bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genesis of antibiotic resistance VIII: monitoring of non‐therapeutic use of antibiotics in biomedical, agricultural ‐ livestock and pharmaceutical research and development process (986.8)
Authors: Kannan Subburaj , Lehler Raul , Miller Monica , Subburaj Prabavathy 
Published: June 2021

A systematic approach has been taken to demonstrate that the unregulated antibiotic use in the R&D is a potential cause for concern in regards to the genesis of Antibiotic Resistance in bacterial pathogens leading to a causing difficulty in treating infectious diseases. Research and development activities are funded either by private foundations or through federal agencies such as National Science Foundation, National Institutes of Health (NIH), Centers for Disease Controls and various other organizations. Federal funding from the NIH require strict has guidelines be met for use and disposal of the reagents originating from recombinant DNA technology including antibiotic resistant gene encompassing plasmids and transgenic plant and animal models. Procurement of antibiotics from commercial vendors such as Sigma‐Aldrich for R&D activities is easy to acquire. Use of antibiotics in lab experiments as well as storage and disposal of unused antibiotics is at the discretion of the lab personal such as lab technicians, undergraduate, and graduate students as well as research fellows who are shuffled around with limited supervision including abrupt termination. The quantity of antibiotics used in the R&D to date is unknown by any standards of Governmental or Non‐Governmental regulation. With a menacing uncertainty of the quantity of antibiotics used in R&D, the disposal of unused medications and the wastes produced which are considered as Non‐Biohazard is poignant in a regular waste disposal.Grant Funding Source: Prefessional Developement Funds from SWTJC, Eagle Pass, texas
Understanding mechanisms of multidrug resistance with guidance from evolution (994.2)
Authors: Gokirmak Tufan , Campanale Joseph , Shipp Lauren , Moy Gary , Hamdoun Amro 
Published: June 2021

Cancer accounts annually for over half a million deaths in the U.S. and 7.6 million deaths worldwide. Although effective chemotherapeutics are available for different types of cancers, multidrug resistance (MDR), mediated by ATP‐binding cassette (ABC) transporters, is responsible for the failure of chemotherapy in most metastatic cancers. Active transport of drugs out of tumor cells by efflux transporters: ABCB1, ABCC1, ABCC2, and ABCG2 (a.k.a., P‐gp, MRP1, and BCRP), is the major mechanism of acquired MDR in cancer. MDR transporters have promiscuous substrate recognition, which makes the design of chemotherapeutic drugs a challenging task. Because high‐resolution crystal structures are not available for every clinically important MDR transporter, comparative mutagenesis is a useful method to understand drug‐transporter interactions. In this study, we adopt a comparative transporter efflux assay approach to define the structural features that mediate the conserved promiscuous substrate recognition using MDR transporter homologs from a basal deuterostome, the purple sea urchin (Strongylocentrotus purpuratus). Despite the vast evolutionary distance, we found that sea urchin MDR transporters have conserved efflux activities for canonical substrates of their closest human homologs. We also found that relatively a few changes in the drug binding pocket could fine‐tune substrate specificity through evolution without destroying the broader pattern of substrate selectivity. Our current efforts focus on determining the conserved residues in the drug‐binding pockets between sea urchin and human MDR transporters and testing their role in canonical substrate efflux by site‐directed mutagenesis. Identification of the critical residues involved in the promiscuous efflux function will broaden our knowledge of how substrate‐transporter interactions occur, and help in the design of better drugs that can traverse the plasma membrane without being recognized by MDR transporters.Grant Funding Source: Supported by NIH and University of California, Cancer Research Coordinating Committee
Ferroportin deficiency impairs manganese metabolism in flatiron mice (995.1)
Authors: Seo Young , Wessling‐Resnick Marianne 
Published: June 2021

