bluuebunny/crossref_metadata_2025 huggingface dataset:
Placoderms (Armored Fish): Dominant Vertebrates of the Devonian Period
Authors: Young Gavin C.
Published: April 2010

Placoderms, the most diverse group of Devonian fishes, were globally distributed in all habitable freshwater and marine environments, like teleost fishes in the modern fauna. Their known evolutionary history (Early Silurian–Late Devonian) spanned at least 70 million years. Known diversity (335 genera) will increase when diverse assemblages from new areas are described. Placoderms first occur in the Early Silurian of China, but their diversity remained low until their main evolutionary radiation in the Early Devonian, after which they became the dominant vertebrates of Devonian seas. Most current placoderm data are derived from the second half of the group's evolutionary history, and recent claims that they form a paraphyletic group are based on highly derived Late Devonian forms; 16 shared derived characters are proposed here to support placoderm monophyly. Interrelationships of seven placoderm orders are unresolved because Silurian forms from China are still poorly known. The relationship of placoderms to the two major extant groups of jawed fishes—osteichthyans (bony fishes) and chondrichthyans (cartilaginous sharks, rays, and chimaeras)—remains uncertain, but the detailed preservation of placoderm internal braincase structures provides insights into the ancestral gnathostome (jawed vertebrate) condition. Placoderms provide the most complex morphological and biogeographic data set for the Middle Paleozoic; marked discrepancies in stratigraphic occurrence between different continental regions indicate strongly endemic faunas that were probably constrained by marine barriers until changes in paleogeography permitted range enlargement into new areas. Placoderm distributions in time and space indicate major faunal interchange between Gondwana and Laurussia near the Frasnian-Famennian boundary; closure of the Devonian equatorial ocean is a possible explanation.
Late Neogene Erosion of the Alps: A Climate Driver?
Authors: Willett Sean D.
Published: April 2010

As with many mountain belts globally, the Alps have seen a large increase in sediment yield in the late Neogene. The hypothesis that this increase results from climate-change impacts on erosion rate over the past ∼5 Ma is testable, given the extensive work completed in the Alps. Sediment budgets, thermochronology-based cooling rates, and estimates of modern rock uplift and erosion in the Western Alps are reviewed to search for correlation in space and time that might fingerprint climatic events. Major increases in sediment yield are apparent starting in the late Messinian (5.5 Mya) and accelerating toward the present day; this suggests the occurrence of a series of climatic changes that increased erosion rates, even as tectonic processes appear to have slowed or stopped. At present, tight correlations in time are difficult to establish and there remain open questions about the role of tectonics in the coupled system.
Toward the Development of “Magmatology”
Authors: Kushiro Ikuo
Published: April 2010

During the past several decades, experimental studies on the genesis and properties of magma have been intensively carried out, and our understanding of the conditions for generation of major-type magmas and their behaviors at depths has been significantly advanced. The author was fortunate to participate in some of these studies. These and subsequent experimental studies should be amalgamated with the studies of magma in other disciplines to develop a field of multidisciplinary research on magma for a better understanding of the genesis and role of magmas in the evolution of Earth and other planets.
Monochloramine-induced toxicity and dysregulation of intracellular Zn2+in parietal cells of rabbit gastric glands
Authors: Kohler Jonathan E. , Dubach J. Matthew , Naik Haley B. , Tai Kaniza , Blass Amy L. , Soybel David I.
Published: April 2010

Monochloramine (NH2Cl) is a potent, thiol-directed oxidant capable of oxidizing thiol (S-H) residues in a wide variety of proteins. Generated in the stomach by the interaction of bacterial and host products, monochloramine has been shown to dysregulate Ca2+homeostasis and disrupt mucosal integrity. In this report, we show that monochloramine also leads to disturbances in intracellular free zinc concentration ([Zn2+]i) in the gastric gland of the rabbit and that the increased Zn2+within the cell causes an independent decrease in cell viability. Changes in [Zn2+]iwere measured by using the fluorescent reporter FluoZin-3, whereas cell viability was assessed by measuring the conversion of calcein-AM to fluorescent calcein, an assay that is not affected by intracellular oxidation state. Cell death was confirmed using propidium iodide and YO-PRO-1 dye uptake measurements. Our experiments demonstrate that [Zn2+]iis increased in gastric glands exposed to NH2Cl and that elevated [Zn2+]idecreases cell viability. Chelation of Zn2+with tetrakis-(2-pyridylmethyl) ethylenediamine decreases the toxicity of NH2Cl, but only when administered concurrently. These findings suggest that the toxic effect of thiol oxidants present during chronic gastritis is partially due to dysregulation of [Zn2+]iearly in the process and that zinc chelation can protect, but not rescue, gastric glands exposed to toxic doses of NH2Cl.
Effects of central sodium on epithelial sodium channels in rat brain
Authors: Wang Hong-Wei , Amin Md Shahrier , El-Shahat Esraa , Huang Bing S. , Tuana Balwant S. , Leenen Frans H. H.
Published: April 2010

