Medical Sciences Commons^™

Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan

Dartmouth Scholarship

Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa and Candida albicans were cocultured on solid medium, a red pigmentation developed that was dependent on P. aeruginosa phenazine biosynthetic genes. Through a genetic screen in combination with biochemical experiments, it was found that a P. aeruginosa-produced precursor to pyocyanin, proposed to be 5-methyl-phenazinium-1-carboxylate (5MPCA), was necessary for the formation of the red pigmentation. The 5MPCA-derived pigment was found to accumulate exclusively within fungal cells, where it retained the ability to be reversibly oxidized and reduced, and its …

Crystallization And Structure Of A Plant Peptide Deformylase, Robert L. Houtz, David W. Rodgers, Lynnette M. A. Dirk, Mark A. Williams

Molecular and Cellular Biochemistry Faculty Patents

This invention relates to the crystal structure of a plant peptide deformylase polypeptide and methods of using the structure to design compounds that modulate the activity of the polypeptide.

Neuroendocrine Peptides Neuropeptide-Y (Npy) And Peptide-Yy (Pyy) Suppress Cl- Secretion And K+ Secretion In Guinea Pig Distal Colon Through Action At Y2-Receptors, Susan T. Halm, Jin Zhang, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Electrogenic Cl^– and K⁺ secretion in isolated mucosa from guinea pig distal colon measured as short-circuit current (I_sc) and transepithelial conductance (G_t) were stimulated by epinephrine (epi), prostaglandin-E₂ (PGE₂) and carbachol (CCh). neuropeptide-Y (NPY) and peptide-YY (PYY) inhibited by 60% Cl^– secretion activated by either PGE₂ or PGE₂+CCh with EC₅₀’s of 16nM and 6nM, respectively. Neither peptide markedly inhibited the transient component of the PGE₂+CCh response. Immunoreactivity (IR) for NPY was present in enteric ganglia and in proximity with crypts. Basolateral membranes of …

Factors Associated With Hydrocarbon Ingestion In Children, Emaduddin Siddiqui, Junaid Razzak, Farah Naz, Sabeena Jalal Khan

Department of Emergency Medicine

OBJECTIVE: To investigate the types of hydrocarbon ingested by children and identify factors associated with hydrocarbons ingestion.

PATIENTS AND METHODS: It was a hospital based case control study in which medical records of sixty seven children with hydrocarbon ingestion, admitted through emergency department between January 2001 to December 2005 of Aga Khan Hospital were reviewed. Variables such as age, sex, types of hydrocarbons, amount ingested, socioeconomic status, family size, number of children, type of containers, trend of ingestion during hot weather, length of stay at hospital along with the outcomes were evaluated.

RESULTS: Out of 67 patients, 53 (79%) were …

Technical Variables In High-Throughput Mirna Expression Profiling: Much Work Remains To Be Done, Peter T. Nelson, Wang-Xia Wang, Bernard R. Wilfred, Guiliang Tang

Pathology and Laboratory Medicine Faculty Publications

MicroRNA (miRNA) gene expression profiling has provided important insights into plant and animal biology. However, there has not been ample published work about pitfalls associated with technical parameters in miRNA gene expression profiling. One source of pertinent information about technical variables in gene expression profiling is the separate and more well-established literature regarding mRNA expression profiling. However, many aspects of miRNA biochemistry are unique. For example, the cellular processing and compartmentation of miRNAs, the differential stability of specific miRNAs, and aspects of global miRNA expression regulation require specific consideration. Additional possible sources of systematic bias in miRNA expression studies include …

Caveolin-1, Tgf-Β Receptor Internalization, And The Pathogenesis Of Systemic Sclerosis, Francesco Del Galdo, Michael P. Lisanti, Sergio A. Jimenez

Jefferson Institute of Molecular Medicine Papers and Presentations

PURPOSE OF REVIEW: To review the scientific literature supporting the participation of caveolin-1 in the pathogenesis of tissue fibrosis and the notion that modulation of the caveolin-1 pathway may represent a novel treatment for systemic sclerosis and other fibrotic diseases.

