-
1
المؤلفون: Hui-qing Qiang, Peter J. Hotez, Jian Xue, Shu-Hua Xiao, Bin Zhan, Na He, Jian Guo
المصدر: Experimental Parasitology. 130:6-12
مصطلحات موضوعية: Male, Necator americanus, Immunology, Antibodies, Helminth, Adaptive Immunity, Albendazole, Microbiology, Necatoriasis, Random Allocation, Antigen, Immunity, Cricetinae, parasitic diseases, medicine, Animals, Mesocricetus, biology, Anticestodal Agents, General Medicine, biology.organism_classification, Acquired immune system, Disease Models, Animal, Infectious Diseases, Antigens, Helminth, Immunoglobulin G, Larva, biology.protein, Parasitology, Antibody, Golden hamster, medicine.drug
الوصف: The aim of the study is to demonstrate and understand the acquired immunity in golden hamsters (Mesocricetus auratus) elicited by primary Necator americanus infective third-stage larvae (L3) infection. Hamsters infected with 150 L3 for 1, 2, 3, 6 and 10 weeks, were challenged with the same number of L3 and sacrificed 25 days post challenge. The primarily infected hamsters exhibited 99-100% protection against subsequent L3 challenge compared to un-infected naive hamsters. The acquired immunity was developed as early as 1 week post L3 infection and lasted up to 10 weeks. Similar protective immunity was obtained in hamsters infected with N. americanus L3 and then treated orally with a single of 100mg/kg albendazole, followed by challenge with N. americanus L3 4 and 8 weeks post-treatment. The infected hamsters exhibited a rise in IgG antibodies against L3 and juvenile adult worm antigens. Histological examination showed that challenging L3 were trapped in the skin of primarily infected hamsters and surrounded or infiltrated by different inflammatory cells. The trapped L3 were damaged and dead followed by the formation of granulomas encasing dead worms. The results demonstrate that hamsters primarily infected with N. americanus L3 develop acquired immunity against re-infection.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::acd678cc9ed8945e8dbd2209628e0d57
https://doi.org/10.1016/j .exppara.2011.10.007 -
2
المؤلفون: Angela L. Williamson, Peter J. Hotez, Shu-Hua Xiao, Gaddam Goud, Jian Xue, Sen Liu, Yueyuan Liu, Bin Zhan, Alex Loukas, Vehid Deumic
المصدر: Experimental Parasitology. 118:32-40
مصطلحات موضوعية: Male, Necator americanus, medicine.medical_treatment, Molecular Sequence Data, Immunology, Hamster, Necatoriasis, Open Reading Frames, Antigen, Cricetinae, parasitic diseases, medicine, Animals, Humans, Amino Acid Sequence, Cloning, Molecular, Hookworm infection, Vaccines, Synthetic, Hookworm vaccine, Base Sequence, Mesocricetus, biology, fungi, General Medicine, biology.organism_classification, Virology, Recombinant Proteins, Cysteine Endopeptidases, Disease Models, Animal, Infectious Diseases, Antigens, Helminth, Larva, Antigens, Surface, Parasitology, Ancylostoma caninum, Sequence Alignment, Adjuvant, medicine.drug
الوصف: We have previously reported the successful adaptation of human hookworm Necator americanus in the golden hamster, Mesocricetus auratus. This animal model was used to test a battery of hookworm (N. americanus and Ancylostoma caninum) recombinant antigens as potential vaccine antigens. Hamsters immunized a leading vaccine candidate N. americanus-Ancylostoma secreted protein 2 (Na-ASP-2) and challenged with N. americanus infective larvae (L3), resulted in 30-46.2% worm reduction over the course of three vaccine trials, relative to adjuvant controls. In addition, significant reduction of worm burdens was also observed in the hamsters immunized with adult hookworm antigens A. caninum aspartic protease 1 (Ac-APR-1); A. caninum-glutathione-S transferase 1 (Ac-GST-1) and Necator cysteine proteases 2 (Na-CP-2) (44.4%, 50.6%, and 29.3%, respectively). Our data on the worm burden reductions afforded by these hookworm antigens approximate the level of protection reported previously from dogs challenged with A. caninum L3, and provide additional evidence to support these hookworm antigens as vaccine candidates for human hookworm infection. The hamster model of N. americanus provides useful information for the selection of antigens to be tested in downstream vaccine development.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8059b2978a9117d475322446c0f91457
https://doi.org/10.1016/j .exppara.2007.05.010 -
3
المؤلفون: Jian Xue, Xiao Shuhua, Bin Zhan, Qiang Huiqing, Peter J. Hotez, Yao Jun-Ming, Ricardo Toshio Fujiwara
المصدر: Experimental Parasitology. 111:219-223
