bluuebunny/crossref_metadata_2025 huggingface dataset:
Extracellular cysteine/cystine redox potential controls lung fibroblast proliferation and matrix expression through upregulation of transforming growth factor-β
Authors: Ramirez Allan , Ramadan Bassel , Ritzenthaler Jeffrey D. , Rivera Hilda N. , Jones Dean P. , Roman Jesse
Published: July 2007

Oxidant stress has been implicated in the pathogenesis of chronic lung disorders like idiopathic pulmonary fibrosis. However, mechanisms that link oxidant stress to fibrogenesis remain partially elucidated. Emerging data suggest an important role for the extracellular thiol/disulfide redox environment. The cysteine (Cys)/cystine (CySS) redox couple represents the predominant low-molecular-weight thiol/disulfide pool found in plasma and is sensitive to aging, smoking, and other host factors. We hypothesized that an oxidized extracellular Cys/CySS redox potential (EhCys/CySS) affects lung fibroblasts by inducing intracellular signals that stimulate proliferation and matrix expression. We tested this hypothesis in primary murine lung fibroblasts and found that an oxidized EhCys/CySS (−46 mV) stimulated lung fibroblast proliferation. Furthermore, it stimulated their expression of fibronectin, a matrix glycoprotein highly expressed in fibrotic lung diseases and implicated in lung injury. This stimulatory effect was dependent on protein kinase C activation. Oxidant stress also increased the phosphorylation of cAMP response element binding protein, a transcription factor known for its ability to stimulate fibronectin expression, and increased the expression of mRNAs and proteins coding for the transcription factors nuclear factor (NF)-κB and mothers against decapentaplegic homolog 3. Fibroblasts cultured in normal (−80 mV) or reduced (−131 mV) EhCys/CySS showed less induction. Furthermore, fibronectin expression in response to an oxidized EhCys/CySS was associated with expression of transforming growth factor-β1 (TGF-β1) and was inhibited by an anti-TGF-β1 antibody and SB-431542, a TGF-β1 receptor inhibitor. These studies suggest that extracellular oxidant stress activates redox-sensitive pathways that stimulate lung fibroblast proliferation and matrix expression through upregulation of TGF-β1.
Ultrastructural evidence of sperm dimorphism in Deladenus sp. (Tylenchomorpha: Sphaerularioidea: Allantonematidae)
Authors: Yushin Vladimir V. , Kosaka Hajime , Kusunoki Manabu
Published: July 2007

The dimorphic spermatozoa of the insect-parasitic nematode Deladenus sp.
(Tylenchomorpha: Sphaerularioidea: Allantonematidae) were studied for the
first time with a transmission electron microscope (TEM). The immature
spermatozoa from the testis of mycetophagous males are 10-12 μm diam. and
4-5 μm long unpolarised cells with a centrally located nucleus without a
nuclear envelope. The cytoplasm contains mitochondria and specific
components, membranous organelles (MO) and fibrous bodies (FB). The MO are
spherical vesicles with an internal system of finger-like invaginations of
the membrane; the spindle-shaped FB consist of tightly packed parallel
fibres. Spermatozoa from the uteri of infective females of Deladenus sp. are
vastly different in size being tiny cells ca 2 μm diam. with a spherical or
oval nucleus. Each cell contains several mitochondria and MO. Although each
individual of Deladenus sp. contains only monomorphic spermatozoa, sperm
dimorphism was revealed after analysis of the whole life cycle. Despite a
difference in size the cytological characters of both types of spermatozoa
conform to the typical rhabditid pattern. The presence of both MO and FB in
sphaerularioidid spermatozoa differentiates the superfamily Sphaerularioidea
from Tylenchoidea whose representatives lack MO in the spermatogenic
cells.
Nematodes from vernal pools in the Santa Rosa Plateau Ecological Reserve, California I. Hirschmanniella santarosae sp. n. (Nematoda: Pratylenchidae), a cryptic sibling species of H. pomponiensis Abdel-Rahman & Maggenti, 1987
Authors: Tandingan De Ley Irma , Mundo-Ocampo Manuel , Yoder Melissa , De Ley Paul
Published: July 2007

Hirschmanniella santarosae sp. n. is described from the largest vernal pool
in the Santa Rosa Plateau Ecological Reserve, Murrieta, California, USA. The
cryptic new species is morphologically very close to H. pomponiensis and H.
gracilis as it can be distinguished from the former only by a more anterior
excretory pore position and by more flattened as well as laterally expanded
stylet knobs, whilst it differs from the latter in the greater distance from
phasmid to tail tip and in the bursal alae ending near the phasmids rather
than near the tail tip. Analysis of the rDNA small subunit (SSU) and D2D3
expansion segments of the large subunit (LSU) shows that H. santarosae sp.
n. is genetically distinct, having respective sequence homology of 98.89%
and 95.9% with H. pomponiensis for these loci. Congruence in SSU and D2D3
gene trees as well as unambiguous character autapomorphies further support
the new species status of H. santarosae sp. n. and sibling relationship with
H. pomponiensis. Although many more isolates and species will need to be
studied before informative biogeographic analyses can be performed, the
presently available sequence data suggest that some Hirschmanniella lineages
have diversified independently on either side of the Atlantic.
Preliminary rulings of the European Court of Justice and their precursors
Authors: Winkel Laurens
Published: July 2007

