SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Blood samples from 407 bovines of "Azienda Marianis", a farm in Friuli Venezia Giulia, Italy, were examined for microfilariae; 143 (35.1%) were positive. A survey in other 23 farms of dairy cattle from 6 Communes of the Province of Udine revealed a prevalence of 11.28%. The prevalence was significantly correlated with the age of animals; in cow was lower than in young animals. Blood microfilariae (210) and adult females (15) were identified as Setaria labiatopapillosa.
The authors describe a trap utilized in the field to catch possible intermediate hosts of Setaria labiatopapillosa attracted by naturally infected bovine. The trap was bulky and stable but also decomposable and removable. It was tested in an area of Friuli Venezia Giulia (Udine province, NE Italy) during 21 nights in the summer 1994 (29/6-29/9) and allowed to catch 16159 mosquitoes and 218 other Diptera, showing a very good efficiency.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effect of aqueous and alcohol extracts of the fruits and leaves of Pongamia pinnata (Linn.) Merr. (Syn. Pongamia glabra Vent, leguminosae) on the spontaneous movements of both the whole worm and the nerve-muscle preparation of Setaria cervi and on the survival of micro fi lariae in vitro was studied. The aqueous and alcohol extracts of fruits and the alcohol extract of leaves caused an inhibition of spontaneous movements of the whole worm and the nerve-muscle preparation of S. cervi. The initial stimulatory effect was not observed with the aqueous extract of fruits on the nerve-muscle preparation. The concentration required to inhibit the movements of the whole worm preparation was 250 micro g/mL for aqueous, 120 micro g/mL for alcohol extract of fruits and 270 microgram/mL for alcohol extracts of the leaves. The concentrations of P. pinnata extracts required to produce an equivalent effect on the nerve-muscle preparation were 25 micro g/mL, 5 micro g/mL and 20 micro g/mL, respectively, suggesting a cuticular permeability barrier.
2,3-Dimethoxy-5-methyl-1,4-benzoquinone (Q0), an analogue of ubiquinone, irreversibly paralyses the adult and microfilariae of the cattle filarial parasite Setaria digitata. The same concentration of Q0 that paralyses the microfilariae of S. digitata also paralyses the microfilariae of the human filarial parasite Wuchereria bancrofti within the same duration. Thus the experiments done in the model S. digitata system can well be extended to the human filarial system. A drug at the level of the quinone-centered energy generating system, perhaps an analogue of quinone like Q0, can inactivate the filarial parasites and may prove to be an effective drug to control filariasis.
The direct interaction of filarial proteins with lung epithelial cells was examined to determine the possible mechanism of inducing cell death, an event that is observed in patients with tropical pulmonary eosinophilia. Exposure of lung epithelial cells to filarial parasitic proteins, Brugia malayi (BmA), Setaria digitata (Sd), and recombinant filarial protein (pGT 7) in vitro for more than 2 days, causes the appearance of DNA fragments both in the cytoplasm and culture supernatants, while no fragmentation was observed in the untreated controls. The release of DNA fragments both in the cytoplasm and the culture supernatants simultaneously, indicates that cell death is induced by a necrotic event rather than apoptosis. Fluorescent-labelled studies also indicate the fragmentation of DNA increasing in a time-dependent manner. Normal cellular function is controlled through several oncogenes. The modulation of specific proto-oncogenes like myc, ras and TNF alpha during exposure to filarial parasitic proteins reveal elevated levels of expression of ras and TNF alpha as early as 2 hours, implicating their involvement prior to DNA fragmentation leading to pathogenesis.
The microfilariae and adults of Setaria cervi, a filarial parasite of Indian water-buffalo (Bubalus bubalis Linn.) and of other ruminants were analysed for various biochemical constituents. Both stages of the parasite were rich in protein, carbohydrate, and lipids while nucleic acids were detectable in only small amounts. Microfilariae and adults contained 10 and 25% dry matter, 57.4 and 63.0% protein, 8.9 and 14.8% carbohydrate, and 12.8 and 9.2% lipid, respectively. Reducing sugars accounted for 52 and 67% respectively of the total carbohydrate in these two stages. Glycogen accounted for 95% of total carbohydrate in the cold PCA soluble fraction of adult worms while its concentration in microfilariae was very low. Glucose was the main constituent of reducing sugars while concentrations of fructose were very low. Microfilariae contained more lipids, nucleic acids, mucopolysaccharides, and total phosphorus than adults. The phospholipid percentage was higher in microfilariae than in adults. The amino acid pattern of both stages was very similar.
