bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene for the serotonin transporter and ADHD: No association with two functional polymorphisms
Authors: Wigg Karen G. , Takhar Amandeep , Ickowicz Abel , Tannock Rosemary , Kennedy James L. , Pathare Tejaswee , Malone Molly , Schachar Russell , Barr Cathy L.
Published: July 2006

Evidence from both human and animal studies implicates the serotonergic system in the development of attention‐deficit hyperactivity disorder (ADHD) including positive association studies for several key serotonergic genes. The serotonin transporter (HTT) regulates the availability of serotonin by reuptake of the neurotransmitter from the synaptic cleft. Several studies have reported an association of this gene to ADHD, specifically the long variant of a common insertion/deletion polymorphism located in the promoter of this gene that results in increased transcription and higher HTT expression. An additional study found no evidence for an association with this polymorphism. Recently, an A/G single nucleotide polymorphism (SNP) was found within the promoter polymorphism with functional studies indicating that the long variant containing the G allele at this site behaves like the short variant. This previously unidentified functional change may have confounded earlier association studies. We investigated the relationship of several variants to ADHD: the promoter polymorphisms, SNP in the 3′ untranslated region (3′UTR) with a reported association to ADHD and a rare, non‐synonymous coding SNP. These polymorphisms were genotyped in 209 ADHD families identified through an affected proband. We did not find evidence for an association of these polymorphisms, or haplotypes of these polymorphisms, to ADHD in this sample. © 2006 Wiley‐Liss, Inc.
Crosstalk of sterol‐dependent and non‐sterol‐dependent signaling in human monocytes after in vitro addition of LDL
Authors: Seres Ildikó , Fóris Gabriella , Kovács Éva , Páll Dénes , Varga Zsuzsa , Balogh Zoltán , Paragh György
Published: July 2006

The aim of the present study was to investigate low density lipoprotein (LDL)‐induced, non‐sterol‐dependent signaling and its possible role in cholesterol balance. LDL in 10 µg ml−1concentration could induce inositol trisphosphate (IP3) and Ca2+signal generation through a pertussis toxin (PT) sensitive G protein in human monocytes. The increase in [Ca2+]i was derived from the intracellular pools. LDL also induced activation and translocation of protein kinase C (PKC) into the cell membrane, by processes, which were significantly inhibited in the first 20 min by preincubation with PT and PKC‐inhibitor H‐7. The PKC‐activating phorbol‐12‐myristate‐13‐acetate (PMA), differently from LDL, enhanced the LDL‐receptor (LDL‐R)‐mediated binding and degradation of [125I]LDL, but inhibited endogenous cholesterol synthesis, and both effects were inhibited by H‐7. The LDL‐induced inhibition of binding and degradation of [125I]LDL was not affected by H‐7, whereas decreased cholesterol synthesis was counteracted by H‐7. These results suggest the existence of a non‐sterol‐dependent signal pathway of LDL‐Rs, by which endogenous cholesterol synthesis, that is, the [14C]acetate incorporation, is regulated through PKC activation. Copyright © 2006 John Wiley & Sons, Ltd.
The effect of shock wave lithotripsy on nitric oxide and malondialdehyde levels in plasma and urine samples
Authors: Aksoy Hülya , Aksoy Yılmaz , Turhan Hamdullah , Keleş Sait , Ziypak Tevfik , Özbey Isa
Published: July 2006

Shock wave lithotripsy (SWL) is accepted as the first treatment choice for most urinary stones, but it has adverse effects on the kidneys. The mechanisms underlying shock wave‐induced renal injury have been discussed and include shear stress, thermal and cavitation effects and free radical formation. We investigated the effects of SWL on plasma and urinary nitrite, a stable metabolite of nitric oxide (NO), and malondialdehyde (MDA) concentrations. Between February and October 2004, 12 men and 8 women with renal calculi were treated using a Dornier MPL‐9000 lithotriptor. The ages ranged from 22 to 45 years (average age: 33.7 years). Plasma and urinary NO and MDA levels were analysed before, immediately after, 30 and 60 min and 24 h after SWL. Plasma NO levels were higher than baseline levels immediately, and at 30, 60 min and 24 h after treatment (p = 0.016, p = 0.031, p = 0.033 and p = 0.045, respectively). Simultaneously, the mean urinary NO levels also showed significant elevation after SWL compared with baseline values, except for 24 h (p = 0.021, p = 0.023 and p = 0.048, respectively). The mean levels of plasma MDA showed statistically significant elevation immediately, and 30 and 60 min after SWL termination compared with pre‐SWL values (p = 0.012, p = 0.008 and p = 0.012, respectively). Urinary MDA levels obtained immediately (p = 0.035), and 30 (p = 0.006) and 60 (p = 0.045) min after SWL were increased compared to pre‐SWL values. We speculate that SWL treatment causes oxidative stress caused by renal ischemia‐reperfusion (I/R) injury. Additionally, the increase of NO production may have prevented renal damage caused by vasoconstriction. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of acute swimming exercise on lactate levels and its relation with zinc in pinealectomized rats
Authors: Baltaci Abdulkerim Kasim , Cumraligil Burhan , Kilic Mehmet , Kaya Oktay
Published: July 2006

