bluuebunny/crossref_metadata_2025 huggingface dataset:
Relaxation of Local-moment Nuclei in Metals
Authors: A Narath
Published: January 2007

The theory of nuclear-spin relaxation for magnetic impurities in non-magnetic metals is reviewed and compared with experiment. Both local-moment as well as localized spin-fluctuation limits of the impurity problem are discussed. The influence of the Kondo effect and of impurity-impurity interactions are briefly considered. The conditions under which observation of the local-moment NMR is practical and the information that can be obtained from such experiments are developed in some detail. Illustrative examples are drawn from recent work on Cu:55Mn and W:59Co alloys. Finally, the limitations of the isotropic conduction electron-local moment exchange model are explored.
On the Dynamics of Sonic-Langmuir Solitons
Authors: Karpman V I
Published: January 2007

The nonstationary evolution of nonlinear Langmuir waves is considered. In particular the process of soliton formation is studied in the case where the perturbation propagates with a speed close to that of sound. The influence of electron collisions on the motion of the soliton is also described.
Upper-Hybrid Solitons
Authors: Kaufman Allan N , Stenflo Lennart
Published: January 2007

A nonlinear upper hybrid wave with negative dispersion propagates across a magnetic field as a soliton, when its pulse speed exceeds the magnetosonic speed.
Relativistic Solitons and Pulsars
Authors: Karpman V I , Norman C A , ter Haar D , Tsytovich V N
Published: January 2007

We consider solitons in which the electrons and/or the positive ions have relativistic random velocities and we discuss possible applications of such solitons to pulsar phenomena.
Effects of Nonlinear Interaction of Monochromatic Waves with Resonant Particles in the Inhomogeneous Plasma
Authors: Karpman V I , Istomin J N , Shklyar D R
Published: January 2007

This paper is a review of results obtained by the authors in the field of non-linear monochromatic wave-particles interaction in the inhomogeneous plasma. The explicit expressions for the nonlinear growth rates and frequency shifts are derived and investigated for the cases of weak and strong inhomogeneity (the physical difference between the two cases is that in the first case there are trapped as well as untrapped particles; in the second one there are only untrapped particles). The modulational instability connected with the frequency shift, arising due to the nonlinearity and inhomogeneity, is considered.
Analytic Theory of Strong Nonlinear Wave Coupling in Plasma
Authors: Falk L R , Tsytovich V N
Published: January 2007

An analytic theory is given for the nonlinear, fixed-phase interaction between two high frequency waves and a low frequency field in a plasma, when the rate of interaction is much larger than the resonant low frequency, i.e. a quasidecay or modified decay process. Strong compensation occurs when the four wave interaction is included, which leads to an ion-dependent instability. Backscattering of electromagnetic waves due to quasidecay and induced scattering on particles is discussed.
Dispersive Oscillations in a System of Three Interacting Waves
Authors: Weiland J
Published: January 2007

Three-wave interaction among positive and negative energy modes as well as among three modes with the same energy sign has been studied in the presence of second order dispersive effects. In the case of positive and negative energy modes a nonlinear frequency shift from third order nonlinear terms has been taken into account in order to obtain limited solutions. The second order dispersive effects have been found to have a strong tendency to introduce oscillations in the wave amplitudes and phases. These oscillations have been described analytically and are found primarily to concern only the mode on which they are excited. To second order they may couple to the oscillations of the other modes and may then grow resonantly. To first order the wave energy is not influenced by the oscillations.
Propagation of Ion Acoustic Perturbations
Authors: Pécseli H L
Published: January 2007

Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered.
Instabilities in Active Molecular Plasma
Authors: Tsintsadze N L , Wilhelmsson H
Published: January 2007

Some properties of active molecular plasmas are considered in the presence of a strong circularly polarized wave. It is shown that the external field may cause new instabilities. Furthermore, new instabilities are found in active molecular hot plasmas even in the absence of external electric fields.
A Method of Analyzing the Resonance Conditions for a Three-Wave Interaction in a Magnetized Plasma
Authors: Gustavsson Hans-George
Published: January 2007

A procedure is formulated for a numerical solution of the problem of satisfying the resonant three-wave coupling conditions. It is applied to simple illustrative cases.
Parameter Constraints for Plasma Turbulent Reactors
Authors: Norman C A , ter Haar D , Tsytovich V N
Published: January 2007

We discuss how one can determine for given values of the electron density, the size, and the magnetic field strength in a system, whether it can be considered to be a plasma turbulent reactor.
The Effects of Comptonization and Fusion- and Decay-Processes on the Properties of Plasma Turbulent Reactors
Authors: Norman C A
Published: January 2007

The effects of Comptonization and Fusion- and Decay-processes on the properties of Plasma Turbulence Reactors (PTRs) is discussed. The possibilities of optically thin and relativistic PTRs are investigated.
Anomalous Reflexion of Laser Radiation due to the Build-up of Ion-sound Waves in a Plasma
Authors: Gustavsson Hans-George
Published: January 2007

A numerical approach is used to study the temporal development of the excitation levels of ion-sound waves and the associated reflexion and transmission properties, when laser radiation falls onto a plasma. The problem is treated in one dimension and the random phase approximation is used.
Coherent Nonlinear Backscattering by Laser-Plasma Interactions
Authors: Anderson D , Wilhelmsson H
Published: January 2007