Mn homeostasis must guard against neurotoxic effects of excess metal while providing a sufficient source for growth and development. Mn is absorbed from the diet by the intestine, while excess metal is excreted into bile by the liver. In vitro evidence suggests that ferroportin (Fpn), a known Fe exporter, can also export Mn. Here we examine the physiological role for Fpn in Mn metabolism using flatiron mice, a genetic model of Fpn deficiency. Flatiron mice harbor a missense mutation (H32R) affecting Fpn localization and iron export activity. These mice fully recapitulate the human iron loading disorder “ferroportin disease”. Compared to littermate wild‐type controls, Mn levels in flatiron mice are reduced in liver by 10% and in blood by 13% (P < 0.05). Using MnSOD activity as a biomarker, Mn deficiency appears as early as 6 weeks of age in flatiron mice. Pharmacokinetic studies show that intestinal 54Mn absorption is reduced in flatiron mice by 60% (P < 0.05). The sum of evidence indicates that Mn deficiency develops in flatiron mice due to reduced intestinal absorption implicating a role for Fpn in this process. Notably, flatiron mice also have 51% less Mn in bile compared to controls (P < 0.05). These data suggest that Fpn plays a key role in Mn homeostasis.Grant Funding Source: Research supported by NIH R01ES014638.
Specific nonlipid agonists of the lysophosphatidic acid type 2 GPCR with subnanomolar potency mitigate radiation injury (998.2)
Authors: Szabo Erzsebet , Patil Renukadevi , Fells James , Norman Derek , Balogh Andrea , Miller Duane , Tigyi Gabor 
Published: June 2021

Previous studies have identified ligands of the LPA2 GPCR as mitigators of high‐dose radiation injury in vitro and in vivo. These early hit compounds originating from the hit scaffold GRI977143 had EC50 values in the hundred nanomolar range. Lead optimization guided by a validated computational model of the LPA2 GPCR led us to explore the structure‐activity relationship of a group of aromatic sulfonamides. The apparent EC50 value for oleoyl lysophosphatidic acid (LPA 18:1) at LPA2 is 1.4 nM. Synthetic modifications of the aromatic sulfonamide scaffold led to the synthesis of compounds RP 10‐73 and 10‐83, which have subnanomolar potency at LPA2. The EC50 value of ligand activated Ca2+ transient in LPA2 reconstituted mouse embryonic fibroblasts derived from LPA1&amp;2 double knockout mice was 0.15 ± 0.02 nM and 6 ± 3.9 pM for RP 10‐73 and 10‐83, respectively. These two nonlipid compounds lack agonist or antagonist activity at other LPA GPCR up to 10 µM when tested for eliciting or inhibiting ligand‐activated Ca2+ responses. RP 10‐73 and 10‐83 rescued cells from apoptosis induced by ionizing radiation or by the radiomimetic chemotherapeutic agent Adriamycin. The protective effect was not detectable in cells lacking the LPA2 receptor subtype indicating that the antiapoptotic effect requires functional LPA2 receptors in the target cell. The pharmacological properties of RP 10‐73 and 10‐83 make them ideal drug candidates for the specific activation of LPA2 in various disease conditions.Grant Funding Source: Supported by NIAID AI‐107331
Second Verse, Same as the First? Structures of Thioredoxin Proteins TrxA and TrxC from Mycobacterium tuberculosis (LB103)
Authors: Junior Amari , Rios Llamosa Brigitte , Richmond Anthony , Rios Llamosa Jhordy , Osademe Isioma , Cobb Michaun , Camacho Alexis , Gonzalez Cruz Jose , Johnson Carol , Neumann Terrence 
Published: June 2021

Mycobacterium tuberculosis, the causative agent for tuberculosis (TB), infected 8.6 million and killed 1.3 million people in 2012 (WHO). TB is most prevalent in countries with a high incidence of infectious diseases, such as HIV, due to weakened immune systems. TB mainly affects the lungs, but can also affect other systems. When a host organism is infected wtih TB, the Mycobacteria in the lungs multiply, often resulting in pneumonia, chest pain, and prolonged coughing. In response, host macrophages, a part of the natural immune system, engulf the Mycobacteria and oxidize bacterial cell proteins in an attempt to destroy it. To protect itself against this attack, the bacterial thioreductase system, consisting of the redox protein thioredoxin reductase (TrxR) and the thioredoxin proteins TrxA, TrxB, and TrxC, gives electrons back to the oxidized proteins. As this system works to maintain cellular redox homeostasis, finding ways to stop it might provide a new method for treating people with TB. TrxA and TrxC have similar structures, thus it can be hypothesized that their functions are similar. Comparing binding sites between the proteins can provide insight if TrxA can react with TrxR similarly to TrxC. By modeling TrxA and TrxC with 3D printing technology, the Messmer SMART Team (Students Modeling A Research Topic) can compare the structures of the thioredoxins which may lead to new strategies for curing or preventing TB.Grant Funding Source: Supported by a grant from NIH‐CTSA.
Incidence and Structural Variety of the Anterior Lateral Ligament of the Knee Joint (LB12)
Authors: Alimohammadi Majid 
Published: June 2021

