bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of NtrC in biofilm formation via controlling expression of the gene encoding an ADP‐glycero‐manno‐heptose‐6‐epimerase in the pathogenic bacterium, Vibrio vulnificus
Authors: Kim Han‐Suk , Lee Mi‐Ae , Chun Se‐Jin , Park Soon‐Jung , Lee Kyu‐Ho
Published: December 2006

To identify the genetic elements required for biofilm formation, we screened a pool of random Vibrio vulnificus mutants for their ability to form biofilms. One mutant displaying significantly decreased biofilm‐forming activity was found to contain a transposon insertion in the ntrC gene. The ntrC gene encodes a well‐known transcriptional activator. We examined how this regulator modulates a biofilm‐forming process in V. vulnificus by searching for NtrC target gene(s). Comparison of the proteomes of ntrC mutant and wild‐type strains grown under planktonic and biofilm stages revealed that synthesis of the protein homologous to GmhD (ADP‐glycero‐manno‐heptose‐6‐epimerase) was elevated during the growth period for biofilm formation and was strongly influenced by NtrC. A luxAB‐transcriptional fusion with the gmhD promoter region indicated that gmhD expression was positively regulated by both NtrC and RpoN. The function of the gmhD gene product in V. vulnificus was assessed by constructing and phenotypic analyses of an isogenic mutant. The gmhD mutant was defective in production of mature lipopolysaccharide (LPS) and exopolysaccharides (EPS), and demonstrated an attenuated ability to form a biofilm. These results suggest that NtrC acts as a key regulator of both LPS and EPS biosyntheses and, thereby, modulates critical steps in biofilm development of V. vulnificus.
Topology‐dependent transcription in linear and circular plasmids of the segmented genome of Borrelia burgdorferi
Authors: Beaurepaire Cécile , Chaconas George
Published: December 2006

The segmented genome of Borrelia burgdorferi, a causative agent of Lyme disease, contains a mixture of over 20 linear and circular plasmids. Genes encoding five paralogous families of plasmid replication proteins are located on both circular and linear DNA molecules. The effect of DNA topology on the transcription of replication proteins from two B. burgdorferi plasmids, cp9 and lp17, was examined using quantitative reverse transcription polymerase chain reaction. Circular to linear conversion of a cp9‐derived plasmid resulted in a 160‐fold decrease in transcript levels of bbc01, believed to encode the replication initiator. A 14.9‐fold reduction in plasmid copy number was also observed, resulting in a net 10.7‐fold lower transcription level per gene copy on a linear versus a circular plasmid. In contrast, expression of the bbd14 replication initiator for the linear plasmid lp17 was 7.2 times higher per gene copy on a linear versus a circular plasmid. Topology‐dependent transcription of these genes may help to block topological interconversions during genome evolution, offers a new avenue for global gene regulation and also has important implications for the design of genetic complementation experiments in B. burgdorferi.
Leaf growth rate per unit thermal time follows QTL‐dependent daily patterns in hundreds of maize lines under naturally fluctuating conditions
Authors: SADOK WALID , NAUDIN PHILIPPE , BOUSSUGE BENOIT , MULLER BERTRAND , WELCKER CLAUDE , TARDIEU FRANCOIS
Published: December 2006

We have analysed daily patterns of leaf elongation rate (LER) in large data sets with 318 genotypes placed in naturally fluctuating temperature and evaporative demand, and examined the effect of targeted alleles on these patterns. The method consisted, firstly, in expressing elongation rate per unit thermal time, so it became temperature independent; secondly, in a joint analysis of diurnal fluctuations of elongation rate and of micrometeorological conditions in several experiments, and finally, in a comparison of daily patterns between groups of genotypes possessing targeted alleles. (1) Conditions for using thermal time at a time step of 15 min were first tested successfully in 318 recombinant inbred lines (RILs) of three mapping populations. (2) An analysis of 1989 time courses revealed a robust daily pattern of LER per unit thermal time (LERth) over several experiments. LERth was constant during the night and was reproducible (for a given RIL) over up to 10 consecutive nights in different experiments. It declined rapidly during the early morning, closely following the daily pattern of transpiration rate. (3) Groups of RILs carrying alleles conferring a high response to temperature had markedly higher night‐time plateau of LER than those with low responses. Groups of RILs with high response to evaporative demand had rapid decreases in elongation rate at the transition between night and day, while this decrease was slower in groups of RILs with low response. These results open the way for using kinetics of responses to environmental stimuli as a phenotyping tool in genetic analyses.
Calmodulin‐binding protein phosphatase PP7 is involved in thermotolerance in Arabidopsis
Authors: LIU HONG‐TAO , LI GUO‐LIANG , CHANG HUI , SUN DA‐YE , ZHOU REN‐GANG , LI BING
Published: December 2006

PP7 is the first protein Ser/Thr phosphatase to be found to interact with calmodulin (CaM) in plants. The T‐DNA insertion AtPP7 knockout line and AtPP7 overexpression lines were employed to study the specific function of AtPP7. The AtPP7 knockout impaired the thermotolerance of Arabidopsis seedlings while the overexpression of AtPP7 resulted in plants with increased thermotolerance. Results from real‐time polymerase chain reaction (PCR) showed that the expression of AtHSP70 and AtHSP101 genes was up‐regulated in AtPP7 overexpression lines after heat shock (HS) at 37 °C for 1 h. Protein gel blot analysis showed that HSP70 protein levels increased in AtPP7 overexpression lines after HS at 37 °C for 2 h. The expression of the AtPP7 gene was also induced by HS at 37 °C in wild‐type Arabidopsis. Using a yeast two‐hybrid screen, we showed an interaction between AtPP7 and CaM. In addition, we found that AtPP7 interacts with an HS transcription factor (HSF), suggesting a possible role for AtPP7 in regulating the expression of heat shock protein (HSP) genes.
Warm and cold parental reproductive environments affect seed properties, fitness, and cold responsiveness in Arabidopsis thaliana progenies
Authors: BLÖDNER C. , GOEBEL C. , FEUSSNER I. , GATZ C. , POLLE A.
Published: December 2006

