bluuebunny/crossref_metadata_2025 huggingface dataset:
Integration of Cardiac CT/MR Imaging with Three‐Dimensional Electroanatomical Mapping to Guide Catheter Manipulation in the Left Atrium: Implications for Catheter Ablation of Atrial Fibrillation
Authors: MALCHANO ZACHARY J. , NEUZIL PETR , CURY RICARDO C. , HOLMVANG GODTFRED , WEICHET JIRI , SCHMIDT EHUD J. , RUSKIN JEREMY N. , REDDY VIVEK Y.
Published: September 2006

Introduction: Preprocedural cardiac imaging (CT/MRI) and intraprocedural electroanatomical mapping (EAM) are commonly used during left atrial (LA) catheter ablation of atrial fibrillation (AF). In the optimal scenario, the imaging datasets would be directly integrated with the EAM system to guide catheter mapping based on the accurate individual cardiac anatomy.

Methods and Results: Strategies to align the EAM and imaging data were assessed by simulations using a life‐size model of the LA and aorta. This revealed that the optimal strategy includes mapping both the aorta and LA. Respiratory changes in cardiac anatomy were evaluated by MR angiography performed in 10 patients during both inspiration and expiration. Comparison of paired images revealed inferior and anterior movement of the LA relative to the aorta with inspiration. Next, image integration was employed in a series of patients (n = 13) scheduled for AF catheter ablation. After preprocedural CT angiography (7 during inspiration and 6 during expiration), three‐dimensional anatomical renderings of these images were integrated with the EAM data in a custom workstation to permit real‐time catheter manipulation within these constructs. The electrophysiologist was blinded to these integrated images, but the accuracy of the process was assessed real‐time by a second operator. This revealed poor alignment during inspiration but good alignment during expiration—the respiratory phase most closely resembling that during EAM.

Conclusions: This study supports the feasibility of integrating preacquired cardiac images with real‐time electroanatomical mapping to guide catheter movement in the LA in a reliable and clinically relevant manner.
QT Interval Correction in Patients with Cirrhosis
Authors: ZAMBRUNI ANDREA , DI MICOLI ANTONIO , LUBISCO ALESSANDRO , DOMENICALI MARCO , TREVISANI FRANCO , BERNARDI MAURO
Published: September 2006

Introduction: QT interval prolongation is a common electrophysiological abnormality in patients with cirrhosis. As QT interval varies with the heart rate, many QT correction formulas have been proposed, the Bazett's one being the most criticized because it overcorrects the QT interval and may be misleading. This study focused on the QT‐RR relationship in patients with cirrhosis to derive a population‐specific QT correction formula.

Methods: One hundred cirrhotic patients of different etiology and severity and 53 healthy controls comparable for age and sex were enrolled. The QT‐RR relationship was analyzed in patients by five regression analysis models to derive the population‐specific QT‐RR equation. The QTc was calculated and compared with those calculated by four common QT correction formulas (Bazett, Fridericia, Framingham, and Hodges). The correlation coefficient QTc‐RR was calculated as a measure of the independence of QTc from the original RR interval.

Results: In patients the QT‐RR relationship was best described by the power equation “QT = 453.65 × RR1/3.02” (R2= 0.41), similar to the Fridericia's formula. Bazett's formula led to the longest QTc (P < 0.0001), which was still significantly influenced by the RR interval (R =−0.39; P < 0.0001), while the estimated equation led to a QTc value not influenced by RR (R =−0.014).

Conclusion: Bazett's correction should be avoided in patients with cirrhosis because it still provides a rate‐dependent QTc value and might be misleading, particularly when assessing the overall preoperative cardiac risk and the effect of drugs affecting the QT interval. In its place, our formula or that of Fridericia can be confidently employed.
Inherited corneal opacifications with an unusual distribution
Authors: Fagerholm Per , Dellby Anette , Bäckman Lennart
Published: September 2006

Purpose:  To describe corneal opacities of a new type and distribution in a small family.

Methods:  Family members were interviewed and examined to establish a pedigree and to detect any corneal abnormalities.

Results:  Two family members presented with corneal opacities. Both had, in the very peripheral cornea, flat, greyish, rounded opacities, 20–200 µm in diameter, on the Descemet's membrane. In addition, the mother had the same type of opacities over the central cornea just inside the Bowman's layer. The remaining parts of the corneas were clear. Vision was unaffected and the opacities caused no discomfort. There was no other corneal pathology. The subjects' general health was good.

Conclusions:  To our knowledge, these types and distribution of corneal opacities have not been described previously. Although the mode of inheritance at this point is uncertain, we believe the changes are of a dystrophic nature.
Vertical root fractures in endodontically treated teeth: diagnostic signs and clinical management
Authors: TAMSE AVIAD
Published: September 2006

A most frustrating complication to root canal therapy is vertical root fracture (VRF) in an endodontically treated tooth. Prognosis most often is hopeless and differential diagnosis from other pathoses may be difficult at times. Nevertheless, proper diagnosis is critical to distinguish a fracture complication from clinical manifestations of periodontal and endodontic diseases. This review emphasizes the importance of the correct diagnosis of VRF, describes the more typical clinical and radiographic features of this disorder, and summarizes its prevalence and multifactorial etiology.
Mechanisms and risk factors for fracture predilection in endodontically treated teeth
Authors: KISHEN ANIL
Published: September 2006

