bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrathymic injection of lentiviral vector curtails the immune response in the periphery of normal mice
Authors: Gottrand Gaëlle , Taleb Kahina , Ragon Isabelle , Bergot Anne‐Sophie , Goldstein Jérémie D. , Marodon Gilles
Published: January 2012

Background

Gene transfer in the thymus, based on HIV‐derived lentiviral vectors, is a promising avenue for modulation of T cell selection and autoimmunity. However, the impact of intrathymic (IT) injections on an antigen‐specific immune response elicited in the periphery of normal mice has not been investigated yet.

Methods

Highly concentrated stocks of lentiviral vectors expressing the soluble form of hemaglutinin of the influenza virus (LvHA) were injected in the thymus of normal BALB/c mice. The CD4 and CD8‐mediated immune responses to HA after peripheral immunization were measured by various parameters.

Results

We first show that a lentiviral vector expressing the luciferase was detected for at least 2 months after IT‐injections. We then show that the LvHA vector could elicit a functional CD4‐ and CD8‐T cell‐mediated immune responses in the peripheral lymphoid organs of BALB/c mice. IT‐injection of the LvHA vector significantly curbed this response: lower numbers of transferred HA‐specific CD4+ T cells were found in LvHA‐injected compared to control animals. Furthermore, lower frequencies of HA‐specific CD8+ T cells, interferon γ‐producing cells and cytotoxic cells were detected from 3 weeks to 3 months in LvHA‐injected mice compared to controls. However, these reduced CD8‐mediated responses were not increased after depletion of CD25+ cells in vitro or in vivo.

Conclusions

The results obtained in the present study show that injection of the LvHA lentiviral vector significantly curtailed the immune response to the same antigen in the periphery. Increased selection of HA‐specific regulatory T cells and negative selection of HA‐specific CD8+ T cell precursors may explain the results. Our work establish the feasibility of IT‐injections of lentiviral vectors to manipulate T cell tolerance in the thymus of normal mice, for basic and pre‐clinical research. Copyright © 2012 John Wiley & Sons, Ltd.
Model order reduction of coupled circuit‐device systems
Authors: Hinze Michael , Kunkel Martin , Steinbrecher Andreas , Stykel Tatjana
Published: January 2012

We consider model order reduction of integrated circuits with semiconductor devices. Such circuits are modeled using modified nodal analysis by differential‐algebraic equations coupled with the nonlinear drift‐diffusion equations. A spatial discretization of these equations with a mixed finite element method yields a high dimensional nonlinear system of differential‐algebraic equations. Balancing‐related model reduction is used to reduce the dimension of the decoupled linear network equations, whereas the semidiscretized semiconductor model is reduced using proper orthogonal decomposition. Because the computational complexity of the reduced‐order model through the nonlinearity of the drift‐diffusion equations still depends on the number of variables of the full model, we apply the discrete empirical interpolation method to further reduce the computational complexity. We provide numerical comparisons that demonstrate the performance of the presented model reduction approach. Copyright © 2012 John Wiley & Sons, Ltd.
No correlation of substantia nigra echogenicity and nigrostriatal degradation in Parkinson's disease
Authors: Lobsien Elmar , Schreiner Simon , Plotkin Michail , Kupsch Andreas , Schreiber Stephan J. , Doepp Florian
Published: January 2012

Background:

Substantia nigra hyperechogenicity assessed by transcranial sonography is a typical finding in up to 90% of patients with idiopathic Parkinson's disease, although its value as a surrogate marker for disease progression in Parkinson's disease is controversial. 123I‐FP‐CIT–single photon emission computed tomography (SPECT) represents an established paraclinical surrogate marker to quantify the nigrostriatal dopaminergic deficit in Parkinson's disease. Whereas most studies found no correlation between extent of substantia nigra echogenicity and the putaminal FP‐CIT binding ratio, a more recent analysis reported opposite results.

Methods:

In 92 patients with Parkinson's disease the substantia nigra echogenicity was compared with the putaminal FP‐CIT binding ratio using an investigator‐independent SPECT analysis protocol and with several clinical parameters.

Results:

No correlation was found between the substantia nigra hyperechogenicity and the FP‐CIT binding ratio or the disease severity.

Conclusions:

Substantia nigra hyperechogenicity does not reflect the degree of the nigrostriatal degeneration or the clinical state of the disease progression. © 2012 Movement Disorder Society
Perioperative Assessment of Patients With Cardiac Implantable Electronic Devices
Authors: Castillo Javier G. , Silvay George , Viles‐González Juan
Published: January 2012

Worldwide, nearly 4 million patients currently have cardiac implantable electronic devices. Due to the increasing number of candidates to receive either pacemakers or implantable cardiac defibrillators, there is no doubt that primary care physicians or anesthesiologists are very likely to interact and deal with this particular patient population. However, besides technologic advancements, several factors have been frequently reported to cause confusion regarding their perioperative care. Therefore, it has become extremely valuable to understand the basic functions and operation of these devices, as well as their functional limitations, to prevent iatrogenic complications and detect potential failure in an early stage. Mt Sinai J Med 79:25–33, 2012. © 2012 Mount Sinai School of Medicine
Role of Simulation in US Physician Licensure and Certification
Authors: Levine Adam I. , Schwartz Andrew D. , Bryson Ethan O. , DeMaria Jr Samuel
Published: January 2012

