5,220 research outputs found
Polyphosphate in thrombosis, hemostasis, and inflammation
This illustrated review focuses on polyphosphate as a potent modulator of the plasma clotting cascade, with possible roles in hemostasis, thrombosis, and inflammation. Polyphosphates are highly anionic, linear polymers of inorganic phosphates that are widespread throughout biology. Infectious microorganisms accumulate polyphosphates with widely varying polymer lengths (from a few phosphates to over a thousand phosphates long), while activated human platelets secrete polyphosphate with a very narrow size distribution (about 60‐100 phosphates long). Work from our lab and others has shown that long‐chain polyphosphate is a potent trigger of clotting via the contact pathway, while polyphosphate of the size secreted by platelets accelerates factor V activation, blocks the anticoagulant activity of tissue factor pathway inhibitor, promotes factor XI activation by thrombin, and makes fibrin fibrils thicker and more resistant to fibrinolysis. Polyphosphate also modulates inflammation by triggering bradykinin release, inhibiting the complement system, and modulating endothelial function. Polyphosphate and nucleic acids have similar physical properties and both will trigger the contact pathway—although polyphosphate is orders of magnitude more procoagulant than either DNA or RNA. Important caveats in these studies include observations that nucleic acids and polyphosphate may co‐purify, and that these preparations can be contaminated with highly procoagulant microparticles if silica‐based purification methods are employed. Polyphosphate has received attention as a possible therapeutic, with some recent studies exploring the use of polyphosphate in a variety of formulations to control bleeding. Other studies are investigating treatments that block polyphosphate function as novel antithrombotics with the possibility of reduced bleeding side effects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147856/1/rth212162_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147856/2/rth212162.pd
Targeting DNA topoisomerase IIα ( TOP2A ) in the hypoxic tumour microenvironment using unidirectional hypoxia‐activated prodrugs ( uHAPs )
The hypoxic tumour microenvironment (hTME), arising from inadequate and chaotic vascularity, can present a major obstacle for the treatment of solid tumours. Hypoxic tumour cells compromise responses to treatment since they can generate resistance to radiotherapy, chemotherapy and immunotherapy. The hTME impairs the delivery of a range of anti-cancer drugs, creates routes for metastasis and exerts selection pressures for aggressive phenotypes; these changes potentially occur within an immunosuppressed environment. Therapeutic strategies aimed at the hTME include targeting the molecular changes associated with hypoxia. An alternative approach is to exploit the prevailing lack of oxygen as a principle for the selective activation of prodrugs to target cellular components within the hTME. This review focuses on the design concepts and rationale for the use of unidirectional Hypoxia-Activated Prodrugs (uHAPs) to target the hTME as exemplified by the uHAPs AQ4N and OCT1002. These agents undergo irreversible reduction in a hypoxic environment to active forms that target DNA topoisomerase IIα (TOP2A). This nuclear enzyme is essential for cell division and is a recognised chemotherapeutic target. An activated uHAP interacts with the enzyme-DNA complex to induce DNA damage, cell cycle arrest and tumour cell death. uHAPs are designed to overcome the shortcomings of conventional HAPs and offer unique pharmacodynamic properties for effective targeting of TOP2A in the hTME. uHAP therapy in combination with standard of care treatments has the potential to enhance outcomes by co-addressing the therapeutic challenge presented by the hTME
A mus-51 RIP allele for transformation of Neurospora crassa
This report describes the construction and characterization of mus-51RIP70, an allele for high-efficiency targeted integration of transgenes into the genome of the model eukaryote Neurospora crassa. Two of the mus-51RIP70 strains investigated in this work (RZS27.10 and RZS27.18) can be obtained from the Fungal Genetics Stock Center. The two deposited strains are, to our knowledge, genetically identical and neither one is preferred over the other for use in Neurospora research
Anti-proliferative but not anti-angiogenic tyrosine kinase inhibitors enrich for cancer stem cells in soft tissue sarcoma.