It is argued that melatonin secreted from the pineal gland regulates the levels of zinc, which is an important trace element. Decreases in zinc levels of pinealectomized rats supports this relationship. There is an increasing amount of evidence suggesting that the pineal gland can have important effects on physical activity. The objective of the present study was to explore the changes in serum lactate levels in pinealectomized rats subjected to acute swimming exercise and its relation with zinc. Forty adult male rats of Spraque Dawley strain were equally allocated to four groups. Group 1: General Control Group. Group 2: Pinealectomized Control Group. Group 3: Swimming Control Group. Group 4: Pinealectomized Swimming Group. Serum zinc, melatonin and lactate levels were determined in the blood samples collected from the animals by a decapitation method. Zinc and melatonin levels were higher in Group 1 than in Groups 2, 3 and 4 (p < 0.01), higher in Group 3 than in Groups 2 and 4 (p < 0.01) and higher in Group 2 than in Group 4 (p < 0.01). The highest lactate levels were found in Group 4 (p < 0.01). Lactate levels in Group 3 were higher than those in Groups 1 and 2 (p < 0.01), while the levels in Groups 1 and 2 did not differ. Pinealectomy results in a significant increase in lactate levels in rats subjected to an acute swimming exercise. This increase in lactate levels may be associated with the decrease observed in zinc levels after pinealectomy. Copyright © 2006 John Wiley & Sons, Ltd.
Multiple‐Functional Capsule Catalysts: A Tailor‐Made Confined Reaction Environment for the Direct Synthesis of Middle Isoparaffins from Syngas
Authors: He Jingjiang , Liu Zhenlin , Yoneyama Yoshiharu , Nishiyama Norikazu , Tsubaki Noritatsu
Published: July 2006

A capsule catalyst for isoparaffin synthesis based on Fischer–Tropsch reaction was designed by coating a H‐ZSM‐5 membrane onto the surface of the pre‐shaped Co/SiO2 pellet. Morphological and chemical analysis showed that the capsule catalyst had a core‐shell structure. A compact, integral shell of H‐ZSM‐5 crystallized firmly on the Co/SiO2 substrate without crack. Syngas passed through the zeolite membrane to reach the Co/SiO2 catalyst to be converted, and all hydrocarbons formed with straight chain structure must enter the zeolite channels to undergo hydrocracking as well as isomerization in this tailor‐made confined reaction environment. A narrow, anti‐Anderson–Schultz–Flory law product distribution was observed on these capsule catalysts. Contrary to a mechanical mixture of H‐ZSM‐5 and Co/SiO2, C10+ hydrocarbons were suppressed completely on this novel capsule catalyst, and the selectivity of middle isoparaffins was considerably improved. The carbon number distribution of the products depended on the thickness of the zeolite membrane, and it was possible to selectively synthesize specified distillates, such as gasoline‐range, or heavier hydrocarbons from syngas directly, by simply adjusting the thickness of the zeolite membrane of the capsule catalyst. This kind of capsule catalysts can be extended to various consecutive reaction systems as the shell and core components are independent catalysts for different reactions. At the same time, shape selectivity and space‐confined effects can be expected for the reactant, intermediates and product of the sequential reactions.
Kramers–Kronig transformation of experimental electronic circular dichroism: Application to the analysis of optical rotatory dispersion in dimethyl‐L‐tartrate
Authors: Polavarapu Prasad L. , Petrovic Ana G. , Zhang Peng
Published: July 2006

When a limited region of the experimental electronic circular dichroism (ECD) spectrum is subjected to Kramers–Kronig (KK) transformation, the resulting optical rotatory dispersion (ORD) may or may not reproduce the experimentally measured ORD in the long‐wavelength nonresonant region. If the KK transform of experimentally measured ECD in a limited wavelength region reproduces the experimentally measured ORD in the long‐wavelength nonresonant region, then that observation indicates that the ORD in the long‐wavelength nonresonant region should be satisfactorily predicted from the correspondingly limited number of electronic transitions in a reliable quantum mechanical calculation. On the other hand, if the KK transform of experimentally measured ECD in a limited region does not reproduce the experimentally measured ORD in the long‐wavelength nonresonant region, then it should be possible to identify the ECD bands in the shorter wavelength region that are responsible for the differences between experimentally observed ORD and KK‐transformed ECD. This approach helps to identify the role of ECD associated with higher energy‐excited states in the nature of ORD in the long‐wavelength nonresonant region. These concepts are demonstrated here by measuring the experimental ECD and ORD for dimethyl‐L‐tartrate in different solvents. While ECD spectra of dimethyl‐L‐tartrate in different solvents show little variation, ORD spectra in the long‐wavelength nonresonant region show marked solvent dependence. These observations are explained using the difference between experimental ORD and KK‐transformed ECD. Quantum mechanical predictions of ECD and ORD are also presented for isolated (R, R)‐dimethyl tartrate at the B3LYP/aug‐cc‐pVDZ level. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Distribution of vasopressin in the forebrain of spotted hyenas
Authors: Rosen Greta J. , De Vries Geert J. , Villalba Constanza , Weldele Mary L. , Place Ned J. , Coscia Elizabeth M. , Glickman Steve E. , Forger Nancy G.
Published: July 2006

