bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ground Reaction Forces generated by a Lower Body Negative Pressure Exercise Device for Space Flight
Authors: Poudel Alisha , Ashari Neeki , Kong Mitchell , Friend James , Hargens Alan 
Published: April 2020

Loss of bone and muscle are leading concerns among astronauts during prolonged space flight. Lower body negative pressure (LBNP) chambers generate gravitational and cardiovascular stresses to maintain musculoskeletal strength and fitness by means of suction pressure. Ground reaction forces (GRFs) generated underneath the user’s feet are directly proportional to the level of negative pressure applied. However, the exact mechanism of GRF generation remains unresolved. We hypothesize that increasing the cross‐sectional area (CSA) of the user’s waist in contact with a flexible waist seal will increase the GRFs generated at a given vacuum pressure. To test our hypothesis, we collected GRFs generated by 6 healthy subjects under two conditions: original (unchanged) CSA of their waist and a greater waist CSA using expanded cushioning around waist of the same subjects. GRFs were measured with LBNP levels ranging from 0 (ambient pressure) to 50 mmHg with subjects lying in supine position to simulate microgravity. The original CSA of 467.7 cm2 ± 69.0 cm2 generated 118 % ± 31 % body weight at −50 mmHg. However, the larger CSA of 1,451.0 cm2 ± 331.0 cm2 generated a mean GRF of 146 % ± 31% body weight at −50 mmHg. A one‐way ANOVA test resulted in p‐values < 0.05 for all pressures, denoting statistically significant increases in larger compared with original CSA GRF. The GRF generated with larger CSA followed this equation GRF = −1.8211 (LBNP) + 0.7899 while the GRF generated with original CSA followed the equation: GRF = −1.5079 (LBNP) + 0.3995. These data support our hypothesis that GRFs generated by LBNP are directly proportional to the waist CSA. Using this new concept, astronauts may generate GRFs at lower LBNP levels to prevent pre‐syncopal symptoms during exercise in space.Support or Funding InformationSupported by NASA grants NNX13AJ12G and NSSC19K0409.Average weight measurements with varying pressures for six volunteers; red is original CSA of subject's waist and blue is larger CSA.Figure 1
Serum‐derived Extracellular Vesicles as Diagnostic Biomarkers for Non‐alcoholic Fatty Liver Disease
Authors: Newman Lauren 
Published: April 2020

IntroductionNon‐alcoholic fatty liver (NAFL) disease is a highly prevalent chronic liver disease with variable severity, from simple steatosis to steatohepatitis (NASH). NASH involves hepatocyte death, inflammatory infiltration and fibrosis, and may progress to cirrhosis or hepatocellular carcinoma. Liver biopsy is currently the only way to definitively diagnose NASH, but this simply provides a static image and due to the highly invasive nature of the procedure, poses risks to patients and is not practical for longitudinal evaluation. Circulating populations of small extracellular vesicles (sEVs), including exosomes (30–150nm) and microvesicles (50–1000nm), are known to exhibit alterations in concentration and molecular cargo in disease states, including NAFL and NASH. Thus, they present the lucrative opportunity to not only diagnose and stage disease in a minimally invasive manner, but also track the efficacy of therapeutic interventions.AimThis study aimed to evaluate the performance of miRNA, derived from global circulating sEVs or hepatocyte‐specific EVs, in distinguishing patients with NAFL and NASH from healthy individuals.MethodsSerum was obtained from healthy volunteers and patients with NAFL and NASH and ExoQuickTM precipitation solution was used to isolate global sEV samples. Magnetic DynaBeads conjugated to anti‐asialoglycoprotein receptor 1 antibody were used for immunoprecipitation of hepatocyte‐specific EVs from global samples. Total RNA was isolated from EV samples using TRIzol reagent and reverse transcribed with TaqMan miRNA RT kit. Expression of miR ‐122, ‐192, ‐128‐3p, ‐451 and ‐16 was determined by RT‐qPCR using TaqMan small RNA assays. Predictive performance of miRNA biomarkers was evaluated by receiver operating characteristic (ROC) analysis.ResultsExpression of liver miRNA (miR ‐122, ‐192, ‐128‐3p) given as ratios to non‐specific EV miRNA (‐451, ‐16) in global circulating EVs was generally greater in patients with NAFL and NASH. In distinguishing all disease from healthy, excellent performance was exhibited by miR‐128‐3p/‐451 and miR‐192/‐451 (AUROC = 0.925 and 0.882, respectively). miR‐122 ratio expression was relatively poor in global EVs but markedly improved in liver‐specific EVs, up to AUROC = 1.000.ConclusionWe provide a proof of principle for the use of EV‐derived miRNA ratio biomarkers in minimally invasive NAFLD diagnosis and describe a method for extracting liver‐specific EVs for this application.Support or Funding InformationNHMRC project grant (1158210) Pfizer Investigator Initiated project grantReceiver operating characteristic (ROC) curves for miR‐122 ratios derived from liver‐specific extracellular vesicles (EVs) in predicting all NAFLD and only fatty liver.Figure 1
Elevated Circulating Cardiac Troponins in Chronically Catheterized Pre‐and Post‐Natal Sheep
Authors: Jonker Sonnet S. 
Published: April 2020

