bluuebunny/crossref_metadata_2025 huggingface dataset:
Excess nitric oxide impairs liver X receptor α‐ATP‐binding cassette transporter A1‐dependent cholesterol efflux in macrophage foam cells (671.1)
Authors: Zhao Jin‐Feng , Shyue Song‐Kun , Wei Jeng , Lee Tzong‐Shyuan
Published: June 2021

Excess nitric oxide (NO) promotes the progression of atherosclerosis by increasing the oxidation of low‐density lipoprotein (LDL) and inflammatory responses. However, little is known about the impact of NO and its underlying molecular mechanism on lipid metabolism of macrophage foam cells. Treatment with S‐nitroso‐N‐acetyl‐D,L‐penicillamine (SNAP), an NO donor, exacerbated oxidized LDL (oxLDL)‐induced cholesterol accumulation in macrophages, because of reduced efficacy of cholesterol efflux. In addition, SNAP decreased the protein level of ATP‐binding cassette transporter A1 (ABCA1) without affecting scavenger receptor type A (SR‐A), CD36, ABCG1 or SR‐B1 levels. This SNAP‐mediated downregulation of ABCA1 was mainly through the effect of NO but not peroxynitrite. Furthermore, the SNAP‐downregulated ABCA1 was due to the decrease in the liver X receptor α (LXRα)‐dependent transcriptional regulation. Moreover, genetic deletion of inducible NOS increased the serum capacity of reverse cholesterol efflux and protein expression of LXRα, ABCA1 and SR‐BI in aortas and retarded atherosclerosis in apolipoprotein E‐deficient mice. Our findings provide new insights in the pro‐atherogenic effect of excess NO on cholesterol metabolism in macrophages.
Temporally distributed mechanisms for skeletal muscle microvascular rarefaction in metabolic syndrome (674.9)
Authors: DeVallance Evan , Chantler Paul , Goodwill Adam , Butcher Joshua , Olfert I. , Brock Robert , Frisbee Jefferson
Published: June 2021

Evolution of metabolic syndrome (MetSyn) and its constituent pathologies is associated with a gradual reduction in skeletal muscle microvessel density (MVD), known as rarefaction. While contributing to elevated vascular resistance at high metabolic demand and impairing mass transport/exchange, the temporal development of rarefaction and the contributing mechanisms which lead to the progressive microvessel loss are critical areas for investigation. Our studies demonstrate that overall reductions to MVD in skeletal muscle of obese Zucker rats (OZR) are well predicted by a chronic loss in vascular nitric oxide (NO) bioavailability. However, prior to any loss in NO, skeletal muscle arterioles from OZR exhibit an early shift in ROS, inflammatory biomarkers and arachidonic acid metabolism, resulting in increased production of TxA2. This increases venular leukocyte adhesion and causes a second, localized oxidant pulse, which initiates microvascular degradation in post‐capillary venules that is strongly associated with plasma MCP‐1 levels. If NO bioavailability is maintained (TEMPOL) after the initial increase in TxA2 and microvessel loss, the total rarefaction magnitude is blunted. Alternately, if actions of TxA2 are chronically inhibited, the initial rarefaction never develops and the subsequent secondary pulse (from NO reductions) is strongly muted. A similar muting of the initial and secondary pulse of rarefaction is manifested if TNF‐α production is inhibited (pentoxifyllene). These results suggest that microvessel rarefaction in OZR represents the integration of an early mild vessel loss that is dependent on TxA2, which creates an environment for the extensive rarefaction that is dependent on low NO bioavailability.

Grant Funding Source: Supported by National Institutes of Health and American Heart Association
The effects of different types of adipose tissue on vascular function in carotid artery from mouse (677.7)
Authors: Laskowski Marta , Golubinskaya Veronika , Johansson Maria , Nilsson Holger
Published: June 2021

Perivascular adipose tissue (PVAT) secretes the dilator substance “adipocyte‐derived‐relaxing‐factor” (ADRF) that has been shown to act mainly through voltage‐dependent (KV) and ATP‐dependent (KATP) potassium channels (K). Malfunction in ADRF may contribute to the metabolic syndrome. A recently suggested ADRF candidate is hydrogen sulfide (H2S) generated by the enzymes CSE, CBS and 3MST.

We have here investigated the effect of ADRF and H2S from three different kinds of adipose tissues (AT) on mouse carotid arteries, and probed the mechanisms involved using specific blockers.

Mesenteric, subcutaneous and brown AT were placed on vessel segments. Myography was used to investigate contractile responses to the α1‐receptor agonist phenylephrine with and without blockers of KV7 (XE991), KATP (glibenclamide), KV (4‐AP) or generally reducing K+ currents by elevated K+ concentration (KPSS). Na2S was used as H2S donor. DL propargylglycine (PAG) was used as CSE blocker. H2S measurements were performed by a selective electrode.

Subcutaneous AT, but not mesenteric or brown AT, had an anti‐contractile effect that was not affected by XE991, 4‐AP or KPSS, but slightly attenuated by glibenclamide. Na2S caused dilatation that was reduced by XE991 but not by PAG. No H2S could be detected in any of the AT supernatants.

