bluuebunny/crossref_metadata_2025 huggingface dataset:
Choanal atresia associated with maternal hyperthyroidism treated with methimazole: A case–control study
Authors: Barbero Pablo , Valdez Rita , Rodríguez Hugo , Tiscornia Carlos , Mansilla Enrique , Allons Adriana , Coll Silvia , Liascovich Rosa
Published: August 2008

Thyrotoxicosis affects 0.2% of pregnant women and antithyroid drugs are the treatment of choice during pregnancy. Several case reports have suggested a relationship between the prenatal use of methimazole (MMI) and choanal atresia in the offspring. However, two epidemiological studies did not find an increased teratogenic risk for MMI. This multicenter case–control study compared the frequency of maternal hyperthyroidism treated with MMI during pregnancy, in children with choanal atresia (cases) and a control group randomly selected (three matched controls according to maternal age for each case). Mothers of cases (N = 61) and controls (N = 183) were interviewed for socio‐demographic questions, obstetrical and genetic history, and exposure during pregnancy to different agents; specifically detailed information regarding hyperthyroidism and MMI intake was obtained. Prenatal exposure to maternal hyperthyroidism treated with MMI was identified in 10/61 cases (16.4%) compared to 2/183 (1.1%) in the control group (OR = 17.75; CI95% = 3.49–121.40). Cases and controls did not differ in their parental degree of education, paternal occupation, twinning, maternal parity, and other exposures during pregnancy. Facial features in exposed cases showed some similarities. Our data suggest that prenatal exposure to maternal hyperthyroidism treated with MMI is associated with choanal atresia. In addition, based on our cases and a critical literature review, we propose that the mother's disease might be the causal factor and not the MMI treatment. © 2008 Wiley‐Liss, Inc.
Mechanical properties of green composites with polycaprolactone and wheat gluten
Authors: Finkenstadt V. L. , Mohamed A. A. , Biresaw G. , Willett J. L.
Published: August 2008

Wheat gluten (WG) was incorporated into polycaprolactone (PCL) (up to 50% w/w) as a filler to form a biodegradable polymer composite. A microscopic examination showed a well‐dispersed particle–matrix system. The composite was evaluated for its tensile properties. The tensile strength of the composite decreased linearly with increasing WG content from 20 (0% WG) to 6 MPa (50% WG). However, the reduction of the tensile strength did not fit the Nicolais–Narkis model, and this indicated that some adhesion between WG and PCL occurred. High elongation (>900%) was observed in PCL–WG composites with up to 20% WG; it decreased to 400% with 35% WG and finally to less than 100% with 40–50% WG. There was a particle‐induced transition at a calculated critical volume of 0.3 corresponding to 30% WG by weight with respect to PCL. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci, 2008
Tree thinking for all biology: the problem with reading phylogenies as ladders of progress
Authors: Omland Kevin E. , Cook Lyn G. , Crisp Michael D.
Published: August 2008

Phylogenies are increasingly prominent across all of biology, especially as DNA sequencing makes more and more trees available. However, their utility is compromised by widespread misconceptions about what phylogenies can tell us, and improved “tree thinking” is crucial. The most‐serious problem comes from reading trees as ladders from “left to right”—many biologists assume that species‐poor lineages that appear “early branching” or “basal” are ancestral—we call this the “primitive lineage fallacy”. This mistake causes misleading inferences about changes in individual characteristics and leads to misrepresentation of the evolutionary process. The problem can be rectified by considering that modern phylogenies of present‐day species and genes show relationships among evolutionary cousins. Emphasizing that these are extant entities in the 21st century will help correct inferences about ancestral characteristics, and will enable us to leave behind 19th century notions about the ladder of progress driving evolution. BioEssays 30:854–867, 2008. © 2008 Wiley Periodicals, Inc.
The birth of therapy with cultured cells
Authors: Green Howard
Published: August 2008

