bluuebunny/crossref_metadata_2025 huggingface dataset:
Financial Derivatives: The New Gold?
Authors: Bryan Dick , Rafferty Michael
Published: July 2006

For many economists, the current period of globalized finance lacks an apparent material anchor such as gold once was. This paper contends that in an important way the anchoring function is currently undertaken by financial derivatives. These contracts are not just about risk management and speculation. Critically also, they are commensurating the values of different financial assets, including different currencies. In so doing they can be seen to be imposing a competitive benchmark into the management of financial assets. Indeed, via this benchmarking, derivatives bring the management of labour to the fore in the stabilization of global financial markets, just as it was at the centre of adjustments under the Gold Standard in the nineteenth century. The paper explains this role of derivatives at the centre of contemporary global finance via a comparison with the way in which gold anchored the globalization of the late nineteenth century.
Manganese enriched diffusion layers on NiAl alloy
Authors: Bartuška P. , Lašek J. , Paidar V.
Published: July 2006

Materials based on Ni–Al intermetallics are prospective high temperature materials. Properties of these intermetallics can often be improved by surface diffusion layers enriched by various metals. In this contribution results of a study are presented about microstructure and composition of Mn enriched diffusion layers on a NiAl alloy.

A pure Mn plate was annealed at 900°C for 4 h in contact with a prism of the NiAl phase. The ordered B2-NiAl ( β′) phase can absorb only a few per cent of manganese without structural changes. When absorbing more Mn, the ordrerd B2-NiAl phase transforms into the disordered bcc β′ NiMnAl phase forming the first structurally different (narrow) layer on NiAl. Its Mn content increases from 25 wt-% (in contact with B2-NiAl phase) up to 35 wt-% across this homogeneous layer. Higher average Mn content in the next layer manifests in precipitation of β-Mn particles (containing several per cent of Ni and Al) from the β″ matrix. Owing to diffusion of Ni and Al into the original Mn plate the β″ NiMnAl precipitates are formed in the Mn matrix containing several per cent of Ni and Al (when studying microstructure and composition at room temperature after annealing).
Pulsed electrode deposition of superhard coatings on steel substrates: Microstructural and chemical study
Authors: Constantino M. E. , Campillo B. , Staia M. H. , Serna S. , Juárez-Islas J. , Sudarshan T. S.
Published: July 2006

Titanium carbide (TiC) coatings have been deposited on steel using the pulsed electrode deposition (PES) technique. Different experimental parametric conditions were used in the deposition process. Microstructural and chemical characterisations of the coatings were performed using electron microscopy and X-ray diffraction techniques. Pulsed electrode technique produced hard coatings, which are commonly defect and crack free. Small TiC and Fe3C particles were randomly distributed in a Fe matrix without any preferred crystallographic orientation. The relationships between the microstructural properties and the deposition processing conditions were also explored.
Plasma nitriding design for aluminium and aluminium alloys
Authors: Visuttipitukul P. , Aizawa T.
Published: July 2006

Plasma nitriding for aluminium and aluminium alloys is a promising processing to improve the wear resistance for automotive parts. Normal plasma nitriding is characterised by three processes: presputtering, aluminium nitride nucleation and nitrided layer growth processes. N2+ presputtering is used to effectively eliminate the preexisting oxide films of Al2O3, covering the surface of aluminium matrix. Relatively long incubation time is required for nucleation process to form AlN islands or nodules on its surface. In addition, formation rate becomes very slow owing to low nitrogen diffusion coefficient in the nitrided layer. Physical and chemical modification methods to this normal nitriding processing are proposed to accelerate the formation rate of nitrided layer. Refinement of grain size in the aluminium matrix increases the formation rate by enlarging grain boundary area as a diffusion path. Crystallographic coherency between TiN and AlN reflects on enhancement of nucleation process by coformation of TiN with AlN. Standing on the nitriding design by physical and chemical modification of inner nitriding mechanism, an alternative plasma nitriding is proposed as the third processing for copper bearing aluminium alloys. In this processing, reduction of duration for nucleation and acceleration of growth rate are attained with the aid of the precipitate, Al2Cu. Crystallographic coherency between AlN and Al2Cu is effective to enhance the formation of AlN nodules and islands. Solid state reaction between Al2Cu and penetrating nitrogen is also significant to form the fine interfacial boundaries as a nitrogen diffusion path and to accelerate the formation rate of nitrided layer.
Enhanced VWF biosynthesis and elevated plasma VWF due to a natural variant in the murine Vwf gene
Authors: Lemmerhirt Heidi L. , Shavit Jordan A. , Levy Gallia G. , Cole Suzanne M. , Long Jeffrey C. , Ginsburg David
Published: July 2006

Both genetic and environmental influences contribute to the wide variation in plasma von Willebrand factor (VWF) levels observed in humans. Inbred mouse strains also have highly variable plasma VWF levels, providing a convenient model in which to study genetic modifiers of VWF. Previously, we identified a major modifier of VWF levels in the mouse (Mvwf1) as a regulatory mutation in murine Galgt2. We now report the identification of an additional murine VWF modifier (Mvwf2). Mvwf2 accounts for approximately 16% of the 8-fold plasma VWF variation (or ∼ 25% of the genetic variation) observed between the A/J and CASA/RkJ strains and maps to the murine Vwf gene itself. Twenty SNPs were identified within the coding regions of the A/J and CASA/RkJ Vwf alleles, and in vitro analysis of recombinant VWF demonstrated that a single SNP (+7970G>A) and the associated nonsynonymous amino acid change (R2657Q) confers a significant increase in VWF biosynthesis from the CASA/RkJ Vwf allele. This change appears to represent a unique gain of function that likely explains the mechanism of Mvwf2 in vivo. The identification of a natural Vwf gene variant among inbred mice affecting biosynthesis suggests that similar genetic variation may contribute to the wide range of VWF levels observed in humans.
Diurnal ventilationviamouthpiece: survival in end-stage Duchenne patients
Authors: Toussaint M. , Steens M. , Wasteels G. , Soudon P.
Published: July 2006

