Background Polyethylene glycol (PEG) is a commonly used bowel preparation for colonoscopy. Unfortunately, the standard large-volume solution may reduce patient compliance. Split-dosing of PEG has ...been studied in various randomized, controlled trials (RCTs). However, results have been conflicting. Objective We conducted a meta-analysis to assess the role of split-dose PEG versus full-dose PEG for bowel preparation before colonoscopy. Design Multiple databases were searched (January 2011). RCTs on adults comparing full-dose and split-dose of PEG for bowel preparation before colonoscopy were included and analyzed by calculating pooled estimates of quality of bowel preparation, preparation compliance, willingness to repeat the same preparation, and side effects by using odds ratio (OR) by fixed and random-effects models. Setting Literature search. Patients Per RCTs. Main Outcome Measurements Satisfactory bowel preparation, willingness to repeat same bowel preparation, patient compliance, and side effects. Results Five trials met inclusion criteria (N = 1232). Split-dose PEG significantly increased the number of satisfactory bowel preparations (OR 3.70; 95% CI, 2.79-4.91; P < .01) and willingness to repeat the same preparation (OR 1.76; 95% CI, 1.06-2.91; P = .03) compared with full-dose PEG. Split-dose PEG also significantly decreased the number of preparation discontinuations (OR 0.53; 95% CI, 0.28-0.98; P = .04) and nausea (OR 0.55; 95% CI, 0.38-0.79; P < .01) compared with full-dose PEG. Limitations Limited number of studies. Conclusions The use of a split-dose PEG for bowel preparation before colonoscopy significantly improved the number of satisfactory bowel preparations, increased patient compliance, and decreased nausea compared with the full-dose PEG.
Peroxisome Proliferator Activated Receptor gamma (PPARγ) agonists, such as the thiazolinediones (TZDs), have been studied for their potential use as cancer therapeutic agents. We investigated the ...effect of four TZDs--Rosiglitazone (Rosi), Ciglitazone (CGZ), Troglitazone (TGZ), and Pioglitazone (Pio)--on ovarian cancer cell proliferation, PPARγ expression and PPAR luciferase reporter activity. We explored whether TZDs act in a PPARγ dependent or independent manner by utilizing molecular approaches to inhibit or overexpress PPARγ activity.
Treatment with CGZ or TGZ for 24 hours decreased proliferation in three ovarian cancer cell lines, Ovcar3, CaOv3, and Skov3, whereas Rosi and Pio had no effect. This decrease in Ovcar3 cell proliferation was due to a higher fraction of cells in the G(0)/G(1) stage of the cell cycle. CGZ and TGZ treatment increased apoptosis after 4 hours of treatment but not after 8 or 12 hours. Treatment with TGZ or CGZ increased PPARγ mRNA expression in Ovcar3 cells; however, protein levels were unchanged. Surprisingly, luciferase promoter assays revealed that none of the TZDs increased PPARγ activity. Overexpression of wild type PPARγ increased reporter activity. This was further augmented by TGZ, Rosi, and Pio indicating that these cells have the endogenous capacity to mediate PPARγ transactivation. To determine whether PPARγ mediates the TZD-induced decrease in proliferation, cells were treated with CGZ or TGZ in the absence or presence of a dominant negative (DN) or wild type overexpression PPARγ construct. Neither vector changed the TZD-mediated cell proliferation suggesting this effect of TZDs on ovarian cancer cells may be PPARγ independent.
CGZ and TGZ cause a decrease in ovarian cancer cell proliferation that is PPARγ independent. This concept is supported by the finding that a DN or overexpression of the wild type PPARγ did not affect the changes in cell proliferation and cell cycle.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We have previously demonstrated that peroxisome proliferator-activated receptor gamma (PPARγ) is expressed and transcriptionally responsive to both synthetic and natural ligands in a variety of human ...breast cancer cells. We also observed significant differences in basal and ligand-mediated transactivation of PPARγ in cells with variable expression of the estrogen receptor. While previous reports indicate that PPARγ can mediate the expression of estrogen target genes, no data have suggested that estrogen receptor (ER) expression can alter the transcriptional regulation of PPARγ target gene expression. Here we have demonstrated that the expression of either ERα or β, but not the androgen or aryl hydrocarbon receptors, lowers both basal and stimulated PPARγ-mediated reporter activity. Interestingly, the presence of an ER antagonist does not inhibit this response while estradiol treatment further inhibits the ligand-stimulated transactivation of PPARγ in cells expressing ERα but not ERβ. Cells transfected with ERα deletion mutants demonstrate that the DNA binding domain of the ER is required to repress PPAR transactivation in these cells. Finally, using RNase protection assays we show that the inhibition of PPAR function is not due to a decrease in the expression of PPARγ. These data suggest that signal cross talk exists bidirectionally between PPARγ and ER in breast cancer cells.
