Publications by authors named "Sandy L Nguyen"

We present new chalcogenide compounds, Ag2Te(MS2)3 (M = V, Nb), built up of alternating planes of [MS2] and [Ag2Te]. The Ag and Te atoms are linearly coordinated by S atoms in the [MS2] layers and held in place by covalent interactions. Structural polymorphism was found by single crystal X-ray diffraction studies, where long-range ordering or disorder of the Ag and Te atoms within the hexagonal planar [Ag2Te] layer yielded two distinct crystal forms.

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The layered compounds RbAg(2)TeS(6) and CsAg(2)TeS(6) crystallize in the noncentrosymmetric space group P6(3)cm, with a = 19.15 Å, c = 14.64 Å, and V = 4648 Å(3) and a = 19.

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Single crystals of ReB(2) have been prepared from an aluminum flux under inert gas flow. The crystals are typically 1-3 mm in diameter and 500 microm thick, growing along the [002] direction with a distinct hexagonal morphology. Vickers microhardness and nanoindentation testing indicate that the (002) plane possesses the highest hardness with measured values of 40.

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Toll-like receptors (TLR) have been shown to be expressed on various types of cancers; however, their functional activity is not known. We examined TLR profiles of human melanoma cells and showed that TLR2, TLR3, and TLR4 were found to be highly expressed. By PCR array analysis, specific stimulation of TLR2, TLR3, and TLR4 on melanoma cells showed significant activation of the adaptor protein MyD88, as well as downstream signal transduction factors nuclear factor-kappaB and inflammatory response-related factors.

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Circulating extracellular nucleic acids derived from body fluids such as blood are commonly analyzed to assess malignant diseases. Efficient isolation, extraction, quantification, modification, and analysis methods remain important for utilizing circulating nucleic acids as potential molecular biomarkers. Our refined techniques of DNA isolation from serum, sodium bisulfite modification of extracted DNA, and methylation analysis provide a robust approach for quantitative analysis of circulating tumor-related DNA.

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Developing a noninvasive test for detecting and monitoring breast cancer progression would help in providing better procedures for the treatment of breast cancer. Increases in the absolute quantity of circulating DNA and DNA integrity have been previously reported in breast cancer patients. LINE1 is one of the most abundant sequences in the human genome, with about 520,000 copies per genome.

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Purpose: Detection of micrometastasis in melanoma-draining lymph nodes is important for staging and prognosis. Immunohistochemical staining (IHC) using S-100p-HMB-45-, and MART-1-specific antibodies is used for detecting metastases in sentinel lymph nodes (SLN). However, improvement in IHC is needed for melanoma micrometastasis detection.

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Introduction: Estrogen receptor (ER)-positive breast cancers are considered prognostically more favorable than ER-negative tumors, whereas human epidermal growth factor receptor (HER)2/neu-positive breast cancers are associated with worse prognosis. The objective of the present study was to determine whether ER-positive and ER-negative status relates to epigenetic changes in breast cancer-related genes. To evaluate epigenetic differences in tumor-related genes relating to ER and HER2/neu status of primary tumors, we examined the promoter methylation status of the promoter region CpG islands of eight major breast tumor-related genes (RASSF1A, CCND2, GSPT1, TWIST, APC, NES1, RARbeta2, and CDH1).

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The role of estrogen receptor alpha (ER-alpha) in melanoma is unknown. ER-alpha expression may be regulated in melanoma via hypermethylation of promoter CpG islands. We assessed ER-alpha hypermethylation in primary and metastatic melanomas and sera as a potential tumor progression marker.

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Purpose: Currently, no validated blood-based assays accurately predict treatment response or outcome in melanoma patients. We hypothesized that methylation of tumor-related genes detected in serum DNA could predict disease outcome and therapeutic response in patients receiving concurrent biochemotherapy (BC) for metastatic melanoma.

Patients And Methods: American Joint Committee on Cancer stage IV melanoma patients (N = 50) had blood drawn before administration of BC.

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