The evolution of simulation from an educational tool to an emerging evaluative tool has been rapid. Physician certification has a long history and serves an important role in assuring that practicing physicians are competent and capable of providing a high level of safe care to patients. Traditional assessment methods have relied mostly on multiple‐choice exams or continuing medical education exercises. These methods may not be adequate to assess all competencies necessary for excellence in medical practice. Simulation enables assessment of physician competencies in real time and represents the next step in physician certification in the modern age of healthcare. Mt Sinai J Med 79:140–153, 2012. © 2012 Mount Sinai School of Medicine
Value of Specialized Preanesthetic Clinic for Cardiac and Major Vascular Surgery Patients
Authors: Flynn Brigid C. , Silvay George
Published: January 2012

In a complicated and specialized population, such as patients undergoing cardiac and major vascular procedures, patients, clinicians, and hospitals may be best served and resources conserved with a specialized preanesthesia clinic. A specialized preanesthesia clinic for cardiac and major vascular procedures has a focused staff usually consisting of practitioners with cardiac and major vascular surgical care experience designed to address the patient evaluation, the information gathering, the necessary consultations, the required testing, and specific needs for the day of cardiac and major vascular surgery. Specialized preanesthesia clinics increase patient satisfaction and may also provide cost containment by decreasing the amount of indiscriminate ordering of expensive preoperative tests and potentially may decrease patient litigation. Resident trainee education can also be enhanced by a specialized preanesthesia clinic for cardiac and major vascular rotations. The ultimate goal of a specialized preanesthesia clinic is to ensure a safe and efficient perioperative cardiac and major vascular surgical experience in complicated patients undergoing complex procedures. Mt Sinai J Med 79:13–24, 2012. © 2012 Mount Sinai School of Medicine
Transfusion medicine problems and solutions for the pediatric hematologist/oncologist
Authors: Luban Naomi L.C. , McBride Eileen , Ford Jason C. , Gupta Sumit
Published: January 2012

Blood component transfusion is an integral part of the care of children with oncologic and hematologic conditions. The complexity of transfusion medicine may however lead to challenges for pediatric hematologists/oncologists. In this review, three commonly encountered areas of transfusion medicine are explored. The approach to the investigation and management of suspected platelet refractoriness is reviewed. The unique transfusion related challenges encountered by children undergoing stem cell transplantation are also discussed. Finally, issues arising out of the care of children with hemoglobinopathies are explored, with an emphasis on the incidence of allo‐ and autoimmunization. Pediatr Blood Cancer 2012; 58: 1106–1111. © 2012 Wiley Periodicals, Inc.
Barriers to and facilitators of treatment engagement for clients with personality disorder: a Delphi survey
Authors: Tetley Amanda , Jinks Mary , Huband Nick , Howells Kevin , McMurran Mary
Published: January 2012

Clients with personality disorder (PD) can encounter difficulties engaging in psychosocial therapy. One way to address this is to identify the factors that contribute to their low engagement. The Multifactor Offender Readiness Model (MORM), a model developed to explain poor treatment engagement in offenders, might guide the identification of engagement difficulties in clients with PD. In this study, we sought to validate and extend the MORM for clients with PD by identifying the perceived barriers to and facilitators of their engagement. A two‐round Delphi Survey was employed to identify clients' and clinicians' levels of agreement on the factors that impair and promote engagement. Seventy‐six clients and 55 clinicians were recruited from English specialist forensic and non‐forensic personality disorder services. Our findings reveal that the perceived barriers to engagement for those with PD are in the most part congruent with the impediments outlined in the MORM. However, we do find some additional barriers relevant specifically to people with PD. A Treatment Readiness Model for Personality Disorder (TReMoPeD), which is an augmented version of the MORM, is presented. This model provides guidance for ways of taking action to improve a client's chance of engaging with services. Copyright © 2012 John Wiley & Sons, Ltd.
The chaperone activity of α‐synuclein: Utilizing deletion mutants to map its interaction with target proteins
Authors: Rekas Agata , Ahn Keun Jae , Kim Jongsun , Carver John A.
Published: January 2012

α‐Synuclein is the principal component of the Lewy body deposits that are characteristic of Parkinson's disease.In vivo, and under physiological conditionsin vitro, α‐synuclein aggregates to form amyloid fibrils, a process that is likely to be associated with the development of Parkinson's disease. α‐Synuclein also possesses chaperone activity to prevent the precipitation of amorphously aggregating target proteins, as demonstratedin vitro. α‐Synuclein is an intrinsically disordered (i.e., unstructured) protein of 140 amino acids in length, and therefore studies on its fragments can be correlated directly to the functional role of these regions in the intact protein. In this study, the fragment containing residues 61–140 [α‐syn(61–140)] was observed to be highly amyloidogenic and was as effective a chaperonein vitroas the full‐length protein, while the N‐ and C‐terminal fragments α‐syn(1–60) and α‐syn(96–140) had no intrinsic chaperone activity. Interestingly, full‐length fibrillar α‐synuclein had greater chaperone activity than nonfibrillar α‐synuclein. It is concluded that the amyloidogenic NAC region (residues 61–95) contains the chaperone‐binding site which is optimized for target protein binding as a result of its β‐sheet formation and/or ordered aggregation by α‐synuclein. On the other hand, the first 60 residues of α‐synuclein modulate the protein's chaperone‐active site, while at the same time protecting α‐synuclein from fibrillation. On its own, however, this fragment [α‐syn(1–60)] had a tendency to aggregate amorphously. As a result of this study, the functional roles of the various regions of α‐synuclein in its chaperone activity have been delineated. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Characterization of Temporary Metabolic Changes Following Cantonese Herbal Tea Intervention
Authors: You Rong , Xu Zhenbo , Hu Songqing , Li Lin
Published: January 2012

