Role of intestinal myofibroblasts in HIV-associated intestinal collagen deposition and immune reconstitution following combination antiretroviral therapy.

Objective: To investigate the potential role of mucosal intestinal myofibroblasts (IMFs) in HIV and associated fibrosis in gut-associated lymphoid tissue.

Design: Profibrotic changes within the secondary lymphoid organs and mucosa have been implicated in failed immune reconstitution following effective combination antiretroviral therapy (cART). Microbial translocation is believed to be sustaining these systemic inflammatory pathways.

Establishment of rules for interpreting ultraviolet autofluorescence microscopy images for noninvasive detection of Barrett's esophagus and dysplasia.

The diagnostic potential of autofluorescence (AF) microscopy under ultraviolet (UV) excitation is explored using ex vivo human specimens. The aim is to establish optical patterns (the rules for interpretation) that correspond to normal and abnormal histologies of the esophagus, spanning from early benign modifications (Barrett's esophagus) to subsequent dysplastic change and progression toward carcinoma. This was achieved by developing an image library categorized by disease progression.

Fluorescence lifetime imaging for the characterization of the biochemical composition of atherosclerotic plaques.

This study investigates the ability of a flexible fiberoptic-based fluorescence lifetime imaging microscopy (FLIM) technique to resolve biochemical features in plaque fibrotic cap associated with plaque instability and based solely on fluorescence decay characteristics. Autofluorescence of atherosclerotic human aorta (11 autopsy samples) was measured at 48 locations through two filters, F377: 377∕50 and F460: 460∕60 nm (center wavelength∕bandwidth). The fluorescence decay dynamic was described by average lifetime (τ) and four Laguerre coefficients (LECs) retrieved through a Laguerre deconvolution technique.

Endomicroscopy imaging of epithelial structures using tissue autofluorescence.

We explore autofluorescence endomicroscopy as a potential tool for real-time visualization of epithelial tissue microstructure and organization in a clinical setting. The design parameters are explored using two experimental systems--an Olympus Medical Systems Corp. stand-alone clinical prototype probe, and a custom built bench-top rigid fiber conduit prototype.

Dynamic tissue analysis using time- and wavelength-resolved fluorescence spectroscopy for atherosclerosis diagnosis.

Simultaneous time- and wavelength-resolved fluorescence spectroscopy (STWRFS) was developed and tested for the dynamic characterization of atherosclerotic tissue ex vivo and arterial vessels in vivo. Autofluorescence, induced by a 337 nm, 700 ps pulsed laser, was split to three wavelength sub-bands using dichroic filters, with each sub-band coupled into a different length of optical fiber for temporal separation. STWRFS allows for fast recording/analysis (few microseconds) of time-resolved fluorescence emission in these sub-bands and rapid scanning.

Characterizing the origin of autofluorescence in human esophageal epithelium under ultraviolet excitation.

The autofluorescence under ultraviolet excitation arising from normal squamous and columnar esophageal mucosa is investigated using multispectral microscopy. The results suggest that the autofluorescence signal arises from the superficial tissue layer due to the short penetration depth of the ultraviolet excitation. As a result, visualization of esophageal epithelial cells and their organization can be attained using wide-field autofluorescence microscopy.

Real-time microscopic imaging of esophageal epithelial disease with autofluorescence under ultraviolet excitation.

Detection of esophageal disease in current clinical practice is limited to visualization of macroscopic epithelial morphology. In this work, we investigate high resolution autofluorescence imaging under ultra violet excitation to visualize microscopic epithelial changes related to disease progression using a bench top prototype microscope. The approach is based on the hypothesis that UV excitation light can only penetrate the superficial layer of cells resulting in autofluorescence images of the epithelial layer without using an additional image sectioning approach.

Fluorescence lifetime imaging microscopy for the characterization of atherosclerotic plaques.

Atherosclerotic plaque composition has been associated with plaque instability and rupture. This study investigates the use of fluorescence lifetime imaging microscopy (FLIM) for mapping plaque composition and assessing features of vulnerability. Measurements were conducted in atherosclerotic human aortic samples using an endoscopic FLIM system (spatial resolution of 35 mum; temporal resolution 200 ps) developed in our lab which allows mapping in one measurement the composition within a volume of 4 mm diameter x 250 mum depth.

Development of a dual-modal tissue diagnostic system combining time-resolved fluorescence spectroscopy and ultrasonic backscatter microscopy.

We report a tissue diagnostic system which combines two complementary techniques of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and ultrasonic backscatter microscopy (UBM). TR-LIFS evaluates the biochemical composition of tissue, while UBM provides tissue microanatomy and enables localization of the region of diagnostic interest. The TR-LIFS component consists of an optical fiber-based time-domain apparatus including a spectrometer, gated multichannel plate photomultiplier, and fast digitizer.

Multimodal near infrared spectral imaging as an exploratory tool for dysplastic esophageal lesion identification.

We explore nine different combinations of fluorescence, light scattering, and polarization spectral imaging approaches in the near-infrare spectral region toward the diagnosis of pathologic and normal esophageal lesions. The combinations of all the imaging techniques were evaluated for maximal sensitivity and specificity. The results suggest that this multimodal approach is capable of highly accurate detection of the presence of pathologic tissue.

Lymphocytic infiltration of bladder after local cellular immunotherapy.

Background: This is a case report of a patient who received cellular immunotherapy, in the form of local injections of autologous stimulated lymphocytes (ASL) into individual tumors in the urinary bladder. A major consideration in cellular immunotherapy being the ability of immune cells to reach all target areas, we hypothesized that direct delivery of effector cells into individual bladder tumors might assure such access.

Methods: ASL were generated by exposing the patient's PBL to phytohemagglutinin and culturing them in the presence of IL-2 to expand the population.

Three-dimensional growth patterns of various human tumor cell lines in simulated microgravity of a NASA bioreactor.

Growth patterns of a number of human tumor cell lines that from three-dimensional structures of various architectures when cultured without carrier beads in a NASA rotary cell culture system are described and illustrated. The culture system, which was designed to mimic microgravity, maintained cells in suspension under very low-shear stress throughout culture. Spheroid (particulate) production occurred within a few hours after culture was started, and spheroids increased in size by cell division and fusion of small spheroids, usually stabilizing at a spheroid diameter of about 0.

Studies of rhodamine-123: effect on rat prostate cancer and human prostate cancer cells in vitro.

The effect of the lipophilic, cationic dye, Rhodamine-123 (Rh-123), on prostate cancer in rats, and on three tumor cell lines in vitro is reported here. The general toxicity of Rh-123 in mice has been found to be minimal. Lobund-Wistar (L-W) rats with the autochthonous prostate cancer of Pollard were treated for six doses with Rh-123 at a dose of 15 mg/kg subcutaneously every other day.