Spirometra mansonoides

Cox, C.S., Phares, C.K. and Schmidt, R.A. (1990) Molecular characterization of the Spirometra mansonoides genome renaturation kinetics, methylation, and hybridization to human cDNA probes. Biochimica et Biophysica Acta 1049, 134-144. 

Pietrzak, S.M. and Saz, H.J. (1981) Succinate decarboxylation to propionate and the associated phosphorylation in Fasciola hepatica and Spirometra mansonoides. Molecular and Biochemical Parasitology 3, 61-70. 

As indicated above, the fact that oxygen is consumed in vitro does not imply that oxygen is utilised in vivo, unless evidence is presented that a similar level of oxygen is available in vivo. Some species (Spirometra mansonoides, Mesocestoides corti, Hymenolepis nana, H. diminuta) can be successfully cultured under strict anaerobic conditions, whereas others (H. microstoma, T. crassiceps, Echinococcus sp.) thrive best under air (796 Chapter 10). The significance of oxidative processes in the energy balance of cestodes is discussed in Chapter 5. 

Many species of cestodes, especially the larvae, contain large numbers of curious concretions, termed calcareous corpuscles, made up of an organic base together with inorganic material. They are composed of concentric lamellae and vary in size in some species they are very large - 16-32 /xm (Spirometra mansonoides, E. granulosus) - but, in most species, they measure about 12 jam. They have been the subject of a number of studies (36, 135, 351, 385, 386, 594, 796, 912, 913, 914), but their composition, formation and, particularly, function still remain poorly understood. 

Spirometra mansonoides succinate, malate Acetate, propionate,... 

It has been purified (445) and shares some properties in common with malic enzymes from mammals and birds in being NADP-dependent, heat-stable and able to decarboxylate oxaloacetate. The malic enzyme of H. microstoma also has a marked specificity for NADP (216), contrasting with that of Spirometra mansonoides, which appears to be both NAD- and NADP-linked (220). Malic enzyme has been demonstrated in a range of other cestodes including Mesocestoides corti (399), Schistocephalus solidus (406), Moniezia expansa (60), Echinococcus spp. (500) and L. intestinalis (502). 

Mitochondria from adult H. diminuta exhibit an NADH-coupled fumarate reductase (Table 5.11). This presents a potential dilemma with respect to the utilisation of intramitochondrial reducing equivalents by this worm. As reducing equivalents are generated by the malic enzyme in the form of NADP, a mechanism for the transfer of hydride ions from NADPH to NAD to produce NADH is required so that electron-transport-associated activities can proceed and terminate with the reduction of fumarate to succinate. Such a mechanism does exist in H. diminuta as there is a non-energy-linked, membrane-associated transhydrogenase (214, 217, 221, 476). This transhydrogenase, which also occurs in H. microstoma (216) and Spirometra mansonoides (220) catalyses the reaction ... 

An acyl-CoA transferase has been detected in sonicated mitochondrial preparations from Spirometra mansonoides (643). 

Fig. 6.4. Time course of CN-[57Co]Cbl (cyanocobalamin) binding to microtriches membranes of Spirometra mansonoides. (After Friedman el a ., 1983.)...

Table 8.8. Spirometra mansonoides comparison of the activities of the plerocercoid growth factor (PGF) to those associated with mammalian growth hormone (GH). (Data from Phares, 1987 ...

Pseudophyllidea Schistocephalus solidus, Ligula intestinalis, Spirometra mansonoides. 

The possibility that parasites can synthesise host or host-like antigens raises the question of whether or not parasites can make use of mRNA to synthesise host protein (799) or whether putative molecular mimicry may actually represent cases of host capture by parasites via natural transfection (perhaps by retroviruses ) - a hypothesis reviewed in detail by Howell (338). It has been pointed out earlier (Chapter 8) that there is evidence to suggest that this may have occurred in the sparganum of Spirometra mansonoides, which is capable of synthesising a growth factor with properties resembling those of a mammalian growth hormone (Tables 8.8 (p. 218) and 8.9 (p. 219)). 

Beach, D. H., Mueller, J. F. Holz, G. G., Jr (1980a). Lipids of stages in the life-cycle of the cestode Spirometra mansonoides. Molecular and Biochemical Parasitology, 1 249-68. 

Berntzen, A. K. Mueller, J. F. (1964). In vitro cultivation of Spirometra mansonoides (Cestoda) from the plerocercoid to the early adult. Journal of Parasitology, 5 705-11. 

Malic enzyme, fumarate reductase and transhydrogenase systems in the mitochondria of adult Spirometra mansonoides (Cestoda). Journal of Experimental Zoology, 206 167-77. 

Characterization of cobalamin receptor sites in brush-border plasma membranes of the tapeworm Spirometra mansonoides. Journal of Biological Chemistry, 258 4261-5. 

Meyer, H., Mueller, J. Meyer, F. (1978). Isolation of an acyl-CoA carboxylase from the tapeworm Spirometra mansonoides. Biochemical and Biophysical Research Communications, 82 834-9. 

Mueller, J. F. (1959). The laboratory propagation of Spirometra mansonoides as an experimental tool. I. Collecting, incubation and hatching of the eggs. Journal of Parasitology, 45 353—61. 

Host-parasite relationships as illustrated by the cestode Spirometra mansonoides. In Host-parasite relationships, ed. J. E. McCauley, pp. 11-58. Oregon State University Press Oregon. 

Phares, C. K. (1984). A method for the solubilization of a human growth hormone analogue for plerocercoids of Spirometra mansonoides. Journal of Parasitology, 70 840-2. 

Steelman, S. L., Glitzer, M. S., Ostlind, D. A. Mueller, J. F. (1971). Biological properties of the growth hormone-like factor from the plerocercoid of Spirometra mansonoides. Recent Progress in Hormone Research, 27 97-120. 

J. F. (1977). The presence and possible function of methylmalonyl CoA mutase and propionyl CoA carboxylase in Spirometra mansonoides. Journal of Parasitology, 63 769-74. 

Small amounts of DA, NA and octopamine have been demonstrated in H. diminuta (46,83). Although the adult cestode Spirometra mansonoides lacked catecholamines, the larvae did express them (52) in contrast, the plerocercoid larvae of D. dendriticum did not have significant catecholamine amounts whereas the adult did (56). These studies emphasize the importance of examining different developmental stages in order to assess the presence/role of a given neuroactive substance. The precise physiological functions of the catecholamines in cestodes have been difficult to determine. 

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