Cantonese herbal tea (CHT) has been consumed in South China to alleviate feelings of discomfort due to the heat and humidity in the body according to the theory of traditional Chinese medicine (TCM). To understand the in vivo mechanism of CHT, a 1H‐NMR‐based metabonomic approach was used to investigate the global biological characterization of rat serum following the intake of CHT and to understand the mechanisms of action of CHT. Serum samples from rats with consecutive CHT intake after 10, 20 and 30 days and corresponding control rats were analysed by high‐resolution 1H‐NMR spectroscopy. Principal component analysis (PCA) and orthogonal projection on latent structures discriminant analysis (OPLS‐DA) were utilized for 1H‐NMR spectra analysis and temporal metabolic changes identification. For the 10‐day CHT intake group, no significant metabolic response was detected, whereas the 20‐day group showed elevation of glucogeneogenesis and a shift in energy metabolism from carbohydrate metabolism to lipid metabolism. In addition, a notable decrease in pyruvate content with a consistent increase in lactate content, and significant decrease in both lipoprotein and glucose contents was observed for the 30‐day group, indicating potential metabolic dysfunction. The metabonomics technique combining metabolic profiles with multivariate analysis enhanced our current understanding of the host's metabolic response to CHT intake. Copyright © 2012 John Wiley & Sons, Ltd.
Chronic Cyanidin‐3‐glucoside Administration Improves Short‐term Spatial Recognition Memory but not Passive Avoidance Learning and Memory in Streptozotocin‐diabetic Rats
Authors: Nasri Sima , Roghani Mehrdad , Baluchnejadmojarad Tourandokht , Balvardi Mahboubeh , Rabani Tahereh
Published: January 2012

This research study was conducted to evaluate the efficacy of chronic cyanidin‐3‐glucoside (C3G) on alleviation of learning and memory deficits in diabetic rats as a result of the observed antidiabetic and antioxidant activity of C3G. Male Wistar rats were divided into control, diabetic, C3G‐treated‐control and ‐diabetic groups. The C3G was administered i.p. at a dose of 10 mg/kg on alternate days for eight weeks. For evaluation of learning and memory, initial latency (IL) and step‐through latency (STL) were determined at the end of study using passive avoidance test. Meanwhile, spatial recognition memory was assessed as alternation in the Y‐maze task. Oxidative stress markers in brain tissue were also measured. It was found that the alternation score of the diabetic rats was lower than that of control (p < 0.01) and C3G‐treated diabetic rats showed a higher alternation score as compared to diabetic group (p < 0.05). Diabetic rats also developed a significant impairment in retention and recall in passive avoidance test (p < 0.01) and C3G treatment of diabetic rats did not produce any significant improvement. Meanwhile, increased level of malondialdehyde (MDA) in diabetic rats was significantly reduced following C3G treatment (p < 0.05). Taken together, chronic C3G could improve short‐term spatial recognition memory disturbance in the Y‐maze test but not retention and recall capability in passive avoidance test in STZ‐diabetic rats. Copyright © 2012 John Wiley & Sons, Ltd.
The Effects of Rooibos (Aspalathus linearis), Green Tea (Camellia sinensis) and Commercial Rooibos and Green Tea Supplements on Epididymal Sperm in Oxidative Stress‐induced Rats
Authors: Awoniyi Dolapo Olaitan , Aboua Yapo Guillaume , Marnewick Jeanine , Brooks Nicole
Published: January 2012

Reactive oxygen species (ROS) are involved in many physiological functions of mammalian sperm. Numerous endogenous antioxidants belonging to both enzymatic and non‐enzymatic groups can remove excess ROS and prevent oxidative stress (OS). This study compares the modulation of OS by rooibos, Chinese green tea and commercial rooibos and green tea supplements in rat sperm. Male Wistar rats (n = 60) were supplemented with fermented rooibos, ‘green’ rooibos, Chinese green tea, rooibos supplement, green tea supplement or water for 10 weeks while OS was induced during the last 2 weeks. Sperm count and motility were significantly higher for rats consuming fermented rooibos and ‘green’ rooibos when compared with the other groups. Catalase activity was significantly higher in the sperm of rats consuming fermented rooibos, ‘green’ rooibos and both the rooibos and green tea supplements. Superoxide dismutase concentration in the sperm of rats supplemented with fermented rooibos, ‘green’ rooibos and green tea was higher. Sperm glutathione levels of rats consuming the fermented and ‘green’ rooibos were also significantly higher. Rooibos fermented and ‘green’ rooibos showed a tendency to lower the levels of ROS and lipid peroxidation when compared with the control group. In conclusion, both rooibos extracts could offer a measure of protection against induced oxidative damage by increasing the antioxidant defence mechanisms and thereby improving the sperm quality and function. Copyright © 2012 John Wiley & Sons, Ltd.
The basic theory, diagnostic, and therapeutic system of traditional Chinese medicine and the challenges they bring to statistics
Authors: Hu Jingqing , Liu Baoyan
Published: January 2012

Traditional Chinese medicine (TCM) has an unique theory system and abundant preventative and therapeutic methods. In recent years, TCM has gradually become the hot topic of application and research around the world. This paper introduces how TCM uses the theory of yin‐yang and five‐phase to explain the mechanism of balancing the function of human body, the methods of diagnosing, abundant therapeutic methods and technologies, and treating principles, analyzes the features of TCM, and points out some of the problems waitiing to be solved in TCM scientific researches and statistical analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Restricted mean models for transplant benefit and urgency
Authors: Xiang Fang , Murray Susan
Published: January 2012

