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Full-Text Articles in Biomedical Engineering and Bioengineering

Kinematic Analysis Of Gait And Deep Knee Flexion For Pre- And Post-Operative Total Knee Arthroplasty, Samantha Collins Nov 2023

Kinematic Analysis Of Gait And Deep Knee Flexion For Pre- And Post-Operative Total Knee Arthroplasty, Samantha Collins

Electronic Theses and Dissertations

Osteoarthritis (OA) is a form of arthritis that develops in the joint due to overuse and aging causing pain, discomfort, and disability. Total Knee Arthroplasty (TKA) is a surgical procedure performed when OA symptoms are severe with an estimated 600,000 patients in the United States currently receiving TKA. Studies have reported dissatisfaction of the knee for 14-39% of patients. This study collected knee kinematics before and after surgery using stereo radiography for precise measurement of gait and deep knee flexion activities. Results showed healthy knee kinematics were not restored and no significant changes could be seen from OA kinematics in …


Exploration Of Motion Capture System To Investigate Human Shoulder Kinematics, Ola Alsaadi Nov 2023

Exploration Of Motion Capture System To Investigate Human Shoulder Kinematics, Ola Alsaadi

Electronic Theses and Dissertations

The glenohumeral joint (GH) is commonly conceptualized as a ball-and-socket joint [1], and its center of rotation (COR) is presumed to coincide with the geometric center of the medial-superior region of the humeral head [2]. Recent research has endorsed improvements in COR estimation through invasive and noninvasive techniques, including cadaver studies, stereophotogrammetry, and motion capture (MOCAP) systems. Despite increased interest in wearable technology within human movement analysis, the problem of COR estimation employing MOCAP systems and its validation against bi-planar fluoroscopy remains relatively unexplored.

This study employed a marker-based MOCAP system to compare the accuracy, error, and precision of three …


Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke Aug 2023

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …


The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo May 2023

The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo

Electronic Theses and Dissertations

This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.

This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …


Re-Engineering Cardio-Oncology Testing Using Biomimetic Heart Slice Cultures., Jessica Miller Dec 2022

Re-Engineering Cardio-Oncology Testing Using Biomimetic Heart Slice Cultures., Jessica Miller

Electronic Theses and Dissertations

28% of drug withdrawal from the market are due to unforeseen disruptions in cardiomyocyte contractility and electrophysiology. The most commonly used platforms for drug testing are in vivo animal models and in vitro cell culture models. While both have been of paramount importance for the discovery and detection of many cardiotoxicities and mechanisms of action, they lack the ability to model an intact human myocardium. This work aims to establish cardiac tissue slices, which are 300-micron thin tissue sections taken from the left ventricular myocardium, as an alternative platform for cardio-oncology studies, specifically cardiotoxicity testing. Additionally, this work aims to …


Establishing The Efficacy Of Non-Cellular Components Of Adipose-Derived Stromal Vascular Fraction In Promoting Angiogenesis., Daniel Benson Dec 2022

Establishing The Efficacy Of Non-Cellular Components Of Adipose-Derived Stromal Vascular Fraction In Promoting Angiogenesis., Daniel Benson

Electronic Theses and Dissertations

Microvascular disease is hallmarked by pathophysiological conditions such as endothelial senescence, intimal thickening which impairs vasodilation, and regression of the capillary beds causing tissue ischemia in the myocardium or in peripheral vascular networks. Adipose-derived stromal vascular fraction (SVF) has previously demonstrated the ability to revascularize tissue. Increasing evidence shows that regenerative cells elicit their therapeutic benefit by paracrine mechanisms, leaving open extracellular vesicles (EVs) as a potential crux of the cell therapy paradigm. To test this idea, three types of gelatin methacrylate hydrogels were employed: SVF gels, EV gels derived from SVF, and blank control gels, which were used in-vitro …


Developing And Characterizing A Novel Tempo Cnf Hydrogel Adjuvant And Delivery System For Aquatic Vaccines, Kora Kukk Aug 2022

