Search results for "allocation"
showing 10 items of 538 documents
No room for males in caves: Female-biased sex ratio in subterranean amphipods of the genus Niphargus.
2021
Sex allocation theory predicts that the proportion of daughters to sons will evolve in response to ecological conditions that determine the costs and benefits of producing each sex. All else being equal, the adult sex ratio (ASR) should also vary with ecological conditions. Many studies of subterranean species reported female-biased ASR, but no systematic study has yet been conducted. We test the hypothesis that the ASR becomes more female-biased with increased isolation from the surface. We compiled a data set of ASRs of 35 species in the subterranean amphipod Niphargus, each living in one of three distinct habitats (surface-subterranean boundary, cave streams, phreatic lakes) representing…
Regular physical exercise before entering military service may protect young adult men from fatigue fractures
2019
Background Bone stress fractures are overuse injuries commonly encountered in sports and military medicine. Some fatigue fractures lead to morbidity and loss of active, physically-demanding training days. We evaluated the incidence, anatomical location, risk factors, and preventive measures for fatigue fractures in young Finnish male conscripts. Methods Five cohorts of 1000 men performing military service, classified according to birth year (1969, 1974, 1979, 1984, 1989), were analysed. Each conscript was followed for his full military service period (180 days for conscripts with rank and file duties, 270 days for those with special training, 362 days for officers and highly trained conscri…
Angiotensin II-induced vascular dysfunction depends on interferon-γ-driven immune cell recruitment and mutual activation of monocytes and NK-cells.
2013
Objective— Immune cells contribute to angiotensin II (ATII)–induced vascular dysfunction and inflammation. Interferon-γ (IFN-γ), an inflammatory cytokine exclusively produced by immune cells, seems to be involved in ATII-driven cardiovascular injury, but the actions and cellular source of IFN-γ remain incompletely understood. Approach and Results— IFN-γ −/− and Tbx21 −/− mice were partially protected from ATII-induced (1 mg/kg per day of ATII, infused subcutaneously by miniosmotic pumps) vascular endothelial and smooth muscle dysfunction, whereas mice overexpressing IFN-γ showed constitutive vascular dysfunction. Absence of T-box expressed in T cells (T-bet), the IFN-γ transcription factor…
Mechanisms underlying the diabetes-induced hyporeactivity of the rabbit carotid artery to atrial natriuretic peptide
2010
Abstract Atrial natriuretic peptide (ANP) plays an important role in the pathophysiology of the vascular complications in diabetes. The working hypothesis was that diabetes might modify the vascular actions of ANP in isolated rabbit carotid arteries and the mechanisms involved in these actions. ANP (10 −12 –10 −7 M) induced a relaxation of precontracted carotid arteries, which was lower in diabetic than in control rabbits. In arteries from both groups of animals, endothelium removal increased the ANP-induced relaxation. Isatin inhibited the relaxation to ANP both in arteries with and without endothelium. Carotid arteries from diabetic rabbits showed a decreased natriuretic peptide receptor…
Changes in lipid metabolism and antioxidant defense status in spontaneously hypertensive rats and Wistar rats fed a diet enriched with fructose and s…
2005
Abstract Objective Larger doses of fructose and saturated fat have been associated with oxidative stress and development of hypertension. The effects of modest amounts of fructose and saturated fatty acids on oxidative stress are unknown. Methods To increase knowledge on this question, 10-wk-old spontaneously hypertensive rats and Wistar rats were fed for 8 wk with a control diet or an experimental diet enriched with fructose (18%) and saturated fatty acids (11%; FS diet). The total antioxidant status of organs and red blood cells was assayed by monitoring the rate of free radical-induced red blood cell hemolysis. Sensitivity of very low-density lipoprotein and low-density lipoprotein (VLDL…
Similar rewarding effects of testosterone in mice rated as short and long attack latency individuals.
2002
An attempt was made to confirm and extend the findings of an earlier study on the rewarding properties of testosterone in male mice using conditioned place preference (CPP). Previous results had only partially demonstrated such an effect because the reinforcement depended on environmental cues such as the colour of the compartment. High individual variability was evident, suggesting that basal levels of aggressiveness may modulate such effects. Animals were pre-screened for aggressive behaviour and allocated to short and long attack latency (SAL and LAL) categories. Five days later the CPP procedure started. This involved pre-conditioning tests, conditioning and post-conditioning tests. SAL…
Retinal light sensitivity of the central visual field among 70- to 81-year-old men and women.
2009
Retinal light sensitivity of the central visual field (0-30 degrees), visual acuity, intraocular pressure and pupillary size were screened in 42 men and 42 women aged 70 to 81 years. The subjects were randomly selected from the population register. After excluding the diagnosed glaucoma cases, the men had better visual field light sensitivity values than the women. They also had lower intraocular pressure and a wider pupillary diameter than the women, whereas there were no differences in visual acuity between the sexes. When the effect of pupillary size was controlled the differences in visual field light sensitivity values between men and women became non-significant. Among these elderly p…
A genetic variant of the atrial natriuretic peptide gene is associated with cardiometabolic protection in the general community
2011
Objectives We sought to define the cardiometabolic phenotype associated with rs5068, a genetic variant of the atrial natriuretic peptide (ANP) gene. Background The ANP and B-type natriuretic peptide play an important role in cardiorenal homeostasis but also exert metabolic actions. Methods We genotyped 1,608 randomly selected residents from Olmsted County, Minnesota. Subjects were well-characterized. Results Genotype frequencies were: AA 89.9%, AG 9.7%, and GG 0.4%; all subsequent analyses were AA versus AG+GG. The G allele was associated with increased plasma levels of N-terminal pro-atrial natriuretic peptide (p = 0.002), after adjustment for age and sex. The minor allele was also associa…
Altered REDD1, myostatin, and Akt/mTOR/FoxO/MAPK signaling in streptozotocin-induced diabetic muscle atrophy
2011
Type 1 diabetes, if poorly controlled, leads to skeletal muscle atrophy, decreasing the quality of life. We aimed to search highly responsive genes in diabetic muscle atrophy in a common diabetes model and to further characterize associated signaling pathways. Mice were killed 1, 3, or 5 wk after streptozotocin or control. Gene expression of calf muscles was analyzed using microarray and protein signaling with Western blotting. We identified translational repressor protein REDD1 (regulated in development and DNA damage responses) that increased seven- to eightfold and was associated with muscle atrophy in diabetes. The diabetes-induced increase in REDD1 was confirmed at the protein level. …
Effects of oxotremorine and physostigmine on the inhibitory avoidance impairment produced by amitriptyline in male and female mice.
2009
We have previously observed that amitriptyline and other antidepressants produce impairing effects on inhibitory avoidance (also called passive avoidance) in mice of both sexes. In the present study we investigated the involvement of the cholinergic system in the inhibitory avoidance impairment produced by acute amitriptyline in male and female CD1 mice. For this purpose, the effects on said task of acute i.p. administration of several doses of amitriptyline, either alone or in combination with the cholinergic agonists oxotremorine and physostigmine, were evaluated. Pre-training administration of 5, 7.5, 10 or 15 mg/kg of amitriptyline produced a significant impairment of inhibitory avoidan…