bluuebunny/crossref_metadata_2025 huggingface dataset:
The association between team climate at work and mental health in the Finnish Health 2000 Study
Authors: Sinokki M , Hinkka K , Ahola K , Koskinen S , Klaukka T , Kivimäki M , Puukka P , Lönnqvist J , Virtanen M
Published: April 2009

Objectives:

Depression, anxiety and alcohol use disorders are common mental health problems in the working population. However, the team climate at work related to these disorders has not been studied using standardised interview methods and it is not known whether poor team climate predicts antidepressant use. This study investigated whether team climate at work was associated with DSM-IV depressive, anxiety and alcohol use disorders and subsequent antidepressant medication in a random sample of Finnish employees.

Methods:

The nationally representative sample comprised 3347 employees aged 30–64 years. Team climate was measured with a self-assessment scale. Diagnoses of depressive, anxiety and alcohol use disorders were based on the Composite International Diagnostic Interview. Data on the purchase of antidepressant medication in a 3-year follow-up period were collected from a nationwide pharmaceutical register of the Social Insurance Institution.

Results:

In the risk factor adjusted models, poor team climate at work was significantly associated with depressive disorders (OR 1.61, 95% CI 1.10 to 2.36) but not with alcohol use disorders. The significance of the association between team climate and anxiety disorders disappeared when the model was adjusted for job control and job demands. Poor team climate also predicted antidepressant medication (OR 1.53, 95% CI 1.02 to 2.30).

Conclusion:

A poor team climate at work is associated with depressive disorders and subsequent antidepressant use.
Smoking in Ghana: a review of tobacco industry activity
Authors: Owusu-Dabo E , Lewis S , McNeill A , Anderson S , Gilmore A , Britton J
Published: April 2009

Background:

African countries are a major potential market for the tobacco industry, and the smoking epidemic is at various stages of evolution across the continent. Ghana is an African country with a low prevalence of smoking despite an active tobacco industry presence for over 50 years. This study explores potential reasons for this apparent lack of industry success.

Objective:

To explore the history of tobacco industry activity in Ghana and to identify potential reasons for the current low prevalence of smoking.

Methods:

A search was made of tobacco industry archives and other local sources to obtain data relevant to marketing and consumption of tobacco in Ghana.

Findings:

British American Tobacco, and latterly the International Tobacco Company and its successor the Meridian Tobacco Company, have been manufacturing cigarettes in Ghana since 1954. After an initial sales boom in the two decades after independence in 1957, the sustained further increases in consumption typical of the tobacco epidemic in most countries did not occur. Possible key reasons include the taking of tobacco companies into state ownership and a lack of foreign exchange to fund tobacco leaf importation in the 1970s, both of which may have inhibited growth at a key stage of development, and the introduction of an advertising ban in 1982. BAT ceased manufacturing cigarettes in Ghana in 2006.

Conclusion:

The tobacco industry has been active in Ghana for over 50 years but with variable success. The combination of an early advertising ban and periods of unfavourable economic conditions, which may have restricted industry growth, are likely to have contributed to the sustained low levels of tobacco consumption in Ghana to date.
Anti-inflammatory Effect of Triterpenoic Acids of Eriobotrya japonica (Thunb.) Lindl. Leaf on Rat Model of Chronic Bronchitis
Authors: Ge Jin-Fang , Wang Ting-Yu , Zhao Bin , Lv Xiong-Wen , Jin Yong , Peng Lei , Yu Shi-Chun , Li Jun
Published: April 2009

This study was designed to investigate the anti-inflammatory effect of Triterpenoic Acids from Eriobotrya japonica (Thunb.) Lindl. (TAL) on chronic bronchitis (CB) in rats. CB model was established by combination of Bacillus Calmette-Guerin (BCG, 5 mg/kg, injected through the caudal vein) and lipopolysaccharide (LPS, 1 g/L, injected through endotracheal intubation). Rats with CB model were treated with TAL (50, 150 and 450 mg/kg) for 3 weeks. The leukocytes in bronchoalveolar lavage fluid (BALF) were counted after Wright staining, the levels of cytokine tumor necrosis factor alpha (TNF-α), interleukin (IL)-8, and IL-10 in the supernatants of lung homogenate were assessed by enzyme-linked immunosorbent assay (ELISA), and the protein expression of nuclear factor kappaB (NF-κB) and intercellular adhesion molecule-1 (ICAM-1) on bronchial epithelium were tested by immunohistochemical staining. As compared to the normal and sham groups, the total number of leukocyte, the differential counts of neutrophils and alveolar macrophage (AM) in BALF, the levels of TNF-α and IL-8 in the supernatants of lung homogenate, and the expression of NF-κB and ICAM-1 on bronchial epithelium in CB rats were significantly increased, while the level of IL-10 was decreased. TAL (50, 150 and 450 mg/kg) attenuated these alterations in model CB rats, which indicates that TAL has anti-inflammatory effect in the rats with CB.
Colorectal responses to distension and feeding in patients with spinal cord injury
Authors: Suttor V. P. , Ng C. , Rutkowski S. , Hansen R. D. , Kellow J. E. , Malcolm A.
Published: April 2009