The present study aimed to assess the impact of diurnal mouthpiece intermittent positive pressure ventilation (MIPPV) as the extension of the nasal intermittent positive pressure ventilation (NIPPV) in Duchenne muscular dystrophy (DMD). In total, 42 DMD patients aged 15–33 yrs, normocapnic at night with NIPPV and receiving MIPPV since end-diurnal hypercapnia, were studied.

Transcutaneous CO2tension (Pt,CO2) was prospectively monitored at the end of the day, before and after MIPPV initiation. Vital capacity (VC), breathing pattern and maximal inspiratory strength were measured. Patients were asked to score the presence (1 point) or absence (0 point) of seven respiratory-linked symptoms before and after MIPPV establishment.

Survival rates reached 88, 77, 58 and 51% after 1, 3, 5 and 7 yrs, respectively. The mean survival rate was 31 yrs. VC stabilised during 5 yrs with MIPPV. Symptom scores significantly decreased andPt,CO2normalised during the day (8.17±2.22 to 5.78±0.73 kPa). No accident and minor side-effects were observed in this 184 cumulated patient-yrs study.

In conclusion, daytime mouthpiece ventilation is safe, prolongs survival and stabilises vital capacity in Duchenne muscular dystrophy patients. It is recommended on the condition that patients are equipped with a self-supporting harness.
Relationship between tracheotomy and ventilator-associated pneumonia: a case–control study
Authors: Nseir S. , Di Pompeo C. , Jozefowicz E. , Cavestri B. , Brisson H. , Nyunga M. , Soubrier S. , Durocher A.
Published: July 2006

The aim of the present study was to determine the relationship between tracheotomy and ventilator-associated pneumonia (VAP).

The study used a retrospective case–control study design based on prospective data. All nontrauma immunocompetent patients, intubated and ventilated for >7 days, were eligible for inclusion in the study. A diagnosis of VAP was based on clinical, radiographical and microbiological criteria. Four matching criteria were used, including duration of mechanical ventilation (MV). The indication and timing of tracheotomy were at the discretion of attending physicians. Univariate and multivariate analyses were performed to determine risk factors for VAP in cases (patients with tracheotomy) and controls (patients without tracheotomy).

In total, 1,402 patients were eligible for inclusion. Surgical tracheotomy was performed in 226 (16%) patients and matching was successful for 177 (78%). The rate of VAP (22versus14 VAP episodes·1,000 MV-days−1) was significantly higher in controls than in cases. The rate of VAP after tracheotomy in cases, or after the corresponding day of MV in controls, was also significantly higher in control than in case patients (9.2versus4.8 VAP episodes·1,000 MV-days−1). In multivariate analysis, neurological failure (odds ratio (95% confidence interval) 2.7 (1.3–5)), antibiotic treatment (2.1 (1.1–3.2)) and tracheotomy (0.18 (0.1–0.3)) were associated with VAP.

In summary, the present study demonstrates that tracheotomy is independently associated with decreased risk for ventilator-associated pneumonia.
Breath condenser coatings affect measurement of biomarkers in exhaled breath condensate
Authors: Rosias P. P. , Robroeks C. M. , Niemarkt H. J. , Kester A. D. , Vernooy J. H. , Suykerbuyk J. , Teunissen J. , Heynens J. , Hendriks H. J. , Jöbsis Q. , Dompeling E.
Published: July 2006

Exhaled breath condensate collection is not yet standardised and biomarker measurements are often close to lower detection limits. In the current study, it was hypothesised that adhesive properties of different condenser coatings interfere with measurements of eicosanoids and proteins in breath condensate.

In vitro,condensate was derived from a collection model using two test solutions (8-isoprostane and albumin) and five condenser coatings (silicone, glass, aluminium, polypropylene and Teflon).In vivo, condensate was collected using these five coatings and the EcoScreen® condenser to measure 8-isoprostane, and three coatings (silicone, glass, EcoScreen®) to measure albumin.

In vitro, silicone and glass coatings had significantly higher albumin recovery compared with the other coatings. A similar trend was observed for 8-isoprostane recovery.In vivo,median (interquartile range) 8-isoprostane concentrations were significantly higher using silicone (9.2 (18.8) pg·mL-1) or glass (3.0 (4.5) pg·mL-1) coating, compared with aluminium (0.5 (2.4) pg·mL-1), polypropylene (0.5 (0.5) pg·mL-1), Teflon (0.5 (0.0) pg·mL-1), and EcoScreen® (0.5 (2.0) pg·mL-1). Albuminin vivowas mainly detectable using glass coating.