The prognosis of root‐filled teeth depends not only on the success of the endodontic treatment but also on the amount of remaining dentine tissue, and the nature of final restoration. Fractures of restored endodontically treated teeth are a common occurrence in clinical practice. This article outlines the mechanisms and risk factors for fracture predilection in endodontically treated teeth. Different mechanisms of fracture resistance in dentine and the biomechanical causes of fracture predilection in restored endodontically treated teeth are described. Furthermore, dentinal, restorative, chemical, microbial, and age‐induced factors that predispose restored endodontically treated teeth to fracture are also reviewed.
Mirtazapine: only for depression?
Authors: San Luis , Arranz Belen
Published: September 2006

Background:

Mirtazapine is an antidepressant first approved in the Netherlands in 1994 for the treatment of major depressive disorder. However, evidence suggests its effectiveness in a variety of other psychiatric disorders and non-psychiatric medical conditions.

Objective:

The present paper reviews the published literature on the off-label indications of Mirtazapine.

Methods:

A search of the relevant literature from MEDLINE, PsycLIT and EMBASE databases, included in the Science Citation Index and available up to March 2006, was conducted using the terms mirtazapine, case-reports, open-label trials and randomized controlled trials. Only articles referring to conditions other than major depression were included in this present review.

Results:

Off-label use of mirtazapine has been reported in panic disorder, post-traumatic stress disorder, generalized anxiety disorder, social phobia, obsessive-compulsive disorder, dysthymia, menopausal depression, poststroke depression, depression as a result of infection with human immunodeficiency virus, elderly depression, Methylenedioxymethamphetamine (MDMA)-induced depression, hot flashes, alcohol and other substance use disorders, sleep disorders, sexual disorders, tension-type headaches, cancer pain, fibromyalgia, schizophrenia and other less frequent conditions.

Conclusions:

So far, data on the off-label usefulness of mirtazapine are limited and mainly based on observations from case reports or open-label studies. However, positive cues suggest that confirmation of these preliminary data with randomized controlled trials may give sufficient evidence to warrant the use of mirtazapine in a broad range of disorders.
Seasonal influences on first-episode admission in affective and non-affective psychosis
Authors: Hallam Karen T , Berk Michael , Kader Linda F. , Conus Phillipe , Lucas Nellie C. , Hasty Melissa , Macneil Craig M. , McGorry Patrick D.
Published: September 2006

Background:

Since bipolar affective disorder has been recorded, clinicians treating patients with this disorder have noted the cyclic nature of episodes, particularly an increase in mania in the spring and summer months and depression during winter.

Objective:

The aim of this study was to investigate seasonality in symptom onset and service admissions over a period of 10 years in a group of patients (n= 359) with first-episode (FE) mania (n= 133), FE schizoaffective disorder (n= 49) and FE schizophrenia (n= 177).

Method:

Patients were recruited if they were between 15 and 28 years of age and if they resided in the geographical mental health service catchment area. The number of patients experiencing symptom onset and service admission over each month and season was recorded.

Results:

In terms of seasonality of time of service admission, the results indicate a high overall seasonality (particularly in men), which was observed in both the schizoaffective and the bipolar groups. In terms of seasonality of symptom onset, the results indicate that seasonality remains in the male bipolar group, but other groups have no seasonal trend.

Conclusions:

This provides further evidence that systems mediating the entrainment of biological rhythms to the environment may be more pronounced in BPAD than in schizoaffective disorder and schizophrenia. These results may help facilitate the preparedness of mental heath services for patients at different times of the year.
Neuropsychological function in bulimia with comorbid borderline personality disorder and depression
Authors: Bourke Cecilia M. , Porter Richard J. , Sullivan Patrick , Bulik Cynthia M. , Carter Frances A. , McIntosh Virginia V. , Joyce Peter R.
Published: September 2006

Background:

In bulimia nervosa (BN), borderline personality disorder (BPD) and major depression (MDD) are frequently comorbid conditions. Executive function has been found to be impaired in BPD and MDD, but the impact of comorbidity on neuropsychological function has rarely been investigated.

Objective:

To investigate neuropsychological function in BN with a focus on comorbid BPD and MDD.

Methods:

One hundred forty-four medication-free female patients entering a study of psychological treatments for BN performed a brief battery of neuropsychological tests. Comorbid MDD and BPD were systematically identified using standard interviews. Neuropsychological test results were compared.

Results:

Forty-one subjects had comorbid BPD and 35 had comorbid MDD, while 15 had both. There was no effect of comorbid MDD, but there was a significant effect of BPD and a significant interaction between the diagnosis of MDD and BPD on executive tasks (trail making and Stroop). Thus, compared with subjects without BPD, subjects with BPD performed significantly worse on tests of executive function, while the group with both comorbidities performed even worse.

Conclusions:

There appears to be an additive effect of BPD and MDD resulting in impaired executive neuropsychological function. Future studies on either disorder and on BN should examine and account for the effect of comorbidity.
Neural mechanisms of the cognitive control of emotion
Authors: Green Melissa J. , Malhi Gin S.
Published: September 2006

Background:

Emotion regulation involves the initiation of new emotional responses and continual alteration of current emotions in response to rapidly changing environmental and social stimuli. The capacity to effectively implement emotion regulation strategies is essential for psychological health; impairments in the ability to regulate emotions may be critical to the development of clinical levels of depression, anxiety and mania.