Long ago, I set out to solve a problem, but something happened along the way: I was diverted by an unexpected observation. Thereafter, the direction of my research was guided at each stage by increasing familiarity with the experimental material and what could be done with it. The result was the birth of therapy with cultured keratinocytes. Subsequent developments soon led to the formation of the company Biosurface Technology (later taken over by the Genzyme Corporation), which provided autologous cultures for burn victims in many parts of the world. Further progress by others led to new therapeutic applications of cultured keratinocytes, such as treatment of an ocular disease and gene therapy. Unfortunately, there have developed serious regulatory problems that are a danger to future progress. As described in this brief history, the initial stages of development of cell therapy for the treatment of human disease were possible only because there was no restraint by committees or governmental regulations. BioEssays 30:897–903, 2008. © 2008 Wiley Periodicals, Inc.
Imaging new neurons in vivo: a pioneering tool to study the cellular biology of depression?
Authors: Römer Benedikt , Sartorius Alexander , Inta Dragos , Vollmayr Barbara , Gass Peter
Published: August 2008

Hippocampal neurogenesis has been implicated in the pathogenesis of and recovery from depression. However, most of the underlying studies were endpoint investigations in experimental animals yielding conflicting results, and it has been under debate to which extent these results could be transferred to human patients. Now, researchers have developed a powerful new tool to address these questions by a non‐invasive method in humans and animals in vivo, using magnetic resonance spectroscopy to detect a biomarker for proliferating progenitor cells that give rise to new neurons.1 This makes it possible to study the role of neural progenitor cells in a wide variety of human brain disorders. BioEssays 30:806–810, 2008. © 2008 Wiley Periodicals, Inc.
Ecoimmunology: is there any room for the neuroendocrine system?
Authors: Ottaviani Enzo , Malagoli Davide , Capri Miriam , Franceschi Claudio
Published: August 2008

Ecological Immunology assumes that immunological defenses must be minimized in terms of cost (energy expenditure). To reach this goal, a complex and still largely unexplored strategy has evolved to assure survival. From invertebrates to vertebrates, an integrated immune–neuroendocrine response appears to be crucial for the hierarchical redistribution of resources within the body according to the specific ecological demands. Thus, on the basis of experimental data on the intimate relationship between stress and immune responses that has been maintained during evolution, we argue that a broader perspective based on the integration of immune and neuroendocrine responses should be adopted to describe the comprehensive strategy that the body utilizes to adapt to dynamic environmental conditions. We discuss the hypothesis that a bow‐tie architecture might be suitable to describe the variety of immune–neuroendocrine inputs that continuously target cells and organs while, at the same time, fulfilling the basic requirement of minimizing the cost of immune–neuroendocrine responses. Bow‐tie architectures are able to convert a variety of stimuli (fan in) into a wide range of fine‐tuned responses (fan out) by passing through the integrating activity of a core (knot) constituted by a limited number of elements. Finally, we argue that the ecologically negotiated immune–neuroendocrine strategies may have deleterious effects in the post‐reproductive period of life when, at least in humans, chronic, low‐grade, systemic inflammation develops, in accordance with the antagonistic pleiotropy theory of aging. BioEssays 30:868–874, 2008. © 2008 Wiley Periodicals, Inc.
The control of size in animals: insights from selector genes
Authors: Crickmore Michael A. , Mann Richard S.
Published: August 2008

How size is controlled during animal development remains a fascinating problem despite decades of research. Here we review key concepts in size biology and develop our thesis that much can be learned by studying how different organ sizes are differentially scaled by homeotic selector genes. A common theme from initial studies using this approach is that morphogen pathways are modified in numerous ways by selector genes to effect size control. We integrate these results with other pathways known to regulate organ size in developing a comprehensive model for organ size control. ©2007 Wiley Periodicals, Inc BioEssays 30:843–853, 2008. © 2008 Wiley Periodicals, Inc.
Nucleic acid‐mediated inflammatory diseases
Authors: Rigby Rachel E. , Leitch Andrea , Jackson Andrew P.
Published: August 2008

Enzymes that degrade nucleic acids are emerging as important players in the pathogenesis of inflammatory disease. This is exemplified by the recent identification of four genes that cause the childhood inflammatory disorder, Aicardi‐Goutières syndrome (AGS). This is an autosomal recessive neurological condition whose clinical and immunological features parallel those of congenital viral infection. The four AGS genes encode two nucleases: TREX1 and the hetero‐trimeric Ribonuclease H2 (RNase H2) complex. The biochemical activity of these enzymes was initially characterised 30 years ago but a role in neurological inflammation was entirely unanticipated until they were found to be mutated in AGS. This has led to a hypothesis that accumulation of intracellular nucleic acids occurs as a consequence of mutation in these enzymes and triggers an inflammatory response through activation of innate immune pattern recognition receptors. ©2007 Wiley Periodicals, Inc BioEssays 30:833–842, 2008. © 2008 Wiley Periodicals, Inc.
Probing Kinase Activities by Electrochemistry, Contact‐Angle Measurements, and Molecular‐Force Interactions
Authors: Wilner Ofer I. , Guidotti Claudio , Wieckowska Agnieszka , Gill Ron , Willner Itamar
Published: August 2008

