bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retinoid‐mediated CYP26a1 expression in primary rat hepatocytes and hepatoma cells
Authors: Li Yang , Chen Guoxun 
Published: June 2021

Vitamin A (or retinol) plays a crucial role in health of humans as a micronutrient. Recently we have shown that retinoid synergize with insulin to induce Gck gene expression in primary rat hepatocytes. Based on data from us and others, we believe that VA may be involved in glucose and lipid metabolism in humans.In cells, retinol (ROL) is reversibly oxidized into retinal (RAL) by retinol dehydrogenase (RDH) and irreversibly into retinoic acid (RA), which is the activator of nuclear receptors‐retinoic acid receptor (RAR) and retinoid X receptor (RXR). We hypothesize that cells may respond to ROL, RAL, and RA depending on the catabolic enzymes of retinoid existing in them. Therefore, we determined and compared the expression levels of CYP26a1, a RA responsive gene, in response to retinoids in both primary rat hepatocytes and HL1C, a rat hepatoma cell line.We observed that ROL, RAL and RA induced expression of CYP26a1 gene in both primary rat hepatocytes and HL1C cells in a dosage dependent manner. RAL and RA induced the expression of CYP26a1 as early as 3 hours and peaked at 9 hours. In addition, we examined the expression levels of RDH and RALDH in primary hepatocytes and HL1C cells. We found that both types of cells have comparable levels of RDH2 and RALDH1 expression. We are currently trying to confirm their roles in mediating the retinoid catabolism and retinoid‐mediated gene expression in different types of cells.Sponsor: Guoxun Chen, 1215 W. Cumberland Ave. 229 Jessie Harris Building, Knoxville, TN37996
TP‐receptor activation potentiates airway stretch‐activated contractions
Authors: Hernandez Jeremy Mark , Janssen Luke Jeffrey 
Published: June 2021

A deep inspiration (DI) produces a bronchodilation in healthy individuals. Conversely, in asthmatics, DIs are ineffective in producing bronchodilation, and can even cause bronchoconstriction. Interestingly, the manner by which a DI is able to cause bronchoconstriction via a stretch‐activated contraction (Rstretch) correlates positively with airway inflammation, during which there is increased production of thromboxane A2 (TxA2) and TP‐receptor activation.In this study we sought to investigate the effect of TP‐receptor activation on airway Rstretch in bovine bronchial segments using the Mayflower organ bath as previously reported by our laboratory. Rstretch was elicited by varying the transmural pressure under isovolumic conditions. Using a pharmacological approach, we showed a reduced Rstretch response in tissues pretreated with indomethacin (Indo), a COX inhibitor; a result mimicked by the TP‐receptor antagonist ICI 192605 and by airway epithelial denudation. U46619, a TP‐receptor agonist elicited enhanced Rstretch responses in a dose‐dependent manner. AH6809, an EP1/DP‐receptor antagonist and AL 8810, an FP‐receptor antagonist had no effect, suggesting PGE2, PGD2, and PGF2 [alpha] are not involved in ASM Rstretch.These data suggest a role for the TP‐receptor and epithelial release of TxA2 in potentiating the effects of airway Rstretch.Research Support: CIHR, NSERC
L‐Citrulline Protects Against Hyperoxia‐Induced Increase in Airway Contractile Responses
Authors: Sopi Ramadan B , Mladenov Mitko , Gjorgoski Icko , Jakupaj Muharrem 
Published: June 2021

Neonatal hyperoxia increases contraction and decreases relaxation of airways in rat pups due to upregulation of arginase activity and decrease of L‐arginine bioavailability to nitric oxide synthase (NOS). Therefore, we tested the hypothesis that supplementation of L‐citrulline will overcome the increased contractile responses of tracheal smooth muscle (TSM) induced by hyperoxia. Tracheal cylinders were excised from rat pups 12 days old, exposed to hyperoxia or room air for seven days. To induce contraction of TSM, electrical field stimulation (EFS) was applied. Hyperoxia increased EFS‐induced contractile responses as compared to room air animals (1.29 ± 0.1 g vs. 0.83 ± 0.2 g). In vitro supplementation of L‐citrulline decreased the contractile responses in hyperoxic group, but did not show any effect in control group under basal conditions. Inhibition of enzymes involved in L‐citrulline recycling prevented this effect of L‐citrulline. Inhibition of NOS, increased airway contraction in control group but did not affect the responses in hyperoxic group. Incubation with exogenous L‐citrulline reversed the increased contractility.These data demonstrate that L‐citrulline/L‐arginine cycle is effective in TSM under conditions of reduced L‐arginine bioavailability to NOS. In vitro supplementation of L‐citrulline reverses the increased contractile responses in hyperoxic animals to control levels.
Macro vascularization of the talus and relationships for triple arthrodesis
Authors: Pizzimenti Marc A , Haugsdal Jaclyn , Phisitkul Phinit 
Published: June 2021