These results give novel insight into the differences in ADRF pathways in different vascular beds and species, which makes other pathways, such as Ca2+‐channels, an interesting target for further examination. Excluding H2S as the dilator substance also makes it necessary to investigate other ADRF candidates.
Two‐dimensional model for prediction of arteriolar NO/O2 modulation by spatiotemporal variations in cell‐free layer (678.13)
Authors: Kim Sangho , Ng Yan Cheng , Namgung Bumseok
Published: June 2021

The role of cell‐free layer (CFL) in modulating nitric oxide (NO) and oxygen (O2) transport has been of particular interest in many microcirculatory studies. Despite the significant roles of CFL in balancing NO/O2 bioavailability in arteriolar tissue, many of previous numerical approaches have relied on a one‐dimensional steady‐state model for simplicity. However, these models are incapable of providing information on the influence of spatiotemporal variations in CFL on the NO/O2 transport under dynamic flow conditions. Therefore, the present study proposes a new two‐dimensional transient model capable of predicting NO/O2 transport modulated by dynamic changes in the CFL width. The CFL width data were obtained from an in vivo experiment performed in the rat cremaster muscle. Our new model revealed that the NO bioavailability could be inversely related to the CFL width. The enhancement of NO production by greater wall shear stress with a thinner CFL could dominate the diffusion barrier role of the CFL preventing NO scavenging by RBCs. In addition, the NO/O2 availability along the vascular wall was not homogeneous and highly regulated by dynamic changes of the local CFL width variation. The time‐averaged spatial variations of the CFL widths on opposite sides of the arteriole exhibited a significant inverse relation. This asymmetric formation of CFL resulted in signifcantly imbalanced NO/O2 bioavailability in the tissues on opposite sides of the arteriole. This work was supported by NMRC/CBRG/0019/2012.

Grant Funding Source: Supported by NMRC/CBRG/0019/2012.
Female rats are less able to suppress learned fear than male rats after coronary ischemia reperfusion (684.11)
Authors: Scrogin Karie , Samarel Allen , Koshman Yevgeniya
Published: June 2021

Anxiety is an independent risk factor for cardiovascular morbidity, particularly in perimenopausal women. We found that female rats subjected to permanent coronary artery ligation (CAL) showed an impaired ability to express recall of fear extinction, while males showed increased fear, but normal extinction memory. Females and males showed similar left ventricular dysfunction after CAL. Here, we examined effects of coronary ischemia and reperfusion (I/R), a more relevant model of human myocardial infarction, on fear extinction in male and female rats. Adult female and male Sprague Dawley rats were subjected to sham I/R or 45 min of coronary artery occlusion followed by reperfusion. Eight weeks after I/R, left ventricular function was reduced in both sexes, but males showed a larger decrease in fractional shortening and ejection fraction than females (p<0.05). Females, but not males subjected to I/R, demonstrated impaired fear extinction compared to sham‐ligated rats. Females subjected to I/R also showed increased fear during extinction recall testing compared to sham‐ligated females (P<0.05). We conclude that cycling female rats are more susceptible to the anxiogenic effect of coronary ischemia.
mTOR inhibition increases learning/memory (684.16)
Authors: Donnelly Ginger , Goyal Ravi
Published: June 2021

Cognitive impairment is a far too common medical problem. Moreover, there is no effective therapy for increasing memory and learning in individuals with such an impairment. Recent studies implicate that mTOR pathway may be involved in learning and behavior. Thus, we tested the hypothesis that mTOR inhibition can increase the learning and memory in mice. We examined spatial learning ability in mTOR heterozygous and control mice by Morris Water Maze. In the control group of mice, we also inhibited mTOR pathway by rapamycin administration and examined its effect on learning and memory.Our results demonstrate that mTOR heterozygous mice had significantly higher ability for spatial learning. Also, inhibition of mTOR in control mice increased the spatial learning ability. We conclude that mTOR inhibition can lead to increased learning ability. However, further investigations are needed to examine the role of mTOR in Alzheimer and disorders in which memory impairment is the major pathology.
Use of social and physical enrichment to improve cognitive abilities of laboratory rats, Rattus norvegicus (684.9)
Authors: Davie Clara
Published: June 2021

Animal cognition studies capture the interest and imagination of undergraduate students and problem‐solving studies by laboratory animals have a valid utility in research based science education. A group of 36 previously un‐enriched, male, adult (1.5 yr old) laboratory rats, Rattus Norvegicus, were used in this study. 18 (one‐half of the colony) non‐enriched laboratory rats were exposed to each other (rats are housed in groups of 3 per cage) for 30 minutes a day, four days a week, over a three‐month period in a ‘play pen’ arena. The ‘play pen’ consists of a running wheel, wooden chew toys, plastic tunnels and wood shavings. The laboratory rats were returned to their non‐enriched housing after their time in the ‘play pen’. 36 laboratory rats were then placed, individually, in a Morris Water Maze. This study was different from previous enrichment and Morris Water Maze studies because it tested the effect of set, daily social enrichment on rat cognitive ability. This experiment asked if a limited amount of social enrichment decreased thigmotaxis. The preliminary findings of this study indicate that enrichment does increase the rat’s cognitive abilities, which may have implications for how we house and treat laboratory rats.
Exercise Increases intrinsic and synaptic excitability of NTS second‐order baroreceptive neurons in SHRs (686.21)
Authors: Chen Chao‐Yin
Published: June 2021