The role of the central nervous system in enteroenteric motor reflexes remains controversial. Our aims were as follows: 1) to evaluate colorectal, rectocolic, gastrocolonic, and gastrorectal reflex responses in patients with cervical spinal cord injury (SCI) and 2) to compare these responses with those in healthy subjects. In six patients with SCI (5 male, 42 ± 4 yr) and six healthy control subjects (5 male, 36 ± 5 yr), 2-min phasic distensions were performed randomly via dual-barostat balloons in the colon and rectum. Continuous colonic and rectal balloon volumes were recorded during distensions and after a 1,000-kcal liquid meal. Mean balloon volumes were recorded before, during, and after phasic distensions and over 60 min postprandially. The colorectal response was similar in control subjects and SCI patients (rectal volume reduction = 28 ± 11% and 15 ± 5% in SCI patients and healthy subjects, respectively); the rectocolic response was variable. The gastrocolonic response was present in all subjects (colonic volume reduction = 49 ± 4% and 44 ± 3% in SCI patients and healthy subjects, respectively), with a time effect in the first 30 min ( P < 0.0001) and a group effect in the second 30 min ( P < 0.004). The gastrorectal response was present in four SCI patients and five healthy subjects (rectal volume reduction = 38 ± 4% and 41 ± 3% in SCI patients and healthy subjects, respectively), with a time effect in the first 30 min ( P < 0.0001) but no group effect in the second 30 min. Intact neural transmission between the spinal cord and higher centers is not essential for normal colorectal motor responses to feeding and distension; however, a degree of central nervous system and neurohormonal modulation of these responses is likely.
Protease-activated receptor-2 stimulates intestinal epithelial chloride transport through activation of PLC and selective PKC isoforms
Authors: van der Merwe Jacques Q. , Moreau France , MacNaughton Wallace K.
Published: April 2009

Serine proteases play important physiological roles through their activity at G protein-coupled protease-activated receptors (PARs). We examined the roles that specific phospholipase (PL) C and protein kinase (PK) C (PKC) isoforms play in the regulation of PAR2-stimulated chloride secretion in intestinal epithelial cells. Confluent SCBN epithelial monolayers were grown on Snapwell supports and mounted in modified Ussing chambers. Short-circuit current ( Isc) responses to basolateral application of the selective PAR2activating peptide, SLIGRL-NH2, were monitored as a measure of net electrogenic ion transport caused by PAR2activation. SLIGRL-NH2induced a transient Iscresponse that was significantly reduced by inhibitors of PLC (U73122), phosphoinositol-PLC (ET-18), phosphatidylcholine-PLC (D609), and phosphatidylinositol 3-kinase (PI3K; LY294002). Immunoblot analysis revealed the phosphorylation of both PLCβ and PLCγ following PAR2activation. Pretreatment of the cells with inhibitors of PKC (GF 109203X), PKCα/βI (Gö6976), and PKCδ (rottlerin), but not PKCζ (selective pseudosubstrate inhibitor), also attenuated this response. Cellular fractionation and immunoblot analysis, as well as confocal immunocytochemistry, revealed increases of PKCβI, PKCδ, and PKCε, but not PKCα or PKCζ, in membrane fractions following PAR2activation. Pretreatment of the cells with U73122, ET-18, or D609 inhibited PKC activation. Inhibition of PI3K activity only prevented PKCδ translocation. Immunoblots revealed that PAR2activation induced phosphorylation of both cRaf and ERK1/2 via PKCδ. Inhibition of PKCβI and PI3K had only a partial effect on this response. We conclude that basolateral PAR2-induced chloride secretion involves activation of PKCβI and PKCδ via a PLC-dependent mechanism resulting in the stimulation of cRaf and ERK1/2 signaling.
Origin and propagation of the slow wave in the canine stomach: the outlines of a gastric conduction system
Authors: Lammers Wim J. E. P. , Ver Donck Luc , Stephen Betty , Smets Dirk , Schuurkes Jan A. J.
Published: April 2009

Slow waves are known to originate orally in the stomach and to propagate toward the antrum, but the exact location of the pacemaker and the precise pattern of propagation have not yet been studied. Using assemblies of 240 extracellular electrodes, simultaneous recordings of electrical activity were made on the fundus, corpus, and antrum in open abdominal anesthetized dogs. The signals were analyzed off-line, pathways of slow wave propagation were reconstructed, and slow wave velocities and amplitudes were measured. The gastric pacemaker is located in the upper part of the fundus, along the greater curvature. Extracellularly recorded slow waves in the pacemaker area exhibited large amplitudes (1.8 ± 1.0 mV) and rapid velocities (1.5 ± 0.9 cm/s), whereas propagation in the remainder of the fundus and in the corpus was slow (0.5 ± 0.2 cm/s) with low-amplitude waveforms (0.8 ± 0.5 mV). In the antrum, slow wave propagation was fast (1.5 ± 0.6 cm/s) with large amplitude deflections (2.0 ± 1.3 mV). Two areas were identified where slow waves did not propagate, the first in the oral medial fundus and the second distal in the antrum. Finally, recordings from the entire ventral surface revealed the presence of three to five simultaneously propagating slow waves. High resolution mapping of the origin and propagation of the slow wave in the canine stomach revealed areas of high amplitude and rapid velocity, areas with fractionated low amplitude and low velocity, and areas with no propagation; all these components together constitute the elements of a gastric conduction system.
Altered gastric chief cell lineage differentiation in histamine-deficient mice
Authors: Nozaki Koji , Weis Victoria , Wang Timothy C. , Falus András , Goldenring James R.
Published: April 2009

