Incubation in uni-parental Arctic breeding waders

Bruinzeel, L., Tulp, I., Jukema, J. & Stepanova, O. 2000. Incubation in mi-parental arctic breeding waders. Ostrich 71 (1 & 2): 345.

Little Stints Calidris minuta are amongst the smallest breeding waders. This, in combination with the fact that they have a peculiar breeding system, in which each adult takes care of her/his own nest and young, puts high demands during incubation. Due to uni-parental feeding system, feeding time is limited. The accumulation of he1 stores prior to breeding may be crucial to get through the 21-day incubation period. Incubation rhythms, body mass dynamics and energy expenditure of Little Stints was studied at Medusa Bay, Western Taimyr in the summer of 1996. Repeated body mass measurements during incubation were taken by catching the birds on the nest. Concurrently, we measured nest attentiveness, using Tiny Talk dataloggers and temperature sensitive probes, which were placed in the nests. Arthropod availability was measured to estimate food availability. In comparison, body mass dynamics were also studied in Curlew Sandpiper, another uni-parental breeder, but three times bigger. The first (preliminary) results of this study were presented.     

Results of the comparative use of virological and bacteriological control of routine disinfection in maternity homes

Bacterial viruses were often detected in washings from different environmental objects; not infrequently, the inoculation of washings from the same objects resulted in the growth of Escherichia coli. The expediency of making parallel tests of washings from these objects for the presence of wild strains of bacterial and viral cultures both during the control of disinfection measures and the determination of the effectiveness of disinfection agents is shown.     

Strains of salmonella with altered antigenic structure]

The authors studied 260 freshly isolated and laboratory cultures of salmonellae belonging to different serological groups. Heterogeneity of the majority of the strains studied by colour fluorescence of the colonies in the oblique light flux was demonstrated. Genetically bound spontaneous stable mutants with a different antigenic composition were selected by this method from a number of serological types. The isolated mutants were in the S-form and failed to differ by morphological, cultural and biochemical properties from the initial parental strains. A study of the antigenic structure by the method of agar immunoelectrophoresis and determination of their serological properties showed the mutants to have disturbances in the processes of O- or K-antigen synthesis.     

Serological method of detecting the antigens of the causative agent of Sonne dysentery in lysates of the fecal inoculates from patients]

Serological method of detection of Sh. sonnei antigens in the lysates of the patients, fecal cultures is suggested and approved. In the majority of cases of the results of bacteriological and serological methods of study of the feces coincided. Data confirming the specificity of the antibody neutralization test (ANT) in Sonne dysentery are presented. In connection with detection of the screening action of the Vi-antigen of typhoid bacilli there were elaborated additional methods for verifying the specificity of the ANT results. It is recommended to keep agar plates after selection of suspicious colonies during the bacteriological test; the lysate of the microbial crop should be additionally subjected to the ANT, this considerably increasing the percentage of laboratory confirmations of dysentery caused by Sh. sonnei.     

Preparation and characterization of bioactive products obtained via the solubilization of brown coal by white rot fungi

We investigated the solubilizing activity of the Basidiomycete fungi Trametes hirsuta and Trametes maxima, with respect to brown coal (lignite) during liquid phase cultivation. We found that the degrading capacity of the fungi is determined by the activity of the ligninolytic enzymes Mn peroxidase and lignin peroxidase. We assessed the growth-stimulating activity of biopreparations (BPs), based on the culture liquids (CL) of the studied fungal strains, which were grown on a rich or minimal medium. We found that the obtained BPs inhibited the growth of wheat shoots and roots at the germination stage, but they either had no effect at later stages of plant growth or showed a mild stimulation. When basidiomycetes were cultivated in the presence of brown coal, the obtained BPs stimulated root growth at the germination stage, and did not influence plant growth (Trametes hirsuta) or stimulated it (Trametes maxima) at later stages. Further, we report a pronounced detoxifying ability of the BPs in respect to the atrazine herbicide. We suggest that this effect is caused by the laccases action, that are present in the studied BPs.     

<Superscript>18</Superscript>F-labeled tyrosine derivatives: Synthesis and experimental studies on accumulation in tumors and abscesses

Tyrosine derivatives labeled with a short-lived fluorine-18 isotope (T _1/2 110 min), namely 2-[¹⁸F]fluoro-L-tyrosine (FTYR) and O-(2′-[¹⁸F]fluoroethyl)-L-tyrosine (FET), promising radiopharmaceuticals (RPs) for positron emission tomography (PET), were obtained by asymmetric syntheses. Accumulation of FTYR and FET in the rat tumor “Glioma 35 rats tumor” and in abscesses induced in Wistar rats muscles was studied and compared with that of a well-known glycolysis radiotracer 2-[¹⁸F]fluoro-2-deoxy-D-glucose (FDG). It was shown that the relative accumulation indices of amino acid RPs were considerably lower than those of FDG. At the same time, tumor/muscle ratios were high enough (2.9 for FET and 3.9 for FTYR 120 min after injection) for reliable tumor visualization. The data obtained indicated a possibility in principle to use FTYR and FET for differentiated PET diagnostics of brain tumors and inflammation lesions. Of the tyrosine derivatives studied, FET seems to be the most promising agent due to a simple and easily automated method of preparation based on direct nucleophilic substitution of the leaving tosyloxy group of an enantiomerically pure Ni-(S)-BPS-(S)-Tyr(CH₂CH₂OTs) precursor by an activated [¹⁸F]fluoride.     

Rho-associated protein kinase is involved in establishing the contractile phenotype of cardiomyocytes

It has been shown that Y-27632, an inhibitor of Rho-associated kinase, delays sarcomere assembly in rat neonatal cardiomyocytes pretreated with angiotensin II. Y-27632 affects the beat rate of cardiomyocytes; however, this effect is only observed at high cell density and, therefore, seems to be related to the formation of gap junctions between adjacent cardiomyocytes. Consistent with this suggestion, we established that Rho-associated kinase is localized in myofibrillar Z-discs of human myocardium and intercalated discs, the structures enriched in gap junctions. We propose that Rho-associated kinase participates in the maturation of the myocardial contractile system through phosphorylation of its molecular targets in Z-discs and intercalated discs.