bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNA polymerases with improved reverse transcriptase activity
Authors: Fiss Ellen H , Suko Shawn , Budker Olga , Martinez Tomas , Stoffel Susanne , Schoenbrunner Nancy , Bauer Keith 
Published: June 2021

There exists a need for enzymes with improved reverse transcriptase activity to increase the sensitivity of diagnostic assays which use RNA targets. In our lab we have produced a collection of chimeric mutant DNA polymerases with modulated proofreading activity. A mutagenized library of one of these DNA pols was screened for improved extension rates on a primed M13 template. Some of the mutants displayed the ability to perform improved RT‐PCR using either Mn2+ or Mg2+. One of the DNA pol mutations, D640G, was transferred to the parent DNA pols of the chimera, Thermatoga maritima and Thermus sp. Z05. These mutants also demonstrated the ability to perform efficient RT‐PCR with reduced RT incubation times.In Z05 the D580 position was mutated to all 19 other amino acids and the resulting proteins were purified. The D580G and K mutants were found to have improved RT activity and increased RT‐PCR sensitivity using TaqMan‐based detection. Enzymatic characterization revealed a 12.5‐fold improvement in the catalytic efficiency of Mn2+‐activated RT for Z05 D580G over wild‐type. The Z05 D580K enzyme also showed significant activity when Mn2+ was replaced by Mg2+ allowing for higher fidelity RT‐PCR.
Reporting of Systematic Reviews of Micronutrients and Health: A Critical Appraisal
Authors: Chung Mei , EPC Team Tufts 
Published: June 2021

BackgroundSystematic review is a valuable tool for evaluating nutrition‐related research and formulating nutrition recommendations.ObjectiveTo evaluate reporting quality of published systematic reviews (SRs) and identify areas for improvement.Design and MethodsAnalysis of all English‐language systematic reviews linking micronutrient intakes to health outcomes in humans. Medline was searched through July 2007 for all eligible reviews. Descriptive and exploratory analyses of factors associated with reporting quality (7 nutrition variable factors and 28 systematic review reporting factors) were performed.ResultsWe found 141 eligible SRs of 21 micronutrients in 84 journals. On the basis of the pre‐determined criteria systematic reviews including only interventional studies (n=90) had more complete reporting (median: 60%, interquartile range, IQR: 50%, 70%) than those including only observational studies (n=31) (median: 55%, IQR: 48%, 62%) or both types of study design (n=20) (median: 47%, IQR: 39%, 52%) (P<0.001). Quality assessments of the primary studies were performed in only 58 (41%) of SRs. Comparing 3‐years before to 3‐years after publication of reporting standards for SRs, the overall reporting quality has improved (51% to 58%, P=0.01) while reporting of nutrition variables remained unchanged (42%, P=0.75). The least reported nutrition variables were baseline nutrient exposures (28%) and impacts of the measurement errors from nutrition exposures (24%).ConclusionThe reporting quality of SRs has improved but the reporting of nutrition variables remains incomplete. This limits their potential use as a tool when formulating nutrition‐related guidelines or recommendations, formulating research agendas and clinical guidelines.Grant Funding SourceAgency for Healthcare Research and Quality (AHRQ), U.S. Department of Health and Human Services (DHHS), and National Institutes of Health (NIH)
Roles of ciliary polycystin and survivin in cardiovascular abnormality in PKD
Authors: AbouAlaiwi Wissam A , Nauli Surya M 
Published: June 2021