The US lung allocation policy estimates each individual's urgency and transplant benefit in defining a lung allocation score (LAS). Transplant benefit, as defined by the Organ Procurement and Transplantation Network Thoracic Committee, is the days of life gained over the following year if transplanted versus not transplanted. Urgency is measured by days of life during the next year without transplant. In both definitions, accurate estimation of wait list days lived, or a wait list restricted mean lifetime, is required. Risk factors are available to estimate patient urgency when listed, with more urgent patients removed from the wait list upon death or transplant. As a patient progresses, priority for transplant (censoring) changes accordingly. Therefore, it is crucial to adjust for dependent censoring in modeling days of life. We develop a model for the restricted mean as a function of covariates, by using pseudo‐observations that account for dependent censoring linked to a series of longitudinal measures (LAS). Simulation results show that our method performs well in situations comparable with the LAS setting. Applying wait list and post‐transplant model results that account for dependent censoring to wait list patients, we obtain estimates of transplant benefit that are larger for many of the more urgent patients in need of transplant. The difference in LAS for an individual, when properly accounting for dependent censoring, has high impact on the priority and timing of an organ offer for these patients. Copyright © 2012 John Wiley & Sons, Ltd.
Bayesian approach to predicting cancer incidence for an area without cancer registration by using cancer incidence data from nearby areas
Authors: Clèries Ramon , Ribes Josepa , Buxo Maria , Ameijide Alberto , Marcos‐Gragera Rafael , Galceran Jaume , Martínez José Miguel , Yasui Yutaka
Published: January 2012

This paper compares three different methods for performing cancer incidence prediction in an area without a cancer registry under a Bayesian framework, using linear and log‐linear age‐period models with either age‐specific slopes or a common slope across age groups. The three methods assume that a nearby area with a cancer registration has similar incidence and mortality patterns as the area of interest without a cancer registry where the cancer incidence prediction is carried out. The three methods differ in modeling strategies: (i) modeling the incidence rate directly; (ii) modeling the ratio of the number of incident cases to that of mortality cases; and (iii) modeling the difference between the incidence rate and the mortality rate. Strategy (iii) is a new approach in this type of projection. Empirical assessment is made using real data from the cancer registry of Tarragona, Spain, to predict cancer incidence in Girona, Spain, and vice versa. Predictions of short‐term (3–4 years) incidence were made for 2001 in Tarragona using observed cancer incidence and mortality data for 1994–1998 from Girona. Short‐term predictions were made for 2002 in Girona using Tarragona's 1994–1998 data. Additionally, long‐term (10 years) incidence rate predictions were made for 2002 in Girona using data from Tarragona for the period 1985–1992. Our results suggest that extrapolating time‐trends of incidence rates minus mortality rates may have the best predictive performance overall. These methods of population‐level disease vincidence prediction are highly relevant to health care planning and policy decisions. Copyright © 2012 John Wiley & Sons, Ltd.
A Cell‐Delivered and Cell‐Activated SN38‐Dextran Prodrug Increases Survival in a Murine Disseminated Pancreatic Cancer Model
Authors: Basel Matthew T. , Balivada Sivasai , Shrestha Tej B. , Seo Gwi‐Moon , Pyle Marla M. , Tamura Masaaki , Bossmann Stefan H. , Troyer Deryl L.
Published: January 2012

Enzyme‐activated prodrugs have been investigated and sought after as highly specific, low‐side‐effect treatments, especially for cancer therapy. Unfortunately, excellent targets for enzyme‐activated therapy are rare. Here a system based on cell delivery that can carry both a prodrug and an activating enzyme to the cancer site is demonstrated. Raw264.7 cells (mouse monocyte/macrophage‐like cells, Mo/Ma) are engineered to express intracellular rabbit carboxylesterase (InCE), which is a potent activator of the prodrug irinotecan to SN38. InCE expression is regulated by the TetOn® system, which silences the gene unless a tetracycline, such as doxycycline, is present. Concurrently, an irinotecan‐like prodrug, which is conjugated to dextran and can be loaded into the cytoplasm of Mo/Ma, is synthesized. To test the system, a murine pancreatic cancer model is generated by intraperitoneal (i.p.) injection of Pan02 cells. Engineered Mo/Ma are loaded with the prodrug and are injected i.p. Two days later, doxycycline was given i.p. to activate InCE, which activated the prodrug. A survival study demonstrates that this system significantly increased survival in a murine pancreatic cancer model. Thus, for the first time, a prodrug/activating enzyme system, which is self‐contained within tumor‐homing cells and can prolong the life of i.p. pancreatic tumor bearing mice, is demonstrated.
P2X receptors in neuroglia
Authors: Verkhratsky Alexei , Pankratov Yuri , Lalo Ulyana , Nedergaard Maiken
Published: January 2012

Different types of ionotropic P2X purinoceptors are expressed in all major types of neuroglia, where they mediate a variety of physiological and pathological signaling. Cortical astrocytes express specific P2X1/5 heteromeric receptors that are activated by ongoing synaptic transmission and can trigger fast local signaling through elevation in cytoplasmic Ca2+ and Na+ concentrations. Oligodendrocytes express several types of P2X receptors that may control their development and mediate axonal–glial interactions. In microglia, P2X4 and P2X7 receptors regulate numerous events associated with microglial activation, motility, and release of proinflammatory factors. WIREs Membr Transp Signal 2012, 1:151–161. doi: 10.1002/wmts.12