In conclusion, a condenser with silicone or glass coating is more efficient for measurement of 8-isoprostane or albumin in exhaled breath condensate, than EcoScreen®, aluminium, polypropylene or Teflon. Guidelines for exhaled breath condensate standardisation should include the most valid condenser coating to measure a specific biomarker.
Home spirometry and asthma severity in children
Authors: Brouwer A. F. J. , Roorda R. J. , Brand P. L. P.
Published: July 2006

The usefulness of peak expiratory flow monitoring is disputed because of the unreliability of written peak flow diaries. The aim of the present study was to examine the relationship of peak flow and forced expiratory volume in one second (FEV1) variation to other estimates of asthma severity in children, using an electronic home spirometer with automatic data storage.

Over a 3-month period, 36 children with mild-to-moderate persistent asthma recorded peak flow and FEV1electronically twice daily and noted an asthma severity score in a written diary. Bronchial responsiveness was assessed at the beginning and bronchodilator response and asthma-specific quality of life at the end of the study.

Variations in peak flow correlated significantly but weakly to bronchial responsiveness and bronchodilator response, but not to the asthma severity score or quality-of-life scores. Within-individual correlations between asthma severity scores and home spirometry indices and between peak flow and FEV1were highly variable.

In conclusion, variations in peak flow and forced expiratory volume in one second, obtained by home spirometry, show poor concordance with other indices of disease activity and with each other. This limits the usefulness of home spirometry in childhood asthma.
Human bronchial fibroblasts express the 5-lipoxygenase pathway
Authors: James Anna J , Penrose John F , Cazaly Angelica M , Holgate Stephen T , Sampson Anthony P
Published: July 2006

Background

Fibroblasts are implicated in sub-epithelial fibrosis in remodeled asthmatic airways and contribute to airway inflammation by releasing cytokines and other mediators. Fibroblast activity is influenced by members of the leukotriene family of bronchoconstrictor and inflammatory mediators, but it is not known whether human bronchial fibroblasts can synthesize leukotrienes.

Methods

The expression of leukotriene biosynthetic enzymes and receptors was investigated in primary fibroblasts from the bronchi of normal and asthmatic adult subjects using RT-PCR, Western blotting, immunocytochemistry and flow cytometry.

Results

These techniques revealed that human bronchial fibroblasts from both subject groups constitutively express 5-lipoxygenase, its activating protein FLAP, the terminal enzymes leukotriene A4hydrolase and leukotriene C4synthase, and receptors for leukotriene B4(BLT1) and cysteinyl-leukotrienes (CysLT1). Human bronchial fibroblasts generated immunoreactive leukotriene B4and cysteinyl-leukotrienes spontaneously and in increased amounts after calcium-dependent activation. Flow cytometry showed that human bronchial fibroblasts transformed to a myofibroblast-like phenotype by culture with transforming growth factor-β1expressed 320–400% more immunofluorescence for leukotriene C4synthase and CysLT1receptors, with 60–80% reductions in leukotriene A4hydrolase and BLT1 receptors.

Conclusion

These results indicate that human bronchial fibroblasts may not only respond to exogenous leukotrienes but also generate leukotrienes implicated in narrowing, inflammation and remodeling of the asthmatic airway.
Genomes of Helicobacter pylori from native Peruvians suggest admixture of ancestral and modern lineages and reveal a western type cag-pathogenicity island
Authors: Devi S Manjulata , Ahmed Irshad , Khan Aleem A , Rahman Syed Asad , Alvi Ayesha , Sechi Leonardo A , Ahmed Niyaz
Published: July 2006

Background

Helicobacter pylori is presumed to be co-evolved with its human host and is a highly diverse gastric pathogen at genetic levels. Ancient origins of H. pylori in the New World are still debatable. It is not clear how different waves of human migrations in South America contributed to the evolution of strain diversity of H. pylori. The objective of our 'phylogeographic' study was to gain fresh insights into these issues through mapping genetic origins of H. pylori of native Peruvians (of Amerindian ancestry) and their genomic comparison with isolates from Spain, and Japan.

Results

For this purpose, we attempted to dissect genetic identity of strains by fluorescent amplified fragment length polymorphism (FAFLP) analysis, multilocus sequence typing (MLST) of the 7 housekeeping genes (atp A, efp, ure I, ppa, mut Y, trp C, yph C) and the sequence analyses of the bab B adhesin and oip A genes. The whole cag pathogenicity-island (cag PAI) from these strains was analyzed using PCR and the geographic type of cag A phosphorylation motif EPIYA was determined by gene sequencing. We observed that while European genotype (hp-Europe) predominates in native Peruvian strains, approximately 20% of these strains represent a sub-population with an Amerindian ancestry (hsp-Amerind). All of these strains however, irrespective of their ancestral affiliation harbored a complete, 'western' type cag PAI and the motifs surrounding it. This indicates a possible acquisition of cag PAI by the hsp-Amerind strains from the European strains, during decades of co-colonization.

Conclusion

Our observations suggest presence of ancestral H. pylori (hsp-Amerind) in Peruvian Amerindians which possibly managed to survive and compete against the Spanish strains that arrived to the New World about 500 years ago. We suggest that this might have happened after native Peruvian H. pylori strains acquired cag PAI sequences, either by new acquisition in cag-negative strains or by recombination in cag positive Amerindian strains.
A comparison of breastfeeding among Han, Uygur and other ethnic groups in Xinjiang, PR China
Authors: Xu Fenglian , Binns Colin , Nazi Guli , Shi Lin , Zhao Yun , Lee Andy
Published: July 2006

Background

Breastfeeding is an important factor in infant health and there have been no previous studies of breastfeeding practices in the different ethnic groups of this region of China. We aimed to compare breastfeeding rates and duration between Han, Uygur and other ethnic groups living in Xinjiang, PR China.

