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Beyond The Dvh - Spatial And Biological Radiotherapy Treatment Planning, Bo Zhao Jan 2010

Beyond The Dvh - Spatial And Biological Radiotherapy Treatment Planning, Bo Zhao

Wayne State University Dissertations

Purpose: Both spatial and biological information are necessary in order to perform true optimization of a treatment plan and for predicting clinical outcome. The goal of this work is to develop an enhanced treatment plan evaluation tool which incorporates biological parameters and retains spatial dose information.

Methods: A software system named SABER (Spatial And Biological Evaluation for Radiotherapy) is developed which provides biological plan evaluation with a novel combination of features. It incorporates hyperradiosensitivity using the induced-repair model and applies the new concept of Dose Convolution Filter (DCF) to simulate dose wash-out …


Study Of The Egfr, Src And Stat3 Pathway In Pancreatic Cancer, Soumya Jaganathan Jan 2010

Study Of The Egfr, Src And Stat3 Pathway In Pancreatic Cancer, Soumya Jaganathan

Electronic Theses and Dissertations

Cancer is associated with many molecular aberrations that support the malignant phenotype. In that regard, aberrant activation of epidermal growth factor receptor (EGFR), Src, and signal transducer and activator of transcription 3 (Stat3) occur concurrently in pancreatic cancer and are implicated in the disease phenotype. Notwithstanding, increasing evidence indicates that therapies that target only EGFR or Src are rather ineffective in modulating the cancer phenotype. The poor therapeutic outcome of the monotherapies targeting EGFR or Src may in part be due to the increased incidence of signaling cross-talks among aberrant signaling pathways in cancer. Molecular details of the signaling integration …


In-Frame Mutagenesis Of Genes Encoding A Selenium-Dependent Molybdenum Hydroxylase And Putative Accessory Proteins In Enterococcus Faecalis, Christopher J. Mallard Jan 2010

In-Frame Mutagenesis Of Genes Encoding A Selenium-Dependent Molybdenum Hydroxylase And Putative Accessory Proteins In Enterococcus Faecalis, Christopher J. Mallard

Electronic Theses and Dissertations

Enterococcus faecalis is a well known nosocomial drug resistant pathogen that is responsible for urinary tract infections, bacteremia, wound infections and endocarditis through the formation of biofilms. It has been shown that 68 genes present within the core genome of E. faecalis are upregulated in biofilm formation. One of those 68 genes is a putative seleniumdependent molybdenum hydroxylase (SDMH). Adjacent to this gene are a series of open reading frames that have been postulated to play a role in the maturation of a labile selenium cofactor. The biosynthesis of this labile cofactor has yet to be studied at either the …


Leiomyosarcoma Arising In The Pancreatic Duct: A Case Report And Review Of The Current Literature, Nicole D. Riddle, Brian C. Quigley, Irwin Browarsky, Marilyn M. Bui Jan 2010

Leiomyosarcoma Arising In The Pancreatic Duct: A Case Report And Review Of The Current Literature, Nicole D. Riddle, Brian C. Quigley, Irwin Browarsky, Marilyn M. Bui

Pathology and Cell Biology Faculty Publications

Context. Leiomyosarcomas are rare malignant smooth muscle tumors that may arise in any organ or tissue that contains smooth muscle, commonly within the gastrointestinal tract. They are most often found in the stomach, large and small intestines, and retroperitoneum. Primary pancreatic leiomyosarcoma is extremely rare, and to the best of our knowledge only 30 cases have been reported in the world literature since 1951. Our case represents the first to have a clear origin from the main pancreatic duct. Case Report. This case was diagnosed in a large, tertiary care center in Tampa, Florida. Pertinent information was obtained …


Epigenetics: Blurring The Line Between Nature And Nurture, Elizabeth H. Rose Jan 2010

Epigenetics: Blurring The Line Between Nature And Nurture, Elizabeth H. Rose

CMC Senior Theses

This long-standing nature versus nurture debate is cited in behavioral and physical expressions of disease dysfunctions, resiliencies, and recovery. Their purposes are noted both in scientific pursuits as well as literature. This discourse has been particularly intense in the fields of psychology, psychiatry, and biology where there is a long history of scientists’ attempts to disprove or discredit others’ intellectual and professional measures. Interestingly, recent advances in the neurosciences and genetic technologies have brought these fields closer together with a new focus – the interactional relationship between nature and nurture – epigenetics.