The extreme virilization of the female spotted hyena raises interesting questions with respect to sexual differentiation of the brain and behavior. Females are larger and more aggressive than adult, non‐natal males and dominate them in social encounters; their external genitalia also are highly masculinized. In many vertebrates, the arginine vasopressin (VP) innervation of the forebrain, particularly that of the lateral septum, is associated with social behaviors such as aggression and dominance. Here, we used immunohistochemistry to examine the distribution of VP cells and fibers in the forebrains of adult spotted hyenas. We find the expected densely staining VP immunoreactive (VP‐ir) neurons in the paraventricular and supraoptic nuclei, as well as an unusually extensive distribution of magnocelluar VP‐ir neurons in accessory regions. A small number of VP‐ir cell bodies are present in the suprachiasmatic nucleus and bed nucleus of the stria terminalis; however, there are extensive VP‐ir fiber networks in presumed projection areas of these nuclei, for example, the subparaventricular zone and lateral septum, respectively. No significant sex differences were detected in the density of VP‐ir fibers in any area examined. In the lateral septum, however, marked variability was observed. Intact females exhibited a dense fiber network, as did two of the four males examined; the two other males had almost no VP‐ir septal fibers. This contrasts with findings in many other vertebrate species, in which VP innervation of the lateral septum is consistently greater in males than in females. J. Comp. Neurol. 498:80–92, 2006. © 2006 Wiley‐Liss, Inc.
Synaptic input to OFF parasol ganglion cells in macaque retina
Authors: Bordt Andrea S. , Hoshi Hideo , Yamada Elizabeth S. , Perryman‐Stout Wendy C. , Marshak David W.
Published: July 2006

A Neurobiotin‐injected OFF parasol cell from midperipheral macaque retina was studied by reconstruction of serial ultrathin sections and compared with ON parasol cells studied previously. In most respects, the synaptic inputs to the two subtypes were similar. Only a few of the amacrine cell processes that provided input to the labeled OFF parasol ganglion cell dendrites made or received inputs within the series, and none of these interactions were with the bipolar cells or other amacrine cells presynaptic to the OFF parasol cell. These findings suggest that the direct inhibitory input to OFF parasol cells originates from other areas of the retina. OFF parasol cells were known to receive inputs from two types of diffuse bipolar cells. To identify candidates for the presynaptic amacrine cells, OFF parasol cells were labeled with Lucifer yellow by using a juxtacellular labeling technique, and amacrine cells known to costratify with them were labeled via immunofluorescent methods. Appositions were observed with amacrine cells containing immunoreactive calretinin, parvalbumin, choline acetylatransferase, and G6‐Gly, a cholecystokinin precursor. These findings suggest that the inhibitory input to parasol cells conveys information about several different attributes of visual stimuli and, particularly, about their global properties. J. Comp. Neurol. 498:46–57, 2006. © 2006 Wiley‐Liss, Inc.
Physiological and morphological characterization of parvalbumin‐containing interneurons of the rat basolateral amygdala
Authors: Rainnie Donald Gordon , Mania Irakli , Mascagni Franco , McDonald Alexander Joseph
Published: July 2006

The basolateral amygdala (BLA) is critical for the generation of emotional behavior and the formation of emotional memory. Understanding the neuronal mechanisms that contribute to emotional information processing in the BLA will ultimately require knowledge of the anatomy and physiology of its constituent neurons. Two major cell classes exist in the BLA, pyramidal projection neurons and nonpyramidal interneurons. Although the properties of projection neurons have been studied in detail, little is known about the properties of BLA interneurons. We have used whole‐cell patch clamp recording techniques to examine the physiological properties of 48 visually identified putative interneurons from the rat anterior basolateral amygdalar nucleus. Here, we report that BLA interneurons can be differentiated into four electrophysiologically distinct subtypes based on their intrinsic membrane properties and their response to afferent synaptic input. Interneuron subtypes were named according to their characteristic firing pattern generated in response to transient depolarizing current injection and were grouped as follows: 1) burst‐firing interneurons (n = 13), 2) regular‐firing interneurons (n = 11), 3) fast‐firing interneurons (n = 10), and 4) stutter‐firing interneurons (n = 14). Post hoc histochemical visualization confirmed that all 48 recorded neurons had morphological properties consistent with their being local circuit interneurons. Moreover, by using triple immunofluorescence (for biocytin, calcium‐binding proteins, and neuropeptides) in conjunction with patch clamp recording, we further demonstrated that over 60% of burst‐firing and stutter‐firing interneurons also expressed the calcium‐binding protein parvalbumin (PV+). These data demonstrate that interneurons of the BLA show both physiological and neurochemical diversity. Moreover, we demonstrate that the burst‐ and stutter‐firing patterns positively correlate with PV+ immunoreactivity, suggesting that these neurons may represent functionally distinct subpopulations. J. Comp. Neurol. 498:142–161, 2006. © 2006 Wiley‐Liss, Inc.
Mosaic deletion of Rb arrests rod differentiation and stimulates ectopic synaptogenesis in the mouse retina
Authors: Johnson Dianna A. , Donovan Stacy L. , Dyer Michael A.
Published: July 2006

The retinoblastoma gene (Rb) regulates neural progenitor cell proliferation and cell fate specification and differentiation. For the developing mouse retina, two distinct functions of Rb have been described: regulation of retinal progenitor cell proliferation and rod photoreceptor development. Cells that would normally become rods fail to mature and remain as immature cells in the outer nuclear layer in the adult. By using Chx10‐Cre;RbLox/− mice, we generated a chimeric retina with alternating apical‐basal stripes of wild‐type and Rb‐deficient tissue. This provides a unique model with which to study synaptogenesis at the outer plexiform layer within regions that lack differentiated rods. In regions where rods failed to differentiate, the outer plexiform layer (OPL) was disrupted. Horizontal cells formed, and their somata were appropriately aligned, but their neurites did not project laterally. Instead many horizonal cell neurites extended apically, forming ectopic synapses with photoreceptors at all levels of the outer nuclear layer. These ectopic photoreceptor terminals contained synaptic ribbons, horizontal cell processes with synaptic vesicles, and a single mitochrondrion characteristic of rod spherules. Rb‐deficient bipolar cells differentiated normally, extended dendrites to the OPL, and formed synapses that were indistinguishable from adjacent wild‐type cells. In contrast to OPL‐positioned synapses, ectopic synapses did not contain bipolar dendrites. This finding suggests that horizontal cells and photoreceptors can form stable synapses that are devoid of bipolar dendrites outside the normal boundaries of the OPL. Finally, analysis of P4, P7, P12, and P15 retinae suggests that the apical horizontal cell processes result from their failure to establish their normal lateral projections during development. J. Comp. Neurol. 498:112–128, 2006. © 2006 Wiley‐Liss, Inc.
Solid‐State Photodimerization of Guest Molecules in Inclusion Compounds
Authors: Zouev Irena , Lavy Tali , Kaftory Menahem
Published: July 2006