Conditions in the parental environment during reproduction can affect the performance of the progenies. The goals of this study were to investigate whether warm or cold temperatures in the parental environment during flowering and seed development affect Arabidopsis thaliana seed properties, growth performance, reproduction and stress tolerance of the progenies, and to find candidate genes for progeny‐related differences in stress responsiveness. Parental plants were raised at 20 °C and maintained from bolting to seed maturity at warm (25 °C) or cold (15 °C) temperatures. Analysis of seed properties revealed significant increases in nitrogen in seeds from warm temperature and significant increases in lipids and in the ratio of α‐linolenic to oleic acid in seeds from the cold parental environment. Progenies of the warm parental environment showed faster germination rates, faster root elongation growth, higher leaf biomass and increased seed production at various temperatures compared with those from the cold parental environment. This indicates that under stable environmental conditions, progenies from warm parental environments had a clear adaptive advantage over those from cold parental environments. This parental effect was presumably transmitted by the higher nitrogen content of the seeds developed in warm conditions. When offspring from parents grown at different temperatures were exposed to chilling or freezing stress, photosynthetic yield recovered faster in progenies originating from cold parental environments. Cold acclimation involved up‐regulation of transcripts of flavanone 3‐hydroxylase (F3H) and pseudo response regulator 9 (PRR9) and down‐regulation of growth‐associated transcription factors (TFs) NAP and AP2domain containing RAP2.3. NAP, a regulator of senescence, and PRR9, a temperature‐sensitive modulator of the circadian clock, were probably involved in mediating parent‐of‐origin effects, because they showed progeny‐related expression differences under chilling. Because low temperatures also delay senescence, cold responsiveness of NAP suggests that this factor is linked with the regulatory network that is important for environmental acclimation of plants.
A novel non‐invasive optical method for quantitative visualization of pH dynamics in the rhizosphere of plants
Authors: BLOSSFELD STEPHAN , GANSERT DIRK
Published: December 2006

A novel optical method for non‐invasive, quantitative and high‐resolution imaging of spatial and temporal pH dynamics in soils mediated by plant roots is introduced. This method overcomes present limitations of measurement of pH, mainly short‐term and punctiform measurements, by recording long‐term dynamics of the micro‐pattern of pH in the root–soil interface without disturbance of the biological and physico‐chemical conditions. Juncus effusus L., rooting in a permanently flooded rhizotron, was selected as the test organism for qualifying the technique. The measurements showed pronounced diurnal variations of pH along the roots, particularly along the elongation zone. Diurnal oscillation of pH caused by the roots reached up to 0.5 units. Long‐term records at 4 s intervals over more than 8 weeks revealed considerable spatial and temporal patterns of pH dynamics in the rhizosphere of about 10% of the pH scale (pH 7.0–8.5). The measured data were validated by the use of pH electrodes. Concomitantly measured oxygen concentration showed hypoxic conditions around root tips (10–70 µmol O2 L−1) and almost anoxic conditions (0.9 µmol O2 L−1) in the bulk soil. The present study qualifies this novel pH‐sensing technique as a powerful analytical tool for quantitative visualization of undisturbed bioprocess dynamics.
Phosphate in the arbuscular mycorrhizal symbiosis: transport properties and regulatory roles
Authors: JAVOT HÉLÈNE , PUMPLIN NATHAN , HARRISON MARIA J.
Published: December 2006

In response to the colonization by arbuscular mycorrhizal (AM) fungi, plants reprioritize their phosphate (Pi)‐uptake strategies to take advantage of nutrient transfer via the fungus. The mechanisms underlying Pi transport are beginning to be understood, and recently, details of the regulation of plant and fungal Pi transporters in the AM symbiosis have been revealed. This review summarizes recent advances in this area and explores current data and hypotheses of how the plant Pi status affects the symbiosis. Finally, suggestions of an interrelationship of Pi and nitrogen (N) in the AM symbiosis are discussed.
Carbonate dissolution revealed by silt grain‐size distribution: comparison of Holocene and Last Glacial Maximum sediments from the pelagic South Atlantic
Authors: FRENZ MICHAEL , HENRICH RÜDIGER
Published: December 2006

The current issue of global warming and the role of the ocean in global exchange of CO2 increases the interest in solid budgets of marine carbonate production and dissolution. The present study utilizes grain‐size composition of pelagic sediments in order to trace spatial and temporal variability of carbonate sedimentation in the South Atlantic for the Holocene and Last Glacial Maximum (LGM, 19–23 cal kyr BP). A decrease in grain size (e.g. sand content, mean grain size of coarse carbonate silt) indicates increased carbonate dissolution as a result of increased fragmentation of calcareous microfossils. The spatial grain‐size pattern suggests a threshold water depth below which a gradual grain‐size decrease becomes increasingly rapid. This water depth is considered as the sedimentary lysocline. For the Holocene time slice, a constant, gradual decrease of foraminifer carbonate of about 5–10% per 1000 m water depth above the lysocline gives evidence for supra‐lysoclinal dissolution. The water depth of the lysocline for the Holocene is tied to the interface of North Atlantic Deep Water and Antarctic Bottom Water (AABW) (ca 4100 m). Submarine ridges which restrict intrusion of AABW into the Angola Basin cause an asymmetry in carbonate preservation across the Mid‐Atlantic Ridge. The lysocline was reconstructed at ca 3100 m for the LGM. These data suggest that the ca 1000 m rise of the lysocline eradicated the Holocene east–west asymmetry.
Revision of the genus Australimyza Harrison (Diptera: Australimyzidae)
Authors: BRAKE IRINA , MATHIS WAYNE N.
Published: December 2006