RECENT FINDINGS: Caveolin-1 plays an important role in the regulation of transforming growth factor-beta (TGF-beta) signaling owing to its participation in TGF-beta receptor internalization. TGF-beta receptor internalized through caveolin-1 lipid rafts undergoes rapid degradation, effectively decreasing TGF-beta signaling. Studies have shown that caveolin-1 knockdown in vitro markedly increased collagen gene expression in normal human lung fibroblasts. Caveolin-1 was reduced in …

Focus On Rna Isolation: Obtaining Rna For Microrna (Mirna) Expression Profiling Analyses Of Neural Tissue, Wang-Xia Wang, Bernard R. Wilfred, Donald A. Baldwin, R. Benjamin Isett, Na Ren, Arnold J. Stromberg, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNAs (miRNAs) are present in all known plant and animal tissues and appear to be somewhat concentrated in the mammalian nervous system. Many different miRNA expression profiling platforms have been described. However, relatively little research has been published to establish the importance of 'upstream' variables in RNA isolation for neural miRNA expression profiling. We tested whether apparent changes in miRNA expression profiles may be associated with tissue processing, RNA isolation techniques, or different cell types in the sample. RNA isolation was performed on a single brain sample using eight different RNA isolation methods, and results were correlated using a conventional …

The Value Of Intraoperative Examination Of Axillary Sentinel Nodes In Carcinoma Of The Breast., Gordon F. Schwartz, Lauren S. Krill, Juan P. Palazzo, Abhijit Dasgupta

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Abstract Axillary sentinel lymph node biopsy (SLNB) has become the standard of care for T1-2, N-0, M-0 carcinoma of the breast. However, the accuracy of frozen section in the intra-operative examination of sentinel nodes (SN) remains controversial. The senior author has championed the use of the intraoperative examination of SN by frozen section ex-amination from the inception of its use, and we present our experience with frozen section examination of SN, confirming that this technique is both practical and highly accurate. Materials & Methods: Between 2000 and 2007, 236 SLNB procedures were performed that were read as “fro-zen section negative.” …

Short-Term Memory, Working Memory, And Executive Functioning In Preschoolers: Longitudinal Predictors Of Mathematical Achievement At Age 7 Years, Rebecca Bull, Kimberly A. Espy, Sandra A. Wiebe

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

This study examined whether measures of short-term memory, working memory, and executive functioning in preschool children predict later proficiency in academic achievement at 7 years of age (third year of primary school). Children were tested in preschool (M age = 4 years, 6 months) on a battery of cognitive measures, and mathematics and reading outcomes (from standardized, norm-referenced school-based assessments) were taken on entry to primary school, and at the end of the first adn third year of primary school. Growth curve analyses examined predictors of math and reading achievement across the duration of the study and revealed that better …

Transport Of Ldl-Derived Cholesterol From The Npc1 Compartment To The Er Involves The Trans-Golgi Network And The Snare Protein Complex, Yasuomi Urano, Hiroshi Watanabe, Stephanie R. Murphy, Yohei Shibuya, Yong Geng, Andrew Peden, Catherine Chang, Ta Yuan Chang

Dartmouth Scholarship

Mammalian cells acquire cholesterol mainly from LDL. LDL enter the endosomes, allowing cholesteryl esters to be hydrolyzed by acid lipase. The hydrolyzed cholesterol (LDL-CHOL) enters the Niemann-Pick type C1 (NPC1)-containing endosomal compartment en route to various destinations. Whether the Golgi is involved in LDL-CHOL transport downstream of the NPC1 compartment has not been demonstrated. Using subcellular fractionation and immunoadsorption to enrich for specific membrane fractions, here we show that, when parental Chinese hamster ovary (CHO) cells are briefly exposed to (3)H-cholesteryl linoleate (CL) labeled-LDL, newly liberated (3)H-LDL-CHOL appears in membranes rich in trans-Golgi network (TGN) long before it becomes available …

Viral Vectors In The Research Laboratory: Just How Safe Are They?, Dawn P. Wooley, Kimberly Kay Morris, Robert Mcrae, John C. Trefry

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.

Identification Of Two Gene Clusters And A Transcriptional Regulator Required For Pseudomonas Aeruginosa Glycine Betaine Catabolism, Matthew J. Wargo, Benjamin S. Szwergold, Deborah A. Hogan

Dartmouth Scholarship

Glycine betaine (GB), which occurs freely in the environment and is an intermediate in the catabolism of choline and carnitine, can serve as a sole source of carbon or nitrogen in Pseudomonas aeruginosa. Twelve mutants defective in growth on GB as the sole carbon source were identified through a genetic screen of a nonredundant PA14 transposon mutant library. Further growth experiments showed that strains with mutations in two genes, gbcA (PA5410) and gbcB (PA5411), were capable of growth on dimethylglycine (DMG), a catabolic product of GB, but not on GB itself. Subsequent nuclear magnetic resonance (NMR) experiments with 1,2-(13)C-labeled choline …

