bluuebunny/crossref_metadata_2025 huggingface dataset:
Applicability of Capnography in the Adult ICU During Physical Therapy: A Systematic Review
Authors: Smith Karen R. , Hubbert Doug R. , Murphree Lisa K.
Published: April 2020

Purpose

The purpose of this review was three‐fold: first, evaluate the strength and quality of the current research evidence on usage of capnography, second, determine whether current evidence regarding the use capnography during physical therapy should be considered when making decisions regarding patient’s response to physical therapy; and third, identify weaknesses in the current evidence and area for continued research.

Background/Significance

Capnography is typically used in emergency departments and postoperatively but is not commonly used during physical therapy. Pulse oximetry is typically used to monitor oxygen desaturation and hypoxemia during physical therapy but does not predict or monitor respiratory depression. Capnography monitoring during exercise and mobility could have benefits for physical therapists monitoring patients during therapy as well as provide prognostic value of patient progress.

Methods and Materials

A literature search was completed using: Science Direct, IOP Science, PLOS one, Google scholar, Wiley, EBSCO Host, CINAHL Complete, Cochrane Library, and PubMed. Keywords: capnometry, capnography accuracy, physical therapy, application of capnography, mobility, monitoring. Articles selected for review were those of original research or systematic review published since 2009 and evaluated for quality using the Oxford Centre for Evidence‐Based Medicine 2011 levels of evidence system.

Results

Twenty‐seven articles are included for this study. Six articles were included in the introduction. Seven articles examined the current practices for use of capnography; six studies looked at the use of capnography in the intensive care unit. Three articles on pulse oximetry and capnography with mobility, two articles on the use of monitoring ventilation and oximetry during exercise, and three studies on biologically‐based assessment tools for physical therapy.

Conclusions

Evidence suggests that monitoring partial pressure end‐tidal carbon dioxide (PETCO2) levels in patients during rest and exercise may provide more prognostic value of possible adverse events in patients with conditions such as heart failure. Monitoring ventilatory responses in patients is valuable in physical therapy as it indicates tolerance to activity. Evidence suggests there is a significant correlation between PETCO2 and cardiac output. Recent research also suggests regardless of mask or cannula used on patients, diagnostic accuracy of measuring PETCO2 is similar during normal and hyper‐ventilatory states. With increasing application of capnography in intensive care settings, studies involving usage in physical therapy are warranted.
Cancer Attenuates Nutrient Activation of Skeletal Muscle mTORC1 in Female Mice
Authors: Counts Brittany , Halle Jessica , Carson James
Published: April 2020

Cancer‐induced metabolic disruptions can alter tissue specific energy demands and has the potential to alter muscle responses to feeding. Mechanistic target of rapamycin complex 1 (mTORC1) signaling axis is activated by nutrient stimuli, and cancer cachexia can suppress basal muscle mTORC1 signaling in mice. However, gaps still remain in our understanding of how the cancer environment effects skeletal muscle nutrient regulation of mTORC1 signaling.

Purpose

We examined the effect of feeding on skeletal muscle mTORC1 signaling in female tumor bearing mice.

Methods

Female C57BL/6 (B6) and ApcMin/+ (MIN) mice were fasted for 12‐hrs during the light cycle. Following the 12‐hr fast, mice were given access to a food pellet for 1‐hr (B6 FED:N=7, MIN FED:N=8) or fasted for another hour (B6 FAST:N=6, MIN FAST:N=7). Circulating blood glucose, and plasma IL‐6 and insulin were taken prior to sacrifice. Gastrocnemius muscle was homogenized for protein analysis. Statistical significance was set at p£0.05.

Results

The MIN FED and MIN FAST groups were not different in percent body weight change, polyp number, plasma IL‐6, and hindlimb muscle mass. 1‐hour food intake was not different between B6 FED and MIN FED mice. Both MIN FED and B6 FED increased stomach mass, blood glucose, and circulating insulin levels. Compared to FAST mice, FED mice increased p70S6K and rpS6 phosphorylation, and was positively associated to insulin in both B6 and MIN mice. 4E‐BP1 phosphorylation was increased in the B6 FED compared to B6 FAST, but this response was blunted in the MIN FED. Additionally, circulating insulin concentration was associated to 4E‐BP1 phosphorylation in the B6 FED, but not in the MIN FED.

Conclusion

The cancer environment can suppress the nutrient‐induced phosphorylation of skeletal muscle 4E‐BP1. Future studies are warranted to determine if the combination of exercise or muscle contraction can improve skeletal muscle mTORC1’s response to nutrients in the female cancer environment

Acknowledgements

NCI R01‐CA121249
Evaluating Data to Determine when Biotherapeutic Vitamin A Supplementation can be Scaled Back in Children <5 Years Old
Authors: Tanumihardjo Sherry A.
Published: April 2020

The World Health Organization recommends that high dose vitamin A supplements be administered to children under the age of 5 years to be used as a biotherapeutic to prevent morbidity and mortality. Vitamin A is essential for vision, immunity, reproduction, and growth. In addition to high dose supplements, many countries add preformed vitamin A to staple foods during processing. The Global Alliance for Vitamin A (GAVA) has set up a decision framework to follow to determine if a country can scale back high dose vitamin A supplements in preschool children. The objective of this work was to evaluate data available in African countries to determine if vitamin A supplements can be scaled back. The framework includes evaluating demographic information, dietary intake data, and biomarkers of vitamin A status. All of these data were available for one province in South Africa, one district in Zambia, and a subgroup of children enrolled in a demographic health survey in Ghana. In South Africa, it was determined that there is enough evidence to scale back high dose supplements in one province, but not enough data to scale back supplementation in the whole country. A similar finding was determined in one area of Zambia where dietary intake is adequate. In Ghana, the evidence is mounting that status has improved, but there are still pockets of vitamin A deficiency that likely benefit from high dose supplementation. In conclusion, overlapping interventions in some countries likely leads to adequate vitamin A intakes and in some cases excess. Vitamin A supplementation is used as a therapy to save children’s lives, but in some areas it may no longer be necessary. The repercussions of vitamin A deficiency are devastating and the world has the means to eradicate it; however, vitamin A excess to the point of toxicity also has health concerns. Therefore, balancing needs with intakes is important for overall health. The GAVA framework can be used in any country that has all of the needed data to evaluate their situation or to determine where more data may be needed.

