Organisms | Open Access Articles | Digital Commons Network™

How Megadrought Causes Extensive Mortality In A Deep-Rooted Shrub Species Normally Resistant To Drought-Induced Dieback: The Role Of A Biotic Mortality Agent, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Gabriella N. Palmeri, Emily R. Lancaster, Gina S. Gilderman, Shaquetta R. Taylor, Kaitlyn E. Sauer, Adriana J. Borges, Avery N.D. Lamb, Sarah B. Jacques, Frank W. Ewers, Stephen D. Davis

School of Medicine Faculty Publications

Southern California experienced unprecedented megadrought between 2012 and 2018. During this time, Malosma laurina, a chaparral species normally resilient to single-year intense drought, developed extensive mortality exceeding 60% throughout low-elevation coastal populations of the Santa Monica Mountains. We assessed the physiological mechanisms by which the advent of megadrought predisposed M. laurina to extensive shoot dieback and whole-plant death. We found that hydraulic conductance of stem xylem (Ks, native) was reduced seven to 11-fold in dieback adult and resprout branches, respectively. Staining of stem xylem vessels revealed that dieback plants experienced 68% solid-blockage, explaining the reduction in water transport. Following Koch's …

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Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen

School of Dentistry Faculty Publications

Locus SMU.243 in Streptococcus mutans was annotated as a member of the DUF2207 family proteins highly conserved in all bacteria but with unknown function. To investigate its role in S. mutans physiology, a SMU.243-deficient mutant was constructed using allelic exchange mutagenesis, and the impacts of SMU.243 deletion on bacterial growth, stress tolerance response, and biofilm formation were analyzed. Compared to the wild-type UA159, S. mutans lacking SMU.243 displayed a reduced growth rate and a reduced overnight culture density (p < 0.01) when grown at low pH and in the presence of methyl viologen. Relative to the parent strain, the deficient mutant also had a reduced survival rate following incubation in a buffer of pH 2.8 (p < 0.01) and in a buffer containing hydrogen peroxide at 58 mM after 60 min (p < 0.001) and had a reduced capacity in biofilm formation especially in the presence of sucrose (p < 0.01). To study any ensuing functional/phenotypical links between SMU.243 and uppP, which is located immediately downstream of SMU.243 and encodes an undecaprenyl pyrophosphate phosphatase involved in recycling of carrier lipid undecaprenyl phosphate, a uppP deficient mutant was generated using allelic exchange mutagenesis. Unlike the SMU.243 mutant, deletion of uppP affected cell envelope biogenesis and caused major increases in susceptibility to bacitracin. In addition, two variant morphological mutants, one forming rough colonies and the other forming mucoid, smooth colonies, also emerged following the deletion of uppP. The results suggest that the SMU.243-encoded protein of the DUF2207 family in S. mutans plays an important role in stress tolerance response and biofilm formation, but unlike the downstream uppP, does not seem to be involved in cell envelope biogenesis, although the exact roles in S. mutans’ physiology awaits further investigation.

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Outpatient Sexually Transmitted Infection Testing And Treatment Patterns In The United States: A Real-World Database Study, Rebecca Lillis, Louis Kuritzky, Zune Huynh, Rodney Arcenas, Avneet Hansra, Roma Shah, Baiyu Yang, Stephanie N. Taylor

School of Medicine Faculty Publications

Background: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the most common notifiable sexually transmitted infections (STIs) in the United States. Because symptoms of these infections often overlap with other urogenital infections, misdiagnosis and incorrect treatment can occur unless appropriate STI diagnostic testing is performed in clinical settings. The objective of this study was to describe STI diagnostic testing and antimicrobial treatment patterns and trends among adolescent and adult men and women with lower genitourinary tract symptoms (LGUTS). Methods: We analyzed insurance claims data from the IBM® MarketScan® Research Databases. Patients included were between 14 and 64 years old with …

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Time Is Ticking For Cervical Cancer, Vijay Kumar, Caitlin Bauer, John H. Stewart

