bluuebunny/crossref_metadata_2025 huggingface dataset:
Different impact from betel quid, alcohol and cigarette: Risk factors for pharyngeal and laryngeal cancer
Authors: Lee Ka‐Wo , Kuo Wen‐Rei , Tsai Shih‐Meng , Wu Deng‐Chyang , Wang Wen‐Ming , Fang Fu‐Min , Chiang Feng‐Yu , Ho Kuen‐Yao , Wang Ling‐Feng , Tai Chih‐Feng , Kao Eing‐Long , Chou Shah‐Hwa , Lee Chien‐Hung , Chai Chee‐Yin , Ko Ying‐Chin
Published: June 2005

The risks of betel quid chewing with or without tobacco, alcohol drinking and cigarette smoking have been well explored in the oral cavity but not in the pharynx and larynx. We conducted a case‐control study to investigate the association of these three risk factors to cancers of the pharynx and larynx in Taiwan. A total cases of 148 pharyngeal cancer, 128 laryngeal cancer and 255 hospital controls, all men, were recruited. Betel quid chewing was a significant independent risk factor (adjusted odds ratio [aOR] = 7.7; 95% confidence interval [CI] = 4.1–15.0) similar to that of alcohol drinking (aOR = 6.6; 95% CI = 3.5–13.0) for pharyngeal cancer, but not for laryngeal cancer (aOR = 1.3; 95% CI = 0.7–2.5) on which cigarette smoking (aOR = 7.1) exerts a stronger significant independent risk than alcohol drinking (aOR = 3.8). For pharyngeal cancers, chewers who consumed >20 quid/day, chewed with inflorescence in the quid or swallowed the betel quid juice were at higher risks; significant dose‐response effects were found in daily quantity of drinking and chewing, and cumulative quantity of drinking. Synergistic effects from the 3 risk factors existed both on the pharynx (aOR = 96.9) and the larynx (aOR = 40.3), and attributed for 93.1% and 92.9% respectively. Our study is the first evidence to show that betel quid chewing without tobacco has different impact on the pharynx (digestive tract) and the larynx (airway), and supports the concept that exposure quantity and direct mucosal contact with the betel quid juice may contribute to carcinogenesis. Our results show an important insight into the impact of betel quid chewing on other sites of the digestive tract other than the oral cavity. © 2005 Wiley‐Liss, Inc.
Use of nonaspirin NSAIDs and risk of lung cancer
Authors: Skriver Mette Vinther , Nørgaard Mette , Poulsen Aslak Harbo , Friis Søren , Harving Henrik , Fryzek Jon , McLaughlin Joseph K. , Blot William J. , Olsen Jørgen H. , Sørensen Henrik Toft
Published: June 2005

Epidemiologic evidence is conflicting regarding the potential for nonsteroidal antiinflammatory drugs (NSAIDs) to lower the risk of lung cancer. We thus determined the incidence of lung cancer among a cohort of over 242,000 adults in Denmark who had been issued NSAID prescriptions during 1991–2002 and calculated the relative risks of this cancer according to the numbers of prescriptions received. Similar analyses were conducted among a subset with chronic obstructive pulmonary disease, of whom the large majority was assumed to have been smokers, as an indirect control for smoking. Utilization of Danish registries ensured essentially complete and unbiased ascertainment of prescriptions and cancer outcomes. The relative risks of lung cancer among NSAID users redeeming 10 or more prescriptions vs. nonusers in the general population and among chronic obstructive pulmonary disease patients were 1.51 (95% CI = 1.33–1.71) and 1.55 (95% CI = 0.93–2.60) and tended to decline with decreasing numbers of NSAIDs prescribed. Separate analyses for adenocarcinoma and squamous cell carcinoma also failed to show reduced risks among NSAID users. Confounding by indication may have contributed to the increased risks, but the study provides no evidence to suggest that recent NSAID intake may be protective for lung cancer. © 2005 Wiley‐Liss, Inc.
High constant incidence rates of second cutaneous melanomas
Authors: Levi Fabio , Randimbison Lalao , Te Van‐Cong , La Vecchia Carlo
Published: June 2005

The incidence of most epithelial cancers rises with a power of age. However, second breast cancers have a high constant incidence independent of age. The skin is one of the few other sites allowing examination of age incidence curves of second neoplasms of the same organ. We considered the risk of second primary cutaneous malignant melanoma (CMM) in a population‐based series of 3,439 first CMM registered and followed‐up between 1974 and 2003 in the Swiss Cantons of Vaud and Neuchâtel (about 786,000 inhabitants). A total of 43 cases of second CMM were observed vs. 9.3 expected, corresponding to a standardized incidence ratio (SIR) of 4.6. The SIR was 8.5 under age 50, 5.7 at age 50–59 and 3.5 at age 60 or over. At 20 years, the cumulative risk of second CMM was 5%. Age‐specific incidence rates of second primary CMM did not vary across age groups 30–39 through 80+, ranging between 1 and 2.5 per 1,000 person‐years. Thus, the risk of CMM is substantially increased in subjects diagnosed with a CMM, and the relative risk is greater at younger age and declines with advancing age. The high constant incidence curve of second CMM is compatible with the occurrence of a single mutational event in a population of susceptible individuals. © 2005 Wiley‐Liss, Inc.
Don't get “hooked” by phishing scams
Authors: Singleton Tommie
Published: June 2005