Understanding the macro vascularization of the talus is important for a number of orthopaedic procedures. In the current study, we outlined the general primary arterial supply to the talar and peritalar regions. Two methods were used to construct the extraosseous vascular map of the talus: macro dissection of embalmed specimens; and CT analysis of unembalmed specimens. The general arterial pattern construct, with variations, was determined by comparing the observed vascular trees with those reported in the literature. Unembalmed specimens were injected with latex containing a barium sulfate suspension, from three access points. CT analysis of the specimens provided 3D assessment of the vascular patterning, which in turn permitted reliable measures and locations for major extraosseous branches supplying the talus relative to major anatomical landmarks. Identifying the locations of these vessels can aid in guiding surgical approaches for triple arthrodesis with minimal vascular disruption.Financial and resource support was provided by the University of Iowa
Analysis of the upper forelimb of Canis dirus to determine physical characteristics that might suggest sociality
Authors: Koper Lindsey , Naples Virginia L 
Published: June 2021

Canis dirus guildayi, or the Western Dire wolf, was the most common predator at Rancho La Brea and is believed to be social as are modern wolves. In this study, the upper forelimb, specifically the scapula, humerus, and ulna of C. dirus were examined. Maps determined from examination of ridges, rugosities and other features reflecting alteration of bone surfaces by muscle attachments were created. Interpretation of significance of muscle scars on these bones was made possible by comparison to dissections of the forelimb musculature of Canis latrans (American coyote) and Urocyon cinereagenteus (Red Fox). The dire wolf is considered a social predator, in part from previous studies that characterized specific healed or partially healed skeletal injuries that parallel those in social modern wolves hunting large prey in groups. Further support for sociality in Dire wolves that also specialized in capture of large prey is suggested by anteroposterior scapular lengthening in some larger individuals. This shape, surface area and muscle scar position allowed for a relatively larger origin of the M. serratus ventralis, a muscle that supports the trunk, assists with inspiration and moves the trunk and the scapular region anteroposteriorly. This capability would allow for increased anteroposterior movement of the limb, an advantage for a pursuit predator cursor hunting in cooperation with conspecifics to capture large prey.Grant Funding Source: Northern Illinois University
Immunohistochemical localization of pituitary adenylate cyclase‐activating polypeptide (PACAP) and its receptor (PAC‐1) in mouse major salivary glands
Authors: Nonaka Naoko , Nakamachi Tomoya , Shioda Seiji , Nakamura Masanori 
Published: June 2021

The control of saliva secretion is mainly under the autonomic nervous control. PACAP is now recognized as the multi‐functional neuropeptide in various organs. We compared the distribution of PACAP and PAC‐1, in major salivary glands; parotid, submandibular and sublingual glands, of young and old C57BL/6 mice. In parotid gland, PACAP was mainly detected in the cells of intercalated ducts. PAC‐1 was detected in the cells of striated duct. In submandibular gland, PACAP was distributed in the nerve fibers adjacent to acini and granular ducts and the strong immunoreaction of PAC‐1 was detected in the tall columnar epithelial cells in granular ducts and some of the cells in the striated ducts. In sublingual gland, while PACAP‐positive neural fibers surrounded the acini, PAC‐1 was expressed mainly in the epithelial cells of striated ducts. These results indicated the PACAP‐positive innervations in three major salivary glands in young and old mice and also suggested the functional differences of PACAP between three salivary glands.Supported by the Grant‐in‐Aid for Scientific Research (20592148, 21592342) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
Central Vein Fibrosis in Cadaveric Livers of the Elderly
Authors: Mak Ki M. , Hoo Nancy M. 
Published: June 2021

