bluuebunny/crossref_metadata_2025_split huggingface dataset:
ROLE OF ESTROGEN THERAPY ASSOCIATED WITH PHYSICAL TRAINING ON OXIDATIVE STRESS PROFILE IN OVARIECTOMIZED RATS
Authors: de Brito Sebastião , de Oliveira Brito Janaina , Bernardes Nathalia , Dias Danielle , Llesuy Susana , Irigoyen Maria-Cláudia , De Angelis Kátia 
Published: June 2021

The aim of study was to verify the effects of 17â estradiol therapy (ET) associated or not with physical training (PT) on cardiac, renal and muscular oxidative stress in ovariectomized (OVX) rats. Female Wistar rats were divided into: control (SC), sedentary OVX (SO), sedentary OVX+ET (SOE) and trained OVX+ET (TOE) (n=8 each group). Estradiol pellets were implanted and PT was performed on a treadmill (8wks). Oxidative stress was evaluated by chemiluminescence (CL), thiobarbituric acid reactive substances (TBARS), redox balance of glutathione (GSH/GSSG), catalase (CAT), superoxide dismutase (SOD) and gluthatione peroxidase (GPx) determinations. Oxidative stress was higher in SO (CL, GSH/GSSG: heart and TBARS: kidney and muscle) than in SC group. The SOE and TOE showed reduction compared to SO group in: cardiac CL (SOE:60%; TOE:61%), renal CL (SOE:45%; TOE:55%) and TBARS (SOE:20%; TOE:27%), and muscle TBARS (SOE:84%; TOE:84%). The cardiac GSH/GSSG was higher in SOE and TOE in relation to SO group (SOE: 14.85 ± 2.18; TOE: 16.20 ± 1.76 vs. SO: 4.59 ± 0.82 umol/g). The SOE and TOE showed increased renal CAT, cardiac and renal GPx compared to SO group, attenuating OVX alterations. In conclusion, long‐term ET, associated or not with PT, improved oxidative stress profile in OVX‐rats, suggesting a positive role of these therapies association after menopause.Financial support: 2009/06865‐8; 2007/57595‐5
Role of bone marrow‐derived mesenchymal stem cells in recovery following cervical spinal hemisection
Authors: Mantilla Carlos B , Zhan Wen-Zhi , Restrepo Laura , Arias Alejandra , Sieck Gary C 
Published: June 2021

Following spinal cord hemisection at C2 (C2SH), removal of descending excitatory drive to phrenic motoneurons results in ipsilateral diaphragm muscle (DIAm) paralysis. Over time, there is partial recovery of rhythmic phrenic activity post‐C2SH. Intrathecal delivery of brain‐derived neurotrophic factor (BDNF) enhances this functional recovery, with 100% of rats displaying rhythmic phrenic activity at 14 days (14D) post‐C2SH; but in humans intrathecal BDNF is associated with adverse effects that limit application. Stem cell transplantation may facilitate a targeted BDNF delivery and minimize side effects. In adult rats, bilateral DIAm EMG activity was chronically monitored before and after C2SH to assess recovery. Wild type, GFP‐expressing bone‐marrow derived mesenchymal stem cells (MSC‐wt) or BDNF‐GFP expressing MSC (MSC‐BDNF) were injected at C2. Seventy % of MSC‐BDNF treated rats displayed functional recovery at 7D and 100% at 14D post‐C2SH. Functional recovery in BDNF‐wt treated C2SH rats was not different from untreated C2SH controls (~10% at 7D and ~40% at 14D). Cellular incorporation of MSC into the spinal cord was evident by GFP immunoreactivity in both MSC groups. We conclude that targeted MSC‐based delivery of BDNF enhances functional recovery of DIAm respiratory activity following an upper cervical spinal cord injury.Supported by NIH grant HL096750 and Mayo Clinic.
cAMP regulates polarization and apoptosis during mammary epithelial acini formation in vitro
Authors: Nedvetsky Pavel I. , Kwon Sang-Ho , Debnath Jayanta , Mostov Keith E. 
Published: June 2021

