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Cadernos de Saude Publica 2001A survey on the prevalence of Dirofilaria immitis and Dipetalonema reconditum was conducted in 1,519 dogs from Maceió and two coastal areas in the State of Alagoas,...
A survey on the prevalence of Dirofilaria immitis and Dipetalonema reconditum was conducted in 1,519 dogs from Maceió and two coastal areas in the State of Alagoas, Northeast Brazil, from 1995 to 1999, by testing for microfilariae in blood. All blood samples were from exclusively domiciled dogs with a known history, showing that the infections were autochthonous, confirming transmission of canine filariasis in these areas. In Greater Metropolitan Maceió, 15 (1.3%) microfilaremic dogs were detected with D. immitis and 15 (1,3%) with D. reconditum. In the southern coastal area there was an estimated prevalence of 12.7% for D. immitis. D. immitis and D. reconditum microfilaria were 298.1 micrometer and 249.2 micrometer long and 7.3 micrometer and 4.4 micrometer wide, respectively. A Witness immunotest that detects D. immitis antigen was used to confirm parasitological results and reveal occult dirofilariasis cases. Of the total 6,579 females examined, 8 (0.1%) Culex quinquefasciatus were observed to be naturally infected with D. immitis larvae. These results proved dirofilariasis transmission in Maceió and demonstrated D. reconditum in the same geographic area.
Topics: Animals; Antigens, Helminth; Brazil; Dipetalonema; Dipetalonema Infections; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Female; Male; Prevalence
PubMed: 11784911
DOI: 10.1590/s0102-311x2001000600021 -
Veterinary Parasitology Dec 2001A dog microfilariae prevalence and risk factor survey was conducted in 51 contiguous municipalities of the Mt. Vesuvius area (Campania region, southern Italy) in order...
A dog microfilariae prevalence and risk factor survey was conducted in 51 contiguous municipalities of the Mt. Vesuvius area (Campania region, southern Italy) in order to add data to the limited epidemiological information available regarding filarial worms in this zone. Between May 1999 and June 2000, blood samples were collected from 351 asymptomatic dogs. Blood samples were examined using a modified Knott's technique and histochemical staining in order to count and identify microfilariae. The results were subjected to statistical analysis and choroplethic municipal maps (MMs) were drawn by a geographical information system (GIS) software. Microfilariae were detected in 63 of the 351 dogs surveyed, constituting a total filarial prevalence of 17.9%. In particular, 56 dogs (15.9%) showed only microfilariae of Dipetalonema reconditum; three dogs (0.8%) only microfilariae of Dirofilaria repens; two dogs (0.6%) microfilariae of both D. reconditum and D. repens and two dogs (0.6%) microfilariae of both Dirofilaria immitis and D. repens. High D. reconditum prevalence was associated with hunting practice, masculine gender and older dogs. There was also a tendency to find high prevalence in dogs sampled in the afternoon. In conclusion, the presence of microfilariae of D. reconditum in 92% of microfilaraemic dogs indicates that this filarial worm was the predominant filarial species in dogs in the Mt. Vesuvius area. In addition, the general trends of the MMs showed that D. immitis and D. repens were present only in a few municipalities, whereas D. reconditum was widely and homogeneously spread throughout the entire study area.
Topics: Animals; Dipetalonema Infections; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Female; Italy; Male; Prevalence; Risk Factors
PubMed: 11777604
DOI: 10.1016/s0304-4017(01)00529-5 -
Veterinary Parasitology Dec 2001The diagnosis of canine heartworm infection is based upon the presence of circulating Dirofilaria immitis microfilariae or on techniques for the detection of serum... (Comparative Study)
Comparative Study
Histochemical differentiation of Dirofilaria immitis, Dirofilaria repens and Acanthocheilonema dracunculoides microfilariae by staining with a commercial kit, Leucognost-SP.
The diagnosis of canine heartworm infection is based upon the presence of circulating Dirofilaria immitis microfilariae or on techniques for the detection of serum antibodies or antigens. In the first of these, discrimination between D. immitis, D. repens and Acanthocheilonema dracunculoides microfilariae is based upon the acid phosphatase histochemical stain. In this paper, we propose an alternative technique for histochemical staining using a commercial kit test of naphthol-AS-OL (Leucognost-SP). This offers the advantages of speed and simplicity as compared to the standard Barka procedure.