Developing And Characterizing A Novel Tempo Cnf Hydrogel Adjuvant And Delivery System For Aquatic Vaccines, Kora Kukk

Electronic Theses and Dissertations

Aquaculture is a large part of the food production sector which is greatly expanding. One of the largest losses in aquaculture is due to pathogens. Current solutions for protecting farmed finfish from pathogens can be very expensive with variable efficiency. Current disease prevention strategies include vaccination. Types of vaccines include immersion vaccines, feed vaccines, and injectable vaccines. The most popular solution is oil-based injectable vaccines due to its protection. However, the oil-based adjuvant used in most of these formulations causes adverse reactions in the fish including reduced growth. These vaccines require multiple administrations throughout the fish’s lifetime causing unwanted handling …


Effect Of Dorsal Quadrant Or Ventral Quadrant Spinal Cord Injury On Gait Features During Locomotion., Anya Nicole Trell Aug 2022

Effect Of Dorsal Quadrant Or Ventral Quadrant Spinal Cord Injury On Gait Features During Locomotion., Anya Nicole Trell

Electronic Theses and Dissertations

In the Unites States, approximately 1.5 million people currently have a spinal cord injury and suffer permanent sensory and motor loss due to the disruption of the spinal cord. Due to the significant morbidity, it is vital to understand the functional impact of disrupting neural descending pathways that modulate spinal neurons involved in intermuscular coordination critical for gait behaviors. Tasks that are more difficult require additional input from these neural pathways; therefore, fourteen feline subjects were familiarized with level overground locomotion and stair descent gait tasks. After collection of baseline kinematic data, the subjects received either a dorsal or ventral …


Real-Time Monitoring Of Cell Death Progress Using Capacitance Spectroscopy, Suyang Wu Dec 2021

Real-Time Monitoring Of Cell Death Progress Using Capacitance Spectroscopy, Suyang Wu

Electronic Theses and Dissertations

Biologics, including the monoclonal antibody (mAb), has experienced rapid development in the last decade. However, the price of biologics is often prohibitively high because of the low process efficiency. Delaying the inevitable cell death improves the productivity of upstream bioprocessing, whose success relies on monitoring the cell death onset that indicates the timing for preventive actions.

This study proposes to develop a real-time monitoring model that quantifies the dying cell percentage in lab-scale bioreactors using capacitance spectroscopy. The capacitance spectroscopy contains cell death-related information due to various physical properties changes during the cell death process, e.g., cytoplasmic conductivity change. The …


Gradient Generating Microfluidic Coculture System For Disease Modeling And Neural Development, Phaneendra Chennampally Dec 2021

Gradient Generating Microfluidic Coculture System For Disease Modeling And Neural Development, Phaneendra Chennampally

Electronic Theses and Dissertations

Cellular microenvironment or cell niche plays an important role in developmental biology and disease pathophysiology. Physical or chemical signals in microenvironment drive the cellular activity. These signaling molecules are generated from the surrounding cells/tissues as part of intercellular communication; a fundamental property of a cell. Dynamic profile of these signaling molecules in the microenvironment plays a pivotal role in transfer of molecular information from cell to cell in disease proliferation or fate determination. Recapitulating these signaling cues in an in vitro study is difficult to achieve using standard cell culture techniques. However microfluidic systems are capable of addressing these issues, …


Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani Aug 2021

Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani

Electronic Theses and Dissertations

Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided …


Bio-Inspired Materials For Electrochemical Sensors, Matthew Joseph Hummel Jan 2021

Bio-Inspired Materials For Electrochemical Sensors, Matthew Joseph Hummel

Electronic Theses and Dissertations

Electrochemical biosensors are a rapidly growing research area that has greatly improved its specificity, accuracy, and precision in the detection of biomolecules in contemporary literature and industry alike. Typically, these systems exist in a three-electrode conformation with a working electrode functioning as the anode, a counter electrode functioning as the cathode, and a reference electrode allowing for the control of potential in the system. The method by which these sensors work is through the sharing of electrons via redox reactions with the target molecule and the working electrode or modifications on its surface. By exploiting the function of biomaterials that …


Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang Jan 2021

Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang

Electronic Theses and Dissertations

Cemented and cementless fixation in total knee arthroplasty (TKA) have been successfully used for decades. As the number of younger and more active patients treated with TKA continues to increase, long-term implant survivorship is of increasing importance. One of the most common complications and hence the reason for revision is mechanical loosening (23.1% of all revised TKA). The loosening mechanisms have been proposed for different fixation types. For cemented fixation, bone remodeling after surgery is regulated by the changes in strain energy density (SED). The recruitment of osteoclasts and osteoblasts is controlled by SED-related signals. Insufficient stimuli can promote bone …


Accurate Measurement Of Healthy Joint Kinematics To Inform Diagnosis And Treatment, Vasiliki Kefala Jan 2021

Accurate Measurement Of Healthy Joint Kinematics To Inform Diagnosis And Treatment, Vasiliki Kefala

Electronic Theses and Dissertations

The description of human motion has a primary importance in different scientific areas such as medicine, sports, physical therapy. Kinematics specifically studies pure motion without reference to the causes of motion such as forces. Understanding the kinematics of human movement is of critical importance in medicine and biology. Motion measure­ment can be used in order to to evaluate functional performance of limbs under normal and abnormal conditions. Kinematic knowledge is also important for diagnosis and surgi­cal treatment of joint disease and the design of implants to rehabilitate function. Accurate joint kinematics is essential to protect articular functionality. An alteration may …


Pilot Study Exploring The Effect Of Targeted Cox-2 Inhibition In Macrophages Responding To Neuronal Injury; Promoting Enhanced Axonal Regeneration, Alyssa Brauckmann May 2020

Pilot Study Exploring The Effect Of Targeted Cox-2 Inhibition In Macrophages Responding To Neuronal Injury; Promoting Enhanced Axonal Regeneration, Alyssa Brauckmann

Electronic Theses and Dissertations

Celecoxib nanoemulsion (CXB-NE) has been developed as a macrophage targeted analgesics by Dr. Janjic and her team at Duquesne University, (Janjic et al, 2018; Liu et al, 2020; Saleem et al, 2019b; Vasudeva et al, 2014). The CXB-NE nanoemulsion carrying a Nonsteroidal Anti-inflammatory (NSAID) inhibitor of COX-2 activity result in a reduction in PGE2 expression in macrophages. Using CXB-NE in rats that have peripheral nerve injury constricting the sciatic nerve relieves hypersensitivity, a pain-like behavior. The treatment also decreases inflammation associated with this chronic constriction injury (Janjic et al, 2018; Saleem et al, 2019b; Stevens et al, 2019). In this …


A Seed Dormancy Gene-Mediated Biotechnology To Mitigate Transgene Flow Into Weedy Rice, Luai Nahar Muhammad Jan 2019

A Seed Dormancy Gene-Mediated Biotechnology To Mitigate Transgene Flow Into Weedy Rice, Luai Nahar Muhammad

Electronic Theses and Dissertations

Transgene flows into wild/weedy relatives may cause ecological and economic problems. Seed dormancy is an adaptive trait that distributes germination over time and promotes persistence of weeds in agroecosystems. Silencing natural genes controlling seed dormancy (SD) could promote germination and reduce weed adaptability. The goal of this project was to develop a transgenic mitigation (TM) technology by linking to a primary transgene with an SD gene-silencing structure, as a tandem construct for transformation, to reduce the risk of gene flow into weed populations. In this research, the Bar (Bialaphos) gene for resistance to the glufosinate herbicide was used as a …


Evaluation Of Drug-Loaded Gold Nanoparticle Cytotoxicity As A Function Of Tumor Tissue Heterogeneity., Hunter Allan Miller Aug 2018

Evaluation Of Drug-Loaded Gold Nanoparticle Cytotoxicity As A Function Of Tumor Tissue Heterogeneity., Hunter Allan Miller