A theoretical analysis is carried out for the problem of coherent nonlinear backscattering of laser radiation by a high density plasma. A number of effects of direct interest to the DT-pellet fusion research are investigated. A simple physical description is introduced, which relies on a nonlinear potential formulation of the scattering equations. The simplicity and the unified nature of the approach enables us to evaluate and compare the influence on the radiation reflectivity of different effects, such as e.g. inhomogeneities, blow-off velocities, temperature gradients, laser band width and relativistic oscillatory velocities. Our understanding of the role played by the various phenomena has consequently improved and we think that our approach should be useful for the interpretation of laser-plasma data obtained by computer simulation or laboratory experiments. The results may also be utilized to estimate how and to what extent one may avoid undesired anomalous reflection when planning new laser-plasma devices.
Generalized Rapidity for Space-like Particles
Authors: I Uschersohn
Published: January 2007

A new longitudinal variable is introduced. It can describe both time-like and space-like particles.
The g-Factor of the 80.1 keV Level in 144Pr
Authors: Chr Bargholtz  , S Beshai  , L Eriksson  , L-E Fröberg  , L Gidefeldt
Published: January 2007

The g-factor of the 80.1 keV level in 144Pr has been determined in an IPAC study of the 53.4-80.1 keV cascade. With an external magnetic field of 21.7(3) kG the precession angle ωτ was measured to be -0.045(12). The result g = -1.2(4) agrees well with that calculated in terms of coupling of the effective moments of the odd particles, g = -1.43(7). From the directional correlation of the 53.4-80.1 keV cascade the mixing ratio of the 53.4 keV transition was determined, δ(E2/M1) = 0.043(3).
The Oxygen Spectrum below 200 Å and the High-limit Terms of O IV
Authors: Bengt Edlén
Published: January 2007

The vacuum-spark spectrum of oxygen in the region below 200 Å is described by means of spectrum reproductions and a table of 214 lines from 198 Å to 94 Å, representing O IV, O V, O VI and traces of O VII. The high-limit term systems of O IV are re-examined, and the result is given in a comprehensive list of terms belonging to the limits 2s2p1Pand 2p2 3P,1D,1S.
Lifetimes and Transition Probabilities in N V
Authors: Y Baudinet-Robinet  , P D Dumont  , E Biémont  , N Grevesse
Published: January 2007

Lifetimes of excited levels in N V have been measured by the beam-foil technique using lines in the ultraviolet spectral range. Transition probabilities are deduced from these results using branching ratios computed in the Coulomb approximation.
Specific Heat Measurements of the C 15 Phase of TaV2
Authors: Per Wennerström  , Stig Byström  , Mats Larsson  , Torsten Lindqvist  , Östen Rapp
Published: January 2007

The specific heat of the cubic Laves compound (C15) TaV2 has been measured in the temperature range 0.4-7 K. TaV2 is found to become superconducting at 3.6 K. The Debye temperature was determined to be 279 K. The normal state electronic contribution (γ) was 8.2 mJ/g-atom·K2.
The Heat Capacity of Liquid Metals
Authors: G Grimvall
Published: January 2007

The heat capacity at constant volumeCVfor liquid Na, K and Hg has been evaluated based on a critical analysis of experimental data. After substraction of the electronic heat capacity,CVsmoothly decreases towards approximately 2kBper atom as the critical temperature is approached.
The Magnetocrystalline Anisotropy Constants of Iron and Iron-silicon Alloys
Authors: Björn Westerstrand  , Per Nordblad  , Lars Nordborg
Published: January 2007

The magnetocrystalline anisotropy constantsk1,k2andk3of iron and of alloys of 1.75, 2.46, 3.56 and 4.59 weight per cent silicon in iron have been measured in the temperature range 4.2-295 K. The measurements have been performed on spherical samples. The field dependence of the anisotropy constantsKn(n= 1,2,...) determined from torque curves is described by

Kn=kn- μ0MnHi,M,n= 1, 2 ....

whereMnare the direction dependent parts of the magnetization, andHi,Mis the component of the field inside the sample along the direction of magnetization. The magnetocrystalline anisotropy constantsknare obtained by extrapolation to zero internal field. The anisotropy of magnetization is reported with values ofM1andM2.
Localization of d-States in Alloys of Transition and Noble Metals
Authors: V V Nemoshkalenko  , V G Aleshin  , V M Pessa  , M G Chudinov
Published: January 2007

We show in this work that the one-electron approximation as applied to studies of the energy bands of transition metals can be successfully used to calculate the distribution of photoelectrons in the X-ray excited electron spectra of pure transition and noble metals. Photoelectron spectra of alloys may differ markedly from the energy distribution of electrons in the same alloys. Furthermore, in calculating the X-ray excited electron spectra of alloys one should take into account a difference between scattering properties of the constituent atomic centers. Detailed investigations on Cu, Pd and Ag metals and Cu-Pd, Cu-Mn and Ag-Pd alloys are carried out here.
The Abundance of Nuclei from Sodium to Silicon in Cosmic Rays
Authors: R Andersson
Published: January 2007

The expected charge spectrum at the top of the atmosphere has been calculated for the charge interval 11 ⩽ Z ⩽ 14. The calculations have been based on the assumption that cosmic ray particles are selected by an ionization process from matter having `normal' composition. The ratios Na/Mg, Al/Si and (Na + Al)/(Mg + Si) have been studied as a function of the amount of matter passed for different transport models and compared with experimental results. If the transport takes place at the constant energy E = 800 MeV/n, the comparisons indicate a path length of about 4 g cm-2 for a slab model and a mean path length larger than or equal to 5 g cm-2 for an exponential model. The possibilities of using 26Al to determine the age of cosmic rays have been discussed. The ratio Na/Al is found to be very advantageous for an age determination but experimental data are not yet sufficiently accurate for this age estimate.
A Double‐Blind, Placebo‐Controlled, Pilot Study of Bovine Lactoferrin Supplementation in Bottle‐fed Infants
Authors: King James C , Cummings Ginny E , Guo Nan , Trivedi Leena , Readmond Bernard X , Keane Virginia , Feigelman Susan , de Waard Rick
Published: January 2007

Background:

Lactoferrin has an array of biological activities that include growth, immune modulation, and antimicrobial effects. The aim of this randomized, placebo‐controlled, double‐blind study was to examine the impact of bovine lactoferrin supplementation in infants.