The possible precursors of the preliminary rulings according to § 234 of the Treaty of the European Union are examined with emphasis on the practice in the Imperial Chancery of the Roman Empire, on Einleitung § 47 of the Prussian Allgemeines Landrecht and on the French référé législatif.
The role of the judge in civil litigation in the 19th century: Case-management avant la lettre in Geneva, The Netherlands and Belgium
Authors: van Rhee C.H.
Published: July 2007

The present article discusses the powers of the judge in civil litigation in three jurisdictions that have been influenced by the French Code of Civil Procedure (1806). It shows that in the 19th century these jurisdictions adopted French law but at the same time tried to reduce party autonomy by increasing the judge's directive powers. This approach was most successful in Geneva. In The Netherlands, changes in the judge's position were less pronounced, whereas a 19th century Belgian draft code, which contained a number of measures that would have increased the judge's case-management powers, was not adopted in practice.
Aggressive Surgical Treatment and Early Return to Sports in Athletes with Grade III Syndesmosis Sprains
Authors: Taylor Dean C. , Tenuta Joachim J. , Uhorchak John M. , Arciero Robert A.
Published: July 2007

Background

Grade III syndesmosis sprains are usually treated with internal fixation. Limited information is available on early weightbearing and early return to activity after operative treatment for grade III syndesmosis sprains.

Hypothesis

Treatment of grade III syndesmosis sprains in intercollegiate athletes with internal fixation, early range of motion, and early weightbearing can lead to rapid return to sport with minimal complications and no ankle problems in midterm follow-up.

Study Design

Case series; Level of evidence, 4.

Methods

We evaluated a consecutive series of intercollegiate athletes treated operatively with 4.5-mm cortical screw fixation for grade III syndesmosis sprains. At 1 week after surgery, patients were allowed to begin range of motion exercises, progressive weightbearing, and gradually return to full activity as tolerated. Outcome measures included time to return to full activity and, at final follow-up, the Sports Ankle Rating System scores.

Results

Six male intercollegiate college athletes met the inclusion criteria for this study. The average time for return to full activity was 41 days (range, 32-48 days). There were no intraoperative complications or complications when resuming in-season sport activities with the screw in place. One screw broke during removal. At an average follow-up of 34.3 months, using the Sports Ankle Rating System, the average clinical rating score was 96.2, the average quality-of-life measure was 96.7, and the average single assessment numeric evaluation was 95.3. Radiographs at final follow-up showed no mortise widening or lateral talar subluxation. Two patients had mild degenerative changes on lateral radiographs with anterior tibial osteophytes.

Conclusions

In selective cases, athletes can return to full activity as early as 6 weeks after internal fixation of grade III syndesmosis sprains.
An Exploratory Analysis of German and U.S. Youthful Homicide Offending
Authors: Titterington Victoria B. , Grundies Volker
Published: July 2007

German and U.S. incident-level homicide files are extracted from the Freiburg Cohort Study and Houston, Texas, respectively, to compare characteristics of criminal homicide perpetrated by persons ages 14 to 30 years between the mid-1980s and 2001. Findings indicate that many of the characteristics of offenders, victims, their relationships to one another, and methods of killing are not culture specific, particularly for female offenders. However, despite a substantial difference between the two areas in overall homicide levels, the offending rates for this 14- to 30-year-old group are 5 to 6 times the overall national rates in each country. Findings further indicate that peak ages for homicide offending by males are 2 to 5 years older for German nationals and immigrants than for specific racial and/or ethnic subgroups of U.S. offenders. Support is found in both countries for the concept of an aging out of crime in the case of homicide.
Siblicide and Genetic Relatedness in Chicago, 1870-1930
Authors: Michalski Richard L. , Russell Daniel P. , Shackelford Todd K. , Weekes-Shackelford Viviana A.
Published: July 2007

Using a sample of siblicides committed in Chicago from 1870 through 1930, the authors tested two predictions heuristically guided by an evolutionary perspective. They predicted a greater proportion of siblicides of in-law siblings will be perpetrated by beatings, relative to the proportion of siblicides of full siblings. This difference did not reach statistical significance although it was in the predicted direction. They found, as predicted, that a significantly greater proportion of accidental deaths occurred with siblicides of full siblings relative to the proportion of siblicides of in-law siblings. Discussion addresses limitations of this research and the need for a national-level database that codes for the genetic relationship between the siblicide victim and offender to capitalize on greater statistical power.
How we diagnose and treat thrombotic manifestations of the antiphospholipid syndrome: a case-based review
Authors: Garcia David A. , Khamashta Munther A. , Crowther Mark A.
Published: July 2007

Antiphospholipid antibodies including anticardiolipin antibodies, lupus anticoagulants, and anti–β2 glycoprotein-1–specific antibodies may identify patients at elevated risk of first or recurrent venous or arterial thromboembolism. Traditionally, published case series supplemented by anecdotal experience have formed the basis of management of patients with these autoantibodies. Over the past several years, studies have described the management of patients with key clinical manifestations of antiphospholipid antibodies, including patients with antiphospholipid antibody syndrome. As a result, evidence-based treatment recommendations are possible for selected patients with, or at risk of, thrombosis in the setting of antiphospholipid antibodies. Unfortunately, most patients encountered in clinical practice do not correspond directly with those enrolled in clinical trials. For such patients, treatment recommendations are based on experience, extrapolation, and less rigorous evidence. This article proposes 5 cases typical of those found in clinical practice and provides recommendations for therapy focused on a series of clinical questions. Whenever possible, the recommendations are based on evidence; however, in many cases, insufficient evidence exists, so the recommendation is experiential.
Aberrant mast-cell differentiation in mice lacking the stem-cell leukemia gene
Authors: Salmon Jessica M. , Slater Nicholas J. , Hall Mark A. , McCormack Matthew P. , Nutt Stephen L. , Jane Stephen M. , Curtis David J.
Published: July 2007