Photochemical dimerization reactions of 1,3‐diphenyl‐1‐propen‐3‐one (chalcone), 9‐acetylanthracene, and 9‐(methoxycarbonyl)anthracene as guest molecules in inclusion compounds with 1,1,6,6‐tetraphenyl‐2,4‐hexadiyne‐1,6‐diol were studied. The irradiation of a single crystal containing chalcone was carried out in a single step and resulted in a single crystal containing the photodimer in full occupancy. In the case of the crystal containing 9‐acetylanthracene, X‐ray diffraction data were collected after irradiation for different periods of time. Only one of the two crystallographically independent pairs of 9‐acetylanthracene underwent solid‐state photodimerization at ca. 11 % conversion to the head‐to‐tail dimer. Photodimerization of the 9‐(methoxycarbonyl)anthracene inclusion compound led, after irradiation for 2.5 h, to ca. 37 % conversion. It was found that the molecules that were arranged in stacks had undergone photodimerization in two different ways, so that on the average it looked as if all the guest molecules had polymerized. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Biogenetically Based Strategy Towards the Polycyclic Core Skeleton of Sarain A
Authors: Ge Cheng Sheng , Hourcade Stéphane , Ferdenzi Antoine , Chiaroni Angèle , Mons Stéphane , Delpech Bernard , Marazano Christian
Published: July 2006

An approach to the polycyclic core of sarain A, based upon a proposed biogenetic route, is presented. Condensation of a protected amino acid with a bromoacrylamide and subsequent addition of malonaldehyde sodium salt and methyl iodide afforded, after stereoselective hydrogenation, a highly functionalized diazabicyclo[4.3.0]nonane system 16. This intermediate possesses the stereochemistry required for the synthesis of the core skeleton of sarain A, a model of which (31) was obtained by an allylsilane strategy previously described by Weinreb and co‐workers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Palladium‐Catalyzed Allylation of Pronucleophiles with Alkynes at 50 °C – Remarkable Effect of 2‐(Dicyclohexylphosphanyl)‐2′‐(dimethylamino)biphenyl as Ligand
Authors: Patil Nitin T. , Song Dschun , Yamamoto Yoshinori
Published: July 2006

The allylation of various pronucleophiles 1a–i with 1‐phenylprop‐1‐yne (2) proceeded very smoothly at 50 °C in the presence of catalytic amounts of Pd2(dba)3·CHCl3 (5 mol‐%) and 2‐(dicyclohexylphosphanyl)‐2′‐(dimethylamino)biphenyl (I; 20 mol‐%) in toluene, whilst when Pd(PPh3)4 or Pd2(dba)3·CHCl3/PPh3 were used, the reaction needed 100 °C for completion.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Development of capillary electrophoresis methods for quantitative determination of taurine in vehicle system and biological media
Authors: da Silva Dayse. L. P. , Rüttinger Hans H. , Mrestani Yahia , Baum Walter F. , Neubert Reinhard H. H.
Published: July 2006

CE methods have been developed for the determination of taurine in pharmaceutical formulation (microemulsion) and in biological media such as sweat. The CE system with end‐column pulsed amperometric detection has been found to be an interesting method in comparison with UV and fluorescence detection for its simplicity and rapidity. A gold‐disk electrode of 100 μm diameter was used as the working electrode. The effects of a field decoupler at the end of the capillary, separation voltage, injection and pressure times were investigated. A detection limit of 4×10−5 mol/L was reached using integrated pulsed amperometric detection, a method successfully applied to taurine analysis of the biological samples such as sweat. For taurine analysis of oil‐in‐water microemulsion, fluorescence detector was the favored method, the detection limit of which was 4×10−11 mol/L.
Preparation and characterization of novel poly[cyclotriphosphazene‐co‐(4,4′‐sulfonyldiphenol)] nanofiber matrices
Authors: Lu Zhu , Weizhong Yuan , Yang Pan , Xiaozhen Tang , Xiaobin Huang
Published: July 2006

Novel poly[cyclotriphosphazene‐co‐(4,4′‐sulfonyldiphenol)] nanofiber matrices were synthesized via a facile one‐pot polymerization. The fibers are 20–50 nm in diameter and 500 nm or more in length. Uniform nanoscale fibers linked covalently with each other and formed three‐dimensional matrices. The highly cross‐linked chemical structure of the nanofiber matrices was measured by means of Fourier transform infrared and quantitative solid‐state NMR spectroscopy. Experiments show the pH had an effect on the hydrolytic degradation of the polymer. The hydrolysis of the matrices could be accelerated by alkaline conditions. The as‐synthesized nanofiber matrices have potential applications in tissue engineering materials. Copyright © 2006 Society of Chemical Industry
Prevalence of acute and post‐traumatic stress disorder and comorbid mental disorders in breast cancer patients during primary cancer care: a prospective study
Authors: Mehnert Anja , Koch Uwe
Published: July 2006

