305 research outputs found
The Effects of Short Work Versus Longer Work Periods Within Intermittent Exercise on VO2 Kinetics, Muscle Deoxygenation and Energy System Contribution
The purpose of this study was to investigate the kinetic response of oxygen uptake (V̇O2)and muscle deoxygenation (HHb) in males (24 yr±3, n = 10) to identical heavy intensity continuous (CONT), and intermittent work; 25 s (25 s work: 3 s recovery (20W)), and 10 s (10 s work: 3 s recovery (20W)), were compared. The τV̇O2 were similar in all conditions (CONT: 44.2 s±9; 25 s: 38.9 s±10; 10 s: 39.4 s±8, p \u3e 0.05), whereas the HHb/ V̇O2 overshoot decreased across conditions (p \u3c 0.05). The increased frequency of recovery periods slowed V̇O2p kinetics suggesting increased activity of the creatine kinase enzyme and increased ATP-PCr contribution, while reducing glycolytic and oxidative phosphorylation contributions to perform the identical work rate. Enhanced microvascular blood flow facilitated an accelerated matching of total O2 delivery to O2 utilization as well with increased recovery periods
Effects of LL-37 on Gingival Fibroblasts: A Role in Periodontal Tissue Remodeling?
Mounting evidence suggests that the host defence peptide, LL-37, plays a role in both inflammation and in wound healing; however, the role of this peptide in the remodeling and maintenance of oral tissues is not yet fully understood. Fibroblasts are the most abundant cell type within the periodontal tissues, and gingival fibroblasts play an important role in maintaining and repairing the gingival tissues which are constantly exposed to external insults. In this study we examined the direct effects of LL-37 treatment on gingival fibroblasts and found that LL-37 significantly increased secretion of both interleukin 8 (IL-8) and IL-6 from these cells. LL-37 tended to decrease matrix metalloproteinase (MMP) activity in gingival fibroblasts, but this decrease did not reach statistical significance. LL-37 significantly increased tissue inhibitor of metalloproteinase-1 (TIMP-1) production by gingival fibroblasts, but had no significant effect on TIMP-2 levels. LL-37 was also shown to significantly increase production of basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), and keratinocyte growth factor (KGF) in gingival fibroblasts. Taken together, these results suggest an important role for the host defence peptide, LL-37, in modulating the fibroblast response to remodeling in periodontal tissues
On the embeddability of certain infinitely divisible probability measures on Lie groups
We describe certain sufficient conditions for an infinitely divisible
probability measure on a class of connected Lie groups to be embeddable in a
continuous one-parameter convolution semigroup of probability measures.
(Theorem 1.3). This enables us in particular to conclude the embeddability of
all infinitely divisible probability measures on certain Lie groups, including
the so called Walnut group (Corollary 1.5). The embeddability is concluded also
under certain other conditions (Corollary 1.4 and Theorem 1.6).Comment: 24 page
Bridging the gap: an exploration of the use and impact of positive action in the UK
Despite laws in Britain permitting limited positive action initiatives to combat disadvantage faced by minority groups in employment since the mid-1970s, the subject has notoriously been a neglected and highly controversial area in the UK. Notwithstanding the potential provided by sections 158 and 159 of the Equality Act 2010, it still appears that organisations prefer to steer clear of this opportunity to address disadvantage suffered by protected groups. Whilst there is a body of work considering the theoretical importance of positive action in the UK, there is a lack of empirical exploration of the practical implications of these provisions. This paper will provide a brief overview of the theoretical context and current positive action legislative provisions within the UK. In light of this context, the early findings of a small-scale qualitative study carried out by the authors will be discussed looking at the experiences of a purposive sample of public and private employers in relation to the positive action provisions of the Equality Act 2010. Early research findings suggest that whilst there was a clear willingness and openness by employers to use of outreach measures in order to redress disadvantage, there was evident wariness regarding a move towards preferential treatment as expounded by section 159. Whilst respondents appeared to appreciate the business case for and utility of the positive action measures under section 158, there was far less enthusiasm for more direct preferential treatment, with many respondents raising serious concerns regarding this. These concerns often reflected a highly sensitive risk-based approach towards any action that could expose their organisation to the possibility of “reverse discrimination”
Effective In Vivo Topical Delivery of siRNA and Gene Silencing in Intact Corneal Epithelium Using a Modified Cell-Penetrating Peptide
Autosomal dominantly inherited genetic disorders such as corneal dystrophies are amenable to allele-specific gene silencing with small interfering RNA (siRNA). siRNA delivered to the cornea by injection, although effective, is not suitable for a frequent long-term treatment regimen, whereas topical delivery of siRNA to the cornea is hampered by the eye surface's protective mechanisms. Herein we describe an attractive and innovative alternative for topical application using cell-penetrating peptide derivatives capable of complexing siRNA non-covalently and delivering them into the cornea. Through a rational design approach, we modified derivatives of a cell-penetrating peptide, peptide for ocular delivery (POD), already proved to diffuse into the corneal layers. These POD derivatives were able to form siRNA-peptide complexes (polyplexes) of size and ζ-potential similar to those reported able to undergo cellular internalization. Successful cytoplasmic release and gene silencing in vitro was obtained when an endosomal disruptor, chloroquine, was added. A palmitoylated-POD, displaying the best delivery properties, was covalently functionalized with trifluoromethylquinoline, an analog of chloroquine. This modified POD, named trifluoromethylquinoline-palmitoyl-POD (QN-Palm-POD), when complexed with siRNA and topically applied to the eye in vivo, resulted in up to 30% knockdown of luciferase reporter gene expression in the corneal epithelium. The methods developed within represent a valid standardized approach that is ideal for screening of a range of delivery formulations
Biodentine Reduces Tumor Necrosis Factor Alpha-induced TRPA1 Expression in Odontoblastlike Cells
International audienceIntroduction: The transient receptor potential (TRP) ion channels have emerged as important cellular sensors in both neuronal and non-neuronal cells, with TRPA1 playing a central role in nociception and neurogenic inflammation. The functionality of TRP channels has been shown to be modulated by inflammatory cytokines. The aim of this study was to investigate the effect of inflammation on odontoblast TRPA1 expression and to determine the effect of Biodentine (Septodent, Paris, France) on inflammatory-induced TRPA1 expression. Methods: Immunohistochemistry was used to study TRPA1 expression in pulp tissue from healthy and carious human teeth. Pulp cells were differentiated to odontoblastlike cells in the presence of 2 mmol/L beta-glycerophosphate, and these cells were used in quantitative polymerase chain reaction, Western blotting, calcium imaging, and patch clamp studies. Results: Immunofluorescent staining revealed. TRPA1 expression in odontoblast cell bodies and odontoblast processes, which was more intense in carious versus healthy teeth. TRPA1 gene expression was induced in cultured odontoblastlike cells by tumor necrosis factor alpha, and this expression was significantly reduced in the presence of Biodentine. The functionality of the TRPA1 channel was shown by calcium microfluorimetry and patch clamp recording, and our results showed a significant reduction in tumor necrosis factor alpha induced TRPA1 responses after Biodentine treatment. Conclusions: In conclusion, this study showed TRPA1 to be modulated by caries-induced inflammation and that Biodentine reduced TRPA1 expression and functional responses
- …