bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipopolysaccharide (LPS)‐induced effects on Na+ transport and inflammatory response‐gene transcription in the guinea‐pig airway epithelium
Authors: Dodrill Michael , Rao K. Murali Krishna , Meighan Terence , Fedan Jeffrey S. 
Published: June 2021

Earlier, we reported that systemic administration of LPS hyperpolarizes transepithelial potential difference (Vt). The increase in Vt was abolished by amiloride and inhibited by indomethacin. These findings suggested an increase in inflammatory‐mediator regulated Na+ transport. We investigated the effects of LPS on the mRNA levels of the epithelial sodium channel α subunit (αENaC), cyclooxygenase (COX) 2, endothelial nitric oxide synthase (eNOS), interleukin (IL)‐1β, inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)α, which regulate ENaC activity and turnover, using real‐time RT‐PCR. Guinea pigs received 4 mg/kg LPS (i.p.); epithelial cells (EC) and alveolar macrophages (AM) were examined after 3 or 18 h. EC COX2 increased by 36±26‐fold at 3 h and was elevated by 15±12‐fold at 18 h. In EC, TNFα, IL‐1β and iNOS were increased at 3 h (32±17‐, 25±12‐ and 7±5‐fold, respectively) and decreased to baseline after 18 h. AM COX2 was elevated at 3 (163±112‐fold) and 18 h (8±7‐fold). AM IL‐1β and AM TNFα were elevated at 3 h (127±60‐ and 20±7‐fold, respectively), and returned to baseline after 18 h. In contrast, AM eNOS increased by 4.7±5.4‐fold only at 18 h. The other transcripts were not increased more than 4‐fold in either tissue at 3 or 18 h. Thus, αENaC mRNA was not affected by LPS. An increase in ENaC transcription cannot explain the LPS‐induced increase in Vt.Funded by NIOSH.
Histamine induces sonic hedgehog secretion across the apical membrane of polarized parietal cells
Authors: Zavros Yana , Orr Melissa A. , Malinowska Danuta H. 
Published: June 2021

Objective:Sonic Hedgehog (Shh) is processed and secreted from parietal cells by a unique acid‐ and protease‐dependent mechanism (Zavros et al., 2007, JBC). The current study seeks to determine the cellular location of Shh within the gastric parietal cell.Methods:Shh expression was studied using cimetidine (resting) or histamine (stimulated)‐treated rabbit gastric glands and immunoisolated tubulovesicles. Apical (AP) and basolateral (BL) Shh secretion was studied using polarized human gastric cancer cells (23132/87).Results:Confocal microscopy of gastric glands triple stained for Shh, H+,K+‐ATPase and zymogen or neck cell markers showed expression of Shh within the canaliculus of stimulated parietal cells. Western blots showed Shh and H+,K+‐ATPase expression in resting immunoisolated tubulovesicles. While the Shh precursor was detected in resting membranes, increased expression of processed Shh was observed in stimulated tubulovesicles. Surface biotinylation of polarized 23132/87 cells revealed expression of the Shh precursor at the AP membrane and processed Shh secreted in the AP media. Shh was not detected in either the BL biotinylated membrane lysates or media.Conclusion:Shh is expressed in H+,K+‐ATPase‐containing membranes suggesting that processing and secretion occurs across the apical membrane of parietal cells.
Protein expression and distribution of murine calcium‐activated chloride channels 1 and 2 (mCLCA1/2) in epithelia of the gastrointestinal (GI) tract and kidney (Ki)
Authors: Thevenod Frank , Wittschen Petra , Torchalski Blazej , Gruber Achim D. 
Published: June 2021