Objective:

This review provides a summary of findings from current research examining the neural mechanisms of emotion regulation by means of conscious cognitive strategies of reappraisal. These findings are considered in the context of related concepts of emotion perception and emotion generation, with discussion of the likely cognitive neuropsychological contributions to emotion regulation and the implications for psychiatric disorders.

Results:

Convergent evidence implicates an inhibitory role of prefrontal cortex and cingulate regions upon subcortical and cortical emotion generation systems in the cognitive control of emotional experience. Concurrent modulation of cortical activity by the peripheral nervous system is highlighted by recent studies using simultaneous physiological and neuroimaging techniques. Individual differences in emotion perception, generation of affect and neuropsychological skills are likely to have direct consequences for emotion regulation.

Conclusions:

Emotion regulation relies on synergy within brain stem, limbic and cortical processes that promote the adaptive perception, generation and regulation of affect. Aberrant emotion processing in any of these stages may disrupt this self-sustaining regulatory system, with the potential to manifest in distinct forms of emotion dysregulation as seen in major psychiatric disorders such as depression, bipolar disorder and schizophrenia.
Addressing the learning deficit in breastfeeding: strategies for change
Authors: Renfrew Mary J. , McFadden Alison , Dykes Fiona , Wallace Louise M. , Abbott Stephen , Burt Sue , Anderson Joanna Kosmala
Published: September 2006

This paper summarizes the findings of the learning needs assessment described in this issue. Limitations and strengths are discussed. The paper describes a national, multi‐sectoral, multidisciplinary picture. Our respondents may over‐represent those with an interest in breastfeeding; if so, the true picture may be even more problematic than described here. Major deficits were identified in the knowledge and skills of practitioners from all backgrounds and all sectors. Many professionals report poor knowledge about breastfeeding and have low levels of confidence and clinical competence. Organizational constraints and barriers to effective education and practice include fragmentation of care and education, lack of facilities, and a low priority being given to breastfeeding. There is a range of current educational provision, although not all is fit for purpose. Voluntary organizations seem to have higher standards than do some current professional learning opportunities. Preferred methods of training include practical observation and mentorship, volunteer counsellor involvement in training programmes, as well as self‐study and online opportunities. Recommendations include: a funded, mandatory, interagency and multidisciplinary approach; appropriate content; support at local and national levels; breastfeeding education to be included in clinical governance and audit mechanisms; and further research and evaluation to examine optimum ways of providing education and training. Organizational barriers could be addressed through a public health policy and evidence‐based approach.
Solution NMR structure of a human FGF‐1 monomer, activated by a hexasaccharide heparin‐analogue
Authors: Canales Angeles , Lozano Rosa , López‐Méndez Blanca , Angulo Jesús , Ojeda Rafael , Nieto Pedro M. , Martín‐Lomas Manuel , Giménez‐Gallego Guillermo , Jiménez‐Barbero Jesús
Published: September 2006

The 3D structure of a complex formed by the acidic fibroblast growth factor (FGF‐1) and a specifically designed synthetic heparin hexasaccharide has been determined by NMR spectroscopy. This hexasaccharide can substitute natural heparins in FGF‐1 mitogenesis assays, in spite of not inducing any apparent dimerization of the growth factor. The use of this well defined synthetic heparin analogue has allowed us to perform a detailed NMR structural analysis of the heparin–FGF interaction, overcoming the limitations of NMR to deal with the high molecular mass and heterogeneity of the FGF‐1 oligomers formed in the presence of natural heparin fragments. Our results confirm that glycosaminoglycans induced FGF‐1 dimerization either in a cis or trans disposition with respect to the heparin chain is not an absolute requirement for biological activity.
Stimulant Medications: A Trade‐off? The Lived Experience of Adolescents With ADHD
Authors: Meaux Julie B. , Hester Carla , Smith Billy , Shoptaw Amy
Published: September 2006

PURPOSE.  The purpose of this study was to gain information and insight about prescription stimulant medication use among children and adolescents with attention deficit–hyperactivity disorder (ADHD) across developmental stages.

DESIGN AND METHODS.  Investigators conducted semistructured qualitative interviews with 15 college students with ADHD. Follow‐up interviews confirmed and validated information obtained during initial interviews.

RESULTS.  Qualitative data analysis resulted in three global categories related to the use of prescription stimulant medication from childhood to late adolescence: (a) the early years, (b) “the trade‐off,” and (c) stimulant medications in college.

PRACTICE IMPLICATIONS.  Increased education about prescription stimulant medications and closer management is needed to reduce side effects and minimize the risks of misuse.
Assessing Emergency Preparedness of Families Caring for Young Children With Diabetes and Other Chronic Illnesses
Authors: Stallwood Lynda G.
Published: September 2006

PURPOSE.  To help children with chronic illnesses and their caregivers assess emergency preparedness.

CONCLUSIONS.  Little work has been done to ascertain patient adherence levels to these recommendations. Additionally, little is known about the seeking patterns of healthcare providers and/or changes in interventions based on certain elements of emergency preparedness, such as the presence of medical alert identification and an emergency kit.

