Significance The normal prostate gland contains the most Zn(II) of all mammalian tissues, and there are marked differences in content between healthy, malignant, benign hyperplastic prostate. Given that multiparametric MRI does not always reliably distinguish these tissue conditions, release ions from response to an external stimulus may prove valuable as a specific biomarker cancer progression. In this work, we show glucose stimulates intracellular stores healthy secretion is reduced...

Given the known water exchange rate limitations of a previously reported Zn(II)-sensitive MRI contrast agent, GdDOTA-diBPEN, new structural targets were rationally designed to increase improve detection sensitivity. These sensors exhibit fine-tuned properties and, depending on individual structure, demonstrate significantly improved longitudinal relaxivities (r1). Two in particular optimized parameters therefore, show exceptionally high about 50 mM(-1) s(-1) upon binding Zn(II) and human...

It has been demonstrated that divalent zinc ions packaged with insulin in β-cell granules can be detected by MRI during glucose-stimulated secretion using a gadolinium-based Zn2+-sensitive agent. This study was designed to evaluate whether simpler agent design having single Zn2+-sensing moieties but variable Zn2+ binding affinities might also detect from the pancreas. Using an implanted MR-compatible window hold pancreas fixed position for imaging, we now demonstrate focally intense "hot...

We have screened peptoid microarrays to identify specific ligands for the RNA hairpin precursor of miR-21, a microRNA involved in cancer and heart disease. Microarrays were printed by spotting library 7680 N-substituted oligoglycines (peptoids) onto glass slides. Two compounds on array specifically bind having sequence predicted secondary structure miR-21 affinity target solution. Their binding induces conformational change around loop, most compound recognizes loop bulged uridine proximal...

The design, synthesis, and properties of a new gadolinium-based copper-responsive magnetic resonance imaging (MRI) contrast agent is presented. sensor (GdL1) has high selectivity for copper ions exhibits 43% increase in r1 relaxivity (20 MHz) upon binding to 1 equiv Cu2+ aqueous buffer. Interestingly, the presence physiological levels human serum albumin (HSA), amplified further up 270%. Additional spectroscopic X-ray absorption spectroscopy (XAS) studies show that coordinated by two...

We have found a small molecule that specifically inhibits cleavage of precursor to the oncogenic miRNA, miR-21, by microprocessor complex Drosha and DGCR8. identified novel ligands for apical loop this from screen 14,024 N-substituted oligoglycines (peptoids) in microarray format. Eight distinct compounds with specific affinity were obtained, three having affinities targeted low micromolar range greater than 15-fold discrimination against closely related hairpin. One these completely miR-21...

A Mn(II)-based zinc-sensitive MRI contrast agent, MnPyC3A-BPEN, was prepared, characterized, and applied in imaging experiments to detect glucose-stimulated zinc secretion (GSZS) from the mouse pancreas prostate

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn unsymmetrical binuclear ruthenium(II) complex of tris(2-pyridyl)-1,3,5-triazine and its identification by proton NMR spectroscopySara Chirayil, Vidyadhar Hegde, Yurngdong Jahng, Randolph P. ThummelCite this: Inorg. Chem. 1991, 30, 13, 2821–2823Publication Date (Print):June 1, 1991Publication History Published online1 May 2002Published inissue 1 June...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of bis(2,2'-bipyridyl-d8)ruthenium(II) dichloride to facilitate NMR structural assignments in complexes with diimine ligandsSara Chirayil and Randolph P. ThummelCite this: Inorg. Chem. 1989, 28, 5, 812–813Publication Date (Print):March 1, 1989Publication History Published online1 May 2002Published inissue 1 March 1989https://pubs.acs.org/doi/10.1021/ic00304a002https://doi.org/10.1021/ic00304a002research-articleACS PublicationsRequest reuse...

We have used NMR spectroscopy to characterize an oligonucleotide stem loop structure based on the pre-element of oncogenic microRNA, miR-21. This predicted stem-loop is cleaved from precursor miR-21 (pre-miR-21) by nuclease Dicer. It also a critical feature recognized protein complex that converts primary transcript (pri-miR-21) into pre-miRNA. The secondary native sequence poorly defined due rapid exchange imino protons with solvent; however, replacement two adjacent putative G•U base pairs...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA ruthenium tris(diimine) complex with three different ligandsRandolph P. Thummel, Francois Lefoulon, and Sara ChirayilCite this: Inorg. Chem. 1987, 26, 18, 3072–3074Publication Date (Print):September 1, 1987Publication History Published online1 May 2002Published inissue 1 September 1987https://doi.org/10.1021/ic00265a031RIGHTS & PERMISSIONSArticle Views325Altmetric-Citations26LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of...

