bluuebunny/crossref_metadata_2025 huggingface dataset:
The Human Multidrug Resistance-Associated Protein (MRP) Gene Family: From Biological Function to Drug Molecular Design
Authors: Ishikawa Toshihisa , Kuo M. Tien , Furuta Kyoji , Suzuki Masaaki
Published: October 2004

The ATP-binding cassette transmembrane proteins
play an important role in transport of drugs as well as
of biologically active endogenous substances. The human
multidrug resistance-associated protein (MRP)
subfamily consists of at least six members, exhibiting
a wide spectrum of biological functions. MRP1 operates
as an ATP-dependent primary active transporter
for substrates conjugated with glucuronide, sulfate or
glutathione. Leukotriene C4 is an important endogenous
substrate for MRP1. Glutathione serves as a cofactor
in MRP1-mediated drug transport as well.

Genes encoding both MRP1 and the catalytic subunit
of γ-glutamylcysteine synthetase (γ-GCS) are coordinately
regulated in cultured cancer cell lines as well as
colorectal cancer tissues from colon cancer patients.
The induction of MRP1 and γ-GCS expression by oxidative
stress varies among different cell lines, and p53
mutations are associated with elevated levels of induction.
To modulate the transport function of MRP1,
we have synthesized novel glutathione derivatives as
photoreactive biochemical probes targeting the transporter
protein. GIF-0019 restored the cellular sensitivity
of MRP1-overexpressing drug-resistant cancer cells
to anticancer prostaglandins in vitro, which was characterized
by enhanced mRNA levels of the cyclin-dependent
kinase inhibitor p21, suppressed c-myc expression
and G1 arrest.
Ethnic Differences in Drug Metabolism
Authors: Zhou Hong-Hao , Liu Zhao-Qian
Published: October 2004

Ethnic differences in drug metabolism are well documented
for a number of drugs. The molecular mechanisms
responsible for ethnic differences in drug metabolism
have been partly clarified because of the
advances in molecular biology in recent years. Gene
dosage determines the drug metabolism as demonstrated
for S-mephenytoin and diazepam metabolism.
Genotype analysis indicates a different frequency for
the mutant alleles in different ethnic populations,
which results in variations in the frequency of subjects
who are homozygous for the mutant allele among the
extensive metabolizers in different ethnic populations.
Ethnic differences in drug metabolism may result from
differences in distribution of a polymorphic trait and
mutations which code for enzymes with abnormal activity
which occur with altered frequency in different
ethnic groups.
A Functional Genomic Study of the Effects of Antipsychotic Agent Chlorpromazine in PC12 Cells
Authors: Kontkanen Outi , Lakso Merja , Wong Garry , Castrén Eero
Published: October 2004

Expression profiling using methods of functional genomics
can be used to investigate changes in gene
transcription induced by drug treatment, which may
lead to discovery of new potential drug targets. Antipsychotic
agents alleviate symptoms of schizophrenia
but the mechanism behind their clinical efficacy is
unclear. We have used the PC12 cell line as a model to
characterize effects of the antipsychotic drug chlorpromazine
on gene expression using high-density complementary
DNA array filters prepared from a rat brain
entorhinal cortex complementary DNA library. Chlorpromazine
treatment positively regulated the expression
of several clones, five of which were selected for
further characterization. Northern blotting experiments
confirmed the increased expression of these
genes after chlorpromazine treatment. Sequencing revealed
that two clones were cytochrome c oxidase and
three were novel genes. Characterization of the function
of these genes could increase our understanding
of the mechanisms of action of antipsychotic drugs,
and might be beneficial for the development of more
effective agents.
Potential Catalysts for the Acetylation of Wood
Authors: Hill C.A.S. , Cetin N.S. , Ozmen N.
Published: October 2004

The potential of several tertiary amine catalysts (pyridine, 4-dimethyl-amino pyridine, N-methyl pyrrolidine
and N-methyl pyrrolidinone) for the acetylation of Corsican pine sapwood, using acetic anhydride,
has been investigated. Rates of reaction were compared with non-catalysed acetylation using acetic
anhydride. The hypernucleophile 4-dimethylamino pyridine was found to be the most effective catalyst
of those studied. At a concentration of only 1% of the catalyst in acetic anhydride, a weight percent gain
of 20% was realised, compared with 7% for the uncatalysed reaction, after 30 minutes system at 100°C.
The influence of substrate swelling upon the rate of reaction with wood is discussed.
Quantification of Muconic Acid-Type Structures in High Molecular Weight Material from Bleach Plant Effluents
Authors: Vilen E. J. , McKague A. B. , Reeve D. W.
Published: October 2004

Effluents from the chlorine dioxide bleaching of chemical pulps were characterized with respect to high
and low molecular weight material, COD, TOC, elemental composition, and carboxylic acid and methyl
ester content. A technique was developed for the quantitative estimation of muconic acid-type structures
as moities of the high molecular weight material. The method is based on the use of quantitative
13C NMR and the pH-dependent cyclization of muconic acids in aqueous solution. 20–40 % of the carboxylic
acids in the high molecular weight material isolated from bleach plant effluents from three softwood
kraft mills were found to exhibit muconic acid-type behaviour.
Acoustic Emission Generated upon Mechano-Sorptive Creep of Wood Bent Across to the Grain under Asymmetrical Moistening
Authors: Molinski Waldemar , Raczkowski Jan , Muszynski Lech
Published: October 2004

