Medical Pathology Commons^™

Stimulation Through Tlr4 Increases Fviii Inhibitor Formation In A Mouse Model Of Hemophilia A, Claire K. Holley

Dissertations and Theses (Open Access)

Hemophilia A is a clotting disorder caused by functional factor VIII (FVIII) deficiency. About 25% of patients treated with therapeutic recombinant FVIII develop antibodies (inhibitors) that render subsequent FVIII treatments ineffective. The immune mechanisms of inhibitor formation are not entirely understood, but circumstantial evidence indicates a role for increased inflammatory response, possibly via stimulation of Toll-like receptors (TLRs), at the time of FVIII immunization. I hypothesized that stimulation through TLR4 in conjunction with FVIII treatments would increase the formation of FVIII inhibitors. To test this hypothesis, FVIII K.O. mice were injected with recombinant human FVIII with or without concomitant doses …

Delayed Thrombus Resolution And Fibroproliferative Vascular Wound Healing From Deficiency Of Type Iii Collagen: A Paradoxical Mechanism For Tissue Fragility, Amy J. Reid

Dissertations and Theses (Open Access)

Vascular Ehlers-Danlos syndrome is a heritable disease of connective tissue caused by mutations in COL3A1, conferring a tissue deficiency of type III collagen. Cutaneous wounds heal poorly in these patients, and they are susceptible to spontaneous and catastrophic rupture of expansible hollow organs like the gut, uterus, and medium-sized to large arteries, which leads to premature death. Although the predisposition for organ rupture is often attributed to inherent tissue fragility, investigation of arteries from a haploinsufficient Col3a1 mouse model (Col3a1^+/-) demonstrates that mutant arteries withstand even supraphysiologic pressures comparably to wild-type vessels. We hypothesize that injury …

Celiac Disease And Neurological Symptoms, Lauren V. Cook

Senior Honors Theses

New research has revealed that Celiac disease, an autoimmune illness affecting the small intestine, has more ties with neurological side effects than once was thought. The classic and most well known presentation of Celiac disease is gastrointestinal, including symptoms such as abdominal pains, nausea, diarrhea, and flatulence. Researchers have more recently found a correlation between Celiac disease and neurological illnesses such as epilepsy, depression, dementia, and ADHD. Physician awareness of the disease and the neurological side of the illness should be heightened in order for patients to receive earlier diagnosis and a better quality of life. Because of the difficulty …

Secretion Of Tcpf By The Vibrio Cholerae Toxin-Coregulated Pilus Biogenesis Apparatus Requires An N-Terminal Determinant, Christina J. Megli, Ronald K. Taylor

Dartmouth Scholarship

Type IV pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. We and others have shown that type IV pili are important for protein secretion across the outer membrane, similar to type II secretion systems. This study explored the relationship between protein secretion and pilus formation in Vibrio cholerae. The toxin-coregulated pilus (TCP), a type IV pilus required for V. cholerae pathogenesis, is necessary for the secretion of the colonization factor TcpF (T. J. Kirn, N. Bose, and R. K. Taylor, Mol. Microbiol. 49:81–92, 2003). This phenomenon is not unique to V. cholerae; secreted …

Neuroinflammation And Psychiatric Illness, Souhel Najjar, Daniel M. Pearlman, Kenneth Alper, Amanda Najjar, Orrin Devinsky

Dartmouth Scholarship

Multiple lines of evidence support the pathogenic role of neuroinflammation in psychiatric illness. While systemic autoimmune diseases are well-documented causes of neuropsychiatric disorders, synaptic autoimmune encephalitides with psychotic symptoms often go under-recognized. Parallel to the link between psychiatric symptoms and autoimmunity in autoimmune diseases, neuroimmunological abnormalities occur in classical psychiatric disorders (for example, major depressive, bipolar, schizophrenia, and obsessive-compulsive disorders). Investigations into the pathophysiology of these conditions traditionally stressed dysregulation of the glutamatergic and monoaminergic systems, but the mechanisms causing these neurotransmitter abnormalities remained elusive. We review the link between autoimmunity and neuropsychiatric disorders, and the human and experimental evidence …

Icad Deficiency In Human Colon Cancer And Predisposition To Colon Tumorigenesis: Linkage To Apoptosis Resistance And Genomic Instability, Youssef Errami, Hassan Brim, Karine Oumouna-Benachour, Mustapha Oumouna, Amarjit S. Naura, Hogyoung Kim, Jihang Ju, Christian J. Davis, Jong G. Kim, Hassan Ashktorab, Kenneth Fallon, Ming Xu, Jianhua Zhang, Luis Del Valle, A Hamid Boulares

