bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perceptions of a Flipped Histology Class: as Polarized as Politics?
Authors: Klein Barbie 
Published: June 2021

Incorporating flipped classrooms in the medical curriculum is gaining popularity, yet the perceived benefits by students are less well known. At the request of the course director, the author of this study developed a flipped class for the immune and lymphatic systems in a traditional semester‐based medical‐level histology course. Students were to prepare prior to class by watching a podcast, reviewing a presentation of laboratory terms, and reading a chapter. Class began with an online quiz over the material followed by a discussion about the questions. Groups then completed three computer‐based clinical cases. To emulate the process of diagnosis, cases were constructed as hyperlinked text documents permitting students to decide between various outcomes at each step before proceeding.Students were invited to complete a survey regarding their experience. Most responded positively, however, were divided about adding more flipped classes. Several students expressed dislike for the amount of preparation required to get the most benefit and some felt that flipped classes are a poor substitute for traditional lectures. The interactive clinical cases were well received by most students and several commented that the cases lead to effective collaboration with classmates. This study indicates that some learners prefer the design of this particular flipped class while others are strongly opposed to deviating from traditional lecturing. The majority of students suggested incorporating a few flipped classes throughout the semester to supplement lecturing.
Acquiring Skills Beyond the Bench Through the Great Diseases ‐ a Teacher‐Scientist Partnership
Authors: Tammen Stephanie , Malanson Katherine , Jacque Berri , Meiri Karina 
Published: June 2021

Young scientists know that being competitive in the job market requires skills and experience beyond the bench. Given the overproduction of biomedical scientists with PhDs relative to the number of openings for secure academic positions, it is critical that young scientists acquire broad skill sets. Participating in curriculum design partnerships with teachers offers scientists a novel career opportunity. Our collaborative curriculum development team of biomedical scientists has partnered with teachers to build inquiry‐based biomedical curricula focused on “Great Diseases” that impact global health (Infectious Disease, Neurological Disorders, Metabolic Disease and Cancer), and now the scientists are also leading dissemination of the curricula in classrooms nationwide. Teachers often feel unprepared to lead students in formulating questions, designing experiments and interpreting data, a major obstacle to implementation of curricula with novel scientific content or authentic science practice. Interacting directly with scientists helps solve this problem. Scientists work with teachers via one‐on‐one virtual meetings, during which the biomedical scientist offers the teacher structured real‐time mentoring in content and helps devise strategies to implement the material in the classroom, at the same time augmenting their knowledge of effective teaching methods. We have found that when teachers participate in structured mentoring their ability to teach about cutting‐edge biomedical science improves, which is passed on to the high school students, the ultimate beneficiaries.Funded through: NIH Grant: R25OD010953‐04, gift from Boston Scientific and Cubist Pharmaceuticals Grant
Biochemical Mechanism for Recruitment of the Checkpoint Activator TOPBP1 to Stalled Replication Forks
Authors: Michael Matthew 
Published: June 2021

During a replication stress response, the ATR protein kinase is activated on stalled replication forks to allow a delay in cell cycle progression, a block to further origin firing, and stabilization of the stalled fork. ATR is recruited to stalled forks via an interaction between its binding partner ATRIP and RPA‐coated single‐stranded DNA (ssDNA). However, binding of ATR‐ATRIP to RPA‐coated ssDNA is not sufficient for ATR activation as both the 9‐1‐1 clamp protein and the checkpoint activator TOPBP1 must also be recruited so that TOPBP1 may activate ATR. The biochemical mechanism for assembly of the checkpoint‐signaling complex has been an important unanswered question in the cell cycle field for many years.Previous work from our laboratory, and other groups, has shown that ATR/ATRIP and TOPBP1/9‐1‐1 are recruited independently to stalled forks, and then come together on the DNA to form an active checkpoint‐signaling complex. Furthermore, we have previously shown that TOPBP1 is required for loading of the 9‐1‐1 clamp, however the means by which TOPBP1 senses the stalled fork to allow checkpoint complex assembly was not previously known. We will present data, obtained using Xenopus egg extracts, showing that direct interaction between TOPBP1 BRCT repeat 2 and RPA‐coated ssDNA is the mechanism for TOPBP1 recruitment. In addition, we present evidence that direct interaction with RPA‐coated ssDNA is a general feature of a subclass of BRCT domains from other proteins, including PTIP and REV1.
Directed Evolution of DinB in Escherichia coli by Hydroxylamine Mutagenesis and UV Selection
Authors: Hollander Judith , Beuning Penny 
Published: June 2021