The stem cell leukemia (SCL) gene encodes a basic helix-loop-helix transcription factor expressed in erythroid, megakaryocyte, and mast-cell lineages. SCL is essential for growth of megakaryocyte and erythroid progenitors. We have used a conditional knockout of SCL (SCL−/Δ) to examine its function in mast cells, critical effectors of the immune system. SCL−/Δ mice had markedly increased numbers of mast-cell progenitors (MCPs) within the peritoneal fluid, bone marrow, and spleen. Fractionation of bone marrow myeloid progenitors demonstrated that these MCPs were present in the megakaryocyte-erythroid–restricted cell fraction. In contrast, unilineage MCPs from control mice were present in the cell fraction with granulocyte-macrophage potential. The aberrant mast-cell differentiation of SCL−/Δ megakaryocyte-erythroid progenitors was associated with increased expression of GATA-2. Despite increased numbers of MCPs in SCL−/Δ mice, numbers of mature tissue mast cells were not increased unless SCL−/Δ mice were treated with IL-3 and stem-cell factor. In part, this may be due to a requirement for SCL in normal mast-cell maturation: SCL−/Δ mast cells had reduced expression of the high-affinity IgE receptor and mast cell proteases, MCP-5 and MCP-6. Together, these studies suggest that loss of SCL leads to aberrant mast-cell differentiation of megakaryocyte-erythroid progenitors.
Apaf-1 and caspase-9 deficiency prevents apoptosis in a Bax-controlled pathway and promotes clonogenic survival during paclitaxel treatment
Authors: Janssen Katja , Pohlmann Stephan , Jänicke Reiner U. , Schulze-Osthoff Klaus , Fischer Ute
Published: July 2007

Taxane derivatives such as paclitaxel elicit their antitumor effects at least in part by induction of apoptosis, but the underlying mechanisms are incompletely understood. Here, we used different cellular models with deficiencies in key regulators of apoptosis to elucidate the mechanism of paclitaxel-induced cell death. Apoptosis by paclitaxel was reported to depend on the activation of the initiator caspase-10; however, we clearly demonstrate that paclitaxel kills murine embryonic fibroblasts (MEFs) devoid of caspase-10 as well as human tumor cell lines deficient in caspase-10, caspase-8, or Fas-associating protein with death domain. In contrast, the lack of Apaf-1 or caspase-9, key regulators of the mitochondrial pathway, not only entirely protected against paclitaxel-induced apoptosis but could even confer clonogenic survival, depending on the cell type and drug concentration. Thus, paclitaxel triggers apoptosis not through caspase-10, but via caspase-9 activation at the apoptosome. This conclusion is supported by the fact that Bcl-2–overexpressing cells and Bax/Bak doubly-deficient MEFs were entirely resistant to paclitaxel-induced apoptosis. Interestingly, also the single knockout of Bim or Bax, but not that of Bak or Bid, conferred partial resistance, suggesting a particular role of these mediators in the cell-death pathway activated by paclitaxel.
Anti–β2-microglobulin monoclonal antibodies induce apoptosis in myeloma cells by recruiting MHC class I to and excluding growth and survival cytokine receptors from lipid rafts
Authors: Yang Jing , Zhang Xiang , Wang Ji , Qian Jianfei , Zhang Liang , Wang Michael , Kwak Larry W. , Yi Qing
Published: July 2007

We recently showed that monoclonal antibodies (mAbs) against β2-microglobulin (β2M) have a remarkably strong apoptotic effect on myeloma cells. The mAbs induced apoptosis by recruiting major histocompatibility complex (MHC) class I to lipid rafts, activated c-Jun N-terminal kinase (JNK), and inhibited phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal–regulated kinase (ERK) pathways. Growth and survival cytokines such as interleukin-6 (IL-6) and insulin-like growth factor-I (IGF-I), which could protect myeloma cells from dexamethasone-induced apoptosis, did not affect mAb-mediated cell death. This study was undertaken to elucidate the mechanisms underlying anti-β2M mAb–induced PI3K/Akt and ERK inhibition and the inability of IL-6 and IGF-I to protect myeloma cells from mAb-induced apoptosis. We focused on lipid rafts and confirmed that these membrane microdomains are required for IL-6 and IGF-I signaling. By recruiting MHC class I into lipid rafts, anti-β2M mAbs excluded IL-6 and IGF-I receptors and their substrates from the rafts. The mAbs not only redistributed the receptors in cell membrane, but also abrogated IL-6– or IGF-I–mediated Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3), PI3K/Akt, and Ras/Raf/ERK pathway signaling, which are otherwise constitutively activated in myeloma cells. Thus, this study further defines the tumoricidal mechanism of the mAbs and provides strong evidence to support the potential of these mAbs as therapeutic agents for myeloma.
Induction of FOXP3 expression in naive human CD4+FOXP3− T cells by T-cell receptor stimulation is transforming growth factor-β–dependent but does not confer a regulatory phenotype
Authors: Tran Dat Q. , Ramsey Heather , Shevach Ethan M.
Published: July 2007

