bluuebunny/crossref_metadata_2025_split huggingface dataset:
Negative feedback regulation of T cells: Interleukin 2 and FOXP3 reciprocity
Authors: Popmihajlov Zoran , Smith Kendall A 
Published: June 2021

TCR activation of human T cells induces FOXP3 expression, but the mechanism remains unknown. We investigated the role of IL2 in the TCR/CD3‐induction of FOXP3 expression by normal human T cells in vitro. Freshly isolated PBM Cells were stimulated in vitro with anti‐CD3(OKT3) with or without anti‐CD25 and/or anti‐IL2 antibodies; human rIL2 was supplied exogenously. Four‐color flow cytometry was used to determine the expression of FOXP3. Anti‐CD3‐activation increased FOXP3 expression in both CD4+ and CD8+ T cells to a peak at 24h and by 96h was back to baseline levels. Both anti‐CD25 and anti‐IL2 caused a dose‐dependent inhibition of anti‐CD3‐stimulated FOXP3 expression, to a maximal suppression of 80% in CD4+ and >90% in CD8+ T cells, while the addition of rIL2 restored and prolonged FOXP3 expression. When anti‐CD3‐activated PBMCs were monitored daily for 4 days, FOXP3 and IL2 remained mutually exclusive, indicating that FOXP3 expression restricts but does not suppress IL2 expression upon TCR/CD3‐restimulation. TCR‐activated FOXP3 expression is primarily regulated by IL2/IL2R signaling and occurs only transiently in a subset of both CD4+ and CD8+ T cells. These results are consistent with an IL2‐dependent negative feedback loop that regulates the T cell immune response via FOXP3, so that FOXP3 cannot be considered solely a phenotypic marker for human T‐Reg cells.Supported by NIAID and the Belfer Foundation.
Vascularized bone marrow transplantation (VBMT) across a fully allogeneic barrier induces immune chimerism with absence of graft versus host disease (GVHD)
Authors: Strande Louise F , Lefebvre Daniel , Tai Chau , Matthews Martha , Marra Steven , Hewitt Charles 
Published: June 2021

Our laboratory developed a model in rats to study cardiac allotransplantation with simultaneous VBMT. We hypothesized VBMT would induce chimerism with the absence of GVHD.Lewis female rats received VBMT (n=9) or VBMT with heterotopic heart transplant (n=5) from ACI male donors. Recipients received 2mg/kg FK506 immunosuppression for 14 days. Sacrifice was electively between 21 to 280 days or at time of heart allograft rejection. To demonstrate chimerism, PCR was performed to identify the donor Y‐specific sequence.None of the rats exhibited clinical signs of GVHD. Four rats expelled the VBMT between days 42 to 201, representing probable technical failure. Remaining rats had no signs of VBMT failure. Histology revealed necrotic bone for the failed VBMTs and areas of viable bone marrow in the successful VBMTs. Two of 5 hearts continued beating up to 280 days. Histology of the cardiac allografts showed viable myocardium. Chimerism was demonstrated in all rats, including the failed VBMTs.We conclude VBMT is capable of inducing chimerism across a fully allogeneic barrier with the absence of GVHD. We hypothesize that VBMT serves as an extra‐thymic site of immune education via it's intricate microstromal network and modulates the host immune response which may then serve as the foundation for solid organ allograft transplantation tolerance induction. Supported by American Heart Association Grant #0555795T.
Upregulation of PIP3‐Dependent Rac Exchanger 1 (P‐Rex1) Promotes Prostate Cancer Metastasis
Authors: Qin Jianbing , Xie Yan , Wang Bo , Wolff Dennis W. , Scofield Margaret A. , Dowd Frank J. , Hoshino Mikio , Tu Yaping 
Published: June 2021