Epithelial cells form tubular and acinar structures notable for a hollow lumen. In three‐dimensional (3D) culture models utilizing MCF10A mammary epithelial cells, hollow acini form due to integrin‐dependent polarization and survival of cells contacting extracellular matrix (ECM), and the apoptosis of inner cells of acini lacking ECM contact. Here, we report that cAMP‐dependent protein kinase A (PKA) promotes hollow acini formation via two mechanisms. First, cAMP accelerates the polarization of outer cells due to ERK/MAPK inhibition. Second, cAMP, promotes the death of inner cells occupying the lumen. In the absence of cAMP, apoptosis is delayed resulting in profound luminal filling. cAMP‐dependent apoptosis is accompanied by a posttrascriptional increase in the proapoptotic protein BIM, which is at least partially ERK‐independent. These data demonstrate that cAMP regulates lumen formation in mammary epithelial cell cultures both through acceleration of polarization of outer cells and apoptosis of inner cells of the acinus.This study was supported by NIH grants to K.E.M (R01 DK074398 and P01 AI53194), S.K. (DK082115), and J.D (RO1 CA126792). P.I.N. was supported by a fellowship from the German Research Society (DFG; Ne‐897/1‐1).
Liver x receptors regulate human organic anion transporter 1 in renal proximal tubule
Authors: Kittayaruksakul Suticha , Soodvilai Sunhapas , Asavapanumas Nithi , Chatsudthipong Varanuj 
Published: June 2021

Liver x receptors (LXRs) play important role in the regulation of cholesterol and glucose homeostasis by regulating several transporters. In this study, we investigated the effects of LXRs on OAT1‐mediated organic anion transport in renal S2 cells expressing hOAT1 and mouse kidney. Exposure the S2 cells to LXRs agonists (TO901317 and GW3965) and their endogenous ligand (22(R)‐hydroxycholesterol) decreased OAT1‐mediated [14C]‐PAH uptake. This inhibition was abolished by co‐incubation with 22(S)‐hydroxycholesterol, a LXRs antagonist. Kinetic analysis revealed that LXRs activation decreased the maximum rate of PAH transport (Jmax) but had no effect on the affinity of the transporter (Kt). Data from western blot analysis showed the decrease in hOAT1 protein expression following LXRs activation. Similarly, we found the inhibition of [14C] PAH uptake in renal cortical slices as well as a decreased mOAT1 protein expression in mouse kidney. Our findings indicated for the first time that OAT1 function was downregulated by LXRs activation in renal proximal tubule.This work is supported by the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program.
Real‐time visualization of calcium oxalate crystals in Drosophila ‐ a gut and renal model of kidney stones
Authors: Bondeson Daniel P , Hirata Taku , Cabrero Pablo , Ritman Erik L , Dow Julian AT , Romero Michael F 
Published: June 2021

BackgroundKidney stones (nephrolithiasis) are an expensive and painful health problem with a complex etiology with ~70% of stones composed of calcium oxalate (CaOx). The Slc26 gene family contains several proteins that transport oxalate in the gut and kidney. Slc26a6 and its homologs exchange Cl− for oxalate (ox2−), as well as SO4 2−, HCO3 − and formate. Slc26a6−/− mice have hyperoxaluria and CaOx stones illustrating a physiologic collaboration between the gut and kidney. We developed a Drosophila genetic model for CaOx stones (dPrestin, Slc26a5/6, manipulation) allowing rapid gut, renal and whole‐body physiological assessment (min/h v. mo/y).Methods(Tissue) First, Malpighian tubules (MT, renal tubule) were dissected from wild type and dPrestin knockdown mutants and soaked in ox2− solutions. CaOx stones were visualized by DIC microscopy. Second, we generated Drosophila expressing eYFP in the MT, MT+gut or whole body. eYFP is a halide (Cl−) sensor, allowing quantification of Cl−/ox2− exchange by native dPrestin. (Whole body) Wild type and dPrestin knockdown flies were fed ox2− enriched food, and flies imaged (CaOx quantified) by micro computed tomography (MicroCT).ResultsExposing dPrestin‐knockdowns to bath ox2− elicited almost no CaOx crystals. However, exposing wt‐MT to ox2− elicited many CaOx crystals in 20 min. Increased CaOx crystal formation was also coupled with an eYFP intensity increase, matching dPrestin Cl−/ox2− exchange characteristics. MicroCT showed more CaOx crystals in flies that fed on ox2− longer.ConclusionsOur observations indicate that Drosophila and dPrestin manipulation can be used for rapid, detailed studies of gut, renal and whole organism oxalate metabolism & CaOx stone formation. [DK83007]
Isolation and characterisation of lipid rafts containing the kidney‐specific Na(+)K(+)2Cl(−) cotransporter
Authors: Dathe Christin , Daigeler Anna , Jankowski Vera , Kaminski Henriette Josephine , Jankowski Joachim , Fähling Michael , Bachmann Sebastian , Paliege Alexander 
Published: June 2021