Support or Funding Information

Support for these studies was obtained from the International Atomic Energy Agency (South Africa), HarvestPlus (Zambia), and GroundWork (Ghana). Evaluation of the data was done independently from the funding agencies on published data.
A cis‐regulatory Element in Intron 1 Cooperates with the Core Promoter during Salinity Induction of Tilapia Glutamine Synthetase
Authors: Kim Chanhee , Kültz Dietmar
Published: April 2020

Mozambique tilapia (O. mossambicus) is a euryhaline fish that tolerates salinity ranging from fresh water (FW) to 120 g/kg (> 3x seawater, SW). Hyperosmotic stress associated with salinity transfer from FW to SW strongly induces glutamine synthetase (GS) transcription in tilapia, including a brain cell line model (OmB cells). In this study we cloned the 5′ regulatory sequence (RS) (including 5′‐flanking region and 5′‐UTR) of the O. mossambicus GS gene to identify osmotic response elements that mediate transcriptional induction. Using enhancer trapping, we discovered a novel osmosensitive mechanism that utilizes an unusual enhancer cassette in intron 1 of the GS gene. This cassette includes a single copy of a cis‐regulatory element (CRE), the osmolality/salinity‐responsive element 1 (OSRE1). We show that intronic OSRE1 is necessary but not sufficient for intron 1‐mediated hyperosmotic GS induction. Furthermore, intron 1 and its interaction with the GS core promoter complex are also necessary for hyperosmotic GS induction. We propose a novel model for hyperosmotic intron 1‐mediated induction of the O. mossambicus GS gene that is based on the interaction of an OSRE1 enhancer, intron 1, and the core GS promotor.

Support or Funding Information

This study was funded by a grant from NSF (IOS‐1656371).
A Rare Occurrence of Left‐Sided Inferior Vena Cava: A case report
Authors: Skowronski Christian , Ngo Han G. , John Jithin , Bukhsh Omar , Silverman Brittany R. , Venuti Judith , Barremkala Malli
Published: April 2020

In this case study we analyzed the presentation of a left‐sided inferior vena cava (IVC) in the abdomen, inferior to the renal vein contributions. The occurrence rate for a left‐sided IVC in the population is reported to be between 0.2–0.5% (
Malaki, Willis, Jones, 2012). Normal development of the IVC is complex with multiple contributions. A left‐sided IVC is believed to be the consequence of the persistence of the left‐sided supracardinal vein and a midline anastomosis, and regression of the right‐sided supracardinal vein (
Mayo, Gray, St. Louis, Grosman, McLoughlin, Wise, 1983). Anatomical dissection of 24 human cadavers (average age = 80 years old) found one cadaver (4.1%) (Female; 75 year‐old) with a left‐sided inferior vena cava. This report contributes to studies gathering data on the population frequency of the left‐to‐right sided vena cava abnormality. Clinically, a left‐sided inferior vena cava is asymptomatic with thromboembolic complications as the chief concern. Knowledge of the potential for a left‐sided inferior vena cava is valuable in surgical and interventional radiology preparation, as well as to prevent a misdiagnosis of left para‐aortic lymphadenopathy (
Malaki, Willis, Jones, 2012).
Lectin Staining Biomarkers for Gene Therapy in GNE Myopathy
Authors: Crowe Kelly E.
Published: April 2020

GNE myopathy (GNEM) is an autosomal recessive disease characterized by muscle wasting and weakness. This disease is caused by mutations in the GNE (UDP‐N‐acetylglucosamine (GlcNAc) 2‐epimerase/N‐acetylmannosamine (ManNAc) kinase) gene, which encodes a bifunctional enzyme that catalyzes the committed step of sialic acid (SA) biosynthesis. As such, GNE mutations found in GNEM impair enzymatic function and generally result in a decrease of SA. Efforts to treat GNEM with gene therapy are currently underway, but given the slowly progressing muscle pathology of GNEM, it becomes important to establish molecular biomarkers to assess such a therapy during the relatively brief timescale of a clinical trial. To do so, we have compared SA abundance in converted myoblasts from GNEM and otherwise normal patients using fluorescently labeled lectins, which can reflect cellular SA levels. Here, we describe changes in SA abundance in GNE myopathy that could serve as surrogate biomarkers for a GNE gene therapy clinical trial.