School of Medicine Faculty Publications

Cervical cancer (CC) is a major health problem among reproductive-age females and comprises a leading cause of cancer-related deaths. Human papillomavirus (HPV) is the major risk factor associated with CC incidence. However, lifestyle is also a critical factor in CC pathogenesis. Despite HPV vaccination introduction, the incidence of CC is increasing worldwide. Therefore, it becomes critical to understand the CC tumor immune microenvironment (TIME) to develop immune cell-based vaccination and immunotherapeutic approaches. The current article discusses the immune environment in the normal cervix of adult females and its role in HPV infection. The subsequent sections discuss the alteration of different …

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Mirnas Signature As Potential Biomarkers For Cervical Precancerous Lesions In Human Papillomavirus Positive Women, Martha I. González-Ramírez, Yurley T. Cardona, María C. Agudelo, Carolina López, Juan J. Florez-Acosta, Samuel Agudelo-Gamboa, Jone Garai, Li Li, Carlos A. Orozco-Castaño, Jovanny Zabaleta, Gloria I. Sánchez

School of Medicine Faculty Publications

Biomarkers to identify women at risk of cervical cancer among those with high-risk HPV infection (hrHPV+) are needed. Deregulated expression of microRNAs (miRNAs) contributes to hrHPV-induced cervical carcinogenesis. We aimed at identifying miRNAs with the capacity to distinguish high (CIN2+) and low (≤ CIN1) grade cervical lesions. We sequenced miRNA libraries from Formalin-Fixed Paraffin-Embedded (FFPE) tissues from women with CIN2+ (n = 10) and age-matched women with ≤ CIN1 (n = 10), randomly and retrospectively selected from a trial that followed women for 24 months after a hrHPV+ test at the screening visit. Five miRNAs differentially expressed were validated by …

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Echinomycin As A Promising Therapeutic Agent Against Kshv-Related Malignancies, Jungang Chen, Zhen Lin, Jiao Song, Karlie Plaisance-Bonstaff, Jennifer James, Shengyu Mu, Steven R. Post, Lu Dai, Zhiqiang Qin

School of Medicine Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of several human cancers, including Kaposi’s sarcoma (KS) and primary effusion lymphoma (PEL), which preferentially arise in immunocompromised patients while lack of effective therapeutic options. Oncoproteins Myc and hypoxia-inducible factor-1α (HIF1α) have been found closely related to KSHV infection, replication and oncogenesis. However, the strategies of dual targeting these two oncoproteins have never been developed and tested for treatments of KSHV-related malignancies. In the current study, we report that treatment of echinomycin dramatically regresses cell growth both in vitro-cultured KSHV + tumor cells and in vivo KS or PEL xenograft mice models, …

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Independent Effects Of Hiv And Antiretroviral Therapy On The Oral Microbiome Identified By Multivariate Analyses, Clifford J. Beall, Elizabeth A. Lilly, Carolina Granada, Kelly Treas, Kenneth R. Dubois, Shahr B. Hashmi, Jose A. Vazquez, Michael E. Hagensee, Ann L. Griffen, Eugene J. Leys, Paul L. Fidel

School of Dentistry Faculty Publications

The oral microbiome is an important predictor of health and disease. We recently reported significant yet modest effects of HIV under highly active antiretroviral therapy (ART) on the oral microbiome (bacterial and fungal) in a large cohort of HIV-positive (HIV+) and matched HIV-negative (HIV-) individuals. As it was unclear whether ART added to or masked further effects of HIV on the oral microbiome, the present study aimed to analyze the effects of HIV and ART independently, which also included HIV- subjects on preexposure prophylaxis (PrEP) therapy. Cross-sectional analyses of the effect of HIV devoid of ART (HIV+ ART- versus matched …

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Moerv14 Mediates The Intracellular Transport Of Cell Membrane Receptors To Govern The Appressorial Formation And Pathogenicity Of Magnaporthe Oryzae, Bin Qian, Xiaotong Su, Ziyuan Ye, Xinyu Liu, Muxing Liu, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Graduate Studies Faculty Publications

