bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serum KL‐6 levels in pediatric patients: Reference values for children and levels in pneumonia, asthma, and measles patients
Authors: Imai Takehide , Takase Masato , Takeda Sachiyo , Kougo Toshiaki 
Published: August 2002

AbstractSerum KL‐6 reflects alveolar damage and regeneration of type II pneumocytes, indicating disease activity in various interstitial lung diseases. We conducted a descriptive and observational multiple case‐control study to determine the distribution of serum KL‐6 levels in pediatric patients with or without respiratory diseases. Subjects were recruited from the patients of a teaching hospital in the suburb of Tokyo. A consecutive series of 401 children (0–16 years old) underwent blood sampling for many clinical reasons. They comprised the following four groups: pneumonia (n = 96), bronchial asthma (n = 101), measles (n = 102), and nonrespiratory diseases (n = 102) as a control group.Standard upper limits of serum KL‐6 in a group of children with nonrespiratory disease were 250 U/mL, or half the adult level. No gender or age differences were observed. Elevated serum KL‐6 concentrations were observed in severe pneumonia, acute exacerbations of asthma, and measles pneumonia. In the measles group, KL‐6 values reflected the presence and severity of complicating pneumonia.We conclude that serum KL‐6 levels exceeding 250 U/mL were rarely observed in children without respiratory diseases. In contrast, a substantial proportion of children with common respiratory diseases showed mild to moderate increases in serum KL‐6 levels. Elevated serum KL‐6 in these children may reflect the presence of alveolar damage, followed by regeneration of type II pneumocytes. However, in order to use serum KL‐6 as a marker of interstitial lung diseases in children, a cutoff level should be determined separately. Pediatr Pulmonol. 2002; 33:135–141. © 2002 Wiley‐Liss, Inc.
Patient‐ventilator interactions in new modes of patient‐triggered ventilation*
Authors: Abubakar Kabir M. , Keszler Martin 
Published: August 2002

AbstractRecently, synchronized modes of conventional mechanical ventilation became available for neonatal ventilatory support, but there has been little information regarding details of patient‐ventilator interactions during pressure support, volume support, or any other volume‐targeted modes of synchronized ventilation in newborn infants. Our objective was to obtain comparative data on patient‐ventilator interactions and stability of delivered tidal volume (VT) for the different modes of synchronized mechanical ventilation in stable ventilated newborn infants. We examined the effects of pressure support ventilation (PSV) and volume guarantee (VG) modes of a prototype Dräger Babylog® ventilator on peak and mean airway pressures (PIP and Paw), inspiratory time (tin), and VT in 23 ventilated newborn infants. Twelve infants were studied while on assist/control (AC) and 11 on synchronized intermittent mandatory ventilation (SIMV). Mean birth weight was 1,650 ± 1,180 g, gestational age 31 ± 6 weeks, and age at time of study was 19 ± 26 days. Data for 400–600 breaths from each infant were downloaded directly from the ventilator pressure and volume‐monitoring module, and analyzed using ANOVA for repeated measures. Mean values and breath‐to‐breath variability were compared for 20‐min periods of AC or SIMV followed by PSV, PSV+VG, and back to baseline AC or SIMV.PSV and PSV+VG led to shorter tin and thus to lower Paw, compared to AC. Mean PIP was similar across all AC modes but more variable during VG, reflecting the servocontrol of PIP. VT did not differ between AC modes, but was significantly less variable with VG added. PSV and PSV+VG led to lower and less variable PIP and Paw, compared to SIMV, because tin was shorter and every breath was supported in PSV and PSV+VG. VT was similar in SIMV, PSV, and PSV+VG, but less variable with PSV+VG. Arterial blood gas tensions were similar across all ventilation modes.We conclude that the ventilator prototype functioned as intended. Breath‐to‐breath tidal volume variability was significantly reduced in VG modes, although not completely eliminated. Pediatr Pulmonol. 2001; 32:71–75. © 2001 Wiley‐Liss, Inc.
Osteoblasts produce soluble factors that induce a gene expression pattern in non‐metastatic prostate cancer cells, similar to that found in bone metastatic prostate cancer cells
Authors: Fu Zheng , Dozmorov Igor M. , Keller Evan T. 
Published: August 2002