Patients and Methods:

Healthy, formula‐fed infants, ≥34 weeks' gestation and ≤4 weeks of age, enrolled in a pediatric clinic. Infants received either formula supplemented with lactoferrin (850 mg/L) or commercial cow milk–based formula (102 mg/L) for 12 months. Growth parameters and information on gastrointestinal, respiratory, and colic illnesses were collected for the infants' first year. Antibodies to immunizations and hematologic parameters were measured at 9 and 12 months.

Results:

The lactoferrin‐enhanced formula was well tolerated. There were significantly fewer lower respiratory tract illnesses, primarily wheezing, in the 26 lactoferrin‐fed (0.15 episodes/y) compared with the 26 regular formula‐fed (0.5 episodes/y) infants (P < 0.05). Significantly higher hematocrit levels at 9 months (37.1% vs 35.4%; P < 0.05) occurred in the lactoferrin‐supplemented group compared with the control formula group.

Conclusions:

Lactoferrin supplementation was associated with potentially beneficial outcomes such as significantly fewer lower respiratory tract illnesses and higher hematocrits. Larger, more focused studies in infants are warranted.
Effects of Oral Administration of Bifidobacterium breve on Fecal Lactic Acid and Short‐chain Fatty Acids in Low Birth Weight Infants
Authors: Wang Chongxin , Shoji Hiromichi , Sato Hiroaki , Nagata Satoru , Ohtsuka Yoshikazu , Shimizu Toshiaki , Yamashiro Yuichiro
Published: January 2007

Objectives:

Short‐chain fatty acids (SCFAs) are known to provide energy to colonocytes, whereas overproduction of SCFAs can cause mucosal injury in premature infants. Our objective was to investigate the effects of the oral administration of Bifidobacterium breve M‐16V (B breve) on fecal lactic acid and SCFAs in low birth weight (LBW) infants.

Patients and Methods:

Fecal lactic, acetic, propionic, and butyric acids from 66 premature infants were analyzed by high‐performance liquid chromatography at 0, 2, and 4 weeks after birth. The subjects included 22 extremely LBW (ELBW, <1000 g), 22 very LBW (VLBW, <1500 g), and 22 LBW (<2500 g) infants. The infants were divided into two groups: those with and those without B. breve supplementation.

Results:

In the control groups, fecal acetic acid and total SCFA concentrations were significantly increased at 2 weeks in the VLBW and LBW infants (P < 0.05) and at 4 weeks in the ELBW, VLBW, and LBW infants (P < 0.01 for each) compared with those at week 0. Fecal lactic acid concentrations showed a similar pattern during follow‐up, but the differences were not significant. Four weeks after B breve administration, the fecal butyric acid concentrations were significantly decreased in the ELBW and VLBW infants (P < 0.05 each), and the ratio of the acetic acid concentrations to the total SCFAs was significantly increased compared with those of the control groups in the ELBW (P < 0.05), VLBW (P < 0.05), and LBW infants (P < 0.01).

Conclusions:

Oral administration of B breve reduces the production of butyric acid, which may be helpful in protecting LBW infants from digestive diseases such as necrotizing enterocolitis.
At What Age Is a Suction Rectal Biopsy Less Likely to Provide Adequate Tissue for Identification of Ganglion Cells?
Authors: Croffie Joseph M , Davis Mary M , Faught Philip R , Corkins Mark R , Gupta Sandeep K , Pfefferkorn Marian D , Molleston Jean P , Fitzgerald Joseph F
Published: January 2007

Objective:

The objective of this study was to determine at what age suction rectal biopsy is less likely to provide adequate tissue to detect submucosal ganglion cells in a child being evaluated for Hirschsprung disease.

Patients and Methods:

Children ≥1 year of age undergoing a rectal biopsy at a single children's hospital had 1 biopsy each obtained simultaneously with a suction biopsy device and a grasp biopsy forceps. The biopsies were examined by 2 pathologists for adequacy of the submucosa (none, scant, adequate, or ample) and the presence of ganglion cells. The 2 specimens were compared with each other.

Results:

One hundred fifty‐two children 1 to 17 years of age were included. Fifty‐three were female. Subjects were grouped into 4 age categories: 1 to 3 years (group A), 4 to 6 years (group B), 7 to 9 years (group C), and ≥10 years (group D). Similar numbers of patients were recruited for each group. Ganglion cells were identified in 73% and 90% by the suction and grasp devices, respectively, in group A. In groups B through D, ganglion cells were identified in 50% to 53% vs 92% to 97% of the suction and grasp biopsies, respectively (P < 0.001). Submucosa was present in 88% (suction) vs 98% (grasp) in group A, 70% vs 95% in group B, 69% vs 94% in group C, and 45% vs 92% in group D.

Conclusion:

The suction rectal biopsy is less likely to provide adequate submucosa for identification of ganglion cells after 3 years of age.
Natalizumab Therapy for Moderate to Severe Crohn Disease in Adolescents
Authors: Hyams Jeffrey S , Wilson David C , Thomas Adrian , Heuschkel Robert , Mitton Sally , Mitchell Brent , Daniels Regina , Libonati Michele A , Zanker Susan , Kugathasan Subra ,   International Natalizumab CD305 Trial Group
Published: January 2007

Objectives:

This study evaluated the safety, tolerability, and efficacy of natalizumab, a humanized monoclonal immunoglobulin‐G4 antibody to α4 integrin, in adolescent patients with moderately to severely active Crohn disease (CD).