The orderly differentiation of cell lineages within gastric glands is regulated by a complicated interplay of local mucosal growth factors and hormones. Histamine secreted from enterochromaffin-like cells plays an important role in not only stimulated gastric acid secretion but also coordination of intramucosal growth and lineage differentiation. We have examined histidine-decarboxylase (HDC)-deficient mice, which lack endogenous histamine synthesis, to evaluate the influence of histamine on differentiation of fundic mucosal lineages and the development of metaplasia following induction of acute oxyntic atrophy. Stomachs from HDC-deficient mice and wild-type mice were evaluated at 8 wk and 12 mo of age. DMP-777 was administrated orally to 6-wk-old mice for 1 to 14 days. Sections of gastric mucosa were stained with antibodies against Mist1, intrinsic factor, H/K-ATPase, trefoil factor 2 (TFF2), chromogranin A, and Ext1 and for the cell cycle marker phospho-histone H3. HDC-deficient mice at 8 wk of age demonstrated a prominent increase in chief cells expressing Mist1 and intrinsic factor. Importantly Mist1-positive mature chief cells were present in the midgland region as well as at the bases of fundic glands, indicating a premature differentiation of chief cells. Mice dually deficient for both HDC and gastrin showed a normal distribution of chief cells in fundic glands. Treatment of HDC-deficient mice with DMP-777 led to loss of parietal cells and an accelerated and exaggerated emergence of mucous cell metaplasia with the presence of dual intrinsic factor and TFF2-expressing cells throughout the gland length, indicative of the emergence of spasmolytic polypeptide-expressing metaplasia (SPEM) from chief cells. These findings indicate that histamine, in concert with gastrin, regulates the appropriate differentiation of chief cells from mucous neck cells as they migrate toward the bases of fundic glands. Nevertheless, histamine is not required for emergence of SPEM following acute oxyntic atrophy.
ADP-ribosylation factors regulate the development of CT signaling in immature human enterocytes
Authors: Lu Lei , Khan Abdullah , Walker W. Allan
Published: April 2009

Diarrheal disease is a major cause of morbidity and mortality in infants and children worldwide. Evidence suggests that the interaction of immature human enterocytes with bacteria and their enterotoxins may account for the increased susceptibility of neonates to diarrheal diseases. However, the precise mechanisms that contribute to the excessive response to cholera toxin by the immature gut are largely unknown. Our aim was to characterize the cellular/molecular changes in Gsαduring gut development. In this study, a colonic human epithelial cell line (T84) was used as representative of a mature enterocyte and a human fetal primary small intestinal cell line (H4) as representative of an immature enterocyte. Using our cell culture model of human intestinal development, we provide consistent evidence that cholera toxin (CT)-mediated Gsαactivation in fetal enterocytes differs from that of mature enterocytes, and the difference may be related to ADP-ribosylation factor (ARF) interaction with the CT-signaling process. Here we demonstrated that ARF1 may play a critical role in clathrin-mediated CT trafficking through the endoplasmic reticulum and Golgi and that ARF6 may facilitate clathrin-mediated CT endocytosis that leads to enhanced Gsαactivation by CT. Collectively, these findings support our hypothesis that there is a developmentally regulated intestinal cellular response to bacterial exotoxins involving complex cellular events that accounts for the increased incidence and severity of toxogenic diarrhea during infancy.
Norepinephrine mediates the transcriptional effects of heterotypic chronic stress on colonic motor function
Authors: Choudhury Barun K. , Shi Xuan-Zheng , Sarna Sushil K.
Published: April 2009

Chronic stress precipitates or exacerbates the symptoms of functional bowel disorders, including motility dysfunction. The cellular mechanisms of these effects are not understood. We tested the hypothesis that heterotypic chronic stress (HeCS) elevates the release of norepinephrine from the adrenal medulla, which enhances transcription of the gene-regulating expression of Cav1.2 (L-type) channels in colonic circular smooth muscle cells, resulting in enhanced colonic motor function. The experiments were performed in rats using a 9-day heterotypic chronic stress (HeCS) protocol. We found that HeCS, but not acute stress, time dependently enhances the contractile response to ACh in colonic circular smooth muscle strips and in single dissociated smooth muscle cells, the plasma levels of norepinephrine and the mRNA and protein expressions of the α1Csubunit of Cav1.2 channels. These effects result in faster colonic transit and increase in defecation rate. The effects of HeCS are blocked by adrenalectomy but not by depletion of norepinephrine in sympathetic neurons. The inhibition of receptors for glucocortocoids, corticotropin-releasing hormone or nicotine also does not block the effects of heterotypic chronic stress. Norepinephrine acts on α- and β3-adrenergic receptors to induce the transcription of α1Csubunit. We conclude that HeCS alters colonic motor function by elevating the plasma levels of norepinephrine. Colonic motor dysfunction is associated with enhanced gene transcription of Cav1.2 channels in circular smooth muscle cells. These findings suggest the potential cellular mechanisms by which heterotypic chronic stress may exacerbate motility dysfunction in patients with irritable bowel syndrome.
Rat and human HARE/stabilin-2 are clearance receptors for high- and low-molecular-weight heparins
Authors: Harris Edward N. , Baggenstoss Bruce A. , Weigel Paul H.
Published: April 2009

The human hyaluronic acid (HA) receptor for endocytosis (HARE/stabilin-2) is the primary clearance receptor for systemic HA, chondroitin sulfates, and heparin, but not for heparan sulfate or keratan sulfate (Harris EN, Weigel JA, Weigel PH. J Biol Chem 283: 17341–17350, 2008). HARE is expressed in the sinusoidal endothelial cells (SECs) of liver and lymph nodes where it acts as a scavenger for uptake and degradation of glycosaminoglycans, both as free chains and proteoglycan fragments. Unfractionated heparin (UFH; ∼14 kDa) and low-molecular-weight heparin (LMWH; ∼4 kDa) are commonly used in treatments for thrombosis and cancer and in surgical and dialysis procedures. The reported half-lives of UFH and LMWH in the blood are ∼1 h and 2–6 h, respectively. In this study, we demonstrate that anti-HARE antibodies specifically block the uptake of LMWH and UFH by isolated rat liver SECs and by human 293 cells expressing recombinant human HARE (hHARE). hHARE has a significant affinity ( Kd= 10 μM) for LMWH, and higher affinity ( Kd= 0.06 μM) for the larger UFH. Rat liver SECs or cells expressing the recombinant 190-kDa HARE isoform internalized both UFH and LMWH, and both heparins cross-compete with each other, suggesting that they share the same binding sites. These cellular results were confirmed in ELISA-like assays using purified soluble 190-hHARE ectodomain. We conclude that both UFH and LMWH are cleared by HARE/Stab2 and that the differences in the affinities of HARE binding to LMWH and UFH likely explain the longer in vivo circulating half-life of LMWH compared with UFH.
Bone morphogenetic protein-4 promotes induction of cardiomyocytes from human embryonic stem cells in serum-based embryoid body development
Authors: Takei Shunsuke , Ichikawa Hinako , Johkura Kohei , Mogi Akimi , No Heesung , Yoshie Susumu , Tomotsune Daihachiro , Sasaki Katsunori
Published: April 2009

