bluuebunny/crossref_metadata_2025 huggingface dataset:
Allometry measurements fromin situvideo recordings can determine the size and swimming speeds of juvenile and adult squidLoligo opalescens(Cephalopoda: Myopsida)
Authors: Zeidberg Louis D.
Published: November 2004

Juvenile and adult Loligo opalescens Berry were video taped in Monterey Bay with the remotely operated vehicle (ROV) Ventana,captured with an otter trawl in Santa Monica Bay, California, and adults were taken from the Monterey Bay fishery. Behavioral observations were made over a 13 h period of video sequences. Allometry measurements were made on 157 squids ranging in size from 12 to 151 mm mantle length (ML). In addition to ML we measured the morphometric characters of fin length(FL), fin width (FW), mantle width (MW), eye diameter (ED), head width (HW), funnel aperture diameter(FA), fourth arm length (AL) and tentacle length(TL). Loligo opalescens changes shape with ontogeny due to negative allometric growth of ED, HW, TL, MW, FA and positive allometric growth of AL, FL and fin area. The allometry measurements were used to determine the size of juvenile squids video-taped in open water. A linear regression can predict dorsal ML in mm from a dimensionless ratio of ML upon ED (r2=0.857, P<0.001). Sizes and velocities of video-taped animals were estimated from 26 video sequences ranging from <1.0 to 8 s. The average velocity for squids ranging from 12–116 mm ML was 0.21 m s–1 and the maximum velocity was 1.60 m s–1(116 mm ML). Allometric measurements can provide scale for 2-dimensional images in order to estimate size, velocity and age of animals.
Biomechanical and energetic determinants of the walk–trot transition in horses
Authors: Griffin Timothy M. , Kram Rodger , Wickler Steven J. , Hoyt Donald F.
Published: November 2004

We studied nine adult horses spanning an eightfold range in body mass(Mb) (90–720 kg) and a twofold range in leg length(L) (0.7–1.4 m). We measured the horses' walk–trot transition speeds using step-wise speed increments as they locomoted on a motorized treadmill. We then measured their rates of oxygen consumption over a wide range of walking and trotting speeds. We interpreted the transition speed results using a simple inverted-pendulum model of walking in which gravity provides the centripetal force necessary to keep the leg in contact with the ground. By studying a large size range of horses, we were naturally able to vary the absolute walking speed that would produce the same ratio of centripetal to gravitational forces. This ratio,(Mbv2/L)/(Mbg),reduces to the dimensionless Froude number(v2/gL), where v is forward speed, L is leg length and g is gravitational acceleration. We found that the absolute walk–trot transition speed increased with size from 1.6 to 2.3 m s–1, but it occurred at nearly the same Froude number (0.35). In addition, horses spontaneously switched between gaits in a narrow range of speeds that corresponded to the metabolically optimal transition speed. These results support the hypotheses that the walk–trot transition is triggered by inverted-pendulum dynamics and occurs at the speed that maximizes metabolic economy.
Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)
Authors: Krochmal Aaron R. , Bakken George S. , LaDuc Travis J.
Published: November 2004

Pitvipers (Viperidae: Crotalinae) possess thermal radiation receptors, the facial pits, which allow them to detect modest temperature fluctuations within their environments. It was previously thought that these organs were used solely to aid in prey acquisition, but recent findings demonstrated that western diamondback rattlesnakes (Crotalus atrox) use them to direct behavioral thermoregulation, suggesting that facial pits might be general purpose organs used to drive a suite of behaviors. To investigate this further, we conducted a phylogenetic survey of viperine thermoregulatory behavior cued by thermal radiation. We assessed this behavior in 12 pitviper species, representing key nodes in the evolution of pitvipers and a broad range of thermal environments, and a single species of true viper (Viperidae:Viperinae), a closely related subfamily of snakes that lack facial pits but possess a putative thermal radiation receptor. All pitviper species were able to rely on their facial pits to direct thermoregulatory movements, while the true viper was unable to do so. Our results suggest that thermoregulatory behavior cued by thermal radiation is a universal role of facial pits and probably represents an ancestral trait among pitvipers. Further, they establish behavioral thermoregulation as a plausible hypothesis explaining the evolutionary origin of the facial pit.
Swimming of larval zebrafish: fin–axis coordination and implications for function and neural control
Authors: Thorsen Dean H. , Cassidy Justin J. , Hale Melina E.
Published: November 2004

Adult actinopterygian fishes typically perform steady forward swimming using either their pectoral fins or their body axis as the primary propulsor. In most species, when axial undulation is employed for swimming, the pectoral fins are tucked (i.e. adducted) against the body; conversely, when pectoral fins are beating, the body axis is held straight. In contrast to adults,larval fishes can combine their pectoral fin and body-axis movements during locomotion; however, little is known about how these locomotor modes are coordinated. With this study we provide a detailed analysis of the coordinated fin and axial movements during slow and fast swimming by examining forward locomotion in larval zebrafish (Danio rerio L.). In addition, we describe the musculature that powers pectoral fin movement in larval zebrafish and discuss its functional implications. As larvae, zebrafish alternate their pectoral fins during slow swimming (0.011±0.001 mm ms–1) in conjunction with axial undulations of the same frequency (18–28 Hz). During fast swimming (0.109±0.030 mm ms–1; 36–67 Hz), the fins are tucked against the body and propulsion occurs by axial undulation alone. We show that during swimming,larval fishes can use a similar limb–axis coordination pattern to that of walking and running salamanders. We suggest that the fin–axis coordination observed in larval zebrafish may be attributed to a primitive neural circuit and that early terrestrial vertebrates may have gained the ability to coordinate limbs and lateral bending by retaining a larval central pattern generator for limb–axis coordination in the adult life history stage.
Spatial vision in the echinoid genusEchinometra
Authors: Blevins Erin , Johnsen Sönke
Published: November 2004