For further resources related to this article, please visit the WIREs website.
P2X receptor‐mediated synaptic transmission
Authors: Lalo Ulyana , Verkhratsky Alexei , Burnstock Geoffrey , Pankratov Yuri
Published: January 2012

Activation of postsynaptic P2X receptors, which occur in many synapses in the central nervous system, following vesicular adenosine triphosphate (ATP) released from presynaptic terminals contributes to the fast excitatory neurotransmission. Postsynaptic P2X receptors mediate fast excitatory postsynaptic currents in synapses located in various brain regions, including medial habenula, hippocampus, and cortex. Synaptic stimulation of P2X receptors can trigger substantial Ca2+ entry and cytosolic Ca2+ signaling at the resting membrane potential due to a high Ca2+ permeability of P2X receptors. In addition, P2X receptors dynamically interact with N‐methyl D‐aspartate (NMDA) receptors, γ‐aminobutyric acid (GABA) receptors, and nicotinic acetylcholine (ACh) receptors. Activation of P2X receptors in the course of synaptic transmission has multiple modulatory effects on synaptic plasticity, either inhibiting or facilitating the long‐term changes of synaptic strength depending on physiological context. WIREs Membr Transp Signal 2012,1:297–309. doi: 10.1002/wmts.28

For further resources related to this article, please visit the WIREs website.
P2X7 receptors and epithelial cancers
Authors: Gorodeski George I.
Published: January 2012

The P2X7A receptor is the main physiological pro‐apoptotic mechanism in epithelia in vivo. The natural ligand of the P2X7A is ATP. The P2X7A is expressed abundantly in epithelial reserve (stem) cells, and it regulates epithelial‐cell terminal differentiation. The high expression of P2X7A in reserve cells renders the cells sensitive to conditions of increased extracellular ATP, in particular upon neoplastic transformation, and to the induction of apoptosis. Cellular expression of the P2X7A is reduced in cancer cells of epithelia derived from the ectoderm, the urogenital sinus, and the distal paramesonephric duct. Low levels of P2X7A have been linked to cancer development because reserve cells harboring a defective P2X7A mechanism can escape P2X7A pro‐apoptotic control. Mechanisms that induce reduced expression of P2X7A in cancer epithelial cells involve hypermethylation of the P2X7 gene and decreased transcription; enhanced degradation of the P2X7 transcript through the action of micro‐RNAs miR‐186 and miR‐150; and epidermal growth factor (EGF) regulated, protein kinase‐A (PKA)‐mediated de‐glycosylation of the P2X7A. Reduced cellular P2X7A content has been proposed as a biomarker for human breast, bladder, ectocervix, endocervix, and endometrial cancers. The chemotherapeutic potential of augmented P2X7A‐dependent apoptosis of neoplastic epithelial cells was recently demonstrated in the mouse in vivo. Local treatment on the skin with the P2X7A‐specific agonist benzoyl‐ATP (BzATP) decreased the development of 7,12‐dimethyl‐benz(a)anthracene (DMBA)/12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced skin papillomas and skin cancers by 50%, by an effect that involves augmentation of keratinocytes reserve cells apoptosis. The P2X7A mechanism represents a novel pharmaceutical target for the prevention and treatment of epithelial neoplasia through the induction of apoptosis. WIREs Membr Transp Signal 2012,1:349–371. doi: 10.1002/wmts.33

For further resources related to this article, please visit the WIREs website.
Effects of environmental factors upon variation in soil respiration of a Zoysia japonica grassland, central Japan
Authors: Inoue Tomoharu , Koizumi Hiroshi
Published: January 2012

The effects of environmental factors on seasonal and annual variations in soil respiration were examined in the cool temperate Zoysia japonica grassland of Japan. Field measurements of soil respiration were conducted using a closed chamber method with an infrared gas analyzer at monthly intervals in the snow‐free seasons from May 2007 to December 2009. There was an exponential relationship between soil respiration and soil temperature, and the soil temperature accounted for 85–86% of seasonal soil respiration variability. Moreover, a positive linear relationship between soil respiration and soil water content was detected in summer (R2 = 0.55, p < 0.001), but not in spring or autumn. Annual soil respiration was estimated at 755, 719, and 1,037 g C m−2 year−1 in 2007, 2008, and 2009, respectively. These interannual variations in soil respiration might be influenced by the strength of precipitation during rainy seasons and the timing of each snow‐melt. Our results suggest that the effects of rainfall and snow‐melt events on soil respiration might be important factors to understand carbon dynamics in grassland ecosystem in Japan.
Synthesis and Characterization of Anionic Polymeric Surfactants Based on Sulfonated Styrene
Authors: El Menam Eissa Abd , El Hefnawy Manal , Bader Samy , Radwan Mohamed , Deef Allah Mohamed
Published: January 2012

A novel series of three anionic polymeric surfactants was prepared by polymerization of sulfonated styrene and allyl esters of long chain fatty acid chlorides (decanoyl, lauroyl and palmitoyl chloride). The unique structural features of these surfactants were confirmed by different spectroscopic tools (IR and H‐NMR). The surface properties of these compounds such as surface tension, interfacial tension, emulsion stability, wetting power, foam height, solubilization and dispersant properties in disperse dye systems were determined and evaluated. A comparative study was done between the chemical structures and surface properties of these compounds. Biodegradability and stability to hydrolysis in acidic and alkaline medium were also determined and evaluated.
A Low‐Protein, High‐Carbohydrate Diet Increases Fatty Acid Uptake and Reduces Norepinephrine‐Induced Lipolysis in Rat Retroperitoneal White Adipose Tissue
Authors: dos Santos Maísa P. , de França Suélem A. , dos Santos José Tiago F. , Buzelle Samyra L. , Bertolini Gisele L. , Garófalo Maria Antonieta R. , do Kettelhut Isis C. , Frasson Danúbia , Chaves Valéria E. , Kawashita Nair H.
Published: January 2012