A single bout of dynamic exercise lowers blood pressure in hypertensive subjects, named post‐exercise hypotension (PEH). We previously showed that exercise reduced GABA release in the NTS. Within the NTS, the balance of excitatory and inhibitory synaptic transmissions is integrated into the intrinsic excitability of baroreceptive neurons to shape baroreflex output from the NTS to downstream synapses. Here, I tested the hypothesis that a single exercise bout increases intrinsic excitability and excitatory synaptic inputs in NTS 2nd‐order baroreceptive neurons. Resting membrane potential (Rem), spiking response to depolarization, inwardly‐rectified K currents (Kir), spontaneous excitatory postsynaptic currents (sEPSCs), and miniature EPSCs were recorded in anatomically identified 2nd‐order baroreceptive neurons in a brainstem slice. Neurons from the PEH group (n=10) had a slightly depolarized Rem and significantly higher spiking activity (p<0.05) at Rem. When the neurons were current‐clamped at ‐60 mV there was no significant difference in spiking activity or spiking response to depolarization between sham and PEH. In addition, Kir currents were smaller in neurons from the PEH group. Neurons from the PEH group (n=7) also had higher sEPSC and mEPSC frequencies (p<0.05). Data suggest that increased intrinsic and synaptic excitability of NTS 2nd‐order baroreceptive neurons may contribute to the PEH.
Effect of chronic fish oil supplementation on renal function parameters of mice fed with a high fat or a high carbohydrate diet (689.9)
Authors: Fernandez Ricardo , Pequito Danielle , Coelho Isabela
Published: June 2021

Fish oil (FO) supplementation, rich in n‐3 PUFA, has a positive effect on various diseases, including cancer, kidney diseases and diabetes. High fat (HFD) and/or high carbohydrate (HC) diets promote obesogenic effects and induce insulin resistance.The objective of this study was evaluate the effect of chronic fish oil supplementation on renal function parameters of mice fed with a HFD or a HC diets. Six weeks male mice were divided in three groups and fed with different diets during eight weeks: regular rodent chow (S), HC or HFD. After this, they were supplemented orally for 30 days with FO, 1g/kg body weight. Renal function parameters, urinary excretion of TXB2 and PGE2, immunolocalization of vimentin, desmin, α‐SMA and PCNA, and intraperitoneal glucose tolerance test were measured in all groups. Fasting glucose levels was significant higher in HFD vs S (139.6±6.2 mg/dL vs 104.5±5.5) (n=13).The HFD group present glucose intolerance, an effect that was not modified by fish oil supplementation. Plasma insulin levels were similar between the groups. Glomerular filtration (creatinine clearance) was lower in HC (0.63±0.10ml/min/kg) and HFD (0.78±0.1) groups if compared to S group (1.58±0.4) (p<0.01, n=10). FO supplementation did not induced significant changes in this parameter. Urinary excretion of TXB2 was also significantly lower in HC (2.0±0.4pg/min) and HFD (2.3±0.6) than S (11.3±3.3). The mean microalbuminuria level (expressed as urine albumin‐creatinine ratio) in the C group was 11.06±2.16ng/mg, a value that increased to 18.24±2.74 in HC and 35.65±7.32 in HFD. Fish oil supplementation in HFD partially reverted the increase in microalbumin excretion (21.33±1.33).The intrarenal expression of vimentin was significantly higher in the interstitium of HC and HFD groups, and in HFD tubules, an effect reverted by FO supplementation. In summary, FO supplementation partially reverted renal alterations induced by HC and HFD diets.

Grant Funding Source: Supported by CAPES (Brazil)
Steviol retards renal cyst growth through reduction of CFTR expression and inhibition of epithelial cell proliferation in a mouse model of polycystic kidney disease (690.2)
Authors: Chatsudthipong Varanuj , Yuajit Chaowalit , Muanprasat Chatchai , Kittayaruksakul Suticha , Fedeles Sorin , Gallagher Anna‐Rachel , Somlo Stefan
Published: June 2021

Cyst growth in ADPKD is associated with cAMP‐activated proliferation of cyst‐lining epithelial cells and transepithelial fluid secretion into the cyst lumen via CFTR chloride channel. It will eventually lead to renal insufficiency and renal failure for which no effective treatment is currently available. We previously reported that steviol retards MDCK cyst growth by inhibiting CFTR channel activity and promoting proteasomal‐mediated CFTR degradation. However, the MDCK cells do not carry the mutated PKD genes and do not recapitulate the complexity of PKD pathogenesis. Therefore, it is imperative to examine the effect of steviol in animal model that closely resembles PKD. In this study, we determined the effect of steviol on renal cyst growth in an orthologous mouse model of human ADPKD (Pkd1flox/flox :Pkhd1‐Cre). The results showed that daily treatment with both 200 mg/kg BW of steviol and 1,000 mg/kg BW of stevioside for 14 days markedly decreased kidney weight and cystic index in these mice. Surprisingly, only steviol markedly reduced blood urea nitrogen and creatinine values. It also reduced cell proliferation but had no effect on cell apoptosis. In addition, steviol suppressed CFTR and mTOR/S6K expressions but stimulated AMP‐activated protein kinase (AMPK) in renal cyst‐lining epithelial cells. These findings indicate that steviol slows cyst progression in PKD mouse model, in part, through the activation of AMPK which subsequently inhibits both CFTR expression and renal epithelial cell proliferation via mTOR/S6K pathway. Most importantly, steviol could markedly improve kidney function in a mouse model of PKD. Steviol thus has potential application for further development as therapeutic compound for the treatment of polycystic kidney disease.

