536 research outputs found
The Acute Effect of Magnesium Supplementation on Endothelial Function: A randomized cross-over pilot study
: Magnesium (Mg) deficiency might be a catalyst in the process of endothelial dysfunction, an early event in the pathogenesis of atherosclerosis. The aim of this study was to determine the acute effect of an oral Mg supplement as compared to control on endothelial function assessed by flow-mediated dilatation (FMD). Nineteen participants (39 years, body mass index (BMI) 22.9 kg/m2 ) completed this randomized cross-over study. Blood pressure (BP) and FMD were measured and blood samples were taken before participants drank 200 mL water, with or without an over the counter Mg supplement (450 mg and 300 mg for men and women). Measurements were repeated at 60 and 120 min. There was a statistically significant two-way interaction between treatment and time on serum Mg (p = 0.037). A difference of −0.085 mm in FMD was observed 60-min post drink in the control group, as compared to baseline FMD, and no difference was observed in the supplement group as compared to baseline. Despite the non-significant interaction between treatment and time on FMD, once adjusted for baseline, the difference seen in the control group and the lack of change in the supplement group at 60 min post-drink suggests that Mg might attenuate the reduction in FMD post-prandiall
Catecholamine stress alters neutrophil trafficking and impairs wound healing by β2-adrenergic receptor-mediated upregulation of IL-6.
Stress-induced hormones can alter the inflammatory response to tissue injury; however, the precise mechanism by which epinephrine influences inflammatory response and wound healing is not well defined. Here we demonstrate that epinephrine alters the neutrophil (polymorphonuclear leukocyte (PMN))-dependent inflammatory response to a cutaneous wound. Using noninvasive real-time imaging of genetically tagged PMNs in a murine skin wound, chronic, epinephrine-mediated stress was modeled by sustained delivery of epinephrine. Prolonged systemic exposure of epinephrine resulted in persistent PMN trafficking to the wound site via an IL-6-mediated mechanism, and this in turn impaired wound repair. Further, we demonstrate that β2-adrenergic receptor-dependent activation of proinflammatory macrophages is critical for epinephrine-mediated IL-6 production. This study expands our current understanding of stress hormone-mediated impairment of wound healing and provides an important mechanistic link to explain how epinephrine stress exacerbates inflammation via increased number and lifetime of PMNs
Non-invasive methods of identifying and tracking wild squid
The ability to identify individual free-living animals in the field is an important method for studying their behavior. Apart from invasive external or internal tags, which may cause injury or abnormal behavior, most cephalopods cannot be tagged, as their skin is too soft and delicate for tag retention. Additionally, cephalopods remove many types of tags. However, body markings have been successfully used as a non invasive method to identify individuals of many different species of animals, including whale sharks, grey whales, seals, and zebras. We developed methods to sex and individually identify Caribbean reef squid, Sepiotheuthis sepioidea. Males showed distinct bright dots on their fins on a Basic Brown background and have a light line at the fin edge while the females had a gradual transition from Brown to Pale towards the edge of their fins without showing distinct fin-dots or lines. In the field we used four characters to distinguish individual S. sepioidea from each other – sex, relative size to each other, scars, and patterns of light-colored dots on their mantles and fins. These dot patterns are individually unique and constant in location through time. Observations in the field were backed up by an image database using illustrations and photography
Non-invasive methods of identifying and tracking wild squid
The ability to identify individual free-living animals in the field is an important method for studying their behavior. Apart from invasive external or internal tags, which may cause injury or abnormal behavior, most cephalopods cannot be tagged, as their skin is too soft and delicate for tag retention. Additionally, cephalopods remove many types of tags. However, body markings have been successfully used as a non invasive method to identify individuals of many different species of animals, including whale sharks, grey whales, seals, and zebras. We developed methods to sex and individually identify Caribbean reef squid, Sepiotheuthis sepioidea. Males showed distinct bright dots on their fins on a Basic Brown background and have a light line at the fin edge while the females had a gradual transition from Brown to Pale towards the edge of their fins without showing distinct fin-dots or lines. In the field we used four characters to distinguish individual S. sepioidea from each other – sex, relative size to each other, scars, and patterns of light-colored dots on their mantles and fins. These dot patterns are individually unique and constant in location through time. Observations in the field were backed up by an image database using illustrations and photography
Mucin 1 (MUC1) is a novel partner for MAL2 in breast carcinoma cells
Background: The MAL2 gene, encoding a four-transmembrane protein of the MAL family, is amplified and overexpressed in breast and other cancers, yet the significance of this is unknown. MAL-like proteins have trafficking functions, but their molecular roles are largely obscure, partly due to a lack of known binding partners