BACKGROUNDCirculating markers of cardiac damage have been reported to be elevated in cord blood of healthy infants. This elevation is reported to be independent of the stress of labor, as elevations are also reported in the cord blood of healthy infants delivered by Caesarian section prior to labor. We hypothesized that circulating markers of cardiac damage are elevated in the late‐term fetus prior to delivery.METHODSThree fetal sheep were surgically instrumented with indwelling catheters in the carotid artery and coronary sinus. Sheep were recovered from surgery, and daily blood samples were taken to determine circulating levels of cardiac troponin I (cTnI), c‐reactive protein (CRP), and N‐terminal pro hormone BNP (nt‐ProBNP) using the Siemens DIMENSION VISTA, and cardiac troponin T (cTnT) using the Roche cobas e601 STAT. Data were visualized to determine trends.RESULTSWe found that circulating cTnI and cTnT levels tend to decline in the week preceding birth. Troponins also were elevated following natural vaginal delivery. CRP and nt‐ProBNP levels were not detectable.CONCLUSIONSThese data support our hypothesis that a cardiac process is releasing cardiac troponins to circulate 1–2 weeks prior to birth. Further investigation is required to determine if this is a transient event, or if levels are high throughout fetal development. We also found that levels decline as term approaches, but that birth re‐stimulates release of these markers of cardiac damage.Support or Funding InformationOHSU Medical Research FoundationCirculating markers of cardiac damage in chronically catheterized perinatal sheep. The x‐intercept represents day of surgery, while the dashed line represents the day of birth. Solid symbols = blood samples from the carotid artery. Open symbols = blood samples from the coronary sinus.Figure 1
Non‐Enzymatic Lysine Lactoylation of Glycolytic Enzymes
Authors: GALLIGAN JAMES , Gaffney Dominique O. , Jennings Erin Q. , Anderson Colin C , Marentette John O. , Shi Taoda , Oxvig Anne-Mette Schou , Streeter Matthew D. , Johannsen Mogens , Spiegel David A. , Chapman Eli , Roede James R 
Published: April 2020

Post‐translational modifications (PTMs) regulate enzyme structure and function to expand the functional proteome. Many of these PTMs are derived from cellular metabolites and serve as feedback and feed‐forward mechanisms of regulation. We have identified a novel PTM that is derived from the glycolytic by‐product, methylglyoxal. This reactive metabolite is rapidly conjugated to glutathione via glyoxalase 1, generating lactoylglutathione (LGSH). LGSH is hydrolyzed by glyoxalase 2 (GLO2), cycling glutathione and generating D‐lactate. We have identified the non‐enzymatic acyl transfer of the lactate moiety from LGSH to protein Lys residues, generating a ‘LactoylLys’ modification on proteins. GLO2 knockout cells have elevated LGSH and consequently, a marked increase in LactoylLys. Using an alkyne‐tagged methylglyoxal analog, we show that these modifications are enriched on glycolytic enzymes and regulate glycolysis. Collectively, these data suggest a previously unexplored feedback mechanism that may serve to regulate glycolytic flux under hyperglycemic or Warburg‐like conditions.Support or Funding InformationFinancial support was provided by National Institutes of Health Grants (R01 ES027593 for J.R.R.), the SENS foundation (D.A.S.), the American Diabetes Association Pathway to Stop Diabetes Grant 1‐17‐VSN‐04 (D.A.S.), and the Velux Foundations (VELUX34148, A‐M.S.O). Mass spectrometry and proteomics data were acquired by the University of Arizona Analytical and Biological Mass Spectrometry Facility supported by NIH/NCI grant CA023074 to the University of Arizona Cancer Center, UA Research Development and Innovation Office, and by the BIO5 Institute of the University of Arizona.Figure 1
Lysyl Oxidase Internalization in Deformed Cardiomyocytes Following Myocardial Ischemia in Mice
Authors: Chu Qing , Xiao Ying , Song Xin , Kang Y. James 
Published: April 2020