Calcium‐activated chloride channels (CLCA) have been implicated as anion channels, channel regulators and cystic fibrosis phenotype modulators, but their function remains unclear. We generated a polyclonal antibody (pAb 849) against a peptide that is common to mCLCA1/2, has ~70% aa identity with mCLCA3/4, but none with mCLCA5/6. pAb 849 detected mCLCA1 expressed in HEK293 by immunoblotting (IB) and immunoprecipitation, where 125 and 90 kDa bands suggest posttranslational modification. Flag‐tagging of mCLCA1 yielded only a 130 kDa band. pAb 849 cross‐reacted with mCLCA3 in IB with bands at 120, 100 and 75 kDa. Using immunohistochemistry and comparison with mCLCA3 (pAb p3a), mCLCA1/2 specific labelling was found in pancreas acini (apical (AP), zymogen granules (ZG)), but not in ducts. pAb 849 IB of ZG membranes yielded a 130 kDa band. Specific signals were also seen in small ducts of seromucous salivary glands (AP, intracellular (IC)) but not in excretory ducts or acini. Stomach parietal (AP, IC) and jejunal crypt cells (AP) were specifically labelled. Signals in stomach mucous and jejunal goblet cells may be due to mCLCA3 cross‐reactivity. Only AP areas of Ki distal tubules were stained. mCLCA1/2 positive tissues do not express mCLCA4, therefore the data indicate mCLCA1/2 expression in AP membranes of GI and Ki and ZG membranes, but a function as secretory proteins cannot be excluded.Funding: German CFF F04/04
Neural control of cutaneous vasoconstriction during lower‐body negative pressure (LBNP) in the heat stressed individual
Authors: Shibasaki Manabu , Rasmussen Peter , Secher Niels H. , Crandall Craig G. 
Published: June 2021

The decrease in cutaneous vascular conductance (CVC) during LBNP in the heat stressed human could be mediated by neural and non‐neural mechanisms. This project further investigated this question. Nerve activity to a forearm was blocked (via axial blockade) in seven healthy subjects. Two intradermal microdialysis probes were placed within the skin of the blocked area. Forearm skin blood flow was measured by laser‐Doppler flowmetry over these microdialysis probes, as well as from skin of the contralateral (non‐blocked) forearm. The absence of sweating and cutaneous vasodilation during heat stress confirmed an effective block. Upon this confirmation, adenosine was perfused through one microdialysis probe to increase skin blood flow similar to that of the non‐blocked site. After internal temperature was elevated ~1.0 °C, 30 mmHg LBNP was applied for 10 min, or until the onset of presyncopal symptoms. LBNP significantly decreased CVC at all three sites (unblocked site: −6.1±2.7; blocked site: −2.5±1.3%max; blocked site with adenosine: −5.4±2.2%max), although the magnitude of reduction in CVC was not different between unblocked and adenosine sites. When combined with prior data, these findings suggest that reductions in CVC to LBNP of heat stressed individuals could have both neural and non‐neural components.Study funded by part by NIH HL61388 & HL84072
Ascorbic acid does not influence skeletal muscle contraction‐induced rapid vasodilation in older healthy humans
Authors: Simpson Carrie B , Kirby Brett S , Carlson Rick E , Schrage William G , Voyles Wyatt F , Dinenno Frank A 
Published: June 2021

Age‐related increases in oxidative stress impair endothelium‐dependent vasodilation in humans, which could possibly explain our recent observations of blunted contraction‐induced rapid vasodilation in older adults. Therefore, we tested the hypothesis that endothelial dysfunction impairs the rapid vasodilator responses to brief muscle contractions in aging humans. In 13 young (24±1 yrs) and 13 healthy older adults (62±2 yrs), we measured forearm blood flow (FBF; Doppler ultrasound) and calculated vascular conductance (FVC) responses to single, 1 sec dynamic contractions at 10, 20, and 40% maximum voluntary contraction (MVC) before and after intra‐arterial administration of ascorbic acid (AA). Prior to AA, peak vasodilator responses to all contraction intensities were impaired ~35–50% in older adults (P<0.05), as were the immediate (1st cardiac cycle post contraction) vasodilator responses at 20 and 40% MVC (~50%; P<0.05). AA did not influence vasodilator responses to sodium nitroprusside in either group, but significantly improved vasodilation to acetylcholine in older adults only (P<0.05). In contrast, AA did not influence contraction‐induced rapid vasodilation in either group (all NS). Together, our findings suggest that endothelial dysfunction is not the primary mechanism underlying impaired contraction‐induced rapid vasodilation with human aging.Supported by AG‐027150
Leucine‐enriched essential amino acid and carbohydrate ingestion in women increases skeletal muscle mTOR and Akt/AS160 signaling
Authors: Drummond Micah J , Dreyer Hans C , Fujita Satoshi , Volpi Elena , Rasmussen Blake B 
Published: June 2021

