bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison between hemolymph and tissue ferritin in response to heavy metal feeding in the wax moth Galleria mellonella
Authors: CHOI Chi‐Won , SEO Dong‐Hwan , YUK Ji‐Eun , YUN Chi‐Young
Published: September 2006

The effects of seven heavy metals on hemolymph and tissue ferritin in Galleria mellonella were examined by western blotting. Hemolymph ferritin was clearly upregulated by Hg, while tissue ferritin was dramatically upregulated by Cd, Cu, Mn, Zn and Ni. The level of hemolymph ferritin for Hg and Cd increased approximately 1.5‐fold over normal controls, while the level of tissue ferritin for Cd, Cu, Mn, Zn and Ni increased more than twofold, indicating that the regulation of hemolymph and tissue ferritin differ with the different heavy metals. Compared to normal control insects not fed CdCl2, ferritin subunit mRNA from the Malpighian tubules, muscle, the gut and the integument was clearly downregulated, as determined by semi‐quantitative reverse transcription–polymerase chain reaction, but ferritin subunit mRNA from the silk gland and the fat body did not show any change. These results suggest that in G. mellonella, tissue ferritin is responsible for Cd stress and is thus important for survival of the moth, and that tissue and hemolymph ferritin have different ferritin‐inducible mechanisms in response to dietary CdCl2.
Lipophorin uptake by the larval fat body and adult ovary in the wax moth Galleria mellonella
Authors: JUNG Eun‐Suk , JOE Jun‐Ho , YUN Hwa‐Kyung
Published: September 2006

Lipophorin (Lp) acts in the circulation of insects to selectively deliver lipids to target tissues. In the present study, we wanted to show that Lp is taken up into larval fat body cells and the adult ovary in Galleria mellonella. Larval fat body and adult ovary tissues were incubated at room temperature for 30 min with fluorescein isothiocyanate (FITC)‐labeled Lp. Fluorescence microscopy and sodium dodecylsulfate (SDS)–polyacrylamide gel electrophoresis (PAGE) revealed that fat body and ovary tissues internalize fluorescence‐labeled Lp. The results suggest that both lipids and proteins are taken up by fat body cells and the ovary and also that large amounts of proteins and lipids taken up can serve as building blocks and as a source of energy. Immunological relationships with other insects were investigated using western blotting. The data showed that the Lp of Galleria mellonella is related to that of Hyphantria cunea.
A new record of Tanysphyrus (Tanysphyroides) major Roelofs (Coleoptera: Curculionidae) from Korea
Authors: KWON Ohseok , PARK Jinyoung , LEE In‐Yong , LEE Jong‐Eun
Published: September 2006

The species Tanysphyrus (Tanysphyroides) major Roelofs is recorded for the first time from Korea. This paper reports the diagnostic characters, and some remarks on its systematics and notes on its biology are also provided.
The hidden symmetry of the Coulomb problem in relativistic quantum mechanics: From Pauli to Dirac
Authors: Khachidze Tamari T. , Khelashvili Anzor A.
Published: September 2006

Additional conserved quantities associated with an extra symmetry govern a wide variety of physical systems ranging from planetary motion to atomic spectra. We give a simple derivation of the hidden symmetry operator for the Dirac equation in a Coulomb field and show that this operator may be reduced to the one introduced by Johnson and Lippmann to include the spin degrees of freedom. This operator has been rarely discussed in the literature and has been neglected in recent textbooks on relativistic quantum mechanics and quantum electrodynamics.
A selected history of expectation bias in physics
Authors: Jeng Monwhea
Published: September 2006

The beliefs of physicists can bias their results toward their expectations in a number of ways. We survey a variety of historical cases of expectation bias in observations, experiments, and calculations.
Determination of the Kelvin equation in the presence of an arbitrary gravitational∕inertial field
Authors: Siboni S.
Published: September 2006

The validity of the Kelvin equation in the presence of an arbitrary stationary field due to gravity or an accelerated reference frame is determined by a fluid-dynamical argument. In this approach capillary rise and the Kelvin effect appear to be different aspects of the same phenomenon. A general form of the Kelvin equation is obtained that does not depend on the applied field. A higher-order approximation than the usual Kelvin equation is derived by using Lagrange’s expansion method. The fluid-dynamical approach is proved to be equivalent to a purely thermodynamical approach provided that the surface free energy in the presence of the external field is appropriately defined. Both the fluid-dynamical and the thermodynamic approach lead to the conclusion that the generalized form of Kelvin equation does not depend on the applied field.
Geometric parametrization of binary elastic collisions
Authors: Rica da Silva Amaro J. , Lemos José P. S.
Published: September 2006

A geometric view of the possible outcomes of elastic collisions of two massive bodies is developed that integrates laboratory, center of mass, and relative body frames in a single diagram. From these diagrams all the scattering properties of binary collisions can be obtained. The particular case of gravitational scattering by a moving massive object corresponds to the slingshot maneuver, and its maximum velocity is obtained.
Numerical implementation of Einstein-Brillouin-Keller quantization for arbitrary potentials
Authors: Larkoski Andrew J. , Ellis David G. , Curtis Lorenzo J.
Published: September 2006