Right this minute, someone has “gone phishing”— hoping to catch you, your company employees, or your customers. Criminals are duping computer users into revealing sensitive information— including bank accounts, social security numbers, credit card numbers, passwords, and more. Here's how to escape getting caught. © 2005 Wiley Periodicals, Inc.
Computational analyses of singlet–singlet and singlet–triplet transitions in mononuclear gold‐capped carbon‐rich conjugated complexes
Authors: Cao Zexing , Zhang Qianer
Published: June 2005

Density functional theory and CASSCF calculations have been used to determine equilibrium geometries and vibrational frequencies of metal‐capped one‐dimensional π‐conjugated complexes (H3P)Au(CC)n(Ph) (n = 1–6), (H3P)Au(CCC6H4)(CCPh), and H3PAu(CCC6H4)CCAuPH3 in their ground states and selected low‐lying ππ* excited states. Vertical excitation energies for spin‐allowed singlet–singlet and spin‐forbidden singlet–triplet transitions determined by the time‐dependent density functional theory show good agreement with available experimental observations. Calculations indicate that the lowest energy 3(ππ*) excited state is unlikely populated by the direct electronic excitation, while the low‐lying singlet and triplet states, slightly higher in energy than the lowest triplet state, are easily accessible by the excitation light used in experiments. A series of radiationless transitions among related excited states yield the lowest 3(ππ*) state, which has enough long lifetimes to exhibit its photochemical reactivities. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1214–1221, 2005
Oogenesis in the viviparous matrotrophic lizard Mabuya brachypoda
Authors: Hernández‐Franyutti Arlette , Uribe Aranzábal Mari Carmen , Guillette Louis J.
Published: June 2005

Oogenesis in the lizard Mabuya brachypoda is seasonal, with oogenesis initiated during May–June and ovulation occurring during July–August. This species ovulates an egg that is microlecithal, having very small yolk stores. The preovulatory oocyte attains a maximum diameter of 0.9–1.3 mm. Two elongated germinal beds, formed by germinal epithelia containing oogonia, early oocytes, and somatic cells, are found on the dorsal surface of each ovary. Although microlecithal eggs are ovulated in this species, oogenesis is characterized by both previtellogenic and vitellogenic stages. During early previtellogenesis, the nucleus of the oocyte contains lampbrush chromosomes, whereas the ooplasm stains lightly with a perinuclear yolk nucleus. During late previtellogenesis the ooplasm displays basophilic staining with fine granular material composed of irregularly distributed bundles of thin fibers. A well‐defined zona pellucida is also observed. The granulosa, initially composed of a single layer of squamous cells during early previtellogenesis, becomes multilayered and polymorphic. As with other squamate reptiles, the granulosa at this stage is formed by three cell types: small, intermediate, and large or pyriform cells. As vitellogenesis progresses the oocyte displays abundant vacuoles and small, but scarce, yolk platelets at the periphery of the oocyte. The zona pellucida attains its maximum thickness during late oogenesis, a period when the granulosa is again reduced to a single layer of squamous cells. The vitellogenic process observed in M. brachypoda corresponds with the earliest vitellogenic stages seen in other viviparous lizard species with larger oocytes. The various species of the genus Mabuya provided us with important models to understand a major transition in the evolution of viviparity, the development of a microlecithal egg. J. Morphol. © 2005 Wiley‐Liss, Inc.
Conditioning stimulus can influence an external urethral sphincter contraction evoked by a magnetic stimulation
Authors: Wefer Bjoern , Reitz André , Knapp Peter A. , Bannowsky Andreas , Juenemann Klaus‐Peter , Schurch Brigitte
Published: June 2005

Aims

To study the effect of a conditioning stimulus on an external urethral sphincter (EUS)contraction evoked by a magnetic stimulation at different time intervals.

Methods

Seven healthy male volunteers underwent EUS pressure measurement. At baseline, magnetic stimulation of the lumbosacral spinal cord above the motor threshold was performed and evoked EUS pressure responses were recorded. The lumbosacral magnetic stimulation was repeated with same intensity, while a selective electrical dorsal penile nerve stimulation below the bulbocavernosus reflex (BCR) threshold was preceding at five different intervals (10, 20, 30, 50, 100 msec). The protocol was performed with empty and full bladder (BLA), and baseline responses were statistically compared to those with combined stimulation.

Results

When the dorsal penile nerve electrical stimulation preceded the lumbosacral magnetic stimulation by 20 msec (P = 0.0048), 50 msec (P = 0.0039), or 100 msec (P = 0.0002), the amplitudes of the EUS pressure response with empty BLA were significantly reduced compared to lumbosacral magnetic stimulation alone. With a filled BLA, the amplitudes of the EUS were significantly reduced only at an interval of 50 msec (P < 0.0001).

Conclusions

A conditional sensory pudendal stimulation seems to have the capacity to inhibit the external urethral sphincter contraction induced by a magnetic stimulation. The inhibitory effect seems to depend on the latency between the peripheral and lumbosacral stimulation as well as on the degree of BLA filling. It remains to be proved if the neuromodulative effect of the conditional stimulus occurs at a spinal or supraspinal level. Neurourol. Urdynam. © 2005 Wiley‐Liss, Inc.
Low‐complexity minimization algorithms
Authors: Di Fiore Carmine , Fanelli Stefano , Zellini Paolo
Published: June 2005

