Open Access. Powered by Scholars. Published by Universities.®

Biomedical Engineering and Bioengineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 32

Full-Text Articles in Biomedical Engineering and Bioengineering

Blue-Light Induced Biosynthesis Of Ros Contributes To The Signaling Mechanism Of Arabidopsis Cryptochrome, Mohamed A. El-Esawi, Louis David Arthaut, Nathalie Jourdan, Alain D'Harlingue, Justin J. Link, Margaret Ahmad, Carlos F. Martino Dec 2017

Blue-Light Induced Biosynthesis Of Ros Contributes To The Signaling Mechanism Of Arabidopsis Cryptochrome, Mohamed A. El-Esawi, Louis David Arthaut, Nathalie Jourdan, Alain D'Harlingue, Justin J. Link, Margaret Ahmad, Carlos F. Martino

Biomedical Engineering and Sciences Faculty Publications

Cryptochromes are evolutionarily conserved blue light receptors with many roles throughout plant growth and development. They undergo conformational changes in response to light enabling interaction with multiple downstream signaling partners. Recently, it has been shown that cryptochromes also synthesize reactive oxygen species (ROS) in response to light, suggesting the possibility of an alternate signaling mechanism. Here we show by fluorescence imaging and microscopy that H202 and ROS accumulate in the plant nucleus after cryptochrome activation. They induce ROS-regulated transcripts including for genes implicated in pathogen defense, biotic and abiotic stress. Mutant cryptochrome alleles that are non-functional in photomorphogenesis retain the …


Targeting The Bacterial Orisome In The Search For New Antibiotics, Julia E. Grimwade, Alan C. Leonard Nov 2017

Targeting The Bacterial Orisome In The Search For New Antibiotics, Julia E. Grimwade, Alan C. Leonard

Biomedical Engineering and Sciences Faculty Publications

There is an urgent need for new antibiotics to combat drug resistant bacteria. Existing antibiotics act on only a small number of proteins and pathways in bacterial cells, and it seems logical that expansion of the target set could lead to development of novel antimicrobial agents. One essential process, not yet exploited for antibiotic discovery, is the initiation stage of chromosome replication, mediated by the bacterial orisome. In all bacteria, orisomes assemble when the initiator protein, DnaA, as well as accessory proteins, bind to a DNA scaffold called the origin of replication (oriC). Orisomes perform the essential tasks of unwinding …


Delivery Of Antioxidant And Anti-Inflammatory Agents For Tissue Engineered Vascular Grafts, Kenyatta S. Washington, Chris A. Bashur Sep 2017

Delivery Of Antioxidant And Anti-Inflammatory Agents For Tissue Engineered Vascular Grafts, Kenyatta S. Washington, Chris A. Bashur

Biomedical Engineering and Sciences Faculty Publications

The treatment of patients with severe coronary and peripheral artery disease represents a significant clinical need, especially for those patients that require a bypass graft and do not have viable veins for autologous grafting. Tissue engineering is being investigated to generate an alternative graft. While tissue engineering requires surgical intervention, the release of pharmacological agents is also an important part of many tissue engineering strategies. Delivery of these agents offers the potential to overcome the major concerns for graft patency and viability. These concerns are related to an extended inflammatory response and its impact on vascular cells such as endothelial …


Cellular Proteomes Drive Tissue-Specific Regulation Of The Heat Shock Response, Jian Ma, Christopher E. Grant, Rosemary Nadine Plagens, Lindsey N. Barrett, Karen S. Kim Guisbert, Eric Guisbert Mar 2017

Cellular Proteomes Drive Tissue-Specific Regulation Of The Heat Shock Response, Jian Ma, Christopher E. Grant, Rosemary Nadine Plagens, Lindsey N. Barrett, Karen S. Kim Guisbert, Eric Guisbert

Biomedical Engineering and Sciences Faculty Publications

The heat shock response (HSR) is a cellular stress response that senses protein misfolding and restores protein folding homeostasis, or proteostasis. We previously identified an HSR regulatory network inCaenorhabditis elegans consisting of highly conserved genes that have important cellular roles in maintaining proteostasis. Unexpectedly, the effects of these genes on the HSR are distinctly tissue-specific. Here, we explore this apparent discrepancy and find that muscle-specific regulation of the HSR by the TRiC/CCT chaperonin is not driven by an enrichment of TRiC/CCT in muscle, but rather by the levels of one of its most abundant substrates, actin. Knockdown of actin subunits …