The Einstein-Brillouin-Keller (EBK) quantization equation is used to determine the energy levels of a two-body system with an arbitrary central potential that allows for bound states. The treatment is based on the conservation laws and avoids both the Newtonian and Schrödinger differential equations. Because analytic solutions for the energy levels do not exist in general, the EBK condition is applied using the Newton-Raphson method and the radial probability density is computed. Potentials appropriate for a diatomic molecule are considered and the effect of the angular momentum on the radial distribution, the nature of the classical orbits, and the possibility of closed orbits is studied.
Radioactivity induced by neutrons: Enrico Fermi and a thermodynamic approach to radiative capture
Authors: De Gregorio Alberto
Published: September 2006

When Fermi learned that slow neutrons are much more effective than fast ones in inducing radioactivity, he explained this phenomenon by mentioning the well-known scattering cross section between neutrons and protons. At this early stage, he did not refer to the capture cross section by target nuclei. At the same time a thermodynamic approach to neutron-proton capture was being discussed by physicists: neutron capture was interpretated as the reverse of deuteron photodissociation and detailed balance among neutrons, protons, deuterons, and radiation was invoked. This thermodynamic approach might underlie Fermi’s early explanation of the great efficiency of slow neutrons. Fermi repeatedly used a thermodynamic approach that had been used in describing some of the physical properties of conductors by Richardson and had been influential in Fermi’s youth.
Magnetic field of a cylindrical coil
Authors: Labinac Velimir , Erceg Nataša , Kotnik-Karuza Dubravka
Published: September 2006

We calculate the magnetic fields of cylindrical coils due to a surface current and a volume current and compare our theoretical results to measured magnetic fields of two coil types: single-layer solenoid and cylindrical thick coil by a simple experimental apparatus. Good agreement is found with the theoretical results.
Dispersion measurements with minimum and maximum deviated beams
Authors: El-Ghussein F. , Wrobel J. M. , Kruger M. B.
Published: September 2006

The prism spectrometer has been the standard apparatus for index of refraction measurements and a typical instrument in undergraduate laboratories for dispersion experiments. Because much care must be employed when aligning a prism spectrometer, a more robust method for measuring index of refraction is needed. By using a laser, prism, rotating platform, and tape measure, we can measure the index of refraction to five significant figures. Due to its ease of use, undergraduates can make more accurate measurements with this method than by using a poorly aligned prism spectrometer. Although a tunable laser is preferable for easily changing wavelengths, two laser pointers, one red and one green, may be used, allowing for an inexpensive method of accurately obtaining the constants in the two-term Cauchy equation relating the index of refraction to the wavelength.
Scattering of a baseball by a bat
Authors: Cross Rod , Nathan Alan M.
Published: September 2006

A ball can be hit faster if it is projected without spin, but it can be hit farther if it is projected with backspin. Measurements of the tradeoff between the speed and spin for a baseball impacting a baseball bat are presented. The results are inconsistent with a collision model in which the ball rolls off the bat and instead imply tangential compliance in the ball, the bat, or both. If the results are extrapolated to the higher speeds that are typical of the game of baseball, they suggest that a curveball can be hit with greater backspin than a fastball, but by an amount that is less than would be the case in the absence of tangential compliance.
The origin of the phase in the interference of Bose-Einstein condensates
Authors: Mullin W. J. , Krotkov R. , Laloë F.
Published: September 2006

We consider the interference of two overlapping ideal Bose-Einstein condensates. The usual description of this phenomenon involves the introduction of a condensate wave function with a definite phase. We investigate the origin of this phase and the theoretical basis of treating interference. It is possible to construct a phase state for which the particle number is uncertain, but the phase is known. How such a state would be prepared before an experiment is not obvious. We show that a phase can also arise from experiments using condensates with known particle numbers. The analysis of measurements in such states also gives us a prescription for preparing phase states. The connection of this procedure to questions of spontaneously broken gauge symmetry and to hidden variables is discussed.
Resource Letter PBA-1: Particle beams and accelerators
Authors: Chao Alexander W.
Published: September 2006

This Resource Letter provides a collection of resources for teaching and research in the field of particle beams and accelerators. I first attempt to give a brief introduction to the facilities, field, and community, and then turn to its literature and educational resources. I also try to include selected websites in the hope of helping the reader explore the web more extensively for specific items.
Student understanding of symmetry and Gauss’s law of electricity
Authors: Singh Chandralekha
Published: September 2006

We investigate the difficulties that students in calculus-based introductory physics courses have with the concepts of symmetry, electric field, and electric flux which are important for applying Gauss’s law. The determination of the electric field using Gauss’s law requires determining the symmetry of a particular charge distribution and predicting the direction of the electric field everywhere if a high symmetry exists. Effective application of Gauss’s law implicitly requires understanding the principle of superposition for electric fields. Helping students learn when Gauss’s law can be readily applied to determine the strength of the electric field, and then helping them learn to determine the appropriate shape of Gaussian surfaces if sufficient symmetry exists, can help develop their reasoning and problem-solving skills. We administered free-response and multiple-choice questions and conducted interviews with individual students using a think-aloud protocol to elucidate the difficulties that students have with the concepts of symmetry, electric field, and electric flux. We also developed a multiple-choice test that targets these conceptual issues to obtain quantitative information about their difficulties and administered it to 541 students in the introductory calculus-based physics courses and to upper-level undergraduates in an electricity and magnetism course and to graduate students enrolled in a teaching assistant seminar course. We find that undergraduate students have many common difficulties with these concepts.
Measuring Boltzmann’s constant with a low-cost atomic force microscope: An undergraduate experiment
Authors: Shusteff M. , Burg T. P. , Manalis S. R.
Published: September 2006