This study aimed at the identification of acute and post‐traumatic stress responses, and comorbid mental disorders in breast cancer patients. Structured clinical interviews for DSM‐IV (SCID) were conducted post‐surgery with 127 patients (t1). Screening measures were used to assess post‐traumatic stress responses, anxiety, and depression at t1 and at 6 months follow‐up (t2). Based on the SCID, prevalence rates were 2.4% for both, cancer‐related ASD and PTSD. Experiences most frequently described as traumatic were the cancer diagnosis itself and subsequent feelings of uncertainty. Patients with lifetime PTSD (8.7%) were more likely to meet the criteria for cancer‐related ASD or PTSD (OR=14.1). Prevalence estimates were 7.1% for Adjustment Disorder, 4.7% for Major Depression, 3.1% for Dysthymic Disorder and 6.3% for Generalized Anxiety Disorder. Using the screening instruments, IES‐R, PCL‐C and HADS, we found PTSD in 18.5% at t1 and 11.2–16.3% at t2. The estimates of anxiety and depression reveal rates of 39.6% (t1) and 32.7% (t2) for anxiety, as well as 16.0% (t1) and 13.3% (t2) for depression (t1) (cut‐off⩾8). The diagnosis of a life‐threatening illness has been included as a potential trauma in the DSM‐IV. However, it has to be critically evaluated whether subjective feelings of uncertainty like fears of treatment count among traumatic stressors, and thus, whether the diagnosis of PTSD is appropriate in this group of cancer patients. However, a large number of women with emotional distress illustrate the need for psychosocial counseling and support in this early treatment phase. Copyright © 2006 John Wiley & Sons, Ltd.
Interatomic potential and elastic constants of rare‐gas crystals under pressure
Authors: Zarochentsev E. V. , Varyukhin V. N. , Troitskaya E. P. , Chabanenko Val. V. , Horbenko E. E.
Published: July 2006

In previous papers, the authors have ab initio constructed a nonempirical pair interatomic potential of rare‐gas crystals. It was constructed for the case of high pressures (strong compression). The equations of state are solved and the elastic constants responsible for the propagation of sound in strongly compressed crystals of rare gases are calculated in the next‐nearest‐neighbor approximation using the interatomic potential proposed by the authors. The results of calculations are in satisfactory agreement with the experimental data. The shear modulus ℬ︁12 is described somewhat less well. The last experiment data show that Cauchy relation is satisfied in krypton consequently the interatomic interaction in the rare‐gas crystals has a central character. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge transfer in single‐ and double‐strand DNAs: Theoretical analysis based on molecular orbital method
Authors: Dedachi Kenichi , Natsume Takayuki , Nakatsu Taisuke , Ishikawa Yasuyuki , Kurita Noriyuki
Published: July 2006

Electrochemical DNA chips determine the sequence of DNA bases by detecting the change in charge conductivity through single‐ or double‐strand DNA. Experimentally, double‐strand DNAs were found to conduct much greater electric current than single‐strand DNAs. To gain insight into the underlying mechanism leading to such a disparity in charge conductivity, the hole/electron conductivities in single‐ and double‐strand DNAs were examined theoretically by molecular dynamics and molecular orbital (MO) calculations. The hole/electron transfer integrals between the neighboring DNA bases were estimated from the frontier MO energy levels. The current‐voltage characteristics of single‐ and double‐strand DNAs, derived from the transfer integrals and the site energy of each DNA base, are qualitatively in agreement with experiment. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Structures and G3X energies of C3H3N+ intermediates
Authors: Elkner Kenneth , Binning R. C. , Bacelo Daniel E.
Published: July 2006

Geometries and energies of 15 stable C3H3N+ structures, potential intermediates in ion–molecule reactions that occur on the C3H3N+ potential energy surface (PES), have been calculated with G3X theory. Accurate energy ordering of the intermediates is needed to understand the initial stage of the reactions. The reactions of N(2D) with cyclopropenyl cation and of HCN and HNC with acetylene cation radical are of interest because they may lead to the formation of cyanoacetylene or some of its isomers in dense interstellar dust clouds. The energetics of the initial phases of these reactions are discussed in light of the calculated energies of reactants and intermediates. The variety of high‐energy intermediates optimized makes it likely that the reactions discussed involve long‐lived complexes and multiple rearrangements. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Prospective, Blinded Comparison of Helical CT and CT Arterial Portography in the Assessment of Hepatic Metastasis from Colorectal Carcinoma
Authors: Schwartz L. , Brody L. , Brown K. , Covey A. , Tuorto S. , Mazumdar M. , Riedel E. , Jarnagin W. , Getrajdman G. , Fong Y.
Published: July 2006

Objective

This prospective blinded comparison of helical CT and helical CT arterial portography aimed to detect liver metastasis from colorectal carcinoma.

Methods and Materials

50 patients with colorectal carcinoma were evaluated comparing helical CT with helical CT arterial portography. Each imaging study was evaluated on a 5‐point ROC scale by radiologists blinded to the other imaging findings, and the results were compared, with the surgical and pathologic findings as the gold standard.

