Biomedical subjects

J K Macko

Publications and source records attributed to J K Macko.

17 recordsLinked to original sources

PubMed1998

Development and morphological variability of Echinococcus granulosus.

Characteristics are presented of Echinococcus granulosus strobila from dogs experimentally infected with protoscolices from a single cyst isolated from the liver of a domestic pig in a central Slovakian district. Adult cestodes are characterized mainly by 28-32 hooks highly variable in shape and size; 26-51 testes situated mostly throughout the proglottis (1 or 3 rows behind the vitelline gland); a lobate ovary; the shape of the uterus, which in 10% of proglottides is more or less spherical, in 62% is saccular with lateral sacculations of variable size, in 27% is saccular without lateral sacculations and in 1% is more or less tubular or strongly ramified; and an intermediately rapid rate of development lasting until between 40 and 44 days p.i. The present report analyzes the high degree of variability of the clone studied, referring to the knowledge on the characteristics of the pig, sheep, and cattle strains of E. granulosus and E. multilocularis species, with which some taxonomic characters of the clone representatives overlap.

Animals↗

PubMed1986

On the problem of retarding definitive host (s.l.).

The significance of the species and individual level in determining the hosts as a category of helminth life cycles is pointed out. From the viewpoint of species level, the categories of intermediate host and definitive host are ascribed to certain organisms as representatives of a certain species on the basis of the fact that a respective stage of helminth life cycle can take place inside them. From the viewpoint of individual level, these types of hosts are determined on the basis of associations between the helminth individual and host individual. In order to avoid discrepancies, which might occur in determining the host type in these ways, it is proposed that the organism, which was determined as intermediate or definitive host at the species level, should be regarded identically also at the individual level. In addition, the existence of retarding definitive host (s.l.) is substantiated on the example of helminths which survived the interorgan migrations and passed to the offsprings through the intrauterine or transmammary route.

Animals↗

PubMed1981

Deliberations on the problems of mammomonogamus species (Nematoda, Syngamidae) in ruminants.

The taxonomy of mammomonogamids parasitic in ruminants is discussed with regard to their different rates of variability in Cuba and Mexico. Since their variability is large and the existence of biological species is not based on their morphology but on the reproduction isolation of populations, the authors came to the conclusion that the specific analysis of mammomonogamids will be convincing only in case that it is carried out using taxonomic experiments of special orientation.

Animals↗

PubMed1979

Population and classification of intrapopulation units of helminths.

The study of the population problems revealed that the population is an elementary evolution unit of a species with biparental way of reproduction. This is a general theoretical definition which the author elaborated in detail for the helminths. With regard to the complicated intraspecific structure of these parasites also the classification of intrapopulation helminth units is proposed.

Animals↗

PubMed1978

On the topical problems of species in general and in relation to helminths.

In the light of the present knowledge of species, the author suggests to accept ten features of species and the general definition of species proposed by Zavadsky (1961, 1968), together with the definition by Mayr (1940) characterizing more concretely the species at the level of biparentally reproducing organisms. The definition by Timofeeff-Ressovsky et al. (1973) may be used for exclusively autogamous species of helminths. From the viewpoint of the species as a taxonomic unit, the paper presents proposals for establishment of a practical standard which would better suit the theoretical idea about the helminth species than it was the case till the present.

Animals↗

PubMed1978

On some theoretical and practical aspects of population variability in helminths.

Possibilities of studies of some microevolutionary processes in helminths on the basis of knowledge of their variability are presented. The practical aspects of the study of helminth variability are also referred to. In conclusion the author states that the investigation of non-morphological characters of helminths, in relation to various morphological structures of phenotypes in the populations of parasite and host, represents a sphere in which the interests of theoretical and practical helminthology meet with one another.

Animals↗

PubMed1977

Contribution to the knowledge of infectivity of Fasciola hepatica adolescariae after their passage through the digestive tract of white mice.

The study of infective elements of Fasciola hepatica which passed through the digestive tract of white mice revealed that those adolescariae (transitive adolescariae) (Table 1), which were not visibly damaged or possessed a more or less digested outer cyst wall, remained infective. The mice infected with transitive adolescariae harboured higher number of trematodes in the livers than those infected with infective elements which had not previously passed through the digestive tract of the definitive host.

Animals↗

PubMed1969