Structured matrix algebras ℒ︁ and a generalized BFGS‐type iterative scheme have been recently investigated to introduce low‐complexity quasi‐Newton methods, named ℒ︁QN, for solving general (non‐structured) minimization problems. In this paper we introduce the ℒ︁kQN methods, which exploitad hocalgebras at each step. Since the structure of the updated matrices can be modified at each iteration, the new methods can better fit the Hessian matrix, thereby improving the rate of convergence of the algorithm. Copyright © 2005 John Wiley & Sons, Ltd.
A new boundary element technique without domain integrals for elastoplastic solids
Authors: Bertoldi Katia , Brun Michele , Bigoni Davide
Published: June 2005

A simple idea is proposed to solve boundary value problems for elastoplastic solids via boundary elements, namely, to use the Green's functions corresponding to both the loading and unloading branches of the tangent constitutive operator to solve for plastic and elastic regions, respectively. In this way, domain integrals are completely avoided in the boundary integral equations. Though a discretization of the region where plastic flow occurs still remains necessary to account for the inhomogeneity of plastic deformation, the elastoplastic analysis reduces, in essence, to a straightforward adaptation of techniques valid for anisotropic linear elastic constitutive equations (the loading branch of the elastoplastic constitutive operator may be viewed formally as a type of anisotropic elastic law). Numerical examples, using J2‐flow theory with linear hardening, demonstrate that the proposed method retains all the advantages related to boundary element formulations, is stable and performs well.

The method presented is for simplicity developed for the associative flow rule; however, a full derivation of Green's function and boundary integral equations is also given for the general case of non‐associative flow rule. It is shown that in the non‐associative case, a domain integral unavoidably arises in the formulation. Copyright © 2005 John Wiley & Sons, Ltd.
Pleomorphic lobular carcinoma of the breast: role of comprehensive molecular pathology in characterization of an entity
Authors: Reis‐Filho Jorge S , Simpson Pete T , Jones Chris , Steele Dawn , Mackay Alan , Iravani Marjan , Fenwick Kerry , Valgeirsson Haukur , Lambros Maryou , Ashworth Alan , Palacios Jose , Schmitt Fernando , Lakhani Sunil R
Published: June 2005

Immunohistochemical analysis of E‐cadherin has changed the way lobular neoplasia is perceived. It has helped to classify difficult cases of carcinoma in situ with indeterminate features and led to the identification of new variants of lobular carcinoma. Pleomorphic lobular carcinoma (PLC) and pleomorphic lobular carcinoma in situ (PLCIS), recently described variants of invasive and in situ classic lobular carcinoma, are reported to be associated with more aggressive clinical behaviour. Although PLC/PLCIS show morphological features of classic lobular neoplasia and lack E‐cadherin expression, it is still unclear whether these lesions evolve through the same genetic pathway as lobular carcinomas or are high‐grade ductal neoplasms that have lost E‐cadherin. Here we have analysed a case of extensive PLCIS and invasive PLC associated with areas of E‐cadherin‐negative carcinoma in situ with indeterminate features, using immunohistochemistry, chromogenic in situ hybridization, high‐resolution comparative genomic hybridization (CGH) and array‐based CGH. We observed that all lesions lacked E‐cadherin and β‐catenin and showed gain of 1q and loss of 16q, features that are typical of lobular carcinomas but are not seen in high‐grade ductal lesions. In addition, amplifications of c‐myc and HER2 were detected in the pleomorphic components, which may account for the high‐grade features in this case and the reported aggressive clinical behaviour of these lesions. Taken together, these data suggest that at least some PLCs may evolve from the same precursor or through the same genetic pathway as classic lobular carcinomas. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Improved Synthesis and X‐Ray Structure of 5‐Aminotetrazolium Nitrate
Authors: von Denffer Moritz , Klapötke Thomas M. , Kramer Gernot , Spieß Gunnar , Welch Jan M. , Heeb Gerhard
Published: June 2005

5‐Aminotetrazolium nitrate was synthesized in high yield and characterized using Raman and multinuclear NMR spectroscopy (1H, 13C, 15N). The molecular structure of 5‐aminotetrazolium nitrate in the crystalline state was determined by X‐ray crystallography: monoclinic, P 21/c, a=1.05493(8) nm, b=0.34556(4) nm, c=1.4606(1) nm, β=90.548(9)°, V=0.53244(8) nm3, Z=4, ϱ=1.847 g cm−3, R1=0.034, wR2 (all data)=0.090. The thermal stability of 5‐aminotetrazolium nitrate was determined using differential scanning calorimetry; the compound decomposes at 167 °C. The enthalpy of combustion (ΔcombH) of 5‐aminotetrazolium nitrate ([CH4N5]+[NO3]−) was determined experimentally using oxygen bomb calorimetry: ΔcombH([CH4N5]+[NO3]−)=−6020±200 kJ kg−1. The standard enthalpy of formation (ΔfH°) of [CH4N5]+[NO3]− was obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): ΔfH°([CH4N5]+[NO3]−(s))=+87 kJ mol−1=+586 kJ kg−1. The detonation velocity (D) and the detonation pressure (P) of 5‐aminotetrazolium nitrate were calculated using the empirical equations by Kamlet and Jacobs: D([CH4N5]+[NO3]−)=8.90 mm μs−1 and P([CH4N5]+[NO3]−)=35.7 GPa.
Statistical properties of the Cooper pair operators
Authors: Kaplan I. G. , Navarro O. , Sánchez J. A.
Published: June 2005