Methods

A longitudinal study of infant feeding practices was undertaken using a sample that included different ethnic groups. Mothers were randomly recruited and interviewed in hospitals and after discharge were contacted in person or by telephone at approximately monthly intervals to obtain details of infant feeding practices. Setting: Xinjiang Uygur Autonomous Region, PR China. Subjects: A total of1219 mothers (578 Han, 360 Uygur and 281 'other minority' mothers) who delivered babies during 2003 and 2004 were interviewed in five hospitals or institutes located in both urban and rural areas.

Results

'Any breastfeeding' rates in Han, Uygur and 'other minority' groups at discharge were 88.5 %, 94.3 % and 97.1 % respectively, and at six months 76.7 %, 54.7 % and 87.6 % respectively. While 'exclusive breastfeeding' rates in the Han, Uygur and 'other minority' groups at discharge were 78.0 %, 34.5 % and 83.1 % respectively, at six months they had fallen to 4.8 %, 0.4 % and 16.8 % respectively. The median duration of 'Exclusive breastfeeding' of Han, Uygur and 'other minority' babies were 1.5, 0.1 and 2.5 months respectively. The Uygur babies were least likely to be 'exclusive breastfed'.

Conclusion

Uygur babies were least likely to be 'exclusive breastfed' and continued to 'any breastfeed' at six month. The 'any breastfeeding' rates in the Han group were lower in the first four months. An education program focused on breastfeeding continuation and exclusive breastfeeding is necessary in Xinjiang, especially for Uygur and Han ethnic groups.
Is occupational exposure to solvents associated with an increased risk for developing systemic scleroderma?
Authors: Kütting Birgitta , Uter Wolfgang , Drexler Hans
Published: July 2006

Background

Our study was aimed to investigate in a German collective if there are any hints for an increased occupational or environmental risk to develop systemic sclerosis, especially, focussing on work-related exposure to solvents. Moreover, we tried to evaluate the feasibility of a sampling method addressing support groups.

Methods

A standardised questionnaire was published in two journals subscribed by members of two different support groups and all members were asked to complete the questionnaire and to return it anonymously. The subjects were not informed on the scientific hypotheses, nor did they know who of them belonged to the case group (scleroderma) or to the control group (multiple sclerosis).

Results

175 questionnaires could be included in the statistical analysis. As expected, a female predominance was in our collective. In the male subpopulation, the occupational exposure to solvents was higher in the case group than in the control-group (70% versus 45.8%).

Based only on the male subgroup, a tendency for an association between occupational exposure to solvents and the risk to develop systemic sclerosis was found.

Conclusion

According to our experience in this case-control-study exposure misclassification, qualitative or quantitative, was an eminent problem. Within such a setting, it is generally very difficult to establish an exact dose-response relationship due to incomplete, imprecise or missing data concerning duration of exposure, frequency of use and kind of solvent. Additionally, a well-known problem in studies based on self-reported questionnaires is the so-called volunteer bias. Unfortunately, but similar to other studies assessing epidemiologic factors in such a rare disease, our study was of limited power, especially in the subgroups defined by gender.
Environmental risk factors differ between rheumatoid arthritis with and without auto-antibodies against cyclic citrullinated peptides
Authors: Pedersen Merete , Jacobsen Søren , Klarlund Mette , Pedersen Bo V , Wiik Allan , Wohlfahrt Jan , Frisch Morten
Published: July 2006

The aim of this study was to evaluate new and previously hypothesised non-genetic risk factors for serologic subtypes of rheumatoid arthritis (RA) defined by the presence or absence of auto-antibodies to cyclic citrullinated peptides (CCP). In a national case-control study, we included 515 patients recently diagnosed with RA according to the American College of Rheumatology 1987 classification criteria and 769 gender- and age-matched population controls. Telephone interviews provided information about non-genetic exposures, and serum samples for patients were tested for anti-CCP-antibodies. Associations between exposure variables and risk of anti-CCP-positive and anti-CCP-negative RA were evaluated using logistic regression. A series of RA subtype-specific risk factors were identified. Tobacco smoking (odds ratio [OR] = 1.65; 95% confidence interval: 1.03–2.64, for >20 versus 0 pack-years) was selectively associated with risk of anti-CCP-positive RA, whereas alcohol consumption exhibited an inverse dose-response association with this RA subtype (OR = 1.98, 1.22–3.19, for 0 versus >0–5 drinks per week). Furthermore, coffee consumption (OR = 2.18; 1.07–4.42, for >10 versus 0 cups per day), ever use of oral contraceptives (OR = 1.65; 1.06–2.57) and having a first-degree relative with schizophrenia (OR = 4.18; 1.54–11.3) appeared more strongly associated with risk of anti-CCP-positive RA. Obesity was selectively associated with risk of anti-CCP-negative RA, with obese individuals being at more than 3-fold increased risk of this subtype compared with normal-weight individuals (OR = 3.45; 1.73–6.87). Age at menarche was the only examined factor that was significantly associated with both serologic subtypes of RA (p-trends = 0.01); women with menarche at age ≥ 15 years had about twice the risk of either RA subtype compared with women with menarche at age ≤ 12 years. Major differences in risk factor profiles suggest distinct etiologies for anti-CCP-positive and anti-CCP-negative RA.
Prostaglandin E2 synthesis in cartilage explants under compression: mPGES-1 is a mechanosensitive gene
Authors: Gosset Marjolaine , Berenbaum Francis , Levy Arlette , Pigenet Audrey , Thirion Sylvie , Saffar Jean-Louis , Jacques Claire
Published: July 2006