Safety Assessment For Tipranavir : A Protease Inhibitor Treatment For Hiv Infected Adults, Jaromir Mikl Jan 2010

Safety Assessment For Tipranavir : A Protease Inhibitor Treatment For Hiv Infected Adults, Jaromir Mikl

Legacy Theses & Dissertations (2009 - 2024)

Dose-limiting adverse events associated with anti-retroviral therapy (ART) generally include gastro-intestinal (GI) issues such as vomiting and nausea. However, serious adverse events (SAEs) do occur, the most frequent of which include liver toxicities and renal impairment as well as recent evidence of cardio-vascular disease (CVD) risk.


The Effect Of L-Tryptophan On The Heart In Rabbits Via Chronic Hypoxia, Fi̇gen Nari̇n, Nazmi̇ Nari̇n, Fatmagül Başarslan, Ali̇ Baykan, Sadetti̇n Sezer, Hülya Akgün, Aynur Akin, Mustafa Akçakuş, Hakan Ceyran Jan 2010

The Effect Of L-Tryptophan On The Heart In Rabbits Via Chronic Hypoxia, Fi̇gen Nari̇n, Nazmi̇ Nari̇n, Fatmagül Başarslan, Ali̇ Baykan, Sadetti̇n Sezer, Hülya Akgün, Aynur Akin, Mustafa Akçakuş, Hakan Ceyran

Turkish Journal of Medical Sciences

To evaluate the protective effect of tryptophan on an experimentally produced hypoxic myocardial injury via biochemical and pathological parameters. Materials and methods: A total of 26 rabbits were divided into 3 groups. Group 1 (n = 9) was only exposed to hypoxia. Group 2 (n = 10) was exposed to hypoxia and received L-tryptophan (200 mg/kg per day, orally for 5 days). Group 3 (n = 7) was the control group. Before the hypoxic injury and after the delivery of the medication, serum samples were taken for troponin-I, creatine kinase myocardial isoenzymes (CK-MB), lactate dehydrogenase (LDH), glutathione peroxidase (GSH-Px), superoxide …


Abnormal Hemoglobins Associated With The Beta-Globin Gene In Antalya Province, Turkey, İbrahi̇m Keser, Aki̇f Yeşi̇li̇pek, Duran Canatan, Güven Lüleci̇ Jan 2010

Abnormal Hemoglobins Associated With The Beta-Globin Gene In Antalya Province, Turkey, İbrahi̇m Keser, Aki̇f Yeşi̇li̇pek, Duran Canatan, Güven Lüleci̇

Turkish Journal of Medical Sciences

Abnormal hemoglobins are the most common hemoglobinopathies after beta-thalassemia in the world. More than 40 abnormal hemoglobin variants have been reported in the Turkish population. Therefore, it is one of the target areas for carrier screening. In our study, we aimed to screen the abnormal hemoglobins that cause clinical thalassemia in the Antalya population. Materials and methods: The present study identified the abnormal hemoglobins associated with the beta-globin gene using different molecular genetic techniques following high performance liquid chromatography (HPLC) results. We studied 972 postnatal and 361 prenatal cases (total: 1333 cases, 2666 chromosomes) with the disorder from 1998 up …


Anti-Diabetic Activity Of Tinospora Cordifolia (Willd.) In Streptozotocin Diabetic Rats; Does It Act Like Sulfonylureas?, Nagaraja Puranik, Kararashah Fakruddin Kammar, Sheela Devi Jan 2010

Anti-Diabetic Activity Of Tinospora Cordifolia (Willd.) In Streptozotocin Diabetic Rats; Does It Act Like Sulfonylureas?, Nagaraja Puranik, Kararashah Fakruddin Kammar, Sheela Devi

Turkish Journal of Medical Sciences

As an alternative medicine to treat diabetes mellitus, many herbal drugs are being studied throughout the world. In the present study, an attempt was made to investigate the anti-diabetic activity of Tinospora cordifolia (Willd.) (TC) stem extracts (both aqueous and alcoholic) in different dosages (200 and 400 mg/kg b.w.) in streptozotocin diabetic albino rats. The probable mechanism by which TC may act as an anti-hyperglycemic drug was also investigated. Materials and methods: The drug was administered orally for 10 days and 30 days in different groups of animal, with each group containing 6 animals. The efficacy of this drug was …