AbstractBACKGROUNDProgressive prostate cancer typically metastasizes to bone where prostate cancer cells gain an osteoblast‐like phenotype and induce osteoblastic metastases through unknown mechanisms. To investigate the biology of prostate cancer skeletal metastases, we compared gene expression between the non‐metastatic LNCaP cell line and its derivative cell line C4‐2B that metastasizes to bone.METHODSTotal RNA from LNCaP and C4‐2B cell lines was isolated and used to probe membrane‐based gene arrays (Comparison 1). Additionally, LNCaP cells were incubated in the absence or presence of conditioned media (CM) from a human osteoblast‐like cell line (HOBIT) and total RNA from these cells was used to probe gene arrays (Comparison 2). Differential expression of genes was confirmed by RT‐PCR.RESULTSOf the 1,176 genes screened, 35 were differentially expressed between LNCaP and C4‐2B cells (Comparison 1). HOBIT‐CM induced differential expression of 30 genes in LNCaP cells (Comparison 2). Interestingly, 19 genes that were differentially expressed in C4‐2B vs. LNCaP also displayed a similar expression pattern in LNCaPs grown in HOBIT‐CM. These genes are primarily involved in motility, metabolism, signal transduction, tumorigenesis, and apoptosis.CONCLUSIONSThese results suggest that osteoblasts produce soluble factors that contribute to the progression of prostate cancer skeletal metastases, including their transition to an osteoblast‐like phenotype. Additionally, these data provide targets to explore for further investigations towards defining the biology of skeletal metastases. Prostate 51: 10–20, 2002. © 2002 Wiley‐Liss, Inc.
Complex functions of mutant p53 alleles from human prostate cancer
Authors: Shi Xu‐Bao , Nesslinger Nancy J. , Deitch Arline D. , Gumerlock Paul H. , deVere White Ralph W. 
Published: August 2002

AbstractBackgroundFew studies have used multiple assays to examine the functionality of mutant p53 in prostate cancer (CaP). We employed seven functional assays to study 16 representative mutant p53 alleles, six from localized and ten from metastatic CaP.MethodsYeast assays were employed to determine loss of function (LOF), partial function (PF), and dominant‐negative status. Assays using p53‐null Saos2 cells were used to determine whether mammalian cells transfected with mutant p53 could up‐regulate the MDR‐1 or PCNA promoters, alter IL‐6 expression or confer the ability to grow in soft agar. As a further test of gain of function (GOF), p53‐null PC3 cells stably transfected with these mutant p53 alleles were examined for cell cycle distributions.ResultsAll 16 mutant p53 alleles demonstrated either total or partial LOF. All but one allele also had at least one gain of function; however, the pattern of GOF was different for each mutant allele. Alleles derived from both localized and metastatic CaP had similar GOF characteristics; however, only alleles from metastatic disease had significantly increased S‐phase fractions.ConclusionsDifferent mutant p53 alleles from CaP had different, complex functional profiles. The lack of predictable patterns for these alleles suggest that each mutation may uniquely affect p53 function. Prostate 51:59–72, 2002. © 2002 Wiley‐Liss, Inc.
Folding of intracellular retinol and retinoic acid binding proteins
Authors: Burns Lora L. , Ropson Ira J. 
Published: August 2002

AbstractThe folding mechanisms of cellular retinol binding protein II (CRBP II), cellular retinoic acid binding protein I (CRABP I), and cellular retinoic acid binding protein II (CRABP II) were examined. These β‐sheet proteins have very similar structures and higher sequence homologies than most proteins in this diverse family. They have similar stabilities and show completely reversible folding at equilibrium with urea as a denaturant. The unfolding kinetics of these proteins were monitored during folding and unfolding by circular dichroism (CD) and fluorescence. During unfolding, CRABP II showed no intermediates, CRABP I had an intermediate with nativelike secondary structure, and CRBP II had an intermediate that lacked secondary structure. The refolding kinetics of these proteins were more similar. Each protein showed a burst‐phase change in intensity by both CD and fluorescence, followed by a single observed phase by both CD and fluorescence and one or two additional refolding phases by fluorescence. The fluorescence spectral properties of the intermediate states were similar and suggested a gradual increase in the amount of native tertiary structure present for each step in a sequential path. However, the rates of folding differed by as much as 3 orders of magnitude and were slower than those expected from the contact order and topology of these proteins. As such, proteins with the same final structure may not follow the same route to the native state. Proteins 2001;43:292–302. © 2001 Wiley‐Liss, Inc.
Proline‐induced hinges in transmembrane helices: Possible roles in ion channel gating
Authors: Tieleman D. Peter , Shrivastava Indira H. , Ulmschneider Martin R. , Sansom Mark S.P. 
Published: August 2002