Acoustic emission (AE) generated in pine wood samples upon bending across the grain under simultaneous
moistening of the tension zone, was measured. The aim of the study was to determine the effect
of external tension load on AE generated during asymmetrical moistening of dry wood samples in water.
The cumulative counts of AE signals recorded during simultaneous moistening of the tension zone of
sample were proportional to the intensity of the mechano-sorptive strain. AE starts when the mechano-sorptive
strain in the tension zone (εT) reaches a value close to 0.8%.
Experimental Data Correction of the Dynamic Elastic Moduli, Velocity and Density of Solid Wood as a Function of Moisture Content above the Fiber Saturation Point
Authors: Wang Song-Yung , Chuang Shih-Tzu
Published: October 2004

Experimentally it was observed that the dynamic modulus of elasticity calculated from the velocity of
stress wave or ultrasonic wave and the density of wood in green condition increased with increasing
moisture content. This statement disagrees with the physical meaning of data observed with static tests,
namely the decreasing of all mechanical properties of wood with increasing moisture content. To elucidate
this discrepancy a simulation procedure was developed to study the effect of free water, present in
wood above the fiber saturation point on wave velocity. For this purpose the coefficient k, related to the
mobility of free water was defined, as a ratio of free water vibrating simultaneously with water present
in cellular wall (k = 0.6 for stress wave velocity and k = 0.7 for ultrasonic velocity). The simulation procedure
using corrected values of velocity and density showed that the elastic moduli are relatively constant
above the FSP, as all the mechanical parameters determined with static tests.
Contractive Force and Transformation of Microfibril with Aqueous Sodium Hydroxide Solution for Wood
Authors: Nakano Takato , Sugiyama Junji , Norimoto Misato
Published: October 2004

The mechanism of longitudinal contraction of Yezo spruce (Picea jezoensisCarr.) during treatment with aqueous NaOH solution is discussed. The contraction of wood samples increased with an increase in the concentration of NaOH solution and in heating temperature. Measurements of the stress relaxation and the twist angle during the alkali treatment showed that the alkali treatment caused the contractive and twist forces of a tracheid cell wall in longitudinal and tangential directions, depending on the components of contractive force. The temperature dependence of the contraction and the thermodynamics led to the conclusion that the longitudinal contraction of samples is due to that of microfibrilsviaan entropy-elastic force.
Dielectric Relaxation Based on Adsorbed Water in Wood Cell Wall under Non-Equilibrium State. 1
Authors: Jinzhen Cao , Guangjie Zhao
Published: October 2004

In order to make clear the molecular mechanism of the dielectric relaxation based on adsorbed water in
wood cell wall during moisture changing process, the temperature and frequency spectrums of dielectric
processes of Sikkim spruce (Picea spinulosa Griff.) were measured in three different adsorption processes.
Three levels of relative humidity used were 40, 80 and 100 %, respectively, and the temperature was
kept at 20°C. In oven-dry state, relaxation process I based on the reorientation of CH2OH groups in
amorphous region of wood cell wall was observed. While in moist state, relaxation process II based on
ionic conductivity and relaxation process III based on the additive reorientation of CH2OH groups and
adsorbed water molecules occurred. Within higher humidity region, relaxation process IV concerned
with adsorbed water in lignin was observed in the initial adsorption period, but it vanished with further
adsorption.
Electron Paramagnetic Resonance Spectroscopic (EPR) Study of Copper Amine Treated Southern Pine in Wood Preservation
Authors: Zhang J. , Kamdem D. P.
Published: October 2004

The structure of copper complexes in copper amine treated wood samples were elucidated by the application
of electron paramagnetic resonance spectroscopy (EPR). EPR axial spectra were observed for all
Cu-amine treated samples irrespective of the formulations. The values of A∥ and g∥ of the axial spectra
indicate that the stereo-structure of copper complexes in copper amine treated wood was either tetragonal-based octahedral or square-based pyramidal. Comparison of electronic parameters of A∥ and g∥ in
Cu-amine treated wood with those of the Cu-amine treating solution and the values in literature suggests
that the interaction of wood with copper amine is through complexation in which wood functional groups
are complexed with copper amine perpendicularly. The copper complexes in both treating solution and
treated wood are in the form of CuN2O2, where copper is ligated with 2 nitrogen and 2 oxygen.
Homolytic Scission of Interunitary Bonds in Lignin Induced by Ultrasonic Irradiation of MWL Dissolved in Dimethylsulfoxide
Authors: Yoshioka Aki , Seino Teruyuki , Tabata Masayoshi , Takai Mitsuo
Published: October 2004

An electron spin resonance (ESR) method combined with a spin trapping technique was applied to trap and characterize unstable radicals which were generated by ultrasonic irradiation of the dimethylsulfoxide (DMSO) solution of a softwood, Yezo Spruce (Picea jezoensiscarr.) lignin. It was found that an unstable secondary carbon radical, ~CH • in the solution was trapped as the stable nitroxide spin adduct when the DMSO solution was subjected to ultrasonic irradiation in the presence of a spin trapping reagent: 2,4,6-tri-tert-butylnitrosobenzene (BNB) at 50°C for 30 min. This means that the alkyl phenyl ether bonds, ~CH-O-phenyl, known as interunitary bonds in lignins were homolytically cleaved by the ultrasonic irradiation, although the phenoxy radical Ph-O •, called guaiacoxy radical, i.e. the counter radical of the secondary carbon radical, was not trapped by the BNB spin trap. This suggests that the trapping of the guaiacoxy radical, having a methoxy group in anortho-position, by the BNB molecule, carrying two bulky butyl groups in theortho-positions, is sterically hindered.
An Analysis of Rolling Shear of Spruce Wood by the Iosipescu Method
Authors: Dumail Jean-François , Olofsson Kenneth , Salmén Lennart
Published: October 2004

Shearing is an essential deformation in the treatment of mechanical pulp fibers into a papermaking pulp.
Knowledge of the contribution of shear to the fiber treatment during processing can be obtained by measurements
on fibers in the form of wood. In this work, an attempt was made to use the Iosipescu method
for testing wood in rolling shear. Despite the small size of the shear region of interest between notches
made in the wood, the results and their dispersion in both the elastic and inelastic ranges were in accordance
with previous results found using other testing methods. The stress-strain relationship was
analysed in relation to the specimen's density profiles in the region of interest. Differences in density
explained up to 50% of the inter-specimen variability in the shear modulus and in the inelastic behavior.