DNA polymerase III (pol III) replicates undamaged DNA in E. coli under normal conditions. However, pol III is unable to replicate past DNA damage and when this happens, the SOS response is induced. The SOS response induces the expression of at least 57 genes that help repair or tolerate the damage. Some of the genes expressed during the SOS response include those encoding the Y‐family polymerases, which are capable of translesion synthesis (TLS). Translesion synthesis is the process by which DNA polymerases replicate damaged DNA without correcting the damage.The dinB gene product (pol IV) is capable of replicating DNA containing minor groove deoxyguanine adducts, such as N2‐furfuryl‐dG and N2‐benzo[a]pyryl‐dG adducts, whereas pol V, a product of the umuC and umuD gene products, is capable of replicating DNA containing lesions caused by ultraviolet (UV) light. Our goal was to induce TLS across UV lesions with variants of pol IV. We used DinB and chimeras of DinB containing fragments of UmuC, with additional random mutations via treatment with hydroxylamine, to identify variants of DinB that have obtained the ability to replicate past UV lesions. This work is supported by the American Cancer Society.
Role of Pore Lining Residues in Drug Modulation of Ligand‐Gated Ion Channels
Authors: Schneider Thomas , Facey Jody‐Ann , Joyce Glenna , Voigt Thomas , Stater Evan , Hyde Michael , Venner Laura , Howard Rebecca 
Published: June 2021

Pentameric ligand‐gated ion channels (pLGICs) such as GABAA, glycine, and nicotinic acetylcholine receptors mediate synaptic transmission by converting chemical signals into electrical impulses. Alcohol, anesthetics, and other drugs have been shown to directly modulate the function of pLGICs, however the precise mechanism through which they act remains to be determined. Although high‐resolution structural details of functionally relevant pLGICs are limited, the structure of the prokaryotic homolog GLIC has been determined in multiple conformations and in the presence of drugs, making it a potentially valuable model system. In order to elucidate the influence of alcohol and other drugs on pLGIC function, site‐directed mutations were introduced to an ethanol‐sensitized GLIC variant at pore‐facing residues that have been shown to play a critical role in channel gating. Mutant ion channels were expressed in Xenopus laevis oocytes and characterized using two‐electrode voltage clamp electrophysiology. Polar substitutions to the pore altered channel sensitivity to proton activation, alcohol potentiation, and anesthetic inhibition, consistent with a role for pore‐lining residues in bridging direct effects of alcohol binding on the ion pathway.This work was support by startup funds from Skidmore College.
Rescuing Nod2, an innate immune receptor of bacterial cell wall fragments, in Crohn Disease
Authors: Grimes Catherine , Mohanan Vishnu 
Published: June 2021

Nucleotide binding oligomerization domain‐containing protein 2 (NOD2, CARD15) is an intracellular host pattern recognition receptor that recognizes fragments of bacterial cell wall. Nod2 is important to human biology, as when it is mutated, it loses the ability to respond properly to bacterial cell wall fragments. In order to determine the mechanisms of misactivation in the Nod2 Crohn's mutants, we developed a cell based system to screen for protein‐protein interactors of Nod2. We identified Hsp70 (heat shock protein 70) as a protein interactor of both wild‐type and mutant Nod2. The objective of this study is to determine the mechanism by which Hsp70 stabilizes Nod2. Induced Hsp70 expression in cells increased Nod2 mediated NF‐kB activation in response to bacterial cell wall stimulation. We found Hsp70 to regulate Nod2′s half‐life, as increasing the Hsp70 level in cells increased Nod2′s half‐life, and down‐regulating Hsp70 decreased Nod2′s half‐life. The expression level of the Crohn's associated Nod2 variants were less compared to wild‐type. The over‐expression of Hsp70 significantly increased Nod2 levels as well as the signaling capacity of the mutants. Thus our study shows that restoring the stability of the Nod2 Crohn's mutants is sufficient for rescuing the ability of these mutations to signal the presence of a bacterial cell wall ligand. Further, we have identified the minimal region of Hsp70 that facilitates the interaction with Nod2. Studies are currently under way to identify pharmacoperones that can potentially stabilize the Crohn's associated Nod2 variants.Funding: This project was supported by the Delaware COBRE program, with a grant from the NIH: NIGMS (1 P30 GM110758‐01) from the National Institutes of Health.
Iodine supplementation reduces elevated total‐ and LDL‐cholesterol in iodine‐deficient, overweight women: a randomized, placebo‐controlled trial in Morocco
Authors: Herter‐Aeberli Isabelle , El Ansari Nawal , Chabaa Laila , Cherkaoui Mohamed , Zimmermann Michael 
Published: June 2021