Liver fibrosis develops in stages with central vein fibrosis (CVF), perisinusoidal fibrosis (PSF) and portal tract fibrosis (PTF) occurring at early, septal fibrosis at late and cirrhosis at end stage. These lesions were seen in the liver of elderly cadavers with diverse causes of death (Mak et al. FASEB J 2010; 24: 446.11). This study examined 50 cadavers (mean age = 81.3±12.5 yrs) for CVF to evaluate its role in liver fibrosis. Paraffin sections were stained for collagens with Sirius red, a marker for fibrosis. 250 central veins were analyzed by morphometry. The mean vein diameter was 71.1±18.2 μm. CVF was considered present when the thickness of collagens in the rim of the vein exceeded 9 μm with extension of fibrous tissue into the perivenous parenchyma. CVF occurred in 25 livers (50%). Of these, 23 (92%) also had PSF, 12 (48%) PTF, 10 (40%) septa formation, 10 (40%) bridging fibrosis and 1 (4%) cirrhosis. Livers without CVF had a lower incidence of PSF (40%, P = .0002), PTF (28%), septa formation (36%) and bridging fibrosis (20%).Conclusion/implicationHistogenesis of CVF is associated with PSF in early fibrogenesis. The fibrosis interferes with intrahepatic blood flow, which stimulates advanced fibrogenesis and subsequent portal hypertension. These changes impair hepatic functions and enhance disease susceptibility in older people. Thus fibrosis in the aging liver may have a detrimental health effect in the elderly.
Comparative anatomy, ontogeny, evolution and phylogeny of primates, with special attention to the phylogenetic position of Tarsius, the relationships of hominoids, and the muscular variations of modern humans
Authors: Diogo Rui Pedro Boliqueime Martins , Wood Bernard 
Published: June 2021

In this presentation we report the results of the first comprehensive cladistic analysis based on muscular characters that addresses the relationships among the major groups of living primates and taxa such as tree‐shrews and colugos (‘flying lemurs'). This analysis is based on information obtained from a review of the literature and from dissections of more than 50 specimens of various primate and non‐primate taxa. The genera included in the analysis were: Rattus, Tupaia, Cynocephalus, Lemur, Propithecus, Loris, Nycticebus, Tarsius, Callithrix, Pithecia, Aotus, Saimiri, Macaca, Papio, Cercopithecus, Colobus, Hylobates, Pongo, Gorilla, Pan and Homo. The cladistic analysis was based on 208 characters concerning the head, neck, pectoral and upper limb muscles of these taxa, using Nona & Winclada 2002. The relationships among the taxa in the most parsimonious trees obtained (L=382; RI=0.53; CI=0.65) largely conform to those supported by recent molecular studies: the Primates, Strepsirrhini, Lemuriformes, New World monkeys, Old World monkeys, the subfamily Cercopithecinae and the Hominoidea are monophyletic groups, and there is strong support for the following relationships among hominoids: [Hylobates, [Pongo, [Gorilla, [Pan, Homo]]]]. Our study revealed that, regarding its muscles, Tarsius is one of the most peculiar primates, displaying some plesiomorphic (e.g., the presence of a distinct muscle spinotrapezius) and derived (e.g., the presence of two series of contrahentes in the hand and of the facial muscle zygomatico‐auricularis) features that are rarely seen in other living primates. We will examine the phylogenetic, evolutionary and medical implications of our data, and discuss the use of myological, molecular and osteological characters in phylogenetic reconstructions.Grant Funding Source: Mathers Foundation, GW Signature Program
Histological and lectin histochemical characterization of the epididymal duct in dromedary camels (Camelus dromedarius)
Authors: Hafez Shireen Abdelgawad , El‐Shafey Samir , Caceci Thomas 
Published: June 2021

Regional microscopic anatomy of the epididymal duct of the dromedary camel was studied using H&E and a combination of Masson's trichrome and Verhoeff's staining. The initial segment of the epididymis was lined with high pseudostratified columnar epithelium with stereocilia; and with varying height levels from place to place giving the duct a “festooned” appearance. The nuclei of principal and basal cells were located in the basal one‐third of the epithelial cells. The duct was surrounded by a layer of circularly oriented smooth muscle cells; this peritubular smooth muscle thickened toward the termination of the epididymal duct. The middle and terminal segments of the epididymal duct were lined with the same type epithelium with no noticeable variations in height. The nuclei were located in the basal one‐half of the cells and spermatozoa were more evident in the lumen of the middle and terminal segments. Histochemical characteristics of epithelial cells were investigated using a panel of different lectins: Con‐A, DBA, MAA, SBA, SNA‐1, and WGA. These showed selective regional binding to different portions of the epididymal duct and varying degrees of binding to different cellular compartments. These regional variations in carbohydrate composition are discussed; they indicate a great deal of functional compartmentalization in the epididymal duct.Grant Funding Source: professional development
Anatomical variants of the puboprostatic ligaments: Are they relevant to outcomes of radical prostatectomy?
Authors: Kim Michael , Johnson Marjorie , Carreno Alfonso Fernandez , Pautler Stephen E. 
Published: June 2021