AbstractA number of ion channels contain transmembrane (TM) α‐helices that contain proline‐induced molecular hinges. These TM helices include the channel‐forming peptide alamethicin (Alm), the S6 helix from voltage‐gated potassium (Kv) channels, and the D5 helix from voltage‐gated chloride (CLC) channels. For both Alm and KvS6, experimental data implicate hinge‐bending motions of the helix in an aspect of channel gating. We have compared the hinge‐bending motions of these TM helices in bilayer‐like environments by multi‐nanosecond MD simulations in an attempt to describe motions of these helices that may underlie possible modes of channel gating. Alm is an α‐helical channel‐forming peptide, which contains a central kink associated with a Gly‐x‐x‐Pro motif in its sequence. Simulations of Alm in a TM orientation for 10 ns in an octane slab indicate that the Gly‐x‐x‐Pro motif acts as a molecular hinge. The S6 helix from Shaker Kv channels contains a Pro‐Val‐Pro motif. Modeling studies and recent experimental data suggest that the KvS6 helix may be kinked in the vicinity of this motif. Simulations (10 ns) of an isolated KvS6 helix in an octane slab and in a POPC bilayer reveal hinge‐bending motions. A pattern‐matching approach was used to search for possible hinge‐bending motifs in the TM helices of other ion channel proteins. This uncovered a conserved Gly‐x‐Pro motif in TM helix D5 of CLC channels. MD simulations of a model of hCLC1‐D5 spanning an octane slab suggest that this channel also contains a TM helix that undergoes hinge‐bending motion. In conclusion, our simulations suggest a model in which hinge‐bending motions of TM helices may play a functional role in the gating mechanisms of several different families of ion channels. Proteins 2001;44:63–72. © 2001 Wiley‐Liss, Inc.
Kinetics of chemical degradation of isoxaflutole: influence of the nature of aqueous buffers (alkanoic acid/sodium salt vs phosphate)
Authors: Beltran Estelle , Fenet Hélène , Cooper Jean‐François , Coste Camille‐Michel 
Published: August 2002

AbstractA kinetic study of the chemical degradation of isoxaflutole (5‐cyclopropyl‐1,2‐oxazol‐4‐yl ααα‐trifluoro‐2‐mesyl‐p‐tolyl ketone) into its diketonitrile derivative (DKN), which is its active herbicide principle, in organic buffers at different pH values was carried out using a HPLC/UV detection method. The values of the pseudo‐first‐order rate constants Kobs for the reaction were calculated and compared with those previously obtained in inorganic buffers. In both cases, Kobs was found to be dependent on pH and temperature, but at pH 5.2 the degradation of isoxaflutole in CH3COOH/CH3COONa buffers was considerably faster than in KH2PO4/Na2HPO4 buffers, indicating that the compound was sensitive to the nature of the reagents used to prepare buffered solutions. The influence of phosphate and acetate concentrations and the influence of the R‐substituent in RCOOH/RCOONa buffers were investigated. For the HA/A− buffers studied, the values of Kobs were linearly dependent on HA and A− concentrations, which meant that the degradation of isoxaflutole was subject to general catalysis. The values of Kobs were also found to be dependent on the number and the position of the CH3 groups of the R‐substituent. The known degradation product of DKN (a benzoic acid derivative) was not detected throughout this study.© 2001 Society of Chemical Industry
Chitin synthesis and inhibition: a revisit
Authors: Cohen Ephraim 
Published: August 2002

AbstractChitin is an abundant biologically important aminopolysaccharide composed of N‐acetyl‐D‐glucosamine units. Individual polymers, which are synthesized intracellularly by chitin synthase (CS), a membrane‐bound glycosyl transferase, are translocated across the plasma membrane and coalesce to form rigid crystallites. These crystallites, inter alia, are integral parts of septa and cell walls in yeast and filamentous fungi, respectively, and of cuticles in invertebrates, notably crustaceans and insects. Despite decades of intensive research, many events associated with the complexity of chitin formation and deposition are still obscure, or only partially understood. The list includes the hormonal control of CS at the transcriptional and translational levels as well as the post‐translational CS packaging; trafficking and guidance of CS clusters to proper sites in the cells and their intricate insertion into the plasma membranes; activation of the catalytic step and its control or modulation; and translocation of chitin chains across cell membranes, their orientation, fibrillogenesis and association with other extracellular structural components such as polysaccharides (fungi) and cuticular proteins (insects). Also the precise biochemical lesions inflicted by CS inhibitors, such as the acylurea insect growth regulators, are largely unclear. The recent isolation and sequencing of insect CS genes should help in elucidating various aspects of chitin biochemistry and inhibition. In particular, the large number of transmembrane segments, characteristic of the insect CS, are speculated to be involved in chitin translocation and are expected to shed light on the mode of action of acylurea insecticides.© 2001 Society of Chemical Industry
A 27‐mer tandem repeat polypeptide in bovine amelogenin: Synthesis and CD spectra
Authors: Renugopalakrishnan V. 
Published: August 2002