Knee osteoarthritis (OA) results, at least in part, from overloading and inflammation leading to cartilage degradation. Prostaglandin E2 (PGE2) is one of the main catabolic factors involved in OA. Its synthesis is the result of cyclooxygenase (COX) and prostaglandin E synthase (PGES) activities whereas NAD+-dependent 15 hydroxy prostaglandin dehydrogenase (15-PGDH) is the key enzyme implicated in the catabolism of PGE2. For both COX and PGES, three isoforms have been described: in cartilage, COX-1 and cytosolic PGES are constitutively expressed whereas COX-2 and microsomal PGES type 1 (mPGES-1) are inducible in an inflammatory context. COX-3 (a variant of COX-1) and mPGES-2 have been recently cloned but little is known about their expression and regulation in cartilage, as is also the case for 15-PGDH. We investigated the regulation of the genes encoding COX and PGES isoforms during mechanical stress applied to cartilage explants. Mouse cartilage explants were subjected to compression (0.5 Hz, 1 MPa) for 2 to 24 hours. After determination of the amount of PGE2 released in the media (enzyme immunoassay), mRNA and proteins were extracted directly from the cartilage explants and analyzed by real-time RT-PCR and western blotting respectively. Mechanical compression of cartilage explants significantly increased PGE2 production in a time-dependent manner. This was not due to the synthesis of IL-1, since pretreatment with interleukin 1 receptor antagonist (IL1-Ra) did not alter the PGE2 synthesis. Interestingly, COX-2 and mPGES-1 mRNA expression significantly increased after 2 hours, in parallel with protein expression, whereas COX-3 and mPGES-2 mRNA expression was not modified. Moreover, we observed a delayed overexpression of 15-PGDH just before the decline of PGE2 synthesis after 18 hours, suggesting that PGE2 synthesis could be altered by the induction of 15-PGDH expression. We conclude that, along with COX-2, dynamic compression induces mPGES-1 mRNA and protein expression in cartilage explants. Thus, the mechanosensitive mPGES-1 enzyme represents a potential therapeutic target in osteoarthritis.
Quantification and regulation of organic and mineral sedimentation in a late-Holocene floodplain as a result of climatic and human impacts (Taligny marsh, Parisian Basin, France)
Authors: Macaire Jean-Jacques , Bernard Jacques , Di-Giovanni Christian , Hinschberger Florent , Limondin-Lozouet Nicole , Visset Lionel
Published: July 2006

Quantification in grams per metres squared per year of the sediment accumulation in a flood plain (‘marsh’) located in the southwestern Parisian basin showed that there is no close relationship between the accumulation of organic matter (OM) and mineral matter (MM) during the late Holocene, and provided an accurate view of the distinct yield and storage conditions of both sediment components. Endogenic OM accumulation in peaty sediments is not related to the climate but to felling of the alder forest and its substitution by Cyperaceae and paludal taxa in the marsh (Iron Age and Middle Ages). MM accumulation expresses mainly the sediment yield on the slopes, determined by landuse. During an initial phase (from the late Neolithic to the early Middle Ages), land-use change from crop cultivation to pastureland, possibly related to climate deterioration, led to a decrease in the sediment yield. During a second phase, since the early Middle Ages, the considerable development of crop cultivation over pasturing, even during periods of climate deterioration (such as the ‘Little Ice Age’), led to a sharp increase in sediment yield. However, although sediment yield was high, the hydrodynamics in the fen did not favour particle retention. Thus, since the Neolithic, yield and storage of OM and MM sediment have been marked by human activities, initially with high climatic stress, but since the Middle Ages without significant climatic stress.
Late-Holocene environment and climatic changes in Ameralik Fjord, southwest Greenland: evidence from the sedimentary record
Authors: Møller H. S. , Jensen K. G. , Kuijpers A. , Aagaard-Sørensen S. , Seidenkrantz M.-S. , Prins M. , Endler R. , Mikkelsen N.
Published: July 2006

Sedimentological and geochemical (XRF) data together with information from diatom and benthic foraminiferal records of a 3.5 m long gravity core from Ameralik Fjord, southern West Greenland, is used for reconstructing late-Holocene environmental changes in this area. The changes are linked to large-scale North Atlantic ocean and climate variability. AMS 14C-dating of benthic foraminifera indicates that the sediment core records the last 4400 years and covers the termination of the Holocene Thermal Maximum (HTM). The late HTM (4.4-3.2 ka BP) is characterized by high accumulation rates of fine (silty) sediments related to strong meltwater discharge from the Inland Ice. The HTM benthic foraminiferal fauna demonstrates the presence of well-ventilated, saline bottom water originating from inflow of subsurface West Greenland Current water of Atlantic (Irminger Sea) origin. The hydrographic conditions were further characterized by limited sea ice probably related to a mild and relatively windy winter climate. After 3.2 ka BP lower fine-grained sedimentation rates, but a larger input from sea-ice rafted or aeolian coarse material prevailed. This can be related to colder atmospheric conditions with a decreased meltwater discharge and more widespread sea-ice cover in the fjord.
Sclerochronological records of Arctica islandica from the inner German Bight
Authors: Epplé Valérie M. , Brey Thomas , Witbaard Rob , Kuhnert Henning , Pätzold Jürgen
Published: July 2006

