bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aging Aggravates Cardiac Dysfunction in Severe, but not in Mild, Pressure‐Overload
Authors: de Boer Martine , van Deel Elza D. , Hoeijmakers Jan H.J. , Duncker Dirk J. 
Published: June 2021

The aging heart undergoes structural and functional alterations, that are reminiscent of changes observed in the failing heart, and which thus may increase the vulnerability of the aging heart to develop heart failure. To investigate the effect of aging on left ventricular (LV) hypertrophy and dysfunction we subjected mice at 3, 12 and 24 mo of age to 8 wk of pressure‐overload produced by transverse aortic constriction (TAC), either mild (mTAC) or severe (sTAC).Aging affected cardiac geometry and function in sham mice, demonstrated by increases in LV weight (~26%) and diameter (~8%) and by decreases in LVdP/dt at 40 mmHg (dP/dtP40) (~13%) and in dP/dtmin (~26%) in 24 mo versus 3 mo old mice (all p<0.05). mTAC produced compensated LV hypertrophy (30–40%) with minimal signs of LV dysfunction, which was similar in all age groups. sTAC resulted in ~75% LV hypertrophy, LV dilation (~20%), global dysfunction and pulmonary congestion in all age groups. However, aging aggravated the responses to sTAC, demonstrated by a further decrease in dP/dtP40 (~30%) and dP/dtmin (~30%) and elevation of lung fluid weight (~27%) and right ventricular weight (~31%) in 24 mo versus 3 mo old mice (all p<0.05). The TAC‐induced increase in expression of atrial natriuretic peptide (ANP) was also most pronounced in the older age groups. In conclusion, the effects of severe pressure‐overload on cardiac hypertrophy and function are aggravated by aging.
Short‐Term ACE Inhibition Produces Long‐Term Protection Against NOS Inhibitor‐Induced Cardiac Dysfunction
Authors: Biwer Lauren Alysse , Xu Haodong , Carroll Chad , Broderick Tom , Hale Taben Mary 
Published: June 2021

ACE inhibition produces changes that persist following cessation of treatment, resulting in a reduced inflammatory, proliferative and fibrotic response to the nitric oxide synthase inhibitor L‐NAME. The present study examines the impact of this pre‐treatment on L‐NAME‐ induced cardiac dysfunction.Young adult spontaneously hypertensive rats were treated with enalapril (E+L) or tap water (C, C+L) for 2 weeks followed by a 2‐week washout period. At this point, C+L and E+L rats were given L‐NAME for 10 days. Hearts were perfused via the Langendorff working heart method, mean arterial pressure was assessed via radiotelemetry, and collagen by hydroxyproline assay.L‐NAME increased MAP by a similar magnitude in C+L and E+L. In the LV, prior enalapril treatment tended to decrease collagen content. L‐NAME caused statistically significant decreases in flow‐mediated functional parameters in C+L rats such as cardiac output (Con: 45±11.1mL/min, C+L: 36±11.3mL/min, E+L:47±7.4mL/min), stroke volume, and coronary flow.Despite equivalent impact on arterial pressure and incidence of myocardial infarction, prior enalapril treatment resulted in preservation of cardiac function following L‐NAME. Understanding the mechanisms by which transient ACE inhibition protects against reductions in cardiac function in the absence of ongoing treatment may reveal novel targets for heart failure treatment.
Heart Rate Variability in Patients with Type 2 Diabetes Mellitus
Authors: Goit Rajesh Kumar , Khadka Rita , Sharma Sanjib Kumar , Limbu Nirmala , Paudel Bishnu Hari 
Published: June 2021