Overexpression Of Timp-3 In Chondrocytes Produces Transient Reduction In Growth Plate Length But Permanently Reduces Adult Bone Quality And Quantity, Blandine Poulet, Ke Liu, Darren A. Plumb, Phoung Vo, Mittal Shah, Katherine Ann Staines, Alexandra Sampson, Hiroyuke Nakamura, Hideaki Nagase, Alessandra Carriero, Sandra J. Shefelbine, Andrew A. Pitsillides, George Bou-Gharios Dec 2016

Overexpression Of Timp-3 In Chondrocytes Produces Transient Reduction In Growth Plate Length But Permanently Reduces Adult Bone Quality And Quantity, Blandine Poulet, Ke Liu, Darren A. Plumb, Phoung Vo, Mittal Shah, Katherine Ann Staines, Alexandra Sampson, Hiroyuke Nakamura, Hideaki Nagase, Alessandra Carriero, Sandra J. Shefelbine, Andrew A. Pitsillides, George Bou-Gharios

Biomedical Engineering and Sciences Faculty Publications

Bone development and length relies on the growth plate formation, which is dependent on degradative enzymes such as MMPs. Indeed, deletion of specific members of this enzyme family in mice results in important joint and bone abnormalities, suggesting a role in skeletal development. As such, the control of MMP activity is vital in the complex process of bone formation and growth. We generated a transgenic mouse line to overexpress TIMP3 in mouse chondrocytes using the Col2a1-chondrocyte promoter. This overexpression in cartilage resulted in a transient shortening of growth plate in homozygote mice but bone length was restored at eight weeks …


The Quantum Biology Of Reactive Oxygen Species Partitioning Impacts Cellular Bioenergetics, Robert J. Usselman, Cristina Chavarriaga, Pablo R. Castello, Maria Procopio, Thorsten Ritz, Edward A. Dratz, David John Singel, Carlos F. Martino Dec 2016

The Quantum Biology Of Reactive Oxygen Species Partitioning Impacts Cellular Bioenergetics, Robert J. Usselman, Cristina Chavarriaga, Pablo R. Castello, Maria Procopio, Thorsten Ritz, Edward A. Dratz, David John Singel, Carlos F. Martino

Biomedical Engineering and Sciences Faculty Publications

Quantum biology is the study of quantum effects on biochemical mechanisms and biological function. We show that the biological production of reactive oxygen species (ROS) in live cells can be influenced by coherent electron spin dynamics, providing a new example of quantum biology in cellular regulation. ROS partitioning appears to be mediated during the activation of molecular oxygen (O2) by reduced flavoenzymes, forming spin-correlated radical pairs (RPs). We find that oscillating magnetic fields at Zeeman resonance alter relative yields of cellular superoxide (O2•−) and hydrogen peroxide (H2O2) ROS products, indicating coherent singlet-triplet mixing at the point of ROS formation. Furthermore, …


Tunneling Nanotubes: An Alternate Route For Propagation Of The Bystander Effect Following Oncolytic Viral Infection, Justin Ady, Venugopal Thayanithy, Kelly Mojica, Phillip Wong, Joshua Carson, Prassanna Rao, Yuman Fong, Emil Lou Dec 2016

Tunneling Nanotubes: An Alternate Route For Propagation Of The Bystander Effect Following Oncolytic Viral Infection, Justin Ady, Venugopal Thayanithy, Kelly Mojica, Phillip Wong, Joshua Carson, Prassanna Rao, Yuman Fong, Emil Lou

Biomedical Engineering and Sciences Faculty Publications

Tunneling nanotubes (TNTs) are ultrafine, filamentous actin-based cytoplasmic extensions which form spontaneously to connect cells at short and long-range distances. We have previously described long-range intercellular communication via TNTs connecting mesothelioma cells in vitro and demonstrated TNTs in intact tumors from patients with mesothelioma. Here, we investigate the ability of TNTs to mediate a viral thymidine kinase based bystander effect after oncolytic viral infection and administration of the nucleoside analog ganciclovir. Using confocal microscopy we assessed the ability of TNTs to propagate enhanced green fluorescent protein (eGFP), which is encoded by the herpes simplex virus NV1066, from infected to uninfected …


