bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of sodium‐independent Pi uptake in Caco2 cells (908.3)
Authors: Candeal Eduardo , Caldas Yupanqui , Guillén Natalia , Levi Moshe , Sorribas Victor 
Published: June 2021

While inorganic phosphate (Pi) uptake in epithelia has both Na‐dependent and Na‐independent components, only Na‐dependent transporters have been identified to date. In this work we have characterized the Na‐independent Pi uptake in the intestinal Caco2BBe cell line, as a preliminary step in the molecular identification of novel intestinal Pi transporters.Caco2BBe cells grown in DMEM were incubated overnight in the presence of 1 or 4mM Pi to mimic the intestinal adaptation to high Pi diet recently described. Only Na‐independent Pi uptake was observed in these cells, which was dramatically increased in cells preincubated with 4mM Pi. Uptake in 1mM Pi adapted cells decreased with alkaline pH, but it increased with the pH at 4mM Pi. The increase in Pi transport at 4mM Pi was completely inhibited by Pi, phosphonoformic acid and oxalate, while DIDS, SITS, SO4=, and CO3= did not. Km values were 0.06 and 0.2 mM after adaptation to 1 and 4 mM Pi, respectively.In conclusion, two different Na‐independent Pi transports are expressed in Caco2BBe cells, one of them being overexpressed when preincubated with high Pi medium. The molecular identity of the transporters are still unkown.
Determining the downstream signaling pathways through which prostaglandin E2 inhibits inflammatory mediator output in in human myometrial cells (911.6)
Authors: Levinson Hayley , Wood Stephen , Slater Donna 
Published: June 2021

Objective: Prostaglandin E2 (PGE2) represses interleukin‐1β (IL‐1β) induced inflammatory mediator output in human myometrial cells via EP2/4 receptors. Downstream EP2/4 signaling involves upregulation of intracellular cAMP which may activate multiple pathways, including protein kinase A (PKA) and exchange proteins activated by cAMP (Epacs).Methods: Myometrial biopsies from term elective Caesarean deliveries prior to labour onset (n=5, 37‐40 weeks gestation) were used to isolate myometrial cells. PKA and Epac gene expression was assessed by RT‐PCR. Myometrial cells were either non‐treated or stimulated with IL‐1β +/‐ co‐treatment with cAMP analogs to selectively activate PKAI, PKAII, or Epacs. Interleukin‐8 (CXCL8) output was measured by ELISA. Statistical analysis was performed by repeated measures ANOVA followed by a Bonferroni test.Results: Expression of both Epac isoforms and six of seven PKA subunits were identified in isolated myometrial cells. IL‐1β increased CXCL8 output in human myometrial cells (p蠄0.001). Co‐treatment with PKAI or PKAII selective cAMP analogs repressed this response (p蠄0.001). No significant repression was observed when cells were co‐treated with the Epac selective cAMP analog.Conclusions: PGE2 mediated repression of IL‐1β induced inflammatory output in human myometrial cells is mediated in part by PKA, but not Epac, signaling pathways.Grant Funding Source: Supported by Canadian Institutes of Health Research and Alberta Innovates‐Health Solutions
Histological characterization of soft‐embalmed porcine tendon and muscle (914.1)
Authors: Martyniuk Amanda , Easteal Ron , Ellis Randy 
Published: June 2021

Embalmed material is used in many fields because of its benefits over fresh materials; however, typical formalin‐fixation results in materials that are vastly different from their original state. Soft‐embalming has received recognition as a viable alternative to fresh or formalin‐fixed materials in education and research, especially in orthopedics. Soft‐embalmed tissue has mainly been characterized by gross features, with minimal investigation into the microscopic features of different types of soft‐embalmed tissues.Deep flexor muscle and tendon were harvested from porcine forelimbs. Samples were soft‐embalmed using one of three different methods: phenol‐based, phenoxyethanol‐based, and Thiel embalming. The samples were visualized using Masson’s trichrome staining immediately following embalming and three weeks later.All types of soft‐embalming displayed typical tendon structural characteristics at both time points. The staining of the tendons ranged from almost entirely blue, as would be expected, to almost entirely red, which was unexpected, depending on the treatment. All soft‐embalmed muscle samples exhibited typical colouring, but there were structural differences. At both time points, muscle of phenol‐based and phenoxyethanol‐based embalming generally exhibited normal muscle structure, while Thiel‐embalmed muscle appeared to have suffered degradation.This histological analysis is a step forward in understanding the effects of different soft‐embalming methods on different tissues, which can aid in determining their efficacy.Grant Funding Source: This research was supported in part by NSERC and CIHR
Human embryonic larynx morphogenesis: three‐dimensional and multiplanar study (918.26)
Authors: Labrouse Marc , Tonnelet Romain , Renard Yohann , Micard Emilien , Duparc Fabrice , Delmas Vincent , Braun Marc 
Published: June 2021