Lysyl oxidase (LOX), a copper‐dependent amine oxidase, catalyzes the cross‐linking of collagen and elastin in extracellular matrix. In response to myocardial ischemia, LOX is over‐produced in cardiomyocytes. The present study was undertaken to understand the relationship between the changes in LOX production and alterations in cardiomyocytes following myocardial ischemia. Male C57BL/6J mice aged 8–12 weeks old were subjected to left anterior descending (LAD) coronary artery ligation to induce ischemic injury. The hearts were collected at 1st, 4th, or 7th day after the surgery and cut into serial frozen/paraffinsections. Histological examination identified typical rod‐shaped cardiomyocytes in sham‐operated mice, which was gradually transformed into rounded‐shaped from 1st to 7th day after LAD artery ligation. Corresponding to the deformation, connexin 43 (Cx43), an important gap junction protein, was decreased in the intercalated discs in ischemic infarct area. There were two isoforms of LOX, pro‐peptide (LOX‐PP) and spliced peptide (active LOX), identified in cardiomyocytes. The active LOX, not the LOX‐PP, was colocalized with Cx43 in the intercalated discs in normal cardiomyocytes. In response to ischemia, the levels of both active LOX and LOX‐PP were increased, and moreover, active LOX was dissociated from Cx43 and relocated in the cytosol of the deformed cardiomyocytes from 1st to 7th day post myocardial ischemia. Our findings suggest that in response to ischemia, the internalization of active LOX from the intercalated discs to the cytosol of cardiomyocytes is likely responsible for the breakage of the intercellular junction, leading to the loss of cell polarity and the consequent deformation cardiomyocytes.Support or Funding InformationWest China Hospital, Sichuan UniversityImmunofluorescence micrographs of LOX in cardiomyocytes. Two isoforms of LOX, pro‐peptide (LOXPP) and spliced peptide (active LOX), identified in cardiomyocytes. The levels of both active LOX and LOX‐PP were increased from 1st to 7th day post myocardial ischemia. Moreover, active LOX relocated in the cytosol of the deformed cardiomyocytes.Figure 1Co‐immunofluorescence micrographs of LOX/LOX‐PP and Cx43. The active LOX, not the LOX‐PP, was colocalized with Cx43 in the intercalated discs in normal cardiomyocytes and was dissociated from Cx43 at 7th day after ischemia.Figure 2
Impact of S220A and E168A mutations on M. tuberculosis Indole‐3‐Glycerol Phosphate Synthase (IGPS) catalysis
Authors: Leon Hernandez Katherine M. 
Published: April 2020