Although eyes are generally considered necessary for image resolution, a diffuse photoreceptive system with directional sensitivity may also have this ability. Two species of the echinoid genus Echinometra were tested for spatial vision by examining their ability to locate and move towards targets of different sizes. The echinoids were significantly oriented(P<0.0001) towards a target with an angular width of 33° (0.3 sr) but were not oriented to targets with angular widths of 26° and 16°. This ability is probably due to the blocking of off-angle light by the spines, which have approximately the correct spacing for the observed resolution. Spatial vision is advantageous for echinoids of this genus because they leave and return to small dark shelters. This first demonstration of spatial vision in an echinoderm sheds further light on the complex optical structures and photobehaviors found in this phylum.
Supramolecular Hydrogels Formed by l-Lysine Derivatives
Authors: Suzuki Masahiro , Yumoto Mariko , Kimura Mutsumi , Shirai Hirofusa , Hanabusa Kenji
Published: November 2004

New hydrogelators based on l-lysine consisting of water-soluble carboxylate and water-insoluble carboxylic acid can gel water below 1 wt %.
Fragmentation Study of Peptides Using Fourier Transform Ion Cyclotron Resonance with Infrared Multiphoton Dissociation: Experiment and Simulation
Authors: Fukui Kazuhiko , Naito Yasuhide , Akiyama Yutaka , Takahashi Katsutoshi
Published: November 2004

In this study, the fragmentation of gas-phase protonated Angiotensin II is investigated using electrospray ionization (ESI), Fourier transform ion cyclotron resonance (FT-ICR) and mass spectrometry (MS) with a laser cleavage infrared multiphoton dissociation (IRMPD) technique. The experimental results show that the spectra peaks for the photoproducts are y2/b6- and y7-type ions, corresponding to the cleavage of His–Pro and Asp–Arg in the parent amino acid sequence. The fragmentation of the peptide under collision-free vacuum conditions is modeled using molecular dynamics simulations (MD). The binding energy for the peptide bonds (C′–N bond) of Angiotensin II is estimated from ab initio calculations. The calculations are directed at predicting experimental measurements of the product ions from the photodissociation of the peptide. The product distributions simulated by the MD dissociation trajectories include predominantly y7/b1 and y2/b6 pair ions.
Mass Spectrometric Identification of Cyclic Polysulfides in Sediment of the Eastern Gulf of Finland. I
Authors: Khoroshko Larisa O. , Takhistov Viatcheslav V. , Petrova Varvara N. , Viktorovskii Igor V. , Lahtiperä Mirja , Paasivirta Jaakko
Published: November 2004

Structures of six cyclic polysulfides, previously unkown as organic environmental pollutants, were analyzed from a sediment sample from the Eastern Gulf of Finland. The determinations were done by gas chromatography (GC) coupled to mass spectrometry. High-resolution mass spectrometry measurements of the isotopic composition of four compounds could be done to confirm their molecular formulae. Total low-resolution mass spectrometry spectra were used to elucidate structures of all six compounds by a thermochemical approach, application of fragmentation rules and by ICLU simulation of the spectra. The compounds were found to be (in the order of GC retention) 1,2,4-trithiacycloheptane, tetrathiacyclopentane, 1,2,4,5-tetrathiacyclohexane, 1,2,3,4-tetrathiacycloheptane, 1,2,3,4-tetrathiacyclohexane and 1,2,4,6-tetrathiacyclooctane.
Mass Spectrometric Identification of Cyclic Polysulfides in Sediment from the Eastern Gulf of Finland. II
Authors: Takhistov Viatcheslav V. , Khoroshko Larisa O. , Viktorovskii Igor V. , Lahtiperä Mirja , Paasivirta Jaakko
Published: November 2004

Nine polysulfides, previously unknown as environmental organic pollutants, were analyzed from a sediment sample from the Eastern Gulf of Finland. The determinations were done by gas chromatography connected to low- and high-resolution mass spectrometers. The structure of the polysulfides was elucidated by determination of the isotopic composition of abundant molecular and fragment ions by high-resolution mass spectrometry (HRMS), the interpretation of ion structures in low-resolution mass spectra (LMRS) using the thermochemical approach, the application of fragmentation rules and performing the ICLU simulation of abundance of ions in isotope clusters. Seven compounds were known from the literature, but mass spectra were reported for only two of them, both recorded from a mixture. Structure evaluation was successful for other substances, but not for the substance(s) in the first eluting GC peak, where HRMS data were not obtained. Suggested structures of the cyclic compounds were (in the order of GC retention) 3,4-dithiacyclohexene, 1,2,3-trithiacyclohexane, 3,4,5-trithiacyclohexene, 1,2,4-trithiacyclohexane, cyclopropyl hydrodisulfide, 1,2-dithiole-3-thione and 1,2,3,4,5-penta-thiacyclo-octane. One acyclic congener identified was dimethyl tetrasulfide.
High Resolution Electrospray and Electrospray Tandem Mass Spectra of Rotenone and its Isoxazoline Cycloadducts
Authors: Cordaro Massimiliano , Donna Leonardo Di , Grassi Giovanni , Maiuolo Loredana , Mazzotti Fabio , Perri Enzo , Sindona Giovanni , Tagarelli Antonio
Published: November 2004