Support or Funding Information

This work was supported by a grant from the Neuromuscular Disease Foundation (NDF).
Class III PI3‐Kinase in Angiotensin II‐Induced Cardiac Hypertrophy
Authors: Sun Chengwen , Zhong Tiecheng , Guo Ang , O’Rourke Stephen T. , Guo Lirong
Published: April 2020

Pathological cardiac hypertrophy could lead to heart failure and sudden cardiac death. Our previous study demonstrated that Class I PI3‐kinase (PI3KC1) contributes to the development of cardiac hypertrophy by elevating intracellular reactive oxygen species (ROS) levels. In the current study, we evaluated the role of Class III PI3‐kinase (PI3KC3) in Ang II‐induced cardiac hypertrophy. Treatment of cultured cardiomyocytes with Ang II (10−6 M) significantly increased the cellular surface area, which was measured under a fluorescence microscope after staining with anti‐alpha‐sarcomeric actin antibodies. In cardiomyocytes, Ang II (10−9‐10−5 M) induced a dose‐dependent activation of PI3KC3, detected using an ELISA kit. More interestingly, Ang II‐induced cardiac hypertrophy was dramatically exacerbated by co‐treatment with 3‐Methyladenine (3‐MA, 10−6 M), a PI3KC3 inhibitor, suggesting that activation of PI3KC3 may play a protective role in Ang II‐induced cardiac hypertrophy. To identify the intracellular signaling pathway involved in the PI3KC3‐mediated protective effect, mitochondrial ROS was measured using MitoSOX in cardiomyocytes treated with control, Ang II (10−6 M), Ang II plus 3‐MA (10−6 M), and 3‐MA alone. The results demonstrated that Ang II treatment significantly increased mitochondrial ROS production and that Ang II‐induced increases in ROS generation were potentiated by co‐treatment with 3‐MA. It is well known that the major intracellular source of ROS is the damaged mitochondria, which is scavenged by autophagy (also called mitophagy) in cardiomyocytes. Thus, we measured autophagy activity by detection of autophagosomes using staining method with MAP‐LC3 antibodies in cardiomyocytes treated with Ang II. Treatment of cardiomyocytes with Ang II (10−9 to 10−5 M) significantly increased autophagy activity with two phases (increased activity at low doses, decreased activity at high doses, peaked at 10−7 M). More interestingly, Ang II (10−6 M)‐induced increases in autophagy were dramatically attenuated by 3‐MA (10−6 M). Taken together, these data suggest that activation of PI3KCIII has a protective effect on Ang II‐induced hypertrophy by enhancing autophagy activity and decreasing mitochondrial ROS generation in cardiomyocytes.

Support or Funding Information

NIH HL143519
Altered Lipid Domains in Pulmonary Arterial Smooth Muscle Facilitate Enhanced Depolarization‐Induced Vasoconstriction following Chronic Hypoxia
Authors: Ahmadian Rosstin , Norton Charles E. , Jernigan Nikki L. , Paffett Michael L. , Naik Jay S. , Walker Benjimen R. , Resta Thomas C.
Published: April 2020

Chronic hypoxia (CH) augments depolarization‐induced pulmonary vasoconstriction through a myofilament Ca2+ sensitization mechanism involving epidermal growth factor receptor (EGFR) and NADPH oxidase‐dependent Rho kinase activation. Although the mechanism that links CH exposure to activation of this pathway is unknown, previous studies support a role for caveolin‐1 and cholesterol to regulate both EGFR and NADPH oxidase. Furthermore, membrane cholesterol content can influence caveolin‐1 interactions with a variety of proteins. Therefore, we hypothesized that derangement of these lipid domain components contributes to increased depolarization‐induced Ca2+ sensitization and pulmonary vasoconstriction following CH.

To test this hypothesis, we examined vasoconstrictor responses to depolarizing concentrations of KCl (30–120 mM) in pressurized, endothelium‐disrupted pulmonary arteries (~150 um diameter) from control and CH (4 wk at 0.5 atm) rats under conditions in which vascular smooth muscle Ca2+ was clamped with ionomycin (3 mM). The effects of altered lipid domains on vasomotor responses were tested utilizing a solution of MβCD and cholesterol (10 mM and 2 mM respectively) to increase cholesterol, and the caveolin‐1 scaffolding domain peptide, AP‐Cav (10 mM). We also assessed the incidence of caveolae using transmission electron microscopy and caveolin‐1 levels by western blotting. Membrane cholesterol content was quantified by filipin (50 mg/ml) fluorescence using confocal microscopy.

In agreement with our hypothesis, CH reduced membrane cholesterol content in pulmonary arterial smooth muscle. However, CH was without effect on caveolin‐1 expression or the incidence of caveolae. CH augmented vasoconstrictor sensitivity in response to depolarizing concentrations of KCl as previously described. Both cholesterol repletion and AP‐Cav prevented effects of CH to enhance KCl‐dependent constriction and normalized reactivity between groups. Interestingly, AP‐Cav restored smooth muscle membrane cholesterol in arteries from CH rats to the level of controls, consistent with evidence that caveolin‐1 can regulate cholesterol trafficking to the cell membrane. These results support an effect of AP‐Cav to attenuate KCl‐dependent vasoconstriction following CH by normalizing membrane cholesterol levels. We conclude that alterations in the lipid domains resulting from reduced cholesterol facilitate enhanced depolarization induced pulmonary vasoconstriction following CH.

Support or Funding Information

NIH Grants R01 HL132883 and T32 HL007736. AHA Grant 13PRE14580015
Using a Mental Obstacle Course to Engage and Elevate Learning in an Anatomy and Physiology Laboratory
Authors: Marvar Sarah Knight , Hazen Rebecca F.
Published: April 2020

OBJECTIVE

In order to increase student engagement and learning in a combined anatomy and physiology undergraduate teaching laboratory we designed a type of mental obstacle course. Students completed a series of ‘quests’ designed to increase student learning and develop skills such as critical thinking and analysis. We used this strategy specifically in classes that lacked dynamic student activities and that we felt might otherwise be less engaging and impactful.