Thymic-derived natural T-regulatory cells (nTregs) are important for the induction of self-tolerance and the control of autoimmunity. Murine CD4+CD25−Foxp3− cells can be induced to express Foxp3 after T-cell receptor (TCR) activation in the presence of transforming growth factor β (TGFβ) and are phenotypically similar to nTregs. Some studies have suggested that TCR stimulation of human CD4+CD25− cells results in the induction of transient expression of FOXP3, but that the induced cells lack a regulatory phenotype. We demonstrate here that TCR stimulation alone was insufficient to induce FOXP3 expression in the absence of TGFβ, whereas high levels of FOXP3 expression could be induced in the presence of TGFβ. Although FOXP3 expression was stable, the TGFβ-induced FOXP3+ T cells were neither anergic nor suppressive and produced high levels of effector cytokines. These results suggest that even high levels of FOXP3 expression are insufficient to define a human CD4+ T cell as a T-regulatory cell.
Urocortin, a CRF-like peptide, restores key indicators of damage in the substantia nigra in a neuroinflammatory model of Parkinson's disease
Authors: Abuirmeileh Amjad , Harkavyi Alexander , Lever Rebecca , Biggs Christopher S , Whitton Peter S
Published: July 2007

We have recently observed that the corticotrophin releasing hormone (CRF) related peptide urocortin (UCN) reverses key features of nigrostriatal damage in the hemiparkinsonian 6-hydroxydopamine lesioned rat. Here we have studied whether similar effects are also evident in the lipopolysaccaride (LPS) neuroinflammatory paradigm of Parkinson's disease (PD). To do this we have measured restoration of normal motor behaviour, retention of nigral dopamine (DA) and also tyrosine hydroxylase (TH) activity. Fourteen days following intranigral injections of LPS and UCN, rats showed only modest circling after DA receptor stimulation with apomorphine, in contrast to those given LPS and vehicle where circling was pronounced. In separate experiments, rats received UCN seven days following LPS, and here apomorphine challenge caused near identical circling intensity to those that received LPS and UCN concomitantly. In a similar and consistent manner with the preservation of motor function, UCN 'protected' the nigra from both DA depletion and loss of TH activity, indicating preservation of DA cells. The effects of UCN were antagonised by the non-selective CRF receptor antagonist α-helical CRF and were not replicated by the selective CRF2 ligand UCN III. This suggests that UCN is acting via CRF1 receptors, which have been shown to be anti-inflammatory in the periphery. Our data therefore indicate that UCN is capable of maintaining adequate nigrostriatal function in vivo, via CRF1 receptors following a neuro-inflammatory challenge. This has potential therapeutic implications in PD.
Vibration Effects on Cognitive Task Performance in a Rural Road Automobile Driving Environment
Authors: Muzammil M. , Hasan Faisal
Published: July 2007

Research has been carried out to investigate the effect of left or right handedness on cognitive performance under the impact of vibration in a rural road-driving environment. Fourteen subjects (7 right handed and 7 left-handed), all males, participated in the study. The independent variables selected were handedness, difficulty index and equivalent level of vibration. The reaction time was measured in ms. The data collected was analysed using 3 factors ANOVA. Results of the present research showed that handedness and the level of equivalent vibration were statistically non-significant while the difficulty index was found to have a significant effect in the driving environment undertaken in the study. The interaction between handedness and difficulty index was also observed to be statistically significant. However, the interaction between vibration level & difficulty index and handedness & vibration level were statistically non-significant. The second order interaction i.e. handedness x vibration level x difficulty index also emerged to be non-significant
Flight Deck Disturbance Management: A Simulator Study of Diagnosis and Recovery From Breakdowns in Pilot-Automation Coordination
Authors: Nikolic Mark I. , Sarter Nadine B.
Published: July 2007

Objective: To examine operator strategies for diagnosing and recovering from errors and disturbances as well as the impact of automation design and time pressure on these processes. Background: Considerable efforts have been directed at error prevention through training and design. However, because errors cannot be eliminated completely, their detection, diagnosis, and recovery must also be supported. Research has focused almost exclusively on error detection. Little is known about error diagnosis and recovery, especially in the context of event-driven tasks and domains. Method: With a confederate pilot, 12 airline pilots flew a 1-hr simulator scenario that involved three challenging automation-related tasks and events that were likely to produce erroneous actions or assessments. Behavioral data were compared with a canonical path to examine pilots' error and disturbance management strategies. Debriefings were conducted to probe pilots' system knowledge. Results: Pilots seldom followed the canonical path to cope with the scenario events. Detection of a disturbance was often delayed. Diagnostic episodes were rare because of pilots' knowledge gaps and time criticality. In many cases, generic inefficient recovery strategies were observed, and pilots relied on high levels of automation to manage the consequences of an error. Conclusion. Our findings describe and explain the nature and shortcomings of pilots' error management activities. They highlight the need for improved automation training and design to achieve more timely detection, accurate explanation, and effective recovery from errors and disturbances. Application: Our findings can inform the design of tools and techniques that support disturbance management in various complex, event-driven environments.
Dopamine and iron mediated fragmentation of galactocerebroside and cardiolipin in micelles
Authors: Yurkova Irina , Kisel Mikhail , Arnhold Juergen , Shadyro Oleg
Published: July 2007

