The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Martin Sapp - One of the best experts on this subject based on the ideXlab platform.
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Induction of type-specific neutralizing antibodies by capsomeres of human papillomavirus type 33.
Virology, 2001Co-Authors: Claudia Fligge, Tzenan Giroglou, Rolf E Streeck, Martin SappAbstract:Abstract The immunogenicity of capsomeres of human papillomavirus type 33 was evaluated in a dose–response analysis. Capsomeres were obtained free of capsids by expression of L1 carrying the single point mutation C427S. Neutralizing antibodies were detected using an in vitro Pseudoinfection assay. Capsomeres induced type-specific, neutralizing antibodies in mice even in the absence of adjuvant. The neutralization titers of immune sera raised without adjuvant were 10- to 20-fold lower than those of antisera to virus-like particles, but virtually identical using Freund's adjuvant. These data indicate that capsomeres may substitute for virus-like particles in future vaccines when used with an adjuvant appropriate for human vaccination.
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human papillomavirus infection requires cell surface heparan sulfate
Journal of Virology, 2001Co-Authors: Tzenan Giroglou, Luise Florin, Frank Schafer, Rolf E Streeck, Martin SappAbstract:Using Pseudoinfection of cell lines, we demonstrate that cell surface heparan sulfate is required for infection by human papillomavirus type 16 (HPV-16) and HPV-33 pseudovirions. Pseudoinfection was inhibited by heparin but not dermatan or chondroitin sulfate, reduced by reducing the level of surface sulfation, and abolished by heparinase treatment. Carboxy-terminally deleted HPV-33 virus-like particles still bound efficiently to heparin. The kinetics of postattachment neutralization by antiserum or heparin indicated that pseudovirions were shifted on the cell surface from a heparin-sensitive into a heparin-resistant mode of binding, possibly involving a secondary receptor. Alpha-6 integrin is not a receptor for HPV-33 Pseudoinfection.
Mathieu Sarasa - One of the best experts on this subject based on the ideXlab platform.
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neatness depends on season age and sex in iberian ibex capra pyrenaica
Behavioral Ecology, 2011Co-Authors: Mathieu Sarasa, Samer A Alasaad, Ramón D C. Soriguer, Jesus M Perez, Emmanuel Serrano, Joseenrique Granados, Paulino Fandos, Jean Joachim, Georges GonzalezAbstract:Heterogeneity in host compatibility is one of the main hypotheses proposed to explain uneven resistance to parasites and uneven parasite load between hosts. It suggests that differences between hosts modulate their predispositions as suitable environments for their potential parasites. Interesting studies of antiparasitic behavior have reported the existence of behavioral traits that are capable of removing foreign particles and of reducing the success of parasitic infections. These traits favor host neatness, although little is known about the heterogeneity of neatness. We used a standardized Pseudoinfection with pseudoectoparasites (PEPs) to test the effects of sex, age, and season on the loss of PEPs by hosts as a means of exploring the factors determining neatness in the Iberian ibex Capra pyrenaica. Behavioral observations were also performed to analyze investment in antiparasitic behavior in terms of sex, age, and season. The life span of PEPs peaked in the period December--January, decreased with host age, and was longer in females than in males. Investment in antiparasitic behavior is also associated with both sex and age and season but in a different pattern with interactions between such factors. Our results disagree with the hypothesis that small-bodied animals should be less compatible to carry contact-transmitted particles, such as ectoparasites, in comparison with larger animals. This preexisting hypothesis is thus an inadequate way of predicting host neatness. Consequently, our experiment underlines the importance that nonimmunological traits play in determining heterogeneity in host compatibility to contact-transmitted foreign bodies and helps improve understanding of neatness and of host--parasite systems. Copyright 2011, Oxford University Press.