The overall objective of this study is to show the incidence of presence of this ligament and its structural variations in both genders. I began to search for this ligament using 34 embalmed cadavers (14 females and 20 males) in December 2013.Each specimen was carefully dissected and photographed. Based on the findings in this study, the “ALL ligament” was present in 64% (9) of female and 85% (17) of male specimens.From structural point of view, in 46% (12) of cases with the “ALL ligament”, this ligament was in the form of a flat band arising from the lateral collateral ligament of the knee and gradually blending with the capsule of the knee joint above the Gerdy’s tubercle. In the remaining cases (14 = 54%) the “ALL ligament” could be followed down to the tibia close to the Gerdy’s tubercle. In this second group, the “ALL ligament” always had some attachments to the anterior end of the body of the lateral meniscus.
The B. subtilis accessory helicase PcrA facilitates replication through transcription units genome‐wide (LB126)
Authors: Merrikh Christopher , Merrikh Houra 
Published: June 2021

In bacteria, transcription and DNA replication occur concurrently, inevitably causing replication‐transcription conflicts. Conflicts can occur both co‐directionally (leading strand genes) and head‐on (lagging strand genes), leading to replisome stalling and restart. Because the majority of genes are co‐oriented with replication in most bacteria, co‐directional conflicts are expected to be highly prevalent, impacting replication speed and genomic stability. Consequently, mechanisms that deal with these conflicts should be critical for the timely and accurate duplication of genomes. Here we report that the essential Bacillus subtilis accessory helicase, PcrA, mitigates both co‐directional and head‐on conflicts between the replication and transcription machineries. Using ChIP‐seq, we have identified genomic regions where PcrA associates and facilitates replication progression. We find that PcrA predominantly associates with co‐directional rDNA and tRNA genes, in a transcription‐dependent manner. When PcrA is depleted, and only when transcription is active, replisome stalling and restart increases in the same areas. PcrA also reduces transcription‐induced replication stalling and restart at other regions, including some head‐on genes. Differential levels of PcrA at engineered head‐on and co‐directional conflicts indicate that its association and activity correlate with conflict severity, rather than transcription levels. These results show that PcrA reduces replisomes stalling, and restart, caused by head‐on and co‐directional replication‐transcription conflicts. Furthermore, these data indicate that during vegetative growth, and in the absence of exogenous stress, the most difficult regions to replicate are co‐directionally transcribed genes. Both the genome co‐orientation bias and these accessory helicases are widely conserved, suggesting that our results are relevant for many other bacterial species.Grant Funding Source: NIH
Mitochondrial quality control and autophagosomal process in Parkinson’s disease model (LB170)
Authors: Sung Hyun , Hollenbeck Peter 
Published: June 2021

Parkinson’s disease (PD) is the second most common neurodegenerative disorder, and can be caused by genetic mutations of PTEN‐induced putative kinase 1 (PINK1) and the E3 ubiquitin ligase, Parkin. It has been proposed that Parkin contributes to policing mitochondrial fidelity by binding to dysfunctional mitochondria via PINK1 and targeting them for autophagic degradation. However, the actual role of PINK1/Parkin in controlling autophagy is unknown. To define more clearly the roles of Parkin in neurons, we quantified the behavior of mitochondria and autophagosomes in motor neurons of live Drosophila melanogaster larvae by time lapse microscopy. We analyzed the life cycle of mitochondria in Parkin mutant animals expressing mitochondrially‐targeted GFP by three distinct criteria: mitochondrial axonal transport, mitochondrial fission‐fusion and mitophagy. Autophagosomal processes were analyzed by studying autophagosomal movement and density via expressed RFP‐atg8. In motor axons, parkin mutants showed reduced flux of both anterograde and retrograde mitochondria and an increase in pause time compared to controls. However, these mutants did not show significant differences in mitochondrial velocities. Morphological measurements from parkin mutants showed that normal fission‐fusion balance was preserved in the axons of segmental nerves, while tubular and hyper‐fused mitochondria were found in the cell bodies. In addition, we did not observe a correlation between mitochondrial length and velocity or direction of axonal movement in parkin mutants. To understand the organization of mitophagy, we quantified mitochondrial density and found that parkin mutants displayed a significantly reduced mitochondrial density in motor axons. Analysis of autophagic vacuoles in parkin mutants showed reduced retrograde axonal flux and reduced density in the motor cell bodies. These results suggest that the differences in axonal mitochondrial flux in disease mutants result from the combined effects of altered mitochondrial motility and density in motor axons. Additionally, Parkin perturbation may disrupt autophagosomal retrograde transport in axons and affect mitochondrial morphology in motor cell bodies.Grant Funding Source: Supported by grant, 5 R01 NS027073 from National Institutes of Health/NINDS
Histological changes in the structure of lateral and medial menisci following the destabilization of the knee in a rat model (LB18)
Authors: Riccardi Margaret , Fraticelli Nicole , Jordan Rebecca , Boehm Karl , Ginsberg Zachary , Marberry Kevin , Kondrashov Peter 
Published: June 2021