Transport activity of the thick ascending limb (TAL) Na(+)K(+)2Cl(−) cotransporter (NKCC2) critically depends on its association with lipid raft membrane microdomains (LR). Aim of the present study was to characterize the protein composition of NKCC2‐containing LR. To this end we isolated detergent‐resistant LR from rat renal outer medullary tissue samples using a discontinuous sucrose gradient and ultracentrifugation (floating assay). NKCC2‐containing LR were purified from total LR by immunoprecipitation. Protein content of the precipitates was analyzed by western blot and mass spectrometry (MS). Floating assay confirmed accumulation of NKCC2 in LR‐enriched fractions. Analysis of the immunoprecipitate demonstrated the presence of NKCC2 and, among others, the lipid raft proteins flotillin‐1 and annexin A2. In conclusion, we have successfully established a protocol for the isolation of NKCC2‐containing LR from kidney samples. Further analysis of the protein content of these LR may provide insight into the regulation of NKCC2 function.Support: DFG FOR667
N‐methyl‐D‐aspartate (NMDA) Channels Regulate Apoptosis in Helicobacter pylori infection by Ammonia‐induced Calcium Permeation Mechanisms
Authors: Seo Ji Hye , Fox James G , Peek Richard M , Hagen Susan J 
Published: June 2021

BackgroundMechanisms that regulate epithelial cell apoptosis in Helicobacter pylori (HP) infection are not well understood. We tested whether ammonia, which is an important cytotoxin produced by HP, increases cell apoptosis by activating N‐methyl‐d‐aspartate (NMDA) channels, which are calcium‐influx channels.MethodsMKN28 cells were transfected with a control or NMDA receptor 2B expression plasmid, creating NR2B+ and NR2B‐ cells. Each cell type was incubated with the wild‐type (WT) cag+ toxigenic HP strain 60190 or its isogenic ureB (uB) mutant, which does not produce ammonia. Calcium permeation and cell viability were tested.ResultsNR2B+ cells incubated with WT HP showed extensive calcium permeation and reduced cell viability that did not occur with uB. Additionally, NR2B+, but not NR2B‐, cells transcriptionally up‐regulated NR2B in the presence of WT but not uB. The surface epithelium from HP‐infected mice also showed a highly significant up‐regulation of NMDA channel expression.ConclusionOur results show that ammonia produced by WT HP transcriptionally up‐regulates NMDA channels to facilitate calcium influx, which significantly reduces cell viability. These results suggest that NMDA channels may be essential to modulate apoptosis pathways during HP infection‐mediated cancer development. This work was supported by NIH DK015681 and by Departmental funding.
Expression of tumor suppressor genes in diet‐induced liver injury: a model of the control of gene expression by gene‐specific CpG island methylation
Authors: Miszewski Susan , Green Ralph , Miller Joshua W 
Published: June 2021

