Digital Commons Network^™

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, W Wade Kothmann, Stephen C Massey, John O'Brien

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, Nan Ge Jin, Lian-Ming Tian, Terry Crow

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

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, Nicole Swann, Nitin Tandon, Ryan Canolty, Timothy M Ellmore, Linda K Mcevoy, Stephen Dreyer, Michael Disano, Adam R Aron

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) …

Neurodevelopmental Outcome & Mr Spectroscopy Of Therapeutic Hypothermia After Pediatric Drowning, Sharon Mieras Perugini

Loma Linda University Electronic Theses, Dissertations & Projects

Despite advances in medical treatment and technology, outcome following pediatric drowning can vary widely from mild to severe impairments and death. Prognosis is often difficult to predict given a number of contributing factors. As such, this study examined the relationship between clinical indicators including submersion duration, initial GCS and PRISM scores, and waking time with outcome as well as metabolite ratios based on magnetic resonance spectroscopy. Research stemming from the area of cardiac arrest as well as anecdotal case study reports of cold water drownings suggests that lowering the body temperature may be helpful and protective. As such, the use …

Study Of The Four Factor Theory Of Women’S Sexual Function, Julie M. Merrell

Loma Linda University Electronic Theses, Dissertations & Projects

Tiefer, Hall, and Tavris (2002) described factors comprising four categories of female sexual function. They suggested that unique factors need to be examined to understand sexual function in women. Socio-cultural, political, or economic factors, partner and relationship factors, psychological factors, and medical factors were described as aspects of women’s lives that can be the source of sexual dysfunction. In a previous study, Merrell (2007) utilized Tiefer et al’s (2002) four factor model of sexual functioning to examine female sexual functioning looking specifically at body shame, relationship satisfaction, positive and negative affect, sexual self-schema, and overall health. Based on the results …

Mutations To Antibiotic Resistance During Stringent Response In B. Subtilis, Chad Hansen, Ronald E. Yasbin, Eduardo A. Robleto

Undergraduate Research Opportunities Program (UROP)

The relA gene in Bacillus subtilis controls a variety of factors during the stringent response which is a response to starvation of amino acids. The stringent response inhibits DNA synthesis and transcription of genes of tRNA, rRNA, and ribosomal proteins and promotes synthesis of the required amino acids. The objective of my project is to determine if a strain of B. subtilis that has a knockout mutation for the relA gene will accumulate a higher number of mutations that confer resistance to antibiotics that inhibit translation. It is proposed that because the relA gene inhibits transcription of ribosomal proteins, a …

Micrornas Involved In Tumor Suppressor And Oncogene Pathways: Implications For Hepatobiliary Neoplasia., Justin L. Mott

Journal Articles: Biochemistry & Molecular Biology

MicroRNAs are a class of small regulatory RNAs that function to modulate protein expression. This control allows for fine-tuning of the cellular phenotype, including regulation of proliferation, cell signaling, and apoptosis; not surprisingly, microRNAs contribute to liver cancer biology. Recent investigations in human liver cancers and tumor-derived cell lines have demonstrated decreased or increased expression of particular microRNAs in hepatobiliary cancer cells. Based on predicted and validated protein targets as well as functional consequences of altered expression, microRNAs with decreased expression in liver tumor cells may normally aid in limiting neoplastic transformation. Conversely, selected microRNAs that are up-regulated in liver …

Cloning And Expression Of A Putative Exported Protein Coding Gene Sas1089 From An Invasive Community Associated Staphylococcus Aureus Strain Mssa476, Nailah Alzaki

All-Inclusive List of Electronic Theses and Dissertations

Originally, methicillin resistant Staphylococcus aureus (MRSA) occurred primarily in the hospital setting and was designated hospital- associated MRSA (HA-MRSA). In recent years, isolates of Staphylococcus aureus from the community (CA-MRSA), found to be methicillin resistant, are not as resistant tooth~ antibiotics as HA-MRSA. However, community strains are noted for their invasiveness causing soft tissue infections with propensity for invasion to deeper sites.