Grant Funding Source: Supported by Thailand Research Fund and Faculty of Science, Mahidol University, Bangkok, Thailand
Adventitial NADPH oxidase‐4 in vascular oxidative stress (693.12)
Authors: Deng Arlinda , Nguyen Huy , Adams Michael , Wang Hui Di
Published: June 2021

BACKGROUND: Many types of hypertension are associated with increased level of angiotensin II and vascular oxidative stress. Previously, we have shown that NOX2, an adventitial NADPH oxidase (NOX) isoform, generates reactive oxygen species in cardiac vascular system. Although NOX4, as another major isoform of NOX, has been reported to generate reactive oxygen species and play a detrimental role, current publications allude to the possibility that NOX4 may play a beneficial role in the blood vessels. The current project examined this aspect by investigating the expression of adventitial NOX4 and reactive oxygen species.

OBJECTIVE: The objective of this study is to test our hypothesis that the expression of adventitial NOX4 would not increase vascular ROS in Angiotensin II‐induced hypertension.

METHOD: Four C57BL and NOX2 knockout mice, sixteen to eighteen weeks of age, were separated into two groups, a normotensive and Angiotensin II infused group. Angiotensin II infused animals developed hypertension. Thoracic aortas were sterilely removed, embedded in paraffin and then fixed on glass slides as 5µm thick sections. Expression of 3’‐nitrotyrosine, a reactive oxygen species indicator, NOX2, and NOX4 were determined by immunoflorescence method.

RESULTS AND CONCLUSION: Similar to NOX2, NOX4 is expressed in both endothelium and adventitia of the aorta. The level of NOX4 in the Angiotensin II‐infused hypertensive is greatly increased about seven times in comparison to normotensive group. 3’‐Nitrotyrosin levels are increased in Angiotensin II infused mouse aorta segments. However, Angiotensin II induced hypertension and NT is not increased in NOX2 knockout mouse while there is significant amount of NOX4 is still expressed. In conclusion, our data indicate that NOX2 but not NOX4 contributes to vascular production of reactive oxygen species and hypertension.

Grant Funding Source: Brock University
The role of amiloride‐insensitive sodium transport in alveolar fluid homeostasis (695.2)
Authors: Chupin Cécile , Rozowsky Simon , Kuebler Wolfgang
Published: June 2021

Under both normal and pathological conditions, the lung fluid balance across the alveolar epithelial barrier is mainly regulated by active sodium transporters. Previous work has largely focused on the critical role of ENaC, yet ~60% of alveolar fluid clearance in rats or humans is amiloride insensitive. We decided to explore the role of the amiloride‐insensitive sodium cotransporters SGLT1 (Na+‐glucose co‐transporter 1) and SNATs (Na+‐coupled neutral amino acid transporters) in the intact lung. In isolated perfused rat lungs, we determined alveolar fluid clearance (AFC) using a double indicator dilution technique and probed for the role of SGLT1 and SNATs by addition of appropriate cotransporter substrates or inhibitors. While addition of the SNAT substrate L‐alanine did not affect basal AFC, it rescued AFC in lungs pre‐treated with amiloride, and this response was blocked by the SNAT inhibitor HgCl2. Analysis of bronchoalveolar lavage fluid revealed > 2‐fold of L‐alanine in the epithelial lining fluid compared to plasma level. RT‐PCR identified mRNAs for all 6 SNAT isoforms in whole lung, yet in alveolar epithelial cells, only SNAT 2 and 5 mRNA and protein were detected. In contrast, no functional involvement of SGLT1 in AFC was detected. These results indicate a new role for SNATs in AFC which becomes unmasked when ENaC is inhibited. SNAT2 and SNAT5 may represent novel targets for the resolution of pulmonary edema.

Grant Funding Source: Funded by CIHR MOP # 245251
Cell confluency modulates cortical stiffness of human bone marrow endothelial cells (696.3)
Authors: Xie Leike , Sun Zhe , Hong Zhongkui , Brown Nicola , Glinskii Olga , Glinsky Vladislav , Meininger Gerald
Published: June 2021

Little is known about mechanical properties of human bone marrow endothelial cells (HBMEC) as culture conditions change. Here, we used atomic force microscopy (AFM) to test the hypothesis that the degree of confluency modifies HBMEC stiffness. Individual cells were compared in non‐confluent and confluent phases. Two HBMEC lines HBME‐1 and HBMEC‐60 immortalized by different methods were cultured until reaching a desired growth phase. Primary HBMEC were used as a reference. Cell stiffness was calculated as Young’s Moduli using a modified Hertz model from AFM cell‐surface force curves. Actin expression was analyzed by immunofluorescence and western blotting (WB). Young’s Moduli were significantly increased in confluent vs non‐confluent HBME‐1 (6.79±2.58 vs 4.73±1.78 kPa, p<0.01) and HBMEC‐60 (4.25±1.14 vs 2.03±1.09 kPa, p<0.01) cells. Non‐confluent HBME‐1 exhibited similar stiffness to the primary HBME (5.49±2.06 kPa). Topographical images revealed denser networks of actin stress fibers in confluent cells. F‐actin labeling confirmed these results. WB data indicated elevated pan‐actin levels in confluent HBMEC. Thus, HBMEC stiffness is influenced by cell confluency in culture and enhanced stiffness is associated with increased actin expression, a major cytoskeletal component contributing to cell mechanical properties.