مصطلحات موضوعية: Male, Veterinary medicine, Necator americanus, Immunology, Pyrantel Pamoate, Physiology, Phenylenediamines, Biology, Albendazole, Tribendimidine, Necatoriasis, Deworming, Sex Factors, Cricetinae, parasitic diseases, medicine, Animals, Anthelmintic, Anthelmintics, Mesocricetus, Infectious dose, Age Factors, General Medicine, biology.organism_classification, Disease Models, Animal, Infectious Diseases, Erythrocyte Count, Female, Parasitology, medicine.drug
الوصف: Laboratory golden hamsters (Mesocricetus auratus) were infected with Necator americanus under several different parasite and host conditions to optimize the model for testing anthelminthic drugs. The results confirmed that male hamsters were more susceptible to infection than females. Host age in the range of 5-15 weeks was not a factor that impacted on adult worm burden, and similar worm burdens were achieved using doses of 150, 250 or 500 N. americanus L3 (NaL3). The largest numbers of adult hookworms were recovered on days 21-28 post-infection, with a significant decrease at days 40-50 post-infection. Therefore adult worm recovery is maximal approximately 11-18 days prior to patency and host blood loss. From these studies a drug evaluation protocol was developed using 150 NaL3 as the infectious dose and then evaluating the anthelminthic effects of the drugs albendazole, tribendimidine, and pyrantel pamoate on days 21-28 post-infection. The model confirms the anthelminthic activity of albendazole, tribendimidine, and pyrantel pamoate and has the potential as a laboratory animal model to detect emerging drug resistance.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8809e4a3fdd28164b905a0468f7f1238
https://doi.org/10.1016/j .exppara.2005.08.002 -
4
المؤلفون: Qiang Hui-Qin, Ren Hainan, Xue Haichou, Liu Sen, Peter J. Hotez, Li Tie-Hua, Xue Jian, Xiao Shuhua
المصدر: Experimental Parasitology. 104:62-66
مصطلحات موضوعية: Male, Necator americanus, Immunology, Physiology, Necatoriasis, Feces, Sex Factors, Cricetinae, parasitic diseases, Parasite Egg Count, Animals, Parasite hosting, Larva, Mesocricetus, biology, Host (biology), General Medicine, biology.organism_classification, Fecundity, Disease Models, Animal, Fertility, Infectious Diseases, Female, Parasitology, Golden hamster
الوصف: The human hookworm Necator americanus was maintained through one hundred generations in the golden hamster (Mesocricetus auratus). The parasite strain employed here was ultimately adapted to hamsters without the requirement for exogenous steroids or other immunosuppressive agents. Moreover, there was no requirement to use neonatal hamsters--successful infections were obtained in 9- to 10-week-old hamsters infected subcutaneously with 250 hookworm larvae. This unique adaptation of N. americanus to hamsters permits its use for purposes of anthelminthic drug and vaccine development.
-
5
المؤلفون: John M. Hawdon, M.A. Perregaux, Brian F. Jones, Peter J. Hotez
المصدر: Experimental Parasitology. 80:205-211
مصطلحات موضوعية: Electrophoresis, Proteases, Ancylostoma, Secretory component, Immunology, Chlorides, Animals, chemistry.chemical_classification, Metalloproteinase, biology, Caseins, Metalloendopeptidases, Feeding Behavior, General Medicine, biology.organism_classification, In vitro, Culture Media, Molecular Weight, Infectious Diseases, Nematode, Enzyme, Biochemistry, chemistry, Zinc Compounds, Larva, Parasitology, Ancylostoma caninum, Phenanthrolines
الوصف: Infective stages of several nematode parasites are known to release proteases in excretory/secretory products. These enzymes are believed to facilitate tissue invasion, although direct evidence is lacking. For these investigations, we employed an assay that uses the resumption of feeding as a marker for early events in the infectious process. When Ancylostoma caninum third-stage infective larvae are stimulated to feed in vitro, they release proteases of approximately 50,000 and 90,000 molecular weight, as determined by substrate gel electrophoresis. The enzymes are inhibited by the zinc chelator 1,10-phenanthroline, but not by the nonchelating isomer 4,7-phenanthroline, indicating that the proteolytic activity is zinc-dependent. Both compounds inhibit in vitro feeding, although inhibition by 1,10-phenanthroline is zinc-dependent, whereas inhibition by 4,7-phenanthroline is zinc-independent. The specific release of proteases associated with the initiation of feeding suggests that the metalloprotease serves an integral function in the transition of the free-living stage to parasitism.