A low‐protein, high‐carbohydrate (LPHC) diet for 15 days increased the lipid content in the carcass and adipose tissues of rats. The aim of this work was to investigate the mechanisms of this lipid increase in the retroperitoneal white adipose tissue (RWAT) of these animals. The LPHC diet induced an approximately two‐ and tenfold increase in serum corticosterone and TNF‐α, respectively. The rate of de novo fatty acid (FA) synthesis in vivo was reduced (50%) in LPHC rats, and the lipoprotein lipase activity increased (100%). In addition, glycerokinase activity increased (60%), and the phosphoenolpyruvate carboxykinase content decreased (27%). Basal [U‐14C]‐glucose incorporation into glycerol‐triacylglycerol did not differ between the groups; however, in the presence of insulin, [U‐14C]‐glucose incorporation increased by 124% in adipocytes from only control rats. The reductions in IRS1 and AKT content as well as AKT phosphorylation in the RWAT from LPHC rats and the absence of an insulin response suggest that these adipocytes have reduced insulin sensitivity. The increase in NE turnover by 45% and the lack of a lipolytic response to NE in adipocytes from LPHC rats imply catecholamine resistance. The data reveal that the increase in fat storage in the RWAT of LPHC rats results from an increase in FA uptake from circulating lipoproteins and glycerol phosphorylation, which is accompanied by an impaired lipolysis that is activated by NE.
Inflammatory changes in adipose tissue enhance expression of GPR84, a medium‐chain fatty acid receptor
Authors: Nagasaki Hiroshi , Kondo Takaaki , Fuchigami Masahiro , Hashimoto Hiroyuki , Sugimura Yoshihisa , Ozaki Nobuaki , Arima Hiroshi , Ota Akira , Oiso Yutaka , Hamada Yoji
Published: January 2012

In this study we aimed to identify the physiological roles of G protein‐coupled receptor 84 (GPR84) in adipose tissue, together with medium‐chain fatty acids (MCFAs), the specific ligands for GPR84. In mice, high‐fat diet up‐regulated GPR84 expression in fat pads. In 3T3‐L1 adipocytes, co‐culture with a macrophage cell line, RAW264, or TNFα remarkably enhanced GPR84 expression. In the presence of TNFα, MCFAs down‐regulated adiponectin mRNA expression in 3T3‐L1 adipocytes. Taken together, our results suggest that GPR84 emerges in adipocytes in response to TNFα from infiltrating macrophages and exacerbates the vicious cycle between adiposity and diabesity.
Exploring the mechanism of lipid transfer during biosynthesis of the acidic lipopeptide antibiotic CDA
Authors: Kraas Femke I. , Giessen Tobias W. , Marahiel Mohamed A.
Published: January 2012

The non‐ribosomally synthesized lipodepsipeptide CDA belongs to the group of acidic lipopeptide antibiotics, whose members feature a fatty acid side chain that strongly affects their antimicrobial activity. This study elucidates the N‐acylation of the N‐terminal serine in the CDA peptide chain. This reaction is referred to as lipoinitiation and is shown to be catalyzed by the dissected starter C domain found at the N‐terminus of Cda‐PSI. The recombinantly produced C domain specifically interacts with 2,3‐epoxyhexanoyl‐S‐ACP and catalyzes the transfer of the fatty acid moiety onto the amino group of PCP‐bound serine with high selectivity for both carrier protein bound substrates at the donor and acceptor site.
Bismuth iodoform paraffin paste hypersensitivity reactions in mastoid cavities following isolation of mucosal lining: a series of 587 patients
Authors: Coulson C J , Pothier D D , Lai P , Rutka J A
Published: January 2012

Aim:

(1) To assess hypersensitivity to bismuth iodoform paraffin paste impregnated ribbon gauze following its use in packing canal wall down mastoidectomy cavities; (2) to determine if isolation of the skin and mucosa from the pack, using thin Silastic sheeting and Cortisporin ointment, reduces hypersensitivity reactions, compared with a previous series; and (3) to review the literature and to determine if bismuth iodoform paraffin paste hypersensitivity precludes the consumption of seafood (due to its high iodine content).

Materials and methods:

All patients undergoing canal wall down mastoidectomy with intra-operative bismuth iodoform paraffin paste packing between 1985 and 2009 were identified and reviewed.

Results:

Of 587 patients identified, the overall bismuth iodoform paraffin paste reaction rate was 1 per cent. All reactions were in patients undergoing revision mastoidectomy procedures, giving a reaction rate for revision procedures of 2.4 per cent.