PRACTICE IMPLICATIONS.   Healthcare providers must discover their patients’ level of emergency preparedness and facilitate the acquisition and implementation of elements of emergency preparedness that meet their patients’ needs.
Recruitment and Retention of Latino Adolescents to a Research Study: Lessons Learned from a Randomized Clinical Trial
Authors: Villarruel Antonia M. , Jemmott Loretta S. , Jemmott John B. , Eakin Brenda L.
Published: September 2006

PURPOSE.  To describe facilitators and barriers to participation and retention of Latino adolescents in a randomized clinical trial.

DESIGN AND METHODS.  Participants were part of a randomized clinical trial designed to reduce HIV sexual risk behavior among Latino youth. Responses from 106 randomly selected respondents from the 3‐month follow‐up were content analyzed.

RESULTS.  Four main facilitator patterns emerged: peer/family support, program incentives, commitment, and desire to help. Participation barriers included conflicts with other commitments, embarrassment, and lack of peer support.

PRACTICE IMPLICATIONS.  Recruitment and retention of Latino adolescents in research studies is critical to building a research base for nursing practice.
Reliability Investigation for Encapsulated Isotropic Conductive Adhesives Flip Chip Interconnection
Authors: Chen Liu Caroline , Lai Zonghe , Cheng Zhaonian , Liu Johan
Published: September 2006

Isotropic conductive adhesives (ICA) are gaining more and more application interests in electronic manufacturing, however, their failure mechanism is not been fully understood. In this paper we present reliability investigations on an encapsulated ICA flip chip interconnection. Experimental work included product lifetime measurement, cross section observation, and whole module warpage scanning. Results revealed that the chip-size effect on the ICA lifetime was obvious. A theoretical analysis was conducted with Finite Element Method (FEM) simulation. Viscoelastic models for adhesives and underfill materials were employed, and the comparison with an elastic model was made. Calculated equivalent stresses Seqv and shear stress σxy fitted well with the experimental lifetime measurement, thus a lifetime relationship similar to the Coffin-Manson formula was established to predict the thermal fatigue life of an encapsulated ICA flip chip. Furthermore, the influences of underfill properties on the ICA reliability were discussed.
An Evaluation of Gold and Copper Wire Bonds on Shear and Pull Testing
Authors: Murali S. , Srikanth N. , Vath Charles J.
Published: September 2006

In microelectronic packaging technology wire bonding is a common interconnect technique. The quality and reliability of wire bonds are generally evaluated by ball shear and stitch pull testing. From the load versus time and load versus tool tip displacement plots of the shear test, three regions can be observed. Region I primarily exhibits elastic-plastic deformation occur, while crack nucleate in region II which propagates in region III which finally ends in a catastrophic failure. Fractographs reveal in the case of gold ball bonds shows fracture occurs in Al bond pad metallization close to Au-Al intermetallics. In Cu ball bonds of 1, 2, and 4ml wire sizes also Al bond pad metallization cracks but penetrate deeper into the pad which indirectly shows that the bonding layer is stronger than that of gold ball bonds. Optical microscopic observation of the sheared copper bond surfaces reveal sticking of Al which provides qualitative information of the area of the bond between the ball bond and the bond pad. In thermally aged gold ball bonds, the gold above the intermetallic layer fractures. The energy required to fracture a gold or copper ball bond of 1ml wire size is around 370J∕m2, while an aged gold ball bond consumes about 520J∕m2. Void nucleation and coalescence mechanism of ductile fracture takes place in the ball and stitch bonds, however, silicon particles may be the preferential void nucleation sites in bond pad aluminum metallization failures. To understand the second bond strength, a stitch pull test was conducted and the results showed the neck of the stitched wire cracks thus leaving behind a tail bond on the lead finger.
Discussion on the Reliability Issues of Solder-Bump and Direct-Solder Bonded Power Device Packages Having Double-Sided Cooling Capability
Authors: Bai John G. , Calata Jesus N. , Lu Guo-Quan
Published: September 2006

Power device packages with solder-bump (SB) and direct-solder (DS) interconnections were fabricated and some of their thermomechanical reliability issues were discussed based on both thermal cycling experiment and finite element analysis (FEA). The SB interconnection shows superior reliability over the DS interconnection in the thermal cycling experiment because the mismatched coefficient of thermal expansion leads to smaller stresses at the SB interconnection under the same temperature changes. On the other hand, FEA results show that the DS package has significantly lower operating temperatures under the same double-sided cooling condition. After considering the operating temperature difference, the DS package was shown to be superior over the SB package in the power cycling analysis.
The Effects of Multiple Zincation Process on Aluminum Bond Pad Surface for Electroless Nickel Immersion Gold Deposition
Authors: Md Arshad M. K. , Ahmad I. , Jalar A. , Omar G. , Hashim U.
Published: September 2006

This paper reports the effects of a multiple zincation process on the Al bond pad surface prior to electroless nickel immersion gold deposition. The study of multiple zincation comprises the surface topography and morphology of the appearance of the Al bond pad. In addition, by comprehension of the effects of the multiple zincation process, the study includes investigating the Al dissolution rate and adhesion strength between eutectic a 37Pb∕63Sn solder ball and an under bump metallurgy (UBM) interface. Scanning electron microscopy, energy dispersive x-ray, atomic force microscopy, focused ion beam, and an Intellectest STORM series FA1500 shear tester were used as analytical tools in this study. The results suggest that the first zincation process follows the contour of the initial bond pad. The second zincation produces a slightly better surface appearance with a smooth and fine Zn crystallite. The Zn crystallites become a continuous film with the deposits looking like an island formation after the third zincation. The smooth surface of the third zincation, as an effect of multiple zincation, is later transferred to Ni and Au surfaces. The smooth surface of the UBM leads to a better shear strength with only a minimum Al dissolved.
Laminar Heat Transfer in Constructal Microchannel Networks With Loops
Authors: Wang Xiang-Qi , Yap Christopher , Mujumdar Arun S.
Published: September 2006