Cardiomyocytes derived from human embryonic stem (ES) cells are a potential source for cell-based therapy for heart diseases. We studied the effect of bone morphogenetic protein (BMP)-4 in the presence of fetal bovine serum (FBS) on cardiac induction from human H1 ES cells during embryoid body (EB) development. Suspension culture for 4 days with 20% FBS produced the best results for the differentiation of early mesoderm and cardiomyocytes. The addition of Noggin reduced the incidence of beating EBs from 23.6% to 5.3%, which indicated the involvement of BMP signaling in the spontaneous cardiac differentiation. In this condition, treatment with 12.5–25 ng/ml BMP-4 during the 4-day suspension optimally promoted the cardiomyocyte differentiation. The incidence of beating EBs at 25 ng/ml BMP-4 reached 95.8% on day 6 of expansion and then plateaued until day 20. In real-time PCR analysis, the cardiac development-related genes MESP1 and Nkx2.5 were upregulated in the EB outgrowths by 25 ng/ml BMP-4. The activation of BMP signaling in EBs was confirmed by the increase in the phosphorylation of Smad1/5/8 and by the nuclear localization of phospho-Smad1/5/8 and Smad4. The addition of 150 ng/ml Noggin considerably decreased the incidence of beating EBs and Nkx2.5 expression, and Noggin alone increased Nestin expression and neural differentiation in EB outgrowths. The cardiomyocytes induced by 25 ng/ml BMP-4 showed proper cell biological characteristics and a course of differentiation as judged from isoproterenol administration, gene expression, protein assay, immunoreactivity, and subcellular structures. No remarkable change in the extent of apoptosis and proliferation in the cardiomyocytes was observed by BMP-4 treatment. These findings showed that BMP-4 in combination with FBS at the appropriate time and concentrations significantly promotes cardiomyocyte induction from human ES cells.
Chronic exposure to fibrin and fibrinogen differentially regulates intracellular Ca2+ in human pulmonary arterial smooth muscle and endothelial cells
Authors: Firth Amy L. , Yau Jocelyn , White Amanda , Chiles Peter G. , Marsh James J. , Morris Timothy A. , Yuan Jason X.-J.
Published: April 2009

Acute pulmonary embolism occurs in more than half a million people a year in the United States. Chronic thromboembolic pulmonary hypertension (CTEPH) develops in ∼4% of these patients due to unresolved thromboemboli. CTEPH is thus a relatively common, progressive, and potentially fatal disease. One currently proposed theory for the poor resolution advocates that modification of fibrinogen in CTEPH patients causes resistance of emboli to fibrinolysis. The current study investigated the regulation of cytosolic Ca2+ ([Ca2+]cyt), central to the control of cell migration, proliferation, and contraction, by chronic exposure of pulmonary artery smooth muscle (PASMC) and endothelial (PAEC) cells to fibrinogen and fibrin. Basal [Ca2+]cyt was substantially elevated in PAEC after culture on fibrinogen, fibrin, and thrombin and in PASMC on fibrinogen and fibrin. In PAEC, fibrinogen significantly decreased the peak [Ca2+]cyt transient ( P <0.001) without a change in the transient peak width (at 50% of the peak height). This response was independent of effects on the proteinase-activated receptor (PAR) 1. Furthermore, chronic exposure to thrombin, an activator of PAR, significantly reduced the peak agonist-induced Ca2+ release in PAEC, but increased it in PASMC. The recovery rate of the agonist-induced [Ca2+]cyt transients decelerated in PASMC chronically exposed to fibrin; a small increase of the peak Ca2+ was also observed. Substantial augmentation of PASMC (but not PAEC) proliferation was observed in response to chronic fibrin exposure. In conclusion, chronic exposure to fibrinogen, fibrin, and thrombin caused differential changes in [Ca2+]cyt in PAEC and PASMC. Such changes in [Ca2+]cyt may contribute to vascular changes in patients who have CTEPH where the pulmonary vasculature is persistently exposed to thromboemboli.
Pulmonary characteristics in COPD and mechanisms of increased work of breathing
Authors: Loring Stephen H. , Garcia-Jacques Mauricio , Malhotra Atul
Published: April 2009

Mechanical characteristics and gas exchange inefficiencies of the lungs contribute to increased work of ventilation in chronic obstructive pulmonary disease (COPD) at rest and exercise, and the energy cost of ventilation is increased in COPD at any external work level. Assuming typical ventilatory variables and respiratory characteristics, we estimated the relative contributions of inspiratory and expiratory resistance, dynamic elastance, intrinsic positive end-expiratory pressure, and gas exchange inefficiency to the work of breathing, finding that the last of these is likely to be of major importance. Dynamic hyperinflation can be seen as both an impediment to inspiratory muscle function and an essential component of adaptation to severe obstruction. Extrinsic restriction, in which the chest wall fails to achieve and maintain abnormally high lung volumes in COPD, can limit ventilatory function and contribute to disability.
Involvement of central angiotensin II type 1 receptors in LPS-induced systemic vasopressin release and blood pressure regulation in rats
Authors: Shimizu Fumihiro , Kasai Toshihiro , Takamata Akira
Published: April 2009