Impaired Corpus Cavernosum Relaxation Is Accompanied By Increased Oxidative Stress And Up-Regulation Of The Rho-Kinase Pathway In Diabetic (Db/Db) Mice, Fernanda Bruschi Marinho Priviero, Haroldo A.F. Toque, Kênia Pedrosa Nunes, Denise Gonçalves Priolli, Cleber Evandro Teixeira, Robert Clinton Webb May 2016

Impaired Corpus Cavernosum Relaxation Is Accompanied By Increased Oxidative Stress And Up-Regulation Of The Rho-Kinase Pathway In Diabetic (Db/Db) Mice, Fernanda Bruschi Marinho Priviero, Haroldo A.F. Toque, Kênia Pedrosa Nunes, Denise Gonçalves Priolli, Cleber Evandro Teixeira, Robert Clinton Webb

Biomedical Engineering and Sciences Faculty Publications

Basal release of nitric oxide from endothelial cells modulates contractile activity in the corpus cavernosum via inhibition of the RhoA/Rho-kinase signaling pathway. We aimed to investigate nitric oxide bioavailability, oxidative stress and the Rho-kinase pathway in the relaxation of the corpus cavernosum of an obese and diabetic model of mice (db/db mice). We hypothesized that in db/db mice impaired relaxation induced by Rho-kinase inhibitor is accompanied by diminished NO bioavailability, increased oxidative stress and upregulation of the RhoA/Rho-kinase signalling pathway. Cavernosal strips from male lean and non-diabetic db/+ and db/db mice were mounted in myographs and isometric force in response …


Impact Of Elastin Incorporation Into Electrochemically Aligned Collagen Fibers On Mechanical Properties And Smooth Muscle Cell Phenotype, Thuy-Uyen Nguyen, Chris A. Bashur, Vipuil Kishore Mar 2016

Impact Of Elastin Incorporation Into Electrochemically Aligned Collagen Fibers On Mechanical Properties And Smooth Muscle Cell Phenotype, Thuy-Uyen Nguyen, Chris A. Bashur, Vipuil Kishore

Biomedical Engineering and Sciences Faculty Publications

Application of tissue-engineered vascular grafts (TEVGs) for the replacement of small-diameter arteries is limited due to thrombosis and intimal hyperplasia. Previous studies have attempted to address the limitations of TEVGs by developing scaffolds that mimic the composition (collagen and elastin) of native arteries to better match the mechanical properties of the graft with the native tissue. However, most existing scaffolds do not recapitulate the aligned topography of the collagen fibers found in native vessels. In the current study, based on the principles of isoelectric focusing, two different types of elastin (soluble and insoluble) were incorporated into highly oriented electrochemically aligned …


Animal Models Of Osteogenesis Imperfecta: Applications In Clinical Research, Tanya A. Enderli, Stephanie R. Burtch, Jara N. Templet, Alessandra Carriero Jan 2016

Animal Models Of Osteogenesis Imperfecta: Applications In Clinical Research, Tanya A. Enderli, Stephanie R. Burtch, Jara N. Templet, Alessandra Carriero

Biomedical Engineering and Sciences Faculty Publications

Osteogenesis imperfecta (OI), commonly known as brittle bone disease, is a genetic disease characterized by extreme bone fragility and consequent skeletal deformities. This connective tissue disorder is caused by mutations in the quality and quantity of the collagen that in turn affect the overall mechanical integrity of the bone, increasing its vulnerability to fracture. Animal models of the disease have played a critical role in the understanding of the pathology and causes of OI and in the investigation of a broad range of clinical therapies for the disease. Currently, at least 20 animal models have been officially recognized to represent …


