Search results for "spring"
showing 10 items of 600 documents
Murine tissue factor disulfide mutation causes a bleeding phenotype with sex specific organ pathology and lethality.
2019
Tissue factor is highly expressed in sub-endothelial tissue. The extracellular allosteric disulfide bond Cys186-Cys209 of human tissue factor shows high evolutionary conservation and in vitro evidence suggests that it significantly contributes to tissue factor procoagulant activity. To investigate the role of this allosteric disulfide bond in vivo, we generated a C213G mutant tissue factor mouse by replacing Cys213 of the corresponding disulfide Cys190-Cys213 in murine tissue factor. A bleeding phenotype was prominent in homozygous C213G tissue factor mice. Pre-natal lethality of 1/3rd of homozygous offspring was observed between E9.5 and E14.5 associated with placental hemorrhages. After b…
N-3 fatty acids modulate Th1 and Th2 dichotomy in diabetic pregnancy and macrosomia.
2006
We assessed the implication of Th (helper)-cells and the modulation of the Th1/Th2 dichotomy by n-3 polyunsaturated fatty acids (PUFA) in type I diabetic pregnancy (DP) and macrosomia. Female gestant rats fed a standard diet or n-3 PUFA regimen were rendered diabetic by administration of five low doses of streptozotocin. The macrosomic (MAC) offspring were sacrificed at the age of 90 days. The mRNAs of IL-2 and IFN-gamma (Th1 cytokines) and IL-4 (Th2 cytokine) were downregulated in the pancreas and spleen of diabetic pregnant rats. The levels of IL-10 mRNA, another Th2 cytokine, were unchanged in the spleen or upregulated in the pancreas of these animals. Feeding an n-3 PUFA diet to rats wi…
Post-weaning xenohormone intake affects adult rat submandibular gland in a sex-dependent manner
2018
International audience; OBJECTIVES: We previously reported that maternal exposure to genistein, vinclozolin, ingested alone or in combination, affects submandibular salivary glands of rats' offspring's. Here, we investigated the responsiveness of submandibular gland when such xenohormone exposure occurs later in life. MATERIALS AND METHODS: Chemicals were given orally to male and female Wistar rats (1mg/kg body weight per day), from weaning to adulthood. Submandibular glands and plasma were collected at postnatal day 100 for histological and molecular analysis. RESULTS: Whereas no effect was observed in females, increases in granular convoluted tubules area coupled with a modification of sa…
Perinatal xenohormone exposure impacts sweet preference and submandibular development in male rats.
2013
Objective To determine the effect of perinatal exposure to low doses of genistein and/or vinclozolin on submandibular salivary gland (SSG) development in juvenile and adult male rats and to establish a link with sweet preference. Material and Methods Female rats received orally (1 mg kg−1 body weight/day) genistein and vinclozolin, alone or in combination, from the first gestational day up to weaning. Sweet preference was assessed at weaning and in adulthood in male offspring; submandibular glands were then collected to study the morphogenesis and mRNA expression of steroid receptors, growth factors and taste related proteins. Results Exposure to genistein and/or vinclozolin resulted in a h…
Single, intense prenatal stress decreases emotionality and enhances learning performance in the adolescent rat offspring: Interaction with a brief, d…
2006
Perinatal manipulations can lead to neurobehavioural changes in the progeny. In this study we investigated, in adolescent male rat offspring, the consequences of a single, intense prenatal stress induced by a 120 min-maternal immobilization at gestational day 16, and of a daily, brief maternal separation from postnatal day 2 until 21, on: unconditioned fear/anxiety-like behaviour in open field and in elevated plus-maze; learning performance in the "Can test", a non-aversive spatial and tactile/visual task; corticosterone plasma levels under basal and stress-induced conditions. Our results indicate that both prenatal stress and maternal separation procedures decrease emotionality and enhance…
Effects of feminizing microsporidia on the masculinizing function of the androgenic gland in Gammarus duebeni
2013
Feminizing parasites enhance their vertical transmission to the host offspring by converting genetic male hosts into phenotypic females. Crustacea are the only invertebrates where sexual differentiation is controlled by a specialised endocrine organ, the androgenic gland, rather than by the gonads. We showed that a feminizing microsporidian Microsporidium sp. inhibits androgenic gland differentiation. We investigated the effect of Microsporidium sp. and a second feminizing microsporidium, Nosema granulosis, on the masculinizing function of the androgenic gland in Gammarus duebeni. Androgenic gland implants had a masculinizing effect on the sexual characteristics and sexual behaviour of reci…
Maternal overnutrition programs hedonic and metabolic phenotypes across generations through sperm tsRNAs
2019
There is a growing body of evidence linking maternal overnutri-tion to obesity and psychopathology that can be conserved acrossmultiple generations. Recently, we demonstrated in a maternalhigh-fat diet (HFD; MHFD) mouse model that MHFD inducedenhanced hedonic behaviors and obesogenic phenotypes thatwere conserved across three generations via the paternal lineage,which was independent of sperm methylome changes. Here, weshow that sperm tRNA-derived small RNAs (tsRNAs) partly contrib-ute to the transmission of such phenotypes. We observe increasedexpression of sperm tsRNAs in the F1 male offspring born to HFD-exposed dams. Microinjection of sperm tsRNAs from the F1-HFDmale into normal zygotes…
Genetic compatibility and sexual selection
2005
In a recent review in TREE [1], Mays and Hill discuss the interface between sexual selection for good genes (i.e. female choice based on traits indicating heritable fitness) and sexual selection for genetic compatibility (i.e. how well the genes of the parents function together in their offspring). We feel that the scope of their contribution is somewhat limited, primarily because they implicitly equate genetic compatibility with genetic dissimilarity. Compatibility does, however, not equal dissimilarity.
Comparison of spring characteristics of titanium-molybdenum alloy and stainless steel
2017
Background Titanium-molybdenum alloy (TMA) and stainless steel (SS) wires are commonly used in orthodontics as arch-wires for tooth movement. However, plastic deformation phenomenon in these arch-wires seems to be a major concern among orthodontists. This study aimed to compare the mechanical properties of TMA and SS wires with different dimensions. Material and Methods Seventy-two wire samples (36 TMA and 36 SS) of three different sizes (19×25, 17×25 and 16×22) were analyzed in vitro, with 12 samples in each group. Various mechanical properties of the wires, including spring-back, bending moment and stiffness were determined using a universal testing machine. Student’s t-test showed statis…
Effect of temperature on the orthodontic clinical applications of NiTi closed-coil springs
2013
NiTi spring coils were used to obtain large deformation under a constant force. The device consists on a NiTi coil spring, superelastic at body temperature, in order to have a stress plateau during the austenitic retransformation during the unloading. The temperature variations induced changes in the spring force. Objectives: The aim of this study is to investigate the effect of the temperature variations in the spring forces and corrosion behaviour simulating the ingestion hot/cold drinks and food. Study D esign: The springs were subjected to a tensile force using universal testing machine MTS-Adamel (100 N load cell). All tests were performed in artificial saliva maintained at different t…