Heat sinks with radial and constructal branching microchannel networks with loops are examined numerically. Radial and constructal networks are embedded in disk-shaped heat sinks. Constructal nets with loops are found to be more robust than the radial ones, when one or more channel segments are blocked. Since complex constructal networks would involve problems in manufacturing, constructal channel nets with loops may be a better choice in engineering applications. Networks with loops and without loops are compared. Results show that the constructal nets with loops provide a great advantage when the structure experiences accidental damage in one or more subchannel segments, since the loop assures the continuity of flow. In spite of blockage, the performance of the network has only a small drop considering the increased pressure drop.
Influence of the Fluid on the Experimental Performances of Triangular Silicon Microheat Pipes
Authors: Pandraud Guillaume , Le Berre Martine , Morfouli Panagiota , Lallemand Monique
Published: September 2006

An experimental study was conducted to determine the performances of silicon microheat pipes (MHPs) filled with different fluids. The MHP arrays are made of 27 triangular microchannels chemically etched in a silicon wafer. This wafer is closed by molecular bonding of a bulk oxidized silicon wafer. The results show that the use of MHPs with low liquid charges can increase the effective thermal conductivity of the array. The best improvement of the effective thermal conductivity of the MHP array is equal to 41% for methanol and pentane, 12% for ethanol and nil for water and FC72.
Comment on "A Keystone Mutualism Drives Pattern in a Power Function"
Authors: Pueyo Salvador , Jovani Roger
Published: September 2006

Vandermeer and Perfecto (Reports, 17 February 2006, p. 1000) maintain that a mutualist ant disrupts the power law distribution of scale insect abundances. However, reanalysis of the data reveals that ants cause an increase in the range of the power law and modify its exponent. We present a tentative, but more realistic, model that is suitable for quantitative predictions.
Exogenous Induction of Cerebral ß-Amyloidogenesis Is Governed by Agent and Host
Authors: Meyer-Luehmann Melanie , Coomaraswamy Janaky , Bolmont Tristan , Kaeser Stephan , Schaefer Claudia , Kilger Ellen , Neuenschwander Anton , Abramowski Dorothee , Frey Peter , Jaton Anneliese L. , Vigouret Jean-Marie , Paganetti Paolo , Walsh Dominic M. , Mathews Paul M. , Ghiso Jorge , Staufenbiel Matthias , Walker Lary C. , Jucker Mathias
Published: September 2006

Protein aggregation is an established pathogenic mechanism in Alzheimer's disease, but little is known about the initiation of this process in vivo. Intracerebral injection of dilute, amyloid-β (Aβ)–containing brain extracts from humans with Alzheimer's disease or β-amyloid precursor protein (APP) transgenic mice induced cerebral β-amyloidosis and associated pathology in APP transgenic mice in a time- and concentration-dependent manner. The seeding activity of brain extracts was reduced or abolished by Aβ immunodepletion, protein denaturation, or by Aβ immunization of the host. The phenotype of the exogenously induced amyloidosis depended on both the host and the source of the agent, suggesting the existence of polymorphic Aβ strains with varying biological activities reminiscent of prion strains.
From Miasmas to Microbes
Authors: Pennington Hugh
Published: September 2006

The Great Stink of Paris and the Nineteenth-Century Struggle Against Filth and Germs
.
By David S. Barnes
. Johns Hopkins University Press, Baltimore, MD, 2006. 328 pp. $35, £23.50. ISBN 0-8018-8349-0.

The author discusses developments in French science, medicine, politics, and culture as he explores how the germ theory of disease changed the science and practice of public health during the 1880s and 1890s.
Saving American Naturalists from Oblivion
Authors: Anker Peder
Published: September 2006

All Creatures
. Naturalists, Collectors, and Biodiversity, 1850-1950.
By Robert E. Kohler
. Princeton University Press, Princeton, NJ, 2006. 379 pp. $35, £22.95. ISBN 0-691-12539-2.

Focusing on the 19th- and 20th-century collecting expeditions that governments, museums, and universities sponsored to inventory fauna and flora, the author examines the practical work that produced much of our current inventory of Earth's biota.
ENTANGLED STATE REPRESENTATION FOR A PARTICLE ON A CIRCLE STUDIED IN TERMS OF BOSONIC OPERATOR REALIZATION OF ANGULAR MOMENTUM
Authors: FAN HONG-YI
Published: September 2006

By introducing the bosonic operator realization of angular momentum, we establish the entangled state representation for describing quantum mechanics of a particle on a circle. The phase operator, the angular momentum eigenstates, the lowering and ascending operators for angular momentum are all well expressed in the bosonic realization with the aid of appropriate entangled states, i.e. we establish a new formalism for the quantum mechanics of a particle on a circle.
NEUTRINO MASS SQUARED DIFFERENCES IN THE EXACT SOLUTION OF A 3-3-1 GAUGE MODEL WITHOUT EXOTIC ELECTRIC CHARGES
Authors: PALCU ADRIAN
Published: September 2006