Failure occurred outside the shearing zone in a large number of specimens. Thus the configuration
chosen was not adapted to provide for the strength of wood in rolling shear. This behavior limited the
amplitude of the strain that could be reached between the notches.
An Investigation of the Crack Tendency on Wood Surfaces After Different Machining Operations
Authors: Stehr Micael , Östlund Sören
Published: October 2004

A hypothesis describing tip-crack generation during different machining operations on sapwood of pine surfaces and the differences between the pith side and bark side were investigated. The goal was to determine whether initial tip-cracks are generated already during the machining operation, before weathering. The evaluation of the results showed that about 10 % of the annual rings on the pith side and about 1% of the annual rings on the bark side have cracks after the machining operation.

A theoretical analysis of an idealised model using the finite element method (FEM) has also been carried out to investigate the tendency for growth of short initial tip-cracks during a simulation of the compression of a wood piece in a conventional planing operation. The analysis seems to confirm that there is a greater risk for cracks on the pith side than on the bark side.
Microfibril Angle Determination of Rattan Fibers and its Influence on the Properties of the Cane
Authors: Abasolo Willie P. , Yoshida Masato , Yamamoto Hiroyuki , Okuyama Takashi
Published: October 2004

The microfibril angle of rattan fibers was determined using the iodine staining method and the X-ray diffraction
technique. The two were compared to assess the applicability of the X-ray technique in estimating
the actual microfibril angle (MFA) of the fiber walls. Likewise, longitudinal Young's modulus
and longitudinal shrinkage were evaluated to determine the influence of MFA on the properties of the
cane. The X-ray technique gave an accurate and objective estimate of the actual MFA of the fiber walls.
A nonlinear relationship existed between MFA and longitudinal Young's modulus while a curvilinear
relationship was observed between MFA and longitudinal shrinkage. This pattern is similar to the behavior
of wood. Thus, it was deduced that the influence of microfibril angle on the properties of rattan cane
is similar to its influence on the properties of wood.
Effects of Element Size and Orientation in the Production of High Strength Resin Impregnated Wood Based Materials
Authors: Yano H. , Mori K. , Collins P.J. , Yazaki Y.
Published: October 2004

The effects of low molecular weight phenolic resin impregnation and high pressure hot pressing (150°C,
30–100 MPa) on the physical and mechanical properties of wood were first investigated by using sawn
wood prepared from a block of Japanese birch (Betula meximowicziana). Subsequently, the effects of
element size and orientation were examined by using sliced veneers, particles and powder prepared from
the remaining portion of the block. Due to the combination of resin impregnation and hot pressing under
high pressure, the specific bending strength at 20°C and 65% RH of sawn wood increased 50% accompanied
by enormous decreases in moisture content, and bending strength reached around 400 MPa. The
mechanical properties of veneer laminated product did not differ significantly from those of sawn wood
product. Among isotropic products, the highest bending strength at 20°C and 65% RH of plywood, particleboard
and powderboard was 242 MPa, 166 MPa and 175 MPa, respectively. The difference of bending
strength between plywood and other isotropic products could be explained by the difference in element
orientation, cross lamination and random distribution. Furthermore, the results for the particleboard
and powderboard showed that when the resin impregnated elements were hot pressed under high pressure,
a decrease in element size did not result in a decrease in bending strength.
Improvement of Antitermitic Activities of Catechin by Combination with Heavy Metals
Authors: Ohmura Wakako , Ohara Seiji
Published: October 2004

Antitermitic activities of catechin-metal complexes were investigated for further utilization of catechin as a termite control agent. Catechin (CA), heavy metal salts (NiCl2, CuCl2, ZnCl2) and CA/metal mixtures with Ni(II), Cu(II) and Zn(II) were subjected to bioassays using a subterranean termite,Coptotermes formosanusShiraki. The astringent properties of each system were assessed by measuring the weight of precipitate with bovine serum albumin (BSA). Changes in UV spectra of the CA/metal mixtures were also measured. CA caused less than 30% mortality after the 21-day test period, and had no BSA-precipitating capacity. The effects of heavy metals on CA activities varied with metal. CA/Ni(II) showed the highest termiticidal activity among tested materials, but exhibited no BSA-precipitating capacity and little change in UV spectrum. On the other hand, both CA/Cu(II) and CA/Zn(II) increased the BSA-precipitating capacity and UV absorption with time after preparing the CA/metal solutions, but their termiticidal activity was almost equal to CA. Termiticidal activity of CA was improved by the addition of Ni(II) but hardly changed by Cu(II) or Zn(II), while astringent properties of CA were hardly changed by addition of Ni(II) but improved by Cu(II) or Zn(II). Termiticidal activity was negatively correlated with astringent property.
Phenol Oxidase Activity and One-Electron Oxidation Activity in Wood Degradation by Soft-Rot Deuteromycetes
Authors: Tanaka Hiromi , Itakura Shuji , Enoki Akio
Published: October 2004