An evaluation of the gas-phase ion chemistry of rotenone (1) by electrospray ionisation (ESI) mass spectrometry (MS) and tandem mass spectrometry (MS2) is presented, aiming at providing tools for its determination in natural and biological matrices. The behaviour of its cycloadducts with benzonitrile-N-oxide (2) and 2,4,6-trimethylbenzonitrile-N-oxide (3) was also evaluated and the MS data thus obtained have provided evidence into the mechanism of formation of the key product ion at m/z 192 which can be considered a marker in the MS and MS2 spectra of rotenone and its derivatives.
Characterization of G-rich and T-Rich Oligonucleotides Using Ion-Pair Reversed-Phase High-Performance Liquid Chromatography/Tandem Electrospray Ionization Mass Spectrometry
Authors: Song Renfang , Zhang Wenbing , Chen Huayong , Ma Huimin , Dong Yulian , Sheng Guoying , Zhou Zhen , Fu Jiamo
Published: November 2004

Characteristics of G-rich and T-rich oligonucleotides were investigated to compare their retention time, total ion current (TIC) intensity, charge-state distribution and product ions using ion-pair reversed-phase high-performance liquid chromatography/tandem electrospray ionization mass spectrometry (IP-RP-HPLC/ESI-MS) at room temperature. Three commonly used mobile phases for the analysis of oligonucleotides, triethylammonium acetate (TEAA), triethylammonium bicarbonate (TEAB) and triethylammonium hexafluoroisopropanol (HFIP) have been utilized. Retention time of G-rich and T-rich oligonucleotide was significantly different in TEAA and TEAB buffer systems, while in the HFIP buffer system it was affected more by the length of oligonucleotides. On the other hand, the ESI-MS ion abundance in the HFIP buffer system was higher than that in both TEAA and TEAB buffers. The TIC intensity of T-rich oligonucleotides was much higher than that of G-rich oligonucleotides in all mobile phases. In addition, much higher charge-state fragments were observed in the HFIP buffer system than that in the case of TEAA and TEAB buffer systems. Product ions of both G-rich and T-rich oligonucleotides were affected by the charge state of the parent ions and collision energy.
Identification of Some Polymeric Materials by Low-Temperature Pyrolysis Mass Spectrometry
Authors: Badawy Sayed M.
Published: November 2004

The application of low-temperature pyrolysis mass spectrometry to the identification of some commercial and synthetic polymers using a direct insertion probe and electron ionization has been studied. The polymers were analyzed directly in the solid probe of a mass spectrometer within the ion source at 70 eV electron impact. The quadrupole mass spectrometer, equipped with gas chromatogram software and a library of low molecular weight compounds, was used to characterize the polymers by measuring the chemical structure of the repeat units and the end groups and to examine the thermal degradation pathways. The polymers investigated show different degradation pathways. Investigation of sequences and determination of the composition of co-polymers were studied. Total ion pyrogram and spectrum subtractions were used to separate and measure spectra of pyrolysis steps at distinctly different temperatures.
N-methyl-N-Trimethylsilyltrifluoroacetamide-Promoted Synthesis and Mass Spectrometric Characterization of Deuterated Ephedrines
Authors: Thevis Mario , Opfermann Georg , Schänzer Wilhelm
Published: November 2004

Synthesis and mass spectrometric characterization of drugs or metabolites labeled by stable isotopes have been of great interest in the fields of clinical, forensic and doping control analysis. Deuterated ephedrine and p-hydroxypseudoephedrine were prepared from corresponding amines by a novel procedure utilizing N-methyl- N-trimethylsilyltrifluoroacetamide and deuterated iodomethane. The mechanism of methylation was studied by mass spectrometry using phenylethylamine as a model compound and a rearrangement based on an intermediate six-membered ring structure with a trimethylsilyl-enol-ether is proposed giving rise to a leaving group of trimethyliodosilane and the desired monomethylated product. Deuterated analogs to frequently quantitated ephedrines were readily synthesized with purities > 90% and mass spectra recorded under different ionization and dissociation conditions presented distinct fragmentation processes, including eliminations of water and methylamine as well as the generation of a benzyl cation.
A New Maximum Likelihood Approach with Asymmetric Residual Distribution for Multicomponent Mass Spectra Analysis
Authors: Heikkonen Jukka , Juujarvi Jouni , Ridderstad Marianna , Kotiaho Tapio , Ketolad Raimo A. , Tarkiainene Virpi
Published: November 2004

This paper proposes a new maximum likelihood approach for the deconvolution of identity and quantity of individual compounds based on the multicomponent mass spectra measured by mass spectrometry (MS). Mixture analysis of multicomponent mass spectra is, typically, based on a linear multicomponent mass spectrum model, where the compounds of the measured spectra to be solved are explicitly stated and assumed to be known. In many cases, however, the measured spectrum may contain unknown compounds that are not explicitly stated in the model and a commonly used least squares (LS) solution fails. Moreover, a standard improvement over the LS method in these cases, namely the M-estimation (ME) approach, also suffers from this same problem. Our method overcomes the limitations of the LS and ME methods by modeling the effect of the unknown compound(s) to the residual of the linear model. The experimental results presented show that this new approach can separate, more robustly, the complex multicomponent mass spectra into their individual constituents compared with the LS and ME methods.
Electrospray Ionization Mass Spectrometry Studies of Rhenium(I) Bipyridyl Complexes
Authors: Zhang Rong , Sun Shiguo , Peng Xiaojun , Suna Licheng
Published: November 2004