The mass splittings for the Majorana neutrinos in the exact solution of a particular 3-3-1 gauge model are computed in detail. Since both sin2θ13≃0 and the mass splitting ratio rΔ≃0.033 are taken into account as phenomenological evidence, the analytical calculations in the leading order seem to predict an inverted mass hierarchy and a matrix with a texture based on a very close approximation to the bi-maximal mixing. The resulting formulas for the mass squared differences can naturally accommodate the available data if the unique free parameter a of the model gets very small values ~ 10-15. Consequently, the smallness of the parameter requires (according to our method) a large breaking scale 〈ϕ〉 ~ 106–107TeV. Hence, the results concerning the neutrino mass splittings lead to a more precise tuning in the exact solution of the 3-3-1 model and enable it — at the same time — to recover all the Standard Model phenomenology and predict the mass spectrum of the new gauge bosons Z′, X, Y in accordance with the actual data. The minimal absolute mass in the neutrino sector is also obtained, m0≃0.0035 eV, in the case of our suitable approximation for the bi-maximal mixing.
THE ROLE OF A DYNAMICAL MEASURE AND DYNAMICAL TENSION IN BRANE CREATION AND GROWTH
Authors: ANSOLDI STEFANO , GUENDELMAN EDUARDO I. , SPALLUCCI EURO
Published: September 2006

The use of a non-Riemannian measure of integration in the action of strings and branes allows the possibility of dynamical tension. In particular, lower dimensional objects living in the string/brane can induce discontinuities in the tension: the effect of pair creation on the string tension is studied. We then investigate the role that these new features can play in string and brane creation and growth. A mechanism is studied by means of which a scalar field can transfer its energy to the tension of strings and branes. An infinite-dimensional symmetry group of this theory is discussed. Creation and growth of bubbles in a formulation that requires mass generation for the bulk gauge fields coupled to the branes is also discussed.
Interleukin-1β increases expression and activity of matrix metalloproteinase-2 in cardiac microvascular endothelial cells: role of PKCα/β1 and MAPKs
Authors: Mountain Deidra J. H. , Singh Mahipal , Menon Bindu , Singh Krishna
Published: September 2006

Matrix metalloproteinases (MMPs), a family of extracellular endopeptidases, are implicated in angiogenesis because of their ability to selectively degrade components of the extracellular matrix. Interleukin-1β (IL-1β), increased in the heart post-myocardial infarction (post-MI), plays a protective role in the pathophysiology of left ventricular (LV) remodeling following MI. Here we studied expression of various angiogenic genes affected by IL-1β in cardiac microvascular endothelial cells (CMECs) and investigated the signaling pathways involved in the regulation of MMP-2. cDNA array analysis of 96 angiogenesis-related genes indicated that IL-1β modulates the expression of numerous genes, notably increasing the expression of MMP-2, not MMP-9. RT-PCR and Western blot analyses confirmed increased expression of MMP-2 in response to IL-1β. Gelatin in-gel zymography and Biotrak activity assay demonstrated that IL-1β increases MMP-2 activity in the conditioned media. IL-1β activated ERK1/2, JNKs, and protein kinase C (PKC), specifically PKCα/β1, and inhibition of these cascades partially inhibited IL-1β-stimulated increases in MMP-2. Inhibition of PKCα/β1 failed to inhibit ERK1/2. However, concurrent inhibition of PKCα/β1 and ERK1/2 almost completely inhibited IL-1β-mediated increases in MMP-2 expression. Inhibition of p38 kinase and nuclear factor-κB (NF-κB) had no effect. Pretreatment with superoxide dismutase (SOD) mimetic, MnTMPyP, increased MMP-2 protein levels, whereas pretreatment with SOD and catalase mimetic, EUK134, partially inhibited IL-1β-stimulated increases in MMP-2 protein levels. Exogenous H2O2 significantly increased MMP-2 protein levels, whereas superoxide generation by xanthine/xanthine oxidase had no effect. This in vitro study suggests that IL-1β modulates expression and activity of MMP-2 in CMECs.
Treatment of cultured myotubes with the proteasome inhibitor β-lactone increases the expression of the transcription factor C/EBPβ
Authors: Wei Wei , Yang Hongmei , Menconi Michael , Cao Peirang , Chamberlain Chester E. , Hasselgren Per-Olof
Published: September 2006