We evaluated the effects of intracerebroventricular (icv) infusion of Na+-rich artificial cerebrospinal fluid (aCSF), with or without the mineralocorticoid receptor (MR) blocker spironolactone, on epithelial Na+ channel (ENaC) subunits and regulators, such as MR, serum/glucocorticoid-inducible kinase 1, neural precursor cells expressed developmentally downregulated 4-like gene, 11β-hydroxylase, and aldosterone synthase, in brain regions of Wistar rats. The effects of icv infusion of the amiloride analog benzamil on brain tissue and CSF Na+ concentration ([Na+]) were also assessed. In the choroid plexus and ependyma of the anteroventral third ventricle, ENaC subunits are present in apical and basal membranes. Na+-rich aCSF increased β-ENaC mRNA and immunoreactivity in the choroid plexus and increased α- and β-ENaC immunoreactivities in the ependyma. Na+-rich aCSF increased α- and β-ENaC-gold-labeled particles in the microvilli of the choroid plexus and in basolateral membranes of the ependyma. Spironolactone only prevented the increase in β-ENaC immunoreactivity in the choroid plexus and ependyma. In the supraoptic nucleus, paraventricular nucleus, and subfornical organ, Na+-rich aCSF did not affect mRNA expression levels of the studied genes. Benzamil significantly increased CSF [Na+] in the control, but not Na+-rich, aCSF group. In contrast, benzamil prevented the increase in hypothalamic tissue [Na+] by Na+-rich aCSF. These results suggest that CSF Na+ upregulates ENaC expression in the brain epithelia, but not in the neurons of hypothalamic nuclei. ENaC in the choroid plexus and ependyma appear to contribute to regulation of Na+ homeostasis in the brain.
A role for the Kölliker-Fuse nucleus in cholinergic modulation of breathing at night during wakefulness and NREM sleep
Authors: Bonis J. M. , Neumueller S. E. , Krause K. L. , Kiner T. , Smith A. , Marshall B. D. , Qian B. , Pan L. G. , Forster H. V.
Published: April 2010

For many years, acetylcholine has been known to contribute to the control of breathing and sleep. To probe further the contributions of cholinergic rostral pontine systems in control of breathing, we designed this study to test the hypothesis that microdialysis (MD) of the muscarinic receptor antagonist atropine into the pontine respiratory group (PRG) would decrease breathing more in animals while awake than while in NREM sleep. In 16 goats, cannulas were bilaterally implanted into rostral pontine tegmental nuclei ( n = 3), the lateral ( n = 3) or medial ( n = 4) parabrachial nuclei, or the Kölliker-Fuse nucleus (KFN; n = 6). After >2 wk of recovery from surgery, the goats were studied during a 45-min period of MD with mock cerebrospinal fluid (mCSF), followed by at least 30 min of recovery and a second 45-min period of MD with atropine. Unilateral and bilateral MD studies were completed during the day and at night. MD of atropine into the KFN at night decreased pulmonary ventilation and breathing frequency and increased inspiratory and expiratory time by 12–14% during both wakefulness and NREM sleep. However, during daytime studies, MD of atropine into the KFN had no effect on these variables. Unilateral and bilateral nighttime MD of atropine into the KFN increased levels of NREM sleep by 63 and 365%, respectively. MD during the day or at night into the other three pontine sites had minimal effects on any variable studied. Finally, compared with MD of mCSF, bilateral MD of atropine decreased levels of acetylcholine and choline in the effluent dialysis fluid. Our data support the concept that the KFN is a significant contributor to cholinergically modulated control of breathing and sleep.
A Semigroup Approach to the System with Primary and Secondary Failures
Authors: Haji Abdukerim
Published: April 2010

We investigate the solution of a repairable parallel
system with primary as well as secondary failures. By using the method of functional
analysis, especially, the spectral theory of linear operators and the theory of C0‐semigroups, we prove well‐posedness of the system and the existence of positive
solution of the system. And then we show that the time‐dependent solution strongly
converges to steady‐state solution, thus we obtain the asymptotic stability of the
time‐dependent solution.
Combining CD19 Redirection and Alloanergization to Generate Tumor-Specific Human T Cells for Allogeneic Cell Therapy of B-Cell Malignancies
Authors: Davies Jeff K. , Singh Harjeet , Huls Helen , Yuk Dongin , Lee Dean A. , Kebriaei Partow , Champlin Richard E. , Nadler Lee M. , Guinan Eva C. , Cooper Laurence J.N.
Published: April 2010

Allogeneic hematopoietic stem-cell transplantation can cure some patients with high-risk B-cell malignancies, but disease relapse following transplantation remains a significant problem. One approach that could be used to augment the donor T-cell–mediated antitumor effect is the infusion of allogeneic donor–derived T cells expressing a chimeric antibody receptor (CAR) specific to the B-cell antigen CD19. However, the use of such cells might result in toxicity in the form of graft-versus-host disease mediated by CD19-specific (CD19-CAR) T cells possessing alloreactive endogenous T-cell receptors. We therefore investigated whether nonalloreactive tumor-specific human T cells could be generated from peripheral blood mononuclear cells of healthy donors by the combination of CD19 redirection via CAR expression and subsequent alloanergization by allostimulation and concomitant blockade of CD28-mediated costimulation. Alloanergization of CD19-CAR T cells resulted in efficient and selective reduction of alloresponses in both CD4+ and CD8+ T cells, including allospecific proliferation and cytokine secretion. Importantly, T-cell effector functions including CAR-dependent proliferation and specific target cytolysis and cytokine production were retained after alloanergization. Our data support the application of CD19 redirection and subsequent alloanergization to generate allogeneic donor T cells for clinical use possessing increased antitumor activity but limited capacity to mediate graft-versus-host disease. Immunotherapy with such cells could potentially reduce disease relapse after allogeneic transplantation without increasing toxicity, thereby improving the outcome of patients undergoing allogeneic transplantation for high-risk B-cell malignancies. Cancer Res; 70(10); 3915–24. ©2010 AACR.
Hypothalamic Dysfunction in a Female with Isolated Hypogonadotropic Hypogonadism and Compound Heterozygous TACR3 Mutations and Clinical Manifestation in Her Heterozygous Mother
Authors: Fukami Maki , Maruyama Tetsuo , Dateki Sumito , Sato Naoko , Yoshimura Yasunori , Ogata Tsutomu
Published: April 2010

