4,043 research outputs found
Chlamydophila (Chlamydia) pneumoniae promotes Ab 1-42 amyloid processing in Neuronal Cells: A Pathogenic Trigger for Alzheimer\u27s Disease
Background: Previously, our laboratory identified Chlamydophila (Chlamydia) pneumoniae (Cpn) in autopsied sporadic AD brains. Furthermore, we have developed a BALB/c mouse model that demonstrated infection-induced amyloid plaques similar to those found in AD, and demonstrated that Cpn infection of neuronal cells inhibited apoptotic pathways of cell death. Hypothesis: Our current studies address whether infection with Cpn in neuronal cells triggers abnormal cleavage of the beta amyloid precursor protein (bAPP) into Ab1-42, thereby contributing to amyloid plaque formation characteristic of the pathology identified in AD. Materials and Methods: Human neuroblastoma cells were infected with the respiratory strain AR39 Cpn in vitro, then amyloid processing was analyzed and quantitated using immunocytochemistry, Western blotting and ELISA assays. Results: Cpn was shown to infect neuronal cells and induce intracellular amyloid processing. Cpn infection yielded cytoplasmic labeling of Ab 1-42 that was increased relative to uninfected cells. The ELISA assay revealed that in neuronal cell lysates, Ab 1-42 in the infected cells was increased 3 to 16-fold over the uninfected cells, from 24 to 72hr post infection. Western blot analysis confirmed an increase in Ab 1-42 in the infected neuronal cell lysates. Conclusions: These data suggest that infection of neuronal cells with Chlamydophila (Chlamydia) pneumoniae alters the processing of bAPP, thereby producing Ab1-42. Therefore, these studies and previous research reported by our laboratory support the implication of Cpn as a pathogenic agent in perpetuating the hallmark amyloid plaque formations observed in AD. This concept holds major therapeutic considerations for future studies.https://digitalcommons.pcom.edu/posters/1004/thumbnail.jp
Mesorectal radiotherapy for early stage rectal cancer: A novel target volume
With the introduction of population-based bowel cancer screening, rectal cancer is diagnosed at earlier stages, yet standard treatment still requires the same extensive surgery that is used for more advanced stages. Organ preserving treatment is rapidly developing and is subject of investigation in numerous clinical trials. The STAR-TREC trial is an international, multi-centre randomised trial investigating organ preservation using (chemo)radiotherapy. Patients with small mrT1-3bN0V0M0 tumours are randomized between three arms: standard TME, organ preservation with SCRT or with CRT. In this trial, the clinical target volume has been tailored to the early staged disease of the included patients. This mesorectal irradiation volume includes the mesorectum and pre-sacral lymph nodes at the level of the tumour, two centimetres below and cranially up to the S2-3 interspace level. In contrast to conventional irradiation volumes, the lateral lymph nodes and the nodes along the superior rectal artery are excluded. As a result, the dose to the bowel, bladder, anal sphincter and the neurovascular plexus in the lower pelvis is substantially decreased, especially when combined with modern irradiation techniques, such as dynamic arc therapy. These lower doses are expected to lead to decreasing acute and late toxicity and beneficial functional outcomes. The implementation of this novel target volume will be accompanied by an extensive quality assurance program in the STAR-TREC trial. We describe the rationale behind the novel, mesorectal only radiotherapy treatment used in the STAR-TREC trial specifically tailored for early stage disease, with the goal of organ preservation
Genetic Status Affects Disease-Specific Mortality But Not the Incidence of Local Recurrence in Patients with Uveal Melanoma
Purpose: Increased disease-specific mortality has been observed among patients with local recurrence (LR) from uveal melanoma (UM), but the underlying mechanism is unknown. The purpose of this study was to determine if copy number alterations of chromosomes 3 and/or 8q, at the time of diagnosis, increase the incidence of LR and if disease-specific mortality among patients with LR depends on the chromosome status of the primary tumor.
Design: Retrospective cohort study.
Participants: The study included 239 consecutive patients with primary UM (choroidal or ciliary body) treated with Ruthenium-106 (Ru-106) brachytherapy from January 2009 to December 2019 at a single national referral center.
Methods: Cox regression modeling and Kaplan–Meier analyses were used to assess the effect of the status of chromosomes 3 and 8q on the incidence of LR and disease-specific mortality after the event of LR. Multistate models were used to illustrate the probabilities over time of patients being alive and disease-free, alive with LR, dead from UM metastases, or dead from other causes split on the status of chromosomes 3 and 8q.