Sclerochronological records of interannual shell growth variability were established for eight modern shells (26 to 163 years of age) of the bivalve Arctica islandica, which were sampled at one site in the inner German Bight. The records indicate generally low synchrony between individuals. Spectral analysis of the whole 163-yr masterchronology indicated a cyclic pattern with a period of 5 and 7 years. The masterchronology correlated poorly to time series of environmental parameters over the last 90 years. High environmental variability in time and space of the dynamic and complex German Bight hydrographic system results in an extraordinarily high ‘noise’ level in the shell growth pattern of Arctica islandica.
santaandvalentinepattern concentric growth of cardiac myocardium in the zebrafish
Authors: Mably John D. , Chuang Lesley P. , Serluca Fabrizio C. , Mohideen Manzoor-Ali P. K. , Chen Jau-Nian , Fishman Mark C.
Published: July 2006

During embryogenesis, the myocardial layer of the primitive heart tube grows outward from the endocardial-lined lumen, with new cells added to generate concentric thickness to the wall. This is a key evolutionary step,demarcating vertebrates from more primitive chordates, and is essential for normal cardiac function. Zebrafish embryos with the recessive lethal mutations santa (san) and valentine (vtn) do not thicken, but do add the proper number of cells to the myocardium. Consequently, the heart chambers are huge, constituted of a monolayered myocardium lined by endocardium. This phenotype is similar to that of the heart of glass (heg) mutation, which we described previously as a novel endocardial expressed gene. By positional cloning, we here identify san as the zebrafish homolog of human CCM1, and vtn as the homolog of human CCM2. Dominant mutations of either in humans cause vascular anomalies in the brain, known as cerebral cavernous malformations. The synergistic effects of morpholino pairs indicate that san, vtn and heg are in a genetic pathway, and san and vtncontain protein motifs, NPxY and PTB domain, respectively, known to interact. This suggests that concentric growth of the myocardium, crucial for blood pressure generation, is dictated by a heg-san-vtnsignaling pathway.
Basement membrane attachment is dispensable for radial glial cell fate and for proliferation, but affects positioning of neuronal subtypes
Authors: Haubst Nicole , Georges-Labouesse Elisabeth , De Arcangelis Adele , Mayer Ulrike , Götz Magdalena
Published: July 2006

Radial glial cells have been shown to act as neuronal precursors in the developing cortex and to maintain their radial processes attached to the basement membrane (BM) during cell division. Here, we examined a potential role of direct signalling from the BM to radial glial cells in three mouse mutants where radial glia attachment to the BM is disrupted. This is the case if the nidogen-binding site of the laminin γ1 chain is mutated, in the absence of α6 integrin or of perlecan, an essential BM component. Surprisingly, cortical radial glial cells lacking contact to the BM were not affected in their proliferation, interkinetic nuclear migration, orientation of cell division and neurogenesis. Only a small subset of precursors was located ectopically within the cortical parenchyma. Notably, however, neuronal subtype composition was severely disturbed at late developmental stages (E18)in the cortex of the laminin γ1III4-/- mice. Thus, although BM attachment seems dispensable for precursor cells, an intact BM is required for adequate neuronal composition of the cerebral cortex.
MicroRNA and 3T3-L1 pre-adipocyte differentiation
Authors: Kajimoto Kazuaki , Naraba Hiroaki , Iwai Naoharu
Published: July 2006

MicroRNAs (miRNAs) have been suggested to play important roles in cell proliferation, apoptosis, and differentiation. In this study, we examined miRNA expression profiles during 3T3-L1 pre-adipocyte differentiation. We constructed miRNA libraries from pre- and post-differentiated 3T3-L1 cells, and identified the expression of 77 previously reported miRNAs and 3 new miRNAs. Next, we investigated the expression levels of 102 miRNAs, including those identified in the libraries, during adipogenesis by Northern blot analysis. Sixty-five miRNAs were detected and the expression of 21 miRNAs was up- or down-regulated during adipogenesis. Intriguingly, changes in the miRNA expression pattern were observed at day 9, when lipid droplets were visible, but not at days 1, 2, or 5 after the induction of differentiation. Antisense inhibition of the up-regulated miRNAs did not affect 3T3-L1 pre-adipocyte differentiation. Although these miRNAs may be involved in modulating adipocyte function, mild down-modulations of the up-regulated miRNAs do not appear to affect 3T3-L1 pre-adipocyte differentiation.
Rapid Brain Natriuretic Peptide Test and Doppler Echocardiography for Early Diagnosis of Mild Heart Failure
Authors: Aspromonte Nadia , Ceci Vincenzo , Chiera Antonella , Coletta Claudio , D’Eri Alessandra , Feola Mauro , Giovinazzo Prospero , Milani Loredano , Noventa Federica , Scardovi Angela Beatrice , Sestili Augusto , Valle Roberto
Published: July 2006

Background: The early identification of patients at risk for the development of clinical heart failure (HF) is a new challenge in an effort to improve outcomes.

Methods: We prospectively evaluated whether the combination of brain natriuretic peptide (BNP) measurements (Triage BNP test, Biosite Diagnostics) and echocardiography would effectively stratify patients with new symptoms in a cost-effective HF program aimed at early diagnosis of mild HF. A total of 252 patients were referred by 100 general practitioners.

