Kyung A. Kang

Precision localization of hidden absorbers in body tissues with phased‐array optical systems

The recurrent difficulties of rapidly localizing a small object in a large volume of highly scattering material such as brain and breast has been the ‘‘stumbling block’’ of optical methods for tumor detection. Amplitude cancellation of in‐ and out‐of‐phase photon diffusion patterns, used in detection of small objects containing highly absorbing and fluorescing contrast agents provides real time, two‐ and three‐dimensional localization of objects of mg size and picamole contents in models of human breast and brain tumors with positional accuracies of millimeters. A simple robust electronic circuit is described and tested to give a phase accuracy of ∼0.1°. An electro‐optical scan rapidly detects small objects in a large volume that simulates the absorption/scattering characteristics of human head or breast.

Preliminary study of real-time fiber optic based protein C biosensor.

Deficiency of protein C (PC), one of the human bodys key anticoagulants, can lead to massive thrombotic complications. There is a diagnostic need to perform real-time assays, in order to quickly identify and treat this disease. An immuno-optical biosensor for the diagnosing of PC deficiencies and monitoring of PC concentrations is being developed for this purpose. Monoclonal antibody against PC (anti-PC) is immobilized on the surface of a tapered quartz fiber that is enclosed in a glass tube (capacity approximately 200 microL). Following sample injection, PC within a sample binds to the anti-PC in a highly specific reaction. The system is then probed with a fluorophore-tagged secondary antibody against PC. Excitation light is applied through the fiber, and the fluorescence intensity is correlated with the PC concentration in the sample. This study presents (1) a feasibility, direct binding assay, (2) a comparison of methods to immobilize anti-PC upon the fiber (direct immobilization vs an avidin-biotin bridge), and (3) effectiveness of an elution step to regenerate the fiber. PC-deficient patients typically have a concentration range less than 2.5 microg/mL. It was found that the sensor could detect PC levels down to 0.1 microg/mL in pure buffer with minimal optimization. Avidin-biotin immobilization of the primary antibody produced enhanced signals, up to 470% of the original intensities. Preliminary fiber regeneration tests achieved nearly a 50% increase in fiber lifetime with the use of a CaCl(2) elution step. Ultimately, further development may lead to automation and the use of the system as a multi-blood factor analyzer.

Preliminary Study of Biosensor Optimization for the Detection of Protein C

Methods to develop an immuno-optical biosensor for the detection and monitoring of Protein C (PC) concentrations are described. A tapered quartz fiber is enclosed in a glass tube (capacity approximately 300 microliters) and monoclonal antibody against PC (anti-PC) is immobilized on the surface of this fiber. PC within a sample, when injected into the chamber, will bind to the anti-PC in a specific reaction. The system is then probed with a fluorophore tagged secondary antibody against PC, also binding to PC in a specific reaction. Excitation light is applied through the fiber, and the amount of fluorescence is correlated with the PC concentration in the sample. This study offers encouraging results for the detection of PC deficiency in real-time.

