Two Phases of Monolayer Tantalum Sulfide on Au(111).

We prepared monolayers of tantalum sulfide on Au(111) by evaporation of Ta in a reactive background of HS. Under sulfur-rich conditions, monolayers of 2H-TaS formed, whereas under sulfur-poor conditions TaS with 0 ≤ ≤ 1 were found. We identified this phase as TaS, a structure that can be derived from 2H-TaS by removal of the bottom S layer.

Band Bending and Valence Band Quantization at Line Defects in MoS.

The variation of the electronic structure normal to 1D defects in quasi-freestanding MoS, grown by molecular beam epitaxy, is investigated through high resolution scanning tunneling spectroscopy at 5 K. Strong upward bending of valence and conduction bands toward the line defects is found for the 4|4E mirror twin boundary and island edges but not for the 4|4P mirror twin boundary. Quantized energy levels in the valence band are observed wherever upward band bending takes place.

Environmental Control of Charge Density Wave Order in Monolayer 2H-TaS.

For quasi-freestanding 2H-TaS in monolayer thickness grown by molecular beam epitaxy on graphene on Ir(111), we find unambiguous evidence for a charge density wave close to a 3 × 3 periodicity. Using scanning tunneling spectroscopy, we determine the magnitude of the partial charge density wave gap. Angle-resolved photoemission spectroscopy, complemented by scanning tunneling spectroscopy for the unoccupied states, makes a tight-binding fit for the band structure of the TaS monolayer possible.

Tumor Infiltrating T Lymphocytes and Apoptosis in Colorectal Cancer.

Dysfunction of the immune system in colorectal cancer (CRC) can be due to a number of reasons including apoptosis of tumour infiltrating lymphocytes (TILs). The aims of this study was to investigate TILs in colorectal cancer and characterize apoptosis of TILs using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay for detecting DNA fragments. We used monoclonal antibodies (mAbs) to T lymphocytes to detect TILs and double immunohistochemistry to assess apoptosis.

Apoptosis of T-cell subsets in colorectal cancer in vivo.

Dysfunction of the immune system in colorectal cancer (CRC) can be due to a number of reasons including apoptosis of tumour infiltrating lymphocytes (TILs). The aims of this study were to characterize, phenotypically, the apoptosis of TILs in CRC, and define the association of these findings with prognostic indicators. We used double immunohistochemistry to assess the apoptosis of T-cell subsets.

Hypoxia-induced EMAP-II transcription in colorectal cancer.

Endothelial monocyte-activating polypeptide-II (p431EMAP-II) is a proinflammatory cytokine and a chemoattractant for mononuclear phagocytes and polymorphonuclear leucocytes, found in culture supernatants of many tumour cell lines. It was demonstrated that p43/EMAP-II induces apoptosis in mitogen-stimulated lymphocytes, and suggested that it may be a constituent of a novel immune evasion mechanism employed by tumour cells. Quantitative real-time reverse transcription- polymerase chain reaction (qRT-PCR) analysis for EMAP-II mRNA was performed for colorectal adenocarcinoma cell lines, DLD-1, HT 29; human umbilical vein endothelial cells (HUVEC); and normal colon under normal and hypoxic conditions.

Selective inhibition of the human tie-1 promoter with triplex-forming oligonucleotides targeted to Ets binding sites.

The Tie receptors (Tie-1 and Tie-2/Tek) are essential for angiogenesis and vascular remodeling/integrity. Tie receptors are up-regulated in tumor-associated endothelium, and their inhibition disrupts angiogenesis and can prevent tumor growth as a consequence. To investigate the potential of anti-gene approaches to inhibit tie gene expression for anti-angiogenic therapy, we have examined triple-helical (triplex) DNA formation at 2 tandem Ets transcription factor binding motifs (designated E-1 and E-2) in the human tie-1 promoter.

Low and high molecular weight poly(L-lysine)s/poly(L-lysine)-DNA complexes initiate mitochondrial-mediated apoptosis differently.

Poly(L-lysine)s, PLLs, are commonly used for DNA compaction and cell transfection. We report that, although PLLs of low (2.9 kDa), L-PLL, and high (27.

