and the rSnSAG4/3 chimera (Domain 1 of SnSAG4 fused to Domain 2 of SnSAG3) exhibited the next best accuracy at 95.2% sensitivity and 100% specificity. Binding ratios and percent positivity (PP) ratios, determined by comparing the mean values for positive versus negative samples, showed that the most advantageous signal to noise ratios were provided by rSnSAG4 and the rSnSAG4/3 chimera. Collectively, our results imply that a polyvalent ELISA based on SnSAG4 and SnSAG3, whether as a cocktail of two proteins or as a single chimeric protein, can give optimal results in serologic testing of serum or CSF for the presence of antibodies against S. neurona. The use of polyvalent SnSAG ELISAs will

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.

Sarcocystis caninum and Sarcocystis svanai n. spp. (Apicomplexa: Sarcocystidae) Associated with Severe Myositis and Hepatitis in the Domestic Dog (Canis familiaris)

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Dubey, J. P.; Sykes, J. E.; Shelton, G. D.; Sharp, N.; Verma, S. K.; Calero-Bernal, R.; Viviano, J.; Sundar, N.; Khan, A.; Grigg, M. E.

2014-01-01

There are several reports of Sarcocystis sarcocysts in muscles of dogs but these species have not been named. Additionally, there are 2 reports of Sarcocystis neurona in dogs. Here, we propose 2 new names, Sarcocystis caninum, and Sarcocystis svanai for sarcocysts associated with clinical muscular sarcocystosis in 4 domestic dogs (Canis familiaris), 1 each from Montana and Colorado in the USA, and 2 from British Columbia, Canada. Only the sarcocyst stage was identified. Most of the sarcocysts identified were S. caninum. Sarcocysts were studied using light microscopy, transmission electron microscopy, and PCR. Based on collective results 2 new species, Sarcocystis caninum and Sarcocystis svanai were designated. Sarcocystis caninum and Sarcocystis svanai were structurally distinct. Sarcocystis caninum sarcocysts were up to 1.2 mm long and up to 75 μm wide. By light microscopy, the sarcocyst wall was relatively thin and smooth. By transmission electron microscopy (TEM), the sarcocyst wall “type 9”, 1–2 μm thick, and contained villar protrusions that lacked microtubules. Bradyzoites in sections were 7–9 μm long. Sarcocysts of S. svanai were few and were identified by TEM. Sarcocystis svanai sarcocysts were “type 1”, thin walled (< 0.5 μm), and the wall lacked villar protrusions but had tiny blebs that did not invaginate. DNA was extracted either from infected frozen muscle biopsies or formalin-fixed paraffin-embedded sections. Dogs were either singly infected with S. caninum or multiply co-infected with S. caninum and S. svanai (the result of a mixed infection) based on multi-locus DNA sequencing and morphology. BLASTn analysis established that the sarcocysts identified in these dogs were similar to, but not identical to S. canis or S. arctosi, parasites found to infect polar bears (Ursus maritimus) or brown bears (Ursus arctosi), respectively. However, the S. caninum sequence showed 100% identify over the 18S rRNA region sequenced to that of S. arctica

Modest genetic differentiation among North American populations of Sarcocystic neurona may reflect expansion in its geographic range

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Sundar, N.; Asmundsson, I.M.; Thomas, N.J.; Samuel, M.D.; Dubey, J.P.; Rosenthal, B.M.

2008-01-01

Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozoon cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossums, Didelphis virginiana, from southern Louisiana.

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Houk, Alice E; Goodwin, David G; Zajac, Anne M; Barr, Stephen C; Dubey, J P; Lindsay, David S

2010-12-01

We examined the prevalence of antibodies to zoonotic protozoan parasites ( Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoans of veterinary importance ( Neospora caninum, Sarcocystis neurona, and Besnoitia darlingi) in a population of North American opossums ( Didelphis virginiana) from Louisiana. Samples from 30 opossums were collected as part of a survey for T. cruzi in Louisiana. Frozen sera from these 30 opossums were examined using an indirect immunofluorescent antibody test (IFAT) against in vitro-produced antigenic stages of these protozoans. Additionally, 24 of the 30 samples were examined using hemoculture, and all 30 were examined in the modified direct agglutination test (MAT) for antibodies to To. gondii. The prevalences of reactive IFAT samples were as follows: 60% for T. cruzi, 27% for To. gondii, 23% for E. cuniculi, 17% for S. neurona, 47% for B. darlingi, and 0% for N. caninum. Hemoculture revealed that 16 (67%) of 24 samples were positive for T. cruzi, compared to 18 of 30 (60%) by IFAT. The sensitivity and specificity for the IFAT compared to hemoculture was 100% for each. The modified direct agglutination test revealed that 9 (30%) of the 30 samples from opossums had antibodies to To. gondii , compared to 8 (27%) using the IFAT. The sensitivity and specificity of the IFAT compared to the MAT was 100% and 72%, respectively.

Prevalence of Sarcocystis neurona sporocysts in opossums (Didelphis virginiana) from rural Mississippi.

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Dubey, J P; Black, S S; Rickard, L G; Rosenthal, B M; Lindsay, D S; Shen, S K; Kwok, O C; Hurst, G; Rashmir-Raven, A

2001-02-26

Sarcocystis species sporocysts were found in intestinal scrapings from 24 of 72 opossums (Didelphis virginiana) from rural Mississippi. The number of sporocysts in each opossum varied from a few ( virginiana suggests that this opossum constitutes an ample reservoir of infection in the southern United States.

Journal of Parasitology

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Dubey, J. P.; Lindsay, D. S.; Kwok, O. C. H.; Shen, S. K.

2001-01-01

The dose-related infectivity of Sarcocystis neurona sporocysts and merozoites. of 2 recent isolates of S. neurona was compared in gamma interferon knockout (KO) mice. Tenfold dilutions of sporocysts or merozoites were bioassayed in mice, cell culture, or both. All 8 mice, fed 1,000 sporocysts, developed neurological signs with demonstrable S. neurona in their tissues. Of 24 mice fed low numbers of sporocysts. (100, 10, 1), 18 became ill by 4 wk postinoculation, and S. neurona was demonstrated...

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

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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

Experimental induction of equine protozoal myeloencephalitis in horses using Sarcocystis sp. sporocysts from the opossum (Didelphis virginiana).

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Fenger, C K; Granstrom, D E; Gajadhar, A A; Williams, N M; McCrillis, S A; Stamper, S; Langemeier, J L; Dubey, J P

1997-02-01

Sarcocystis sp. sporocysts isolated from eight feral opossums (Didelphis virginiana) were pooled and fed to 18 commercially reared budgerigars (Melopsittacus undulatus), 14 wild-caught sparrows (Passer domesticus), one wild-caught slate-colored Junco (Junco hyemalis) and five weanling horses (Equus caballus). All budgerigars died within 5 weeks post inoculation (wpi). Histologic examination revealed meronts within the pulmonary epithelia and typical Sarcocystis falcatula sarcocysts developing in the leg muscles. Sparrows were euthanized 13 and 17 wpi and their carcasses were fed to four laboratory raised opossums. Sporocysts were detected in the feces of two opossums on 15 days post inoculation (dpi) and in a third opossum on 40 dpi. Fecal samples from the fourth opossum remained negative; however, sporocysts were found in intestinal digests from all four opossums. Sporocysts were not found in feces or intestinal digest of an additional opossum that was fed three uninoculated sparrows. Five foals were fed sporocysts (Foals 2, 3, 4, 5, and 7) and two foals were maintained as uninoculated controls (Foals 1 and 6). Sporocysts from two additional feral opossums also were fed to foals. Foal 5 was given 0.05 mg kg-1 dexamethasone sodium phosphate daily beginning 2 days before inoculation for a total of 2 weeks. Horse sera were tested three times per week, and cerebrospinal fluid (CSF) samples were tested biweekly for anti-Sarcocystis neurona antibodies by Western blot analysis. No foals had any S. neurona-specific antibodies by Western blot analysis prior to sporocysts ingestion. Seroconversion occurred in Foals 3, 5, and 7 by 24 dpi, followed by positive CSF tests on 28 dpi. Foals 2 and 4 seroconverted by 40 dpi. Cerebrospinal fluid from Foal 2 tested positive by 42 dpi, but Foal 4 remained seronegative throughout the study. Sera and CSF from control Foals 1 and 6 remained seronegative. All foals with positive CSF developed neurologic clinical signs. Neurologic disease

Mieloencefalite protozoária eqüina (Relato de caso.

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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,

Accurate antemortem diagnosis of equine protozoal myeloencephalitis (EPM) based on detecting intrathecal antibodies against Sarcocystis neurona using the SnSAG2 and SnSAG4/3 ELISAs.

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Reed, S M; Howe, D K; Morrow, J K; Graves, A; Yeargan, M R; Johnson, A L; MacKay, R J; Furr, M; Saville, W J A; Williams, N M

2013-01-01

Recent work demonstrated the value of antigen-specific antibody indices (AI and C-value) to detect intrathecal antibody production against Sarcocystis neurona for antemortem diagnosis of equine protozoal myeloencephalitis (EPM). The study was conducted to assess whether the antigen-specific antibody indices can be reduced to a simple serum : cerebrospinal fluid (CSF) titer ratio to achieve accurate EPM diagnosis. Paired serum and CSF samples from 128 horses diagnosed by postmortem examination. The sample set included 44 EPM cases, 35 cervical-vertebral malformation (CVM) cases, 39 neurologic cases other than EPM or CVM, and 10 non-neurologic cases. Antibodies against S. neurona were measured in serum and CSF pairs using the SnSAG2 and SnSAG4/3 (SnSAG2, 4/3) ELISAs, and the ratio of each respective serum titer to CSF titer was determined. Likelihood ratios and diagnostic sensitivity and specificity were calculated based on serum titers, CSF titers, and serum : CSF titer ratios. Excellent diagnostic sensitivity and specificity was obtained from the SnSAG2, 4/3 serum : CSF titer ratio. Sensitivity and specificity of 93.2 and 81.1%, respectively, were achieved using a ratio cutoff of ≤100, whereas sensitivity and specificity were 86.4 and 95.9%, respectively, if a more rigorous cutoff of ≤50 was used. Antibody titers in CSF also provided good diagnostic accuracy. Serum antibody titers alone yielded much lower sensitivity and specificity. The study confirms the value of detecting intrathecal antibody production for antemortem diagnosis of EPM, and they further show that the antigen-specific antibody indices can be reduced in practice to a simple serum : CSF titer ratio. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Accipiter hawks (Accipitridae) confirmed as definitive hosts of Sarcocystis turdusi, Sarcocystis cornixi and Sarcocystis sp. ex Phalacrocorax carbo.

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Mayr, Sylvia L; Maier, Kristina; Müller, Jana; Enderlein, Dirk; Gruber, Achim D; Lierz, Michael

2016-08-01

Sarcocystis is a large genus of protozoan parasites with complex heteroxenous life cycles. For many species, either the intermediate or the definitive host is still unknown. In this study, 116 Accipiter hawks (Eurasian sparrowhawks and northern goshawks) were investigated for the presence of Sarcocystis spp. in their intestinal tract or their faeces. To gain a wide distribution, samples were collected throughout Germany within 2 years. It was possible to detect Sarcocystis-like oocysts in 65 samples. Sequencing of the ITS region or species-specific PCR identified 33 samples as Sarcocystis turdusi/Sarcocystis sp. ex A. nisus (18), Sarcocystis calchasi (6), Sarcocystis columbae (3), Sarcocystis cornixi (3) and Sarcocystis sp. ex Phalacrocorax carbo (3). Besides the known infestation with S. columbae, S. sp. ex A. nisus and S. calchasi the Accipiter hawks were thereby confirmed as definitive host of S. turdusi, S. cornixi and S. sp. ex Phalacrocorax carbo for the first time.

Prevalence of agglutinating antibodies to Toxoplasma gondii and Sarcocystis neurona in beavers (Castor canadensis) from Massachusetts

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Jordan, C.N.; Kaur, T.; Koenen, K.; DeStefano, S.; Zajac, A.M.; Lindsay, D.S.

2005-01-01

The present study examined the seroprevalence of Toxoplasma gondii and Sarcocystls neurona in a population of beavers (Castor canadensis) from Massachusetts. Sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. Blood was collected onto filter paper and shipped to the Department of Biomedical Sciences, Virginia Tech, Blacksburg, Virginia, for parasite testing. The samples were tested at dilutions of 1:25, 1:50, and 1:100 against each parasite antigen by modified agglutination tests to determine whether antibodies to either parasite were present in the blood. Six of 62 samples (10%) were positive for T. gondii, with 2 samples having titers of 1:25 and 4 having titers of 1:50. Four of 62 samples (6%) were positive for S. neurona, with 2 samples having titers of 1:25 and 2 having titers of 1:50. ?? American Society of Pathologists 2005.

Unusual Necrotizing Encephalitis in Raccoons and Skunks Concurrently Infected With Canine Distemper Virus and Sarcocystis sp.

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Kubiski, S V; Sisó, S; Church, M E; Cartoceti, A N; Barr, B; Pesavento, P A

2016-05-01

Canine distemper virus commonly infects free-ranging, terrestrial mesopredators throughout the United States. Due to the immunosuppressive effects of the virus, concurrent opportunistic infections are also common. Among these, secondary systemic protozoal infections have been described in a number of species. We report an unusual presentation of necrotizing encephalitis associated withSarcocystissp in four raccoons and one skunk concurrently infected with canine distemper virus. Lesions were characterized by variably sized necrotizing cavitations composed of abundant mineral admixed with inflammatory cells and protozoa.Sarcocystissp was confirmed via immunohistochemistry using a monoclonal antibody toSarcocystis neurona The pathologic changes are similar to lesions in human AIDS patients infected withToxoplasma gondii. © The Author(s) 2015.

J Vet Med

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Lewis, SR; Ellison, SP; Dascanio, JJ; Lindsay, DS; Gogal, RM; Werre, SR; Surendran, N; Breen, ME; Heid, BM; Andrews, FM; Buechner-Maxwell, VA; Witonsky, SG

2014-01-01

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. Al...

Diversity of Sarcocystis spp shed by opossums in Brazil inferred with phylogenetic analysis of DNA coding ITS1, cytochrome B, and surface antigens.

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Valadas, Samantha Y O B; da Silva, Juliana I G; Lopes, Estela Gallucci; Keid, Lara B; Zwarg, Ticiana; de Oliveira, Alice S; Sanches, Thaís C; Joppert, Adriana M; Pena, Hilda F J; Oliveira, Tricia M F S; Ferreira, Helena L; Soares, Rodrigo M

2016-05-01

Although few species of Sarcocystis are known to use marsupials of the genus Didelphis as definitive host, an extensive diversity of alleles of surface antigen genes (sag2, sag3, and sag4) has been described in samples of didelphid opossums in Brazil. In this work, we studied 25 samples of Sarcocystis derived from gastrointestinal tract of opossums of the genus Didelphis by accessing the variability of sag2, sag3, sag4, gene encoding cytochrome b (cytB) and first internal transcribed spacer (ITS1). Reference samples of Sarcocystis neurona (SN138) and Sarcocystis falcatula (SF1) maintained in cell culture were also analyzed. We found four allele variants of cytB, seven allele variants of ITS1, 10 allele variants of sag2, 13 allele variants of sag3, and 6 allele variants of sag4. None of the sporocyst-derived sequences obtained from Brazilian opossums revealed 100% identity to SN138 at cytB gene, nor to SN138 or SF1 at ITS1 locus. In addition, none of the sag alleles were found identical to either SF1 or SN138 homologous sequences, and a high number of new sag allele types were found other than those previously described in Brazil. Out of ten sag2 alleles, four are novel, while eight out of 13 sag3 alleles are novel and one out of six sag4 alleles is novel. Further studies are needed to clarify if such a vast repertoire of allele variants of Sarcocystis is the consequence of re-assortments driven by sexual exchange, in order to form individuals with highly diverse characteristics, such as pathogenicity, host spectrum, among others or if it only represents allele variants of different species with different biological traits. Copyright © 2016 Elsevier Inc. All rights reserved.

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

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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).

Clinical Toxoplasma gondii, Hammondia heydorni, and Sarcocystis spp. infections in dogs.

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Dubey, J P; Ross, A D; Fritz, D

2003-12-01

Concurrent infections with coccidians Toxoplasma gondii, Sarcocystis spp., and a Hammondia heydorni-like parasite were identified in tissues of three littermate pups on a Kelpie dog breeding farm in Australia. In total, 20 pups in four litters had died following vaccination with an attenuated distemper virus vaccine. Toxoplasma gondii tachyzoites were identified immunohistochemically in tissues of two dogs. Sarcocystis sp. sporocysts were seen in the intestinal lamina propria of two dogs. Asexual and sexual stages of H. heydorni-like parasite were found in enterocytes of the small intestine of two dogs. Ultrastructural development of schizonts and gamonts of this parasite is described. None of the protozoa in these dogs reacted with antibodies to Neospora caninum. Feeding of uncooked tissue of sheep was considered to be the likely source of infection for these coccidians in dogs.

Inhibitory Activities of Epidermal Growth Factor Receptor Tyrosine Kinase-Targeted Dihydroxyisoflavone and Trihydroxydeoxybenzoin Derivatives on Sarcocystis neurona, Neospora caninum, and Cryptosporidium parvum Development

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Gargala, G.; Baishanbo, A.; Favennec, L.; François, A.; Ballet, J. J.; Rossignol, J.-F.

2005-01-01

Several gene sequences of parasitic protozoa belonging to protein kinase gene families and epidermal growth factor (EGF)-like peptides, which act via binding to receptor tyrosine kinases of the EGF receptor (EGFR) family, appear to mediate host-protozoan interactions. As a clue to EGFR protein tyrosine kinase (PTK) mediation and a novel approach for identifying anticoccidial agents, activities against Sarcocystis neurona, Neospora caninum, and Cryptosporidium parvum grown in BM and HCT-8 cell cultures of 52 EGFR PTK inhibitor isoflavone analogs (dihydroxyisoflavone and trihydroxydeoxybenzoine derivatives) were investigated. Their cytotoxicities against host cells were either absent, mild, or moderate by a nitroblue tetrazolium test. At concentrations ranging from 5 to 10 μg/ml, 20 and 5 analogs, including RM-6427 and RM-6428, exhibited an in vitro inhibitory effect of ≥95% against at least one parasite or against all three, respectively. In immunosuppressed Cryptosporidium parvum-infected Mongolian gerbils orally treated with either 200 or 400 mg of agent RM-6427/kg of body weight/day for 8 days, fecal microscopic oocyst shedding was abolished in 6/10 animals (P of 0.05, respectively). After RM-6427 therapy (200 mg/kg/day for 8 days), the reduction in the ratio of animals with intracellular parasites was nearly significant in ileum (P = 0.067) and more marked in the biliary tract (P < 0.0013) than after nitazoxanide or paromomycin treatment (0.05 < P < 0.004). RM-6428 treatment at a regimen of 400 mg/kg/day for 12 days inhibited oocyst shedding, measured using flow cytometry from day 4 (P < 0.05) to day 12 (P < 0.02) of therapy, when 2/15 animals had no shedding (P < 0.0001) and 11/15 were free of gut and/or biliary tract parasites (P < 0.01). No mucosal alteration was microscopically observed for treated or untreated infected gerbils. To our knowledge, this report is the first to suggest that the isoflavone class of agents has the potential for

Molecular identification of Sarcocystis halieti n. sp., Sarcocystis lari and Sarcocystis truncata in the intestine of a white-tailed sea eagle (Haliaeetus albicilla in Norway

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Bjørn Gjerde

2018-04-01

Full Text Available An emaciated white-tailed sea eagle (Haliaeetus albicilla from Western Norway was found and nursed briefly before it died. The necropsy revealed that the principal cause of death was an inflammation and occlusion of the bile ducts. A secondary finding was the presence in the intestinal mucosa of numerous sporulated Sarcocystis oocysts measuring 21.8–22.8 × 16.0–17.0 μm. The aim of this study was to identify these oocysts to species level using molecular methods. Genomic DNA was extracted from 10 mucosal scrapings containing oocysts and subjected to PCR amplification and sequencing of four DNA regions: the 18S and 28S rRNA genes, the ITS1 region and the cox1 gene. DNA of three previously known Sarcocystis spp. was identified, but only two of these, Sarcocystis halieti n. sp. and Sarcocystis lari, both employing sea birds as intermediate hosts, were considered to have used the sea eagle as a definitive host and to have formed oocysts in its intestine. The third species found, Sarcocystis truncata, employs red deer as intermediate hosts and seems to use felids as definitive hosts based on its phylogenetic position and prevalence. The sea eagle had probably recently ingested portions of one of the latter hosts (red deer or cat/lynx containing stages (sarcocysts/oocysts and thus DNA of S. truncata. The species S. halieti and S. lari could only be unambiguously separated from their most closely related congeners on the basis of their ITS1 sequences. This is the first report of Sarcocystis oocysts in sea eagles and the first identification to species level of Sarcocystis oocysts in any type of eagle. The sea eagle also acted as intermediate host of an unidentified Sarcocystis spp. as evidenced by the finding of six thin-walled sarcocysts in a histological section of cardiac muscle. Keywords: Sarcocystis, Haliaeetus albicilla, Oocysts, ITS1, Cox1, Phylogeny

Journal of Parasitology

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Cheadle, M. A.; Lindsay, D. S.; Greiner, E. C.

2006-01-01

Serum was collected from laboratory-reared Virginia opossums (Didelphis virginiana) to determine whether experimentally infected opossums shedding Sarcocystis neurona sporocysts develop serum antibodies to S. neurona merozoite antigens. Three opossums were fed muscles from nine-banded armadillos (Dasypus novemcinctus), and 5 were fed muscles from striped skunks (Mephitis mephitis). Serum was also collected from 26 automobile-killed opossums to determine whether antibodies to S. neurona were p...

Neuronas espejo y el aprendizaje en anestesia

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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...

Sarcocystis caninum and Sarcocystis svanai n. spp. (Apicomplexa: Sarcocystidae) associated with severe myositis and hepatitis in the domestic dog (Canis familiaris)

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Sarcocystis species have a 2-host life cycle with carnivores as definitive hosts and herbivores as intermediate hosts. Occasionally dogs are definitive as well as intermediate hosts for Sarcocystis species. There are several reports of Sarcocystis sarcocysts in muscles of dogs but these species have...

Molecular evidence of Sarcocystis species in captive snakes in Japan.

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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.

Sarcocystis sinensis is the most prevalent thick-walled Sarcocystis species in beef on sale for consumers in Germany.

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Moré, G; Pantchev, A; Skuballa, J; Langenmayer, M C; Maksimov, P; Conraths, F J; Venturini, M C; Schares, G

2014-06-01

Bovines are intermediate hosts of Sarcocystis cruzi, Sarcocystis hirsuta, and Sarcocystis hominis, which use canids, felids, or primates as definitive hosts, respectively. Cattle represent also intermediate hosts of Sarcocystis sinensis, but the definitive hosts of this parasite are not yet known. Sarcocystosis in cattle is frequently asymptomatic. The infection is characterized by the presence of thin-walled (S. cruzi) or thick-walled muscle cysts or sarcocysts (S. hominis, S. sinensis, and S. hirsuta). Recent reports suggest high prevalence of the zoonotic S. hominis in beef in Europe. We therefore aimed at differentiating Sarcocystis spp. in beef offered to consumers in Germany using molecular and microscopical methods, focusing on those species producing thick-walled sarcocysts. A total of 257 beef samples were obtained from different butcheries and supermarkets in Germany and processed by conventional and multiplex real-time PCR. In addition, 130 of these samples were processed by light microscopy and in 24.6% thick-walled cysts were detected. Transmission electron microscopical analysis of six of these samples revealed an ultrastructural cyst wall pattern compatible with S. sinensis in five samples and with S. hominis in one sample. PCR-amplified 18S ribosomal DNA (rDNA) fragments of 28 individual thick-walled cysts were sequenced, and sequence identities of ≥98% with S. sinensis (n = 22), S. hominis (n = 5) and S. hirsuta (n = 1) were observed. Moreover, nine Sarcocystis sp. 18S rDNA full length gene sequences were obtained, five of S. sinensis, three of S. hominis, and one of S. hirsuta. Out of all samples (n = 257), 174 (67.7%) tested positive by conventional PCR and 179 (69.6%) by multiplex real-time PCR for Sarcocystis spp. Regarding individual species, 134 (52%), 95 (37%), 17 (6.6%), and 16 (6.2%) were positive for S. cruzi, S. sinensis, S. hirsuta, and S. hominis, respectively. In conclusion, S. sinensis is the most prevalent thick

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.

Sarcocystis in Biology of Foodborne Parasites CRC Press

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People can contract infections by consuming beef infected with Sarcocystis hominis or pork infected with Sarcocystis suihominis. Proper cooking can eliminate this foodborne risk of infection. Here, the biology of such parasites is thoroughly reviewed, focusing on the epidemiology, diagnosis, treat...

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

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Marion Wassermann

Full Text Available 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.

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.

ACOPLAMIENTO EXCITATORIO E INHIBITORIO DE NEURONAS PULSANTES ACOPLADAS

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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.

El sistema de neuronas espejo: evidencias fisiológicas e hipótesis funcionales

OpenAIRE

Yorio, Alberto A.

2010-01-01

En este trabajo se comentan algunas evidencias anatómicas y fisiológicas que presenta una red de neuronas con propiedades de integración sensoriomotoras, denominadas "neuronas espejo". Estas neuronas se caracterizan por codificar las acciones tanto realizadas por el propio individuo, como observadas; constituirían el sustrato neural de la comprensión del significado de las acciones de otros individuos. Se plantean además otras hipótesis que vinculan el sistema de neuronas espejo con la codifi...

First report of cerebellar abiotrophy in an Arabian foal from Argentina

African Journals Online (AJOL)

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.

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...

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

OpenAIRE

John Bautista; José R Navarro

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...

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

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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

Modelos de neuronas artificiales en software para su uso en preparaciones de electrofisiología

OpenAIRE

Cubillos Martínez, Jenniffer

2016-01-01

Este proyecto tiene por objetivo la implementación y validación online o en tiempo real de circuitos híbridos compuestos por neuronas vivas de sistemas biológicos y neuronas electrónicas implementadas en software. En estos circuitos híbridos las neuronas vivas y las neuronas artificiales interactúan bidireccionalmente a través de sinapsis artificiales. El desarrollo de estos circuitos híbridos es de gran interés en el contexto de la investigación en neurociencia ya que permiten...

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

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.

Molecular characterisation of Sarcocystis bovifelis, Sarcocystis bovini n. sp., Sarcocystis hirsuta and Sarcocystis cruzi from cattle (Bos taurus) and Sarcocystis sinensis from water buffaloes (Bubalus bubalis).

Science.gov (United States)

Gjerde, Bjørn

2016-04-01

About 200 individual sarcocysts were excised from 12 samples of cattle beef from five countries (Argentina, Brazil, Germany, New Zealand, Uruguay) and tentatively identified to species or cyst type on the basis of their size and shape and cyst wall morphology. Genomic DNA was extracted from 147 of these sarcocysts and used initially for PCR amplification and sequencing of the partial mitochondrial cytochrome c oxidase subunit I gene (cox1) in order to identify the sarcocysts to species and/or sequence type. In addition, seven Sarcocystis sinensis-like sarcocysts collected from the oesophagus of water buffaloes in Egypt were examined at cox1 for comparative purposes. Based on the results from the cox1 marker, selected sarcocyst isolates from both hosts were further characterised at one to three regions of the nuclear ribosomal (r) DNA unit, i.e. the complete 18S rRNA gene, the complete internal transcribed spacer 1 (ITS1) region and the partial 28S rRNA gene. This was done in order to compare the results with previous molecular identifications based on 18S rRNA gene sequences and to evaluate the utility of these regions for species delimitations and phylogenetic inferences. On the basis of sarcocyst morphology and molecular data, primarily the cox1 sequences, four Sarcocystis spp. were identified in the samples of cattle beef. Twenty-two microscopic sarcocysts (1 × 0.1 mm) with hair-like protrusions were assigned to Sarcocystis cruzi, 56 macroscopic sarcocysts (3-8 × 0.5 mm) with finger-like protrusions were assigned to Sarcocystis hirsuta and 45 and 24 microscopic sarcocysts (1-3 × 0.1-0.2 mm) with finger-like protrusions were assigned to Sarcocystis bovifelis and Sarcocystis bovini n. sp., respectively. Sarcocysts of S. cruzi were identified in samples of beef from Argentina and Uruguay; sarcocysts of S. hirsuta in samples from Argentina, Brazil, Germany and New Zealand; sarcocysts of S. bovifelis in samples from Argentina and Germany; and

Seroprevalence of Neospora spp. in horses from Central Province of ...