Magnaporthe oryzae causes rice blasts posing serious threats to food security worldwide. During infection, M. oryzae utilizes several transmembrane receptor proteins that sense cell surface cues to induce highly specialized infectious structures called appressoria. However, little is known about the mechanisms of intracellular receptor tracking and their function. Here, we described that disrupting the coat protein complex II (COPII) cargo protein MoErv14 severely affects appressorium formation and pathogenicity as the ΔMoerv14 mutant is defective not only in cAMP production but also in the phosphorylation of the mitogen-activated protein kinase (MAPK) MoPmk1. Studies also showed that either externally supplementing cAMP or …

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Decoupling Body Shape And Mass Distribution In Birds And Their Dinosaurian Ancestors, Sophie Macaulay, Tatjana Hoehfurtner, Samuel R.R. Cross, Ryan D. Marek, John R. Hutchinson, Emma R. Schachner, Alice E. Maher, Karl T. Bates

School of Medicine Faculty Publications

It is accepted that non-avian theropod dinosaurs, with their long muscular tails and small forelimbs, had a centre-of-mass close to the hip, while extant birds, with their reduced tails and enlarged wings have their mass centred more cranially. Transition between these states is considered crucial to two key innovations in the avian locomotor system: crouched bipedalism and powered flight. Here we use image-based models to challenge this dichotomy. Rather than a phylogenetic distinction between ‘dinosaurian’ and ‘avian’ conditions, we find terrestrial versus volant taxa occupy distinct regions of centre-of-mass morphospace consistent with the disparate demands of terrestrial bipedalism and flight. …

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Endogenous Mirna-Based Innate-Immunity Against Sars-Cov-2 Invasion Of The Brain, Walter J. Lukiw, Aileen I. Pogue

School of Medicine Faculty Publications

The severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, possesses an unusually large positive-sense, single-stranded viral RNA (ssvRNA) genome of about ~29,903 nucleotides (nt). In many respects, this ssvRNA resembles a very large, polycistronic messenger RNA (mRNA) possessing a 5′-methyl cap (m7GpppN), a 3′- and 5′-untranslated region (3′-UTR, 5′-UTR), and a poly-adenylated (poly-A+) tail. As such, the SARS-CoV-2 ssvRNA is susceptible to targeting by small non-coding RNA (sncRNA) and/or microRNA (miRNA), as well as neutralization and/or inhibition of its infectivity via the human body’s natural complement of about ~2650 miRNA species. Depending on host cell and tissue …

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Implementation Of Mrsa Nasal Swabs As An Antimicrobial Stewardship Intervention To Decrease Anti-Mrsa Therapy In Covid-19 Infection, Alaina Dekerlegand, Emily Johnston, Britney Mellor, Melanie Rae Schrack, Catherine O’Neal

School of Medicine Faculty Publications

In the early stages of treating patients with SARS-CoV-2, limited information was available to guide antimicrobial stewardship interventions. The COVID-19 Task Force and Antimicrobial Stewardship Committee, at a 988-bed academic medical center, implemented the use of methicillin-resistant Staphylococcus aureus (MRSA) nasal swab polymerase chain reaction (PCR) testing to assist with the de-escalation of anti-MRSA therapy in patients with suspected superimposed bacterial pneumonia in COVID-19. A retrospective study was conducted to evaluate the impact of MRSA nasal swab PCR testing on the rate of anti-MRSA therapy between 13 April 2020 and 26 July 2020. A total of 122 patients were included …

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Impact Of Alcohol On Bone Health In People Living With Hiv: Integrating Clinical Data From Serum Bone Markers With Morphometric Analysis In A Non-Human Primate Model, Alexandra Denys, Allison Norman, Daniel S. Perrien, Larry J. Suva, Liz Simon, Lee S. Mcdaniel, Tekeda Ferguson, Kim Pedersen, David Welsh, Patricia E. Molina, Martin J.J. Ronis