Topics: Acid Phosphatase; Animals; Diagnosis, Differential; Dipetalonema; Dipetalonema Infections; Dirofilaria; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Histocytochemistry; Microfilariae; Reagent Kits, Diagnostic
PubMed: 11705664
DOI: 10.1016/s0304-4017(01)00516-7 -
The British Journal of Ophthalmology Nov 2001
Topics: Anesthesia, Local; Animals; Dipetalonema; Dipetalonema Infections; Eye Infections, Parasitic; Filaricides; Humans; Male; Middle Aged; Treatment Outcome
PubMed: 11702740
DOI: 10.1136/bjo.85.11.1384i -
Acta Tropica Sep 2001Bay 44-4400 was used as a spot on formulation and administered in single doses of 25 and 100 mg/kg to Acanthocheilonema viteae, Brugia malayi, and Litomosoides...
Effects of Bay 44-4400, a new cyclodepsipeptide, on developing stages of filariae (Acanthocheilonema viteae, Brugia malayi, Litomosoides sigmodontis) in the rodent Mastomys coucha.
Bay 44-4400 was used as a spot on formulation and administered in single doses of 25 and 100 mg/kg to Acanthocheilonema viteae, Brugia malayi, and Litomosoides sigmodontis infected Mastomys coucha on various dates during prepatency, aiming to affect third stage larvae, fourth stage larvae or preadult worms. Microfilaraemia levels were controlled in comparison to untreated controls until necropsies were performed 100 days p.i. (A. viteae, L. sigmodontis) and 150 days p.i. (B. malayi) to determine the numbers of surviving worms and the condition of intrauterine developing stages. A significant proportion (86-100%) of larval and preadult stages of A. viteae were killed by Bay 44-4400 at a dose of 100 mg/kg. A dose of 25 mg/kg had only insignificant effects on the developing parasites, however, it strongly reduced microfilaraemia levels caused by surviving worms in the early phase of patency. Larval and preadult B. malayi and L. sigmodontis were not killed by Bay 44-4400 to a significant degree. Microfilaraemia developing by surviving parasites was generally and significantly reduced throughout the observation period when treatment was performed to affect the preadult parasites. In the other cases variable results were obtained. Intrauterine early embryonic stages were found to be pathologically altered in worms which had been treated at a preadult stage.
Topics: Administration, Cutaneous; Animals; Brugia malayi; Dipetalonema; Dipetalonema Infections; Disease Models, Animal; Filariasis; Filaricides; Filarioidea; Larva; Microfilariae; Muridae; Peptides, Cyclic
PubMed: 11495640
DOI: 10.1016/s0001-706x(01)00144-9 -
Contemporary Topics in Laboratory... Mar 2000An adult wild-caught female tamarin (Saguinus mystax) housed in a biomedical research facility was found moribund and extremely dehydrated, with severe diarrhea. She...
An adult wild-caught female tamarin (Saguinus mystax) housed in a biomedical research facility was found moribund and extremely dehydrated, with severe diarrhea. She initially responded to supportive therapy but died 3 days later. Necropsy findings included hyperemia of the colonic mucosa, mesenteric lymphadenopathy, acanthocephalid parasites (Prosthenorchis elegans) embedded in the mucosa of the terminal ileum and cecum, and free filarid nematodes (Dipetalonema sp.) in the abdominal cavity. Campylobacter sp. was recovered from the colon. With the exception of changes associated with the parasites, significant histologic changes were limited to the colon. Changes consistent with acute enteric viral infection were found against a background of chronic inflammation. Enterocytes were variably hypertrophied, degenerate, and attenuated. Numerous epithelial syncytial cells were present, and some affected cells (uni- as well as multinucleated) contained intranuclear inclusions. Lymphoid follicles were mildly depleted and contained rare syncytia. Measles (Morbillivirus) infection was confirmed by using immunohistochemistry, reverse transcriptase polymerase chain reaction, and Southern blot analysis. In contrast to the cutaneous rash, respiratory involvement, and low mortality characteristic of Old World monkeys with measles, severe diarrhea with high mortality occurs in New World monkeys with this disease. In addition, our case differs from previous reports of measles in New World monkeys in that syncytial cell formation apparently was limited to the colon of our animal.