Three different methods to investigate the activity of a protein kinase (casein kinase, CK2) are described. The phosphorylation of the sequence‐specific peptide (1) by CK2 was monitored by electrochemical impedance spectroscopy (EIS). Phosphorylation of the peptide monolayer assembled on a Au electrode yields a negatively charged surface that electrostatically repels the negatively charged redox label [Fe(CN)6]3−/4−, thus increasing the interfacial electron‐transfer resistance. The phosphorylation process by CK2 is further amplified by the association of the anti‐phosphorylated peptide antibody to the monolayer. Binding of the antibody insulates the electrode surface, thus increasing the interfacial electron‐transfer resistance in the presence of the redox label. This method enabled the quantitative analysis of the concentration of CK2 with a detection limit of ten units. The second method employed involved contact‐angle measurements. Although the peptide 1‐functionalized electrode revealed a contact angle of 67.5°, phosphorylation of the peptide yielded a surface with enhanced hydrophilicity, 36.8°. The biocatalyzed cleavage of the phosphate units with alkaline phosphatase regenerates the hydrophobic peptide monolayer, contact angle 55.3°. The third method to characterize the CK2 system involved chemical force measurements between the phosphorylated peptide monolayer associated with the Au surface and a Au tip functionalized with the anti‐phosphorylated peptide antibody. Although no significant rupture forces existed between the modified tip and the 1‐functionalized surface (6±2 pN), significant rupture forces (multiples of 120±20 pN) were observed between the phosphorylated monolayer‐modified surface and the antibody‐functionalized tip. This rupture force is attributed to the dissociation of a simple binding event between the phosphorylated peptide and the fluorescent antibody (Fab) binding region.
Electrochemically Controlled Formation/Dissociation of Phosphonate‐Cavitand/Methylpyridinium Complexes
Authors: Gadenne Benoît , Semeraro Monica , Yebeutchou Roger M. , Tancini Francesca , Pirondini Laura , Dalcanale Enrico , Credi Alberto
Published: August 2008

The phosphorus‐bridged cavitand 1 self‐assembles very efficiently in CH2Cl2 with either the monopyridinium guest 2+ or the bispyridinium guest 32+. In the first case a 1:1 complex is obtained, whereas in the second case both 1:1 and 2:1 host–guest complexes are observed. The association between 1 and either one of the guests causes the quenching of the cavitand fluorescence; in the case of the adduct between 1 and 32+, the fluorescence of the latter is also quenched. Cavitand complexation is found to affect the reduction potential values of the electroactive guests. Voltammetric and spectroelectrochemical measurements show that upon one‐electron reduction both guests are released from the cavity of 1. Owing to the chemical reversibility of such redox processes, the supramolecular complexes can be re‐assembled upon removal of the extra electron from the guest. Systems of this kind are promising for the construction of switchable nanoscale devices and self‐assembling supramolecular materials, the structure and properties of which can be reversibly controlled by electrochemical stimuli.
Intracellular Uptake and Photodynamic Activity of Water‐Soluble [60]‐ and [70]Fullerenes Incorporated in Liposomes
Authors: Doi Yuki , Ikeda Atsushi , Akiyama Motofusa , Nagano Mai , Shigematsu Tamami , Ogawa Takuya , Takeya Tatsuo , Nagasaki Takeshi
Published: August 2008

