Biomedical Engineering and Bioengineering Commons^™

Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) replicates in macrophages, but is inhibited by IFN-$\gamma$ or LPS. IFN-$\gamma$ and/or LPS induced nitrite production in mouse peritoneal macrophages, macrophage cell lines (RAW264.7 and J774A.1) and McCoy cells. Kinetic studies indicated that peak production occurred 48 hours post-treatment. CT infection itself was insufficient to induce nitrite production, but resulted in enhancement of nitrite production in IFN-$\gamma$-treated cells. Treatment with IFN-$\gamma$ or LPS resulted in significant inhibition of CT replication in these cells. Strong correlation between nitrite production and inhibition of CT replication was observed in RAW264.7 and J774A.1 cells (correlation coefficients: $-$0.93 and $-$0.94, p $<$ 0.001). N$\sp{\rm g}$- monomethyl-L-arginine (L-NMMA) specifically inhibited nitrite production and partially reversed inhibition of CT replication in macrophage cell lines. NOS mRNA was measured in RAW264.7 cells by Northern blot and Dot blot hybridization. Strong correlation between NOS mRNA expression and inhibition of CT replication (correlation coefficient: $-$0.97, p $<$ 0.05) was observed. Anti-TNF-$\alpha$ antibody completely neutralized the biological activity of TNF-$\alpha$ secreted by LPS-treated RAW264.7 cells, yet the antibody neither reduced nitrite production nor restored CT replication. Combination of the antibody and L-NMMA significantly enhanced restoration of CT replication. In peritoneal macrophages, inhibition of CT replication induced by IFN-$\gamma$ was partially restored by L-NMMA or anti-TNF-$\alpha$ antibody. In McCoy cells, inhibition of CT replication induced by IFN-$\gamma$ and LPS was not significantly restored by L-NMMA. Great restoration of CT replication by 1 mM L-NMMA was observed in LPS-treated J774A.1 cells (31%), but not in IFN-$\gamma$-treated cells (5%). Our data indicate that (1) NO production is one of the mechanisms for inhibition of CT replication in IFN-$\gamma$-activated peritoneal macrophages and RAW264.7 cells; (2) NO plays a significant role in CT inhibition in LPS-treated macrophage cell lines, but not peritoneal macrophages; (3) TNF-$\alpha$ may be associated with inhibition, but the mechanism(s) may not involve NO production; (4) NO production may not be the mechanism for CT inhibition in McCoy cells treated with IFN-$\gamma$ and LPS.

Toward Virtual Digital Mammograms For Research And Training In Tumor Detection, Charles F. Babbs, Leslie A. Geddes

Weldon School of Biomedical Engineering Faculty Working Papers

Research in the processing, compression, transmission, and interpretation of digital radiographic images requires evaluation of a wide variety of test images, varying in format, in spatial resolution, and in anatomic content. To evaluate the diagnostic performance of observers using novel versus conventional image formats, large numbers of test images containing known abnormalities are required. This report describes a method for creating high resolution, virtual digital mammograms from computational models of the human breast that include branched lobulated ducts and suspensory ligaments embedded in fatty subcutaneous tissue. Breast phantoms may include any of three types of simulated tumors (fibroadenomas, invasive ductal …

Creation Of Prototype Aircrew Protection Equipment Based On Face Anthropometry, Martin E. Piccus, Gary A. Smith, Brian K. Standley, Tami L. Volk, Linda B. Wildes

Theses and Dissertations

The objective of this research is to develop a process which will analyze and group human faces, concentrating on the oxygen mask seal area, into a minimum number of generic yet distinct face types. The shape and size, or form, of the face is described by bending energies. This bending energy provides the features for the grouping of similar face types, while distinguishing representatives for each cluster. The face tariffs are the percentage of faces grouped under a representative face. The representative faces are then transformed Into three-dimensional solids using computer-aided design. A rapid prototype creates the solids or plugs …

The Afit Multielectrode Array For Neural Recording And Simulation: Design, Testing, And Encapsulation, James R. Reid Jr

