800 research outputs found
Hyaluronan Synthase Elevation in Metastatic Prostate Carcinoma Cells Correlates with Hyaluronan Surface Retention, a Prerequisite for Rapid Adhesion to Bone Marrow Endothelial Cells
Bone marrow is the primary site of metastasis in patients with advanced stage prostate cancer. Prostate carcinoma cells metastasizing to bone must initially adhere to endothelial cells in the bone marrow sinusoids. In this report, we have modeled that interaction in vitro using two bone marrow endothelial cell (BMEC) lines and four prostate adenocarcinoma cell lines to investigate the adhesion mechanism. Highly metastatic PC3 and PC3M-LN4 cells were found to adhere rapidly and specifically (70-90%) to BMEC-1 and trHBMEC bone marrow endothelial cells, but not to human umbilical vein endothelial cells (15-25%). Specific adhesion to BMEC-1 and trHBMEC was dependent upon the presence of a hyaluronan (HA) pericellular matrix assembled on the prostate carcinoma cells. DU145 and LNCaP cells were only weakly adherent and retained no cell surface HA. Maximal BMEC adhesion and RA encapsulation were associated with high levels of HA synthesis by the prostate carcinoma cells. Up-regulation of HA synthase isoforms Has2 and Has3 relative to levels expressed by normal prostate corresponded to elevated HA synthesis and avid BMEC adhesion. These results support a model in which tumor cells with up-regulated HA synthase expression assemble a cell surface hyaluronan matrix that promotes adhesion to bone marrow endothelial cells. This interaction could contribute to preferential bone metastasis by prostate carcinoma cells
Adolescents’ use of purpose built shade in secondary schools: cluster randomised controlled trial
Objective To examine whether students use or avoid newly shaded areas created by shade sails installed at schools
Hyaluronidase Hyal1 Increases Tumor Cell Proliferation and Motility through Accelerated Vesicle Trafficking
Background: Hyal1 is a turnover enzyme for hyaluronan that accelerates metastatic cancer by increasing cell motility.
Results: Hyal1-overexpressing cells have a higher rate of endocytosis that impacts cargo internalization and recycling.
Conclusion: The higher rate of vesicle trafficking increases motility receptor function and nutrient uptake.
Significance: This novel mechanism implicates Hyal1 trafficking in multiple signaling events during tumor progression
Hyaluronan turnover and hypoxic brown adipocytic differentiation are co-localized with ossification in calcified human aortic valves
The calcification process in aortic stenosis has garnered considerable interest but only limited investigation into selected signaling pathways. This study investigated mechanisms related to hypoxia, hyaluronan homeostasis, brown adipocytic differentiation, and ossification within calcified valves. Surgically explanted calcified aortic valves (nï¾ =ï¾ 14) were immunostained for markers relevant to these mechanisms and evaluated in the center (NodCtr) and edge (NodEdge) of the calcified nodule (NodCtr), tissue directly surrounding nodule (NodSurr); center and tissue surrounding small モprenodulesï¾” (PreNod, PreNodSurr); and normal fibrosa layer (CollFibr). Pearson correlations were determined between staining intensities of markers within regions. Ossification markers primarily localized to NodCtr and NodEdge, along with markers related to hyaluronan turnover and hypoxia. Markers of brown adipocytic differentiation were frequently co-localized with markers of hypoxia. In NodCtr and NodSurr, brown fat and ossification markers correlated with hyaluronidase-1, whereas these markers, as well as hypoxia, correlated with hyaluronan synthases in NodEdge. The protein product of tumor necrosis factor-? stimulated gene-6 strongly correlated with ossification markers and hyaluronidase in the regions surrounding the nodules (NodSurr, PreNodSurr). In conclusion, this study suggests roles for hyaluronan homeostasis and the promotion of hypoxia by cells demonstrating brown fat markers in calcific aortic valve disease
Alpha-2-adrenergic receptor agonists for the prevention of delirium and cognitive decline after open heart surgery (ALPHA2PREVENT): protocol for a multicentre randomised controlled trial
INTRODUCTION: Postoperative delirium is common in older cardiac surgery patients and associated with negative short-term and long-term outcomes. The alpha-2-adrenergic receptor agonist dexmedetomidine shows promise as prophylaxis and treatment for delirium in intensive care units (ICU) and postoperative settings. Clonidine has similar pharmacological properties and can be administered both parenterally and orally. We aim to study whether repurposing of clonidine can represent a novel treatment option for delirium, and the possible effects of dexmedetomidine and clonidine on long-term cognitive trajectories, motor activity patterns and biomarkers of neuronal injury, and whether these effects are associated with frailty status. METHODS AND ANALYSIS: This five-centre, double-blind randomised controlled trial will include 900 cardiac surgery patients aged 70+ years. Participants will be randomised 1:1:1 to dexmedetomidine or clonidine or placebo. The study drug will be given as a continuous intravenous infusion from the start of cardiopulmonary bypass, at a rate of 0.4 µg/kg/hour. The infusion rate will be decreased to 0.2 µg/kg/hour postoperatively and be continued until discharge from the ICU or 24 hours postoperatively, whichever happens first.Primary end point is the 7-day cumulative incidence of postoperative delirium (Diagnostic and Statistical Manual of Mental Disorders, fifth edition). Secondary end points include the composite end point of coma, delirium or death, in addition to delirium severity and motor activity patterns, levels of circulating biomarkers of neuronal injury, cognitive function and frailty status 1 and 6 months after surgery. ETHICS AND DISSEMINATION: This trial is approved by the Regional Committee for Ethics in Medical Research in Norway (South-East Norway) and by the Norwegian Medicines Agency. Dissemination plans include publication in peer-reviewed medical journals and presentation at scientific meetings. TRIAL REGISTRATION NUMBER: NCT05029050
Hyaluronidase Hyal1 Increases Tumor Cell Proliferation and Motility through Accelerated Vesicle Trafficking
Background: Hyal1 is a turnover enzyme for hyaluronan that accelerates metastatic cancer by increasing cell motility.