The purpose of this study was to evaluate the involvement of central angiotensin II (ANG II) and ANG II type 1 (AT1) receptors in systemic release of arginine vasopressin (AVP) and blood pressure regulation during endotoxemia. LPS (150 μg/kg) was injected intravenously 30 min after intracerebroventricular (icv) losartan (50 μg), an AT1receptor antagonist, or subcutaneous (sc) captopril (50 mg/kg), an angiotensin-converting enzyme inhibitor. Rats with icv and sc saline injections served as control. LPS administration increased plasma AVP concentration from 2.1 ± 0.2 to 15.2 ± 2.5 pg/ml (60 min after LPS injection) without significant changes in plasma osmolality or hematocrit. LPS-induced AVP secretion was significantly attenuated by pretreatment with icv losartan (2.3 ± 0.5 to 3.7 ± 0.5 pg/ml) but was not attenuated after peripheral captopril treatment (2.2 ± 0.6 to 17.6 ± 4.2 pg/ml). LPS administration significantly decreased systolic blood pressure (SBP) by 22.7 ± 5.4 mmHg after intravenous LPS injection in icv losartan-treated rats, while SBP remained unchanged in vehicle-treated or sc captopril-treated rats by intravenous LPS. These results indicate that central AT1receptors, not responsive to peripheral ANG II, play an important role in systemic AVP secretion and maintenance of blood pressure during endotoxemia.
Paradoxical conducting airway responses and heterogeneous regional ventilation after histamine inhalation in rabbit studied by synchrotron radiation CT
Authors: Bayat Sam , Porra Liisa , Suhonen Heikki , Suortti Pekka , Sovijärvi Anssi R. A.
Published: April 2009

We studied both central conducting airway response and changes in the distribution of regional ventilation induced by inhaled histamine in healthy anesthetized and mechanically ventilated rabbit using a novel xenon-enhanced synchrotron radiation computed tomography (CT) imaging technique, K-edge subtraction imaging (KES). Images of specific ventilation were obtained using serial KES during xenon washin, in three axial lung slices, at baseline and twice after inhalation of histamine aerosol (50 or 125 mg/ml) in two groups of animals ( n = 6 each). Histamine inhalation caused large clustered areas of poor ventilation, characterized by a drop in average specific ventilation (sV̇m), but an increase in sV̇min the remaining lung zones indicating ventilation redistribution. Ventilation heterogeneity, estimated as coefficient of variation (CV) of sV̇msignificantly increased following histamine inhalation. The area of ventilation defects and CV were significantly larger with the higher histamine dose. In conducting airways, histamine inhalation caused a heterogeneous airway response combining narrowing and dilatation in individual airways of different generations, with the probability for constriction increasing peripherally. This finding provides further in vivo evidence that airway reactivity in response to inhaled histamine is complex and that airway response may vary substantially with location within the bronchial tree.
Role of local muscle contractile activity in the exercise-induced increase in NR4A receptor mRNA expression
Authors: Kawasaki Emi , Hokari Fumi , Sasaki Maiko , Sakai Atsushi , Koshinaka Keiichi , Kawanaka Kentaro
Published: April 2009

Exercise upregulates the expression of NR4A receptors, which are involved in regulation of glucose and fatty acid utilization genes in skeletal muscle. The aims of our study were 1) to determine the role of local contractile activity on NR4A mRNA expression in skeletal muscle during exercise; and 2) to elucidate the mechanisms underlying the induction of NR4A mRNA expression in response to muscle contractile activity. Rats were subjected to an acute 3-h low-intensity swimming or a 3-h low-intensity treadmill running as a model of endurance exercise. Low-intensity swimming increased NR4A1 and NR4A3 mRNA in triceps but not in soleus muscle. Conversely, low-intensity treadmill running increased NR4A1 and NR4A3 mRNA in soleus but not in triceps muscle. NR4A mRNA increased concomitantly with reduced postexercise muscle glycogen, suggesting that gene expression of NR4A receptors occurs in muscles recruited during exercise. Furthermore, in resting rats, an acute 1-h local electrical stimulation of a motor nerve to the tibialis anterior muscle caused increases in NR4A1 and NR4A3 mRNA relative to the contralateral control muscle of the same animals. On the other hand, after 6 h of hindlimb immobilization, NR4A1 and NR4A3 mRNA were reduced in immobilized soleus muscle relative to contralateral control muscle. In addition, both NR4A1 and NR4A3 mRNA in epitrochlearis muscle were increased after 6-h incubation with 0.5 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside, which activates AMP-activated protein kinase. These results suggest that 1) local muscle contractile activity is required for increased expressions of NR4A1 and NR4A3 mRNA during exercise; and 2) muscle contractile activity-induced increases in NR4A1 and NR4A3 mRNA may be mediated by AMPK activation, at least in part.
Effect of lung transplant and volume reduction surgery on respiratory muscle function
Authors: Estenne Marc
Published: April 2009

Lung transplantation and lung volume reduction surgery have opened a new therapeutic era for patients with advanced emphysema. In addition to providing impressive clinical benefits, they have helped us better understand how the chest wall and respiratory muscles adapt to chronic hyperinflation. This article reviews the effects of these procedures on respiratory muscle and chest wall function. Inspiratory (including diaphragm) and expiratory muscle strength are often close to normal after unilateral and bilateral transplantation, although some patients have marked weakness. After bilateral transplantation for emphysema, graft volume is normal at full inflation but remains greater than normal at end expiration, which results from structural changes in the chest wall. In contrast, patients with unilateral transplantation have a reduction in graft volume at full inflation. The mediastinum is displaced toward the graft at end expiration, which reduces the surface area of the diaphragm on the transplanted side, and it moves toward the native lung during tidal and full inspiration and toward the graft during tidal and forced expiration. Lung volume reduction produces an increase in contractility, length and surface area of the diaphragm, and increases its contribution to tidal volume; at the same time, neural drive to the muscle and respiratory load are reduced, such that diaphragm neuromechanical coupling is improved. Diaphragm configuration and rib cage dimensions are only minimally affected by the procedure. Single-lung transplantation and lung volume reduction favorably impact on the disadvantageous size interaction by which the lungs are functionally restricted by the chest wall in emphysema.
Regulation of Oxygen Homeostasis by Hypoxia-Inducible Factor 1
Authors: Semenza Gregg L.
Published: April 2009