Electrospray ionization mass spectrometry has been employed to study the formation of fragment ions from a series of rhenium(I) bipyridyl complexes [(4,4′-di-(COOEt)2-bpy) Re(CO)3XPyPF6], where bpy is 2,2′-bipyridine, Py is pyridine and X is H, 4-methyl, 3-methyl, 4-hydroxyl, 3-hydroxyl, 4-amino, or 3-amino of the pyridine ligand. The effects of substituents (X) on the stability of the complexes has been investigated with the increase of fragmentor voltages. For different X substitutents, the stability of the complexes increases as X becomes more electron-donating from H to CH3, OH and NH2. For the same substitutent, the p-substituted pyridines have a stronger stabilizing effect than the corresponding m-substituted ones. Ligand exchange reaction was found in acetonitrile, where the pyridine ligand has been replaced by the solvent, indicated by the formation of [M–PF6–XPy+MeCN]+ in the fragmentation.
Comparison of Three Types of Mass Spectrometer for High-Performance Liquid Chromatography/Mass Spectrometry Analysis of Perfluoroalkylated Substances and Fluorotelomer Alcohols
Authors: Berger Urs , Langlois Ingrid , Oehme Michael , Kallenborn Roland
Published: November 2004

The performance of three different types of mass spectrometer (MS) coupled to high performance liquid chromatography (HPLC), was compared for trace analysis of perfluoroalkylated substances (PFAS) and fluorotelomer alcohols (FTOHs). An ion trap MS in the full-scan and product-ion mass spectrometry (MS2) mode, time-of-flight (ToF) high-resolution MS and quadrupole MS in the selected ion mode, as well as triple quadrupole tandem MS were tested. Electrospray ionisation in the negative-ion mode [ESI(–)] was best suited for all instruments and compounds. PFAS could only be separated by a buffered mobile phase, but the presence of buffer suppressed the ionisation of FTOHs. Therefore, two independent chromatographic methods were developed for the two compound classes. Mass spectra and product-ion spectra obtained by in-source and collision-induced dissociation fragmentation are discussed, including ion adduct formation. Product ion yields of PFAS were only in the range of 0.3 to 12%, independent of the applied MS instrument. Ion trap MS2 gave product ion yields of 20 to 62% for FTOHs, whereas only 4.1 to 5.8% were obtained by triple quadrupole tandem MS. Ion trap MS was best suited for qualitative analysis and structure elucidation of branched isomeric structures of PFAS. Providing typical detection limits of 5 ng injected in MS2 mode, it was not sensitive enough for selective trace amount quantification. ToF high-resolution MS was the only technique combining high selectivity and excellent sensitivity for PFAS analysis (detection limits of 2 to 10 pg), but lacked the possibilities of MS/MS. Triple-quadrupole tandem MS was the method of choice for quantification of FTOHs with detection limits in the low pg range. It is also well suited for the determination of PFAS, although its detection limits of 10 to 100 pg in tandem MS mode are about one order of magnitude higher than for ToF MS.
Characterization of Novel Monoclonal Antibodies for Prostate-Specific Antigen (PSA) with Potency to Recognize PSA Bound to α2-Macroglobulin
Authors: Baumgart Yvonne , Otto Andreas , Schäfer Angelika , Usbeck Elke , Cott Christiane , Schott Astrid , Tornack Maria , Wenzel Anett , Mossie Andualem , Birkenmeier Gerd
Published: November 2004

Background: Different molecular forms of prostate-specific antigen (PSA) have been used to differentiate between benign prostatic hyperplasia and prostate cancer. Detecting PSA bound to endogenous inhibitors such as α1-antichymotrypsin (ACT) and α2-macroglobulin (α2M) is often difficult because of epitope masking or sensitivity problems. Here we report the characterization of four novel mouse monoclonal antibodies (mabs) obtained by immunization with PSA-α2M complexes. Their ability to detect free PSA and PSA-inhibitor complexes was shown, and their epitopes were analyzed by phage display technology.

Methods: The properties of the mabs were studied by competition and sandwich assays and by Western blotting. Epitope mapping was performed by screening of a phage display peptide library.

Results: All four mabs recognized free PSA, PSA-ACT, and PSA-α2M complexes, but to various degrees. With different combinations of mabs in competition experiments, antibodies were identified that enhance binding of other mabs to PSA, forming the molecular basis of a very sensitive assay for the detection of PSA and PSA-ACT complexes. Mabs with highest reactivity for PSA-α2M were selected to establish an immunoassay for that complex. Western blot analysis revealed that all mabs recognized conformational epitopes of PSA. These findings were supported by phage display results demonstrating mimotopes in the PSA molecule.