Mgra Represses Biofilm Formation In Staphylococcus Aureus, Maria P. Trotonda, Sandeep Tamber, Guido Memmi, Ambrose L. Cheung

Dartmouth Scholarship

MgrA is a pleiotropic regulator that controls autolysis, virulence, and efflux pump activity in Staphylococcus aureus. We recently found that mgrA mutants of strains RN6390, SH1000, and MW2 also displayed enhanced biofilm formation compared with their respective parents. The biofilms formed by mgrA mutants of RN6390 and MW2 are independent of sigB and ica loci, two genetic elements that have been previously associated with biofilm formation in S. aureus. Biofilms formed by mgrA mutants are dependent on the expression of surface proteins mediated by the sortase gene srtA. Extracellular DNA was also a crucial component of the early biofilm of …

Ovarian Cancer: Emerging Concept On Cancer Stem Cells., Moorthy P. Ponnusamy, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Emerging evidence suggests that the capacity of a tumor to grow and propagate is dependent on a small subset of cells within a tumor, termed cancer stem cells. In fact, cancer cells, like stem cells, can proliferate indefinitely through a dysregulated cellular self-renewal capacity. Cancer stem cells may originate due to the distribution into self-renewal and differentiation pathways occurring in multi-potential stem cells, tissue-specific stem cells, progenitor cells and cancer cells. Recent studies have shown that ovarian cancer also contains stem cells or tumor-initiating cells. Moreover, ovarian serous adenocarcinomas were disaggregated and subjected to growth conditions to select for self-renewing, …

Global Analysis Of Gene Expression Changes During Retinoic Acid-Induced Growth Arrest And Differentiation Of Melanoma: Comparison To Differentially Expressed Genes In Melanocytes Vs Melanoma, Mary H. Estler, Goran Boskovic, James Denvir, Sarah Miles, Donald A. Primerano, Richard M. Niles

Biochemistry and Microbiology

BACKGROUND: The incidence of malignant melanoma has significantly increased over the last decade. Some of these malignancies are susceptible to the growth inhibitory and pro-differentiating effects of all-trans-retinoic acid (RA). The molecular changes responsible for the biological activity of RA in melanoma are not well understood.

RESULTS: In an analysis of sequential global gene expression changes during a 4-48 h RA treatment of B16 mouse melanoma cells, we found that RA increased the expression of 757 genes and decreased the expression of 737 genes. We also compared the gene expression profile (no RA treatment) between non-malignant melan-a mouse melanocytes and …

Factors Contributing To The Biofilm-Deficient Phenotype Of Staphylococcus Aureus Sara Mutants, Laura H. Tsang, James E. Cassat, Lindsey N. Shaw, Karen E. Beenken, Mark S. Smeltzer

Molecular Biosciences Faculty Publications

Mutation of sarA in Staphylococcus aureus results in a reduced capacity to form a biofilm, but the mechanistic basis for this remains unknown. Previous transcriptional profiling experiments identified a number of genes that are differentially expressed both in a biofilm and in a sarA mutant. This included genes involved in acid tolerance and the production of nucleolytic and proteolytic exoenzymes. Based on this we generated mutations in alsSD, nuc and sspA in the S. aureus clinical isolate UAMS-1 and its isogenic sarA mutant and assessed the impact on biofilm formation. Because expression of alsSD was increased in a biofilm but …

The Untapped Power Of "We Don't Know": Epistemological Humility In The Era Of Covid-19, Diasinou Fioravante, Rong-Yu Liu, John H. Byrne

Faculty, Staff and Student Publications

The neuropeptide Phe-Met-Arg-Phe-NH(2) (FMRFa) can induce transcription-dependent long-term synaptic depression (LTD) in Aplysia sensorimotor synapses. We investigated the role of the ubiquitin-proteasome system and the regulation of one of its components, ubiquitin C-terminal hydrolase (ap-uch), in LTD. LTD was sensitive to presynaptic inhibition of the proteasome and was associated with upregulation of ap-uch mRNA and protein. This upregulation appeared to be mediated by CREB2, which is generally regarded as a transcription repressor. Binding of CREB2 to the promoter region of ap-uch was accompanied by histone hyperacetylation, suggesting that CREB2 cannot only inhibit but also promote gene expression. CREB2 was phosphorylated …

Creating Partnerships To Improve Health: An Overview Of Community-Based Participatory Research., Debbie Salas-Lopez Md, Mph

Department of Medicine

No abstract provided.