Theses and Dissertations

A two-dimensional, X-Y addressable, multiplexed array of 256 electrodes (16 x 16) has been fabricated using conventional semiconductor processing techniques. The individual electrodes are 16O microns x 160 microns, approximating the size of the cortical columns; the overall array size is 3910 microns x 3910 microns. The array has been fitted to a chronically implantable package and tested for several days in a simulated neural environment. EEG-like data were collected successfully from individual electrodes in the array. This array improves on a previous design of a 16 electrode (4 x 4) array that was chronically implanted on the cortex of …

Optimization Of Flow In The Collecting Duct During The Concentrating Mode And The Diluting Mode In A Nephron Population Of Two Different Length With The Renin Angiotensin System And Adh Mechanism, Sivakumar Subramanian

Theses

Our present study is to find out how the short and long nephrons are interacting in the human kidney to adjust the flow in the collecting duct to have the maximum flow during the diluting mode and minimum flow during the concentrating mode. The best lengths for the short nephron and long nephron are calculated during the concentrating mode and the diluting mode by using the Newton-Raphson method. If one wants the kidney to perform only the above mentioned functions, a design criteria for an artificial kidney has been proposed. These studies have provided qualitative information regarding the concentrating mechanism …

Computer Assisted Molecular Modeling Of Thymidine Nucleoside Analog Inhibitors Of Hiv-1 Reverse Transcriptase, Mark A. Fisher

Theses

An active analog approach to receptor mapping was used to identify the three dimensional structural characteristics associated with a series of thymidine nucleoside analog inhibitors of HIV-1 reverse transcriptase (RT) that may be essential for their activity. Atomic substitutions at the 5 and 3' positions of nucleoside analogs confer global structural and electrostatic changes that result in either increased or diminished inhibitory activity. From a structural perspective, the activity differences can be attributed to the presentation of select atoms in three dimensional motifs that are common to all active compounds and absent or distorted in inactive/poorly active compounds.

The identification …

An Analysis Of A Custom Expanding Total Femoral Prosthesis With A Rotating Hinge Knee, Ramarao Gundlapalli, V. Gundlapalli

Theses

Osteosarcoma is the most common malignant bone tumor in the pediatric age group. This thesis presents the analysis of a total femoral prosthesis implanted in a 9 year old black male. The design includes a bipolar, expanding mid-shaft component, and a rotating hinge knee used in the reconstruction of the patient's right lower limb after surgical resection of the femur. The areas being analyzed are (i) the trochanteric attachment, (ii) the expanding component, and (iii) the rotating hinge knee. The stresses acting on the cables reconnecting the greater and lesser trochanter were determined for bipedal stance, single-legged stance, stance phase …

Closure To "Darcy-Weisbach Roughness Coefficients For Gravel And Cobble Surface", John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Biological Systems Engineering: Papers and Publications

The writers appreciate the interest expressed by the discussers in this manuscript, and are pleased to have the opportunity to further discuss this material. The discussion states that the writers have generally examined a condition already investigated in other previous studies. Reynolds number values and roughness element size for the articles referenced by the discussers are shown in Table 5. Since flow rate and Reynolds number values were not given by Ferro and Giordano (1991), data from this study are not included in Table 5.
It can be seen from Table 5 that the roughness element sizes examined by Bathurst …

The Effects Of Luminance Boundaries On Color Perception, Richard E. Kronauer, Charles F. Stromeyer Iii, Alex Chaparro

Publications

The luminance and red-green chromatic detection mechanisms respond to, respectively, the sum and difference of the long-wave (L) and middle-wave (M) zone contrast signals. The most-detectable stimulus is not a small patch of luminance drifting grating, as suggested by others, but rather a small, foveal red-green chromatic flash. Even at the smallest test size examined, 2.3' diameter, the red-green mechanism i~s more sensitive than the luminance mechanism, which has profound implication for visual physiology. When a suprathreshold luminance flash (a pedestal) occurs coincidentally with a red-green chromatic flash, detection of color is facilitated ~2-fold, regardless of spot size, as shown …