Conclusion: The results presented here could aid in the further development of clinically relevant assays for PSA and PSA-α2M complexes.
The Novel Apolipoprotein A5 Is Present in Human Serum, Is Associated with VLDL, HDL, and Chylomicrons, and Circulates at Very Low Concentrations Compared with Other Apolipoproteins
Authors: O’Brien Peter J , Alborn William E , Sloan John H , Ulmer Maverick , Boodhoo Amechand , Knierman Michael D , Schultze Albert E , Konrad Robert J
Published: November 2004

Background: The recently discovered apolipoprotein A5 (ApoA5) is fast gaining attention as a key regulator of serum triglyceride concentrations. An ApoA5 mouse knock-out model produced an approximately fourfold increase in serum triglycerides, whereas a knock-in model with human ApoA5 produced 50–70% lower concentrations of mouse serum triglycerides. In addition, peroxisome proliferator-activated receptor-α agonists, which are used clinically to lower serum triglyceride concentrations, cause increased ApoA5 mRNA expression. Despite these compelling molecular biology data, relatively little is known about ApoA5 protein in human serum.

Methods: To better understand circulating concentrations and lipoprotein particle distribution of ApoA5, we expressed the recombinant human ApoA5 protein and raised antibodies against both the NH2 and COOH termini.

Results: Using the above reagents, we demonstrate for the first time that ApoA5 is present in human serum, although at much lower concentrations than other apolipoproteins such as ApoA1. Using a dual-antibody sandwich ELISA that we developed, we observed ApoA5 concentrations in human serum ranging from 24 to 406 μg/L compared with ∼1 g/L for ApoA1. We also examined the lipoprotein particle distribution of ApoA5 and found that ApoA5 was detectable in VLDL, HDL, and chylomicrons, but not LDL.

Conclusions: These data demonstrate for the first time that ApoA5 is a secreted protein present in human serum and is associated with specific lipoprotein particles. In addition, our data indicate that the circulating concentration of human ApoA5 is very low compared with other apolipoproteins.
Older Age Is a Risk Factor for the Development of Cardiovascular Sequelae in Kawasaki Disease
Authors: Muta Hiromi , Ishii Masahiro , Sakaue Takahiko , Egami Kimiyasu , Furui Jun , Sugahara Yoko , Akagi Teiji , Nakamura Yoshikazu , Yanagawa Hiroshi , Matsuishi Toyojiro
Published: November 2004

Objectives. To clarify the characteristics of Kawasaki disease (KD) in children 6 years and older and to determine whether age is a risk factor for cardiovascular abnormalities.

Methods. Patients who had KD and were reported between 1999 and 2000 in the 16th nationwide survey of KD in Japan (n = 15 314) were analyzed. Patients who were aged 6 years or older (older group) were matched with patients who were aged 6 months to 3 years and were treated at the same hospital (younger groups). The total number of analyzed patients was 1498 (749 matched pairs).

Results. The proportion of complete KD in the older group was similar to that in the younger group. Recurrent cases in the older group were significantly more common than those in the younger group (9% vs 2%). The proportion of patients who were treated with intravenous γ-globulin in the older group was significantly lower than that in the younger group (82% vs 87%). The proportion of older group patients who were treated with intravenous γ-globulin at or after 7 days of illness was significantly higher than that in the younger group (35% vs 14%). There was a higher prevalence of cardiovascular abnormalities in the older group than in the younger group (20% vs 15%). Multivariate logistic regression analysis showed that older age was an independent risk factor for cardiovascular sequelae (odds ratio: 1.58; 95% confidence interval: 1.01–2.46).

Conclusions. In children older than 6 years, age is an independent risk factor for cardiovascular sequelae in KD.
Head Circumference and Body Proportions Before and During Growth Hormone Treatment in Short Children Who Were Born Small for Gestational Age
Authors: Arends Nicolette J.T. , Boonstra Venje H. , Hokken-Koelega Anita C.S.
Published: November 2004

Objective. Although short children who were born small for gestational age (SGA) seem to have normal body proportions, objective data both before and during growth hormone (GH) treatment are very limited. Therefore, we investigated in a large group of short children who were born SGA the effects of GH treatment versus no treatment on head circumference (HC) and body proportions. Furthermore, we studied differences in linear growth and HC between SGA children who were born with a low birth length and birth weight (SGAL+W) and SGA children who were born with a low birth length only (SGAL).

Methods. An open-labeled, GH-controlled, multicenter study was conducted for 3 years. Non–GH-deficient short SGA children (n = 87), with a mean age (standard deviation) of 5.9 (1.5) years, were randomized to either a GH group (n = 61), receiving GH in a dose of 33 μg/kg/day, or an untreated control group (n = 26). Height; weight; HC; sitting height; armspan; and hand, tibial, and foot size were measured and expressed as standard deviation score (SDS) adjusting for gender and age.

Results. At baseline, all anthropometric measurements, except HC SDS, were significantly lower compared with −2 SDS. During GH treatment, all anthropometric measurements normalized in accordance to the normalization of height SDS. At the start of the study, mean HC SDS was significantly lower in SGAL+W children compared with SGAL children. It is interesting that most (14 of 16) children with an HC SDS less than −2.00 had been born SGAL+W. During GH treatment, the 3-year increase in height, HC, and other anthropometric measurements was comparable between SGAL+W and SGAL children. In both SGAL+W and SGAL control subjects, no changes in SDSs of height, HC, and other anthropometric measurements were found during the 3-year follow-up period.

Conclusions. Untreated short SGA children have normal body proportions with the exception of HC, which is relatively large in many of these children. SGAL+W children still had a smaller HC at the age of 5.9 years compared with SGAL children. Three years of GH treatment induced a proportionate growth resulting in a normalization of height and other anthropometric measurements, including HC, in contrast to untreated SGA control subjects.
Population-Based Impact of Pneumococcal Conjugate Vaccine in Young Children
Authors: Poehling Katherine A. , Lafleur Bonnie J. , Szilagyi Peter G. , Edwards Kathryn M. , Mitchel Ed , Barth Richard , Schwartz Benjamin , Griffin Marie R.
Published: November 2004

Objective. To determine the population impact of pneumococcal conjugate vaccine (PCV) on pneumococcal-related diseases, including pneumonia and otitis media.

