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Articles 91 - 108 of 108

Full-Text Articles in Biomedical Engineering and Bioengineering

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 …

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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 …

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Quantification Of In Vivo Oxidative Damage In Caenorhabditis Elegans During Aging By Endogenous F3-Isoprostane Measurement, Christiaan F. Labuschagne, Edwin C.A. Stigter, Margriet M.W.B. Hendriks, Ruud Berger, Joshua Rokach, Hendrik C. Korswagen, Arjan B. Brenkman Jan 2013

Quantification Of In Vivo Oxidative Damage In Caenorhabditis Elegans During Aging By Endogenous F3-Isoprostane Measurement, Christiaan F. Labuschagne, Edwin C.A. Stigter, Margriet M.W.B. Hendriks, Ruud Berger, Joshua Rokach, Hendrik C. Korswagen, Arjan B. Brenkman

Chemistry and Chemical Engineering Faculty Publications

Oxidative damage is thought to be a major cause in development of pathologies and aging. However, quantification of oxidative damage is methodologically difficult. Here, we present a robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach for accurate, sensitive, and linear in vivo quantification of endogenous oxidative damage in the nematode Caenorhabditis elegans, based on F3-isoprostanes. F3-isoprostanes are prostaglandin-like markers of oxidative damage derived from lipid peroxidation by Reactive Oxygen Species (ROS). Oxidative damage was quantified in whole animals and in multiple cellular compartments, including mitochondria and peroxisomes. Mutants of the mitochondrial electron transport proteins mev-1 and clk-1 showed increased oxidative damage …

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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 …

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Evaluating And Training Intraoperative Analysis Of The Mitral Valve, Neil A. Tenenholtz Jan 2013

Evaluating And Training Intraoperative Analysis Of The Mitral Valve, Neil A. Tenenholtz

Link Foundation Modeling, Simulation and Training Fellowship Reports

Mitral valve repair is the recommended method of treating valve incompetency. However, the procedure is quite difficult and, as a result, underperformed due to surgeon’s need to predict the closed valve shape of the patient’s arrested heart. While the interactive process of predicting closed valve shape is achieved by physically manipulating valve tissue (known as valve analysis), surgical training consists of traditional, non-interactive pedagogy (e.g., book-based learning and lectures) followed by an apprenticeship model where the trainee is gradually given hands-on experience, resulting in post-medical school training that is often 10 years or greater. The continuing education of practicing cardiac …

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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 …

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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 …

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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 …

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Oxidized Derivatives Of Ω-3 Fatty Acids: Identification Of Ipf 3Α-Vi In Human Urine, John A. Lawson, Seongjin Kim, William S. Powell, Garret Gerald A. Fitzgerald, Joshua Rokach Nov 2006

Oxidized Derivatives Of Ω-3 Fatty Acids: Identification Of Ipf 3Α-Vi In Human Urine, John A. Lawson, Seongjin Kim, William S. Powell, Garret Gerald A. Fitzgerald, Joshua Rokach

Chemistry and Chemical Engineering Faculty Publications

Isoprostanes (iPs) are prostaglandin-like molecules derived from autoxidation of polyunsaturated fatty acids (PUFAs). Urinary iP levels have been used as indices of in vivo lipid peroxidation. Thus far, it has only been possible to measure iPs derived from arachidonic acid in urine, because levels of iPs/neuroprostanes (nPs) derived from ω3-PUFAs have been found to be below detection limits of available assays. Because of the interest in ω3-PUFA dietary supplementation, we developed specific methods to measure nPF4α-VI and iPF3α-VI [derived from 4,7,10,13,16,19-docosahexaenoic acid (DHA) and 5,8,11,14,17-eicosapentaenoic acid (EPA)] using a combination of chemical synthesis, gas chromatography/mass spectrometry (GC/MS), andliquid chromatography tandem …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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.

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In Vitro Activities Of 2,2'-Bipyridyl Analogs Against Mycobacterium Leprae, Arvind Madhav Dhople, Maria Antonia Ibáñez, Anita A. Dhople Dec 1994

In Vitro Activities Of 2,2'-Bipyridyl Analogs Against Mycobacterium Leprae, Arvind Madhav Dhople, Maria Antonia Ibáñez, Anita A. Dhople

Biomedical Engineering and Sciences Faculty Publications

In vitro susceptibility of Mycobacterium leprae to two bipyridyl analogs was studied by using two biochemical parameters to measure the metabolic activity of the organism. VUF-8514 at 0.16 μg/ml, but not VUF-8842, completely inhibited the metabolic activity of M. leprae, and the action was bactericidal. When compared to rifampin (MIC 0.3 μg/ml), VUF-8514 was equally bactericidal against M. leprae.

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Growth Of Saprophytic And Pathogenic Leptospira: Evaluation Of Medium, Temperature, Inoculum, And Cost, Mary A. Finn, Ronald H. Jones Jan 1976

Growth Of Saprophytic And Pathogenic Leptospira: Evaluation Of Medium, Temperature, Inoculum, And Cost, Mary A. Finn, Ronald H. Jones

Biomedical Engineering and Sciences Faculty Publications

Of four media tested, a tissue culture medium supplemented with a bovine serum albumin oleic acid complex provided the best leptospiral growth and cost efficiency.

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