Leukocyte Extravasation Into The Pancreatic Tissue In Transgenic Mice Expressing Interleukin 10 In The Islets Of Langerhans., Lise Wogensen, Xiaojian Huang, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Transgenic expression of interleukin 10 (IL-10) in the islets of Langerhans leads to a pronounced pancreatic inflammation, without inflammation of the islets of Langerhans and without diabetes. A scattered infiltration of macrophages (M pi) precedes localized accumulations of CD4+ and CD8+ T lymphocytes, B lymphocytes, and M pi. This recruitment of inflammatory cells to the pancreas is somewhat surprising, since the biological activities of IL-10 in vitro indicate that IL-10 is a powerful immunosuppressive cytokine. Since endothelial cells play a major role in leukocyte extravasation, we examined if vascular changes and extralymphoid induction of peripheral and mucosal type vascular addressins …

Blur Identification And Restoration Of Images Of Coronary Microvessel, Kuen Tak Wong

Theses

The objective of this research was to identify the blur characteristics of the blurred images of the rat coronary microvessel, and the information of the blur characteristics was used to restore the blurred images. The blur characteristics were analyzed by using the image power cepstrum. The Wiener filter was implemented to restore the images. There were two types of point spread functions proposed and studied for the restoration. They were: defocus blur PSF and motion blur PSF. The images were transferred from HP A900 system to an AVS workstation. The images were processed and manipulated by the AVS, and showed …

Computer Simulation Of Intracranial Hemodynamics During The Induction Phase Of Anesthesia, Gopinath P. Sundaram

Theses

The induction of general anesthesia is associated with severe hemodynamic compromises which, in turn, may cause acute elevation of intracranial pressure (ICP). Quantitative assessment of cerebrovascular responses arising from multiple mechanical and pharmacological interventions occurring in a short time interval require a large number of human studies which are difficult to perform. The purpose of this project is to evaluate the effect of various stimuli on the intracranial hemodynamics during induction using a mathematical model of cerebrovascular circulation.

A five compartmental model of the cerebrovascular system is used for our simulation. Autoregulation is modeled by adjusting arterial-arteriolar resistance in order …

Study Of Emg Frequency Behavior, Mark Steven Fiedorowicz

Theses

It has previously been determined that the power spectral density of an electromyogram shifts towards lower frequencies over time during an isometric contraction. In this study the power spectral density curve was examined to see if changes would occur over a period of time as a subject walked on a treadmill at various speeds. The shapes of the power spectral densities recorded from the soleus shifted to the lower frequencies over time. The parameters associated with the curves showed trends. One of the parameters, zero crossing, demonstrated adaptation and fatigue in all four patients, for the first portion of the …

Comparison Of Heart Rate With Chest Wall Vibrations, Kofi M. Arbuah

Theses

A study is done using a Microwave Interferometer as a computer-assisted non-invasive cardiopulmonary monitor. The Microwave Interferometer is used to record the mechanical vibration of the anterior chest wall by recording the velocity of the displacement of the chest wall. The objective is to first, record mechanical vibrations of the anterior chest wall at different heart rates, and second, attempt to identify the relation between heart rate and chest wall vibration.

The system uses two channels, the first signal produced by the Microwave Interferometer is a record of the velocity of the displacement of the chest wall caused by the …

A Multicompartmental Model For The Simulation Of Soluble Gas Exchange In The Lungs, Chitaranjan Varadhan

Theses

No abstract provided.

A Review Of Acetabular Prostheses For Total Hip Arthroplasty, Jennifer Anne Citarella

Theses

This study explores the evolution, design, and clinical progress of contemporary prostheses used in orthopaedic reconstruction of the socket of the hip joint. A literature search was performed to study acetabular implants, as used in total hip arthroplasty. The history of the design of these implants is chronicled. Next, the anatomy of the acetabular region and the surgical technique performed to replace the hip socket are presented. A comprehensive discussion of the design features, rationale, and clinical results for commercially available cemented and cementless prostheses follows.

Hydroxyapatite, a bioceramic which has just recently been approved for applications in total hip …

An Experimental Investigation Of Wear Behavior Of Ultra-High Molecular Weight Polyethylene Under Sliding Motion, Elham Zand-Moghaddam

Theses

This project investigates the effect of sliding motion on the materials that are used as bearing surfaces of human total-joint replacement prostheses.