Men respond to an essential amino acid and carbohydrate ingestion with a rapid and large increase in mTOR signaling and muscle protein synthesis. However, it is not known whether women have a similar response. We hypothesized that anabolic signaling and changes in cell energy status would be similar between men and women following nutrient ingestion. Seven young female subjects ingested a leucine‐enriched essential amino acid (0.35g/kg fat free mass) and carbohydrate (0.5 g/kg fat free mass) nutrient solution. Muscle biopsies from the vastus lateralis were obtained at baseline and 1h following nutrient ingestion. Immunobloting techniques were used to identify the phosphorylation pattern of three key nutrient‐sensitive signaling pathways: mTOR, Akt/AS160 and AMPK. mTOR signaling was enhanced as indicated by significantly increased phosphorylation of mTOR at Ser2448 and its downstream effectors S6K1 (Thr389) and 4E‐BP1 (Thr37/46) while eEF2 phosphorylation at Thr56 was significantly decreased (P<0.05). In addition, Akt (Thr473) and AS160 phosphorylation were increased; however, AMPKα phosphorylation at Thr172 was unchanged. We conclude that mTOR signaling in women following essential amino acid and carbohydrate ingestion is similar to the response in men. Furthermore, the increase in glucose uptake following nutrient ingestion is associated with an increased phosphorylation of human muscle AS160.Funded by NIH grant # R01 AR049877
Muscle Atrophy and Increased Atrogin‐1 Occur in Fast‐ but not Slow‐Muscle Early in Acute Streptozotocin‐Induced Diabetes
Authors: Templeton Erika L , Motyl Katie , McCabe Laura , Wiseman Robert 
Published: June 2021

The onset of diabetes is characterized by a loss of glucose homeostasis as well as a loss in lean body mass. Recent reports suggest that muscle loss may be fiber type specific and correlated with oxidative capacity (Sandri et al., 2006. PNAS, 103:16260–5). To test this hypothesis a streptozotocin (STZ) ‐treated animal model was used. BALB/c mice were injected with 40 ug/g STZ over the course of 5 days with sham injected controls. Maximal weight loss was observed 5 days post‐injection. Animals were sacrificed at this time and plasma, tibialis anterior (TA) (fast‐twitch), and soleus (SOL) (slow‐twitch), muscles were harvested, weighed and rapidly frozen at −80°C. Plasma glucose levels rose from approximately 150 to 270 mg/dL by day 5. TA muscles decreased in mass from 46 ± 2 to 39 ± 1 mg with no detectable change in SOL weights. Real‐time PCR showed atrogin‐1 mRNA was two‐fold increased in STZ‐treated TA muscles relative to sham‐injected controls but there was no change in SOL expression. Both muscle mass and atrogin‐1 expression show fast‐fiber specific effects under STZ‐treatment that are absent in the more oxidative SOL muscles. These data suggest that oxidative capacity and/or genes controlling oxidative capacity protect against the loss in mass possibly by retarding atrogin‐1 expression.Supported by NIH DK 061184
Intermittent Hypoxic Conditioning Suppresses Angina And Arrhythmias In Patients With Ischemic Heart Disease
Authors: Manukhina Eugenia , Lyamina Svetlana , Mallet Robert T , Downey H Fred , Lyamina Nadezhda 
Published: June 2021