BackgroundPolycystic kidney disease (PKD) is characterized by the development of fluid‐filled cysts in the kidney. However, cardiovascular hypertension and aneurysm represent the most serious life‐threatening complications in PKD patients. We have recently shown that polycystins are localized to the endothelial cilia and function in regulating intracellular calcium and nitric oxide synthesis in response to fluid‐shear stress.Methods and ResultsWe show here that two different PKD endothelial cells, Pkd1 (29%) and Tg737 (32%), are characterized by abnormal cell division (p<0.05, compared to wild type cells). We also observe a significant centrosomal over‐duplication, multipolar spindle formation, nuclear fragmentation and polyploidism leading to chromosome instability and mitotic catastrophe in Pkd1 (16%) and Tg737 (20%). These mitotic abnormalities are associated with the down‐regulation of survivin, an inhibitor of apoptosis and a chromosomal passenger protein involved in mitotic spindle checkpoint and regulation of chromosomal segregation.ConclusionTaken together, our findings provide a novel evidence of the roles for ciliary polycystins in regulating cell division through survivin expression and confirm the proposed involvement of cilia in cell division, parallel to their roles as fluid mechanosensors.
Autonomic Responses of Men and Women to Particulate Exposures
Authors: Evans Joyce McClendon , Patwardhan Abhijit , Jenkins Roger , Ilgner Ralph , Hartman Eric , Jayanthi Ashwin , Knapp Charles 
Published: June 2021

Nonsmokers have demonstrated harmful (decreased heart rate variability) cardiovascular effects when seated in smoking, compared to non smoking, waiting rooms (Pope, 2001), but this study did not control for gender, environmental effects, or exposure to other particulates. We studied 40 (21 w, 19 m) volunteers exposed to 4 aerosols: 3 particulates, environmental tobacco smoke (ETS), cooking oil fumes (Coil), wood smoke (WS), and a nonparticulate, water vapor (Sham). Exposures were conducted in a controlled environmental chamber. Each subject was tested on 3 days and results averaged.ResultsSympathetic control of heart rate (Lo/Hi frequency spectral power RRI), was greater in men than women, for ETS and Coil, compared to WS and Sham. Sympathetic control of vasomotion (LF spectral power of systolic pressure (LFSAP)), increased across particulate, not sham, exposures, peaking in recovery. At breathing frequency, men's LFSAP doubled after 10 min ETS exposure.ConclusionsExposures to particulates increased sympathetic control of heart rate and peripheral vasomotion, with a greater response in men than women during ETS and Coil. In controlled conditions, autonomic activity in non smoking men and women exposed to low level, short term particulate concentrations (this study) were similar to longer term, higher level exposures to ETS and to direct smoking. Supported by the External Research Program of Philip Morris USA.
Acute mountain sickness (AMS) at 3048m is exacerbated by dehydration
Authors: Sils Ingrid , Castellani John W , Beidleman Beth A , Muza Stephen R 
Published: June 2021

Epidemiological evidence suggests that AMS has a higher incidence (IAMS) in people who are dehydrated, yet the effect of dehydration on IAMS and severity (SAMS) has not been prospectively tested. This study assessed AMS following rapid ascent to 3048m (ALT) in euhydrated (EU) and dehydrated (DE) subjects (SS). Seven males (mean±SD, 25±7yr, 82±11kg) participated in four trials over two weeks. On the day before a trial, SS either DE by 4% or remained EU while exercising in a climatic chamber (50oC, 20%RH). The next morning they ascended either to ALT or remained near sea‐level (152m, SL) for 8h in a hypobaric chamber (27oC, 34%RH). IAMS and SAMS were assessed using the cerebral factor score (AMS‐C) calculated from the Environmental Symptoms Questionnaire at 45min, 3h and 71/2h after ascent. Between 45min and 3h SS performed tasks ranging from low to high exertion.ResultsArterial oxygen saturation (SaO2) was lower at ALT vs SL (90±2% vs 97±1%, p< 0.001). IAMS increased with DE (SL‐EU: 0/7 (0%); SL‐DE: 1/7 (14.3%); ALT‐EU: 2/7 (28.6%); ALT‐DE: 5/7 (71.4%)). SAMS increased somewhat with DE at SL (EU, 0.14±0.20; DE, 0.52±0.45; p<0.07) and at ALT (EU, 0.41±0.26; DE, 1.11±0.98; p<0.07). These results suggest that 4% DE increases SL resident's susceptibility and severity of AMS with rapid ascent and exposure to 3048m. Funded by US Army MRMC ATO IV.MD.2006.01. Authors' views are not official U.S. Army or DoD policy.
Intact peripheral chemoreflex regulation of sympathetic vasomotor tone in breath hold divers after detraining period
Authors: Breskovic Toni , Valic Zoran , Lipp Axel , Heusser Karsten , Ivancev Vladimir , Tank Jens , Dzamonja Gordan , Jordan Jens , Shoemaker Kevin J , Dujic Zeljko 
Published: June 2021

