-
Tropical Medicine & International... Feb 1998To determine mitogenic and antigen-specific cellular immune responses of two species of rodents, viz. Meriones unguiculatus and Mastomys coucha to assess the usefulness...
OBJECTIVE
To determine mitogenic and antigen-specific cellular immune responses of two species of rodents, viz. Meriones unguiculatus and Mastomys coucha to assess the usefulness of the A. viteae/Mastomys model for cellular immune studies in experimental filariasis.
METHODS
Lymphocyte blast transformation test (LTT) using spleen cells of normal and A. viteae infected animals.
RESULTS
The proliferative response of gerbils was much higher than that of Mastomys to both ConA and filarial antigens. Cells of both species of rodents did not respond to microfilarial (mf) antigen, however, their mitogenic response differed during infection. Some degree of nonspecific suppression was observed in gerbils during prepatent and patent stages of infection, while Mastomys revealed highest proliferation during patent microfilaraemia. Mastomys cells did not respond to adult or mf antigen, while adult-specific proliferation was detected in the case of gerbils.
CONCLUSION
The A. viteae/gerbil model shows more similarity to human filarial infection regarding cellular immune response. Markedly low responsiveness of a high percentage of Mastomys and wide variations in the cellular response to nonspecific mitogen limit the usefulness of Mastomys coucha in immunological studies, especially cellular immunity.
Topics: Animals; Antigens, Helminth; Dipetalonema; Dipetalonema Infections; Disease Models, Animal; Gerbillinae; Humans; Immune Tolerance; Immunity, Cellular; Lymphocyte Activation; Male; Microfilariae; Muridae
PubMed: 9537274
DOI: 10.1046/j.1365-3156.1998.00161.x -
Tierarztliche Praxis. Ausgabe K,... Feb 1998Between January 1995 and December 1996 nonendemic or only regionally occurring arthropodborne parasites including ehrlichiae and parasitic arthropods in Germany were...
Between January 1995 and December 1996 nonendemic or only regionally occurring arthropodborne parasites including ehrlichiae and parasitic arthropods in Germany were detected in 484 dogs, whereby at least 15 species were involved. Listed in decreasing order, Leishmania infections occurred most frequently, followed by infections/infestations with Babesia canis, Ehrlichia canis, Rhipicephalus sanguineus, Dirofilaria immitis and Dermacentor reticulatus. The other species, namely Babesia gibsoni, Trypanosoma congolense, Hepatozoon canis, Ehrlichia platys, Dirofilaria repens, Dipetalonema reconditum, Dermacentor marginatus, Boophilus microplus and Cordylobia anthropophaga were demonstrated in a few or single dogs. Irrespective of the pathogen-species, most of the dogs had travelled with their owners to Mediterranean countries or to Portugal or had been imported from there. Infections with B. canis were diagnosed very frequently in dogs returning from Hungary. Of the 28 dogs with previous residence in Germany only, twelve and four animals were infected with B. canis and E. canis, respectively, and seven and five dogs were infested with R. sanguineus and D. marginatus, respectively.
Topics: Animals; Arthropods; Dermacentor; Dog Diseases; Dogs; Germany; Hungary; Incidence; Mediterranean Region; Parasitic Diseases, Animal; Portugal; Travel
PubMed: 9531673
DOI: No ID Found -
Journal of Immunology (Baltimore, Md. :... Mar 1998Filarial nematodes infect more than 100 million people in the tropics, causing elephantiasis, chronic skin lesions, and blindness. The parasites are long-lived as a...
Filarial nematodes infect more than 100 million people in the tropics, causing elephantiasis, chronic skin lesions, and blindness. The parasites are long-lived as a consequence of being able to evade the host immune system, but an understanding of the molecular mechanisms underlying this evasion remains elusive. In this study, we demonstrate that ES-62 (2 microg/ml), a phosphorylcholine (PC)-containing glycoprotein released by the rodent filarial parasite Acanthocheilonema viteae, is able to polyclonally activate certain protein tyrosine kinase and mitogen-activating protein kinase signal-transduction elements in B lymphocytes. Although this interaction is insufficient to cause B lymphocyte proliferation per se, it serves to desensitize the cells to subsequent activation of the phosphoinositide-3-kinase and Ras mitogen-activating protein kinase pathways, and hence also to proliferation, via the Ag receptor. The active component of ES-62 appears to be PC, a molecule recently shown to act as an intracellular signal transducer, as the results obtained with ES-62 are broadly mimicked by PC alone. As PC-containing secreted products (PC-ES) are also released by human filarial parasites, our data suggest that PC-ES, by interfering with B cell function, could play a role in prolonging filarial infection in parasitized individuals.
