1,144 research outputs found

    Topical Menthol, Ice, Peripheral Blood Flow, and Perceived Discomfort

    Get PDF
    Context : Injury management commonly includes decreasing arterial blood flow to the affected site in an attempt to reduce microvascular blood flow and edema and limit the induction of inflammation. Applied separately, ice and menthol gel decrease arterial blood flow, but the combined effects of ice and menthol gel on arterial blood flow are unknown. Objectives : To compare radial artery blood flow, arterial diameter, and perceived discomfort before and after the application of 1 of 4 treatment conditions. Design : Experimental crossover design. Setting : Clinical laboratory. Participants or Other Participants : Ten healthy men, 9 healthy women (mean age = 25.68 years, mean height = 1.73 m, mean weight = 76.73 kg). Intervention(s) : Four treatment conditions were randomly applied for 20 minutes to the right forearm of participants on 4 different days separated by at least 24 hours: (1) 3.5 mL menthol gel, (2) 0.5 kg of crushed ice, (3) 3.5 mL of menthol gel and 0.5 kg of crushed ice, or (4) no treatment (control). Main Outcome Measure(s) : Using high-resolution ultrasound, we measured right radial artery diameter (cm) and blood flow (mL/min) every 5 minutes for 20 minutes after the treatment was applied. Discomfort with the treatment was documented using a 1-to-10 intensity scale. Results : Radial artery blood flow decreased (P \u3c .05) from baseline in the ice (−20% to −24%), menthol (−17% to −24%), and ice and menthol (−36% to −39%) treatments but not in the control (3% to 9%) at 5, 10, and 15 minutes. At 20 minutes after baseline, only the ice (−27%) and combined ice and menthol (−38%) treatments exhibited reductions in blood flow (P \u3c .05). Discomfort was less with menthol than with the ice treatment at 5, 10, and 20 minutes after application (P \u3c .05). Arterial diameter and heart rate did not change. Conclusions : The application of 3.5 mL of menthol was similar to the application of 0.5 kg of crushed ice in reducing peripheral blood flood. Combining crushed ice with menthol appeared to have an additive effect on reducing blood flow

    Two-Level Systems in Evaporated Amorphous Silicon

    Full text link
    In ee-beam evaporated amorphous silicon (aa-Si), the densities of two-level systems (TLS), n0n_{0} and P‾\overline{P}, determined from specific heat CC and internal friction Q−1Q^{-1} measurements, respectively, have been shown to vary by over three orders of magnitude. Here we show that n0n_{0} and P‾\overline{P} are proportional to each other with a constant of proportionality that is consistent with the measurement time dependence proposed by Black and Halperin and does not require the introduction of additional anomalous TLS. However, n0n_{0} and P‾\overline{P} depend strongly on the atomic density of the film (nSin_{\rm Si}) which depends on both film thickness and growth temperature suggesting that the aa-Si structure is heterogeneous with nanovoids or other lower density regions forming in a dense amorphous network. A review of literature data shows that this atomic density dependence is not unique to aa-Si. These findings suggest that TLS are not intrinsic to an amorphous network but require a heterogeneous structure to form

    A Framework for the Impact of IT on Organizational Performance

    Get PDF
    Abstract: Purpose -Despite the constant stream of research investigating information technology (IT) business value, IT capabilities, and competitive advantage, researchers are calling for a more coherent understanding of the firm-level impacts of IT, and how those firm-level impacts can be measured. The purpose of this study is to investigate the multitude of organization-level studies of the impact of IT. Originality/value -The research framework proposed provides a comprehensive snapshot of IS studies on organizational performance. IT business value | organizational impact | productivity rate | profitability | financia

    Information technology issues in healthcare: Hospital CEO and CIO perspectives.

    Get PDF
    Healthcare Information Technology (HIT) is widely regarded as a key to improving the quality of healthcare in the United States and potentially reducing its cost. Yet, its implementation is a continuous challenge for the healthcare industry. In this article, we report the results of a survey distributed to CEOs and CIOs at 1400 U.S. hospitals regarding their perceptions of the key information technology (IT) issues in healthcare. Among the top ten issues, the implementation of electronic medical records is ranked the highest. Included in the top ten are issues related to: improving healthcare quality by the use of information technology; change management, privacy, security, and accuracy of electronic records; and decision support applications. While some differences existed, we found much similarity between the views of the CEOs and the CIOs with both groups being characterized as conservative and risk-averse in their entrepreneurial orientation. No major differences were observed between urban and rural hospitals, or large and small hospitals. Given the heightened interest in healthcare IT, these results have wide implications for many stakeholders in this burgeoning industr