We discuss a low-cost atomic force microscope that we have designed and built for use in an undergraduate teaching laboratory. This microscope gives students hands-on access to nano-Newton force measurements and subangstrom position measurements. The apparatus relies mainly on off-the-shelf components and utilizes an interferometric position sensor known as the interdigitated (ID) cantilever to obtain high resolution. The mechanical properties of the ID readout enable a robust and open design that makes it possible for students to directly control it. Its pedagogical advantage is that students interact with a complete instrument system and learn measurement principles in context. One undergraduate experiment enabled by this apparatus is a measurement of Boltzmann’s constant, which is done by recording the thermal noise power spectrum of a microfabricated cantilever beam. In addition to gaining an appreciation of the lower limits of position and force measurements, students learn to apply numerous concepts such as digital sampling, Fourier-domain analysis, noise sources, and error propagation.
Photoelectric effect experiment with computer control and data acquisition
Authors: Kraftmakher Yaakov
Published: September 2006

This note shows how to take reverse currents into account in a vacuum phototube and to measure stopping potentials more reliably with a computer data-acquisition system. The work function of the emitter is determined from the photoemission threshold.
Pitch cue learning in chinchillas: The role of spectral region in the training stimulus
Authors: Shofner William P. , Whitmer William M.
Published: September 2006

Chinchillas were trained to discriminate a cosine-phase harmonic tone complex (COS) from wideband noise (WBN) and tested in a stimulus generalization paradigm with tone complexes in which phase differed between frequency regions. In this split-phase condition, responses to complexes made of random-phase low frequencies, cosine-phase high frequencies were similar to responses to the COS-training stimulus. However, responses to complexes made of cosine-phase low frequencies, random-phase high frequencies were generally lower than their responses to the COS-training stimulus. When tested with sine-phase (SIN) and random-phase (RND) tone complexes, responses were large for SIN, but were small for RND. Chinchillas were then trained to discriminate infinitely-iterated rippled noise (IIRN) from WBN and tested with noises in which the spectral ripple differed between frequency regions. In this split-spectrum condition, responses were large to noises made of rippled-spectrum low frequencies, flat-spectrum high frequencies, whereas responses were generally lower to noises made of flat-spectrum low frequencies, rippled-spectrum high frequencies. The results suggest that chinchillas listen across all frequencies, but attend to high frequencies when discriminating COS from WBN and attend to low frequencies when discriminating IIRN from WBN.
Energy exchange in uncorrelated ray fields of vibroacoustics
Authors: Bot Alain Le
Published: September 2006

This paper is concerned with the basic equations governing energy and intensity in incoherent ray fields. Some fictitious sources are distributed on the boundary of the domain but also on diffracting wedges and peaks. Their powers are determined by some appropriate boundary integral equations. Once these powers are known, energy and intensity inside the domain are given by a simple superposition of contributions of these sources. All paths of propagation are taken into account including direct, reflected, refracted, transmitted, and diffracted rays, but also, radiation by surface, edge or corner modes, and the reciprocal paths for structural response. This theory unifies several fields from the “radiosity method” in room acoustics which determines the reverberation time to the “radiative transfer method” in structural dynamics which gives the repartition of vibrational energy inside subsystems of built-up structures. This is therefore a candidate for an alternative to statistical energy analysis when fields are nondiffuse.
ON THE INFLUENCE OF PARAMETER θ- ON PERFORMANCE OF RBF NEURAL NETWORKS TRAINED WITH THE DYNAMIC DECAY ADJUSTMENT ALGORITHM
Authors: OLIVEIRA ADRIANO L. I. , MEDEIROS ERICLES A. , ROCHA THYAGO A. B. V. , BEZERRA MIGUEL E. R. , VERAS RONALDO C.
Published: September 2006

The dynamic decay adjustment (DDA) algorithm is a fast constructive algorithm for training RBF neural networks (RBFNs) and probabilistic neural networks (PNNs). The algorithm has two parameters, namely, θ+ and θ-. The papers which introduced DDA argued that those parameters would not heavily influence classification performance and therefore they recommended using always the default values of these parameters. In contrast, this paper shows that smaller values of parameter θ- can, for a considerable number of datasets, result in strong improvement in generalization performance. The experiments described here were carried out using twenty benchmark classification datasets from both Proben1 and the UCI repositories. The results show that for eleven of the datasets, the parameter θ- strongly influenced classification performance. The influence of θ- was also noticeable, although much less, on six of the datasets considered. This paper also compares the performance of RBF-DDA with θ- selection with both AdaBoost and Support Vector Machines (SVMs).
A DELAYED NEURAL NETWORK METHOD FOR SOLVING CONVEX OPTIMIZATION PROBLEMS
Authors: YANG YONGQING , CAO JINDE
Published: September 2006

In this paper, the delayed projection neural network for a class of solving convex programming problem is proposed. The existence of solution and global exponential stability of the proposed network are proved, which can guarantee to converge at an exact optimal solution of the convex programming problems. Several examples are given to show the effectiveness of the proposed network.
ALGORITHMIC COMPLEXITY OF QUANTUM STATES
Authors: MORA CATERINA E. , BRIEGEL HANS J.
Published: September 2006