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and thin-layer chromatography (TLC) have been used to study dopamine and iron mediated free-radical transformation of lipids in their hydrophilic parts. It has been shown that the action of the dopamine/Fe2+ system on galactocerebroside or cardiolipin, which are the components of mixed micelles, results in formation of ceramide or phosphatidic acid and phosphatidylhydroxyacetone, respectively. These data, when combined with results obtained using the ascorbate/Fe2+/H2O2 oxidizing system with the same substrates, demonstrate that the formation of these products proceeds via an OH-radical induced fragmentation taking place in polar moiety of the starting lipids.
Ionic liquid-functionalized SBA-15 mesoporous material: efficient heterogeneous catalyst in versatile organic reactions
Authors: Xu Li-Wen , Yang Ming-Song , Jiang Jian-Xiong , Qiu Hua-Yu , Lai Guo-Qiao
Published: July 2007

Ionic liquid-functionalized mesoporous materials exhibited high catalytic activity in versatile organic reactions, such as cycloaddition of carbon dioxide (CO2) with epoxide, aza-Michael addition of amines to α, β-unsaturated carbonyl compounds, and the Biginelli reaction of aldehyde, ethyl acetoacetate and urea. Recycling of the catalyst in these reactions could be carried out and the catalyst used at least five times without significant loss in activity.
Fractional Hamilton’s equations of motion in fractional time
Authors: Muslih Sami , Baleanu Dumitru , Rabei Eqab
Published: July 2007

The Hamiltonian formulation for mechanical systems containing Riemman-Liouville fractional derivatives are investigated in fractional time. The fractional Hamilton’s equations are obtained and two examples are investigated in detail.
Luminescent properties of Li2 (Ca0.99, Eu0.01) SiO4: B3+ particles as a potential bluish green phosphor for ultraviolet light-emitting diodes
Authors: Yao Shanshan , Chen Donghua
Published: July 2007

In our study, the 1% mol Eu2+ doped Li2CaSiO4: B3+ phosphors were prepared by the combustion method as fluorescent material for ultraviolet, light-emitting diodes (UV-LEDs) used as a light source. The properties of Li2 (Ca0.99, Eu0.01) SiO4: B3+ phosphors with urea concentration, doping boric acid and a series of initiating combustion temperature were investigated. The crystallization and particle sizes of Li2 (Ca0.99, Eu0.01) SiO4: B3+ has been investigated by using powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). Luminescence measurements showed that the phosphors can be efficiently excited by UV to the visible region, and exhibited bluish green light with a peak of 480 nm. The results showed that the boric acid was effective in improving the luminescence intensity of Li2 (Ca0.99, Eu0.01) SiO4: B3+ and the optimum molar ratio of boric acid to calcium nitrate was about 0.06. The optimized phosphors Li2 (Ca0.99, Eu0.01) SiO4: B0.063+ showed 180% improved emission intensity compared with that of the Li2 (Ca0.99, Eu0.01) SiO4 phosphors under ultraviolet (λex =287 nm) excitation.
New dynamic scaling in increasing systems
Authors: Pastor Juan , Galeano Javier
Published: July 2007

We report a new dynamic scaling ansatz for systems whose system size is increasing with time. We apply this new hypothesis in the Eden model in two geometries. In strip geometry, we impose the system to increase with a power law, L ∼ h a. In increasing linear clusters, if a < 1/z, where z is the dynamic exponent, the correlation length reaches the whole system, and we find two regimes: the first, where the interface fluctuations initially grow with an exponent β = 0.3, and the second, where a crossover comes out and fluctuations evolve as h aα. If a = 1/z, there is not a crossover and fluctuations keep on growing in a unique regimen with the same exponent β. In particular, in circular geometry, a = 1, we find this kind of regime and in consequence, a unique regime holds.
The impact of insulin resistance on endothelial function, progenitor cells and repair
Authors: Cubbon Richard M , Rajwani Adil , Wheatcroft Stephen B
Published: July 2007

The structural and functional integrity of the vascular endothelium plays a critical role in vascular homeo-stasis. Insulin resistance, an important risk factor for cardiovascular disease, is thought to promote atherosclerosis through a reciprocal relationship with endothelial dysfunction. In health, cumulative damage to endothelial cells incurred by exposure to risk factors is mitigated by endogenous reparative processes. Disruption of the balance between endothelial damage and repair may mediate atherosclerotic progression. Bone marrow-derived ‘endothelial progenitor cells' (EPC) have been identified as significant contributors to endogenous vascular repair. Insulin resistance is associated with a spectrum of biochemical abnormalities which have the potential to reduce the availability of EPCs and diminish their capacity for vascular repair. Many lifestyle and pharmacological interventions which improve insulin resistance also increase the numbers and functionality of EPCs. Cell-based therapies may also hold promise for the prevention and treatment of cardiovascular disease.
Tris(4‐cyanophenyl)amine: Simple Synthesis via Self‐assembly; Strong Fluorescence in Solution, Nano/microcrystals, and Solid
Authors: Patra A. , Anthony S. P. , Radhakrishnan T. P.
Published: July 2007