Grant Funding Source: Supported by NIH Grants HL095486 (GAM), CA160461 (VVG), VA BLR&D Service Award 1I01BX000609 (VVG)
Upregulation of translational machinery in hypertrophied urinary bladder in rat with partial bladder outlet obstruction (704.4)
Authors: Shen Shanwei , Xia Chunmei , Lee Seong Ho , Kim Misong , Lysiak Jeffrey , Liu Miao , Zakari Madaniah , Steers William , Qiao Liya
Published: June 2021

Partial bladder outlet obstruction (pBOO) causes considerable remodeling of the urinary bladder resulting in bladder organ hypertrophy. The serine/threonine protein kinase Akt serves as a convergent point in signaling networks and plays a critical role in cellular survival and growth. At 2 weeks after surgically induction of pBOO in rat, the phosphorylation (activation) level of the Akt isoform Akt1 was significantly increased in the urinary bladder, whereas the activity of Akt2 was not changed. In the urinary bladder with pBOO, excessive collagen deposition played a significant role in bladder hypertrophy, however, real‐time PCR showed that collagen mRNA level was not changed when compared to control. This was consistent to that the phosphorylation (activation) level of mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K), and 4E‐BP1, a protein synthesis pathway downstream of Akt1, were increased in pBOO bladder. The increases in protein synthesis also resulted in detrusor smooth muscle cellular hypertrophy examined by an increase in the relative level of α‐smooth muscle actin against nuclear protein histone H3. These results suggest that an increased protein synthesis regulated by Akt1‐mediated translational machinery may underlie pBOO‐induced bladder hypertrophy resulting from excessive collagen deposition and detrusor smooth muscle cellular hypertrophy.

Grant Funding Source: DK077917
A preliminary study to measure plasma volume using hydroxyethyl starch (707.6)
Authors: Morawski Lauren , Simon Mallory , Davis John , Luetkemeier Maurie
Published: June 2021

Purpose: This study tested the potential of using hydroxyethyl starch (HESPAN) as an indicator to measure plasma volume. Methods: Fifty‐ml of whole blood was collected in tubes containing EDTA from ten subjects (n=10, male=6, female=4) between the ages of 18 and 60. The blood samples were centrifuged at 3000‐rpm for 20 min. The plasma was removed and inserted into an artificial circulation system constructed from Tygon tubing, a central mixing chamber, and a peristaltic pump. For each subject, the initial glucose level was measured using an Accu‐Chek Active glucose monitor. Ten 0.5‐ml aliquots of a 6% HESPAN solution were sequentially added into the system and allowed to circulate for a period of six minutes. Two‐mL plasma samples were withdrawn between the additions of each aliquot, treated with concentrated hydrochloric acid for hydrolysis of the HESPAN starch to glucose monosaccharide units, and neutralized with TRIS buffer. The resulting samples were then used to measure the increase in plasma glucose concentration. Results: A graph was constructed displaying the relationship between HESPAN concentration and increases in plasma glucose levels. It was determined that there was a nearly linear relationship resulting in an r2 value of 0.9395. Conclusions: Using HESPAN, as an indicator may be valid technique to measure plasma volume due to the linear relationship between HESPAN concentration increases in plasma glucose.
Iron supplementation at high altitude induces inflammation and oxidative injury to lung tissues in rats (708.7)
Authors: Salama Samir , Omar Hany , Maghrabi Ibrahim , AlSaeed Mohammed , EL‐Tarras Adel
Published: June 2021

Iron supplementation is recommended at high altitudes to meet the demand for the high altitude‐associated physiological polycythemia. Iron is a major player in redox reactions and may exacerbate the high altitudes‐associated oxidative stress. The aim of this study was to explore the potential iron‐induced oxidative lung tissues injury in rats at high altitude. Using histopathological examination and spectrophotometry, our results showed that iron supplementation at 6000 feet altitude induced severe congestion, emphysema, and inflammatory cell infiltration to lung tissues. The levels of pro‐inflammatory cytokines (IL‐1β, IL‐6, TNF‐α), lipid peroxidation, and protein oxidation in lung tissues were significantly elevated. Antioxidant capacity of lung tissues was significantly reduced. Trolox alleviated the lung histological impairments, significantly decreased the pro‐inflammatory cytokines, and restored the oxidative stress markers. Together, our findings highlight the limitations of iron supplementation at high altitudes and suggest Trolox as a protective measure.

Grant Funding Source: Supported by HARC grant number 8‐ط ‐1434 to SAS, Taif University
Effects of sub‐anesthetic sevoflurane on cardiorespiratory responses to severe arterial hypoxia in the rabbit (709.4)
Authors: O'Donnell Jonathan , Quail Anthony , Cottee David , White Saxon
Published: June 2021

Volatile anesthetics may alter reflexes to hypoxia through actions at the carotid body chemoreceptors. The effects of sevoflurane (Sev) in sub‐anesthetic concentrations on integrated chemoreflex control during hypoxia are unknown. The cardiorespiratory responses to end‐tidal Sev (0.18%, 0.37% or 1.86%) were studied in 7 rabbits. Ventilation (VE), tidal volume (VT), respiratory rate (f), heart rate (HR) and arterial pressure (AP) were measured in awake rabbits breathing room air, then 5 minutes of hypoxia (PaO2 < 35 mm Hg), during Sev alone, and Sev plus hypoxia. In awake rabbits hypoxia produced an increase in VE and VT (p<0.05) while f was unchanged. HR fell and AP rose (p<0.05). During normoxia, VT increased and f decreased with all concentrations of Sev, while VE only fell at 0.37% and 1.86% (p<0.05). HR increased with at all concentrations while AP decreased at 0.37% and 1.86% (p<0.05). With hypoxia and Sev, the increase in VT was the same as awake levels at all concentrations associated with a small rise in f (p<0.05). VE increased to levels seen in the awake state at lower concentrations of Sev but was attenuated at 1.86% (p<0.05). The hypoxia induced bradycardia and rise in AP were attenuated by increasing doses of Sev and abolished at 1.86% (p<0.05). Sub‐anesthetic depressant effects of Sev on the cardiorespiratory responses to hypoxia are selective and therefore unlikely to be the result of carotid body inhibition.