We give a definition for the Kolmogorov complexity of a pure quantum state. In classical information theory, the algorithmic complexity of a string is a measure of the information needed by a universal machine to reproduce the string itself. We define the complexity of a quantum state by means of the classical description complexity of an (abstract) experimental procedure that allows us to prepare the state with a given fidelity. We argue that our definition satisfies the intuitive idea of complexity as a measure of "how difficult" it is to prepare a state. We apply this definition to give an upper bound on the algorithmic complexity of a number of known states. Furthermore, we establish a connection between the entanglement of a quantum state and its algorithmic complexity.
QUANTUM BIT STRING SEALING
Authors: HE GUANG PING
Published: September 2006

Though it was proven that secure quantum sealing of a single classical bit is impossible in principle, here we propose an unconditionally secure quantum sealing protocol which seals a classical bit string. Any reader can obtain each bit of the sealed string with an arbitrarily small error rate, while reading the string is detectable. The protocol is simple and easy to implement. The possibility of using this protocol to seal a single bit in practice is also briefly discussed.
AN ECONOMICAL ROUTE TO ONE-WAY QUANTUM COMPUTATION
Authors: TAME M. S. , PATERNOSTRO M. , KIM M. S. , VEDRAL V.
Published: September 2006

We assess the effects of a realistic intrinsic model for imperfections in cluster states by introducing noisy cluster states and characterizing their role in the one-way computational model. A suitable strategy to counter-affect these non-idealities is represented by the use of small clusters, stripped of any redundancy, which leads to the search for compact schemes for one-way quantum computation. In light of this, we quantitatively address the behavior of a simple four-qubit cluster which simulates a controlled-NOT under the influences of our model for decoherence. Our scheme can be particularly useful in an all-optical setup and the strategy we address can be directly applied in those experimental situations where small cluster states can be constucted.
QUANTUM-CLASSICAL CORRESPONDENCE IN THE ORACLE MODEL OF COMPUTATION
Authors: WÓJCIK ANTONI , CHHAJLANY RAVINDRA W.
Published: September 2006

The oracle model of computation is believed to allow a rigorous proof of quantum over classical computational superiority. Since quantum and classical oracles are essentially different, a correspondence principle is commonly implicitly used as a platform for comparison of oracle complexity. Here, we question the grounds on which this correspondence is based. Obviously, results on quantum speed-up depend on the chosen correspondence. So, we introduce the notion of genuine quantum speed-up which can serve as a tool for reliable comparison of quantum versus classical complexity, independent of the chosen correspondence principle.
QUANTUM PHASE TRANSITION AND ENTANGLEMENT IN THE TRANSVERSE-FIELD ISING MODEL
Authors: CAO JUNPENG , XIONG GANG , WANG YUPENG , WANG X. R.
Published: September 2006

We present an exact calculation of the global entanglement for the ground state of the transverse-field Ising model. We obtain the analytical expressions for the correlation functions, concurrence and the global entanglement of the system for arbitrary number of particles in the ground state. We prove that the inflexion of the global entanglement exactly corresponds to the quantum phase transition point of the system.
SECURE DETERMINISTIC BIDIRECTIONAL COMMUNICATION WITHOUT ENTANGLEMENT
Authors: MAN ZHONG-XIAO , XIA YUN-JIE , ZHANG ZHAN-JUN
Published: September 2006

In light of Lucamarini–Mancini's secure deterministic communication without entanglement [Phys. Rev. Lett94, (2005) 140501], by introducing an additional operation for encoding and additional classical information for decoding, we propose a new secure deterministic bidirectional communication protocol without using entanglement. In our protocol, two legitimate users can simultaneously exchange their different secret messages in a direct way with a set of communication devices. The proposed protocol is asymptotically secure in the limit of transmitting long messages.
p21 and mTERT are novel markers for determining different ischemic time periods in renal ischemia-reperfusion injury
Authors: Hochegger Kathrin , Koppelstaetter Christian , Tagwerker Andrea , Huber Julia M. , Heininger Dorothea , Mayer Gert , Rosenkranz Alexander R.
Published: September 2006

In many clinical settings, the duration of renal ischemia and therefore the outcome of acute renal failure cannot be determined adequately. Renal ischemia reperfusion injury is known to shorten telomeres and upregulate stress-induced genes, such as the cyclin-dependent kinase (CDK) inhibitor p21. So far, the expression and role of CDK inhibitors, as well as mouse telomerase reverse transcriptase (mTERT), has not been investigated in a model with variable lasting ischemic periods. Male C57Bl/6 mice were subjected to renal ischemia reperfusion injury by clamping both renal pedicles for 10, 20, 30, and 45 min, and the kidneys were allowed to be reperfused for 3, 24, and 48 h. Expression of different CDK inhibitors and mTERT was evaluated. Mice developed signs of acute renal failure linear to the duration of the ischemic period. Real-time PCR revealed that mTERT was only significantly upregulated in kidneys after short ischemic periods (20 min). In contrast, p21 was constantly upregulated in kidneys after long ischemic intervals (30 and 45 min), but not in kidneys, which were clamped for shorter periods. Mainly, tubular cells contributed to the observed increase in p21 expression. Targeting p21 via the selective p53 inhibitor pifithrin-α was able to prevent acute renal failure when administered immediately before ischemia. The expression of another CDK inhibitor, namely p16, was differentially regulated, depending on the time of reperfusion. Taken together, we detected mTERT and p21 as “indicator” genes for short and long ischemic intervals, respectively. These two proteins might also be possible new therapeutic targets in the treatment and prevention of acute renal failure.
Tonal Perceptions in Normal Laryngeal, Esophageal, and Electrolaryngeal Speech of Mandarin
Authors: Liu Hanjun , Wan Mingxi , Ng Manwa L. , Wang Supin , Lu Chunmei
Published: September 2006