-
6
المؤلفون: Xue Haichou, Shen Binggui, Zhan Bin, Xue Jian, Qiang Huiqing, Peter J. Hotez, Liu Sen, Li Tie-Hua, Xiao Shuhua
المصدر: Experimental parasitology. 105(3-4)
مصطلحات موضوعية: Male, Necator americanus, Immunology, Zoology, Hamster, Necatoriasis, Feces, Sex Factors, Cricetinae, parasitic diseases, medicine, Parasite hosting, Animals, Humans, Serial Passage, Larva, biology, Mesocricetus, General Medicine, biology.organism_classification, medicine.disease, Disease Models, Animal, Infectious Diseases, Microscopy, Electron, Scanning, Parasitology, Female, Golden hamster
الوصف: Through 100 passages, the human hookworm Necator americanus was adapted to the golden hamster, Mesocricetus auratus, without either the requirement for exogenous steroids or other immunosuppressive agents, nor the requirement to infect hamsters as pups. Adult N. americanus recovered from infected hamsters were morphologically similar to those from infected humans in Sichuan Province, China, although they were smaller and the females produced fewer eggs. The natural history and kinetics of N. americanus infection was different in female and male hamsters. Female hamsters supported low intensity infections that lasted for approximately two months. In contrast, the peak intensity of infection in male hamsters was high, but this situation lasted less than for 4 weeks at which time many of the hookworms were expelled. However, even after the major parasite expulsion, the total number of hookworms consistently remained higher in chronically infected male hamsters compared with female hamsters. The hamster model of N. americanus is potentially useful for studying the development of new anthelminthic drugs and vaccines.
-
7
المؤلفون: Neal L. Rosen, William H. Konigsberg, John Lifter, Mary S. Bogucki, Masahiko Onodera, Peter J. Hotez, Frank F. Richards
المصدر: Experimental Parasitology. 53:1-10
مصطلحات موضوعية: chemistry.chemical_classification, Antiserum, biology, Immunology, Heterologous, General Medicine, biology.organism_classification, Fragment crystallizable region, Molecular biology, Immunoglobulin G, Infectious Diseases, chemistry, Antigen, parasitic diseases, biology.protein, Trypanosoma, Parasitology, Antibody, Glycoprotein
الوصف: A radioimmunoassay (RIA) for the variant-specific glycoproteins (VSG-1 and VSG-2) of two sequentially appearing variants of Trypanosoma congolense has been devised. When the isoelectrically focused VSG-1 components (VSG-1a, VSG-1b, and VSG-1c) are used as inhibitors of the VSG-1-anti-VSG-1 interaction, the RIA inhibition curves resemble each other, although minor differences in the high-affinity region of the curves can be detected. The heterologous antigen (VSG-2) does not inhibit the VSG-1-anti-VSG-1 interaction except at very high concentrations, indicating there is little cross-reactivity between highly purified VSG-1 and VSG-2. Nevertheless, heterologous antiserum, directed against VSG-2, will inhibit the VSG-1 -anti-VSG-1 interaction, and this property is shared to a significant degree by rabbit antiserum directed against an unrelated antigen. We have interpreted these findings as suggesting that: (1) there may be a constant region common to both VSG proteins, and (2) the constant region of the immunoglobulin molecule may also bind VSG proteins. Preliminary experiments show that the VSG-1 molecule augments binding of the Clq component of complement to the Fc region of immunoglobulin G.
-
8
المؤلفون: Gary Davis, Neal L. Rosen, Masahiko Onodera, Peter J. Hotez, Frank F. Richards, Curtis L. Patton, William H. Konigsberg, John Lifter, Mary S. Bogucki
المصدر: Experimental Parasitology. 52:210-218
مصطلحات موضوعية: clone (Java method), Immunology, Trypanosoma brucei, Homology (biology), Epitope, parasitic diseases, Antigenic variation, Peptide sequence, Gene, chemistry.chemical_classification, biology, Isoelectric focusing, Tsetse fly, General Medicine, biology.organism_classification, Molecular biology, Virology, Amino acid, Infectious Diseases, Biochemistry, chemistry, Concanavalin A, biology.protein, Trypanosoma, Parasitology, Glycoprotein
الوصف: Two sequential variant-specific glycoproteins have been purified from two variants of Trypanosoma congolense expressed during a relapsing infection. Isolation of the two glycoproteins, termed VSG-1 and VSG-2, respectively, employed glycerol lysis followed by purification on concanavalin A, Sephadex G-25, and gradient-eluted DE-52 columns. Partially purified VSG proteins were immunologically cross-reactive, but highly purified VSGs showed no cross-reactivity under the conditions employed. Both VSG-1 and VSG-2 consisted of a triplet of polypeptides. Although each member of a triplet subset could be distinguished by isoelectric focusing, all three gave identical N-terminal amino acid sequences and nearly identical tryptic peptide maps. The members of the VSG-1 polypeptide subset differed from those of the VSG-2 subset both with regard to N-terminal amino acid sequence and in tryptic peptide map patterns. Comparison of N-terminal sequences of VSG-1 and VSG-2 did, however, show that the sequences could be aligned to give a modest degree of amino acid homology (27%). This alignment also produced a minimum in the number of two-base changes, suggesting that the observed homology is not a coincidence and that these two proteins may well have arisen by gene duplication followed by retention of multiple point mutations.
إعادة تعيين المنقحات
عرض المنقحات (%%عد%%)