The purpose of this study was to describe the human larynx embryology, using three‐dimensional reconstructions from seven human embryos histological sections, and to compare our results with literature.Seven human embryos from two historic French collections (Paris‐Descartes University's Delmas‐Rouvière collection and Rouen University's Tardif collection) stained with hematoxylin &amp; eosin or Masson's trichrome were reclassified according to the Carnegie Atlas criteria (CS (Carnegie stages) 17, 18, 19, 21 and 22).A local made computer software developed by IADI lab (INSERM U947, Nancy) allowed automatic slices selection, automatic rigid registration, and dust filtering. Once registration had been completed, DICOM files were used with ORS Visual software (v1.5, Montreal), which allowed multiple display and post‐processing possibilities (3D VR; orthogonal/curved multiplanar reformation). Due to large size files, image processing was performed on PC with Windows 7 (64 bit) and 20 GB RAM.Three‐dimensional and multiplanar study of the larynx morphogenesis was possible with appropriate thresholding. In the first stages of this study, the early laryngeal aditus was visible. Two posterior elevations, the arytenoid swellings, one anterior, the epiglottis, and the vocal folds were seen in the last stages.Human embryonic larynx morphogenesis works are very rare because of the smallness of this anatomical structure. Our study, using historic human embryos histological sections has shown the larynx growth. This demonstration was completely novel and had never been published previously, to our knowledge. Indeed, our method is fully respectful towards the microscopic structure unlike methods using Amira© segmentation and triangulation process. The precise knowledge of this morphogenesis will help to better understand congenital malformations.
Phenotypic similarities and dissimilarities in a Paleoamerican sample: what are the implications in modeling the first migrations into the New World (918.4)
Authors: Alsup Kathleen 
Published: June 2021

Researchers can interpret craniometric phenotypic similarities and dissimilarities in very different ways. This can have important implications in developing theories and models used to interpret many anthropological questions. The purpose of this poster is to investigate the craniometric relationships of a Paleoamerican sample and discuss the implications of these relationships between the crania.A sample of 33 crania, with published dates of 7000 years BP or older, were investigated. 18 cranial measurements were utilized. Cranial variation was analyzed through the calculation of Mahalanobis distances between each pair of crania. A principal coordinate analysis was used to visualize the general phenotypic patterns among the crania.The distance relationships among the Paleoamerican crania suggest a separation between the South American and North and Central American specimens. There does not appear to be distinct differences among the South American specimens from different areas and sites.Further discussion of the results include the implications of heterogeneity of the complete Paleoamerican sample, the distinctness of many North American and Central American crania and the relative homogeneity of the South American subsample. Further analysis of these points may be of great interest in modeling the first migration(s) into the Americas.
The body mass estimation from human talus: inductive approach and 3D morphometric study (919.1)
Authors: Jung Go‐Un , Lee U‐Young , Kim Dong‐Ho , Kwak Dai‐Soon , Ahn Yong‐Woo , Kim Yi‐Suk 
Published: June 2021

