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The Central African Journal of Medicine Feb 1968
Topics: Adult; Brain Diseases; Dipetalonema; Filariasis; Humans; Male; Tropical Medicine; Zimbabwe
PubMed: 5689555
DOI: No ID Found -
Journal of the American Veterinary... May 1992Clinical records of 6,977 dogs examined at the small animal clinic of the University of Tennessee College of Veterinary Medicine from January 1980 through December 1989...
Clinical records of 6,977 dogs examined at the small animal clinic of the University of Tennessee College of Veterinary Medicine from January 1980 through December 1989 were analyzed to determine the prevalence and changing frequency of Dirofilaria immitis and Dipetalonema reconditum infection. Using the Knott's test on these dogs, 805 (11.54%) tested positive for microfilariae, with D immitis in 430 dogs (6.16%), and Dip reconditum in 375 dogs (5.37%). Statistical analysis confirmed that the prevalence of D immitis and that of Dip reconditum were essentially equal in the population of dogs included in this study. There was a slight decrease in the prevalence of D immitis over the 10 years examined, but the prevalence of Dip reconditum remained constant. The results were not affected by year-to-year variability in the number of examinations performed. On the basis of our findings, in eastern Tennessee, those veterinarians who diagnose heartworm infection by the presence of microfilariae without differentiating the species involved, risk misdiagnosing 50% of the cases. If the patterns of prevalence seen in recent years continue, the chances of error may actually increase.
Topics: Animals; Dipetalonema; Dipetalonema Infections; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Prevalence; Retrospective Studies; Tennessee
PubMed: 1612997
DOI: No ID Found -
The American Journal of Tropical... Jul 1983Methods are described for the cryopreservation of third-stage larvae of Brugia malayi. Optimum conditions utilized larvae free from the mosquito host frozen at the rate...
Methods are described for the cryopreservation of third-stage larvae of Brugia malayi. Optimum conditions utilized larvae free from the mosquito host frozen at the rate of -1 degree or -0.8 degrees C per min in medium containing 9% dimethyl sulfoxide and 0.004 M polyvinylpyrrolidone. Nonfrozen or thawed larvae were inoculated intraperitoneally into jirds (Meriones unguiculatus), the thawed larvae after cryogenic storage for 5-378 days. In general, the percentage of adult worms recovered at necropsy was comparable between the two groups and ranged from a mean of 6-9% of the larval inoculum. In addition, three of four patas monkeys (Erythrocebus patas) inoculated with thawed B. malayi larvae developed patent infections. The cryopreservation of third-stage larvae of Dipetalonema viteae also is discussed.
Topics: Animals; Brugia; Dipetalonema; Filarioidea; Freezing; Preservation, Biological
PubMed: 6683940
DOI: 10.4269/ajtmh.1983.32.767 -
Parasite Immunology Dec 1999ES-62 is a phosphorylcholine (PC)-containing glycoprotein which is secreted by the rodent filarial nematode Acanthocheilonema viteae. A homologue exists in the human... (Review)
Review
ES-62 is a phosphorylcholine (PC)-containing glycoprotein which is secreted by the rodent filarial nematode Acanthocheilonema viteae. A homologue exists in the human filarial nematode Brugia malayi and indeed PC is found attached to glycoproteins of many, if not all, filarial species. At concentrations equivalent to those found for PC-containing molecules in the bloodstream of parasitized humans, ES-62 is able to polyclonally activate certain protein tyrosine kinase and mitogen-activating protein kinase signal-transduction elements in B and T lymphocytes following in-vitro exposure. Although this interaction is insufficient to cause lymphocyte proliferation per se, it serves to desensitize the cells to subsequent activation of the phosphoinositide-3-kinase, protein kinase C and Ras mitogen-activating protein kinase pathways and hence also to proliferation via the antigen receptors. The active component of ES-62 appears to be PC, as the results obtained with ES-62 are broadly mimicked by PC conjugated to BSA or PC alone. Although PC can also be shown to desensitize B cells following in-vivo administration, not all cells are affected, as it is still possible to generate an antibody response. Dissection of this response indicates that it is of the Th2 type.
Topics: Animals; Antibodies, Helminth; B-Lymphocytes; Dipetalonema; Glycoproteins; Helminth Proteins; Humans; Interleukin-4; Molecular Sequence Data; Phosphatidylinositol 3-Kinases; Phosphorylcholine; Protein Kinase C; Signal Transduction; T-Lymphocytes; ras Proteins
PubMed: 10583862
DOI: 10.1046/j.1365-3024.1999.00267.x -
Annals of Tropical Medicine and... Jun 1955
Topics: Animals; Dipetalonema; Dirofilaria; Filariasis; Parasites; Primates
PubMed: 13239074
DOI: 10.1080/00034983.1955.11685658 -
The Journal of Parasitology Dec 1985Dipetalonema viteae was studied in the jird, Meriones unguiculatus, to determine the mechanism controlling the level of peripheral microfilaremia. Jirds killed 40 days...
Dipetalonema viteae was studied in the jird, Meriones unguiculatus, to determine the mechanism controlling the level of peripheral microfilaremia. Jirds killed 40 days after infection served as donors of female worms of known age and reproductive status. These worms were transplanted into uninfected jirds and the resultant microfilaremias were monitored. After approximately 100 days, the recipient jirds were killed and 58% of the transplanted worms were recovered alive but depleted of sperm and microfilariae, regardless of the total number implanted in a given host. A direct linear relationship between microfilaremia and the number of recovered adult worms was found. Based on the uniform absence of sperm and microfilariae in the recovered worms it was concluded that female worms, under the conditions of the present study, do not control the peripheral microfilaremia in multi-worm infections through a reduced parturition rate.