Topics: Amino Acid Sequence; Animals; B-Lymphocytes; Calcium-Calmodulin-Dependent Protein Kinases; Dipetalonema; Helminth Proteins; Humans; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Phosphatidylinositol 3-Kinases; Phosphorylation; Phosphorylcholine; Protein-Tyrosine Kinases; Rabbits; Sphingomyelin Phosphodiesterase; ras Proteins
PubMed: 9510168
DOI: No ID Found -
Acta Tropica Oct 1997To assess the current status of Dirofilaria immitis infection and to determine whether there were other canine filarial infections in north Taiwan, postmortem...
To assess the current status of Dirofilaria immitis infection and to determine whether there were other canine filarial infections in north Taiwan, postmortem examination was conducted in 180 stray dogs more than 12 months old. Blood and serum samples were examined using a modified Knott's test and an antigen-detecting enzyme-linked immunosorbent assay (ELISA) kit, respectively. Filarial infection was found in 60.6% of the dogs: 55% with D. immitis and 12.2% Dipetalonema reconditum. Moreover, the ELISA was determined to be more sensitive than the Knott's test. Although canine heartworm infection in Taiwan has been attributed to the unrestricted import of dogs from endemic areas, the results of this study indicate that transmission of D. immitis and Dip. reconditum may occur indigenously in the local canine population. This study is also the first record of Dip. reconditum in Taiwan.
Topics: Animals; Dipetalonema Infections; Dirofilariasis; Dog Diseases; Dogs; Enzyme-Linked Immunosorbent Assay; Female; Male; Prevalence; Taiwan
PubMed: 9352007
DOI: 10.1016/s0001-706x(97)00081-8 -
International Journal For Parasitology Aug 1997cDNA, synthesised from total RNA from Acanthocheilonema viteae, was amplified by PCR with a primer derived from the spliced leader 1 sequence of nematodes and oligo-dT....
cDNA, synthesised from total RNA from Acanthocheilonema viteae, was amplified by PCR with a primer derived from the spliced leader 1 sequence of nematodes and oligo-dT. Due to the great number of side products observed in the reaction, a biotinylated oligo-dT primer was used for cDNA-synthesis and the first cycles of PCR. After binding of the PCR products to streptavidin/paramagnetic particles, the (+)strands of the cDNAs were recovered and reamplified. Analysis of the PCR products obtained revealed the presence of full-length cDNAs of at least 1.7 kbp in size in amplified total cDNA from microfilariae, postinfective L3, and adult worms. The total cDNA, from only 20 ex vivo recovered postinfective L3, was efficiently amplified.
Topics: Animals; DNA Primers; DNA, Complementary; Dipetalonema; Dipetalonema Infections; Female; Gerbillinae; Microfilariae; Parasitology; Polymerase Chain Reaction; RNA Precursors; RNA, Helminth
PubMed: 9292312
DOI: 10.1016/s0020-7519(97)00062-3 -
Tierarztliche Praxis Jul 1997Between June 1993 and May 1996 infections with filariae were diagnosed in 80 dogs. Five animals were infected with Dirofilaria repens and three other dogs with...
Between June 1993 and May 1996 infections with filariae were diagnosed in 80 dogs. Five animals were infected with Dirofilaria repens and three other dogs with Dipetalonema reconditum. One of the D. reconditum positive dogs was also infected with Dirofilaria immitis. An epidemiological analysis of the cases was possible for three D. repens and two D. reconditum infected dogs. Two of the dogs with D. repens infections had been imported from Italy or Greece, the third dog had been taken by its owner to Hungary and former Yugoslavia. The dogs infected with D. reconditum were imported from Corse or Spain. Regarding the other 72 dogs with filariae, 45 animals were infected with D. immitis. For 27 dogs being negative in the D. immitis ELISA, microfilariae have been demonstrated. However, a histochemical species differentiation of the microfilariae was not possible because fresh blood smears were not available.
Topics: Animals; Dipetalonema; Dipetalonema Infections; Dirofilaria; Dirofilariasis; Dog Diseases; Dogs; Female; Germany; Greece; Hungary; Italy; Male; Spain; Species Specificity; Travel; Yugoslavia
PubMed: 9312900
DOI: No ID Found -
Tropical Medicine & International... Jun 1997CDRI Compound 92/138, a synthetic analogue of aplysinopsin, was evaluated in experimental filarial infections, Litomosoides carinii in cotton rats (Sigmodon hispidus)...