METHODS

In laboratory classes of 15 students, we designed between 5–8 stations comprised of multistep quests on a specific aspect of the central topic of the laboratory. Students worked in small groups of 2–3, could consult with peers and use outside resources available to them to complete the tasks. The groups of students were required to complete the quests and submit their answers in order to finish the class. Examples of quests that we used were reviewing x‐ray images of various human pathologies of the skeletal system and answering a series of questions about those images including anatomical information, normal physiological processes and apparent pathology of the case. A second example was students were required to create a model of a synovial joint using modeling clay and then annotate the model with information on anatomical features and their functions.

RESULTS

As a class we reviewed the tasks and the answers in order to correct any mistakes and student misconceptions. A week later we reviewed the material in quiz form to assess the success of the obstacle course on student understanding. We found that some of the tasks were more successful than others and were occasionally surprised by the results, such as the ability of the students to recall some of the clinical cases from a task.

CONCLUSIONS

The quest laboratory set‐up was popular with students and increased their engagement with the material and with each other. Using student feedback and quiz results we plan to improve the design of the tasks and further increase student engagement and understanding.
Effects of Intrathoracic Pressure changes on Diaphragmatic Blood Flow during Mechanical Ventilation
Authors: Horn Andrew Gary , Baumfalk Dryden R. , Schulze Kiana Marie , Colburn Trenton David , Weber Ramona Elaine , Kunkel Olivia Nicole , Bruells Christian S. , Musch Timothy I. , Poole David C. , Behnke Bradley Jon
Published: April 2020

Introduction

Although mechanical ventilation (MV) is a life‐saving intervention, prolonged MV can lead to deleterious effects on diaphragm function, such as ventilator‐induced diaphragmatic dysfunction (VIDD) and vascular incompetence. Specifically, prolonged MV elicits time‐dependent reductions in diaphragm blood flow, induces vascular dysfunction, and limits the hyperemic response to contractions associated with weaning. During MV, positive‐end expiratory pressure (PEEP) is used to maintain small airway patency and mitigate alveolar damage; yet increased intrathoracic pressure with high levels of PEEP may impair diaphragm perfusion.

Purpose

To test the following hypotheses: 1) Diaphragm blood flow during MV will be less with high vs. low‐peep, and 2) ablation of intrathoracic pressures (via pneumothorax (PTX)) will not alter diaphragm blood flow during MV vs. the low‐peep condition.

Methods

Female Sprague‐Dawley rats (~5 mo) were randomly divided into low PEEP (LP; 1cmH2O, n=7) or high PEEP (HP; 9 cmH2O, n=6) groups during mechanical ventilation. Blood flow, via the fluorescent microsphere technique, was determined during spontaneous breathing (SB) and 10 minutes after intubation and the onset of MV with LP or HP. Thereafter, for a third determination of diaphragm blood flow, the LP group underwent a surgical laparotomy (LAP; to determine effects of intrabdominal pressure on perfusion) and the HP group was subjected to a pneumothorax (PTX), with microsphere infusions occurring 10 minutes after the completion of surgery. Following the final fluorescent microsphere infusion, tissues were harvested for blood flow analysis. The diaphragm was sectioned into costal (ventral, medial, and dorsal) and crural portions to determine diaphragmatic blood flow distribution.

Results

Compared to SB, both LP and HP MV significantly reduced diaphragm medial costal blood flow (LP, 61.9 ± 7.5 vs 43.8 ± 4.9; HP, 46.2 ± 7.7 vs 21.8 ± 3.7 mL/100g/min; P≤0.05). HP MV significantly reduced blood flow to the ventral and medial costal diaphragm compared to LP MV (P≤0.05). In the HP MV+PTX condition, medial and dorsal costal blood flow was significantly increased versus HP MV (P≤0.05). LP MV + LAP did not significantly increase diaphragm blood flow compared to LP MV. Diaphragm perfusion during HP MV+PTX and LP MV were not different (P>0.05).

Conclusion

This study demonstrates that HP MV reduces diaphragmatic blood flow to a greater extent than LP MV. Following a PTX in the HP MV condition, diaphragmatic blood flow is not different compared to the LP MV condition, suggesting that the reductions in diaphragmatic blood flow with LP MV are independent of intrathoracic pressure changes, and due likely to diaphragm quiescence.

Support or Funding Information

Supported by: NIH HL137156‐01A1
Targeting of the membrane‐anchored Rab GAP (GTPase accelerating protein) Gyp8 to peroxisomes is regulated by the AAA ATPase Msp1
Authors: Nickerson Daniel Patrick , Quinn Monique , Lin Ariel , Mora Adrian , Vuong Chau , Connolly Sean , Delgado Beatriz
Published: April 2020

Eukaryotic cells use vesicular transport to build and maintain membrane‐bound organelles housing specific biochemical functions. Rab GTPase signaling proteins (Rabs) are key regulators of vesicular transport, controlling where and when membranes dock and fuse, ensuring lipid and protein cargoes are delivered to appropriate destinations. Rabs depend upon GTPase accelerating proteins (GAPs) to trigger GTP hydrolysis and return the signaling active, GTP‐bound Rab to its inactive, GDP‐bound state. Rab GAPs contribute to the efficiency and fidelity of transport pathways, and defective Rab GAPs are implicated in a variety of human diseases. Rab GAPs tend to be cytosolic proteins that transiently localize at membranes to survey for their client Rab. We report that the yeast Rab GAP Gyp8 is an atypical transmembrane (TM) GAP whose association with peroxisomes is regulated by the AAA ATPase Msp1, a chaperone that functions to remove tail‐anchored proteins from peroxisomes and mitochondria. Computational analysis of Gyp8 predicted a single‐pass TM domain near the carboxy terminus, characteristic of a tail‐anchored protein. Fluoresence microscopy indicated that GFP‐tagged Gyp8 co‐localized with endoplasmic reticulum (ER) and peroxisomal markers in wild type cells. In the absence of peroxisomes, GFP‐Gyp8 redistributed to the ER. Loss of Msp1 chaperone function resulted in mislocalization of GFP‐Gyp8 to mitochondrial membranes. Subcellular fractionation biochemically demonstrated that Gyp8 localized exclusively to a membrane fraction containing peroxisomes. Truncation analyses of Gyp8 indicated that the TM and luminal domains are necessary and sufficient to direct localization to peroxisomes. Growth and viability experiments of cells lacking specific Rab GAPs indicate a peroxisome‐specific carbon utilization defect in cells lacking Gyp8. These data represent the first report in any experimental system of a Rab GAP that localizes to peroxisomes.