African Journals Online (AJOL)

HP

2013-02-27

Feb 27, 2013 ... sample size was quite small to draw any clinical conclusion when compared with previous studies. In veterinary medicine, ELISA techniques have been used to detect antibodies to coccidian parasites such as. Sarcocystis neurona, N. caninum and Toxoplasma gondii in livestock and other animals (Baszler ...

Electron microscope study of Sarcocystis sp

Science.gov (United States)

Zeve, V.H.; Price, D.L.; Herman, C.M.

1966-01-01

Sarcocystis sp. obtained from wild populations of grackles, Quiscalus quiscula (Linn.), were examined to clarify the effect of the parasite on the host. Electron micrographs are presented to show areas of muscle destruction adjacent to the parasite which appear to be mechanically produced by the parasite. The microtubules within the villus-like projections of the cyst suggest that their possible function is absorptive and/or conductive with regard to the production of a toxin or the conveyance of nutritive material to the developing cells. The proposed function of submembranous filaments and their relation to the conoid is discussed. Similarities in the ultrastructure to Toxoplasma and other protozoa tend to negate the relegation of Sarcocystis to the fungi and further emphasize its protozoan nature.

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

Co-infection of Sarcocystis sp. and Hadjelia truncata in fantail pigeons (Columba livia domestica

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M. Khordadmehr

2018-03-01

Full Text Available Hadjelia truncata belongs to the family Habronematidae which affects different groups of birds such as Columbiformes. A large number of Sarcocystis sp. may infect birds as intermediate hosts, but wild Columbiformes, include pigeons, are rarely affected. The present study describes mixed infection of two pigeon flocks with sarcocystosis and nematodiasis (H. truncata which had neurologic and gas-trointestinal clinical signs. The common clinical signs included progressive weight loss, pectoral muscle atrophy, white diarrhoea, depression, torticollis, paralysis, trembling, and 23.4% mortality. At necropsy, a large number of nematodes were detected in the gizzards and diagnosed as H. truncata in parasitological studies. For greater certainty, histopathological examination was conducted routinely. Different development stage of this nematode associated with severe inflammatory cells infiltration and necrosis were observed in tissue sections. Accidentally, the large number of Sarcocystis cysts was observed in tunica muscularis mucosa of gizzard associated with infiltration of inflammatory cells, hyaline degeneration and necrosis around degenerated cysts.

A Study of Sarcocystis Infection in Mincemeat Using Digestion Method in Ghazvin, Iran

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Jaber Davoudi

2017-03-01

Full Text Available Background & Aims of the Study: Sarcocystiosis is a zoonosis appeared in domestic animals caused by various species of Sarcocystis. This protozoan disease has worldwide distribution among human and many species of animals. Humans acquire infection by eating of raw and under cooked beef, pork or mincemeat containing schizonts of Sarcocystis hominis and S. suihominis. The aim of present study is to detect prevalence of the Sarcocystis spp. infection in mincemeat samples at Ghazvin province of Iran. Materials & Methods:  Three hundred mincemeat samples of 150 sheep and 150 cattle were collected from butchers (in spring 2013 in different areas of Ghazvin province, Iran. The statistical analysis was done by independence sample t test, using SPSS ver. 22.0.0 (Chicago, IL, USA. Results: the finding of this study showed that the highest prevalence of Sarcocystis infection rate was observed in cattle (92.8% and the lowest of that was evident in sheep (85.6%. The highest infection rates in both types of minced meat samples were in May (45 and 49 minced meat of sheep and cattle, respectively. Conclusions: The results revealed that Ghazvin province has the highest Sarcocystis infection rate. Regarding to the high prevalence of Sarcocystis contamination in this study, prevention of eating raw or under-cooked meat is strongly recommended.

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.

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

Science.gov (United States)

Sarcocystis sarcocysts are common in muscles of herbivores but are rare in muscles of carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA for the first time. Tongues of 57 foxes were examined for Sarcocystis infection using sev...

Las neuronas de la conciencia

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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.

Protozoal meningoencephalitis in sea otters (Enhydra lutris): A histopathological and immunohistochemical study of naturally occurring cases

Science.gov (United States)

Thomas, N.J.; Dubey, J.P.; Lindsay, D.S.; Cole, Rebecca 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. neuronameningoencephalitis, multifocal to diffuse gliosis was widespread in grey matter and consistently present in the molecular layer of the cerebellum. In T. gondiimeningoencephalitis, 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.

Sarcocystis spp. in red deer (Cervus elaphus, fallow deer (Dama dama, and pudu (Pudu pudu in southern Chile

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Esteban Reyes Lobão-Tello

Full Text Available ABSTRACT: Worldwinde, cervids are considered an important source of infection and dissemination of a wide variety of pathogens, both for farm animals and humans. Among this diseases is sarcosporidiosis, which is a parasitic disease caused by Sarcocystis spp. (Protozoa: Apicomplexa. Most frequent clinical signs are hemolytic anemia, weakness, weight loss and decrease of growth and some species of Sarcocystis might cause abortions. The clinical disease in ruminants is fairly rare but the infection is very frequent. Infections are accumulative and the parasite does not generate immunity in any of the hosts. Ovine sarcosporidiosis is a serious issue in the some regions of Chile due to the macrocysts located in the muscle which means condemnation of the whole carcass. Sarcocystis spp. has been widely reported in red deer and other cervid species but in Chile the situation remains unknown. Nowadays there is little to no evidence of Sarcocystis in foreign deer in Chile and there is only one report of the parasite on pudu. The main goal of this study is to demonstrate the presence of Sarcocystis spp. in myocardium of red deer and fallow deer in Chile, and confirm the presence of Sarcocystis spp. in pudu. All cervid cases from 1994 to 2013 of the Institute of Animal Pathology of the Universidad Austral de Chile were reviewed. The animals selected were those in which a myocardium sample was taken. From the histopathological samples observed, it was found that 5 of the 9 red deer, 1 of the 4 fallow deer and in 11 of the 23 pudu there were Sarcocystis cysts in the myocardium. This study represents the first record for Chile of Sarcocystis spp. in myocardium of red deer and fallow deer. Stablishing the red deer, fallow deer and pudu as hosts of Sarcocystis aids to have a better understanding of the parasite epidemiology in Chile and the role of wild and captive cervids in the maintenance and spread of these parasites.

Caracterização molecular de Sarcocystis spp. em amostras de carne

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Marta E.M. Alves

Full Text Available RESUMO: A sarcocistose é uma doença distribuída mundialmente, podendo acometer aves, répteis e diversos mamíferos, incluindo o homem. O objetivo desse trabalho foi detectar a presença de Sarcocystis spp. e caracterizar as espécies encontradas em 375 amostras de produtos cárneos (filé mignon bovino, carne moída bovina e salame colonial. Para isso, foi realizada a detecção do parasita através da técnica de PCR para amplificação parcial do gene 18S rRNA e sua caracterização molecular utilizando o polimorfismo no comprimento do fragmento de restrição (RFLP com as enzimas de restrição Bcl I, Rsa I e Alu I. A ocorrência de Sarcocystis spp. foi de 17% (64/375 do total de amostras testadas pelo PCR. Entre os produtos cárneos avaliados, 5,6% (7/125 das amostras de filé mignon, 12,8% (16/125 de carne moída e 32,8% (41/125 de embutido colonial, foram positivas para presença do DNA do Sarcocystis spp. Entre estas amostras positivas, as espécies caracterizadas foram Sarcocystis hirsuta e Sarcocystis hominis com prevalências de 93,7% (60/64 e 6,3% (4/64, respectivamente. Considerando à relevância da sarcocistose na área da saúde pública, a ocorrência de S. hominis encontrado neste estudo, pode ser um fator de risco para a contaminação humana. Porém, a presença do DNA deste protozoário não significa necessariamente potencial de infecção aos humanos, pois cuidados nos processos de fabricação podem reduzir a viabilidade dos cistos.

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 ...

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...

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.

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...... the six species in phylogenetic analyses of the Sarcocystidae, and also to investigate the phylogenetic relationships between the species from reindeer and those from other hosts. The study also aimed at revealing whether the inclusion of six Sarcocystis species from the same intermediate host would have....... tarandivulpes, formed a sister group to other Sarcocystis species with a canine definitive host. The position of S. hardangeri on the tree suggested that it uses another type of definitive host than the other Sarcocystis species in this clade. Considering the geographical distribution and infection intensity...

High prevalence of Sarcocystis calchasi sporocysts in European Accipiter hawks.

Science.gov (United States)

Olias, Philipp; Olias, Lena; Krücken, Jürgen; Lierz, Michael; Gruber, Achim D

2011-02-10

The emerging Sarcocystis calchasi induces a severe and lethal central nervous disease in its intermediate host, the domestic pigeon (Columba livia f. domestica). Experimental studies have identified the Northern goshawk (Accipiter g. gentilis) as final host. Phylogenetically closely related European sparrowhawks (Accipiter n. nisus) and wood pigeons (Columba palumbus) have been found to harbor genetically closely related Sarcocystis spp. However, data on the prevalence and potential interspecies occurrence of these parasites are lacking. Here, we report that European Accipiter hawks (Accipitrinae) are highly infected with S. calchasi, S. columbae and Sarcocystis sp. ex A. nisus in their small intestine. Thirty-one of 50 (62%) Northern goshawks necropsied during 1997-2008 were positive for S. calchasi in a newly established species-specific semi-nested PCR assay based on the first internal transcribed spacer region. Unexpectedly, 14 of 20 (71.4%) European sparrowhawks tested also positive. In addition, birds of both species were found to be infested with S. columbae and an, as yet, unnamed Sarcocystis sp. recently isolated from European sparrowhawks. These findings raise new questions about the host specificity of S. calchasi and its high virulence in domestic pigeons, since sparrowhawks only rarely prey on pigeons. Notably, isolated sporocysts from both infected Accipiter spp. measured 8 μm × 11.9 μm, precluding a preliminary identification of S. calchasi in feces of Accipiter hawks based on morphology alone. Importantly, three of four Northern goshawks used in falconry tested positive for S. calchasi. In conclusion, the results indicate that both European Accipter spp. in Germany serve as natural final hosts of S. calchasi and suggest that falconry and pigeon sport may serve as risk factors for the spread of this pathogen in domestic pigeons. Copyright © 2010 Elsevier B.V. All rights reserved.

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...

Virus de rabia en cultivos de neuronas sensoriales de ratón adulto

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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

Fate of macrosarcocyst of Sarcocystis gigantea in sheep

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N. S. Al-Hyali1, E. R. Kennany2 and L.Y. Khalil1

2011-01-01

Full Text Available This study was conducted to detect the fate of macrosarcocysts of Sarcocystis gigantea in the tongue and eosophagus of naturally infected sheep, via collection of 25 samples, 10 of which showed calcification. The results showed presence of white different size grains on the wall of the pale eosophagus, in addition to presence of nodules containing white chalky materials and on cutting by knife produced grunting sound which indicated calcification. Histopathological results showed presence of granulomatous nodules that contained necrotic centers infiltration by inflammatory cells. Some of which were free from zoites in addition to presence of calcium salt precipitation, which represented dystrophic calcification. Eosinophilic myositis appeared in the tongue was associated with ruptured cyst and released zoites in muscular tissue. Some histological sections revealed ruptured macrocystis with thin wall deposited between muscle bundles. In conclusion, this study showed that the fate of macrocysts included the formation of granulomatous nodules associated with dystrophic calcification and dead zoites in eosophagous more than that in the tongue.

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

OpenAIRE

FARIAS RODRIGUEZ, PAULA ANDREA; 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...

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

Anti-Neospora caninum and anti-Sarcocystis spp. specific antibodies cross-react with Besnoitia besnoiti and influence the serological diagnosis of bovine besnoitiosis.

Science.gov (United States)

García-Lunar, P; Moré, G; Campero, L; Ortega-Mora, L M; Álvarez-García, G

2015-11-30

Bovine besnoitiosis control remains a challenge because the disease continues to spread and control relies solely on accurate diagnosis coupled to management measures. However, recent studies have reported that routinely used ELISAs may raise a high number of false-positive results. Herein, cross-reactions between Besnoitia besnoiti antigens and anti-Neospora caninum and/or anti-Sarcocystis spp.-specific antibodies were studied in an in house ELISA since N. caninum and Sarcocystis spp. are closely related parasites, and both infections are highly prevalent in cattle worldwide. The serum panel was composed of the following categories: sera from B. besnoiti-seronegative (n=75) and -seropositive cattle (n=66), B. besnoiti-based-ELISA false-positive reactors (n=96) together with N. caninum (n=36) and Sarcocystis spp. (n=42) -seropositive reference cattle sera. B. besnoiti tachyzoite based western blot (WB) results classified animals as seropositive or seronegative. Sera were analyzed for the detection of anti-N. caninum by WB and ELISA and anti-Sarcocystis spp.-specific antibodies by WB and IFAT. Those samples recognizing a Sarcocystis spp. 18-20 kDa antigenic region and N. caninum 17-18 kDa immunodominant antigen were considered to be Sarcocystis spp. and N. caninum seropositive, respectively. The category of B. besnoiti based-ELISA false-positive reactors showed the highest number of sera with specific anti-Sarcocystis spp. and anti-N. caninum antibodies (74%; 71/96), followed by the N. caninum-seropositive cattle category (52.8%; 19/36). In contrast, few B. besnoiti-seronegative and -seropositive cattle showed antibodies against Sarcocystis spp. and N. caninum (10.7%; 8/75 and 1.5%; 1/66), respectively). This study revealed that B. besnoiti false-positive ELISA results were associated not only with the presence of anti-N. caninum and anti-Sarcocystis spp. antibodies (χ(2): 78.36; pbovine besnoitiosis. Copyright © 2015 Elsevier B.V. All rights reserved.

New Sarcocystis species with a snake-gecko life cycle

Czech Academy of Sciences Publication Activity Database

Šlapeta, J.; Modrý, D.; Koudela, Břetislav

1998-01-01

Roč. 45, č. 1 (1998), s. 7 ISSN 1066-5234. [New Sarcocystis species with a snake -gecko life cycle. 01.01.1998-02.01.1998, Praha] R&D Projects: GA ČR GA508/95/0273 Subject RIV: fp - Other Medical Disciplines

COMPARTIMENTACIÓN INTERCELULAR DEL ACETATO EN NEURONAS Y ASTROCITOS DURANTE LA PRELACTANCIA

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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.

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

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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.

Genotyping of Toxoplasma gondii and Sarcocystis spp. in road-killed wild mammals from the Central Western Region of the State of São Paulo, Brazil.

Science.gov (United States)

Richini-Pereira, Virgínia Bodelão; Marson, Pâmela Merlo; Silva, Rodrigo Costa da; Langoni, Helio

2016-01-01

Road-killed wild animals host zoonotic pathogens such as Toxoplasma gondii, offering a new opportunity for the epidemiological study of these infectious organisms. This investigation aimed to determine the presence of T. gondii and other apicomplexan parasites in tissue samples of 64 road-killed wild animals, using polymerase chain reaction (PCR). Positive samples were then typed by PCR-restriction fragment length polymorphism (RFLP) using 7 markers: SAG1, 5'-3'SAG2, SAG3, BTUB, c29-6, PK1, and Apico. PCR-RFLP targeting 18S ribosomal RNA (rRNA) genes was also performed on all samples to detect other apicomplexan parasites. T. gondii DNA was detected in 16 tissue samples from 8 individual animals, as follows: 1 Cerdocyon thous (crab-eating fox), 1 Didelphis albiventris (white-eared opossum), 1 Lutreolina crassicaudata (lutrine opossum), 2 Myrmecophaga tridactyla (giant anteater), 1 Procyon cancrivorus (crab-eating raccoon), and 2 Sphiggurus spinosus (Paraguay hairy dwarf porcupine). Seven different T. gondii genotypes were identified, 6 of which were novel. Typing by 18S rRNA verified these 16 T. gondii-infected samples, and identified 1 Sarcocystis spp.-infected animal [Dasypus novemcinctus (nine-banded armadillo)]. The amplified T. gondii (GenBank accession No. L37415.1) and Sarcocystis spp. 18S rRNA products were confirmed by sequencing. Our results indicate that T. gondii is commonly present in wild mammals, which act as sources of infection for humans and animals, including other wild species. The approach employed herein proved useful for detecting T. gondii and Sarcocystis spp. in the environment and identifying their natural reservoirs, contributing to our understanding of host-parasite interactions.

Genotyping of Toxoplasma gondii and Sarcocystis spp. in road-killed wild mammals from the Central Western Region of the State of São Paulo, Brazil

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Virgínia Bodelão Richini-Pereira

Full Text Available Abstract INTRODUCTION: Road-killed wild animals host zoonotic pathogens such as Toxoplasma gondii, offering a new opportunity for the epidemiological study of these infectious organisms. METHODS This investigation aimed to determine the presence of T. gondii and other apicomplexan parasites in tissue samples of 64 road-killed wild animals, using polymerase chain reaction (PCR. Positive samples were then typed by PCR-restriction fragment length polymorphism (RFLP using 7 markers: SAG1, 5′-3′SAG2, SAG3, BTUB, c29-6, PK1, and Apico. PCR-RFLP targeting 18S ribosomal RNA (rRNA genes was also performed on all samples to detect other apicomplexan parasites. RESULTS T. gondii DNA was detected in 16 tissue samples from 8 individual animals, as follows: 1 Cerdocyon thous (crab-eating fox, 1 Didelphis albiventris (white-eared opossum, 1 Lutreolina crassicaudata (lutrine opossum, 2 Myrmecophaga tridactyla (giant anteater, 1 Procyon cancrivorus (crab-eating raccoon, and 2 Sphiggurus spinosus (Paraguay hairy dwarf porcupine. Seven different T. gondii genotypes were identified, 6 of which were novel. Typing by 18S rRNA verified these 16 T. gondii-infected samples, and identified 1 Sarcocystis spp.-infected animal [Dasypus novemcinctus (nine-banded armadillo]. The amplified T. gondii (GenBank accession No. L37415.1 and Sarcocystis spp. 18S rRNA products were confirmed by sequencing. CONCLUSIONS Our results indicate that T. gondii is commonly present in wild mammals, which act as sources of infection for humans and animals, including other wild species. The approach employed herein proved useful for detecting T. gondii and Sarcocystis spp. in the environment and identifying their natural reservoirs, contributing to our understanding of host-parasite interactions.

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)

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...

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...

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

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

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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.

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

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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.

Detection of Zoonotic Protozoa Toxoplasma gondii and Sarcocystis suihominis in Wild Boars from Spain.

Science.gov (United States)

Calero-Bernal, R; Pérez-Martín, J E; Reina, D; Serrano, F J; Frontera, E; Fuentes, I; Dubey, J P

2016-08-01

Food safety regulations require the control of the presence of protozoa in meats destined for human consumption. Wild boar (Sus scrofa) meat may constitute a source of zoonoses. A 23.8% (688/2881) seroprevalence of anti-Toxoplasma gondii antibodies and 72.2% (662/910) Sarcocystis sarcocysts prevalence were detected among wild boars hunted in Southwestern areas of Spain. Identity of Sarcocystis spp. was performed by RFLP-PCR and sequencing, detecting S. miescheriana (7/8) and the zoonotic S. suihominis (1/8). Risk assessment studies of these coccidian in meats destined to human consumption are needed. © 2015 Blackwell Verlag GmbH.

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

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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

Sarcocystis chloropusae (protozoa: Sarcocystidae) n. sp. from the common moorhen (Gallinula chloropus) from Egypt.

Science.gov (United States)

El-Morsey, A; El-Seify, M; Desouky, A Y; Abdel-Aziz, M M; Sakai, H; Yanai, T

2015-07-01

A new name Sarcocystis chloropusae is proposed for a parasite previously found in two of 25 common moorhen (Gallinula chloropus) from Brolos Lake, Egypt. Sarcocysts were microscopic, up to 650 μm long, the cyst wall was up to 4.5 μm thick, and contained villar protrusions that were up to 4 μm long and up to 2 μm wide. The villar protrusions were crowded, contained vesicles but lacked microtubules. The ground substance layer was smooth. The bradyzoites were up to 12 μm long and up to 2 μm wide. Molecular characterization and phylogenetic analysis of the (ITS-1) supported the conclusion that the Sarcocystis in G. chloropus is a distinct species.

Mecanismos de regulación de la glucolisis en neuronas y su función en supervivencia celular

OpenAIRE

Rodríguez Rodríguez, Patricia

2014-01-01

[ES] El mantenimiento de un correcto equilibrio en el metabolismo energético neuronal es esencial para la supervivencia celular. Existen datos que indican que la neurotransmisión glutamatérgica activa señales moleculares que afectan tanto a la captación de glucosa por las neuronas como a sus vias de metabolización. En esta tesis doctoral describimos un método sensible y específico para la determinación de flujos metabólicos por vía de las pentosas-fosfato y por glucolisis en neuronas a...

Polyparasitism Is Associated with Increased Disease Severity in Toxoplasma gondii-Infected Marine Sentinel Species

Science.gov (United States)

Gibson, Amanda K.; Raverty, Stephen; Lambourn, Dyanna M.; Huggins, Jessica; Magargal, Spencer L.; Grigg, Michael E.

2011-01-01

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 polyparasitism as

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

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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

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

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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

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.

2015-01-01

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

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

Gene Discovery in the Apicomplexa as Revealed by EST Sequencing and Assembly of a Comparative Gene Database

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Li, Li; Brunk, Brian P.; Kissinger, Jessica C.; Pape, Deana; Tang, Keliang; Cole, Robert H.; Martin, John; Wylie, Todd; Dante, Mike; Fogarty, Steven J.; Howe, Daniel K.; Liberator, Paul; Diaz, Carmen; Anderson, Jennifer; White, Michael; Jerome, Maria E.; Johnson, Emily A.; Radke, Jay A.; Stoeckert, Christian J.; Waterston, Robert H.; Clifton, Sandra W.; Roos, David S.; Sibley, L. David

2003-01-01

Large-scale EST sequencing projects for several important parasites within the phylum Apicomplexa were undertaken for the purpose of gene discovery. Included were several parasites of medical importance (Plasmodium falciparum, Toxoplasma gondii) and others of veterinary importance (Eimeria tenella, Sarcocystis neurona, and Neospora caninum). A total of 55,192 ESTs, deposited into dbEST/GenBank, were included in the analyses. The resulting sequences have been clustered into nonredundant gene assemblies and deposited into a relational database that supports a variety of sequence and text searches. This database has been used to compare the gene assemblies using BLAST similarity comparisons to the public protein databases to identify putative genes. Of these new entries, ∼15%–20% represent putative homologs with a conservative cutoff of p neurona: , , , , , , , , , , , , , –, –, –, –, –. Eimeria tenella: –, –, –, –, –, –, –, –, – , –, –, –, –, –, –, –, –, –, –, –. Neospora caninum: –, –, , – , –, –.] PMID:12618375

Morphological and molecular characteristics of Sarcocystis bertrami from horses and donkeys in China

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Sarcocystis cysts collected from donkeys and horses were studied by morphological and molecular methods. Morphological studies performed by light microscopy (LM) revealed that each of two types of cysts were present in samples from both donkey and horse. These two types of cysts, type I (larger) and...

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

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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.

Sarcocystis canis associated hepatitis in a Steller sea lion (Eumetopias jubatus) from Alaska.

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Welsh, Trista; Burek-Huntington, Kathy; Savage, Kate; Rosenthal, Benjamin; Dubey, J P

2014-04-01

Sarcocystis canis infection was associated with hepatitis in a Steller sea lion (Eumetopias jubatus). Intrahepatocellular protozoal schizonts were among areas of necrosis and inflammation. The parasite was genetically identical to S. canis and is the first report in a Steller sea lion, indicating another intermediate host species for S. canis.

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

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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.

A new molecular approach to assess the occurrence of Sarcocystis spp. in cattle and products thereof: preliminary data

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Francesco Chiesa

2013-11-01

Full Text Available The genus Sarcocystis consists of more than 200 species. Those protozoa are characterised by a biological cycle composed by two obligatory hosts, definitive and intermediate. Apart from being possibly pathogenic for the intermediate host, a number of authors consider the intestinal sarcocystosis a minor zoonotic disease. Humans, in fact, can act as definitive host for two sarcosporidian species, S. suihominis e S. hominis, being infected through the consumption of raw or undercooked pig and bovine meat, respectively. Other two species could parasitise cattle: S. cruzi and S. hirsuta, having canids and felids as definitive hosts, respectively. The three species differentiate from each other in dimensions and cystic wall morphology, this latter being the basis for taxonomical studies. In 2010, the European Food Safety Authority (EFSA highlighted the absence of reliable methods for epidemiological studies on the presence of Sarcocystis spp. in animals and products thereof. On this basis, the present study has been developed a new molecular method for the identification of Sarcocystis in bovine meat. For the development of the polymerase chain reaction (PCR protocol, a set of samples of bovine meat from cattle (N=15, slaughtered at the didactic abattoir at the Veterinary Faculty of Turin University, has been collected, sequenced and used as reference samples during the study. A second set of samples (N=29, gathered from the same abattoir (N=12 and from abattoirs of Piedmont region (N=17, has been used for applicability tests. The overall positive rate for Sarcocystis spp. in our samples has been 91% (40/44, with S. cruzi representing the species with higher rates (68%, followed by S. hominis (43% and S. hirsuta (2%. Based on the results of specificity and applicability tests performed in this study, the newly developed protocol proved to be reliable and suitable for epidemiologic purposes.

De las neuronas espejo a la neuropolítica moral

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Olson, Gary

2008-01-01

Este artículo presenta el descubrimiento del sistema de neuronas espejo, que muestran que los mecanismo neuronales revelan que los humanos estamos «cableados" para la empatia, 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 empatia a nivel social, formul...

Razvojno porijeklo intersticijskih neurona i regionalne razlike u njihovoj raspodjeli, brojnosti i fenotipovima u mozgu čovjeka [Developmental origin of white matter interstitial neurons and their regional differences in distribution, morpology and phenotype in human brain

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Sedmak, Goran

2013-01-01

Broj intersticijskih neurona u bijeloj tvari moždane kore čovjeka do sada nije bio poznat. Intersticijski neuroni čine veliku populaciju neurona u bijeloj tvari ljudskog telencefalona, a vjeruje se da su uključeni u patogenezu mnogih razvojnih i degenerativnih bolesti i poremećaja mozga. Stoga je bitno poznavati njihovu regionalnu raspodjelu te morfološke i molekularne fenotipove. U ovom radu smo analizirali brojnost,i fenotipove intersticijskih neurona u pet različitih kortikalnih područja. ...

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

Science.gov (United States)

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 fr...

PENGGUNAAN PROTOZOA SARCOCYSTIS SINGAPORENSIS (APICOMPLEXA: SARCOCYSTIDAE UNTUK PENGENDALIAN TIKUS SAWAH RATTUS ARGENTIVENTER

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Maryani Cyccu Tobing, Ameilia Zuliyanti Siregar, Lisnawita, dan Meirani.

2011-11-01

Full Text Available The use of protozoan Sarcocystis singaporensis (Apicomplexa: Sarcocystidae for control rice field rat Rattus argentiventer.  Rats are still a number-one-pest in field rice of various areas in Indonesia. Biological control using microparasite                         Sarcocystis singaporensis (Apicomplexa: Sarcocystidae is a highly host-specific protozoan for controlling the rats. The objective of this research was to study the use of protozoa parasite S. singaporensis against rodent pest Rattus argentiventer. The design of experiment was Factorial Randomized Complete Design with ten treatments and four replications.  The first factor was sporocyt doses of S. singaporensis (control; 1 x 105; 2 x 105; 3 x 105; 4 x 105, while the second factor was rats sexual category (male and female. The results showed that dose of sporocysts S. singaporensis was significantly different but rats’ sexual category has no effect on the treatments. The highest mortalities was on dose  4 x 105 (100% at 12.08 days, food consumption decreased two to four days before rats died, weight of rats decreased because of the infection of S. singaporensis.

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...

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 ...

The life-cycle and ultrastructure of Sarcocystis ameivamastigodryasi n. sp., in the lizard Ameiva ameiva (Teiidae and the snake Mastigodryas bifossatus (Colubridae(1

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Lainson R.

2000-12-01

Full Text Available Sarcocysts in muscles of the teiid lizard Ameiva ameivafrom north Brazil were fed to the colubrid snake Mastigodryas bifossatus, the faeces of which had been shown to be devoid of coccidial oocysts or sporocysts. When necropsied 16 days later the snake was shown to have developed a massive intestinal infection of Sarcocystis. Mature sporocysts from another, naturally infected M. bifossatus were fed to juvenile specimens of A. ameiva in which no sarcocysts could be detected in tail muscle biopsies. When examined 30 and 47 days later they had very large numbers of sarcocysts in their tail and tongue muscles. The parasite is given the name of Sarcocystis ameivamastigodryasi n. sp. An ultrastructural study has been made of the sarcocyst and of the parasite's sporulation in the lamina propria of the snake: the latter provides details of the wall formation process in developing sporocysts. Attempts to infect a specimen of the boid Boa constrictor constrictor by feeding it with infected Ameivafailed, suggesting that sporocysts previously recorded in genera of the family Boidae may be those of a different species of Sarcocystis.