Grant Funding Source: Supported by John Hunter Hospital Charitable Trust
Upregulation of GPR50 in a white adipose depot of diet‐induced obese mice requires intact leptin signaling (711.11)
Authors: Faulkner Jessica , Gomolak Jessica , Hall John , Garrett Michael , Didion Sean
Published: June 2021

Whole transcriptome analysis of white adipose from C57BL6 mice fed control (10% kcal) or high‐fat diet (HFD; 60% kcal) for 12 and 24 wks identified GPR50 as the most upregulated gene in response to a HFD (eg, 60‐fold in reproductive adipose at 12 wks). We tested the hypothesis that GPR50 upregulation occurs earlier than 12 wks of HFD in reproductive adipose of C57BL6 mice and in genetic models of obesity. GPR50 expression was assessed via qRT‐PCR in reproductive adipose from C57BL6 mice fed control or HFD for 1, 4, 12 and 24 wks and in db/db leptin receptor‐deficient and melanocortin 4 receptor‐deficient (MC4R‐/‐) mice. GPR50 adipose expression of 1 wk HFD mice trended higher than control (0.44‐fold±0.69, n=4; P=0.28). However, 4 wks HFD was associated with significantly higher GPR50 expression compared to control (2.77‐fold±0.73, n=4; P=0.01). qRT‐PCR confirmed GPR50 increase in adipose with 12 and 24 wks HFD compared to controls (26.4‐fold±0.73, n=4; P<0.0001 & 221‐fold±2.8, n=4; P<0.0001, respectively). Adipose GPR50 expression was less in 12 wks HFD db/db mice than in HFD C57BL6 when both were compared to their control (0.61‐fold±0.13, n=2‐3). GPR50 in adipose of MC4R‐/‐ increased compared to control but not to the same degree as 24 wks HFD C57BL6 (4.9‐fold±2.1, n=4; P=0.03). These data indicate that intact leptin signaling may be required for GPR50 upregulation in white adipose of HFD‐induced obese mice.

Grant Funding Source: Supported by NIH HL‐089884 and HL‐107632
Functional characterization of a novel noncoding RNA TIFm71 (711.2)
Authors: Li Zhang , Wang Davis , Li Iris , Cheung Wing Tai
Published: June 2021

Noncoding RNAs which do not encode proteins are involved in many crucial biological processes and are increasingly important. The transcript of a novel CXC chemokine TIF (Tumor‐Induced Factor) which was identified originally from mas‐ induced xenograft has a long 3’‐UTR containing an antisense Alu element. The Alu elements are conserved repeat sequences that belong to the SINE family of retrotransposons found abundantly in primate genomes and their functions remain elusive. Our study showed that a 71nt fragment named as TIFm71 embedded in the middle of Alu element was processed out from TIF mRNA transcript and played regulatory role independently. TIFm71 was predicted to fold into a stem loop structure which is similar to pre‐miRNAs. Using TIFm71‐overexpressing stable cell line, we found that TIFm71 overexpression induced epithelial‐mesenchymal transition (EMT) and the stable clone displayed higher cell mobility. Western protein analysis showed a higher phosphorylated ERK protein level, which suggested that TIFm71 induced EMT through ERK pathway. In addition, a GFP reporter system was used to probe the regulatory role of TIFm71 on gene expression. Comparing to the control, a significant reduction of GFP protein was noted, suggesting that TIFm71 negatively regulated the expression of the coding transcript.
Assessment of multivariate classification analysis methods on 3‐dimensional anatomical distribution of functionally identified cat pre‐Bötzinger complex microinjection sites (712.15)
Authors: Cordovez Juan , O'Neal Marvin , Solomon Irene
Published: June 2021

Previous work from our laboratory has demonstrated that multiple patterns of phrenic motor output can be elicited by chemical stimulation of anatomically distinct sub‐regions of the in vivo adult cat pre‐Bötzinger complex. To gain further insight into the anatomical distribution of the microinjection sites yielding these different discharge patterns, we implemented two multivariate classification analysis methods: Fisher Linear Discriminant (FLD) and probabilistic neural network (PNN). For FLD analysis, the multivariate data were transformed into univariate observations by computing the inverse of a pooled variance‐covariance matrix, which was then translated back to the histological coordinates to predict physical sub‐region boundaries. For PNN analysis, a 3‐layered radial basis neural network was created with (1) the input vector for each discharge pattern yielding an output value according to how close the input vector was to each pattern weight vector, (2) the contributions for each class of inputs was summed to produce a net output vector of probabilities; and (3) a transfer function was applied to the outputs to identify the maximum probabilities and produce a classification decision. While each analysis method has its advantages (and disadvantages), both were able to predicte all of the observed phrenic discharge patterns based solely on the 3‐D coordinates of the microinjection sites. We suggest, however, that FLD analysis may be better suited for these data.

