James F. Leary

Lymphocytes in the human gastric mucosa during Helicobacter pylori have a T helper cell 1 phenotype

BACKGROUND & AIMS Studies have shown that gastric T cells are increased during Helicobacter pylori infection. The purpose of this study was to characterize the human gastric T-cell responses in the presence or absence of H. pylori. METHODS T-cell surface antigens were examined by immunohistochemistry or after isolation for evaluation of surface antigens and cytoplasmic cytokines using flow cytometry. RESULTS CD4+ and CD8+ T cells were increased in situ during infection with H. pylori. Freshly isolated gastric T cells expressed cytoplasmic interferon gamma (IFN-gamma) and interleukin (IL)-2 after a brief stimulation. Simultaneous four-color flow cytometry demonstrated that both CD8+ and CD4+ T cells expressed IFN-gamma. Because stimulation through CD30 favors the induction of IL-5 and Th2 cells, gastric and colonic T cells were examined for CD30 expression. Consistent with the notion that Th2 cells are found in the intestine, CD30 was evident throughout the lamina propria of the colon but was virtually absent in the stomach. Furthermore, freshly isolated gastric T cells produced little IL-4 and virtually no IL-5 or tumor necrosis factor beta. CONCLUSIONS These observations show that gastric T cells resemble the Th1 type, which may explain their failure to induce immunity to H. pylori and their ability to contribute to the pathogenesis of gastric disease.

Tumor-targeting hyaluronic acid nanoparticles for photodynamic imaging and therapy

Tumor-targeted imaging and therapy have been the challenging issue in the clinical field. Herein, we report tumor-targeting hyaluronic acid nanoparticles (HANPs) as the carrier of the hydrophobic photosensitizer, chlorin e6 (Ce6) for simultaneous photodynamic imaging and therapy. First, self-assembled HANPs were synthesized by chemical conjugation of aminated 5β-cholanic acid, polyethylene glycol (PEG), and black hole quencher3 (BHQ3) to the HA polymers. Second, Ce6 was readily loaded into the HANPs by a simple dialysis method resulting in Ce6-loaded hyaluronic acid nanoparticles (Ce6-HANPs), wherein in the loading efficiency of Ce6 was higher than 80%. The resulting Ce6-HANPs showed stable nano-structure in aqueous condition and rapid uptake into tumor cells. In particular Ce6-HANPs were rapidly degraded by hyaluronidases abundant in cytosol of tumor cells, which may enable intracellular release of Ce6 at the tumor tissue. After an intravenous injection into the tumor-bearing mice, Ce6-HANPs could efficiently reach the tumor tissue via the passive targeting mechanism and specifically enter tumor cells through the receptor-mediated endocytosis based on the interactions between HA of nanoparticles and CD44, the HA receptor on the surface of tumor cells. Upon laser irradiation, Ce6 which was released from the nanoparticles could generate fluorescence and singlet oxygen inside tumor cells, resulting in effective suppression of tumor growth. Overall, it was demonstrated that Ce6-HANPs could be successfully applied to in vivo photodynamic tumor imaging and therapy simultaneously.

Conjugated polymer nanoparticles for biomedical in vivo imaging

Conjugated polymer nanoparticles, produced by in situ colloidal Knoevenagel polymerization, show advantageous properties (bright emission, colloidal/chemical stability and mesoscopic size range) that allow the successful in vivo application to real-time sentinel lymph node mapping in a mouse model.

Nanoparticles for multimodal in vivo imaging in nanomedicine

While nanoparticles are usually designed for targeted drug delivery, they can also simultaneously provide diagnostic information by a variety of in vivo imaging methods. These diagnostic capabilities make use of specific properties of nanoparticle core materials. Near-infrared fluorescent probes provide optical detection of cells targeted by real-time nanoparticle-distribution studies within the organ compartments of live, anesthetized animals. By combining different imaging modalities, we can start with deep-body imaging by magnetic resonance imaging or computed tomography, and by using optical imaging, get down to the resolution required for real-time fluorescence-guided surgery.

Nanotechnology in ophthalmology.