Prostatic zinc content is a known biomarker for discriminating normal healthy tissue from benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Given that not readily measured without biopsy, we have been exploring noninvasive imaging methods to detect these diagnostic differences using zinc-responsive MRI contrast agent. During studies in mice, observed bolus of glucose stimulates secretion the fasted mice. This discovery allowed use Gd-based sensor differential regions versus...

Paramagnetic chemical exchange saturation transfer (paraCEST) agents are well-suited for imaging tissue pH because the basis of CEST, exchange, is inherently sensitive to pH. Several previous pH-sensitive paraCEST were based on an exchanging Ln3+ -bound water molecule as CEST antenna but this design often added additional line-broadening bulk signal due T2 exchange. We report herein a agent that lacks inner-sphere contains one Ln-bound -OH group activation. The Yb3+ complex, Yb(1), displayed...

Abstract Background Excessive lactate production, a hallmark of cancer, is largely formed by the reduction pyruvate via dehydrogenase (LDH) to l -lactate. Although d -lactate can also be produced from glucose methylglyoxal pathway in small amounts, less known about amount cancer cells. Since stereoisomers cannot distinguished conventional 1 H NMR spectroscopy, chiral shift reagent was used fully resolve resonances - and Methods The production first demonstrated freshly isolated red blood...

An imaging method for detecting β-cell function in real-time the rodent pancreas could provide new insights into biological mechanisms involving loss of during development type 2 diabetes and testing drugs designed to modulate insulin secretion. In this study, we used a zinc-responsive MRI contrast agent an optimized 2D show that glucose stimulated zinc secretion can be detected as functionally active “hot spots” tail rat pancreas. A comparison functional images with histological markers...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBisannelated derivatives of 2,2'-bipyridineRandolph P. Thummel, Francois Lefoulon, Sara Chirayil, and Veronique GoulleCite this: J. Org. Chem. 1988, 53, 20, 4745–4747Publication Date (Print):September 1, 1988Publication History Published online1 May 2002Published inissue 1 September 1988https://pubs.acs.org/doi/10.1021/jo00255a015https://doi.org/10.1021/jo00255a015research-articleACS PublicationsRequest reuse permissionsArticle...

Non-invasive beta cell function measurements may provide valuable information for improving diabetes diagnostics and disease management as the integrity of pancreatic cells have been found to be compromised in Type-1 Type-2 diabetes. Currently, available assays either lack functional or spatial identification cells. In this work, we introduce a method assess non-human primate pancreas non-invasively with MRI using Gd-based zinc(II) sensor contrast agent, Gd-CP027. Additionally, highlight...

Abstract Remote control of cells : A polypeptide has been made that stimulates proliferation and migration upon photochemical activation. This light‐activated enables spatially defined cell populations at the scale tissue organization; this is accomplished without physically contacting or modifying their substrate. magnified image Polypeptide growth differentiation factors modulate a wide variety behaviors can be used to manipulate in vitro for engineering basic studies biology. To emulate...

Objectives In the United States, prostate cancer (PCa) is most common in men. Multi-parametric magnetic resonance imaging (MRI) increasingly being relied upon for diagnosis and characterization of PCa, but differentiating malignancy from benign prostatic hyperplasia (BPH) transition zone using MRI can be challenging. The characteristically high levels zinc human tissue a close relationship between malignant proliferation homeostatic dysregulation create opportunities to visualize PCa with...

Parahydrogen-induced polarization (PHIP) followed by transfer to

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIncorporation of the quinoline-5,8-quinone moiety into polyaza cavitiesRandolph P. Thummel, Sara Chirayil, Christophe Hery, Jean Luc Lim, and Tie Lin WangCite this: J. Org. Chem. 1993, 58, 7, 1666–1671Publication Date (Print):March 1, 1993Publication History Published online1 May 2002Published inissue 1 March 1993https://pubs.acs.org/doi/10.1021/jo00059a012https://doi.org/10.1021/jo00059a012research-articleACS PublicationsRequest reuse...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHeteroaromatic fused derivatives of tetracyclo[6.3.0.04,11.O5,9]undecaneJean Luc Lim, Sara Chirayil, and Randolph P. ThummelCite this: J. Org. Chem. 1991, 56, 4, 1492–1500Publication Date (Print):February 1, 1991Publication History Published online1 May 2002Published inissue 1 February 1991https://pubs.acs.org/doi/10.1021/jo00004a029https://doi.org/10.1021/jo00004a029research-articleACS PublicationsRequest reuse permissionsArticle...