Methods. Using administrative data from Tennessee Medicaid and 3 commercial insurance plans in upstate New York, we measured annual rates of medical visits for pneumococcal-related diseases (pneumococcal and nonspecific pneumonia and invasive disease; otitis media) and pneumococcal-unrelated diseases (other acute respiratory illnesses). Disease rates before (1995–2000 in Tennessee; 1998–2000 in New York) and after (2000–2002) PCV licensure were calculated for children aged <2 years (eligible for PCV) and those 3 to 5 years (not routinely given PCV). Because annual variations should affect both age groups similarly and vaccine-related outcomes should preferentially decline in younger children, ratios (<2:3–5 years) of disease rates before and after PCV licensure were compared. Expected disease rates were calculated for children aged <2 years in each postvaccine year. The difference between observed and expected disease rates was the estimated vaccine effect.

Results. In 2001–2002, there were 67 380 and 9485 child-years of observation for Tennessee and New York children aged <2 years, respectively. We observed fewer visits for pneumonia and invasive disease per 1000 children than expected in both regions: 20 fewer emergency department or outpatient visits in Tennessee and 33 fewer outpatient visits in New York. Otitis media visits declined by 118 and 430 per 1000 children in Tennessee and New York, respectively.

Conclusions. Adding PCV to the childhood immunization schedule was associated with a 10-fold greater reduction in pneumonia and a 100-fold greater reduction in otitis media than the previously reported reduction in culture-confirmed invasive pneumococcal diseases of 1.3 episodes per 1000 children aged <2 years. Although additional studies are needed to confirm the impact of routine immunization with PCV on pneumococcal-related disease, these results suggest that its impact is substantially greater than the effects on invasive disease alone.
Does Sleep or Sleep Deprivation Increase Epileptiform Discharges in Pediatric Electroencephalograms?
Authors: Gilbert Donald L. , DeRoos Steven , Bare Mary A.
Published: November 2004

Objective. Sleep deprivation before obtaining an electroencephalogram (EEG) is believed both to increase the likelihood of sleep during an EEG and to increase the detection of interictal epileptiform discharges. However, depriving a child of sleep poses a burden on both the parent and the child. The objective of this study was to compare the effects of sleep, standard sleep deprivation, partial sleep deprivation, and no sleep deprivation on the odds of an epileptiform abnormality in outpatient pediatric EEGs.

Methods. Data were collected from all pediatric EEGs performed at a busy, university-based neurologic practice during two 2-month periods. During the first period, all EEGs were performed as ordered, either standard sleep-deprived (SSD) or non–sleep-deprived (NSD). During the second 2 months, SSD EEGs were performed per routine. However, non-SSD families were instructed to keep their children awake 2 hours later the night before the EEG. Those who complied were classified as partially sleep-deprived (PSD). Patient characteristics across protocols were compared with χ2 and analysis of variance tests as appropriate. The odds of epileptiform and abnormal findings associated with sleep, NSD, PSD, and SSD EEGs were calculated using logistic regression.

Results. Of 820 eligible EEGs, sleep occurred in 22% of NSD, 44% of PSD, and 57% of SSD EEGs. The sample size of this study allowed for an 85% power, with α of .05, to detect an absolute increased EEG yield of 10%. Neither the presence of sleep (odds ratio [OR]: 0.99; 95% confidence interval [CI]: 0.69-1.42) nor the use of PSD (OR: 0.90; 95% CI: 0.50-1.62) or SSD (OR: 0.96; 95% CI: 0.63-1.47) protocols increased the odds of epileptiform EEGs.

Conclusions. Sleep deprivation should not be used routinely to increase the yield of pediatric EEGs.
Puberty and the Onset of Substance Use and Abuse
Authors: Patton George C. , McMorris Barbara J. , Toumbourou John W. , Hemphill Sheryl A. , Donath Susan , Catalano Richard F.
Published: November 2004

Objective. Substance abuse remains one of the major threats to adolescent health in Western cultures. The study aim was to ascertain the extent of association between pubertal development and early adolescent substance use.

Methods. The design was a cross-sectional survey of 10- to 15-year-old subjects in the states of Washington, United States, and Victoria, Australia. Participants were 5769 students in grades 5, 7, and 9, drawn as a 2-stage cluster sample in each state, and the questionnaire was completed in the school classrooms. The main outcomes of the study were lifetime substance use (tobacco use, having been drunk, or cannabis use), recent substance use (tobacco, alcohol, or cannabis use in the previous month), and substance abuse (daily smoking, any binge drinking, drinking at least weekly, or cannabis use at least weekly).

Results. The odds of lifetime substance use were almost twofold higher (odds ratio [OR]: 1.7; 95% confidence interval [CI]: 1.4–2.1) in midpuberty (Tanner stage III) and were threefold higher (OR: 3.1; 95% CI: 2.4–4.2) in late puberty (Tanner stage IV/V), after adjustment for age and school grade level. Recent substance use was moderately higher (OR: 1.4; 95% CI: 1.0–1.9) in midpuberty and more than twofold higher (OR: 2.3; 95% CI: 1.7–3.3) in late puberty. The odds of substance abuse were twofold higher (OR: 2.0; 95% CI: 1.2–3.2) in midpuberty and more than threefold higher (OR: 3.5; 95% CI: 2.2–5.4) in late puberty. Reporting most friends as substance users was more likely in the later stages of pubertal development, a relationship that accounted in part for the association found between later pubertal stage and substance abuse.