Electronic Theses and Dissertations

The inherent heterogeneity of tumor tissue presents a major challenge to nanoparticle-medicated drug delivery. This heterogeneity spans from the molecular to the cellular (cell types) and to the tissue (vasculature, extra-cellular matrix) scales. Here we employ computational modeling to evaluate therapeutic response as a function of vascular-induced tumor tissue heterogeneity. Using data with three-layered gold nanoparticles loaded with cisplatin, nanotherapy is simulated with different levels of tissue heterogeneity, and the treatment response is measured in terms of tumor regression. The results show that tumor vascular density non-trivially influences the nanoparticle uptake and washout, and the associated tissue response. The drug …


Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard May 2018

Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard

Electronic Theses and Dissertations

Electrophysiological measurements have been used in recent history to classify instantaneous physiological configurations, e.g., hand gestures. This work investigates the feasibility of working with changes in physiological configurations over time (i.e., longitudinally) using a variety of algorithms from the machine learning domain. We demonstrate a high degree of classification accuracy for a binary classification problem derived from electromyography measurements before and after a 35-day bedrest. The problem difficulty is increased with a more dynamic experiment testing for changes in astronaut sensorimotor performance by taking electromyography and force plate measurements before, during, and after a jump from a small platform. A …


Development Of Low Frequency Electron Paramagnetic Resonance Methods And Instrumentation For Biological Applications, Laura A. Buchanan Jan 2018

Development Of Low Frequency Electron Paramagnetic Resonance Methods And Instrumentation For Biological Applications, Laura A. Buchanan

Electronic Theses and Dissertations

EPR is a powerful biophysical tool that can be used to measure tumor physiology. With the addition of magnetic field gradients, the spectral properties of paramagnetic species can be mapped. To facilitate EPR imaging, methods and instrumentation at frequencies between 250 MHz and 1 GHz were developed.

At low spin concentrations, the rapid scan background signal is often many times larger than the EPR signal of interest. To help remove the background contribution, a data acquisition procedure that takes advantage of a cross-loop resonator and bipolar power supplies was developed at 250 MHz. In this procedure, two scans are collected. …


Predictive Modeling Of Hip Dislocation: Assessment Of Surgical And Patient Factors To Reduce The Occurrence Of Hip Instability And Adverse Clinical Outcomes, Daniel N. Huff Jan 2018

Predictive Modeling Of Hip Dislocation: Assessment Of Surgical And Patient Factors To Reduce The Occurrence Of Hip Instability And Adverse Clinical Outcomes, Daniel N. Huff

Electronic Theses and Dissertations

Instability and dislocation remain leading indications for revision of primary Total Hip Arthroplasty (THA). Many studies have addressed the links between implant design and propensity for dislocation, however a comprehensive review of the ability of modern THA constructs to protect against joint instability is needed.

Accordingly, the objective of this study is to provide objective data about THA risks to be considered in the treatment algorithm to protect against adverse joint loading conditions and joint instability. Adverse loading conditions were assessed in a population of activities of daily living using data from telemetric hip implant representation in an FE simulation …


Ex-Vivo Slaughterhouse Porcine Crystalloid-Perfused Beating Heart Via Langendorff Method, Rahiemin Talukder Jan 2016

Ex-Vivo Slaughterhouse Porcine Crystalloid-Perfused Beating Heart Via Langendorff Method, Rahiemin Talukder

Electronic Theses and Dissertations

The objective of this study was to resuscitate isolated beating porcine hearts obtained from slaughterhouse swine for a minimum of 1 hour with a crystalloid buffer reperfusion instead of blood via an extracorporeal Langendorff apparatus. The isolated beating heart functions outside of the body under simulated physiologic conditions. Live functional anatomy was controlled under benchtop experimental settings. Porcine hearts (26 total) were topically cooled with saline. 300mL of 25°C cardioplegia with 20KU Streptokinase was preflushed via aortic root. WIT was less than 5 minutes. 1L 4°C cardioplegia was flushed antegrade with aortic cannula (Group 1) or coronary catheterization (Group 2). …