The body mass (BM) that is gauging physical characteristics of individuals is still challengeable information to acquire from the skeletal remains in the fields of biological anthropology. The aim of this study is to develop the BM‐predicting equations from the talus using 3D morphometrics and investigate whether the estimated BM can be used as a biological profile in forensic anthropology.The right‐side talus in type of 3D models obtained from 76 Koreans (32 males and 44 females) of known stature, bi‐iliac breadth, and femoral head diameter were used. In this study, the inductive approach is needed in order to construct information about the weight for the CT‐based Digital Korean Collection, applying morphometric and mechanical method for assuming the weight of the individuals from the collection. For developing BM‐predicting equations, nine variables of 3D talus were measured through Mimics software (Materialise NV, Leuven, Belgium) and statistical analyses were performed using SPSS 20.0 (SPSS Inc., Chicago, IL). Overall this study, analysis of covariance found no statistically significant differences between sexes in most talar measurements except that talar length is just not. The linear regression analyses revealed that talar height was the most highly correlated measurement with the BM (R2 = 0.702, SEE = 3.73), followed by talar length (R2 = 0.701, SEE = 3.74) and talar width (R2 = 0.631, SEE = 4.15). Through the multiple regression analysis, four measurements of talar height, talar length, trochlear breadth and head height were selected as a BM‐predicting equations by stepwise selection with increasing the coefficient of determination (Adjusted R2 = 0.779, SEE = 3.19). In conclusion, the BM‐predicting equations were developed and expected this study do role as a stimulus of further study for assessment the effectiveness of anthropological body mass estimation serving as a biological profile.Grant Funding Source: Supported by the National Research Foundation of Korea (NRF‐2013R1A1A2009306)
Microscopic analysis of characteristic surface features of a set of retrieved total hip implants (922.13)
Authors: Burbano Maria , Roy Diana , Russell Robert , Huo Michael , Rodrigues Danieli 
Published: June 2021

Introduction: Total Hip Arthroplasty (THA) is considered one of the most successful orthopaedic interventions used for joint replacement. The purpose of this study was to characterize the particular surface features common to retrieved THA implants, in order to point out principal characteristics that lead to their failure.Methods: A set of fourteen retrieved implants was studied, their designs varying from metal‐on‐polyethylene (MoP), ceramic‐on‐polyethylene (CoP) and metal‐on‐metal (MoM). All specimens were analyzed using digital microscopy (Keyence VHX2000). Particularly corroded and scratched areas were further analyzed under Scanning Electron Microscopy (SEM, JEOL 5600), and Energy Dispersive X‐ray Spectrometer (EDS, JEOL 5600).Results: The surface analysis revealed certain patterns of features. The implants were divided in their components (cup, liner, head and stem), each of which was studied for common characteristics. Large amount of scratching was found throughout all of the heads and cups, followed by biological deposition on the surfaces, pitting and finally one single case of corrosion.Conclusion: The high level of scratching observed on the bearing surfaces of the implants leads to the belief that mechanical events induced failure of the implants. This study encourages surgeons to place higher importance of implant placement and material choice when applying THA.Grant Funding Source: Supported by the University of Texas at Dallas startup funds (Dr. Rodrigues)
Evidence for the hypothesis that two forms of human DNA polymerase δ participate in DNA replication (925.2)
Authors: Lin Szu Hua Sharon , Zhang Sufang , Lee Ernest , Zhang Zhongtao 
Published: June 2021

Eukaryotic DNA polymerase δ (Pol δ) is the polymerase primarily involved in lagging strand DNA synthesis. Human Pol δ is a heterotetramer (Pol δ4) composed of four subunits. The p12 subunit is degraded in response to DNA damage, resulting in the in vivo conversion of Pol δ4 to Pol δ3, the trimer lacking p12. Thus, Pol δ3 is the form that is involved in DNA repair. The hypothesis that Pol δ3 is also capable of performing lagging strand DNA synthesis was tested in a reconstituted system for Okazaki fragment processing using purified enzymes and model oligonucleotide substrates. In the combined Pol δ3/Fen1 reactions, the products formed by removal of the downstream blocking primer were almost exclusively mononucleotides, showing that the reaction proceeded by nick translation, and was not affected by Fen1 concentrations. With Pol δ4/Fen1, the products were 1‐10 nts at low Fen1 concentrations, showing that the reaction proceeded by the short flap pathway. As Fen1 concentrations were increased the product size was shifted to mono‐nucleotides, i.e.,. to a nick translation mode. These studies show that Pol δ3 is ideally suited for Okazaki fragment processing. In parallel studies, we have shown that p12 is degraded during the G1/S transition so that a mixture of Pol δ4 and Pol δ3 is present in S phase, under the control of CRL4Cdt2, which also regulates the degradation of the licensing factors Cdt1, Set8 and p21.Grant Funding Source: Supported by GM31973 and ES14737
Tpz1 switches telomeres between ON and OFF states (926.3)
Authors: Qiao Feng 
Published: June 2021