BackgroundIncreasing studies implicate cancer stem cells (CSCs) as the source of resistance and relapse following conventional cytotoxic therapies. Few studies have examined the response of CSCs to targeted therapies, such as tyrosine kinase inhibitors (TKIs). We hypothesized that TKIs would have differential effects on CSC populations depending on their mechanism of action (anti-proliferative vs. anti-angiogenic).MethodsWe exposed human sarcoma cell lines to sorafenib, regorafenib, and pazopanib and assessed cell viability and expression of CSC markers (ALDH, CD24, CD44, and CD133). We evaluated survival and CSC phenotype in mice harboring sarcoma metastases after TKI therapy. We exposed dissociated primary sarcoma tumors to sorafenib, regorafenib, and pazopanib, and we used tissue microarray (TMA) and primary sarcoma samples to evaluate the frequency and intensity of CSC markers after neoadjuvant therapy with sorafenib and pazopanib. Parametric and non-parametric statistical analyses were performed as appropriate.ResultsAfter functionally validating the CSC phenotype of ALDHbright sarcoma cells, we observed that sorafenib and regorafenib were cytotoxic to sarcoma cell lines (P < 0.05), with a corresponding 1.4 - 2.8 fold increase in ALDHbright cells from baseline (P < 0.05). In contrast, we observed negligible effects on viability and CSC sub-populations with pazopanib. At low doses, there was progressive CSC enrichment in vitro after longer term exposure to sorafenib although the anti-proliferative effects were attenuated. In vivo, sorafenib improved median survival by 11 days (P < 0.05), but enriched ALDHbright cells 2.5 - 2.8 fold (P < 0.05). Analysis of primary human sarcoma samples revealed direct cytotoxicity following exposure to sorafenib and regorafenib with a corresponding increase in ALDHbright cells (P < 0.05). Again, negligible effects from pazopanib were observed. TMA analysis of archived specimens from sarcoma patients treated with sorafenib demonstrated significant enrichment for ALDHbright cells in the post-treatment resection specimen (P < 0.05), whereas clinical specimens obtained longitudinally from a patient treated with pazopanib showed no enrichment for ALDHbright cells (P > 0.05).ConclusionsAnti-proliferative TKIs appear to enrich for sarcoma CSCs while anti-angiogenic TKIs do not. The rational selection of targeted therapies for sarcoma patients may benefit from an awareness of the differential impact of TKIs on CSC populations
Can patient characteristics explain variance in ultrasound strain elastography measures of the quadratus femoris and patellar tendons?
Objectives To explore the associations between participant characteristics and magnitudes of difference in paired elastography measures of knee tendon from different ultrasound systems, and to compare strain elastography pattern description. Materials and Methods Quadriceps and patellar tendons of 20 healthy volunteers (40 tendons) were examined by an experienced operator employing two ultrasound systems (GE S8 and Esaote MyLab 70XVG). Pearson/Spearman correlations explored the influence of participant characteristics (BMI, body fat %, leg circumference, activity level) on the magnitude of differences between measures. Paired-sample t test or Wilcoxon signed rank test were performed to compare repeated measures of individual ultrasound systems. Results The quadriceps tendon was characteristically stiffer than the patellar tendon. Participant characteristics were associated with within machine differences of the distal quadriceps tendon (BMI; r = 0.49, p = 0.028–0.03 and body fat %; r = 0.43, p = 0.05–0.056) ER measures. Conclusions Anthropometric and body composition parameters were associated with within machine differences for elasticity measures, where high BMI and body fat % contribute to paired measurement variance at the distal quadriceps tendon. Strain elastography protocols should be standardised, repeated ER measures performed using the same US system and patient characteristics considered for future clinical applications
Understanding genetic regulation of UV-B responses in Arabidopsis thaliana
Light plays a major signaling role in plant growth and development, which
directly involves plant photoreceptors. UV-B radiation (280-320nm) is also an integral
component of sunlight that may cause damage to macromolecules or activate adaptive
responses. Using genes known to be UV-inducible from previous microarray
experiments, I measured gene expression after UV-B exposure using real-time PCR in
wild-type Arabidopsis seedlings, and then compared wild-type gene expression to
expression in a putative UV-B photoreceptor mutant. I also monitored the effect of UV-B
on growth, which was measured by leaf rosette diameter. In two experimental settings,
there were significant differences between treatments (Mylar and cellulose diacetate),
genotypes (mutant and wild-type), and their interaction. Based on these results, I
conclude that the candidate gene fits the phenotype of a UV-B photoreceptor and confers
increased growth in the greenhouse when the photoreceptor is present in plants exposed
to UV-B radiation
Intermachine variation of ultrasound strain elastographic measures of the quadriceps and patellar tendons in healthy participants