The present study attempted to investigate if alaryngeal speakers of Mandarin Chinese could differentially produce the four tone levels of Mandarin: high-level, mid-rising, falling-rising and high-falling, as perceived by native listeners. Syllables /ma/ and /ba/ produced at four different tone levels by 8 normal laryngeal (NL), 7 standard esophageal (SE), and 8 electrolaryngeal (EL) speakers of Mandarin were perceived by 8 naïve listeners. Results from the listening experiments showed a higher percent correct identification of tone for NL speech than SE and EL speech. Perceptual data showed different patterns of tone confusion associated with the three types of speech. SE and EL speakers were not able to produce the four tone levels as accurately as were NL speakers. NL speakers achieved a near-perfect level of accuracy in signaling tonal contrasts. SE speakers produced the falling-rising and high-falling tones more accurately than high-level and mid-rising tones, but tonal confusions existed between mid-rising tone and falling-rising tone, and between high-level tone and high-falling tone. In EL phonation, high-level tone was produced more accurately than the other tones which were often misidentified as a high-level tone.
Acoustic Changes Related to Laryngeal Examination with a Rigid Telescope
Authors: Ng Manwa L. , Bailey Rita L.
Published: September 2006

The influence on voice quality of the insertion of endoscopic equipment with tongue anchoring and head position requirements during endoscopic evaluation has not been fully investigated. The present study attempted to examine the influence of: (1) the presence of a rigid endoscope and tongue anchoring, and (2) the angle of position technique (70-degree and 90-degree) on participants’ vocal output during sustained production of the vowel /i/. Five acoustic measurements including fundamental frequency (F₀) values, percent jitter values, relative average perturbation of F₀ shimmer, and noise-to-harmonic ratios were used to represent participants’ voice quality. Results indicated that F₀ values were significantly influenced by the angle of sitting position, while percent jitter values, relative average perturbation of F₀, shimmer, and noise- to-harmonic ratios were affected by the presence of a rigid endoscope and tongue anchoring.
Effects of Vocal Training on Respiratory Kinematics during Singing Tasks
Authors: Mendes Ana P. , Brown W.S. , Sapienza Christine , Rothman Howard B.
Published: September 2006

This longitudinal study determined the effects of vocal training (VT) on respiratory kinematics and muscle activity during singing tasks. Four voice students, 3 females and 1 male, were recorded during singing tasks once a semester for 3 consecutive semesters. Respiratory kinematic measures included lung volume, rib cage (RCE) and abdominal excursions (ABE). Surface electromyographic measures included burst duration (BD) and peak amplitude (PA) of the pectoralis major, rectus abdominis and external oblique muscles. Descriptive statistics revealed that RCE and ABE increased from the 1st to the 2nd semester, but decreased from the 2nd to the 3rd semester of VT. Overall, mean BD decreased from the 1st to the 2nd semester and increased from the 2nd to the 3rd semester. Mean PA increased from the 1st to the 2nd semester and decreased from the 2nd to the 3rd semester of VT. RCE and muscle force generation of the above muscles increased as the demand level and the length of the phonatory tasks increased. Interpretation of the results suggests that the respiratory system is highly responsive to VT, after only 3 semesters of training.
Retrospective Diagnosis of Pallister-Killian Syndrome by CGH Array
Authors: Delahaye Andrée , Pipiras Eva , Delorme-Vincent Catherine , Benkhalifa Moncef , Kasakyan Serdar , Devisme Louise , Wolf Jean-Philippe , Benzacken Brigitte
Published: September 2006

Objective and Methods: We report a girl presenting with a polymalformation syndrome. Despite a normal karyotype on peripheral lymphocytes and the unavailability of cultured fibroblasts, a tetrasomy 12p was identified on pulmonary DNA extracted from a postmortem biopsy, by use of comparative genomic hybridization (CGH) and confirmed by CGH array. The clinical picture of our patient was consistent, but not specific of the diagnosis of Pallister-Killian syndrome. She presented with the association of antenatal polyhydramnios, craniofacial dysmorphic features, skeletal abnormalities, and a congenital cardiopathy. Conclusion: We discuss the usefulness of CGH and CGH array in prenatal and constitutional cytogenetics.
Antenatal Ultrasonographic Appearance of Isolated Fetal Ascites
Authors: Staboulidou I. , Schauer J. , Rau G.A. , Hass R. , Hollwitz B. , Scharf A.
Published: September 2006

