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At least 19 recordsLinked to original sources
PubMed1979

A comparison of the formalin-ether concentration and trichrome-stained smear methods for the recovery and identification of intestinal protozoa.

The detection and identification of intestinal protozoa were compared using the formalin-ether concentration technique and trichrome smears. Using the polyvinyl alcohol (PVA) one-vial collection method, 13,194 outpatient samples were examined by both methods. Twenty-three percent or 3077 specimens were positive for one or more species of intestinal protozoa. Of the pathogenic protozoa identified, 96.3 percent of the trophozoites and 44.2 percent of the cysts were identified only by the trichrome-stained smear. It is recommended that both procedures by included in the examination of fecal sepcimens for protozoa.

Dientamoeba↗
PubMed1979

Conversion of dihydroorotate to orotate in parasitic protozoa.

The conversion of dihydroorotate to orotate, one of the key reactions in the de novo pyrimidine biosynthetic pathway, has been studied in a number of parasitic protozoa. Enzyme activities capable of carrying out this reaction were detected in six members of the Kinetoplastida (Trypanosoma brucei, Trypanosoma congolense, Trypanosoma vivax, Trypanosoma lewisi, Trypanosoma cruzi, Leishmania enriettii) and three members of the genus Plasmodium (P. knowlesi, P. berghei, P. gallinaceum). The mechanism of the reaction in the two groups of protozoa were quite distinct. In the Kinetoplastida, the enzyme is an hydroxylase which occurs in the soluble fraction of the cell and probably requires tetrahydrobiopterin for activity. In contrast, in Plasmodium, the enzyme is a dehydrogenase which is particulate, probably mitochondrial, and intimately connected to the electron transport chain to which it passes electrons directly, probably at the ubiquinone level. Neither activity is regulated by fully formed pyrimidines. The enzyme in Plasmodium is similar in mechanism to the isofunctional mammalian enzyme. However, since malarial ubiquinones are apparently different from those in the mammal and since menoctone, which is active in vivo in experimental malaria, is a good inhibitor of the malarial enzyme, it could represent a useful target for chemotherapeutic attack. The enzyme in the Kinetoplastida is quite distinct from that in the mammal so that it too apparently falls into this category, though none of the currently used antitrypanosomal drugs appears to block it activity at physiological concentrations.

Animals↗
PubMed1978

Some factors controlling the attachment of the rumen holotrich protozoa Isotricha intestinalis and I. prostoma to plant particles in vitro.

The rumen holotrich protozoa Isotricha intestinalis and I. prostoma showed chemotaxis to sucrose, glucose and fructose. They attached themselves, by means of an organelle on the anterior cell surface, to particulate sources of these carbohydrates provided soluble protein was present in the medium. The concentration of protein eliciting attachment varied with the species and the state of nutrition of the cell, but was between 20 and 150 microgram ml-1. Attachment occurred only if the concentration of carbohydrate, at its source, exceeded the chemotaxis threshold concentration (50 micrometer for sucrose) and if it was less than 1 mM. At concentrations exceeding 1 mM, indiscriminate attachment to gas-liquid and solid-liquid interfaces occurred, provided the protein concentration was high enough to elicit attachment. In the rumen, soluble carbohydrates diffusing from food particles may attract the protozoa which attach themselves to the particles in the presence of soluble plant protein at less than 20 microgram ml-1; these conditions exist in the host animal soon after feeding when fed infrequently. The attachment mechanism may confer an ecological advantage on the Isotricha spp. over other rumen organisms dependent on soluble carbohydrates as energy and carbon sources.

Animals↗
PubMed1977

Poly(ethylene oxide), a new slowing agent for protozoa.