Abstract The species of Australimyza Harrison are revised and the saprophagous larvae are described for the first time. The phylogenetic analysis revealed two species groups and one ungrouped species. One species group is distributed in New Zealand and associated subantarctic islands; all other species occur in Australia. Four new species, A. glandulifera, A. kaikoura, A. mcalpinei and A. victoria, are described, A. anisotomae is synonymized with A. australensis and a neotype is designated for the latter species. A lectotype is designated for A. macquariensis.
Association between Messinian drainage network formation and major tectonic activity in the Marche Apennines (Italy)
Authors: Scarselli Sonia , Simpson Guy D. H. , Allen Philip A. , Minelli Giorgio , Gaudenzi Lorenzo
Published: December 2006

The Marche Apennines (Italy) offer an excellent opportunity to constrain the temporal and spatial relationships between drainage network formation and tectonic activity. Using a combination of field data, seismic lines and boreholes we show that the main deformation phase took place during the Messinian when the area, affected by the Messinian sea level drop, emerged and evolved from marine to continental conditions. The results highlight that during the Messinian emersion a drainage network developed contemporaneously with an increase in tectonic activity that could be related to sea level fall and river erosion. The present‐day river system, which is dominated by transverse rivers that cut straight across the tectonic grain, is located in older Messinian palaeovalleys, even though the region was subsequently covered by water until the late Pliocene–early Pleistocene.
A simple and reliable assay for detecting specific nucleotide sequences in plants using optical thin‐film biosensor chips
Authors: Bai Su‐Lan , Zhong Xiaobo , Ma Ligeng , Zheng Wenjie , Fan Liu‐Min , Wei Ning , Deng Xing Wang
Published: December 2006

Here we report the adaptation and optimization of an efficient, accurate and inexpensive assay that employs custom‐designed silicon‐based optical thin‐film biosensor chips to detect unique transgenes in genetically modified (GM) crops and SNP markers in model plant genomes. Briefly, aldehyde‐attached sequence‐specific single‐stranded oligonucleotide probes are arrayed and covalently attached to a hydrazine‐derivatized biosensor chip surface. Unique DNA sequences (or genes) are detected by hybridizing biotinylated PCR amplicons of the DNA sequences to probes on the chip surface. In the SNP assay, target sequences (PCR amplicons) are hybridized in the presence of a mixture of biotinylated detector probes and a thermostable DNA ligase. Only perfect matches between the probe and target sequences, but not those with even a single nucleotide mismatch, can be covalently fixed on the chip surface. In both cases, the presence of specific target sequences is signified by a color change on the chip surface (gold to blue/purple) after brief incubation with an anti‐biotin IgG horseradish peroxidase (HRP) to generate a precipitable product from an HRP substrate. Highly sensitive and accurate identification of PCR targets can be completed within 30 min. This assay is extremely robust, exhibits high sensitivity and specificity, and is flexible from low to high throughput and very economical. This technology can be customized for any nucleotide sequence‐based identification assay and widely applied in crop breeding, trait mapping, and other work requiring positive detection of specific nucleotide sequences.
Characterization of the centromere and peri‐centromere retrotransposons inBrassica rapaand their distribution in relatedBrassicaspecies
Authors: Lim Ki‐Byung , Yang Tae‐Jin , Hwang Yoon‐Jung , Kim Jung Sun , Park Jee‐Young , Kwon Soo‐Jin , Kim JinA , Choi Beom‐Soon , Lim Myung‐Ho , Jin Mina , Kim Ho‐Il , de Jong Hans , Bancroft Ian , Lim YongPyo , Park Beom‐Seok
Published: December 2006

We report the identification and characterization of the major repeats in the centromeric and peri‐centromeric heterochromatin ofBrassica rapa.The analysis involved the characterization of 88 629 bacterial artificial chromosomes (BAC) end sequences and the complete sequences of two BAC clones. We identified centromere‐specific retrotransposons ofBrassica(CRB) and various peri‐centromere‐specific retrotransposons (PCRBr). Three copies of the CRB were identified in one BAC clone as nested insertions within a tandem array of 24 copies of a 176 bp centromeric repeat, CentBr. A complex mosaic structure consisting of nine PCRBr elements and large blocks of 238 bp degenerate tandem repeats (TR238) were found in or near a derivative of 5S–25S rDNA sequences. The chromosomal positions of selected repeats were determined usingin situhybridization. These revealed that CRB is a major component of all centromeres in three diploidBrassicaspecies and their allotetraploid relatives. However, CentBr was not detected in the most distantly related of the diploid species analyzed,B. nigra. PCRBr and TR238 were found to be major components in the peri‐centromeric heterochromatin blocks of four chromosomes ofB. rapa.These repetitive elements were not identified inB. oleraceaorB. nigra, indicating that they are A‐genome‐specific.
The petunia restorer of fertility protein is part of a large mitochondrial complex that interacts with transcripts of the CMS‐associated locus
Authors: Gillman Jason D. , Bentolila Stéphane , Hanson Maureen R.
Published: December 2006