A methyl‐deficient diet (MDD), lacking choline and folate and low in methionine, causes liver injury in rats. We investigated the effects of epigenetic factors on hepatic gene expression in the MDD model. Weanling, male Fisher 344 rats were assigned to receive: 1) control diet for 12 weeks, 2) MDD for 12 weeks, or 3) MDD for 9 weeks followed by methyl repletion with control diet for 3 weeks (MRD). Hepatic RNA and DNA were isolated from 3 rats per dietary group. Gene expression was assessed by microarray and RT‐PCR. Gene‐specific methylation was assessed by pyrosequencing. Microarray analysis revealed ≥4‐fold increase in expression of over 150 genes in the MDD group compared with the controls. Decreased expression toward control levels was observed in the MRD group for most of these genes, and was associated with recovery from liver injury. Among the genes that followed this pattern of expression were the tumor suppressor genes, glutathione‐S‐transferase pi 1 (GSTP1) and metallothionein 2A (MT2A). Methylation patterns of gene specific CpG islands for GSTP1 and MT2A followed inverse trends, with decreased levels of methylation associated with increased gene expression in the MDD group compared with the control and MRD groups. This model of liver injury shows upregulation of tumor suppressor genes associated with diet‐induced suppression of DNA methylation.Funding: American Cancer Society
Dietary antioxidant density in usual diet improves inflammatory biomarkers in overweight postmenopausal women
Authors: Wang Ying , Yang Meng , Vance Terrence M , Lee Sang-Gil , Davis Catherine G , Chun Ock K , Koo Sung I 
Published: June 2021

Total antioxidant capacity (TAC) of typical diets has been found to be associated with increased plasma TAC level and antioxidant enzyme activities. However, its relationship with long term change in inflammation biomarkers is unknown. We aimed to examine whether increased dietary TAC can improve inflammatory biomarkers in a high risk population. Forty postmenopausal, overweight, non‐smoking, but apparently healthy women aged 40–70 y were recruited for a 9‐month longitudinal study. Seven‐day food records and 12‐h fasting blood samples were collected at baseline and at the end of the observational study for dietary and plasma biomarker assessments. At baseline, no association between dietary TAC and inflammatory biomarkers was identified. Over the 9 months, the increase in dietary TAC was accompanied by an inverse change in fasting blood glucose level (p<0.01). It also had a negative partial correlation with E‐selectin level (p<0.05) when age, ethnicity, change in BMI, and changes in blood cholesterol and triglyceride levels were adjusted. When participants were divided into two groups by positive and negative changes in dietary TAC over 9 months, participants having positive change in dietary TAC had a smaller increase in MCP‐1 compared to the negative TAC change group (p<0.05). Findings suggest that modification of dietary TAC might be an effective long term strategy for improving inflammatory biomarkers.Grant Funding Source : Donaghue Nutrition Research Program
Decrease of Postprandial Endothelial Dysfunction by Spice Mix added to High Fat Meat Patty in Men with Type 2 Diabetes Mellitus
Authors: Li Zhaoping , Henning Susanne , Zhang Yanjun , Zerlin Alona , Thames Gail , Tseng Chi-Hong , Heber David 
Published: June 2021

BackgroundHigh fat intake has been demonstrated to promote endothelial dysfunction possibly through an increase in lipid peroxidation and decrease in serum nitric oxide.Objectivestudy the effect of spice mixture on malondialdehyde (MDA) production, serum nitric oxide and postprandial endothelial dysfunction measured as peripheral arterial tonometry (PAT).MethodsHamburger meat was mixed with and without spice prior to cooking. Twenty‐two males with type 2 DM on diet or oral medications consumed control burgers with salt only (CB) or salt and spice mix (SPB) in randomized order.ResultEighteen subjects completed the study. Two hours after consumption of the burger, the PAT score decreased by 9.7±21.5% for CB and increased by 18.0±42.4% for SPB. The change of PAT score after CB and SPB was significantly different (p=0.025). The postprandial concentration of glucose, insulin and triglycerides were similar in all subjects after CB or SPB. Urine MDA excretion in μmol/g creatinine was reduced by 31 percent (p<0.001) in the subjects consuming the SPB compared to the CB group. The average urine nitric oxide concentration 6 hours after consumption of burgers was 9.09±5.7 mcM/mg after CB and 12.37±7.00 mcM/mg after SB with a p value of 0.053.ConclusionThis study demonstrates the benefits of a polyphenol‐rich spice mixture in promoting vascular health when added to cooked meats.
The ‘Unskilled and unaware’ effect is linear in a real‐world anatomy setting
Authors: Finn Gabrielle Maria , Sawdon Marina A 
Published: June 2021