Background/Aims:TAC3 and TACR3 have recently been shown to be causative genes for an autosomal recessive form of isolated hypogonadotropic hypogonadism (IHH). Here, we report a Japanese female with IHH and compound heterozygous TACR3 mutations and her heterozygous parents, and discuss the primary lesion for IHH and clinical findings. Case Report: This female was identified through mutation analysis of TAC3 and TACR3 in 57 patients with IHH. At 24 years of age, an initial standard GnRH test showed poor gonadotropin response (LH <0.2–0.6 IU/l), whereas the second GnRH test performed after GnRH priming (100 µg i.m. for 5 consecutive days) revealed ameliorated gonadotropin responses (LH 0.3–6.4 IU/l; FSH 2.2–9.6 IU/l). The mother exhibited several features suggestive of mild IHH, whereas the father showed an apparently normal phenotype. Results: She had a paternally derived nonsense mutation at exon 1 (Y145X) and a maternally inherited single nucleotide (G) deletion from the conserved ‘GT’ splice donor site of intron 1 (IVS1+1delG). Conclusions: The results suggest hypothalamic dysfunction as the primary cause for IHH in patients with biallelic TACR3 mutations and clinical manifestation in heterozygous females, together with the rarity of TAC3 and TACR3 mutations in patients with IHH.
Patent Foramen Ovale with Atrial Septal Aneurysm May Contribute to White Matter Lesions in Stroke Patients
Authors: Ueno Yuji , Shimada Yoshiaki , Tanaka Ryota , Miyamoto Nobukazu , Tanaka Yasutaka , Hattori Nobutaka , Urabe Takao
Published: April 2010

Background: The purpose of the present study was to assess the contribution of embolic etiologies, patent foramen ovale (PFO) and atrial septal aneurysm (ASA), to cerebral white matter lesions (WMLs) in ischemic stroke patients. Methods: Patients with acute ischemic stroke who underwent transesophageal echocardiography were prospectively studied to investigate the relationships between the prevalence of PFO and ASA and the degree of WMLs. The patients were classified into four groups based on transesophageal echocardiography findings: (1) the PFO group (patients having PFO but not ASA); (2) the ASA group (patients having ASA but not PFO); (3) the PFO-ASA group (patients having both PFO and ASA), and (4) the non-septal abnormalities group (non-SA group, patients with neither PFO nor ASA). Based on MRI findings, the patients were also subdivided into grades 0, 1, 2, and 3 according to the Fazekas classification. Results: 115 patients (age, 69 ± 11 years; 41 females) were enrolled; 49 (43%) were in the PFO group, 4 (3%) were in the ASA group, 23 (20%) were in the PFO-ASA group, and 39 (34%) were in the non-SA group. The PFO-ASA group had significantly increased WMLs compared to the other three groups (p = 0.004). On multiple logistic regression analysis, the coexistence of PFO and ASA was significantly associated with the degree of WMLs (odds ratio: 2.40; 95% confidence interval: 1.11–5.17; p = 0.026) when the PFO-ASA and non-SA groups were compared. Conclusions: The coexistence of PFO with ASA could play an important pathogenic role in WML severity.
Multidisciplinary Care Improves Outcome of Patients with Stage 5 Chronic Kidney Disease
Authors: Fenton Anthony , Sayar Zara , Dodds Annette , Dasgupta Indranil
Published: April 2010

Background and Objectives: Multidisciplinary care (MDC) is known to improve the management of chronic diseases. In this study, we investigated whether MDC improves outcomes in patients with advanced chronic kidney disease. Design, Setting, Participants and Measurements: In this retrospective case-control study we have compared the outcomes at the point of starting dialysis and beyond between a cohort of MDC patients (n = 171) and a cohort of nephrology patients (n = 194). The groups were well-matched demographically and were seen in the clinic for at least 3 months before starting dialysis. Dialysis access, blood pressure, haemoglobin, various biochemical parameters, hospital admissions, and survival were compared between the 2 groups. Results: In the MDC group, 68.4% started dialysis with permanent access compared with 58.8% in the nephrologist group (p = 0.04). The mean haemoglobin in the MDC group was 10.28 ± 1.86 versus 9.81 ± 1.76 g/dl in the nephrology group (p = 0.02). There was no difference between the groups in terms of blood pressure control or serum calcium, phosphate, or albumin levels. There were fewer hospital admissions in the MDC cohort (1.42 vs. 2.52 admissions per patient per year, p = 0.005). Kaplan-Meier survival analysis showed that patient survival was significantly better in the MDC group (p = 0.033). Conclusions: This study demonstrates that patients attending a multidisciplinary clinic are better prepared for dialysis treatment, have fewer hospital admissions after start of dialysis, and have a higher patient survival compared to those attending a traditional nephrology clinic.
Serum Oxidized LDL Is Inversely Associated with HDL2-Cholesterol Subclass in Renal Failure Patients on Hemodialysis
Authors: Samouilidou E. , Karpouza A. , Grapsa E. , Tzanatou-Exarchou H.
Published: April 2010

Background:Dyslipoproteinemia and oxidative modification of LDL (oxLDL) are common symptoms in patients suffering from chronic renal failure on hemodialysis (HD), and contribute to the development of oxidative stress. High-density lipoprotein cholesterol (HDL-C) protects against atherosclerosis by inhibiting the oxidation of lipoproteins and by supporting reverse cholesterol transport. This study intends to examine the association of oxLDL with HDL2 and HDL3 subclasses of HDL-C in HD patients, in order to elucidate whether oxidative stress influences HDL-C composition. Methods: Thirty-four patients on HD and 21 age- and sex-matched controls were studied. HDL2 and HDL3-C subclasses were isolated from serum according to a single-step precipitation method following a homogenous HDL-C assay. oxLDL was measured by ELISA. Results: In HD patients, oxLDL concentration was higher compared to the controls (1.40 ± 0.47 vs. 0.21 ± 0.05 mg/l, p = 0.017) and was significantly associated to total cholesterol (r = 0.480, p = 0.044), LDL-C (r = 0.544, p = 0.019), HDL-C (r = –0.589, p = 0.027) and C-reactive protein (r = 0.578, p = 0.024). Comparing HDL-C subclasses, only HDL2-C was negatively correlated to oxLDL levels (r = –0.565, p = 0.035). Conclusions: In HD patients, high serum levels of oxLDL are associated with low HDL2-C subclass levels. This might suggest that oxidative stress affects the HDL subclass more related to the protecting activity of HDL-C, contributing to atherosclerosis development.
Tissue Accumulation of Lanthanum as Compared to Aluminum in Rats with Chronic Renal Failure – Possible Harmful Effects after Long-Term Exposure
Authors: Nikolov Igor G. , Joki Nobuhiko , Vicca Stéphanie , Patey Natacha , Auchère Daniel , Benchitrit Joyce , Flinois Jean-Pierre , Ziol Marianne , Beaune Philippe , Drüeke Tilman B. , Lacour Bernard
Published: April 2010