A class of nuclear genes termed ‘restorers of fertility’ (Rf) acts to suppress the expression of abnormal mitochondrial genes associated with cytoplasmic male sterility (CMS). In petunia, both the nuclear Rf gene and mitochondrial CMS‐associated gene have previously been identified. The CMS‐associated gene is an aberrant chimera in which portions of several mitochondrially encoded genes are fused to an unknown reading frame. The dominant Rf allele reduces the CMS‐associated protein to nearly undetectable levels and alters the RNA population derived from the CMS locus, but its mechanism of action has not been determined. The petuniaRf gene is a member of the pentatricopeptide repeat gene family (PPR), an unusually large gene family in Arabidopsis (approximately 450 genes) compared with yeast (five genes) and mammalian genomes (six genes). The PPR gene family has been implicated in the control of organelle gene expression. To gain insight into the mode of action of PPR genes, we generated transgenic petunia plants expressing a functional tagged version of Rf. Analysis of the restorer protein revealed that it is part of a soluble mitochondrial inner‐membrane‐associated, RNase‐sensitive high‐molecular‐weight protein complex. The complex is associated with mRNA derived from the CMS locus.
BIOMARKER: Phosphatidylethanol as a sensitive and specific biomarker—comparison with gamma‐glutamyl transpeptidase, mean corpuscular volume and carbohydrate‐deficient transferrin
Authors: Hartmann Susanne , Aradottir Steina , Graf Marc , Wiesbeck Gerhard , Lesch Otto , Ramskogler Katrin , Wolfersdorf Manfred , Alling Christer , Wurst Friedrich Martin
Published: December 2006

Phosphatidylethanol (PEth), a direct ethanol metabolite, is detectable in blood for more than 2 weeks after sustained ethanol intake. Our aim was to assess the usefulness of PEth [comparing sensitivity, specificity and the area under the curve (AUC)] as compared with carbohydrate‐deficient transferrin (CDT), gamma‐glutamyl transpeptidase (GGT) and mean corpuscular volume (MCV), calculating the results from sober patients against those from alcohol‐dependent patients during withdrawal. Fifty‐six alcohol‐dependent patients (ICD‐10 F 10.25) in detoxification, age 43 years, GGT 81 U/l, MCV 96.4 fl, %CDT 4.2, 1400 g ethanol intake in the last 7 days (median), were included in the study. Over the time of 1 year, 52 samples from 35 sober forensic psychiatric addicted in‐patients [age 34 years, GGT 16 U/l, MCV 91 fl, CDT 0.5 (median)] in a closed ward were drawn and used for comparison . PEth was measured in heparinized whole blood with a high‐performance liquid chromatography method. GGT, MCV and %CDT were measured using routine methods. A receiver operating characteristic curve analysis was carried out, with ‘current drinking status’ (sober/drinking) as the state variable and PEth, MCV, GGT and CDT as test variables. The resulting AUC was 0.974 (P < 0.0001, confidence interval 0.932–1.016) for PEth. At a cut‐off of 0.36 µmol/l, the sensitivity was 94.5% and specificity 100%. The AUC for CDT, GGT and MCV were 0.931, 0.894 and 0.883, respectively. A significant Spearman’s rank correlation was found between PEth and GGT (r = 0.739), CDT (r = 0.643), MVC (r = 0.639) and grams of ethanol consumed in the last 7 days (r = 0.802). Our data suggest that PEth has potential to be a sensitive and specific biomarker, having been found in previous studies to indicate longer lasting intake of higher amounts of alcohol.
PRECLINICAL STUDY: Ghrelin administration into tegmental areas stimulates locomotor activity and increases extracellular concentration of dopamine in the nucleus accumbens
Authors: Jerlhag Elisabet , Egecioglu Emil , Dickson Suzanne L. , Douhan Annika , Svensson Lennart , Engel Jörgen A.
Published: December 2006

Ghrelin stimulates appetite, increases food intake and causes adiposity by mechanisms that include direct actions on the brain. Previously, we showed that intracerebroventricular administration of ghrelin has stimulatory and dopamine‐enhancing properties. These effects of ghrelin are mediated via central nicotine receptors, suggesting that ghrelin can activate the acetylcholine–dopamine reward link. This reward link consists of cholinergic input from the laterodorsal tegmental area (LDTg) to the mesolimbic dopamine system that originates in the ventral tegmental area (VTA) and projects to the nucleus accumbens. Given that growth hormone secretagogue receptors (GHSR‐1A) are expressed in the VTA and LDTg, brain areas involved in reward, the present series of experiments were undertaken to examine the hypothesis that these regions may mediate the stimulatory and dopamine‐enhancing effects of ghrelin, by means of locomotor activity and in vivo microdialysis in freely moving mice. We found that local administration of ghrelin into the VTA (1 µg in 1 µl) induced an increase in locomotor activity and in the extracellular concentration of accumbal dopamine. In addition, local administration of ghrelin into the LDTg (1 µg in 1 µl) caused a locomotor stimulation and an increase in the extracellular levels of accumbal dopamine. Taken together, this indicates that ghrelin might, via activation of GHSR‐1A in the VTA and LDTg, stimulate the acetylcholine–dopamine reward link, implicating that ghrelin is a part of the neurochemical overlap between the reward systems and those that regulate energy balance.
PRECLINICAL STUDY: Differential effects of ethanol on IFN‐γ‐ and TNF‐α‐producing splenic T lymphocytes in a murine model of gram‐negative pneumonia
Authors: Lanzke Nadine , Kleinwächter Robin , Kerschischnik Saskia , Sargsyan Lilit , Groneberg David A. , Kamradt Thomas , Liesenfeld Oliver , Krenn Veit , Sander Michael , Spies Claudia
Published: December 2006