Wood degradation, one-electron oxidation activity as assayed by ethylene production from 2-keto-4-thiomethylbutyric acid, and phenol oxidase activity were measured in cultures of six deuteromycete
fungi, with glucose or wood as the carbon source. The four fungi that degraded Japanese beech wood
had higher one-electron oxidation activities in wood-containing cultures than in glucose-containing cultures.
These four fungi also had measurable phenol oxidase activity in wood-containing cultures, but not
in glucose-containing cultures. The two mould fungi that did not significantly degrade wood had no phenol
oxidase activity in either wood- or glucose-containing cultures. The one-electron oxidation activity
in intact cultures of the soft-rot deuteromycetes was roughly related with the rate of weight loss during
wood degradation in those cultures. However, there was no clear relationship between phenol oxidase
activity and either one-electron oxidation activity or the rate of wood weight loss, either over time, or in
total. Most of the one-electron oxidation activity resulted from phenol oxidase and hydroxyl radical.
Most of the phenol oxidase activity resulted from laccase.
Periodicity as a Factor in the Generation of Isotropic Compressive Growth Stress Between Microfibrils in Cell Wall Formation during a Twenty-Four Hour Period
Authors: Yoshida Masato , Hosoo Yoshihiro , Okuyama Takashi
Published: October 2004

Field emission scanning electron microscopy and energy-dispersive X-ray microanalysis were used to
investigate the generation of growth stress in connection with the deposition of cell wall materials along
the innermost surface of radial walls during secondary wall formation of differentiating tracheids of
Cryptomeria japonica. Samples were collected when the turgor pressure of the tree was low (16:00 h),
and when the pressure was high (6:00 h). In samples collected at 16:00 h, cellulose microfibrils deposited
on the innermost surface of radial walls were clearly evident and amorphous material was rarely
found. Conversely, in samples collected at 6:00 h, cellulose microfibrils were rarely observed and the
amorphous material was prevalent. Cellulose microfibrils were evident, however, after removing the
amorphous material with chlorite. The concentration of potassium on the inner surface of radial walls
was greater at 6:00 h than at 16:00 h. After chlorite treatment, the concentration of potassium measured
in the samples collected at 6:00 h decreased to a level equivalent to that in samples collected at 16:00 h
and thus potassium was found to be associated with the amorphous material on the cellulose microfibrils.
The amorphous material is probably a matrix of hemicellulose and monolignol, material that is
abundant on the inner surface of developing cell walls, especially during expansion (as a result of high
turgor pressure) of differentiating tracheids. A matrix of hemicellulose and lignin deposited in the
expanded gaps between cellulose microfibrils and daily expansion of the gaps probably produces an
isotropic compressive stress (growth stress). This paper demonstrates periodicity in cell wall formation
as a result of the cycles of compressive growth in the differentiating cell wall.
Production of Volatile Organic Compounds by Trichoderma in Media Containing Different Amino Acids and Their Effect on Selected Wood Decay Fungi
Authors: Bruce Alan , Wheatley Ron E. , Humphris Sonia N. , Hackett Christine A. , Florence Maria E.J.
Published: October 2004

The paper describes an experiment to evaluate the effect of subtle changes to the amino acid composition of the growth medium on the production of volatile organic compounds (VOCs) by aTrichoderma aureovirideisolate and the consequent inhibition of wood decay fungi. A synthetic medium was produced to represent the C:N ratio and major amino acid content of Scots pine sapwood. Changes in the amino acid content of the medium produced very significant differences in the VOC output produced by theTrichodermaisolate and in the levels of inhibition of the target wood decay fungi. Principal component analysis of the VOC profiles indicated that aldehyde and ketone components were associated with the greatest inhibition of the target fungi. The implications of the results for the use ofTrichodermaisolates as biological control agents of decay fungi in wood are discussed.
Effects of Alkali Pretreatment on Surface Properties and Green Color Conservation of Moso Bamboo (Phyllostachys pubescens Mazel)
Authors: Chang Shang-Tzen , Yeh Ting-Feng
Published: October 2004

Standing bamboo culms have an attractive greenish skin. Once harvested, however, they turn yellow and the color starts to decay. These adverse properties limit their applications and degrade their performance. Chromated copper arsenate (CCA) based preservatives have been reported to be good protectors for preserving the green color of bamboo culms. An alkali pretreatment was required before applying CCA. However, the mechanism of alkali pretreatment on color conservation is not fully understood. In this study, morphology, wettability, chemical and pigment changes of moso bamboo (Phyllostachys pubescensMazel) were studied after treating with four alkali reagents. The results showed that 2% KOH effectively removed the waxes and capes of silica cells on moso bamboo surface and also increased the surface wettability much better than treatments with 4% K2CO3, 10% K2CO3, 4% Na2CO3, or 4% NaHCO3. The KOH pretreatment also results in a better penetration and reaction with the green color protector (5% Boliden K-33, type-B CCA), and subsequently preserved the green color appearance of moso bamboo.
Lignin Degradation in Oxygen Delignification Catalysed by [PMo7V5O40]8- Polyanion. Part II. Study on Lignin Monomeric Model Compounds
Authors: Evtuguin D.V. , Neto C. Pascoal , Carapuça H. , Soares J.
Published: October 2004