Self‐assessment ability in medical students and practising physicians is generally poor yet essential for academic progress and professional development.The aim of this study was to determine undergraduate medical students ability to accurately self assess their exam performance in a real‐world, high‐stakes exam setting, something not previously investigated. Medical students (n=199) participated in a self‐assessment exercise. Students predicted their exam score on the anatomy practical exam. Students’ predicted exam scores were correlated with their actual attained exam scores. Demographic data was analysed. A negative correlation was found between students’ predicted and attained exam scores. There was no relationship between the students’ entry status into medical school and self‐assessment ability or between sexes. The number of hours of additional self‐directed learning undertaken did not influence students’ self‐assessment. Our results demonstrate the ‘unskilled and unaware’ phenomenon in a real‐world, higher‐stakes and practice‐related setting. Poor performers over estimated their ability, and conversely, high achievers underestimated their performance. We present evidence of a strong, significant linear relationship between medical students’ ability to self‐assess their performance in an anatomy practical exam, and their actual performance; in a real world setting.Grant Funding Source : Internal funding
Anatomy Knowledge: A critical Component of Clinical Care
Authors: Lazarus Michelle Denise , Chincilli Vernon M , Kauffman Gordon L 
Published: June 2021

Many undergraduate medical school curricula have undergone changes resulting in reduced anatomy teaching time. We hypothesized that anatomy course development would be enhanced by understanding essential components of clinical anatomy. Surveys were administered to clinicians who were asked to rate the clinical relevance of anatomy using an 11 point likert scale. Clinicians were divided into 3 categories: Surgical (S, n = 30), procedural (P, n = 39), and non‐procedural specialist (NPS, n = 16) or primary care (NPP, n = 36). Clinicians categorized as S perceived that the role of anatomy in the clinic was more important (mean = 9.83) then other clinical groups. While each clinical group ranked anatomy as important in the clinic (mean ≥7), the NPP group's rating was the lowest (mean = 7.94). Physical exam was identified as an area of clinical care in which all specialties rely heavily on anatomy knowledge (average mean = 9.14). The role of anatomy in patient treatment and communication with colleagues were among the areas of clinical care which varied widely among the clinicians surveyed (p≤0.005), suggesting some specialty specific roles of clinical anatomy. The evidence obtained with this targeted needs assessment suggests the need for formal educational review of pertinent anatomy and will serve as the basis for courses designed to transition basic anatomical sciences to their application in the clinical setting.Grant Funding Source: n/a
Meta‐analysis of interaction between dietary magnesium intake and genetic risk variants on diabetes phenotypes in the CHARGE Consortium
Authors: Hruby Adela , Ngwa Julius S. , Meigs James B. , Nettleton Jennifer A. , McKeown Nicola M. ,   the CHARGE Nutrition Working Group
Published: June 2021

