450 research outputs found
Identifying Genes Involved in Paraganglioma Genesis
The paraganglion system is composed of a collection of chromaffin cells that is
distributed throughout the body. Embryonically, chromaffin cells arise from the
neuroectodermal tissue of the neural crest and are thought to migrate along the
innervating nerves or vasculature towards their primordial location to form the
paraganglia. The largest paraganglion is the adrenal medulla, an important
neuroendocrine organ, which is the body’s main source of catecholamines (adrenalin,
noradrenalin and dopamine). The adrenal medulla receives input from the sympathetic
nervous system through preganglionic fibers upon which it releases its secretions directly
into the blood. Besides this adrenal station there are many extra‐adrenal paraganglia that
are distributed along the body axis and located in the proximity of ganglia of the
sympathetic chain or in association with cranial nerves and blood vessels
Cell Line Derived 5-FU and Irinotecan Drug-Sensitivity Profiles Evaluated in Adjuvant Colon Cancer Trial Data.
This study evaluates whether gene signatures for chemosensitivity for irinotecan and 5-fluorouracil (5-FU) derived from in vitro grown cancer cell lines can predict clinical sensitivity to these drugs.
To test if an irinotecan signature and a SN-38 signature could identify patients who benefitted from the addition of irinotecan to 5-FU, we used gene expression profiles based on cell lines and clinical tumor material. These profiles were applied to expression data obtained from pretreatment formalin fixed paraffin embedded (FFPE) tumor tissue from 636 stage III colon cancer patients enrolled in the PETACC-3 prospective randomized clinical trial. A 5-FU profile developed similarly was assessed by comparing the PETACC-3 cohort with a cohort of 359 stage II colon cancer patients who underwent surgery but received no adjuvant therapy.
There was no statistically significant association between the irinotecan or SN-38 profiles and benefit from irinotecan. The 5-FU sensitivity profile showed a statistically significant association with relapse free survival (RFS) (hazard ratio (HR) = 0.54 (0.41-0.71), p<1e-05) and overall survival (HR = 0.47 (0.34-0.63), p<1e-06) in the PETACC-3 subpopulation. The effect of the 5-FU profile remained significant in a multivariable Cox Proportional Hazards model, adjusting for several relevant clinicopathological parameters. No statistically significant effect of the 5-FU profile was observed in the untreated cohort of 359 patients (relapse free survival, p = 0.671).
The irinotecan predictor had no predictive value. The 5-FU predictor was prognostic in stage III patients in PETACC-3 but not in stage II patients with no adjuvant therapy. This suggests a potential predictive ability of the 5-FU sensitivity profile to identify colon cancer patients who may benefit from 5-FU, however, any biomarker predicting benefit for adjuvant 5-FU must be rigorously evaluated in independent cohorts. Given differences between the two study cohorts, the present results should be further validated
Plantar calcaneal spurs in older people: longitudinal traction or vertical compression?
<p>Abstract</p> <p>Background</p> <p>Plantar calcaneal spurs are common, however their pathophysiology is poorly understood. This study aimed to evaluate the prevalence and correlates of plantar calcaneal spurs in a large sample of older people.</p> <p>Methods</p> <p>Weightbearing lateral foot radiographs of 216 people (140 women and 76 men) aged 62 to 94 years (mean age 75.9, <smcaps>SD</smcaps> 6.6) were examined for plantar calcaneal and Achilles tendon spurs. Associations between the presence of spurs and sex, body mass index, radiographic measures of foot posture, self-reported co-morbidities and current or previous heel pain were then explored.</p> <p>Results</p> <p>Of the 216 participants, 119 (55%) had at least one plantar calcaneal spur and 103 (48%) had at least one Achilles tendon spur. Those with plantar calcaneal spurs were more likely to have Achilles tendon spurs (odds ratio [OR] = 2.0, 95% confidence interval [CI] 1.2 to 3.5). Prevalence of spurs did not differ according to sex. Participants with plantar calcaneal spurs were more likely to be obese (OR = 7.9, 95% CI 3.6 to 17.0), report osteoarthritis (OR = 2.6, 95% CI 1.6 to 4.8) and have current or previous heel pain (OR = 4.6, 95% CI 2.3 to 9.4). No relationship was found between the presence of calcaneal spurs and radiographic measures of foot posture.</p> <p>Conclusion</p> <p>Calcaneal spurs are common in older men and women and are related to obesity, osteoarthritis and current or previous heel pain, but are unrelated to radiographic measurements of foot posture. These findings support the theory that plantar calcaneal spurs may be an adaptive response to vertical compression of the heel rather than longitudinal traction at the calcaneal enthesis.</p