Vanillyl and veratryl alcohols were used as monomeric lignin model compounds in experiments aiming
to enhance the understanding of the lignin oxidation mechanisms involved in the oxygen delignification
in acidic media catalysed by [PMo7V5O40]8− (HPA-5) heteropolyanion. Based on the model compound
experiments, the first step of lignin oxidation is suggested to be a one-electron oxidation by the catalyst.
This step is followed by coupling reactions and/or by further oxidation by the catalyst. The ratio of coupling/oxidation reaction products depends on the oxidation conditions and decreases with temperature
raise. The higher oxidation rate of vanillyl alcohol as compared to the veratryl alcohol in the reaction
system O2/HPA-5 was explained by the redox properties of the catalyst. The insufficiently high redox
potential of HPA-5 did not allow the efficient oxidation of veratryl alcohol. The former was oxidised by
VO2
+ ions dissociated from the HPA-5 under the acidic conditions. The reactivity of different lignin
structural units in the reaction system O2/HPA-5 was estimated by electrochemical methods using various
lignin model compounds.
Softening Characteristics of Wet Wood under Quasi Static Loading
Authors: Hamdan S. , Dwianto W. , Morooka T. , Norimoto M.
Published: October 2004

In order to examine the possible influences of temperature on the wood constituents, two groups of wood
species namely softwood (needle leaf wood) and hardwood (broad leaf wood) were subjected to heat or
steam treatment during large radial compression between 0°C and 200°C. Two well-defined softening
regions are observed. Both species showed the glass transition Tg of lignin at ~ 90°C and ~ 60°C for
softwood and hardwood respectively and a second transition region at ~ 160°C. The softening behavior
between the first and second transition in softwood is in contrast with the softening behavior of hardwood.
This difference reflects the difference in the distribution of the relaxation process due to lignin,
which suggests the difference in chemical structure of lignin between softwood and hardwood.
Wood Preservation Based on In situ Polymerization of Bioactive Monomers. Part 2. Fungal Resistance and Thermal Properties of Treated Wood
Authors: Ibach Rebecca E. , Rowell Roger M.
Published: October 2004

This paper is the second in a two-part series on in situ polymerization of bioactive monomers as an alternative to conventional preservative treatments. In this part of the study, bioactive monomers were evaluated for their ability to provide resistance to decay and protection against fire. Five bioactive monomers were synthesized: (1) pentachlorophenolyl acrylate (PCPA), (2) tributyltin acrylate (TBTA), (3) 8-hydroxyquinolyl acrylate (HQA), (4) 5,7-dibromo-8-hydroxyquinolyl acrylate (DBHQA), and (5) diethyl-N1N-bis (acryloxyethyl) aminomethyl phosphonate (Fyrol 6 acrylate, F6A). Southern pine sapwood samples were treated with acrylate solutions at different retention levels and with various amounts of crosslinker (trimethylolpropane trimethacrylate, TMPTM), then polymerized in situ. Methyl methacrylate (MMA) was used as the control. Biological resistance to the brown-rot fungus Gloeophyllum trabeum was determined on acetone-leached and unleached samples. PCPA showed some biological efficacy in the absence of crosslinker, but otherwise provided no more protection than did MMA alone.

TBTA was biologically effective at all retention levels except with crosslinker concentration ≥10 %. HQA was biologically effective at ≥ 2% retention. F6A was not biologically effective, although unleached wood treated with 10% F6A and 5% or no crosslinker showed some resistance to decay. The 5% DBHQA plus 5% crosslinker treatment was biologically effective in both leached and unleached wood. The effects of the highest treatment level of each monomer, after polymerization, were also evaluated by thermogravimetric analysis. All treatments provided some resistance to fire. The best treatment was 10 % F6A, which resulted in the lowest mass loss (67.0 %) and the lowest maximum temperature of pyrolysis (308.5 °C).
Wood Surface Energy and Time Dependence of Wettability: A Comparison of Different Wood Surfaces Using an Acid-Base Approach
Authors: Gindl Milojka , Sinn Gerhard , Reiterer Alexander , Tschegg Stefanie
Published: October 2004

Using four different wood species, the wetting behaviour of sanded wood surfaces was compared with that of microtomed surfaces. Sanding caused lower contact angles and lower total surface free energies. Electron donor components were considered to be responsible for the observed changes according to the applied acid-base approach. The time behaviour of sanded surfaces differed from the microtomed reference, insofar as the volume of a deposited drop of water decreased very rapidly as soon as it was applied, indicating fast penetration into the wood. A qualitative analysis by SEM revealed a heavily torn upper-most cell layer on sanded surfaces, which was assumed to be responsible for the increased surface free energy and enhanced penetration.
Diagnostik von Hämoglobinopathien / Diagnosis of hemoglobinopathies
Authors: Kohne Elisabeth
Published: October 2004

Zusammenfassung Hämoglobinopathien bilden eine Gruppe von überwiegend autosomal rezessiv vererbten Krankheiten, die charakterisiert sind entweder durch die reduzierte Synthese von einer oder mehreren normalen Globinketten = Thalassämie-Syndrome oder durch die Produktion von strukturell abnormen Globinkettens = Hämoglobinstrukturanomalien. Durch die seit langem kontinuierlich steigende Einwanderung von Millionen Menschen aus den Hauptverbreitungsgebieten der Hämoglobinopathien erhöht sich hierzulande der Bedarf an Methoden und Richtlinien für eine einfache, effiziente Diagnostik. Die multiethnische Zusammensetzung der Bevölkerung kann spezielle diagnostische Probleme aufwerfen, für welche die einfache Hb-Elektrophorese und/oder HPLC nicht ausreicht.