The Cooper pair has the total spin S = 0. So, in accordance with the Pauli principle, the wave functions describing the Cooper pair system should have the boson permutation symmetry, but the pairon operators (Cooper's pair operators) do not obey the boson commutation relations. The pairon operators may not be considered neither as the Bose operators, nor as the Fermi operators. In this work, we analyze the statistical properties and the commutation relations for the pairon operator and reveal that they correspond to the modified parafermi statistics of rank p = 1. Two different expressions for the Cooper pair number operator are presented. We demonstrate that the calculations with a Hamiltonian expressed via pairon operators is more convenient using the commutation properties of these operators without presenting them as a product of fermion operators. This allows to study problems in which the interactions between Cooper's pair are also included. The problem of two interacting Cooper's pairs is discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum criticality in ultracold atoms on optical lattices
Authors: Rigol Marcos , Muramatsu Alejandro
Published: June 2005

In recent years degenerate quantum gases confined in optical lattices developed as a new field of research bridging the areas of quantum optics, atomic physics, and condensed matter physics. It offers the possibility of manipulating quantum many‐body systems with an unprecedented flexibility, so that they can be considered as analog simulators of condensed matter systems. Particularly interesting is the possibility of creating strongly correlated bosonic or fermionic systems. We review here recent numerical simulations, where quantum critical behavior is studied both in and out of equilibrium. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physical principles of barrierless thermoelectric cooling
Authors: Gurevich Yu. G. , Logvinov Georgiy N. , Oscar Angeles Fragoso
Published: June 2005

A new approach is suggested to explain thermoelectric cooling. It is based on an analysis of this phenomenon from the point of view of the energy balance equation. It is shown that in the general case the thermoelectric cooling at a junction of two semiconductors is determined by the barrier cooling effect (the Peltier effect) and the barrierless cooling effect. The latter is a new thermoelectric effect originating only at the finite value of the junction surface thermal conductivity. The influence of the surface thermal resistance on both the Peltier effect and the barrierless cooling effect has been studied. It is shown that the Peltier effect is reduced with an increase of the junction surface thermal resistance while the barrierless cooling effect occurs more strictly with an increase of the surface thermal resistance. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum dynamics of a system of coupled nonlinear oscillators: Spectral and information entropy‐based analysis
Authors: Maji Kaushik , Bhattacharyya S. P.
Published: June 2005

The quantum dynamics of the evolution of a system of a few coupled nonlinear oscillators is studied. The spectral entropy and the quantal information entropy, as well as their correlation functions, are computed and used to identify distinctive phases of the evolution. The two entropy functions lead to similar conclusions. It appears that adiabatic switching of the nonlinear interaction does not affect the nature of the short time dynamics but affects the dynamics over intermediate time scales. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Hydrogen bond character and proton transfer behavior in water–thiophenol clusters and their cation radicals: Insight into water number size dependence
Authors: Song Lianxiang , Bu Yuxiang , Li Ping
Published: June 2005

The molecular structures and vibrational frequencies of [C6H5SH–(H2O)n]•+ (n = 1–4) clusters are studied employing B3LYP density functional theory (DFT) with a 6‐311++G** basis set. The features related to structures of the SH stretching vibrational spectrum of the thiophenol and of the intermolecular stretching vibration of S…HO are also obtained and discussed in detail. The stable structures show that the hydrogen bonds between the thiophenol cation radical and water molecules are stronger than that between neutral thiophenol and water molecules and become stronger along with the increased water number n. Thus, the possibility of proton transfer depends on the water number; that is, the position of the proton of the thiophenol cation radical lies on the water number n. The theoretically obtained charge distribution and energy indicate simultaneously that (i) the cluster ions with n = 1–2 have the proton‐nontransferred form; (ii) the cluster ion with n = 3 settles mainly on the proton‐transferred branched form; and (iii) in the case of n = 4 cluster ions, can be a mixture of proton‐transferred ringed and branched forms. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Analysis of 7‐methylguanine using isotope dilution and gas chromatography/electron‐capture negative chemical ionization mass spectrometry
Authors: Chiang Su‐Yin , Huang Tai‐Hung , Uang Shi‐Nian , Wu Hong‐Dar Isaac , Wei Yi‐Chiech , Lin Hui‐Yi , Swenberg James A. , Wu Kuen‐Yuh
Published: June 2005

This paper presents results obtained for in vivo endogenous and exogenous 7‐methylguanine (7‐MG) analyzed using a method incorporating gas chromatography with electron‐capture negative chemical ionization mass spectrometry and isotope dilution (GC/EC‐ID‐MS). 13C4‐Labeled 7‐MG was synthesized to serve as an internal standard to improve accuracy of quantitation, and was used to analyze 7‐MG in livers of control mice and dacarbazine‐treated mice. The results confirm that 7‐MG in tissue DNA can be measured using this GC/EC‐ID‐MS method with excellent sensitivity and specificity. Administration of 0, 30, and 60 mg/kg dacarbazine to mice led to dose‐dependent increases in the formation of 7‐MG. The results indicate that this method could be applied to the analysis of endogenous and exogenous 7‐MG in human tissues for future molecular epidemiology studies on potential health effects caused by methylating agents. Copyright © 2005 John Wiley & Sons, Ltd.
Some fundamental and technical aspects of the quantitative analysis of pharmaceutical drugs by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Sleno Lekha , Volmer Dietrich A.
Published: June 2005