Phospho1 Deficiency Transiently Modifies Bone Architecture Yet Produces Consistent Modification In Osteocyte Differentiation And Vascular Porosity With Ageing, Behzad Javaheri, Alessandra Carriero, Katherine Ann Staines, Y.-M. Chang, D. A. Houston, Karla J. Oldknow, José Luis Millán, Bassir N. Kazeruni, Phil L. Salmon, Sandra J. Shefelbine Dec 2015

Phospho1 Deficiency Transiently Modifies Bone Architecture Yet Produces Consistent Modification In Osteocyte Differentiation And Vascular Porosity With Ageing, Behzad Javaheri, Alessandra Carriero, Katherine Ann Staines, Y.-M. Chang, D. A. Houston, Karla J. Oldknow, José Luis Millán, Bassir N. Kazeruni, Phil L. Salmon, Sandra J. Shefelbine

Biomedical Engineering and Sciences Faculty Publications

PHOSPHO1 is one of principal proteins involved in initiating bone matrix mineralisation. Recent studies have found that Phospho1 KO mice ( Phospho1-R74X) display multiple skeletal abnormalities with spontaneous fractures, bowed long bones, osteomalacia and scoliosis. These analyses have however been limited to young mice and it remains unclear whether the role of PHOSPHO1 is conserved in the mature murine skeleton where bone turnover is limited. In this study, we have used ex-vivo computerised tomography to examine the effect of Phospho1 deletion on tibial bone architecture in mice at a range of ages (5, 7, 16 and 34. weeks of age) …


The Effect Of Recency To Human Mobility, Hugo Barbosa, Fernando B. De Lima-Neto, Alexandre Evsukoff, Ronaldo Menezes Dec 2015

The Effect Of Recency To Human Mobility, Hugo Barbosa, Fernando B. De Lima-Neto, Alexandre Evsukoff, Ronaldo Menezes

Biomedical Engineering and Sciences Faculty Publications

In recent years, we have seen scientists attempt to model and explain human dynamics and in particular human movement. Many aspects of our complex life are affected by human movement such as disease spread and epidemics modeling, city planning, wireless network development, and disaster relief, to name a few. Given the myriad of applications, it is clear that a complete understanding of how people move in space can lead to considerable benefits to our society. In most of the recent works, scientists have focused on the idea that people movements are biased towards frequently-visited locations. According to them, human movement …


Effects Of Normal And Abnormal Loading Conditions On Morphogenesis Of The Prenatal Hip Joint: Application To Hip Dysplasia, Mario Giorgi, Alessandra Carriero, Sandra J. Shefelbine, Niamh C. Nowlan Jun 2015

Effects Of Normal And Abnormal Loading Conditions On Morphogenesis Of The Prenatal Hip Joint: Application To Hip Dysplasia, Mario Giorgi, Alessandra Carriero, Sandra J. Shefelbine, Niamh C. Nowlan

Biomedical Engineering and Sciences Faculty Publications

Joint morphogenesis is an important phase of prenatal joint development during which the opposing cartilaginous rudiments acquire their reciprocal and interlocking shapes. At an early stage of development, the prenatal hip joint is formed of a deep acetabular cavity that almost totally encloses the head. By the time of birth, the acetabulum has become shallower and the femoral head has lost substantial sphericity, reducing joint coverage and stability. In this study, we use a dynamic mechanobiological simulation to explore the effects of normal (symmetric), reduced and abnormal (asymmetric) prenatal movements on hip joint shape, to understand their importance for postnatal …


The Orisome: Structure And Function, Julia E. Grimwade, Alan C. Leonard Jun 2015

The Orisome: Structure And Function, Julia E. Grimwade, Alan C. Leonard

Biomedical Engineering and Sciences Faculty Publications

During the cell division cycle of all bacteria, DNA-protein complexes termed orisomes trigger the onset of chromosome duplication. Orisome assembly is both staged and stringently regulated to ensure that DNA synthesis begins at a precise time and only once at each origin per cycle. Orisomes comprise multiple copies of the initiator protein DnaA, which oligomerizes after interacting with specifically positioned recognition sites in the unique chromosomal replication origin, oriC. Since DnaA is highly conserved, it is logical to expect that all bacterial orisomes will share fundamental attributes. Indeed, although mechanistic details remain to be determined, all bacterial orisomes are capable …


