In memory of Yuri Sergeevich Balashov (25.XII.1931–28.IX.2012)

The biographical notes describe the life and scientific activities of Yuri S. Balashov, an outstanding Russian parasitologist and Chief Editor of Parazitologiya.     

Tarsal gland of ixodid ticks (Ixodidae)]

In the tarsi of all legs of Ixodes persulcatus, Dermacentor daghestanicus, Rhipicephalus turanicus and Hyalomma asiaticum the multicellular gland was observed. The gland is formed by a single layer of glandular cells that form a central cavity where two ciliary structures in a cuticular (scolopoid) sheath are situated. A possible function of the gland is discussed in the article.     

云南瓶尔小草属一新种

Ophioglossum yongrenense Ching ex Z. R. He et W. M. Chu, sp. nov.Species nova aspectu inter O. kawamuram Tagawa et O. parvum Nishida et Kurita Japonicae, differt a priore frondibus pro parte laminis sterilibus praeditis (in illa frondibus omnino laminis sterilibus non praeditis), a posteriore frondibus pro parte laminis sterilibus non praeditis (in O. parvo Nishida et Kurita frondibus omino laminis sterilibus praeditis).……     

The tarsal gland of ixodid ticks <Emphasis Type="Italic">Ixodes persulcatus</Emphasis> and <Emphasis Type="Italic">Ixodes ricinus</Emphasis> (Mesostigmata,Ixodidae)

A complicated multicellular gland is situated in all the leg tarsi, occupying from one third to half the segment. The glandular cells form a single-layer sack; the inner surface of the gland cavity is covered with the multi-layer membrane. Cuticular rods (“sinews”) of muscles moving the claw pass inside the gland cavity. The glandular cells are characterized by the presence of numerous microvilli on their apical surfaces and by the presence of secretory vacuoles. The basal part of each secretory cell is characterized by accumulations of lipid vacuoles and glycogen granules. Problems concerning the possible role of tarsal gland in the production of the trace pheromone are discussed.     

Polypharmacy in the management of patients with schizophrenia on risperidone in a tertiary-care hospital in Malaysia

The present study was conducted primarily to determine the occurrence of polypharmacy in patients with schizophrenia on risperidone. The secondary aim was to ascertain the incidence of inappropriate prescribing with anticholinergics. A retrospective review of the medical records of all patients who were being followed up at the out-patient clinic of a tertiary-care hospital in Malaysia was conducted. Only patients who were being prescribed risperidone between 1 June 2008 and 31 December 2008 were included in the study. Demographic data such as patient’s age, gender and race were obtained from the patient’s medical records. In total, 113 patients met the selection criteria. Polypharmacy was found to occur in 34 patients (30.09%), with the majority (76.47%) being on two antipsychotics. In total, 27 patients (34.18%) on monotherapy with risperidone were prescribed an anticholinergic on scheduled dosing, while 19 patients (24.05%) were prescribed it on an as-needed basis. Of the patients on polypharmacy, 26 (76.47%) were on scheduled dosing of anticholinergics, while three (8.82%) were taking the medication on an as-needed basis. Polypharmacy should be avoided, and the use of anticholinergics should be closely reviewed. By adopting more efficient prescribing practices, costs can be reduced and financial resources can instead be channelled towards more beneficial areas for the patients.     

The main evolutionary trends in sensory organs and questing behavior of Parasitiform ticks and mites

Studies of sensory organs in ticks and mites of the order Parasitiformes by methods of electron microscopy and electrophysiology started in Russia in the middle of the 1970s due to the activity of Prof. Balashov and with his personal participation. A review of the data accumulated since that time allowed tracing the main evolutionary trends in the morphology of the main composite sensory organs (palpal and tarsal organs of mites, Haller’s organ of ticks, and eyes). Close association between the evolution of questing behavior and the evolution of sensory organs is demonstrated.     

Ultrastructure of the tarsal receptor complex in the gamasid mite Histionyssus criceti (Hirstionyssidae)

The main distant receptor organ of H. criceti, situated on the tarsus of each first leg, was studied by scanning and transmitting electron microscopy. The organ contains 6 types of sensilla, including 4 distant ones (two types of olfactory sensilla, differing in wall thickness, and 2 types of probable chemo-thermosensitive sensilla, possessing different double-walled hairs), and also taste organs of common structure and microchaeta. Cilia of all the sensilla contain 13 pairs of peripheral fibers. Comparative analysis of fine structure of distant sensilla in bloodsucking insects, ticks and mites made it possible to show, that blood-sucking gamasids and ticks possess similar number of homologous sensillar types, that formed on a common ground as the specific adaptation to blood-sucking.     

Ultrastructural studies of Haller's organ in the argasid tick, Argas tridentatus (Argasidae)]

Haller's organ in A. tridentatus consists of a capsule and an anterior group of sensilla. The capsule is the hollow in the cuticle on the dorsal surface of the first tarsus, where 4 pored hairs of olfactory sensilla are situated under the cover of the roof, formed by an anostomosis of the upper brunches of pleomorphs (capsule's bottom non-sensory cuticular outgrowths). The canal of the accessory ampullaceous sensillum opens in a capsule near the bottom. The anterior group of sensilla consists of two parts: proximal part, containing pored grooved and thin hairs, is homologous to the anterior grouf of ixodid ticks, and distal one which has no homologues in ixodids. Fine structure of all the sensilla in the mentioned parts of Haller's organ is described in detail.