ObjectivesTo evaluate intermachine variation and compare intraoperator and interoperator agreement and repeatability characteristics of 2 ultrasound (US) systems for measurements of quadriceps and patellar tendons by strain elastography (SE).MethodsForty tendons from 20 healthy participants were investigated by operators with different experience (operator 1, 12 years of US experience and >50 SE examinations; operator 2, no US experience and 1 day of SE training). Repeated measures were performed on GE Healthcare (Waukesha, WI) and Esaote (Genoa, Italy) US systems. The percentage of agreement, Cohen κ, intraclass correlation coefficient, and correlation tests assessed agreement, repeatability, and associations of SE measures. A paired t test and Wilcoxon signed rank test assessed differences in SE measures. ResultsThe study participants included 5 male and 15 female volunteers (mean [range] age, 29.3 [21–39] years). Better agreement and repeatability characteristics were observed for the patellar compared to the quadriceps tendon and the color score (CS) method over the elasticity ratio (ER). Intraoperator agreement was better for the experienced operator. Intraoperator repeatability was achieved in 55% of ER (intraclass correlation coefficient, 0.40–0.91; P [less than] .05) and 77% to 85% (κ = –0.25–1) of CS measures. Interoperator repeatability was achieved in 35% (t /z , –2.93–7.94; P [less than] .001–.048) of all ER measures. No significant differences in proximal (z , –0.13– –0.78) and distal patellar (z , –1.52–2.26; P > .5) patellar ER measures were observed. Seventy‐four percent to 75% mean agreement (κ = 0–0.5) for CS measures comparable across both US systems was observed. Intermachine ER associations were poor (r = –0.39–0.13; P > .05), whereas greater than 70% agreement (κ = –0.87–0.53) for the CS was achieved. ConclusionsThe reproducibility of knee tendon SE measurements is influenced by the operator experience, US system, and tendon site
Implementing evidence-informed policy into practice for health care professionals managing people with low back pain in Australian rural settings: A preliminary prospective single-cohort study
Objective: To provide access to professional development opportunities for health care professionals, especially in rural Australian regions, consistent with recommendations in the Australian National Pain Strategy and state government policy. Design and Setting: A preliminary prospective, single-cohort study design, which aligned health policy with evidence-informed clinical practice, evaluated the implementation and effectiveness of an interprofessional, health care provider pain education program (hPEP) for management of nonspecific low back pain (nsLBP) in rural Western Australia. Intervention: The 6.5-hour hPEP intervention was delivered to 60 care providers (caseload nsLBP 19.8% ± 22.5) at four rural WA regions. Outcome Measures: Outcomes were recorded at baseline and 2 months post-intervention regarding attitudes, beliefs (modified Health Care Providers Pain and Impairment Relationship Scale [HC-PAIRS]), Back Pain Beliefs Questionnaire [BBQ]), and self-reported evidence-based clinical practice (knowledge and skills regarding nsLBP, rated on a 5-point Likert scale with 1 = nil and 5 = excellent).Results: hPEP was feasible to implement. At 2 months post-hPEP, responders' (response rate 53%) improved evidence-based beliefs were indicated by HC-PAIRS scores: baseline mean (SD) [43.2 (9.3)]; mean difference (95% CI) [−5.9 (−8.6 to −3.1)]; and BBQ baseline [34.3 (6.8)]; mean difference [2.1 (0.5 to 3.6)]. Positive shifts were observed for all measures of clinical knowledge and skills (P < 0.001) and increased assistance with planning lifestyle changes (P < 0.001), advice on self-management (P = 0.010), and for decreased referrals for spinal imaging (P = 0.03). Conclusions: This policy-into-practice educational program is feasible to implement in rural Western Australia (WA). While preliminary data are encouraging, a further randomized controlled trial is recommended
Restoring identity: The use of religion as a mechanism to transition between an identity of sexual offending to a non-offending identity
This study examines the unique experience of participants who during their reintegration back into the community, following a conviction for sexual offending, re-engaged with religious and spiritual communities. To explore meaning Interpretative Phenomenological Analysis (IPA) was adopted. Four in-depth interviews of men convicted for sexual crimes were undertaken and analysed. Findings indicate that through religious affiliation participants were: exposed to new prosocial networks; provided opportunities to seek forgiveness; felt a sense of belonging and affiliation; and were psychologically comforted. However, the study also found that the process of identity transition from ‘offender’ to ‘non-offender’ was not seamless or straightforward for those with an innate sexual deviancy towards children, caution is therefore advised
Communicating geographical risks in crisis management : the need for research
In any crisis, there is a great deal of uncertainty, often geographical uncertainty or, more precisely, spatiotemporal uncertainty. Examples include the spread of contamination from an industrial accident, drifting volcanic ash, and the path of a hurricane. Estimating spatiotemporal probabilities is usually a difficult task, but that is not our primary concern. Rather, we ask how analysts can communicate spatiotemporal uncertainty to those handling the crisis. We comment on the somewhat limited literature on the representation of spatial uncertainty on maps. We note that many cognitive issues arise and that the potential for confusion is high. We note that in the early stages of handling a crisis, the uncertainties involved may be deep, i.e., difficult or impossible to quantify in the time available. In such circumstance, we suggest the idea of presenting multiple scenarios
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