A Ten-Year Search For Synchronous Cells: Obstacles, Solutions, And Practical Applications, Charles E. Helmstetter Mar 2015

A Ten-Year Search For Synchronous Cells: Obstacles, Solutions, And Practical Applications, Charles E. Helmstetter

Biomedical Engineering and Sciences Faculty Publications

My effort to use synchronously dividing cultures to examine the Escherichia coli cell cycle involved a 10-year struggle with failure after failure punctuated by a few gratifying successes, especially at the end. In this essay, I recount my personal journey in this obsessive experimental pursuit. That narrative is followed by a description of a simplified version of the "baby machine," a technique that was developed to obtain minimally disturbed, synchronously growing E. coli cells. Subsequent studies with this methodology led to an understanding of the basic properties of the relationship between chromosome replication and cell division. Accordingly, I end this …


Differential Protein Expression Of Caco-2 Cells Treated With Selenium Nanoparticles Compared With Sodium Selenite And Selenomethionine, Linglin Fu, Xuxia Yan, Xinming Ruan, Junda Lin, Yanbo Wang Dec 2014

Differential Protein Expression Of Caco-2 Cells Treated With Selenium Nanoparticles Compared With Sodium Selenite And Selenomethionine, Linglin Fu, Xuxia Yan, Xinming Ruan, Junda Lin, Yanbo Wang

Biomedical Engineering and Sciences Faculty Publications

The study was designed to determine the differential protein expression of Caco-2 cells treated with different forms of selenium including sodium selenite, selenomethionine (Se-Met), and selenium nanoparticles (nano-Se). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) were used to identify the differentially expressed proteins. The results indicated that seven protein spots, ubiquitin-conjugating enzyme E2 (E2), glutathione synthetases (GS), triosephosphate isomerase (TSP), T-complex protein 1 subunit zeta (TCPZ), lamin-B1, heterogeneous nuclear ribonucleoprotein F (hnRNP F), and superoxide dismutase [Cu-Zn] (Cu, Zn-SOD) were significantly different among all the groups. According to the order of control, sodium selenite, Se-Met, and Nano-Se, the …


Reference Point Indentation Is Not Indicative Of Whole Mouse Bone Measures Of Stress Intensity Fracture Toughness, Alessandra Carriero, Jan L. Bruse, Karla J. Oldknow, José Luis Millán, Colin Farquharson, Sandra J. Shefelbine Oct 2014

Reference Point Indentation Is Not Indicative Of Whole Mouse Bone Measures Of Stress Intensity Fracture Toughness, Alessandra Carriero, Jan L. Bruse, Karla J. Oldknow, José Luis Millán, Colin Farquharson, Sandra J. Shefelbine

Biomedical Engineering and Sciences Faculty Publications

Bone fragility is a concern for aged and diseased bone. Measuring bone toughness and understanding fracture properties of the bone are critical for predicting fracture risk associated with age and disease and for preclinical testing of therapies. A reference point indentation technique (BioDent) has recently been developed to determine bone's resistance to fracture in a minimally invasive way by measuring the indentation distance increase (IDI) between the first and last indentations over cyclic indentations in the same position. In this study, we investigate the relationship between fracture toughness KC and reference point indentation parameters (i.e. IDI, total indentation distance (TID) …


Ranbp9 Overexpression Accelerates Loss Of Pre And Postsynaptic Proteins In The Apδe9 Transgenic Mouse Brain, Hongjie Wang, Ruizhi Wang, Shaohua Xu, Madepalli Krishnappa Lakshmana Jan 2014

Ranbp9 Overexpression Accelerates Loss Of Pre And Postsynaptic Proteins In The Apδe9 Transgenic Mouse Brain, Hongjie Wang, Ruizhi Wang, Shaohua Xu, Madepalli Krishnappa Lakshmana

Biomedical Engineering and Sciences Faculty Publications

There is now compelling evidence that the neurodegenerative process in Alzheimer's disease (AD) begins in synapses. Loss of synaptic proteins and functional synapses in the amyloid precursor protein (APP) transgenic mouse models of AD is well established. However, what is the earliest age at which such loss of synapses occurs, and whether known markers of AD progression accelerate functional deficits is completely unknown. We previously showed that RanBP9 overexpression leads to robustly increased amyloid β peptide (Aβ) generation leading to enhanced amyloid plaque burden in a mouse model of AD. In this study we compared synaptic protein levels among four …