Topics: Animals; Dipetalonema; Dipetalonema Infections; Female; Filariasis; Gerbillinae; Male; Microfilariae; Time Factors
PubMed: 4093807
DOI: No ID Found -
Tropical Medicine and Parasitology :... Dec 1988Previous attempts to assess nematode viability have been critically reviewed and the need to apply more objective biochemical criteria emphasized. The practicalities of... (Review)
Review
Previous attempts to assess nematode viability have been critically reviewed and the need to apply more objective biochemical criteria emphasized. The practicalities of assay development have been discussed with regard to sensitivity, selectivity and methodological considerations. The biochemical basis and assay methology for six assays (adenine leakage, adenine uptake, leucine uptake, 14CO2 evolution, lactate output and MTT reduction) that we have recently evaluated are detailed. The viability of Acanthocheilonema viteae females exposed for 120 h in vitro to 17 standard compounds (at 10 microM) has been assessed using these six assays and compared relative to motility indices from the micromotility meter. It was concluded that, despite the slightly superior sensitivity of the 14CO2 evolution assay, the MTT reduction method was most suitable for field use due to its technical and practical simplicity, and its applicability to fragments of onchocercal tissue. It was suggested that, in the absence of a better in vitro assay, the feasability of using MTT reduction together with histology should be assessed in a validation exercise with Onchocerca gibsoni.
Topics: Animals; Anthelmintics; Carbon Dioxide; Dipetalonema; Nematoda; Onchocerca
PubMed: 3147506
DOI: No ID Found -
International Journal For Parasitology Feb 1989A simple three-step colorimetric assay based on the tetrazolium salt MTT (3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) has been developed for...
A simple three-step colorimetric assay based on the tetrazolium salt MTT (3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) has been developed for quantifying filarial viability. Living (but not dead) filariae take up MTT and rapidly reduce it to formazan, so staining themselves dark blue. This colour change which is easily seen provides a rapid qualitative test for filarial viability. Quantitative data can be obtained by solubilizing formazan out of the worm with DMSO and measuring the absorbance of the resulting solution at 510 nm. To date the technique has been demonstrated in several species of filariae including Onchocerca volvulus. MTT reduction is thought to be selective for NADH-dependent dehydrogenase activity in viable worms. The reaction occurs readily in all developmental stages of Dipetalonema viteae including fragments of filarial tissue. Enzyme activity in viable intact D. viteae appears to be primarily associated with the hypodermis/muscle cells, with minimal formazan formation in the gut and reproductive tracts. The application of this MTT assay as a parameter for quantifying in vitro drugs effects is described. Assay procedures have been developed and optimized with D. viteae and Brugia pahangi for the assessment of effects of macrofilariae and microfilarial release, and the activity of a range of antifilarial standards reported. Several potential applications of the technique to studies on filarial biology are discussed.
Topics: Animals; Brugia; Colorimetry; Dipetalonema; Female; Microfilariae
PubMed: 2707965
DOI: 10.1016/0020-7519(89)90024-6 -
Australian Veterinary Journal Jan 1973
Review
Topics: Acid Phosphatase; Animals; Blood; Centrifugation; Diagnosis, Differential; Dipetalonema; Dirofilariasis; Dog Diseases; Dogs; Female; Filarioidea; Filtration; Hematocrit; Histocytochemistry; Male; Methylene Blue; Nematode Infections; Saponins
PubMed: 4571749
DOI: 10.1111/j.1751-0813.1973.tb14671.x -
Parasite Immunology Sep 1985The platelets from normal rats interact with microfilariae of Dipetalonema viteae in vitro in the presence of antibodies leading to the killing of the parasite. The...
The platelets from normal rats interact with microfilariae of Dipetalonema viteae in vitro in the presence of antibodies leading to the killing of the parasite. The antibody involved in this reaction is identified as IgE because the absorption of immune rat serum on anti-rat IgE column or the pretreatment of platelets with anti-Fc epsilon receptor resulted in a significant reduction in the percentage of killing of microfilariae. This antibody, which mediates platelet activity towards microfilariae, appears early in the secondary infection and persists for a short period of time. This short-lasting IgE antibody is not apparently present in the form of large complexes since the supernatant but not the pellet after ultracentrifugation was able to mediate killing of microfilariae by platelets. IgE-dependent platelet-mediated parasite killing is neither stage- nor species-specific because the microfilariae (LI) of Brugia malayi or of Loa loa and infective larvae (L3) of D. viteae or of B. malayi were killed when they were incubated with the serum obtained from rats at day 8 after secondary infection with adult D. viteae worms. The results of the present study suggest that platelets can actively participate in the immunological killing of filarial larvae.
Topics: Animals; Blood Platelets; Cytotoxicity, Immunologic; Dipetalonema; Filarioidea; Immunoglobulin E; In Vitro Techniques; Male; Microfilariae; Platelet Aggregation; Rats; Rats, Inbred Strains; Receptors, Fc; Receptors, IgE; Species Specificity
PubMed: 2933630
DOI: 10.1111/j.1365-3024.1985.tb00096.x