ObjectiveTo study heart rate variability (HRV) in patients with type 2 diabetic mellitus (T2DM).MethodsHRV of 60 patients with T2DM and 30 controls were assessed. Resting ECG at spontaneous respiration was recorded for 5 minutes in supine position. The data are expressed as median (interquartile range). The p value <0.05 was considered statistically significant.ResultsAll the time domain measures SDNN [26 (15.5–35) vs 36 (30–40.25) ms, p=0.002], RMSSD [25.9 (11.95–40.45) vs 36.65 (27.05–44.13) ms, p=0.002], NN50 [13.5 (1–70) vs 58 (15.5–86.5) count, p=0.002] and pNN50 [3.5 (0.23–21.83) vs 16.4 (4.45–27.63) %, p=0.002] were significantly lower in T2DM. In frequency domain, LF power [81 (32–148.75) vs 126 (85.25–237.75) ms2, p=0.007], LF power [28.8 (20.78–36.13) vs 36.05 (24.6–43.5) %, p=0.008], HF power [81 (16.75–187.75) vs 182.5 (121.5–281.75) ms2, p=0.001] and HF power [42.15 (27.73–50.65) vs 51.6 (43.58–62.05) %, p=0.001] were significantly lower in T2DM whereas LF nu [45.25 (35.28–63.93) vs 44.65 (33.7–65.35)] and LF/HF ratio [0.776 (0.543–1.13) vs 0.7005 (0.397–0.999)] were comparable. In Poincare plot, SD1 [18.5 (8.73–28.98) vs 26.2 (19.33–31.65) ms, p=0.003] and SD2 [37 (26.13–51.18) vs 48.6(39.63–56.15) ms, p=0.002] were lower in T2DM.ConclusionsPatients with T2DM have reduced cardiovascular autonomic control especially parasympathetic control.
Acute effects of different continuous positive airway pressures (CPAP) on cardiovascular autonomic control in healthy subjects
Authors: Tobaldini Eleonora , Wu Maddalena A. , Cogliati Chiara B. , Torzillo Daniela , Pecis Marica , Mellace Luca , Morris Kendall F. , Porta Alberto , Montano Nicola 
Published: June 2021

CPAP is associated with cardiovascular and respiratory changes and plays a key role in the management of respiratory failure. Scanty data are available on the effects of CPAP on autonomic control in healthy subjects.The aim of this study was to evaluate the effects of different pressures on cardiorespiratory and autonomic variables in young volunteers.In 11 subjects we recorded ECG, continuous blood pressure (BP), respiration and end tidal CO2 (etCO2) at baseline (B) and during CPAP application using a face mask. Three different CPAP pressures (4,8 and 12 cmH20) were delivered in random order in each session.Spectral analysis of heart rate variability (HRV) was used to assess sympathovagal balance: low frequency (LF) and high frequency (HF) oscillations are markers of sympathetic and parasympathetic modulation respectively. Spontaneous baroreflex sensitivity (BRS) was calculated using the spectral alpha index.CPAP induced a significant decrease in heart rate (HR) and an increase in total power (TP) compared to B. No changes in HR and TP were observed among the different pressures. LF, HF, respiratory frequency and BRS were not affected by CPAP. EtCO2 and BP were unmodified during the experiments.The data suggest that CPAP acutely modifies HR and TP independently by changes in sympathovagal balance and BRS; direct mechanical effects induced by CPAP might explain these preliminary data. ASI Grant
Pharmacological pacemaker current inhibition improves hyperadrenergic postural tachycardia in human subjects
Authors: Schroeder Christoph , Tank Jens , Heusser Karsten , Rieck Daniela , Luft Friedrich C , Jordan Jens 
Published: June 2021

BackgroundPostural tachycardia syndrome (POTS) patients show excessive cardiac sympathetic drive with standing. The pacemaker current I(f) mediates sympathetic influences on heart rate.HypothesisPharmacological I(f) inhibition with ivabradine improves upright tachycardia in a human pharmacological POTS model.MethodsIn a double‐blind, randomized, three‐way crossover study, 21 healthy men ingested the selective norepinephrine transporter inhibitor reboxetine 8 mg to raise cardiac sympathetic drive and in addition placebo, 7.5 mg ivabradine, or 95 mg metoprolol (positive control) on separate days. We applied 60° head‐up tilt for 20 minutes followed by additional lower body negative pressure.ResultsResting heart rate was 67±11 bpm with placebo, 65±12 bpm with ivabradine, and 59±7 bpm with metoprolol. During head‐up tilt, heart rate increased 53±17 bpm with placebo. Compared with placebo, ivabradine and metoprolol reduced upright heart rate by 12 (95% CI 4–21, p<.006) and 21 (95% CI 13–30, p<.0001) bpm, respectively. Orthostatic tolerance was not affected by either treatment.ConclusionThe cardiac hyperadrenergic state induced by pharmacological norepinephrine transporter inhibition is a useful model for human pharmacological research. Using this model, we showed that I(f) inhibition ameliorates hyperadrenergic orthostatic tachycardia. Funded by Deutsche Forschungsgemeinschaft.
Changes in peripheral but not central pulse wave velocity with estradiol administration is positively correlated with muscle sympathetic nerve activity
Authors: Miner Jennifer Ann , Miner Jonathon Cory , Kaplan Paul F , Minson Christopher T 
Published: June 2021