Ranbp9 Aggravates Synaptic Damage In The Mouse Brain And Is Inversely Correlated To Spinophilin Levels In Alzheimer's Brain Synaptosomes, Juan Pablo Palavicini, Hongjie Wang, Elisabetta Bianchi, Shaohua Xu, Jagadeesh S. Rao, David E. Kang, Madepalli K. Lakshmana Jun 2013

Ranbp9 Aggravates Synaptic Damage In The Mouse Brain And Is Inversely Correlated To Spinophilin Levels In Alzheimer's Brain Synaptosomes, Juan Pablo Palavicini, Hongjie Wang, Elisabetta Bianchi, Shaohua Xu, Jagadeesh S. Rao, David E. Kang, Madepalli K. Lakshmana

Biomedical Engineering and Sciences Faculty Publications

We previously demonstrated that over expression of RanBP9 led to enhanced Ab generation in a variety of cell lines and primary neuronal cultures, and subsequently, we confirmed increased amyloid plaque burden in a mouse model of Alzheimer’s disease (AD). In the present study, we found striking reduction of spinophilin protein levels when RanBP9 is overexpressed. At 12 months of age, we found spinophilin levels reduced by 70% (Po0.001) in the cortex of APDE9/RanBP9 mice compared with that in wild-type (WT) controls. In the hippocampus, the spinophilin levels were reduced by 45% (Po0.01) in the APDE9/RanBP9 mice. Spinophilin immunoreactivity was also …


Techniques To Quantify The Size Of Protein Colloids In Amyloid Fiber Formation, Jonathan R. Anson, Chia-Hung Lu, Lingwen Cui, Xiaojing Yang, Shaohua Xu Jan 2013

Techniques To Quantify The Size Of Protein Colloids In Amyloid Fiber Formation, Jonathan R. Anson, Chia-Hung Lu, Lingwen Cui, Xiaojing Yang, Shaohua Xu

Biomedical Engineering and Sciences Faculty Publications

A new method for the analysis of protein colloidal diameter has been developed using three existing protein concentration quantification techniques, absorption at 280 nm, colloidal gold assay, and DC protein assay. Protein colloids are formed in the process of aggregation and are thought to be intermediates in protein self-assembly and formation of amyloid fiber. Deposition of the protein fibers in tissues leads to numerous human diseases including Alzheimer’s. Lysozyme was incubated at pH 2.0, 55°C, an environment conducive to amyloid fiber formation. The protein colloids present in the supernatant of the samples after centrifugation were studied over a time course …


Theranostic Oxygen Delivery Using Ultrasound And Microbubbles, James J. Kwan, Mehmet Kaya, Mark A. Borden, Paul A. Dayton Dec 2012

Theranostic Oxygen Delivery Using Ultrasound And Microbubbles, James J. Kwan, Mehmet Kaya, Mark A. Borden, Paul A. Dayton

Biomedical Engineering and Sciences Faculty Publications

Means to overcome tumor hypoxia have been the subject of clinical investigations since the 1960’s; however these studies have yet to find a treatment which is widely accepted. It has been known for nearly a century that hypoxic cells are more resistant to radiotherapy than aerobic cells, and tumor hypoxia is a major factor leading to the resistance of tumors to radiation treatment as well as several cytotoxic agents. In this manuscript, the application of ultrasound combined with oxygen-carrier microbubbles is demonstrated as a method to locally increase dissolved oxygen. Microbubbles can also be imaged by ultrasound, thus providing the …


Unstable Spinocerebellar Ataxia Type 10 (Attct) (Agaat) Repeats Are Associated With Aberrant Replication At The Atx10 Locus And Replication Origin-Dependent Expansion At An Ectopic Site In Human Cells, Guoqi Liu, John J. Bissler, Richard R. Sinden, Michael Leffak Nov 2011