School of Medicine Faculty Publications

People living with HIV (PLWH) represent a vulnerable population to adverse musculoskeletal outcomes due to HIV infection, antiretroviral therapy (ART), and at-risk alcohol use. Developing measures to prevent skeletal degeneration in this group requires a grasp of the relationship between alcohol use and low bone mass in both the PLWH population and its constituents as defined by sex, age, and race. We examined the association of alcohol use with serum biochemical markers of bone health in a diverse cohort of PLWH enrolled in the New Orleans Alcohol Use in HIV (NOAH) study. To explore the effects of alcohol on bone …

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Solid-State Nmr Analysis Of Unlabeled Fungal Cell Walls From Aspergillus And Candida Species, Liyanage D. Fernando, Malitha C. Dickwella Widanage, S. Chandra Shekar, Frederic Mentink-Vigier, Ping Wang, Sungsool Wi, Tuo Wang

School of Medicine Faculty Publications

Fungal infections cause high mortality in immunocompromised individuals, which has emerged as a significant threat to human health. The efforts devoted to the development of antifungal agents targeting the cell wall polysaccharides have been hindered by our incomplete picture of the assembly and remodeling of fungal cell walls. High-resolution solid-state nuclear magnetic resonance (ss NMR) studies have substantially revised our understanding of the polymorphic structure of polysaccharides and the nanoscale organization of cell walls in Aspergillus fumigatus and multiple other fungi. However, this approach requires 13C/15N-enrichment of the sample being studied, severely restricting its application. Here we employ the dynamic …

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Full-Text Articles in Organisms

School of Medicine Faculty Publications

Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen

School of Dentistry Faculty Publications

Outpatient Sexually Transmitted Infection Testing And Treatment Patterns In The United States: A Real-World Database Study, Rebecca Lillis, Louis Kuritzky, Zune Huynh, Rodney Arcenas, Avneet Hansra, Roma Shah, Baiyu Yang, Stephanie N. Taylor

School of Medicine Faculty Publications

Time Is Ticking For Cervical Cancer, Vijay Kumar, Caitlin Bauer, John H. Stewart

School of Medicine Faculty Publications

School of Medicine Faculty Publications

Echinomycin As A Promising Therapeutic Agent Against Kshv-Related Malignancies, Jungang Chen, Zhen Lin, Jiao Song, Karlie Plaisance-Bonstaff, Jennifer James, Shengyu Mu, Steven R. Post, Lu Dai, Zhiqiang Qin

School of Medicine Faculty Publications

School of Dentistry Faculty Publications

Moerv14 Mediates The Intracellular Transport Of Cell Membrane Receptors To Govern The Appressorial Formation And Pathogenicity Of Magnaporthe Oryzae, Bin Qian, Xiaotong Su, Ziyuan Ye, Xinyu Liu, Muxing Liu, Haifeng Zhang, Ping Wang, Zhengguang Zhang

School of Graduate Studies Faculty Publications

Decoupling Body Shape And Mass Distribution In Birds And Their Dinosaurian Ancestors, Sophie Macaulay, Tatjana Hoehfurtner, Samuel R.R. Cross, Ryan D. Marek, John R. Hutchinson, Emma R. Schachner, Alice E. Maher, Karl T. Bates

School of Medicine Faculty Publications

Endogenous Mirna-Based Innate-Immunity Against Sars-Cov-2 Invasion Of The Brain, Walter J. Lukiw, Aileen I. Pogue

School of Medicine Faculty Publications

Implementation Of Mrsa Nasal Swabs As An Antimicrobial Stewardship Intervention To Decrease Anti-Mrsa Therapy In Covid-19 Infection, Alaina Dekerlegand, Emily Johnston, Britney Mellor, Melanie Rae Schrack, Catherine O’Neal

School of Medicine Faculty Publications

School of Medicine Faculty Publications

Solid-State Nmr Analysis Of Unlabeled Fungal Cell Walls From Aspergillus And Candida Species, Liyanage D. Fernando, Malitha C. Dickwella Widanage, S. Chandra Shekar, Frederic Mentink-Vigier, Ping Wang, Sungsool Wi, Tuo Wang

School of Medicine Faculty Publications