Disclosure Of Apoe Genotype For Risk Of Alzheimer's Disease, Peter J. Whitehouse, Melissa Barber Butson

Faculty Scholarship

BACKGROUND: The apolipoprotein E (APOE) genotype provides information on the risk of Alzheimer's disease, but the genotyping of patients and their family members has been discouraged. We examined the effect of genotype disclosure in a prospective, randomized, controlled trial. METHODS: We randomly assigned 162 asymptomatic adults who had a parent with Alzheimer's disease to receive the results of their own APOE genotyping (disclosure group) or not to receive such results (nondisclosure group). We measured symptoms of anxiety, depression, and test-related distress 6 weeks, 6 months, and 1 year after disclosure or nondisclosure. RESULTS: There were no significant differences between the …

Postprandial Effects Of Pecans Ingestion On Plasma Level Of Nutrients, Polyphenolic Compounds And Biomarkers Of Antioxidant Status In Human Volunteers, Chatrapa Hudthagosol

Loma Linda University Electronic Theses, Dissertations & Projects

Pecans (Carya illinoinensis) are rich sources of polyphenolic compounds and nutrients, which have antioxidant capacity results in favorable reductions in plasma lipids and lipoproteins. However, the health benefits of pecans may not be limited to blood lipid changes. There has been very little investigation into the contribution of bioactive components found in nuts to antioxidant protection. The purposes of the study were 1) to determine the impact of pecan consumption on concentration of total plasma polyphenols and their peak concentration over time. 2) to measure the effect of a pecan diet on postprandial levels of plasma lipid peroxidation …

Investigation Of Magnetic Resonance Imaging And Spectroscopy For The Detection Of Breast Cancer, Robert Thomas Etnire

UNLV Theses, Dissertations, Professional Papers, and Capstones

Magnetic resonance imaging (MRI) of the breast offers an alternative to screening mammography which may benefit those women at high risk for breast cancer, women under the age of 40, and those with dense breast tissue. One concern with MRI is the number of high false positives. Coupling MRI with magnetic resonance spectroscopy(MRS) may lower the number of false positives, and thus improve the diagnostic capabilities of MRI for the clinician. MRS for breast imaging focuses on the total choline containing compounds in the spectra in the suspected breast lesion to analyze areas of concern. The results of the study …

An Evaluation Of Methicillin Resistant Staphylococcus Aureus Survival On Five Environmental Surfaces Under Two Different Humidities, With And Without The Addition Of Bovine Serum Albumin, Courtney Ann Coughenour

UNLV Theses, Dissertations, Professional Papers, and Capstones

The spread of antibiotic resistant bacteria is a major public health concern, as they result in greater healthcare costs and increased morbidity and mortality rates. Methicillin resistant Staphylococcus aureus (MRSA) is one organism of particular concern, with the number of infections increasing in epidemic proportion. Bacterial surface contamination with MRSA is significant, as it may serve as a reservoir for transmission and have negative health implications. The purpose of this study was to evaluate survival of MRSA on five environmental surface materials; glass, wood, vinyl, plastic, and cloth. The effect of relative humidity (RH) and bovine serum albumin (BSA) were …

An Evaluation Of Plastic Toys For Lead Contamination In Day Care Centers In The Las Vegas Valley, Joseph Alan Greenway

UNLV Theses, Dissertations, Professional Papers, and Capstones

The harmful effect of childhood exposure to environmental lead continues to be a major health concern. This study examined lead contamination within the plastic of children's toys. It was also hypothesized that the use of lead as a stabilizer would result in higher incidents of elevated lead (> 600 ppm) in polyvinyl chloride plastics (PVC) than non-PVC plastics. It was also hypothesized that, due to the use lead chromate, yellow toys would have higher incidents of elevated lead (> 600 ppm) than toys of other colors. Toy samples were limited to those found in day care centers in Las Vegas, …