To investigate how estrogen affects autonomic and cardiovascular function, we measured muscle sympathetic nerve activity (MSNA), and central and peripheral pulse wave velocities (PWV) in 8 young healthy women after 3 days of endogenous sex hormone suppression (via gonadotropin‐releasing hormone antagonism). Five subjects continued hormone suppression for 2 days, combined with 0.2mg/day transdermal estradiol, and were retested. Estradiol administration decreased peripheral PWV (p<0.05), a finding that does not exist during normal menstrual fluctuations. There was no change in central PWV (p=0.27). In addition, we used linear regression analyses to explore the relationship between MSNA and PWV. Across all subjects and conditions, peripheral (brachial‐ankle) PWV was positively correlated with MSNA bursts/min (R2=0.33, p=0.05) and bursts/100 heartbeats (R2=0.39, p=0.03), whereas no relationships existed between central (carotid‐femoral) PWV and MSNA parameters (bursts/min, R2<0.01, p=0.90; and bursts/100 heartbeats, R2<0.01, p=0.77). These data suggest sympathetic outflow to the peripheral arteries may explain the changes in peripheral PWV with estrogen administration. Degree of sympathetic innervation in the specific arteries studied may explain the differences between peripheral and central PWV measurements.Supported by NIH Grant HL081671.
Proteomic Analyses on Mitochondria in Rats model of Heart failure
Authors: Liu Tingting , Chen Le , Kim Eunjung , Knowlton Anne 
Published: June 2021

Mitochondrial dysfunction contributes significantly to the decline in cardiac function in heart failure. We hypothesized that there would be abnormalities in mitochondrial structure and proteome with the progression of heart failure.MethodsWe used our established high LAD ligation to generate ischemic heart failure in 3 month old male rats. Rats were studied at 9 weeks post ligation.ResultsEcho confirmed the presence of heart failure post ligation. Electron microscopy of left ventricle (LV) samples showed many mitochondrial changes including decreased size, increased number, abnormal distribution, and cristae loss. Mitochondrial functional studies showed that total ATP was decreased and mitochondrial respiration impaired in heart failure. Analysis of LV mitochondrial protein by 2D gel and mass spec identified 27 differentially expressed proteins, with 12 up‐regulated and 15 down‐regulated proteins in the failing heart. Ongoing work is investigating additional target proteins and their regulation. Supported by HL077281.
Enhanced tetrahydrobiopterin contributes to sodium restriction‐induced improvements in large elastic artery compliance in older adults with elevated systolic blood pressure
Authors: Racine Matthew Lee , Geolfos Candace J , DeVan Allison E , Gates Phillip E , Chonchol Michel , Seals Douglas R , Jablonski Kristen L 
Published: June 2021