Gender Differences In Motivation To Resolve Eating And Body Image Concerns In College Students, Harold L. Merriman, C. Jayne Brahler, Laura Dinan, Lauren Finzer

Physical Therapy Faculty Publications

The objective of this study was to identify similarities and differences between college women and men with respect to their eating and body image concerns, weight fluctuation and level of motivation to resolve these concerns. 101 University of Dayton students participated in this study. Students completed an eating and body concern survey online.

Body image concerns were significantly greater for females compared to males (p=0.007) and significantly greater as motivation level to resolve the concerns increased (p=0.019). Eating concerns followed the same trends but did not reach statistical significance. Weight fluctuation in both genders increased significantly as motivation level increased …

Immune Evasion By Rabies Viruses Through The Maintenance Of Blood-Brain Barrier Integrity., Anirban Roy, Douglas C. Hooper

Department of Cancer Biology Faculty Papers

The attenuated rabies virus (RV) strain Challenge Virus Standard (CVS)-F3 and a highly pathogenic strain associated with the silver-haired bats (SHBRV) can both be cleared from the central nervous system (CNS) tissues by appropriate antiviral immune mechanisms if the effectors are provided access across the blood-brain barrier (BBB). In the case of SHBRV infection, antiviral immunity develops normally in the periphery but fails to open the BBB, generally resulting in a lethal outcome. To determine whether or not an absence in the CNS targeted immune response is associated with the infection with other pathogenic RV strains, we have assessed the …

Illusory Vowels Resulting From Perceptual Continuity: A Functional Magnetic Resonance Imaging Study, Antje Heinrich, Robert P Carlyon, Matthew H Davis, Ingrid Johnsrude

Brain and Mind Institute Researchers' Publications

We used functional magnetic resonance imaging to study the neural processing of vowels whose perception depends on the continuity illusion. Participants heard sequences of two-formant vowels under a number of listening conditions. In the "vowel conditions," both formants were always present simultaneously and the stimuli were perceived as speech-like. Contrasted with a range of nonspeech sounds, these vowels elicited activity in the posterior middle temporal gyrus (MTG) and superior temporal sulcus (STS). When the two formants alternated in time, the "speech-likeness" of the sounds was reduced. It could be partially restored by filling the silent gaps in each formant with …

Variable Judgments Of Decisional Capacity In Cognitively Impaired Research Subjects, Marion B. Patterson, Peter J. Whitehouse

Faculty Scholarship

OBJECTIVES: To compare assessments of the decisional capacity of cognitively impaired patients by research assistants (RAs) and by family caregiver/proxies and to determine whether either or both groups judge capacity differently depending on the specific (hypothetical) research enrollment decision being made. DESIGN: Cross-sectional. SETTING: Three clinics, one each in Ohio, Kentucky, and Illinois. PARTICIPANTS: One hundred forty-nine patients with established dementia diagnoses and their caregiver/proxies. MEASUREMENTS: As part of a longer interview, patients were asked about future enrollment in five hypothetical research projects with varying risks and benefits. After patients reported each decision and reasons for that decision, RAs (using …

Molecular Processes That Handle — And Mishandle — Dietary Lipids, Kevin Jon Williams

Department of Medicine Faculty Papers

Overconsumption of lipid-rich diets, in conjunction with physical inactivity, disables and kills staggering numbers of people worldwide. Recent advances in our molecular understanding of cholesterol and triglyceride transport from the small intestine to the rest of the body provide a detailed picture of the fed/fasted and active/sedentary states. Key surprises include the unexpected nature of many pivotal molecular mediators, as well as their dysregulation — but possible reversibility — in obesity, diabetes, inactivity, and related conditions. These mechanistic insights provide new opportunities to correct dyslipoproteinemia, accelerated atherosclerosis, insulin resistance, and other deadly sequelae of overnutrition and underexertion.

Answering The Cdc's Call For Universal Hiv Testing: Assesing The Impact On A Tertiary Care Referral Center Via A Blinded Seroprevalence Study, Margaret Hoffman-Terry Md, Facp, K Nadeem Ahmed Md, Joseph L. Yozviak Do, Facp, Sherrine Eid Mph, Timothy J. Friel Md, Kimberly A. Pacella, Luther Rhodes Iii Md

Department of Medicine

No abstract provided.

The Cytoplasmic Tail Of The Rabies Virus G Protein Is An Essential Domain Controlling Death/Survival In Human Neuronal Cells, Christophe Prehaud, Mireille Lafage, Gene S. Tan, Françoise Mégret, Pauline Ménager, Matthias Schnell, Henri Buc, Monique Lafon

Department of Microbiology and Immunology Faculty Papers

Poster presentation.