Molecular Analyses Of Salmonella Serotype Typhi And Salmonella Serotype Paratyphi B Strains Isolated In Turkey, Istar Dolapçi, Bi̇rsel Erdem, Alper Tekeli̇, Ebru Us, Mehseti̇ Bayramova, Begüm Saran, Fi̇kret Şahi̇n Jan 2010

Molecular Analyses Of Salmonella Serotype Typhi And Salmonella Serotype Paratyphi B Strains Isolated In Turkey, Istar Dolapçi, Bi̇rsel Erdem, Alper Tekeli̇, Ebru Us, Mehseti̇ Bayramova, Begüm Saran, Fi̇kret Şahi̇n

Turkish Journal of Medical Sciences

To investigate the characteristics of Salmonella serotype Typhi and Salmonella serotype Paratyphi B, which still remain significant in Turkey. Materials and methods: Eighteen S. Typhi and 42 S. Paratyphi B strains isolated from clinical samples were investigated by plasmid profile analysis, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR), and pulsed field gel electrophoresis (PFGE) methods. Results: Plasmid profile analysis showed that 10 out of 18 (56%) S. Typhi isolates harbored 1 to 3 plasmids, and 11 out of 42 (26.2%) S. Paratyphi B isolates harbored 1 to 4 plasmids. PFGE performed with restriction enzyme AvrII grouped both S. Typhi and …


Investigation Of Premenstrual Syndrome And Contributing Factors Among University Students*, Nülüfer Erbi̇l, Ayşenur Karaca, Tülay Kiriş Jan 2010

Investigation Of Premenstrual Syndrome And Contributing Factors Among University Students*, Nülüfer Erbi̇l, Ayşenur Karaca, Tülay Kiriş

Turkish Journal of Medical Sciences

To determine the frequency of premenstrual syndrome (PMS) and to investigate contributing factors for PMS among female students in a university dormitory in Ordu. Materials and methods: This descriptive study was conducted with female students at a public university dormitory in Ordu, in the East Black Sea region of Turkey. The sample contained 300 female students at the university dormitory. The study was conducted between 3 January and 12 January 2007. The research data were collected via a 22-item socio-demographic information questionnaire and the Premenstrual Syndrome Scale (PMSS) developed by Gençdoğan. Results: It was determined that the participants' mean age …


Comparison Of Quality Of Life In Hepatitis B Virus Carriers Versus Chronic Hepatitis B Virus Carriers Versus The Normal Population, Meltem Işikgöz Taşbakan, Özen Önen Sertöz, Hüsnü Pullukçu, Şebnem Çalik, Oğuz Reşat Si̇pahi̇, Tansu Yamazhan Jan 2010

Comparison Of Quality Of Life In Hepatitis B Virus Carriers Versus Chronic Hepatitis B Virus Carriers Versus The Normal Population, Meltem Işikgöz Taşbakan, Özen Önen Sertöz, Hüsnü Pullukçu, Şebnem Çalik, Oğuz Reşat Si̇pahi̇, Tansu Yamazhan

Turkish Journal of Medical Sciences

To compare health related quality of life (HRQOL) in hepatitis B virus (HBV) carriers versus chronic HBV disease carriers versus the normal population. Materials and methods: The study sample consisted of 2 groups. HBV carriers were recruited from individuals who were regularly followed-up at the Infectious Diseases and Clinical Microbiology outpatient clinic of our setting due to inactivity in HBV infection. The control group was recruited from the same outpatient clinic among patients who had a diagnosis of chronic HBV infection and who were not undergoing active treatment yet. Both groups were requested to fill in the short form 36 …


Patterned Cell Cultures For High Throughput Studies Of Cell Electrophysiology And Drug Screening Applications, Anupama Natarajan Jan 2010

Patterned Cell Cultures For High Throughput Studies Of Cell Electrophysiology And Drug Screening Applications, Anupama Natarajan