Prevalencia de Sarcocystis sp. en vacunos, ovinos y caprinos beneficiados en los camales de Lima

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Julia Castro

2014-06-01

Full Text Available Se ha realizado el presente estudio para determinar la prevalencia de Sarcocystis sp. en vacunos, ovinos y caprinos utilizando el método del tríquinoscopio con muestras de tejido cardíaco y esófago. Los resultados mostraron que de 85 muestras de tejido cardíaco de ganado vacuno, 76 fueron positivas (89.5%; de 134 muestras de ganado ovino 122 fueron positivas (91.04% mientras que de 63 muestras de ganado capriino solo en 33 (52.4% se encontró la presencia del parásito. En cuanto a las muestras de esófago los porcentajes de parasitismo fueron los siguientes: 2% para el vacuno; 39.8% para el ovino y 76.2% para el caprino. Estos valores indicaron que el mayor parasitismo en vacunos y ovinos está localizado en el corazón, mientras que en caprinos el órgano más infestado es el esófago. Por lo tanto existe un elevado parasitismo por Sarcocystis sp. en el ganado beneficiado para consumo humano.

The Sarcocystis-cyst containing beef and pork as the sources of natural intestinal sarcocystosis in Thai people.

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Bunyaratvej, Sukhum; Unpunyo, Piyapong; Pongtippan, Atcharaporn

2007-10-01

Human intestinal sarcocystosis is a zoonotic disease caused by two coccidians, i.e. Sarcocystis fusiformis (syn. S. bovihominis, S. hominis) due to consumption of raw infected beef and Sarcocystis meischeriana (syn. S. suihominis) due to consumption of infected raw pork. In 1987, survey of the macroscopic S. fusiformis cysts in market beef mainly from old water buffalos aged more than 15 years were commonly observed in Bangkok. In 2005, the macroscopic cyst was no longer seen in beef of cattle and water buffalo aged less than three years. The epidemiological investigation of Sarcocystis spp. infected meat in Bangkok and Lampang. Samples for each of the tongue and beef of cattle and water buffalo, pork from Bangkok markets and pork of domestic swine from some remote villages in various subprovinces (Ampurs) in Lampang were obtained for microscopic examination by H and E and selectively by PAS staining. The microscopic S. fusiformis cysts were seen in all five specimens of tongues and ten specimens of muscles of cattle and water buffalo obtained from fresh-food markets in Bangkok. Ten samples of pork from Bangkok markets revealed no coccidian infection. The microscopic S. meischeriana cysts were seen in three specimens of swine muscles collected from two subprovinces in Lampang. The present merozoites in coccidian cysts retrieved from beef and pork are similar to those previously observed in human intestine. This may histologically indicate an invasive sarcocystosis by both species leading to a condition presently known as chronic inflammation of undetermined etiology in man.

Sarcocystis spp. in domestic sheep in Kunming City, China: prevalence, morphology, and molecular characteristics

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Hu Jun-Jie

2017-01-01

Full Text Available Sheep (Ovis aries are intermediate hosts for at least six named species of Sarcocystis: S. tenella, S. arieticanis, S. gigantea, S. medusiformis, S. mihoensis, and S. microps. Here, only two species, S. tenella and S. arieticanis, were found in 79 of 86 sheep (91.9% in Kunming, China, based on their morphological characteristics. Four genetic markers, i.e., 18S rRNA gene, 28S rRNA gene, mitochondrial cox1 gene, and ITS-1 region, were sequenced and characterized for the two species of Sarcocystis. Sequences of the three former markers for S. tenella shared high identities with those of S. capracanis in goats, i.e., 99.0%, 98.3%, and 93.6%, respectively; the same three marker sequences of S. arieticanis shared high identities with those of S. hircicanis in goats, i.e., 98.5%, 96.5%, and 92.5%, respectively. No sequences in GenBank were found to significantly resemble the ITS-1 regions of S. tenella and S. arieticanis. Identities of the four genetic markers for S. tenella and S. arieticanis were 96.3%, 95.4%, 82.5%, and 66.2%, respectively.

Sarcocystis spp. in domestic sheep in Kunming City, China: prevalence, morphology, and molecular characteristics.

Science.gov (United States)

Hu, Jun-Jie; Huang, Si; Wen, Tao; Esch, Gerald W; Liang, Yu; Li, Hong-Liang

2017-01-01

Sheep (Ovis aries) are intermediate hosts for at least six named species of Sarcocystis: S. tenella, S. arieticanis, S. gigantea, S. medusiformis, S. mihoensis, and S. microps. Here, only two species, S. tenella and S. arieticanis, were found in 79 of 86 sheep (91.9%) in Kunming, China, based on their morphological characteristics. Four genetic markers, i.e., 18S rRNA gene, 28S rRNA gene, mitochondrial cox1 gene, and ITS-1 region, were sequenced and characterized for the two species of Sarcocystis. Sequences of the three former markers for S. tenella shared high identities with those of S. capracanis in goats, i.e., 99.0%, 98.3%, and 93.6%, respectively; the same three marker sequences of S. arieticanis shared high identities with those of S. hircicanis in goats, i.e., 98.5%, 96.5%, and 92.5%, respectively. No sequences in GenBank were found to significantly resemble the ITS-1 regions of S. tenella and S. arieticanis. Identities of the four genetic markers for S. tenella and S. arieticanis were 96.3%, 95.4%, 82.5%, and 66.2%, respectively. © J.-J. Hu et al., published by EDP Sciences, 2017.

Association of eosinophilic myositis with an unusual species of Sarcocystis in a beef cow.

Science.gov (United States)

Gajadhar, A A; Yates, W D; Allen, J R

1987-01-01

The carcass of a mature cow had numerous, disseminated lesions typical of eosinophilic myositis. To elucidate the nature and possible cause of the lesions, histological sections were examined by light microscopy and selected areas were removed and processed for electron microscopy. The lesions were granulomatous in nature. Each granuloma contained at its centre an intact or ruptured sarcocyst associated with degenerate muscle fibers. Surrounding this was a layer of epithelioid cells and an intense accumulation of inflammatory cells, most of which were eosinophils. The primary cyst wall of the sarcocysts in these granulomas consisted of hair-like protrusions that featured many unusual electron-dense bodies. Sarcocysts with ultrastructures characteristic of Sarcocystis cruzi and Sarcocystis hirsuta were also present in muscle from the same animal, but these sarcocysts lacked any associated cellular responses. The eosinophilic myositis in this case appeared to be associated with sarcocystosis of an unknown species. Possibly, the inflammatory reaction was due to the host-parasite interaction in an unusual host. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:3115553

Phylogeny and sequence variability of the Sarcocystis singaporensis Zaman and Colley, (1975) 1976 ssrDNA

Czech Academy of Sciences Publication Activity Database

Šlapeta, Jan Roger; Kyselová, Iveta; Richardson, A. O.; Modrý, David; Lukeš, Julius

2002-01-01

Roč. 88, č. 9 (2002), s. 810-815 ISSN 0932-0113 R&D Projects: GA ČR GA524/00/P015; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6022909 Keywords : Sarcocystis * phylogeny * ssrDNA Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.046, year: 2002

Ultrastructure of the cysts of Sarcocystis rangi from skeletal muscle of reindeer (Rangifer tarandus tarandus

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Bjørn Gjerde

1985-05-01

Full Text Available Mature muscle cysts of Sarcocystis rangi from Rangifer tarandus were examined by transmission electron microscopy. The long and slender cysts were located within skeletal muscle cells, and were bounded by a unit membrane, the cyst membrane. The cysts were provided with closely spaced flexible, hairlike surface processes, measuring up to 12.6 |im in length and 0.3 to 0.6 \\lm in diameter. The projections had a smooth surface, whereas the cyst membrane formed numerous hexagonally packed vesicular invaginations between the bases of the projections. The cyst membrane was reinforced by an underlying thin layer of electron-dense material, except at the points where it was invaginated. Cyst ground substance formed a thin layer at the periphery of the cysts, filled the core of the projections, and formed thin septa that divided the interior of the cysts into numerous compartments. Most compartments contained a large number of tightly packed cystozoites, whereas a few metrocytes were forund in each of a few compartments at the periphery of the cysts. Some of the cystozoites multiplied by endodyogeny. The metrocytes displayed a vacuolation of their cytoplasm. The cysts of S. rangi were similar in surface morphology to the sarcocysts of certain other Sarcocystis species reported from other intermediate hosts.Ultrastrukturen til cyster av Sarcocystis rangi frå skjelettmuskulaturen hos rein.Abstract in Norwegian / Samandrag: Muskelcyster av S. rangi frå rein vart undersøkt ved transmisjonselektronmikroskopi. Dei lange cystene låg intracellulært i skjelettmuskelceller, og var avgrensa av ein elementærmembran, cystemembranen. Cystene var utstyrt med talrike hårliknande overflateprosessar, som strekte seg langsetter cysteoverflata. Prcsessane var opptil 12.6 Hm lange, og målte 0.3 til 0.6 \\lm i diameter. Prosessane hadde ei glatt overflate, medan cystemembranen danna talrike regelmessige ordna, små invaginasjonar innimellom basis av prosessane

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...

Reduced Levels of Nitric Oxide Metabolites in Cerebrospinal Fluid Are Associated with Equine Protozoal Myeloencephalitis

Science.gov (United States)

Njoku, Chinedu J.; Saville, William J. A.; Reed, Stephen M.; Oglesbee, Michael J.; Rajala-Schultz, Päivi J.; Stich, Roger W.

2002-01-01

Equine protozoal myeloencephalitis (EPM) is a disease of horses that is primarily associated with infection with the apicomplexan Sarcocystis neurona. Infection with this parasite alone is not sufficient to induce the disease, and the mechanism of neuropathogenesis associated with EPM has not been reported. Nitric oxide (NO) functions as a neurotransmitter, a vasodilator, and an immune effector and is produced in response to several parasitic protozoa. The purpose of this work was to determine if the concentration of NO metabolites (NOx−) in the cerebrospinal fluid (CSF) is correlated with the development of EPM. CSF NOx− levels were measured before and after transport-stressed, acclimated, or dexamethasone-treated horses (n = 3 per group) were experimentally infected with S. neurona sporocysts. CSF NOx− levels were also compared between horses that were diagnosed with EPM after natural infection with S. neurona and horses that did not have clinical signs of disease or that showed no evidence of infection with the parasite (n = 105). Among the experimentally infected animals, the mean CSF NOx− levels of the transport-stressed group, which had the most severe clinical signs, was reduced after infection, while these values were found to increase after infection in the remaining groups that had less severe signs of EPM. Under natural conditions, horses with EPM (n = 65) had a lower mean CSF NOx− concentration than clinically normal horses with antibodies (Abs) against S. neurona (n = 15) in CSF, and horses that developed ataxia (n = 81) had a significantly lower mean CSF NOx− concentration than horses that did not have neurologic signs (n = 24). In conclusion, lower CSF NOx− levels were associated with clinical EPM, suggesting that measurement of CSF NOx− levels could improve the accuracy of diagnostic tests that are based upon detection of S. neurona-specific Abs in CSF alone and that reduced NO levels could be causatively related to the development

Sarcocystis inghami n. sp. (Sporozoa: Sarcocystidae) from the skeletal muscles of the Virginia opossum Didelphis virginiana in Michigan.

Science.gov (United States)

Elsheikha, Hany M; Fitzgerald, Scott D; Mansfield, Linda S; Saeed, A Mahdi

2003-09-01

This report describes the newly identified Sarcocystis inghami n. sp. from the skeletal muscles of opossums (Mammalia: Didelphidae) that were collected from south central Michigan (42 degrees 43'-42 degrees 79'N, 84 degrees 18'-84 degrees 86'W), USA. The new species is distinguished from all species described from North and South American opossums by the distinctive morphology of the villar protrusions on the cyst wall. Sarcocysts of S. inghami are microscopic, up to 700 microm long and 110 microm wide. The sarcocyst wall is up to 7 microm thick, with long, stalked protrusions which average 5.5 x 1.2 microm. These are constricted at the base, expanded laterally, rounded off distally and occasionally bifid. The villar protrusions have numerous microtubules without electron-dense bodies that extend from the tips into the granular layer. Bradyzoites are 10.7 x 4.3 (8-12 x 4-5) microm. This is the second species of Sarcocystis sarcocyst described from the Virginia opossum in North America.

Sarcocystis greineri n. sp. (Protozoa: Sarcocystidae) in the Virginia opossum (Didelphis virginiana).

Science.gov (United States)

Cheadle, M A

2001-10-01

Sarcocysts were found in the skeletal muscles of road-killed and live-trapped opossums collected in north central Florida. Sarcocysts were spindle-shaped and macroscopic and had an average measurement of 3.8 mm by 154.6 microm. Sarcocysts were only observed in skeletal muscle. Sarcocysts have invaginations throughout the sarcocyst wall, which is approximately 1 microm thick. Protrusions on the sarcocyst wall are stumpy and digitlike and contain fibrillar elements that extend from the interior portion of the cyst wall through the villi. A new name, Sarcocystis greineri, is proposed for this species.

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.

Virus de rabia en cultivos de neuronas sensoriales de ratón adulto

OpenAIRE

H. Hurtado; Jaime E. Castellanos; R. Pérez

2000-01-01

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 ner...

Prevalence of Sarcocystis sp. in cattle, sheep and goats in abattoirs of Lima

OpenAIRE

Castro, Julia; Leguía, Guillermo

2014-01-01

Se ha realizado el presente estudio para determinar la prevalencia de Sarcocystis sp. en vacunos, ovinos y caprinos utilizando el método del tríquinoscopio con muestras de tejido cardíaco y esófago. Los resultados mostraron que de 85 muestras de tejido cardíaco de ganado vacuno, 76 fueron positivas (89.5%); de 134 muestras de ganado ovino 122 fueron positivas (91.04%) mientras que de 63 muestras de ganado capriino solo en 33 (52.4%) se encontró la presencia del parásito. En cuanto a las...

Histological identification of muscular sarcocystis: A report of two cases

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Mani Makhija

2012-01-01

Full Text Available 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 cyst wall are the reliable features to distinguish this parasite from other parasites of the same phylum. The incidence of human infection is rising in Southeast Asia and histopathology is an important method for the diagnosis of muscular infection. It is important to recognize the histomorphology of this parasite and its differentiation from similar parasites.

Prevalence and histopathological finding of thin-walled and thick-walled Sarcocysts in slaughtered cattle of Karaj abattoir, Iran.

Science.gov (United States)

Nourollahi-Fard, Saeid R; Kheirandish, Reza; Sattari, Saeid

2015-06-01

Sarcocystosis is a zoonotic disease caused by Sarcocystis spp. with obligatory two host life cycle generally alternating between an herbivorous intermediate host and a carnivorous definitive host. Some species of this coccidian parasite can cause considerable morbidity and mortality in cattle. The present study was set to investigate the prevalence of Sarcocystis spp. and type of cyst wall in slaughtered cattle of Karaj abattoir, Iran. For this purpose 125 cattle (88 males and 37 females) were investigated for the presence of macroscopic and microscopic Sarcocystis cysts in muscular tissues. No macroscopic Sarcocystis cysts were found in any of the samples. In light microscopy, 121 out of 125 cattle (96.8 %) had thin-walled cysts of Sarcocystis cruzi, while 43 out of them (34.4 %) had thick-walled Sarcocystis cyst. In this survey, the most infected tissue was esophagus and heart and the less was diaphragm. Thin-walled cysts (S. cruzi) mostly found in heart and skeletal muscle showed the less. However, thick-walled cyst (S. hominis or S. hirsuta) mostly were detected in diaphragm, heart muscle showed no thick-walled cyst. No significant relation was observed between age and sex and the rate of infection. The results showed that Sarcocystis cyst is prevalent in cattle in the North part of Iran and the evaluation of infection potential can be useful when considering control programs.

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....

Filosofía y ciencia: el problema de las otras mentes y las neuronas espejo

OpenAIRE

Raúl Robles Chamorro

2014-01-01

Resumen El propósito del siguiente artículo es mostrar cómo el descubrimiento de las neuronas espejo ayudó a resolver uno de los tantos y eternos problemas de la filosofía: el problema de las otras mentes, y cómo este hecho particular es solo el síntoma de una enfermedad que acosa a la filosofía desde hace bastante tiempo: el haber llegado a su limite y sin embargo no acudir a las herramientas que la ciencia le puede proporcionar para superar su actual estancamiento y así volver a ser una ...

Experimentos con una protección basada en redes de neuronas artificiales

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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

Factores tróficos en neuronas dopaminérgicas mesencefálicas

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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.

Parasite distribution and early-stage encephalitis in Sarcocystis calchasi infections in domestic pigeons (Columba livia f. domestica).

Science.gov (United States)

Maier, Kristina; Olias, Philipp; Enderlein, Dirk; Klopfleisch, Robert; Mayr, Sylvia L; Gruber, Achim D; Lierz, Michael

2015-01-01

Pigeon protozoal encephalitis is a biphasic, neurologic disease of domestic pigeons (Columba livia f. domestica) caused by the apicomplexan parasite Sarcocystis calchasi. Despite severe inflammatory lesions of the brain, associated parasitic stages have only rarely been identified and the cause of the lesions is still unclear. The aim of this study was therefore to characterize the tissue distribution of S. calchasi within pigeons between the two clinical phases and during the occurrence of neurological signs. For this purpose, a semi-quantitative real-time polymerase chain reaction (PCR) was developed. Forty-five domestic pigeons were infected orally (via a cannula into the crop) with 200 S. calchasi sporocysts and euthanized in groups of three pigeons at intervals of 2 to 10 days over a period of 61 days. Tissue samples including brain and skeletal muscle were examined by histology, immunohistochemistry, and PCR. Schizonts were detected in the liver of one pigeon at day 10 post infection. A mild encephalitis was detected at day 20 post infection, around 4 weeks before the onset of neurological signs. At the same time, immature sarcocysts were present in the skeletal muscle. In seven pigeons a few sarcocysts were identified in the brain, but not associated with any lesion. These results suggest that the encephalitis is induced at a very early stage of the S. calchasi lifecycle rather than in the chronic phase of pigeon protozoal encephalitis. Despite the increasing severity of lesions in the central nervous system, the amount of sarcocysts did not increase. This supports the hypothesis of a delayed-type hypersensitivity response as the cause of the encephalitis. The study also demonstrated that S. calchasi DNA is detectable in tissues negative by histological methods, indicating a higher sensitivity of the real-time PCR.

Discovery of three novel coccidian parasites infecting California sea lions (Zalophus californianus), with evidence of sexual replication and interspecies pathogenicity.

Science.gov (United States)

Colegrove, Kathleen M; Grigg, Michael E; Carlson-Bremer, Daphne; Miller, Robin H; Gulland, Frances M D; Ferguson, David J P; Rejmanek, Daniel; Barr, Bradd C; Nordhausen, Robert; Melli, Ann C; Conrad, Patricia A

2011-10-01

Enteric protozoal infection was identified in 5 stranded California sea lions (Zalophus californianus). Microscopically, the apical cytoplasm of distal jejunal enterocytes contained multiple stages of coccidian parasites, including schizonts with merozoites and spherical gametocytes, which were morphologically similar to coccidians. By histopathology, organisms appeared to be confined to the intestine and accompanied by only mild enteritis. Using electron microscopy, both sexual (microgametocytes, macrogamonts) and asexual (schizonts, merozoites) coccidian stages were identified in enterocytes within parasitophorous vacuoles, consistent with apicomplexan development in a definitive host. Serology was negative for tissue cyst-forming coccidians, and immunohistochemistry for Toxoplasma gondii was inconclusive and negative for Neospora caninum and Sarcocystis neurona. Analysis of ITS-1 gene sequences amplified from frozen or formalin-fixed paraffin-embedded intestinal sections identified DNA sequences with closest homology to Neospora sp. (80%); these novel sequences were referred to as belonging to coccidian parasites "A," "B," and "C." Subsequent molecular analyses completed on a neonatal harbor seal (Phoca vitulina) with protozoal lymphadenitis, hepatitis, myocarditis, and encephalitis showed that it was infected with a coccidian parasite bearing the "C" sequence type. Our results indicate that sea lions likely serve as definitive hosts for 3 newly described coccidian parasites, at least 1 of which is pathogenic in a marine mammal intermediate host species.

Testing the Sarcocystis neurona vaccine using an equine protozoal myeloencephalitis challenge model

Science.gov (United States)

Equine protozoal myeloencephalitis (EPM) is an important equine neurologic disorder, and treatments for the disease are often unrewarding. Prevention of the disease is the most important aspect for EPM, and a killed vaccine was developed for just that purpose. Evaluation of the vaccine has been hamp...

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 plas...

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.

RESONANCIA ELECTRICA EN EL RANGO THETA (0) EN NEURONAS DE LA CAPA II DEL NUCLEO CORTICAL ANTERIOR DE LA AMIGDALA

OpenAIRE

PEZZOLI GONZALEZ; MAURIZIO FERNANDO; PEZZOLI GONZALEZ; MAURIZIO FERNANDO

2010-01-01

El complejo de la amígdala participa en procesar información sensorial relevante desde el punto de vista emocional. La información sensorial olfativa entra desde el bulbo olfatorio (OB) a este complejo a través de la corteza olfatoria, la cual incluye los núcleos corticales de la amígdala. En ratas las neuronas mitrales del OB y aquellas de la capa II del núcleo cortical anterior (ACo) y la corteza periamigdaloide división medial (P A Cm) presentan oscilaciones intrínsecas del ...

RESONANCIA ELECTRICA EN EL RANGO THETA (8) EN NEURONAS DE LA CAPA II DEL NUCLEO CORTICAL ANTERIOR DE LA AMIGDALA

OpenAIRE

PEZZOLI GONZALEZ, MARURIZIO FERNANDO

2010-01-01

El complejo de la amígdala participa en procesar información sensorial relevante desde el punto de vista emocional. La información sensorial olfativa entra desde el bulbo olfatorio (OB) a este complejo a través de la corteza olfatoria, la cual incluye los núcleos corticales de la amígdala. En ratas las neuronas mitrales del OB y aquellas de la capa II del núcleo cortical anterior (ACo) y la corteza periamigdaloide división medial (P A Cm) presentan oscilaciones intrínsecas del potencial de...

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 ...

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...

DISCOVERY OF THREE NOVEL COCCIDIAN PARASITES INFECTING CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS), WITH EVIDENCE OF SEXUAL REPLICATION AND INTERSPECIES PATHOGENICITY

Science.gov (United States)

Colegrove, Kathleen M.; Grigg, Michael E.; Carlson-Bremer, Daphne; Miller, Robin H.; Gulland, Frances M. D.; Ferguson, David J. P.; Rejmanek, Daniel; Barr, Bradd C.; Nordhausen, Robert; Melli, Ann C.; Conrad, Patricia A.

2016-01-01

Enteric protozoal infection was identified in 5 stranded California sea lions (Zalophus californianus). Microscopically, the apical cytoplasm of distal jejunal enterocytes contained multiple stages of coccidian parasites, including schizonts with merozoites and spherical gametocytes, which were morphologically similar to coccidians. By histopathology, organisms appeared to be confined to the intestine and accompanied by only mild enteritis. Using electron microscopy, both sexual (microgametocytes, macrogamonts) and asexual (schizonts, merozoites) coccidian stages were identified in enterocytes within parasitophorous vacuoles, consistent with apicomplexan development in a definitive host. Serology was negative for tissue cyst-forming coccidians, and immunohistochemistry for Toxoplasma gondii was inconclusive and negative for Neospora caninum and Sarcocystis neurona. Analysis of ITS-1 gene sequences amplified from frozen or formalin-fixed paraffin-embedded intestinal sections identified DNA sequences with closest homology to Neospora sp. (80%); these novel sequences were referred to as belonging to coccidian parasites ‘‘A,’’ ‘‘B,’’ and ‘‘C.’’ Subsequent molecular analyses completed on a neonatal harbor seal (Phoca vitulina) with protozoal lymphadenitis, hepatitis, myocarditis, and encephalitis showed that it was infected with a coccidian parasite bearing the ‘‘C’’ sequence type. Our results indicate that sea lions likely serve as definitive hosts for 3 newly described coccidian parasites, at least 1 of which is pathogenic in a marine mammal intermediate host species. PMID:21495828

Evolutionary relationships among cyst-forming coccidia Sarcocystis spp. (Alveolata: Apicomplexa: Coccidea) in endemic African tree vipers and perspective for evolution of heteroxenous life cycle

Czech Academy of Sciences Publication Activity Database

Šlapeta, Jan Roger; Modrý, David; Votýpka, Jan; Jirků, Milan; Lukeš, Julius; Koudela, Břetislav

2003-01-01

Roč. 27, č. 3 (2003), s. 464-475 ISSN 1055-7903 R&D Projects: GA ČR GA524/00/P015; GA AV ČR KSK6005114 Grant - others:GA FRVŠ(CZ) 1268/2001 Institutional research plan: CEZ:AV0Z6022909 Keywords : coccidia * Sarcocystis * evolution Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.826, year: 2003

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

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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.

The Neurona at Home project: Simulating a large-scale cellular automata brain in a distributed computing environment

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Acedo, L.; Villanueva-Oller, J.; Moraño, J. A.; Villanueva, R.-J.

2013-01-01

The Berkeley Open Infrastructure for Network Computing (BOINC) has become the standard open source solution for grid computing in the Internet. Volunteers use their computers to complete an small part of the task assigned by a dedicated server. We have developed a BOINC project called Neurona@Home whose objective is to simulate a cellular automata random network with, at least, one million neurons. We consider a cellular automata version of the integrate-and-fire model in which excitatory and inhibitory nodes can activate or deactivate neighbor nodes according to a set of probabilistic rules. Our aim is to determine the phase diagram of the model and its behaviour and to compare it with the electroencephalographic signals measured in real brains.

Funcionalidad del sistema de neuronas espejo y su implicación en los procesos de aprendizaje motor por observación

OpenAIRE

Lago Rodríguez, Ángel

2016-01-01

[Resumen] El descubrimiento de las denominadas neuronas espejo, a comienzos de los años 90 del siglo XX, ha dado pie a la realización de un gran número de investigaciones en las que se han utilizado técnicas de examen neurofisiológico (p.ej.: Estimulación Magnética Transcraneal) y de neuroimagen cerebral (p.ej.: Resonancia Magnética Funcional) con el objeto de explorar cuáles son las funciones que desempeñan, cuales son las propiedades de los estímulos que logran activarlas, y en qué áreas ce...

Prevalence and site specificity of Sarcocystis greineri sarcocysts in Virginia opossum (Didelphis virginiana) in Florida.

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Baird, K L; Cheadle, M A; Greiner, E C

2002-06-01

Sarcocysts of Sarcocystis greineri in the Virginia opossum (Didelphis virginiana) were observed for documenting sarcocyst prevalence, seasonal prevalence, and muscle specificity. Characteristics of sarcocysts found in striated muscle were recorded, as were light microscopy measurements. Overall prevalence of sarcocysts in striated muscle was 10.0% (24/240). No statistical difference (P = 0.156) in prevalence was detected between summer (13.1%; 16/122) and fall (6.7%; 8/118). Sarcocysts were found in muscles of the diaphragm, leg, breast, tongue, back, and esophagus. Diaphragm had the highest specificity of 72.7% (8/11), which was significantly different (P = 0.05) when compared with tongue and esophagus at 16.6% (1/6). Breast and leg muscle had a specificity of sarcocysts of 54.5% (6/11), whereas 27.2% (3/11) of back muscles contained sarcocysts.

First report of cerebellar abiotrophy in an Arabian foal from Argentina

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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.

Ultrastructural study of the development of Sarcocystis singaporensis sarcocysts in the muscles of its rat host

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Paperna I.

2002-06-01

Full Text Available Laboratory rats fed sporocysts of Sarcocystis singaporensis (Zaman & Colley, 1975 Zaman & Colley, 1976 originating from Singapore were euthanized 22, 23, 33 and 80 days later. Sporocysts were extracted from feces of either naturally or laboratory-infected Python reticulatus. Electron microscopically examined tongue and esophageal muscles yielded images of successive developing stages of sarcocysts. The primary wall evolved from a continuous thin layer into folds and later, into villar protrusions. At all stages the wall was interrupted by pinocytotic-like indentations. Young sarcocysts contained only metrocytes, they divided by endodyogeny into daughter metrocytes. The first bradyzoites appeared only 33 d.p.i. Sarcocysts by 80 d.p.i. were enclosed in a fully differentiated primary wall and contained almost entirely bradyzoites.

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.

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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.