Telomeres are nucleoprotein complexes comprising telomeric DNA repeats bound by multiprotein shelterin complex. A dynamic binary switch between telomerase‐extendible and ‐nonextendible telomeric states determines telomere length homeostasis. However, the molecular nature of the two states is largely unknown. Here, we show that, in fission yeast, Tpz1 (the ortholog of human TPP1)‐mediated complete linkage within the shelterin complex, bridging telomeric dsDNA to ssDNA, controls telomerase‐nonextendible state. Disruption of this linkage leads to unregulated telomere elongation while still retaining the shelterin components on telomeres. Therefore, the linkage within the shelterin components, rather than the individual shelterin components per se, defines the telomerase‐nonextendible state. Furthermore, epistasis analyses reveal that Tpz1 also participates in the activation of telomeres to the extendible state via its interaction with Ccq1. Tpz1‐Ccq1 interaction triggers the protein processing of shelterin components and causes the conformational change of the sheltering complex, which in turn switches the telomere from the nonextendible to the extendible state. Our results reveal Tpz1 as the key regulator that switches telomeres between ON and OFF states.Grant Funding Source: Supported by R01‐GM098943
Mechanism of hRev1 polymerase action on G‐quadruplex DNA (927.3)
Authors: Eddy Sarah , Zafar Maroof , Ketkar Amit , Maddukuri Leena , Eoff Robert 
Published: June 2021

Faithful replication of genomic information is crucial for maintenance of cellular function and integrity. DNA can adopt non‐B‐form structures in vivo, such as stable G‐quadruplex DNA (QDNA). The accurate replication of QDNA is important, as these structures regulate transcription of oncogenes and telomere dynamics. Recent studies have implicated Rev1 polymerase in successful QDNA replication. We hypothesized that human Rev1 might help maintain fork progress at QDNA sites because of its unique protein template‐directed mechanism of DNA replication and sought to investigate the hRev1 biochemical mechanism of action on QDNA substrates. We find that hRev1 preferentially binds to QDNA substrates. hRev1 is able to catalyze dCMP insertion, but the efficiency of nucleotidyl transfer is impaired opposite tetrad‐guanines. Results from dimethyl sulfate footprinting and stopped‐flow fluorescence assays are consistent with the notion that hRev1 can disrupt QDNA structures without performing nucleotidyl transfer. The specific molecular features that allow hRev1 to bind and disrupt QDNA are the subject of ongoing experiments. In conclusion, our study has identified new properties related to the functional and mechanistic role assumed by hRev1 in QDNA replication.Grant Funding Source: Supported in part by USPHS R00 GM084460 (R.L.E.)
Examining the temporal expression and regulation of type I MAGE proteins in spermatogenesis (930.4)
Authors: Quintana Mercedes , Fon Tacer Klementina , Hao Yi‐Heng , Potts Ryan 
Published: June 2021

Background: Type I Melanoma Antigen Gene (MAGE) proteins are normally expressed in the trophoblast and germline cell lineages, but are aberrantly expressed in various human cancers. Recently, MAGEs were shown to enhance the activity of E3 RING ligases, however the physiological function of MAGEs in the testis and tumorigenesis is yet unknown. With these questions in mind the aim of the project was to confirm germline specific expression of MAGE genes, and assess whether the temporal pattern of MAGE gene expression is associated with specific developmental stages of spermatogenesis.Methods Testes were collected from C57BI/6 mice at different times during postnatal development. Spermatogenic cells were isolated and enriched using velocity sedimentation in 2‐4% BSA gradient. Expression of type I MAGEs was measured from collected spermatogenic cells using RT‐QPCR. Interaction of type‐I human MAGEs and human ZBTB16/PLZF stem cell marker protein was explored by co‐immunoprecipiration experiments in HeLa cells using exogenously expressed tagged forms of the proteins.Results MAGE‐B4 was expressed in spermatogonia during mitosis. MAGE‐As were expressed in spermatogonia during mitosis and prepachytene spermatogonia before entering meiosis. MAGE‐B1, ‐Al1, and ‐Al2 were expressed in haploid spermatids in spermiogenesis. MAGE‐B3, ‐B16, ‐B18 and ‐Al3 were expressed in all germ cells and somatic cells during spermatogenesis. Additionally, human MAGE‐A11 and ‐A12 were shown to interact with human ZBTB16/PLZF.Conclusion Type I MAGEs are expressed in different developmental stages of spermatogenesis, suggesting diverse functions. Future investigation is necessary to determine if MAGE‐A genes regulate the activity of ZBTB16/PLZF.Grant Funding Source: CPRIT R117
MAML1 mediates MEF2C degradation independent of ubiquitination (930.5)
Authors: Zein Ivan , White Brandon 
Published: June 2021