Background: Lanthanum (La) carbonate is a new treatment for hyperphosphatemia. We tested the effects of oral La carbonate and aluminum hydroxide, respectively, on tissue accumulation and liver function in rats with chronic renal failure (CRF). Methods: Adult male non-CRF and CRF rats were randomly assigned to 3 groups receiving either standard diet (St.D), or the same diet supplemented with 3% La carbonate (non-CRF La vs. CRF La) or 3% aluminum hydroxide (non-CRF Al vs. CRF Al). Results: After 12 weeks, serum phosphorus was decreased in both CRF La and Al groups. Urinary La and Al excretion was increased in these two groups, and so was liver and bone La content, and liver Al content. Both total body and liver weight were decreased in CRF La and CRF Al rats. Liver cell proliferation was decreased in these groups, while plasma total alkaline phosphatases and alanine aminotransferase were increased. Hepatic total cytochrome p450 content was reduced in CRF La, but not in CRF Al rats. Conclusion: Long-term oral La overload in rats with CRF was associated with a decrease in liver (and total body) weight and mild alterations of liver function, as was Al overload, possibly as a consequence of trace element accumulation.
Association between Albuminuria, Carotid Atherosclerosis, Arterial Stiffness, and Peripheral Arterial Disease in Korean Type 2 Diabetic Patients
Authors: Choi Seong-Woo , Yun Woo-Jun , Kim Hey-Yeon , Lee Young-Hoon , Kweon Sun-Seog , Rhee Jung-Ae , Choi Jin-Su , Shin Min-Ho
Published: April 2010

Background: To evaluate the association between albuminuria, carotid atherosclerosis, arterial stiffness, and peripheral arterial disease (PAD) in Korean type 2 diabetic patients. Methods: In total, 673 type 2 diabetic patients registered with the public health center participated. Following an overnight fast, venous blood and urine samples were collected and analyzed. The carotid intima-media thickness (IMT), amount of carotid plaque, brachial ankle pulse wave velocity (baPWV), and the ankle-brachial index of each patient were also assessed. Results: Albuminuria was significantly associated with PAD (odds ratio (OR) 2.33; 95% confidence interval (CI) 1.28–4.25 for normoalbuminuria vs. microalbuminuria and OR 3.28; 95% CI 1.40–7.66 for normoalbuminuria vs. macroalbuminuria), but not with carotid plaque. The mean baPWV differed significantly according to the level of albumin relative to the creatinine ratio (1,764.79, 1,778.98, and 2,001.33, respectively; p < 0.001), while no significant difference was observed in the mean IMT value (0.73, 0.74, and 0.72, respectively; p = 0.399). Conclusions: Albuminuria was significantly associated with baPWV and PAD, but not with carotid plaque or CCA-IMT, in Korean type 2 diabetic patients.
Is It Effective to Raise the Irradiation Dose from 80 to 85 Gy in Gamma Knife Radiosurgery for Trigeminal Neuralgia?
Authors: Kim Yong Hwy , Kim Dong Gyu , Kim Jin Wook , Kim Young-Hoon , Han Jung Ho , Chung Hyun-Tai , Paek Sun Ha
Published: April 2010

Objective: In order to assess the effect of raising gamma knife radiosurgery (GKS) doses from 80 to 85 Gy for the treatment of trigeminal neuralgia (TN), the authors analyzed the outcomes of GKS in each group. Patients and Methods: The authors retrospectively collected follow-up data of 104 GKS procedures conducted for TN. Doses of 80 and 85 Gy were prescribed for 60 and 44 patients, respectively. The target was 2–4 mm anterior to the junction of the trigeminal nerve and pons. Outcomes were quantified based on facial pain levels and classified using the Barrow Neurological Institute scale. Results: Actuarial rates of a favorable pain control outcome at 1 and 3 years after GKS were 75.0 and 61.2% for 80 Gy and 65.9 and 60.3% for 85 Gy. Post-GKS facial sensory loss developed in 20.6%. There was no statistically significant difference in pain control rate between the two groups. Time to maximal pain relief was shorter in the 85-Gy group. Protracted morbidity before GKS was a favorable prognostic factor of pain control in a multivariate analysis. Conclusion: According to our finding that 85 Gy brought more rapid clinical improvement without causing more complications, 85 Gy seems to be preferable to 80 Gy, but prospective randomized trials are mandatory to get a more definite conclusion on the optimal dose for GKS of TN.
Spinal Cord Stimulation to Abort Painful Spasms of Atypical Stiff Limb Syndrome
Authors: Ughratdar I. , Sivakumar G. , Basu S.
Published: April 2010