Completion of the life cycle of Sarcocystis zuoi , a parasite from the Norway rat, Rattus norvegicus.

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Hu, Jun-Jie; Meng, Yu; Guo, Yan-Mei; Liao, Jie-Ying; Song, Jing-Ling

2012-06-01

Transmission experiments were performed to elucidate the life cycle of Sarcocystis zuoi found in Norway rats ( Rattus norvegicus ) in China. Two king rat snakes ( Elaphe carinata ) fed sarcocysts from the muscles of 4 naturally infected Norway rats shed sporocysts measuring 10.8 ± 0.7 × 8.0 ± 0.7 µm, with a prepatent period of 8-9 days. Sporocysts from the intestine of 2 experimentally infected king rat snakes were given to the laboratory Sprague-Dawley (SD) rats ( R. norvegicus ) and Kunming (KM) mice ( Mus musculus ). Microscopic sarcocysts developed in the skeletal muscles of SD rats. No sarcocysts were observed in KM mice. Characters of ultrastructure and molecule of sarcocysts from SD rats were confirmed as S. zuoi . Our results indicate that king rat snake is the definitive host of S. zuoi .

Sarcocystis nesbitti causes acute, relapsing febrile myositis with a high attack rate: description of a large outbreak of muscular sarcocystosis in Pangkor Island, Malaysia, 2012.

OpenAIRE

Claire M Italiano; Kum Thong Wong; Sazaly AbuBakar; Yee Ling Lau; Norlisah Ramli; Sharifah Faridah Syed Omar; Maria Kahar Bador; Chong Tin Tan

2014-01-01

BACKGROUND: From the 17th to 19th January 2012, a group of 92 college students and teachers attended a retreat in a hotel located on Pangkor Island, off the west coast of Peninsular Malaysia. Following the onset of symptoms in many participants who presented to our institute, an investigation was undertaken which ultimately identified Sarcocystis nesbitti as the cause of this outbreak. METHODOLOGY/PRINCIPAL FINDINGS: All retreat participants were identified, and clinical and epidemiological i...

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

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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

Cytokine Gene Expression in Response to SnSAG1 in Horses with Equine Protozoal Myeloencephalitis

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Spencer, Jennifer A.; Deinnocentes, Patricia; Moyana, Edith M.; Guarino, Anthony J.; Ellison, Siobhan E.; Bird, R. Curtis; Blagburn, Byron L.

2005-01-01

Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome seen in horses from the Americas and is mainly caused by Sarcocystis neurona. Recently, a 29-kDa surface antigen from S. neurona merozoites was identified as being highly immunodominant on a Western blot. This antigen has been sequenced and cloned, and the expressed protein has been named SnSAG1. In a previous study, cell-mediated immune responses to SnSAG1 were shown to be statistically significantly reduced in horses with EPM in comparison to EPM-negative control horses. It therefore appears as though the parasite is able to induce immunosuppression towards parasite-derived antigens as parasite-specific responses are decreased. Isolated peripheral blood lymphocytes from 21 EPM (cerebrospinal fluid [CSF] Western blot)-negative horses with no clinical signs and 21 horses with clinical signs of EPM (CSF Western blot positive) were cocultured with SnSAG1 for 48 and 72 h, and the effect on cytokine production was investigated by means of reverse transcriptase PCR. Cytokines assayed include gamma interferon (IFN-γ), tumor necrosis factor alpha, interleukin (IL)-2, IL-4, and IL-6. β-Actin was used as the housekeeping gene. A Wilcoxon signed-rank test of the findings indicated that there was a statistically significant decrease in IFN-γ production after 48 h in culture for samples from horses with clinical disease. There was also a statistically significant increase in IL-4 production after 72 h in culture for samples from horses with EPM. These results further support the notion that this parasite is able to subvert the immune system in horses with clinical disease. PMID:15879026

Review of sarcocystosis in Malaysia.

Science.gov (United States)

Kan, S P; Pathmanathan, R

1991-12-01

Sarcocystis is a tissue coccidian with an obligatory two-host life cycle. The sexual generations of gametogony and sporogony occur in the lamina propria of the small intestine of definitive hosts which shed infective sporocysts in their stools and present with intestinal sarcocystosis. Asexual multiplication occurs in the skeletal and cardiac muscles of intermediate hosts which harbor Sarcocystis cysts in their muscles and present with muscular sarcocystosis. In Malaysia, Sarcocystis cysts have been reported from many domestic and wild animals, including domestic and field rats, moonrats, bandicoots, slow loris, buffalo, and monkey, and man. The known definitive hosts for some species of Sarcocystis are the domestic cat, dog and the reticulated python. Human muscular sarcocystosis in Malaysia is a zoonotic infection acquired by contamination of food or drink with sporocysts shed by definitive hosts. The cysts reported in human muscle resembled those seen in the moonrat, Echinosorex gymnurus, and the long-tailed monkey, Macaca fascicularis. While human intestinal sarcocystosis has not been reported in Malaysia so far, it can be assumed that such cases may not be infrequent in view of the occurrence of Sarcocystis cysts in meat animals, such as buffalo. The overall seroprevalence of 19.8% reported among the main racial groups in Malaysia indicates that sarcocystosis (both the intestinal and muscular forms) may be emerging as a significant food-borne zoonotic infection in the country.

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.

Evaluation of the shedding of Sarcocystis falcatula sporocysts in experimentally infected Virginia opossums (Didelphis virginiana).

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Porter, R A; Ginn, P E; Dame, J B; Greiner, E C

2001-02-26

Five Virginia opossums (Didelphis virginiana) were fed muscles of brown-headed cowbirds (Molothrus ater) containing sarcocysts of Sarcocystis falcatula. Shedding of sporocysts was confirmed in all five opossums by fecal flotation. Counts were conducted daily for 2 weeks and then biweekly until the animals were euthanized and necropsied. The average prepatent period was 9.8 (7-16) days. The number of sporocysts shed varied greatly between the opossums with maximum mean shedding occurring at 71.6 (26-112) days post-infection (DPI). Average sporocyst production was 1480 sporocysts/gram of feces (SPG). Maximum output was 37,000 SPG. Average fecal yield in captivity was 17.5g of feces/day. Opossums shed 25,900 sporocysts/day (average) and a maximum of 647,500 sporocysts/day. All opossums shed sporocysts until time of euthanasia (46-200 DPI). Histologically, numerous sporocysts were present in the lamina propria at necropsy, primarily in the proximal half of the small intestine. Sporocysts were generally in clusters within the lamina propria of the luminal two-thirds of the villi. Sporocysts were found less frequently in the epithelium. No evidence of ongoing gametogony or other development was evident.

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

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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.

Sarcocystis nesbitti causes acute, relapsing febrile myositis with a high attack rate: description of a large outbreak of muscular sarcocystosis in Pangkor Island, Malaysia, 2012.

Science.gov (United States)

Italiano, Claire M; Wong, Kum Thong; AbuBakar, Sazaly; Lau, Yee Ling; Ramli, Norlisah; Syed Omar, Sharifah Faridah; Kahar Bador, Maria; Tan, Chong Tin

2014-05-01

From the 17th to 19th January 2012, a group of 92 college students and teachers attended a retreat in a hotel located on Pangkor Island, off the west coast of Peninsular Malaysia. Following the onset of symptoms in many participants who presented to our institute, an investigation was undertaken which ultimately identified Sarcocystis nesbitti as the cause of this outbreak. All retreat participants were identified, and clinical and epidemiological information was obtained via clinical review and self-reported answers to a structured questionnaire. Laboratory, imaging and muscle biopsy results were evaluated and possible sources of exposure, in particular water supply, were investigated. At an average of 9-11 days upon return from the retreat, 89 (97%) of the participants became ill. A vast majority of 94% had fever with 57% of these persons experiencing relapsing fever. Myalgia was present in 91% of patients. Facial swelling from myositis of jaw muscles occurred in 9 (10%) patients. The median duration of symptoms was 17 days (IQR 7 to 30 days; range 3 to 112). Out of 4 muscle biopsies, sarcocysts were identified in 3. S. nesbitti was identified by PCR in 3 of the 4 biopsies including one biopsy without observed sarcocyst. Non-Malaysians had a median duration of symptoms longer than that of Malaysians (27.5 days vs. 14 days, p = 0.001) and were more likely to experience moderate or severe myalgia compared to mild myalgia (83.3% vs. 40.0%, p = 0.002). The similarity of the symptoms and clustered time of onset suggests that all affected persons had muscular sarcocystosis. This is the largest human outbreak of sarcocystosis ever reported, with the specific Sarcocystis species identified. The largely non-specific clinical features of this illness suggest that S. nesbitti may be an under diagnosed infection in the tropics.

Acute fatal sarcocystosis hepatitis in an Indo-Pacific bottlenose dolphin (Tursiops aduncus) in Hong Kong.

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Calero-Bernal, R; Mauroo, N F; Hui, S W; Kuiken, T; van de Bildt, M W G; de Jong, A W; Osterhaus, A D M E; Sims, L; Gendron-Fitzpatrick, A; Carmena, D; Cerqueira-Cézar, C K; Rosenthal, B M; Dubey, J P

2017-02-15

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 4year old male Indo-Pacific bottlenose dolphin (Tursiops aduncus) from Hong Kong associated with a S. canis-like infection. Diagnosis was made based on clinical presentation, histopathology, transmission electron microscopy (TEM), and molecular characterization. Microscopically, S. canis-like like infection was confined to the liver. Immature and mature schizonts were found in hepatocytes and the parasite was associated with generalized hepatic necrosis. By TEM, schizonts divided by endopolygeny, and merozoites lacked rhoptries. Molecular characterization of parasites present in liver and brain tissues at the cox1 gene showed a high degree of identity (97-98%) and clustered together with Sarcocystis canis, S. lutrae, S. arctica, S. speeri, S. turdusi, and S. rileyi in a phylogenetic study. This is the first report of S. canis-like infection from Asia. Published by Elsevier B.V.

Molecular detection of Sarcocystis aucheniae in the blood of llamas from Argentina.

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Martin, Mara; Decker Franco, Cecilia; Romero, Sandra; Carletti, Tamara; Schnittger, Leonhard; Florin-Christensen, Monica

Sarcocystis aucheniae are apicomplexan protozoa that infect South American camelids (SACs), giving rise to macroscopic cysts similar to rice grains in skeletal muscles. Visual detection of macrocysts in slaughtered animals hampers commercialization of SAC meat, a highly relevant economic exploitation for Andean rural families. Importantly, the consumption of undercooked S. aucheniae-infested meat causes gastroenteritis. A carnivore definitive host, possibly the dog, acquires the parasite when feeding on infected SAC meat, and later eliminates infective oocysts in its feces. The parasite cycle is completed when SACs ingest contaminated water or pastures. We hypothesized that parasite DNA can be detected in SAC blood using molecular methods. In order to test this hypothesis, a seminested PCR format was specifically designed to target the hypervariable 18S rRNA gene region of S. aucheniae. PCR conditions were optimized using genomic DNA extracted from macrocyst bradyzoites. A detection limit of up to 1 parasite in 10μl of llama blood was established based on DNA samples extracted from aliquots of S. aucheniae bradyzoite-spiked non-infected llama blood. The seminested PCR allowed to detect natural infections of S. aucheniae in llama blood samples originating in the Andean flatlands of Argentina. Specific amplification of S. aucheniae DNA was corroborated by amplicon sequencing. This is the first report of S. aucheniae detection in llama blood, which provides a valuable diagnostic tool for epidemiological studies and for the evaluation of the efficacy of control measures for this parasitosis. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Sarcocystis nesbitti causes acute, relapsing febrile myositis with a high attack rate: description of a large outbreak of muscular sarcocystosis in Pangkor Island, Malaysia, 2012.

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Claire M Italiano

2014-05-01

Full Text Available BACKGROUND: From the 17th to 19th January 2012, a group of 92 college students and teachers attended a retreat in a hotel located on Pangkor Island, off the west coast of Peninsular Malaysia. Following the onset of symptoms in many participants who presented to our institute, an investigation was undertaken which ultimately identified Sarcocystis nesbitti as the cause of this outbreak. METHODOLOGY/PRINCIPAL FINDINGS: All retreat participants were identified, and clinical and epidemiological information was obtained via clinical review and self-reported answers to a structured questionnaire. Laboratory, imaging and muscle biopsy results were evaluated and possible sources of exposure, in particular water supply, were investigated. At an average of 9-11 days upon return from the retreat, 89 (97% of the participants became ill. A vast majority of 94% had fever with 57% of these persons experiencing relapsing fever. Myalgia was present in 91% of patients. Facial swelling from myositis of jaw muscles occurred in 9 (10% patients. The median duration of symptoms was 17 days (IQR 7 to 30 days; range 3 to 112. Out of 4 muscle biopsies, sarcocysts were identified in 3. S. nesbitti was identified by PCR in 3 of the 4 biopsies including one biopsy without observed sarcocyst. Non-Malaysians had a median duration of symptoms longer than that of Malaysians (27.5 days vs. 14 days, p = 0.001 and were more likely to experience moderate or severe myalgia compared to mild myalgia (83.3% vs. 40.0%, p = 0.002. CONCLUSIONS/SIGNIFICANCE: The similarity of the symptoms and clustered time of onset suggests that all affected persons had muscular sarcocystosis. This is the largest human outbreak of sarcocystosis ever reported, with the specific Sarcocystis species identified. The largely non-specific clinical features of this illness suggest that S. nesbitti may be an under diagnosed infection in the tropics.

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

Science.gov (United States)

Goldstein, Tracey; Gill, Verena A.; Tuomi, Pamela A.; Monson, Daniel H.; Burdin, Alexander; Conrad, Patricia A.; Dunn, J. Lawrence; Field, Cara L.; Johnson, Christine K.; Jessup, David A.; Bodkin, James L.; Doroff, Angela 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.

RNG1 is a Late Marker of the Apical Polar Ring in Toxoplasma gondii

Science.gov (United States)

Tran, Johnson Q.; de Leon, Jessica C.; Li, Catherine; Huynh, My-Hang; Beatty, Wandy; Morrissette, Naomi S.

2010-01-01

The asexually proliferating stages of apicomplexan parasites cause acute symptoms of diseases such as malaria, cryptosporidiosis and toxoplasmosis. These stages are characterized by the presence of two independent microtubule organizing centers (MTOCs). Centrioles are found at the poles of the intranuclear spindle. The apical polar ring (APR), a MTOC unique to apicomplexans, organizes subpellicular microtubules which impose cell shape and apical polarity on these protozoa. Here we describe the characteristics of a novel protein that localizes to the APR of Toxoplasma gondii which we have named ring-1 (RNG1). There are related RNG1 proteins in Neospora caninum and Sarcocystis neurona but no obvious homologs in Plasmodium spp., Cryptosporidium spp. or Babesia spp. RNG1 is a small, low-complexity, detergent-insoluble protein that assembles at the APR very late in the process of daughter parasite replication. We were unable to knock-out the RNG1 gene, suggesting that its gene product is essential. Tagged RNG1 lines have also allowed us to visualize the APR during growth of Toxoplasma in the microtubule-disrupting drug oryzalin. Oryzalin inhibits nuclear division and cytokinesis although Toxoplasma growth continues, and similar to earlier observations of unchecked centriole duplication in oryzalin-treated parasites, the APR continues to duplicate during aberrant parasite growth. PMID:20658557

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

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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

Human and animal sarcocystosis in Malaysia: A review

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Baha Latif

2016-11-01

Full Text Available Sarcocystosis is a zoonotic disease caused by a coccidian intracellular protozoan parasite of the genus Sarcocystis. More than 200 Sarcocystis species have been recorded and the parasites are found in mammals, birds and reptiles. They require two hosts to complete their life cycle. In Malaysia, sarcocystosis was reported as a potential emerging food and water-borne disease after a series of large outbreak of human infections. There was not enough attention given before even though it was reported in both humans and animals. The first human case of invasive muscular sarcocystosis among local Malaysian was reported in 1975. Besides, a retrospective autopsy examination on 100 tongues revealed 21% positive cases. On top of that, a sero-epidemiological survey conducted in 243 subjects in West Malaysia showed that 19.7% had Sarcocystis antibodies. The clinical symptoms of muscular sarcocystosis were first described comprehensively in 1999. Meanwhile, many types of animals including livestock were found harbor the sarcocysts in their tissue. The first case of human intestinal sarcocystosis was reported in 2014. This review indicates that human sarcocystosis is currently endemic in Malaysia and parallel to that reported in animals. However, more studies and investigations need to be conducted since the source of human infection remains unknown.

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

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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

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

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

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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

The Development of a Novel, Validated, Rapid and Simple Method for the Detection of Sarcocystis fayeri in Horse Meat in the Sanitary Control Setting.

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Furukawa, Masato; Minegishi, Yasutaka; Izumiyama, Shinji; Yagita, Kenji; Mori, Hideto; Uemura, Taku; Etoh, Yoshiki; Maeda, Eriko; Sasaki, Mari; Ichinose, Kazuya; Harada, Seiya; Kamata, Yoichi; Otagiri, Masaki; Sugita-Konishi, Yoshiko; Ohnishi, Takahiro

2016-01-01

Sarcocystis fayeri (S. fayeri) is a newly identified causative agent of foodborne disease that is associated with the consumption of raw horse meat. The testing methods prescribed by the Ministry of Health, Labour and Welfare of Japan are time consuming and require the use of expensive equipment and a high level of technical expertise. Accordingly, these methods are not suitable for use in the routine sanitary control setting to prevent outbreaks of foodborne disease. In order to solve these problems, we have developed a new, rapid and simple testing method using LAMP, which takes only 1 hour to perform and which does not involve the use of any expensive equipment or expert techniques. For the validation of this method, an inter-laboratory study was performed among 5 institutes using 10 samples infected with various concentrations of S. fayeri. The results of the inter-laboratory study demonstrated that our LAMP method could detect S. fayeri at concentrations greater than 10(4) copies/g. Thus, this new method could be useful in screening for S. fayeri as a routine sanitary control procedure.

[Control of toxicity of Sarcocystis fayeri in horsemeat by freezing treatment and prevention of food poisoning caused by raw consumption of horsemeat].

Science.gov (United States)

Harada, Seiya; Furukawa, Masato; Tokuoka, Eisuke; Matsumoto, Kazutoshi; Yahiro, Shunsuke; Miyasaka, Jiro; Saito, Morihiro; Kamata, Yoichi; Watanabe, Maiko; Irikura, Daisuke; Matsumoto, Hiroshi; Sugita-Konishi, Yoshiko

2013-01-01

More than 27 outbreaks per year of food poisoning caused by consuming horse meat were reported in Kumamoto Prefecture (including Kumamoto City) from January 2009 to September 2011. It was found that the causative agent of the outbreaks was a protein with a molecular weight of 15 kDa that had originated from bradyzoites of Sarcocystis fayeri parasitizing the horse meat. Rabit ileal loop tests showed that pepsin treatment of homogenates of frozen horse meat containing the cysts of S. fayeri induced loss of toxicity, presumably by digestion of the proteinous causative agent(s). Slices of horse meat containing the cysts were frozen at below -20°C for various periods. The cysts were collected after thawing the slices, then treated in an artificial stomach juice containing pepsin. The bradyzoites of the cysts kept at -20°C for 48 hr or more completely disappeared. Simultaneously, the 15 kDa protein also disappeared in the frozen cysts. After notifying the public and recommending freezing treatment of horse meat, no subsequent cases of food poisoning were reported. This indicates that freezing of horse meat is effective to prevent the occurrence of food poisoning caused by consuming raw horse meat containing S. fayeri.

First report of human intestinal sarcocystosis in Cambodia.

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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.

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

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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.

Why our brains cherish humanity: Mirror neurons and colamus humanitatem

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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.

Redes neuronales de propagación inversa

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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.

Toxic Neuronal Death by Glyeraldehyde-3-Phosphate Dehydrogenase and Mitochondria

Science.gov (United States)

2003-08-01

bra ins (Sunaga et a l., 1995), and GAPDH nu- clear accumula t ion is presen t in associa t ion with apoptosis in n igra l neurona l nuclei in...GAPDH glycolyt ic act ivity does not appear to be a ltered in HD bra in t issue (Kish et a l., 1998). Neurona l loss, likely by apoptosis, is cen t...well pla tes and par t ia lly neurona lly differen- t ia ted (PND) for 6 days in the same media supplemented with 100 ng/ml 7S nerve growth factor [NGF

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

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

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.

2009-01-01

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. PMID:19720009

MODELANDO EL CRECIMIENTO DE NEURITAS

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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.

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.

Copying the development: mirror neurons in child development

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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.

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

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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.

Quantitative analysis of basal dendritic tree of layer III pyramidal neurons in different areas of adult human frontal cortex

OpenAIRE

Zeba, Martina; Jovanov-Milošević, Nataša; Petanjek, Zdravko

2008-01-01

Istraživanja mozga u primata ukazala su na dominantnu ulogu kortiko-kortikalnih piramidnih neurona IIIc sloja u neurobiologiji spoznajnih funkcija. U ovom radu prikazujemo rezultate usporedbene kvantitativne analize morfologije dendritičkog stabla najvećih neurona sloja IIIc impregniranih Golgi metodom, između tri različite Brodmannove areje (BA) frontalnog režnja mozga odraslog čovjeka: primarna motorna BA4, asocijativna magnopiramidalna BA9, te obostrano, govorna Brocina BA45. Statističkom ...

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

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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.

Desarrollo de una herramienta de arquitectura abierta para la visualización y análisis de señales EEG

OpenAIRE

Arango, Ramiro; Naranjo, John Jairo

2010-01-01

El sistema nervioso funciona mediante contactos eléctricos entre neuronas, configurando circuitos específicos para cada función neurológica. La electroencefalografía es una técnica exploratoria no invasiva, que permite registrar la actividad bioeléctrica (ondas cerebrales) de las neuronas de la corteza cerebral, mediante unos aparatos adecuados y la colocación previa de unos electrodos, en unas posiciones estándar. El registro gráfico obtenido se denomina electroencefalogr...

Dynamics of spontaneous activity in the cerebral cortex across brain states

OpenAIRE

Jercog, Daniel Alejandro

2013-01-01

[spa] La actividad espontánea en la corteza cerebral cambia en diferentes estados cerebrales. Durante estados desincronizados (e.g. estado de vigilia, sueño MOR), las poblaciones de neuronas en los potenciales de acción en una manera aparentemente estocástica y no correlacionada. Por el contrario, durante estados sincronizados (e.g. sueño de ondas lentas, anestesia) las neuronas corticales muestran la alternancia entre periodos de reposo (DOWN) y los períodos de actividad (UP) de manera coher...

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

Pathogen exposure and blood chemistry in the Washington 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.

2013-01-01

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).

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...

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...

El espejo de la acción y la encarnación de la cognición

OpenAIRE

Yorio, Alberto A.

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...

Evaluación de la expresión de las proteínas de choque térmico

OpenAIRE

Rodríguez Bernal, Ángela María

2009-01-01

En el tejido nervioso las neuronas son altamente sensibles a varios tipos de daño como la isquemia, la hipoxia la hipoglicemia, la infección y el trauma. Al respecto, también se sabe que la sensibilidad de las s neuronas a estos tipos de daño varía entre diferentes zonas cerebrales. En el tratamiento de patologías como aneurismas del sistema nerviosos, o durante procedimientos como la angioplastia intracraneana, con frecuencia es necesario realizar la oclusión temporal de una arteria lo que b...

Efecto de la pérdida de la inervación dopaminérgica del núcleo subtalámico sobre la conducta motora de ratas

OpenAIRE

Nancy Pavón-Fuentes; Lisette Blanco-Lezcano; Lourdes Lorigados-Pedre; Lázaro Álvarez-González; Lisis Martínez-Martí; Raúl Macías-González

2010-01-01

Actualmente la enfermedad de Parkinson es considerada como un trastorno del sistema nervioso central que afecta a los ganglios basales. Las características anatomopatológicas más prominentes de esta enfermedad son: degeneración de las células dopaminérgicas de la substantia nigra pars compacta (SNc), la existencia de gliosis y la presencia de cuerpos eosinófilos de inclusión. La relevancia fisiológica de la modulación directa de las neuronas del núcleo subtalámico (NST) por neuronas dopaminér...

Sistema glutamatérgico II: alteraciones en isquemia, alzheimer y esquizofrenia

OpenAIRE

Pimienta Jiménez, Hernán J; Medina Marín, Adriana M; Betancourth, Martha I

2003-01-01

Las neuronas piramidales de la corteza cerebral utilizan ácido glutámico como neurotransmisor. Diferentes tipos de aferentes convergen sobre ellas. Al mismo tiempo, estas células dan lugar a fibras eferentes que interconectan ampliamente variados sectores de la corteza, los núcleos de la base y el tálamo. La tríada de interacciones recíprocas entre neuronas glutamatérgicas, gabaérgicas y monoaminérgicas en regiones límbicas, en la neocorteza y en centros reguladores de la función cortical, co...

Mirror Neurons, Theatrical Mirrors and the Honor Code

OpenAIRE

Greer, M.G. (Margaret G.)

2012-01-01

Este artículo relaciona el descubrimiento de cierta clase de células cerebrales denominados «neuronas espejo», que pueden ayudar a explicar la base biológica de la naturaleza pre-conceptual, pre-lingüística de la cognición humana, a la teoría lacaniana de la formación de la subjetividad humana en el espacio del Otro. Así explica la naturaleza inter-sujetiva del honor que Lope describe en Los comendadores de Córdoba como «aquélla que consiste en otro». La teoría de las neuronas espejo muestra ...

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

OpenAIRE

Myriam L. Velandia; José V. Montoya; Marlén Martínez; Sandra Perdomo; Jaime E. Castellanos

2002-01-01

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 espi...

La célula de schwann

OpenAIRE

Perdomo, Sandra; Spinel, Clara

2011-01-01

Las neuronas son las células del sistema nervioso y están recubiertas y protegidas por células gliales. En el sistema nerviosos periférico las células de Schwann (CS) son la glía de los nervios. Las prolongaciones o neuritas (axón y dendrita) de los cuerpos de las neuronas son recubiertas por las CS y constituyen las fibras nerviosas. La relación íntima entre la CS y la neurita se determina durante el desarrollo embrionario. La CS es esencial en la migración correcta de las neuritas hacia su ...

La célula de Schwann The Schwann Cell

OpenAIRE

Spinel Clara; Perdomo Sandra

2004-01-01

Las neuronas son las células del sistema nervioso y están recubiertas y protegidas por células gliales. En el sistema nerviosos periférico las células de Schwann (CS) son la glía de los nervios. Las prolongaciones o neuritas (axón y dendrita) de los cuerpos de las neuronas son recubiertas por las CS y constituyen las fibras nerviosas. La relación íntima entre la CS y la neurita se determina durante el desarrollo embrionario. La CS es esencial en la migración correcta de las neuritas hacia su ...

Los fármacos antidepresivos como reguladores de la neurogénesis hipocámpica de roedores y humanos adultos

OpenAIRE

Ramírez-Rodríguez, Gerardo; Laguna-Chimal, José; Vega-Rivera, Nelly M.; Ortiz-López, Leonardo; Méndez-Cuesta, Luis; Estrada-Camarena, Erika M.; Babu, Harish

2011-01-01

El hallazgo de la formación de nuevas neuronas en el giro dentado (GD) del hipocampo amplió el conocimiento acerca de la plasticidad del encéfalo. En este sentido, la neurogénesis es un proceso que involucra diferentes eventos celulares tales como: la división de las células madre, la proliferación de los neuroblastos, la migración y la sobrevivencia celular, así como la maduración dendrítica, la elongación axonal y la integración de las neuronas nuevas a los circuitos neuronales existentes. ...

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

Tissue types (image)

Science.gov (United States)

... are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue supports ... binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of the ...

SARCOSPORIDIOSIS - MEDICAL IMPORTANCE AND DIAGNOSIS

Directory of Open Access Journals (Sweden)

Milena Misic

2004-07-01

Full Text Available Sarcosporidiosis (Sarcocystis infection is caused by an intracellular protozoan parasite that predominantly affects animals. It can rarely be found in human skeletal and cardiac muscle in humans. There are two different forms of sarcosporidiosis in humans. These cases of muscular sarcocystosis were probably zoonotic in origin and associated with close contact with definitive hosts (both domestic and wild animals thus permitting the contamination of food and drink with sporocystis shed by these definitive hosts. The second mode of infection for humans is ingested animal tissues which containing sporozoites (e.g., undercooked meats. These sporozoited directly intestinal epithelial cells and can enter the circulation in an manner similiar to those released from oocysts from the intermediate or accidental host.