Conclusion:

Reactions are an uncommon event following post-operative mastoid cavity packing using bismuth iodoform paraffin paste. Reaction rates may be lowered by preparing the cavity with Silastic sheeting and Cortisporin ointment prior to packing, thus isolating the skin and mucosal surfaces. Development of such a reaction does not preclude the consumption of seafood.
The Impact of Personality and Culture on the Job Demands-Control Model of Job Stress
Authors: Györkös Christina , Becker Jurgen , Massoudi Koorosh , de Bruin Gideon P. , Rossier Jérôme
Published: January 2012

Among the various work stress models, one of the most popular has been the job demands-control (JDC) model developed by Karasek (1979 ), which postulates that work-related strain is highest under work conditions characterized by high demands and low autonomy. The absence of social support at work further increases negative outcomes. This model, however, does not apply equally to all individuals and to all cultures. This review demonstrates how various individual characteristics, especially some personality dimensions, influence the JDC model and could thus be considered buffering or moderator factors. Moreover, we review how the cultural context impacts this model as suggested by results obtained in European, American, and Asian contexts. Yet there are almost no data from Africa or South America. More crosscultural studies including populations from these continents would be valuable for a better understanding of the impact of the cultural context on the JDC model.
Evaluation and improvements of two community models in simulating dry deposition velocities for peroxyacetyl nitrate (PAN) over a coniferous forest
Authors: Wu Zhiyong , Wang Xuemei , Turnipseed Andrew A. , Chen Fei , Zhang Leiming , Guenther Alex B. , Karl Thomas , Huey L. G. , Niyogi Dev , Xia Beicheng , Alapaty Kiran
Published: January 2012

Dry deposition velocities (Vd) for peroxyacetyl nitrate (PAN) calculated using two community dry deposition models with different treatments of both stomatal and nonstomatal uptakes were evaluated using measurements of PAN eddy covariance fluxes over a Loblolly pine forest in July 2003. The observed daytime maximum of Vd(PAN) was ∼1.0 cm s−1on average, while the estimates by the WRF‐Chem dry deposition module (WDDM) and the Noah land surface model coupled with a photosynthesis‐based Gas Exchange Model (Noah‐GEM) were only 0.2 cm s−1 and 0.6 cm s−1, respectively. The observations also showed considerable PAN deposition at night with typical Vd values of 0.2–0.6 cm s−1, while the estimated values from both models were less than 0.1 cm s−1. Noah‐GEM modeled more realistic stomatal resistance (Rs) than WDDM, as compared with observations of water vapor exchange fluxes. The poor performance of WDDM for stomatal uptake is mainly due to its lack of dependence on leaf area index. Thermal decomposition was found to be relatively unimportant for measured PAN fluxes as shown by the lack of a relationship between measured total surface conductance and temperature. Thus, a large part of the underprediction in Vd from both models should be caused by the underestimation of nonstomatal uptake, in particular, the cuticle uptake. Sensitivity tests on both stomatal and nonstomatal resistances terms were conducted and some recommendations were provided.
Ozone loss rates in the Arctic winter stratosphere during 1994–2000 derived from POAM II/III and ILAS observations: Implications for relationships among ozone loss, PSC occurrence, and temperature
Authors: Terao Yukio , Sugita Takafumi , Sasano Yasuhiro
Published: January 2012

Quantitative chemical ozone loss rates at the 475 K isentropic surface inside the Arctic polar vortex are evaluated for six winters (January through March) using a satellite‐based Match technique. Satellite observational data are taken from the Polar Ozone and Aerosol Measurement (POAM) II for 1994–1996, the Improved Limb Atmospheric Spectrometer (ILAS) for 1997, and the POAM III for 1999–2000. The largest ozone loss rates were observed in the end of January 1995 (∼50 ± 20 ppbv d−1), February 1996 (∼40–50 ± 15 ppbv d−1), February 1997 (∼40 ± 8 ppbv d−1), January 2000 (∼60 ± 30 ppbv d−1), and early March 2000 (∼40 ± 10 ppbv d−1). The probability of polar stratospheric cloud (PSC) existence is estimated using aerosol extinction coefficient data from POAM II/III and ILAS. Ozone loss and the PSC probability are strongly correlated and an absolute increase of 10% in the PSC probability is found to amplify the chemical ozone loss rate during Arctic winter by approximately 25 ± 6 ppbv per day or 3.2 ± 0.7 ppbv per sunlit hour. Relationships between average Arctic winter ozone loss rates and various PSC‐ and temperature‐related indices are investigated, including the area of polar vortex that is colder than the threshold temperature for PSC existence (APSC), the PSC formation potential (PFP), and the potential for activation of chlorine (PACl). Of these three, PACl provides the best proxy representation of interannual variability in Arctic ozone loss at the 475 K level. Large ozone loss occurred primarily for air masses that experienced low temperatures between 187 K and 195 K within the previous 10 days and the ozone loss rates clearly increase with decreasing the minimum temperature. The particularly large ozone losses of ∼9 ± 3 ppbv per sunlit hour in February 1996 and January 2000 were associated with low minimum temperatures of 187–189 K, simultaneously with high PSC probabilities.
Observation of atmospheric oxygen/nitrogen ratio aboard a cargo ship using gas chromatography/thermal conductivity detector
Authors: Yamagishi Hiroaki , Tohjima Yasunori , Mukai Hitoshi , Nojiri Yukihiro , Miyazaki Chihiro , Katsumata Keiichi
Published: January 2012