Electronic Theses and Dissertations

Over the last decade, the field of tissue and bio-engineering has seen an increase in the development of in vitro high-throughput hybrid systems that can be used to understand cell function and behavior at the cellular and tissue levels. These tools would have a wide array of applications including for implants, drug discovery, and toxicology, as well as for studying cell developmental behavior and as disease models. Currently, there are a limited number of efficient, functional drug screening assays in the pharmacology industry and studies of cell-surface interactions are complicated and invasive. Most cell physiology studies are performed using conventional …


Studies On A Novel Human Cardiospecific Transcription Factor And Its Involvement In Omi/Htra2 Mediated Cell Death, Meenakshi Puthucode Balakrishnan Jan 2010

Studies On A Novel Human Cardiospecific Transcription Factor And Its Involvement In Omi/Htra2 Mediated Cell Death, Meenakshi Puthucode Balakrishnan

Electronic Theses and Dissertations

Omi/HtrA2 is a mitochondrial serine protease that is known to translocate to the cytoplasm upon induction of apoptosis and to activate caspase-dependent and caspase-independent cell death. The molecular mechanism of Omi/HtrA2's function is not clear but involves degradation of specific substrates. These substrates include cytoplasmic, mitochondrial, as well as nuclear proteins. We have isolated a new Omi/HtrA2 interactor, the THAP5 protein. THAP5 is a fifth member of a large family of transcription factors that are involved in cell proliferation, apoptosis, cell cycle control, chromosome segregation, chromatin modification and transcriptional regulation. THAP5 is an approximately 50kDa nuclear protein, with a restricted …


Penile Mondor's Disease Can Be Effectively Treated With The Use Of An Acetyl Salicylic Acid And Pentoxifylline Combination, Mürsel Davarci, Eşref Oğuz Güven, Ahmet Gökçe, Fati̇h Rüştü Yalçinkaya, Ahmet Namik Ki̇per, Mevlana Derya Balbay Jan 2010

Penile Mondor's Disease Can Be Effectively Treated With The Use Of An Acetyl Salicylic Acid And Pentoxifylline Combination, Mürsel Davarci, Eşref Oğuz Güven, Ahmet Gökçe, Fati̇h Rüştü Yalçinkaya, Ahmet Namik Ki̇per, Mevlana Derya Balbay

Turkish Journal of Medical Sciences

Since penile Mondor's disease is a rare condition, different treatment choices are used. Herein we recommend a new treatment strategy with acetylsalicylic acid and pentoxifylline, which was tested in 14 patients with penile Mondor's disease. Materials and methods: Fourteen patients with the clinical presentation of penile Mondor's disease were included. Patients were given acetylsalicylic acid (ASA) 500 mg qid and pentoxifylline 600 mg bid for 14 days. Physical examinations were performed in all patients. In addition, ultrasonic examinations were done before the treatment and on days 7 and 14 of treatment to evaluate dorsal vein thrombosis. Results: Physical examinations revealed …


The Cytokine, Interleukin-7, Transcriptionally Regulates The Gene Expression Of The Hexokinase Ii To Mediate Glucose Utilization, Mounir Chehtane Jan 2010

The Cytokine, Interleukin-7, Transcriptionally Regulates The Gene Expression Of The Hexokinase Ii To Mediate Glucose Utilization, Mounir Chehtane

Electronic Theses and Dissertations

The cytokine, interleukin-7 (IL-7), has essential growth activities that maintain the homeostatic balance of the immune system. Little is known of the mechanism by which IL-7 signaling regulates metabolic activity in support of its vital function in lymphocytes. We observed that IL-7 deprivation caused a rapid decline in ATP levels that were attributable to loss of intracellular glucose retention. To identify the transducer of the IL-7 metabolic signal, we examined the expression of three important regulators of glucose metabolism, the glucose transporter, GLUT-1, and two glycolytic enzymes, Hexokinase II (HXKII) and phosphofructokinase-1 (PFK1), using an IL-7-dependent T-cell line and primary …


Interleukin-7 Differentially Regulates The Activation, Proliferation, And Homing Of T-Cells: Implications For Immunotherapy, Christina Kittipatarin Jan 2010

Interleukin-7 Differentially Regulates The Activation, Proliferation, And Homing Of T-Cells: Implications For Immunotherapy, Christina Kittipatarin