Intermittent hypoxic conditioning (IHC) greatly reduces ischemia‐reperfusion cardiac injury and arrhythmias in animal experiments. The present study evaluated clinical benefits of IHC in 53 patients with ischemic heart disease (IHD) and extrasystolic arrhythmias. Twenty daily sessions of IHC were performed by alternately inspiring 10% O2 and atmospheric air for 3 min each (each hypoxic exposure 20–60 min/session). Twelve patients received sham IHT (inspiration of atmospheric air; SHAM). Thirteen patients received only drug therapy (CONT). ECG was monitored for 24 h before and after 20 days of respective therapy and at 3 months after IHC. All patients received standard medical therapy for IHD. Table shows % of patients with complete (CS) or partial (PS) suppression of arrhythmias and change in anti‐anginal medication (Δ Dose). Percent reduction in frequency of anginal attacks (#AA) and % reduction in AA duration are also reported.IHC produced no serious adverse effects, although initially IHC caused mild dizziness in 12% of patients and drowsiness in 31% of patients. Three months after IHC therapy, 88% of patients had no increase in arrhythmias or AA. Therefore IHC safely augments standard medical therapy for patients with IHD.
Exogenous ATP regulates excitation‐induced force in isolated muscle through the P2Y receptor family
Authors: Broch‐Lips Martin , Pedersen Thomas Holm , Nielsen Ole Bækgaard 
Published: June 2021

In skeletal muscles, contractions elicit a release of ATP into the extracellular space. Extracellular ATP has been recognized as an autocrine and paracrine signaling molecule acting on two purinergic receptor families; the metabotrophic P2Y receptors and the ionotropic P2X receptors. In this study we investigate the role of P2 receptors on the excitability and contractility of isolated skeletal muscle.Tetanic force production and M‐wave amplitude and area were investigated in isolated rat soleus muscles incubated in Krebs‐Ringer buffer. Exogenously added P2‐receptor agonist (ATP) and phospholipase C (PLC) inhibitor (U73122) were used to investigate P2‐receptor mediated effects on muscle function under conditions with compromised muscle excitability.When the excitability of muscles was depressed by elevating [K+]o to 10 mM, tetanic force was reduced to 24 ± 2 % of initial force at 4 mM K+. However, upon addition of 1 mM ATP, force was recovered to 65 ± 8 % of initial force at 4 mM K+ (P < 0.001, n = 5). The force recovery was accompanied by a recovery of M‐wave area and amplitude from 20 ± 5 to 81 ± 11 % (P < 0.05) and 8 ± 1 to 47 ± 11 % (P < 0.05) of initial M‐wave area and amplitude at 4 mM K+, respectively (n = 4). ATP induced force recovery could be eliminated by 50 μM PLC inhibitor indicating that the force recovery was mediated by the P2Y receptor family.Danish Medical Research Council (j. nr. 271‐05‐0304)
Repetitive bouts of mechanical compression improve systemic markers of endothelial function in patients with coronary artery disease
Authors: Casey Darren Patrick , Conti C Richard , Nichols Wilmer W , Choi Calvin Y , Khuddus Matheen A , Braith Randy W 
Published: June 2021

We hypothesized that repetitive mechanical compression (MC) of the lower limbs would lead to favorable changes in peripheral endothelial function in patients with coronary artery disease (CAD). To test this hypothesis, 35 1‐hour sessions of MC were administered to CAD patients (n=12). Each session consisted of sequential inflation and deflation of compressible cuffs wrapped around the calves and lower and upper thighs. Compressed air pressure (300mmHg) was applied in a sequence synchronized with the cardiac cycle. Eight (n=8) CAD patients served as sham controls (CON). Brachial (b) and femoral (f) artery flow‐mediated dilation (FMD) and plasma levels of nitric oxide metabolites (NOx) and asymmetric dimethylarginine (ADMA) were assessed pre and post intervention. The MC group demonstrated increases in b‐FMD (3.7 ± 0.2 vs. 5.7 ± 0.4 %, P < 0.05) and f‐FMD (2.7 ± 0.2 vs. 3.5 ± 0.3%, P < 0.05). Additionally, a 40% increase in NOx (22.8 ± 2.2 vs. 31.9 ± 4.5 [mu]mol/L, P < 0.05) and a 26% decrease in ADMA (0.62 ± 0.06 vs. 0.46 ± 0.03 [mu]mol/L, P < 0.05) were observed in the MC group. There were no significant changes in any outcome measures for the CON group. These results suggest that external mechanical compression of the lower limbs improves markers of peripheral endothelial function in CAD patients. This effect is likely attributed to increases in shear stress on the endothelium.Supported by NIH R01 HL‐077571‐01
Beta‐2 adrenergic receptor haplotype and echocardiographic indices in heart failure patients
Authors: Eisenach John H , Snyder EM , Hulsebus ML , Turner ST , Johnson BD 
Published: June 2021

