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K Niewiadomska

Publications and source records attributed to K Niewiadomska.

At least 19 recordsLinked to original sources
PubMed1997

Ultrastructural studies on the sporocyst wall of Diplostomum pseudospathaceum Niewiadomska, 1984 (Digenea, Diplostomidae).

The sporocyst wall of the daughter sporocyst of Diplostomum pseudospathaceum is composed of many elements. It is covered by a syncytial layer of cytoplasm connected to sunken nucleated perikarya (cytons), lying underneath the outer-circular and the inner longitudinal muscle layers. The outer tegumental part forms numerous microvilli covered by glycocalyx and contains many microfilaments, single ribosomes, electron-dense granules and short electron-lucid cisternae. No other cell organelles were seen in this layer. The cytons include all the organelles needed for cell metabolism. The sporocyst wall also contains the sarcoplasmic parts of the muscle cells; large vacuolar cells filled with electron-transparent vacuoles; macrophagic cells containing numerous phagosomes and sending extensions separating the sporocyst wall from the brood chamber; flame cells and reproductive cells. Nerve fibres, filled with neurosecretory granules, are seen among the sporocyst wall cells. The uniciliate sensory receptors are inserted in the outer tegumental part.

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PubMed1996

Cholinergic and aminergic nervous systems in developing cercariae and metacercariae of Diplostomum pseudospathaceum Niewiadomska, 1984 (Digenea).

Comparative studies on the cholinergic (ChNS) and aminergic (ANS) nervous systems were carried out in developing cercariae and metacercariae of Diplostomum pseudospathaceum. A method for the localization of cholinesterase and nonspecific esterase activities, and the method for the histofluorescence of biogenic amines were used. The first traces of the ChNS were found in the cercarial embryo, and during growth of the cercaria, the brain ganglia and commissure, as well as anterior and posterior nerve trunks joined by commissures, were progressively developed. The fully developed ChNS was observed in the emerged cercaria. Further development in metacercariae leads to an orthogon-like structure. Histofluorescence of catecholamines appeared in the brain ganglia and the proximal part of the ventral trunks only in young cercaria (having furcae, tail stem and body of the same size). The emerged cercaria had an ANS different from the ChNS (in part of the nervous system there was no fluorescence). The differences disappeared during the development of the metacercaria. The evolutionary and functional interpretation of the various developmental rates of the ChNS and ANS were discussed.

Animals↗
PubMed1996

Ultrastructure of sensory endings in Diplostomum pseudospathaceum Niewiadomska, 1984 cercariae (Digenea, Diplostomidae).

Using TEM techniques, 13 types of sensory endings were revealed on the body and tail of cercariae of D. pseudospathaceum. They differ in the presence or absences of cilia, number of cilia, number of electron-dense rings, basal body type and collar shape. The following groups of sensory endings were distinguished: uniciliate with a short (5 types), moderately long (one type) or long cilium (4 types); multiciliate sensory pits (2 types); and nonciliate sensory bulbs. Most sensory endings with long cilium and nonciliate sensory bulbs were found on the tail stem. All the breviciliate sensory endings and multiciliate sensory tips, as well as 1 type with long cilium, were situated on the cercarial body. The uniciliate sensory endings with a moderately long cilium were found on the furcae. The ultrastructural variety of sensory endings in different groups of Digenea, as well as their supposed functions, are discussed.

Animals↗
PubMed1996

[Role of host behavior in the life cycle of parasites].

Parasite is an organism which, at least in a part of its ontogeny uses another living organism as a proper environment for its life. In the "parasite-host" relationships, formed by both these components, the parasite itself bears the burden of formation and maintenance of these relationships in a balance. Three factors play the main role in this process: (1) physiological adaptations of the parasite, enabling survival in the host body and resistance against defence reactions of the host; (2) morphological adaptations, leading to changes in the body structure of the parasite, dependent on location in the host body; and (3) behavioural adaptations assuring contacts of parasites with their hosts. In the process of evolution most groups of parasites evolved a complicated life cycle, with change of host and outer environment, succeeding in maturation of the parasite and production of the offspring. To pursuit this aim the parasite takes advantage from the behaviour of its potential host, its food preferences (e.g. by inclusion into a food chain), periodic or circadian migrations, and generally from its mode of life. The parasite modifies behaviour of its hosts, sometimes to a high degree, especially the behaviour of intermediate hosts, making them more conspicuously displayed for predators, the most often their final hosts. The parasite itself changes also its behaviour to be more attractive for a potential host or to enhance the possibility of finding a proper host. Finally, in a host population the parasite bears upon the position of particular host individuals by degradation of dominants and shifting them from reproduction. This phenomenon may be considered as a self-defence of the host population against reproduction of ill individuals, weaken by a burden of parasites.

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PubMed1991

Trematodes nervous system.

Three main themes are discussed: 1. Development of the nervous system in the ontogeny of digenetic trematodes; 2. Central and integumentary nervous elements in Cercaria echinata (Echinostomatidae), their evolution in metacercaria and adult; 3. Chaetotaxy and systematics. The structure of the nervous system in digenetic trematodes is based on the occurrence of various neurotransmitters in the nerve tissue. Two major trends in the evolution of the nervous system from cercaria to adult are discerned, one leading to definitive, small number of commissures, established early in the development of the cercaria, the other one leading to formation of great number of commissures completed in the adult. Structure of the nervous system in sporocystic and/or redial generations in various groups of trematodes is compared. Its primitiveness in relation to that of other generations is noted. The central nervous system of Cercaria echinata is pointed out by fixation in glioxylic acid and examination in green light fluorescence. The integumentary sensory elements observed in light microscope, SEM and transmission electron microscope reveal a large variety in structures; propositions are made about their functions. In the corresponding metacercaria, the anterior part of the central nervous system remains unchanged; meanwhile the posterior part increases; several integumentary sensory elements disappear and poorly developed structures, improve; in the adult, transformations are completed. In about 200 various species of cercariae, the sensory receptors are arranged in a conspicuous relation with the nervous system. The study of their number and position; the chaetotaxy is used in systematics and allows very accurate conclusions in specific or infraspecific identifications and in all high taxonomical levels: family, sub-order, super-order. In the same way, miracidial and redial chaetotaxy are used n taxonomy.

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PubMed1990

[Trichomonadida and their hosts].

Relations of particular genera of Monocercomonadidae and Trichomonadidae with groups of hosts are discussed. Main hosts of these flagellates are insects (mainly termites) and cold-blooded vertebrates (amphibians and reptiles); the proper location within the host body is the intestine. Some representatives of these flagellates have changed their host and location and occur now in warm-blooded vertebrates (birds and mammals) and in man, usually in organs other than the intestine. Change of localization within the host body is probably responsible for growing pathogenicity of these flagellates.

Amphibians↗
PubMed1987

The nervous system of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomatidae). III. Structure of the nervous system in the adult stage.

The nervous system of adult Diplostomum pseudospathaceum Niewiadomska, 1984 was studied using Koelle's (1951) method for revealing cholinesterase activity. The nervous system in the fore body grows but its pattern remains the same as in the metacercaria: three pairs of stems connected by numerous commissures and differentiated innervation of various organs in this part of the body. In the elongated hind body the nervous system develops according to another pattern: two pairs of stems connected by a number of commissures form a loose net surrounding the whole segment. The net is more dense at the body end around the genital opening and copulatory organs. A brief discussion of the development of the nervous system of D. pseudospathaceum from cercaria to adult stage is given.

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