Haemosporidian parasites of a European passerine wintering in South Asia: diversity, mixed infections and effect on host condition.

We studied haemosporidian parasites in the scarlet rosefinch Carpodacus erythrinus in a small isolated semicolony during an eight-year period using molecular methods of parasite detection. The scarlet rosefinch is an interesting model of parasite host species. It winters in South Asia which represents a rare exception among European passerines. Males express yellow to red carotenoid-based plumage ornament which is a good predictor of male reproductive success. In 240 blood samples originating from 199 adult individuals, the total parasite prevalence reached 60%. Prevalence varied among years from 36 to 81% in Haemoproteus, 8 to 22% in Plasmodium, and 0 to 14% in Leucocytozoon. Twenty parasite lineages were detected (Haemoproteus: 5 lineages, Plasmodium: 10 lineages, and Leucocytozoon: 5 lineages). Among them, the Haemoproteus ROFI2 lineage, which is a host-specific parasite lineage of the scarlet rosefinch, was the most frequently found. Parasite lineages showed varying degree of lineage specificity. While Haemoproteus lineages detected in the scarlet rosefinch have relatively narrow host breadth restricted mainly to Fringillidae family, Leucocytozoon and Plasmodium lineages generally showed wider host range. The presence of some parasite lineages hitherto detected in sedentary European passerines (SISKIN1, CCF3, BT2) or in Culicoides biting midges at the same locality (ROFI1) suggest local transmission. On the contrary, lineages LK05 and FANTAIL1 that were previously reported exclusively from Asian hosts imply parasite transmission at the scarlet rosefinch wintering sites in South Asia. Mixed infections were found in 17% of infected samples and comprised mainly the most frequent lineages. The pattern of concomitant infections seemed to be rather random and matched expected levels based on lineage frequencies. Between-year comparisons revealed that in a majority of the repeatedly captured individual hosts the infection status remained unchanged (individuals stayed uninfected or possessed the same parasite lineages). However, 16 gains and 8 losses of lineages were also reported. We have not found any effect of haemosporidians on male carotenoid ornament expression or host body mass.

Endophagy of biting midges attacking cavity-nesting birds.

Feeding behaviour, host preferences and the spectrum of available hosts determine the role of vectors in pathogen transmission. Feeding preferences of blood-feeding Diptera depend on, among others factors, the willingness of flies to attack their hosts either in the open (exophagy) or in enclosed places (endophagy). As far as ornithophilic blood-feeding Diptera are concerned, the biting midges (Diptera: Ceratopogonidae) and blackflies (Diptera: Simuliidae) are generally considered to be strictly exophagous. We determined which blood-sucking Diptera enter nest cavities and feed on birds by placing sticky foil traps inside artificial nest boxes. A total of 667 females of eight species of biting midges of the genus Culicoides (Latreille, 1809) were captured on traps during 2006-2007, with Culicoides truncorum (Edwards, 1939) being the dominant species. DNA blood analyses of blood-engorged females proved that midges actually fed on birds nesting in the boxes. Three species were identified as endophagous: Culicoides truncorum, Culicoides pictipennis (Staeger, 1839), and Culicoides minutissimus (Zetterstedt, 1855). Our study represents the first evidence that ornithophilic biting midges are endophagous. The fact that we caught no blackflies in the bird boxes supports the exophagy of blackflies. We believe that our findings are important for surveillance programmes focusing on Diptera that transmit various bird pathogens.

Mechanical and microwave absorbing properties of carbon-filled polyurethane.

Polyurethane (PU) matrix composites were prepared with various carbon fillers at different filler contents in order to investigate their structure, mechanical and microwave absorbing properties. As fillers, flat carbon microparticles, carbon microfibers and multiwalled carbon nanotubes (MWNT) were used. The microstructure of the composite was examined by scanning electron microscopy and transmission electron microscopy. Mechanical properties, namely universal hardness, plastic hardness, elastic modulus and creep were assessed by means of depth sensing indentation test. Mechanical properties of PU composite filled with different fillers were investigated and the composite always exhibited higher hardness, elastic modulus and creep resistance than un-filled PU. Influence of filler shape, content and dispersion was also investigated.

[The past and the present of cardiac glycosides. III. Pharmacokinetics]. / Minulost a soucasnost srdecních glykozidu. III. Farmakokinetika.

The molecular structure is one of the keypoints that govern both the extent of extracardiac action of cardiac glycosides and their different kinetics. The apolar, fat soluble digitoxin is very well absorbed from the intestine, its onset of action is slow, binds to a high degree to albumin and undergoes enterohepatic recirculation which accounts for a long elimination half time and stability of plasmatic levels. Digitoxin is largely excreted via gastrointestinal tract. The absorption of digoxin is less reliable, onset of action occurs earlier and the binding to albumin is considerably less than that of digitoxin. The drawback, however small, of digoxin lies in a lower stability of plasma levels and prevailing renal excretion. The molecule of strophatin is highly polar, its absorption from the intestine negligible and can be administered only intravenously. The onset of action is prompt, elimination half time short and about half the injected amount is excreted extrarenally.

[The past and present of cardiac glycosides. II. Structure, physical and chemical properties. Pharmacodynamics]. / Minulost a soucasnost srdecních glykozidu. II. Struktura, fyzikální a chemické vlastnosti. Farmakodynamika.

An outline is presented on the physical and chemical properties and structure of the most important cardiac glycosides, i.e. digoxin, digitoxin and g-strophanthin. The overall effects of cardiac glycosides on the cardiovascular system not only are a composite of changes in the force of ventricular contraction and heart rate but also result from effects on the autonomic nervous system and on vascular smooth muscle. Furthermore reflex adjustments to the initial hemodynamic changes caused by the drug are also important. In the normal heart and circulation cardiac glycosides increase inotropy and decrease the chronotropy and dromotropy of the heart. They increase the peripheral vascular resistance and venous tone. Cardiac output remains unchanged or decreases slightly owing to increased peripheral vascular resistance and slowed heart rate. In patients with compromised cardiac inotropy the effects of the glycosides on the heart is essentially the same as in normal subjects, however by suppressing the enhanced sympathetic activity the negative chronotropic and dromotropic effects are more prominent. Peripheral vascular resistance is lowered, cardiac output and venous capacity are increased.

The lymphocytic reaction to blood donation in the peripheral blood of healthy blood donors.

This study was undertaken to provide more information on the lymphocytic reaction to blood loss in the peripheral blood of healthy blood donors. Number of lymphocytes as well as lymphocytic nucleolar coefficient and number of lymphocytes classified according to the presence of functionally dominant nucleoli in their nuclei were studied 10 minutes, 2 and 24 hours, 2, 4, 6, and 8 weeks after blood donation. In general, the number of these cells increased rapidly after blood donation reaching maximal values of 2-24 hours, then it slowly returned to the original values after 4-8 weeks depending on the functionally dominant nucleolar type in their nuclei. According to the presented results the lymphocytic reaction may also differ in new and repeated blood donors as well as in various seasons of the year. In contrast, no differences were observed between male and female blood donors after the first blood donation in one and the same season of the year. The values of the lymphocytic nucleolar coefficient increased after blood donation and were usually different in new and repeated blood donors. Some differences of the nucleolar coefficient were also found in various seasons of the year before as well as after blood donation.

Hydrophilized polyethylene catheters.

Complications arising in the application of polyethylene catheters in surgery may be reduced by their surface hydrophilization. This study describes a combination of chemical transformation and coating with a hydrophilic gel. Modified catheters were tolerated well by the patients and in contrast with the original catheters, they did not lead to the formation of thrombi or phlebitis.