Grant Funding Source: Supported by HL63175
Modulation of respiration during the stimulation of two cortical masticatory areas in the rat brain (712.2)
Authors: Condrey Jillian , Tsai Hsiu‐Wen , Davenport Paul
Published: June 2021

There are distinct cortical masticatory areas, CMAs, which induce different patterns of jaw movements when stimulated: A‐area and P‐area. Swallowing is inhibited during A‐area stimulation but P‐area stimulation elicits both chew and swallow. The neural integration of chewing, swallowing, and breathing is poorly understood. We tested the hypothesis that stimulation of the A‐area will not alter breathing; whereas, P‐area stimulation will cause inhibition of breathing during an elicited swallow. Animals were implanted with EMG electrodes in the inferior pharyngeal constrictor, diaphragm, masseter, caudal digastricus, and cranial digastricus muscles. After 4‐7 days recovery, the rats were anesthetized and placed in a stereotaxic apparatus. The CMAs were exposed. A‐area and P‐area were stimulated at 30 Hz, 0.02 ms pulse width with 1‐10 second trains using a concentric electrode. Swallows were also elicited by probing the oropharynx before, during and after cortical stimulation. Swallows elicited before cortical stimulation increased Te and Ttot. A‐area stimulation elicited only chew muscle activity with no effect on breathing. P‐area stimulation elicited swallows which increased Te and Ttot. These results suggest that A‐area stimulation does not modulate respiration, whereas, P‐area stimulation does. This suggests that these areas may be involved in cortical control of upper airway behavior.
Student‐developed learning resources for the anatomical sciences (719.12)
Authors: Eastwood Jennifer , Doubleday Alison
Published: June 2021

The process of creating learning resources provides students with opportunities to explore information, create study aids, and identify learning gaps prior to an examination. We present two examples of activities for the anatomical sciences that engage students through resource building and provide formative assessment opportunities.

At UIC first‐year dental students produce video narrations in the anatomy laboratory. Videos are created on instructor‐controlled devices and viewable online via a password‐protected link on a secure site. Students review videos and instructors correct inaccuracies in subsequent classes. All students and instructors can comment on videos within the secure site. Students find that the process of taking videos helps them organize their thoughts and students can better prepare for the laboratory by viewing other groups’ videos.

At OUWB, first and second year medical students develop practice practical questions in histology lab. Students select and capture images from virtual histology slides and use presentation software to develop image‐based questions. The instructor compiles, corrects, and posts slides for the class. Misconceptions can be quickly identified and addressed with students prior to summative assessment. Students find these practice questions valuable and frequently approach the instructors with questions generated from the use of this resource.
Developing character during medical education (719.14)
Authors: Dormer Kenneth , Wells Jason , Hemrick Mark , Swanson Robert
Published: June 2021

Character (qualities that determine one’s response to events regardless of circumstances) determines success and is important because of powerful influences physicians have on patients’ health and well‐being. Medical education should endorse good character, e.g. compassion, empathy, discernment, generosity, honor, justice, self‐control, truthfulness and virtue. Important for patient care, we designed a curriculum to promote character in future physicians. Curricular examples: Neurophysiology: Pornography addiction can destroy marriages, families and culture. Its addiction is taught to encourage a physician’s compassion and to facilitate physician‐patient education of self‐control and virtue. Cardiovascular: Prolonged stress, unresolved anger and CRH release with cardiovascular sequelae, lead to major health problems. Attentiveness and sensitivity are taught to recognize and treat stress preventatively, not only in disease. GI/Nutrition: Responsibility and self‐control in diet, fitness, and wellness are promoted in students, as good examples for future patients. Anatomical Sciences: Unselfishness and self‐control are important in a patient for healthy sexual relationships. Female reproductive tracts allow for pathology (sperm proteins accessing the bloodstream can drag endometrial cells into the Pouch of Douglas) if honor doesn’t restrain intercourse during menstruation.
A comparison of traditional and engaging lecture methods in a large, professional‐level course (719.9)
Authors: Miller Cynthia , Metz Michael
Published: June 2021

In engaging lectures, also referred to as broken or interactive lectures, students are given short periods of lecture, followed by “breaks” that can consist of minute papers, problem sets, brainstorming sessions, or open discussion. While many studies have shown positive effects when engaging lectures are used in undergraduate settings, the literature surrounding use of the learning technique for professional students is inconclusive. The novelty of this study design allowed a direct comparison of engaging physiology lectures vs. didactic lecture formats in the same cohort of 120 first‐year School of Dentistry D.M.D students. All students were taught five physiological systems using traditional lecture methods and six physiological systems using engaging lecture methods. The use of engaging lectures led to a statistically significant higher average on unit exams compared to traditional didactic lectures (8.6% higher, p<.05). Furthermore, students demonstrated an improved long‐term retention of information via higher scores on the comprehensive final exam (22.9% higher in engaging lecture sections, p<.05). Many qualitative improvements were also indicated via student surveys and evaluations, including an increased perceived effectiveness of lectures, decrease in distractions during lecture, and increased confidence with the material.
Development of a scientific teaching faculty resource site (720.6)
Authors: Palmer Melissa , Holm Noah , Stern Marshall , Hathaway Marcia , Martinson Krishona , White Michael
Published: June 2021