Prostate cancer affects men worldwide and is frequently treated by radical prostatectomy. The puboprostatic ligaments anchor the prostate to the pubis and must be manipulated for successful prostate removal. Previous studies have identified these ligaments but have not characterized variations typically observed. This study aims to classify the variants and investigate possible relationships between ligament type and post‐operative outcomes. Videos of 300 robot‐assisted laparoscopic radical prostatectomies (RARP) were viewed and images of the puboprostatic ligaments were isolated. The ligaments were classified based on morphology into a four‐class system: Fused, V‐shaped, Inverted V‐shape, Parallel. Initial results show that the majority of ligaments are parallel (37%) while fused ligaments are least common (2.7%). V‐shaped ligaments and inverted V‐shaped ligaments were identified in 19.7% and 11% of the population, respectively. This study proposes a puboprostatic ligament classification system that could be adopted universally, allowing better prediction of post‐operative outcomes. Further validation of our proposed classification system and investigation into its clinical significance is ongoing.Grant Funding Source: Internal
Tubulobulbar complexes in Sertoli cell primary cultures
Authors: Du Min , Chan Alex , De Asis Marc , Cipollone Jane , Roskelley Calvin , Vogl Wayne 
Published: June 2021

In the seminiferous epithelium, unique double membrane structures termed tubulobulbar complexes (TBCs) develop in association with basal junction complexes between Sertoli cells. These actin‐related structures are thought to internalize intercellular junctions during the movement of spermatocytes from basal to adluminal compartments of the epithelium. We are establishing a primary Sertoli cell culture system to study the role of basal TBCs in junction turnover. We confirm that Sertoli cells isolated from 20 day‐old rat pups morphologically differentiate when grown on Matrigel in Transwells. The cells are high cuboidal to columnar in shape with basal nuclei, and with basal junction complexes similar to the appearance of junction complexes between Sertoli cells in vivo. Significantly, TBCs and TBC‐like structures develop in association with intercellular junctions. Double‐membrane coated‐pits, together with double‐membrane tubular structures capped by coated‐pits are observed in regions related to ectoplasmic specializations. When immunostained for integral junction proteins, “rod‐like” structures are observed to extend into the cell from the periphery. These observations indicate that TBCs are able to develop in differentiated Sertoli cells in culture, making further functional analyses of TBCs possible in vitro. Supported by an NSERC Discovery Grant to AWV.Grant Funding Source: NSERC
Spectrin and plectin are present at apical tubulobulbar complexes in the seminiferous epithelium
Authors: de Asis Marc Aristaeus , Vogl A. Wayne 
Published: June 2021

Tubulobulbar complexes (TBCs) are actin‐related double membrane structures that are suspected to internalize intercellular junctions, a process that is crucial for junction turnover and sperm release. At apical sites of adhesion between spermatids and Sertoli cells, each TBC consists of a tubulobulbar projection of the spermatid plasma membrane, the surrounding attached plasma membrane of the adjacent Sertoli cell, and an actin network cuff. In other systems, spectrin is part of the membrane skeleton that links actin filaments to the plasma membrane. Others previously have reported that the protein is present at differentiating germ cells and epididymal spermatozoa. Plectin links cytoskeletal elements to each other and to the plasma membrane. We probed the seminiferous epithelium for spectrin, plectin and actin on fixed frozen sections of rat testis and fixed epithelial fragments. Both in sections and in epithelial fragments, beta‐spectrin II and plectin are localized to apical actin‐related tubulobulbar. Neither protein is concentrated at actin‐related intercellular adhesion junctions (ectoplasmic specializations). Our results demonstrate that both spectrin and plectin are present in Sertoli cells at tubulobulbar complexes. Supported by an NSERC Discovery Grant to AWV.Grant Funding Source: NSERC
The C‐terminus of Decorin Regulates Class II Small Leucine Rich Proteoglycans (SLRPs) in Corneal Stromal Matrix Assembly
Authors: Chen Shoujun , Kao Winston , Birk David 
Published: June 2021

