Landscape pattern and genetic structure of a yellow-necked mouse <Emphasis Type="Italic">Apodemus flavicollis</Emphasis> population in north-eastern Poland

Reduced connectivity among local populations inhabiting a spatially heterogeneous landscape may restrict gene flow and thus contribute to diminished genetic variation within a population. The aim of this study was to determine the role of geographic distance and habitat barriers in developing genetic structure of a yellow-necked mouse Apodemus flavicollis (Melchior, 1834) population, taking into consideration the spatial organization of the landscape. A field study was carried out in two plots located in NE Poland that differed considerably in terms of the scale of habitat fragmentation: (1) a continuous forest complex, and (2) a mosaic of smaller forest habitats. The plots were separated by a water barrier comprised of a chain of lakes. DNA samples from a total of 654 individuals were examined by microsatellite analysis (5 loci). The results showed that the yellow-necked mouse population was characterized by a poorly pronounced genetic structure throughout the study area, although the statistical significance of F _ST for most location pairs indicated that gene flow in the area was not free. The division of the mouse population into three genetically distinct groups clearly demonstrated the significant role of water bodies as a natural barrier effectively hindering free movement of animals and thus gene flow. Analysis of the genetic structure of the mouse population throughout the study area and also within the distinguished groups indicated that the entire study population may be considered as a single metapopulation. Our results suggest that geographic distance alone is not the predominant factor affecting the genetic structure of population, but in the mosaic landscape the relative isolation of individual forest fragments, and barriers hindering movements of individuals and limiting gene flow among local populations played a much more important role.     

Effect of addition of buserelin acetate to the extender on motility and viability of bovine spermatozoa

The present study was aimed to determine the effect of GnRH analog (buserelin acetate) on the quality of bovine spermatozoa stored at 16°?C for 24?h. Semen collected in the summer season from June to September from healthy Polish Holstein–Friesian bulls. Ejaculates were centrifuged, divided and diluted to the final concentration of 240?×?10⁶ spermatozoa/mL using animal protein–free commercial BIOXcell^® extender (IMV Technologies, L’aigle, France) (Control) or with BIOXcell^® extender supplemented with buserelin acetate and stored 0, 8 and 24?h. Sperm motility parameters analysis was performed using a computer-assisted sperm analysis (CASA) system. The viability of spermatozoa was performed using flow cytometer. The addition of buserelin acetate to BIOXcell^® extender did positively affect the total motility (was higher in the observed samples with the addition of 2?µg/mL and 4?µg/mL than in the control group), progressive motile (forward progressing sperm was significantly increased (p?<?0.05) over the control group at the 0?h and 8?h of incubation following the supplementation of 2, 4 and 8?μg/mL buserelin acetate) and viability of spermatozoa (the number of live spermatozoa was significantly higher (p?<?0.05) in 2?µg/mL and 4?µg/mL samples with buserelin acetate at 8th hour of incubation and in sample with 4?µg/mL at 24th hour of incubation compared to the control group). We recommend adding 4?µg/mL to the extender to improve the quality of bovine semen.     

Exploring the anti-apoptotic role of HAX-1 versus BCL-XL in cytokine-dependent bone marrow-derived cells from mice

HS-1-associated protein X-1 (HAX-1) is a multi-functional protein that has been implicated in the regulation of apoptosis, cell motility and calcium homeostasis. In the present study, we set out to assess the postulated functional resemblance of HAX-1 to the BCL-2 family of anti-apoptotic proteins using non-transformed, cytokine-dependent murine bone marrow cells as a model system. BCL-X_L, but not HAX-1 protected against cytokine withdrawal-induced apoptosis while HAX-1 and BCL-X_L significantly reduced thapsigargin-triggered (calcium-dependent) apoptosis. The data argue in favor of cell type- and stimulus-specific roles of HAX-1 in regulation of cell survival.     

Opiate activity of a bone marrow humoral factor which stimulates antibody production

The radioceptor method was used to demonstrate that humoral factor of the bone marrow, a stimulant of antibody production (SAP), contains substances that competitively remove 3H-morphine and 3H-met-enkephalin from opiate receptors of the rat brain, and 3H-met-enkephalin from specific binding sites on human lymphocytes. Comparison of the magnitudes EC50 SAP obtained during the removal of labeled opiates allows a suggestion to be made that opiates contained by the preparation under study have a greater capability to interact with delta-type opiate receptors rather than with those of the mu-type.     

Physical activity and risk of rheumatoid arthritis in women: a population-based prospective study

IntroductionOnly one study has analysed the association between exercise and development of rheumatoid arthritis (RA), showing no association. Aim of this paper was to evaluate the association of physical activity in all its aspect with RA.MethodsTo examine this association, middle age and elderly women from the Swedish Mammography Cohort, a population-based prospective study, were analysed. Data on physical activity were collected in 1997 by self-administrated food-frequency questionnaire. Risk of RA associated with physical activity was estimated using Cox proportional hazard regression models.ResultsAmong 30,112 women born between 1914 and 1948 followed-up from January 1, 2003 to December 31, 2010, 201 RA cases were identified (226,477 person-years). There was a statistically significant 35% lower risk of RA (relative risk (RR), 0.65; 95% confidence interval (CI), 0.43-0.96) among women in the highest category of leisure-time activity (combining more than 20 minute per day of walking/bicycling (median 40–60 minute per day) and more than 1 hour per week of exercise (median 2–3 hours per week)) as compared to women in the lowest category (less than 20 minute per day of walking/bicycling and less than 1 hour per week of exercise). A non-statistically significant decreased risk was observed for household work (−32%) and work/occupation (−15%), while an increased risk was observed for leisure-time physical inactivity (+27%). Daily energy expenditure was not associated with risk of RA.ConclusionsThis prospective population-based cohort study of women supports the hypothesis that physical activity can be a protective factor in the etiology of rheumatoid arthritis. Our results add to accumulated evidence on benefits of modifiable leisure-time physical activity for prevention of many other chronic diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0560-2) contains supplementary material, which is available to authorized users.