The incidence of bacterial pneumonia is increased in alcoholic patients. Alcohol consumption has been shown to impair cytokine production. Tumor necrosis factor alpha (TNF‐α) and interferon gamma (IFN‐γ) are critical for host defense against Klebsiella pneumoniae (K. pneumoniae). In order to examine the influence of alcohol on the immune response to infection, we investigated the frequency of TNF‐α and IFN‐γ produced by splenic T‐lymphocytes in a murine model of gram‐negative pneumonia initiated after 8 days of alcohol treatment. Thirty‐two Balb/c mice were pretreated with ethanol (3 mg/g body weight) or saline intraperitoneally over 8 days. On day 7 half of each group was administered K. pneumoniae. Mice were sacrificed 24 hours later to excise lungs and liver for histological assessment and spleens for cell isolation. IFN‐γ‐ and TNF‐α‐producing CD4+ and CD8+ lymphocytes were determined by FACS analysis. In mice with Klebsiella infection, the percentages of IFN‐γ‐producing CD4+ (P < 0.01) and CD8+ (P < 0.01) were significantly decreased, the percentages of TNF‐α‐producing CD4+ (P = 0.01) and CD8+ (P < 0.01) T cells were significantly elevated after alcohol treatment compared with mice with saline treatment. The histological assessment showed an aggravation of K. pneumoniae‐induced pneumonia in alcohol‐treated mice. Alcohol differentially affects IFN‐γ and TNF‐α production in Klebsiella‐infected mice. Both effects obviously led to a weakened immune response as seen by increased histological damage. This suggests a role of T cells in the increased susceptibility of the alcoholic host to nosocomial infection due to inadequate cytokine response.
IMAGING STUDY: Gray matter volume abnormalities and externalizing symptoms in subjects at high risk for alcohol dependence
Authors: Benegal Vivek , Antony George , Venkatasubramanian Ganesan , Jayakumar Peruvumba N.
Published: December 2006

Reduced right amygdala volumes have been reported in young, alcohol‐naïve subjects at high risk (HR) for alcohol dependence. The differences in brain morphometry have been associated with an excess of externalizing behaviors in these subjects. This may reflect a neurobiological vulnerability to alcohol dependence. Existing Magnetic Resonance Imaging (MRI) studies on these subjects have examined only a few, pre‐selected brain regions using the manual regions of interest (ROI) approach. MRI of HR subjects (n = 20) and age, sex, and handedness‐matched low‐risk (LR) subjects (n = 21) were analyzed using optimized voxel‐based morphometry and ROI approach. The externalizing symptoms of these subjects and their fathers were measured using the Semi‐Structured Assessment for the Genetics of Alcoholism. HR subjects had significantly smaller volumes of superior frontal, cingulate and parahippocampal gyri, amygdala, thalamus and cerebellum. These gray matter volumes correlated negatively with externalizing symptoms scores. Subjects at HR for alcoholism have reduced volumes of critical areas of brain gray matter, which are associated with increased externalizing symptoms. These represent key endophenotypes of alcoholism.
PRECLINICAL STUDY: Difference in magnitude of psychostimulant‐induced extracellular norepinephrine in the ventral tegmental area contributes to discrepant prefrontal dopamine outflow
Authors: Pan Wynn H. T. , Hsieh Min‐Chien , Wu Hsiao‐Hua , Lin Shi‐Kwang
Published: December 2006

The dopamine (DA) efflux in the medial prefrontal cortex (mPFC) can be modulated by the interaction between afferent norepinephrine (NE) and somatodendritic DA in the ventral tegmental area (VTA). However, it is unclear how locally administered amphetamine (AMPH) or cocaine in the VTA results in discrepant response of DA efflux in the mPFC. In this study, intra‐VTA infusion of AMPH (1000 µM) or cocaine (200 µM) in anesthetized rats was employed to study the concurrent profile of extracellular DA level in the VTA and mPFC. In addition, the extracellular NE levels during the intra‐VTA infusion of these two psychostimulants were analyzed to compare their effects on prefrontal DA efflux. During the intra‐VTA infusion of AMPH, both extracellular DA and NE increased significantly in the VTA (270 ± 12% and 819 ± 40%, respectively). Meanwhile, the DA efflux in the mPFC elevated significantly. During the intra‐VTA infusion of cocaine, the extracellular DA and NE in the VTA also increased (271 ± 21% and 150 ± 15%, respectively). However, the DA efflux decreased significantly in the mPFC. Noteworthy, the increase of extracellular NE in the VTA was much more robust via AMPH infusion, as compared with cocaine. It is suggested that AMPH and cocaine enhance the extracellular NE concentrations in the VTA in different magnitudes, which in turn contribute to discrepant profiles of distal DA efflux in the mPFC.
GENETIC STUDY: Significant impact of MTHFR C677T polymorphism on plasma homovanillic acid (HVA) levels among alcohol‐dependent patients
Authors: Lutz Ulrich C. , Batra Anil , Wiatr Gerlinde , Machicao Fausto , Kolb Werner , Maurer Sandra , Buchkremer Gerhard , Köhnke Michael D.
Published: December 2006