Stiff limb syndrome (SLS) is a rare chronic condition which can result in significant debility. We report the case of a 44-year-old man suffering from severe painful spasms in his right leg with a diagnosis of SLS. He had been initially treated for his pain with a spinal cord stimulator but presented with exacerbation of pain secondary to a lead fracture for which he underwent revision of the stimulator. Postoperative programming unexpectedly resulted in not only control of his pain but also an ability to abort his spasmodic episodes related to SLS. To our knowledge, spinal cord stimulation has not been previously used for SLS and our report opens up another avenue for this rare condition. We provide a brief overview of SLS and propose an underlying mechanism for the observed phenomenon.
Combined Ablative Neurosurgical Procedures in a Patient with Mixed Spastic and Dystonic Cerebral Palsy
Authors: Sitthinamsuwan Bunpot , Chanvanitkulchai Kannachod , Nunta-aree Sarun , Kumthornthip Witsanu , Pisarnpong Apichart , Ploypetch Teerada
Published: April 2010

Background: Harmful generalized spasticity is an obstacle in rehabilitation and caregiving. Neurosurgical intervention is a therapeutic option for patients with severe spasticity who do not respond to nonoperative management. Currently, intrathecal baclofen therapy (ITB) is a good alternative treatment for such patients. However, the ITB device is costly and the intrathecal drug is not available in Thailand. Case Description: We report a combined use of ablative neurosurgical procedures in a patient with severe generalized spasticity and disabling cervical dystonia (CD). The assembled operations including selective peripheral denervation for CD, microsurgical dorsal root entry zone lesion for upper limb spasticity, and selective dorsal rhizotomy for lower limb spasticity were conducted in a single session. Furthermore, recurrent spasticity of the upper extremities was subsequently treated by selective peripheral neurotomy. Results: The spasticity and CD totally disappeared after all operations. The patient became able to sit and perform head turning. Additionally, we also found an improvement in swallowing and the voluntary movement of the lower limbs.
Cutaneous Low-Dose Radiation Increases Tissue Vascularity through Upregulation of Angiogenic and Vasculogenic Pathways
Authors: Thanik Vishal D. , Chang Christopher C. , Lerman Oren Z. , Greives Matthew R. , Le Huong , Warren Stephen M. , Schneider Robert J. , Formenti Sylvia C. , Saadeh Pierre B. , Levine Jamie P.
Published: April 2010

Background/Aims: Neovascularization involves angiogenesis and vasculogenesis mediated by cytokines and soluble chemokines. The predominant stimulus is ischemia, however, recent data suggest that ionizing radiation (IR) has angiogenic potential. In this study we evaluated whether IR increases vascularity and perfusion in vivo. Methods: In wild-type mice, a full-thickness, pedicled skin flap was created and isolated for localized irradiation at a dose of 5 Gy. Serial Doppler analysis of the flap was performed. The skin flaps were then harvested at various time points for vascularity and histologic analysis. Blood was concurrently harvested for serum and hematopoietic progenitor cell population analysis. Results: IR to an ischemic flap augmented the angiogenic cytokines SDF-1 and VEGF. Serum MMP-9 and s-kit levels, which are critical for progenitor cell mobilization, were also increased. When hematopoietic progenitor cells were evaluated by Sca1+/Flk1+ cells, a correlate 2-fold increase was seen compared to controls. When the flaps were examined, both vascularity and perfusion were increased. Conclusion: In this study we demonstrate that local, low-dose IR upregulates angiogenic chemokines and results in progenitor cell mobilization to the systemic circulation. There is a resultant increase in the vascularity of the irradiated flap, suggesting that the pro-angiogenic effects of IR can be harnessed locally.
Microvascular Endothelial Cell Responses in vitro and in vivo: Modulation by Zoledronic Acid and Paclitaxel?
Authors: Michailidou Maria , Brown Hannah K. , Lefley Diane V. , Evans Alyson , Cross Simon S. , Coleman Robert E. , Brown Nicola J. , Holen Ingunn
Published: April 2010

Background/Aims: The cytotoxic agent paclitaxel and the anti-resorptive drug zoledronic acid are used in the early and advanced breast cancer setting, respectively. Both agents have been demonstrated to have anti-tumour and anti-endothelial actions. Combining paclitaxel with zoledronic acid induces a synergistic increase in apoptotic breast cancer cell death in vitro, suggesting an increased anti-tumour effect in vivo, but any specific effects on the normal microvasculature and potential side-effects of this combination remain to be established. Methods: The effects of zoledronic acid and paclitaxel were investigated, alone and in combination, on human microvascular endothelial cells in vitro, using functional assays including proliferation, migration, tubule formation and apoptosis. The in vivo effect of the drugs on the normal microvasculature was determined using the dorsal microcirculation chamber model. Results/Conclusion: Zoledronic acid reduced human dermal microvascular endothelial cell (HuDMEC) proliferation, caused accumulation of cells in S phase, and inhibited migration, tube formation and Rap1a prenylation. Paclitaxel significantly inhibited tube formation and proliferation, and increased endothelial necrosis; the combination induced HuDMEC apoptosis and further enhanced the inhibition of tube formation and migration. The combination caused minimal effects on the normal microvasculature in vivo, suggesting that this potential therapeutic strategy is not associated with deleterious microvascular side-effects.
Short Homologous Peptides Based on C-Terminal Sequences of Fibrinogen β- and γ-Chains (Haptides) Affect Cardiovascular Function by eNOS Inhibition
Authors: Basheer Maamoun , Schwalb Herzl , Gilon Dan , Doviner Victoria , Sherman Yoav , Shapira Oz M. , Gorodetsky Raphael
Published: April 2010