Myocyte Enhancer Factor 2C (MEF2C), a member of a family of transcription factors involved in muscle cell differentiation and proliferation, is known to interact with Mastermind‐like 1 (MAML1). MAML1 transcriptional coactivator was originally identified in the Notch pathway and is also involved in the beta‐catenin, p53, and MEF2C signaling pathways. MAML1 was previously shown to interact with MEF2C and is required for muscle development in the absence of Notch. Since MAML1 was shown to act as a coactivator of Notch while also to induce degradation of the Notch Intracellular Domain, we speculated whether or not MAML1 could also serve a similar function with MEF2C. Our results indicate that MEF2C is degraded in the presence of MAML1. However, this degradation is significantly reduced when using a MAML1 deletion mutant (75‐300). Furthermore, treatment with lactacystin, a proteasome inhibitor, did not inhibit MEF2C degradation while the use of lysosome inhibitors significantly attenuated MEF2C turnover. Our findings suggest that MEF2C degradation is mediated by MAML1 through a lysosomal degradation pathway, independent of the ubiquitin‐proteasomal pathway.Grant Funding Source: Supported by NSF‐RUI Grant#1052039 to JBW
A second degradation signal within the short‐lived transcription factor MATalpha2 (937.1)
Authors: Hickey Christopher , Hochstrasser Mark 
Published: June 2021

The yeast transcriptional repressor MATalpha2 (alpha2) is a short‐lived protein known to be ubiquitylated by at least two distinct pathways, one involving the ubiquitin ligase (E3) Doa10 and the other operating with the E3 Slx5/Slx8. Simultaneous perturbation of both pathways leads to considerable stabilization of alpha2 (approximately 6‐fold); however, deletion of either pathway alone only leads to moderate stabilization of alpha2 (approximately 2‐fold). Although a degradation signal within alpha2, known as Deg1, is well established for Doa10‐dependent degradation, little is known about the determinants within alpha2 that direct its Doa10‐independent degradation. Here we report that alpha2 contains an additional degradation signal, termed Deg2, that is non‐overlapping with Deg1 and leads to ubiquitin‐dependent degradation when fused to normally long‐lived proteins. We also report numerous mutations within Deg2 that result in stabilization of alpha2, including several mutations in the homeodomain that impair the ability of alpha2 to interact with DNA. These data further our understanding of one of the best‐studied substrates of the ubiquitin‐proteasome system and highlight a previously encountered link between the ability of a transcription factor to function and its ubiquitin‐dependent degradation.Grant Funding Source: Supported by the U.S. National Institute of General Medical Sciences
Structural basis of Rifampin resistance in bacterial RNA polymerase (939.1)
Authors: Murakami Katsuhiko 
Published: June 2021

For over four decades, Rifampin (Rif), a semi‐synthetic derivative of Rifamycin, has been used as a first line antibiotic treatment of tuberculosis and is the cornerstone of current short‐term tuberculosis treatment. The mode of action involves tight Rif binding to a beta subunit of bacterial RNA polymerase (RNAP) to inhibit RNA transcription. Although many Rif resistant (RifR) strains with mutations in the Rif‐binding pocket can be isolated in bacterial culture, only three specific RifR mutations account for over 80 % of Mycobacterium tuberculosis (MTB) RifR strains in clinical isolates due to RifR associated fitness costs.In this study, we have determined the X‐ray crystal structures of the E. coli RNAP RifR mutants each having one of three major RifR mutations found in clinical isolates. Each RifR RNAP structure shows a unique conformation of the Rif binding pocket and their structural deviations from the wild‐type Rif binding pocket are consistent with their Rif resistances suggesting that the RifR results from alternating the shape complementary between the Rif binding pocket and Rif rather than disrupting their hydrophilic and hydrophobic interactions. This study provides an important step for understanding the structure−activity relationship of Rif against RifR RNAP inhibition and toward developing superior Rif analogues against RifR MTB.Grant Funding Source: Supported by NIH