Tissue bionics: examples in biomimetic tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Green, David W [Bone and Joint Research Group, Developmental Origins of Health and Disease, General Hospital, University of Southampton, SO16 6YD (United Kingdom)], E-mail: Hindoostuart@googlemail.com

2008-09-01

Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

Tissue bionics: examples in biomimetic tissue engineering

International Nuclear Information System (INIS)

Green, David W

2008-01-01

Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic

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 treatment of hunting dogs may be an

Tissue engineering

CERN Document Server

Fisher, John P; Bronzino, Joseph D

2007-01-01

Increasingly viewed as the future of medicine, the field of tissue engineering is still in its infancy. As evidenced in both the scientific and popular press, there exists considerable excitement surrounding the strategy of regenerative medicine. To achieve its highest potential, a series of technological advances must be made. Putting the numerous breakthroughs made in this field into a broad context, Tissue Engineering disseminates current thinking on the development of engineered tissues. Divided into three sections, the book covers the fundamentals of tissue engineering, enabling technologies, and tissue engineering applications. It examines the properties of stem cells, primary cells, growth factors, and extracellular matrix as well as their impact on the development of tissue engineered devices. Contributions focus on those strategies typically incorporated into tissue engineered devices or utilized in their development, including scaffolds, nanocomposites, bioreactors, drug delivery systems, and gene t...

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.

Efecto de la conductancia de potasio Kv3.1 en la tasa y frecuencia de disparo de un axón no mielinado

Directory of Open Access Journals (Sweden)

Oscar Emilio Hernández Bustos

2011-01-01

Full Text Available Objetivo: Determinar la relación entre la conductancia de potasio Kv3.1 y la tasa de disparo (Td de un modelo neuronal llamado neurona1 formado por un soma, un cuello y un axón no mielinado durante un estímulo de corriente de 10 ms de duración y a 40°C. Materiales y métodos: A partir del software libre NEURON se simuló la propagación de ráfagas de potenciales de acción a través de neurona1, variando la conductancia específica máxima de potasio Kv3.1 (GKv3.1 relativa a la conductancia específica máxima de potasio (GK estudiada por A.L. Hodgkin y A.F. Huxley en 1952, de tal forma que GKv3.1+GK=1.6S/ cm2. Resultados: En una estructura neuronal con las características biofísicas de neurona1, Td varía en forma sigmoidea para 0 ¿ GKv3.1/GK ¿ 0.455 y decae exponencialmente para 0.455 < GKv3.1/GK ¿ 15, respectivamente. Para el primer caso, Td aumenta 11 veces más que la frecuencia (f respecto del número de espigas en cada ráfaga. Conclusión: La observación de la conductancia de potasio del tipo Kv3.1 en algún tipo de neurona no implica necesariamente la propagación de ráfagas de alta tasa de disparo. Su efecto es más pronunciado (11 veces en la modulación de Td que en el aumento de f.

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

Localization of IAA transporting tissue by tissue printing and autoradiography

International Nuclear Information System (INIS)

Mee-Rye Cha; Evans, M.L.; Hangarter, R.P.

1991-01-01

Tissue printing on nitrocellulose membranes provides a useful technique for visualizing anatomical details of tissue morphology of cut ends of stem segments. Basal ends of Coleus stem and corn coleoptile segments that were transporting 14 C-IAA were gently blotted onto DEAE-nitrocellulose for several minutes to allow 14 C-IAA to efflux from the tissue. Because of the anion exchange properties of DEAE-nitrocellulose the 14 C-IAA remains on the membrane at the point it leaves the transporting tissue. Autoradiography of the DEAE membrane allowed indirect visualization of the tissues preferentially involved in auxin transport. The authors observed that polar transport through the stem segments occurred primarily through or in association with vascular tissues. However, in Coleus stems, substantial amounts of the label appeared to move through the tissue by diffusion as well as by active transport

Engineering Complex Tissues

Science.gov (United States)

MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

2010-01-01

This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

Tissue

Directory of Open Access Journals (Sweden)

David Morrissey

2012-01-01

Full Text Available Purpose. In vivo gene therapy directed at tissues of mesenchymal origin could potentially augment healing. We aimed to assess the duration and magnitude of transene expression in vivo in mice and ex vivo in human tissues. Methods. Using bioluminescence imaging, plasmid and adenoviral vector-based transgene expression in murine quadriceps in vivo was examined. Temporal control was assessed using a doxycycline-inducible system. An ex vivo model was developed and optimised using murine tissue, and applied in ex vivo human tissue. Results. In vivo plasmid-based transgene expression did not silence in murine muscle, unlike in liver. Although maximum luciferase expression was higher in muscle with adenoviral delivery compared with plasmid, expression reduced over time. The inducible promoter cassette successfully regulated gene expression with maximum levels a factor of 11 greater than baseline. Expression was re-induced to a similar level on a temporal basis. Luciferase expression was readily detected ex vivo in human muscle and tendon. Conclusions. Plasmid constructs resulted in long-term in vivo gene expression in skeletal muscle, in a controllable fashion utilising an inducible promoter in combination with oral agents. Successful plasmid gene transfection in human ex vivo mesenchymal tissue was demonstrated for the first time.

Effects of tissue mechanical properties on susceptibility to histotripsy-induced tissue damage

Science.gov (United States)

Vlaisavljevich, Eli; Kim, Yohan; Owens, Gabe; Roberts, William; Cain, Charles; Xu, Zhen

2014-01-01

Histotripsy is a non-invasive tissue ablation method capable of fractionating tissue by controlling acoustic cavitation. To determine the fractionation susceptibility of various tissues, we investigated histotripsy-induced damage on tissue phantoms and ex vivo tissues with different mechanical strengths. A histotripsy bubble cloud was formed at tissue phantom surfaces using 5-cycle long ultrasound pulses with peak negative pressure of 18 MPa and PRFs of 10, 100, and 1000 Hz. Results showed significantly smaller lesions were generated in tissue phantoms of higher mechanical strength. Histotripsy was also applied to 43 different ex vivo porcine tissues with a wide range of mechanical properties. Gross morphology demonstrated stronger tissues with higher ultimate stress, higher density, and lower water content were more resistant to histotripsy damage in comparison to weaker tissues. Based on these results, a self-limiting vessel-sparing treatment strategy was developed in an attempt to preserve major vessels while fractionating the surrounding target tissue. This strategy was tested in porcine liver in vivo. After treatment, major hepatic blood vessels and bile ducts remained intact within a completely fractionated liver volume. These results identify varying susceptibilities of tissues to histotripsy therapy and provide a rational basis to optimize histotripsy parameters for treatment of specific tissues.

Use of Synthetic Nerve Grafts to Restore Cavernous Nerve Function Following Prostate Cancer Surgery: In Vitro and In Vivo Studies

National Research Council Canada - National Science Library

Konety, Badrinath R

2006-01-01

.... Schwann cell and neurona stem cells en neurite growth are being investigated. Tubulized sheets of the polymer with and without those factors/cells have been used to microsurgically replace resected cavernous nerve...

Tissue-specific mRNA expression profiling in grape berry tissues

Science.gov (United States)

Grimplet, Jerome; Deluc, Laurent G; Tillett, Richard L; Wheatley, Matthew D; Schlauch, Karen A; Cramer, Grant R; Cushman, John C

2007-01-01

Background Berries of grape (Vitis vinifera) contain three major tissue types (skin, pulp and seed) all of which contribute to the aroma, color, and flavor characters of wine. The pericarp, which is composed of the exocarp (skin) and mesocarp (pulp), not only functions to protect and feed the developing seed, but also to assist in the dispersal of the mature seed by avian and mammalian vectors. The skin provides volatile and nonvolatile aroma and color compounds, the pulp contributes organic acids and sugars, and the seeds provide condensed tannins, all of which are important to the formation of organoleptic characteristics of wine. In order to understand the transcriptional network responsible for controlling tissue-specific mRNA expression patterns, mRNA expression profiling was conducted on each tissue of mature berries of V. vinifera Cabernet Sauvignon using the Affymetrix GeneChip® Vitis oligonucleotide microarray ver. 1.0. In order to monitor the influence of water-deficit stress on tissue-specific expression patterns, mRNA expression profiles were also compared from mature berries harvested from vines subjected to well-watered or water-deficit conditions. Results Overall, berry tissues were found to express approximately 76% of genes represented on the Vitis microarray. Approximately 60% of these genes exhibited significant differential expression in one or more of the three major tissue types with more than 28% of genes showing pronounced (2-fold or greater) differences in mRNA expression. The largest difference in tissue-specific expression was observed between the seed and pulp/skin. Exocarp tissue, which is involved in pathogen defense and pigment production, showed higher mRNA abundance relative to other berry tissues for genes involved with flavonoid biosynthesis, pathogen resistance, and cell wall modification. Mesocarp tissue, which is considered a nutritive tissue, exhibited a higher mRNA abundance of genes involved in cell wall function and

Tissue-specific mRNA expression profiling in grape berry tissues

Directory of Open Access Journals (Sweden)

Cramer Grant R

2007-06-01

Full Text Available Abstract Background Berries of grape (Vitis vinifera contain three major tissue types (skin, pulp and seed all of which contribute to the aroma, color, and flavor characters of wine. The pericarp, which is composed of the exocarp (skin and mesocarp (pulp, not only functions to protect and feed the developing seed, but also to assist in the dispersal of the mature seed by avian and mammalian vectors. The skin provides volatile and nonvolatile aroma and color compounds, the pulp contributes organic acids and sugars, and the seeds provide condensed tannins, all of which are important to the formation of organoleptic characteristics of wine. In order to understand the transcriptional network responsible for controlling tissue-specific mRNA expression patterns, mRNA expression profiling was conducted on each tissue of mature berries of V. vinifera Cabernet Sauvignon using the Affymetrix GeneChip® Vitis oligonucleotide microarray ver. 1.0. In order to monitor the influence of water-deficit stress on tissue-specific expression patterns, mRNA expression profiles were also compared from mature berries harvested from vines subjected to well-watered or water-deficit conditions. Results Overall, berry tissues were found to express approximately 76% of genes represented on the Vitis microarray. Approximately 60% of these genes exhibited significant differential expression in one or more of the three major tissue types with more than 28% of genes showing pronounced (2-fold or greater differences in mRNA expression. The largest difference in tissue-specific expression was observed between the seed and pulp/skin. Exocarp tissue, which is involved in pathogen defense and pigment production, showed higher mRNA abundance relative to other berry tissues for genes involved with flavonoid biosynthesis, pathogen resistance, and cell wall modification. Mesocarp tissue, which is considered a nutritive tissue, exhibited a higher mRNA abundance of genes involved in cell

Monitoring of tissue optical properties during thermal coagulation of ex vivo tissues.

Science.gov (United States)

Nagarajan, Vivek Krishna; Yu, Bing

2016-09-01

Real-time monitoring of tissue status during thermal ablation of tumors is critical to ensure complete destruction of tumor mass, while avoiding tissue charring and excessive damage to normal tissues. Currently, magnetic resonance thermometry (MRT), along with magnetic resonance imaging (MRI), is the most commonly used technique for monitoring and assessing thermal ablation process in soft tissues. MRT/MRI is very expensive, bulky, and often subject to motion artifacts. On the other hand, light propagation within tissue is sensitive to changes in tissue microstructure and physiology which could be used to directly quantify the extent of tissue damage. Furthermore, optical monitoring can be a portable, and cost-effective alternative for monitoring a thermal ablation process. The main objective of this study, is to establish a correlation between changes in tissue optical properties and the status of tissue coagulation/damage during heating of ex vivo tissues. A portable diffuse reflectance spectroscopy system and a side-firing fiber-optic probe were developed to study the absorption (μa (λ)), and reduced scattering coefficients (μ's (λ)) of native and coagulated ex vivo porcine, and chicken breast tissues. In the first experiment, both porcine and chicken breast tissues were heated at discrete temperature points between 24 and 140°C for 2 minutes. Diffuse reflectance spectra (430-630 nm) of native and coagulated tissues were recorded prior to, and post heating. In a second experiment, porcine tissue samples were heated at 70°C and diffuse reflectance spectra were recorded continuously during heating. The μa (λ) and μ's (λ) of the tissues were extracted from the measured diffuse reflectance spectra using an inverse Monte-Carlo model of diffuse reflectance. Tissue heating was stopped when the wavelength-averaged scattering plateaued. The wavelength-averaged optical properties, and , for native porcine tissues (n = 66) at room temperature, were 5.4�

Soft Tissue Sarcoma

Science.gov (United States)

... muscles, tendons, fat, and blood vessels. Soft tissue sarcoma is a cancer of these soft tissues. There ... have certain genetic diseases. Doctors diagnose soft tissue sarcomas with a biopsy. Treatments include surgery to remove ...

Ontology-based, Tissue MicroArray oriented, image centered tissue bank

Directory of Open Access Journals (Sweden)

Viti Federica

2008-04-01

Full Text Available Abstract Background Tissue MicroArray technique is becoming increasingly important in pathology for the validation of experimental data from transcriptomic analysis. This approach produces many images which need to be properly managed, if possible with an infrastructure able to support tissue sharing between institutes. Moreover, the available frameworks oriented to Tissue MicroArray provide good storage for clinical patient, sample treatment and block construction information, but their utility is limited by the lack of data integration with biomolecular information. Results In this work we propose a Tissue MicroArray web oriented system to support researchers in managing bio-samples and, through the use of ontologies, enables tissue sharing aimed at the design of Tissue MicroArray experiments and results evaluation. Indeed, our system provides ontological description both for pre-analysis tissue images and for post-process analysis image results, which is crucial for information exchange. Moreover, working on well-defined terms it is then possible to query web resources for literature articles to integrate both pathology and bioinformatics data. Conclusions Using this system, users associate an ontology-based description to each image uploaded into the database and also integrate results with the ontological description of biosequences identified in every tissue. Moreover, it is possible to integrate the ontological description provided by the user with a full compliant gene ontology definition, enabling statistical studies about correlation between the analyzed pathology and the most commonly related biological processes.

Modeling collagen remodeling in tissue engineered cardiovascular tissues

NARCIS (Netherlands)

Soares, A.L.F.

2012-01-01

Commonly, heart valve replacements consist of non-living materials lacking the ability to grow, repair and remodel. Tissue engineering (TE) offers a promising alternative to these replacement strategies since it can overcome its disadvantages. The technique aims to create an autologous living tissue

Development of tissue bank

Directory of Open Access Journals (Sweden)

R P Narayan

2012-01-01

Full Text Available The history of tissue banking is as old as the use of skin grafting for resurfacing of burn wounds. Beneficial effects of tissue grafts led to wide spread use of auto and allograft for management of varied clinical conditions like skin wounds, bone defects following trauma or tumor ablation. Availability of adequate amount of tissues at the time of requirement was the biggest challenge that forced clinicians to find out techniques to preserve the living tissue for prolonged period of time for later use and thus the foundation of tissue banking was started in early twentieth century. Harvesting, processing, storage and transportation of human tissues for clinical use is the major activity of tissue banks. Low temperature storage of processed tissue is the best preservation technique at present. Tissue banking organization is a very complex system and needs high technical expertise and skilled personnel for proper functioning in a dedicated facility. A small lapse/deviation from the established protocol leads to loss of precious tissues and or harm to recipients as well as the risk of transmission of deadly diseases and tumors. Strict tissue transplant acts and stringent regulations help to streamline the whole process of tissue banking safe for recipients and to community as whole.

Ethical tissue: a not-for-profit model for human tissue supply.

Science.gov (United States)

Adams, Kevin; Martin, Sandie

2011-02-01

Following legislative changes in 2004 and the establishment of the Human Tissue Authority, access to human tissues for biomedical research became a more onerous and tightly regulated process. Ethical Tissue was established to meet the growing demand for human tissues, using a process that provided ease of access by researchers whilst maintaining the highest ethical and regulatory standards. The establishment of a licensed research tissue bank entailed several key criteria covering ethical, legal, financial and logistical issues being met. A wide range of stakeholders, including the HTA, University of Bradford, flagged LREC, hospital trusts and clinical groups were also integral to the process.

Tissue Classification

DEFF Research Database (Denmark)

Van Leemput, Koen; Puonti, Oula

2015-01-01

Computational methods for automatically segmenting magnetic resonance images of the brain have seen tremendous advances in recent years. So-called tissue classification techniques, aimed at extracting the three main brain tissue classes (white matter, gray matter, and cerebrospinal fluid), are now...... well established. In their simplest form, these methods classify voxels independently based on their intensity alone, although much more sophisticated models are typically used in practice. This article aims to give an overview of often-used computational techniques for brain tissue classification...

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.

Connective Tissue Disorders

Science.gov (United States)

... of connective tissue. Over 200 disorders that impact connective tissue. There are different types: Genetic disorders, such as Ehlers-Danlos syndrome, Marfan syndrome, and osteogenesis imperfecta Autoimmune disorders, such as lupus and scleroderma Cancers, like some types of soft tissue sarcoma Each ...

Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces

Science.gov (United States)

Boys, Alexander J.; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J.; Estroff, Lara A.

2017-01-01

Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors. PMID:29333332

Engineering Musculoskeletal Tissue Interfaces

Directory of Open Access Journals (Sweden)

Ece Bayrak

2018-04-01

Full Text Available Tissue engineering aims to bring together biomaterials, cells, and signaling molecules within properly designed microenvironments in order to create viable treatment options for the lost or malfunctioning tissues. Design and production of scaffolds and cell-laden grafts that mimic the complex structural and functional features of tissues are among the most important elements of tissue engineering strategy. Although all tissues have their own complex structure, an even more complex case in terms of engineering a proper carrier material is encountered at the tissue interfaces, where two distinct tissues come together. The interfaces in the body can be examined in four categories; cartilage-bone and ligament-bone interfaces at the knee and the spine, tendon-bone interfaces at the shoulder and the feet, and muscle-tendon interface at the skeletal system. These interfaces are seen mainly at the soft-to-hard tissue transitions and they are especially susceptible to injury and tear due to the biomechanical inconsistency between these tissues where high strain fields are present. Therefore, engineering the musculoskeletal tissue interfaces remain a challenge. This review focuses on recent advancements in strategies for musculoskeletal interface engineering using different biomaterial-based platforms and surface modification techniques.

Dynamic impact indentation of hydrated biological tissues and tissue surrogate gels

Science.gov (United States)

Ilke Kalcioglu, Z.; Qu, Meng; Strawhecker, Kenneth E.; Shazly, Tarek; Edelman, Elazer; VanLandingham, Mark R.; Smith, James F.; Van Vliet, Krystyn J.

2011-03-01

For both materials engineering research and applied biomedicine, a growing need exists to quantify mechanical behaviour of tissues under defined hydration and loading conditions. In particular, characterisation under dynamic contact-loading conditions can enable quantitative predictions of deformation due to high rate 'impact' events typical of industrial accidents and ballistic insults. The impact indentation responses were examined of both hydrated tissues and candidate tissue surrogate materials. The goals of this work were to determine the mechanical response of fully hydrated soft tissues under defined dynamic loading conditions, and to identify design principles by which synthetic, air-stable polymers could mimic those responses. Soft tissues from two organs (liver and heart), a commercially available tissue surrogate gel (Perma-Gel™) and three styrenic block copolymer gels were investigated. Impact indentation enabled quantification of resistance to penetration and energy dissipative constants under the rates and energy densities of interest for tissue surrogate applications. These analyses indicated that the energy dissipation capacity under dynamic impact increased with increasing diblock concentration in the styrenic gels. Under the impact rates employed (2 mm/s to 20 mm/s, corresponding to approximate strain energy densities from 0.4 kJ/m3 to 20 kJ/m3), the energy dissipation capacities of fully hydrated soft tissues were ultimately well matched by a 50/50 triblock/diblock composition that is stable in ambient environments. More generally, the methodologies detailed here facilitate further optimisation of impact energy dissipation capacity of polymer-based tissue surrogate materials, either in air or in fluids.

The volume of fluid injected into the tissue expander and the tissue expansion

Directory of Open Access Journals (Sweden)

Mahmood Omranifard

2014-01-01

Full Text Available Background: Replacement of the lost tissue is the major concerns of the plastic surgeons. Expanded area should be coherent with the surrounding tissue. Tissue expansion technique is the reforming methods the skin tissue scarcities. Several methods for tissue expansion are available; including usage of silicon balloon and injecting fluid into the tissue expander. Materials and Methods: In a clinical trial study, 35 patients, with burn scars, in the face, skull and neck area were studied. We provided a tissue expander device with capacities of 125, 250 and 350cc. Fluid was injected inside the device, 3 consecutive weeks with 1-week interval. After 3 months the device was set out and the tissue expansion was measured using a transparent board and the results were analyzed. Multiple regression was done by SPSS 20 to analyze the data. Results: Regression model showed Skin expansion was positively correlated with the volume of the injected fluid. For each centimeter square of skin expansion, about 6-8 ml of fluid must be injected. Conclusion: Correction of skin defects resulting from burning scar is possible using tissue expanders. The tissue expansion is correlated with the amount of the injected fluid.

Tissue banking in australia.

Science.gov (United States)

Ireland, Lynette; McKelvie, Helen

2003-01-01

The legal structure for the regulation of tissue banking has existed for many years. In Australia, the donation of human tissue is regulated by legislation in each of the eight States and Territories. These substantially uniform Acts were passed in the late 1970's and early 1980's, based on model legislation and underpinned by the concept of consensual giving. However, it was not until the early 1990's that tissue banking came under the notice of regulatory authorities. Since then the Australian Government has moved quickly to oversee the tissue banking sector in Australia. Banked human tissue has been deemed to be a therapeutic good under the Therapeutic Goods Act 1989, and tissue banks are required to be licensed by the Therapeutic Goods Administration and are audited for compliance with the Code of Good Manufacturing Practice- Human Blood and Tissues. In addition, tissue banks must comply with a myriad of other standards, guidelines and recommendations.

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.

3D Printer Generated Tissue iMolds for Cleared Tissue Using Single- and Multi-Photon Microscopy for Deep Tissue Evaluation.

Science.gov (United States)

Miller, Sean J; Rothstein, Jeffrey D

2017-01-01

Pathological analyses and methodology has recently undergone a dramatic revolution. With the creation of tissue clearing methods such as CLARITY and CUBIC, groups can now achieve complete transparency in tissue samples in nano-porous hydrogels. Cleared tissue is then imagined in a semi-aqueous medium that matches the refractive index of the objective being used. However, one major challenge is the ability to control tissue movement during imaging and to relocate precise locations post sequential clearing and re-staining. Using 3D printers, we designed tissue molds that fit precisely around the specimen being imaged. First, images are taken of the specimen, followed by importing and design of a structural mold, then printed with affordable plastics by a 3D printer. With our novel design, we have innovated tissue molds called innovative molds (iMolds) that can be generated in any laboratory and are customized for any organ, tissue, or bone matter being imaged. Furthermore, the inexpensive and reusable tissue molds are made compatible for any microscope such as single and multi-photon confocal with varying stage dimensions. Excitingly, iMolds can also be generated to hold multiple organs in one mold, making reconstruction and imaging much easier. Taken together, with iMolds it is now possible to image cleared tissue in clearing medium while limiting movement and being able to relocate precise anatomical and cellular locations on sequential imaging events in any basic laboratory. This system provides great potential for screening widespread effects of therapeutics and disease across entire organ systems.

The influence of freezing and tissue porosity on the material properties of vegetable tissues

International Nuclear Information System (INIS)

Ralfs, Julie D.

2002-01-01

Tissue porosity and fluid flow have been shown to be important parameters affecting the mechanical and sensorial behaviour of edible plant tissues. The quantity of fluid and the manner with which it was released on compression of the plant tissue were also important regarding the sensory perception and a good indication of any structural damage resulting from freezing, for example. Potato, carrot and Chinese water chestnut were used to study the effects freezing has on model plant tissues. Mechanical and structural measurements of the plant tissue were correlated with sensory analysis. Conventional freezing was shown to cause severe structural damage predominantly in the form of cavities between or through cells, resulting in decreases in mechanical strength and stiffness, and samples that were perceived in the mouth as 'soft' and 'wet'. The location and size of the cavities formed from ice crystals, depended on the particular plant tissue being frozen, the processing it was subjected to prior to freezing, the size of the sample and the cooling regime employed to freeze the tissue. Cavitation in the tissue resulted in an increase in tissue porosity, which enabled fluid to flow more easily from the tissue on compression, thus affecting the mechanical properties and sensory perception. Freezing damage to plant tissues was shown to be reduced, and sometimes prevented, when active antifreeze proteins (AFPs) were introduced into the tissues by vacuum infiltration or transformation and the tissue was frozen at a suitable cooling rate. Theoretical modelling was applied to the fluid flow and porosity data to test the validity of the models and to subsequently predict the mechanical behaviour of potato from the structural properties of the tissue. (author)

Soft tissue engineering with micronized-gingival connective tissues.

Science.gov (United States)

Noda, Sawako; Sumita, Yoshinori; Ohba, Seigo; Yamamoto, Hideyuki; Asahina, Izumi

2018-01-01

The free gingival graft (FGG) and connective tissue graft (CTG) are currently considered to be the gold standards for keratinized gingival tissue reconstruction and augmentation. However, these procedures have some disadvantages in harvesting large grafts, such as donor-site morbidity as well as insufficient gingival width and thickness at the recipient site post-treatment. To solve these problems, we focused on an alternative strategy using micronized tissue transplantation (micro-graft). In this study, we first investigated whether transplantation of micronized gingival connective tissues (MGCTs) promotes skin wound healing. MGCTs (≤100 µm) were obtained by mincing a small piece (8 mm 3 ) of porcine keratinized gingiva using the RIGENERA system. The MGCTs were then transplanted to a full skin defect (5 mm in diameter) on the dorsal surface of immunodeficient mice after seeding to an atelocollagen matrix. Transplantations of atelocollagen matrixes with and without micronized dermis were employed as experimental controls. The results indicated that MGCTs markedly promote the vascularization and epithelialization of the defect area 14 days after transplantation compared to the experimental controls. After 21 days, complete wound closure with low contraction was obtained only in the MGCT grafts. Tracking analysis of transplanted MGCTs revealed that some mesenchymal cells derived from MGCTs can survive during healing and may function to assist in wound healing. We propose here that micro-grafting with MGCTs represents an alternative strategy for keratinized tissue reconstruction that is characterized by low morbidity and ready availability. © 2017 Wiley Periodicals, Inc.

The interplay between tissue growth and scaffold degradation in engineered tissue constructs

KAUST Repository

O’Dea, R. D.

2012-09-18

In vitro tissue engineering is emerging as a potential tool to meet the high demand for replacement tissue, caused by the increased incidence of tissue degeneration and damage. A key challenge in this field is ensuring that the mechanical properties of the engineered tissue are appropriate for the in vivo environment. Achieving this goal will require detailed understanding of the interplay between cell proliferation, extracellular matrix (ECM) deposition and scaffold degradation. In this paper, we use a mathematical model (based upon a multiphase continuum framework) to investigate the interplay between tissue growth and scaffold degradation during tissue construct evolution in vitro. Our model accommodates a cell population and culture medium, modelled as viscous fluids, together with a porous scaffold and ECM deposited by the cells, represented as rigid porous materials. We focus on tissue growth within a perfusion bioreactor system, and investigate how the predicted tissue composition is altered under the influence of (1) differential interactions between cells and the supporting scaffold and their associated ECM, (2) scaffold degradation, and (3) mechanotransduction-regulated cell proliferation and ECM deposition. Numerical simulation of the model equations reveals that scaffold heterogeneity typical of that obtained from μCT scans of tissue engineering scaffolds can lead to significant variation in the flow-induced mechanical stimuli experienced by cells seeded in the scaffold. This leads to strong heterogeneity in the deposition of ECM. Furthermore, preferential adherence of cells to the ECM in favour of the artificial scaffold appears to have no significant influence on the eventual construct composition; adherence of cells to these supporting structures does, however, lead to cell and ECM distributions which mimic and exaggerate the heterogeneity of the underlying scaffold. Such phenomena have important ramifications for the mechanical integrity of

A portrait of tissue phosphoprotein stability in the clinical tissue procurement process.