The water-soluble, viscoelastic resin Polyox WSR 301), a poly(ethylene oxide) of high molecular weight (approximately 4 million) is introduces as a new slowing agent for protozoa. Generally, as the kinetic viscosity of the resin increased from 0.25% to 1% (w/v), the swimming velocity of Euglena gracilis, Didnium nasutum, Paramecium aurelia, Blepharisma undulans, and Prorodon platyodon decreased. The 1.0% solution had the highest viscosity and decreased velocity more effectively than 1.0% methyl cellulose and Protoslo solutions. The Polyox solutions differed from those of methyl cellulose and Protoslo by having, in addition to viscous drag, an elastic recoil that pulled the protozoa backwards when their swimming efforts stopped. The toxicity of these slowing agents was determined using 10 P. aurelia/test slide preparation. Paramecium numbers decreased in 1.0% methyl cellulose and Protoslo to nearly zero by 24 hr; in Polyox, not only were most these ciliates alive after 24 hr, but many survived for 96 hr and divisions occurred in 0.25% and 0.50% solutions.

Animals↗
PubMed1979

Ciliate protozoa in the rumen of Brazilian water buffalo, Bubalus bubalis Linnaeus.

Total numbers and distribution of genera, subgenera and species were determined for the ciliate protozoa in rumen contents of 4 Brazilian water buffalo Bubalus bubalis Linnaeus. The fauna of one animal, housed in close proximity to European and zebu-type cattle, differed considerably from that of the remaining animals, which were somewhat isolated on a large ranch. Several of the protozoan species observed in the semi-isolated animals were first described in rumen contents from humped Indian cattle, and their subsequent occurrence in other hosts and geographic locations has been limited or absent. In all, 49 different species of protozoa were found, 8 of which have not been previously described. Three of the new species belong to the genus Entodinium: E. ciculum sp. n., E. spinonucleatum sp. n. and E. triangulum sp. n.; 4 to Diplodinium (Ostracodinium): D. (O.) brazili sp. n., D. (O.) esalqum sp. n., D. (O.) nucleolobum sp. n., and D. (O.) tiete sp. n.; and one to Diplodinium (Eudiplodinium): D. (E.) bubalus sp. n.

Animals↗
PubMed1977

Antimicrobial action of compound 48/80 against protozoa, bacteria, and fungi.

Compound 48/80 inhibited the growth of protozoa, bacteria, and fungi but had no effect on the multiplication of viruses. All susceptible organisms were inhibited by 10 microgram/ml of crude compound 48/80, and some were inhibited by as little as 0.1 microgram/ml. Against Tetrahymena pyriformis, this drug was seven times more potent than quinine. Separation of compound 48/80 into different fractions indicated that some antimicrobial activity could be separated from the histamine-liberating activity. It was found that compound 48/80 is not surface active at 500 microgram/ml.

Animals↗
PubMed1978

[Effect of glycolysis inhibitors on the uptake of metronidazole by the protozoa Tritrichomonas foetus and Entamoeba invadens].

Uptake of metronidazole by the anaerobic protozoa, Tritichomonas foetus and Entamoeba invadens is dependent on the energy metabolism of these organisms. The inhibitors of glycolysis, iodoacetamide and sodium fluoride, inhibit the uptake. An atmosphere of hydrogen eliminates this inhibition in the hydrogenase-containing T. foetus but not in E. invadens which lacks the enzyme.

Energy Metabolism↗
PubMed1977

Biochemical and technical considerations regarding the mass production of certain parasitic protozoa.

This article summarizes the most relevant biochemical knowledge about growth factors as specific essential components of culture media, and calls attention to their significance with respect to the mass cultivation of some parasitic protozoa-e.g., Trypanosoma and Leishmania spp. and amoebae. Details of recent developments and techniques of parasite fermentation are reviewed.

Amino Acids↗
PubMed1977

Heat-labile enterotoxigenic Escherichia coli and intestinal protozoa in asymptomatic travellers.