The threefold symmetric molecule, tris(4‐cyanophenyl)amine (TCPA) is synthesized from 4‐fluorocyanobenzene by treatment with potassium carbonate in dimethylsulfoxide; the occurrence of the reaction without any amine reagent suggests the involvement of a novel self‐assembly process. A reprecipitation strategy provides stable colloids containing highly monodisperse nano/microcrystals with well‐defined cubic morphology and sizes tunable from 250 to 500 nm. The solution, colloid, and solid states of TCPA exhibit strong blue fluorescence; the colloid shows dual emission with an unusually small Stokes shift. Computational investigations are carried out on the molecule and supramolecular assemblies derived from the crystal structure. Coupled with detailed spectroscopic studies, they show that the emission in the colloidal and solid states can be attributed to energy levels resulting from the intermolecular interactions within different aggregation motifs in the condensed phase and energy cascades between them. The computations also reveal the presence of cooperative interactions in the molecular crystal contributing to its high thermal stability. The strong light emission exhibited by TCPA, concurrently in the solution, nano/microcrystal, and solid states establishes it as a novel molecular material of potential practical utility; it has led to the exploration of the underlying mechanism that describes the phenomena observed in the different physical states.
Removal of basic dyes from aqueous solutions using starch‐graft‐acrylic acid copolymers
Authors: Güçlü Gamze , Keleş Sibel
Published: July 2007

Graft copolymerization of acrylic acid (AA) onto starch was carried out with ceric ammonium nitrate as initiator under nitrogen atmosphere. The grafting percentages (GP%) of starch‐graft‐AA (St‐gr‐AA) copolymers were determined. When the AA molar concentrations were 0.3 and 0.5 mol/L, GP% of St‐gr‐AA copolymers were 10.5% (St‐gr‐AA‐1) and 14% (St‐gr‐AA‐2), respectively. St‐gr‐AA copolymers have been used for the adsorption of basic dye (Safranine T) from aqueous solutions. Effects of various parameters such as treatment time, initial pH of the solution (pH = 2–6), initial dye concentration (50– 500 mg/L), and GP% of starch graft copolymers were investigated.Basic dye removal capacities of the copolymers increase along with the augment of initial concentration of the adsorbate, GP% of the copolymers, and pH. The adsorption capacities for St‐gr‐AA‐1 and St‐gr‐AA‐2 reach 116.5 and 204 mg/g, respectively. Equilibrium adsorption data were obtained and fitted very well to Freundlich model. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Aluminium‐filled low‐density polyethylene—structural, morphological, and mechanical properties
Authors: Dasture M. D. , Kelkar D. S.
Published: July 2007

Low‐density polyethylene (LDPE) was filled with aluminium (Al) powder having concentrations of 1, 4, and 6% w/w. The samples in the form of disc containing the above concentration of Al powder were obtained using hot press molder. The structural properties have been investigated using density measurement and WAXD techniques. The morphology of pure LDPE and Al‐filled LDPE samples has been studied from scanning electron micrographs. The modulus of elasticity of the samples has been determined using Instron tensile tester. Results indicate that the crystallinity of LDPE component increases with the concentration of aluminium filler. Morphological changes also have been observed. The Young's modulus (Y) generally increases and becomes maximum for 4% Al‐filled LDPE sample. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Spectroscopic and molecular modeling studies of the interaction between cytidine and human serum albumin and its analytical application
Authors: Cui Fengling , Wang Junli , Yao Xiaojun , Wang Li , Zhang Qiangzhai , Qu Guirong
Published: July 2007

In this study, the interaction between cytidine and human serum albumin (HSA) was investigated for the first time by fluorescence spectroscopy in combination with UV absorption spectrum and molecular modeling under simulative physiological conditions. Experimental results indicated that cytidine had a strong ability to quench the intrinsic fluorescence of human serum albumin. The binding constants (K) at different temperatures, thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) of HSA‐cytidine had been calculated according to the relevant fluorescence data, which indicated that the hydrophobic and electrostatic interactions played a major role, which was in agreement with the results of molecular modeling study. In addition, the effects of other ions on the binding constants were also studied. Furthermore, synchronous fluorescence technology was successfully applied to the determination of human serum albumin added into the cytidine solution. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 174–182, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Astressin‐amide and astressin‐acid are structurally different in dimethylsulfoxide
Authors: Grace Christy Rani R. , Cervini Laura , Gulyas Jozsef , Rivier Jean , Riek Roland
Published: July 2007

The C‐terminally amidated CRF antagonist astressin binds to CRF‐R1 or CRF‐R2 receptors with low nanomolar affinity while the corresponding astressin‐acid has >100 times less affinity. To understand the role of the amide group in binding, the conformations of astressin‐amide and astressin‐acid were studied in DMSO using NMR techniques. The 3D NMR structures show that the backbones of both analogs prefer an α‐helical conformation, with a small kink around Gln26. However, astressin‐amide has a well‐defined helical structure from Leu27 to Ile41 and a conformation very similar to the bioactive conformation reported by our group (Grace et al., Proc Natl Acad Sci USA 2007, 104, 4858–4863). In contrast, astressin‐acid has an irregular helical conformation from Arg35 onward, including a rearrangement of the side chains in that region. This structural difference highlights the crucial role of the C‐terminal amidation for stabilization of astressin's bioactive conformation. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 196–205, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Optimal design of metabolic flux analysis experiments for anchorage‐dependent mammalian cells using a cellular automaton model
Authors: Meadows Adam L. , Roy Siddhartha , Clark Douglas S. , Blanch Harvey W.
Published: July 2007