Haptides are a family of 19–21-mer cell-binding and permeating peptides homologous to sequences in the C termini on both fibrinogen β- and γ-chain (Cβ and preCγ, respectively). The effect of the Haptides on the cardiovascular system was studied by different assays, including the activity of isolated perfused rat heart and blood vessels in the organ bath. Haptides (50–80 µg/ml) decreased the hemodynamic functions of perfused rat hearts by up to 60% (p < 0.05) in a dose-dependent manner. Whole fibrinogen or a control nonrelated peptide (Cα) did not show such an effect. The NO donor, sodium nitroprusside, reversed the inhibitory effects of Haptides. L-NAME, an endothelial nitric oxide synthase (eNOS) inhibitor, did not further augment the effect of the Haptides. Perfused FITCHaptides were attached to the coronary endothelium. In myocardial homogenates and HUVEC, Haptides significantly decreased eNOS activity, but had no effect on the contraction of isolated cultured adult cardiomyocytes. Haptides also significantly enhanced the contraction of rings of rat aorta and human mammary artery vessels ex vivo only when the endothelium was intact. Haptides seem to affect the coronary endothelium, but not the cardiomyocytes, by inhibiting eNOS activity, causing vasoconstriction, temporary ischemia and impaired myocardial function that seem to be related to the amino acid composition of the Haptides.
Oxidized Low-Density Lipoprotein Induces Apoptosis in Endothelial Progenitor Cells by Inactivating the Phosphoinositide 3-Kinase/Akt Pathway
Authors: Tie Guodong , Yan Jinglian , Yang Yagai , Park Brian D. , Messina Julia A. , Raffai Robert L. , Nowicki Philip T. , Messina Louis M.
Published: April 2010

We tested the hypothesis that oxidized low-density lipoprotein (oxLDL)-induced inactivation of Akt within endothelial progenitor cells (EPCs) is mediated at the level of Phosphoinositide 3-kinase (PI3K), specifically by nitrosylation of the p85 subunit of PI3K, and that this action is critical in provoking oxLDL-induced EPC apoptosis. Hypercholesterolemic ApoE null mice had a significant reduction of the phosphorylated Akt (p-Akt)/Akt ratio in EPCs, as well as a greater percentage of apoptosis in these cells than EPCs isolated from wild-type (WT) C57Bl/6 mice. EPCs were isolated from WT spleen and exposed to oxLDL in vitro. oxLDL increased O2– and H2O2 in these cells and induced a dose- and time-dependent reduction in the p-Akt/Akt ratio and increase in EPC apoptosis. These effects were significantly reduced by the antioxidants superoxide dismutase, L-NAME, epicatechin and FeTPPs. oxLDL also induced nitrosylation of the p85 subunit of PI3K and subsequent dissociation of the p85 and p110 subunits, an effect significantly reduced by all the antioxidant agents tested. EPC transfection with a constitutively active Akt isoform (Ad-myrAkt) significantly reduced oxLDL-induced apoptosis of WT EPCs. The present findings indicate that oxLDL disrupts the PI3K/Akt signaling pathway at the level of p85 in EPCs. This dysfunction can be reversed by ex vivo antioxidant therapy.
High-Resolution Transcriptional Profiling of Chemical-Stimulated Dendritic Cells Identifies Immunogenic Contact Allergens, but Not Prohaptens
Authors: Ott H. , Wiederholt T. , Andresen Bergström M. , Heise R. , Skazik C. , Czaja K. , Marquardt Y. , Karlberg A.-T. , Merk H.-F. , Baron J.M.
Published: April 2010

Allergic contact dermatitis is a complex syndrome and knowledge about the in vitro detection of small-molecular-weight compounds, particularly prohaptens, is limited. Therefore, we investigated chemical-induced gene expression changes in human antigen-presenting cells upon stimulation with immunogenic contact allergens, prohaptens and irritants. Monocyte-derived dendritic cells (moDCs) and THP-1 cells were stimulated with the prohapten cinnamic alcohol (CAlc), the hapten cinnamic aldehyde (CAld), an irritant and an obligatory sensitizer in vitro. Whole-genome screening and consecutive PCR analysis of differential gene expression in moDCs stimulated with either CAld or the obligatory sensitizer revealed coregulation of 11 marker genes which were related to immunological reactions (IL-8, CD1e, CD200R1, PLA2G5, TNFRSF11A), oxidative or metabolic stress responses (AKR1C3, SLC7A11, GCLM) or other processes (DPYLS3, TFPI, TRIM16). In contrast, the prohapten CAlc and the irritant did not change marker gene expression. In THP-1 cells, CAld and the positive control elicited similar expression changes in only 4 of the previously identified genes (IL-8, TRIM16, CD200R1, GCLM). In conclusion, we provide important insights into the pathophysiological basis of allergic contact dermatitis, identify marker genes suitable for skin hazard assessment and demonstrate that contact-allergenic prohaptens escape in in vitro detection if their skin metabolism is not taken into account.
Gene-Specific Epigenetic Regulation in Serious Infections with Systemic Inflammation
Authors: McCall Charles E. , Yoza Barbara , Liu Tiefu , El Gazzar Mohamed
Published: April 2010

Inflammation is a fundamental biologic process that is evolutionally conserved by a germ line code. The interplay between epigenetics and environment directs the code into temporally distinct inflammatory responses, which can be acute or chronic. Here, we discuss the epigenetic processes of innate immune cells during serious infections with systemic inflammation in four stages: homeostasis, incitement, evolution, and resolution. We describe feed-forward loops of serious infections with systemic inflammation that create gene-specific silent facultative heterochromatin and active euchromatin according to gene function, and speculate on the role of epigenetics in survival.
Enhanced Abdominal Aortic Aneurysm Formation in Thrombin-Activatable Procarboxypeptidase B–Deficient Mice
Authors: Schultz Geoffrey , Tedesco Maureen M. , Sho Eiketsu , Nishimura Toshihiko , Sharif Shadi , Du Xiaoyan , Myles Timothy , Morser John , Dalman Ronald L. , Leung Lawrence L.K.
Published: April 2010

Objective—

To determine whether procarboxypeptidase B (pCPB)
−/−
mice are susceptible to accelerated abdominal aortic aneurysm (AAA) development secondary to unregulated OPN-mediated mural inflammation in the absence of CPB inhibition.