Insights Into Btb-Cul3 Ubiquitin Ligases From The Structures Of Spop-Substrate Complexes, Min Zhuang

Theses and Dissertations (ETD)

Cullin-Ring ubiquitin ligases (CRLs) are E3 complexes that specifically recognize substrates through substrate adaptors. In the largest CRL subfamily, Cul3 binds a BTB domain, and a protein-interaction domain such as MATH recruits substrates for ubiquitination. Here we present biochemical and structural analyses of the MATH and BTB domain containing protein, SPOP, which regulates diverse signaling pathways. First, we identified a conserved SPOP Binding Consensus (SBC) motif in the transcriptional regulator Ci, the protein phosphatase Puc, and the chromatin component MacroH2A. The SBC motif specifically binds the MATH domain of SPOP, and is required for Puc ubiquitination in vitro and in …

Immunomodulatory Effects Of Novel Therapies For Stroke, Aaron A. Hall

USF Tampa Graduate Theses and Dissertations

Each year, approximately 795,000 people suffer a new or recurrent stroke. About 610,000 of these are first attacks, and 185,000 are recurrent attacks (Carandang et al. 2006). Currently the only FDA approved treatment for ischemic stroke is recombinant tissue plasminogen activator (Alteplase) (Marler and Goldstein 2003). Unfortunately its use is restricted to a short, 4.5 hour, time window. Two promising therapies in the treatment of stroke at delayed timepoints are human umbilical cord blood cells (HUCBC) and the sigma receptor agonist DTG

The first series of experiments were conducted to characterize the effects of sigma receptors on various aspects of …

Evaluating Statistical Methods Used To Estimate The Number Of Postsynaptic Receptors, Georgios Kalantzis, Yoshira Kubota, Harel Z Shouval

Faculty, Staff and Student Publications

Calcium levels in spines play a significant role in determining the sign and magnitude of synaptic plasticity. The magnitude of calcium influx into spines is highly dependent on influx through N-methyl D-aspartate (NMDA) receptors, and therefore depends on the number of postsynaptic NMDA receptors in each spine. We have calculated previously how the number of postsynaptic NMDA receptors determines the mean and variance of calcium transients in the postsynaptic density, and how this alters the shape of plasticity curves. However, the number of postsynaptic NMDA receptors in the postsynaptic density is not well known. Anatomical methods for estimating the number …

The Proteolytic Stability And Cytotoxicity Studies Of L‐Aspartic Acid And L‐Diaminopropionic Acid Derived Β‐Peptides And A Mixed Α/Β‐Peptide, Sahar Ahmed, Kamaljit Kaur

Pharmacy Faculty Articles and Research

The use of peptides as drugs in pharmaceutical applications is hindered by their susceptibility to proteolysis and therefore low bioavailability. β‐Peptides that contain an additional methylene group in the backbone, are gaining recognition from a pharmaceutical stand point as they are considerably more resilient to proteolysis and metabolism. Recently, we reported two new classes of β‐peptides, β³‐ and β²‐peptides derived from l‐aspartic acid and l‐diaminopropionic acid, respectively. Here, we report the proteolytic stability of these β‐peptidic compounds and a mixed α /β‐peptide against three enzymes (pronase, trypsin and elastase), as well as, human serum. The …

To See Or Not To See: Prestimulus Α Phase Predicts Visual Awareness, Kyle E. Mathewson, Gabriele Gratton, Monica Fabiani, Diane M. Beck, Tony Ro

Publications and Research

We often fail to see something that at other times is readily detectable. Because the visual stimulus itself is unchanged, this variability in conscious awareness is likely related to changes in the brain. Here we show that the phase of EEG α rhythm measured over posterior brain regions can reliably predict both subsequent visual detection and stimulus-elicited cortical activation levels in a metacontrast masking paradigm. When a visual target presentation coincides with the trough of an α wave, cortical activation is suppressed as early as 100 ms after stimulus onset, and observers are less likely to detect the target. Thus, …