We tested the hypothesis that peripheral chemoreceptor function in response to hypoxia is normal in breath‐hold divers (BHD) after detraining period. We compared ventilatory, sympathetic (MSNA), heart rate and blood pressure responses to isocapnic hypoxia in 11 BHD and 11 control subjects. The study was carried out at least one month after all divers finished most intensive apnea training. After baseline period for instrumentation, subjects breathed isocapnic hypoxic mixture to reduce arterial saturation to 0.8. During hypoxia burst frequency (MSNAf) and total activity (MSNAt, au/min) increased similarly in both groups (27% and 60% in BHD and 30% and 66% in controls), respectively. Increased MSNAf and MSNAt returned to baseline after 20 min after termination of hypoxia. Hypoxia‐induced stimulation of minute ventilation was similar in both groups. Cardiac output was increased during hypoxia and since mean blood pressure was unchanged, total peripheral resistance was similarly reduced in both groups. We conclude that elite divers at least 1 month after the end of intensive training/competition period have normal peripheral chemosensitivity without any ventilatory, hemodynamic and autonomic differences from those observed in control subjects.This study was supported by the Croatian Ministry of Science, Education and Sports.
Resveratrol prevents RV/T changes in a neonatal model of hypoxia induced pulmonary hypertension
Authors: Slutzky Jessica Lauren , Natale Elizabeth K , Sprinkle Spencer L , Chicoine Louis G 
Published: June 2021

AbstractResveratrol (trans‐3,5,4′‐trihydroxystilbene) is a polyphenolic compound found in red wine and possesses anti‐inflammatory, antioxidant, and antifibrotic properties. We tested the hypothesis that daily resveratrol treatment would attenuate the development of hypoxia induced pulmonary hypertension (PHT). Two day old Spague‐Dawley rats were treated with daily SQ injections of resveratrol (100 mg/kg) or vehicle and placed in normoxia or hypobaric hypoxia (435 torr) for 14 days. Measurement of right ventricle wall weight divided by the total heart weight (RV/T) was used as a measure of PHT. RV/T was greatest in vehicle treated neonatal rats exposed to chronic hypoxia (0.46 ± 0.03, P<0.05 compared to the other 3 groups), whereas, normoxic vehicle treated (0.23 ± 0.02), normoxic resveratrol treated (0.24 ± 0.02), and hypoxic resveratrol treated (0.29 ± 0.03) RV/T where not different from each other. Hypoxic exposure resulted in lower (P<0.05) body weights than in normoxic exposure, and resveratrol did not affect body weight in either normoxic or hypoxic pups (weight at harvest was 36.0 ± 0.8 g normoxic vehicle, 39.3 ± 1.3 g normoxic resveratrol, 27.1 ± 1.2 g hypoxic vehicle, and 25.6 ± 1.1 g hypoxic resveratrol). These results suggest that resveratrol prevents chronic hypoxia induced pulmonary hypertension and may be clinically useful in the treatment of pulmonary hypertensive disease.
Use of resveratrol and quercetin combination as potential therapeutic for treatment of in‐stent restenosis and thrombosis
Authors: Khandelwal Alok Radheyshyam , Hebert Valeria , Dugas Tammy R 
Published: June 2021