The purpose of the present paper was to study some of the underlying physical and technical aspects of high‐throughput quantitative matrix‐assisted laser desorption/ionization (MALDI) of small drug molecules. A prototype MALDI‐triple quadrupole instrument equipped with a high repetition rate laser was employed. Initially, the detection limits and dynamic ranges for the quantitation of four drugs (quinidine, danofloxacin, ramipril and nadolol) were determined. Internal standards were carefully chosen for each of these analytes in terms of structure similarity and fragmentation pathways. Three organic matrices were tested for these assays, resulting in different crystallization behaviors and measurement reproducibilities. α‐Cyano‐4‐hydroxycinnamic acid yielded the best results and was subsequently employed for the quantitative determination of all four analytes. Further experiments considered the role of laser energy and pulse rate on the ablated areas as well as ion signals. Light microscope and scanning electron microscope images allowed the examination of the ablated area of the MALDI spots. The images showed convincing evidence that the ablated area was virtually void of crystals after analysis, with no preferential removal of material in the center of the laser's path. Average values for the amount of material ablated were determined to be 3.9 ± 0.5% of the total spot size, and as low as 19.5 attomoles of analyte were detectable for our most sensitive analyte, ramipril. It was calculated that, under these assay conditions, it was possible to accurately quantify less than 1 femtomole of all analytes with the use of appropriately pure internal standards. These studies showed very promising results for the quantitative nature of MALDI for small molecules with molecular weights less than 500 Da. Copyright © 2005 John Wiley & Sons, Ltd.
Intact human holo‐transferrin interaction with oxaliplatin
Authors: Zhao Yuan‐Yuan , Mandal Rupasri , Li Xing‐Fang
Published: June 2005

We report the interaction of intact human holo‐transferrin (holo‐Tf) with oxaliplatin (an anticancer drug), and the characterization of a complex composed of (1:1) intact holo‐Tf and the parent oxaliplatin molecule using nanoelectrospray ionization quadrupole time‐of‐flight mass spectrometry (nanoESI‐QTOF‐MS). The molecular weight of this complex was determined to be 80 077 Da, which was an increase of 397 mass units compared to the protein alone (79 680 Da), suggesting that a parent drug molecule was bound to the intact protein. We further examined the interaction between the intact protein and oxaliplatin using size‐exclusion high‐performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS). The protein complex and free oxaliplatin were separated by HPLC and quantitatively determined by simultaneous monitoring of both 195Pt and 56Fe using ICPMS. The HPLC/ICPMS detected both Pt and Fe signals at retention time of 2.6 min, identifying the protein–drug complex. The Fe signal at 2.6 min did not change with the increase in incubation time of the reaction mixture containing holo‐Tf and oxaliplatin, while the Pt signal at the same retention time increased over time, further demonstrating that the formation of this complex does not affect the protein‐bound Fe. The binding constant of the (1:1) intact human holo‐Tf–oxaliplatin complex was determined to be 7.7 × 105 M−1. Both nanoESI‐MS and HPLC/ICPMS results support that the holo‐Tf and parent oxaliplatin molecules form complexes through non‐covalent binding, suggesting that holo‐Tf may be a useful carrier for oxaliplatin delivery. Copyright © 2005 John Wiley & Sons, Ltd.
Negative gas‐phase ion chemistry of GeH4: a quadrupole ion trap study
Authors: Operti Lorenza , Rabezzana Roberto , Turco Francesca , Vaglio Gian Angelo
Published: June 2005

Gas‐phase anion/molecule reactions of germanium hydride were studied by quadrupole ion trap (QIT) mass spectrometry. Under chemical ionization (CI) conditions and with a sample pressure of about 5.0 × 10−5 Torr, clustering reactions proceed up to the formation of Ge5H ion clusters. With increasing cluster size, the most abundant ion species are those with the lowest content of hydrogen. Reaction sequences obtained by ion isolation were determined for primary, secondary and tertiary germane ions, and reaction enthalpies were calculated for reactions of primary ions. Ion/neutral condensation processes followed by single and double dehydrogenation are by far the most important reactions; moreover, isotope scrambling is observed for almost every reactant ion. These results are in good agreement with previously published data and indicate that germane negative ions are quite efficient in formation and growth of ionic clusters, which can be considered suitable precursors of amorphous solid hydrogenated germanium used in the semiconductor field. Copyright © 2005 John Wiley & Sons, Ltd.
Liquid chromatography/electrospray ionization mass spectrometry method for the quantification of valproic acid in human plasma
Authors: Ramakrishna N. V. S. , Vishwottam K. N. , Manoj S. , Koteshwara M. , Santosh M. , Chidambara J. , Kumar B. Ravi
Published: June 2005

A simple, sensitive and rapid liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) method was developed and validated for the quantification of valproic acid, an antiepileptic drug, in human plasma using benzoic acid as internal standard (IS). Following solid‐phase extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase C18 column and analyzed by MS in the single ion monitoring mode using the respective [M–H]− ions, m/z 143 for valproic acid and m/z 121 for the IS. The assay exhibited a linear dynamic range of 0.5–60 µg/mL for valproic acid in human plasma. The lower limit of quantification was 500 ng/mL with a relative standard deviation of less than 10%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The average absolute recoveries of valproic acid and the IS from spiked plasma samples were 96.1 ± 4.2 and 95.6 ± 2.7%, respectively. A run time of 4.5 min for each sample made it possible to analyze more than 250 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability and bioequivalence studies. Copyright © 2005 John Wiley & Sons, Ltd.
A gas chromatographic/mass spectrometric method for tracing the microbial conversion of glucose into amino sugars in soil
Authors: He Hongbo , Xie Hongtu , Zhang Xudong , Wang Yanhong , Wu Yeye
Published: June 2005

