Publications by authors named "Valerie A Williams"

Background: The lung cancer screening program at St Elizabeth Healthcare (Kentucky, USA) began in 2013. Over 33,000 low-dose computed tomography lung cancer screens have been performed. From 2015 through 2021, 2595 lung cancers were diagnosed systemwide.

View Article and Find Full Text PDF

Elemental silver was used as a reducing agent in the atom transfer radical polymerization (ATRP) of acrylates. Silver wire, in conjunction with a CuBr(2)/TPMA catalyst, enabled the controlled, rapid preparation of polyacrylates with dispersity values down to Đ = 1.03.

View Article and Find Full Text PDF

Nacnac-based tetradentate chelates, {nacnac-(CH2py)2}(-) ({nn(PM)2}(-)) and {nacnac-(CH2py)(CHpy)}(n) ({nn(PM)(PI)}(n)) have been investigated in iron complexes. Treatment of Fe{N(TMS)2}2(THF) with {nn(PM)2}H afforded {nn(PM)2}FeN(TMS)2 [1-N(TMS)2], which led to {nn(PM)2}FeCl (1-Cl) from HCl and to {nn(PM)2}FeN3 (1-N3) upon salt metathesis. Dehydroamination of 1-N(TMS)2 was induced by L (L = PMe3, CO) to afford {nn(PM)(PI)}Fe(PMe3)2 [2-(PMe3)2] and {nn(PM)(PI)}FeCO (3-CO).

View Article and Find Full Text PDF

Molecular orbital analysis depicts the CNC(nb) backbone of the smif (1,3-di-(2-pyridyl)-2-azaallyl) ligand as having singlet diradical and/or ionic character where electrophilic or nucleophilic attack is plausible. Reversible dimerization of (smif)Fe{N(SiMe3)2} (1) to [{(Me3Si)2N}Fe]2(μ-κ(3),κ(3)-N,py2-smif,smif) (2) may be construed as diradical coupling. A proton transfer within the backbone-methylated, and o-pyridine-methylated smif of putative ((b)Me2(o)Me2smif)FeN(SiMe3)2 (8) provides a route to [{(Me3Si)2N}Fe]2(μ-κ(4),κ(4)-N,py2,C-((b)Me,(b)CH2,(o)Me2(smif)H))2 (9).

View Article and Find Full Text PDF

A heterobimetallic complex with the first unsupported bond between an actinide and a group 13 element, (CpSiMe3)3U-AlCp* (Cp* = C5Me5) (1), was synthesized by reaction of (CpSiMe3)3U and 1/4(Cp*Al)4 in toluene. Density functional theory calculations indicate that the U-Al bond exhibits some covalent character resulting from a Cp*Al-->U charge-transfer.

View Article and Find Full Text PDF

Background: The increasing adoption of endoscopic therapies and expectant surveillance for patients with high grade dysplasia (HGD) in Barrett's esophagus has created considerable controversy regarding the ideal treatment choice. Confusion may be due, in part, to a limited understanding of the outcomes associated with surgical resection for HGD and extrapolation of data derived from patients undergoing an esophagectomy for invasive cancer. The purpose of our study was to document the perioperative and symptomatic outcomes and long-term survival after esophagectomy for HGD of the esophagus.

View Article and Find Full Text PDF

Hypothesis: Bile acid exposure can induce caudal-related homeobox 2 (CDX2) messenger RNA (mRNA) expression, a transcription factor that plays a crucial role in the development of Barrett esophagus. We investigated mucin 2 (MUC2) and CDX2 mRNA expression before and after treatment with deoxycholic acid in 4 human esophageal cell lines.

Design, Setting, And Participants: Four human esophageal cell lines-(1) normal squamous cells immortalized by SV40 (Het-1A), (2) adenocarcinoma (SEG-1), and (3 and 4) squamous cell carcinoma (HKESC-1 and HKESC-2)-were exposed in culture for 1 to 24 hours to 100 microM to 1000 microM deoxycholic acid.

View Article and Find Full Text PDF

Introduction: Clinical evidence strongly suggests that bile acids are important in the development of Barrett's esophagus, although the mechanism remains unknown. Caudal-related homeobox 2 (CDX2) is a transcription factor recently implicated in early differentiation and maintenance of normal intestinal epithelium and is suggested to play a key role in the pathogenesis of intestinal metaplasia in Barrett's esophagus.

Objective: The aim of this study was to investigate the effect of primary and secondary bile acids on CDX2 mRNA expression in human esophageal cells.

View Article and Find Full Text PDF

The decision for, and choice of, a remedial antireflux procedure after a failed fundoplication is a challenging clinical problem. Success depends upon many factors including the primary symptom responsible for failure, the severity of underlying anatomic and physiologic defects, and the number and type of previous remedial attempts. Satisfactory outcomes after reoperative fundoplication have been reported to be as low as 50%.

View Article and Find Full Text PDF

The incidence of esophageal adenocarcinoma is rising faster the any other cancer in the United States. Studies from around the world strongly suggest that for early cancers of the lower esophagus and cardia, en bloc esophagogastrectomy results in significantly better survival rates than does transhiatal esophagogastrectomy.

View Article and Find Full Text PDF

Background: Assessment of the cervical spine (c-spine) in the obtunded blunt trauma patient remains a diagnostic dilemma. In 2002, our institution implemented a new c-spine clearance guideline utilizing c-spine computed tomography (CT) and magnetic resonance imaging (MRI). This study evaluates the safety and efficacy of this guideline.

View Article and Find Full Text PDF