Measurements of atmospheric O2/N2 ratio and CO2 concentration have been used to analyze the −ΔO2/ΔCO2 ratio to obtain information on CO2 sources, e.g., anthropogenic or terrestrial biogenic sources (respiration or wildfire). In this study we report on the development of a shipboard system for measuring atmospheric O2/N2 ratio by using the gas chromatography/thermal conductivity detector (GC/TCD) technique. The standard error for a one hour average (N = 6) is found to be ± 5 per meg (±1 ppm). The shipboard measurements have been conducted since the end of September 2007 on the Voluntary Observing Ship TRANS FUTURE 5, a cargo ship sailing between Japan, Australia, and New Zealand every six weeks. Spatially, the observation covers latitudes between 41°S and 33°N over the western Pacific. Air masses with high CO2 concentration are observed along the coastline of Australia and New Zealand. In more than two thirds of the cases (17 of 23 events) detected between September 2007 and July 2009, values of the −ΔO2/ΔCO2 ratio are less than 1.15, indicating dominance of biogenic sources (e.g., respiration or wildfire) of CO2.
Insulin-Induced Generation of Reactive Oxygen Species and Uncoupling of Nitric Oxide Synthase Underlie the Cerebrovascular Insulin Resistance in Obese Rats
Authors: Katakam Prasad VG , Snipes James A , Steed Mesia M , Busija David W
Published: January 2012

Hyperinsulinemia accompanying insulin resistance (IR) is an independent risk factor for stroke. The objective is to examine the cerebrovascular actions of insulin in Zucker obese (ZO) rats with IR and Zucker lean (ZL) control rats. Diameter measurements of cerebral arteries showed diminished insulin-induced vasodilation in ZO compared with ZL. Endothelial denudation revealed vasoconstriction to insulin that was greater in ZO compared with ZL. Nonspecific inhibition of nitric oxide synthase (NOS) paradoxically improved vasodilation in ZO. Scavenging of reactive oxygen species (ROS), supplementation of tetrahydrobiopterin (BH4) precursor, and inhibition of neuronal NOS or NADPH oxidase or cyclooxygenase (COX) improved insulin-induced vasodilation in ZO. Immunoblot experiments revealed that insulin-induced phosphorylation of Akt, endothelial NOS, and expression of GTP cyclohydrolase-I (GTP-CH) were diminished, but phosphorylation of PKC and ERK was enhanced in ZO arteries. Fluorescence studies showed increased ROS in ZO arteries in response to insulin that was sensitive to NOS inhibition and BH4 supplementation. Thus, a vicious cycle of abnormal insulin-induced ROS generation instigating NOS uncoupling leading to further ROS production underlies the cerebrovascular IR in ZO rats. In addition, decreased bioavailability and impaired synthesis of BH4 by GTP-CH induced by insulin promoted NOS uncoupling.
Functional Significance of Central D1 Receptors in Cognition: Beyond Working Memory
Authors: Takahashi Hidehiko , Yamada Makiko , Suhara Tetsuya
Published: January 2012

The role of dopamine D1 receptors in prefrontal cortex function, including working memory, is well acknowledged. However, relatively little is known about their role in other cognitive or emotional functions. We measured both D1 and D2 receptors in the brain using positron emission tomography in healthy subjects, with the aim of elucidating how regional D1 and D2 receptors are differentially involved in cognitive and emotional functions beyond working memory. We found an inverted U-shaped relation between prefrontal D1 receptor availability and Wisconsin Card Sorting Test performance, indicating that too little or too much D1 receptor stimulation impairs working memory or set shifting. In addition, variability of D1 receptor availability in the amygdala and striatum was related to individual differences in emotional responses and decision-making processes, respectively. These observations suggest that the variability of available D1 receptors might be associated with individual differences in brain functions that require phasic dopamine release. An interdisciplinary approach combining molecular imaging of dopamine neurotransmission with cognitive neuroscience and clinical psychiatry will provide new perspectives for understanding the neurobiology of neuropsychiatric disorders such as schizophrenia, addiction and Parkinson's disease, as well as novel therapeutics for cognitive impairments observed in them.
The biological cost of consciousness
Authors: Baars Bernard
Published: January 2012

Some philosophers maintain that consciousness as subjective experience has no biological function. However, conscious brain events seem very different from unconscious ones. The cortex and thalamus support the reportable qualitative contents of consciousness. Subcortical structures like the cerebellum do not. Likewise, attended sensory stimuli are typically reportable as conscious, while memories of those stimuli are not so reportable until they are specifically recalled.Reports of conscious experiences in normal humans always involve subjectivity and an implicit observing ego. Unconscious brain events are not reportable, even under optimal conditions of report. While there are claimed exceptions to these points, they are rare or poorly validated.Normal consciousness also implies high availability (rapid conscious access) of the questions routinely asked of neurological patients in the Mental Status Examination, such as common sense features of personal identity, time, place, and social context. Along with “current concerns,” recent conscious contents, and the like, these contents correspond to high frequency items in working memory. While working memory contents are not immediately conscious, they can be rapidly re-called to consciousness.The anatomy and physiology of reportable conscious sensorimotor contents are ultraconserved over perhaps 200 million years of mammalian evolution. By comparison, full-fledged language is thought to arise some 100,000 years ago in homo sapiens, while writing, which enables accel-erated cultural development, dates between 2.5 and 6 millennia. Contrary to some claims, therefore, conscious waking precedes language by hundreds of millions of years.Like other major adaptations, conscious and unconscious brain events have distinctive biological pros and cons. These involve information processing efficiency, metabolic costs and benefits, and behavioral pros and cons. The well known momentary limited capacity of conscious contents is an example of an information processing cost, while the very large and energy-hungry corticothalamic system makes costly metabolic demands.After a century of scientific neglect, fundamental concepts like “conscious,” “unconscious,” “voluntary” and “non-voluntary” are still vitally important, because they refer to major biopsychological phenomena that otherwise are difficult to discuss.