Support or Funding Information

Funded by grants from the CSUSB Office of Student Research and Associated Students Inc.
A New Player in Glucose Counterregulation: the Glycemic Effects of Neuronostatin through GPR107 and Enhanced Glucagon Secretion
Authors: Grote Stephen , Mahmood Ammar , Samson Willis , Yosten Gina
Published: April 2020

Regulation of blood glucose is a tightly controlled system with numerous players, woven by both hyperglycemic and hypoglycemic agents that interact in secretion and signaling mechanisms. However, this complex system is deranged in both Type 1 and Type 2 Diabetes, in the response to hyperglycemia (insulin) and hypoglycemia (counterregulatory factors such as glucagon). In treating diabetes with insulin and antidiabetic agents, there is significant risk of hypoglycemia due to improper dosing or inadequate food intake. In addition, repeated bouts of hypoglycemia diminish the counterregulatory response and blunt awareness of symptoms, creating a vicious cycle of unawareness and increasingly severe hypoglycemia. There is great need for better understanding of the players and mechanisms in blood glucose maintenance, and specifically in diabetic hypoglycemia.

We recently identified a novel peptide, neuronostatin (NST), encoded in the somatostatin prohormone and found in all somatostatin‐positive tissues. However, the activity of NST is functionally distinct from other prosomatostatin products. Furthermore, it appears the physiologic stimuli of the peptides are different and that the peptides are sequestered in separate secretory vesicles. Our group identified the orphan GPCR, GPR107, as a cognate receptor of NST. Through an interaction with GPR107, NST enhanced glucagon release from isolated islets and immortalized alpha cells. NST also reduced release of insulin in response to high glucose conditions in isolated islets. Based off our findings, we hypothesized that NST is a component of the pancreatic arm of the counterregulatory response. In support of our hypothesis, an infusion of NST substantially increased plasma glucose levels over 30 minutes in male rats, and diminished the insulin response to hyperglycemia in a glucose tolerance test. Additionally, antagonism of the glucagon receptor did not prevent the hyperglycemic effects of NST, suggesting the peptide can act independent of glucagon to increase blood glucose. In insulin‐induced hypoglycemia, NST blunts the drop in blood glucose, further reinforcing the role of NST in counterregulation. The secretion of NST release also appears tied to glucose levels. Fasting blood glucose raised plasma NST levels in rats and humans, and exposure to low glucose stimulated NST release from human islets.

Further experiments will confirm the regulatory mechanisms involved in the release of NST, and the importance of its receptor, GPR107. We propose that NST could represent a novel therapeutic target for the treatment and prevention of hypoglycemia in diabetes.

Support or Funding Information

This work was funded by the NIDDK and the Helmsley Charitable Trust.
Impaired bile secretion promotes hepatobiliary injury in Sickle Cell Disease.
Authors: Pradhan-Sundd Tirthadipa , Vats Ravi , Tutuncuoglu Egemen , Singh Sucha
Published: April 2020

Hepatic crisis is an emergent complication affecting sickle cell disease (SCD) patients, however, the molecular mechanism of sickle cell hepatobiliary crisis remains poorly understood. Here, we use intravital imaging to show that sinusoidal ischemia occurs in the liver of transgenic‐humanized SCD mice under basal condition. SCD mice manifested progressive hepatomegaly, liver injury and hyperbilirubinemia. RNA‐sequence analysis identified dysregulation of genes encoding proteins responsible for fibrosis, bile acid synthesis, bile transport and cholesterol metabolism in the SCD mice liver. Immunohistochemical analysis confirmed inflammation, fibrosis and increased ductular reaction in SCD mice. Intravital imaging also revealed impaired bile secretion into the bile canaliculi, which was associated with loss of apical bile transporters and bile acid biosynthetic enzymes, hepatic bile accumulation, and activation of Farnesoid X receptor (FXR) and small heterodimer partner (Shp) in SCD mice liver. These findings are the first to identify that impaired bile acid synthesis and misexpression of bile transporters promote intrahepatic bile accumulation and impaired bile secretion, leading to hepatobiliary injury of SCD. Improved understanding of these processes could potentially benefit the development of new therapies to treat sickle cell hepatic crisis.