Results: Among the study population, the median BNP value was 78 ng/L (range, 5–1491 ng/L). BNP concentrations were lower among patients without heart disease [median 15 ng/L (range, 5–167 ng/L); n = 96] than among patients with confirmed HF [median, 165 ng/L (22–1491 ng/L); n = 157; Mann–Whitney U-test, 12.3; P <0.001]. Patients were grouped into diastolic dysfunction [BNP, 195 (223) ng/L], systolic dysfunction [BNP, 290 (394) ng/L], and both systolic and diastolic dysfunction [BNP, 776 (506) ng/L]. In this model, a cutoff value of 50 ng/L BNP increases the diagnostic accuracy in predicting mild HF, avoiding 41 echocardiograms per 100 patients studied, with a net saving of 14% of total costs.

Conclusions: Blood BNP concentrations, in a costeffective targeted screening, can play an important role in diagnosing mild HF and stratifying patients into risk groups of cardiac dysfunction.
Rapid Screening of 4000 Individuals for Germ-line Variations in the BRAF Gene
Authors: James Michael R , Dumeni Troy , Stark Mitchell S , Duffy David L , Montgomery Grant W , Martin Nicholas G , Hayward Nicholas K
Published: July 2006

Background: The BRAF gene is frequently somatically altered in malignant melanoma. A majority of variations are at the valine 600 residue leading to a V600E substitution that constitutively activates the kinase. We screened 4000 patient and control DNAs for germ-line variations at the valine 600 residue.

Methods: We developed a novel assay by adapting single-base variation assays and software for MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry to screen for all 5 reported variants at codon 600 of the BRAF gene. We screened a case-control collection comprising samples from 1082 melanoma patients and 154 of their unaffected relatives from 1278 families and from 2744 individuals from 659 unselected twin families with no history of melanoma. A panel of 66 melanoma cell lines was used for variation-positive controls.

Results: All melanoma cell lines that we had found previously to carry a codon 600 variation were verified in this study. Three of the 4 possible variants (V600E n = 47, V600K n = 2, V600R n = 1) were detected, but no case of V600D was available. No germ-line variants were found in the samples from the 3980 melanoma patients or from the control individuals.

Conclusions: This new assay is a high-throughput, automated alternative to standard sequencing and can be used as a rapid initial screen for somatic variants associated with melanoma. Germ-line variants at valine 600 are unlikely to exist and do not contribute to the reported role of the BRAF gene in melanoma predisposition.
Poiseuille Flow Geometry Inferred from Velocities of Wetting Fronts in Soils
Authors: Germann P. F. , Hensel D.
Published: July 2006

Soil structure can significantly enhance or modify infiltration rates and flow pathways in undisturbed field soils. Relations between features of soil structure and features of infiltration were elucidated from the velocities of wetting fronts. To study flow geometries during wetting, 100 sprinkler infiltration experiments were performed in situ at 25 different sites. Applied sprinkler irrigation rates ranged from 20 to 100 mm h−1 and lasted 1 h. Time domain reflectometry (TDR)‐based observations of soil moisture time series at various depths yielded 215 velocities of wetting fronts between 0.2 and 5.5 mm s−1 Application of Poiseuille's Law to the velocities resulted in radii and densities of equivalent Poiseuille pores in the ranges of 5 to 30 μm and of 2 × 106 to 2 × 108 m−2, respectively. From the equivalent Poiseuille pores capillary heads were estimated to be in the range of −2.0 to −0.2 m. They served as initial conditions for modeling infiltration with the HYDRUS‐2D code using hydraulic properties representative of the sand, silt, loam, and clay soil textural classes. The observed in situ wetting velocities indicated preferential flow; however, the calculated equivalent pore radii suggested that no macropores were required to initiate preferential flow. HYDRUS‐2D reproduced the bulk of observed wetting velocities when hydraulic properties typical of sandy soils were used.
Receptor for Advanced Glycation End Products Is Involved in Impaired Angiogenic Response in Diabetes
Authors: Shoji Takuhito , Koyama Hidenori , Morioka Tomoaki , Tanaka Shinji , Kizu Akane , Motoyama Kohka , Mori Katsuhito , Fukumoto Shinya , Shioi Atsushi , Shimogaito Noriko , Takeuchi Masayoshi , Yamamoto Yasuhiko , Yonekura Hideto , Yamamoto Hiroshi , Nishizawa Yoshiki
Published: July 2006

Angiogenic response is impaired in diabetes. Here, we examined the involvement of receptor for advanced glycation end products (RAGE) in diabetes-related impairment of angiogenesis in vivo. Angiogenesis was determined in reconstituted basement membrane protein (matrigel) plugs containing vascular endothelial growth factor (VEGF) implanted into nondiabetic or insulin-deficient diabetic wild-type or RAGE−/− mice. The total, endothelial, and smooth muscle (or pericytes) cells in the matrigel were significantly decreased in diabetes, with the regulation dependent on RAGE. In the matrigel, proangiogenic VEGF expression was decreased, while antiangiogenic thrombospondin-1 was upregulated in diabetic mice, regardless of the presence of RAGE. In wild-type mice, proliferating cell nuclear antigen (PCNA)-positive cells in the matrigel were significantly less in diabetic than in nondiabetic mice, while the numbers of transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells were significantly higher. This alteration in PCNA- and TUNEL-positive cells in diabetes was not observed in RAGE−/− mice. Similarly, the percentage of nuclear factor κB–activated cells is enhanced in diabetes, with the regulation dependent on the presence of RAGE. Importantly, adenovirus-mediated overexpression of endogenous secretory RAGE, a decoy receptor for RAGE, restores diabetes-associated impairment of angiogenic response in vivo. Thus, RAGE appears to be involved in impairment of angiogenesis in diabetes, and blockade of RAGE might be a potential therapeutic target.
Insulin Regulation of Skeletal Muscle PDK4 mRNA Expression Is Impaired in Acute Insulin-Resistant States
Authors: Kim Young I. , Lee Felix N. , Choi Woo S. , Lee Sarah , Youn Jang H.
Published: July 2006