Amino sugars in soils are heterogeneous and have been used as microbial residue biomarkers to investigate the microbial contribution to soil organic matter. However, it is not clear what the available carbon source is and how glucose is utilized for the synthesis of soil amino sugars. This paper presents a new gas chromatography/mass spectrometry (GC/MS) approach for the identification of 13C incorporation into three amino sugars, D‐glucosamine, D‐galactosamine, and muramic acid, in soil incubated with U‐13C‐glucose. Method evaluation showed that the chemical ionization (CI) mode was suitable for all these amino sugars, but that electron impact (EI) mode was applicable only to glucosamine and galactosamine. The 13C conversion rate was estimated based on the abundance ratio of the ions corresponding to the masses of the ions F + n and F (where n is the skeleton carbon number in the fragment ions F of the amino sugars) and calculated as atom percentage excess. The reproducibility of the method was excellent and clearly adequate for the present purpose. In addition, the new approach is highly accurate as tested with mixtures of U‐13C‐glucose and natural glucose. Copyright © 2005 John Wiley & Sons, Ltd.
Removal of metabolite interference during liquid chromatography/tandem mass spectrometry using high‐field asymmetric waveform ion mobility spectrometry
Authors: Kapron James T. , Jemal Mohammed , Duncan Glenn , Kolakowski Beata , Purves Randy
Published: June 2005

The effect of metabolite interference during liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis of an amine drug was investigated using FAIMS (high‐Field Asymmetric waveform Ion Mobility Spectrometry). The selected reaction monitoring (SRM) transition used for the drug exhibited an interference due to in‐source conversion of the N‐oxide metabolite to generate an ion isobaric with the drug. The on‐line FAIMS device removed the metabolite interference before entrance to the mass spectrometer. FAIMS was used to demonstrate the relative accuracy and precision of drug analysis even in the presence of a co‐eluting metabolite that may undergo in‐source conversion. Copyright © 2005 John Wiley & Sons, Ltd.
On the random 2‐stage minimum spanning tree
Authors: Flaxman Abraham D. , Frieze Alan , Krivelevich Michael
Published: June 2005

It is known [A. M. Frieze, Discrete Appl Math 10 (1985), 47–56] that if the edge costs of the complete graph Kn are independent random variables, uniformly distributed between 0 and 1, then the expected cost of the minimum spanning tree is asymptotically equal to $\zeta(3)=\sum_{i=1}^{\infty}i^{-3}$. Here we consider the following stochastic two‐stage version of this optimization problem. There are two sets of edge costs cM: E → ℝ and cT: E → ℝ, called Monday's prices and Tuesday's prices, respectively. For each edge e, both costs cM(e) and cT(e) are independent random variables, uniformly distributed in [0, 1]. The Monday costs are revealed first. The algorithm has to decide on Monday for each edge e whether to buy it at Monday's price cM(e), or to wait until its Tuesday price cT(e) appears. The set of edges XM bought on Monday is then completed by the set of edges XT bought on Tuesday to form a spanning tree. If both Monday's and Tuesday's prices were revealed simultaneously, then the optimal solution would have expected cost ζ(3)/2 + o(1). We show that, in the case of two‐stage optimization, the expected value of the optimal cost exceeds ζ(3)/2 by an absolute constant ε > 0. We also consider a threshold heuristic, where the algorithm buys on Monday only edges of cost less than α and completes them on Tuesday in an optimal way, and show that the optimal choice for α is α = 1/n with the expected cost ζ(3) − 1/2 + o(1). The threshold heuristic is shown to be sub‐optimal. Finally we discuss the directed version of the problem, where the task is to construct a spanning out‐arborescence rooted at a fixed vertex r, and show, somewhat surprisingly, that in this case a simple variant of the threshold heuristic gives the asymptotically optimal value 1 − 1/e + o(1). © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Summary of ISO/TC 201 standard: XV. ISO 20341:2003—Surface chemical analysis—secondary ion mass spectrometry—method for estimating depth resolution parameters with multiple delta‐layer reference materials
Authors: Moon D. W.
Published: June 2005

This International Standard specifies procedures for estimating three depth resolution parameters, via the leading‐edge decay length, the trailing‐edge decay length and Gaussian broadening, in SIMS depth profiling using multiple delta‐layer reference materials. This International Standard is not applicable to delta‐layers where the chemical and physical state of the near‐surface region, modified by the incident primary ions, is not in the steady state. Copyright © 2005 John Wiley & Sons, Ltd.
Disability Rights, Prenatal Diagnosis and Eugenics: A Cross‐Cultural View
Authors: Raz Aviad E.
Published: June 2005

This paper considers the disability rights critique of genetic testing in the context of different communities and the issue of nondirectiveness. Despite the wide usage of genetic diagnosis in Israel, no public debate has emerged there concerning disability rights and prenatal testing. The common attitude that emerged from interviews with Israeli representatives of organizations “of’’ and “for’’ people with genetic diseases and congenital disabilities can be described as a two‐fold view of disability: support of genetic testing during pregnancy, and support of the disabled person after birth. This two‐fold view is explained as a secular construction situated in legal, economic and cultural contexts. The paper concludes by considering the implications of the “two‐fold view’’ of disability for the profession of genetic counseling. It is argued that awareness of the existence of conflicting views among clients—such as the view of the ‘disability critique’ as well as of the “two‐fold view of disability’’—should strengthen the significance of nondirectiveness.
Global solutions and finite time blow up for damped semilinear wave equations
Authors: Gazzola Filippo , Squassina Marco
Published: June 2005