ObjectiveWhether higher serum TSH caused by iodine deficiency adversely affects serum lipids is unknown. Our objective was to determine if correction of iodine deficiency in adults decreases serum TSH and thereby improves the lipid profile. We also measured the effect of iodine repletion on parameters of glucose metabolism and subclinical inflammation.MethodsIn an area of moderate iodine deficiency in Morocco, we randomized overweight women (n=163; mean±SD age 38.6±6.7 y and mean BMI 32.4±4.1 kg/m2) to receive 200 µg iodine daily for 6 months or placebo tablets. At baseline, 3 and 6 months, we measured serum TSH, free T3 and T4, Tg, total, LDL‐ and HDL‐cholestrol, triglycerides, leptin, glucose, insulin, C‐peptide, C‐reactive protein, and urinary iodine concentrations (UIC).ResultsAt baseline, median (95%CI) UIC was 41.6 (37.3, 47.1) µg/L and prevalences of subclinical hypothyroidism, hypothyroxinemia, and hypercholesterolemia were 4, 14.5, and 40.5%, respectively. There were significant time by treatment effects on: UIC and free T4 (higher with treatment; p<0.001), serum TSH and Tg (lower with treatment; p<0.024, p<0.001). Treatment decreased the prevalence of hypercholesterolemia and elevated LDL cholesterol (at 6 months, comparing treatment vs control: 21.5% vs. 34.8% and 35.4% vs. 44.9%; p=0.005, p=0.068)ConclusionsCorrection of iodine deficiency in overweight women decreases serum TSH, reduces hypercholesterolemia and improves the lipid profile. Thus, iodine prophylaxis may help reduce cardiovascular disease risk in populations with high rates of obesity.
Beneficial Effects of a Nutritional Composition on Diabetic Risk Factors and Complications in LDLr‐/‐. Leiden Mice
Authors: Schoemaker Marieke , van Tol Eric , Kooistra Teake , Kleemann Robert , Wielinga Peter 
Published: June 2021

Obesity frequently associates with chronic inflammatory diseases, including type 2 diabetes. In this study, a combination of a protein hydrolysate, LCPUFAs and a probiotic strain was investigated on the development of high fat diet ‐induced diabetic risk factors and complications in LDLr‐/‐.Leiden mice.Male LDLr‐/‐.Leiden mice at 12 wks of age received a high fat diet (HFD) for 21 wks with or without a combination of an extensive casein hydrolysate, docosahexaenoic acid (DHA), arachidonic acid (ARA), and Lactobacillus Rhamnosus GG (LGG). Both HFD and intervention diet were isocaloric and casein from HFD was replaced with casein hydrolysate in the test diets. The addition of DHA/ARA in the test diets was controlled for in the HFD. Moreover, a PBS gavage control group was included to control for potential effects of LGG gavage.There were significant beneficial effects of the hydrolysate/ARA/DHA/LGG composition versus the HFD control group including reduced body weight gain, lower plasma levels of insulin, cholesterol and triglycerides, lower systemic inflammation, improved adipose tissue quality and mass, and improved kidney and liver function. In a follow up study, evaluating the individual components of the test formulation, some of the outcomes were attributable to the hydrolysate or LGG.A combination of an extensive casein hydrolysate, ARA, DHA and LGG reduces the detrimental effects of HFD on the development of obesity and its metabolic complications. Main risk factors for the metabolic syndrome such as adipose tissue and chronic inflammation were markedly reduced which could provide a rationale for the beneficial effects observed.
PKC Activation Leads to Increased RGS2 Protein Levels
Authors: Aschermann Lauren , Sjogren Benita 
Published: June 2021