Dietary sodium restriction (DSR) improves carotid artery compliance (CC) in middle‐aged and older adults (MA/O) with moderately elevated systolic blood pressure (SBP), but the mechanisms of action are unknown. Reduced tetrahydrobiopterin (BH4) bioactivity contributes to age‐associated vascular dysfunction. We hypothesized that increased BH4 bioavailability may contribute to improvements in CC with DSR. SBP was reduced following 4 weeks of a low sodium (LS; 56±11 mmol/day; 125±2 mmHg) vs. normal sodium (NS; 160±7 mmol/day; 141±4 mmHg) diet (p<0.001; randomized, cross‐over design; 5M/4F; 61±3 yrs). Baseline CC was 43% greater during the LS vs. NS condition (0.14±0.02 vs. 0.097±0.02 mm/mmHg, p=0.05). Acute oral BH4 administration (10 mg/kg) improved CC vs. placebo during the NS condition (0.13±0.02 mm/mmHg, p<0.05) to levels not significantly different than the LS placebo state, but had no effect on CC during the LS condition (0.14±0.02 mm/mmHg). BH4 had no significant influence on SBP in either condition (LS, 127±3 mmHg, p=0.30; NS, 138±3 mmHg; p=0.13). Results were similar when presented as the β‐stiffness index, a more BP‐independent expression of carotid artery distensibility. These findings are consistent with the hypothesis that DSR improves CC in MA/O with moderately elevated SBP in part by enhancing BH4 bioavailability.NIH AG013038, AG006537, AG03114, AG033994, RR025780
Vascular hyperpolarization contributes to onset and steady‐state exercise hyperemia in humans
Authors: Crecelius Anne R. , Kirby Brett S. , Richards Jennifer C. , Garcia Leora J. , Luckasen Gary J. , Larson Dennis G. , Dinenno Frank A. 
Published: June 2021

We tested the hypothesis that vascular hyperpolarization contributes to both the onset and steady‐state hyperemic response to exercise. In Protocol 1 (n=11), forearm blood flow (FBF; Doppler ultrasound) was measured during rhythmic handgrip exercise at 10% maximal voluntary contraction for 5 minutes under control (intra‐arterial saline; T1) conditions, after combined inhibition of Na+/K+ATPase and KIR channels [via ouabain and barium chloride (BaCl2), respectively; T2] alone and in the presence of combined nitric oxide synthase (L‐NMMA) and cyclooxygenase inhibition (ketorolac; T3). Drugs were not infused during exercise due to potential influences on basal vascular tone. The total hyperemic responses were significantly (P<0.05) attenuated from control at 30 seconds (50 ± 4 and 65 ± 2%), 1 minute (34 ± 4 and 41 ± 3%), and 2 minutes (20 ± 4 and 23 ± 4%; T2 and T3 respectively) of exercise. FBF was not different in the last 2 minutes of exercise. In Protocol 2 (n=6), all study drugs were infused prior to and during exercise to assess the impact on steady‐state hyperemia. Steady‐state FBF was significantly reduced during T2 vs T1 (123 ± 18 vs 156 ± 21 ml/min; −21 ± 4%), and further reduced during T3 (108 ± 17 ml/min; −32 ± 3%). Our data indicate vascular hyperpolarization as a novel contributing vasodilatory pathway in the complex blood flow response to exercise at the onset and during steady‐state hyperemia.Supported by HL102720
RESTORATION OF RETINAL GANGLION CELL DENDRITIC ARBORS AFTER AXONAL INJURY IN VIVO.
Authors: Di Polo Adriana 
Published: June 2021

PurposeDendrites are major determinants of how retinal neurons integrate and process incoming information. We showed that retinal ganglion cells (RGCs) undergo shrinkage of dendritic arbors soon after axotomy, but the molecular mechanisms that underlie injury‐induced dendritic remodeling are poorly understood. Here, we investigated the role of the mTOR (mammalian target of rapamycin) pathway in RGC dendritic structure and synaptic input after acute optic nerve lesion.MethodsAdult transgenic mice carrying the yellow fluorescent protein (YFP) gene were subjected to optic nerve axotomy. Retinal mTOR activity was manipulated by intraocular injection of siRNA against the mTOR repressor REDD2 or by intraperitoneal administration of the mTOR inhibitor rapamycin. Retinal whole‐mounts were prepared and RGC dendritic trees were 3‐D reconstructed.ResultsOptic nerve axotomy leads to marked downregulation of mTOR activity in RGCs correlating with dendritic shrinkage prior to RGC death onset. siREDD2 stimulated mTOR activity in injured RGCs leading to increased dendritic length, surface and complexity compared to control retinas. Importantly, increased mTOR activity in RGCs restored glutamatergic bipolar cell inputs onto RGC dendritic shafts.ConclusionWe report a novel role for the mTOR pathway in the restoration of RGC dendritic arbors and excitatory synaptic input after acute optic nerve lesion.
Knowledge and perceptions on high blood pressure risk, healthy lifestyles, and use of mobile phone in 3 Latin American countries
Authors: Ramirez-Zea Manuel , Estrada Karin , Letona Paola , Beratarrechea Andrea , Diez-Canseco Francisco , Miranda Jaime J , Rubinstein Adolfo , Salguero Julissa , Martinez Homero 
Published: June 2021