School of Medicine Faculty Publications

We previously showed that DNA fragmentation factor, which comprises a caspase-3-activated DNase (CAD) and its inhibitor (ICAD), may influence the rate of cell death by generating PARP-1-activating DNA breaks. Here we tested the hypothesis that ICAD-deficient colon epithelial cells exhibiting resistance to death stimuli may accumulate additional genetic modifications, leading to a tumorigenic phenotype. We show that ICAD deficiency may be associated with colon malignancy in humans. Indeed, an examination of ICAD expression using immunohistochemistry in an array of both colon cancer and normal tissues revealed that ICAD expression levels were severely compromised in the cancerous tissues. Upon DNA damage …

Development Of A Diagnostic Test Set To Assess Agreement In Breast Pathology: Practical Application Of The Guidelines For Reporting Reliability And Agreement Studies (Grras), Natalia V. Oster, Patricia A. Carney, Kimberly H. Allison, Donald L. Weaver, Lisa Reisch, Gary Longton, Tracy Onega

Dartmouth Scholarship

Diagnostic test sets are a valuable research tool that contributes importantly to the validity and reliability of studies that assess agreement in breast pathology. In order to fully understand the strengths and weaknesses of any agreement and reliability study, however, the methods should be fully reported. In this paper we provide a step-by-step description of the methods used to create four complex test sets for a study of diagnostic agreement among pathologists interpreting breast biopsy specimens. We use the newly developed Guidelines for Reporting Reliability and Agreement Studies (GRRAS) as a basis to report these methods.

Molecular Architecture Of The Uncleaved Hiv-1 Envelope Glycoprotein Trimer, Youdong Mao, Luis Castillo-Menendez, Liping Wang, Christopher Gu, Alon Herschhorn, Anik Désormeaux, Andrés Finzi, Shi-Hua Xiang, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer, a membrane-fusing machine, mediates virus entry into host cells and is the sole virusspecific target for neutralizing antibodies. Binding the receptors, CD4 and CCR5/CXCR4, triggers Env conformational changes from the metastable unliganded state to the fusion-active state. We used cryo-electron microscopy to obtain a 6-Å structure of the membranebound, heavily glycosylated HIV-1 Env trimer in its uncleaved and unliganded state. The spatial organization of secondary structure elements reveals that the unliganded conformations of both gp120 and gp41 subunits differ from those induced by receptor binding. The gp120 trimer association domains, which …

Variations In The Biological Functions Of Hiv-1 Clade C Envelope In A Shiv-Infected Rhesus Macaque During Disease Progression, For Yue Tso, Levon Abrahamyan, Shiu-Lok Hu, Ruth M. Ruprecht, Charles Wood

Nebraska Center for Virology: Faculty Publications

A better understanding of how the biological functions of the HIV-1 envelope (Env) changes during disease progression may aid the design of an efficacious anti-HIV-1 vaccine. Although studies from patient had provided some insights on this issue, the differences in the study cohorts and methodology had make it difficult to reach a consensus of the variations in the HIV-1 Env functions during disease progression. To this end, an animal model that can be infected under controlled environment and reflect the disease course of HIV-1 infection in human will be beneficial. Such an animal model was previously demonstrated by the infection …

Kaposi’S Sarcoma-Associated Herpesvirus Transactivator Rta Induces Cell Cycle Arrest In G0/G1 Phase By Stabilizing And Promoting Nuclear Localization Of P27Kip, Pankaj Kumar, Charles Wood

Nebraska Center for Virology: Faculty Publications

The Kaposi’s sarcoma-associated herpesvirus (KSHV) immediate-early gene, replication, and transcription activator (KRta) is a key viral protein that serves as the master regulator for viral lytic replication. In this study, we investigated the role of K-Rta in cell cycle regulation and found that the expression of K-Rta in doxycycline (Dox)-inducible BJAB cells induced cell cycle arrest in G₀/G₁ phase. Western blot analysis of key cell cycle regulators revealed that K-Rta-mediated cell cycle arrest was associated with a decrease in cyclin A and phosphorylated Rb (pS807/pS811) protein levels, both markers of S phase progression, and an increase in …

Low-Abundance Resistant Mutations In Hiv-1 Subtype C Antiretroviral Therapy-Naïve Individuals As Revealed By Pyrosequencing, Sandra Gonzalez, Damien C. Tully, Clement Gondwe, Charles Wood