Patients and Methods:

In a single‐arm study, 38 adolescent patients (ages 12–17 y) with active CD (Pediatric Crohn Disease Activity Index [PCDAI] >30) received 3 intravenous infusions of natalizumab (3 mg/kg) at 0, 4 and 8 weeks. The primary analysis was safety, assessed by adverse events, laboratory results, and vital signs. Pharmacokinetic and pharmacodynamic measurements and formation of anti‐natalizumab antibodies also were analyzed. Efficacy outcomes were assessed by changes in PCDAI, quality of life (IMPACT III), and levels of C‐reactive protein and serum albumin.

Results:

Thirty‐one patients (82%) received 3 natalizumab infusions. The most common adverse events were headache (26%), pyrexia (21%) and CD exacerbation (24%). Clinical response (≥15‐point decrease from baseline PCDAI) and remission (PCDAI ≤10) rates were greatest at week 10 (55% and 29%, respectively). Three patients (8%) tested positive for anti‐natalizumab antibodies. The peak level (61.0 and 66.3 μg/mL) and half‐life (92.3 and 96.3 h) of natalizumab were comparable after the first and third infusions. Mean α4 integrin receptor saturation was 93% at 2 hours and <40% at 4 weeks after the first and third infusions. Increase from baseline in circulating lymphocytes ranged from 106% to 122% at 2 weeks and 45% to 65% at 4 weeks after each infusion.

Conclusion:

Natalizumab (3 mg/kg) was well tolerated in these adolescent patients with active CD, with a safety and efficacy profile similar to that of adult natalizumab‐treated CD patients. Future studies should evaluate long‐term safety and efficacy.
Influence of Different Intravenous Lipid Emulsions on Hepatobiliary Dysfunction in a Rabbit Model
Authors: Kohl Martina , Wedel Thilo , Entenmann Andreas , Stuttmann Julia , Bendiks Meike , Loff Steffan , Köster Stefan , Ortfeld Stefan , Bos Inge
Published: January 2007

Objectives:

Long‐term total parenteral nutrition (TPN) in children is often complicated by the development of cholestasis, liver fibrosis, and liver failure. High doses of intravenous lipids may be involved in the pathogenesis of hepatobiliary dysfunction. The purpose of this study was to determine whether the use of 2 newly developed lipid emulsions could reduce liver damage.

Materials and Methods:

Three groups of prepubescent rabbits received TPN including a lipid emulsion either based on soybean oil, olive oil, or soybean oil with n‐3 fatty acids added. Enterally fed animals served as controls. After 21 d the animals were killed. Serum samples were obtained at the beginning and end of the study period. Specimens were processed for histological evaluation using a specific score to assess the severity of liver damage.

Results:

Biochemical parameters did not predict the extent of liver damage. Hydropic degeneration as an indicator of toxic liver injury was the predominant histological alteration regardless of the type of lipids infused. The extent of fibrosis did not significantly differ among treatment groups except for animals infused with n‐3 fatty acids exhibiting increased fibrotic transformation as compared with controls.

Conclusion:

In our animal model, the use of a lipid emulsion with a reduced amount of polyunsaturated fatty acids was not superior to a lipid emulsion based on soybean oil. Long‐term application of n‐3 fatty acids was associated with more extensive fibrosis. Therefore, intravenous n‐3 fatty acids containing lipid preparations (fish oil) should not be used in patients for long‐term TPN.
Colorectal Carcinoma in Childhood: A Retrospective Multicenter Study
Authors: Kravarusic Dragan , Feigin Elad , Dlugy Elena , Steinberg Ran , Baazov Arthur , Erez Ilan , Lazar Ludvig , Kapuller Vadim , Grunspan Moshe , Ash Shifra , Freud Enrique
Published: January 2007

Objectives:

Colorectal carcinoma, a common adult malignancy, has an estimated childhood incidence of 0.3 to 1.5/million in Western countries and 0.2/million in Israel. Diagnosis is difficult because adult screening measures are unfeasible in children. The tumor is frequently associated with predisposing genetic factors, aggressive biological behavior, and poor prognosis. The aim of this multicenter study was to document the clinical profile, treatment and prognosis of colorectal carcinoma in children in Israel.

Patients and Methods:

The clinical, laboratory, therapeutic, and prognostic parameters of all 7 children from 4 medical centers in Israel who were diagnosed with colorectal carcinoma over a 25‐y period were reviewed.

Results:

Patients presented with rectal bleeding (4 of 7), abdominal pain (2 of 7), and abdominal distension (2 of 7). Average time to diagnosis was 6 months. Six patients underwent surgery (1 refused), and 5 received chemotherapy. Histopathological studies showed poorly differentiated mucinous adenocarcinoma, signet‐ring type, in 4 cases, moderately differentiated adenocarcinoma in 2, and well‐differentiated carcinoma in 1. Three patients died of the disease, 2 shortly after diagnosis. One patient with recurrent metastatic disease was lost to follow‐up.

Conclusion:

Colorectal carcinoma in children is characterized by aggressive tumor behavior and delayed diagnosis, resulting in a worse prognosis than in adults. Heightened physician awareness of the possibility of this disease in children, with special attention to adolescents with predisposing factors and rectal bleeding, could help to improve outcome.
Risk Factors for Small Bowel Bacterial Overgrowth in Cystic Fibrosis
Authors: Fridge Jacqueline L , Conrad Carol , Gerson Lauren , Castillo Ricardo O , Cox Kenneth
Published: January 2007

Objectives:

The purpose of this study was to determine the prevalence of small bowel bacterial overgrowth in patients with pancreatic‐insufficient cystic fibrosis (CF) compared with age‐matched controls and to identify potential risk factors for small bowel bacterial overgrowth.