Electronic Theses and Dissertations

Interleukin-7 (IL-7) is an essential lymphocyte growth factor required for the survival and proliferation of mature T-cells. As a therapeutic agent, IL-7 has the potential to restore T-cell numbers following immune depletion and to promote immunity against cancers. While the survival function of IL-7 is well established, less is known about how it supports T-cell expansion, a critical feature of the immune response. To study the biological effects of IL-7 on T-cell growth, we developed an in vitro culture technique to expand T-cells ex vivo. A significant finding from our studies is that IL-7 did not induce the expansion of …


Magnetic Nanosensors For Multiplexed Bacterial Pathogenesis Identification, Charalambos Kaittanis Jan 2010

Magnetic Nanosensors For Multiplexed Bacterial Pathogenesis Identification, Charalambos Kaittanis

Electronic Theses and Dissertations

Developing diagnostic modalities that utilize nanomaterials and miniaturized detectors can have an impact in point-of-care diagnostics. Diagnostic systems that (i) are sensitive, robust, and portable, (ii) allow detection in clinical samples, (iii) require minimal sample preparation yielding results quickly, and (iv) can simultaneously quantify multiple targets, would have a great potential in biomedical research and public healthcare. Bacterial infections still cause pathogenesis throughout the world (Chapter I). The emergence of multi-drug resistant strains, the potential appearance of bacterial pandemics, the increased occurrence of bacterial nosocomial infections, the wide-scale food poisoning incidents and the use of bacteria in biowarfare highlight the …


Electroconvulsive Shock Ameliorates Disease Processes And Extends Survival In Huntington Mutant Mice, Akanksha Baharani Jan 2010

Electroconvulsive Shock Ameliorates Disease Processes And Extends Survival In Huntington Mutant Mice, Akanksha Baharani

Electronic Theses and Dissertations

Huntington's disease (HD) is a devastating autosomal dominantly inherited neurological disorder caused by an abnormal expansion of CAG trinucleotide repeats in the gene coding for the Nterminal region of the huntingtin (Htt) protein, which leads to the formation of a polyglutamine stretch. The greater the CAG repeats, the earlier the onset of the disease. The polyglutamine stretch destabilizes the Htt protein leading to misfolding, abnormal processing, aggregation, and inclusion formation. Mutant Htt protein is believed to damage and kill neurons in the striatum by a mechanism involving increased oxidative and metabolic stress, and impaired adaptive cellular stress responses. A large …


Transplantation Of Ips Cells Reduces Apoptosis And Fibrosis And Improves Cardiac Function In Streptozotocin-Induced Diabetic Rats, Sarah Elizabeth Neel Jan 2010

Transplantation Of Ips Cells Reduces Apoptosis And Fibrosis And Improves Cardiac Function In Streptozotocin-Induced Diabetic Rats, Sarah Elizabeth Neel

Electronic Theses and Dissertations

Background: Streptozotocin (STZ) induced diabetes leads to various complications including cardiomyopathy. Recent data suggests transplanted bone marrow stem cells improve cardiac function in diabetic cardiomyopathy. However, whether modified ES, iPS cells, or factors released from these cells can inhibit apoptosis and fibrosis remains completely unknown. The present study was designed to determine the effects of transplanted ES cells overexpressing pancreatic transcription factor 1 a (Ptf1a), a propancreatic endodermal transcription factor, iPS cells, or their respective conditioned media (CM) on diabetic cardiomyopathy. Methods: Experimental diabetes was induced in male Sprague Dawley rats (8-10 weeks old) by intraperitoneal STZ injections (65 mg/kg …


Red Blood Cell And Hemoglobin Dependent Modulation Of Reactive Species Metabolism: Implications For Vascular Homeostasis, Dario A. Vitturi Jan 2010

Red Blood Cell And Hemoglobin Dependent Modulation Of Reactive Species Metabolism: Implications For Vascular Homeostasis, Dario A. Vitturi

All ETDs from UAB

The recent discovery that red blood cells might mediate hypoxic blood flow together with accumulating evidence that suggests a role for the modulation of vascular inflammation has reshaped the way we think about the function of these cells. In this thesis we investigate the mechanisms that regulate these newly appreciated functions and focus on i) the ability of red cells to couple oxygen sensing with nitrite reduction and nitric oxide formation and ii) the role of the beta93cys, a conserved residue amongst mammalian hemoglobins and whose function remains unclear. Data will be presented that demonstrate that nitrite reduction to nitric …