Results

Of the 127 lesions found at pathology identified as metastatic colorectal cancer, helical CT correctly identified 85 (69%) and CT portography 96 (76%). When subgroups with lesions <3 cm (48 patients) and patients with maximum tumor size <3 cm (18 patients) were considered, CT portography was always better than helical CT in terms of sensitivity, specificity, positive predictive value, and negative predictive value. ROC analysis adjusting for multiple lesions per patient revealed significantly greater area under the curve (AUC) for the subgroup of lesions <3 cm (CT‐AUC of 77% and CT portography AUC of 81%; P = 0.002).

Conclusions

For identification of large metastases, helical CT and CT portography have similar yield. However, for detection of small liver metastases, CT portography remains superior for lesion detectability.
Laparoscopic Treatment of Benign Insulinomas Localized in the Body and Tail of the Pancreas: A Single‐center Experience
Authors: Toniato Antonio , Meduri Francesco , Foletto Mirto , Avogaro Angelo , Pelizzo MariaRosa
Published: July 2006

Background

The increasingly widespread use of minimally invasive surgery has allowed surgeons to exploit this approach for complex procedures, such as pancreatic resections, though its actual role outside simple operations remains debated.

Methods

This is a study of 12 consecutive patients, 5 men and 7 women, with pancreatic insulinoma who were treated at our institution from 2000 to September 2005. All patients presented with typical symptoms and laboratory findings of hyperinsulinism and were good candidates for laparoscopic surgery. Preoperative diagnostic work‐up, operating time, postoperative complication rate, length of hospital stayd and clinical outcome were assessed.

Results

Successful laparoscopic resection was performed in 11 out of 12 patients: 4 had tumor enucleation, and 7 had distal pancreatectomy; among these latter 5 had spleen‐preserving distal pancreatectomy. In 1 case conversion to open surgery was necessary. Mean operative time was 170 minutes. The median tumor size was 18 mm, and all the insulinomas were benign. Four complications were observed in this group, and the median hospital stay was 8 days.

Conclusions

The laparoscopic approach proved to be feasible and safe, although the average operative time was longer and demanded good surgical skills as well as precise localization of the tumor and definition of its nature. Tumors located in the body or tail of the pancreas that are benign in nature can better benefit of laparoscopic approach.
Posterior Tibial Tendon Insufficiency Results at Different Stages
Authors: Deland Jonathan T. , Page Alexandra , Sung Il-Hoon , O'Malley Martin J. , Inda David , Choung Steven
Published: July 2006

The results of surgical treatment of posterior tibial tendon insufficiency (PTTI) may be different at different stages of the disease. No single study has compared the results at different stages. This comparison can be helpful to the patient and physician if the patient asks “What if I wait and the disease progresses, how will my results be different?” A preliminary study comparing results for stage IIa, stage IIb (advanced stage II), and stage III was performed followed by a larger study comparing IIa and IIb with 26 and 22 patients, respectively. American Orthopaedic Foot and Ankle Society (AOFAS) outcome scores as well as radiographs and functional questions were used. Nearly all patients, regardless of stage, felt they were helped by surgical treatment. However, the lowest AOFAS score was in stage III, the most advanced stage investigated in this study. In comparing stage IIa and IIb patients, stage IIb patients had a statistically higher incidence of lateral discomfort. Although statistically significant differences were not found in all comparisons, this study suggests that the results of surgical treatment for PTTI declines with increasing stage or severity of disease.
A Transfer Function for Estimating Paleoceanographic Conditions Based on Deep-Sea Surface Sediment Distribution of Radiolarian Assemblages in the South Atlantic
Authors: Morley Joseph J.
Published: July 2006

A quantitative analysis of radiolarian species in 57 deep-sea surface sediment samples from the South Atlantic Ocean produced four geographically distinct assemblages (tropical, polar, gyre margin, and subtropical). The distributions of these assemblages or factors coincide with present-day patterns of sea-surface temperatures or water masses.

These four assemblages were used to construct a transfer function relating radiolarian distribution in the surface sediments to present-day winter and summer temperatures using standard regression techniques. As a test of the quality of this transfer function, temperatures were estimated on surface sediment samples from the eastern South Pacific. The temperatures produced by the transfer function compared favorably with the observed (present-day) winter and summer sea-surface temperatures at these sites.
Sedimentology and Palynology of Middle Wisconsinan Deposits in the Pecatonica River Valley, Wisconsin and Illinois
Authors: Whittecar G. Richard , Davis Anthony M.
Published: July 2006

The bedrock valley of the Pecatonica River north of Freeport, Illinois, contains a thick valley-fill complex of alluvium and drift. Within the valley, loess-capped benches surround hills of silty Illinoian drift. Beneath these benches lie thick deposits of poorly sorted stony silt interbedded with thin lenses of silt, sand, and organic-rich loam. Channel deposits and peat cap the diamicton in places. We interpret the stony silts as solifluction debris shed from silty slopes within the valley-fill during the Early or Middle Wisconsinan (Altonian). Top and bottom radiocarbon dates from a 2.5-m section of peat overlying the diamicton are 26,820 ± 200 and 40,500 ± 1700 yr B.P., respectively. We informally refer to the stony silts, channel sediments, and peat as the “Martintown unit.” Geomorphic position, sediment input, and macrofossils suggest that the dated peat was deposited in a floodplain pond (oxbow?). The pollen record from the peat indicates that a boreal forest dominated this area during the Middle Wisconsinan (late Altonian and Farmdalian). Two pollen zones are recognized: a basal Zone I with Pinus slightly more abundant than Picea and with few herbs and shrubs, and an upper Zone II dominated by Picea and with a larger representation of herbaceous and shrub taxa. Little displacement of vegetation zones is indicated, even though ice advanced to within 100 km of the site during the time of peat accumulation. Because of the problems involved in clearly defining Middle Wisconsinan forest-tundra in mid-latitudes by using analogs of Holocene forest-tundra in high latitudes, caution is required in making geomorphic inferences solely from vegetation data. Together, though, pollen and sediment data indicate that during the Middle Wisconsinan, Pecatonica hillslopes progressed through a sequence of instability-stability-instability related to climatic fluctuations.
Isotopic Evidence of Holocene Climatic Change in the San Juan Mountains, Colorado
Authors: Friedman Irving , Carrara Paul , Gleason Jim
Published: July 2006