A class of damped wave equations with superlinear source term is considered. It is shown that every global solution is uniformly bounded in the natural phase space. Global existence of solutions with initial data in the potential well is obtained. Finally, not only finite time blow up for solutions starting in the unstable set is proved, but also high energy initial data for which the solution blows up are constructed.
Proliferative feeder cells support prolonged expansion of human embryonic stem cells
Authors: Xie Chang‐Qing , Lin Ge , Yuan Ding , Wang Jian , Liu Tian‐Cheng , Lu Guang‐Xiu
Published: June 2005

Long‐term proliferation of human embryonic stem (hES) cells is currently achieved by co‐culturing with mitotically inactive primary mouse embryonic fibroblasts (mEFs), which serve as feeder cells. This study explores the possibility that proliferative mEFs can be used as feeder cells to maintain the prolonged expansion of hES cells. All undifferentiated hES cell clumps were re‐plated on six different densities of proliferative mEFs. hES colonies cultured on 1 × 105–5 × 105 proliferative mEFs amplified over 130 days of continuous culture and remained undifferentiated, as did those cultured on mitotically inactive mEFs. This suggests that certain densities of proliferative mEFs can maintain the propagation of hES cells, which may be helpful for identifying the cytokines and adhesion molecules that are required for their self‐renewal.
Evidence that erythrocytes are highly susceptible to exercise oxidative stress: FT‐IR spectrometric studies at the molecular level
Authors: Petibois Cyril , Déléris Gérard
Published: June 2005

We tested the hypothesis that usual exercise oxidative stress strongly affects erythrocytes viability. A 120‐min physical exercise with progressive intensity was used as a model of oxidative stress. FT‐IR spectrometry was used to determine structural changes in erythrocyte contents (phospholipids, proteins, lactate, and glucose) from blood samples taken every 20 min. Carbonyl formation from amino acid residues (P = 0.03) and hemoglobin unfolding (P = 0.01) could be identified as main protein denaturation markers during oxidative stress. Higher unsaturation level (P = 0.001) in phospholipids fatty acyl chains were also observed while VO2 increased (P < 0.05). The increase in lactacidosis affected primarily hemoglobin unfolding (P = 0.02). Finally, two distinct cellular events occurred during oxidative stress: 1—phospholipids peroxidation correlated to VO2, but lactacidosis and hemoconcentration remained secondary factors; 2—hemoglobin denaturation was mainly observed through unfolding and carbonylation, and lactacidosis and hemoconcentration were important contributing factors.
Teacher reports of ADHD symptoms in Italian children at the end of first grade
Authors: Mugnaini Daniele , Masi Gabriele , Brovedani Paola , Chelazzi Chiara , Matas Marzenka , Romagnoli Caterina , Zuddas Alessandro
Published: June 2005

Objective:

To determine the prevalence of teacher-rated ADHD symptoms in Italian first-graders.

Method:

1891 first-graders aged 6.6–7.4 years were evaluated using a 34-item DSM-IV-referenced ADHD teacher rating questionnaire which included all the 18 DSM-IV ADHD diagnostic criteria, some Oppositional-Defiant Disorder (ODD), Conduct Disorder (CD), depression and anxiety symptoms, and questions about the child's social and scholastic impairment.

Results:

Criteria for ADHD were met in 7.1% (n = 135) of the subjects (10.4% males and 3.8% females), 3.5% with the Inattentive subtype, 2.3% with the Hyperactive/Impulsive subtype and 1.3% with a Combined subtype. Internalizing (depression and/or anxiety) symptoms were reported in 25.9% of the subjects with ADHD symptoms, 17% showed externalizing symptoms (ODD or CD), and 12.6% showed both. Comorbid symptoms were 10 times more frequent than in subjects without ADHD symptoms. Inattentive subtype and scholastic impairment were more frequent in females, Hyperactive/Impulsive subtype and social impairment were more frequent in males.

Conclusions:

Even though the real prevalence of ADHD in first graders is presumably lower than that found in the present study, this screening procedure might allow detecting those children who could benefit from referral for more comprehensive assessments.
Negative evidences in association between apolipoprotein E polymorphism and panic disorder
Authors: Martínez-Barrondo S. , Sáiz P.A. , Morales B. , García-Portilla M.P. , Coto E. , Álvarez V. , Bascarán M.T. , Bousoño M. , Bobes J.
Published: June 2005

The aim is to investigate the association between apolipoprotein E (ApoE) and panic disorder (PD). Genotyping 92 PD patients [Diagnostic Statistic Manual IV (DSM IV) criteria] and 174 controls no differences were found between both groups. Variation in the ApoE-gene was not associated with the development of PD.
An Overview of the Quadra Nano by Tomtec
Authors: Astle Thomas W.
Published: June 2005

The advancement of technology in life science has created a need for improved accuracy and precision in pipetting small volumes1 from 50 nL up to and above 10 μL. Tomtec has adapted ink-jet technology2−6 to meet this need in their Nano pipettor heads. A coefficient of variation (CV) of 5% is achievable at 50-nL volumes, improving to 1-2% at 1 μL and above. A pipettor must aspirate from a source and dispense to a destination, then repeat the process without detectable carryover. The Nano head 8 and Nano head 16 achieve this utilizing a novel standpipe design that permits a fast wash through of the liquid handling channels. Each pipettor may be individually controlled, creating another dimension in pipetting flexibility.
Effect of quorum sensing agents on the growth kinetics of Pseudomonas spp. of raw milk origin
Authors: Dunstall George , Rowe Michael T , Wisdom G Brian , Kilpatrick David
Published: June 2005