Nanotechnology involves the creation and use of materials and devices at the size scale of intracellular structures and molecules, and involves systems and constructs in the order of <100 nm. The aim of nanomedicine is the comprehensive monitoring, control, construction, repair, defence, and improvement of human biological systems at the molecular level, using engineered nanodevices and nanostructures that operate massively in parallel at the single-cell level, ultimately to achieve medical benefit. In this review we consider general principles of nanotechnology as applied to nanomedicine (e.g., biomimicry and pseudointelligence). Some applications of nanotechnology to ophthalmology are described (including treatment of oxidative stress; measurement of intraocular pressure; theragnostics; use of nanoparticles to treat choroidal new vessels, prevent scarring after glaucoma surgery, and treat retinal degenerative disease with gene therapy; prosthetics; and regenerative nanomedicine). Nanotechnology will revolutionize our approach to current therapeutic challenges (e.g., drug delivery, postoperative scarring) and will enable us to address currently unsolvable problems (e.g., sight-restoring therapy for patients with retinal degenerative disease). Obstacles to the incorporation of nanotechnology remain, such as safe manufacturing techniques and unintended biological consequences of nanomaterial use. These obstacles are not insurmountable, and revolutionary treatments for ophthalmic diseases are expected to result from this burgeoning field.

Theranostic nanoparticles for future personalized medicine.

The concept of personalized medicine has recently emerged as a promising way to address unmet medical needs. Due to the limitations of standard diagnostic and therapeutic strategies, the disease treatment is moving towards tailored treatment for individual patients, considering the inter-individual variability in therapeutic response. Theranostics, which involves the combination of therapy and diagnostic imaging into a single system, may fulfill the promise of personalized medicine. By integrating molecular imaging functionalities into therapy, theranostic approach could be advantageous in therapy selection, treatment planning, objective response monitoring and follow-up therapy planning based on the specific molecular characteristics of a disease. Although the field of therapy and imaging of its response have been independently developed thus far, developing imaging strategies can be fully exploited to revolutionize the theranostic systems in combination with the therapy modality. In this review, we describe the recent advances in molecular imaging technologies that have been specifically developed to evaluate the therapeutic efficacy for theranostic purposes.

Getting the Right Cells to the Array: Gene Expression Microarray Analysis of Cell Mixtures and Sorted Cells

Most biological samples are cell mixtures. Some basic questions are still unanswered about analyzing these heterogeneous samples using gene expression microarray technology (MAT). How meaningful is a cell mixtures overall gene expression profile (GEP)? Is it necessary to purify the cells of interest before microarray analysis, and how much purity is needed? How much does the purification itself distort the GEP, and how well can the GEP of a small cell subset be recovered?

Cytomics—New Technologies: Towards a Human Cytome Project

Molecular cell systems research (cytomics) aims at the understanding of the molecular architecture and functionality of cell systems (cytomes) by single‐cell analysis in combination with exhaustive bioinformatic knowledge extraction. In this way, loss of information as a consequence of molecular averaging by cell or tissue homogenisation is avoided.

Laser Flow Cytometric Light Scatter and Fluorescence Pulse Width and Pulse Rise-Time Sizing of Mammalian Cells'

In laser flow cytometry, an increasingly popular technique of analytical cytology, quantitative measurements of interest include cell and nuclear diameters. Electronic circuitry for a new cell sizing technique has been developed which measured the time that signal pulses from either fluorescence or light scatter sensors exceed a preset constant fraction of the peak signal amplitude (pulse width) or the time that it takes a signal to rise between constant fractions of the peak signal amplitude on the rising side of the pulse (pulse rise-time). These pulse width or pulse rise-time measurements were related to cell or nuclear diameters and were used in combination to determine nuclear size to cell size ratios. This method of sizing was found to be independent of fluorescent or light-absorbing stain intensity, linearly related to cell or nuclear diameter, and capable of resolving small diameter differences.

Mitochondrial glutathione modulates TNF-α-induced endothelial cell dysfunction

Abstract The effect of glutathione (GSH) depletion by L-buthionine-[S,R]-sulphoximine (BSO) on tumor necrosis factor-α (TNF-α)-induced adhesion molecule expression and mononuclear leukocyte adhesion to human umbilical vein endothelial cells (HUVECs) was investigated. Cells with marked depletion of cytoplasmic GSH, but with an intact pool of mitochondrial GSH, only slightly enhanced TNF-α-induced E-selectin and vascular cell adhesion molecule-1 (VCAM-1) expression, compared with the control. However, TNF-α-induced expression of both molecules was markedly enhanced when the mitochondrial GSH pool was diminished to