Transient Reversal of Episome Silencing Precedes VP16-Dependent Transcription during Reactivation of Latent HSV-1 in Neurons
Herpes simplex virus type-1 (HSV-1) establishes latency in peripheral neurons, creating a permanent source of recurrent infections. The latent genome is assembled into chromatin and lytic cycle genes are silenced. Processes that orchestrate reentry into productive replication (reactivation) remain poorly understood. We have used latently infected cultures of primary superior cervical ganglion (SCG) sympathetic neurons to profile viral gene expression following a defined reactivation stimulus. Lytic genes are transcribed in two distinct phases, differing in their reliance on protein synthesis, viral DNA replication and the essential initiator protein VP16. The first phase does not require viral proteins and has the appearance of a transient, widespread de-repression of the previously silent lytic genes. This allows synthesis of viral regulatory proteins including VP16, which accumulate in the cytoplasm of the host neuron. During the second phase, VP16 and its cellular cofactor HCF-1, which is also predominantly cytoplasmic, concentrate in the nucleus where they assemble an activator complex on viral promoters. The transactivation function supplied by VP16 promotes increased viral lytic gene transcription leading to the onset of genome amplification and the production of infectious viral particles. Thus regulated localization of de novo synthesized VP16 is likely to be a critical determinant of HSV-1 reactivation in sympathetic neurons
γ-H2AX Kinetics as a Novel Approach to High Content Screening for Small Molecule Radiosensitizers
Persistence of γ-H2AX after ionizing radiation (IR) or drug therapy is a robust reporter of unrepaired DNA double strand breaks in treated cells.DU-145 prostate cancer cells were treated with a chemical library ±IR and assayed for persistence of γ-H2AX using an automated 96-well immunocytochemistry assay at 4 hours after treatment. Hits that resulted in persistence of γ-H2AX foci were tested for effects on cell survival. The molecular targets of hits were validated by molecular, genetic and biochemical assays and in vivo activity was tested in a validated Drosophila cancer model.We identified 2 compounds, MS0019266 and MS0017509, which markedly increased persistence of γ-H2AX, apoptosis and radiosensitization in DU-145 cells. Chemical evaluation demonstrated that both compounds exhibited structurally similar and biochemical assays confirmed that these compounds inhibit ribonucleotide reductase. DNA microarray analysis and immunoblotting demonstrates that MS0019266 significantly decreased polo-like kinase 1 gene and protein expression. MS0019266 demonstrated in vivo antitumor activity without significant whole organism toxicity.MS0019266 and MS0017509 are promising compounds that may be candidates for further development as radiosensitizing compounds as inhibitors of ribonucleotide reductase
Latest observations on the low energy excess in CRESST-III
The CRESST experiment observes an unexplained excess of events at low
energies. In the current CRESST-III data-taking campaign we are operating
detector modules with different designs to narrow down the possible
explanations. In this work, we show first observations of the ongoing
measurement, focusing on the comparison of time, energy and temperature
dependence of the excess in several detectors. These exclude dark matter,
radioactive backgrounds and intrinsic sources related to the crystal bulk as a
major contribution.Comment: 10 pages, 5 figures; to be published in IDM2022 proceeding
Observation of a low energy nuclear recoil peak in the neutron calibration data of the CRESST-III Experiment
New-generation direct searches for low mass dark matter feature detection
thresholds at energies well below 100 eV, much lower than the energies of
commonly used X-ray calibration sources. This requires new calibration sources
with sub-keV energies. When searching for nuclear recoil signals, the
calibration source should ideally cause mono-energetic nuclear recoils in the
relevant energy range. Recently, a new calibration method based on the
radiative neutron capture on W with subsequent de-excitation via single
-emission leading to a nuclear recoil peak at 112 eV was proposed. The
CRESST-III dark matter search operated several CaWO-based detector
modules with detection thresholds below 100 eV in the past years. We report the
observation of a peak around the expected energy of 112 eV in the data of three
different detector modules recorded while irradiated with neutrons from
different AmBe calibration sources. We compare the properties of the observed
peaks with Geant-4 simulations and assess the prospects of using this for the
energy calibration of CRESST-III detectors.Comment: 8 pages, 4 figures; submitted to Phys. Rev.
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