Background: Isolated fetal ascites can be caused by many heterogeneous disorders and is associated with a variety of conditions. Cloacal anomalies are rare abnormalities with a highly variable array of sonographic symptoms, which make them difficult to diagnose antenatally. We present a case with isolated fetal ascites without hydronephrosis caused by a cloacal malformation. Case: A 28-year-old woman, gravida 2, para 1, was referred to our unit at 18 weeks gestation with a hyperdense structure in the fetal liver. Cordocentesis revealed a normal karyotype and negative viral titers. Isolated fetal ascites occurred for the first time at 23 weeks gestation. Serial ultrasounds showed progressive fetal ascites with no hydronephrosis at any time and no other malformations apart from the previously diagnosed hyperechogenic liver structure. After the insertion of an abdomino-amniotic shunt, a temporary reduction of the sonographically detectable ascites could be achieved. Cesarean delivery was necessary due to a pathological CTG at 33 weeks of gestation. The baby was born with a markedly distended abdomen. Postnatal radiologic examination showed two fistulae between the cloaca and the notedly dilated vagina and the rectum respectively. At the age of 3 months a vaginoplasty was performed, which involved creating a correctly positioned vaginal opening, reconstruction of the urethra and rectum as well as occlusion of the two fistulae. Conclusion: In view of the examinations, performed before and after delivery, it has to be assumed that fetal urine drained via the cloaca through the fallopian tubes into the abdomen. In contrast to usual appearance of cloacal malformations no hydronephrosis was detected and the kidney function was normal at all times. To our knowledge, this is the first published case of isolated fetal ascites without hydronephrosis caused by a cloacal malformation.
Prenatal Diagnosis and Postnatal Management of Diffuse Congenital Hyperinsulinism: A Case Report
Authors: Peranteau William H. , Ganguly Arupa , Steinmuller Laura , Thornton Paul , Johnson Mark P. , Howell Lori J. , Stanley Charles A. , Adzick N. Scott
Published: September 2006

We present the first case of the prenatal diagnosis of congenital hyperinsulinism based on the genetic analysis of known family mutations in the SUR1 gene. An amniocentesis was performed at 16 weeks gestation at which time two mutations in the SUR1 gene were identified consistent with the diagnosis of diffuse hyperinsulinism. The mother was transported to our facility and underwent an elective cesarian section at 38 weeks gestation. The diagnosis was confirmed and treatment was initiated within the first minutes of life. After a short course of failed medical management, the patient underwent a 98% pancreatectomy with subsequent good glycemic control. This case highlights the benefits of the timely in utero diagnosis of hyperinsulinism by mutational analysis.
A Rare Form of Abruptio Placenta and Clinical Presentation in a Preterm Labor Case: Breus’ Mole
Authors: Koçak Müberra , Kandemir Ömer , Şen Serdar , Başkan Bahar , Demir Ömer Faruk
Published: September 2006

A normotensive pregnant woman who had no historical risk factors for abruption placenta and found to have Breus’ mole that indicates the pattern of single or multiple hematoma protrude above the chorionic plate was encountered. The case resembled a large fetal abdominal wall defect coexisting with a singleton live-born fetus at 27 weeks of gestational age is presented. The obstetric ultrasound showed that multiple coiled masses in the amniotic cavity, both the fetus and the placenta were normal. After two courses of tocolysis therapy, a healthy and, 1,400 g live-born infant was delivered through cesarean section due to fetal distress. Apgar scores at 1 and 5 min were 5 and 8, respectively. The infant died on postnatal day 6 due to severe respiratory distress and prematurity. This rare condition probably occurs frequently in missed abortion and the etiology is unknown, but is probably related to circulatory disturbance on maternal site. We report a rare clinical presentation and review the literature of Breus’ mole.
Gene-Based Therapy for Hypertension – Do Preclinical Data Suggest a Promising Future?
Authors: Puddu Giovanni Maria , Cravero Eleonora , Ferrari Eleonora , Muscari Antonio , Puddu Paolo
Published: September 2006

Many experimental studies have obtained a prolonged control of blood pressure through gene treatment. This consists in the administration of genes coding for vasodilator proteins (the ‘sense’ approach), or of nucleotide sequences that are complementary to the mRNA of vasoconstrictor proteins, which are consequently synthesized in smaller amounts (the ‘antisense’ approach). Examples of the sense approach include the genes encoding endothelial nitric oxide synthase and kallikrein. Examples of the second type of approach are the antisense oligodeoxynucleotides to angiotensin-converting enzyme and endothelin-1. Also, RNA molecules, such as ribozymes and small interfering RNAs, are capable to inhibit RNA function. Whole sense genes are usually administered through viral vectors, while antisense oligonucleotides may be administered with plasmids or liposomes. Both viral and non-viral vectors have advantages and disadvantages. Despite the still persisting limitations, the possibility exists that in the future some forms of genetic treatment will be extended to the clinical setting, allowing a prolonged control of essential hypertension and its end-organ sequelae.
Binding and Signal Transduction Characteristics of the Nonpeptide Vasopressin V1A Receptor-Selective Antagonist YM218 in Cultured Rat Mesangial Cells
Authors: Tahara Atsuo , Tsukada Junko , Tomura Yuichi , Kusayama Toshiyuki , Momose Kazuhiro , Taniguchi Nobuaki , Suzuki Takeshi , Yatsu Takeyuki , Shibasaki Masayuki
Published: September 2006