Methods and Results—

Thrombin/thrombomodulin cleaves thrombin-activatable pCPB or thrombin-activatable fibrinolysis inhibitor, activating CPB, which inhibits the generation of plasmin and inactivates proinflammatory mediators (complement C5a and thrombin-cleaved osteopontin [OPN]). Apolipoprotein E
−/−
OPN
−/−
mice are protected from experimental AAA formation. Murine AAAs were created via intra-aortic porcine pancreatic elastase (PPE) infusion. Increased mortality secondary to AAA rupture was observed in pCPB
−/−
mice at the standard PPE dose. At reduced doses of PPE, pCPB
−/−
mice developed larger AAAs than wild-type controls (1.01±0.27 versus 0.68±0.05 mm;
P
=0.02 [mean±SD]). C5
−/−
and OPN
−/−
mice were not protected against AAA development. Treatment with tranexamic acid inhibited plasmin generation and abrogated enhanced AAA progression in pCPB
−/−
mice.

Conclusion—

This study establishes the role of CPB in experimental AAA disease, indicating that CPB has a broad anti-inflammatory role in vivo. Enhanced AAA formation in the PPE model is the result of increased plasmin generation, not unregulated C5a- or OPN-mediated mural inflammation.
Derivation of Endothelial Cells From Human Embryonic Stem Cells by Directed Differentiation
Authors: Kane Nicole M. , Meloni Marco , Spencer Helen L. , Craig Margaret A. , Strehl Raimund , Milligan Graeme , Houslay Miles D. , Mountford Joanne C. , Emanueli Costanza , Baker Andrew H.
Published: April 2010

Objective—To develop an embryoid body-free directed differentiation protocol for the rapid generation of functional vascular endothelial cells derived from human embryonic stem cells (hESCs) and to assess the system for microRNA regulation and angiogenesis.

Methods and Results—The production of defined cell lineages from hESCs is a critical requirement for evaluating their potential in regenerative medicine. We developed a feeder- and serum-free protocol. Directed endothelial differentiation of hESCs revealed rapid loss of pluripotency markers and progressive induction of mRNA and protein expression of vascular markers (including CD31 and vascular endothelial [VE]-cadherin) and angiogenic growth factors (including vascular endothelial growth factor), increased expression of angiogenesis-associated microRNAs (including miR-126 and miR-210), and induction of endothelial cell morphological features. In vitro, differentiated cells produced nitric oxide, migrated across a wound, and formed tubular structures in both the absence and the presence of 3D matrices (Matrigel). In vivo, we showed that cells that differentiated for 10 days before implantation were efficient at the induction of therapeutic neovascularization and that hESC-derived cells were incorporated into the blood-perfused vasculature of recipient mice.

Conclusion—The directed differentiation of hESCs is efficient and effective for the differentiation of functional endothelial cells from hESCs.
Endothelial Cell Adhesion to the Extracellular Matrix Induces c-Src–Dependent VEGFR-3 Phosphorylation Without the Activation of the Receptor Intrinsic Kinase Activity
Authors: Galvagni Federico , Pennacchini Susanna , Salameh Ahmad , Rocchigiani Marina , Neri Francesco , Orlandini Maurizio , Petraglia Felice , Gotta Stefano , Sardone Gian Luca , Matteucci Giacomo , Terstappen Georg C. , Oliviero Salvatore
Published: April 2010

Rationale
:

Integrins cooperate with growth factor receptors to promote downstream signaling for cell proliferation and migration. However, the mechanism of receptor activation is still unknown.

Objective
:

To analyze the mechanism of phosphorylation of the vascular endothelial growth factor receptor (VEGFR)-3 by cell adhesion.

Methods and Results
:

We show that VEGFR-3 phosphorylation, induced by cell attachment to the extracellular matrix, is independent from the intrinsic kinase activity of the receptor, as evidenced from phosphorylation cell adhesion experiments with a mutant kinase dead receptor or in the presence of the specific kinase inhibitor MAZ 51. Cell adhesion experiments in the presence of the c-Src inhibitor PP2 or in fibroblast triple knockout for c-Src, Yes, and Fyn (SYF) demonstrate that VEGFR-3 phosphorylation, induced by extracellular matrix, is mediated by c-Src. Kinase assays in vitro with recombinant c-Src show that VEGFR-3 is a direct c-Src target and mass spectrometry analysis identified the sites phosphorylated by c-Src as tyrosine 830, 833, 853, 1063, 1333, and 1337, demonstrating that integrin-mediated receptor phosphorylation induces a phosphorylation pattern that is distinct from that induced by growth factors. Furthermore, pull-down assays show that integrin-mediated VEGFR-3 phosphorylation activates the recruitment to the receptor of the adaptor proteins CRKI/II and SHC inducing activation of JNK.

Conclusions
:

These data suggest that cell adhesion to extracellular matrix induces a downstream signaling using the tyrosine kinase receptor VEGFR-3 as scaffold.
Differential Regulation of Vascular Tone and Remodeling via Stimulation of Type 2 and Type 6 Adenylyl Cyclases in the Ductus Arteriosus
Authors: Yokoyama Utako , Minamisawa Susumu , Katayama Ayako , Tang Tong , Suzuki Sayaka , Iwatsubo Kousaku , Iwasaki Shiho , Kurotani Reiko , Okumura Satoshi , Sato Motohiko , Yokota Shumpei , Hammond H. Kirk , Ishikawa Yoshihiro
Published: April 2010

Rationale:Prostaglandin (PG)E2, which increases intracellular cAMP via activation of adenylyl cyclases (ACs), induces vasodilation and hyaluronan-mediated intimal thickening (IT) in the ductus arteriosus (DA) during late gestation. After birth, however, differential regulation of vasodilation and IT is preferable for treatment of patients with patent DA and DA-dependent congenital cardiac malformations.

Objective:Our objectives were to examine whether AC isoforms play differential roles in DA vasodilation and IT.

