pulmonary mucus hydration assay using rotational and translational diffusion of gold nanorods with polarization-sensitive optical coherence tomography.

Significance: Assessing the nanostructure of polymer solutions and biofluids is broadly useful for understanding drug delivery and disease progression and for monitoring therapy.

Aim: Our objective is to quantify bronchial mucus solids concentration (wt. %) during hypertonic saline (HTS) treatment via nanostructurally constrained diffusion of gold nanorods (GNRs) monitored by polarization-sensitive optical coherence tomography (PS-OCT).

Improving birth certificate data accuracy in Alabama.

Objective: Accurate vital statistics data are critical for monitoring population health and strategizing public health interventions. Previous analyses of statewide birth data have identified several factors that may reduce birth certificate accuracy including systematic errors and limited data review by clinicians. The aim of this initiative was to increase the proportion of hospitals in Alabama reporting accurate birth certificate data from 67% to 87% within 1 year.

Effect of finishing technique on the occurrence and length of microcracks in resin-based materials.

Purpose: To evaluate the presence and length of microcracks in resin-based materials finished with different techniques, using optical coherence tomography (OCT).

Methods: Standardized Class V preparations (3x2x2mm) were made in the facial and lingual surfaces of 20 recently-extracted human third molars. 20 preparations were restored with a resin-based composite material (RBC; Filtek Supreme Ultra) and the other 20 with a resin-modified glass-ionomer material (RMGI; Ketac Nano).

Diffusion tensor optical coherence tomography.

In situ measurements of diffusive particle transport provide insight into tissue architecture, drug delivery, and cellular function. Analogous to diffusion-tensor magnetic resonance imaging (DT-MRI), where the anisotropic diffusion of water molecules is mapped on the millimeter scale to elucidate the fibrous structure of tissue, here we propose diffusion-tensor optical coherence tomography (DT-OCT) for measuring directional diffusivity and flow of optically scattering particles within tissue. Because DT-OCT is sensitive to the sub-resolution motion of Brownian particles as they are constrained by tissue macromolecules, it has the potential to quantify nanoporous anisotropic tissue structure at micrometer resolution as relevant to extracellular matrices, neurons, and capillaries.

Quantification of the Effect of Toxicants on the Intracellular Kinetic Energy and Cross-Sectional Area of Mammary Epithelial Organoids by OCT Fluctuation Spectroscopy.

The ability to assess toxicant exposures of 3D in vitro mammary models that recapitulate the tissue microenvironment can aid in our understanding of environmental exposure risk over time. Longitudinal studies of 3D model systems, however, are cumbersome and suffer from a lack of high-throughput toxicological assays. In this study, we establish a noninvasive and label-free optical coherence tomography (OCT)-based imaging platform for tracking exposure-response relationships in 3D human mammary epithelial organoid models.

Direct monitoring of pulmonary disease treatment biomarkers using plasmonic gold nanorods with diffusion-sensitive OCT.

The solid concentration of pulmonary mucus (wt%) is critical to respiratory health. In patients with respiratory disease, such as Cystic Fibrosis (CF) and Chronic Obstructive Pulmonary Disorder (COPD), mucus hydration is impaired, resulting in high wt%. Mucus with high wt% is a hallmark of pulmonary disease that leads to obstructed airways, inflammation, and infection.

Diffusion-sensitive optical coherence tomography for real-time monitoring of mucus thinning treatments.

Mucus hydration (wt%) has become an increasingly useful metric in real-time assessment of respiratory health in diseases like cystic fibrosis and COPD, with higher wt% indicative of diseased states. However, available rheological techniques are lacking. Gold nanorods (GNRs) are attractive biological probes whose diffusion through tissue is sensitive to the correlation length of comprising biopolymers.

Magnetic and Plasmonic Contrast Agents in Optical Coherence Tomography.

Optical coherence tomography (OCT) has gained widespread application for many biomedical applications, yet the traditional array of contrast agents used in incoherent imaging modalities do not provide contrast in OCT. Owing to the high biocompatibility of iron oxides and noble metals, magnetic and plasmonic nanoparticles, respectively, have been developed as OCT contrast agents to enable a range of biological and pre-clinical studies. Here we provide a review of these developments within the past decade, including an overview of the physical contrast mechanisms and classes of OCT system hardware addons needed for magnetic and plasmonic nanoparticle contrast.

Imaging Extracellular Matrix Remodeling In Vitro by Diffusion-Sensitive Optical Coherence Tomography.

The mammary gland extracellular matrix (ECM) is comprised of biopolymers, primarily collagen I, that are created and maintained by stromal fibroblasts. ECM remodeling by fibroblasts results in changes in ECM fiber spacing (pores) that have been shown to play a critical role in the aggressiveness of breast cancer. However, minimally invasive methods to measure the spatial distribution of ECM pore areas within tissues and in vitro 3D culture models are currently lacking.

Probing biological nanotopology via diffusion of weakly constrained plasmonic nanorods with optical coherence tomography.

Biological materials exhibit complex nanotopology, i.e., a composite liquid and solid phase structure that is heterogeneous on the nanoscale.

Hollow steel tips for reducing distal fiber burn-back during thulium fiber laser lithotripsy.