Activation of Rac by guanine‐nucleotide exchange factors (GEFs) plays an important role in cell migration, a critical component of tumor metastasis. We investigated the role of P‐Rex1, a novel specific GEF for Rac, in human prostate cancer metastasis. P‐Rex1 was almost undetectable in a normal prostate epithelial cell line (PrEC) and two prostate cancer cell lines with little metastatic ability (LNCaP and CWR22Rv1), but was clearly detectable in more metastatic prostate cancer cell lines (DU‐145, PC3‐LN4 and PC‐3). Studies of human prostate tumor specimens revealed a four‐fold increase in P‐Rex1 protein expression in localized cancer cells and a five‐fold increase in lymph node prostate metastasis when compared to normal prostate tissues. Rates of migration and invasion in transwell chamber assays for various prostate cancer cell lines were directly correlated with their P‐Rex1 expression levels. Moreover, manipulating P‐Rex1 levels in these cells caused parallel changes in migration and invasion. In vivo studies found that the tumor growth rate of a stable CWR22Rv1 cell line expressing P‐Rex1 was unchanged while metastasis was promoted. Altogether, our results identify P‐Rex1 as an important regulator of prostate cancer metastatic progression and suggest that it may be targeted for prevention and treatment of prostate cancer metastasis.(Supported by Nebraska State LB595 to Y. Tu.)
Effects of exercise on expression of skeletal muscle acyl‐CoA synthetase isoform gene expression in obese African‐American and Caucasian women
Authors: Woodlief Tracey Leigh , Sweazey Melanie A. , File Courtney , Hickner Robert C. , Neufer P. Darrell , Cortright Ronald N. 
Published: June 2021

Reduced skeletal muscle (SKM) mitochondrial fatty acid oxidation (FAO) in African‐American women (AAW) may be due to reduced activity of Acyl‐CoA Synthetase‐long form (ACSL). However, endurance exercise training (EET) has been shown to increase SKM FAO in both AAW and Caucasian women (CW). The purpose was to determine the metabolic flexibility of SKM to expand the activity of ACSL in response to EET in obese (BMI 35–40 kg/m2) AAW and CW women. Following a 12 hr fast, biopsies from AAW and CW were obtained from either the rectus abdominus or vastus lateralis before and 4 h after acute exercise in the sedentary and trained (10 d and 8 wk of cycle ergometry) condition. Assays for total ACSL activity, protein content, and gene expression of ACSL 1, 3, 4, 5, and 6 isoforms were assessed. In rectus abdominus, lower (P<0.05) ACSL‐5 protein content was observed in obese AAW vs. CW. Prior to EET, total ACSL activity in vastus lateralis was lower in both obese groups compared to leans, although activity was lower in obese AAW. 10 days of EET did not result in elevated ACSL activity in either obese AAW or CW. However, following 8 wk of EET, both groups demonstrated increased enzyme activity. In response to acute exercise, ACSL‐1 and ‐3 isoform gene expression rose solely in CW. In the trained, rested state, ACSL‐1 and ‐3 isoform expression was elevated in obese CW only (P < 0.05). Results support ACSL as a potential molecular mechanism to explain reduced SKM mitochondrial oxidative capacity in AAW although the increase in FAO in AAW after EET can not be explained by ACSL isoform gene expression.Supported by NIH DK065183‐01 and DK075880‐01
IT TECHNOLOGY ENABLES SAME‐DAY PAP TEST
Authors: Markovic Olivera , Markovic Nenad Svetomir 
Published: June 2021

INTRODUCTIONThe MarkPap® test, a new improved biomarker‐based assay for cytological cervical cancer screening was introduced to the Experimental Biology audience in 2004. In clinical trials, this test was found to be more sensitive and with less false negatives than the control Pap test. The biomarker is amenable for digital imaging and we have developed a prototype of a device to exploit on this characteristic and to explore whether human participation could be efficiently replaced with electronic communication technology for the purpose of mass cervical cancer screening.METHODWe developed a prototype of a device‐‐composed of biomarker‐based cytology and digital imaging included into an IT communication network‐serving, at the input side, the providers of specimen image files and, at the output site, the image evaluators (result providers). We tested our IT communication protocol, and began developing a diagnostic protocol.RESULTSThe striking improvement was achieved with the time reduction between specimen arriving in the laboratory and providing the final results from a remote site. The time for specimen staining, screening, image and demographic data collection, filing a series of typical abnormal images into case folders, forwarding those folders to the central processing unit, alerting the examiners, login, reviewing the folders, consulting other experts if necessary, writing case reports and reporting the results back, could be achieved for approximately two hours per evaluation of an abnormal slide.CONCLUSIONThis result indicates that using IT technology for telecytopathology‐based cervical cancer screening could transform the current practice into a same‐day pap test‐a huge improvement in time and cost of labor.
Porcine coronary collaterals after stimulated myocardial ischemia: count and location
Authors: Spaan Jos , Wijngaard Jeroen van den , Schulten Henny , van Horssen Pepijn , Siebes Maria , Post Mark 
Published: June 2021