In diesem Review wird das breite Spektrum hämatologischer und biochemischer Untersuchungen dargestellt, des weiteren die analytischen Stufenpläne und die signifikanten Laborparameter. Die Charakteristika der HbS-, HbC-, und HbE-Hämoglobinopathien, der α- und β-Thalassämien und deren komplexe Kombinationsformen werden beschrieben und die diagnostische Bedeutung von Laborbefunden der wichtigsten Hämoglobinkrankheiten dargestellt.
Low Density Lipoprotein-Heterogenität als prognostischer Marker kardiovaskulärer Erkrankungen / Low density lipoprotein heterogeneity for risk evaluation of cardiovascular disease
Authors: Winkler Karl
Published: October 2004

Zusammenfassung Generell ist die Bestimmung von Low Density Lipoprotein-Subfraktionen (LDL-Subfraktionen) zur Aufklärung pathophysiologischer Zusammenhänge im Bereich der vaskulären Medizin und für die Risikoabschätzung kardiovaskulärer Erkrankungen von Bedeutung. Es gibt verschiedene Methoden zur Bestimmung von LDL-Subfraktionen, welche sich unterschiedliche physiko-chemische Eigenschaften der LDL zu Nutze machen. So trennen Ultrazentrifugationsmethoden nach Dichte, die Gradientengelelektrophorese (GGE) und das Magnetresonanzverfahren (NMR) nach Größe auf. Für differentialdiagnostische Zwecke oder bei der routinemäßigen Abschätzung des kardiovaskulären Risikos ist die Analytik der LDL-Subfraktionen derzeit aber wenig sinnvoll. Dies liegt zum einen an den teilweise aufwändigen Techniken, zum anderen an der schlechten Standardisierung der Methoden und der noch offenen klinischen Relevanz der gewonnenen Ergebnisse.
Blutungszeit in vitro am PFA-100®: Präanalytik bei der Blutentnahme / Bleeding time in vitro measured by the PFA-100® system: Pre-analytical conditions for blood collection
Authors: Lutze G. , Kropf S.
Published: October 2004

Zusammenfassung Bei Wiederholungsuntersuchungen am Plättchenfunktionsanalyzer PFA-100® (Dade Behring) können die Citratblut-Verschlusszeiten bei derselben Person in kurzem zeitlichen Abstand oder auch bei derselben Blutentnahme stark variieren. In dieser Arbeit wurden bestimmte präanalytische Faktoren überprüft bzw. neu untersucht. Die Abhängigkeit von der Citratkonzentration (0,105 mol/l oder 0,129 mol/l), die sich in signifikant unterschiedlichen Referenzbereichen ausdrückte, konnte bestätigt werden. Bei Anwendung verschiedener Blutentnahmetechniken (freies Einlaufen, Monovetten, Vacutainer, Kanülen ohne Schlauch, Butterfly) waren die Mittelwerte und Standardabweichungen der Gesamtheit aller Probanden einer Gruppe vergleichbar. Bei Einzelpersonen unterschieden sich die Ergebnisse dagegen oft stark. Von beträchtlichem Ausmaß waren häufig auch die Differenzen zwischen Doppelbestimmungen. Die mehrfaktorielle Varianzanalyse bestätigte letztere als Hauptursache für die beobachteten Differenzen, nicht die Entnahmetechniken selbst. Bei Vergleichs- und Verlaufsuntersuchungen sind Änderungen zwischen zwei Messungen mit Kollagen-Epinephrin-Messzellen erst dann als deutlich zu betrachten, wenn die Verschlusszeiten um mindestens 50 Sekunden differieren. Verantwortlich hierfür können Chargenunterschiede der Messzellen, Unterschiede der Einzelmesszellen innerhalb einer Charge oder eine Variabilität des individuellen Aperturverschlusses sein. Die PFA-100®-Methode ist daher eher als “halbquantitativ” zu bezeichnen.
Molecular Cytogenetic Maps of Sorghum Linkage Groups 2 and 8
Authors: Kim Jeong-Soon , Klein Patricia E , Klein Robert R , Price H James , Mullet John E , Stelly David M
Published: October 2004

To integrate genetic, physical, and cytological perspectives of the Sorghum bicolor genome, we selected 40 landed bacterial artificial chromosome (BAC) clones that contain different linkage map markers, 21 from linkage group 2 (LG-02) and 19 from linkage group 8 (LG-08). Multi-BAC probe cocktails were constructed for each chromosome from the landed BACs, which were also preevaluated for FISH signal quality, relative position, and collective chromosome coverage. Comparison to the corresponding linkage map revealed full concordance of locus order between cytological and prior segregation analyses. The pericentromeric heterochromatin constituted a large quasi-uniform block in each bivalent and was especially large in the bivalent corresponding to LG-08. Centromere positions in LG-02 and LG-08 were progressively delimited using FISH to identify landed BACs for which the FISH signals visibly flanked the centromere. Alignment of linkage and cytological maps revealed that pericentromeric heterochromatin of these sorghum chromosomes is largely devoid of recombination, which is mostly relegated to the more distal regions, which are largely euchromatic. This suggests that the sorghum genome is thus even more amenable to physical mapping of genes and positional cloning than the C-value alone might suggest. As a prelude to positional cloning of the fertility restorer, Rf1, FISH of BAC clones flanking the Rf1 locus was used to delimit the chromosomal position of the gene. FISH of BACs that contain the most proximal linkage markers enabled localization of Rf1 to a ∼0.4-Mbp euchromatic region of LG-08. Cytogenetic analyses of Rf1 and other trait loci will aid in assessing the feasibility of positional cloning and help formulate strategies required for cloning this and other agriculturally critical genes.
Genetics of Hybrid Incompatibility Between Lycopersicon esculentum and L. hirsutum
Authors: Moyle Leonie C , Graham Elaine B
Published: October 2004