The enzyme 5,10‐methylenetetrahydrofolate reductase (MTHFR) synthesizes 5‐methyltetrahydrofolate. It plays a critical role in homocysteine metabolism. A high impact of MTHFR C677T polymorphism on plasma homocysteine levels has been observed among alcoholics. Recent studies indicate that homocysteine has toxic effects on dopaminergic neurons. Thus it lowers levels of homovanillic acid (HVA) in the striatal region in rats. Alcoholics had significantly lower plasma HVA concentrations compared with healthy controls. Aim of this study is to elucidate whether HVA plasma levels in alcoholics are influenced by MTHFR C677T polymorphism. A total of 142 alcohol‐dependent patients and 101 healthy controls were examined regarding plasma HVA concentration and MTHFR C677T genotype. Blood samples of alcoholics were obtained after a minimum of 22 days of abstinence. Among alcohol‐dependent patients MTHFR C677T polymorphism was significantly associated with plasma HVA levels: carriers of MTHFR C677T T‐allele had significantly lower HVA plasma levels compared with homozygote carriers of C‐allele: 11.9 ng/ml versus 14.4 ng/ml (χ2: 5.39; P = 0.02). In healthy control subjects plasma HVA levels did not differ significantly between MTHFR C677T T‐allele carriers and homozygote carriers of C‐allele: 15.1 ng/ml versus 15.3 ng/ml (χ2: 0.04; P = 0.82). The data suggest an influence of MTHFR C677T polymorphism on plasma HVA among alcohol‐dependent patients. This might be due to neurotoxic effects of homocysteine on the dopaminergic system or direct impairment of monoamine metabolism. Future studies should try to elucidate whether this effect is reversible during alcohol abstinence.
Does the patient‐held record improve continuity and related outcomes in cancer care: a systematic review
Authors: Gysels Marjolein , Richardson Alison , Higginson Irene J.
Published: December 2006

Objectives  To assess the effectiveness of the patient‐held record (PHR) in cancer care.

Background  Patients with cancer may receive care from different services resulting in gaps. A PHR could provide continuity and patient involvement in care.

Search strategy  Relevant literature was identified through five electronic databases (Medline, Embase, Cinahl, CCTR and CDSR) and hand searches.

Inclusion criteria  Patient‐held records in cancer care with the purpose of improving communication and information exchange between and within different levels of care and to promote continuity of care and patients’ involvement in their own care.

Data extraction and synthesis  Data extraction recorded characteristics of intervention, type of study and factors that contributed to methodological quality of individual studies. Data were then contrasted by setting, objectives, population, study design, outcome measures and changes in outcome, including knowledge, satisfaction, anxiety and depression. Methodological quality of randomized control trials and non‐experimental studies were assessed with separate standard grading scales.

Main results and conclusions  Seven randomized control trials and six non‐experimental studies were identified. Evaluations of the PHR have reached equivocal findings. Randomized trials found an absence of effect, non‐experimental evaluations shed light on the conditions for its successful use. Most patients welcomed introduction of a PHR. Main problems related to its suitability for different patient groups and the lack of agreement between patients and health professionals regarding its function. Further research is required to determine the conditions under which the PHR can realize its potential as a tool to promote continuity of care and patient participation.
Depressed patients’ perceptions of depression treatment decision‐making
Authors: Simon Daniela , Loh Andreas , Wills Celia E. , Härter Martin
Published: December 2006

Objective  Little is known about the feasibility and effects of patient‐clinician shared decision‐making (SDM) for depression treatment. Within a goal of informing the design of a SDM intervention, the objective of this study was to investigate depressed patients’ perceptions of the treatment decision‐making process with general practitioners (GPs).

Setting and participants  Data were gathered from a convenience sample of 40 depressed patients to understand key aspects of treatment decision‐making from the patient perspective. The sample varied in depression severity and type of setting in which treatment was sought.

Main variables studied  Semi‐structured interview questions focused on patients’ prior experiences with depression and treatment, perceptions of the treatment decision‐making process, and needs and expectations about treatment. Current depression severity was also assessed.

Results  Patient lack of insight regarding depression severity substantially delayed patient engagement in treatment seeking and decision‐making. Patients expected their GPs to be a first and main source of objective information and discussion about depression and treatment and to provide emotional support for decision‐making. Patients also identified needs for additional information about depression and its treatment, as well as concerns about certain aspects of treatment.

Conclusions  The depression treatment context has some aspects that differ from treatment decision‐making for other types of health conditions. SDM approaches for depression treatment should be adapted based on depression severity and patient‐identified needs.
A bird can't fly on one wing: patient views on waiting for hip and knee replacement surgery
Authors: Conner‐Spady Barbara L. , Johnston Geoffrey H. , Sanmartin Claudia , McGurran John J. , Noseworthy Tom W. ,   the Saskatchewan Surgical Care Network/Western Canada Waiting List Project Research and Evaluation Working Group Committee
Published: December 2006

Objectives  To obtain patients’ perspectives on acceptable waiting times for hip or knee replacement surgery.

Methods  A questionnaire with both open‐ and close‐ended items was mailed to 432 consecutive patients who had hip or knee replacement surgery 3–12 months previously in Saskatchewan, Canada. A content analysis was used to analyse the text data from the open‐ended questions.

Results  The sample of 303 (response rate 70%) was 59% female with a mean age of 70 years (SD 11). The median waiting time from the decision date to surgery was 17 weeks. Individuals who rated their waiting time very acceptable (48%) had a median waiting time of 13 weeks compared with a median waiting time of 22 weeks for those who rated it unacceptable (23%). The two most common determinants of acceptability were patient expectations and pain and its impact on patient quality of life. The median maximum acceptable waiting time was 13 weeks and median ideal waiting time, 8.6 weeks. Seventy‐nine per cent felt that those in greater need (higher severity) should go before them on the waiting list. Patient ratings of maximum acceptable waiting time were based on: pain and loss of mobility, time needed to prepare for surgery, and severity at the time of seeing the surgeon. In consideration of changing their surgeon to one with a shorter waiting list, 68% would not.

Conclusions  Patient views on waiting times are not only related to quality of life issues, but also to prior expectations and notions of fairness and priority. Understanding patient views on waiting for surgery has implications for better management of waiting times and experiences for joint replacement.
T lymphocytes expressing CCR3 are increased in allergic rhinitis compared with non‐allergic controls and following allergen immunotherapy
Authors: Francis J. N. , Lloyd C. M. , Sabroe I. , Durham S. R. , Till S. J.
Published: December 2006

Background:  In T cell‐associated allergic inflammation, homing of T‐helper 2 (Th2) effector cells to mucosal sites may be influenced by chemokine receptor expression. Previous studies have identified CCR3 and CCR4 as putative markers of Th2 cells and CCR5 and CXCR3 as markers of Th1 cells. The aim of this study was to assess differential chemokine receptor expression from symptomatic atopic grass pollen‐sensitive subjects, compared with patients on high‐dose allergen injection immunotherapy (IT) and healthy controls.