Little is known about whether genetic variation modifies the effect of magnesium (Mg) intake on two important diabetes risk factors: fasting glucose (FG) and insulin (FI). We examined interactions between dietary Mg and genetic variants associated with glucose (16 SNPs), insulin (2 SNPs), or Mg homeostasis and transport (8 SNPs), on FG or FI. Fifteen cohorts provided dietary, genetic, FG (mmol/L), and FI (pmol/L, ln‐transformed) data on up to 52,170 participants without diabetes. Analyses included: associations of Mg with FG or FI; associations of SNPs with FG or FI; and interactions between Mg and each SNP on FG or FI. Cohort‐level results adjusted for age, sex, energy intake, study center, and population substructure were meta‐analyzed using inverse variance‐weighted, fixed‐effect methods. Statistical significance was α=0.0015 (Bonferroni correction for 34 tests). FG (β: ‐0.012 mmol/L; 95%CI: −0.015, −0.008) and FI (−2.4% or β: −0.024 ln‐pmol/L; 95%CI −0.027, −0.020) were lower per 50 mg/day greater intake of Mg. No interaction was observed (p=0.0198–0.9364). Consistent with other studies, higher Mg intake associated with lower FG and FI. There was no evidence that genetic variants at these loci influence the association between dietary Mg and FG or FI.Grant Funding Source: NIH/NIDDK Training Grant
Involvement of Sp1 in Transcriptional Regulation of Atp7a During Hypoxia
Authors: Xie Liwei , Collins James 
Published: June 2021

Genes with GC‐rich promoters were preferentially induced in the rodent intestine during iron deficiency. Moreover, promoters of iron homeostasis related genes (e.g. Dmt1, Dcytb) contain evolutionarily conserved Sp1 binding sites (GC‐rich sequences). The Menkes copper ATPase (Atp7a) gene was strongly induced during iron deficiency, and we previously demonstrated that Atp7a was co‐regulated with iron transport related genes by HIF2α. In this study, we sought to test the role of Sp‐like trans‐acting factors in transcriptional regulation of Atp7a. Phylogenetic footprinting revealed several conserved Sp‐like binding sites in the Atp7a promoter. These sites were mutated in a −224 bp promoter construct driving the luciferase reporter gene. Several of these sites participated in the induction of promoter activity in response to hypoxia in transfected rat intestinal epithelial (IEC‐6) cells. Moreover, phosphorylation of Sp1 increased in IEC‐6 cells exposed to hypoxia; Sp1 is known to be regulated by phosphorylation, which increases DNA binding and trans‐activation properties. Further studies will explore Sp factor interaction with the Atp7a promoter by chromatin immunoprecipitation (ChIP) assay in IEC‐6 cells and in intestine of iron deficient rats. Current data suggest that synergistic interactions between Sp1 (or a related factor) and HIF2α mediate induction of Atp7a gene expression during hypoxia.Grant Funding Source : 1R01 DK074867
Using natural stable calcium isotopes to rapidly assess changes in bone mineral balance using a bed rest model to induce bone loss
Authors: Morgan Jennifer L. L. , Skulan Joseph L. , Gordon Gwyneth E. , Romaniello Stephen J. , Smith Scott M. , Anbar Ariel D. 
Published: June 2021

Spaceflight and metabolic bone diseases disrupt normal bone mineral balance (BMB) resulting in bone loss. Bed rest, by stimulating bone loss, provides the opportunity to evaluate new methods to monitor BMB in healthy individuals suffering bone loss. Natural variations in the Ca isotope ratio occur because bone formation depletes soft tissue of light Ca isotopes preferentially, while bone resorption releases that isotopically light Ca back into soft tissue (Skulan & DePaolo, 1999). Using a bed rest model, we demonstrate that the Ca isotope ratio of urine shifts in a direction consistent with bone loss after just 7 days of bed rest, long before measurable changes in bone mineral density (BMD) occur. The Ca isotope variations are consistent with changes observed in urinary N‐teleopeptide, a bone resorption marker. Bone specific alkaline phosphatase, a bone formation marker, is unchanged. The established relationship between Ca isotopes and BMB can be used to quantitatively translate changes in the Ca isotope ratio to changes in BMD using a mathematical model. This model predicts that subjects lost 0.25 ± 0.07% (± SD) of their bone mass from day 7 to 30 of bed rest, consistent with bone loss rates from 90 day bed rest studies as measured by DXA scans. The rapid signal observed using Ca isotopes and the potential to quantitatively assess bone loss makes this technique particularly well suited for the study of bone metabolism.Grant Funding Source: NASA Human Research Program. Dr. Morgan is supported through an appointment to the NASA Postdoctoral Program at JSC, administered by ORAU.