Patients and Methods:

Fifty patients, 25 pancreatic‐insufficient CF study patients (mean age, 17 y) and 25 gastrointestinal clinic control patients (mean age, 15 y), completed a glucose‐hydrogen breath test after an overnight fast. Study patients completed a quality‐of‐life questionnaire modified from the Cystic Fibrosis Questionnaire. The medical history of each patient was compared with breath test results. A positive breath test was defined as a fasting hydrogen ≥15 ppm or a rise of ≥10 ppm hydrogen over baseline during the test.

Results:

The prevalence of positive breath tests was higher in the CF study group (56%) than in the control group (20%) (P = 0.02). The mean fasting hydrogen levels of patients in the study and control groups were 22 and 5 ppm (P = 0.0001). The mean questionnaire scores were not significantly different between breath test–positive and –negative study patients. The use of azithromycin was associated with an increased risk of a positive breath test. Use of laxatives and inhaled ipratropium was associated with a decreased risk of a positive breath test.

Conclusions:

Patients with CF were more likely to have elevated fasting hydrogen levels compared with controls. This suggests a high prevalence of small bowel bacterial overgrowth in CF patients. Medications commonly used by CF patients may influence intestinal health.
Efficacy of Rice‐based Oral Rehydration Solution Containing Recombinant Human Lactoferrin and Lysozyme in Peruvian Children With Acute Diarrhea
Authors: Zavaleta Nelly , Figueroa Dante , Rivera Juan , Sánchez Julia , Alfaro Segundo , Lönnerdal Bo
Published: January 2007

Objective:

To compare glucose and rice‐based oral rehydration solution with rice‐based oral rehydration solution containing recombinant human lactoferrin and recombinant human lysozyme in diarrhea outcomes.

Patients and Methods:

We conducted a randomized, double‐blind controlled trial in children with acute diarrhea and dehydration. One hundred and forty children 5 to 33 months old were block randomized to receive low osmolarity WHO‐ORS (G‐ORS), rice‐based ORS (R‐ORS), or rice‐based ORS plus lactoferrin and lysozyme (Lf/Lz‐R‐ORS). Intake and output were monitored for 48 h in the ORU, with continued monitoring through home and clinic follow‐up for 14 d.

Results:

The G‐ORS and R‐ORS groups did not show any differences in diarrhea outcomes and were therefore combined as the control group. Intent‐to‐treat analysis showed a significant decrease in duration of diarrhea (3.67 d vs 5.21 d, P = 0.05) in the Lf/Lz‐R‐ORS group as compared with the control group and a significant increase in the number of children who achieved 48 h with solid stool, 85% vs 69% (P < 0.05). There were also decreases in volume of diarrhea and the percentage of children who had a new diarrhea episode after achieving the endpoint.

Conclusions:

Addition of recombinant human lactoferrin and lysozyme to a rice‐based oral rehydration solution had beneficial effects on children with acute diarrhea.
Comparison of Monoclonal and Polyclonal ELISAs for Fecal Elastase in Patients With Cystic Fibrosis and Pancreatic Insufficiency
Authors: Borowitz Drucy , Lin Rong , Baker Susan S
Published: January 2007

Objectives:

Two enzyme‐linked immunosorbent assay methodologies are used to detect pancreatic insufficiency: monoclonal and polyclonal. We sought to compare these assays in patients with cystic fibrosis and to correlate these with the coefficient of fat absorption (CFA).

Study Design:

As part of a larger study, subjects had stool elastase measured by both methods while taking exogenous enzymes. Subjects subsequently stopped enzymes and had a fecal fat balance study performed; the CFA was then calculated.

Results:

One hundred twenty‐four subjects participated in this substudy. The median values for the monoclonal and polyclonal assays were 0.3 and 22.75 μg/g, respectively. The correlation coefficient between the 2 tests was 0.86 (P < 0.0001). The correlation coefficients between CFA and the monoclonal and polyclonal assays were 0.24 (P = 0.006) and 0.10 (P = 0.27), respectively. If the criterion standard definition of pancreatic insufficiency was set at a CFA < 90% and the test definition of pancreatic insufficiency was set at <100 μg/g, then the monoclonal and polyclonal assay positive predictive values were 97.6% (120 of 123) and 97.4% (111 of 114), respectively.

Conclusions:

The positive predictive value of both monoclonal and polyclonal fecal elastase in patients with cystic fibrosis is extremely good; however, correlation of either test with CFA was poor. The median value for the polyclonal elastase assay is higher than for the monoclonal assay, which could potentially lead to lower sensitivity of the polyclonal assay at lower cutpoints for the monoclonal assay is used.
Polymorphisms of Tumor Necrosis Factor‐α but Not MDR1 Influence Response to Medical Therapy in Pediatric‐Onset Inflammatory Bowel Disease
Authors: Cucchiara Salvatore , Latiano Anna , Palmieri Orazio , Canani Roberto Berni , D'Incà Renata , Guariso Graziella , Vieni Giuseppe , De Venuto Domenica , Riegler Gabriele , de'Angelis Gian Luigi , Guagnozzi Danila , Bascietto Cinzia , Miele Erasmo , Valvano Maria Rosa , Bossa Fabrizio , Annese Vito ,   Italian Society of Pediatric Gastroenterology and Nutrition
Published: January 2007

Aim:

We investigated the contribution of variants of tumour necrosis factor (TNF)‐α and MDR1 genes in the predisposition and response to medical therapy in a large pediatric cohort of patients with Crohn disease (CD) and ulcerative colitis (UC).