Support or Funding Information

TP‐S is funded by PLRC pilot and feasibility award and Community Liver Alliance Pilot Grant award.
Dynamic resistance training attenuate cardiac and renal oxidative stress profile in spontaneously hypertensive male rats
Authors: Shecaira Tânia Plens , de Araujo Amanda Aparecida , Mesquita Frederico , Allioni Gabriela Abrahão , Paixão Camila , da Silva Dias Danielle , Stoyell-Conti Felipe Fernandes , Bernardes Nathalia , De Angelis Kátia
Published: April 2020

Cardiovascular diseases are the leading cause of death in the world. Hypertension and physical inactivity being the main risk factors for its development and oxidative stress is largely related to the pathogenesis and maintenance of hypertension. In addition, the literature is scarce regarding the benefits of resistance training. Therefore, this study aims to evaluate the effects of dynamic resistance training (DRT) on oxidative stress of spontaneously hypertensive rats (SHR). For this, 16 young SHR were divided into 2 groups (n = 8): SM ‐ sedentary males and TM ‐ trained males. They were submitted to the maximum effort test and trained for 8 weeks, and the SM group remained sedentary during the same period. Oxidative stress analyzes were performed on cardiac and renal tissue. As a result, the TM group increased physical capacity compared to the SM group (TM: 737±39.4 vs. SM: 476±50.3 g) and there was no difference in body weight (p=0.97). There was a reduction in lipoperoxidation only in cardiac tissue (TM: 6985±521 vs. SM: 9211±683 cps/mg protein), as well as protein oxidation (TM: 4.91±0.23 vs MS: 6.12±0.23 nmol/mg protein). Hydrogen peroxide was reduced only in renal tissue (TM: 6.83±1.78 vs. SM: 35.54±4.64 nmoles H2O2/g of tissue). There was no difference in the antioxidant enzyme catalase (p>0.05) but there was an increase in superoxide dismutase in both tissues (Heart: TM: 25.38±1.43 vs. SM: 20.08±1.53 USOD/mg protein; Kidney: TM: 7.71±0.22 VS. SM: 7.00±0.16 USOD/mg protein). In addition, the TM group increased the oxidized‐reduced glutathione ratio in cardiac tissue (TM: 11.32±0.47 vs. SM: 8.63±0.32). Thus, we can conclude that moderate‐intensity DRT was able to reduce oxidative stress, reducing target organ damage and increasing antioxidant defenses in a hypertension model. These findings, coupled with the well‐described benefits of aerobic exercise training, may contribute to a reduced risk of cardiovascular events.

Support or Funding Information

FAPESP: 2015/10329‐5, CAPES.
Rutin flavonoid attenuates oxidative stress and decreases morphological changes in experimental mucositis model
Authors: Campos Leticia Cavalcante , Carioca Levi Costa , de Sousa Fideles Lázaro , de Miranda João Antônio Leal , Barbosa Maria Lucianny Lima , Ricardo Nágila Maria Pontes Silva , Ribeiro Maria Elenir Nobre Pinho , Cerqueira Gilberto Santos
Published: April 2020

Intestinal mucositis is a frequent complication in the treatment of cancer with 5‐fluorouracil (5‐FU) chemotherapeutic agent. Rutin bioflavonoid extracted from Dimorphandra gardneriana has been reported as a potent anti‐inflammatory and antioxidant agent. Therefore, this study aims to investigate whether rutin reverses morphological elevations and oxidative stress promoted by 5‐fluorouracil in an experimental model of intestinal mucositis in mice. Swiss mice stratified into the following groups were used: Saline group (0.9% NaCl), 5‐FU group, Rutin group (RUT) (200 mg/kg Rutin, vo). For the oxidative damage evaluation, the levels of the reduced antioxidant glutathione and the lipid peroxidation product, malondylaldehyde, of the duodenal segments were determined. To investigate the morphological changes, hematoxylin and eosin staining was performed. The 5‐FU group showed a significant increase in MDA levels (8127 ± 561.5, p <0.05) when compared to the saline group (4587 ± 367.5, p <0.05). For GSH levels, 5‐FU (20.48 ± 4.89, p <0.05) promoted a significant decrease in duodenum antioxidant levels when compared to the saline group (112.8 ± 19.45, p <0.05). Pretreatment with RUT 200 mg/kg decreased MDA levels (3750 ± 405.3, p <0.05) and increased GSH levels (74.67 ± 12.73, p <0.05) when compared to the 5‐FU injury group. The results of the histopathological analysis showed that 5‐FU promoted structural alterations of the intestinal mucosa, reduction of villus height, deepening of the crypts and inflammatory infiltrate, compared to the Saline group, characterized by the integrity of the villi and crypts and absence of inflammatory infiltrate. Rutin‐treated animals showed a significant reversal of antineoplastic‐induced morphological changes. From the results we found that rutin promotes attenuation of oxidative stress by reducing the levels of Malonylaldehyde and increasing the levels of the antioxidant glutathione. In addition, we found that rutin reverses antineoplastic‐induced morphological changes.
The Pattern of EGR1 Expression During Chick Limb Development Suggests a Role in Regulating SHH Expression and/or Termination
Authors: Wilson Matthew Neil Cahill , Cooper Allen M. , Waston Billy A. , Pira Charmaine U. , Oberg Kerby
Published: April 2020

Limb development is governed by a complex interplay between three signaling centers that mediate growth along three coordinate axes. The apical ectodermal ridge (AER), zone of polarizing activity (ZPA) and the dorsal ectoderm regulate the proximal‐distal, anterior‐posterior and dorsal‐ventral axes, respectively. Development occurs along these three axes to create an asymmetrical limb and is highly dependent on crosstalk between fibroblast growth factors (FGFs) from the AER and sonic hedgehog (SHH) from the ZPA. The mechanisms and intermediate players between FGF and SHH are poorly characterized. Previous work in our lab identified a number of FGF‐responsive candidate genes. Most notably early growth response 1 (EGR1), encoding a zinc finger type protein, was identified as the gene with the most robust induction in response to FGF. EGR1 has been shown to play a role in tendon development but to date its expression in the developing limb has not been well characterized. We found EGR1 to have low endogenous expression in the chick limb by whole mount in situ hybridization (WMISH). We highlighted the WMISH pattern of EGR1 using a 3 hr cycloheximide pretreatment to enhance RNA accumulation. This approach revealed that EGR1 is expressed subjacent to the AER and overlaps the ZPA during robust SHH expression (Hamburger‐Hamilton stage 17 (HH17) through HH24). In contrast, as SHH expression wanes (HH25–26), EGR1 expression recedes from the posterior ZPA, and persists in the anterior progress zone underlying the AER. In addition, EGR1 expression extends proximally from the anterior border of the progress zone. The reduction of EGR1 within the ZPA coincident with the decline in SHH may indicate a role for EGR1 in optimizing SHH expression and triggering termination.
Associations of Plasma Extravesicular (EV) MicroRNA Levels in Seropositive and Seronegative Rheumatoid Arthritis (RA)
Authors: Almodovar Nickolas , Delgado-Cruzata Lisette , Alvarez Milena Rodriguez , Bravo Toni Ann , Hinson Shante
Published: April 2020