The role of the proteasome in the regulation of cellular levels of the transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) is poorly understood. We tested the hypothesis that C/EBPβ levels in cultured myotubes are regulated, at least in part, by proteasome activity. Treatment of cultured L6 myotubes, a rat skeletal muscle cell line, with the specific proteasome inhibitor β-lactone resulted in increased nuclear levels of C/EBPβ as determined by Western blotting and immunofluorescent detection. This effect of β-lactone reflected inhibited degradation of C/EBPβ. Surprisingly, the increased C/EBPβ levels in β-lactone-treated myotubes did not result in increased DNA-binding activity. In additional experiments, treatment of the myotubes with β-lactone resulted in increased nuclear levels of growth arrest DNA damage/C/EBP homologous protein (Gadd153/CHOP), a dominant-negative member of the C/EBP family that can form heterodimers with other members of the C/EBP family and block DNA binding. Coimmunoprecipitation and immunofluorescent detection provided evidence that C/EBPβ and Gadd153/CHOP interacted and colocalized in the nuclei of the β-lactone-treated myotubes. When Gadd153/CHOP expression was downregulated by transfection of myotubes with siRNA targeting Gadd153/CHOP, C/EBPβ DNA-binding activity was restored in β-lactone-treated myotubes. The results suggest that C/EBPβ is degraded by a proteasome-dependent mechanism in skeletal muscle cells and that Gadd153/CHOP can interact with C/EBPβ and block its DNA-binding activity. The observations are important because they increase the understanding of the complex regulation of the expression and activity of C/EBPβ in skeletal muscle.
Cell-based imaging of sodium iodide symporter activity with the yellow fluorescent protein variant YFP-H148Q/I152L
Authors: Rhoden Kerry J. , Cianchetta Stefano , Stivani Valeria , Portulano Carla , Galietta Luis J. V. , Romeo Giovanni
Published: September 2006

The sodium iodide symporter (NIS) mediates iodide (I−) transport in the thyroid gland and other tissues and is of increasing importance as a therapeutic target and nuclear imaging reporter. NIS activity in vitro is currently measured with radiotracers and electrophysiological techniques. We report on the development of a novel live cell imaging assay of NIS activity using the I−-sensitive and genetically encodable yellow fluorescent protein (YFP) variant YFP-H148Q/I152L. In FRTL-5 thyrocytes stably expressing YFP-H148Q/I152L, I− induced a rapid and reversible decrease in cellular fluorescence characterized by 1) high affinity for extracellular I− (35 μM), 2) inhibition by the NIS inhibitor perchlorate, 3) extracellular Na+ dependence, and 4) TSH dependence, suggesting that fluorescence changes are due to I− influx via NIS. Individual cells within a population of FRTL-5 cells exhibited a 3.5-fold variation in the rate of NIS-mediated I− influx, illustrating the utility of YFP-H148Q/I152L to detect cell-to-cell difference in NIS activity. I− also caused a perchlorate-sensitive decrease in YFP-H148Q/I152L fluorescence in COS-7 cells expressing NIS but not in cells lacking NIS. These results demonstrate that YFP-H148Q/I152L is a sensitive biosensor of NIS-mediated I− uptake in thyroid cells and in nonthyroidal cells following gene transfer and suggest that fluorescence detection of cellular I− may be a useful tool by which to study the pathophysiology and pharmacology of NIS.
Cytokine expression and AIF-1-mediated activation of Rac2 in vascular smooth muscle cells: a role for Rac2 in VSMC activation
Authors: Tian Ying , Autieri Michael V.
Published: September 2006

Allograft inflammatory factor-1 (AIF-1) is a cytoplasmic, calcium-binding, inflammation-responsive scaffold protein involved in vascular smooth muscle cell (VSMC) migration and proliferation. The objective of this study is to characterize AIF-1 functional protein interactions that may regulate VSMC activation. Through use of a bacterial two-hybrid screen, we identified a molecular interaction between AIF-1 and the small GTPase, Rac2, which was verified by pull-down and colocalization experiments. This was unexpected in that Rac2 expression had been considered to be restricted to hematopoietic cells. The Rac2/AIF-1 interaction is functional, in that a loss-of-function, point-mutated AIF-1 does not interact with Rac2; Rac2 colocalizes with AIF-1 in the cytoplasm of VSMC and cotranslocates to lamellopodia upon platelet-derived growth factor stimulation; and AIF-1 expression in VSMC leads to Rac2 activation. Because Rac2 function in VSMC had not been described, we focused on characterization of its function in these cells. Rac2 protein expression in VSMC is inducible by inflammatory cytokines, and Rac2 activation in VSMC is also responsive to inflammatory cytokines. Rac2 expression and activation patterns differ from the ubiquitously expressed Rac1. We hypothesized that Rac2 participates in VSMC activation. Retroviral overexpression of Rac2 in primary VSMC leads to increased migration, activation of the NADPH oxidation cascade, and increased activation of the Rac2 effector protein Pak1 and its proximal effectors, ERK1/2, and p38 ( P < 0.05 for all). The major points of this study indicate a functional interaction between AIF-1 and Rac2 in VSMC leading to Rac2 activation and a potential function for Rac2 in inflammation-driven VSMC response to injury.
Endoplasmic reticulum stress and the unfolded protein response regulate genomic cystic fibrosis transmembrane conductance regulator expression
Authors: Rab András , Bartoszewski Rafal , Jurkuvenaite Asta , Wakefield John , Collawn James F. , Bebők Zsuzsa
Published: September 2006