Water‐soluble fullerenes have attracted attention as promising compounds that have been used to forge new paths in the field of photo‐biochemistry. To prepare water‐soluble fullerenes, we employed lipid‐membrane‐incorporated fullerenes (LMICx; x=60 or 70) by using the fullerene exchange method from a γ‐cyclodextrin (γ‐CD) cavity to vesicles. LMIC60 have low toxicity in the dark and engender cell death by photoirradiation (λ>350 nm). Furthermore, the photodynamic activity of LMIC70 is 4.7‐fold that of LMIC60 for the same photon flux (λ>400 nm). One of the reasons for the higher phototoxicity of LMIC70 is the higher generation of singlet oxygen (1O2) in LMIC70 than in LMIC60. The difference between LMIC60 and LMIC70 is considered to be simply derived from the amount of light absorption in the 400–700 nm region that is suitable for photodynamic therapy (PDT). To the best of our knowledge, this is the first case in which biological activity of C70 and its derivatives toward HeLa cells has been assayed.
Structural transition during thermal denaturation of collagen in the solution and film states
Authors: Shanmugam Ganesh , Polavarapu Prasad L.
Published: August 2008

Temperature dependent vibrational circular dichroism (VCD) spectra of type I collagen, in solution and film states, have been measured. These spectra obtained for solution sample suggest that the thermal denaturation of collagen results in transition from poly‐L‐proline II (PPII) to unordered structure. The PPII structure of collagen is identified by the presence of negative VCD couplet in the amide I region, while the formation of unordered structure is indicated by the disappearance of VCD in the amide I region. The temperature dependent spectra obtained for the supported collagen film indicated a biphasic transition, which is believed to be the first vibrational spectroscopic report to support a biphasic transition during thermal denaturation of collagen film. The temperature dependent spectra of collagen films suggest that the thermal stability of collagen structure depends on its state and decreases in the order: supported film > free standing film > solution state. These observations are believed to be significant in the VCD spectroscopic analysis of secondary structures of proteins and peptides. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Stereo‐selective activity of menthol on GABAAreceptor
Authors: Corvalán Natalia A. , Zygadlo Julio A. , García Daniel A.
Published: August 2008

Menthol is a naturally occurring compound, which has three chiral centers that define eight possible optically actives stereoisomers. Neuroactivity of menthol and related agents by affecting neuronal intracellular signaling or by modulation of neurotransmitter‐gated currents has been reported. Furthermore, stereo‐selectivity of menthol in its analgesic activity as well as in its sensory properties and other biological activities was also described. The present study is the first contribution to the description of stereo‐selectivity of GABAAreceptor against the most possible isomers of menthol, discussed in terms of their chirality. The results showed that only (+)‐menthol, among the five stereoisomers analyzed, was active, stimulating in a dose‐response manner the binding of an allosteric GABAAreceptor ligand. Taking into account these results, and comparing them with those of some active phenolic compounds, it is strongly suggested that the existence of a relative spatial location of its substituents with respect to the ring (equatorial position of all substituents and (1S,2R,5S)‐configuration) as well as the presence in the cyclic molecule of an aliphatic non polar group (isopropyl) with free rotation near to a polar group (hydroxyl) are crucial points to demonstrate activity on the receptor. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Gas chromatographic enantioseparation of unfunctionalized chiral alkanes: A challenge in separation science (overview, state of the art, and perspectives)
Authors: Sicoli Giuseppe , Kreidler Diana , Czesla Harri , Hopf Henning , Schurig Volker
Published: August 2008

The chromatographic enantioseparation of small unfunctionalized chiral alkanes C*HR1R2R3 (R = alkyl) represents a challenge in separation science. Because of the lack of any functional groups, enantiorecognition in the presence of a chiral selector is solely based upon weak enantioselective Van der Waals forces. Racemic alkanes containing seven and eight carbon atoms, i.e. 3‐methylhexane (C7), 2,3‐dimethylpentane (C7), 3‐methylheptane (C8), 3,4‐dimethylhexane (C8), 2,4‐dimethylhexane (C8), 2,3‐dimethylhexane (C8), and 2,2,3‐trimethylpentane (C8) have been gas chromatographically enantioseparated on different modified cyclodextrins. The substitution pattern and cavity size of the cyclodextrin selectors have a pronounced effect on the degree of enantiorecognition observed. Thermodynamic parameters of enantiorecognition between four chiral alkanes and octakis(6‐O‐methyl‐2,3‐di‐O‐pentyl)‐γ‐cyclodextrin (Lipodex G) have been determined. The possible role of molecular inclusion is indicated by the complete loss of enantioselectivity when the cyclodextrins are replaced by the corresponding linear dextrins (“acyclodextrins”). The enantioseparations of all seven chiral C7‐C8 alkanes, six of them simultaneously, has been achieved on mixed binary selector systems whereby two different modified cyclodextrins are present in one gas chromatographic column. The smallest chiral (nonisotopically labeled) allene, i.e., 2,3‐pentadiene, has been resolved gas chromatographically on a cyclodextrin selector. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Enantiomeric separation of chiral ruthenium(II) complexes using capillary electrophoresis
Authors: Jiang Chunxia , Tong Man‐Yung , Armstrong Daniel W. , Perera Sirantha , Bao Ye , MacDonnell Frederick M.
Published: August 2008