Methods:  We examined chemokine receptor expression (CCR1–7 and CXCR1–4) by flow cytometry of peripheral blood CD4+ and CD8+ T cells. We also depleted peripheral blood mononuclear cell (PBMC) populations of CCR3+ CD4+ cells by magnetic bead separation and cells were stimulated with grass pollen allergen for 6 days. Cytokine production was measured by enzyme‐linked immunosorbent assay.

Results:  On freshly isolated PBMC, atopic individuals exhibited increased numbers of CCR3+ CD4+ cells compared with normal controls (P < 0.01). CCR3 expression in IT patients was reduced compared with matched atopic rhinitic controls (P < 0.05) and comparable with that observed in normal subjects. Depletion of CCR3+ CD4+ cells from allergen‐stimulated PBMC cultures resulted in decreased interleukin (IL)‐5 production compared with whole CD4+ populations (P < 0.05). Freshly isolated CCR3+ CD4+ cells have significantly higher intracellular IL‐4 and lower IFN‐γ levels than CCR3− CD4+ cells. CD4+ T cells cultured from both peripheral cells and nasal biopsies demonstrated increased expression of CCR3 in the presence of IL‐4 (P < 0.05).

Conclusion:  CCR3+ CD4+ T cells are increased in allergic rhinitis, are reduced by allergen IT, have a Th2 phenotype and contribute to allergen‐specific responses. Strategies against CCR3+ T cells may be effective in human allergic diseases.
Relationship between matrix metalloproteinases MMP‐2, MMP‐9, tissue inhibitor of matrix metalloproteinases‐1 and IL‐5, IL‐8 in nasal polyps
Authors: Chen Y.‐S. , Langhammer T. , Westhofen M. , Lorenzen J.
Published: December 2006

Background:  Nasal polyps (NP), a subgroup of chronic rhinosinusitis, are characterized by interleukin 5 (IL‐5) mediated infiltration of eosinophils in sinus mucosa, leading to pseudostratified ciliated columnar epithelium, thickening of the epithelial basement membrane and tissue edema. Matrix metalloproteinases (MMP) constitute a large group of Zn2+ dependent endopeptidases with the ability to degrade extracellular matrix and are possibly responsible for the development of tissue edema in chronic sinusitis.

Objective:  The aim of this study was to determine the expression of MMP‐2, MMP‐9 and tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1) mRNA and to locate the distribution of MMP‐2, MMP‐9 and TIMP‐1 by immunohistochemistry in ethmoid sinus mucosa in NP. Furthermore the correlation between IL‐5 or IL‐8 and MMP‐2, MMP‐9 or TIMP‐1 is examined.

Methods:  Nasal polyps of 33 patients and 18 specimens of inferior turbinate mucosa were examined by real time RT‐PCR for MMP‐2, MMP‐9, TIMP‐1, IL‐5 and IL‐8 mRNA expression. Immunohistochemical labeling for MMP‐2, MMP‐9 and TIMP‐1 was performed.

Results:  Differences between both locations were detectable for MMP‐9 (P < 0.001) and IL‐5 (P = 0.003) but not for MMP‐2 (P = 0.278), TIMP‐1 (P = 0.515) and IL‐8 (P = 0.386). Correlation was detected only between TIMP‐1 and IL‐5 (r = 0.422, P = 0.014). Cytoplasmic staining of MMP‐2 was present in the apical part of the ciliated cells, submucosal glands and in smooth muscle cells. Matrix metalloproteinase‐9 was expressed in surface epithelium, in seromucous glands and in polymorphonuclear cells.

Conclusions:  Expression of MMP‐9 and IL‐5 mRNA are associated with NP. The correlation between IL‐5 and TIMP‐1 indicates the role of TIMP‐1 in maintaining the homeostasis in NP.
Relevance of the determination of serum‐specific IgE antibodies in the diagnosis of immediate β‐lactam allergy
Authors: Fontaine C. , Mayorga C. , Bousquet P. J. , Arnoux B. , Torres M.‐J. , Blanca M. , Demoly P.
Published: December 2006

Background:  Allergic reactions to β‐lactams are the most frequent cause of adverse drug reactions mediated by specific immunologic mechanisms. They can be explored by in vivo and/or in vitro tests. The measurement of serum‐specific immunoglobulin E (IgE) presents several advantages: safety, simplicity, and availability to nonallergologist physicians.

Objectives:  To establish the diagnostic value of specific IgE determination in the diagnosis procedure of immediate β‐lactam allergy.

Methods:  The in vitro determination of β‐lactam‐specific IgE antibodies was compared in three well‐defined groups of patients (n = 45): one with negative skin tests and a positive drug provocation test, another with positive skin tests, and a third control exposed population with good tolerance. Two techniques were used: the CAP‐FEIA system (Phadia®) commercially available and a homemade radioallergosorbent test (RAST).

Results:  The specificity of CAP‐FEIA ranged from 83.3% to 100% and sensitivity from 0% to 25% depending on initial clinical manifestations. The specificity of RAST was between 66.7% and 83.3% and sensitivity 42.9% and 75%. In the subgroup of patients with an anaphylactic shock and negative skin tests, the sensitivity and specificity of RAST were 75%. Positive and negative predictive values were 45.5% and 77.1% with CAP‐FEIA and 38.5% and 81.5% with RAST, respectively.