We recently reported altered cardiovascular structure and function in heart failure (HF) patients based on the Arg16/Gly and Gln27/Glu beta‐2 adrenergic receptor (ADRB2) polymorphisms. The purpose of this study was to extend the echocardiographic analysis based on haplotype combination of ADRB2 at nucleotides −654, 46 79, 252, 491, 523, in a larger database of HF patients (n=126, age 56±1yr, LV ejection fraction, LVEF 29±1%, BMI 28±0.4kg/m2, mean±SEM) and healthy controls (n=100, age 50±2yr, LVEF 63±0.7%, BMI 25±0.3kg/m2). The most common haplotypes in both HF and control were 2, 8, and 12 (2=AACGCC, 8=GGCACA, and 12=GGGGCC, for nucleotides −654, 46, 79, 252, 491, and 523). Cardiac function did not differ according to haplotype pairs in the control subjects. In HF, the widest discrepancies were between haplotype pair 2/2 (which includes the Arg16+Gln27 homozygotes) and haplotype pair 12/12 (which includes the Gly16+Glu27 homozygotes), respectively: 2/2 displayed lower cardiac index (2.3±0.1 v 2.7±0.1 l/min/m2), greater left atrial diameter (53±2 v 47±2 mm), shorter LV decel time (185±11 v 224±14 msec), and greater right ventricular pressure (44±2 v 33±2 mmHg) p<0.05 for all). These data suggest that in HF, haplotype variation of the ADRB2 is associated with differences in cardiac function, and SNP positions 16 and 27 remain major loci of interest.Support: K23RR‐17520, HL‐71478.
Misconceptions about Edward Jenner and the Eradication of Smallpox
Authors: Schneider Suzanne 
Published: June 2021

In the 18th century smallpox was a scourge that infected 60% and killed 10% of England's population. On May 14, 1796 a young English doctor persuaded a local farmer to allow his 8 yr‐old son, James Phipps, to be infected, first with cowpox, then with smallpox. The boy did develop cowpox but was resistant to smallpox. The boy was the first to be “vaccinated” until 1979, when the World Health Organization declared smallpox eradicated. There are several misconceptions about this story.Edward Jenner was not the first to use cowpox to prevent smallpox. Other doctors in England were doing the same, but Jenner brought attention to this procedure. He self‐published his results after his original paper was rejected.His experiments seem unethical. Actually, his procedures were not unusual for his times. Even today his work would pose an interesting risk/benefit dilemma. Jenner remained friends with James, who was a pall bearer at his funeral.Jenner theorized the virus started with an infected horse hoof disease. Later it was discovered that the virus passes from rodent to cat to cow to milkmaid.Jenner was a small country doctor, astute but with little education. Jenner, from a prestigious family, apprenticed with a local doctor at the age of 13 for seven years. He then trained in medicine at St. George's Hospital in London. After 2 years he returned home to became a gentleman doctor and well‐known naturalist. Lack of medical diploma was not unusual, with only two official medical schools in England.Smallpox is eradicated. The virus does exist today, in frozen vials stored in Atlanta and Moscow. The virus is preserved to develop vaccines in case the virus reappears or is unleased by terrorists.
The activation of immunoreceptor NKG2D in MPTP‐induced animal models stimulates the pathogenesis of Parkinson's disease
Authors: Tay Samuel SW , Chao Yinxia , He Beiping 
Published: June 2021