Microengineering The Neural Tube, Christopher Demers Aug 2015

Microengineering The Neural Tube, Christopher Demers

Electronic Theses and Dissertations

Early embryonic development is a complex and highly regulated orchestra of instructive cues that collectively guide naïve stem cells towards progressively more specialized fates. In the neural tube, the precursor structure to the brain and spinal cord, these signals emanate from ‘organizing centers’ surrounding the neural tube. These organizing centers send out soluble cues or morphogens that diffuse tens to hundreds of microns to recipient cells residing in the neural tube. Re-creating this dynamic landscape of cues in vitro is impossible using standard cell culture tools and techniques. However, microfluidics is perfectly suited to fill this gap, allowing precise control …


Analysis Of The Performance Of Peanut Fame In A Single Cylinder Idi Engine And Investigations Of Neat Methyl Ester Influence On Fuel Quality, Jeffery Lewis Jan 2011

Analysis Of The Performance Of Peanut Fame In A Single Cylinder Idi Engine And Investigations Of Neat Methyl Ester Influence On Fuel Quality, Jeffery Lewis

Electronic Theses and Dissertations

Author's abstract: To meet evolving standards set forth by the U.S. EPA and U.S. Energy Policy it is necessary to consider a variety of feedstock for biofuels synthesis and to understand the role individual fatty acids contribute to the overall performance. It is the belief of the authors that excess peanut production would provide an excellent source for high quality biodiesel feedstock, and the complete property and combustion analysis of the fatty acid components will provide insight for future biofuel developments. The preliminary investigations of the project focused on the combustion performance and thermal efficiency of peanut FAME and its …


A Computer Science Approach To Identify And Classify Hyperactivated Spermatozoa, Norbert Kaula Jan 2009

A Computer Science Approach To Identify And Classify Hyperactivated Spermatozoa, Norbert Kaula

Electronic Theses and Dissertations

Effective Assisted Reproductive Technology (ART) relies in part upon accurate but easily conducted measurements of sperm motion parameters. Several established methods are widely used to assess possible reasons for male infertility, in human and veterinary Andrology clinics. Computer-assisted sperm analysis (CASA) devices quantitatively assess sperm motion parameters, which have been defined by the World Health Organization, and include the percentage of motile cells in a sample and the motion characteristics of individual cells, such as curvilinear velocity (VCL), average path velocity (VAP) and straight line velocity (VSL). However, CASA analyses fail to define hyperactive sperm motility or determine the prevalence …


Generation Of Recombinant Mouse Embryonic Stem Cell Lines And Theirapplication For In Vivo Bioluminiscence Imaging In The Heart, Ramana Kammili Jan 2008

Generation Of Recombinant Mouse Embryonic Stem Cell Lines And Theirapplication For In Vivo Bioluminiscence Imaging In The Heart, Ramana Kammili

Electronic Theses and Dissertations

Cardiovascular disease is the major cause of death in the United States, with 80 million people suffering from some form of heart disease each year. One major limitation is the inability of the heart to repair the damaged tissue. Stem cell therapy holds enormous promise to repair and regenerate the damaged myocardium, but there are many technical difficulties that must first be overcome. One such difficulty is the present lack of ability to track and assess transplanted stem cells over time in vivo. The central hypothesis of this thesis is that in vivo bioluminescence imaging is a safe and useful …


Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen Dec 1993

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.


Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites May 1991

Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites

Electronic Theses and Dissertations

Glycerophospholipids of mammalian cells exist as chemically diverse structures with various fatty acids at the sn-1 and sn-2 positions. Arachidonic acid, a polyunsaturated fatty acid, which may be converted to biologically active eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, is found predominantly in the sn-2 position of glycerophospholipids. The purpose of this study was to examine, at the level of the individual molecular species, the incorporation of arachidonate into phospholipids and its release from phospholipids during stimulation. In this way, the specificity of the enzymes controlling arachidonate metabolism could be examined in order to clarify the processes that control the …