We examined the genetics of hybrid incompatibility between two closely related diploid hermaphroditic plant species. Using a set of near-isogenic lines (NILs) representing 85% of the genome of the wild species Lycopersicon hirsutum (Solanum habrochaites) in the genetic background of the cultivated tomato L. esculentum (S. lycopersicum), we found that hybrid pollen and seed infertility are each based on 5–11 QTL that individually reduce hybrid fitness by 36–90%. Seed infertility QTL act additively or recessively, consistent with findings in other systems where incompatibility loci have largely been recessive. Genetic lengths of introgressed chromosomal segments explain little of the variation for hybrid incompatibility among NILs, arguing against an infinitesimal model of hybrid incompatibility and reinforcing our inference of a limited number of discrete incompatibility factors between these species. In addition, male (pollen) and other (seed) incompatibility factors are roughly comparable in number. The latter two findings contrast strongly with data from Drosophila where hybrid incompatibility can be highly polygenic and complex, and male sterility evolves substantially faster than female sterility or hybrid inviability. The observed differences between Lycopersicon and Drosophila might be due to differences in sex determination system, reproductive and mating biology, and/or the prevalence of sexual interactions such as sexual selection.
Longevity and Metabolism in Drosophila melanogaster
Authors: Khazaeli Aziz A , Van Voorhies Wayne , Curtsinger James W
Published: October 2004

We measured age-specific metabolic rates in 2861 individual Drosophila melanogaster adult males to determine how genetic variation in metabolism is related to life span. Using recombinant inbred (RI) lines derived from populations artificially selected for long life, resting metabolic rates were measured at 5, 16, 29, and 47 days posteclosion, while life spans were measured in the same genotypes in mixed-sex population cages and in single-sex vials. We observed much heritable variation between lines in age-specific metabolic rates, evidence for genotype × age interaction, and moderate to large heritabilities at all ages except the youngest. Four traits exhibit evidence of coordinate genetic control: day 16 and day 29 metabolic rates, life span in population cages, and life span in vials. Quantitative trait loci (QTL) for those traits map to the same locations on three major chromosomes, and additive genetic effects are all positively correlated. In contrast, metabolic rates at the youngest and oldest ages are unrelated to metabolic rates at other ages and to survival. We suggest that artificial selection for long life via delayed reproduction also selects for increased metabolism at intermediate ages. Contrary to predictions of the “rate of living” theory, we find no evidence that metabolic rate varies inversely with survival, at the level of either line means or additive effects of QTL.
Genetic Diversity, Recombination and Cryptic Clades in Pseudomonas viridiflava Infecting Natural Populations of Arabidopsis thalianaSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY604840, AY604841, AY604842, AY604843, AY604844, AY604845, AY604846, AY604847, AY604848 and AY606338, AY606800.
Authors: Goss Erica M , Kreitman Martin , Bergelson Joy
Published: October 2004

Species-level genetic diversity and recombination in bacterial pathogens of wild plant populations have been nearly unexplored. Pseudomonas viridiflava is a common natural bacterial pathogen of Arabidopsis thaliana, for which pathogen defense genes and mechanisms are becoming increasing well known. The genetic variation contained within a worldwide sample of P. viridiflava collected from wild populations of A. thaliana was investigated using five genomic sequence fragments totaling 2.3 kb. Two distinct and deeply diverged clades were found within the P. viridiflava sample and in close proximity in multiple populations, each genetically diverse with synonymous variation as high as 9.3% in one of these clades. Within clades, there is evidence of frequent recombination within and between each sequenced locus and little geographic differentiation. Isolates from both clades were also found in a small sample of other herbaceous species in Midwest populations, indicating a possibly broad host range for P. viridiflava. The high levels of genetic variation and recombination together with a lack of geographic differentiation in this pathogen distinguish it from other bacterial plant pathogens for which intraspecific variation has been examined.
Mapping of a Milk Production Quantitative Trait Locus to a 420-kb Region on Bovine Chromosome 6
Authors: Olsen Hanne Gro , Lien Sigbjørn , Gautier Mathieu , Nilsen Heidi , Roseth Arne , Berg Paul R , Sundsaasen Kristil K , Svendsen Morten , Meuwissen Theo H E
Published: October 2004

A QTL affecting milk production traits was previously mapped to an interval of 7.5 cM on chromosome 6 in Norwegian dairy cattle. This article aimed to refine this position by increasing the map density in the region by a set of single-nucleotide polymorphisms and analyzing the data with a combined linkage and linkage disequilibrium approach. Through a series of single- and multitrait and single- and multipoint analyses, the QTL was positioned to an interval surrounded by the genes ABCG2 and LAP3. As no recombinations were detected in this interval, physical mapping was required for further refining. By using radiation hybrid mapping as well as BAC clones, the bovine and human comparative maps in the region are resolved, and the QTL is mapped within a distance of 420 kb.
Coalescent-Based Association Mapping and Fine Mapping of Complex Trait Loci
Authors: Zöllner Sebastian , Pritchard Jonathan K
Published: October 2004

