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J Nosek

Publications and source records attributed to J Nosek.

At least 73 records · Page 4Linked to original sources

Isolation of Tettnang virus from Ixodes ricinus ticks in Czechoslovakia.

Three virus strains closely related to Tettnang virus were isolated from nymphs and males of Ixodes ricinus tick in Moravia and Slovakia. The virus isolates were lethal for suckling mice on intracerebral (i.c.) inoculation but the virus titres in the brain were low. The incubation period of 5--12 days in the first mouse passage was shortened to 3 days in further passages. Infection of mice was accompanied by ultrastructural changes in the cytoplasm of neurons. Groups of spherical virus particles 75 to 80 nm in diameter occurred within simple vacuoles.

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Ultrastructure of some cutaneous sense organs in Dermacentor marginatus nymphs.

The fine structure of the integumentary glands and mechanoreceptory setae in Dermacentor marginatus nymphs is described. The integumentary gland is localized in the epidermal layer and secretory products pass through the duct lumen and two cuticular lips to the surface. Ultrastructure of cuticular cavity represents triangular form with lateral folds. The mechanoreceptor setae are composed of glandular cells localized in the epidermal layer and cuticular setae movably articulated to the cuticle by means of a compact fibrillar ring around the base.

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Reaction of the host to the tick bite III. The bite of viruliferous Ixodes ricinus female.

No distinct internal cement formation was observed at the penetration site of the mouth parts of Ixodes ricinus females during their feeding on golden hamsters. At 2 h, the chelicera were already deeply inserted into the dermal tissue. Beginning after 4 hours, the proliferation of collagen and conus formation became evident. The internal cell-free area was structureless and showed PAS positivity, while the outer collagen layer was rich in fibrocytes and negative for PAS staining. Both layers showed positivity when stained for collagen. The conus extending into the subdermal connective tissue was surrounded by an infiltrate of mononuclear and polynuclear leukocytes. The half-engorged females showed specific fluorescence of the TBE antigen in columnar epidermal cells. The penetration of the TBE virus into host tissue lasted probably only for a few hours, as virus was succesfully transmitted to golden hamsters during 2 h feeding of the viruliferous I. ricinus females.

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Arboviruses in birds captured in Slovakia.

Virus neutralizing (VN) antibodies against Sindbis, tick-borne encephalitis (TBE), West Nile (WN), Tahyna and Calovo viruses were found in birds captured in Slovakia. In parallel, Sindbis, TBE and WN viruses were isolated from the blood, brain and liver of migrating birds.

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Reaction of the host to the tick-bite. II. Distribution of tick borne encephalitis virus in sucking ticks.

No reactive histological changes of the dermis and no cement cone formation were observed at the insertion site of tick mouthparts by feeding of H. inermis larvae. Conversely, cement formation was observed by feeding of H. inermis female. Fully fed D. marginatus larvae on viraemic mice showed bright fluorescence in oesophagus, suboesophageal ganglion, salivary glands, a few gut cells and in lumen of Malpighian tubuli. We consider the penetration of virus from oesophagus to suboesophageal ganglion as the possible route of primary virus infection. Sections through the D. reticulatus nymphs during virus transmission (38 hours after attachment) showed specific fluorescence in epidermis and gut cells. This finding is in agreement with the secretory activity of epidermial and gut cells during feeding.

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Virus neutralizing antibodies to arboviruses in birds of the order Anseriformes in Czechoslovakia.

Sera from birds of the order Anseriformes in Czechoslovakia were examined for virus neutralizing (VN) antibodies to arboviruses. VN antibodies to Sindbis, Calovo and Tahyna viruses were found in 15, 5 and 6 out of 106 greylag goose (Anser anser) sera. Out of 38 ducks, 6 mallards (Anas platyrhynchos) and 1 garganey (Anas querquedula) contained VN antibodies to Sindbis virus, 6 mallards to Calovo virus, 4 mallards and 1 garganey to Tahyna virus, 2 mallards and 1 garganey to tick-borne encephalitis (TE) virus and 1 mallard to West Nile (WN) virus.

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