The Prognostic Value Of Histological Grade In The Outcome Of Patients With Invasive Breast Cancer, Gül Dağlar, Yunus Nadi̇ Yüksek, Ahmet Uğur Gözalan, Tanju Tütüncü, Yeşi̇m Güngör, Nuri̇ Aydin Kama Jan 2010

The Prognostic Value Of Histological Grade In The Outcome Of Patients With Invasive Breast Cancer, Gül Dağlar, Yunus Nadi̇ Yüksek, Ahmet Uğur Gözalan, Tanju Tütüncü, Yeşi̇m Güngör, Nuri̇ Aydin Kama

Turkish Journal of Medical Sciences

Prognostic factors are useful for the prediction of survival in breast cancer patients. According to many studies, tumor size and lymph node stage are the most powerful predictors of tumor behavior. The aim of the present study was to investigate the prognostic value of tumor histological grade. Materials and methods: The study included 214 operable breast cancer patients treated at the same institution that were evaluated to determine the prognostic value of tumor histological grade. Clinico-histopathological features of the patients were also evaluated for overall survival (OS) and disease-free survival (DFS). Results: Tumor histological grade was an independent factor in …


Chronic Pain And Depression: A Descriptive Survey Among Adult Primary Health Care Centre Patients, Nüket Paksoy Erbaydar, Nesri̇n Çi̇li̇ngi̇roğlu Jan 2010

Chronic Pain And Depression: A Descriptive Survey Among Adult Primary Health Care Centre Patients, Nüket Paksoy Erbaydar, Nesri̇n Çi̇li̇ngi̇roğlu

Turkish Journal of Medical Sciences

Knowledge of chronic pain and its relationship to depression among primary health care patients in Turkey is inadequate. The aim of this study was to evaluate the frequency of chronic pain and its relationship to depression. Materials and methods: In this descriptive study, data was collected with a questionnaire based on sociodemographic and pain-related characteristics, which was administered to a study population (n = 259) of primary care patients, 18-64 years old. The Visual Analogue Scale (VAS) (min-max = 0-10) and Beck Depression Inventory (BDI) (min-max = 0-63) were used for the assessment of pain severity and depression. Results: Of …


Subacute Neural Stem Cell Therapy For Traumatic Brain Injury Jan 2010

Subacute Neural Stem Cell Therapy For Traumatic Brain Injury

Faculty, Staff and Student Publications

A protocol is described using lipid mutants and thiol-specific chemical reagents to study lipid-dependent and host-specific membrane protein topogenesis by the substituted-cysteine accessibility method as applied to transmembrane domains (SCAM). SCAM is adapted to follow changes in membrane protein topology as a function of changes in membrane lipid composition. The strategy described can be adapted to any membrane system.


Il-4(-/-) Mice With Lethal Mesocestoides Corti Infections--Reduced Th2 Cytokines And Alternatively Activated Macrophages., A. E. O'Connell, L. A. Kerepesi, G. L. Vandergrift, D. R. Herbert, T J. Van Winkle, D. C. Hooper, E J. Pearce, D. Abraham Dec 2009

Il-4(-/-) Mice With Lethal Mesocestoides Corti Infections--Reduced Th2 Cytokines And Alternatively Activated Macrophages., A. E. O'Connell, L. A. Kerepesi, G. L. Vandergrift, D. R. Herbert, T J. Van Winkle, D. C. Hooper, E J. Pearce, D. Abraham

Department of Microbiology and Immunology Faculty Papers

Protection against Mesocestoides corti, a cestode that invades vital organs, is dependent on the production of IL-4, as IL-4(-/-) mice were found to have higher parasite burdens when compared with wild-type mice. The goal of this study was to investigate the role of IL-4 in immunity to M. corti, focusing on the immunological profile and on potential mediators of pathology. IL-4(-/-) mice infected with M. corti showed 100% mortality by 32 days, whereas wild-type mice survived for approximately 1 year. Parasite burdens were significantly increased in the liver, peritoneal, and thoracic cavities of IL-4(-/-) mice, associated with impaired recruitment of …


Biological Diversity Of Prokaryotic Type Iv Secretion Systems, Cristina E Alvarez-Martinez, Peter J Christie Dec 2009

Biological Diversity Of Prokaryotic Type Iv Secretion Systems, Cristina E Alvarez-Martinez, Peter J Christie