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Original Article Neatness depends on season, age, and sex in Iberian ibex Capra pyrenaica
2011Co-Authors: Mathieu Sarasa, Jesús B M. Pérez, Samer A Alasaad, Emmanuel C Serrano, Ramón D C. Soriguer, Paulino E F, Jean F Joachim, Georges GonzalezbAbstract:Heterogeneity in host compatibility is one of the main hypotheses proposed to explain uneven resistance to parasites and uneven parasite load between hosts. It suggests that differences between hosts modulate their predispositions as suitable environments for their potential parasites. Interesting studies of antiparasitic behavior have reported the existence of behavioral traits that are capable of removing foreign particles and of reducing the success of parasitic infections. These traits favor host neatness, although little is known about the heterogeneity of neatness. We used a standardized Pseudoinfection with pseudoectoparasites (PEPs) to test the effects of sex, age, and season on the loss of PEPs by hosts as a means of exploring the factors determining neatness in the Iberian ibex Capra pyrenaica. Behavioral observations were also performed to analyze investment in antiparasitic behavior in terms of sex, age, and season. The life span of PEPs peaked in the period December–January, decreased with host age, and was longer in females than in males. Investment in antiparasitic behavior is also associated with both sex and age and season but in a different pattern with interactions between such factors. Our results disagree with the hypothesis that small-bodie
Clinton A White - One of the best experts on this subject based on the ideXlab platform.
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capillaria hepatica Pseudoinfection
American Journal of Tropical Medicine and Hygiene, 2013Co-Authors: Miguel M Cabada, Martha Lopez, Clinton A WhiteAbstract:A 54-year-old male Matsigenka native from the Manu jungle of Peru presented with the eggs shown in Figure 1. Kato Katz (Figure 2) testing revealed 1,500 eggs/g stool. The white blood cell count with differential, liver enzymes, and sputum examination were normal. No treatment was administered; however, repeated stool testing was negative. Pseudocapillariasis caused by Capillaria hepatica was diagnosed. The transient shedding of C. hepatica eggs (which are not usually found in the stools in hepatic capillariasis), lack of eosinophilia, and normal liver enzymes supported the diagnosis. The patient admitted eating liver of a South American Tapir (Tapirus terrestris) shortly before testing. These animals harbor unembryonated non-infective C. hepatica eggs in the liver parenchyma.1 The unembryonated eggs reach the environment after the infected animal dies or eggs are shed in the stools of predators feeding on infected carcasses. After spending 4–8 weeks in the environment, eggs become embryonated and are able to infect the liver if ingested. Hepatic capillariasis is an uncommon human zoonotic disease distributed worldwide. It causes prolonged fever, hepatomegaly, and abdominal pain associated with eosinophilia. In contrast, C. hepatica Pseudoinfection caused by feeding on livers harboring unembryonated eggs is asymptomatic.2 Figure 1. Spontaneous rapid sedimentation test. Egg with a thick striated wall (open arrows) and flat bipolar plugs (arrow) compatible with C. hepatica (Magnification: 400×; scale bar: 50 μm). Figure 2. Kato Katz test showing the same type of eggs (Magnification: 400×; scale bar: 50 μm).
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images in clinical tropical medicine capillaria hepatica Pseudoinfection
2013Co-Authors: Miguel M Cabada, Martha Lopez, Clinton A WhiteAbstract:A 54-year-old male Matsigenka native from the Manu jungle of Peru presented with the eggs shown in Figure 1. Kato Katz (Figure 2) testing revealed 1,500 eggs/g stool. The white blood cell count with differential, liver enzymes, and sputum examination were normal. No treatment was administered; however, repeated stool testing was negative. Pseudocapillariasis caused by Capillaria hepatica was diagnosed. The transient shedding of C. hepatica eggs (which are not usually found in the stools in hepatic capillariasis), lack of eosinophilia, and normal liver enzymes supported the diagnosis. The patient admitted eating liver of a South American Tapir (Tapirus terrestris) shortly before testing. These animals harbor unembryonated non-infective C. hepatica eggs in the liver parenchyma. 1 The unembryonated eggs reach the environment after the infected animal dies or eggs are shed in the stools of predators feeding on infected carcasses. After spending 4–8 weeks in the environment, eggs become embryonated and are able to infect the liver if ingested. Hepatic capillariasis is an uncommon human zoonotic disease distributed worldwide. It causes prolonged fever, hepatomegaly, and abdominal pain associated with eosinophilia. In contrast, C. hepatica Pseudoinfection caused by feeding on livers harboring unembryonated eggs is asymptomatic. 2
Tzenan Giroglou - One of the best experts on this subject based on the ideXlab platform.