We previously showed that insulin has a profound effect to suppress pyruvate dehydrogenase kinase (PDK) 4 expression in rat skeletal muscle. In the present study, we examined whether insulin’s effect on PDK4 expression is impaired in acute insulin-resistant states and, if so, whether this change is accompanied by decreased insulin’s effects to stimulate Akt and forkhead box class O (FOXO) 1 phosphorylation. To induce insulin resistance, conscious overnight-fasted rats received a constant infusion of Intralipid or lactate for 5 h, while a control group received saline infusion. Following the initial infusions, each group received saline or insulin infusion (n = 6 or 7 each) for an additional 5 h, while saline, Intralipid, or lactate infusion was continued. Plasma glucose was clamped at basal levels during the insulin infusion. Compared with the control group, Intralipid and lactate infusions decreased glucose infusion rates required to clamp plasma glucose by ∼60% (P < 0.01), confirming the induction of insulin resistance. Insulin’s ability to suppress PDK4 mRNA level was impaired in skeletal muscle with Intralipid and lactate infusions, resulting in two- to threefold higher PDK4 mRNA levels with insulin (P < 0.05). Insulin stimulation of Akt and FOXO1 phosphorylation was also significantly decreased with Intralipid and lactate infusions. These data suggest that insulin’s effect to suppress PDK4 gene expression in skeletal muscle is impaired in insulin-resistant states, and this may be due to impaired insulin signaling for stimulation of Akt and FOXO1 phosphorylation. Impaired insulin’s effect to suppress PDK4 expression may explain the association between PDK4 overexpression and insulin resistance in skeletal muscle.
ERK1/2 Control Phosphorylation and Protein Level of cAMP-Responsive Element–Binding Protein
Authors: Costes Safia , Broca Christophe , Bertrand Gyslaine , Lajoix Anne-Dominique , Bataille Dominique , Bockaert Joel , Dalle Stéphane
Published: July 2006

cAMP-responsive element–binding protein (CREB) is required for β-cell survival by regulating expression of crucial genes such as bcl-2 and IRS-2. Using MIN6 cells and isolated rat pancreatic islets, we investigated the signaling pathway that controls phosphorylation and protein level of CREB. We observed that 10 mmol/l glucose–induced CREB phosphorylation was totally inhibited by the protein kinase A (PKA) inhibitor H89 (2 μmol/l) and reduced by 50% with the extracellular signal–regulated kinase (ERK)1/2 inhibitor PD98059 (20 μmol/l). This indicates that ERK1/2, reported to be located downstream of PKA, participates in the PKA-mediated CREB phosphorylation elicited by glucose. In ERK1/2-downregulated MIN6 cells by siRNA, glucose-stimulated CREB phosphorylation was highly reduced and CREB protein content was decreased by 60%. In MIN6 cells and islets cultured for 24–48 h in optimal glucose concentration (10 mmol/l), which promotes survival, blockade of ERK1/2 activity with PD98059 caused a significant decrease in CREB protein level, whereas CREB mRNA remained unaffected (measured by real-time quantitative PCR). This was associated with loss of bcl-2 mRNA and protein contents, caspase-3 activation, and emergence of ultrastructural apoptotic features detected by electron microscopy. Our results indicate that ERK1 and -2 control the phosphorylation and protein level of CREB and play a key role in glucose-mediated pancreatic β-cell survival.
An IGF-I Gene Polymorphism Modifies the Risk of Diabetic Retinopathy
Authors: Rietveld Ingrid , Ikram M. Kamran , Vingerling Johannes R. , Hofman Albert , Pols Huibert A.P. , Lamberts Steven W.J. , de Jong Paulus T.V.M. , van Duijn Cornelia M. , Janssen Joop A.M.J.L.
Published: July 2006

The role of IGF-I in the pathogenesis of diabetic retinopathy is unclear. We studied, prospectively, the relationship between an IGF-I gene polymorphism, retinal vessel diameters, and incident diabetic retinopathy in subjects with impaired glucose tolerance (IGT) or type 2 diabetes. In all 5,505 participants of the population-based Rotterdam Study (775 with IGT, 394 with type 2 diabetes, and 4,336 control subjects), fundus color transparencies were taken at baseline (between 1990 and 1993) and at follow-up (from 1997 to 1999). The wild-type genotype (i.e., carriers of the 192- or 194-bp alleles) was present in 72.7% of the participants, while 27.3% were variant carriers. Variant carriers with IGT or type 2 diabetes appeared to have larger retinal arteriolar and venular diameters at baseline than individuals with the wild-type genotype, but these differences did not reach statistical significance. This trend was especially observed in subjects who developed retinopathy at follow-up. In variant carriers with IGT/diabetes, an increase (odds ratio 1.8 [95% CI 1.0–3.2]; P = 0.04) in the risk of retinopathy was observed compared with participants with the wild-type genotype. In conclusion, our findings suggest that this IGF-I gene polymorphism is associated with an increased risk of diabetic retinopathy.