Real emission corrections to Higgs production via gluon-fusion, at order
α
s
4, lead to a Higgs plus two-jet final state. We present the calculation of these scattering amplitudes, as induced by ...top-quark triangle-, box- and pentagon-loop diagrams. These diagrams are evaluated analytically for arbitrary top mass
m
t
. We study the renormalization and factorization scale-dependence of the resulting
H+2 jet cross section, and discuss phenomenologically important distributions at the LHC. The gluon-fusion results are compared to expectations for weak-boson fusion cross sections.
Peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily and is highly expressed in many human tumors including breast cancer. PPARgamma ...has been identified as a potential target for breast cancer therapy based on the fact that its activation by synthetic ligands affects the differentiation, proliferation, and apoptosis of cancer cells. However, the controversial nature of current studies and disappointing results from clinical trials raise questions about the contribution of PPARgamma signaling in breast cancer development in the absence of stimulation by exogenous ligands. Recent reports from both in vitro and in vivo studies are inconsistent and suggest that endogenous activation of PPARgamma plays a much more complex role in initiation and progression of cancer than previously thought.
We have previously demonstrated that an increase in expression of PPARgamma1 in MCF-7 breast cancer cells is driven by a tumor-specific promoter. Myc-associated zinc finger protein (MAZ) was identified as a transcriptional mediator of PPARgamma1 expression in these cells. In this study, using RNA interference (RNAi) to inhibit PPARgamma1 expression directly or via down-regulation of MAZ, we report for the first time that a decrease in PPARgamma1 expression results in reduced cellular proliferation in MCF-7 breast cancer cells. Furthermore, we demonstrate that these changes in proliferation are associated with a significant decrease in cell transition from G1 to the S phase. Using a dominant-negative mutant of PPARgamma1, Delta462, we confirmed that PPARgamma1 acts as a pro-survival factor and showed that this phenomenon is not limited to MCF-7 cells. Finally, we demonstrate that down-regulation of PPARgamma1 expression leads to an induction of apoptosis in MCF-7 cells, confirmed by analyzing Bcl-2 expression and PARP-1 cleavage.
Thus, these findings suggest that an increase in PPARgamma1 signaling observed in breast cancer contributes to an imbalance between proliferation and apoptosis, and may be an important hallmark of breast tumorigenesis. The results presented here also warrant further investigation regarding the use of PPARgamma ligands in patients who are predisposed or already diagnosed with breast cancer.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Real-emission corrections to gg-->H, which lead to H+2 jet events, are calculated at order alpha(4)(s). Contributions include top-quark triangles, boxes, and pentagon diagrams and are evaluated ...analytically for arbitrary top mass m(t). This new source of H+2 jet events is compared to the weak-boson fusion cross section for a range of Higgs boson masses. The heavy top-mass approximation appears to work well for intermediate Higgs-boson masses, provided that the transverse momenta of the final-state partons are smaller than the top-quark mass.
Millions of tons of acetyl derivatives such as acetic acid and acetic anhydride are produced each year. These building blocks of chemical industry are elaborated into esters, amides, and eventually ...polymer materials, pharmaceuticals, and other consumer products. Most acetyls are produced industrially using homogeneous precious metal catalysts, principally rhodium and iridium complexes. We report here that abundant nickel can be paired with imidazole-derived carbenes or the corresponding salts to catalyze methyl ester carbonylation with turnover frequency (TOF) exceeding 150 hour
–1
and turnover number (TON) exceeding 1600, benchmarks that invite comparisons to state-of-the-art rhodium-based systems and considerably surpass known triphenylphosphine-based nickel catalysts, which operate with TOF ~7 hour
–1
and TON ~100 under the same conditions.
Editor’s summary
The conversion of methanol to acetic acid and related ester carbonylation reactions are cornerstones of modern industrial chemistry. Current practice relies on precious rhodium or iridium catalysts for the carbon monoxide insertion chemistry. Yoo
et al
. now report promising laboratory-scale results using more Earth-abundant nickel as the catalyst. Key to the robustness of the nickel under the reaction conditions is complexation with N-heterocycle carbene ligands in place of more conventional phosphines. —Jake S. Yeston
Imidazole-derived carbene ligands establish the promise of abundant nickel catalysts in industrially relevant carbonylations.
We present universal factorization formulas describing the behavior of one-loop QCD amplitudes as external momenta become either soft or collinear. Our results are valid to all orders in the ...dimensional regularization parameter, {epsilon}. Terms through O({epsilon}{sup 2}) can contribute in infrared divergent phase space integrals associated with next-to-next-to-leading order jet cross sections. (c) 1999 The American Physical Society.
Sixty-two patients with coccidioidal meningitis underwent neuroimaging. Magnetic resonance imaging detected neuroimaging abnormalities in 76% of patients, and computed tomography scanning detected ...neuroimaging abnormalities in 41.6%. The most common abnormal neuroimaging findings were hydrocephalus (51.6%), basilar meningitis (46.8%), and cerebral infarction (38.7%). Significantly elevated mortality rates were associated with hydrocephalus and hydrocephalus coexisting with infarction. Basilar meningitis did not influence outcome. Patients without neuroimaging abnormalities had a mortality rate of 7.7%.
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