Effects of carotenoids, immune activation and immune suppression on the intensity of chronic coccidiosis in greenfinches

Allocation trade-offs of carotenoids between their use in the immune system and production of integumentary colouration have been suggested as a proximate mechanism maintaining honesty of signal traits. We tested how dietary carotenoid supplementation, immune activation and immune suppression affect intensity of coccidian infection in captive greenfinches Carduelis chloris, a passerine with carotenoid-based plumage. Immune activation with phytohaemagglutinin (PHA) decreased body mass among birds not supplemented with lutein, while among the carotenoid-fed birds, PHA had no effect on mass dynamics. Immune suppression with dexamethasone (DEX) induced loss of body mass and reduced the swelling response to PHA. DEX and PHA increased the concentration of circulating heterophils. Lutein supplementation increased plasma carotenoid levels but had no effect on the swelling response induced by PHA. PHA and DEX treatments did not affect plasma carotenoids. Immune stimulation by PHA suppressed the infection, but only among carotenoid-supplemented birds. Priming of the immune system can thus aid in suppressing chronic infection but only when sufficient amount of carotenoids is available. Our experiment shows the importance of carotenoids in immune response, but also the complicated nature of this impact, which could be the reason for inconsistent results in studies investigating the immunomodulatory effects of carotenoids. The findings about involvement of carotenoids in modulation of an immune response against coccidiosis suggest that carotenoid-based ornaments may honestly signal individuals’ ability to manage chronic infections.     

Comparison of the stability of glutathione and related synthetic tetrapeptides by HPLC and capillary electrophoresis.

Glutathione and related peptides are interesting targets as protectors of biological systems against an oxidative injury. Two novel glutathione analogues, UPF1 and UPF15, have been designed and synthesised. As a result of different reactions taking place, the thiol-containing compounds oxidise to disulfides. In this study, the stability of UPF1, UPF15 and glutathione in various solutions was investigated by using HPLC and CE. The results showed that UPF1 and UPF15 are powerful hydroxyl radical scavengers and their dimerisation process velocity is higher than that of glutathione.     

What Causes Men's Violence against Women?

What Causes Men's Violence against Women? Michéle Harway and James M. O'Neil. eds. Thousand Oaks, CA: Sage Publications, 1999. 296pp.     

Increase in the number of contacts of endoplasmic reticulum with mitochondria and plasma membrane in yeast cells stimulated to division with He-Ne laser light

We studied the ultrastructure of Torulopsis sphaerica yeast cells irradiated with He-Ne laser (lambda = 632.8 nm, dose--460 J/m2) and then cultured for 6 h in the nutrient with 1% glucose by aeration. The length of membranes of endoplasmic reticulum (ER) and the number of its associations with mitochondria (M) and plasma membrane (PM) were measured on ultrathin sections. A distance of less than 50 nm between heterogeneous membranes was considered as an "association". The cells from irradiated cultures are characterized by the following features: 1) the length of cortical ER membranes in relation to cellular perimeter, and the length of perinuclear ER membranes in relation to nuclear perimeter increase, resp., by 21 and 79%; 2) the number of ER-PM associations per cellular section, and that per unit of PM length increase, resp., by 26 and 41%; 3) the number of ER-M association in relation to the total mitochondrial perimeter, and to perimitochondrial ER increase by 80 and 87%, resp. The latter may be associated with Ca2+ uptake by mitochondria associated with ER, which results in activation of respiration and ATP production.     

A microcalorimetric perfusion vessel used for measurements of total activity in sediment samples

A multichannel microcalorimeter of the heat-conduction type was equipped with a prototype of a perfusion vessel and was used to measure the total activity during long time periods in natural, aquatic sedimnet samples from aerobic environments. The effect of addition of organic substances, a pollutant and bacteria was studied. The water phase of the sediment phase of the sediment samples was aerated with humidified air and stirred uring measurements. The total activity of the actual sediment was also measured in an ampoule system, for comparison. Aeration of the samples led to an increased heat production rate.     

AKINETE PRODUCTION OF ANABAENA LEMMERMANNII AND A. CYLINDRICA (CYANOPHYCEAE) IN NATURAL POPULATIONS OF N‐ AND P‐LIMITED COASTAL MESOCOSMS1

A strong biomass increase of two Anabaena species was observed in natural plankton community enclosed into nine large mesocosms (51 m³) and manipulated with mineral nutrients and an organic carbon source during a 3‐week period in the coastal Baltic Sea. The water column and settled material from the bottom of the mesocosms were sampled at 2‐day intervals. Planktonic populations of Anabaena lemmermannii Richter and A. cylindrica Lemmermann and sedimentation rates of akinetes to the bottom were quantified. Comparing mesocosms with artificially induced nitrogen and phosphorus limitation, we found that during the third week of the experiment, the population size of A. lemmermannii was clearly higher in nitrogen‐limited units (by a factor of 2.4), whereas the production rate of akinetes was higher in the phosphorus‐limited units (by a factor of 2.5). Input of freshly produced A. lemmermannii akinetes to the benthos was on average 15 × 10⁶ and 6 × 10⁶ cells· m^?2·d^?1 in the P^? and N^? limited mesocosms, respectively. Our estimates of specific akinete production rate of A. lemmermannii in P^? and N^? limited mesocosms revealed an even larger divergence (a factor of 5.5), being on average 2.4 and 0.4 akinetes·10^?3 vegetative cells^?1·d^?1, respectively. The phosphorus addition effectively reduced akinete production of A. lemmermannii. Differences in the nutrient manipulation had no apparent effect on the biomass and akinete production of A. cylindrica. The akinete production pattern of A. cylindrica revealed a 1‐week delay compared with the vegetative population peak, whereas such a delay was not obvious in A. lemmermannii.     

Immunodetection of 3-nitrotyrosine in the liver of zymosan-treated rats with a new monoclonal antibody: comparison to analysis by HPLC.

Zymosan-induced peritonitis is associated with an increased production of reactive nitrogen oxides that may contribute to the often-observed failure of multiple organ systems in this model of acute inflammation. Quantitative biochemical evidence is provided for a marked 13-fold increase in protein-bound 3-nitrotyrosine (NTyr), a biomarker of reactive nitrogen oxides, in liver tissue of zymosan-treated rats. In order to investigate the localization of NTyr in this affected tissue, a monoclonal antibody, designated 39B6, was raised against 3-(4-hydroxy-3-nitrophenylacetamido) propionic acid-bovine serum albumin conjugate and its performance characterized. 39B6 was judged by competition ELISA to be approximately 2 orders of magnitude more sensitive than a commercial anti-NTyr monoclonal antibody. Binding characteristics of 39B6 were similar, but not identical, to that of a commercial affinity-purified polyclonal antibody in ELISA and immunohistochemical analyses. Western blot experiments revealed high specificity of 39B6 against NTyr and increased immunoreactivity of specific proteins from liver tissue homogenates of zymosan-treated rats. Immunohistochemical analysis of liver sections indicated a marked zymosan-induced increase in immunofluorescent staining, which was particularly intense in or adjacent to nonparenchymal cells, but not in the parenchymal cells of this tissue. Quantitative analysis of fractions enriched in these cell populations corroborated the immunofluorescent data, although the relative amounts detected in response to zymosan treatment was greatly reduced compared to whole liver tissue. These results demonstrate the high specificity of the newly developed antibody and its usefulness in Western blot and immunohistochemical analysis for NTyr, confirm the presence of NTyr by complementary methods, and suggest the possible involvement of reactive nitrogen oxides in hepatic vascular dysfunction.