Neuroinflammation in Parkinson's disease (PD) involves the activation of microglia, complement receptor system and possibly systemic natural killer (NK) cells, suggesting that innate immunity has an important role in the pathogenesis of this disease. We examined NK cell activity and the expression of its regulatory molecules in the substantia nigra of MPTP induced PD models and compared the results with those of healthy controls. Expression of the immunoreceptor NKG2D was significantly increased in the PD models, thereby inducing dopaminergic neurons in the substantia nigra compacta (SNc) to become susceptible to NK cells after the latter bind to receptors on their target cells. It is hypothesized that the activation by NK cells via their target iimunoreceptor NKG2D stimulates neuroinflammation leading to PD in MPTP‐induced animal models.Supported by an Academic Research Grant R181‐000‐096‐112 from the National University of Singapore.
Cwc24p, a novel S. cerevisiae RING‐finger protein, affects U3 snoRNA splicing and rRNA processing
Authors: Goldfeder Mauricio Barbugiani , Oliveira Carla Columbano 
Published: June 2021

Ribosome biogenesis involve the extensive processing of a precursor rRNA 35S by approximately 150 trans‐acting factors, giving rise to the mature rRNAs. Among these factors are snoRNPs (small nucleolar ribonucleoproteins), that are formed by a guide snoRNA (that base‐pairs with target sites within the pre‐rRNA) and evolutionarily conserved proteins. In this work we present the functional characterization of Cwc24p, a novel S. cerevisiae RING‐finger that interacts with Nop17p (a box C/D snoRNP assembly factor) and with Cef1p (a splicing factor, component of the NTC complex). Consistent with the interaction data, Cwc24p localizes to the cell nucleus. Using a conditional strain (GAL1::CWC24) we observed a small defect in rRNA processing upon depletion of Cwc24p. In order to investigate the involvement of Cwc24p in splicing, a splicing‐specific microarray analysis was conducted and revealed that depletion of Cwc24p leads to the accumulation of both U3 pre‐snoRNAs. U3 snoRNA, which is transcribed from two intron‐containing genes in yeast, is involved in the early cleavages of 35S pre‐rRNA, and the defective splicing of pre‐U3 detected in cells depleted of Cwc24p may be responsible for the accumulation of the 35S precursor rRNA. These results led us to the conclusion that Cwc24p is involved in pre‐U3 snoRNA splicing, indirectly affecting pre‐rRNA processing.Supported by FAPESP and CAPES
Evaluation of vascular endothelial staining by various antibodies in human and xenograft tumors using three different methods of fixation
Authors: Breckenkamp Ann E , Mintze Karen , Barnes Versie , Vance Tasha , Pierson Nicholas , Pangallo Jenna , Sandusky George 
Published: June 2021

AbstractLight microscopy was used to compare the staining of various antibodies against the vascular endothelial markers CD31, CD34, CD105, EphB2, and EphB4 in human and xenograft tissues that were fixed in three different fixatives: 4% paraformaldehyde (PF), 10% Neutral Buffered Formalin (NBF), or Zinc‐Tris (ZT). Since the ability of an antibody to bind to its target molecule depends on the fixation method, it would be useful to identify antibodies that stain tumor vasculature regardless of which fixative was used to preserve the tissue. Each antibody evaluated was optimized in ZT fixed tissues, and the protocol was used to stain all samples, except for two antibodies that did not stain ZT fixed tissues. Bethyl Laboratories Rabbit Anti‐Human CD31 (#IHC‐00055) and Cell Signaling Mouse Anti‐Human CD34 (#3569) gave excellent staining in human tissues prepared in 4% PF, 10% NBF, and ZT, in contrast to the other antibodies evaluated. The Bethyl antibody also gave moderate staining in HCT116 xenografts prepared in all three fixatives, making it the only antibody evaluated that was useful for staining vasculature in human breast, colon, and lung tissues and xenografts for all three fixatives.