The δD of cellulose from 14C-dated wood, collected in the San Juan Mountains of southwestern Colorado, decreased by about 45‰ from 9600 to 3100 yr B.P. and an additional 25‰ to the present. The wood samples are from trees that grew above present-day tree line and reflect a time of warmer average summer temperatures. These changes in δD are interpreted to indicate a major change during the Holocene in the sources of moisture, in the seasonality of precipitation, or in both.
Comparison of Two Indicators of Climatic Change: Tree Growth and Lake Superior Water Supplies
Authors: Brinkmann W.A.R.
Published: July 2006

Many proxy indicators of past climate integrate the effects of temperature and precipitation, and not all indicators integrate these effects in the same way. This poses a problem in the reconstruction of past climate. A study of the response of tree growth around Lake Superior and the water supplies to that lake to summer climate shows differences and similarities in response. Tree growth is positively correlated with precipitation—although the response is reduced when conditions are very wet—and negatively correlated with temperature. In contrast, the water supplied to the lake are positively correlated with both precipitation and temperature; the correlation with temperature is, however, not very strong. Multiple regression models developed to assess the relative magnitudes of the similarities and differences show that the similarity in response to precipitation accounts for about 30% of the variance in water supplies, the nonlinear response of trees—represented by a log transformation—accounts for an additional 15%, and the difference in response to temperature is equivalent to about 30% of the variance in water supplies.
A Last Interglacial Fauna from the Eastern Sahara
Authors: Kowalski Kazimierz , Neer Wim van , Bocheński Zygmunt , Młynarski Marian , Rzebik-Kowalska Barbara , Szyndlar Zbigniew , Gautier Achilles , Schild Romuald , Close Angela E. , Wendorf Fred
Published: July 2006

Recent work on the middle Paleolithic at Bir Tarfawi, in the hyperarid Eastern Sahara (<1 mm of rain per annum), has yielded a rich faunal assemblage, including several thousand remains of fish, amphibians, reptiles, birds, and small mammals. They are derived from the sediments of two consecutive lakes dated by several techniques to about 135,000 yr B.P. Fifty-nine taxa have been identified and indicate that at times during the Last Interglaciation the area received at least 500 mm of rainfall as a result of the northward shift of the monsoon belt, and that, on several occasions, there may have been water connections between Bir Tarfawi and unidentified but permanent bodies of water elsewhere.
U-Series Dating of Last Interglacial High Sea Stands: Barbados Revisited
Authors: Ku Teh-Lung , Ivanovich M. , Luo Shangde
Published: July 2006

U-series chronologies of the emerged coral limestone terraces on Barbados, West Indies, together with those of the terraces from New Guinea, have formed the basis for most late Pleistocene eustatic models. The so-called “Barbados sea level model” has been challenged in recent years, however. A major issue is whether during oxygen isotope stage 5e, when Rendezvous Hill reef complex on Barbados Island formed, the sea rose above the present position for one relatively brief period of <10,000 yr, or for two or more periods spanning approximately from 140,000 to 115,000 yr B.P. Evidence for the latter scenario has not come from initial studies of Barbados but from elsewhere; it is also inconclusive because of the dating uncertainties involved. We have carried out careful redeterminations of U-series ages on a suite of 29 Acropora palmata samples systematically collected from four of the lowest terraces on the island. Diagenetic disturbance may have caused the age spreads at some sampling outcrops. A model for the diagenetic exchange of uranium isotopes in coral samples with those in groundwater explains the anomalous 234U/238U ratios in samples with apparently unaltered mineralogy (aragonite) and trace element (Mg and Sr) chemistry. It shows that age dispersions of 5–10% can be engendered by a U exchange coefficient of the order of 10−6 yr−1. The lower-limit terrace ages, estimated from averaging the multiple measurements, are 81,000 ± 2000 yr (Worthing), 105,000 ± 1000 yr (Ventnor), 120,000 ± 2000 yr (Maxwell), and 117,000 ± 3000 yr (Rendezvous Hill). No evidence was found of previously inferred bipartite sea levels centering around 118,000 and 135,000 yr ago. This study documents the need of dating coral with the high precision/sensitivity mass-spectrometric techniques for future resolution of the temporal relationships among sea level changes, climate oscillations, and astronomical forcing—relationships originally addressed by the Barbados sea level model.
Discordant 14C Ages from Buried Tidal-Marsh Soils in the Cascadia Subduction Zone, Southern Oregon Coast
Authors: Nelson Alan R.
Published: July 2006