Oxygen transport to tissue XXIX

ISOTT Roots, Founding, Beyond.- Dietrich W Lubbers: Celebration of a Life Dedicated to Research into Oxygen Transport to Tissue.- A. Oxygen Transport in Tissue.- Investigation of frontal cortex, motor cortex and systemic haemodynamic changes during anagram solving.- Do red blood cell ss-Amyloid interactions alter oxygen delivery in Alzheimers disease?.- UNCOUPLING PROTEIN-2 IN DIABETIC KIDNEYS: Increased protein expression correlates to increased non-transport related oxygen consumption.- MEASUREMENT OF OXYGENATION AT THE SITE OF STEM CELL THERAPY IN A MURINE MODEL OF MYOCARDIAL INFARCTION.- Oxygen pressures in the interstitial space and their skeletal muscle and tumors in vivo.- B. Other Metabolite Transport in tissue.- ADJUVANT INDUCED GLUCOSE UPTAKE BY ACTIVATED T CELLS IS NOT CORRELATED WITH INCREASED SURVIVAL.- Lactate with oxygen incites angiogeniSIS.- C. Blood, Hemostasis and Hemodynamics.- ACTIVATED PROTEIN C MODULATES CHEMOKINE RESPONSE AND TISSUE INJURY IN EXPERIMENTAL SEPSIS.- MANIPULATION OF THE AFFINITY BETWEEN PROTEIN AND METAL IONS BY IMIDAZOLE AND PH FOR METAL AFFINITY PURIFICATION OF PROTEIN C FROM COHN FRACTION IV-1.- Separation of factor V Leiden molecule, a mutated form of human factor V, from plasma of homozygous patient.- A simple volume related model of arterial blood pressure generation.- D. Tumor, Cancer and Oncology.- STRIKINGLY HIGH RESPIRATORY QUOTIENTS: A FURTHER CHARACTERISTIC OF THE TUMOR PATHOPHYSIOME.- Endogenous hypoxia markers: Case not proven!.- RAD18 SIGNALS DNA POLYMERASE IOTA TO STALLED REPLICATION FORKS IN CELLS ENTERING S-PHASE WITH DNA DAMAGE.- ALANINE IN HI: A SILENT MUTATION CRIES OUT!.- Biomathematics in Cancer Detection: SIMULATION OF LIPOGENESIS IN CANCER.- Activity of drug efflux transporters in tumor cells under hypoxic conditions.- Antioxidants reduce consequences of radiation exposure.- Anti-cancer effect of resveratrol is associated with induction of apoptosisvia a mitochondrial pathway alignment.- E. Tissue Engineering.- Computationally determined shear on cells grown in orbiting culture dishes.- Formation of capillary structure on micro patterned biomaterials.- F. Bio-Instrumentation.- Error analysis of finite-spectral-linewidth illumination in optical oximetry systems.- Changes in the attenuation of near infrared spectra in the healthy adult brain during hypoxaemia cannot be accounted for solely by changes in the concentrations of oxy- and deoxy-haemoglobin.- Assessment of oxygenation and perfusion in the tongue and oral mucosa by visible spectrophotometry and laser doppler flowmetry in healthy subjects.- Cerebral tissue oxygen saturation calculated using spontaneous low frequency hemoglobin oscillations measured by near infrared spectroscopy in adult ventilated patients.- Biosensor for diagnosing factor V leiden, a single amino acid mutated abnormality of factor V.- Scanning laser ophthalmoscope-particle tracking method to assess blood velocity during hypoxia and hyperoxia.- F. Nano-Bio Technology.- Highly sensitive, rapid, reliable, and automatic cardiovascular disease diagnosis with nanoparticle fluorescence enhancer and MEMS.- Tumor specific nano-entity for optical detection and hyperthermia treatment of breast cancer.- LHRH receptor targeted therapy for breast cancer.- G. Translational and Clinical Studies.- Saturation of hemoglobin in intracranial arteries is similar in patients with Hemodynamically relevant and irrelevant stenosis of the internal carotid artery.- A three-tiered approach for calibration of a biosensor to detect estrogen mimics.- Biosensors for Detecting Estrogen-like molecules and protein Biomarkers.- H. Modeling and Analysis of Metabolism and Transport. This section was contributed by the Center for Modeling Integrated Metabolic Systems (MIMS) of the Case Western Reserve University, Cleveland, OH.- MUSCLE OXYGEN UPTAKE DIFFERS FROM CONSUMP

Protein C Detection Via Fluorophore Mediated Immuno-Optical Biosensor

Hemostasis is a physiological state where the concentration of coagulants in a human body is well balanced with that of anticoagulants. For oxygen to be properly transported to the entire body, hemostasis must be maintained at all times. Protein C (PC) is one of only a few anticoagulating factors in the bloodstream. As a potent anticoagulant and antithrombotic, PC plays a key role in regulating hemostasis, ensuring the proper transport of oxygen throughout the body. When anticoagulants are not maintained at sufficient levels, the resulting inhibition of oxygen flow produces massive clotting problems. If PC deficiency is not diagnosed and properly treated immediately, an individual may experience debilitating trauma, thrombo-embolic insults in major organs, or death (Bruley and Drohan, 1990). This paper presents a continuation of the research initiated by Kang, et al., concerning the development of a PC biosensor. Background information regarding to the activation of PC, as well as the frequency of occurrence of PC deficiency, has been presented at the 23rd Annual ISOTT Conference (Kang, et al., in press).

