208 research outputs found
NAIL COSMETICS
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66131/1/j.1365-4362.1992.tb01368.x.pd
Random Walks on Stochastic Temporal Networks
In the study of dynamical processes on networks, there has been intense focus
on network structure -- i.e., the arrangement of edges and their associated
weights -- but the effects of the temporal patterns of edges remains poorly
understood. In this chapter, we develop a mathematical framework for random
walks on temporal networks using an approach that provides a compromise between
abstract but unrealistic models and data-driven but non-mathematical
approaches. To do this, we introduce a stochastic model for temporal networks
in which we summarize the temporal and structural organization of a system
using a matrix of waiting-time distributions. We show that random walks on
stochastic temporal networks can be described exactly by an
integro-differential master equation and derive an analytical expression for
its asymptotic steady state. We also discuss how our work might be useful to
help build centrality measures for temporal networks.Comment: Chapter in Temporal Networks (Petter Holme and Jari Saramaki
editors). Springer. Berlin, Heidelberg 2013. The book chapter contains minor
corrections and modifications. This chapter is based on arXiv:1112.3324,
which contains additional calculations and numerical simulation
Androgen receptor footprint on the way to prostate cancer progression
The prostate gland is exquisitely sensitive to androgen receptor (AR) signaling. AR signaling is obligatory for prostate development and changes in AR levels, its ligands or shifts in AR mode of action are reflected in the physiology of the prostate. The AR is intimately linked to prostate cancer biology through the regulation of epithelial proliferation, suppression of apoptosis and the development of castration-resistant disease. Thus, AR is the primary therapeutic target in various prostate diseases such as BPH and cancer. Although some tumors lose AR expression, most retain the AR and have elevated levels and/or shifts in activity that are required for tumor progression and metastasis. New AR inhibitors currently in clinical trials with higher receptor affinity and specificity may improve prostate cancer patient outcome. Several events play an important role in initiation, primary tumor development and metastatic spread. Androgen receptor activity and promoter specificity change due to altered coregulator expression. Changes in epigenetic surveillance alter the AR cistrome. Both systemic and local inflammation increases with PCa progression affecting AR levels, activity, and requirement for ligand. Our current understanding of AR biology suggest that global androgen suppression may drive the development of castration-resistant disease and therefore the question remains: Does effective inhibition of AR activity mark the end of the road for PCa or only a sharp turn toward a different type of malignancy
One-year prevalence and the impact of migraine and tension-type headache in Turkey: a nationwide home-based study in adults
Several studies have shown that the prevalence of migraine and tension-type headache (TTH) varied between different geographical regions. Therefore, there is a need of a nationwide prevalence study for headache in our country, located between Asia and Europe. This nationwide study was designed to estimate the 1-year prevalence of migraine and TTH and analyse the clinical features, the impact as well as the demographic and socio-economic characteristics of the participant households in Turkey. We planned to investigate 6,000 representative households in 21 cities of Turkey; and a total of 5,323 households (response rate of 89%) aged between 18 and 65 years were examined for headache by 33 trained physicians at home on the basis of the diagnostic criteria of the second edition of the International Classification of Headache Disorders (ICHD-II). The electronically registered questionnaire was based on the headache features, the associated symptoms, demographic and socio-economic situation and history. Of 5,323 participants (48.8% women; mean age 35.9 ± 12 years) 44.6% reported recurrent headaches during the last 1 year and 871 were diagnosed with migraine at a prevalence rate of 16.4% (8.5% in men and 24.6% in women), whereas only 270 were diagnosed with TTH at a prevalence rate of 5.1% (5.7% in men and 4.5% in women). The 1-year prevalence of probable migraine was 12.4% and probable TTH was 9.5% additionally. The rate of migraine with aura among migraineurs was 21.5%. The prevalence of migraine was highest among 35–40-year-old women while there