Conclusion:  These results indicate that, although the specificity of β‐lactam‐specific IgE measurement is good, sensitivity is low. Immunoglobulin E measurement should be limited to patients with a clinical history of anaphylactic shock and negative skin tests in order to avoid a drug provocation test. More sensitive assays should be developed.
Distinct expression and inhibitory function of B and T lymphocyte attenuator on human T cells
Authors: Wang X.‐F. , Chen Y.‐J. , Wang Q. , Ge Y. , Dai Q. , Yang K.‐F. , Fang‐Xie  , Zhou Y.‐H. , Hu Y.‐M. , Mao Y.‐X. , Zhang X.‐G.
Published: December 2006

B and T lymphocyte attenuator (BTLA) has been recently identified as a new inhibitory receptor of the CD28 superfamily, with similarities to cytotoxic T lymphocyte activation antigen (CTLA)‐4 and programmed death (PD)‐1. Engagement of BTLA on T lymphocytes can profoundly reduce the T cell receptor (TCR)‐mediated activation. In this study, we generated four monoclonal antibodies (mAbs) against human BTLA. Using the produced mAb 8H9, the BTLA molecule was found to distinctly express on many subgroups of immunocytes and show a regulatory expression, which was in accordance with its unique ligand herpes virus entry mediator (HVEM) in the process of T cell activation. In addition, the expression of BTLA was increased in the CD4+ and CD8+ T cells of pleural fluid in lung cancer patients. Furthermore, we showed that the BTLA‐induced negative signals could be triggered by mAb 7D7. Cross‐linking of BTLA with mAb 7D7 suppressed T lymphocyte proliferation, downregulated the expression of T cell activation marker CD25, and inhibited the production of interferon (IFN)‐γ, interleukin (IL)‐2, IL‐4, and IL‐10.
CD31/PECAM‐1 genotyping and haplotype analyses show population diversity
Authors: Robbins F.‐M. , Hartzman R. J.
Published: December 2006

Using direct sequencing of complementary DNA products, the sequences of human CD31 from exon 1 through exon 16 of 179 individuals (139 unrelated) were systematically examined. Of the 14 biallelic single nucleotide polymorphic sites detected, 7 polymorphic sites involved amino acid substitution. These 14 polymorphic sites yielded 18 observed CD31 alleles and 9 predicted CD31 polypeptide sequences. Based on molecular haplotyping and family pedigree analysis, linkage disequilibrium among some single nucleotide polymorphic sites was observed. Single nucleotide polymorphism frequencies between populations were also measured using dot‐blot hybridization with DNA or peptide nucleic acid probes.
Expression of APOBEC3G in kidney cells
Authors: Komohara Y. , Suekane S. , Noguchi M. , Matsuoka K. , Yamada A. , Itoh K.
Published: December 2006

The apolipoprotein B mRNA‐editing enzyme, catalytic polypeptide‐like 3G (APOBEC3G), a member of the APOBEC family possessing DNA mutator activity through cytosine deamination, is reported to play an important role in host defense against infections such as those of hepatitis B virus and human immunodeficiency virus. Here, we examined the expression of APOBEC3G in human kidney cells to better understand its biological role against infection. APOBEC3G was immunohistochemically detectable in kidney mesangial cells and also to some extent in kidney epithelial tubular cells. In addition, overexpression of APOBEC3G was shown in renal carcinoma tissues and cell lines. APOBEC3G expression was upregulated by inflammatory cytokines, such as interferon, interleukin‐6, and tumor necrosis factor. These results may provide new insight into the role of APOBEC3G in host defense against viral infection and cancer.
Expression of Toll‐like receptors in chronic hepatitis C virus infection
Authors: Sato Ken , Ishikawa Tetsuya , Okumura Akihiko , Yamauchi Taeko , Sato Sayaka , Ayada Minoru , Matsumoto Eiji , Hotta Naoki , Oohashi Tomohiko , Fukuzawa Yoshitaka , Kakumu Shinichi
Published: December 2006

Background:  Toll‐like receptors (TLRs) are involved in innate immunity. Certain viruses interact with TLRs and mediate antiviral effects as well as immune responses. The aim of this study was to investigate the effect of TLRs on pathogenesis in hepatitis C virus (HCV)‐infected patients.

Methods:  Peripheral blood mononuclear cells (PBMC) and CD14+ (monocytes) or CD14– cells from 25 patients with chronic liver disease and 15 healthy subjects were studied for expression of TLRs 2–9 and cytokines of extracted RNA using real‐time PCR. Then TLR expression was examined in HepG2 cells transfected with entire or parts (core–NS3, NS3–NS5B) of the HCV open reading frame. TLR expression was calculated as the relative mRNA levels.

Results:  Expression of TLRs 4, 7 and 8 in CD14+ cells of PBMC was increased in patients. Levels of tumor necrosis factor (TNF)‐α, interleukin (IL)‐6 and IL‐12 p35 for PBMC were also increased in patients. When PBMC were incubated with HCV core protein, enhancement of TLR2 expression and suppression of TLR4 and TLR7 were noted in patients. Similar alteration of TLRs expression was observed in controls. Among HepG2 transfectants, only TLR3 expression was changed; it was suppressed in entire gene transfectant and enhanced in core–NS3 transfectant. Expression of some proteins related to the TLR signaling pathway was suppressed in the entire gene transfectant.

Conclusions:  The results suggest a correlation between expression levels of TLRs and cytokines, and chronic HCV infection. TLR3 recognizes double‐stranded RNA and induces type 1 interferon synthesis. Collectively, suppressed expression of TLR3 in cells transfected with entire HCV may be responsible for continuous HCV infection, although a part of the HCV gene enhances its expression.