Rheumatoid arthritis (RA) is an autoimmune disease associated with inflammation. This disease, exacerbated by lower socioeconomic status, disproportionately hinders the quality of life for Hispanic populations. Although the etiology of this disease is still unclear, many speculate the role of epigenetic factors. Among the epigenetic mechanisms proposed to mediate RA are microRNAs (miRNAs). These are a class of small noncoding RNA molecules which predominantly are involved in the post‐transcriptional regulation of gene expression. We hypothesize specific circulating miRNA targets can identify the RA phenotype, and correlate with clinical characteristics of the disease. To test this hypothesis, thirty Hispanic individuals recruited to the Epigenetics of RA (ERA) study samples were investigated. microRNAs were extracted from the serum circulating extracellular vesicles (exosomes) of twenty‐one RA patients and six controls. Levels of 800 miRNA targets were measured blindly using the Nanostring nCounter miRNA Expression Panel and analyzed using nSolver Analysis Software. Five miRNAs (miR‐1261, miR‐4532, miR‐802, miR‐595, miR‐373‐3p) were differentially expressed between seropositive and seronegative RA (p≤0.05). miR‐802 and miR‐1261 positively correlated with ACPA levels (Pearson Coeff.ACPA= 0.608, p=0.001) and ID Pain (Pearson Coeff.ID Pain= 0.472, p=0.041), respectively. No other RA clinical variables were correlated with miRNA levels. Discriminant function analysis identify miR‐1261 (p=0.004) and ACPA (p=0.002) as the strongest biomarkers differentiating seronegative from seropositive RA. We are currently validating these miRNAs associations with RA by qPCR. Understanding which miRNAs play a pivotal role in the etiology of RA in Hispanic patients can provide opportunities to address health disparities in this disease.
A study of T7 RNA polymerase‐Template interaction utilizing CRISPR/dCas9 protein
Authors: Enkhbaatar Khulan , Rohlman Christopher E.
Published: April 2020

The CRISPR system is an adaptive immune mechanism present in many bacteria and the majority of characterized Archaea. This system binds to nucleic acids, which can be RNA or DNA and modifies specific sequences at desired locations. Although the CRISPR system can form the basis of a flexible genomic engineering toolkit, its molecular basis of interaction with DNA, RNA and other proteins during transcription is not yet clear. This research is investigating the structural and chemical interaction between dCas9, DNA and RNA polymerase at the point of the transcription blockade. This modified CRISPR system consists of two components. dCas9 protein has the ability to bind DNA at a specific location when guided by a complementary RNA molecule. This complementary RNA is called guide RNA (gRNA). T7 RNA polymerase in vitro transcription of purified U5 DNA template was optimized with respect to time, template and rNTP concentration. This established conditions under which to pause transcription, utilizing dCas9 protein, and analyze protein, polymerase, and nucleic acid interactions.
Characterizing Donor‐Specific T Cells in Islet Transplant Recipients Using scRNA‐seq
Authors: Trende Reed Fearing , Ramachandran Sabarinathan , Hering Bernhard , Matson Anders
Published: April 2020

Organ transplants remain an effective treatment of various end‐stage diseases. Induction of tolerance has remained the elusive goal of transplant community to overcome the mortality and morbidity associated with chronic immunosuppression for long term function of the transplanted organs. We have developed a tolerogenic protocol using apoptotic donor leukocytes (ADLs) that circumvents the need for immunosuppressants and have established the efficacy of ADLs for islet transplants in macaques with diabetes. However, the mechanism by which ADLs induce tolerance has not been fully elucidated. Single‐cell RNA‐sequencing (scRNA‐seq) has proven to be a powerful tool for precisely tracking changes to specific cell types and cell developmental trajectories. Flow sorting using fluorochrome‐labelled MHC class II tetramers was used to isolate donor‐specific T cells from macaques that did and did not receive ADLs prior to an islet transplant, and scRNA‐seq on the 10X Genomics platform was used to characterize these cells. Transcription profiling, TCR fingerprinting and functional clustering of the scRNA‐seq data was used to describe how treatment with ADLs altered specific T cell subtypes, as well as how they develop and interconvert between subtypes. Additionally, combining scRNA‐seq data with the macaques’ clinical outcomes will enable identification of biomarkers that can alert physicians to the fate of the transplanted islets (tolerance or rejection). The results of this project enable a better understanding of the fundamental molecular mechanisms of tolerance induced by ADLs, and further validation studies of the identified biomarkers could greatly aid the physicians’ ability to non‐invasively monitor transplant recipients.