IntroductionAim is to quantify number and location of intramural collateral connections following chronic coronary obstruction.MethodIn 7 anesthetized pigs an ameroid constrictor, AC, was placed around the left circumflex artery, LCX, stimulating coronary collateral formation. After six weeks the animals were anesthetized again and the heart harvested, the left main, LM, Right, RCA and LCX distal of the constrictor were cannulated. All arteries were flushed with saline and filled with fluorescent polymer. The hearts were processed in an Imaging Cryomicrotome and images (2000 x 2000 pixels) of the cutting plane taken before each cut of 40 µm thick. The stack of about 4000 images contains information on the coronary vessels down to 20 µm. An algorithm was developed to identify closed arterial pathways induced by collateral connections, CC.ResultsHearts had 23 (8.3 sdev) subendocardial CC's , 12 midmyocardial and only 4 epicardial. Intramural connections always bridged between normal preexisting vessels but were not restricted to boundaries between boundaries of the LCX territories. 4 control hearts did not show more then 5 CC.ConclusionsThe diffuse presence of coronary collaterals in contrast to collaterals directly connecting the LCX with the LAD or the LCX with the RCA are suggestive of regional activation of coronary collateral growth stimulating pathways.
Structural aspects of extracellular EGFR signaling
Authors: Ferguson Kathryn M. 
Published: June 2021

In terms of dimerization mechanism, it is now clear that the EGFR family is an outlier. Whereas all other well‐studied RTKs are activated by ligand‐mediated dimerization, members of the EGFR family undergo a ligand‐stabilized conformational change that precedes entirely receptor‐mediated dimerization. A "dimerization arm" protrudes from domain II and "hooks" the other molecule in the dimer. In its inactive state the receptor adopts a very different conformation in which the dimerization arm is buried in an intramolecular interaction or tether. A major domain rearrangement is required to transition from this "tethered" state to the extended state that can dimerize. The implications of this mechanism for activation and inactivation of EGFR will be discussed in light of recent developments. It is well established that dysregulation of EGFR, and other members of this family, is linked to many cancers. Several EGFR targeted therapies are in use in the clinic and many more are in advanced stages of clinical trials. Our current understanding of the inhibition of EGFR dimerization and activation by clinically relevant antibodies will be discussed.This research is supported by a Career Award in the Biomedical Sciences from the Burroughs Wellcome Fund and by NIH grant R01‐CA112552. Kathryn Ferguson is the Dennis and Marsha Dammerman Scholar of the Damon Runyon Cancer Research Foundation.
Intestinal Regeneration after Irradiation: Stem cells and IGF‐I
Authors: Scull Brooks Patrick , Magness Scott , Lee Ginny , Lund P. Kay 
Published: June 2021

Abdominal irradiation causes damage and loss of intestinal epithelium that requires proliferation of surviving stem cells for regeneration. Evidence for this role of stem cells is indirect due to lack of stem cell biomarkers. This study tested the hypothesis that SOX9 marks proliferating stem cells after irradiation and that insulin‐like growth factor I (IGF‐I) promotes survival or expansion of SOX9 positive cells.Wild type or SOX9‐GFP mice were killed 1 through 9 days after 14Gy of abdominal irradiation and intestines collected. Morphology was assessed by H&E. Immunofluorescence for SOX9 and Ki67 and visualization of SOX9‐GFP tested if SOX9 marked proliferating microcolonies or regenerating crypts. Effects of IGF‐I on SOX9 were evaluated by immunoblot.There was almost complete loss of small intestinal crypts and damage to colon epithelium by days 3‐5 after irradiation. Hyperplastic regenerating crypts were observed on days 5‐9. SOX9‐GFP marked and SOX9 co‐localized with Ki67 in microcolonies and hyperplastic, regenerating intestinal crypts. IGF‐1 treatment increased SOX9 protein levels.SOX9 provides a new biomarker of putative stem cells in microcolonies and regenerating crypts in the intestine after irradiation. The SOX9‐GFP reporter mouse provides a useful model to evaluate stem cell survival and expansion, and effects of trophic therapies during regeneration after irradiation.NIH DK40247‐16
Regulation of MicroRNA Biogenesis
Authors: Kim Narry 
Published: June 2021