    Tumor predisposition in mice mutant for p63 and p73: Evidence for broader tumor suppressor functions for the p53 family

    Get PDF
    Summaryp63 and p73 are functionally and structurally related to the tumor suppressor p53. However, their own role in tumor suppression is unclear. Given the p53-like properties of p63 and p73, we tested whether they are involved in tumor suppression by aging mice heterozygous for mutations in all p53 family genes and scored for spontaneous tumors. We show here that p63+/−;p73+/− mice develop spontaneous tumors. Loss of p63 and p73 can also cooperate with loss of p53 in tumor development. Mice heterozygous for mutations in both p53 and p63 or p53 and p73 displayed higher tumor burden and metastasis compared to p53+/− mice. These findings provide evidence for a broader role for the p53 family than has been previously reported

    Caspase-2-Mediated Cleavage of Mdm2 Creates a p53-Induced Positive Feedback Loop

    Get PDF
    Caspase-2 is an evolutionarily conserved caspase, yet its biological function and cleavage targets are poorly understood. Caspase-2 is activated by the p53 target gene product PIDD (also known as LRDD) in a complex called the Caspase-2-PIDDosome. We show that PIDD expression promotes growth arrest and chemotherapy resistance by a mechanism that depends on Caspase-2 and wild-type p53. PIDD-induced Caspase-2 directly cleaves the E3 ubiquitin ligase Mdm2 at Asp 367, leading to loss of the C-terminal RING domain responsible for p53 ubiquitination. As a consequence, N-terminally truncated Mdm2 binds p53 and promotes its stability. Upon DNA damage, p53 induction of the Caspase-2-PIDDosome creates a positive feedback loop that inhibits Mdm2 and reinforces p53 stability and activity, contributing to cell survival and drug resistance. These data establish Mdm2 as a cleavage target of Caspase-2 and provide insight into a mechanism of Mdm2 inhibition that impacts p53 dynamics upon genotoxic stress.Virginia and D.K. Ludwig Fund for Cancer Research (Postdoctoral Fellowship)Human Frontier Science Program (Strasbourg, France) (Fellowship)National Cancer Institute (U.S.) (Cancer Center Support (Core) Grant P30-CA14051

    Survival of pancreatic cancer cells lacking KRAS function

    Get PDF
    Activating mutations in the proto-oncogene KRAS are a hallmark of pancreatic ductal adenocarcinoma (PDAC), an aggressive malignancy with few effective therapeutic options. Despite efforts to develop KRAS-targeted drugs, the absolute dependence of PDAC cells on KRAS remains incompletely understood. Here we model complete KRAS inhibition using CRISPR/Cas-mediated genome editing and demonstrate that KRAS is dispensable in a subset of human and mouse PDAC cells. Remarkably, nearly all KRAS deficient cells exhibit phosphoinositide 3-kinase (PI3K)-dependent mitogen-activated protein kinase (MAPK) signaling and induced sensitivity to PI3K inhibitors. Furthermore, comparison of gene expression profiles of PDAC cells retaining or lacking KRAS reveal a role of KRAS in the suppression of metastasis-related genes. Collectively, these data underscore the potential for PDAC resistance to even the very best KRAS inhibitors and provide insights into mechanisms of response and resistance to KRAS inhibition

    Circadian Rhythm Disruption Promotes Lung Tumorigenesis

    Get PDF
    Circadian rhythms are 24-hr oscillations that control a variety of biological processes in living systems, including two hallmarks of cancer, cell division and metabolism. Circadian rhythm disruption by shift work is associated with greater risk for cancer development and poor prognosis, suggesting a putative tumor-suppressive role for circadian rhythm homeostasis. Using a genetically engineered mouse model of lung adenocarcinoma, we have characterized the effects of circadian rhythm disruption on lung tumorigenesis. We demonstrate that both physiologic perturbation (jet lag) and genetic mutation of the central circadian clock components decreased survival and promoted lung tumor growth and progression. The core circadian genes Per2 and Bmal1 were shown to have cell-autonomous tumor-suppressive roles in transformation and lung tumor progression. Loss of the central clock components led to increased c-Myc expression, enhanced proliferation, and metabolic dysregulation. Our findings demonstrate that both systemic and somatic disruption of circadian rhythms contribute to cancer progression
    • …
    corecore