Metazoan organisms are dependent on a continuous supply of O2for survival. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that regulates oxygen homeostasis and plays key roles in development, physiology, and disease. HIF-1 activity is induced in response to continuous hypoxia, intermittent hypoxia, growth factor stimulation, and Ca2+signaling. HIF-1 mediates adaptive responses to hypoxia, including erythropoiesis, angiogenesis, and metabolic reprogramming. In each case, HIF-1 regulates the expression of multiple genes encoding key components of the response pathway. HIF-1 also mediates maladaptive responses to chronic continuous and intermittent hypoxia, which underlie the development of pulmonary and systemic hypertension, respectively.
In Vivo Imaging of Stem Cells and Beta Cells Using Direct Cell Labeling and Reporter Gene Methods
Authors: Kraitchman Dara L. , Bulte Jeff W.M.
Published: April 2009

Cellular transplantation therapy offers a means to stimulate cardiovascular repair either by direct (graft-induced) or indirect (host-induced) tissue regeneration or angiogenesis. Typically, autologous or donor cells of specific subpopulations are expanded exogenously before administration to enrich the cells most likely to participate in tissue repair. In animal models of cardiovascular disease, the fate of these exogenous cells can be determined using histopathology. Recently, methods to label cells with contrast agents or transduce cells with reporter genes to produce imaging beacons has enabled the serial and dynamic assessment of the survival, fate, and engraftment of these cells with noninvasive imaging. Although cell tracking methods for cardiovascular applications have been most studied in stem or progenitor cells, research in tracking of whole islet transplants and particularly insulin producing beta cells has implications to the cardiovascular community attributable to the vascular changes associated with diabetes mellitus. In this review article, we will explore some of the state-of-the art methods for stem, progenitor, and beta cell tracking.
Rosuvastatin Increases Extracellular Adenosine Formation in Humans In Vivo
Authors: Meijer Patrick , Oyen Wim J.G. , Dekker Douwe , van den Broek Petra H.H. , Wouters Constatijn W. , Boerman Otto C. , Scheffer Gert Jan , Smits Paul , Rongen Gerard A.
Published: April 2009

Objective—Statins may increase extracellular adenosine formation from adenosine monophosphate by enhancing ecto-5′-nucleotidase activity. This theory was tested in humans using dipyridamole-induced vasodilation as a read-out for local adenosine formation. Dipyridamole inhibits the transport of extracellular adenosine into the cytosol resulting in increased extracellular adenosine and subsequent vasodilation. In addition, we studied the effect of statin therapy in a forearm model of ischemia-reperfusion injury.

Methods and Results—Volunteers randomly received rosuvastatin or placebo in a double-blind parallel design (n=21). The forearm vasodilator response to intraarterial dipyridamole was determined in the absence and presence of the adenosine antagonist caffeine. During a separate visit the vasodilator response to nitroprusside and adenosine was established. In addition, healthy men were randomly divided in 3 groups to receive either placebo (n=10), rosuvastatin (n=22), or rosuvastatin combined with intravenous caffeine (n=12). Subsequently, volunteers performed forearm ischemic exercise. At reperfusion, Tc-99m–labeled annexin A5 was infused intravenously and scintigraphic images were acquired, providing an early marker of cell injury. Rosuvastatin treatment significantly increased the vasodilator response to dipyridamole, which was prevented by caffeine. Rosuvastatin did not influence the response to either sodium nitroprusside or adenosine indicating a specific interaction between rosuvastatin and dipyridamole, which does not result from an effect of rosuvastatin on adenosine clearance nor adenosine-receptor affinity or efficacy. Rosuvastatin increased tolerance to ischemia-reperfusion injury, which was attenuated by caffeine.

Conclusions—Rosuvastatin increases extracellular adenosine formation, which provides protection against ischemia-reperfusion injury in humans in vivo. Therefore, statins and dipyridamole may interact synergistically.
Reduced Collagen Biosynthesis Is the Hallmark of Cerebral Aneurysm
Authors: Aoki Tomohiro , Kataoka Hiroharu , Ishibashi Ryota , Nozaki Kazuhiko , Morishita Ryuuichi , Hashimoto Nobuo
Published: April 2009

Background—

Reduced extracellular matrix is a prominent feature of cerebral aneurysms (CAs). We previously reported excessive ECM degradation in CA walls. In the present study, we examined collagen biosynthesis in CA walls and the molecular mechanisms underlying it in CA progression.

Methods and Results—

RT-PCR and immunohistochemistry showed reduced expression of procollagen type I, III, and lysyl oxidase (LOX) in CA walls. Treatment with the LOX inhibitor β-aminopropionitrile resulted in enhanced progression of CA. Expression of procollagen type I, III, and LOX was inhibited by interleukin-1β (IL-1β) in cultured rat aortic smooth muscle cells (RASMCs) in vitro. Nuclear factor κ-B (NF-κB) was activated in IL-1β-stimulated RASMCs, and treatment with NF-κB decoy oligodeoxynucleotides (ODN) restored reduced expression of procollagen type I, III, and LOX in vitro. NF-κB decoy ODNs ameliorated the expression of procollagen type I, III, and LOX in CA walls in vivo.