MicroRNAs (miRNAs) play key roles in diverse pathways in eukaryotes, and the dysregulation of miRNA biogenesis is often associated with human diseases. Biogenesis of canonical miRNAs is initiated by RNA polymerase II‐mediated transcription. The primary transcript (pri‐miRNA) gets processed into mature miRNA by two RNase III type enzymes; Drosha and Dicer. Drosha cleaves a pri‐miRNA and releases a small hairpin (called pre‐miRNA). Pre‐miRNA is subsequently cleaved by Dicer into ~22 nt mature miRNA. Mature miRNA is then accepted by the Argonaute protein to constitute the RNA silencing complex.Regulation of miRNA biogenesis can be achieved at either transcriptional or post‐transcriptional level. Post‐transcriptional control is widespread and can take place at multiple steps including Drosha processing, nuclear export, Dicer processing, RNA editing, uridylation, and decay. We have been investigating the regulatory mechanisms of cancer‐associated miRNAs. We identified several specific RNA binding proteins that post‐transcriptionally regulate miRNA biogenesis. This talk will focus on the roles of the RNA binding proteins in miRNA biogenesis in cancer and stem cells.
Using Anatomy to teach medical students teamwork skills
Authors: Lerner Susan M , Laitman Jeffrey T. , Reidenberg Joy S , Friedman Erica S 
Published: June 2021

An aim of our medical curriculum is to teach teamwork skills. We implemented a team building curriculum for first year students in 2007 using anatomy as a vehicle for learning these skills. The course was restructured to involve both team teaching and its assessment. Dissection teams were split into two groups that alternated dissection responsibilities and teaching the cohort not present. To reinforce the team concept, standard practical exams were replaced by "Table Conferences" (faculty/teaching assistant run in‐lab oral quizzes) with all members receiving the same grade. This year they will also do a team graded project based on CT images of their cadavers. Students completed peer and self evaluations of team dynamics and a survey of the team building curriculum. 79% felt that they developed teaching skills that supported team learning. 79% agreed that teamwork enhanced their educational experience in anatomy and that the curriculum provided additional benefits outside of anatomy. We conclude that educating and assessing students in a group environment improves teamwork skills. The anatomy experience encourages students to use a team approach to problem solving that will last throughout medical school and beyond.Grant Funding SourceN/a
Mechanical and Mesenchymal Mechanisms of Secondary Chondrogenesis
Authors: Solem Richard Christian , Eames Brian Frank , Tokita Masayoshi , Schneider Richard A 
Published: June 2021

Strategies for treatment of skeletal malformation and injury benefit from an understanding of the molecular and biomechanical mechanisms of secondary cartilage development. We conduct a series of experiments using two species of quail and duck, which exhibit considerably different musculoskeletal morphologies. In duck, mandibular elevator muscles attach to a pronounced secondary cartilage on the jaw. An equivalent cartilage is absent in quail. We hypothesize that species‐specific differences in jaw morphology related to the mode of feeding, and a concomitant dissimilarity in the local mechanical environment promote formation of secondary cartilage in duck versus quail. We test our hypothesis by employing two experimental approaches. First, we alter the mechanical environment in embryonic duck by paralyzing skeletal muscles, or by inhibiting stretch‐activated Ca+2 channels. Second, we re‐pattern the duck jaw complex to resemble that found in quail by transplanting neural crest mesenchyme destined to form skeletal and connective tissues of the jaw. This mesenchyme is known to generate species‐specific pattern. Both experimental approaches inhibit secondary cartilage development, as evidenced by genetic and immunohistochemical data. We conclude that mesenchyme‐dependent changes in gene expression, musculoskeletal pattern, and mechanical forces control secondary cartilage induction.Grant Funding SourceNone
Community‐based multidisciplinary weight management program in Mexico: Determinants of success
Authors: Kaufer‐Horwitz Martha , Vázquez Verónica , Reynoso Ricardo , Zamora Margarita , Soriano Ruth , Manjarrez Iliana , González Lizbeth , Rocha Ingrid , Soto Valeria , Eduardo García‐García 
Published: June 2021