Vasopressin (AVP) causes mesangial cell contraction, proliferation and hypertrophy. The present study investigated the effects of YM218, a potent, nonpeptide AVP V1A receptor-selective antagonist, on rat mesangial cells using binding, signal transduction and cell growth assays. Specific binding of 3H-AVP to rat mesangial cell plasma membranes was dependent upon time, temperature and membrane protein concentration. Scatchard plot analysis of equilibrium binding data revealed the existence of a single class of high-affinity binding sites with the expected V1A receptor profile. YM218 showed high affinity for V1A receptors, exhibiting a Ki value of 0.19 nmol/l. AVP concentration-dependently increased intracellular Ca2+ ([Ca2+]i) levels, stimulated mitogen-activated protein (MAP) kinase and induced hyperplasia. Conversely, YM218 potently suppressed [Ca2+]i elevation, activation of MAP kinase and hyperplasia induced by AVP. These results indicate that YM218 displays both high affinity for rat mesangial cell V1A receptors and high potency in inhibiting AVP-induced signal transduction and growth response. Therefore, YM218 is a useful pharmacologic tool for investigating the physiologic and pathophysiologic roles of AVP in kidney, and may have clinical application in the prevention or regression of mesangial cell growth.
Outcomes of Cognitively Impaired Not Demented at 2 Years in the Canadian Cohort Study of Cognitive Impairment and Related Dementias
Authors: Hsiung Ging-Yuek R. , Donald Alan , Grand Jacob , Black Sandra E. , Bouchard Remi W. , Gauthier Serge G. , Loy-English Inge , Hogan David B. , Kertesz Andrew , Rockwood Kenneth , Feldman Howard H.
Published: September 2006

Background: People who are cognitively impaired not demented (CIND) can be at an increased risk for developing dementia, but little is known about the natural history of CIND in clinical settings. Method: We examined the 2-year outcome of CIND subjects in the Canadian Cohort Study of Cognitive Impairment and Related Dementias.CIND was diagnosed when at least one positive item was endorsed on the DSM-III-R dementia criteria, but not all criteria were met. CIND was further subclassified as: pre-Alzheimer’s disease (pre-AD), vascular cognitive impairment (VCI-ND), non-AD degenerative, psychiatric, other neurologic, other medical conditions, mixed disorders and no etiology identified (not otherwise specified [NOS]). Result: Of 146 CIND patients with 2-year follow-up data available, 49 (34%) progressed to dementia, while 20 (14%) recovered to not cognitively impaired (NCI). Progressors were significantly older than stable CIND and reverters (p < 0.0001; mean age = 71.1, 64.3, and 59.1, respectively), and there were significantly (p = 0.001) more ApoE Ε4 carriers among progressors (67%) than stable CIND (29%) and reverters (12%). Pre-AD CIND and VCI-ND had the highest rate of conversion to dementia (41.0 and 40.0%, respectively), while psychiatric CIND and CIND NOS had highest rate of recovery to NCI (20.0 and 30.0%, respectively). All conversions in pre-AD CIND were to ‘probable AD’. Conclusion: CIND consists of a heterogeneous group of disorders that can be classified syndromically. Many subclassess – not just those with pre-AD CIND – are at high risk of progression to dementia, usually to Alzheimer’s disease.
Salt Loading on Plasma Asymmetrical Dimethylarginine and the Protective Role of Potassium Supplement in Normotensive Salt-Sensitive Asians
Authors: Fang Yuan , Mu Jian-Jun , He Lang-Chong , Wang Si-Cen , Liu Zhi-Quan
Published: September 2006

Asymmetrical dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase. Because endothelial NO pathway is compromised in patients with salt-sensitive hypertension, we investigated whether the plasma ADMA can be modulated by chronic salt loading in normotensive salt-sensitive persons and its relationship with NO, and we further determined whether or not dietary potassium supplementation can reverse them. Sixty normotensive subjects (aged 20 to 60 years) were selected from a rural community of Northern China. All of the people were sequentially maintained on a low-salt diet for 7 days (3 g/day, NaCl), then a high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for another 7 days (4.5 g/day, KCl). After salt loading, the plasma ADMA concentrations increased significantly in salt-sensitive subjects (0.89±0.02 μmol/L versus 0.51±0.02 μmol/L;
P
<0.05), whereas the plasma NOx levels reduced considerably (41.8±2.1 μmol/L versus 63.5±2.1 μmol/L;
P
<0.01). All of the abnormalities normalized when dietary potassium were supplemented (0.52±0.03 μmol/L versus 0.89±0.02 μmol/L for ADMA and 58.1±0.9 μmol/L versus 41.8±2.1 μmol/L for NOx). Statistically significant correlations were found among plasma ADMA level, the mean blood pressure, and the level of NO after salt loading in normotensive salt sensitive individuals. Our study indicates that high dietary potassium intake reduces blood pressure and ADMA levels while increasing NO bioactivity in normotensive salt-sensitive but not salt-resistant Asian subjects after salt loading.
Association Between Arterial Properties and Renal Sodium Handling in a General Population
Authors: Seidlerová Jitka , Staessen Jan A. , Maillard Marc , Nawrot Tim , Zhang Haifeng , Bochud Murielle , Kuznetsova Tatiana , Richart Tom , Van Bortel Luc M. , Struijker-Boudier Harry A. , Manunta Paolo , Burnier Michel , Fagard Robert , Filipovský Jan
Published: September 2006