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Induction of type-specific neutralizing antibodies by capsomeres of human papillomavirus type 33.
Virology, 2001Co-Authors: Claudia Fligge, Tzenan Giroglou, Rolf E Streeck, Martin SappAbstract:Abstract The immunogenicity of capsomeres of human papillomavirus type 33 was evaluated in a dose–response analysis. Capsomeres were obtained free of capsids by expression of L1 carrying the single point mutation C427S. Neutralizing antibodies were detected using an in vitro Pseudoinfection assay. Capsomeres induced type-specific, neutralizing antibodies in mice even in the absence of adjuvant. The neutralization titers of immune sera raised without adjuvant were 10- to 20-fold lower than those of antisera to virus-like particles, but virtually identical using Freund's adjuvant. These data indicate that capsomeres may substitute for virus-like particles in future vaccines when used with an adjuvant appropriate for human vaccination.
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human papillomavirus infection requires cell surface heparan sulfate
Journal of Virology, 2001Co-Authors: Tzenan Giroglou, Luise Florin, Frank Schafer, Rolf E Streeck, Martin SappAbstract:Using Pseudoinfection of cell lines, we demonstrate that cell surface heparan sulfate is required for infection by human papillomavirus type 16 (HPV-16) and HPV-33 pseudovirions. Pseudoinfection was inhibited by heparin but not dermatan or chondroitin sulfate, reduced by reducing the level of surface sulfation, and abolished by heparinase treatment. Carboxy-terminally deleted HPV-33 virus-like particles still bound efficiently to heparin. The kinetics of postattachment neutralization by antiserum or heparin indicated that pseudovirions were shifted on the cell surface from a heparin-sensitive into a heparin-resistant mode of binding, possibly involving a secondary receptor. Alpha-6 integrin is not a receptor for HPV-33 Pseudoinfection.
Rolf E Streeck - One of the best experts on this subject based on the ideXlab platform.
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Induction of type-specific neutralizing antibodies by capsomeres of human papillomavirus type 33.
Virology, 2001Co-Authors: Claudia Fligge, Tzenan Giroglou, Rolf E Streeck, Martin SappAbstract:Abstract The immunogenicity of capsomeres of human papillomavirus type 33 was evaluated in a dose–response analysis. Capsomeres were obtained free of capsids by expression of L1 carrying the single point mutation C427S. Neutralizing antibodies were detected using an in vitro Pseudoinfection assay. Capsomeres induced type-specific, neutralizing antibodies in mice even in the absence of adjuvant. The neutralization titers of immune sera raised without adjuvant were 10- to 20-fold lower than those of antisera to virus-like particles, but virtually identical using Freund's adjuvant. These data indicate that capsomeres may substitute for virus-like particles in future vaccines when used with an adjuvant appropriate for human vaccination.
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human papillomavirus infection requires cell surface heparan sulfate
Journal of Virology, 2001Co-Authors: Tzenan Giroglou, Luise Florin, Frank Schafer, Rolf E Streeck, Martin SappAbstract:Using Pseudoinfection of cell lines, we demonstrate that cell surface heparan sulfate is required for infection by human papillomavirus type 16 (HPV-16) and HPV-33 pseudovirions. Pseudoinfection was inhibited by heparin but not dermatan or chondroitin sulfate, reduced by reducing the level of surface sulfation, and abolished by heparinase treatment. Carboxy-terminally deleted HPV-33 virus-like particles still bound efficiently to heparin. The kinetics of postattachment neutralization by antiserum or heparin indicated that pseudovirions were shifted on the cell surface from a heparin-sensitive into a heparin-resistant mode of binding, possibly involving a secondary receptor. Alpha-6 integrin is not a receptor for HPV-33 Pseudoinfection.