Recent epidemiological studies suggest restenosis and acute in‐stent thrombosis as important complications of carotid angioplasty and stenting. Our objective was to identify a drug combination that would inhibit both restenosis and thrombosis. We studied two red wine polyphenols, resveratrol (RESV) and quercetin (QUER) that emerged as lead candidates in our prior in vitro studies using platelets and vascular smooth muscle cells. B6.129 female mice were fed a high fat diet containing RESV (50 mg/kg), QUER (10 mg/kg) and RESV plus QUER for 2 weeks. The carotid artery denudation procedure was performed and the mice were again administered the high fat diet‐containing polyphenols for 2 weeks. After sacrifice, the carotid arteries were excised for morphometric analysis and serum, collected for measurement of TXB2 as a marker for platelet activation. Our results indicate RESV, but not QUER, significantly decreased the restenotic index (p<0.05). Interestingly, with combination treatment, QUER potentiated RESV‐mediated decrease in neointimal hyperplasia (p<0.01). Conversely, QUER, but not RESV, significantly decreased serum TXB2 levels, with RESV potentiating the effects of QUER (p<0.01). In conclusion, our studies suggest that in combination, RESV and QUER can synergize to effectively reduce the pathogenesis of restenosis. Future implications include the use of this drug combination in drug eluting stents.Grant Funding SourceRO1‐HL082472
Thyroid hormone analogue 3,5‐diiodothyropropionic acid (DITPA) promotes healthy vasculature in the adult myocardium independent of thyroid metabolic effects
Authors: Liu Yingheng , Wang Dajun , Redetzke Rebecca , Gerdes Anthony Martin 
Published: June 2021

Patients with hypothyroidism are at higher risk for coronary vascular disease. Patients with diabetes and related vascular complications also have an increased incidence of low thyroid function. While thyroid hormones (THs) may be key regulators of healthy vasculature, potential undesirable side effects hinder their use in the treatment of vascular disorders. TH analogs such as DITPA may provide a safer treatment option. We hypothesized that the vascular growth promoting effects of DITPA can be obtained with little or no effect on cardiac function and metabolism. Thyroidectomized Sprague Dawley rats were given slow‐release pellets with either thyroxine (T4, 2.7‐mg or 5.2‐mg) or DITPA (80‐mg) for 6 weeks and compared to placebo. Hypothyroidism led to reductions in cardiac function, heart mass, body temperature, and myocardial arterioles. High dose T4 prevented arteriolar loss and development of hypothyroidism. Low dose T4 partially prevented the reduction in cardiac function but had minimal effects on arteriolar loss. In contrast, DITPA treatment prevented myocardial arteriolar loss but not progression of hypothyroid‐induced changes in cardiac function and metabolism. Results suggested that DITPA can promote healthy vasculature independently from its thyroid related metabolic effects. Drugs in this class may provide new therapeutic options for patients with vascular disease.Grant Funding SourceP20RR017662 from the National Center for Research Resources
Obstetrical adaptation in the human bony pelvis: A morphometric approach
Authors: Brown Kirsten Marie , DeLeon Valerie , Ruff Christopher 
Published: June 2021

Previous work documenting pelvic sexual dimorphism and variation in humans has relied primarily on typology and linear measurements. However, these allow only limited interpretation of adaptive changes in pelvic morphology. The bony pelvis is a complex, 3D structure, and anatomical features are expected to respond differentially to obstetric selective pressures. This study is a 3D geometric morphometric analysis of pelvic morphology in a cadaveric sample of American black males (n=19) and females (n=20). Forty‐four biologically relevant landmarks were digitized on articulated pelves. Generalized Procrustes Analysis (GPA) and Euclidean Distance Matrix Analysis (EDMA) were used to localize areas of shape changes between the sexes.GPA analysis showed significant shape differences between the sexes; relative to other landmarks, the pubis moves inferiorly, the sacrum moves posteriorly, and the ischial tuberosities and the ischial spines move laterally in the female. EDMA analysis demonstrated that the posterior space is more sexually dimorphic than the anterior space. These results suggest that obstetrical adaptation involves the mediolateral expansion of the pelvic midplane and outlet and the posterior displacement of the sacrum. Obstetric adaptation is more pronounced posteriorly, suggesting that variation in the anterior space may be contrained by biomechanical requirements.Grant Funding SourceNone
Double whole‐mount staining for bone deposition and resorption
Authors: Edsall Sara , Franz‐Odendaal Tamara 
Published: June 2021