Unstable Spinocerebellar Ataxia Type 10 (Attct) (Agaat) Repeats Are Associated With Aberrant Replication At The Atx10 Locus And Replication Origin-Dependent Expansion At An Ectopic Site In Human Cells, Guoqi Liu, John J. Bissler, Richard R. Sinden, Michael Leffak

Biomedical Engineering and Sciences Faculty Publications

Spinocerebellar ataxia type 10 (SCA10) is associated with expansion of (ATTCT)n repeats (where n is the number of repeats) within the ataxin 10 (ATX10/E46L) gene. The demonstration that (ATTCT)n tracts can act as DNA unwinding elements (DUEs) in vitro has suggested that aberrant replication origin activity occurs at expanded (ATTCT)n tracts and may lead to their instability. Here, we confirm these predictions. The wild-type ATX10 locus displays inefficient origin activity, but origin activity is elevated at the expanded ATX10 loci in patient-derived cells. To test whether (ATTCT)n tracts can potentiate origin activity, cell lines were constructed that contain ectopic copies …


Effects Of Phosphate-Buffered Saline Concentration And Incubation Time On The Mechanical And Structural Properties Of Electrochemically Aligned Collagen Threads, Jorge Alfredo Uquillas, Vipuil Kishore, Ozan Akkus Jun 2011

Effects Of Phosphate-Buffered Saline Concentration And Incubation Time On The Mechanical And Structural Properties Of Electrochemically Aligned Collagen Threads, Jorge Alfredo Uquillas, Vipuil Kishore, Ozan Akkus

Biomedical Engineering and Sciences Faculty Publications

A key step during the synthesis of collagen constructs is the incubation of monomeric collagen in phosphate buffer saline (PBS) to promote fibrillogenesis in the collagen network. Optimal PBS-treatment conditions for monomeric collagen solutions to induce gelation are well established in the literature. Recently, a report in the literature (Cheng et al 2008 Biomaterials 29 3278-88) showed a novel method to fabricate highly oriented electrochemically aligned collagen (ELAC) threads which have orders of magnitude greater packing density than collagen gels. The optimal PBS-treatment conditions for induction of D-banding pattern in such a dense and anisotropic collagen network are unknown. This …


Short-Pulse Laser Propagation Through Tissue Medium For Tumor Detection, Gopalendu Pal, Kunal Mitra, Tuan Vo-Dinh Feb 2006

Short-Pulse Laser Propagation Through Tissue Medium For Tumor Detection, Gopalendu Pal, Kunal Mitra, Tuan Vo-Dinh

Biomedical Engineering and Sciences Faculty Publications

The objective of this paper is to perform a comprehensive experimental and numerical analysis of the short pulse laser interaction with tissue medium with the goal of tumor / cancer diagnostics. For short pulse laser source, the shape of output signal is a function of the optical properties of the medium and hence the scattered temporal optical signal helps in understanding of the medium characteristics. Initially experiments are performed on tissue phantoms imbedded with inhomogeneities in order to optimize the time-resolved optical detection scheme. Both the temporal and the spatial profiles of the scattered reflected and transmitted optical signals are …


A Concept For Early Cancer Detection And Therapy, Ronald W. Waynant, Ilko K. Ilev, Kunal Mitra Sep 2003

A Concept For Early Cancer Detection And Therapy, Ronald W. Waynant, Ilko K. Ilev, Kunal Mitra

Biomedical Engineering and Sciences Faculty Publications

Early detection and treatment of breast cancer is least costly in terms of dollars, morbidity and mortality. With new early detection x-ray technology, tumors can be found, diagnosed and treated at a much smaller size than is currently possible. This paper proposes the development of a high resolution, high quality imaging system. It is a laser-driven x-ray system with time-gated detection that removes scattering noise in the image and produces resolution on the order of 10 μm. This higher resolution and higher image quality will enable the detection of one or two millimeter tumors hopefully detecting them before metastasis. We …


Short Pulse Laser Propagation Through Tissues, Champak Das, Ashish Trivedi, Kunal Mitra, Tuan Vo-Dinh Jul 2003

Short Pulse Laser Propagation Through Tissues, Champak Das, Ashish Trivedi, Kunal Mitra, Tuan Vo-Dinh