AbstractCD spectra of a tandem 27‐mer repeat polypeptide, Gln‐Pro‐His‐Gln‐Pro‐Leu‐Gln‐Pro‐His‐Gln‐Pro‐Leu‐Gln‐Pro‐Met‐(Gln‐Pro‐Leu)4, from bovine amelogenin synthesized by standard solid‐phase synthesis manifests an archtypical CD pattern of a β‐spiral structure in phosphate buffer at pH 5.2 and trifluoroethanol (TFE), CF3OH. β‐spiral structure is unique to a class of diverse proteins including amelogenins conferring unusual physicochemical properties. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Antimicrobial activity of honokiol and magnolol isolated from Magnolia officinalis
Authors: Ho Kun‐Yen , Tsai Chi‐Cheng , Chen Chi‐Pien , Huang Jiing‐Sheng , Lin Chun‐Ching 
Published: August 2002

AbstractThe antimicrobial activity of honokiol and magnolol, the main constituents of Magnolia officinalis was investigated. The antimicrobial activity was assayed by the agar dilution method using brain heart infusion medium and the minimum inhibitory concentration (MIC) were determined for each compound using a twofold serial dilution assay. The results showed that honokiol and magnolol have a marked antimicrobial effect (MIC = 25 µg/mL) against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Micrococcus luteus and Bacillus subtilis, but did not show antimicrobial activity (MIC ≥ 100 µg/mL) for Shigella flexneii, Staphylococcus epidermidis, Enterobacter aerogenes, Proteus vulgaris, Escherichia coli and Pseudomonas aeruginosa. Our results indicate that honokiol and magnolol, although less potent than tetracycline, show a significant antimicrobial activity for periodontal pathogens. Hence we suggest that honokiol and magnolol might have the potential to be an adjunct in the treatment of periodontitis. Copyright © 2001 John Wiley & Sons, Ltd.
Immunomodulatory principles of Pelargonium sidoides
Authors: Kayser O. , Kolodziej H. , Kiderlen A. F. 
Published: August 2002

AbstractExtracts and isolated constituents (coumarins and phenols) of Pelargonium sidoides DC, a plant species used in folk medicine by the Southern African native population, were evaluated for their effects on nonspecific immune functions. Although this herbal medicine is also successfully employed in modern phytotherapy in Europe to cure infectious diseases of the respiratory tract, the scientific basis of its remedial effects is still unclear. Thus, functional bioassays including an in vitro model for intracellular infection with Leishmania parasites, an extracellular Leishmania growth assay, a fibroblast‐virus protection assay (IFN activity), a fibroblast‐lysis assay (TNF activity) and a biochemical assay for inorganic nitric oxides (iNO) were employed. None of the test samples revealed significant activity against extracellular, promastigote Leishmania donovani, the causative agent of human visceral leishmaniasis. In contrast, apart from the coumarin samples, all the Pelargonium extracts (EC50 <0.1–3.3 μg/mL), gallic acid (EC50 4.4 μg/mL) and its methyl ester (EC50 12.5μg/mL) significantly reduced the intracellular survival of L. donovani amastigotes within murine macrophages. These data indicate that the samples acted indirectly on Leishmania parasites, possibly by activating leishmanicidal macrophage functions. Macrophage activation was confirmed by detection of tumour necrosis factor (TNF‐α) and inorganic nitric oxides (iNO) in supernatants of sample‐treated macrophage cultures. Synthesis of iNO is a well‐known effector mechanism of macrophages against microorganisms such as Leishmania. Interestingly, blocking iNO‐synthase with L‐NMMA had no substantial effect on sample‐induced intracellular Leishmania kill. From bioassay‐guided fractionation, gallic acid and its methyl ester present in large amounts in P. sidoides and in its active extracts, were identified as the prominent immunomodulatory principle for this herbal medicine. The results, when taken together with recent reported antibacterial activity, provide a rational basis for both the traditional and the present utilization of P. sidoides in the claimed conditions. Copyright © 2001 John Wiley & Sons, Ltd.
On misinterpretation of the asymptotic property of system time‐between‐failures
Authors: Chambal Stephen P. , Keats J. Bert 
Published: August 2002