Conclusions. Pubertal stage was associated with higher rates of substance use and abuse independent of age and school grade level. Early maturers had higher levels of substance use because they entered the risk period at an earlier point than did late maturers. The study findings support prevention strategies and policies that decrease recreational substance use within the peer social group in the early teens.
Congenital Aplastic Anemia Caused by Mutations in the SBDS Gene: A Rare Presentation of Shwachman-Diamond Syndrome
Authors: Kuijpers Taco W. , Nannenberg Eline , Alders Marielle , Bredius Robbert , Hennekam Raoul C. M.
Published: November 2004

Clinical Findings. Aplastic anemia was diagnosed at birth for a first child from healthy nonconsanguineous parents. The girl had hypoglycemia, which normalized within 2 months. Cow milk allergy was suspected initially, because of skin lesions and diarrhea, followed by severe growth retardation. Clinical and radiologic symptoms gradually became typical for Shwachman-Diamond syndrome. Two common mutations in the SBDS gene (183-184TA→CT [K62X] and IVS2(258)+2T→ C [C84fs]) were found.

Results. Bone marrow transplantation from a matched unrelated donor was unsuccessful. The genetic information from the deceased patient enabled us to perform prenatal molecular studies during the subsequent pregnancy, successfully predicting a nonaffected child.

Conclusions. This report describes for the first time the hematologic abnormalities of congenital aplastic anemia and prolonged neonatal hypoglycemia as the presenting symptoms of Shwachman-Diamond syndrome. The finding of common mutations in the presence of these symptoms at birth suggests the lack of a clear phenotype-genotype relationship in this syndrome.
Sleep of Excessively Crying Infants: A 24-Hour Ambulatory Sleep Polygraphy Study
Authors: Kirjavainen Jarkko , Lehtonen Liisa , Kirjavainen Turkka , Kero Pentti
Published: November 2004

Objective. Parents’ reports suggest that excessively crying or colicky infants sleep less compared with control subjects. The aim of this study was to determine the sleep-wake structure of excessively crying infants throughout a 24-hour cycle.

Methods. A 24-hour sleep polygraphy study was conducted at home for 24 excessively crying infants and 23 control subjects at the age of 6 weeks. In addition, parental diaries were kept for 4 days.

Results. In sleep polygraphy recordings, no major differences between study groups were observed in either the duration or the structure of the 24-hour sleep. In the diaries, the parents overestimated the amount of sleep in both study groups. The parents of the control infants overestimated the amount of sleep more than the parents of excessively crying infants (69.8 minutes [standard deviation: 79.3] compared with 27.1 minutes [standard deviation: 65.4], respectively). In excessively crying infants, the proportion of rapid eye movement sleep was higher during the 3-hour period from the beginning of the first long sleep in the evening and lower during the preceding 3-hour period compared with the control group.

Conclusions. The results of this study suggest that diary-based studies are prone to be biased as the parents of the control infants are more likely to overestimate the amount of infant’s sleep and, therefore, report more sleep than the parents of the crying infants. Although no differences in the total amount of sleep or proportions of sleep stages were observed, excessively crying infants may be characterized by a disturbance that affects rapid eye movement and non–rapid eye movement sleep stage proportion during evening hours.
Circumstances Surrounding the Deaths of Hospitalized Children: Opportunities for Pediatric Palliative Care
Authors: Carter Brian S. , Howenstein Matthew , Gilmer Mary Jo , Throop Pat , France Dan , Whitlock James A.
Published: November 2004

Objectives. Little is known regarding the assessment and treatment of symptoms during end-of-life (EOL) care for children. This study was conducted to describe the circumstances surrounding the deaths of hospitalized terminally ill children, especially pain and symptom management by the multidisciplinary pediatric care team.

Design. Patients in the neonatal intensive care unit, pediatric critical care unit, or general pediatric units of Vanderbilt Children’s Hospital who were hospitalized at the time of death, between July 1, 2000, and June 30, 2001, were identified. Children eligible for the survey had received inpatient EOL care at the hospital for at least 24 hours before death. A retrospective medical record review was completed to describe documentation of care for these children and their families during the last 72 hours of life.

Results. Records of children who had received inpatient EOL care were identified (n = 105). A majority (87%) of children were in an intensive care setting at the time of death. Most deaths occurred in the pediatric critical care unit (56%), followed by the neonatal intensive care unit (31%). Pain medication was received by 90% of the children in the last 72 hours of life, and 55% received additional comfort care measures. The presence of symptoms other than pain was infrequently documented.

Conclusions. The duration of hospitalization for most children dying in this inpatient setting was sufficient for provision of interdisciplinary pediatric palliative care. Management of pain and other symptoms was accomplished for many children. The documentation of pain and symptom assessment and management can be improved but requires new tools.
A Simple Treatment for Head Lice: Dry-On, Suffocation-Based Pediculicide
Authors: Pearlman Dale Lawrence
Published: November 2004

Objectives. The emergence of drug-resistant lice has created the need for new therapies. This study assesses a new method without neurotoxins, extensive household cleaning, or nit removal.