Topics: Animals; Blotting, Southern; Cell Nucleus; Colitis; Colon; DNA, Viral; Diarrhea; Fatal Outcome; Female; Immunohistochemistry; Inclusion Bodies, Viral; Intestinal Mucosa; Measles; Monkey Diseases; Morbillivirus; Reverse Transcriptase Polymerase Chain Reaction; Saguinus
PubMed: 11487241
DOI: No ID Found -
Journal of the American Animal Hospital... 2001Using antigen capture and filter tests, 6,078 dogs throughout the state of Washington were examined for filariasis between July 1, 1997 and October 31, 1999. In western...
Using antigen capture and filter tests, 6,078 dogs throughout the state of Washington were examined for filariasis between July 1, 1997 and October 31, 1999. In western Washington, 791 males and 901 females examined were outdoors, not on prophylaxis, and had traveled out of the state; 6/791 (0.8%) males and 7/901 (0.8%) females were infected with Dirofilaria immitis (D. immitis), and one (0.1%) male and one (0.1%) female were infected with Dipetalonema reconditum (D. reconditum). There were also 392 males and 362 females examined that were outdoors, not on prophylaxis, and had not traveled out of western Washington. One (0.1%) female was infected with D. immitis, and two (0.5%) males and one (0.2%) female were infected with D. reconditum. In eastern Washington, 707 males and 826 females examined were outdoors, not on prophylaxis, and had traveled out of the state; 9/707 (1.0%) males and 4/826 (0.5%) females were infected with D. immitis, and no D. reconditum was found. There were also 376 males and 412 females examined that were outdoors, not on prophylaxis, and had not traveled out of the state. Three (0.8%) males and three (0.7%) females had D. immitis. One (0.2%) female had D. reconditum. Distribution of D. immitis-infected, nontravel dogs in eastern Washington was only found between 120 degrees and 119 degrees west longitude in the communities of Richland, Moses Lake, Okanogan, and Omak. Enzootic transmission of D. immitis and D. reconditum is occurring in both eastern and western Washington.
Topics: Animals; Antigens, Helminth; Dipetalonema; Dipetalonema Infections; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Enzyme-Linked Immunosorbent Assay; Female; Male; Prevalence; Risk Factors; Sex Distribution; Washington
PubMed: 11450834
DOI: 10.5326/15473317-37-4-339 -
Journal of Immunology (Baltimore, Md. :... Jul 2001Parasite survival and host health may depend on the ability of the parasite to modulate the host immune response by the release of immunomodulatory molecules....
Parasite survival and host health may depend on the ability of the parasite to modulate the host immune response by the release of immunomodulatory molecules. Excretory-secretory (ES)-62, one such well-defined molecule, is a major secreted protein of the rodent filarial nematode Acanthocheilonema viteae, and has homologues in human filarial nematodes. Previously we have shown that ES-62 is exclusively associated with a Th2 Ab response in mice. Here we provide a rationale for this polarized immune response by showing that the parasite molecule suppresses the IFN-gamma/LPS-induced production, by macrophages, of bioactive IL-12 (p70), a key cytokine in the development of Th1 responses. This suppression of the induction of a component of the host immune response extends to the production of the proinflammatory cytokines IL-6 and TNF-alpha, but not NO. The molecular mechanism underlying these findings awaits elucidation but, intriguingly, the initial response of macrophages to ES-62 is to demonstrate a low and transient release of these cytokines before becoming refractory to further release induced by IFN-gamma/LPS. The relevance of our observations is underscored by the finding that macrophages recovered from mice exposed to "physiological" levels of ES-62 by the novel approach of continuous release from implanted osmotic pumps in vivo were similarly refractory to release of IL-12, TNF-alpha, IL-6, but not NO, ex vivo. Therefore, our results suggest that exposure to ES-62 renders macrophages subsequently unable to produce Th1/proinflammatory cytokines. This likely contributes to the generation of immune responses with an anti-inflammatory Th2 phenotype, a well-documented feature of filarial nematode infection.
Topics: Adjuvants, Immunologic; Animals; Cell Survival; Cells, Cultured; Cytokines; Dipetalonema; Dose-Response Relationship, Immunologic; Drug Combinations; Glycoproteins; Helminth Proteins; Immunosuppressive Agents; Infusion Pumps, Implantable; Interferon-gamma; Interleukin-12; Interleukin-6; Lipopolysaccharides; Macrophage Activation; Macrophages, Peritoneal; Male; Mice; Mice, Inbred BALB C; Nitric Oxide; RNA, Messenger; Tumor Necrosis Factor-alpha
PubMed: 11441102
DOI: 10.4049/jimmunol.167.2.940 -
Journal of Immunology (Baltimore, Md. :... Jun 2001Unraveling the molecular mechanisms by which filarial nematodes, major human pathogens in the tropics, evade the host immune system remains an elusive goal. We have...