The tests are performed with a specially designed equipment based on pin-on-disk machine. The testing machine is designed and constructed to reproduce sliding motion, applied to spherical ended metal "Canine-Head" components such as dog hip acting on a flat polyethylene surface. The sliding motion is performed by applying different constant loads for 5,000,000 cycles. The tests are carried out with the wear specimen lubricated by deionized water.

The purpose is to produce delamination, which is the severe wear …

Evaluation Of A Ceramic Roof Coating, William H. Allen, Jay D. Harmon, Dale E. Linvill, Matthew V. Bramblett

Jay D. Harmon

Surfaces treated with a ceramic roof coating (CRC) marketed as AZTEC No. 100 were compared to untreated and white painted surfaces. Dry-bulb and black globe temperatures in the space below or behind the surface were the criteria for comparison. Comparisons included small horizontal panels with open sides, small unvented galvanized steel and styrofoam boxes, and an open-side steel poultry building. The CRC was effective in reducing temperatures in the enclosed test boxes, but less effective with open-side test panels and the open-side steel building. Tests also indicated the CRC is characterized by high emissivity (0.95) and reflectivity (0.87). The evidence …

Analysis Of Cutthroat Flume Discharge Ratings, Liyan Ren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sixteeen sets of original laboratory data collected by many investigators for various Cutthroat flume sizes are thoroughly reviewed and organized. Best-fit discharge parameters are obtained by performing the free-flow analysis and the submerged-flow analysis. Then, the transition submergence can be calculated. Afterwards, the unified free-flow and submerged-flow discharge parameters are developed for each flume size in order to generalize the calibrations for Cutthroat flumes. This is a very tedious process requiring a trial-and-error approach. Finally, comparisons are made of the measured laboratory discharges with the predicted discharges for both free flow and submerged flow using both the best-fit and the …

Competitive Enzyme Immunoassay By Polyclonal Antibodies Against Organophosphorus Pesticides, Kuo-Lan Wen

Theses and Dissertations in Biomedical Sciences

Organophosphorus compounds (OPs) comprise one of the major classes of pesticides in use today because they are highly effective and less toxic. Because of their extensive use, there is a need for monitoring OPs in water and vegetables. Gas chromatography (GC) is the usual method for OPs screening, but it is time-consuming and has the high cost of instrumentation. The goal of this project was to find an easy method which was sensitive and had less instrumentation required to test OPs.

Microwells and microtubes were utilized as the solid-phase immobilization for the development of an enzyme immunoassay for OPs. A …

Simulated Thermal Performance Of A Solar Heated Floor, Michael F. Kocher, James A. Deshazer, Gerald R. Bodman

Biological Systems Engineering: Papers and Publications

A low cost, simple solar heating system consisting of an active collector with an In-Floor Heat Distribution and Storage (IFHDS) system was developed in response to the energy crisis of the 1970s. A two-dimensional finite difference model was developed and used to simulate the performance of IFHDS system cross-sections. Simulation runs were conducted with a steady-periodic model for the temperature of the solar-heated air in the IFHDS system cross-section. The steady periodic simulation results indicated IFHDS system energy efficiency increases with decreasing air temperature in the room above the IFHDS system, peak temperature of the solar-heated air in the IFHDS …

Critical Shear Stress And Critical Flow Rates For Initiation Of Rilling, John E. Gilley, W. J. Elliot, J. M. Laflen, J. R. Simanton

Biological Systems Engineering: Papers and Publications

This study was conducted to identify critical shear stress and critical flow rates required to initiate rilling on selected sites. The data used in this investigation were collected from soils located throughout the USA where crop residues had been removed, and moldboard plowing and disking had occurred. Runoff and soil loss measurements were made on sites where simulated rainfall was applied to preformed rills. Multiple regression analyses were used to relate critical shear stress values and critical flow rates to selected soil properties. The soil-based regression equations were found to provide reliable estimates. Information identified in this study will improve …

Computer Aided Finite Element Stress Analysis Of A Three Dimension Mandibular Bone Model Using I-Deas Software, Yixiong Xu

Theses

A three dimensional model of half of the mandibular bone, with 487 tetrahedra elements and 1,047 nodes, is established and analyzed by means of I-DEAS software. The masseter muscle is assumed to be 15° deviation from y-axis, and the Umetani boundary conditions are allowed to be varied. A 337 lb force was applied along the midline of the mandible to simulate a trauma force caused by the auto accident. The maximum principal stress is 18,400 psi and the minimum principal stress is -1,340 psi. Depending on the experimental results of dispalcement and maximum principal stress, the conclusions are drawn: 1) …