Patients and Methods:

In this study, 200 patients with CD, 186 patients with UC, 434 parents (217 trios), and 347 healthy unrelated controls were investigated. Single‐nucleotide polymorphisms −G308A and −C857T of the TNF‐α gene and C3435T of the MDR1 gene were investigated and correlated with clinical subphenotypes and efficacy of medical therapy.

Results:

The frequency of the −308A allele of the TNF‐α gene was significantly increased in both patients with CD (15%; odds ratio [OR] = 2.79; P < 0.01) and patients with UC (11%; OR = 1.96; P < 0.003) compared with controls (6%). Carriers of this allele were 27% in CD (OR = 2.94; P < 0.01) and 19% in UC (OR = 1.86; P = 0.015) compared with 11% in healthy controls. No significant difference was found for both the −C857T and C3435T single‐nucleotide polymorphisms. With the genotype/phenotype analysis, no correlation in patients with UC with the MDR1 gene was found. CD carriers of the −308A allele had a higher frequency of surgical resection (35% vs 20%; OR = 2.1; P = 0.035) and more frequent resistance to steroids (22% vs 8%; OR = 0.29; P = 0.032) compared with noncarriers. These findings were confirmed by stepwise logistic regression.

Conclusions:

In our pediatric cohort, the promoter −308A polymorphism of TNF‐α but not the MDR1 gene is significantly involved in the predisposition to both CD and UC. This polymorphism carries a significant reduction in response to steroid therapy, probably leading to a more frequent need for surgical resection.
Small Volume Enemas Do Not Accelerate Meconium Evacuation in Very Low Birth Weight Infants
Authors: Haiden Nadja , Jilma Bernd , Gerhold Bernadette , Klebermass Katrin , Prusa Andrea R , Kuhle Stefan , Rohrmeister Klaudia , Kohlhauser‐Vollmuth Christina , Pollak Arnold
Published: January 2007

We hypothesized that small volume enemas accelerate meconium evacuation in very low birth weight (VLBW) infants. In a randomized controlled trial, VLBW infants (n = 81) received either repeated daily small volume enemas if complete spontaneous meconium passage failed within 24 h or no intervention. Small volume enemas did not accelerate complete meconium evacuation, which occurred after 6.0 to 9.6 (95% CI) d in the intervention group and after 7.7 to 11.0 (95% CI) d in the control group. No adverse events were observed. Daily administration of small volume enemas had no effect on total meconium evacuation defined by the time of last meconium passage.
Hepatitis B “By Proxy”: An Emerging Presentation of Chronic Hepatitis B in Children
Authors: Sciveres Marco , Maggiore Giuseppe
Published: January 2007

We report on 6 adopted asymptomatic children in whom chronic HBV infection was identified through the occurrence of an acute hepatitis B in a family member. All of the children had serum HBV‐DNA >2000 pg/mL. Acute hepatitis B in a family should alert the physician regarding the possibility of existing chronic HBV infection in other members of the family, especially newly adopted children, leading to a quick evaluation of their HBV status and to an efficacious protection of susceptible family members.
Risk for Nonalcoholic Fatty Liver Disease in Hispanic Youth With BMI ≥95th Percentile
Authors: Quirós‐Tejeira Rubén E , Rivera Chantal A , Ziba Taonga T , Mehta Nitesh , Smith C Wayne , Butte Nancy F
Published: January 2007

Objectives:

To characterize children at risk for nonalcoholic fatty liver disease (NAFLD) and to explore possible mechanisms underlying the development of NAFLD in Hispanic youth with a body mass index ≥95th percentile.

Patients and Methods:

Hispanic nonoverweight (n = 475) and overweight (n = 517) children, ages 4 to 19 y, were characterized in terms of body composition (dual‐energy x‐ray absorptiometry), maturation (Tanner stage), diet (24‐h recall), physical activity (accelerometry), fitness (maximal oxygen uptake), and biochemical profile (fasting alanine aminotransferase [ALT], glucose, insulin, and lipids; inflammation markers such as adiponectin, leptin, C‐reactive protein, and soluble intercellular adhesion molecule‐1; and total antioxidants) using standard laboratory techniques. Risk for NAFLD was defined by fasting serum ALT values >97.5th percentile for age‐ and sex‐specific reference values.

Results:

Fasting serum ALT was elevated in 24% of overweight children and in only 4% of nonoverweight children. Therefore, to identify risk factors associated with elevated ALT, the remaining statistical analysis was restricted to the overweight group. The percentage of overweight children with elevated ALT did not differ by sex, age, or Tanner stage. Weight, body mass index, z score, waist‐to‐hip ratio, fat‐free mass, fat mass, and percent truncal fat mass were higher in the overweight children with elevated ALT. Fasting insulin, glucose, and homeostasis model‐insulin resistance were higher in the overweight children with elevated ALT, as were triglycerides, total cholesterol, low‐density lipoprotein, thyroid‐stimulating hormone, and triiodothyronine. Fasting serum leptin, C‐reactive protein, and soluble intercellular adhesion molecule‐1 were significantly higher and adiponectin was lower in the overweight children with elevated ALT.