Metabolic flux analysis (MFA) is widely used to quantify metabolic pathway activity. Typical applications involve isotopically labeled substrates, which require both metabolic and isotopic steady states for simplified data analysis. For bacterial systems, these steady states are readily achieved in chemostat cultures. However, mammalian cells are often anchorage dependent and experiments are typically conducted in batch or fed‐batch systems, such as tissue culture dishes or microcarrier‐containing bioreactors. Surface adherence may cause deviations from exponential growth, resulting in metabolically heterogeneous populations and a varying number of cellular “nearest neighbors” that may affect the observed metabolism. Here, we discuss different growth models suitable for deconvoluting these effects and their application to the design and optimization of MFA experiments employing surface‐adherent mammalian cells. We describe a stochastic two‐dimensional (2D) cellular automaton model, with empirical descriptions of cell number and non‐growing cell fraction, suitable for easy application to most anchorage‐dependent mammalian cell cultures. Model utility was verified by studying the impact of contact inhibition on the growth rate, specific extracellular flux rates, and isotopic labeling in lactate for MCF7 cells, a commonly studied breast cancer cell line. The model successfully defined the time over which exponential growth and a metabolically homogeneous growing cell population could be assumed. The cellular automaton model developed is shown to be a useful tool in designing optimal MFA experiments. Biotechnol. Bioeng. 2007; 98: 221–229. © 2007 Wiley Periodicals, Inc.
Monitoring of dissolved oxygen and cellular bioenergetics within a pancreatic substitute
Authors: Gross Jeffrey D. , Long R.C. , Constantinidis I. , Sambanis A.
Published: July 2007

This work investigated the use of nuclear magnetic resonance (NMR) spectroscopy in combination with a mathematical model of an encapsulated cell system as a method for rapidly assessing the status of a pancreatic substitute. To validate this method, an in vitro experiment was performed in which the encapsulated cells were perfused in an NMR‐compatible system and the dissolved oxygen (DO) concentration of the perfusing medium was lowered from 0.20 to 0.05 mM, then returned to 0.20 mM in a stepwise fashion. The cellular metabolic activity and bioenergetics were evaluated by measuring the oxygen consumption rate (via DO sensors) and nucleotide triphosphate levels (via 31P NMR). By incorporating a perfluorocarbon emulsion into the alginate beads, the cellular oxygenation state was monitored by measuring the average intrabead DO (AIDO) concentration by 19F NMR. The in vitro measurements were then compared with model predictions based on the measured external DO concentration and time. Model‐predicted cell growth and AIDO closely matched the experimentally acquired data. As the DO concentrations both external to and within the pancreatic substitute are needed to apply this methodology in vivo, the feasibility of measuring the DO concentration from two distinct bead populations implanted in the peritoneal cavity of mice was established. It is concluded that PFC incorporation and 19F NMR measurements, in combination with a mechanistic model of the encapsulated system, allow the tracking of the state of a pancreatic substitute in vitro and potentially in vivo. Biotechnol. Bioeng. 2007; 98: 261–270. © 2007 Wiley Periodicals, Inc.
Rectal cancer surgery without mechanical bowel preparation
Authors: Bretagnol F , Alves A , Ricci A , Valleur P , Panis Y
Published: July 2007

Background

Eight randomized clinical trials and two meta-analyses recently questioned the value of preoperative mechanical bowel preparation (MBP) in colorectal surgery. However, very few patients having rectal surgery were included in these studies. The aim of this study was to assess whether rectal cancer surgery can be performed safely without MBP.

Methods

The postoperative course was assessed in 52 consecutive unselected patients who underwent rectal cancer resection and sphincter preservation without MBP. This group was compared with a group of 61 matched patients in whom MBP was performed before surgery.

Results

The overall morbidity rate after rectal resection was higher in patients who had MBP than in those who did not (51 versus 31 per cent; P = 0·036). The incidence of symptomatic anastomotic leakage was similar in the two groups (8 versus 10 per cent respectively; P = 1·000). Although not significant, peritonitis occurred more frequently in the absence of MBP (2 versus 6 per cent; P = 0·294). A trend towards a higher rate of infectious complications was noted in patients who had MBP (23 versus 12 per cent; P = 0·141), but MBP was associated with a significantly higher rate of infectious extra-abdominal complications (11 versus 0 per cent; P = 0·014). Mean hospital stay was significantly longer in the MBP group (12 versus 10 days; P = 0·022).

Conclusion

Elective rectal surgery for cancer without MBP may be associated with reduced postoperative morbidity.
Photoreactivity and Photopolymerization of Silicon‐Bridged [1]Ferrocenophanes in the Presence of Terpyridine Initiators: Unprecedented Cleavage of Both Iron–Cyclopentadienyl Bonds in the Presence of Chlorosilanes
Authors: Chan Wing Yan , Lough Alan J. , Manners Ian
Published: July 2007

The photopolymerisation of sila[1]ferrocenophane [Fe(η‐C5H4)2SiMe2] (3) with 4,4′,4′′‐tri‐tert‐butyl‐2,2′:6′,2′′‐terpyridine (tBu3terpy) as initiator has been explored. High‐molecular‐weight polyferrocenylsilane (PFS) [{Fe(η‐C5H4)2SiMe2}n] (5) was formed in high yield when a stoichiometric amount of tBu3terpy was used at 5 °C. Photopolymerisation of ferrocenophane 3 at higher temperatures gave PFS 5 in lower yield and with a reduced molecular weight as a result of a slower propagation rate. Remarkably, when Me3SiCl was added as a capping agent before photopolymerisation, subsequent photolysis of the reaction mixture resulted in the unprecedented cleavage of both iron–Cp bonds in ferrocenophane 3: iron(II) complex [Fe(tBu3terpy)2Cl2] (7Cl) was formed and the silane fragment (C5H4SiMe3)2SiMe2 (8) was released. The iron–Cp bond cleavage reaction also proceeded in ambient light, although longer reaction times were required. In addition, the unexpected cleavage chemistry in the presence of Me3SiCl was found to be applicable to other photoactive ferrocenes such as benzoylferrocene. For benzoylferrocene and ferrocenophane 3, the presence of metal‐to‐ligand charge transfer (MLCT) character in their low‐energy transitions in the visible region probably facilitates photolytic iron–Cp bond cleavage, but this reactivity is suppressed when the strength of the iron–Cp bond is increased by the presence of electron‐donating substituents on the cyclopentadienyl rings.
Shaping immunity in healthy and diseased tissues
Authors: Borst Jannie , Ricciardi‐Castagnoli Paola
Published: July 2007