The use of thulium fiber laser (TFL) as a potential alternative laser lithotripter to the clinical holmium:YAG laser is being studied. The TFL's Gaussian spatial beam profile provides efficient coupling of higher laser power into smaller core fibers without proximal fiber tip degradation. Smaller fiber diameters are more desirable, because they free up space in the single working channel of the ureteroscope for increased saline irrigation rates and allow maximum ureteroscope deflection.

Detachable fiber optic tips for use in thulium fiber laser lithotripsy.

The thulium fiber laser (TFL) has recently been proposed as an alternative to the Holmium:YAG (Ho:YAG) laser for lithotripsy. The TFL's Gaussian spatial beam profile provides higher power transmission through smaller optical fibers with reduced proximal fiber tip damage, and improved saline irrigation and flexibility through the ureteroscope. However, distal fiber tip damage may still occur during stone fragmentation, resulting in disposal of the entire fiber after the procedure.

Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers.

Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers.

Enhanced thulium fiber laser lithotripsy using micro-pulse train modulation.

The thulium fiber laser (TFL) is currently being studied as an alternative to the conventional holmium:YAG (Ho:YAG) laser for lithotripsy. The diode-pumped TFL may be electronically modulated to operate with variable parameters (e.g.

Comparison of holmium:YAG and thulium fiber laser lithotripsy: ablation thresholds, ablation rates, and retropulsion effects.

The holmium:YAG (Ho:YAG) laser lithotriptor is capable of operating at high pulse energies, but efficient operation is limited to low pulse rates (∼10 Hz) during lithotripsy. On the contrary, the thulium fiber laser (TFL) is limited to low pulse energies, but can operate efficiently at high pulse rates (up to 1000 Hz). This study compares stone ablation threshold, ablation rate, and retropulsion for the two different Ho:YAG and TFL operation modes.

Holmium:YAG (lambda = 2,120 nm) versus thulium fiber (lambda = 1,908 nm) laser lithotripsy.

Introduction: The holmium:YAG laser is currently the most common laser lithotripter. However, recent experimental studies have demonstrated that the thulium fiber laser is also capable of vaporizing urinary stones. The high-temperature water absorption coefficient for the thulium wavelength (mu(a) = 160 cm(-1) at lambda = 1,908 nm) is significantly higher than for the holmium wavelength (mu(a) = 28 cm(-1) at lambda = 2,120 nm).

Thulium fiber laser lithotripsy using tapered fibers.

Introduction: The Thulium fiber laser has recently been tested as a potential alternative to the Holmium:YAG laser for lithotripsy. This study explores use of a short taper for expanding the Thulium fiber laser beam at the distal tip of a small-core fiber.

Methods: Thulium fiber laser radiation with a wavelength of 1,908 nm, 10 Hz pulse rate, 70 mJ pulse energy, and 1-millisecond pulse duration was delivered through a 2-m-length fiber with 150-microm-core-input-end, 300-microm-core-output-end, and 5-mm-length taper, in contact with human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each).

Stationary sources of airborne lead: a comparison of emissions data for southern California.

Estimates for the air releases of lead from stationary point sources are considered for the South Coast Air Basin of California. We have examined four databases published by U.S.

The direct glucuronidation of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) by human and rabbit liver microsomes.

The glucuronidation of the food-borne heterocyclic amine 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine (PhIP) was investigated using hepatic microsomes from several species. PhIP-glucuronic acid conjugates were formed in an NADPH-free system using microsomes from rabbit, dog, guinea pig, and human. Rat, hamster, and mouse microsomes were incapable of directly producing PhIP-glucuronides.

Effect of lingual vibrotactile stimulation on the averaged cortical evoked response.

This study was designed to determine the feasibility of using lingual vibrotactile stimulation to elicit an averaged evoked response and to investigate the effects of two supra-threshold intensity levels of lingual vibrotactile stimulation on the electro-cortical activity of the brain. The evoked responses were analyzed according to the amplitude of N1-P2 (in microvolts). Analysis indicates that the tongue can successfully be used as a stimulus site in the elicitation of an evoked response.

Estrogen regulation of superoxide dismutase in normal rat mammary tissues and mammary tumors.

Multiple electrophoretic molecular variants of superoxide dismutase were demonstrated in normal rat mammary tissues and DMBA-induced rat mammary tumors. The specific activities of Cu/Zu superoxide dismutase in mammary tumors of estrogen-treated rats were not significantly different from those activities seen in normal rat mammary tissues. However, the enzyme activities of mammary tumors from untreated rats (no estrogen) were significantly lower than the activities of normal rat mammary tissues.

Temporal summation effects on lingual vibrotactile thresholds.

Ascending lingual vibrotactile thresholds at 250 Hz were obtained for four groups of normal-speaking adult subjects. Stimulus durations were varied for each respective group. Threshold values plotted as a function of stimulus duration indicated a temporal summation function occurring up to 200 msec.

Comparison of the methods of limits and electrodermal response for determination of lingual vibrotactile thresholds.

Lingual vibrotactile thresholds were obtained from 30 adult Ss by the method of limits and operant conditioning of the electrodermal response. Sensitivity of the tongue was measured at 250 Hz. Comparisons of lingual threshold data showed that thresholds obtained by the method of limits were significantly lower than those obtained by the electrodermal response technique.