BackgroundPreventive interventions for high blood pressure (HBP) are urgently needed in developing countries.ObjectiveFormative research to assess perceptions and knowledge on HBP risk, healthy lifestyle and use of mobile phone for health advice among adults living in urban areas in Argentina, Peru and Guatemala.MethodsFocus group discussion segmented by gender (4/country, 5–13 subjects each) with healthy men and women, 30–59 yrs old. Qualitative analysis was done by topic (HBP, healthy lifestyles, use of mobile phone), country and sex.ResultsWomen related HBP to salt intake, menopause, pregnancy and breastfeeding; men related HBP to salt intake, being over 50 yrs and to a cause of death. Barriers identified to follow a healthy diet were: income, knowledge, overeating and time. Men also mentioned eating away from home as a barrier. Women saw physical activity as a group event and men as a structured activity (e.g. gym workouts). All subjects perceived their mobile phone as a daily necessity. Men tended to be more possessive with their mobile phone, while women more often shared it with other family members. No relevant differences were found among countries.ConclusionsGender differences in perceived HBP risk, food preparation, eating habits and physical activity choices should be specifically addressed. Mobile phones seem to be a useful tool to deliver health advice.Funding: NHLBI HHSN 268200900028C
Does infant mood affect offered bottle size? An exploratory analysis of secondary objectives of the Baby‐Mine study
Authors: Nicklas Jennifer C , Greer Betty P , Burney Janie L , Kavanagh Katie F 
Published: June 2021

A secondary objective of a larger project assessing impact of bottle contents on rate of infant weight gain was to evaluate the relationship between infant mood and offered bottle size. Mothers of healthy, term, formula‐fed infants (< 3 months) were recruited via fliers, social media websites, and a birth registry. Mothers were asked, at two time points, to record infant intake for 48 hours and to indicate infant mood prior to each offered bottle (unhappy, neither, or happy). Mid‐point analysis consisted of 31 mothers with complete data at both time points (TP): TP1 ~2.3 mo of age and TP2 ~4.1 mo of age. The sample was somewhat heavily weighted towards male infants (58.1%). Average birthweight was 3230g, and infants gained an average of 27.4g/d while in the study. Average size of bottles offered increased from TP1 (4.8oz) to TP2 (5.8oz). Mood categorization resulted in 45.2% of infants categorized as “happy” at TP1 and 51.6% as “neither” at TP2. ANOVA, with mood as the categorical variable, detected no relationship between mood and bottle size offered. Additional categorization of bottle size into “small” (≤ 4 oz) and “large” (>4 oz) did not result in significant findings. However, the sample size at the mid‐point evaluation likely precludes the detection of a significant difference, should it exist, and a larger sample size is needed. Data collection is ongoing and more robust results and suggested future work will be presented.Funds: USDA/NIFA/AFRI Award ‐2010‐85215‐20663.
Development of a home feeding intervention for resource‐limited parents of 3–5 year old children
Authors: Reznar Melissa , Hoerr Sharon , Murashima Megumi 
Published: June 2021