Intraretinal Signaling By Ganglion Cell Photoreceptors To Dopaminergic Amacrine Neurons, Dao-Qi Zhang, Kwoon Y. Wong, Patricia J. Sollars, David M. Berson, Gary E. Pickard, Douglas G. Mcmahon

School of Veterinary and Biomedical Sciences: Faculty Publications

Retinal dopaminergic amacrine neurons (DA neurons) play a central role in reconfiguring retinal function according to prevailing illumination conditions, yet the mechanisms by which light regulates their activity are poorly understood. We investigated the means by which sustained light responses are evoked in DA neurons. Sustained light responses were driven by cationic currents and persisted in vitro and in vivo in the presence of L-AP4, a blocker of retinal ON-bipolar cells. Several characteristics of these L-AP4-resistant light responses suggested that they were driven by melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), including long latencies, marked poststimulus persistence, and a peak …

Deregulation Of Muc4 In Gastric Adenocarcinoma: Potential Pathobiological Implication In Poorly Differentiated Non-Signet Ring Cell Type Gastric Cancer., S. Senapati, P. Chaturvedi, P. Sharma, G Venkatraman, Jane L. Meza, W. El-Rifai, H. K. Roy, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

MUC4 is a large, heavily glycosylated transmembrane mucin, that is implicated in the pathogenesis of various types of cancers. To date, no extensive study has been done to check the expression and functional significance of MUC4 in different types of gastric adenocarcinomas. Here, we report the expression profile of MUC4 in gastric adenocarcinomas and its function in poorly differentiated gastric non-signet ring cell carcinoma (non-SRCC) type cells. Immunohistochemical analysis using tissue microarray (TMA) showed a significant difference in MUC4 expression between normal adjacent (n = 45) and gastric adenocarcinoma (n = 83; P < 0.001). MUC4 expression was not associated with tumour type, stage or with the degree of differentiation. To gain further insight into the significance of MUC4 expression in gastric non-SRCC cells, MUC4 was ectopically expressed in AGS, a poorly differentiated gastric non-signet ring cell line. The MUC4 overexpressing cells (AGS-MUC4) showed a significant increase (P < 0.005) in cell motility and a decrease in cellular aggregation as compared with the vector-transfected cells. Furthermore, in vivo tumorigenicity analysis revealed that animals transplanted with the MUC4 overexpressing cells (AGS-MUC4) had a greater incidence of tumours (83%) in comparison to empty vector control (17%). In addition, the expression of MUC4 resulted in enhanced expression of total cellular ErbB2 and phosphorylated ErbB2. In conclusion, our results showed that MUC4 is overexpressed in gastric adenocarcinoma tissues, and that it has a role in promoting aggressive properties in poorly differentiated gastric non-SRCC cells through the activation of the ErbB2 oncoprotein.

Emerging Issues In Forensic Dna Profiling: Databases And Advisory Boards, Dan E. Krane

Biological Sciences Faculty Publications

No abstract provided.

Intravenous Inoculation Of Silver-Haired Bat Rabies Virus, But Not Of A Canine Strain, Elicits Lethal Encephalophathy In Mice By Fast Brain Invasion Via Neurosecretory Hypothalamic Fibers, Mirjam Ar Preuss, Marie-Luise Faber, Gene S. Tan, Bernhard Dietzschold, Matthias J. Schnell, Eberhard Weihe

Department of Microbiology and Immunology Faculty Papers

No abstract provided.

Presence Of Endometrial Adenocarcinoma In Situ In Complex Atypical Endometrial Hyperplasia Is Associated With Increased Incidence Of Endometrial Carcinoma In Subsequent Hysterectomy., Khush Mittal, Matjaz Sebenik, Cybil Irwin, Zhijije Yan, Dorota Popiolek, John Curtin, Juan Palazzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The distinction of complex atypical endometrial hyperplasia from endometrial adenocarcinoma is often problematic. Foci of back-to-back arrangement of glands or foci of cribriform arrangement of glands smaller than 2.1 mm in diameter are considered insufficient for the diagnosis of endometrial adenocarcinoma by some authors, and sufficient to be diagnosed as endometrial adenocarcinoma by other authors. We refer to these foci as endometrial adenocarcinoma in situ. In this study, we evaluated findings in subsequent hysterectomy in complex atypical endometrial hyperplasia patients with and without adenocarcinoma in situ. Follow-up findings, including the presence or absence of endometrial adenocarcinoma in the hysterectomy specimen, …