Methods to detect osteoblasts, bone depositing cells, and osteoclasts, bone resorpting cells are known. These methods involve enzymatic procedures (alkaline phosphatase and tartrate‐resistant acid phosphatase) and are usually conducted on sectioned material; with the procedure for each type of staining conducted on adjacent serial sections. We have optimised a procedure to whole‐mount stain the same zebrafish for both bone deposition and resorption. The alkaline phosphatase procedure stains osteoblasts a purple colour and the tartrate‐resistant acid phosphatase gives a red colour; making the two cell types easily distinguishable. The stained specimen can be decalcified if necessary and sectioned, with preservation of the cell staining. We have applied this methodology to whole fish at various stages of development and have focused our investigations on the jaw, fins and vertebral column regions. Bone deposition was clearly observed in the mandible and maxilla; the developing fins, the ends of fin ray segments and the edges of the developing calvariae. On similarly aged fish, bone resorption was detected in the neural spines of the vertebrae; mandible and maxilla; with very limited amounts within the fins. We believe this methodology would be useful to the field of skeletal biology as it enables double staining of the same specimen and avoids lengthy resin embedding procedures. Funding NSERC, CanadaGrant Funding SourceNSERC, Canada
Interplay between Mre11 nuclease and Dna2 nuclease/helicase in DSB repair and at telomeres
Authors: Campbell Judith L , Budd Martin E , Polaczek Piotr 
Published: June 2021

The Mre11/Rad50/Xrs2 complex is a central player in DSB repair and is the first protein to arrive at a newly formed break. 5' to 3' resection at the end of a break is an early and a necessary step for repair. Although MRX may be important for this step, the associated nuclease has 3' to 5' polarity, opposite to the expected 5' to 3' polarity; and more important, Mre11 nuclease deficient mutants are only mildly sensitive to DSB‐inducing agents. Thus, there is some gene that compensates for Mre11 nuclease deficiency. We show that the Dna2 nuclease/helicase, which is essential for DNA replication, can perform this role, probably working in 5' to 3' resection. The helicase activity of Dna2 is toxic in this reaction in the absence of the nuclease activity. 3' to 5' resection by Dna2 is inhibited by RPA.Dna2 and Mre11 are also known to play important but ill‐defined roles at telomeres. We show, however, that their interaction at telomeres may have a different outcome from that at internal DSBs, since double mutants show significant accumulation of single‐stranded DNA at telomeres.Supported by USPHS.
Correcting metabolic deficits with allogeneic bone marrow stem cells in the cat
Authors: Vulliet Richard , Halloran Mitch , Tallon Kelli , Lyons Leslie , Rogers Quinton , Fascetti Andrea 
Published: June 2021