The enzyme indole‐3‐glycerol phosphate synthase (IGPS) catalyzes the conversion of 1‐(o‐carboxyphenylamino)‐1‐deoxyribulose‐5‐phosphate (CdRP) to indole‐3‐glycerol (IGP) in the tryptophan biosynthetic pathway in bacterial organisms (Scheme 1). The tryptophan biosynthetic pathway is necessary for bacterial life, therefore, this enzyme represents a potential target for antibacterial drug development against pathogenic organisms. Because IGPS is absent in humans, no concerns for homolog selectivity need to be considered. Our goal is to investigate substrate/ligand binding and the catalytic mechanism of M. tuberculosis IGPS to facilitate inhibitor discovery. To study how this enzyme interacts with ligands and catalyzes the reaction, mutated plasmids that code for M. tuberculosis IGPS wildtype, as well as mutants S220A and E168A, were expressed in E. coli and purified via a His‐tag. The wildtype and the active site mutants S220A and E168A were studied via kinetic assays. Based on previously reported results, we suspected that Ser220 may be involved in ligand and substrate binding in M. tuberculosis IGPS. We hypothesized that Glu168 plays an important role in either catalysis or binding. We measured wildtype activity following the rate at which the product IGP is produced monitoring fluorescence with an excitation wavelength of 280 nm and an emission wavelength of 340 nm. We have found that the mutant E168A has no detectable activity, indicating that residue E168 plays a critical role in catalysis. We have also found that the catalytic activity of S220A is greatly reduced compared to the wildtype enzyme, indicating that S220 plays an important role as well. Understanding the roles that the active site residues play in M. tuberculosis IGPS ligand binding and catalysis will contribute to future drug discovery efforts.Support or Funding InformationNIH grant 1R15GM126467‐01 titled “Investigation of Substrate Specificity, Mechanism, and Inhibition of IGPS”Scheme 1. Reaction Catalyzed by MtIGPS and a Proposed MechanismFigure 1
NRF from Diceratella elliptica (DC.) Jonsell. as Strong and Safe Insulin Resistance Modulator and NASH Preventer
Authors: Mohammed Eman D. , Zhang Zechuan , Tian Wenfang , Gangarapu Venkatanarayana , Al-Gendy A. A. , Chen Jun , Wei Jifu , Sun Beicheng 
Published: April 2020

BackgroundInsulin resistance (IR) and lipotoxicity were evidenced as the major nonalcoholic steatohepatitis (NASH) initiators. Absence of the effective treatment against NASH progression raised our aim to discover a new fraction rich in glucosinolates (GLS) hydrolysis products from Diceratella elliptica (DC.) Jonsell, with promising insulin sensitizing activity & anti‐NASH potentiality.PurposeOur study aimed to extract and prepare a nitriles rich fraction (NRF) from Diceratella elliptica (DC.) Jonsell, investigate its insulin‐sensitizing & anti‐NASH potentiality.Study DesignNRF was prepared using natural autolysis and compounds were identified. Seventy male Wistar rats were feed high fat diet (HFD) or normal pellets for 35 days. In HFD rats, Streptozotocin (STZ) has been injected in day 14th and treatment has been started on day 21st with either NRF (30, 60 and 120 mg/kg; orally) or pioglitazone (PioG) (10 mg/kg; i.p) beside HFD. While, NRF‐alone rats were treated with NRF (120 mg/kg; orally) beside the normal pellets. Body weight, glucose homeostasis, hepatopathological examinations were performed.MethodsBoth GLC/MS and HPLC were used for compounds’ identification while UV spectrophotometer was used for total glucosinolates (GLS) quantification. The biochemical and general molecular investigations concerned with liver lipotoxicity, oxidative stress, inflammation and insulin signalling pathway have been done and confirmed with the computational prediction of the major compounds’ targets.ResultsButenyl and benzyl GLS were the major along with other volatile compounds. NRF had significantly increased the insulin sensitivity and improved NASH‐hisptopathology showing hepatoprotective effect. While, the fraction’s anti‐NASH potentiality was evidenced in the normalized hepatic steatosis markers, inflammation and oxidative stress key transcriptional factors resulting in induction of insulin receptor substrates (IRSs) phosphorylation and its downstream effectors.ConclusionNRF has reversed IR, stimulated leptin secretion and prevented NASH initiation showing promising anti‐NASH and anti‐fibrotic effects with no side effects. Isolation of benzyl nitrile as a single compound and re‐investigate it in IR‐NASH model is recommended.Support or Funding InformationThis work was funded by Chinese Governmental Scholarship (CSC No. 2017GBJ001933), Beijing, China.Figure 1
The Effect of Cartilage Thickness on Reconstructions of Range of Motion and Muscle Leverage in Extinct Tetrapods
Authors: Dao Brandon , Chevalier-Horgan Christine L. , Pierce Stephanie E. , Molnar Julia L. 
Published: April 2020