Support or Funding Information

Funding from Diabetes Research Wellness Foundation
Effects of Increased Hemoglobin Oxygen Affinity on Cerebrovascular Reserve Capacity in Sickle Cell Disease
Authors: Courelli Vasiliki , Kusmanov Madi , Munoz Carlos , Cabrales Pedro
Published: April 2020

Sickle cell disease (SCD) is associated with a high incidence of ischemic stroke. SCD is characterized by hemolytic anemia, resulting in limited oxygen (O2) delivery to tissues, increased nitric oxide (NO) scavenging, and impaired cerebrovascular hemodynamics. Cerebral blood flow (CBF) is a key metric in determining proper O2 delivery to cerebral tissue. CBF is tightly regulated to maintain constancy of cerebral perfusion by both local mechanisms and autonomic control. Independent from cerebral autoregulation, the influence of the partial arterial carbon dioxide (PaCO2) tension on CBFis known as the cerebrovascular CO2 responsiveness and reflects the vasodilatory capacity of the cerebral vasculature or cerebrovascular reserve capacity. Since cerebrovascular CO2 responsiveness is oxygen dependent and has been related to an increased stroke risk in microvascular diseases such as SCD. This study determines the effects of changes in hemoglobin O2 affinity in cerebrovascular CO2 responsiveness in SCD. CBF was measured using a laser Doppler probe placed over the cortex. The Hb O2 affinity was manipulated via intravenous administration of 5‐hydroxymethyl‐2‐furfural (5HMF), to decrease the Hb‐O2 affinity of homozygous Townes transgenic SCD mice form 32 mmHg to 16 mmHg. To estimate the cerebrovascular reserve capacity animals were challenged with hypercapnia (5% CO2/21% O2 over 20 minutes) for three cycles. Animals with increased Hb O2 affinity showed increased cerebrovascular reserve capacity compared to animals with normal Hb O2 affinity. In conclusion, increasing Hb‐O2 affinity of sickle cell mice protects cerebrovascular CO2 responsiveness, suggesting a increased cerebrovascular reserve capacity which might protect from stroke in SCD.

Support or Funding Information

This work was supported by the NIH Heart Lung and Blood Institute under Grants T32‐HL105373, R01‐HL126945, and the DOD DMRDP under Grant W81XWH‐18‐1‐0059
Anatomical Sciences Educational Outreach: A tool for boosting science education.
Authors: Mbagwu Smart I. , Okafor Izuchukwu A. , Eze Chinyere E. , Anokwulu Osmond
Published: April 2020

There is an increasing loss of interest in sciences amongst secondary school and university students despite the growing need for scientists. In order to address this, science advocacy at early childhood and post primary education is undoubtedly imminent for the identification and grooming of the next generation of scientists. This may often require the introduction of special non‐curricular based programs for students at different levels. Considering this, we initiated an anatomical sciences‐inspired educational outreach project tagged “Science Advocacy Program for Youngsters” (SAPFY) for school children in public and private primary and secondary schools in Nnewi, Anambra State, Nigeria. The program was aimed at promoting basic science education by providing suplementary practical‐based skills in science education, enhancing science teaching and learning skills and inspiring science careers through exposure to scientific research and career opportunities especially in the areas of anatomical sciences. The program held over a 3‐day period at the Department of Anatomy, Nnamdi Azikiwe University, Nnewi Campus, Nigeria with a total of 200 participants comprised of primary and secondary school students, teachers and facilitators. The program was organized in four sessions to include introductory lessons on science, anatomy and careers in anatomical sciences. The other sessions involved hands‐on activities, career‐guide interactive sessions and guided tour of the Anatomy museum. Pre‐event assessment of the participants perception about science was performed, while post‐event evaluation to observe the impact of the outreach on the attitude of the participants towards science and their overall perception about the event was performed using feedback forms. We observed a general positivity towards science by the participants and significant outcome of the impact of the event on their attitude towards science. The participants described the event to be educative, inspiring, interactive, expository, fun and innovative. The impact of the outreach programme revealed positive outcomes indicating that the outreach can create a support system capable of providing recommendable modalities for a seamless learning experience for science‐based topics

Support or Funding Information

American Association for Anatomy
Loss of HAND2 and HOXD13 Binding Sites in the ZPA Regulatory Sequence (ZRS) is not Sufficient to Disrupt Activity in the Limb
Authors: Ball Kathryn F. , Underhill Abbie K. , Pira Charmaine U. , Oberg Kerby C.
Published: April 2020

The ZPA regulatory sequence (ZRS) is a limb‐specific enhancer that localizes Sonic Hedgehog (SHH) expression to the zone of polarizing activity (ZPA), which consequently regulates anteroposterior patterning in the developing limb. ZRS deletion lacks SHH expression in the limb resulting in loss of posterior limb structures, while ZRS single nucleotide variants (SNVs) can lead to ectopic SHH expression causing preaxial polydactyly (PPD). However, the ZRS mechanism of action is not well characterized. HAND2 and HOXD13 are key transcription factors in SHH regulation that bind to the ZRS, potentially modulating SHH transcription. The present study’s objective was to determine the role of HAND2 and HOXD13 binding sites in ZRS function. To evaluate ZRS enhancer activity, ZRS was cloned into an enhancer‐GFP reporter construct. HAND2 and HOXD13 binding sites were altered using site‐directed mutagenesis, and contructs were electroporated into presumptive limb buds in Hamburger‐Hamilton stage 14 chicken embryos. GFP expression was evaluated 48 hours post‐electroporation. ZRS with mutated HAND2 and HOXD13 binding sites retained activity in the limb bud in a pattern that overlapped ZRS activity. This is unexpected since HAND2 and HOXD13 are known to be critical for SHH expression. Future work is needed to clarify the binding site(s) critical to activity and to characterize the factors involved in ZRS function.

Support or Funding Information

Supported in part by a grant from the Department of Pathology, Loma Linda University.