Human Sperm Characteristics with Regard to Cobalt,Chromium, and Lead in Semen and Activity of Catalase in Seminal Plasma

Biological Trace Element Research - We analyzed cobalt (Co), chromium (Cr), and lead (Pb) concentrations in human semen and catalase CAT activity in seminal plasma and the effects of their...     

Prevalence of agglutinating antibodies against<Emphasis Type="Italic"> Listeria monocytogenes</Emphasis> in chicks of the white stork (<Emphasis Type="Italic">Ciconia ciconia</Emphasis> Linnaeus, 1758) in Poland

In 2002 and 2003, blood samples from white stork (Ciconia ciconia) chicks were examined for the presence of antibodies against Listeria monocytogenes. Listeria antibodies were detected in 121 (59%) of 205 chick samples. The probability of Listeria antibodies being present increased with chick age; chicks detected with Listeria antibodies were in better condition than those without the bacterium.     

Melatonin and thyroxine response to pollution in white stork nestlings (Ciconia ciconia): aspects of rhythmicity and age

There is growing evidence that ubiquitous environmental contaminants may interfere with vertebrate endocrine systems. The selected endocrine biomarkers are used to indicate the condition of free-ranging populations of wildlife, including avian species. The aim of this study was to determine the impact of environment quality on serum thyroxine (T4) and melatonin (Mel) in white stork nestlings (Ciconia ciconia) living in different locations: small villages in natural areas surrounded by forests and crop fields, near the city and near the copper smelter. We extended our analyses to examine the hormones' day-night changes in conjunction with chicks' age. Total serum T4 and Mel was measured by RIA. T4 level, as a decisive measure of thyroid hormone productivity, was significantly lower in the nestlings exposed to pollutants from the copper smelter. Mel, as a well-known scavenger of free radicals, was elevated in the nestlings in the area near the copper smelter. This study indicates that alteration in T4 and Mel levels could be a useful marker of exposure of nestling wild storks to different toxic substances in field studies. Mel is postulated to be a susceptible defensive molecule as a protective mechanism for organisms.     

An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.     

Structure based virtual screening of ligands to identify cysteinyl leukotriene receptor 1 antagonist

Montelukast and Zafirlukast are known leukotriene receptor antagonists prescribed in asthma treatment. However, these fall short as mono therapy and are frequently used in combination with inhaled glucocorticosteroids with or without long acting beta 2 agonists. Therefore, it is of interest to apply ligand and structure based virtual screening strategies to identify compounds akin to lead compounds Montelukast and Zafirlukast. Hence, compounds with structures having 95% similarity to these compounds were retrieved from NCBI׳s PubChem database. Compounds similar to lead were grouped and docked at the antagonist binding site of cysteinyl leukotriene receptor 1. This exercise identified compounds UNII 70RV86E50Q (Pub Cid 71587778) and Sure CN 9587085 (Pub Cid 19793614) with higher predicted binding compared to Montelukast and Zafirlukast. It is shown that the compound Sure CN 9587085 showed appreciable ligand receptor interaction compared to UNII 70RV86E50Q. Thus, the compound Sure CN 9587085 is selected as a potent antagonist to cysteinyl leukotriene receptor 1 for further consideration in vitro and in vivo validation.     

The thermal properties of some nests of the Eurasian Tree Sparrow Passer montanus

Using an electronic apparatus simulating a bird roosting in a nest at night, we examined the insulating qualities of Eurasian Tree Sparrow (Passer montanus) nests built in nest boxes under winter conditions. Nests of different construction were compared with an empty box, and with roosting in open air. Energy savings in an empty box accounted for 18%, in boxes with incomplete nests for 23% and in boxes with complete nests up to 36%. The insulating value of nests mostly depended on their completeness and the proportion of feathers in the lining.     

The susceptibility of Proteus mirabilis strains isolated from white stork (Ciconia ciconia)

Proteus sp. rods are ubiquitous bacteria, widespread in the environment and classified also as opportunistic human pathogens. The aim of our study was to evaluate susceptibility of Proteus mirabilis strains isolated from white stork (Ciconia ciconia) regarding as his natural bacterial flora, compare and discuss their results with data obtained from scientific literature for clinical strains of the same species. Susceptibility of 59 P. mirabilis strains was estimated for 27 antimicrobials using disc-diffusion method and the ability to produce extended spectrum beta-lactamases was evaluated by double disc synergy test. Environmental P. mirabilis strains isolated from white stork were assessed as more susceptible to most of the examined antimicrobials and production of extended spectrum beta-lactamases was not noted amongst them.     