were no differences in age groups among men and in TTH overall. More than 2/3 of migraineurs had ever consulted a physician whereas only 1/3 of patients with TTH had ever consulted a physician. For women, the migraine prevalence was higher among the ones with a lower income, while among men, it did not show any change by income. Migraine prevalence was lower in those with a lower educational status compared to those with a high educational status. Chronic daily headache was present in 3.3% and the prevalence of medication overuse headache was 2.1% in our population. There was an important impact of migraine with a monthly frequency of 5.9 ± 6, and an attack duration of 35.1 ± 72 h, but only 4.9% were on prophylactic treatment. The one-year prevalence of migraine estimated as 16.4% was similar or even higher than world-wide reported migraine prevalence figures and identical to a previous nation-wide study conducted in 1998, whereas the TTH prevalence was much lower using the same methodology with the ICHD-II criteria
Neuronal Sirt3 Protects against Excitotoxic Injury in Mouse Cortical Neuron Culture
BACKGROUND: Sirtuins (Sirt), a family of nicotinamide adenine nucleotide (NAD) dependent deacetylases, are implicated in energy metabolism and life span. Among the known Sirt isoforms (Sirt1-7), Sirt3 was identified as a stress responsive deacetylase recently shown to play a role in protecting cells under stress conditions. Here, we demonstrated the presence of Sirt3 in neurons, and characterized the role of Sirt3 in neuron survival under NMDA-induced excitotoxicity. METHODOLOGY/PRINCIPAL FINDINGS: To induce excitotoxic injury, we exposed primary cultured mouse cortical neurons to NMDA (30 µM). NMDA induced a rapid decrease of cytoplasmic NAD (but not mitochondrial NAD) in neurons through poly (ADP-ribose) polymerase-1 (PARP-1) activation. Mitochondrial Sirt3 was increased following PARP-1 mediated NAD depletion, which was reversed by either inhibition of PARP-1 or exogenous NAD. We found that massive reactive oxygen species (ROS) produced under this NAD depleted condition mediated the increase in mitochondrial Sirt3. By transfecting primary neurons with a Sirt3 overexpressing plasmid or Sirt3 siRNA, we showed that Sirt3 is required for neuroprotection against excitotoxicity. CONCLUSIONS: This study demonstrated for the first time that mitochondrial Sirt3 acts as a prosurvival factor playing an essential role to protect neurons under excitotoxic injury
Chronic migraine plus medication overuse headache: two entities or not?
Chronic migraine (CM) represents migraine natural evolution from its episodic form. It is realized through a chronicization phase that may require months or years and varies from patient to patient. The transition to more frequent attacks pattern is influenced by lifestyle, life events, comorbid conditions and personal genetic terrain, and it often leads to acute drugs overuse. Medication overuse headache (MOH) may complicate every type of headache and all the drugs employed for headache treatment can cause MOH. The first step in the management of CM complicated by medication overuse must be the withdrawal of the overused drugs and a detoxification treatment. The goal is not only to detoxify the patient and stop the chronic headache but also to improve responsiveness to acute or prophylactic drugs. Different methods have been suggested: gradual or abrupt withdrawal; home treatment, hospitalization, or a day-hospital setting; re-prophylaxes performed immediately or at the end of the wash-out period. Up to now, only topiramate and local injection of onabotulinumtoxinA have shown efficacy as therapeutic agents for re-prophylaxis after detoxification in patients with CM with and without medication overuse. Although the two treatments showed similar efficacy, onabotulinumtoxinA is associated with a better adverse events profile. Recently, the Phase III Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) clinical program proved that patients with CM, even those with MOH, are the ones most likely to benefit from onabotulinumtoxinA treatment. Furthermore, it provided an injection paradigm that can be used as a guide for a correct administration of onabotulinumtoxinA
A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis
Introduction: Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA. Methods: A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring. Results: In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively. Conclusion: Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target. Systematic review: PROSPERO registration number: CRD 4201300500
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