Biomedical Engineering and Sciences Faculty Publications

An experimental and numerical study is performed to analyze short pulse laser propagation through tissue phantoms without and with inhomogeneities/tumors imbedded in it. Short pulse laser probing techniques has distinct advantages over conventional very large pulse width or cw lasers primarily due to the additional information conveyed about the tissue interior by the temporal variation of the observed signal. Both the scattered temporal transmitted and reflected optical signals are measured experimentally using a streak camera for samples irradiated with a short pulse laser source. Parametric study involving different scattering and absorption coefficients of tissue phantoms and inhomogeneities as well as …


Novel Modeling Techniques For Tumor Diagnostics Using Pulsed Laser Sources, Mohamed Sakami, Kunal Mitra, Tuan Vo-Dinh May 2002

Novel Modeling Techniques For Tumor Diagnostics Using Pulsed Laser Sources, Mohamed Sakami, Kunal Mitra, Tuan Vo-Dinh

Biomedical Engineering and Sciences Faculty Publications

In this paper, a two-dimensional transient radiation transport algorithm is developed to analyze short pulse laser transport through a tissue medium having tumors and inhomogeneities imbedded in it. Short pulse probing techniques have distinct advantages over conventional very large pulse width or cw lasers primarily due to the additional information conveyed about the tissue interior by the temporal variation of the observed signal. The distinct feature is the multiple scattering induced temporal signatures that persists for time periods greater than the duration of the source pulse and is a function of the source pulse width, the scattering/absorbing properties and nature …


Use Of Short-Pulse Laser For Optical Tomography Of Tissues, Kunal Mitra, Tuan Vo-Dinh Jun 2001

Use Of Short-Pulse Laser For Optical Tomography Of Tissues, Kunal Mitra, Tuan Vo-Dinh

Biomedical Engineering and Sciences Faculty Publications

This paper analyzes the short pulse laser propagation through tissues for development of a time-resolved optical tomography system for detection of tumors and inhomogeneities in tissues. Traditional method for analyzing optical transport in tissues is the parabolic or diffusion approximation in which the energy flux is assumed proportional to the fluence (intensity averaged over all solid angles) gradients. The inherent drawback in this model is that it predicts infinite speed of propagation of the optical signal. In this paper accurate hyperbolic or wave nature of transient radiative transfer formulation is used to overcome such drawbacks. The transmitted and reflected intensity …


Waveguide Delivery Of X Rays For Minimally Invasive Tumor Therapy, Ronald W. Waynant, Ilko K. Ilev, Kunal Mitra May 2001

Waveguide Delivery Of X Rays For Minimally Invasive Tumor Therapy, Ronald W. Waynant, Ilko K. Ilev, Kunal Mitra

Biomedical Engineering and Sciences Faculty Publications

We are studying the potential use of x-rays, which are collected by non-imaging optics and delivered through stereotactically guided needles by hollow waveguides, for irradiation of tumors. X-rays have greater transparency in tissue than most longer optical wavelengths and may provide a more uniform dose to a tumor without harming normal tissue. Dosimetry is the key to minimal damage. We are investigating the use of fiber optics, tipped with calibrated scintillators and strategically located near the tumor, to measure the delivered dose. We are testing this procedure by using a 3 ns, variable accelerator voltage Fexitron 706 to produce approximately …


In Vitro Activity Of Levofloxacin, Singly And In Combination With Rifamycin Analogs, Against Mycobacterium Leprae, Arvind Madhav Dhople, Maria Antonia Ibáñez Sep 1995

In Vitro Activity Of Levofloxacin, Singly And In Combination With Rifamycin Analogs, Against Mycobacterium Leprae, Arvind Madhav Dhople, Maria Antonia Ibáñez

Biomedical Engineering and Sciences Faculty Publications

The in vitro susceptibility of Mycobacterium leprae to levofloxacin was studied by using two biochemical parameters to measure the metabolic activity of the organism. Levofloxacin consistently exhibited twofold greater bactericidal activity than ofloxacin, with the MIC being 0.75 μg/ml. When combined with one of the three rifamycin analogs, synergism was obtained with KRM-1648 and rifabutin but not with rifampin.