Nebraska Center for Virology: Faculty Publications

Given the recent scale-up of antiretroviral therapy (ART) in sub-Saharan Africa, we sought to determine how often and at what levels do drug-resistant mutant variants exist in ART-naïve HIV subtype C infected individuals. Samples from 10 ART-naïve Zambian individuals were subjected to ultra-deep pyrosequencing (UDPS) to characterize the frequency of low-abundance drug resistance mutations in the pol gene. Low-abundance clinically relevant variants were detected for nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) in eight of the ten subjects. Intermediate to high-level resistance was predicted for the majority of NRTIs. Mutations conferring resistance to …

Clade C Hiv-1 Isolates Circulating In Southern Africa Exhibit A Greater Frequency Of Dicysteine Motif-Containing Tat Variants Than Those In Southeast Asia And Cause Increased Neurovirulence, Vasudev R. Rao, Ujjwal Neogi, Joshua S, Talboom, Ligia Padilla, Mustafizur Rahman, Cari Fritz-French, Sandra Gonzalez-Ramirez, Anjali Verma, Charles Wood, Ruth M. Ruprecht, Udaykumar Ranga, Tasnim Azim, Vinayaka R. Prasad

Nebraska Center for Virology: Faculty Publications

Background: HIV-1 Clade C (Subtype C; HIV-1C) is responsible for greater than 50% of infections worldwide. Unlike clade B HIV-1 (Subtype B; HIV-1B), which is known to cause HIV associated dementia (HAD) in approximately 15% to 30% of the infected individuals, HIV-1C has been linked with lower prevalence of HAD (0 to 6%) in India and Ethiopia. However, recent studies report a higher prevalence of HAD in South Africa, Zambia and Botswana, where HIV-1C infections predominate. Therefore, we examined whether Southern African HIV-1C is genetically distinct and investigated its neurovirulence. HIV-1 Tat protein is a viral determinant of neurocognitive dysfunction. …

Global Neuroaids Roundtable, Jeymohan Joseph, Cristian L. Achim, Michael J. Boivin, Bruce J. Brew, David B. Clifford, Deborah A. Colosi, Ronald J. Ellis, Robert K. Heaton, Amadou Gallo-Diop, Igor Grant, Georgette D. Kanmogne, Mahendra Kumar, Scott Letendre, Thomas D. Marcotte, Avindra Nath, Carlos A. Pardo, Robert H. Paul, Lynn Pulliam, Kevin Robertson, Walter Royal Iii, Ned Sacktor, Pasiri Sithinamsuwan, Davey M. Smith, Victor Valcour, Brian Wigdahl, Charles Wood

Nebraska Center for Virology: Faculty Publications

In May 2012, the Division of AIDS Research at the National Institute of Mental Health (NIMH) organized the “Global NeuroAIDS Roundtable” in conjunction with the 11th International Symposium on Neurovirology and the 2012 Conference on HIV in the Nervous System. The meeting was held in New York, NY, USA and brought together NIMH-funded investigators who are currently working on projects related to the neurological complications of AIDS (NeuroAIDS) in Africa, Asia, Eastern Europe, and Latin America in order to provide an opportunity to share their recent findings and discuss the challenges encountered within each country. The major goals of the …

Aβ Alters The Dna Methylation Status Of Cell-Fate Genes In An Alzheimer’S Disease Model, Gary D. Isaacs, Noor Taher, Courtney Mckenzie, Rebecca Garrett, Matthew Baker, Nena Fox

Faculty Publications and Presentations

Alzheimer’s disease (AD) is characterized by neurofibrillary tangles and extracellular amyloid-β plaques (Aβ). Despite ongoing research, some ambiguity remains surrounding the role of Aβ in the pathogenesis of this neurodegenerative disease. While several studies have focused on the mutations associated with AD, our understanding of the epigenetic contributions to the disease remains less clear. To that end, we determined the changes in DNA methylation in differentiated human neurons with and without Aβ treatment. We isolated the DNA from neurons treated with Aβ or vehicle, and digested the two samples with either a methylation-sensitive (HpaII) or a methylation-insensitive (MspI) restriction endonuclease. …

Different Mechanisms Of Inflammation Induced In Virus And Autoimmune-Mediated Models Of Multiple Sclerosis In C57bl6 Mice., Abhinoy Kishore, Anurag Kanaujia, Soma Nag, A M Rostami, Lawrence C. Kenyon, Kenneth S Shindler, Jayasri Das Sarma

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the human central nervous system (CNS). Neurotropic demyelinating strain of MHV (MHV-A59 or its isogenic recombinant strain RSA59) induces MS-like disease in mice mediated by microglia, along with a small population of T cells. The mechanism of demyelination is at least in part due to microglia-mediated myelin stripping, with some direct axonal injury. Immunization with myelin oligodendrocyte glycoprotein (MOG) induces experimental autoimmune encephalomyelitis (EAE), a mainly CD4(+) T-cell-mediated disease, although CD8(+) T cells may play a significant role in demyelination. It is possible that both autoimmune and nonimmune mechanisms such as …