Faculty, Staff and Student Publications

Type IV secretion systems (T4SS) translocate DNA and protein substrates across prokaryotic cell envelopes generally by a mechanism requiring direct contact with a target cell. Three types of T4SS have been described: (i) conjugation systems, operationally defined as machines that translocate DNA substrates intercellularly by a contact-dependent process; (ii) effector translocator systems, functioning to deliver proteins or other macromolecules to eukaryotic target cells; and (iii) DNA release/uptake systems, which translocate DNA to or from the extracellular milieu. Studies of a few paradigmatic systems, notably the conjugation systems of plasmids F, R388, RP4, and pKM101 and the Agrobacterium tumefaciens VirB/VirD4 system, …


Dopamine-Stimulated Dephosphorylation Of Connexin 36 Mediates Aii Amacrine Cell Uncoupling Nov 2009

Dopamine-Stimulated Dephosphorylation Of Connexin 36 Mediates Aii Amacrine Cell Uncoupling

Faculty, Staff and Student Publications

Gap junction proteins form the substrate for electrical coupling between neurons. These electrical synapses are widespread in the CNS and serve a variety of important functions. In the retina, connexin 36 (Cx36) gap junctions couple AII amacrine cells and are a requisite component of the high-sensitivity rod photoreceptor pathway. AII amacrine cell coupling strength is dynamically regulated by background light intensity, and uncoupling is thought to be mediated by dopamine signaling via D(1)-like receptors. One proposed mechanism for this uncoupling involves dopamine-stimulated phosphorylation of Cx36 at regulatory sites, mediated by protein kinase A. Here we provide evidence against this hypothesis …


5-Ht And Gaba Modulate Intrinsic Excitability Of Type I Interneurons In Hermissenda Nov 2009

5-Ht And Gaba Modulate Intrinsic Excitability Of Type I Interneurons In Hermissenda

Faculty, Staff and Student Publications

The sensory neurons (photoreceptors) in the visual system of Hermissenda are one site of plasticity produced by Pavlovian conditioning. A second site of plasticity produced by conditioning is the type I interneurons in the cerebropleural ganglia. Both photoreceptors and statocyst hair cells of the graviceptive system form monosynaptic connections with identified type I interneurons. Two proposed neurotransmitters in the graviceptive system, serotonin (5-HT) and gamma-aminobutyric acid (GABA), have been shown to modify synaptic strength and intrinsic neuronal excitability in identified photoreceptors. However, the potential role of 5-HT and GABA in plasticity of type I interneurons has not been investigated. Here …


The Brain In Its Body: Motor Control And Sensing In A Biomechanical Context, Hillel J. Chiel Oct 2009

The Brain In Its Body: Motor Control And Sensing In A Biomechanical Context, Hillel J. Chiel

Faculty Scholarship

Although it is widely recognized that adaptive behavior emerges from the ongoing interactions among the nervous system, the body, and the environment, it has only become possible in recent years to experimentally study and to simulate these interacting systems. We briefly review work on molluscan feeding, maintenance of postural control in cats and humans, simulations of locomotion in lamprey, insect, cat and salamander, and active vibrissal sensing in rats to illustrate the insights that can be derived from studies of neural control and sensing within a biomechanical context. These studies illustrate that control may be shared between the nervous system …


Intracranial Eeg Reveals A Time- And Frequency-Specific Role For The Right Inferior Frontal Gyrus And Primary Motor Cortex In Stopping Initiated Responses, Linda K Mcevoy Oct 2009

Intracranial Eeg Reveals A Time- And Frequency-Specific Role For The Right Inferior Frontal Gyrus And Primary Motor Cortex In Stopping Initiated Responses, Linda K Mcevoy

Faculty, Staff and Student Publications

Inappropriate response tendencies may be stopped via a specific fronto/basal ganglia/primary motor cortical network. We sought to characterize the functional role of two regions in this putative stopping network, the right inferior frontal gyrus (IFG) and the primary motor cortex (M1), using electocorticography from subdural electrodes in four patients while they performed a stop-signal task. On each trial, a motor response was initiated, and on a minority of trials a stop signal instructed the patient to try to stop the response. For each patient, there was a greater right IFG response in the beta frequency band ( approximately 16 Hz) …