Peaty, tidal-marsh soils interbedded with estuarine mud in late Holocene stratigraphic sequences near Coos Bay, Oregon, may have been submerged and buried during great (M > 8) subduction earthquakes, smaller localized earthquakes, or by nontectonic processes. Radiocarbon dating might help distinguish among these alternatives by showing that soils at different sites were submerged at different times along this part of the Cascadia subduction zone. But comparison of conventional 14C ages for different materials from the same buried soils shows that they contain materials that differ in age by many hundreds of years. Errors in calibrated soil ages represent about the same length of time as recurrence times for submergence events (150–500 yr)—this similarity precludes using conventional 14C ages to distinguish buried soils along the southern Oregon coast. Accelerator mass spectrometer 14C ages of carefully selected macrofossils from the tops of peaty soils should provide more precise estimates of the times of submergence events.
Correlation of Distal Tephra Layers in Loess in the Channeled Scabland and Palouse of Washington state
Authors: Busacca Alan J. , Nelstead Kevin T. , McDonald Eric V. , Purser Michael D.
Published: July 2006

Thirty-two distal tephra layers that are interbedded in Quaternary loess at 13 sites in the Channeled Scabland and Palouse were sampled as part of a regional study of the stratigraphy and chronology of dominantly windblown sediments on the Columbia Plateau. An electron microprobe was used to determine the elemental composition of volcanic glass in all of the samples and also to determine the composition of ilmenite in 14 of them. Two of the distal tephra layers correlate with Glacier Peak eruptions (11,200 yr B.P.), five with Mount St. Helens tephra set S (13,000 yr B.P.), and nine with Mount St. Helens tephra set C (ca. 36,000 yr B.P.) based on analysis of glass and ilmenite in reference pumices from Glacier Peak, Mount St. Helens, Mount Mazama, Mount Rainier, and Mount Jefferson, on the calculation of similarity coefficients for comparisons of both glass and ilmenite reference compositions with those of distal tephras, and on considerations of stratigraphic position. The composition of glass and ilmenite and the stratigraphic position of one distal tephra layer in the loess suggests that it is from an eruption of Mount St. Helens at least several thousand years older than the set C eruptions. Glass composition and stratigraphic position of a distal tephra at another site in loess suggested a possible correlation with some layers of the Pumice Castle eruptive sequence at Mount Mazama (ca. 70,000 yr B.P.), but similarity coefficients on ilmenite of only 45 and 48 fail to support the correlation and show why multiple correlation methods should be used. Similarity coefficients higher than 96 for both glass and ilmenite establish a correlation with Mount St. Helens layer Cw for distal layers in two widely separated sites. These layers are in sedimentary successions that are closely associated with giant floods in the Channeled Scabland. The 36,000 yr B.P. radiocarbon age of the Mount St. Helens set C establishes a minimum limiting date for an episode of flooding that predates the widespread late Wisconsin floods. A correlation of distal tephra layers at two other sites in the Scabland and Palouse establishes a chronostratigraphic link to a still-older episode of flooding within the Brunhes Normal Polarity Chron. Six distal tephra layers in pre-late Quaternary loess that are not correlated with known or dated eruptions have compositions and distinctive stratigraphic positions relative to magnetic reversal boundaries that make them key markers for future work.
Selective recruitment of src family kinase Hck by leukocyte integrin αMβ2 but not αLβ2 or αXβ2
Authors: Tang Ren-Hong , Law S.K. Alex , Tan Suet-Mien
Published: July 2006

Integrins are type I heterodimeric (α/β) cell adhesion molecules. They trigger cell‐signaling by recruiting cytosolic molecules to their cytoplasmic tails. Integrin α cytoplasmic tail contributes towards integrin function specificity, an important feature of integrins having different α subunits but sharing the same β subunit. Herein, we show that the src family kinase Hck co‐capped selectively with leukocyte integrin αMβ2 but not αLβ2 or αXβ2. This was disrupted when the αM cytoplasmic tail was substituted with that of αL or αX. Co‐capping was recovered by αL or αX cytoplasmic tail truncation or forced separation of the α and β cytoplasmic tails via salt‐bridge disruption.
Cost‐effective approaches to in vitro fertilization: Means to improve access
Authors: Hovatta O. , Cooke I.
Published: July 2006

Many childless couples would like to have access to in vitro fertilization (IVF) through public‐sector programs, but such programs are scant because of the high costs that IVF entails today. A solution for health departments worldwide might be to leave IVF methods requiring expensive equipment and ovarian stimulating hormones — such as human recombinant gonadotropins, plus gonadotropin‐releasing hormone analogues to prevent a surge of luteinizing hormone — to the private sector. Rather, health departments could focus on methods using less equipment and no ovarian stimulating agent at all if possible. If not possible, inexpensive clomiphene citrate could be used, combined with human menopausal gonadotropin if needed. Before embryo transfer, oocyte maturation could occur in vitro or in a makeshift incubator: a tube closed, wrapped, and left in the woman's vagina for 24 h. To prevent short‐ and long‐term costs as well as possible lifelong problems, the transfer of multiple embryos should not be performed.
Cervical cancer: A call for political will
Authors: Pollack A.E. , Balkin M.S. , Denny L.
Published: July 2006

Cervical cancer kills over a quarter of a million women worldwide on an annual basis, with 80% of these deaths occurring in developing countries. Cytology‐based screening programs, widely used in industrialized countries, are difficult to implement in low‐resource settings. Non‐cytological methods for screening and treatment have been developed and studied over the last decade. Given the barriers to widespread, good quality screening and early treatment, the most promising new prevention strategy will be the introduction of a vaccine to prevent human papillomavirus infection, the cause of cervical cancer. Understanding women's health‐seeking behaviors is critical to successful dissemination and uptake of both screening and vaccine prevention strategies.