Conclusions—

Collagen biosynthesis was significantly inhibited at the transcriptional level and in the posttranscriptional enzymatic modification in CA walls through upregulated expression of IL-1β and the NF-κB pathway. Reduced collagen biosynthesis may contribute to CA progression, and inhibition of this process may lead to the prevention of the progression and rupture of CAs.
HDL-Cholesterol, Blood Pressure, and Asymmetric Dimethylarginine Are Significantly Associated With Arterial Wall Thickness in Children
Authors: Ayer Julian G. , Harmer Jason A. , Nakhla Shirley , Xuan Wei , Ng Martin K.C. , Raitakari Olli T. , Marks Guy B. , Celermajer David S.
Published: April 2009

Objective—

Atherosclerosis is found at autopsy in the arteries of adolescents and young adults. Arterial wall thickening may be assessed in vivo by ultrasound measurement of the carotid intima media thickness (CIMT), a marker of subclinical atherosclerosis. As the determinants of arterial wall thickness in childhood are unknown, we assessed the influence of cardiovascular risk factors on CIMT in 8-year-old children.

Methods and Results—

A community-based sample of 405 children (age 8.0±0.1 years, 49% girls) had anthropometry, family history, blood pressure (BP), and CIMT measured. A blood sample was collected for HDL and non-HDL cholesterol, apolipoproteins A1 and B, high-sensitivity C-reactive protein, bilirubin, and asymmetric dimethylarginine (ADMA, an endogenous nitric oxide inhibitor). CIMT was significantly associated with systolic BP (
r
=0.17,
P
<0.001), diastolic BP (
r
=0.10,
P
=0.04), HDL (
r
=−0.13,
P
=0.02), and ADMA (
r
=0.18,
P
=0.001). CIMT was significantly higher in children with premature parental CHD (0.63±0.07 versus 0.59±0.06 mm,
P
=0.03). On multivariate analysis, HDL (β coefficient=−0.02,
P
=0.04), ADMA (β coefficient=0.05,
P
<0.001), and systolic BP (β coefficient=0.001,
P
=0.003) were significantly and independently associated with CIMT.

Conclusions—

Lower HDL-cholesterol, higher levels of ADMA, and systolic BP are significantly associated with greater arterial wall thickness in early childhood.
Glucose 6-Phosphate Dehydrogenase Is Regulated Through c-Src–Mediated Tyrosine Phosphorylation in Endothelial Cells
Authors: Pan Shi , World Cameron J. , Kovacs Christopher J. , Berk Bradford C.
Published: April 2009

Objective—

Glucose 6-phosphate dehydrogenase (G6PD) maintains cellular NADPH levels, which are essential for cellular functions, such as vascular endothelial growth factor (VEGF)-induced angiogenesis. The molecular mechanisms regulating G6PD in angiogenesis are not fully understood. Because tyrosine phosphorylation is a key regulatory pathway for VEGF-mediated endothelial cell (EC) responses, we investigated tyrosine phosphorylation of G6PD and the role of the nonreceptor tyrosine kinase Src.

Methods and Results—

VEGF increased G6PD membrane translocation as measured by a plasma membrane sheet assay, whereas tyrosine kinase inhibitor PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo [3,4-d] pyramidine) decreased G6PD translocation by 100%. Furthermore, G6PD tyrosine phosphorylation and plasma membrane activity were increased by VEGF. In resting ECs, tyrosine kinase inhibitors PP2 and herbimycin A decreased basal G6PD activity by ∼25%, whereas transfection with kinase inactive Src (KD-Src) decreased basal activity by ∼30%. In mouse embryonic fibroblasts, Src-deficient (SYF) cells showed ∼22% lower basal G6PD activity than Src-expressing S
+
YF cells. In addition, Src directly phosphorylated G6PD assayed by in vitro kinase assay. In ECs transfected with the G6PD mutants Y428F, Y507F (presumptive sites for Src-phosphorylation) or double mutant Y428F/Y507F, G6PD tyrosine phosphorylation was significantly decreased. Finally, G6PD tyrosine mutants (Y428F, Y507F, and Y428F/Y507F) decreased VEGF-mediated Akt phosphorylation and EC migration.

Conclusions—

G6PD activity and membrane association are regulated by Src-mediated tyrosine phosphorylation, which contributes to VEGF-mediated cellular responses in EC.
Insulin Increases Reendothelialization and Inhibits Cell Migration and Neointimal Growth After Arterial Injury
Authors: Breen Danna M. , Chan Kalam K. , Dhaliwall Jiwanjeet K. , Ward Michael R. , Al Koudsi Nael , Lam Loretta , De Souza Melissa , Ghanim Husam , Dandona Paresh , Stewart Duncan J. , Bendeck Michelle P. , Giacca Adria
Published: April 2009

Objective—

Insulin has both growth-promoting and protective vascular effects in vitro, however the predominant effect in vivo is unclear. We investigated the effects of insulin in vivo on neointimal growth after arterial injury.

Methods and Results—

Rats were given subcutaneous control (C) or insulin implants (3U/d;I) 3 days before arterial (carotid or aortic) balloon catheter injury. Normoglycemia was maintained by oral glucose and, after surgery, by intraperitoneal glucose infusion (saline in C). Insulin decreased intimal area (
P
<0.01) but did not change intimal cell proliferation or apoptosis. However, insulin inhibited cell migration into the intima (
P
<0.01) and increased expression of smooth muscle cell (SMC) differentiation markers (
P
<0.05). Insulin also increased reendothelialization (
P
<0.01) and the number of circulating progenitor cells (
P
<0.05).