AbstractIf a system, not necessarily one in series, is composed of components having various time‐to‐failure distributions and components are replaced good‐as‐new as they fail, then the system time‐between‐failure distribution tends toward the exponential. Many practicing reliability engineers, incorrectly invoking this property, model their systems with an exponential time‐to‐failure. We show, under two conditions, using a hypothetical fleet of vehicles, the severity of this error. Modeling time‐to‐failure as exponential results in gross over‐sparing and high unavailability costs as well. Copyright © 2001 John Wiley & Sons, Ltd.
Optimal control of a deteriorating process with a quadratic loss function
Authors: Al‐Fawzan M. A. , Rahim M. A. 
Published: August 2002

AbstractThis paper considers the optimal determination of the length of the production run and the initial setting of a process that exhibits a linear drift that can start at a random point in time. Quadratic off‐target costs and time‐based costs of maintenance and salvage value are included in the formulation. The model includes other models proposed in the literature as particular cases. Numerical examples are provided to illustrate the application of the proposed model. Copyright © 2001 John Wiley & Sons, Ltd.
Potential harmonic approximation in atomic three‐body systems with Fues–Kratzer‐type potential
Authors: Yalçin Zeynel , Şimşek Mehmet 
Published: August 2002

AbstractBy using the matrix form of the Fues–Kratzer‐type (FK) potential, V(r) = Ẑ(Ω)/r + Â/r2, three‐body problems of two‐electron atomic systems are solved with the PHGLP expansion method. The atomic wave functions Ψ(Ω) are constructed in terms of generalized Laguarre polynomials (GLP) and potential harmonics (PH). The calculations of the ground‐state energies of atoms from He to Si12+ are tabulated using Deng et al.'s procedure and also the effect of the new potential onto excited states of 1S Li+ are illustrated. Then, we calculated excited state energies (n1S, n = 1–3) of the atoms from He to Si12+ with the FK potential. The present results are compared with other theoretical calculations. It is pointed out that convergences of our results are more rapid than the results of the pure Coulombic interaction, and, so, this article increases the efficiency of the calculation for atomic three‐body systems. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Quantum criticality at the large‐dimensional limit: Three‐body Coulomb systems
Authors: Shi Qicun , Kais Sabre 
Published: August 2002

AbstractWe present quantum phase transitions and critical phenomena at the large‐dimension (D) limit for three‐body ABA Coulomb systems with charges (Q,q,Q) and masses (M,m,M). The Hamiltonian depends linearly on two parameters λ=∣Q/q∣ and κ=[1+(m/M)]−1. The system exhibits critical points with mean field critical exponents (α=0, β=½, δ=3, γ=1). We calculate the critical curve λc(κ) through which all systems undergo a continuous‐phase transition from the symmetrical configuration, the two like particles have the same distance from the reference particle, to the unsymmetrical phase. The critical curve at D→∞ limit is a convex function of κ and very similar to the one obtained at D=3 with variational calculations. We also calculated the line of zero angular correlation in the mass polarization term, which separates the symmetrical phase to an atom‐like region and a molecule‐like region. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Determination of 4‐hydroxytamoxifen in mouse plasma in the pg/mL range by gradient capillary liquid chromatography/tandem mass spectrometry
Authors: Plumb R. S. , Warwick H. , Higton D. , Dear G. J. , Mallett D. N. 
Published: August 2002

AbstractCapillary high‐performance liquid chromatography (HPLC; 300 µm i.d.) coupled to tandem mass spectrometry has been used to determine the concentration of 4‐hydroxytamoxifen in mouse plasma in the pg/mL range following the administration of Tamoxifen. A limit of quantification (LOQ) of 100 pg/mL was achieved using only 25 µL of plasma. The on‐column sensitivity was determined to be 100 fg. The column performance was determined isocratically before and after the assay and showed only a 15% reduction in performance after 70 injections of plasma extract. No significant peak band broadening was observed due to the mass spectrometer interface using a standard TurboIonspray source. Copyright © 2001 John Wiley & Sons, Ltd.