Microfilariae of bovine filarial parasite Setaria cervi are equipped with the enzymes of glycolysis, pentose phosphate and PEP-succinate pathways and thus resemble the adult form in its metabolic pattern. Malate dehydrogenase was the most active enzyme in microfilariae followed by lactic dehydrogenase and fumarase, while phosphoglucoisomerase, PEP-carboxykinase and FDP-aldolase were comparatively less active. The very low ratio of PK/PEPCK in S. cervi microfilariae indicates active fixation of CO2 into PEP to produce oxalacetate. Centperazine and diethylcarbamazine significantly inhibited PEP-carboxykinase, fumarate reductase and succinic dehydrogenase, suggesting that these antifilarials probably exert microfilaricidal action by blocking the PEP-succinate pathway.
Spermine and spermidine were found to be the principal polyamines in the bovine filarial parasite Setaria cervi, whereas putrescine was observed in very low amounts. Studies conducted on the enzymes of polyamine biosynthesis revealed low activity for S-adenosyl-methionine decarboxylase, questionable and negligible activities for the decarboxylation of ornithine and arginine, and appreciable activity for ornithine aminotransferase. Uptake studies with radiolabeled putrescine, spermidine and spermine showed that these amines are rapidly taken up from the medium by an active uptake process. The uptake was temperature-sensitive and abolished at 0-4 degrees C. The questionable presence of biosynthetic enzymes such as ornithine and arginine decarboxylase and, on the other hand, an effective uptake mechanism indicate that the parasite may depend on the host for its polyamine requirement, thereby indicating a possible target for chemotherapy.
In the cattle filarial parasite Setaria digitata the mitochondria like particles have been shown to possess NADH dependent fumarate reduction coupled with site I electron transport associated phosphorylation. This reduction is catalysed by the fumarate reductase system. The Km for fumarate is 1.47 mM and that for NADH is 0.33 mM. This activity is sensitive to rotenone, antimycin A and o-Hydroxy diphenyl. One ATP is produced for each pair of electrons transferred to fumarate. The fumarate reductase system consisting of NADH-coenzyme Q reductase, cytochrome b like component(s) and succinate dehydrogenase/fumarate reductase is thus very important and hence specific inhibitors of the system may prove useful in the effective control of filariasis.
Polyamine levels of some helminth parasites were analyzed by reverse phase HPLC of benzoyl derivatives. Setaria cervi, Acanthocheilonema viteae, Hymenolepis nana, H. diminuta, and Ascaridia galli contained higher levels of spermine than spermidine while in Ancylostoma ceylanicum and Nippostrongylus brasiliensis the spermidine levels were higher than spermine; putrescine was either absent or present in minor quantities. The enzymes of polyamine biosynthesis viz., ornithine decarboxylase, S-adenosyl methionine (SAM)-decarboxylase, and arginine decarboxylase were present in very low to negligible amounts in all the parasites examined. A. ceylanicum exhibited high activity of ornithine amino transferase (OAT) and catalyzed appreciable decarboxylation of ornithine. The ornithine decarboxylating activity of A. ceylanicum was localized in the particulate fraction containing mitochondria, not inhibited by alpha-difluoromethyl ornithine, the specific inhibitor of ornithine decarboxylase (ODC), but inhibited in the presence of glutamate, suggesting the involvement of mitochondrial OAT rather than a true ODC in ornithine decarboxylation in this parasite. Significant activity of polyamine oxidase was also detected in helminth parasites. The absence of polyamine biosynthesizing enzymes in helminth parasites suggests their dependence on hosts for uptake and interconversion of polyamines, providing a potential target for chemotherapy.