Science.gov (United States)

Espina, Virginia; Edmiston, Kirsten H; Heiby, Michael; Pierobon, Mariaelena; Sciro, Manuela; Merritt, Barbara; Banks, Stacey; Deng, Jianghong; VanMeter, Amy J; Geho, David H; Pastore, Lucia; Sennesh, Joel; Petricoin, Emanuel F; Liotta, Lance A

2008-10-01

Little is known about the preanalytical fluctuations of phosphoproteins during tissue procurement for molecular profiling. This information is crucial to establish guidelines for the reliable measurement of these analytes. To develop phosphoprotein profiles of tissue subjected to the trauma of excision, we measured the fidelity of 53 signal pathway phosphoproteins over time in tissue specimens procured in a community clinical practice. This information provides strategies for potential surrogate markers of stability and the design of phosphoprotein preservative/fixation solutions. Eleven different specimen collection time course experiments revealed augmentation (+/-20% from the time 0 sample) of signal pathway phosphoprotein levels as well as decreases over time independent of tissue type, post-translational modification, and protein subcellular location (tissues included breast, colon, lung, ovary, and uterus (endometrium/myometrium) and metastatic melanoma). Comparison across tissue specimens showed an >20% decrease of protein kinase B (AKT) Ser-473 (p 20% increases within 90-min postprocurement. Endothelial nitric-oxide synthase Ser-1177 did not change over the time period evaluated with breast or leiomyoma tissue. Treatment with phosphatase or kinase inhibitors alone revealed that tissue kinase pathways are active ex vivo. Combinations of kinase and phosphatase inhibitors appeared to stabilize proteins that exhibited increases in the presence of phosphatase inhibitors alone (ATF-2 Thr-71, SAPK/JNK Thr-183/Tyr-185, STAT1 Tyr-701, JAK1 Tyr-1022/1023, and PAK1/PAK2 Ser-199/204/192/197). This time course study 1) establishes the dynamic nature of specific phosphoproteins in excised tissue, 2) demonstrates augmented phosphorylation in the presence of phosphatase inhibitors, 3) shows that kinase inhibitors block the upsurge in phosphorylation of phosphoproteins, 4) provides a rational strategy for room temperature preservation of proteins, and 5) constitutes a

Mixed Connective Tissue Disease

Science.gov (United States)

Mixed connective tissue disease Overview Mixed connective tissue disease has signs and symptoms of a combination of disorders — primarily lupus, scleroderma and polymyositis. For this reason, mixed connective tissue disease ...

Cell and Tissue Engineering

CERN Document Server

2012-01-01

“Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

The use of animal tissues alongside human tissue: Cultural and ethical considerations.

Science.gov (United States)

Kaw, Anu; Jones, D Gareth; Zhang, Ming

2016-01-01

Teaching and research facilities often use cadaveric material alongside animal tissues, although there appear to be differences in the way we handle, treat, and dispose of human cadaveric material compared to animal tissue. This study sought to analyze cultural and ethical considerations and provides policy recommendations on the use of animal tissues alongside human tissue. The status of human and animal remains and the respect because of human and animal tissues were compared and analyzed from ethical, legal, and cultural perspectives. The use of animal organs and tissues is carried out within the context of understanding human anatomy and function. Consequently, the interests of human donors are to be pre-eminent in any policies that are enunciated, so that if any donors find the presence of animal remains unacceptable, the latter should not be employed. The major differences appear to lie in differences in our perceptions of their respective intrinsic and instrumental values. Animals are considered to have lesser intrinsic value and greater instrumental value than humans. These differences stem from the role played by culture and ethical considerations, and are manifested in the resulting legal frameworks. In light of this discussion, six policy recommendations are proposed, encompassing the nature of consent, respect for animal tissues as well as human remains, and appropriate separation of both sets of tissues in preparation and display. © 2015 Wiley Periodicals, Inc.

The influence of freezing and tissue porosity on the material properties of vegetable tissues

Energy Technology Data Exchange (ETDEWEB)

Ralfs, Julie D

2002-07-01

Tissue porosity and fluid flow have been shown to be important parameters affecting the mechanical and sensorial behaviour of edible plant tissues. The quantity of fluid and the manner with which it was released on compression of the plant tissue were also important regarding the sensory perception and a good indication of any structural damage resulting from freezing, for example. Potato, carrot and Chinese water chestnut were used to study the effects freezing has on model plant tissues. Mechanical and structural measurements of the plant tissue were correlated with sensory analysis. Conventional freezing was shown to cause severe structural damage predominantly in the form of cavities between or through cells, resulting in decreases in mechanical strength and stiffness, and samples that were perceived in the mouth as 'soft' and 'wet'. The location and size of the cavities formed from ice crystals, depended on the particular plant tissue being frozen, the processing it was subjected to prior to freezing, the size of the sample and the cooling regime employed to freeze the tissue. Cavitation in the tissue resulted in an increase in tissue porosity, which enabled fluid to flow more easily from the tissue on compression, thus affecting the mechanical properties and sensory perception. Freezing damage to plant tissues was shown to be reduced, and sometimes prevented, when active antifreeze proteins (AFPs) were introduced into the tissues by vacuum infiltration or transformation and the tissue was frozen at a suitable cooling rate. Theoretical modelling was applied to the fluid flow and porosity data to test the validity of the models and to subsequently predict the mechanical behaviour of potato from the structural properties of the tissue. (author)

Adipose tissue-derived stem cells in oral mucosa tissue engineering ...

African Journals Online (AJOL)

Jane

2011-10-10

Oct 10, 2011 ... stem cells (ADSCs) may play an important role in this field. In this research ..... Adipose tissue is derived from embryonic mesodermal precursors and .... Clonogenic multipotent stem cells in human adipose tissue differentiate ...

Tissue engineering in dentistry.

Science.gov (United States)

Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

2014-08-01

of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the

Detection of neuronal tissue in meat using tissue specific DNA modifications

Directory of Open Access Journals (Sweden)

Harris N.

2004-01-01

Full Text Available A method has been developed to differentiate between non-muscle tissues such as liver, kidney and heart and that of muscle in meat samples using tissue specific DNA detection. Only muscle tissue is considered meat from the point of view of labelling (Food Labelling [Amendment] (England Regulations 2003 and Quantitative Ingredient Declaration (QUID, and also certain parts of the carcass are prohibited to be used in raw meat products (Meat Products [England] Regulations 2003. Included in the prohibited offal are brain and spinal cord. The described methodology has therefore been developed primarily to enforce labelling rules but also to contribute to the enforcement of BSE legislation on the detection of Central Nervous System (CNS tissue. The latter requires the removal of Specified Risk Material (SRM, such as bovine and ovine brain and spinal cord, from the food chain. Current methodologies for detection of CNS tissue include histological examination, analysis of cholesterol content and immunodetection. These can potentially be time consuming, less applicable to processed samples and may not be readily adapted to high throughput sample analysis. The objective of this work was therefore to develop a DNAbased detection assay that exploits the sensitivity and specificity of PCR and is potentially applicable to more highly processed food samples. For neuronal tissue, the DNA target selected was the promoter for Glial Fibrillary Acidic Protein (GFAP, a gene whose expression is restricted to astroglial cells within CNS tissue. The promoter fragments from both cattle and sheep have been isolated and key differences in the methylation patterns of certain CpG dinucleotides in the sequences from bovine and sheep brain and spinal cord and the corresponding skeletal muscle identified. These have been used to design a PCR assay exploiting Methylation Specific PCR (MSP to specifically amplify the neuronal tissue derived sequence and therefore identify the

Decellularized Tissue and Cell-Derived Extracellular Matrices as Scaffolds for Orthopaedic Tissue Engineering

Science.gov (United States)

Cheng, Christina W.; Solorio, Loran D.; Alsberg, Eben

2014-01-01

The reconstruction of musculoskeletal defects is a constant challenge for orthopaedic surgeons. Musculoskeletal injuries such as fractures, chondral lesions, infections and tumor debulking can often lead to large tissue voids requiring reconstruction with tissue grafts. Autografts are currently the gold standard in orthopaedic tissue reconstruction; however, there is a limit to the amount of tissue that can be harvested before compromising the donor site. Tissue engineering strategies using allogeneic or xenogeneic decellularized bone, cartilage, skeletal muscle, tendon and ligament have emerged as promising potential alternative treatment. The extracellular matrix provides a natural scaffold for cell attachment, proliferation and differentiation. Decellularization of in vitro cell-derived matrices can also enable the generation of autologous constructs from tissue specific cells or progenitor cells. Although decellularized bone tissue is widely used clinically in orthopaedic applications, the exciting potential of decellularized cartilage, skeletal muscle, tendon and ligament cell-derived matrices has only recently begun to be explored for ultimate translation to the orthopaedic clinic. PMID:24417915

Undifferentiated Connective Tissue Disease

Science.gov (United States)

... Home Conditions Undifferentiated Connective Tissue Disease (UCTD) Undifferentiated Connective Tissue Disease (UCTD) Make an Appointment Find a Doctor ... by Barbara Goldstein, MD (February 01, 2016) Undifferentiated connective tissue disease (UCTD) is a systemic autoimmune disease. This ...

Prevalence of encysted apicomplexans in muscles of raptors.

Science.gov (United States)

Lindsay, D S; Blagburn, B L

1999-01-28

An acid-pepsin digestion technique was used to examine portions of breast muscle and heart from raptors for encysted protozoans. Apicomplexan zoites were present in 52 (45.6%) of the 114 samples examined: 11 of 12 (91.7%) red-shouldered hawks (Buteo lineatus), 20 of 34 (58.8%) red-tailed hawks (Buteo jamaicensis), two of seven (28.6%) Cooper's hawks (Accipiter cooperi), three of four (75%) sharp-shinned hawks (Accipiter striatus), one (100%) Mississippi kites (Ictinia misisippiensis), one of two (50%) American kestrels (Falco sparverius), one bald eagle (Haliaeetus leucocephalus), one of two (50%) golden eagles (Aquila chrysaetos), one of three (33%) turkey vultures (Cathartes aura), two of three (66.7%) black vultures (Coragyps atratus), three of six (50%) great-horned owls (Bubo virginianus), five of 15 (33.3%) barred owls (Strix varia), and one of 12 (8.3%) screech owls (Asio otus). Encysted protozoans were not observed in digests of tissues from three broad-winged hawks (Buteo platypterus), four ospreys (Pandion haliaetus), and five barn owls (Tyto alba). Apicomplexan cysts resembling Sarcocystis species were observed in tissue sections of muscles from 28 (37.8%) of 74 raptors.

Growing tissues in real and simulated microgravity: new methods for tissue engineering.

Science.gov (United States)

Grimm, Daniela; Wehland, Markus; Pietsch, Jessica; Aleshcheva, Ganna; Wise, Petra; van Loon, Jack; Ulbrich, Claudia; Magnusson, Nils E; Infanger, Manfred; Bauer, Johann

2014-12-01

Tissue engineering in simulated (s-) and real microgravity (r-μg) is currently a topic in Space medicine contributing to biomedical sciences and their applications on Earth. The principal aim of this review is to highlight the advances and accomplishments in the field of tissue engineering that could be achieved by culturing cells in Space or by devices created to simulate microgravity on Earth. Understanding the biology of three-dimensional (3D) multicellular structures is very important for a more complete appreciation of in vivo tissue function and advancing in vitro tissue engineering efforts. Various cells exposed to r-μg in Space or to s-μg created by a random positioning machine, a 2D-clinostat, or a rotating wall vessel bioreactor grew in the form of 3D tissues. Hence, these methods represent a new strategy for tissue engineering of a variety of tissues, such as regenerated cartilage, artificial vessel constructs, and other organ tissues as well as multicellular cancer spheroids. These aggregates are used to study molecular mechanisms involved in angiogenesis, cancer development, and biology and for pharmacological testing of, for example, chemotherapeutic drugs or inhibitors of neoangiogenesis. Moreover, they are useful for studying multicellular responses in toxicology and radiation biology, or for performing coculture experiments. The future will show whether these tissue-engineered constructs can be used for medical transplantations. Unveiling the mechanisms of microgravity-dependent molecular and cellular changes is an up-to-date requirement for improving Space medicine and developing new treatment strategies that can be translated to in vivo models while reducing the use of laboratory animals.

Random lasing in human tissues

International Nuclear Information System (INIS)

Polson, Randal C.; Vardeny, Z. Valy

2004-01-01

A random collection of scatterers in a gain medium can produce coherent laser emission lines dubbed 'random lasing'. We show that biological tissues, including human tissues, can support coherent random lasing when infiltrated with a concentrated laser dye solution. To extract a typical random resonator size within the tissue we average the power Fourier transform of random laser spectra collected from many excitation locations in the tissue; we verified this procedure by a computer simulation. Surprisingly, we found that malignant tissues show many more laser lines compared to healthy tissues taken from the same organ. Consequently, the obtained typical random resonator was found to be different for healthy and cancerous tissues, and this may lead to a technique for separating malignant from healthy tissues for diagnostic imaging

Synovial tissue research

DEFF Research Database (Denmark)

Orr, Carl; Sousa, Elsa; Boyle, David L

2017-01-01

The synovium is the major target tissue of inflammatory arthritides such as rheumatoid arthritis. The study of synovial tissue has advanced considerably throughout the past few decades from arthroplasty and blind needle biopsy to the use of arthroscopic and ultrasonographic technologies that enable...... easier visualization and improve the reliability of synovial biopsies. Rapid progress has been made in using synovial tissue to study disease pathogenesis, to stratify patients, to discover biomarkers and novel targets, and to validate therapies, and this progress has been facilitated by increasingly...... diverse and sophisticated analytical and technological approaches. In this Review, we describe these approaches, and summarize how their use in synovial tissue research has improved our understanding of rheumatoid arthritis and identified candidate biomarkers that could be used in disease diagnosis...

The importance of establishing an international network of tissue banks and regional tissue processing centers.

Science.gov (United States)

Morales Pedraza, Jorge

2014-03-01

During the past four decades, many tissue banks have been established across the world with the aim of supplying sterilized tissues for clinical use and research purposes. Between 1972 and 2005, the International Atomic Energy Agency supported the establishment of more than sixty of these tissue banks in Latin America and the Caribbean, Asia and the Pacific, Africa and Eastern Europe; promoted the use of the ionizing radiation technique for the sterilization of the processed tissues; and encouraged cooperation between the established tissue banks during the implementation of its program on radiation and tissue banking at national, regional and international levels. Taking into account that several of the established tissue banks have gained a rich experience in the procurement, processing, sterilization, storage, and medical use of sterilized tissues, it is time now to strengthen further international and regional cooperation among interested tissue banks located in different countries. The purpose of this cooperation is to share the experience gained by these banks in the procurement, processing, sterilization, storage, and used of different types of tissues in certain medical treatments and research activities. This could be done through the establishment of a network of tissue banks and a limited number of regional tissue processing centers in different regions of the world.

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.

Practical experience in post-mortem tissue donation in consideration of the European tissue law.

Science.gov (United States)

Karbe, Thomas; Braun, Christian; Wulff, Birgit; Schröder, Ann Sophie; Püschel, Klaus; Bratzke, Hansjürgen; Parzeller, Markus

2010-03-01

In consequence of the European guidelines of safety and quality standards for the donation, retrieval, storing and distribution of human tissues and cells the purpose of tissue transplantation was implemented into German legislation in May 2007. The law came into effect on August 1st 2007 considering of the European rules. The Institutes for Legal Medicine of the University of Frankfurt/Main and the University Medical Center Hamburg-Eppendorf developed a model for tissue retrieval. The Institute of Legal Medicine (I.f.R.) at the University Medical Center Hamburg cooperates with the German Institute of Cell and Tissue Replacement (Deutsches Institut für Zell--und Gewebeersatz DIZG). Potential post-mortem tissue donors (PMTD) among the deceased are selected by standardized sets of defined criteria. The procedure is guided by the intended exclusion criteria of the tissue regulation draft (German Transplant Law TPG GewV) in accordance with the European Guideline (2006/17/EC). Following the identification of the donor and subsequent removal of tissue, the retrieved samples were sent to the DIZG, a non-profit tissue bank according to the tissue regulation. Here the final processing into transplantable tissue grafts takes place, which then results in the allocation of tissue to hospitals in Germany and other European countries. The Center of Legal Medicine at the Johann Wolfgang Goethe-University Medical Center Frankfurt/Main cooperates since 2000 with Tutogen, a pharmaceutical company. Harvesting of musculoskeletal tissues follows corresponding regulations. To verify the outcome of PMTD at the I.f.R. Hamburg, two-statistic analysis over 12 and 4 months have been implemented. Our results have shown an increasing number of potential appropriate PMTD within the second inquiry interval but a relatively small and unvaryingly rate of successful post-mortem tissue retrievals similar to the first examination period. Thus, the aim of the model developed by the I.f.R. is to

DNA from keratinous tissue

DEFF Research Database (Denmark)

Bengtsson, Camilla F.; Olsen, Maja E.; Brandt, Luise Ørsted

2011-01-01

Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient...... genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle – although little...... systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear...

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.

Quantitative frequency-domain fluorescence spectroscopy in tissues and tissue-like media

Science.gov (United States)

Cerussi, Albert Edward

1999-09-01

In the never-ending quest for improved medical technology at lower cost, modern near-infrared optical spectroscopy offers the possibility of inexpensive technology for quantitative and non-invasive diagnoses. Hemoglobin is the dominant chromophore in the 700-900 nm spectral region and as such it allows for the optical assessment of hemoglobin concentration and tissue oxygenation by absorption spectroscopy. However, there are many other important physiologically relevant compounds or physiological states that cannot be effectively sensed via optical methods because of poor optical contrast. In such cases, contrast enhancements are required. Fluorescence spectroscopy is an attractive component of optical tissue spectroscopy. Exogenous fluorophores, as well as some endogenous ones, may furnish the desperately needed sensitivity and specificity that is lacking in near-infrared optical tissue spectroscopy. The main focus of this thesis was to investigate the generation and propagation of fluorescence photons inside tissues and tissue-like media (i.e., scattering dominated media). The standard concepts of fluorescence spectroscopy have been incorporated into a diffusion-based picture that is sometimes referred to as photon migration. The novelty of this work lies in the successful quantitative recovery of fluorescence lifetimes, absolute fluorescence quantum yields, fluorophore concentrations, emission spectra, and both scattering and absorption coefficients at the emission wavelength from a tissue-like medium. All of these parameters are sensitive to the fluorophore local environment and hence are indicators of the tissue's physiological state. One application demonstrating the capabilities of frequency-domain lifetime spectroscopy in tissue-like media is a study of the binding of ethidium bromide to bovine leukocytes in fresh milk. Ethidium bromide is a fluorescent dye that is commonly used to label DNA, and hence visualize chromosomes in cells. The lifetime of

Quantitative characterization of viscoelastic behavior in tissue-mimicking phantoms and ex vivo animal tissues.

Directory of Open Access Journals (Sweden)

Ashkan Maccabi

Full Text Available Viscoelasticity of soft tissue is often related to pathology, and therefore, has become an important diagnostic indicator in the clinical assessment of suspect tissue. Surgeons, particularly within head and neck subsites, typically use palpation techniques for intra-operative tumor detection. This detection method, however, is highly subjective and often fails to detect small or deep abnormalities. Vibroacoustography (VA and similar methods have previously been used to distinguish tissue with high-contrast, but a firm understanding of the main contrast mechanism has yet to be verified. The contributions of tissue mechanical properties in VA images have been difficult to verify given the limited literature on viscoelastic properties of various normal and diseased tissue. This paper aims to investigate viscoelasticity theory and present a detailed description of viscoelastic experimental results obtained in tissue-mimicking phantoms (TMPs and ex vivo tissues to verify the main contrast mechanism in VA and similar imaging modalities. A spherical-tip micro-indentation technique was employed with the Hertzian model to acquire absolute, quantitative, point measurements of the elastic modulus (E, long term shear modulus (η, and time constant (τ in homogeneous TMPs and ex vivo tissue in rat liver and porcine liver and gallbladder. Viscoelastic differences observed between porcine liver and gallbladder tissue suggest that imaging modalities which utilize the mechanical properties of tissue as a primary contrast mechanism can potentially be used to quantitatively differentiate between proximate organs in a clinical setting. These results may facilitate more accurate tissue modeling and add information not currently available to the field of systems characterization and biomedical research.

Quantitative characterization of viscoelastic behavior in tissue-mimicking phantoms and ex vivo animal tissues.

Science.gov (United States)

Maccabi, Ashkan; Shin, Andrew; Namiri, Nikan K; Bajwa, Neha; St John, Maie; Taylor, Zachary D; Grundfest, Warren; Saddik, George N

2018-01-01

Viscoelasticity of soft tissue is often related to pathology, and therefore, has become an important diagnostic indicator in the clinical assessment of suspect tissue. Surgeons, particularly within head and neck subsites, typically use palpation techniques for intra-operative tumor detection. This detection method, however, is highly subjective and often fails to detect small or deep abnormalities. Vibroacoustography (VA) and similar methods have previously been used to distinguish tissue with high-contrast, but a firm understanding of the main contrast mechanism has yet to be verified. The contributions of tissue mechanical properties in VA images have been difficult to verify given the limited literature on viscoelastic properties of various normal and diseased tissue. This paper aims to investigate viscoelasticity theory and present a detailed description of viscoelastic experimental results obtained in tissue-mimicking phantoms (TMPs) and ex vivo tissues to verify the main contrast mechanism in VA and similar imaging modalities. A spherical-tip micro-indentation technique was employed with the Hertzian model to acquire absolute, quantitative, point measurements of the elastic modulus (E), long term shear modulus (η), and time constant (τ) in homogeneous TMPs and ex vivo tissue in rat liver and porcine liver and gallbladder. Viscoelastic differences observed between porcine liver and gallbladder tissue suggest that imaging modalities which utilize the mechanical properties of tissue as a primary contrast mechanism can potentially be used to quantitatively differentiate between proximate organs in a clinical setting. These results may facilitate more accurate tissue modeling and add information not currently available to the field of systems characterization and biomedical research.

FRD tissue archive

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The fishery genetics tissue collection has over 80,000 tissues stored in 95% ethanol representing fishes and invertebrates collected globally but with a focus on the...

Automated Detection of Connective Tissue by Tissue Counter Analysis and Classification and Regression Trees

Directory of Open Access Journals (Sweden)

Josef Smolle

2001-01-01

Full Text Available Objective: To evaluate the feasibility of the CART (Classification and Regression Tree procedure for the recognition of microscopic structures in tissue counter analysis. Methods: Digital microscopic images of H&E stained slides of normal human skin and of primary malignant melanoma were overlayed with regularly distributed square measuring masks (elements and grey value, texture and colour features within each mask were recorded. In the learning set, elements were interactively labeled as representing either connective tissue of the reticular dermis, other tissue components or background. Subsequently, CART models were based on these data sets. Results: Implementation of the CART classification rules into the image analysis program showed that in an independent test set 94.1% of elements classified as connective tissue of the reticular dermis were correctly labeled. Automated measurements of the total amount of tissue and of the amount of connective tissue within a slide showed high reproducibility (r=0.97 and r=0.94, respectively; p < 0.001. Conclusions: CART procedure in tissue counter analysis yields simple and reproducible classification rules for tissue elements.

Tissue/blood partition coefficients for xenon in various adipose tissue depots in man

DEFF Research Database (Denmark)

Bülow, J; Jelnes, Rolf; Astrup, A

1987-01-01

Tissue/blood partition coefficients (lambda) for xenon were calculated for subcutaneous adipose tissue from the abdominal wall and the thigh, and for the perirenal adipose tissue after chemical analysis of the tissues for lipid, water and protein content. The lambda in the perirenal tissue...... was found to correlate linearly to the relative body weight (RBW) in per cent with the regression equation lambda = 0.045 . RBW + 0.99. The subcutaneous lambda on the abdomen correlated linearly to the local skinfold thickness (SFT) with the equation lambda = 0.22 SFT + 2.99. Similarly lambda on the thigh...... correlated to SFT with the equation lambda = 0.20 . SFT + 4.63. It is concluded that the previously accepted lambda value of 10 is generally too high in perirenal as well as in subcutaneous tissue. Thus, by application of the present regression equations, it is possible to obtain more exact estimates...

Radiosterilization of Tissues Preserved for Clinical Purposes: Effect on Tissue Antigenicity

International Nuclear Information System (INIS)

Ostrowski, K.; Kossowska, B.; Moskalewski, S.; Komender, A.; Kurnatowski, W.

1967-01-01

The first part of the paper contains practical considerations on the radiosterilization of preserved human bone, human and calf cartilage, cow’s fascia and aponeurosis, based on material from the Tissue Bank which produces about 2500 transplants yearly. The method of preservation and packing of each type of tissue is mentioned briefly. The preserved tissues are irradiated in a cobalt bomb or in a nuclear reactor. The conditions of irradiation and the control of sterility are described. The advantages and disadvantages of radiosterilization are discussed on the basis of the authors’ own experience and clinical reports of surgeons using radiosterilized tissues in practice. In the second part of the paper, experimental studies on the influence of freezing, lyophilization and radiosterilization on tissue antigenicity are reported. The regional lymph node reacts to an antigenic stimulus by an increased production of large, pyroninophylic cells, so-called ''blast'' cells. The rabbits used as recipients received grafts of allogeneic cancellous bone, fresh or subjected to different experimental procedures. Smears from lymph node cell suspension were prepared and the percentage of blast cells was estimated. On the basis of the lymph node response, it appears that freezing and lyophilization, as well as radiosterilization, may abolish the antigenicity of cancellous bone. The practical implication of these results for methods of preservation of tissues for clinical purposes is discussed. (author)

Degradable polymers for tissue engineering

NARCIS (Netherlands)

van Dijkhuizen-Radersma, Riemke; Moroni, Lorenzo; van Apeldoorn, Aart A.; Zhang, Zheng; Grijpma, Dirk W.; van Blitterswijk, Clemens A.

2008-01-01

This chapter elaborates the degradable polymers for tissue engineering and their required scaffold material in tissue engineering. It recognizes the examples of degradable polymers broadly used in tissue engineering. Tissue engineering is the persuasion of the body to heal itself through the

Autopsy Tissue Program

International Nuclear Information System (INIS)

Fox, T.; Tietjen, G.

1979-01-01

The Autopsy Tissue Program was begun in 1960. To date, tissues on 900 or more persons in 7 geographic regions have been collected and analyzed for plutonium content. The tissues generally consist of lung, liver, kidney, lymph, bone, and gonadal tissue for each individual. The original objective of the program was to determine the level of plutonium in human tissues due solely to fall-out from weapons testing. The baseline thus established was to be used to evaluate future changes. From the first, this program was beset with chemical and statistical difficulties. Many factors whose effects were not recognized and not planned for were found later to be important. Privacy and ethical considerations hindered the gathering of adequate data. Since the chemists were looking for amounts of plutonium very close to background, possible contamination was a very real problem. Widely used chemical techniques introduced a host of statistical problems. The difficulties encountered touch on areas common to large data sets, unusual outlier detection methods, minimum detection limits, problems with Aliquot sizes, and time-trends in the data. The conclusions point out areas to which the biologists will have to devote much more careful attention than was believed

DESARROLLO COMPARADO DE LA CORTEZA CEREBRAL UNA POSIBLE PREPLACA EN REPTILES.

OpenAIRE

MONTIEL EULEFI, JUAN FIDEL; MONTIEL EULEFI, JUAN FIDEL

2006-01-01

La preplaca es una capa cortical transiente que es dividida en una zona marginal superficial y una subplaca profunda, mediante el ingreso de neuronas que formarán la placa cortical durante el desarrollo cortical. La preplaca y sus derivados se constituyen 76p.

Tissue-electronics interfaces: from implantable devices to engineered tissues

Science.gov (United States)

Feiner, Ron; Dvir, Tal

2018-01-01

Biomedical electronic devices are interfaced with the human body to extract precise medical data and to interfere with tissue function by providing electrical stimuli. In this Review, we outline physiologically and pathologically relevant tissue properties and processes that are important for designing implantable electronic devices. We summarize design principles for flexible and stretchable electronics that adapt to the mechanics of soft tissues, such as those including conducting polymers, liquid metal alloys, metallic buckling and meandering architectures. We further discuss technologies for inserting devices into the body in a minimally invasive manner and for eliminating them without further intervention. Finally, we introduce the concept of integrating electronic devices with biomaterials and cells, and we envision how such technologies may lead to the development of bionic organs for regenerative medicine.

Plant Tissue Culture

Indian Academy of Sciences (India)

Admin

Plant tissue culture is a technique of culturing plant cells, tissues and organs on ... working methods (Box 2) and discovery of the need for B vita- mins and auxins for ... Kotte (Germany) reported some success with growing isolated root tips.

A Tissue Engineered Model of Aging: Interdependence and Cooperative Effects in Failing Tissues.

Science.gov (United States)

Acun, A; Vural, D C; Zorlutuna, P

2017-07-11

Aging remains a fundamental open problem in modern biology. Although there exist a number of theories on aging on the cellular scale, nearly nothing is known about how microscopic failures cascade to macroscopic failures of tissues, organs and ultimately the organism. The goal of this work is to bridge microscopic cell failure to macroscopic manifestations of aging. We use tissue engineered constructs to control the cellular-level damage and cell-cell distance in individual tissues to establish the role of complex interdependence and interactions between cells in aging tissues. We found that while microscopic mechanisms drive aging, the interdependency between cells plays a major role in tissue death, providing evidence on how cellular aging is connected to its higher systemic consequences.

Biomaterials for tissue engineering applications.