Electronic learning forums improve student academic experiences by increasing accessibility, accommodating various learning styles and deepening student mastery of the subject matter when applied appropriately and creatively. They allow students to have flexibility in their academic schedule and location, and many of today’s students enter college with a worldview that expects technology‐rich learning environments. With limited active‐learning classrooms and laboratory space available at times, many instructors have expressed an interest in developing online courses. Unfortunately, instructors and administrators have expressed concerns about variability in the quality of course design, implementation and pedagogy. Constructing curricula with deliberate pedagogically sound student interactions are an important aspect of any plan for developing and improving eLearning. The main thrusts of this poster detail the development of a new and current website for faculty that focuses on the improvement of all online curricula heavily centered on scientific teaching. This Scientific Teaching Faculty Resource Site is open‐ended and scalable, and concentrates on improving pedagogical expertise by aiding faculty interested in computer technologies like screen capture, video editing, or newer technologies like “Flipgrid”. The website also provides instruction and advice on how to implement these technologies into the virtual classroom. Student video projects from our Human and Animal Physiology course are featured. The Scientific Teaching Faculty Resource Site also serves as an exemplary model for online course design. Comprehensive surveys will be given to students this semester gathering preliminary baseline data on existing online courses and again following completion of the website and subsequent course modifications. Faculty will also be asked to provide feedback on their experience in order to meet pedagogical needs effectively.
Students as anatomy peer teachers ő a new course to develop teaching skills in a flourishing community of learning (721.11)
Authors: Barash Alon , Reis Shmuel , Dickman Nomy , Biswas Sima , Karasik David
Published: June 2021

Objective: In response to shortage of doctors in Israel, a new medical faculty was set up at Bar Ilan University in Galilee. Basic Science and clinical teachers were recruited overseas and locally, but junior faculty, such as teacher assistants (TA), were difficult to find in this remote locale. Thus, a peer teacher course for students was designed to develop anatomy teaching skills.

Method: Students participated in the 5‐day Teaching Assistant course, set up by the departments of Medical Education & Anatomy. 20 preclinical students attended the course. Topics covered included the basics of didactics and pedagogic approaches, small group teaching skills, and advanced practical skills in cadaveric dissection.

Results: On the Likert scale the overall rating for the course was 3.85. Learning prosection and anatomy demonstration skills scored 4.3 and 4.15, respectively. TA Students appeared at ease in the dissecting room amongst their peers. They were able to prepare and lead a Case‐Based Learning session with more confidence.

Conclusion: Students as peer teachers can make a great contribution to the teaching faculty. Personal gain in terms of confidence, focus and motivation are at least as important as practical dissection and teaching skills. Among the lessons learned for the future are: a need to provide a radiological hands‐on experience (e.g. CT, MRI & US) and the necessity to emphasise on ethical values, since these TAs will be facing such questions from their peers.
Through the eyes of future medical student teachers: the growing role of teaching assistants in medical education (721.13)
Authors: Laitman Benjamin , Maffucci Patrick , Shaw Phyllis , Mak Ki , Eddleman Keith , Lerner Susan , Reidenberg Joy , Laitman Jeffrey
Published: June 2021

As much of the education of medical students in their clinical years is now conducted by residents, it is becoming increasingly important that medical students at all levels learn the importance of various aspects of teaching, from in‐class instruction to conducting evaluations. The following report will discuss the changes implemented in our first year medical school “Structures” course, a new entity at the Icahn School of Medicine at Mount Sinai consisting of Gross Anatomy, Histology, and Embryology.

Approximately 70 TAs take part in teaching for this course, with roles ranging from organizing review sessions, to assisting in the preparation of exams and in‐lab assessment of students. In an effort to integrate TAs more into the teaching process, Structures TAs became responsible for organizing weekly review sessions, comprehensive midterm and final exam review sessions, and, especially of note, became a larger part of the course’s evaluations. Over the past few years, the anatomy course at Mount Sinai has adopted an assessment strategy called “table conferences” in place of practical examinations. Traditionally, in these table conferences, a group of five or six students are questioned about aspects of their dissection, both practical and conceptual, by an evaluator. While historically done by faculty members, this year, in Structures, Senior TAs became responsible for conducting the majority of these table conferences.

Overall, we found that increased TA involvement in all aspects of the course has been an overwhelmingly positive experience for students, TAs, and faculty alike. It is our hope to completely shift table conferences to Senior TAs and to further increase the involvement of both Senior TAs and second year TAs in the course in the future. We believe participating in this TA paradigm will play a major role in shaping our students as educators.
Use of Peer Instruction in an interactive medical histology laboratory (721.16)
Authors: Balch Maria , Hawes Sara , Borges Nicole , Ream Larry
Published: June 2021

Our previous study exploring the use of an Audience Response System (ARS) to promote active learning and group interactivity in a medical school histology laboratory determined the method to be effective in stimulating discussion, enhancing peer interaction, and applying the material. Separately, the instructional strategy known as Peer Instruction (PI) provides a model for student interaction using a controlled questioning process. Upon implementation of PI, published studies report increases in students’ conceptual reasoning and quantitative problem solving skills. Our study seeks to further develop the concept of ARS in a histology course by implementing the use of PI in a medical histology laboratory setting.

Presenting clinically‐relevant questions associated with microscope images using the PI model provides a system through which visual learning, pattern recognition, group interaction, and clinical application are simultaneously addressed. The benefits of Peer Instruction Laboratory Sessions (PILS) are evaluated by obtaining individual student assessments from the PILS using ARS data and comparing them to corresponding student laboratory exam scores. This data comparison thus helps to quantify the impact of PILS on visual application and long term material retention.