Main Outcome Measures: Incidence of LR and disease-specific mortality.
Results: Local recurrence was observed in 42 patients (16%). Overall incidence of LR was not affected by aberrations of chromosomes 3 and/or 8q (P = 0.87). Although LR occurred earlier in patients with aberrations of chromosomes 3 and/or 8q compared with patients with a normal copy number of chromosomes 3 and 8q, the median time from primary diagnosis to LR was 1.6 years (interquartile range [IQR], 1.0–2.0) and 3.2 years (IQR, 2.1–5.0), respectively. Cox regression found LR to be an independent risk factor for disease-specific mortality (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.5–5.0) among all patients, but multistate models demonstrated a low risk of disease-specific death among patients with normal chromosomes 3 and 8q status, even after an LR.
Conclusions: Copy number alterations of chromosome 3 and/or 8q in the primary UM did not increase the overall incidence of LR. However, the development of an LR enhanced the risk of disease-specific mortality among patients with copy number alterations of chromosomes 3 and/or 8q. Even after an LR, disease-specific mortality remained low among patients with normal copy numbers of chromosomes 3 and 8q.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article
Critical Exponents, Hyperscaling and Universal Amplitude Ratios for Two- and Three-Dimensional Self-Avoiding Walks
We make a high-precision Monte Carlo study of two- and three-dimensional
self-avoiding walks (SAWs) of length up to 80000 steps, using the pivot
algorithm and the Karp-Luby algorithm. We study the critical exponents
and as well as several universal amplitude ratios; in
particular, we make an extremely sensitive test of the hyperscaling relation
. In two dimensions, we confirm the predicted
exponent and the hyperscaling relation; we estimate the universal
ratios , and (68\% confidence
limits). In three dimensions, we estimate with a
correction-to-scaling exponent (subjective 68\%
confidence limits). This value for agrees excellently with the
field-theoretic renormalization-group prediction, but there is some discrepancy
for . Earlier Monte Carlo estimates of , which were , are now seen to be biased by corrections to scaling. We estimate the
universal ratios and ; since , hyperscaling holds. The approach to
is from above, contrary to the prediction of the two-parameter
renormalization-group theory. We critically reexamine this theory, and explain
where the error lies.Comment: 87 pages including 12 figures, 1029558 bytes Postscript
(NYU-TH-94/09/01
Upsilon (1S+2S+3S) production in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and cold-nuclear matter effects
The three Upsilon states, Upsilon(1S+2S+3S), are measured in d+Au and p+p
collisions at sqrt(s_NN)=200 GeV and rapidities 1.2<|y|<2.2 by the PHENIX
experiment at the Relativistic Heavy-Ion Collider. Cross sections for the
inclusive Upsilon(1S+2S+3S) production are obtained. The inclusive yields per
binary collision for d+Au collisions relative to those in p+p collisions
(R_dAu) are found to be 0.62 +/- 0.26 (stat) +/- 0.13 (syst) in the gold-going
direction and 0.91 +/- 0.33 (stat) +/- 0.16 (syst) in the deuteron-going
direction. The measured results are compared to a nuclear-shadowing model,
EPS09 [JHEP 04, 065 (2009)], combined with a final-state breakup cross section,
sigma_br, and compared to lower energy p+A results. We also compare the results
to the PHENIX J/psi results [Phys. Rev. Lett. 107, 142301 (2011)]. The rapidity
dependence of the observed Upsilon suppression is consistent with lower energy
p+A measurements.Comment: 495 authors, 11 pages, 9 figures, 5 tables. Submitted to Phys. Rev.
C. Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
Double Spin Asymmetry of Electrons from Heavy Flavor Decays in p+p Collisions at sqrt(s)=200 GeV
We report on the first measurement of double-spin asymmetry, A_LL, of
electrons from the decays of hadrons containing heavy flavor in longitudinally
polarized p+p collisions at sqrt(s)=200 GeV for p_T= 0.5 to 3.0 GeV/c. The
asymmetry was measured at mid-rapidity (|eta|<0.35) with the PHENIX detector at
the Relativistic Heavy Ion Collider. The measured asymmetries are consistent
with zero within the statistical errors. We obtained a constraint for the
polarized gluon distribution in the proton of |Delta g/g(log{_10}x=
-1.6^+0.5_-0.4, {mu}=m_T^c)|^2 < 0.033 (1 sigma), based on a leading-order
perturbative-quantum-chromodynamics model, using the measured asymmetry.Comment: 385 authors, 17 pages, 15 figures, 5 tables. Submitted to Phys. Rev.
D. Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
The predictive and prognostic potential of plasma telomerase reverse transcriptase (TERT) RNA in rectal cancer patients
Background: Preoperative chemoradiotherapy (CRT) followed by surgery is the standard care for locally advanced rectal cancer,
but tumour response to CRT and disease outcome are variable. The current study aimed to investigate the effectiveness of plasma
telomerase reverse transcriptase (TERT) levels in predicting tumour response and clinical outcome.
Methods: 176 rectal cancer patients were included. Plasma samples were collected at baseline (before CRT\ubcT0), 2 weeks after
CRT was initiated (T1), post-CRT and before surgery (T2), and 4\u20138 months after surgery (T3) time points. Plasma TERT mRNA levels
and total cell-free RNA were determined using real-time PCR.
Results: Plasma levels of TERT were significantly lower at T2 (Po0.0001) in responders than in non-responders. Post-CRT TERT
levels and the differences between pre- and post-CRT TERT levels independently predicted tumour response, and the prediction
model had an area under curve of 0.80 (95% confidence interval (CI) 0.73\u20130.87). Multiple analysis demonstrated that patients with
detectable TERT levels at T2 and T3 time points had a risk of disease progression 2.13 (95% CI 1.10\u20134.11)-fold and 4.55 (95% CI
1.48\u201313.95)-fold higher, respectively, than those with undetectable plasma TERT levels.
Conclusions: Plasma TERT levels are independent markers of tumour response and are prognostic of disease progression in rectal
cancer patients who undergo neoadjuvant therapy
Measurement of long-range angular correlation and quadrupole anisotropy of pions and (anti)protons in central Au collisions at =200 GeV
We present azimuthal angular correlations between charged hadrons and energy
deposited in calorimeter towers in central Au and minimum bias
collisions at GeV. The charged hadron is measured at
midrapidity , and the energy is measured at large rapidity
(, Au-going direction). An enhanced near-side angular
correlation across 2.75 is observed in Au collisions.
Using the event plane method applied to the Au-going energy distribution, we
extract the anisotropy strength for inclusive charged hadrons at
midrapidity up to GeV/. We also present the measurement of
for identified and (anti)protons in central Au collisions,
and observe a mass-ordering pattern similar to that seen in heavy ion
collisions. These results are compared with viscous hydrodynamic calculations
and measurements from Pb at TeV. The magnitude of
the mass-ordering in Au is found to be smaller than that in Pb
collisions, which may indicate smaller radial flow in lower energy Au
collisions.Comment: 424 authors, 8 pages, and 4 figures. v2 is version accepted for
publication in Phys. Rev. Lett. Published version will be at
http://www.phenix.bnl.gov/phenix/WWW/info/pp1/161/ Plain text data tables
will be at http://www.phenix.bnl.gov/papers.htm
Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d+Au collisions at sqrt(s_NN)=200 GeV
The PHENIX experiment has measured open heavy-flavor production via
semileptonic decay muons over the transverse momentum range 1 < pT < 6 GeV/c at
forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p+p collisions at
?sNN = 200 GeV. In central d+Au collisions an enhancement (suppression) of
heavy-flavor muon production is observed at backward (forward) rapidity
relative to the yield in p+p collisions scaled by the number of binary
collisions. Modification of the gluon density distribution in the Au nucleus
contributes in terms of anti-shadowing enhancement and shadowing suppression;
however, the enhancement seen at backward rapidity exceeds expectations from
this effect alone. These results, implying an important role for additional
cold nuclear matter effects, serves as a key baseline for heavy-quark
measurements in A+A collisions and in constraining the magnitude of charmonia
breakup effects at the Relativistic Heavy Ion Collider and the Large Hadron
Collider.Comment: 424 authors, 69 insitutions, 8 pages, 4 figures. Submitted to
Physical Review Letters. Plain text data tables for the points plotted in
figures for this and previous PHENIX publications are (or will be) publicly
available at http://www.phenix.bnl.gov/papers.htm
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