Thirty-two asymptomatic travellers who had recently journeyed in the Near, Middle, and Far East and had experienced a high incidence of diarrhoeal disease were screened for heat-labile enterotoxigenic Escherichia coli (ent+ E. coli) and other bacterial and parasitic pathogens. Six percent were colonized with ent+ E. coli and while other bacterial pathogens were not found, the intestinal protozoa Giardia lamblia (13%), Entamoeba histolytica (6%), Entamoeba coli (6%), Endolimax nana (6%), and Entamoeba hartmanni (3%) were detected in the stools. Ent+ E. coli, G. lamblia and E. histolytica should be considered in the differential diagnosis of gastrointestinal disease in travellers returning from the Orient. Furthermore, these travellers may be a potential source for the introduction of ent+ E. coli into communities where such organisms are relatively rare.

Adult↗
PubMed1978

[Effect of lipid preparations isolated from protozoa on experimental leishmaniasis in golden hamsters].

The effect of lipid preparations Nos. 59 and 60 isolated from Protozoa on experimental leishmaniosis of golden hamsters was studied. Preparations Nos. 59 and 60 are water-soluble derivatives of fatty acids isolated from Trypanosoma lewisi and Astasia longa respectively. It was found that both preparations administered to the animals simultaneously with the causative agent or after formation of the leishmaniosis infiltrates inhibited the development of the disease clinical signs. Such an effect of the preparations was observed only during the period of the animals exposure to them. After discontinuation of the treatment the development of the clinical process proceeded the same as in the control animals. The lipid preparation No. 60 differing from preparation No. 59 by high content of C20-poly-unsaturated fatty acids was more active and induced a significant decrease in the size of the leishmaniosis infiltrates formed. Preparation No. 60 was more effective in the treatment of the animals infected with L. tropica major than in the animals infected with L. tropica minor. Preparation No. 59 had no significant effect on multiplication and morphology of the parazites.

Animals↗
PubMed1979

[A study of the frequency of protozoa and yeasts isolated from the parodontium of 509 subjects (author's transl)].

The protozoa Entamoeba gingivalis and Trichomonas tenax together with yeasts of the genus Candida were investigated in the mouth (gums or neck of tooth) of 509 healthy or diabetic subjects. A study of the possible correlation between presence of these parasites and various local or general factors, showed that neither the sex, maxillo-facial anomalies nor smoking had any influence on parasite incidence. Entamoeba gingivalis was encountered in 85 per cent of subjects free from parodontopathy. Numerous factors influenced the presence of Trichomonas tenax: age, social status, alcohol consumption, dental condition and gingival pathology. Presence of Candida was associated with diabetes, poor buccal hygiene and dental condition.

Adolescent↗
PubMed1979

Clinical and histologic observations of actively induced resistance to Eimeria ferrisi Levine and Ivens, 1965 (Protozoa: Eimeriidae) in the mouse (Mus musculus).

Actively induced resistance to Eimeria ferrisi was studied clinically and histologically in Mus musculus. Results indicated that a partial resistance to challenge was obtained. Initially infected animals had severe symptoms of coccidiosis but the symptoms diminished as the infections progressed. Previously infected mice had only slight symptoms of infection when challenged. Challenge doses produced severe coccidiosis in the non-immune controls although none died. Six mice died at peak patency during the immunizing inoculations. Histologic examination indicated that parasite numbers were reduced in resistant animals. The reduction appeared greatest during late sexual development. Tissues from resistant animals showed little evidence of damage and appeared to contain an increased amount of lymphoid tissue. Tissues from non-immunized mice killed after challenge were heavily infected and contained extruded blood, mucous, and cellular debris in the gut lumen. Considerable destruction of host epithelial cells occurred. The observations are discussed and compared to other coccidial immunity studies.

Animals↗
PubMed1975

Effect of insulin on the glucose uptake of protozoa.

Insulin stimulates the glucose uptake of Tetrahymena pyriformis. This shows the presence of insulin receptors in Tetrahymena, consequently receptors may be present in a level of phylogenesis, where the natural contact between the given hormone and the cell is unnecessary and impossible.

Animals↗