Science.gov (United States)

Keane, Timothy J; Badylak, Stephen F

2014-06-01

With advancements in biological and engineering sciences, the definition of an ideal biomaterial has evolved over the past 50 years from a substance that is inert to one that has select bioinductive properties and integrates well with adjacent host tissue. Biomaterials are a fundamental component of tissue engineering, which aims to replace diseased, damaged, or missing tissue with reconstructed functional tissue. Most biomaterials are less than satisfactory for pediatric patients because the scaffold must adapt to the growth and development of the surrounding tissues and organs over time. The pediatric community, therefore, provides a distinct challenge for the tissue engineering community. Copyright © 2014. Published by Elsevier Inc.

Pulp and periodontal tissue repair - regeneration or tissue metaplasia after dental trauma. A review

DEFF Research Database (Denmark)

Andreasen, Jens O

2012-01-01

Healing subsequent to dental trauma is known to be very complex, a result explained by the variability of the types of dental trauma (six luxations, nine fracture types, and their combinations). On top of that, at least 16 different cellular systems get involved in more severe trauma types each o...... of tissue replaces the injured). In this study, a review is given of the impact of trauma to various dental tissues such as alveolar bone, periodontal ligament, cementum, Hertvigs epithelial root sheath, and the pulp....... of them with a different potential for healing with repair, i.e. (re-establishment of tissue continuity without functional restitution) and regeneration (where the injured or lost tissue is replaced with new tissue with identical tissue anatomy and function) and finally metaplasia (where a new type...

Chitin Scaffolds in Tissue Engineering

Science.gov (United States)

Jayakumar, Rangasamy; Chennazhi, Krishna Prasad; Srinivasan, Sowmya; Nair, Shantikumar V.; Furuike, Tetsuya; Tamura, Hiroshi

2011-01-01

Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine. PMID:21673928

Tissue-specific regulation of mouse MicroRNA genes in endoderm-derived tissues

OpenAIRE

Gao, Yan; Schug, Jonathan; McKenna, Lindsay B.; Le Lay, John; Kaestner, Klaus H.; Greenbaum, Linda E.

2010-01-01

MicroRNAs fine-tune the activity of hundreds of protein-coding genes. The identification of tissue-specific microRNAs and their promoters has been constrained by the limited sensitivity of prior microRNA quantification methods. Here, we determine the entire microRNAome of three endoderm-derived tissues, liver, jejunum and pancreas, using ultra-high throughput sequencing. Although many microRNA genes are expressed at comparable levels, 162 microRNAs exhibited striking tissue-specificity. After...

Structural and evolutionary adaptation of rhoptry kinases and pseudokinases, a family of coccidian virulence factors

Science.gov (United States)

2013-01-01

Background The widespread protozoan parasite Toxoplasma gondii interferes with host cell functions by exporting the contents of a unique apical organelle, the rhoptry. Among the mix of secreted proteins are an expanded, lineage-specific family of protein kinases termed rhoptry kinases (ROPKs), several of which have been shown to be key virulence factors, including the pseudokinase ROP5. The extent and details of the diversification of this protein family are poorly understood. Results In this study, we comprehensively catalogued the ROPK family in the genomes of Toxoplasma gondii, Neospora caninum and Eimeria tenella, as well as portions of the unfinished genome of Sarcocystis neurona, and classified the identified genes into 42 distinct subfamilies. We systematically compared the rhoptry kinase protein sequences and structures to each other and to the broader superfamily of eukaryotic protein kinases to study the patterns of diversification and neofunctionalization in the ROPK family and its subfamilies. We identified three ROPK sub-clades of particular interest: those bearing a structurally conserved N-terminal extension to the kinase domain (NTE), an E. tenella-specific expansion, and a basal cluster including ROP35 and BPK1 that we term ROPKL. Structural analysis in light of the solved structures ROP2, ROP5, ROP8 and in comparison to typical eukaryotic protein kinases revealed ROPK-specific conservation patterns in two key regions of the kinase domain, surrounding a ROPK-conserved insert in the kinase hinge region and a disulfide bridge in the kinase substrate-binding lobe. We also examined conservation patterns specific to the NTE-bearing clade. We discuss the possible functional consequences of each. Conclusions Our work sheds light on several important but previously unrecognized features shared among rhoptry kinases, as well as the essential differences between active and degenerate protein kinases. We identify the most distinctive ROPK-specific features

Structural and evolutionary adaptation of rhoptry kinases and pseudokinases, a family of coccidian virulence factors.

Science.gov (United States)

Talevich, Eric; Kannan, Natarajan

2013-06-06

The widespread protozoan parasite Toxoplasma gondii interferes with host cell functions by exporting the contents of a unique apical organelle, the rhoptry. Among the mix of secreted proteins are an expanded, lineage-specific family of protein kinases termed rhoptry kinases (ROPKs), several of which have been shown to be key virulence factors, including the pseudokinase ROP5. The extent and details of the diversification of this protein family are poorly understood. In this study, we comprehensively catalogued the ROPK family in the genomes of Toxoplasma gondii, Neospora caninum and Eimeria tenella, as well as portions of the unfinished genome of Sarcocystis neurona, and classified the identified genes into 42 distinct subfamilies. We systematically compared the rhoptry kinase protein sequences and structures to each other and to the broader superfamily of eukaryotic protein kinases to study the patterns of diversification and neofunctionalization in the ROPK family and its subfamilies. We identified three ROPK sub-clades of particular interest: those bearing a structurally conserved N-terminal extension to the kinase domain (NTE), an E. tenella-specific expansion, and a basal cluster including ROP35 and BPK1 that we term ROPKL. Structural analysis in light of the solved structures ROP2, ROP5, ROP8 and in comparison to typical eukaryotic protein kinases revealed ROPK-specific conservation patterns in two key regions of the kinase domain, surrounding a ROPK-conserved insert in the kinase hinge region and a disulfide bridge in the kinase substrate-binding lobe. We also examined conservation patterns specific to the NTE-bearing clade. We discuss the possible functional consequences of each. Our work sheds light on several important but previously unrecognized features shared among rhoptry kinases, as well as the essential differences between active and degenerate protein kinases. We identify the most distinctive ROPK-specific features conserved across both active

Collecting and Storing Tissue, Blood, and Bone Marrow Samples From Patients With Rhabdomyosarcoma or Other Soft Tissue Sarcoma

Science.gov (United States)

2017-12-11

Adult Rhabdomyosarcoma; Childhood Desmoplastic Small Round Cell Tumor; Chordoma; Desmoid Tumor; Metastatic Childhood Soft Tissue Sarcoma; Nonmetastatic Childhood Soft Tissue Sarcoma; Previously Treated Childhood Rhabdomyosarcoma; Previously Untreated Childhood Rhabdomyosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Stage I Adult Soft Tissue Sarcoma; Stage II Adult Soft Tissue Sarcoma; Stage III Adult Soft Tissue Sarcoma; Stage IV Adult Soft Tissue Sarcoma

Tissue banking and clinical research on radiation and ethylene oxide sterilization of tissue grafts

International Nuclear Information System (INIS)

Pe Khin

1987-06-01

The research works carried out in Rangoon, Burma under the Agency supported project RC4420/RB have dealt with an elucidation of the radiation interaction(s) with the species of biomolecules such as proteins, lipids, collagens, connective tissues present in the cleaned and freeze-dried non-viable tissue grafts. Radiation as a cool process furthermore effectively helps to destroy the microbial bioburden as the undesirable contaminants which may associate the tissue grafts. Radiation also concomitantly helps to suppress the tissue-specific immunogenicity. All these attributes of radiation induced effects have proved successful towards the development of a sterilization process. A series of non-viable tissue grafts, such as bone, nerve, fascia, dura, cartilage, chorion-amnion (as dressings in burn wounds) and tympanic membrane have been successfully attempted in Burma and many more possibilities seem to still remain unexplored. Radiation sterilization modality has proved as a blessing for the promotion of clinical surgical applications of tissue allografts in the corrective/reconstructive surgery on the disability cases due to diseases which accompany tissue losses. The investigator in Burma has reported on the case histories where freeze dried radiation sterilized tissue allografts have been successfully used in the osteogenic inductions (bone grafts); midear tympanoplasty; partial recovery of nerve sensation throught nerve allografts; rapid healing of high degree burn wounds through the use of amnion dressings. Besides, there have been a widespread surgical use of radiation sterilized dura and fascia as allografts. A national tissue banking facility has been established in Burma surrounding the processing and clinical utilization of tissue allografts which has involved over ten hospital centres throughout the country. Radiation induced effects on the biomolecules of clinical significance in the tissue grafts have been researched to help gain insight into a better

Bone Marrow Adipose Tissue: To Be or Not To Be a Typical Adipose Tissue?

OpenAIRE

Hardouin, Pierre; Rharass, Tareck; Lucas, Stéphanie

2016-01-01

Bone marrow adipose tissue (BMAT) emerges as a distinct fat depot whose importance has been proved in the bone–fat interaction. Indeed, it is well recognized that adipokines and free fatty acids released by adipocytes can directly or indirectly interfere with cells of bone remodeling or hematopoiesis. In pathological states, such as osteoporosis, each of adipose tissues – subcutaneous white adipose tissue (WAT), visceral WAT, brown adipose tissue (BAT), and BMAT – is differently associated wi...

Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

International Nuclear Information System (INIS)

Juneja, Prabhjot; Harris, Emma J.; Kirby, Anna M.; Evans, Philip M.

2012-01-01

Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue segmentation

Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

Energy Technology Data Exchange (ETDEWEB)

Juneja, Prabhjot, E-mail: Prabhjot.Juneja@icr.ac.uk [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom); Harris, Emma J. [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom); Kirby, Anna M. [Department of Academic Radiotherapy, Royal Marsden National Health Service Foundation Trust, Sutton (United Kingdom); Evans, Philip M. [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom)

2012-11-01

Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue

Commercial considerations in tissue engineering.

Science.gov (United States)

Mansbridge, Jonathan

2006-10-01

Tissue engineering is a field with immense promise. Using the example of an early tissue-engineered skin implant, Dermagraft, factors involved in the successful commercial development of devices of this type are explored. Tissue engineering has to strike a balance between tissue culture, which is a resource-intensive activity, and business considerations that are concerned with minimizing cost and maximizing customer convenience. Bioreactor design takes place in a highly regulated environment, so factors to be incorporated into the concept include not only tissue culture considerations but also matters related to asepsis, scaleup, automation and ease of use by the final customer. Dermagraft is an allogeneic tissue. Stasis preservation, in this case cryopreservation, is essential in allogeneic tissue engineering, allowing sterility testing, inventory control and, in the case of Dermagraft, a cellular stress that may be important for hormesis following implantation. Although the use of allogeneic cells provides advantages in manufacturing under suitable conditions, it raises the spectre of immunological rejection. Such rejection has not been experienced with Dermagraft. Possible reasons for this and the vision of further application of allogeneic tissues are important considerations in future tissue-engineered cellular devices. This review illustrates approaches that indicate some of the criteria that may provide a basis for further developments. Marketing is a further requirement for success, which entails understanding of the mechanism of action of the procedure, and is illustrated for Dermagraft. The success of a tissue-engineered product is dependent on many interacting operations, some discussed here, each of which must be performed simultaneously and well.

Bioprinting for Neural Tissue Engineering.

Science.gov (United States)

Knowlton, Stephanie; Anand, Shivesh; Shah, Twisha; Tasoglu, Savas

2018-01-01

Bioprinting is a method by which a cell-encapsulating bioink is patterned to create complex tissue architectures. Given the potential impact of this technology on neural research, we review the current state-of-the-art approaches for bioprinting neural tissues. While 2D neural cultures are ubiquitous for studying neural cells, 3D cultures can more accurately replicate the microenvironment of neural tissues. By bioprinting neuronal constructs, one can precisely control the microenvironment by specifically formulating the bioink for neural tissues, and by spatially patterning cell types and scaffold properties in three dimensions. We review a range of bioprinted neural tissue models and discuss how they can be used to observe how neurons behave, understand disease processes, develop new therapies and, ultimately, design replacement tissues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variation in tissue outcome of ovine and human engineered heart valve constructs : relevance for tissue engineering

NARCIS (Netherlands)

Geemen, van D.; Driessen - Mol, A.; Grootzwagers, L.G.M.; Soekhradj - Soechit, R.S.; Riem Vis, P.W.; Baaijens, F.P.T.; Bouten, C.V.C.

AIM: Clinical application of tissue engineered heart valves requires precise control of the tissue culture process to predict tissue composition and mechanical properties prior to implantation, and to understand the variation in tissue outcome. To this end we investigated cellular phenotype and

Soft tissue modelling with conical springs.

Science.gov (United States)

Omar, Nadzeri; Zhong, Yongmin; Jazar, Reza N; Subic, Aleksandar; Smith, Julian; Shirinzadeh, Bijan

2015-01-01

This paper presents a new method for real-time modelling soft tissue deformation. It improves the traditional mass-spring model with conical springs to deal with nonlinear mechanical behaviours of soft tissues. A conical spring model is developed to predict soft tissue deformation with reference to deformation patterns. The model parameters are formulated according to tissue deformation patterns and the nonlinear behaviours of soft tissues are modelled with the stiffness variation of conical spring. Experimental results show that the proposed method can describe different tissue deformation patterns using one single equation and also exhibit the typical mechanical behaviours of soft tissues.

Diffuse reflectance spectroscopy for optical soft tissue differentiation as remote feedback control for tissue-specific laser surgery.

Science.gov (United States)

Stelzle, Florian; Tangermann-Gerk, Katja; Adler, Werner; Zam, Azhar; Schmidt, Michael; Douplik, Alexandre; Nkenke, Emeka

2010-04-01

Laser surgery does not provide haptic feedback for operating layer-by-layer and thereby preserving vulnerable anatomical structures like nerve tissue or blood vessels. Diffuse reflectance spectra can facilitate remote optical tissue differentiation. It is the aim of the study to use this technique on soft tissue samples, to set a technological basis for a remote optical feedback system for tissue-specific laser surgery. Diffuse reflectance spectra (wavelength range: 350-650 nm) of ex vivo types of soft tissue (a total of 10,800 spectra) of the midfacial region of domestic pigs were remotely measured under reduced environmental light conditions and analyzed in order to differentiate between skin, mucosa, muscle, subcutaneous fat, and nerve tissue. We performed a principal components (PC) analysis (PCA) to reduce the number of variables. Linear discriminant analysis (LDA) was utilized for classification. For the tissue differentiation, we calculated the specificity and sensitivity by receiver operating characteristic (ROC) analysis and the area under curve (AUC). Six PCs were found to be adequate for tissue differentiation with diffuse reflectance spectra using LDA. All of the types of soft tissue could be differentiated with high specificity and sensitivity. Only the tissue pairs nervous tissue/fatty tissue and nervous tissue/mucosa showed a decline of differentiation due to bio-structural similarity. However, both of these tissue pairs could still be differentiated with a specificity and sensitivity of more than 90%. Analyzing diffuse reflectance spectroscopy with PCA and LDA allows for remote differentiation of biological tissue. Considering the limitations of the ex vivo conditions, the obtained results are promising and set a basis for the further development of a feedback system for tissue-specific laser surgery. (c) 2010 Wiley-Liss, Inc.

Tissue Discrimination by Uncorrected Autofluorescence Spectra: A Proof-of-Principle Study for Tissue-Specific Laser Surgery

Directory of Open Access Journals (Sweden)

Katja Tangermann-Gerk

2013-10-01

Full Text Available Laser surgery provides a number of advantages over conventional surgery. However, it implies large risks for sensitive tissue structures due to its characteristic non-tissue-specific ablation. The present study investigates the discrimination of nine different ex vivo tissue types by using uncorrected (raw autofluorescence spectra for the development of a remote feedback control system for tissue-selective laser surgery. Autofluorescence spectra (excitation wavelength 377 ± 50 nm were measured from nine different ex vivo tissue types, obtained from 15 domestic pig cadavers. For data analysis, a wavelength range between 450 nm and 650 nm was investigated. Principal Component Analysis (PCA and Quadratic Discriminant Analysis (QDA were used to discriminate the tissue types. ROC analysis showed that PCA, followed by QDA, could differentiate all investigated tissue types with AUC results between 1.00 and 0.97. Sensitivity reached values between 93% and 100% and specificity values between 94% and 100%. This ex vivo study shows a high differentiation potential for physiological tissue types when performing autofluorescence spectroscopy followed by PCA and QDA. The uncorrected autofluorescence spectra are suitable for reliable tissue discrimination and have a high potential to meet the challenges necessary for an optical feedback system for tissue-specific laser surgery.

Collagenous Extracellular Matrix Biomaterials for Tissue Engineering: Lessons from the Common Sea Urchin Tissue

Science.gov (United States)

Goh, Kheng Lim; Holmes, David F.

2017-01-01

Scaffolds for tissue engineering application may be made from a collagenous extracellular matrix (ECM) of connective tissues because the ECM can mimic the functions of the target tissue. The primary sources of collagenous ECM material are calf skin and bone. However, these sources are associated with the risk of having bovine spongiform encephalopathy or transmissible spongiform encephalopathy. Alternative sources for collagenous ECM materials may be derived from livestock, e.g., pigs, and from marine animals, e.g., sea urchins. Collagenous ECM of the sea urchin possesses structural features and mechanical properties that are similar to those of mammalian ones. However, even more intriguing is that some tissues such as the ligamentous catch apparatus can exhibit mutability, namely rapid reversible changes in the tissue mechanical properties. These tissues are known as mutable collagenous tissues (MCTs). The mutability of these tissues has been the subject of on-going investigations, covering the biochemistry, structural biology and mechanical properties of the collagenous components. Recent studies point to a nerve-control system for regulating the ECM macromolecules that are involved in the sliding action of collagen fibrils in the MCT. This review discusses the key attributes of the structure and function of the ECM of the sea urchin ligaments that are related to the fibril-fibril sliding action—the focus is on the respective components within the hierarchical architecture of the tissue. In this context, structure refers to size, shape and separation distance of the ECM components while function is associated with mechanical properties e.g., strength and stiffness. For simplicity, the components that address the different length scale from the largest to the smallest are as follows: collagen fibres, collagen fibrils, interfibrillar matrix and collagen molecules. Application of recent theories of stress transfer and fracture mechanisms in fibre reinforced

Collagenous Extracellular Matrix Biomaterials for Tissue Engineering: Lessons from the Common Sea Urchin Tissue.

Science.gov (United States)

Goh, Kheng Lim; Holmes, David F

2017-04-25

Scaffolds for tissue engineering application may be made from a collagenous extracellular matrix (ECM) of connective tissues because the ECM can mimic the functions of the target tissue. The primary sources of collagenous ECM material are calf skin and bone. However, these sources are associated with the risk of having bovine spongiform encephalopathy or transmissible spongiform encephalopathy. Alternative sources for collagenous ECM materials may be derived from livestock, e.g., pigs, and from marine animals, e.g., sea urchins. Collagenous ECM of the sea urchin possesses structural features and mechanical properties that are similar to those of mammalian ones. However, even more intriguing is that some tissues such as the ligamentous catch apparatus can exhibit mutability, namely rapid reversible changes in the tissue mechanical properties. These tissues are known as mutable collagenous tissues (MCTs). The mutability of these tissues has been the subject of on-going investigations, covering the biochemistry, structural biology and mechanical properties of the collagenous components. Recent studies point to a nerve-control system for regulating the ECM macromolecules that are involved in the sliding action of collagen fibrils in the MCT. This review discusses the key attributes of the structure and function of the ECM of the sea urchin ligaments that are related to the fibril-fibril sliding action-the focus is on the respective components within the hierarchical architecture of the tissue. In this context, structure refers to size, shape and separation distance of the ECM components while function is associated with mechanical properties e.g., strength and stiffness. For simplicity, the components that address the different length scale from the largest to the smallest are as follows: collagen fibres, collagen fibrils, interfibrillar matrix and collagen molecules. Application of recent theories of stress transfer and fracture mechanisms in fibre reinforced

Collagenous Extracellular Matrix Biomaterials for Tissue Engineering: Lessons from the Common Sea Urchin Tissue

Directory of Open Access Journals (Sweden)

Kheng Lim Goh

2017-04-01

Full Text Available Scaffolds for tissue engineering application may be made from a collagenous extracellular matrix (ECM of connective tissues because the ECM can mimic the functions of the target tissue. The primary sources of collagenous ECM material are calf skin and bone. However, these sources are associated with the risk of having bovine spongiform encephalopathy or transmissible spongiform encephalopathy. Alternative sources for collagenous ECM materials may be derived from livestock, e.g., pigs, and from marine animals, e.g., sea urchins. Collagenous ECM of the sea urchin possesses structural features and mechanical properties that are similar to those of mammalian ones. However, even more intriguing is that some tissues such as the ligamentous catch apparatus can exhibit mutability, namely rapid reversible changes in the tissue mechanical properties. These tissues are known as mutable collagenous tissues (MCTs. The mutability of these tissues has been the subject of on-going investigations, covering the biochemistry, structural biology and mechanical properties of the collagenous components. Recent studies point to a nerve-control system for regulating the ECM macromolecules that are involved in the sliding action of collagen fibrils in the MCT. This review discusses the key attributes of the structure and function of the ECM of the sea urchin ligaments that are related to the fibril-fibril sliding action—the focus is on the respective components within the hierarchical architecture of the tissue. In this context, structure refers to size, shape and separation distance of the ECM components while function is associated with mechanical properties e.g., strength and stiffness. For simplicity, the components that address the different length scale from the largest to the smallest are as follows: collagen fibres, collagen fibrils, interfibrillar matrix and collagen molecules. Application of recent theories of stress transfer and fracture mechanisms in fibre

2010 Great Lakes Human Health Fish Tissue Study Fish Tissue Data Dictionary

Science.gov (United States)

The Office of Science and Technology (OST) is providing the fish tissue results from the 2010 Great Lakes Human Health Fish Tissue Study (GLHHFTS). This document includes the “data dictionary” for Mercury, PFC, PBDE and PCBs.

Clinical management of soft tissue sarcomas

International Nuclear Information System (INIS)

Pinedo, H.M.; Verweij, J.

1986-01-01

This book is concerned with the clinical management of soft tissue sarcomas. Topics covered include: Radiotherapy; Pathology of soft tissue sarcomas; Surgical treatment of soft tissue sarcomas; and Chemotherapy in advanced soft tissue sarcomas

Patch esophagoplasty using an in-body-tissue-engineered collagenous connective tissue membrane.

Science.gov (United States)

Okuyama, Hiroomi; Umeda, Satoshi; Takama, Yuichi; Terasawa, Takeshi; Nakayama, Yasuhide

2018-02-01

Although many approaches to esophageal replacement have been investigated, these efforts have thus far only met limited success. In-body-tissue-engineered connective tissue tubes have been reported to be effective as vascular replacement grafts. The aim of this study was to investigate the usefulness of an In-body-tissue-engineered collagenous connective tissue membrane, "Biosheet", as a novel esophageal scaffold in a beagle model. We prepared Biosheets by embedding specially designed molds into subcutaneous pouches in beagles. After 1-2months, the molds, which were filled with ingrown connective tissues, were harvested. Rectangular-shaped Biosheets (10×20mm) were then implanted to replace defects of the same size that had been created in the cervical esophagus of the beagle. An endoscopic evaluation was performed at 4 and 12weeks after implantation. The esophagus was harvested and subjected to a histological evaluation at 4 (n=2) and 12weeks (n=2) after implantation. The animal study protocols were approved by the National Cerebral and Cardiovascular Centre Research Institute Committee (No. 16048). The Biosheets showed sufficient strength and flexibility to replace the esophagus defect. All animals survived with full oral feeding during the study period. No anastomotic leakage was observed. An endoscopic study at 4 and 12weeks after implantation revealed that the anastomotic sites and the internal surface of the Biosheets were smooth, without stenosis. A histological analysis at 4weeks after implantation demonstrated that stratified squamous epithelium was regenerated on the internal surface of the Biosheets. A histological analysis at 12weeks after implantation showed the regeneration of muscle tissue in the implanted Biosheets. The long-term results of patch esophagoplasty using Biosheets showed regeneration of stratified squamous epithelium and muscular tissues in the implanted sheets. These results suggest that Biosheets may be useful as a novel esophageal

Aging changes in organs - tissue - cells

Science.gov (United States)

... and structure to the skin and internal organs. Epithelial tissue provides a covering for deeper body layers. The ... such as the gastrointestinal system, are made of epithelial tissue. Muscle tissue includes three types of tissue: Striated ...

Tissue type plasminogen activator regulates myeloid-cell dependent neoangiogenesis during tissue regeneration

DEFF Research Database (Denmark)

Ohki, Makiko; Ohki, Yuichi; Ishihara, Makoto

2010-01-01

tissue regeneration is not well understood. Bone marrow (BM)-derived myeloid cells facilitate angiogenesis during tissue regeneration. Here, we report that a serpin-resistant form of tPA by activating the extracellular proteases matrix metalloproteinase-9 and plasmin expands the myeloid cell pool......-A. Remarkably, transplantation of BM-derived tPA-mobilized CD11b(+) cells and VEGFR-1(+) cells, but not carrier-mobilized cells or CD11b(-) cells, accelerates neovascularization and ischemic tissue regeneration. Inhibition of VEGF signaling suppresses tPA-induced neovascularization in a model of hind limb...... and mobilizes CD45(+)CD11b(+) proangiogenic, myeloid cells, a process dependent on vascular endothelial growth factor-A (VEGF-A) and Kit ligand signaling. tPA improves the incorporation of CD11b(+) cells into ischemic tissues and increases expression of neoangiogenesis-related genes, including VEGF...

Neural tissue-spheres

DEFF Research Database (Denmark)

Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

2007-01-01

By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... content, thus allowing experimental studies of neural precursor cells and their niche...

The PAXgene(® tissue system preserves phosphoproteins in human tissue specimens and enables comprehensive protein biomarker research.

Directory of Open Access Journals (Sweden)

Sibylle Gündisch

Full Text Available Precise quantitation of protein biomarkers in clinical tissue specimens is a prerequisite for accurate and effective diagnosis, prognosis, and personalized medicine. Although progress is being made, protein analysis from formalin-fixed and paraffin-embedded tissues is still challenging. In previous reports, we showed that the novel formalin-free tissue preservation technology, the PAXgene Tissue System, allows the extraction of intact and immunoreactive proteins from PAXgene-fixed and paraffin-embedded (PFPE tissues. In the current study, we focused on the analysis of phosphoproteins and the applicability of two-dimensional gel electrophoresis (2D-PAGE and enzyme-linked immunosorbent assay (ELISA to the analysis of a variety of malignant and non-malignant human tissues. Using western blot analysis, we found that phosphoproteins are quantitatively preserved in PFPE tissues, and signal intensities are comparable to that in paired, frozen tissues. Furthermore, proteins extracted from PFPE samples are suitable for 2D-PAGE and can be quantified by ELISA specific for denatured proteins. In summary, the PAXgene Tissue System reliably preserves phosphoproteins in human tissue samples, even after prolonged fixation or stabilization times, and is compatible with methods for protein analysis such as 2D-PAGE and ELISA. We conclude that the PAXgene Tissue System has the potential to serve as a versatile tissue fixative for modern pathology.

[Cellular subcutaneous tissue. Anatomic observations].

Science.gov (United States)

Marquart-Elbaz, C; Varnaison, E; Sick, H; Grosshans, E; Cribier, B

2001-11-01

We showed in a companion paper that the definition of the French "subcutaneous cellular tissue" considerably varied from the 18th to the end of the 20th centuries and has not yet reached a consensus. To address the anatomic reality of this "subcutaneous cellular tissue", we investigated the anatomic structures underlying the fat tissue in normal human skin. Sixty specimens were excised from the surface to the deep structures (bone, muscle, cartilage) on different body sites of 3 cadavers from the Institut d'Anatomie Normale de Strasbourg. Samples were paraffin-embedded, stained and analysed with a binocular microscope taking x 1 photographs. Specimens were also excised and fixed after subcutaneous injection of Indian ink, after mechanic tissue splitting and after performing artificial skin folds. The aspects of the deep parts of the skin greatly varied according to their anatomic localisation. Below the adipose tissue, we often found a lamellar fibrous layer which extended from the interlobular septa and contained horizontally distributed fat cells. No specific tissue below the hypodermis was observed. Artificial skin folds concerned either exclusively the dermis, when they were superficial or included the hypodermis, but no specific structure was apparent in the center of the fold. India ink diffused to the adipose tissue, mainly along the septa, but did not localise in a specific subcutaneous compartment. This study shows that the histologic aspects of the deep part of the skin depend mainly on the anatomic localisation. Skin is composed of epidermis, dermis and hypodermis and thus the hypodermis can not be considered as being "subcutaneous". A difficult to individualise, fibrous lamellar structure in continuity with the interlobular septa is often found under the fat lobules. This structure is a cleavage line, as is always the case with loose connective tissues, but belongs to the hypodermis (i.e. fat tissue). No specific tissue nor any virtual space was

Tritium metabolism in rat tissues

International Nuclear Information System (INIS)

Takeda, H.