Investigating structure‐function relationships in the locomotor system requires an understanding of the complex interactions between bones, cartilage and muscles. This is especially true when examining how these musculoskeletal structures evolved over time and across different environments in both extant and extinct species. We aimed to quantify the effect of different assumptions about cartilage thickness on reconstructions of femur length, hip range of motion (ROM), and muscle leverage in Acanthostega gunnari, one of the earliest known tetrapods and an important species in the vertebrate water‐land transition. We began by examining the hindlimbs of two extant salamanders, Dicamptodon ensatus and Ambystoma mexicanum, using contrast‐enhanced micro‐CT in order to extrapolate the degree to which cartilage thickness might affect femur length in a fossil taxon with salamander‐like morphology. Data visualization software was used to measure the distal and proximal cartilage caps of the femora in each of the extant species. Three‐dimensional modeling software was then used to estimate the center of rotation of the hip joint of Acanthostega. Then, cartilage correction factors were applied based on the measurements from the extant taxa. The limit of ROM was defined as the point at which either the femur contacted the pelvis, or less than 50% of the femoral head remained within the acetabulum. Finally, we used biomechanical modeling software to map muscles onto the bones of Acanthostega and plotted their leverage to examine how assumptions about cartilage affect reconstructions of muscle leverage. Cartilage caps on the proximal end of the femur in Dicamptodon and Ambystoma measured 36% and 14% of femur length, respectively. Taking the most conservative estimate, we modeled Acanthostega with cartilage caps of 0, 7.5 and 13% femur length. The greatest variation in muscle leverage occurred in muscles whose axes of movement were nearly perpendicular to the femur (70–120% of the mean moment arm), as opposed to those muscles whose axes were nearly parallel (less than 10%). We also found that assuming the highest percentage of cartilage increased ROM in protraction and retraction by 15–20° and in elevation and depression by 15–30° but had little to no effect on long‐axis rotation. These results will help to predict the effects of unpreserved soft tissues in future studies that reconstruct ROM and muscle leverage in extinct animals.Effect of different cartilage correction factors on reconstructed hip muscle leverage in the early tetrapod Acanthostega gunnari.The y‐axis shows coefficient of variation of muscle leverage (standard deviation/mean moment arms) across cartilage correction factors of 0, 7.5 and 13% femur length. Moment arms were measured in 3 axes of movement for muscles that cross the hip joint. The greatest effects occurred in muscles with lines of action nearly perpendicular to the femur.Figure 1
ADVANCED YOGA PRACTICE AND REHABILITATION OF RECURRENT SHOULDER DISLOCATION: A CASE REPORT
Authors: singh umesh pal 
Published: April 2020

The background of being a physician, yoga practitioner, and recurrent shoulder dislocation sufferer, gave me an opportunity for developing unique and detailed insights into how the design and biomechanics of the human body works, and just as important, how it doesn’t. By successfully applying the knowledge of the structure and function of latissimus dorsi (lat) muscle into my advanced yoga practice, I could be able to rehabilitate my shoulder problem up to a great extent – You can see the difference in the time‐lapse photographs of my body showing striking improvement in my condition.There are very few muscles in the body whose functionality is as important as the lats. They affect major functions throughout the body i.e., reaching, walking, and respiratory movements. Problem is that most people have uneven lat strength. Keeping them uneven, however, can cause shoulder problems of instability (subluxation and even dislocation), low back, neck, and spine issues.Optimally strengthening and stretching the latissimus dorsi is critical for overall balance and stability ‐ that is required for everyday tasks. The problem is that lats are a very hard muscle to access and make good use of. But, via yoga practice (gravity assisted and resisted bodyweight exercises), we can keep both the lats (weak and strong) online ‐ consciously engaged – so that tension integrity can be attained and maintained (Sherington’s principles). This understanding can lead to the judicious application of interventions to improve a person’s abilities!Gravity is the primary mode of intervention ‐ the postural reflexes provide the basis for automatic control of posture, balance, and coordination in a gravity‐based environment. Moreover, Gravity workout can increase awareness of our feelings, help release myofascial and arthrogenic fixations, and mitigate stress response through vagal stimulation by utilizing specific movements or positions, breathing practices, and meditation – you can do them throughout the day to loosen the body and calm the mind.The exercise program presented in this article can be helpful in optimizing the function of your shoulder.Results ‐ time‐lapse photographs of the body showing improvement of my conditionSupport or Funding InformationNAScapular dyskinesis – we can changeFigure 1