Regulator of G protein Signaling 2 (RGS2) is a member of a family of proteins that regulate G protein‐coupled receptor (GPCR) mediated signaling by accelerating GTP hydrolysis on active Gα subunits. RGS2 has been indicated to play an important role in regulating cardiovascular function. RGS2‐/‐ mice are hypertensive, are prone to heart failure and show increased responses to vasoconstrictors, such as Angiotensin II. Strategies to increase RGS2 protein levels could thus be a beneficial therapeutic strategy. More detailed information on how RGS2 protein levels are regulated would facilitate these drug discovery efforts.A previous high‐throughput cell‐based screen of natural product extracts identified Indolactam V (ILV), a known PKC activator, to selectively increase protein levels of RGS2. Utilizing the PathHunter ProLabel assay; a β‐galatosidase complementation assay that measures relative protein levels, we found that ILV, as well as phorbol 12‐myristate 13‐acetate (PMA), selectively increase RGS2 protein levels in a time and concentration dependent manner. This effect was blocked by PKC inhibitors indicating a mechanism mediated by PKC. Stimulation of a Gq coupled receptor also results in an increase in RGS2 protein, indicating that this could be a novel feedback mechanism for Gq signaling. This study is continuing to dissect the mechanism by which PKC activation leads to increased RGS2 protein levels. Overall, these studies will lead to increased understanding of how RGS2 protein levels are regulated.
The Water Channel Aquaporin 1 is Associated with Human Atherosclerotic Lesions and Attenuates Progression of Atherosclerosis in Male Mice Independent of Blood Pressure
Authors: Stubbe Jane , Wintmo Pamela , Johansen Søren , Hansen Pernille , Lindholt Jes , Rasmussen Lars , Bie Peter , Jensen Boye 
Published: June 2021

The water channel aquaporin 1 (AQP1) supports tumor growth by facilitating endothelial cell migration in tumor neovascularization. We tested the hypothesis that AQP1 promotes neovascularization of growing vascular lesions and aneurysms using human vascular tissue and AQP1‐/‐Apolipoprotein E (ApoE)‐/‐mice. AQP1 was localized in the neovasculature in human atherosclerotic lesions and in human abdominal aortic aneurysm wall, while in internal thoracic arteries AQP1 was restricted to endothelial cells and adventitial vasa vasorum. In female ApoE‐/‐ mice with lesion burden aortic AQP1 mRNA expression was augmented. AQP1 was localized in endothelial cells, vasa vasorum and intralesional cells at the aortic root. Lesion burden did not differ between AQP1‐/‐ApoE ‐/‐ and ApoE ‐/‐ mice after 8 and 16 weeks on western diet (WD, n =13‐15). Male AQP1‐/‐ApoE‐/‐ mice fed WD and treated with angiotensin II (ANGII) for 4 weeks had elevated atherosclerotic lesion burden compared to ApoE‐/‐ mice (11± 1 vs. 4 ± 2 %, n =10‐11, p<0.02). Freely moving AQP1‐/‐ApoE‐/‐ and ApoE‐/‐ mice showed similar blood pressure responses to ANGII i.v. infusion (60ng/kg*day for 7 d) measured by indwelling catheters (nighttime: 129 ± 4 and 128 ± 5 mmHg, respectively). It is concluded that AQP1 is associated with intralesional neovasculature in humans and mice. AQP1 accelerates ANGII‐induced atherosclerosis in male mice independent of blood pressure.Supported by A. Andersen grant and J. & O. Madsens grant
Impaired Compensatory Responses to Hypovolemic Circulatory Stress in Women with Vasovagal Syncope
Authors: Skoog Johan , Lindenberger Marcus , Zachrisson Helene , Länne Toste 
Published: June 2021

ObjectiveA fall in cardiac output (CO) due to a reduced venous return has been suggested as an important factor for the hemodynamic instability in vasovagal syncope (VVS). The aim was to investigate compensatory mechanisms to defend central blood volume during hypovolemic stress in women with VVS.Design and MethodsSingle (30 mmHg) and graded (20 to 70 mmHg) lower body negative pressure (LBNP) were used to create hypovolemic stress in 15 young women with VVS and 15 matched controls. Peripheral mobilization of venous blood from the arm (capacitance response), net fluid absorption and lower limb blood pooling were evaluated with volumetric technique. Hemodynamic responses and plasma norepinephrine (P‐NE) were measured.ResultsAlthough CO decreased in both groups during graded LBNP (P < 0.05), VVS presented a significantly lower CO at LBNP of 40 mmHg (P = 0.045). Mobilization of capacitance blood from the peripheral circulation (ml/100 ml) was reduced in VVS (LBNP 40 mmHg, 0.194±0.02 vs. 0.299±0.02, P = 0.007; LBNP 50 mmHg, 0.172±0.01 vs. 0.314±0.04, P = 0.003), and net fluid absorption was ~40% lower (P = 0.019). VVS displayed a blunted percentage increase in P‐NE (P = 0.009) and a reduced maximal percentage increase in TPR (P = 0.041) during graded LBNP. Lower limb blood pooling was comparable in VVS and controls.ConclusionsImportant compensatory mechanisms to defend central blood volume during hypovolemic stress were impaired in VVS. This may seriously impede maintenance of cardiac output during hypovolemic stress and could contribute to the pathogenesis of VVS.
Secreted Klotho Augments the Therapeutic Potential of Mesenchymal Stem Cells for Monocrotaline‐induced Pulmonary Arterial Hypertension
Authors: Varshney Rohan , Wu Chengxiang , Ali Quaisar , Sun Zhongjie 
Published: June 2021