Three month‐old rats underwent destabilization of the medial meniscus (DMM) surgery, to replicate meniscal damage, or sham surgery as a control, and were sacrificed 8 weeks later. Knees were fixed in formalin, decalcified, embedded in paraffin, and sectioned coronally at 12 µm. Sections were stained with hematoxylin and eosin and scored by 2 investigators using point counting with a grid probe. Based on existing data, each square was scored as one of the 4 tissue types normally present in the meniscus: dense connective tissue, fibrocartilage, hyaline cartilage, or bone. Percentages of these tissue types were used to quantify the histological composition of the menisci.Preliminary data on the histological composition of the lateral and medial menisci showed a significant difference between the two. In the control group, the lateral meniscus contained significantly more hyaline cartilage than the medial. In the DMM group, the lateral meniscus contained more bone and hyaline cartilage than the medial. The comparison of the histological composition of the menisci between the DMM and control groups revealed a statistically significant increase in the percentage of bone in the lateral meniscus in the DMM group.The changes in the architecture of the knee following the destabilization of the medial meniscus in the rat model resulted in the increased ossification of the lateral meniscus compared to the control.
Comparative analysis of cancer driver genes between human and six non‐human primates (LB182)
Authors: Lopez Darryl , Montague Michael , Warren Wesley 
Published: June 2021

Cancer incidences among non‐human primates compared to humans are very low, however the causative factors are unknown. The difference could be derived from a combination of immunity, environmental factors, longer life expectancy in humans, and genetic variation. Detailed genome sequences for human and six other non‐human primates (Pan troglodytes, Gorilla gorilla, Pongo abelii, Callithrix jacchus, Macaca mulatta, and Otolemur garnettii) make it possible to assess whether genetic differences contribute to cancer susceptibility. We obtained a list of high‐confidence driver genes common to tumors from twelve different cancer types and examined a subset of these across non‐human primate orthologs. Empirical Bayes methods were used to test for adaptive evolution by examining the rate of non‐synonymous substitutions, and a number of genes contained amino acid sites with evidence for positive selection along the human lineage. We suggest that some of the driver genes in human common to various cancer types have a higher variability compared to non‐human primates, and that further examination of these genes is warranted.Grant Funding Source: HG00668702
Creating a comparative map of the facial nerve: A cadaveric study (LB19)
Authors: Jenkinson Ashley , Nusse Gloria 
Published: June 2021

This study will explore the facial nerve through detailed dissection of the left and right sides of a male and female cadaver with respect to major facial landmarks. A map will be created using qualitative analysis in order to compare the position and variability of the nerve branches. A photo expose will demonstrate the dissections and the comparative map in order to gain a better appreciation for the location, functionality, and importance of the nerve.The facial nerve (CNVII), controls the muscles involved in facial expression, aids in the perception of taste and is involved in the production of tears. The facial nerve is composed of 10,000 neurons, 7,000 of which are directly involved in the expression of emotion. CNVII exits the skull through the stylomastoid foramen and from there, branches into five distinct rami under the parotid gland. The frontal branch controls the movement and expression of the forehead. The zygomatic branch is involved in ear movement. The buccal branch controls the movement of the upper lip, nostril, and corner of the mouth. The marginal mandibular branch is involved in depression of the lower lip and chin. And finally, the cervical branch controls the chin muscles and superficial neck muscles.Grant Funding Source: none
Novel variations in the anatomical relationship between the piriformis muscle and sciatic nerve: a cadaveric study (LB2)
Authors: Harrell Kelly 
Published: June 2021