Neisseria Oralis Sp. Nov., Isolated From Healthy Gingival Plaque And Clinical Samples, William J. Wolfgang, Teresa V. Passaretti, Reashma Jose, Jocelyn Cole, An Coorevits, Andrea N. Carpenter, Sherly Jose, Anita Van Landschoot, Jacques Izard, Donna J. Kohlerschmidt, Peter Vandamme, Floyd E. Dewhirst, Mark A. Fisher, Kimberlee A. Musser

Department of Food Science and Technology: Faculty Publications

A polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida, and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbor, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the …

Purpose And Criteria For Blood Smear Scan, Blood Smear Examination, And Blood Smear Review., Gene Gulati, Jinming Song, Alina Dulau Florea, Jerald Gong

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

A microscopic examination of an appropriately prepared and well-stained blood smear by a knowledgeable laboratory professional is necessary and clinically useful in a number of circumstances and for a variety of reasons. In this article, an attempt is made to delineate the purpose and criteria for blood smear examination in a variety of circumstances that are encountered in everyday laboratory hematology practice. A blood smear scan serves to at least (a) verify the flagged automated hematology results and (b) determine if a manual differential leukocyte count needs to be performed. Blood smear examination/manual differential leukocyte count with complete blood count …

Ethanol Diverts Early Neuronal Differentiation Trajectory Of Embryonic Stem Cells By Disrupting The Balance Of Lineage Specifiers., Rosa Sánchez-Alvarez, Saurabh Gayen, Rajanikanth Vadigepalli, Helen Anni

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Ethanol is a toxin responsible for the neurodevelopmental deficits of Fetal Alcohol Spectrum Disorders (FASD). Recent evidence suggests that ethanol modulates the protein expression of lineage specifier transcription factors Oct4 (Pou5f1) and Sox2 in early stages of mouse embryonic stem (ES) cell differentiation. We hypothesized that ethanol induced an imbalance in the expression of Oct4 and Sox2 in early differentiation, that dysregulated the expression of associated and target genes and signaling molecules and diverted cells from neuroectodermal (NE) formation.

METHODOLOGY/PRINCIPAL FINDINGS: We showed modulation by ethanol of 33 genes during ES cell differentiation, using high throughput microfluidic dynamic array …

The Contributions Of Hif-Target Genes To Tumor Growth In Rcc., Ting Zhang, Xiaohua Niu, Lili Liao, Eun-Ah Cho, Haifeng Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Somatic mutations or loss of expression of tumor suppressor VHL happen in the vast majority of clear cell Renal Cell Carcinoma, and it's causal for kidney cancer development. Without VHL, constitutively active transcription factor HIF is strongly oncogenic and is essential for tumor growth. However, the contribution of individual HIF-responsive genes to tumor growth is not well understood. In this study we examined the contribution of important HIF-responsive genes such as VEGF, CCND1, ANGPTL4, EGLN3, ENO2, GLUT1 and IGFBP3 to tumor growth in a xenograft model using immune-compromised nude mice. We found that the suppression of VEGF or CCND1 impaired …

Rhob Controls Coordination Of Adult Angiogenesis And Lymphangiogenesis Following Injury By Regulating Vezf1-Mediated Transcription., Damien Gerald, Irit Adini, Sharon Shechter, Carole Perruzzi, Joseph Varnau, Benjamin Hopkins, Shiva Kazerounian, Peter Kurschat, Stephanie Blachon, Santosh Khedkar, Mandrita Bagchi, David Sherris, George C Prendergast, Michael Klagsbrun, Heidi Stuhlmann, Alan C Rigby, Janice A Nagy, Laura E Benjamin

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mechanisms governing the distinct temporal dynamics that characterize post-natal angiogenesis and lymphangiogenesis elicited by cutaneous wounds and inflammation remain unclear. RhoB, a stress-induced small GTPase, modulates cellular responses to growth factors, genotoxic stress and neoplastic transformation. Here we show, using RhoB null mice, that loss of RhoB decreases pathological angiogenesis in the ischaemic retina and reduces angiogenesis in response to cutaneous wounding, but enhances lymphangiogenesis following both dermal wounding and inflammatory challenge. We link these unique and opposing roles of RhoB in blood versus lymphatic vasculatures to the RhoB-mediated differential regulation of sprouting and proliferation in primary human blood versus …