From Traumatic Brain Injury To Posttraumatic Epilepsy: What Animal Models Tell Us About The Process And Treatment Options, Asla Pitkänen, Riikka J. Immonen, Olli H.J. Gröhn, Irina Kharatishvili

Biomedicine and Animal Models in Research Collection

A large number of animal models of traumatic brain injury (TBI) are already available for studies on mechanisms and experimental treatments of TBI. Immediate and early seizures have been described in many of these models with focal or mixed type (both gray and white matter damage) injury. Recent long-term video-electroencephalography (EEG) monitoring studies have demonstrated that TBI produced by lateral fluid-percussion injury in rats results in the development of late seizures, that is, epilepsy. These animals develop hippocampal alterations that are well described in status epilepticus–induced spontaneous seizure models and human posttraumatic epilepsy (PTE). In addition, these rats have damage …

Naloxone's Pentapeptide Binding Site On Filamin A Blocks Mu Opioid Receptor–Gs Coupling And Creb Activation Of Acute Morphine, Hoau-Yan Wang, Lindsay H. Burns

Publications and Research

Chronic morphine causes the mu opioid receptor (MOR) to switch its coupling from Gi/o to Gs, resulting in excitatory signaling via both Gαs and its Gβγ dimer. Ultra-low-dose naloxone (NLX) prevents this switch and attenuates opioid tolerance and dependence. This protective effect is mediated via a high-affinity interaction of NLX to a pentapeptide region in c-terminal filamin A (FLNA), a scaffolding protein interacting with MOR. In organotypic striatal slice cultures, we now show that acute morphine induces a dose-dependent Go-to-Gs coupling switch at 5 and 15 min that resolves by 1 hr. The acute Gs coupling induced by 100 µM …

Effect Of Growth Hormone On Hippocampal Synaptic Function During Sleep Deprivation, Eun Young Kim

Theses, Dissertations and Capstones

Long term potentiation (LTP) in the hippocampus is considered a cellular basis of learning memory. Sleep deprivation, especially rapid eye movement (REM) sleep deprivation, impairs learning and memory as well as LTP. Since most of the previous LTP studies were conducted in the in vitro condition, the full consequences of sleep deprivation (SD) in the living animal are yet to be found. Thus, I tested hippocampal LTP in living animals after 5 days of REM sleep deprivation to determine the effect of SD in vivo. SD also disrupts growth hormone (GH) release. Recent evidence indicates that GH regulates cognitive and …

Nerve, Muscle, Blood, Toil, Tears, And Sweat: England’S Pioneering Biophysicist, Soldier, And Statesman, Khan

Departmental Papers (Biology)

No abstract provided.

Are Morphological Specializations Of The Hyolingual System In Chameleons And Salamanders Tuned To Demands On Performance?, Anthony Herrel, Stephen M. Deban, Vicky Schaerlaeken, Jean-Pierre Timmermans, D. Adriaens

Integrative Biology Faculty and Staff Publications

Extremely specialized and long tongues used for prey capture have evolved independently in plethodontid salamanders and chameleons. In both systems, the demands on tongue projection are probably similar: to maximize projection velocity and distance. Consequently, many of the design features of the projection system in these two groups have converged to an astonishing degree. Both involve the use of power amplification systems based on helically wound muscle fibers that load internal connective tissue sheets as illustrated in previous studies. Demands imposed on tongue retraction, however, are different to some degree. Although in both groups there is a clear demand for …

Expression Of Semaphorin 3f And Its Receptors In Epithelial Ovarian Cancer, Fallopian Tubes, And Secondary Müllerian Tissues, Christina D. Drenberg, Sandra Livingston, Ren Chen, Patricia A. Kruk, Santo V. Nicosia

