Avian haemosporidian parasites infection in wild birds inhabiting Minami-daito Island of the Northwest Pacific, Japan.

Haemosporidian parasites infection among wild birds inhabiting Minami-daito Island was studied. Blood films from 183 birds representing 4 species of 4 families were examined microscopically. Avian haemosporidian parasites were detected in 3 species with an overall prevalence of 59.6%. None of the 30 Daito scops owls (Otus scops interpositus) examined were infected. Either Haemoproteus sp. or Plasmodium sp. infection was found in 14 of 31 (45.2%) Borodino islands white-eyes (Zosterops japonicus daitoensis). Plasmodium spp. were found in 94 of 102 (92.2%) bull-headed shrikes (Lanius bucephalus) and 1 of 20 (5%) tree sparrows (Passer montanus).

Competitive solubilization of cholesterol and ß-sitosterol with changing biliary lipid compositions in model intestinal solution.

We used a model intestinal solution to understand the mechanisms of cholesterol lowering by the addition of plant sterols. The experimental results of the competitive solubilization of cholesterol and ß-sitosterol in vitro give useful information about these mechanisms. The states of the model intestinal solution as a solubilizer were analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) by changing the number of components, and the bile salt and phosphatidylcholine concentrations. There were aggregates of different sizes: liposomes and mixed micelles depending on their components and concentrations. The maximum solubilization of cholesterol increased from 0.2mM to 1.3mM when adding fatty compounds in the pure bile salts system, which is almost the same as the full components model intestinal solution. Therefore, an excessive intake of fatty compounds may also increase cholesterol absorption in vivo. Even if the components of the model intestinal solution were modified from the standard condition, there were not remarkable differences in the selectivity of cholesterol and ß-sitosterol in competitive solubilization. With the addition of ß-sitosterol, the maximum solubilization of cholesterol decreases to almost half of that in the system with only cholesterol, except for PC-rich systems. In general, the different structures of aggregates considerably influence the maximum solubilization of sterols but not the selectivity of cholesterol and ß-sitosterol in the competitive solubilization. The Gibbs energy change (ΔG°) of the solubilization of ß-sitosterol showed a more negative value than cholesterol by -4 to -6kJmol(-1), which indicates that ß-sitosterol is energetically favored relative to cholesterol in the model intestinal solution, regardless of the different systems.