1982-01-01

As part of a series of studies designed to evaluate the relative radiotoxicity of various tritiated compounds, metabolism of tritium in rat tissues was studied after administration of tritiated water, leucine, thymidine, and glucose. The distribution and retention of tritium varied widely, depending on the chemical compound administered. Tritium introduced as tritiated water behaved essentially as body water and became uniformly distributed among the tissues. However, tritium administered as organic compounds resulted in relatively high incorporation into tissue constituents other than water, and its distribution differed among the various tissues. Moreover, the excretion rate of tritium from tissues was slower for tritiated organic compounds than for tritiated water. Administrationof tritiated organic compounds results in higher radiation doses to the tissues than does administration of tritiated water. Among the tritiated compounds examined, for equal radioactivity administered, leucine gave the highest radiation dose, followed in turn by thymidine, glucose, and water. (author)

Computational Modeling in Tissue Engineering

CERN Document Server

2013-01-01

One of the major challenges in tissue engineering is the translation of biological knowledge on complex cell and tissue behavior into a predictive and robust engineering process. Mastering this complexity is an essential step towards clinical applications of tissue engineering. This volume discusses computational modeling tools that allow studying the biological complexity in a more quantitative way. More specifically, computational tools can help in:  (i) quantifying and optimizing the tissue engineering product, e.g. by adapting scaffold design to optimize micro-environmental signals or by adapting selection criteria to improve homogeneity of the selected cell population; (ii) quantifying and optimizing the tissue engineering process, e.g. by adapting bioreactor design to improve quality and quantity of the final product; and (iii) assessing the influence of the in vivo environment on the behavior of the tissue engineering product, e.g. by investigating vascular ingrowth. The book presents examples of each...

How to assess the plasma delivery of RONS into tissue fluid and tissue

Science.gov (United States)

Oh, Jun-Seok; Szili, Endre J.; Gaur, Nishtha; Hong, Sung-Ha; Furuta, Hiroshi; Kurita, Hirofumi; Mizuno, Akira; Hatta, Akimitsu; Short, Robert D.

2016-08-01

The efficacy of helium (He) and argon (Ar) plasma jets are being investigated for different healthcare applications including wound and cancer therapy, sterilisation and surface disinfections. Current research points to a potential link between the generation of reactive oxygen and nitrogen species (RONS) and outcomes in a range of biological and medical applications. As new data accrue, further strengthening this link, it becomes important to understand the controlled delivery of RONS into solutions, tissue fluids and tissues. This paper investigates the use of He and Ar plasma jets to deliver three RONS (hydrogen peroxide—H2O2, nitrite—\\text{NO}2- and nitrate—\\text{NO}3- ) and molecular oxygen (O2) directly into deionised (DI) water, or indirectly into DI water through an agarose target. The DI water is used in place of tissue fluid and the agarose target serves as a surrogate of tissue. Direct plasma jet treatments deliver more RONS and O2 than the through-agarose treatments for equivalent treatments times. The former only deliver RONS whilst the plasma jets are ignited; the latter continues to deliver RONS into the DI water long after the plasmas are extinguished. The He plasma jet is more effective at delivering H2O2 and \\text{NO}2- directly into DI water, but the Ar plasma jet is more effective at nitrating the DI water in both direct and through-agarose treatments. DI water directly treated with the plasma jets is deoxygenated, with the He plasma jet purging more O2 than the Ar plasma jet. This effect is known as ‘sparging’. In contrast, for through-agarose treatments both jets oxygenated the DI water. These results indicate that in the context of direct and indirect plasma jet treatments of real tissue fluids and tissue, the choice of process gas (He or Ar) could have a profound effect on the concentrations of RONS and O2. Irrespective of operating gas, sparging of tissue fluid (in an open wound) for long prolonged periods during direct plasma

Breast Cancer Tissue Repository

National Research Council Canada - National Science Library

Iglehart, J

1997-01-01

The Breast Tissue Repository at Duke enters its fourth year of finding. The purpose of the Repository at Duke is to provide substantial quantities of frozen tissue for explorative molecular studies...

Soft Tissue Sarcoma—Health Professional Version

Science.gov (United States)

Soft tissue sarcomas are malignant tumors that arise in any of the mesodermal tissues of the extremities, trunk and retroperitoneum, or head and neck. Soft tissue sarcomas may be heterogeneous. Find evidence-based information on soft tissue sarcoma treatment and research.

VISUALIZATION OF BIOLOGICAL TISSUE IMPEDANCE PARAMETERS

Directory of Open Access Journals (Sweden)

V. I. Bankov

2016-01-01

Full Text Available Objective. Investigation the opportunity for measurement of biological tissue impedance to visualize its parameters.Materials and methods. Studies were undertook on the experimental facility, consists of registrating measuring cell, constructed from flat inductors system, formed in oscillatory circuit, herewith investigated biological tissue is the part of this oscillatory circuit. An excitation of oscillatory circuit fulfilled by means of exciter inductor which forms impulse complex modulated electromagnetic field (ICM EMF. The measurement process and visualizations provided by set of certificated instruments: a digital oscillograph AKTAKOM ADS-2221MV, a digital generator АКТАКОМ AWG-4150 (both with software and a gauge RLC E7-22. Comparative dynamic studies of fixed volume and weight pig’s blood, adipose tissue, muscular tissue impedance were conducted by contact versus contactless methods. Contactless method in contrast to contact method gives opportunity to obtain the real morphological visualization of biological tissue irrespective of their nature.Results. Comparison of contact and contactless methods of impedance measurement shows that the inductance to capacitance ratio X(L / X(C was equal: 17 – for muscular tissue, 4 – for blood, 1 – for adipose tissue. It demonstrates the technical correspondence of both impedance registration methods. If propose the base relevance of X (L and X (C parameters for biological tissue impedance so contactless measurement method for sure shows insulating properties of adipose tissue and high conductivity for blood and muscular tissue in fixed volume-weight parameters. Registration of biological tissue impedance complex parameters by contactless method with the help of induced ICM EMF in fixed volume of biological tissue uncovers the most important informative volumes to characterize morphofunctional condition of biological tissue namely X (L / X (C.Conclusion. Contactless method of biological

Tumor tissue slice cultures as a platform for analyzing tissue-penetration and biological activities of nanoparticles.

Science.gov (United States)

Merz, Lea; Höbel, Sabrina; Kallendrusch, Sonja; Ewe, Alexander; Bechmann, Ingo; Franke, Heike; Merz, Felicitas; Aigner, Achim

2017-03-01

The success of therapeutic nanoparticles depends, among others, on their ability to penetrate a tissue for actually reaching the target cells, and their efficient cellular uptake in the context of intact tissue and stroma. Various nanoparticle modifications have been implemented for altering physicochemical and biological properties. Their analysis, however, so far mainly relies on cell culture experiments which only poorly reflect the in vivo situation, or is based on in vivo experiments that are often complicated by whole-body pharmacokinetics and are rather tedious especially when analyzing larger nanoparticle sets. For the more precise analysis of nanoparticle properties at their desired site of action, efficient ex vivo systems closely mimicking in vivo tissue properties are needed. In this paper, we describe the setup of organotypic tumor tissue slice cultures for the analysis of tissue-penetrating properties and biological activities of nanoparticles. As a model system, we employ 350μm thick slice cultures from different tumor xenograft tissues, and analyze modified or non-modified polyethylenimine (PEI) complexes as well as their lipopolyplex derivatives for siRNA delivery. The described conditions for tissue slice preparation and culture ensure excellent tissue preservation for at least 14days, thus allowing for prolonged experimentation and analysis. When using fluorescently labeled siRNA for complex visualization, fluorescence microscopy of cryo-sectioned tissue slices reveals different degrees of nanoparticle tissue penetration, dependent on their surface charge. More importantly, the determination of siRNA-mediated knockdown efficacies of an endogenous target gene, the oncogenic survival factor Survivin, reveals the possibility to accurately assess biological nanoparticle activities in situ, i.e. in living cells in their original environment. Taken together, we establish tumor (xenograft) tissue slices for the accurate and facile ex vivo assessment of

Tissue bioengineering and artificial organs.

Science.gov (United States)

Llames, Sara; García, Eva; Otero Hernández, Jesús; Meana, Alvaro

2012-01-01

The scarcity of organs and tissues for transplant and the need of immunosuppressive drugs to avoid rejection constitute two reasons that justify organ and tissue production in the laboratory. Tissue engineering based tissues (TE) could allow to regenerate the whole organ from a fragment or even to produce several organs from an organ donor for grafting purposes. TE is based in: (1) the ex vivo expansion of cells, (2) the seeding of these expanded cells in tridimensional structures that mimic physiological conditions and, (3) grafting the prototype. In order to graft big structures it is necessary that the organ or tissue produced "ex vivo" bears a vascular tree to ensure the nutrition of its deep layers. At present, no technology has been developed to provide this vascular tree to TE derived products. Thus, these tissues must be thin enough to acquire nutrients during the first days by diffusion from surrounding tissues. This fact constitutes nowadays the greatest limitation of technologies for organ development in the laboratory.In this chapter, all these problems and their possible solutions are commented. Also, the present status of TE techniques in the regeneration of different organ systems is reviewed.

A constitutive model of soft tissue: From nanoscale collagen to tissue continuum

KAUST Repository

Tang, Huang

2009-04-08

Soft collagenous tissue features many hierarchies of structure, starting from tropocollagen molecules that form fibrils, and proceeding to a bundle of fibrils that form fibers. Here we report the development of an atomistically informed continuum model of collagenous tissue. Results from full atomistic and molecular modeling are linked with a continuum theory of a fiber-reinforced composite, handshaking the fibril scale to the fiber and continuum scale in a hierarchical multi-scale simulation approach. Our model enables us to study the continuum-level response of the tissue as a function of cross-link density, making a link between nanoscale collagen features and material properties at larger tissue scales. The results illustrate a strong dependence of the continuum response as a function of nanoscopic structural features, providing evidence for the notion that the molecular basis for protein materials is important in defining their larger-scale mechanical properties. © 2009 Biomedical Engineering Society.

Biomaterials for Tissue Engineering

Science.gov (United States)

Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

2013-01-01

Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

Breast reconstruction - natural tissue

Science.gov (United States)

... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

Fabrication and characterization of scaffold from cadaver goat-lung tissue for skin tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Gupta, Sweta K. [Department of Polymer and Process Engineering, Indian Institute of Technology, Roorkee (India); Dinda, Amit K. [Department of Pathology, All India Institute of Medical Sciences, New Delhi (India); Potdar, Pravin D. [Department of Molecular Medicine, Jaslok Hospital and Research Centre, Mumbai (India); Mishra, Narayan C., E-mail: mishrawise@gmail.com [Department of Polymer and Process Engineering, Indian Institute of Technology, Roorkee (India)

2013-10-15

The present study aims to fabricate scaffold from cadaver goat-lung tissue and evaluate it for skin tissue engineering applications. Decellularized goat-lung scaffold was fabricated by removing cells from cadaver goat-lung tissue enzymatically, to have cell-free 3D-architecture of natural extracellular matrix. DNA quantification assay and Hematoxylin and eosin staining confirmed the absence of cellular material in the decellularized lung-tissue. SEM analysis of decellularized scaffold shows the intrinsic porous structure of lung tissue with well-preserved pore-to-pore interconnectivity. FTIR analysis confirmed non-denaturation and well maintainance of collagenous protein structure of decellularized scaffold. MTT assay, SEM analysis and H and E staining of human skin-derived Mesenchymal Stem cell, seeded over the decellularized scaffold, confirms stem cell attachment, viability, biocompatibility and proliferation over the decellularized scaffold. Expression of Keratin18 gene, along with CD105, CD73 and CD44, by human skin-derived Mesenchymal Stem cells over decellularized scaffold signifies that the cells are viable, proliferating and migrating, and have maintained their critical cellular functions in the presence of scaffold. Thus, overall study proves the applicability of the goat-lung tissue derived decellularized scaffold for skin tissue engineering applications. - Highlights: • We successfully fabricated decellularized scaffold from cadaver goat-lung tissue. • Decellularized goat-lung scaffolds were found to be highly porous. • Skin derived MSC shows high cell viability and proliferation over the scaffold. • Phenotype of MSCs was well maintained over the scaffold. • The scaffold shows potential for applications in skin tissue engineering.

Fabrication and characterization of scaffold from cadaver goat-lung tissue for skin tissue engineering applications

International Nuclear Information System (INIS)

Gupta, Sweta K.; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

2013-01-01

The present study aims to fabricate scaffold from cadaver goat-lung tissue and evaluate it for skin tissue engineering applications. Decellularized goat-lung scaffold was fabricated by removing cells from cadaver goat-lung tissue enzymatically, to have cell-free 3D-architecture of natural extracellular matrix. DNA quantification assay and Hematoxylin and eosin staining confirmed the absence of cellular material in the decellularized lung-tissue. SEM analysis of decellularized scaffold shows the intrinsic porous structure of lung tissue with well-preserved pore-to-pore interconnectivity. FTIR analysis confirmed non-denaturation and well maintainance of collagenous protein structure of decellularized scaffold. MTT assay, SEM analysis and H and E staining of human skin-derived Mesenchymal Stem cell, seeded over the decellularized scaffold, confirms stem cell attachment, viability, biocompatibility and proliferation over the decellularized scaffold. Expression of Keratin18 gene, along with CD105, CD73 and CD44, by human skin-derived Mesenchymal Stem cells over decellularized scaffold signifies that the cells are viable, proliferating and migrating, and have maintained their critical cellular functions in the presence of scaffold. Thus, overall study proves the applicability of the goat-lung tissue derived decellularized scaffold for skin tissue engineering applications. - Highlights: • We successfully fabricated decellularized scaffold from cadaver goat-lung tissue. • Decellularized goat-lung scaffolds were found to be highly porous. • Skin derived MSC shows high cell viability and proliferation over the scaffold. • Phenotype of MSCs was well maintained over the scaffold. • The scaffold shows potential for applications in skin tissue engineering

Multimodality instrument for tissue characterization

Science.gov (United States)

Mah, Robert W. (Inventor); Andrews, Russell J. (Inventor)

2004-01-01

A system with multimodality instrument for tissue identification includes a computer-controlled motor driven heuristic probe with a multisensory tip. For neurosurgical applications, the instrument is mounted on a stereotactic frame for the probe to penetrate the brain in a precisely controlled fashion. The resistance of the brain tissue being penetrated is continually monitored by a miniaturized strain gauge attached to the probe tip. Other modality sensors may be mounted near the probe tip to provide real-time tissue characterizations and the ability to detect the proximity of blood vessels, thus eliminating errors normally associated with registration of pre-operative scans, tissue swelling, elastic tissue deformation, human judgement, etc., and rendering surgical procedures safer, more accurate, and efficient. A neural network program adaptively learns the information on resistance and other characteristic features of normal brain tissue during the surgery and provides near real-time modeling. A fuzzy logic interface to the neural network program incorporates expert medical knowledge in the learning process. Identification of abnormal brain tissue is determined by the detection of change and comparison with previously learned models of abnormal brain tissues. The operation of the instrument is controlled through a user friendly graphical interface. Patient data is presented in a 3D stereographics display. Acoustic feedback of selected information may optionally be provided. Upon detection of the close proximity to blood vessels or abnormal brain tissue, the computer-controlled motor immediately stops probe penetration. The use of this system will make surgical procedures safer, more accurate, and more efficient. Other applications of this system include the detection, prognosis and treatment of breast cancer, prostate cancer, spinal diseases, and use in general exploratory surgery.

Fibrovascular tissue in bilateral juxtafoveal telangiectasis.

Science.gov (United States)

Park, D; Schatz, H; McDonald, H R; Johnson, R N

1996-09-01

To study the natural history and retinal findings associated with the intraretinal and subretinal fibrovascular tissues that develop in the late phases of bilateral juxtafoveal telangiectasis. The records of 10 patients (11 eyes) with bilateral juxtafoveal telangiectasis who developed these fibrovascular tissues were examined. Throughout the follow-up period (average 44 months), only 2 eyes (18%) lost 2 or more lines of vision; the final visual acuities were similar for the eyes both with and without fibrovascular tissues. Sixty-four percent of fibrovascular tissues showed little to no growth. Eyes with fibrovascular tissue commonly had retinal pigment epithelial hyperplasia (72%), draining retinal venules (82%), and retinal vascular distortion (64%). Fibrovascular tissues of bilateral juxtafoveal telangiectasis have little proliferative potential and minimal effects on visual acuity. Nevertheless, these fibrovascular tissues do remodel over time, leading to retinal vascular distortion. Given these benign findings, the role of laser photocoagulation treatment of these tissues is questionable.

Biomimetic heterogenous elastic tissue development.

Science.gov (United States)

Tsai, Kai Jen; Dixon, Simon; Hale, Luke Richard; Darbyshire, Arnold; Martin, Daniel; de Mel, Achala

2017-01-01

There is an unmet need for artificial tissue to address current limitations with donor organs and problems with donor site morbidity. Despite the success with sophisticated tissue engineering endeavours, which employ cells as building blocks, they are limited to dedicated labs suitable for cell culture, with associated high costs and long tissue maturation times before available for clinical use. Direct 3D printing presents rapid, bespoke, acellular solutions for skull and bone repair or replacement, and can potentially address the need for elastic tissue, which is a major constituent of smooth muscle, cartilage, ligaments and connective tissue that support organs. Thermoplastic polyurethanes are one of the most versatile elastomeric polymers. Their segmented block copolymeric nature, comprising of hard and soft segments allows for an almost limitless potential to control physical properties and mechanical behaviour. Here we show direct 3D printing of biocompatible thermoplastic polyurethanes with Fused Deposition Modelling, with a view to presenting cell independent in-situ tissue substitutes. This method can expeditiously and economically produce heterogenous, biomimetic elastic tissue substitutes with controlled porosity to potentially facilitate vascularisation. The flexibility of this application is shown here with tubular constructs as exemplars. We demonstrate how these 3D printed constructs can be post-processed to incorporate bioactive molecules. This efficacious strategy, when combined with the privileges of digital healthcare, can be used to produce bespoke elastic tissue substitutes in-situ, independent of extensive cell culture and may be developed as a point-of-care therapy approach.

Connective tissue: cancer patients’ attitudes towards medical research using excised (tumour) tissue

NARCIS (Netherlands)

Vermeulen, E.; Schmidt, M.K.; Cornel, M.C.; Knoppers, B.M.; van Leeuwen, F.E.; Aaronson, N.K.

2011-01-01

The objective of this article is to explore the views of Dutch cancer patients on the use of excised and stored (tumor) tissues in medical research. Excised tissues are routinely stored in hospitals for future diagnostic use. They are also important for scientific research. This article discusses

Scalable robotic biofabrication of tissue spheroids

International Nuclear Information System (INIS)

Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V; Brown, J; Beaver, W; Da Silva, J V L

2011-01-01

Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

Scalable robotic biofabrication of tissue spheroids

Energy Technology Data Exchange (ETDEWEB)

Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V [Advanced Tissue Biofabrication Center, Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC (United States); Brown, J [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Beaver, W [York Technical College, Rock Hill, SC (United States); Da Silva, J V L, E-mail: mironovv@musc.edu [Renato Archer Information Technology Center-CTI, Campinas (Brazil)

2011-06-15

Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

Functional Attachment of Soft Tissues to Bone: Development, Healing, and Tissue Engineering

Science.gov (United States)

Lu, Helen H.; Thomopoulos, Stavros

2014-01-01

Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue–to-bone interface, and concludes with a summary of challenges and future directions. PMID:23642244

Functional evaluation of artificial skeletal muscle tissue constructs fabricated by a magnetic force-based tissue engineering technique.

Science.gov (United States)

Yamamoto, Yasunori; Ito, Akira; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

2011-01-01

Skeletal muscle tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional artificial skeletal muscle tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the artificial tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the artificial tissue constructs contracted to generate a physical force (the maximum twitch force, 33.2 μN [1.06 mN/mm2]). Rheobase and chronaxie of the tissue were determined as 4.45 V and 0.72 ms, respectively. These results indicate that the artificial skeletal muscle tissue constructs fabricated in this study were physiologically functional and the data obtained for the evaluation of their functional properties may provide useful information for future skeletal muscle tissue engineering studies.

The comparison of thermal tissue injuries caused by ultrasonic scalpel and electrocautery use in rabbit tongue tissue

Science.gov (United States)

Beriat, Guclu Kaan; Akmansu, Sefik Halit; Ezerarslan, Hande; Dogan, Cem; Han, Unsal; Saglam, Mehmet; Senel, Oytun Okan; Kocaturk, Sinan

2012-01-01

The aim of this study compares to the increase in tissue temperature and the thermal histological effects of ultrasonic scalpel, bipolar and unipolar electrosurgery incisions in the tongue tissue of rabbits. This study evaluates the histopathological changes related to thermal change and the maximum temperature values in the peripheral tissue brought about by the incisions carried out by the three methods in a comparative way. To assess thermal tissue damage induced by the three instruments, maximum tissue temperatures were measured during the surgical procedure and tongue tissue samples were examined histopathologically following the surgery. The mean maximum temperature values of the groups were 93.93±2.76 C° for the unipolar electrocautery group, whereas 85.07±5.95 C° for the bipolar electrocautery group, and 108.23±7.64 C° for the ultrasonic scalpel group. There was a statistically significant relationship between the increase in maximum temperature values and the separation among tissue layers, edema, congestion, necrosis, hemorrhage, destruction in blood vessel walls and fibrin accumulation, and between the existence of fibrin thrombus and tissue damage depth (pelectrocautery use gives way to less temperature increase in the tissues and less thermal tissue damage in comparison to the other methods. PMID:22938541

Tissues Use Resident Dendritic Cells and Macrophages to Maintain Homeostasis and to Regain Homeostasis upon Tissue Injury: The Immunoregulatory Role of Changing Tissue Environments

Science.gov (United States)

Lech, Maciej; Gröbmayr, Regina; Weidenbusch, Marc; Anders, Hans-Joachim

2012-01-01

Most tissues harbor resident mononuclear phagocytes, that is, dendritic cells and macrophages. A classification that sufficiently covers their phenotypic heterogeneity and plasticity during homeostasis and disease does not yet exist because cell culture-based phenotypes often do not match those found in vivo. The plasticity of mononuclear phagocytes becomes obvious during dynamic or complex disease processes. Different data interpretation also originates from different conceptual perspectives. An immune-centric view assumes that a particular priming of phagocytes then causes a particular type of pathology in target tissues, conceptually similar to antigen-specific T-cell priming. A tissue-centric view assumes that changing tissue microenvironments shape the phenotypes of their resident and infiltrating mononuclear phagocytes to fulfill the tissue's need to maintain or regain homeostasis. Here we discuss the latter concept, for example, why different organs host different types of mononuclear phagocytes during homeostasis. We further discuss how injuries alter tissue environments and how this primes mononuclear phagocytes to enforce this particular environment, for example, to support host defense and pathogen clearance, to support the resolution of inflammation, to support epithelial and mesenchymal healing, and to support the resolution of fibrosis to the smallest possible scar. Thus, organ- and disease phase-specific microenvironments determine macrophage and dendritic cell heterogeneity in a temporal and spatial manner, which assures their support to maintain and regain homeostasis in whatever condition. Mononuclear phagocytes contributions to tissue pathologies relate to their central roles in orchestrating all stages of host defense and wound healing, which often become maladaptive processes, especially in sterile and/or diffuse tissue injuries. PMID:23251037

Tissue Harmonic Synthetic Aperture Imaging

DEFF Research Database (Denmark)

Rasmussen, Joachim

The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB...

Plant tissue culture techniques

Directory of Open Access Journals (Sweden)

Rolf Dieter Illg

1991-01-01

Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

TISSUES 2.0: an integrative web resource on mammalian tissue expression.

Science.gov (United States)

Palasca, Oana; Santos, Alberto; Stolte, Christian; Gorodkin, Jan; Jensen, Lars Juhl

2018-01-01

Physiological and molecular similarities between organisms make it possible to translate findings from simpler experimental systems—model organisms—into more complex ones, such as human. This translation facilitates the understanding of biological processes under normal or disease conditions. Researchers aiming to identify the similarities and differences between organisms at the molecular level need resources collecting multi-organism tissue expression data. We have developed a database of gene–tissue associations in human, mouse, rat and pig by integrating multiple sources of evidence: transcriptomics covering all four species and proteomics (human only), manually curated and mined from the scientific literature. Through a scoring scheme, these associations are made comparable across all sources of evidence and across organisms. Furthermore, the scoring produces a confidence score assigned to each of the associations. The TISSUES database (version 2.0) is publicly accessible through a user-friendly web interface and as part of the STRING app for Cytoscape. In addition, we analyzed the agreement between datasets, across and within organisms, and identified that the agreement is mainly affected by the quality of the datasets rather than by the technologies used or organisms compared. http://tissues.jensenlab.org/

Mechanics of needle-tissue interaction

NARCIS (Netherlands)

Roesthuis, Roy; van Veen, Youri; Jahya, Alex; Misra, Sarthak

2011-01-01

When a needle is inserted into soft tissue, interac- tion forces are developed at the needle tip and along the needle shaft. The needle tip force is due to cutting of the tissue, and the force along the needle shaft is due to friction between needle and tissue. In this study, the friction force is

Neutron RBE for normal tissues

International Nuclear Information System (INIS)

Field, S.B.; Hornsey, S.

1979-01-01

RBE for various normal tissues is considered as a function of neutron dose per fraction. Results from a variety of centres are reviewed. It is shown that RBE is dependent on neutron energy and is tissue dependent, but is not specially high for the more critical tissues or for damage occurring late after irradiation. (author)

Protein signature of lung cancer tissues.

Directory of Open Access Journals (Sweden)

Michael R Mehan

Full Text Available Lung cancer remains the most common cause of cancer-related mortality. We applied a highly multiplexed proteomic technology (SOMAscan to compare protein expression signatures of non small-cell lung cancer (NSCLC tissues with healthy adjacent and distant tissues from surgical resections. In this first report of SOMAscan applied to tissues, we highlight 36 proteins that exhibit the largest expression differences between matched tumor and non-tumor tissues. The concentrations of twenty proteins increased and sixteen decreased in tumor tissue, thirteen of which are novel for NSCLC. NSCLC tissue biomarkers identified here overlap with a core set identified in a large serum-based NSCLC study with SOMAscan. We show that large-scale comparative analysis of protein expression can be used to develop novel histochemical probes. As expected, relative differences in protein expression are greater in tissues than in serum. The combined results from tissue and serum present the most extensive view to date of the complex changes in NSCLC protein expression and provide important implications for diagnosis and treatment.

Fabrication and characterization of scaffold from cadaver goat-lung tissue for skin tissue engineering applications.

Science.gov (United States)

Gupta, Sweta K; Dinda, Amit K; Potdar, Pravin D; Mishra, Narayan C

2013-10-01

The present study aims to fabricate scaffold from cadaver goat-lung tissue and evaluate it for skin tissue engineering applications. Decellularized goat-lung scaffold was fabricated by removing cells from cadaver goat-lung tissue enzymatically, to have cell-free 3D-architecture of natural extracellular matrix. DNA quantification assay and Hematoxylin and eosin staining confirmed the absence of cellular material in the decellularized lung-tissue. SEM analysis of decellularized scaffold shows the intrinsic porous structure of lung tissue with well-preserved pore-to-pore interconnectivity. FTIR analysis confirmed non-denaturation and well maintainance of collagenous protein structure of decellularized scaffold. MTT assay, SEM analysis and H&E staining of human skin-derived Mesenchymal Stem cell, seeded over the decellularized scaffold, confirms stem cell attachment, viability, biocompatibility and proliferation over the decellularized scaffold. Expression of Keratin18 gene, along with CD105, CD73 and CD44, by human skin-derived Mesenchymal Stem cells over decellularized scaffold signifies that the cells are viable, proliferating and migrating, and have maintained their critical cellular functions in the presence of scaffold. Thus, overall study proves the applicability of the goat-lung tissue derived decellularized scaffold for skin tissue engineering applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Micro- and nanotechnology in cardiovascular tissue engineering

International Nuclear Information System (INIS)

Zhang Boyang; Xiao Yun; Hsieh, Anne; Thavandiran, Nimalan; Radisic, Milica

2011-01-01

While in nature the formation of complex tissues is gradually shaped by the long journey of development, in tissue engineering constructing complex tissues relies heavily on our ability to directly manipulate and control the micro-cellular environment in vitro. Not surprisingly, advancements in both microfabrication and nanofabrication have powered the field of tissue engineering in many aspects. Focusing on cardiac tissue engineering, this paper highlights the applications of fabrication techniques in various aspects of tissue engineering research: (1) cell responses to micro- and nanopatterned topographical cues, (2) cell responses to patterned biochemical cues, (3) controlled 3D scaffolds, (4) patterned tissue vascularization and (5) electromechanical regulation of tissue assembly and function.

Biomechanics and mechanobiology in functional tissue engineering