Psychrotrophs, particularly strains of Pseudomonas fluorescens, dominate the microflora of refrigerated raw milk and secrete heat-stable extracellular enzymes (proteases and lipases) which survive pasteurisation and even UHT heat treatments and degrade the casein and fat components of raw milk causing a reduction in cheese yield, gelation of UHT milk and off flavours in many dairy products. These enzymes are usually produced in the late log/early stationary growth phases when the cell density is high. This fact indicated that induction of these enzymes may be a candidate for quorum sensing, a phenomenon by which bacteria can sense and respond to cell population size by means of chemical signals based on the homoserine lactone molecule. It is assumed that the production of these enzymes contributes to the selective advantage of psychrotrophs and hence have a significant effect on their growth kinetics. In the work reported here nine proprietary homoserine lactone compounds were screened, using water as a control, for their effect on the lag phase duration (LPD) and exponential growth rate (EGR) of three strains of Pseudomonas fluorescens isolated from refrigerated raw milk after 1, 3 and 5 days storage. Two compounds viz. N-benzoyloxycarbonyl-L-homoserine lactone and N-3-oxyhexanoyl-DL-homoserine lactone were found to significantly (P<0·001) reduce the LPD and increase the EGR of the three strains. Further work with these compounds is warranted, monitoring growth in parallel with enzyme production, to determine the extent to which extracellular enzyme production is mediated by the quorum sensing phenomenon in this species.
Growth hormone acts on the synthesis and secretion of α-casein in bovine mammary epithelial cells
Authors: Sakamoto Kazuhito , Komatsu Tokushi , Kobayashi Takuya , Rose Michael T , Aso Hisashi , Hagino Akihiko , Obara Yoshiaki
Published: June 2005

To study the effect of growth hormone (GH) on the functions of mammary epithelia, we examined the effect of GH on the synthesis and secretion of α-casein in a bovine mammary epithelial cell (BMEC) clonal line, which was established from a 26-d-pregnant Holstein heifer. GH receptors (GHR) were observed in the BMEC on the membrane as well as in the cytoplasm. After BMEC were plated onto cell culture inserts, GH stimulated α-casein release in both the presence and absence of the lactogenic hormone complex, which included dexamethasone, insulin and prolactin (DIP). DIP enhanced the effect of GH on α-casein release. Although αs1-casein mRNA expression was not detected in untreated control cells, its expression was observed in BMEC in response to the GH, DIP and GH+DIP treatments. Expression was greater for GH and GH+DIP than for just DIP. Expression of GHR mRNA was increased by DIP treatment, while the mRNA expression was little changed by GH treatment. We conclude that GH acts on BMEC and induces the expression of both the α-casein gene and protein. GHR gene expression was shown to be regulated by DIP and GHR. GHR may be involved in a synergic effect between GH and DIP on casein secretion. These results suggest that GH, in addition to its widely accepted homeorhetic role in vivo, also can act on the mammary parenchyma, and that the effects of GH on mammary epithelial cells could partly account for the clear galactopoietic effect of recombinant bovine GH seen in lactating dairy cows.
A comparison between feeding systems (pasture and TMR) and the effect of vitamin E supplementation on plasma and milk fatty acid profiles in dairy cows
Authors: Kay Jane K , Roche John R , Kolver Eric S , Thomson Norman A , Baumgard Lance H
Published: June 2005

Unidentified constituents in fresh pasture increase milk fat cis-9, trans-11 conjugated linoleic acid (CLA) concentration, and prevent milk fat depression, even though ruminal conditions conducive to reducing milk fat synthesis exist. One possible explanation is vitamin E (α-tocopherol), a constituent high in fresh pasture, but naturally low in conserved/dried forages and cereal grains. Twenty late-lactating dairy cows previously consuming a total mixed ration (TMR) were randomly allocated to one of two dietary treatments for 21 d: TMR (control; n=10); and TMR plus an additional 10000 i.u. α-tocopherol/d (VIT E; n=10). These cows were simultaneously compared with 13 late-lactation dairy cows previously grazing fresh pasture (PAS) balanced for age, parity and genetic merit. Average daily α-tocopherol intakes were approximately 468, 10520 and 1590 i.u./cow for the control, VIT E and PAS treatments, respectively. Dietary α-tocopherol supplementation (VIT E v. control) slightly increased milk fat content by 0·23 percentage units, but did not significantly alter milk fatty acid composition. Plasma trans-11 18[ratio ]1 (VA) content tended to increase and trans-10 18[ratio ]1 levels numerically declined following α-tocopherol supplementation suggesting possible changes in rumen biohydrogenation products. In addition, increased α-tocopherol intake in TMR-fed cows decreased serum urea levels and tended to alter milk fat 15[ratio ]0 suggesting changes in rumen microbial populations. However, when compared with cows grazing pasture, TMR-fed cows supplemented with α-tocopherol, still produced milk with lower cis-9, trans-11 CLA and VA, and higher trans-10 18[ratio ]1 concentrations suggesting α-tocopherol is not a primary reason for milk fatty acid profile differences between pasture and TMR-fed cows. Therefore, additional unknown pasture constituents favour production of fatty acids originating from the cis-9, trans-11 instead of the trans-10, cis-12 CLA biohydrogenation pathways.