CDRI Compound 92/138, a synthetic analogue of aplysinopsin, was evaluated in experimental filarial infections, Litomosoides carinii in cotton rats (Sigmodon hispidus) and Acanthocheilonema viteae in Mastomys coucha. The compound killed 63.8 and 90% of adult L. carinii and A. viteae at doses of 30 and 50 mg/kg (i.p.) respectively given for 5 days. By the oral route, at 100 mg/kg for 5 days the compound caused 50.9 and 57% mortality of adult L. carinii and A. viteae, respectively. At 200 mg/kg administered orally on days 0, 10 and 25 post-infection, it reduced establishment of adult A. viteae by 68.5%. We also found 43.7 and 37.8% effect in vivo respectively on L3 and L4 stages of A. viteae at a single dose of 250 mg/kg, p.o. The compound was active in vitro at 100 micrograms/ml concentration and caused a significant decline in MTT reduction and 14C-glucose uptake by adult filariids. Thus synthetic marine aplysinopsin could provide a new pharmacophore for the development of antifilarial agents.
Topics: Animals; Dipetalonema Infections; Drug Evaluation, Preclinical; Filariasis; Filaricides; Filarioidea; Imidazoles; Indoles; Male; Muridae; Sigmodontinae
PubMed: 9236820
DOI: 10.1046/j.1365-3156.1997.d01-321.x -
Magnetic Resonance Imaging 19971H Magnetic resonance imaging and 31P magnetic resonance spectroscopy (MRS) have been carried out in experimental rodent filariasis, i.e., Acanthocheilonema viteae... (Comparative Study)
Comparative Study
1H Magnetic resonance imaging and 31P magnetic resonance spectroscopy (MRS) have been carried out in experimental rodent filariasis, i.e., Acanthocheilonema viteae infection in the rodent host, Mastomys coucha. The T2-weighted image of the infected host shows fine hyperintense thread like structures of adult filariid nests in the cervical region. 31P MRS of normal and infected hosts, localized over the same region of interest, show seven major peaks corresponding to phosphomonoesters (including glucose-6-phosphate, fructose-6-phosphate, fructose-1-6-diphosphate, phosphorylcholine, and adenine monophosphate or AMP), inorganic phosphate, glycerophosphorylcholine, phosphoenolpyruvate, phosphocreatine and nucleoside di- and tri-phosphates. Concentrations of phosphomonoesters (PMEs) are higher in the normal rodent compared with the infected ones. In vivo 31P MRS provides a non-invasive assessment of tissue bioenergetics and phospholipid metabolism.
Topics: Animals; Dipetalonema; Dipetalonema Infections; Energy Metabolism; Female; Host-Parasite Interactions; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Muridae; Phospholipids; Phosphorus; Phosphorus Isotopes; Rats
PubMed: 9408140
DOI: 10.1016/s0730-725x(97)00180-x -
Indian Journal of Experimental Biology Jan 1997The quick and easy method of tetrazolium based colorimetric assay with MTT [3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] was used to test the viability...
The quick and easy method of tetrazolium based colorimetric assay with MTT [3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] was used to test the viability of the adult parasites of a rodent filariid Acanthocheilonema viteae in vitro. The ideal conditions required for antifilarial screening were determined by correlating the MTT reduction ability of worms with their size and age in the vertebrate host, also the duration of incubation and temperature of the in vitro culture. It was observed that the worms collected from the host after 90 days of L3 (infective larvae) exposure were not suitable for in vitro screen as they could not reduce MTT to that extent as the worms of early infection. Healthy and full grown worms and also those incubated at 37 degrees C for 16 hr or more caused maximum MTT reduction. Thus, it is recommended to select healthy adult filariids of proper age and size (male > 3.5 cm; female > 7.0 cm). The incubation temperature of the in vitro culture system needs to be adjusted to 37 degrees C and parasites might be exposed to drugs upto 24 hr without much alteration in MTT reduction of untreated controls.
Topics: Animals; Cold Temperature; Colorimetry; Coloring Agents; Dipetalonema; Female; Filariasis; Hot Temperature; Male; Muridae; Tetrazolium Salts; Thiazoles
PubMed: 9279136
DOI: No ID Found -
Parasitology Research 1997A purified 41-kDa protein of the rodent filaria Acanthocheilonema viteae was shown to protect jirds against a challenge infection. Subcutaneous immunization with the... (Comparative Study)
Comparative Study
A purified 41-kDa protein of the rodent filaria Acanthocheilonema viteae was shown to protect jirds against a challenge infection. Subcutaneous immunization with the protein reduced the number of adult worms by up to 65% and the number of circulating microfilariae declined by up to 93% in these animals. The protein is located in the muscle tissues of adult worms and was identified as tropomyosin by N-terminal sequencing of the purified protein.
Topics: Amino Acid Sequence; Animals; Antigens, Helminth; Dipetalonema; Dipetalonema Infections; Female; Gerbillinae; Male; Molecular Sequence Data; Rodent Diseases; Sequence Analysis; Sequence Homology, Amino Acid; Tropomyosin; Vaccination
PubMed: 9134565
DOI: 10.1007/s004360050269