1. A Mg2+ independent, Ca(2+)-ATPase requiring high concentrations of Ca2+ (5 mM) for the activation, equally distributed in cuticle-muscular-hypodermis, genital organs and gastrointestinal tissues and mainly localized in 10,000 g pellet fraction, was identified in Setaria cervi, a bovine filarial parasite. 2. Filarial enzyme showed Km value of 3.33 mM for ATP as computed from the double reciprocal Lineweaver-Burk plot. 3. The enzyme could be completely solubilized by sonication with about 4-fold increase in specific activity of the enzyme. 4. The enzyme showed about 2-fold activation by the calmodulin fractions isolated from S. cervi and rat brain homogenates. 5. The enzyme was highly sensitive to inhibition with some phenothiazine derivatives. Trifluoperazine was observed to be the most potent inhibitor followed by promethazine and chlorpromazine. 6. Some anthelmintics viz. diethycarbamazine and centperazine were found to be highly potent inhibitors of the enzyme, significant inhibition of filarial Ca(2+)-ATPase was also observed with levamisole and suramine. 7. Studies indicate Ca(2+)-ATPase of S. cervi as a potential chemotherapeutic target.
Analysis of biogenic monoamines and their metabolites in Setaria cervi adults by reverse phase high performance liquid chromatography (HPLC) revealed dopamine as the major monoamine followed by norepinephrine and 5-hydroxytryptamine (5-HT). 5-Hydroxy indole acetic acid and tryptophan were also detected in significant amounts. A particulate-bound monoamine oxidase (MAO, EC 1.4.3.4.) catalysing the oxidative deamination of several amines was also demonstrated in both microfilariae and adults. The enzyme from the parasites exhibited unusually high Km values for various monoamines. Dopamine was oxidized at the maximum rate while putrescine was not utilized as the substrate. MAO was predominantly associated with the mitochondrial fraction and concentrated mainly in the cuticle-muscle-hypodermis layer of the filariid. The enzyme was most active around pH 7.5 and 37 +/- 2 degrees C, relatively stable in the frozen state but was thermolabile. The specific MAO inhibitors, clorgyline and deprenyl, inhibited the enzyme with Ki values of 2 x 10(-7) M and 5 x 10(-6) M, respectively. Diethylcarbamazine, suramin, levamisole and centperazine significantly inhibited MAO activity. (The characteristics of the enzyme indicated that it may have a role in host-parasite interactions).
Scanning electron microscopy studies of adult Setaria cervi male worms showed the presence of horn-like lateral appendages and characteristic striated bands on the ventral side of the tail. All other features were indistinguishable from other members of the genus Setaria.
Several key enzymes related to carbohydrate metabolism were assayed in Setaria digitata. In the cytosolic fraction pyruvate kinase, phosphoenolpyruvate carboxykinase, malate dehydrogenase, malic enzyme, aspartate transaminase and alanine transaminase were found. Among the TCA cycle enzymes succinate dehydrogenase, fumarate reductase, fumarase (malate dehydration), malate dehydrogenase (malate oxidation and oxaloacetate reduction) and malic enzyme (malate decarboxylation) were detected in the mitochondrial fraction. Only reduced nicotinamide adenine dinucleotide (NADH) dehydrogenase, NADH oxidase and NADH-cytochrome c reductase were found in the mitochondrial fraction. The significance of these results with respect to the metabolic capabilities of the worm are discussed.
In this communication an immunodiagnostic approach has been adopted for detection of antigen and antibody in amicrofilaeamic Mf(-) patients by countercurrent immuno electrophoresis (CCIE) and immunodiffusion (ID). Using Setaria cervi and Immune Complex (IC) antigens, out of fifteen clinical cases the number of positive patients in CCIE were twelve and ten respectively. Sixty percent of the Mf(-) cases were positive in antigen detection against both the homologous and heterologous antibody. In ID nine Mf(-) cases gave precipitin bands against S. cervi antigen while with IC antigens ten patients were positive. In similar experiments, it was found that out of fifteen Mf(-) cases nine and eleven patients were positive in antigen detection against microfilaraemic Mf(+) sera and S. cervi antibody respectively. All the Mf(+) cases were positive in both antibody and antigen detection. From the standpoint of immunodiagnosis the data were analysed by two-way analysis of variance study and a newly developed system using Binomial distribution. The sera from the control group were negative in all the immunodiagnostic tests.