The goal of this study is to assess variations in the anatomical relationship between the piriformis muscle and sciatic nerve in a cadaveric population. Currently, Beaton and Anson’s 1937 classification of piriformis‐sciatic arrangements is widely accepted and used for clinical evaluation and diagnosis of Piriformis Syndrome—a dynamic sciatic nerve impingement by the piriformis muscle. This study (n=164 limbs) revealed two clinically important differences to Beaton and Anson’s original findings. First, the Type “B” classification was observed in 18.3% of the cases, representing a 63.9% increase from Beaton and Anson’s original report. Additionally, two Type “B” subsets with potential clinical consequences were observed. Type “B2” included a vascular component, wherein the inferior gluteal artery and vein coursed between the common fibular and tibial divisions of the sciatic nerve (4.3% of total cases). Type “B3” included an additional nerve component, wherein the inferior gluteal nerve coursed between the piriformis muscle and adjacent to the common fibular division, to reach the gluteus maximus muscle (1.0% of total cases). Collectively, these observations expand the current classification of piriformis‐sciatic arrangement, and carry clinical significance for the evaluation and treatment of Piriformis Syndrome.Grant Funding Source: n/a
Structural biology of heteromeric class B G protein‐coupled receptors (LB216)
Authors: Moad Heather , Pioszak Augen 
Published: June 2021

The calcitonin family peptides calcitonin (CT), amylin (AMY), calcitonin gene‐related peptide (CGRP), and adrenomedullin (AM) regulate diverse processes including calcium homeostasis, blood glucose levels, vasodilation, and vascular development. Their receptors are heteromeric cell surface protein complexes comprised of a class B GPCR subunit, either the calcitonin receptor (CTR) or the calcitonin‐like receptor (CLR), in association with a peptide selectivity‐determining receptor activity modifying protein (RAMP) subunit. CTR alone is the CT receptor and CTR complexes with any of three RAMPs are AMY receptors. The CLR‐RAMP1 complex is a CGRP receptor, whereas CLR complexes with either RAMP2 or ‐3 are AM receptors. How RAMPs determine calcitonin family peptide selectivity is unclear and the receptor stoichiometries are a topic of debate. Here, we report unique methods for bacterial production of recombinant CLR‐RAMP extracellular domain (ECD) complexes engineered for structure/function studies and use of the novel constructs for peptide binding studies and crystallization. In addition, we describe recombinant CTR ECD production in HEK293T cells, and production of the integral membrane portions of the receptors in the E. coli inner membrane for structure/function studies. Our results indicate that the CTR and CLR ECDs are sufficient to determine peptide binding selectivity, identify peptide residues critical for receptor binding, shed light on the receptor stoichiometries, and provide methods that will facilitate structural studies of these therapeutically important GPCRs.Grant Funding Source: Supported by NIH grant R01GM104251
TLR4 in monocytes plays a pivotal role on monocyte adhesion to vascular endothelium (LB226)
Authors: Lee Seung‐Jin , Seo Kyo‐Won , Bae Jin‐Ung , Kim Chi Dae 
Published: June 2021

Toll‐like receptor 4 (TLR4) is known to mediate monocyte adhesion to endothelial cells via an increased expression of adhesion molecules on endothelial cells (EC), however, its role on the expression of monocyte adhesion molecules is unclear. In the present study, we investigated the role of TLR4 on the expression of monocyte adhesion molecules, and determined the functional role of TLR4‐induced adhesion molecules on monocyte adhesion to vascular endothelium. When THP‐1 monocytes were stimulated with Kdo2‐Lipid A (KLA), a specific TLR4 agonist, Mac‐1 expression was markedly increased in association with an increased adhesion of monocytes to EC. These were attenuated by anti‐Mac‐1 antibody, suggesting a functional role of TLR4‐induced Mac‐1 on monocyte adhesion on EC. In monocytes treated with MK886, a 5‐lipoxygenase (LO) inhibitor, both Mac‐1 expression and monocyte adhesion to EC induced by KLA were markedly attenuated. Moreover, KLA increased the expression of mRNA and protein of 5‐LO, suggesting a pivotal role of 5‐LO on these processes. In in vivo studies, KLA increased monocyte adhesion to aortic endothelium of wild‐type (WT) mice, which was attenuated in WT mice treated with anti‐Mac‐1 antibody as well as in TLR4‐deficient mice. Taken together, TLR4‐mediated expression of Mac‐1 in monocytes plays a pivotal role on monocyte adhesion to vascular endothelium, leading to increased foam cell formation in the development of atherosclerosis.Grant Funding Source: None