Methods. One hundred thirty-three subjects participated in 2 open clinical trials. In the first trial, 93 subjects completed treatment using a nontoxic, dry-on, suffocation-based, pediculicide lotion, minimal household cleaning measures, and physical removal of the nits. In the second trial, 40 subjects completed treatment using an identical protocol except that the nits were not removed. Head lice infestation was defined as a wet combing test showing lice. Cure was defined as a wet combing test showing no lice, with an absence of symptoms. Subjects were contacted 6 months later, for assessment of their disease status.

Results. Cure was achieved for 97% of the patients in the first trial and 95% in the second trial. Remission at the follow-up assessment was reported for 77 of 82 subjects (94%) in the first trial and 36 of 38 subjects (95%) in the second trial. There was no statistical difference in cure rates or remission rates between the protocols with and without nit removal. The overall cure rate was 96%, with a remission rate of 94%. There were no adverse effects.

Conclusions. Dry-on, suffocation-based, pediculicide lotion effectively treats head lice without neurotoxins, nit removal, or extensive house cleaning. These results are comparable or superior to the results previously reported for treatments with permethrin, pyrethrin, and malathion.
Predictors of Hospital Readmission of Manitoba Newborns Within Six Weeks Postbirth Discharge: A Population-Based Study
Authors: Martens Patricia J. , Derksen Shelley , Gupta Sumit
Published: November 2004

Objectives. To examine the proportion, geographic variation, and predictors of infant hospital readmission within 6 weeks of the postbirth discharge.

Methods. A cross-sectional, population-based study was conducted of all infants who were born from 1997 through 2001, linkable to the birth mother, and discharged alive from the hospital (N = 68 681) using hospital discharge files in the Canadian province of Manitoba. The following predictors of readmission were examined using logistic regression: preterm, low birth weight, neighborhood income, geographic location (the North, Rural South, and Urban areas of Winnipeg and Brandon), breastfeeding status, length of stay, maternal age, and type of delivery. Using 9 non-Winnipeg regions and 12 Winnipeg subregions, ecologic correlations (1-tailed Spearman) between newborn hospital readmission rates and the following were examined: 1) a region's overall health status, measured by the premature mortality rate (PMR), or death before aged 75 years and 2) a region's socioeconomic risk, using the Socio-Economic Factor Index (SEFI).

Results. The proportion of infants who were readmitted to the hospital at least once within 6 weeks of postbirth hospital discharge was 3.95%, with respiratory illness the leading cause (22.3% of readmissions). Risk of readmission was higher for infants who were born preterm (adjusted odds ratio [AOR]: 1.80; 95% confidence interval [CI]: 1.55–2.10), who were of the 3 lowest income quintiles (lowest: AOR: 2.02; 95% CI: 1.77–2.32; low: AOR: 1.48; 95% CI: 1.29–1.71; middle: AOR: 1.26; 95% CI: 1.08–1.47), who resided in the North (AOR: 1.85; 95% CI: 1.66–2.07) or Rural South (AOR: 1.25; 95% CI: 1.14–1.36), who were not breastfed (AOR: 1.32; 95% CI: 1.20–1.44), whose mother's age was 17 or younger (AOR: 1.30; 95% CI: 1.10–1.55), whose mother was 18 to 19 years of age (AOR: 1.25; 95% CI: 1.09–144), or who were born by cesarean section (AOR: 1.30; 95% CI: 1.19–1.43). Regional readmission rates were correlated with PMR (9 non-Winnipeg regions: r = 0.77 for PMR and r = 0.68 for SEFI; 12 Winnipeg Community Areas: r = 0.49 for PMR and r = 0.73 for SEFI).

Conclusions. Income and geography are strongly associated with newborn hospital readmission. Modifiable risk factors include increasing breastfeeding rates, decreasing cesarean section rates, and decreasing adolescent pregnancy rates (or increasing adolescent parental support), but these need additional study to establish causation.
Use of Voice Recognition Software in an Outpatient Pediatric Specialty Practice
Authors: Issenman Robert M. , Jaffer Iqbal H.
Published: November 2004

Background. Voice recognition software (VRS), with specialized medical vocabulary, is being promoted to enhance physician efficiency, decrease costs, and improve patient safety. This study reports the experience of a pediatric subspecialist (pediatric gastroenterology) physician with the use of Dragon Naturally Speaking (version 6; ScanSoft Inc, Peabody, MA), incorporated for use with a proprietary electronic medical record, in a large university medical center ambulatory care service.

Methods. After 2 hours of group orientation and 2 hours of individual VRS instruction, the physician trained the software for 1 month (30 letters) during a hospital slowdown. Set-up, dictation, and correction times for the physician and medical transcriptionist were recorded for these training sessions, as well as for 42 subsequently dictated letters. Figures were extrapolated to the yearly clinic volume for the physician, to estimate costs (physician: $110 per hour; transcriptionist: $11 per hour, US dollars).

Results. The use of VRS required an additional 200% of physician dictation and correction time (9 minutes vs 3 minutes), compared with the use of electronic signatures for letters typed by an experienced transcriptionist and imported into the electronic medical record. When the cost of the license agreement and the costs of physician and transcriptionist time were included, the use of the software cost 100% more, for the amount of dictation performed annually by the physician.

Conclusions. VRS is an intriguing technology. It holds the possibility of streamlining medical practice. However, the learning curve and accuracy of the tested version of the software limit broad physician acceptance at this time.