About one hundred immunologists recently met in Capo Caccia, Sardinia, for the first of three events that will comprise the EMBO Conference Series, organised by the ENII, on Molecular and Cellular Mechanisms of Immune Regulation. The 2007 Conference focused on how immunity is shaped in healthy and diseased tissues.
The Influence of the Gas Diffusion Layer on Water Management in Polymer Electrolyte Fuel Cells
Authors: Holmström N. , Ihonen J. , Lundblad A. , Lindbergh G.
Published: July 2007

Performance losses due to flooding of gas diffusion layers (GDLs) and flow fields as well as membrane dehydration are two of the major problems in PEFC. In this investigation, the effect of GDL on the cell water management in PEFC is studied using segmented and single cell experiments. The behaviour of four different commercial GDLs was investigated at both high and low inlet humidity conditions by galvanostatic fuel cell experiments. The influence of varying reactant humidity and gas composition was studied. The results at high inlet humidity show that none of the studied GDLs are significantly flooded on the anode side. On the other hand, when some of the GDLs are used on the cathode side they are flooded, leading to increased mass transfer losses. The results at low inlet humidity conditions show that the characteristics of the GDL influence the membrane hydration. It is also shown that inlet humidity on the anode side has a major effect on flooding at the cathode.
Second primary head and neck tumor risk in patients with cervical cancer—SEER data analysis
Authors: Rose Ragin Camille C. , Taioli Emanuela
Published: July 2007

Background.

Human papillomavirus (HPV) causes >99% of cervical carcinomas and is associated with approximately 25% of head and neck squamous cell carcinomas (HNSCCs). The role of HPV infection in HNSCC development after a first diagnosis of cervical cancer is unknown.

Methods.

Using the National Cancer Institute's Surveillance, Epidemiology, and End Results data, the authors compared the risk of second primary cancer (SPC) HNSCC in patients with cervical cancer with the general population and with females with other primary cancers.

Results.

The lifetime risk of SPC HNSCC for patients with cervical cancer was higher than in the general population (standardized incidence ratio [SIR]: 1.7). When compared with that in females with other cancers, the risk of anogenital and oropharyngeal SPC was in excess, but not of SPC in the oral cavity.

Conclusion.

Patients with cervical cancer develop an excess SPC HNSCC in comparison with females with other cancers. A possible role of HPV is suggested. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Amino acid substitutions in the hepatitis C virus core region are the important predictor of hepatocarcinogenesis
Authors: Akuta Norio , Suzuki Fumitaka , Kawamura Yusuke , Yatsuji Hiromi , Sezaki Hitomi , Suzuki Yoshiyuki , Hosaka Tetsuya , Kobayashi Masahiro , Kobayashi Mariko , Arase Yasuji , Ikeda Kenji , Kumada Hiromitsu
Published: July 2007

We showed previously that amino acid (aa) substitutions in hepatitis C virus core region (HCV-CR) are negative predictors of virologic response to pegylated interferon (IFN) plus ribavirin therapy. HCV-CR induces hepatocellular carcinoma in transgenic mice, but the clinical impact is still unclear. To evaluate the impact of aa substitutions in HCV-CR on hepatocarcinogenesis, we performed a follow-up study on 313 noncirrhotic consecutive naïve patients infected with HCV genotype 1b who received IFN monotherapy. The median follow-up was 14.7 years. A sustained virologic response (SVR) after the first IFN was achieved by 65 patients (20.8%) (group A). Of 248 patients (79.2%) of non-SVR after first IFN, 112 (35.8%) did not receive additional IFN (group B), and the remaining 136 (43.5%) received multicourse IFN monotherapy (group C). As a whole, cumulative hepatocarcinogenesis rates in double wild-type (arginine at aa 70/leucine at aa 91) of HCV-CR were significantly lower than those in nondouble wild-type. Multivariate analyses identified 3 parameters (fibrosis stage 3, nondouble wild-type of HCV-CR, and group B) that tended to or significantly influenced hepatocarcinogenesis independently. With regard to hepatocarcinogenesis rates in group C according to HCV-CR and the mean alanine aminotransferase (ALT) during IFN-free period, significantly higher rates were noted in patients of nondouble wild-type with ALT levels of more than 1.5 times the upper limit of normal (25.7%) compared with the others (2.4%).

Conclusion:

Amino acid substitutions in the HCV-CR are the important predictor of hepatocarcinogenesis. In multicourse IFN therapy to nondouble wild-type, we emphasize the importance of reducing the risk of hepatocarcinogenesis by mean ALT during an IFN-free period below 1.5 times the upper limit of normal.