PurposeTo describe the development and pilot testing of a dualmedia nutrition intervention for parents of 3–5 year old children enrolled in a federal preschool program.MethodsA multidisciplinary team developed a self‐guided workbook with complementary DVD clips featuring parents discussing family food experiences. In a pilot test, 42 parents and their preschool children were randomly assigned to an intervention (n=23) or control group (n=19) for 8 weeks, with a 6‐week post‐visit. Participants completed 2 evaluations for program acceptability and success.ResultsFive topics comprised the intervention: 1) home food environment, 2) food modeling, 3) praise, 4) mealtime fun, and 5) difficult mealtime behaviors. Sixteen parents in the intervention (70%) and 19 in the control group (100%) completed the pilot. Intervention parents rated the program favorably, with a majority agreeing or strongly agreeing that the program was beneficial (94%), suggested good ways to handle problems (81%), and was effective in changing mealtimes (94%). Only 56% parents agreed or strongly agreed that they as parents needed such a program.ConclusionsThis parent feeding intervention was well received, but needs testing in a larger, wider audience. Targeting parents with higher perceived need might enhance program effectiveness.Financial support: NIH NICHHD Grant Number 1R21HD064876‐ 01A1
β‐Cryptoxanthin supplementation inhibits carcinogen‐initiated and nicotine‐promoted lung tumor development in AJ mice
Authors: Iskandar Anita , Liu Chun , Ernst Hansgeorg , Choi Sang-Woon , Ausman Lynne , Wang Xiang-Dong 
Published: June 2021

Recent epidemiologic studies show that increased dietary β‐cryptoxanthin (BCX) intake, rather than β‐carotene used in earlier human trials, is associated with reduced risk of lung cancer. However, BCX efficacy on lung carcinogenesis has not been reported. Here, we report the protective effects of different doses of BCX against lung carcinogenesis at the initiation and promotion stages in AJ mouse models. In the tobacco carcinogen NNK‐initiated lung carcinogenesis model, we found a 52–63% reduction of lung tumor multiplicity in mice pre‐treated with BCX at 0.2 and 2 mg kg BW‐1 d‐1, as compared to the NNK group, P<0.01. In the NNK‐initiated and nicotine‐promoted lung cancer model, we found that nicotine not only induced emphysema, a risk for lung cancer, but also increased greatly lung tumor multiplicity of the NNK‐treated mice. Notably, BCX at 2 and 4 mg kg BW‐1 d‐1 prevented nicotine‐induced emphysema and decreased tumor multiplicity by 86–91%, P<0.01. BCX protection was associated with suppressions of lung AKT activation, IL‐6 and early growth response‐1 mRNA. Unlike β‐carotene reported in prior animal studies, BCX induced retinoic acid receptor‐β mRNA. By HPLC analysis, liver BCX, not retinol, increased in the BCX supplemented mice. Our data suggest that BCX is a unique chemopreventive agent for lung cancer prevention, which is likely to be independent of its provitamin A activity.Grant Funding Source : NIH R01CA104932
Exploring Shopping Habits and Nutrition Knowledge of Single Mothers in Transitional Housing
Authors: Sweitzer Sara Johnson , Romo Maria , McAllaster Michael , Briley Margaret E 
Published: June 2021

ObjectiveTransitional housing offers an opportunity for nutrition intervention for single mothers with children. As they transition out of homelessness mothers and children are frequently reestablishing lifestyle dietary habits that include budgeting, grocery shopping and food preparation. This study examined the nutrition knowledge and food purchasing habits of single mothers in transitional housing.MethodsMothers at a small transitional housing project in central Texas were invited to participate in a nutrition study. Data collection included mother questionnaires for dietary habits and nutrition knowledge, grocery receipts as well as heights and weights.ResultsThe mothers (n=21) averaged 36.2 years old with an average BMI of 30.4. Mothers reported frequently drinking milk, 75% (n= 16) and occasionally using the food label when purchasing, 52.3% (n=11). The top five types of foods the mothers purchased were fruit, 11.4% (n=34), sugar sweetened beverages, 11.1% (n=33), Dairy products, 9.7% (n=29), vegetables, 8.7% (n=26), and candy/confections, 6.7% (n=20).ConclusionSingle mothers that are in a supportive housing environment would benefit from a targeted nutrition intervention that addressed food behaviors, nutrition knowledge and food purchasing guidance.