Conclusions—

These results are the first demonstration that insulin has a protective effect on both SMC and endothelium in vivo, resulting in inhibition of neointimal growth after vessel injury.
Accelerated Lipid-Induced Atherogenesis in Galectin-3-Deficient Mice
Authors: Iacobini Carla , Menini Stefano , Ricci Carlo , Scipioni Angela , Sansoni Viola , Cordone Samantha , Taurino Maurizio , Serino Matteo , Marano Giuseppe , Federici Massimo , Pricci Flavia , Pugliese Giuseppe
Published: April 2009

Objective—

Modified lipoproteins, particularly oxidized LDLs, are believed to evoke an inflammatory response which participates in all stages of atherosclerosis. Disposal of these particles is mediated through receptors which may trigger proinflammatory signaling pathways leading to vascular injury. This study was aimed at assessing the role in atherogenesis of one of these receptors, galectin-3.

Methods and Results—

Galectin-3-deficient and wild-type mice were fed an atherogenic diet or standard chow for 8 months. Lesion area and length were higher in galectin-3-deficient versus wild-type mice. At the level of the aortic sinus, wild-type animals showed only fatty streaks, whereas galectin-3-deficient mice developed complex lesions, associated with extensive inflammatory changes. This was indicated by the presence of T lymphocytes with activated Th1-phenotype and by more marked monocyte-macrophage infiltration, inflammatory mediator expression, vascular cell apoptosis, and proinflammatory transcription factor activation. Increased accumulation of oxidixed LDLs and lipoxidation products and upregulation of other receptors for these compounds, including the proinflammatory RAGE, were detected in galectin-3-deficient versus wild-type mice.

Conclusions—

These data suggest a unique protective role for galectin-3 in the uptake and effective removal of modified lipoproteins, with concurrent downregulation of proinflammatory pathways responsible for atherosclerosis initiation and progression.
Antiinflammatory Effects of the ETS Factor ERG in Endothelial Cells Are Mediated Through Transcriptional Repression of the Interleukin-8 Gene
Authors: Yuan Lei , Nikolova-Krstevski Vesna , Zhan Yumei , Kondo Maiko , Bhasin Manoj , Varghese Laya , Yano Kiichiro , Carman Chris V. , Aird William C. , Oettgen Peter
Published: April 2009

ERG (Ets-related gene) is an ETS transcription factor that has recently been shown to regulate a number of endothelial cell (EC)-restricted genes including VE-cadherin, von Willebrand factor, endoglin, and intercellular adhesion molecule-2. Our preliminary data demonstrate that unlike other ETS factors, ERG exhibits a highly EC-restricted pattern of expression in cultured primary cells and several adult mouse tissues including the heart, lung, and brain. In response to inflammatory stimuli, such as tumor necrosis factor-α, we observed a marked reduction of ERG expression in ECs. To further define the role of ERG in the regulation of normal EC function, we used RNA interference to knock down ERG. Microarray analysis of RNA derived from ERG small interfering RNA– or tumor necrosis factor-α–treated human umbilical vein (HUV)ECs revealed significant overlap (
P
<0.01) in the genes that are up- or downregulated. Of particular interest to us was a significant change in expression of interleukin (IL)-8 at both protein and RNA levels. Exposure of ECs to tumor necrosis factor-α is known to be associated with increased neutrophil attachment. We observed that knockdown of ERG in HUVECs is similarly associated with increased neutrophil attachment compared to control small interfering RNA–treated cells. This enhanced adhesion could be blocked with IL-8 neutralizing or IL-8 receptor blocking antibodies. ERG can inhibit the activity of the IL-8 promoter in a dose dependent manner. Direct binding of ERG to the IL-8 promoter in ECs was confirmed by chromatin immunoprecipitation. In summary, our findings support a role for ERG in promoting antiinflammatory effects in ECs through repression of inflammatory genes such as IL-8.
Genetic Fate Mapping Identifies Second Heart Field Progenitor Cells As a Source of Adipocytes in Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: Lombardi Raffaella , Dong Jinjiang , Rodriguez Gabriela , Bell Achim , Leung Tack Ki , Schwartz Robert J. , Willerson James T. , Brugada Ramon , Marian Ali J.
Published: April 2009

The phenotypic hallmark of arrhythmogenic right ventricular cardiomyopathy, a genetic disease of desmosomal proteins, is fibroadipocytic replacement of the right ventricle. Cellular origin of excess adipocytes, the responsible mechanism(s) and the basis for predominant involvement of the right ventricle are unknown. We generated 3 sets of lineage tracer mice regulated by cardiac lineage promoters α-myosin heavy chain (αMyHC), Nkx2.5, or Mef2C. We conditionally expressed the reporter enhanced yellow fluorescent protein while concomitantly deleting the desmosomal protein desmoplakin in cardiac myocyte lineages using the Cre-LoxP technique. Lineage tracer mice showed excess fibroadiposis and increased numbers of adipocytes in the hearts. Few adipocytes in the hearts of αMyHC-regulated lineage tracer mice, but the majority of adipocytes in the hearts of Nkx2.5- and Mef2C-regulated lineage tracer mice, expressed enhanced yellow fluorescent protein. In addition, rare cells coexpressed adipogenic transcription factors and the second heart field markers Isl1 and Mef2C in the lineage tracer mouse hearts and in human myocardium from patients with arrhythmogenic right ventricular cardiomyopathy. To delineate the responsible mechanism, we generated transgenic mice expressing desmosomal protein plakoglobin in myocyte lineages. Transgene plakoglobin translocated to nucleus, detected by immunoblotting and immunofluorescence staining and coimmunoprecipitated with Tcf7l2, a canonical Wnt signaling transcription factor. Expression levels of canonical Wnt/Tcf7l2 targets bone morphogenetic protein 7 and Wnt5b, which promote adipogenesis, were increased and expression level of connective tissue growth factor, an inhibitor of adipogenesis, was decreased. We conclude adipocytes in arrhythmogenic right ventricular cardiomyopathy originate from the second heart field cardiac progenitors, which switch to an adipogenic fate because of suppressed canonical Wnt signaling by nuclear plakoglobin.