ObjectiveKlotho is an anti‐aging gene. The purpose of this study is to investigate if secreted Klotho (SKL) in synergy with mesenchymal stem cells (MSCs) improves monocrotaline (MCT)‐induced pulmonary vascular dysfunction and pulmonary arterial hypertension (PAH).Methods & ResultsWe generated lentivirus carrying SKL‐GFP or GFP genes driven by a CMV promoter. MSCs were transfected with SKL‐GFP or GFP. Four groups of male rats were treated with MCT (60 mg/Kg, IP) while an additional group was given saline (control). Three days later, four MCT‐treated groups received IV delivery of MSCs, MSC‐GFP, MSC‐SKL‐GFP, and no treatment, respectively. MCT significantly increased right ventricular (RV) systolic blood pressure. Interestingly, MSC‐SKL‐GFP significantly attenuated the MCT‐induced increase in RV pressure (Saline 17.27 ± 4.86, MCT 31.88 ± 1.39, MCT + MSC‐SKL ‐GFP 23.35 ± 3.26). Ex vivo vascular relaxing responses to acetylcholine were decreased in small pulmonary arteries (PA) in MCT‐treated rats, indicating that MCT causes pulmonary vascular endothelial dysfunction. MSCs overexpressing SKL improved MCT‐induced PA endothelial dysfunction. MSC overexpressing SKL also significantly attenuated RV hypertrophy. MSCs alone, however, improved MCT‐induced PAH, PA endothelial dysfunction and RV hypertrophy but not to a significant level.ConclusionMSCs overexpressing SKL attenuated MCT‐induced PAH, PA endothelial dysfunction, and RV hypertrophy. SKL augments the therapeutic effect of MSCs in PAH.
Raptor and Rictor Both Contribute to the Development and Progression of Pulmonary Arterial Hypertension
Authors: Tang Haiyang , Chen Jiwang , Fraidenburg Dustin , Gu Yali , Garcia Joe , Makino Ayako , Yuan Jason 
Published: June 2021

Pulmonary arterial hypertension (PAH) is a rare but progressive and fatal disease that results in increased pulmonary vascular resistance (PVR). The aim of this study is to examine whether mTOR complexes in pulmonary arterial smooth muscle cells (PASMCs) are involved in the pathogenesis of PAH.MethodsThe mice with smooth muscle cells conditional and inducible knockout of mTOR, Raptor or Rictor were used in hypoxia‐mediated Pulmonary Hypertension (PH) model. Right ventricle systolic pressures (RVSP) and right ventricular hypertrophy, by RV/ (LV+S) ratios, were measured. Animals were treated with dual inhibitor of mTORC1/2 for protective and reversal groups and PH will be assessed by RVSP and RVH measurements.ResultsmTOR conditional and inducible knockout mice had significantly lower RVSP, RV/LV+S ratios, and displayed less pulmonary vascular remodeling when exposed to hypoxia compared to their WT mice. Conditional deletion of Raptor or Rictor in smooth muscle cells was also found to prevent hypoxia‐induced PH and vascular remodeling. Treatment with dual inhibitor of mTORC1/2 attenuated the rise in RVSP and the development of RV hypertrophy in hypoxia‐induced PH.ConclusionBoth Raptor and Rictor play significant roles in pulmonary vascular remodeling associated with PH. Dual inhibition of mTORC1/2 attenuated hypoxia‐induced PH. The PI3K‐Akt1‐mTOR signaling pathway will continue to be a focus of research aimed at determining factors which effect pulmonary vascular remodeling and focusing on both complexes of mTOR may lead to novel therapeutic targets for PAH.