Conclusions:

The risk for developing NAFLD was high in the overweight Hispanic children. The proportion of “at risk” children was not influenced by gender, age, or maturation. The risk for elevated ALT was predicted by the severity of obesity, central adiposity, hyperinsulinemia, hypertriglyceridemia, elevated thyroid‐stimulating hormone, and systemic inflammation.
Hepatosplenic T Cell Lymphoma Associated With Infliximab Use in Young Patients Treated for Inflammatory Bowel Disease
Authors: Mackey Ann Corken , Green Lanh , Liang Li‐ching , Dinndorf Patricia , Avigan Mark
Published: January 2007

Hepatosplenic T cell lymphoma (HSTCL) are rare cancers (≈100 published cases worldwide) and comprise 5% of peripheral T cell lymphomas. As of October 5, 2006, the FDA's Adverse Event Reporting System has received 8 cases of HSTCL in young patients using infliximab, a tumor necrosis factor‐α blocking agent, to treat inflammatory bowel disease (6 of the 8 cases had a fatal outcome). All 8 patients were receiving concomitant immunosuppressant therapy (eg, azathioprine, prednisone). It has not been established that infliximab had an exclusive or primary role in the pathogenesis of these HSTCL cases; however, it appears that patients using this product may be at greater risk for developing this rare lymphoma.
Characterization of a novel Toll/interleukin‐1 receptor (TIR)‐TIR gene differentially expressed in common bean (Phaseolus vulgaris cv. Othello) undergoing a defence response to the geminivirus Bean dwarf mosaic virus
Authors: SEO YOUNG‐SU , JEON JONG‐SEONG , ROJAS MARIA R. , GILBERTSON ROBERT L.
Published: January 2007

Common bean (Phaseolus vulgaris L.) cultivar (cv.) Othello develops a hypersensitive response‐associated vascular resistance to infection by Bean dwarf mosaic virus (BDMV), a single‐stranded DNA virus (genus Begomovirus, family Geminiviridae). A PCR‐based cDNA subtraction approach was used to identify genes involved in this resistance response. Eighteen clones, potentially involved with BDMV resistance, were identified based upon being up‐regulated in BDMV‐infected tissues and/or having sequence similarity with known resistance‐associated genes. Analysis of these clones revealed potential genes involved in pathogen defence, including pathogenesis‐related protein genes and resistance gene analogues (RGAs). Further characterization of one RGA, F1‐10, revealed that it encodes a predicted protein with a double Toll/interleukin‐1 receptor (TIR) motif. Full‐length (F1‐10) and spliced (F1‐10sp) forms of the RGA were strongly up‐regulated in BDMV‐infected cv. Othello hypocotyl tissues by 4 days post‐inoculation, but not in equivalent mock‐inoculated tissues. In agroinfiltration experiments, F1‐10, but not F1‐10sp, mediated resistance to BDMV in the susceptible common bean cv. Topcrop. By contrast, transgenic Nicotiana benthamiana lines expressing F1‐10 or F1‐10sp were not resistant to BDMV. Interestingly, when these transgenic lines were inoculated with the potyvirus Bean yellow mosaic virus, some F1‐10 lines showed a more severe symptom phenotype compared with non‐transgenic control plants. Based on these findings, F1‐10 was named: Phaseolus vulgaris VIRUS response TIR‐TIR GENE 1 (PvVTT1).
Ferricrocin synthesis inMagnaporthe griseaand its role in pathogenicity in rice
Authors: HOF CAROLIN , EISFELD KATRIN , WELZEL KAI , ANTELO LUIS , FOSTER ANDREW J. , ANKE HEIDRUN
Published: January 2007

Iron is an essential element for the growth of nearly all organisms. In order to overcome the problem of its low bioavailability, microorganisms (including fungi) secrete siderophores, high‐affinity iron chelators. As the acquisition of iron is also a key step in infection processes, siderophores have been considered as potential virulence factors in several host–pathogen interactions. Most fungi produce siderophores of the hydroxamate‐type, which are synthesized by non‐ribosomal peptide synthetases (NRPSs).Magnaporthe grisea, the causal agent of rice blast disease, produces ferricrocin as intracellular storage siderophore and excretes coprogens. In theM. griseagenome we identifiedSSM1, an NRPS gene, and a gene encoding anl‐ornithine N5‐monooxygenase (OMO1) that is clustered withSSM1and responsible for catalysing the first step in siderophore biosynthesis, the N5hydroxylation of ornithine. Disruption ofSSM1confirmed that the gene encodes ferricrocin synthetase. Pathogenicity of these mutants towards rice was reduced, suggesting a role of this siderophore in pathogenicity ofM. grisea.
Zucchini yellow mosaic virus: insect transmission and pathogenicity —the tails of two proteins
Authors: GAL‐ON AMIT
Published: January 2007

Taxonomy: Zucchini yellow mosaic virus (ZYMV) is a member of genus Potyvirus, family Potyviridae. ZYMV is a positive‐strand RNA virus.

 Physical properties: Virions are flexuous filaments of 680–730 nm in length and 11–13 nm in diameter, composed of about 2000 subunits of a single 31‐kDa protein (calculated). The genome RNA size is 9.6 kb covalently linked to a viral‐encoded protein (the VPg) at the 5′ end, and with a 3′ poly A tail. The 5′ end of the sequence is AU‐rich (69%).

 Viral proteins: The genome is expressed as a polyprotein cleaved by three viral proteases and processed into ten putative mature proteins. The structural coat protein is processed from the carboxyl terminus of the polyprotein and is highly immunogenic.

 Host and symptoms: Natural and experimental infection has been reported mainly in the Cucurbitaceae. Experimental local lesion hosts include Chenopodium amaranticolour, C. quinoa and Gomphrena globosa. Some ZYMV strains cause symptomless infection as in Ranunculus sardous, Nicotiana benthamiana and Sesamum indicum. ZYMV causes stunting and major foliar deformation with dark green blisters and mosaics in cucurbit hosts, eventually developing a filamentous leaf phenotype. In general, symptoms are severe on cucurbit hosts and cause dramatic reductions in yields due to severe fruit deformation. The virus is present in all the plant tissues at relatively high concentrations (c. 0.1 mg/mL of purified virus per 1 g fresh leaf tissue). The most suitable species for maintenance and purification is Cucurbita pepo.

