Disease relevance of Trematoda

• Toxicity of cadmium and zinc to Diplostomum spathaceum (Trematoda: Diplostomidae) cercarial survival [1].
• Fascioliasis decreased liver drug metabolizing enzymes which were specifically induced by both phenobarbitone and Arochlor, this could be due to either the specific action of toxic excretions of flukes or to the particular localization of tissue damage within the liver lobule [2].
• These effects suggest that the hyperplasia of the bile duct that is induced by liver flukes involves stimulation of collagen deposition through their release of proline [3].
• Based on fluke mortality, hexachlorophene administered at the rate of 12 to 26 mg/kg of body weight was lethal to 5 of 10 mature flukes in seven deer [4].
• The protection of 80 Nigerian trade cattle from trypanosomiasis and liver flukes using Samorin 1 and Trodax 2 [5].

High impact information on Trematoda

• Adult Schistosoma mansoni blood flukes reside in the mesenteric veins of their vertebrate hosts, where they absorb immense quantities of glucose through their tegument by facilitated diffusion [6].
• Stimulation of flukes with 0.1 mM serotonin results in a reduction of the propionate/acetate 13C enrichment ratio consistent with functional "compartmentation" of glycogen pools having different structures and/or specific enrichment in 13C [7].
• The functions of the cathepsin B-like proteases in liver flukes are unknown and analysis has been hindered by a lack of protein for study, since the protein is produced in small amounts by juvenile flukes [8].
• Two cathepsin L proteinases, cathepsin L1 and cathepsin L2, secreted by liver flukes may be involved in tissue penetration, nutrition, and protection from immune attack [9].
• Altered drug influx/efflux and enhanced metabolic activity in triclabendazole-resistant liver flukes [10].

Biological context of Trematoda

• Glucose equivalents were incorporated into glycogen in intact flukes with label at both the C-1 and C-6 positions during perfusion with [1-13C]glucose as a consequence of "substrate cycling" at the phosphofructokinase/fructosebisphosphatase enzyme couple [7].
• Through recent EST and genome sequencing efforts, it has become clear that members of the Trematoda possess many of the elaborate signal transduction systems that have been delineated in other invertebrate model systems like Drosophila melanogaster and Caenorhabditis elegans [11].
• Sequencing of beta-tubulin cDNAs from triclabendazole-susceptible and triclabendazole-resistant flukes revealed no amino acid differences between their respective primary amino acid sequences [12].
• In order to characterize the forms genetically, nucleotide sequences of ribosomal internal transcribed spacer (ITS1 and ITS2) and mitochondrial cytochrome c oxidase I (COI) and NADH dehydrogenase I (NDI) genes in 34 liver flukes from 16 prefectures in Japan were analysed [13].
• Total RNA obtained from whole adult liver flukes was used in a polymerase chain reaction to isolate and amplify a region of approximately 650 base pairs in the small subunit rRNA [14].

Anatomical context of Trematoda

• However, while the specific enzyme activity remained constant throughout development, there was a preferential increase in proline production relative to protein content of the flukes just prior to their migration into the bile ducts [15].
• In previous studies using the Big Blue transgenic mouse assay, we demonstrated an increase in lacI mutations in liver cells harvested from mice harboring F. hepatica flukes when compared to uninfected control animals [16].
• A4-1 reacted with the substance that located on the gut epithelium and in the luminal contents of both the adult and larval flukes [17].
• Biomphalaria glabrata (Gastropoda): effect of urethane on the morphology and function of hemocytes, and on susceptibility to Schistosoma mansoni (Trematoda) [18].
• The genital primordia in excysted metacercariae were differentiated into those of metraterm, Mehlis' gland, ovary and cirrus pouch, with the primordial testes appearing on day 1 p.i. The vitellaria and eggs in the uterus were present in flukes on days 2 and 4 p.i., respectively [19].

Associations of Trematoda with chemical compounds

• Differences in SOD isoenzyme profiles between the extracts were observed in native polyacrylamide gel electrophoresis: the somatic and detergent-soluble extracts exhibited 1 band of activity while the E-S products from immature and adults flukes contained 2 and 3 migrating bands, respectively [20].
• Incubating the cystatin-sensitized plates with partially purified cysteine proteinases from flukes instead of the ES products also maintained a similar high ELISA reactivity [21].
• Evidence was collected to show that this may be a selective process since flukes which had survived exposure to rafoxanide and closantel in vivo (in sheep) had lower activity levels of GST than flukes from untreated sheep [22].
• Most notably, dopamine appeared to depress considerably the large elevation of internal malate which is a characteristic effect of diamphenethide-amine on liver flukes [23].
• Activation of succinate dehydrogenase from adult Fasciola hepatica (Trematoda) [24].

Gene context of Trematoda

• At the same time, we found an increase in interleukin-10 production by peritoneal cells (in close contact with the flukes) and decreased nitric oxide levels [25].
• Thus, liver flukes may secrete molecules that downregulate Th1 responses [26].
• Immunocytochemical studies, using an anti-tubulin antibody, showed that tubulin organization was disrupted in the tegument of triclabendazole-susceptible flukes [12].
• Sera of rabbits infected for 3 weeks reacted much more strongly with glycoproteins of immature flukes than with glycoproteins of mature flukes as compared to sera of rabbits infected for 9 weeks [27].
• Flukes were cultured overnight in RPMI-1640 medium, and the resulting ES products concentrated by dialysis (cut-off 1.2 kDa) before use [28].

Analytical, diagnostic and therapeutic context of Trematoda

• Autoradiography on sections of these flukes reveal a time-dependent differential incorporation of tritium-labelled amino acids in various tissues [29].
• Scanning and transmission electron microscopy revealed extensive damage to the tegument of triclabendazole-susceptible F. hepatica, whereas triclabendazole-resistant flukes showed only localized and relatively minor disruption of the tegument covering the spines [12].
• Necropsy of untreated control animals revealed a mean burden of 360 flukes with a mean (+/- se) surface area of 171 +/- 64.3 mm2, whereas the fluke burdens in the closantel and triclabendazole-treated animals 14 weeks after treatment were 61 (83 per cent reduction) and 21 (94 per cent reduction), respectively [30].
• Isoelectric focusing of soluble proteins was performed on polyacrylamide gels using whole-body proteins from adult flukes [31].
• Surface changes to flukes of the two isolates were assessed by scanning electron microscopy following treatment in vitro for 24 h in triclabendazole sulphoxide (15 and 50 microg/ml) [32].

References