BackgroundStrategies to improve success rates in weight managements programs are needed.ObjectiveTo identify the determinants of success (weight loss =5%) of patients attending a 6 month (7 appointments) multidisciplinary weight management program at the National Institute of Medical Sciences and Nutrition in Mexico City.Subjects and methods1216 obese patients who voluntarily entered the program were evaluated. Assessment at baseline included general and socioeconomic (age, gender, schooling, civil status, appointments, previous treatment), anthropometrical (BMI, waist circumference, previous weight loss), clinical (blood pressure), metabolic (glucose, lipid profile) psychological (emotional eating, conscience of disease, anxiety and depression scores, family support, motivation stage, and diagnosis of food disorders) measurements. A stepwise logistic regression model for success was developed, with socioeconomic, anthropometrical, metabolic, clinical and psychological characteristics as independent variables.ResultsPatients were 38.8±11.7 years old with a BMI of 43.8±8.4; 74% were female; 62.9% of participants had BMI=40. Success rate was 43%. Determinants of success were socioeconomic class (OR=1.51, 95%CI 1.11‐2.07), number of visits (OR=2.09, 95%CI 1.44‐3.04), previous treatment (OR=0.49, 95%CI 0.25‐0.97) and anxiety score (OR 0.94, 95%CI 0.88‐0.99).ConclusionsStrategies to help patients deal with stress should be implemented and efforts to ensure compliance should be made to ensure the expected weight loss.
The temporal evaluation of proteomic research on angioplasty‐induced neointimal formation in rat carotid arteries
Authors: Wu Chieh‐Hsi , Huang Hsianh‐Tien 
Published: June 2021

Angioplasty is the major clinical application for restoring blood circulation of coronary stenosis. However, there have been 40% patients suffered from restenosis within 6 months. We aimed in this study to explore the related proteins involved in restenosis. The neointimal formation of the injured vessels at various time points was evidenced by the histological assay. The protein profiles from the injured vessels at various time points were analyzed by two‐dimensional gel electrophoresis (2DE) and mass spectrometry. Western blot analysis was subjected to confirm the presence of these proteins in the vessels affected by angioplasty. The neointimal formation was evidenced starting from 7 days after angioplasty. Four proteins have been identified by mass spectrometry as PDIA3, GSTp, GLUD1, and PGK1 with protein expression level in a time‐dependent manner after angioplasty. Of which, PDIA3 was most expressed at 7 days after angioplasty while GSTp, GLUD1 and PGK1 were all induced the most at 2 hours after angioplasty. The activity of MMP3 was most potent at 2 hours after angioplasty whereas that of MMP2 was at 7 days after angioplasty. FAD and PI3K were most expressed at 14days after angioplasty.Our results indicate that these proteins are importantly involved in the process of neointimal formation, suggesting their potential roles as biomarkers and therapeutic targets for restenosis.
Absence of Inhibitor of Nuclear Factor κ B Kinase‐Mediated Suppression of Vascular Endothelial Function in Middle‐Aged/Older Adults Who Exercise
Authors: Walker Ashley E , Pierce Gary L , Lesniewski Lisa A , Lawson Brooke R , Magerko Katherine A , Seals Douglas R 
Published: June 2021

We determined if reduced bioactivity of the inhibitor of nuclear factor κ B kinase (IKKB) contributes to enhanced vascular endothelial function in habitually exercising (EX) vs. sedentary (SED) middle‐aged and older adults. BMI was lower (P < 0.05) in EX (n = 5 [5 m], 63 ± 3 y) than in SED (n = 7 [5 m], 61 ± 2 y), but other coronary risk factors did not differ. EX and SED were studied after 4 d of oral treatment with placebo or salsalate (3000‐4500 mg/d), an inhibitor of IKKB (randomized double‐blind crossover). During placebo, brachial artery flow‐mediated dilation (FMD), a measure of endothelium‐dependent dilation, was ~150% greater in EX vs. SED (%Δ: 6.16 ± 0.59 vs. 2.46 ± 0.62; mmΔ: 0.24 ± 0.02 vs. 0.10 ± 0.02; both P = 0.001). Salsalate increased FMD in SED (5.76 ± 0.49 %Δ and 0.23 ± 0.01 mmΔ, P < 0.001 vs. SED placebo) to levels not different from EX placebo (P > 0.30), but had no effect on EX (6.55 ± 1.21 %Δ and 0.24 ± 0.03 mmΔ). Infusion of the antioxidant vitamin C increased FMD by ~80% (P < 0.05) in SED during placebo, but had no effect in SED during salsalate or in EX during either conditions (all P > 0.10). Endothelium‐independent dilation (sublingual nitroglycerin) did not differ between groups or conditions (all p > 0.05). An absence of IKKB bioactivity and reduced oxidative stress contribute to enhanced vascular endothelial function in middle‐aged/older adults who exercise.NIH AG031617, AG006537, AG013038, AG022241, RR00051; AHA 0715735Z