The purpose of this work is to study the regulatory role of the decorin in corneal stromal matrix assembly. In human congenital stromal corneal dystrophy mutant decorin is expressed with a truncated C‐terminus. A transgenic mouse model of the disease was created in a decorin wild type background. Both wild type and mutant decorin were expressed in mutant mice. Corneal opacities developed throughout the stroma in mutant mice, but were more severe in posterior stroma. The orthogonal lamellar structure was disrupted, with relatively normal lamellae separated by abnormal zones. In these abnormal zones, collagen fibrils were heterogeneous in diameter with increased and irregular inter‐fibril spacing. The aberrant zone was more obvious near keratocyte suggested an area differential dysfunctional matrix assembly. Expression of all class II stromal SLRPs was altered in the mutant mouse. Both lumican and keratocan were down‐regulated, and fibromodulin was up‐regulated. The C‐terminus of decorin is implicated in maintenance of protein core conformation and ligand binding. The data suggest that loss of the C‐terminus altered decorin binding directly or indirectly through other extracellular matrix components to keratocytes, changing the interactions between decorin and other SLRPs. These interactions are important for the rigid control of fibrillogenesis and fibril organization in cornea stromal matrix assembly.Grant Funding Source: NIH grants EY05129, AR 44745 (DEB), 2010 postdoctoral fellowship from American Association of Anatomists (SC), 2010 postdoctoral fellowship from Fight for Sight (SC).
Genome‐wide Analysis Reveals Novel Molecular Features of Mouse Recombination
Authors: Brick Kevin , Gregoretti Ivan , Smagulova Fatima , Khil Pavel , Camerini‐Otero Rafael Daniel , Petukhova Galina 
Published: June 2021

Meiotic recombination occurs at discrete genomic loci known as recombination hotspots. To date, the lack of scalable, genome wide assays has limited studies of hotspot formation.Recombination begins with the formation of DNA double‐stranded breaks (DSBs) by the meiosis specific SPO11. Strand resection from the DSB exposes single stranded 3′ overhangs which are bound by recombinases (RAD51, DMC1). We performed ChIP against DMC1 & RAD51, followed by Solexa sequencing (ChIP‐Seq) to generate the first direct map of DSB hotspots in a mammalian genome. We identified 9,874 DSB hotspots at high resolution, including a large cluster in the pseudo‐autosomal region, the site of an obligate recombination event.Mouse hotspots are over‐represented in genes, have a distinct DNA skew pattern and hotspot DNA encodes a preference for nucleosome binding which is manifested in‐vivo. A consensus motif, found at 73% of hotspots is highly similar to the predicted binding site for PRDM9, a histone methyltransferase implicated in hotspot formation. The motif quality also correlates with hotspot strength. ChIP‐Seq against H3K4me3 showed that testis‐specific H3K4me3 peaks are co‐centered with 94% of hotspots, alluding to a central role for this motif, for PRDM9 and for H3K4me3 in DSB formation.The Intramural Research Program of the NIDDK, NIH, supported this research.
Functional Characterization of the Interactions of the 70‐kD Heat Shock Proteins (Hsp70s) with Lipids
Authors: Nikolaidis Nikolas , McCallister Chelsea Marie , Donnelly Gabrielle , Chaudhari Sunil 
Published: June 2021

Hsp70s are essential for cellular homeostasis and survival. Apart from their functions as molecular chaperones, specific Hsp70s interact with lipids. It has been proposed that this interaction allows Hsp70s to stabilize biological membranes and be integral parts of signaling and trafficking pathways. Despite their importance, the Hsp70‐lipid interactions remain largely undefined, since it is unknown which Hsp70s bind to lipids and what types of lipids they bind. To this end, we generated recombinant proteins of three mouse Hsp70s, and by using protein lipid overlay and vesicle sedimentation assays we determined that these proteins bind to phospholipids with significantly different affinities and specificities. To further characterize the Hsp70‐lipid interactions and facilitate future mutagenesis analysis, we determined the precise location of the Hsp70‐lipid binding by generating overlapping fragments of the Hsp70 protein. Lipid‐binding assays revealed the presence of at least two regions on the Hsp70 molecule responsible for binding to lipids. Our data strongly suggest that Hsp70s are functionally differentiated with respect to their lipid‐binding properties. Moreover, the high specificity of the interaction of specific Hsp70s to particular lipids suggests that these interactions could facilitate their translocation, anchorage, and function at cellular membranes.This project was supported by funds from CSUPERB and CSUF to NN