Results: Hyal1-overexpressing cells have a higher rate of endocytosis that impacts cargo internalization and recycling.
Conclusion: The higher rate of vesicle trafficking increases motility receptor function and nutrient uptake.
Significance: This novel mechanism implicates Hyal1 trafficking in multiple signaling events during tumor progression
Physical function endpoints in cancer cachexia clinical trials: Systematic Review 1 of the cachexia endpoints series
In cancer cachexia trials, measures of physical function are commonly used as endpoints. For drug trials to obtain regulatory approval, efficacy in physical function endpoints may be needed alongside other measures. However, it is not clear which physical function endpoints should be used. The aim of this systematic review was to assess the frequency and diversity of physical function endpoints in cancer cachexia trials. Following a comprehensive electronic literature search of MEDLINE, Embase and Cochrane (1990-2021), records were retrieved. Eligible trials met the following criteria: adults (≥18 years), controlled design, more than 40 participants, use of a cachexia intervention for more than 14 days and use of a physical function endpoint. Physical function measures were classified as an objective measure (hand grip strength [HGS], stair climb power [SCP], timed up and go [TUG] test, 6-min walking test [6MWT] and short physical performance battery [SPPB]), clinician assessment of function (Karnofsky Performance Status [KPS] or Eastern Cooperative Oncology Group-Performance Status [ECOG-PS]) or patient-reported outcomes (physical function subscale of the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaires [EORTC QLQ-C30 or C15]). Data extraction was performed using Covidence and followed PRISMA guidance (PROSPERO registration: CRD42022276710). A total of 5975 potential studies were examined and 71 were eligible. Pharmacological interventions were assessed in 38 trials (54%). Of these, 11 (29%, n = 1184) examined megestrol and 5 (13%, n = 1928) examined anamorelin; nutritional interventions were assessed in 21 trials (30%); and exercise-based interventions were assessed in 6 trials (8%). The remaining six trials (8%) assessed multimodal interventions. Among the objective measures of physical function (assessed as primary or secondary endpoints), HGS was most commonly examined (33 trials, n = 5081) and demonstrated a statistically significant finding in 12 (36%) trials (n = 2091). The 6MWT was assessed in 12 trials (n = 1074) and was statistically significant in 4 (33%) trials (n = 403), whereas SCP, TUG and SPPB were each assessed in 3 trials. KPS was more commonly assessed than the newer ECOG-PS (16 vs. 9 trials), and patient-reported EORTC QLQ-C30 physical function was reported in 25 trials. HGS is the most commonly used physical function endpoint in cancer cachexia clinical trials. However, heterogeneity in study design, populations, intervention and endpoint selection make it difficult to comment on the optimal endpoint and how to measure this. We offer several recommendations/considerations to improve the design of future clinical trials in cancer cachexia
Tidal and groundwater fluxes to a shallow, microtidal estuary : constraining inputs through field observations and hydrodynamic modeling
This paper is not subject to U.S. copyright. The definitive version was published in Estuaries and Coasts 35 (2012): 1285-1298, doi:10.1007/s12237-012-9515-x.Increased nutrient loading to estuaries has led to
eutrophication, degraded water quality, and ecological transformations.
Quantifying nutrient loads in systems with significant
groundwater input can be difficult due to the
challenge of measuring groundwater fluxes. We quantified
tidal and freshwater fluxes over an 8-week period at the
entrance of West Falmouth Harbor, Massachusetts, a eutrophic,
groundwater-fed estuary. Fluxes were estimated from
velocity and salinity measurements and a total exchange
flow (TEF) methodology. Intermittent cross-sectional measurements
of velocity and salinity were used to convert point
measurements to cross-sectionally averaged values over the
entire deployment (index relationships). The estimated
mean freshwater flux (0.19 m3/s) for the 8-week period
was mainly due to groundwater input (0.21 m3/s) with
contributions from precipitation to the estuary surface
(0.026 m3/s) and removal by evaporation (0.048 m3/s).
Spring–neap variations in freshwater export that appeared
in shorter-term averages were mostly artifacts of the index
relationships. Hydrodynamic modeling with steady groundwater
input demonstrated that while the TEF methodology resolves the freshwater flux signal, calibration of the index–
salinity relationships during spring tide conditions only was
responsible for most of the spring–neap signal. The mean
freshwater flux over the entire period estimated from the
combination of the index-velocity, index–salinity, and TEF
calculations were consistent with the model, suggesting that
this methodology is a reliable way of estimating freshwater
fluxes in the estuary over timescales greater than the spring–
neap cycle. Combining this type of field campaign with
hydrodynamic modeling provides guidance for estimating
both magnitude of groundwater input and estuarine storage
of freshwater and sets the stage for robust estimation of the
nutrient load in groundwater.Funding was provided by the USGS Coastal and
Marine Geology Program and by National Science Foundation Award
#0420575 from the Biocomplexity/Coupled Biogeochemical Cycles
Program
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