Methods and Results:AC2 and AC6 were more highly expressed in rat DA than in the aorta during the perinatal period. AC6-targeted siRNA counteracted PGE1-induced hyaluronan production in rat DA smooth muscle cells. Overexpression of AC6 enhanced PGE1-induced hyaluronan production and induced IT in DA explants. Furthermore, IT of the DA was less marked in mice lacking AC6 than in wild-type and AC5-deficient mice. Stimulation of AC2 attenuated AC6-induced hyaluronan production via inhibition of the p38 mitogen-activated protein kinase pathway and AC6-induced IT of the DA. An AC2/6 activator, 6-[N-(2-isothiocyanatoethyl) aminocarbonyl] forskolin (FD1), did not induce hyaluronan-mediated IT in DA explants, although an AC5/6 activator, 6-[3-(dimethylamino)propionyl]-14,15-dihydroforskolin (FD6) did. Moreover, FD1 induced longer vasodilation of the DA than did PGE1without significant adverse effects in vivo.

Conclusions:AC6 is responsible for hyaluronan-mediated IT of the DA and AC2 inhibited AC6-induced hyaluronan production. Stimulation of both AC2 and AC6 by FD1 induced longer vasodilation without hyaluronan-mediated IT in the DA in vivo. FD1 may be a novel alternative therapy to currently available PGE therapy for patients with DA-dependent congenital heart disease.
ABCA1 and ABCG1 Protect Against Oxidative Stress–Induced Macrophage Apoptosis During Efferocytosis
Authors: Yvan-Charvet Laurent , Pagler Tamara A. , Seimon Tracie A. , Thorp Edward , Welch Carrie L. , Witztum Joseph L. , Tabas Ira , Tall Alan R.
Published: April 2010

Rationale
:

Antiatherogenic effects of plasma high-density lipoprotein (HDL) include the ability to inhibit apoptosis of macrophage foam cells. The ATP-binding cassette transporters ABCA1 and ABCG1 have a major role in promoting cholesterol efflux from macrophages to apolipoprotein A-1 and HDL and are upregulated during the phagocytosis of apoptotic cells (efferocytosis).

Objective
:

The goal of this study was to determine the roles of ABCA1 and ABCG1 in preserving the viability of macrophages during efferocytosis.

Methods and Results
:

We show that despite similar clearance of apoptotic cells, peritoneal macrophages from
Abca1
−/−
Abcg1
−/−
,
Abcg1
−/−
, and, to a lesser extent,
Abca1
−/−
mice are much more prone to apoptosis during efferocytosis compared to wild-type cells. Similar findings were observed following incubations with oxidized phospholipids, and the ability of HDL to protect against oxidized phospholipid-induced apoptosis was markedly reduced in
Abca1
−/−
Abcg1
−/−
and
Abcg1
−/−
cells. These effects were independent of any role of ABCA1 and ABCG1 in mediating oxidized phospholipid efflux but were reversed by cyclodextrin-mediated cholesterol efflux. The apoptotic response observed in
Abca1
−/−
Abcg1
−/−
macrophages after oxidized phospholipid exposure or engulfment of apoptotic cells was dependent on an excessive oxidative burst secondary to enhanced assembly of NADPH oxidase (NOX)2 complexes, leading to sustained Jnk activation which turned on the apoptotic cell death program. Increased NOX2 assembly required Toll-like receptors 2/4 and MyD88 signaling, which are known to be enhanced in transporter deficient cells in a lipid raft–dependent fashion.

Conclusions
:

We identified a new beneficial role of ABCA1, ABCG1 and HDL in dampening the oxidative burst and preserving viability of macrophages following exposure to oxidized phospholipids and/or apoptotic cells.
Prevalence of Asymptomatic Carotid Artery Stenosis in the General Population
Authors: de Weerd Marjolein , Greving Jacoba P. , Hedblad Bo , Lorenz Matthias W. , Mathiesen Ellisiv B. , O'Leary Daniel H. , Rosvall Maria , Sitzer Matthias , Buskens Erik , Bots Michiel L.
Published: April 2010

Background and Purpose—

In the discussion on the cost-effectiveness of screening, precise estimates of severe asymptomatic carotid stenosis are vital. Accordingly, we assessed the prevalence of moderate and severe asymptomatic carotid stenosis by age and sex using pooled cohort data.

Methods—

We performed an individual participant data meta-analysis (23 706 participants) of 4 population-based studies (Malmö Diet and Cancer Study, Tromsø, Carotid Atherosclerosis Progression Study, and Cardiovascular Health Study). Outcomes of interest were asymptomatic moderate (≥50%) and severe carotid stenosis (≥70%).

Results—

Prevalence of moderate asymptomatic carotid stenosis ranged from 0.2% (95% CI, 0.0% to 0.4%) in men aged <50 years to 7.5% (5.2% to 10.5%) in men aged ≥80 years. For women, this prevalence increased from 0% (0% to 0.2%) to 5.0% (3.1% to 7.5%). Prevalence of severe asymptomatic carotid stenosis ranged from 0.1% (0.0% to 0.3%) in men aged <50 years to 3.1% (1.7% to 5.3%) in men aged ≥80. For women, this prevalence increased from 0% (0.0% to 0.2%) to 0.9% (0.3% to 2.4%).

Conclusions—

The prevalence of severe asymptomatic carotid stenosis in the general population ranges from 0% to 3.1%, which is useful information in the discussion on the cost-effectiveness of screening.
Cooperation and Community Structure in Artificial Ecosystems
Authors: Lindgren Kristian , Nordahl Mats G.
Published: April 2010

We review results on the evolution of cooperation based on the iterated Prisoner's Dilemma. Coevolution of strategies is discussed both in situations where everyone plays against everyone, and for spatial games. Simple artificial ecologies are constructed by incorporating an explicit resource flow and predatory interactions into models of coevolving strategies. Properties of food webs are reviewed, and we discuss what artificial ecologies can teach us about community structure.