The unfolded protein response (UPR) is a cellular recovery mechanism activated by endoplasmic reticulum (ER) stress. The UPR is coordinated with the ER-associated degradation (ERAD) to regulate the protein load at the ER. In the present study, we tested how membrane protein biogenesis is regulated through the UPR in epithelia, using the cystic fibrosis transmembrane conductance regulator (CFTR) as a model. Pharmacological methods such as proteasome inhibition and treatment with brefeldin A and tunicamycin were used to induce ER stress and activate the UPR as monitored by increased levels of spliced XBP1 and BiP mRNA. The results indicate that activation of the UPR is followed by a significant decrease in genomic CFTR mRNA levels without significant changes in the mRNA levels of another membrane protein, the transferrin receptor. We also tested whether overexpression of a wild-type CFTR transgene in epithelia expressing endogenous wild-type CFTR activated the UPR. Although CFTR maturation is inefficient in this setting, the UPR was not activated. However, pharmacological induction of ER stress in these cells also led to decreased endogenous CFTR mRNA levels without affecting recombinant CFTR message levels. These results demonstrate that under ER stress conditions, endogenous CFTR biogenesis is regulated by the UPR through alterations in mRNA levels and posttranslationally by ERAD, whereas recombinant CFTR expression is regulated only by ERAD.
Action of epoxyeicosatrienoic acids on cellular function
Authors: Spector Arthur A. , Norris Andrew W.
Published: September 2006

Epoxyeicosatrienoic acids (EETs), which function primarily as autocrine and paracrine mediators in the cardiovascular and renal systems, are synthesized from arachidonic acid by cytochrome P-450 epoxygenases. They activate smooth muscle large-conductance Ca2+-activated K+ channels, producing hyperpolarization and vasorelaxation. EETs also have anti-inflammatory effects in the vasculature and kidney, stimulate angiogenesis, and have mitogenic effects in the kidney. Many of the functional effects of EETs occur through activation of signal transduction pathways and modulation of gene expression, events probably initiated by binding to a putative cell surface EET receptor. However, EETs are rapidly taken up by cells and are incorporated into and released from phospholipids, suggesting that some functional effects may occur through a direct interaction between the EET and an intracellular effector system. In this regard, EETs and several of their metabolites activate peroxisome proliferator-activated receptor α (PPARα) and PPARγ, suggesting that some functional effects may result from PPAR activation. EETs are metabolized primarily by conversion to dihydroxyeicosatrienoic acids (DHETs), a reaction catalyzed by soluble epoxide hydrolase (sEH). Many potentially beneficial actions of EETs are attenuated upon conversion to DHETs, which do not appear to be essential under routine conditions. Therefore, sEH is considered a potential therapeutic target for enhancing the beneficial functions of EETs.
Enteric descending and afferent neural signaling stimulated by giant migrating contractions: essential contributing factors to visceral pain
Authors: Sarna Sushil K.
Published: September 2006

We investigated whether strong compression of an intestinal segment by giant migrating contractions (GMCs) initiates pseudoaffective signals from the gut, similar to those initiated by its distension with a balloon. The experiments were performed on conscious dogs by using close intra-arterial infusions of test substances that affect the receptors only in the infused segment. The stimulation of GMCs by close intra-arterial infusion of CGRP or distension of an intestinal segment by balloon increased the heart rate; the increase in heart rate was greater when the balloon distension and GMCs occurred concurrently in separate intestinal segments. The suppression of contractility in the distended segment blocked the increase in heart rate. By contrast, the stimulation of rhythmic phasic contractions (RPCs) or their spontaneous occurrence did not increase the heart rate. The occurrence of GMCs as well as intestinal distension also produced descending inhibition. The descending inhibition was blocked by the inhibition of nitric oxide synthase, but it was unaffected by the inhibition of adenylyl cyclase, purinergic receptors P2X and P2Y, and muscarinic receptors M1 and M2. The synaptic transmission for descending inhibition was mediated primarily by nicotinic receptors and activation of nitric oxide synthase. It was unaffected by the inhibition of tachykinin receptors NK1, NK2, and NK3; serotonin receptors 5-HT1A, 5-HT2/5-HT1C, 5-HT3, and 5-HT4; and muscarinic receptors. Our findings show that GMCs, but not RPCs, initiate pseudoaffective signals from the gut. In the presence of visceral hypersensitivity or impaired descending inhibition, the GMCs may become a noxious stimulus.
Inhibition of NaCl appetite when DOCA-treated rats drink saline
Authors: Stricker Edward M. , Bushey Michael A. , Hoffmann Myriam L. , McGhee Marilyn , Cason Angela M. , Smith James C.
Published: September 2006

Marked increases in the consumption of concentrated NaCl solution were elicited in rats by daily injection of the synthetic mineralocorticoid, deoxycorticosterone acetate (DOCA). DOCA-treated rats drank different volumes of NaCl solution depending on its concentration (between 0.15 M and 0.50 M), with less consumed (in milliliters) the more concentrated the fluid was. In consequence, total Na+ intake (in milliequivalents) was roughly similar in all groups. Gastric emptying of Na+ also diminished as the concentration of the ingested NaCl solution increased, and the delivery of Na+ to the small intestine was remarkably similar in all groups. Cumulative volume of ingested fluid in the stomach and small intestine was very closely related to intake (in milliliters) of the concentrated NaCl solutions. Systemic plasma Na+ levels did not increase until after rats stopped consuming concentrated NaCl solution, although they were elevated at the onset of water ingestion. The situation appeared to be different when 0.15 M NaCl was consumed. This isotonic solution emptied and was absorbed relatively rapidly, and DOCA-treated rats drank larger amounts of it throughout a 1-h test period than when they drank concentrated NaCl solutions. Collectively, these findings suggest that saline consumption by DOCA-treated rats may be inhibited by two presystemic factors, one related to the volume of ingested fluid (i.e., distension of the stomach and small intestine) and one related to its concentration (i.e., elevated osmolality of fluid in the small intestine and/or in adjacent visceral tissue).