A Study Of Pulsation Of Chest Wall Using Microwave Interferometer, Paul Zeno

Theses

The microwave interferometer is utilized to pick up vibrations of the anterior chest wall produced by the cardiac activity. The objective of this project is to find the causes of different peaks in the output of the microwave interferometer. The output of the microwave interferometer is recorded simultaneously with EKG and jugular pressure pulses. Eighteen subjects had their mechanical vibrations of the chest wall, EKG and jugular pressure pulses recorded. The processed interferometer data, when compared with EKG and jugular pressure pulses appear to have a close relation to the mechanical events in the cardiac cycle. Four peaks in the …

Dynamics Of Blood Coagulation, Jie Gao

Theses

In this paper we present a new method to analyze whole blood coagulation dynamics. Using a PC-286 computer equipped with a DASH-16 AID board.

The row data from a SONOCLOT analyzer is amplified and digitized on the DASH-16 A/D board and stored in the PC-286 hard disk. The data is filtered through a digital Butterworth filter. The filtered data is then fit to mathematical relationship by the least square method. The coefficients which define the mathematical relationships are used to identify blood specimens with normal coagulation dynamics as distinguished from specimens with abnormal dynamics.

The digital filter and curve-fitting routine …

A Review Of Energy Storing Prosthetic Feet And Computer Aided Structural Optimization Of A Below-Knee Prosthesis, Poonam Gope Lalwani

Theses

Because people with physical disabilities have shown an interest in participation in sports, a new class of prosthetic feet known as "energy storing prosthetic feet" has been developed. These new developments in prosthetic foot design utilize energy storage and return to improve ambulation. This thesis reviews the design, materials, advantages and disadvantages of various energy storing prosthetic feet. Research studies, comparing gait in below-knee amputees using different prosthetic designs, can be applied to the design of prosthetic feet that are lighter, stronger and more reliable. Comparisions among these feet are reviewed in the context of functional capability and patient satisfaction. …

Fingerprint Pattern Recognition For Medical Uses, Feng You

Theses

The purpose of my research is to provide a method to automatically classify fingerprints into three subgroups: whorl, loop and arch, which can help medical scientists to study the relationship between fingerprint patterns and medical disorders. In the research, two different kinds of approaches were developed. The first one is performing pattern recognition in the frequency domain, which uses the feature of Fourier spectrum. That is, prominent peaks in the spectrum give the principal direction of fingerprint patterns. Using the above feature, we can obtain the principal direction of every subregion, after which the pattern of the whole image can …

The Thermal Model Of The Rat Under Hemorrhagic Shock Hypothermia With Microwave Intervention, Liu Zhe

Theses

A whole body thermal model simulating heat distribution and temperature regulation in rats during hemorrhagic shock and during post-shock microwave core rewarming period was developed. An electrical circuit was used to simulate the thermal system and a software named PSpice? was used to analyze the circuit. The temperature regulation as the result of the simulation is demonstrated to match the measured temperature histories of rats in hemorrhagic shock and the microwave rewarming experiment.

The blood pressure drop and cardiac output decrease were considered in the simulation and the so called "set point temperature" was investigated in the model. Linear decrease …

Burnham, Colton, And Pollock Reply, Nancy Burnham, Rj Colton, Hm Pollock

Nancy A. Burnham

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 3.0 License. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author (s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder

Interposed Abdominal Compression-Cpr: A Case Study In Cardiac Arrest Research, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

When the abdomen is compressed manually in counterpoint to the rhythm of chest compression, in the performance of interposed abdominal compression-CPR, artificial circulation is approximately doubled in animal experiments and in electronic models of the circulatory system. These studies suggest that external manual compression of the abdominal aorta acts like an intra-aortic balloon pump to increase aortic pressure, whereas external manual compression of the abdominal veins acts to prime the right heart and pulmonary vessels before the next chest compression. As a result, perfusion pressures and flows are increased. Several clinical studies of this technique have shown promising results, including …