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V I Shchedrin

Publications and source records attributed to V I Shchedrin.

28 records · Page 2Linked to original sources

[Blood digestion and the formation of a plague block in Ceratophyllus tesquorum fleas].

The fleas of C. tesquorum are characterized by high protease activity in the epithelium and contents of the stomach, quick hemolysis of erythrocytes and low blood coagulation. Rare blockformation in C. tesquorum and its long terms under experimental conditions are apparently associated with changes in the quantity of plague microbes in the digestive tract depending on the stage of blood digestion: reduced during the hemolysis of erythrocytes and increased when it was over.

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[The ability of flea species on the common vole from mountainous Dagestan to transmit and preserve the causative agent of plague].

The infection ability and terms of preservation of plague microbe in fleas of common vole from Dagestan high-mountain plague focus (Frontopsylla causasica, Megabothris turbidus, Ctenophthalmus intermedius and Amphipsylla rossica) was studied experimentally. Block formation and transmission of the infection by F. caucasica and M. turbidus was observed. The transmission of plague microbe by Ct. intermedius fleas was first carried out. These species of fleas preserve the infection for a long time. Experiments with fleas of A. rossica yielded negative results.

Animals↗

[Characteristics of the multiplication of a virulent strain of the plague microbe in Xenopsylla cheopis fleas infected parenterally].

Xenopsylla cheopis fleas infected parenterally with the virulent strain of plague microbe of gerbil variant preserved the agent to the end of their lives. In the body cavity the microbes retained their ability for reproduction which was, however, limited. During the first seven days after the infection the number of microbes slightly increased and later became stabilized. Its mean indices (mean g) varied within the limits of 500 to 2000 microbe cells per 1 individual, maximum index rarely exceeded 30 000 microbe cells. Parenteral infection with plague agent did not affect essentially the longevity of fleas.

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[Method of disinfecting plague-infected fleas in preparation for electron microscopic study].

During fixation of fleas infected with plague agent (with preliminary cut heads, limbs and posterior part of the abdomen) in 2.5% glutaric dialdehyde or 2% osmium tetroxide their disinfection was obtained in two days. After double fixation with 2-hour exposure in each of these fixators disinfection of the material was acheived only after additional 2-day maintenance in 70% ethyl alcohol. Fleas, which had been placed into fixators or in 70% ethyl alcohol after double fixation without preliminary dissection, were disinfected completely only in 10 days.

Animals↗