Highly scattering optical system identificationvia frequency response analysis of NIR-TRS spectra

Frequency response analysis via pulse testing is often used for the characterization of engineering systems. Near infrared-time resolved spectroscopy (NIR-TRS) is a frequently used technique for the analysis of biological system properties. Since the TRS input is a very sharp photon pulse, a well designed TRS input pulse can produce a multi-frequency response over the useful frequency range for the system identification.This new approach for analyzing NIR-TRS provides new optical system parameters (e.g., magnitude ratio and phase shift at multi-frequencies, system time constant, system order, and steady state gain) that are not available by traditional TRS spectra analysis.In this paper, the basic theory of pulse reduction is introduced for the multi-modulation frequency response of TRS spectra. Homogeneous system response with various absorption and scattering properties were analyzed for the multi-system parameters. In heterogeneous systems, the position of the localized absorber is correlated with the multi-parameters, which can ultimately be used to enhance medical imaging.

Determination of a biological absorber depth utilizing multiple source-detector separations and multiple frequency values of near-infrared time-resolved spectroscopy

Visualization of the photon path in scattering media is attempted through the use of frequency response analysis of near‐infrared time‐resolved spectroscopy (NIR‐TRS) spectra. The effect of the source−detector distances and the modulation frequency on the photon path is examined. It was found that the use of multifrequency information could lead to the possibility of obtaining the information of an absorbers depth without increasing the number of measurements.

Protein C Separation from Human Blood Plasma Cohn Fraction IV-1 Using Immobilized Metal Affinity Chromatography

Protein C is an anticoagulant and antithrombotic. Because Protein C is a zymogen of a serine protease, therefore, it must first be activated before it has anticoagulant properties. Protein C can be activated in different ways but the most prevalent is by a complex of thrombin with thrombomodulin (TM) to form the activated form of Protein C (APC) [1]. Activated PC functions as an anticoagulant by inactivation of the coagulation cofactors Villa and Va (‘a’ denotes activated form), thus preventing generation of the enzymes factor Xa and thrombin [2, 3].

Frequency Response by Pulse Reduction for the Analysis of TRS Spectra

Biological systems can be analyzed by near infrared (NIR) spectroscopy in two ways: (1) A system can be characterized by studying its photon absorption and scattering as a lumped parameter system. A good example of this approach is the measurement of hemoglobin oxygen saturation (or other chromophore concentration) in an organ of the human body under various physiological conditions; (2) Heterogeneities in an organ can be located, for instance imaging of brain or breast tumors. Since the degree of light absorption by various chromophores (oxy/deoxy hemoglobin, cytochrome aa3, etc.) and that of its scattering by biological scatterers (mitochondria, fat particles, etc.) reflects the physiological state, it is important to obtain accurately the absorption and scattering coefficients of a homogeneous system. At the same time, accurate measurement of the intensity and the phase shift difference at specific positions relative to the surrounding tissue is crucial for imaging.

Application of Near‐IR Time‐Resolved Spectroscopy and Frequency Response Analysis for Deep Vein Thrombosis Detection

Frequency response analysis is applied to analyze NIR‐TRS spectra in a tissue model with a simulated thrombus. The value changes in parameters obtained from frequency response analysis are correlated with heterogeneity position in three dimensions. The goal of this research is to noninvasively localize deep vein thrombosis in the human leg through the use of this novel combination.