Relationship between arrival date, hatching date and breeding success of the white stork (Ciconia ciconia) in Slovakia

Changes in the spring arrival dates of migrant birds have been reported from a range of locations and many authors have focused on long-term trends and their relationship to temperature and other climatic events. Perhaps more importantly, changed arrival dates may have consequences for the breeding dates of birds which strongly influence breeding success. In this paper we take the opportunity provided by a monitoring scheme of the white stork (Ciconia ciconia) to examine several features of the timing of arrival and breeding in relation to chick production in Slovakia during the period 1978–2002. First arrival dates ranged from 5^th March to 30^th April, and hatching dates varied between 26^th April and 8^th July. Generally, early arriving pairs started breeding earlier and a shorter interval between the arrival of the first partner and breeding, expressed here as hatching date, resulted in higher breeding success.     

West Nile virus experimental evolution in vivo and the trade-off hypothesis

In nature, arthropod-borne viruses (arboviruses) perpetuate through alternating replication in vertebrate and invertebrate hosts. The trade-off hypothesis proposes that these viruses maintain adequate replicative fitness in two disparate hosts in exchange for superior fitness in one host. Releasing the virus from the constraints of a two-host cycle should thus facilitate adaptation to a single host. This theory has been addressed in a variety of systems, but remains poorly understood. We sought to determine the fitness implications of alternating host replication for West Nile virus (WNV) using an in vivo model system. Previously, WNV was serially or alternately passed 20 times in vivo in chicks or mosquitoes and resulting viruses were characterized genetically. In this study, these test viruses were competed in vivo in fitness assays against an unpassed marked reference virus. Fitness was assayed in chicks and in two important WNV vectors, Culex pipiens and Culex quinquefasciatus. Chick-specialized virus displayed clear fitness gains in chicks and in Cx. pipiens but not in Cx. quinquefasciatus. Cx. pipiens-specialized virus experienced reduced fitness in chicks and little change in either mosquito species. These data suggest that when fitness is measured in birds the trade-off hypothesis is supported; but in mosquitoes it is not. Overall, these results suggest that WNV evolution is driven by alternate cycles of genetic expansion in mosquitoes, where purifying selection is weak and genetic diversity generated, and restriction in birds, where purifying selection is strong.     

Experimental Passage of St. Louis Encephalitis Virus In Vivo in Mosquitoes and Chickens Reveals Evolutionarily Significant Virus Characteristics

St. Louis encephalitis virus (SLEV; Flaviviridae, flavivirus) was the major cause of epidemic flaviviral encephalitis in the U.S. prior to the introduction of West Nile virus (WNV) in 1999. However, outbreaks of SLEV have been significantly more limited then WNV in terms of levels of activity and geographic dispersal. One possible explanation for these variable levels of activity is that differences in the potential for each virus to adapt to its host cycle exist. The need for arboviruses to replicate in disparate hosts is thought to result in constraints on both evolution and host-specific adaptation. If cycling is the cause of genetic stability observed in nature and arboviruses lack host specialization, then sequential passage should result in both the accumulation of mutations and specialized viruses better suited for replication in that host. Previous studies suggest that WNV and SLEV differ in capacity for both genetic change and host specialization, and in the costs each accrues from specializing. In an attempt to clarify how selective pressures contribute to epidemiological patterns of WNV and SLEV, we evaluated mutant spectra size, consensus genetic change, and phenotypic changes for SLEV in vivo following 20 sequential passages via inoculation in either Culex pipiens mosquitoes or chickens. Results demonstrate that the capacity for genetic change is large for SLEV and that the size of the mutant spectrum is host-dependent using our passage methodology. Despite this, a general lack of consensus change resulted from passage in either host, a result that contrasts with the idea that constraints on evolution in nature result from host cycling alone. Results also suggest that a high level of adaptation to both hosts already exists, despite host cycling. A strain significantly more infectious in chickens did emerge from one lineage of chicken passage, yet other lineages and all mosquito passage strains did not display measurable host-specific fitness gains. In addition, increased infectivity in chickens did not decrease infectivity in mosquitoes, which further contrasts the concept of fitness trade-offs for arboviruses.