Porphyrin-magnetite nanoconjugates for biological imaging
<p>Background: The use of silica coated magnetic nanoparticles as contrast agents has resulted in the production of
highly stable, non-toxic solutions that can be manipulated via an external magnetic field. As a result, the
interaction of these nanocomposites with cells is of vital importance in understanding their behaviour and
biocompatibility. Here we report the preparation, characterisation and potential application of new “two-in-one”
magnetic fluorescent nanocomposites composed of silica-coated magnetite nanoparticles covalently linked to a
porphyrin moiety.</p>
<p>Method: The experiments were performed by administering porphyrin functionalised silica-coated magnetite
nanoparticles to THP-1 cells, a human acute monocytic leukaemia cell line. Cells were cultured in RPMI 1640
medium with 25 mM HEPES supplemented with heat-inactivated foetal bovine serum (FBS).</p>
<p>Results: We have synthesised, characterised and analysed in vitro, a new multimodal (magnetic and fluorescent)
porphyrin magnetic nanoparticle composite (PMNC). Initial co-incubation experiments performed with THP-1
macrophage cells were promising; however the PMNC photobleached under confocal microscopy study. bmercaptoethanol (b-ME) was employed to counteract this problem and resulted not only in enhanced
fluorescence emission, but also allowed for elongated imaging and increased exposure times of the PMNC in a
cellular environment.</p>
<p>Conclusion: Our experiments have demonstrated that b-ME visibly enhances the emission intensity. No deleterious
effects to the cells were witnessed upon co-incubation with b-ME alone and no increases in background
fluorescence were recorded. These results should present an interest for further development of in vitro biological
imaging techniques.</p>
Comparison of gait patterns between young and elderly women: an examination of coordination
This study investigated intralimb coordination during walking in Young and Elderly women using the theoretical model of dynamical systems. Twenty females, ten Young (M age = 24.6 yrs, SD = 3.2 yrs), and ten Elderly (M age = 73.7 yrs, SD = 4.9 yrs), were videotaped during free speed gait and gait perturbed by an ankle weight. Two parameters, one describing the phasing relationship between segments (mean absolute relative phase) and the other the variability of this relationship (deviation in phase), were calculated from the kinematics. Two-way ANOVA (age and weight) with repeated measures on weight indicated that during the braking period the weight increased the mean absolute relative phase between the shank and the thigh and decreased it between the foot and the shank. The Elderly women had significantly smaller values for the mean absolute relative phase between the shank and the thigh during the braking period. For the same period, deviation in phase increased for the segmental relationship between the shank and the thigh. The findings suggest that changes in intralimb coordination take place due to asymmetrical weighting and the aging process. These changes are mostly present during the braking period
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PTSD and DNA Methylation in Select Immune Function Gene Promoter Regions: A Repeated Measures Case-Control Study of U.S. Military Service Members
Background: The underlying molecular mechanisms of PTSD are largely unknown. Distinct expression signatures for PTSD have been found, in particular for immune activation transcripts. DNA methylation may be significant in the pathophysiology of PTSD, since the process is intrinsically linked to gene expression. We evaluated temporal changes in DNA methylation in select promoter regions of immune system-related genes in U.S. military service members with a PTSD diagnosis, pre- and post-diagnosis, and in controls. Methods: Cases (n = 75) had a post-deployment diagnosis of PTSD in their medical record. Controls (n = 75) were randomly selected service members with no PTSD diagnosis. DNA was extracted from pre- and post-deployment sera. DNA methylation (%5-mC) was quantified at specific CpG sites in promoter regions of insulin-like growth factor 2 (IGF2), long non-coding RNA transcript H19, interleukin-8 (IL8), IL16, and IL18 via pyrosequencing. We used multivariate analysis of variance and generalized linear models to calculate adjusted means (adjusted for age, gender, and race) to make temporal comparisons of %5-mC for cases (pre- to post-deployment) versus controls (pre- to post-deployment). Results: There were significant differences in the change of %5-mC pre- to post-deployment between cases and controls for H19 (cases: +0.57%, controls: −1.97%; p = 0.04) and IL18 (cases: +1.39%, controls: −3.83%; p = 0.01). For H19 the difference was driven by a significant reduction in %5-mC among controls; for IL18 the difference was driven by both a reduction in %5-mC among controls and an increase in %5-mC among cases. Stratified analyses revealed more pronounced differences in the adjusted means of pre-post H19 and IL18 methylation differences for cases versus controls among older service members, males, service members of white race, and those with shorter deployments (6–12 months). Conclusion: In the study of deployed personnel, those who did not develop PTSD had reduced %5-mC levels of H19 and IL18 after deployment, while those who did develop PTSD had increased levels of IL18. Additionally, pre-deployment the people who later became cases had lower levels of IL18 %5-mC compared with controls. These findings are preliminary and should be investigated in larger studies
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