 Transmission: ZYMV is efficiently transmitted by aphids in a non‐persistent manner. The coat protein (CP) and the helper component‐protease (HC‐Pro) are required for aphid transmission, through the CP DAG motif and the HC‐Pro KLSC and PTK motifs. Mechanical transmission is efficient both in the laboratory and naturally.

 Economic importance: ZYMV disease is a major constraint in the production of cucurbits world‐wide. The virus can cause massive damage (to total loss) to cucurbit crops, and prevents the growth of some cucurbit crops in certain areas. Control of ZYMV requires the integration of conventional resistance and transgenic breeding along with cross‐protection technologies.
Functional analysis of NLP genes from Botrytis elliptica
Authors: STAATS MARTIJN , VAN BAARLEN PETER , SCHOUTEN ALEXANDER , VAN KAN JAN A. L.
Published: January 2007

We functionally analysed two Nep1‐like protein (NLP) genes from Botrytis elliptica (a specialized pathogen of lily), encoding proteins homologous to the necrosis and ethylene‐inducing protein (NEP1) from Fusarium oxysporum. Single gene replacement mutants were made for BeNEP1 and BeNEP2, providing the first example of transformation and successful targeted mutagenesis in this fungus. The virulence of both mutants on lily leaves was not affected. BeNEP1 and BeNEP2 were individually expressed in the yeast Pichia pastoris, and the necrosis‐inducing activity was tested by infiltration of both proteins into leaves of several monocots and eudicots. Necrotic symptoms developed on the eudicots tobacco, Nicotiana benthamiana and Arabidopsis thaliana, and cell death was induced in tomato cell suspensions. No necrotic symptoms developed on leaves of the monocots rice, maize and lily. These results support the hypothesis that the necrosis‐inducing activity of NLPs is limited to eudicots. We conclude that NLPs are not essential virulence factors and they do not function as host‐selective toxins for B. elliptica.
Biogeochemical interactions between iron and sulphate in freshwater wetlands and their implications for interspecific competition between aquatic macrophytes
Authors: VAN DER WELLE MARLIES E. W. , SMOLDERS ALFONS J.P. , OP DEN CAMP HUUB J.M. , ROELOFS JAN G.M. , LAMERS LEON P.M.
Published: January 2007

1. Wetlands are threatened by desiccation, eutrophication and changing water quality, generally leading to greatly altered biogeochemical processes. Sulphate pollution can lead to severe eutrophication and sulphide toxicity, but may also interact with the availability of iron and other metals.

2. In the present study, we examined the biogeochemical interactions between sulphate and iron availability, and their effects on aquatic macrophytes, in a field experiment with enclosures. The natural iron supply by groundwater was mimicked by adding iron to the sediment, and the effect of increased sulphate concentrations in the surface water was also studied. The enclosure experiment was performed in a mesotrophic, anaerobic ditch in a peat meadow reserve in the Netherlands. In all enclosures, three Stratiotes aloides plants were introduced to serve as indicator species.

3. Addition of sulphate led to the mobilisation of phosphate, whereas addition of iron or both iron and sulphate did not affect P mobilisation. Growth of S. aloides was decreased by both iron addition and sulphate addition (sulphide toxicity). Addition of iron under sulphidic conditions, however, led to mutual detoxification of both toxicants (iron and sulphide) and did not decrease S. aloides growth. The uptake of metals was highest in the treatment involving sulphate addition, probably as a result of increased mineralisation of the peat soil.

4. Growth of Elodea nuttallii, which grew naturally in the enclosures, was stimulated by iron or iron plus sulphate addition. It did not, however, grow in the enclosures with sulphate addition, as a result of sulphide toxicity or sulphide‐induced iron deficiency. Under iron‐rich conditions, E. nuttallii appeared to be a better competitor than S. aloides and depressed the growth of the latter species.

5. We propose that the growth of S. aloides is directly regulated by interactions between sulphide and iron and indirectly by the effects of both compounds on the competitive strength of E. nuttallii. In general, we conclude that biogeochemical interactions between sulphate and iron can have a strong influence on plant species composition in freshwater wetlands, because of direct effects or changes in the competitive strength of plant species related to differential sensitivity to either iron or sulphide.
Ecological relationships between stream communities and spatial scale: implications for designing catchment‐level monitoring programmes
Authors: JOHNSON RICHARD K. , FURSE MIKE T. , HERING DANIEL , SANDIN LEONARD
Published: January 2007

1. Stream communities are structured by factors acting over multiple spatial and temporal scales. Identifying what factors are driving spatial patterns in stream communities is a central aim of ecology.

2. Here we used two large European data sets of fish, invertebrates, macrophytes, benthic diatoms and environmental data in two stream groups (lowland and mountain) to determine the importance of variables at different spatial scales (geographical, regional, local) on community structure.

3. Both geographical position and ecoregion were selected first in canonical correspondence analysis (CCA), clearly showing the broad spatial gradients covered in the data set. Secondary predictors (after accounting for spatial and/or ecoregion effects) were similar between stream groups and among the four organism groups. In particular, conductivity and N concentration were strong predictors reflecting catchment land use.

4. Using partial CCA, we assessed the individual importance of the three spatial scales on the community structure of the four organism groups in the two stream groups. The majority of among‐site variability (22–29%) was accounted for by local scale variables (e.g. water chemistry and substratum type), with regional and spatial variables accounting 11–13% and 5–6%, respectively. Our findings indicate that the four organism groups are responding similarly to the different levels of spatial scale, implying much redundancy which should be consider when implementing studies of bioassessment.