We outline a general coalescent framework for using genotype data in linkage disequilibrium-based mapping studies. Our approach unifies two main goals of gene mapping that have generally been treated separately in the past: detecting association (i.e., significance testing) and estimating the location of the causative variation. To tackle the problem, we separate the inference into two stages. First, we use Markov chain Monte Carlo to sample from the posterior distribution of coalescent genealogies of all the sampled chromosomes without regard to phenotype. Then, averaging across genealogies, we estimate the likelihood of the phenotype data under various models for mutation and penetrance at an unobserved disease locus. The essential signal that these models look for is that in the presence of disease susceptibility variants in a region, there is nonrandom clustering of the chromosomes on the tree according to phenotype. The extent of nonrandom clustering is captured by the likelihood and can be used to construct significance tests or Bayesian posterior distributions for location. A novelty of our framework is that it can naturally accommodate quantitative data. We describe applications of the method to simulated data and to data from a Mendelian locus (CFTR, responsible for cystic fibrosis) and from a proposed complex trait locus (calpain-10, implicated in type 2 diabetes).
The Bacillus subtilis sin Operon
Authors: Voigt Christopher A , Wolf Denise M , Arkin Adam P
Published: October 2004

The strategy of combining genes from a regulatory protein and its antagonist within the same operon, but controlling their activities differentially, can lead to diverse regulatory functions. This protein-antagonist motif is ubiquitous and present in evolutionarily unrelated regulatory pathways. Using the sin operon from the Bacillus subtilis sporulation pathway as a model system, we built a theoretical model, parameterized it using data from the literature, and used bifurcation analyses to determine the circuit functions it could encode. The model demonstrated that this motif can generate a bistable switch with tunable control over the switching threshold and the degree of population heterogeneity. Further, the model predicted that a small perturbation of a single critical parameter can bias this architecture into functioning like a graded response, a bistable switch, an oscillator, or a pulse generator. By mapping the parameters of the model to specific DNA regions and comparing the genomic sequences of Bacillus species, we showed that phylogenetic variation tends to occur in those regions that tune the switch threshold without disturbing the circuit function. The dynamical plasticity of the protein-antagonist operon motif suggests that it is an evolutionarily convergent design selected not only for particular immediate function but also for its evolvability.
Epistasis Underlying a Fitness Trait Within a Natural Population of the Pitcher-Plant Mosquito, Wyeomyia smithii
Authors: Bradshaw William E , Haggerty Brian P , Holzapfel Christina M
Published: October 2004

We selected on divergent photoperiodic response in three separate lines from a natural population of the pitcher-plant mosquito, Wyeomyia smithii. Line crosses reveal that there exists within a population, diverse epistatic variation for a fitness trait that could contribute to adaptive potential following founder events or rapid climate change.
Communication Between Parental and Developing Genomes During Tetrahymena Nuclear Differentiation Is Likely Mediated by Homologous RNAs
Authors: Chalker Douglas L , Fuller Patrick , Yao Meng-Chao
Published: October 2004

Approximately 6000 DNA elements, totaling nearly 15 Mb, are coordinately excised from the developing somatic genome of Tetrahymena thermophila. An RNA interference (RNAi)-related mechanism has been implicated in the targeting of these germline-limited sequences for chromatin modification and subsequent DNA rearrangement. The excision of individual DNA segments can be inhibited if the homologous sequence is placed within the parental somatic nucleus, indicating that communication occurs between the parental and developing genomes. To determine how the DNA content of one nucleus is communicated to the other, we assessed DNA rearrangement occurring in wild-type cells that were mated to cells that contained the normally germline-limited M element within their somatic nuclei. M-element rearrangement was blocked in the wild-type cell even when no genetic exchange occurred between mating partners, a finding that is inconsistent with any genetic imprinting models. This inhibition by the parental somatic nucleus was rapidly established between 5 and 6 hr of conjugation, near or shortly after the time that zygotic nuclei are formed. M-element small RNAs (sRNAs) that are believed to direct its rearrangement were found to rapidly accumulate during the first few hours of conjugation before stabilizing to a low, steady-state level. The period between 5 and 6 hr during which sRNA levels stabilize correlates with the time after which the parental genome can block DNA rearrangement. These data lead us to suggest that homologous sRNAs serve as mediators to communicate sequence-specific information between the parental and developing genomes, thereby regulating genome-wide DNA rearrangement, and that these sRNAs can be effectively compared to the somatic genome of both parents.
A Novel Meiotic Drive Locus Almost Completely Distorts Segregation in Mimulus (Monkeyflower) Hybrids
Authors: Fishman Lila , Willis John H
Published: October 2004

We report the discovery, mapping, and characterization of a meiotic drive locus (D) exhibiting nearly 100% nonrandom transmission in hybrids between two species of yellow monkeyflowers, outcrossing Mimulus guttatus and selfing M. nasutus. Only 1% of F2 hybrids were M. nasutus homozygotes at the marker most tightly linked to D. We used a set of reciprocal backcrosses to distinguish among male-specific, female-specific, and zygote-specific sources of transmission ratio distortion. Transmission was severely distorted only when the heterozygous F1 acted as the female parent in crosses to either parental species, ruling out pollen competition and zygote mortality as potential sources of drive. After four generations of backcrossing to M. nasutus, nearly isogenic lines were still >90% heterozygous at markers linked to D, suggesting that heterozygosity at the drive locus alone is sufficient for nonrandom transmission. A lack of dramatic female fitness costs in these lines rules out alternatives involving ovule or seed mortality and points to a truly meiotic mechanism of drive. The strength and direction of drive in this system is consistent with population genetic theory of selfish element evolution under different mating systems. These results are the first empirical demonstration of the strong female-specific drive predicted by new models of selfish centromere turnover.