A two-stage poly(ethylenimine)-mediated cytotoxicity: implications for gene transfer/therapy.

Poly(ethylenimine) (PEI) is a cationic macromolecule commonly used in gene transfer/therapy protocols with high transfection efficiency both in vitro and in vivo. PEI is also cytotoxic, but the molecular basis of its cytotoxicity is poorly understood. Here, we have demonstrated that branched (25 kDa) and linear (750 kDa) PEI can both induce membrane damage and initiate apoptosis in three clinically relevant human cell lines (Jurkat T cells, umbilical vein endothelial cells, and THLE3 hepatocyte-like cells).

Nanomedicine: current status and future prospects.

Applications of nanotechnology for treatment, diagnosis, monitoring, and control of biological systems has recently been referred to as "nanomedicine" by the National Institutes of Health. Research into the rational delivery and targeting of pharmaceutical, therapeutic, and diagnostic agents is at the forefront of projects in nanomedicine. These involve the identification of precise targets (cells and receptors) related to specific clinical conditions and choice of the appropriate nanocarriers to achieve the required responses while minimizing the side effects.

Identification of an HLA-A*0201 cytotoxic T lymphocyte epitope specific to the endothelial antigen Tie-2.

Tie-2 stabilises pericyte-endothelial interactions during angiogenesis and is highly expressed on endothelium during several diseases, including arthritis, age-related macular degeneration and cancer. A vaccine that targets endothelium overexpressing Tie-2 may result in vessel damage and stimulate an inflammatory cascade resulting in disease regression. We have identified a region unique to Tie-2 (amino acids 1-196) that is homologous in humans and mice.

Colorectal cancer cells induce lymphocyte apoptosis by an endothelial monocyte-activating polypeptide-II-dependent mechanism.

Endothelial monocyte-activating polypeptide-II (EMAP-II) was first isolated from cell growth medium conditioned by tumor cells, and is closely related or identical with the p43 component of the mammalian multisynthase complex. In its secreted form, EMAP-II has multiple cytokine-like activities in vitro, inducing procoagulant activity on the surface of endothelial cells, increasing expression of E- and P-selectins and TNF-R1, and directing migration of monocytes and neutrophils. EMAP-II has also been shown to induce apoptosis in endothelial cells, leading to the suggestion that it is a proinflammatory polypeptide with antiangiogenic activity.

Biologic effects induced in vitro by PM10 from three different zones of Mexico City.

Exposure to urban airborne particles is associated with an increase in morbidity and mortality. There is little experimental evidence of the mechanisms involved and the role of particle composition. We assessed cytotoxicity (crystal violet assay), apoptosis [terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) or annexin V assay], DNA breakage (comet assay), and production of proinflammatory mediators [tumor necrosis factor Alpha (TNF-Alpha), interleukin 6 (IL-6), prostaglandin E2 (PGE2)] (enzyme-linked immunosorbent assay), and E-selectin (flow cytometry) in cell lines exposed to particulate matter < 10 microm in size (PM10) obtained from the northern, central, and southern zones of Mexico City.

Vascular endothelial growth factor-D expression is an independent prognostic marker for survival in colorectal carcinoma.

The angiogenic factor vascular endothelial growth factor-D (VEGF-D) isa ligand for VEGF receptor-3 (VEGFR-3/Flt-4) and receptor-2 (VEGFR-2/KDR)and is implicated in the development of lymphatic vessels and promotion of lymphatic metastases. We assessed the expression of VEGF-D and VEGFR-3 in relation to microvessel density (MVD) in colorectal carcinomas (CRC), adenomas, and adjacent normal tissue by immunohistochemistry on consecutive archival sections. VEGF-D was detected in malignant and benign epithelium and in some smooth muscle of the colorectum.

Selective expression of erg isoforms in human endothelial cells.

Erg and Fli-1 are closely related members of the ets family of transcription factors. There are at least five human Erg isoforms (Erg-1, Erg-2, Erg-3/p55(Erg), p49(Erg) and p38(Erg)) produced through differential mRNA splicing and alternative use of translational start codons. However, relatively little is known about the expression or function of these isoforms in vitro or their distribution in vivo.