Pathology and Cell Biology Faculty Publications

While semaphorins and their receptors appear to play a role in tumor carcinogenesis, little is known about the role of semaphorin 3F (S3F) in epithelial ovarian cancer (EOC) development. Therefore, we sought to determine the clinical relationship between S3F and its receptors, neuropilin-2 (NP-2) and neuropilin-1 (NP-1) with EOC progression. We analyzed the immunohistological expression of S3F, NP-2, and NP-1 in clinical specimens of normal ovaries (N), benign cystadenomas (Cy), well-differentiated adenocarcinomas (WD), poorly-differentiated adenocarcinomas (PD), inclusion cysts (IC), paraovarian cysts (PC), and fallopian tubes (FT). Tissue sections were evaluated for staining intensity and percentage of immunoreactive epithelia. We found …

Persistencia De Anticuerpos Maternales Contra El Virus De La Peste Porcina Clásica En Lechones Nacidos De Marranas En Granjas Con Diferentes Estrategias De Vacunación, Katherine J. Portilla, Albert Manchego S., Hermelinda G. Rivera, Mariluz Araínga, Marcy Ramierz V.

Journal Articles: Pharmacology & Experimental Neuroscience

In the study evaluated was the persistence of maternal antibodies levels Classical Swine Fever Against the virus (CSFV) in Vaccinated piglets born from sows from two farms (A and B) With different strategies against CSFV vaccination. In farm A sows were vaccinated at 90 days of gestation and in farm B at 18 - 21 days postpartum. Serum samples were collected from piglets of both farms, at first (n=15), third (n=15), fifth (n=15) and seventh (n=15) weeks of age, and from 15 sows from each farm A for detection of antibodies against CSFV by the indirect ELISA test. All piglets …

A Rare Case Of Pilomatricoma With Bullous Appearance, Ayşe Serap Karadağ, Meral Ekşi̇oğlu, Eki̇n Özlük, Gülfer Akbay, Alev Eken, Savaş Serel, Hesna Müzeyyen Astarci

Turkish Journal of Medical Sciences

Background: Pilomatricoma is a rare, benign adnexal tumor differentiating toward elements of the hair matrix and shaft. It typically presents as a solitary, deep, dermal nodule. In addition, bullous changes can be rarely seen. Methods: A 16-year-old girl with firm, mobile, multilobule and non-tender mass that has a soft, hemorrhagic blister-like formation on the left infraclavicular region is described. Results: The histopathologic findings were consistent with pilomatricoma. In the dermis above the tumor, there were numerous dilated lymphatic and blood vessels. No pathologic elastic fibrils were identified with elastin stains. Collagen fibrils were normal with Mason trichrome stain. Conclusions: The …

Disseminated Superficial Actinic Porokeratosis: A Case Report, Asli Eralp, Yeşi̇m Kaymak

Turkish Journal of Medical Sciences

Disseminated superficial actinic porokeratosis (DSAP) is a type of porokeratosis observed in parts of the skin exposed to intense sunlight and usually appears in the third or fourth decade of life. Since it is a rare disorder, herein we present our experience of a 57-year-old man with DSAP. Dermatological examination of the patient revealed pink/red multiple papular lesions, ranging in diameter from 0.5 to 1 cm, with an atrophic center and hyperkeratotic contours limited to sun-exposed skin parts especially in the extremities and rarely in trunk. Cryotherapy was effective in healing the lesions.

Evaluation Of The Knowledge Of Hospital Cleaning Staff About Prevention Of Nosocomial Infections, Tansu Yamazhan, Meltem Işikgöz Taşbakan, Şebnem Çalik, Hüsnü Pullukçu, Oğuz Reşat Si̇pahi̇, Sercan Ulusoy

Turkish Journal of Medical Sciences

Aims: Detection of risk groups and infection sources and awareness of the routes of transmission of infections are important for prevention of hospital infections. In this study, we aimed to evaluate the knowledge level and the behavior models of hospital cleaning staff about nosocomial infections. Materials and Methods: A 21-item questionnaire about nosocomial infections was administered to the hospital cleaning staff. Results: Out of 290 hospital cleaning staff, 240 (82.7%, 122 male, 118 female, aged 36.2±8.7) were included in the study. When evaluated according to their educational status, 55.4% had graduated from primary school. Fifty-four percent of the staff had …