National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
The role of humoral factors in the snail immune response against schistosomes
Košťáková, Monika ; Horák, Petr (advisor) ; Dvořák, Jiří (referee)
Digenetic trematodes such as Schistosoma mansoni use molluscs, mainly Gastropoda in their life cycle, as their intermediary hosts. e internal defense system (IDS) of snails is composed of immune cells called hemocytes, which are the main effectors and act jointly with soluble components. Humoral factors could in uence directly the parasite's larval stage, the activity of hemocytes and also may serve in recognition of the parasite. Lectins are considered to be the main component of humoral immunity. ey have a primary role in non-self recognition. Other protein group with lectin-like activity called FRePs was found in Biomphalaria glabrata. eir unique structure contains a brinogen and an immunoglobulin-like domain. Cytokine-like molecules may play very important role in defense as well. Many molecules are present in hemolymph and their levels change during infection. e response to parasitosis is therefore very complex and still awaits further clari cation.
Ontogenesis of trematode larval stages of the family Fasciolidae in the intermediate snail hosts.
Pankrác, Jan ; Kašný, Martin (advisor) ; Soldánová, Miroslava (referee)
The family Fasciolidae is an important group of trematodes including serious pathogens of humans and livestock. The life cycle is divided into two phases - sexual reproduction in the definitive host body (large land mammals) and an asexual reproduction in the intermediate host body (aquatic snails of the family Lymnaeidae and Planorbidae). Development within the snail host is characterized by production of large amounts of parasite larvae (sporocyst, rediae, cercariae). Cercariae released from the snail immediately start to transform into metacercariae, the larval stages infectious for definitive host. Snail phase of infection is generally accompanied by number of mostly negative symptoms (massive pathological changes, often followed by reduction of fertility). This summary reveals that current knowledge concerning the ontogenetic development of fasciolids in the intermediate host is uncomplete and unequally investigated. According to this summary is also obvious that some of the published findings are universally valid for all members of the family Fasciolidae and other are characteristic only for particular species.
Early embryonal development and morphogenesis of selected organ systems of the rediae and cercariae of Fascioloides magna.
Pankrác, Jan ; Kašný, Martin (advisor) ; Macůrková, Marie (referee)
Fascioloides magna (giant liver fluke) is a digenetic trematode with two-host life cycle and high veterinary importancy. Typical definitive host is a deer (Cervidae), but many other species from different families can be accidentally infected, for example sheep, goat or cattle. Very important role in the life cycle of F. magna has the first host - fresh water snail of the family Lymnaeidae. Three different life stages of F. magna, two of them with ability of reproduction - sporocysts and rediae develop in the body of snail. The third stage - cercaria is produced by rediae. Cercariae are able to escape from the snail, encyst and become infective for the definitive host. Since the second half of the 19th century many researchers studied the development of particular stages in the first intermediate host, but many characteristics of this process are still not fully understood. This thesis should reveal some of unanswered questions concerning to the reproduction and ontogenetic development of trematodes, which is presented on the examples of three organ systems - muscles, nerves and excretory system of rediae and cercariae of F. magna.
Ontogenesis of trematode larval stages of the family Fasciolidae in the intermediate snail hosts.
Pankrác, Jan ; Kašný, Martin (advisor) ; Soldánová, Miroslava (referee)
The family Fasciolidae is an important group of trematodes including serious pathogens of humans and livestock. The life cycle is divided into two phases - sexual reproduction in the definitive host body (large land mammals) and an asexual reproduction in the intermediate host body (aquatic snails of the family Lymnaeidae and Planorbidae). Development within the snail host is characterized by production of large amounts of parasite larvae (sporocyst, rediae, cercariae). Cercariae released from the snail immediately start to transform into metacercariae, the larval stages infectious for definitive host. Snail phase of infection is generally accompanied by number of mostly negative symptoms (massive pathological changes, often followed by reduction of fertility). This summary reveals that current knowledge concerning the ontogenetic development of fasciolids in the intermediate host is uncomplete and unequally investigated. According to this summary is also obvious that some of the published findings are universally valid for all members of the family Fasciolidae and other are characteristic only for particular species.
The role of humoral factors in the snail immune response against schistosomes
Košťáková, Monika ; Dvořák, Jiří (referee) ; Horák, Petr (advisor)
Digenetic trematodes such as Schistosoma mansoni use molluscs, mainly Gastropoda in their life cycle, as their intermediary hosts. e internal defense system (IDS) of snails is composed of immune cells called hemocytes, which are the main effectors and act jointly with soluble components. Humoral factors could in uence directly the parasite's larval stage, the activity of hemocytes and also may serve in recognition of the parasite. Lectins are considered to be the main component of humoral immunity. ey have a primary role in non-self recognition. Other protein group with lectin-like activity called FRePs was found in Biomphalaria glabrata. eir unique structure contains a brinogen and an immunoglobulin-like domain. Cytokine-like molecules may play very important role in defense as well. Many molecules are present in hemolymph and their levels change during infection. e response to parasitosis is therefore very complex and still awaits further clari cation.
Geometric - morphometric study of gastropod shells \kur{Hexaplex trunculus} from Croatian coast line of the Adriatic sea
MACÍK, Jiří
The shape variability of three hundred shells of sea snail Hexaplex trunculus (Linné, 1758) of three sites of Croatian coast line was compared. No criteria were found for distinguishing among males, females and imposex disabled females by traditional morphometry. With the help of traditional morphometry and geometric morphometry, differences in the shape of shells among the three investigated populations were identified. On the shells of H. Trunculus, there were found moderate sexual differences using the geometric-morphometric methods. The results separated females from the remaining two categories (males and masculinized females).

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