We investigated the potential of allogeneic lipoprotein lipase (LpL) +/+ expressing bone marrow stromal cells (MSCs) to correct the metabolic deficiency in LpL‐/‐ cats. Bone marrow was harvested from LpL+/+ cats and fifty million MSCs injected into LpL‐/‐ cats twice using two week intervals. Plasma turbidity, triglycerides, cholesterol and lipase activity were monitored prior to and following the injection of the MSCs. Injection of MSCs resulted in a decrease in the plasma lipid profile three to five days following administration. Following the first injection, there was a modest decrease in plasma turbidity and lipids that correlated with a slight increase in LpL activity. The second injection resulted in a much larger increase in LpL activity and a greater decrease in plasma turbidity and lipids. Injection of allogeneic MSCs corrects the LpL‐/‐ genetic defect and transiently returns the plasma lipid profile to near normal in a dose dependent manner. The enhanced response following the second injection suggests an accumulation of LpL+/+ MSCs might occur. Using this dose and injection protocol, the bi‐phasic duration of therapeutic action appears to last approximately three months. This is a very powerful and robust animal model for studying cytokinetics and cytotherapeutics.This research was support by the Center for Companion Animal Research at U C Davis and the Winn Feline Research Foundation.
THE EFFECT OF RESVERATROL AND ZINC ON INTRACELLULAR ZINC STATUS IN NHPrE CELLS
Authors: ZHANG JUN JUN , WU MIN , SCHOENE NORBERTA W. , CHENG WEN‐HSING , WANG THOMAS T. Y. , ALSHATWI ALI , ALSAIF MOHAMMED , LEI KAI Y. 
Published: June 2021

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated in 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 µM) and 4 levels of zinc [0, 4, 16 and 32 µM or zinc deficient (ZD), zinc normal (ZN), zinc adequate (ZA) and zinc supplemented (ZS), respectively]. Among each zinc treatment, a progressive reduction in cell growth or increase in cellular total zinc was observed with increases of resveratrol from 2.5, 5 and 10 µM or from 5 and 10 µM, respectively. In ZS cells, a much higher increase in cellular total zinc was observed as early as 1 µM resveratrol. A flow cytometry study revealed that the resveratrol (10 µM) induced G2/M arrest was responsible for the depressed cell growth. Data from an in vitro experiment using zinquin, as an indicator of intracellular free Zn(II) status, demonstrated complex formation between resveratrol and zinc ion. Zinquin ethyl ester fluorescence spectrofluorimetry and microscope imaging revealed that intracellular labile free zinc decreased in ZD and ZN NHPrE cells but increased in high zinc (ZA and ZS) cells. Furthermore, increases in cellular zinc status induced enhanced levels of reactive oxygen species (ROS) as well as senescence detected by morphological and histochemical changes in cells treated with 2.5 or 10 µM resveratrol, especially in ZA and ZS cells. Thus, increases in free labile zinc may induce ROS and senescence.Grant Funding SourceUNIV. MARYLAND
Effects of low and high carbohydrate meals on postprandial plasma lipid concentrations
Authors: Bergman Sarah , Kumagai Melissa , Smith Julie , Gillingham Melanie , Stadler Diane 
Published: June 2021

BackgroundChronic postprandial hyperlipidemia is associated with increased risk of cardiovascular disease (CVD). Very low carbohydrate (VLC) diets are a popular choice for weight‐loss, but acute effects of VLC diets on postprandial plasma fatty acids have not been tested.MethodsFour healthy, normal weight adults participated in a randomized crossover feeding study. Subjects consumed a standard diet [51% carbohydrate (CHO), 14% protein, 35% fat] for 3 days. On day 4 participants consumed either VLC (4%) or high CHO [HC (58%)] meals. Subjects then repeated standard diet and alternate test meals. Pre‐ and postprandial concentrations of plasma triglycerides (TG) and individual fatty acids were analyzed by modified Wahlefeld method and GC/MS, respectively. Differences between diets were compared by paired t‐tests.ResultsTG were significantly higher on the VLC diet compared to the HC diet (Area under the curve for TG: VLC 1217±420 and HC1033±369 mg·h/dL, p=0.03). Saturated fatty acids (SFA) were significantly higher 4 hours after a VLC meal (VLC 19960±1094 vs HC 12193±906 µmol/L, p=0.020). There was no difference in postprandial omega‐6 or omega‐3 fatty acid concentrations between diets.ConclusionsPlasma‐TG and SFA were higher after the VLC meals when compared to the HC meals. Chronic elevation of postprandial lipids may contribute to the development of CVD. Supported by the Graduate Programs in Human Nutrition, PHS Grant UL1 RR024140, and National Center for Complementary and Alternative Medicine (R21 AT002753‐01).