A filarial nematode-secreted phosphorylcholine-containing glycoprotein uncouples the B cell antigen receptor from extracellular signal-regulated kinase-mitogen-activated protein kinase by promoting the surface Ig-mediated recruitment of Src homology 2 domain-containing tyrosine phosphatase-1 and...
Unraveling the molecular mechanisms by which filarial nematodes, major human pathogens in the tropics, evade the host immune system remains an elusive goal. We have previously shown that excretory-secretory product-62 (ES-62), a homologue of phosphorylcholine-containing molecules that are secreted by human parasites and which is active in rodent models of filarial infection, is able to polyclonally activate certain protein tyrosine kinase and mitogen-activating protein kinase signal transduction elements in B lymphocytes. Such activation mediates desensitization of subsequent B cell Ag receptor (BCR) ligation-induced activation of extracellular signal-regulated kinase-mitogen-activated protein (ErkMAP) kinase and ultimately B cell proliferation. We now show that the desensitization is due to ES-62 targeting two major regulatory sites of B cell activation. Firstly, pre-exposure to ES-62 primes subsequent BCR-mediated recruitment of SHP-1 tyrosine phosphatase to abolish recruitment of the RasErkMAP kinase cascade via the Igalphabeta-ShcGrb2Sos adaptor complex interactions. Secondly, any ongoing ErkMAP kinase signaling in ES-62-primed B cells is terminated by the MAP kinase phosphatase, Pac-1 that is activated consequently to challenge via the BCR.
Topics: Animals; Antigens, CD; Antigens, Helminth; CD79 Antigens; Dipetalonema; Dual Specificity Phosphatase 2; Enzyme Activation; Glycoproteins; Helminth Proteins; Intracellular Signaling Peptides and Proteins; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; Phosphorylation; Phosphorylcholine; Protein Phosphatase 1; Protein Phosphatase 2; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Protein Tyrosine Phosphatases; Receptors, Antigen, B-Cell; Tyrosine; src Homology Domains; src-Family Kinases
PubMed: 11390499
DOI: 10.4049/jimmunol.166.12.7462 -
Experimental Parasitology Apr 2001The radical gas nitric oxide (NO) is synthesized by nitric oxide synthase (NOS) from l-arginine and molecular oxygen. Nitric oxide is an important signaling molecule in...
The radical gas nitric oxide (NO) is synthesized by nitric oxide synthase (NOS) from l-arginine and molecular oxygen. Nitric oxide is an important signaling molecule in invertebrate and vertebrate systems. Previously we have shown that NOS is localized to more tissues in Brugia malayi than has been reported in Ascaris suum. In this paper, we analyze the distribution of NOS in Acanthocheilonema viteae, a filarial nematode that differs from B. malayi in that A. viteae females release microfilariae without a sheath. A. viteae is also one of a few filarial parasites without the Wolbachia intracellular endosymbiont. By use of a specific antibody, NOS was demonstrated in extracts of A. viteae and Dirofilaria immitis. The localization pattern of NOS in A. viteae was similar to that seen in B. malayi, with the enzyme localized to the body wall muscles of both sexes, developing spermatozoa, intrauterine sperm, and early embryos. By use of DAF-2, a fluorescent indicator specific for nitric oxide, the embryos of B. malayi and A. viteae were demonstrated to produce NO ex utero. The near identical staining patterns seen in A. viteae and B. malayi argue that NO is not produced by Wolbachia, nor is it produced by the nematodes in response to the infection. Localization of NOS to the sperm of filarial nematodes suggests a role for NO during fertilization as has been described for sea urchin and ascidian fertilization. Demonstration of the activity of embryonic NOS supports our earlier hypothesis that NO is a signaling molecule during embryogenesis in filarial nematodes.
Topics: Animals; Brugia malayi; Dipetalonema; Female; Gerbillinae; Immunohistochemistry; Male; Nitric Oxide; Nitric Oxide Synthase
PubMed: 11384164
DOI: 10.1006/expr.2001.4613