Mean arterial pressure drives pressure–natriuresis and determines arterial structure and function. In a population sample, we investigated the relation between arterial characteristics and renal sodium handling as assessed by the clearance of endogenous lithium. We ultrasonographically measured diameter, cross-sectional compliance (CC) and distensibility (DC) of the carotid, brachial, and femoral arteries in 1069 untreated subjects (mean age: 41.6 years; 50.1% women; 18.8% hypertensive subjects). While accounting for covariates and standardizing for the sodium excretion rate in both sexes, CC and DC of the femoral artery increased with higher fractional distal sodium reabsorption. Differences associated with a 1-SD change in fractional distal reabsorption of sodium were 51.7 mm
2
/kPa×10
−3
(95% CI: 23.9 to 79.5;
P
=0.0002) and 0.56×10
−3
/kPa (95% CI: 0.17 to 0.94;
P
=0.004) for femoral CC and DC, respectively. In women as well as in men, a 1-SD increment in fractional proximal sodium reabsorption was associated with decreases in femoral and brachial diameter, amounting to 111.6 μm (95% CI: 38.2 to 185.1;
P
=0.003) and 52.5 μm (95% CI: 10.0 to 94.9;
P
=0.016), respectively. There was no consistent association between the properties of the elastic carotid artery and renal sodium handling. In conclusion, higher fractional sodium reabsorption in the distal nephron is associated with higher femoral CC and DC, and higher proximal sodium reabsorption is associated with decreased brachial and femoral diameters. These findings demonstrate that there might be an influence of renal sodium handling on arterial properties or vice versa or that common mechanisms might influence both arterial and renal function.
Clinical Utility and Safety of a Protocol for Noncardiac and Cardiac Magnetic Resonance Imaging of Patients With Permanent Pacemakers and Implantable-Cardioverter Defibrillators at 1.5 Tesla
Authors: Nazarian Saman , Roguin Ariel , Zviman Menekhem M. , Lardo Albert C. , Dickfeld Timm L. , Calkins Hugh , Weiss Robert G. , Berger Ronald D. , Bluemke David A. , Halperin Henry R.
Published: September 2006

Background—

Magnetic resonance imaging (MRI) is an important diagnostic modality currently unavailable for millions of patients because of the presence of implantable cardiac devices. We sought to evaluate the diagnostic utility and safety of noncardiac and cardiac MRI at 1.5T using a protocol that incorporates device selection and programming and limits the estimated specific absorption rate of MRI sequences.

Methods and Results—

Patients with no imaging alternative and with devices shown to be MRI safe by in vitro phantom and in vivo animal testing were enrolled. Of 55 patients who underwent 68 MRI studies, 31 had a pacemaker, and 24 had an implantable defibrillator. Pacing mode was changed to “asynchronous” for pacemaker-dependent patients and to “demand” for others. Magnet response and tachyarrhythmia functions were disabled. Blood pressure, ECG, oximetry, and symptoms were monitored. Efforts were made to limit the system-estimated whole-body average specific absorption rate to 2.0 W/kg (successful in >99% of sequences) while maintaining the diagnostic capability of MRI. No episodes of inappropriate inhibition or activation of pacing were observed. There were no significant differences between baseline and immediate or long-term (median 99 days after MRI) sensing amplitudes, lead impedances, or pacing thresholds. Diagnostic questions were answered in 100% of nonthoracic and 93% of thoracic studies. Clinical findings included diagnosis of vascular abnormalities (9 patients), diagnosis or staging of malignancy (9 patients), and assessment of cardiac viability (13 patients).

Conclusions—

Given appropriate precautions, noncardiac and cardiac MRI can potentially be safely performed in patients with selected implantable pacemaker and defibrillator systems.
Localization of Na
+
Channel Isoforms at the Atrioventricular Junction and Atrioventricular Node in the Rat
Authors: Yoo Shin , Dobrzynski Halina , Fedorov Vadim V. , Xu Shang-Zhong , Yamanushi Tomoko T. , Jones Sandra A. , Yamamoto Mitsuru , Nikolski Vladmir P. , Efimov Igor R. , Boyett Mark R.
Published: September 2006

Background—

The electrical activity of the atrioventricular node (AVN) is functionally heterogeneous, but how this relates to distinct cell types and the 3-dimensional structure of the AVN is unknown. To address this, we have studied the expression of Na
v
1.5 and other Na
+
channel isoforms in the AVN.

Methods and Results—

The rat AVN was identified by Masson’s trichrome staining together with immunolabeling of marker proteins: connexin40, connexin43, desmoplakin, atrial natriuretic peptide, and hyperpolarization-activated and cyclic nucleotide–gated channel 4. Na
+
channel expression was investigated with immunohistochemistry with isoform-specific Na
+
channel antibodies. Na
v
1.1 was distributed in a similar manner to Na
v
1.5. Na
v
1.2 was not detected. Na
v
1.3 labeling was present in nerve fibers and cell bodies (but not myocytes) and was abundant in the penetrating atrioventricular (AV) bundle and the common bundle but was much less abundant in other regions. Na
v
1.5 labeling was abundant in the atrial and ventricular myocardium and the left bundle branch. Na
v
1.5 labeling was absent in the open node, penetrating AV bundle, AV ring bundle, and common bundle but present at a reduced level in the inferior nodal extension and transitional zone. Na
v
1.6 was not detected.

Conclusions—

Our findings provide molecular evidence of multiple electrophysiological cell types at the AV junction. Impaired AV conduction as a result of mutations in or loss of Na
v
1.5 must be the result of impaired conduction in the AVN inputs (inferior nodal extension and transitional zone) or output (bundle branches) rather than the AVN itself (open node and penetrating AV bundle).