Capillary zone electrophoresis (CZE) and micellar capillary electrophoresis (MCE) were applied for the enantiomeric separation of nine mononuclear tris(diimine)ruthenium(II) complexes as well as the separation of all stereoisomers of a dinuclear tris(diimine)ruthenium(II) complex. Nine cyclodextrin (CD) based chiral selectors were examined as run buffer additives to evaluate their effectiveness in the enantiomeric separation of tris(diimine)ruthenium(II) complexes. Seven showed enantioselectivity. Sulfated γ‐cyclodextrin (SGC), with four baseline and three partial separations, was found to be the most useful chiral selector. In CZE mode, the derivatized γ‐CDs were more effective than β‐CDs while sulfated CDs work better than carboxymethyl CDs. In MCE mode, hydroxypropyl β‐CD separated the greatest number of tris(diimine) ruthenium(II) complexes. The effects of chiral selector concentration, run buffer pH and concentration, the concentration ratio between chiral selector and other factors were investigated. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Visualization of Intrinsically Disordered Regions of Proteins by High‐Speed Atomic Force Microscopy
Authors: Miyagi Atsushi , Tsunaka Yasuo , Uchihashi Takayuki , Mayanagi Kouta , Hirose Susumu , Morikawa Kosuke , Ando Toshio
Published: August 2008

Intrinsically disordered (ID) regions of proteins are recognized to be involved in biological processes such as transcription, translation, and cellular signal transduction. Despite the important roles of ID regions, effective methods to observe these thin and flexible structures directly were not available. Herein, we use high‐speed atomic force microscopy (AFM) to observe the heterodimeric FACT (facilitates chromatin transcription) protein, which is predicted to have large ID regions in each subunit. Successive AFM images of FACT on a mica surface, captured at rates of 5–17 frames per second, clearly reveal two distinct tail‐like segments that protrude from the main body of FACT and fluctuate in position. Using deletion mutants of FACT, we identify these tail segments as the two major ID regions predicted from the amino acid sequences. Their mechanical properties estimated from the AFM images suggest that they have more relaxed structures than random coils. These observations demonstrate that this state‐of‐the‐art microscopy method can be used to characterize unstructured protein segments that are difficult to visualize with other experimental techniques.
Intrusive images in grief: an exploratory study
Authors: Boelen Paul A. , Huntjens Rafaele J. C.
Published: August 2008

The relevance of intrusive mental imagery to the understanding and treatment of psychological disorders is increasingly acknowledged. Little research has been done on intrusive imagery in grief. Using a sample of 131 mourners, recruited from professional and lay mental health care workers, the current study examined the frequency and correlates of four specific intrusive images: (a) positive intrusive memories of the lost person; (b) intrusive images of the death event; (c) re‐enactment fantasies; and (d) negative images of the future. Findings revealed that these intrusions were common and that the occurrence of these intrusions hardly varied across subgroups of mourners. All four intrusions were correlated with the severity of complicated grief symptoms, and intrusions (b), (c) and (d) were also correlated with the severity of symptoms of depression and anxiety. Findings have potential theoretical and clinical implications and indicate that a more comprehensive study of intrusions among bereaved people is warranted. Copyright © 2008 John Wiley & Sons, Ltd.
Emotion regulation as mediator of treatment outcome in therapy for deliberate self‐harm
Authors: Slee Nadja , Spinhoven Philip , Garnefski Nadia , Arensman Ella
Published: August 2008

This study presents the outcomes of mediator analyses as part of a randomized controlled trial of Cognitive‐Behavioural Therapy (CBT) for young people who engage in deliberate self‐harm (DSH). The study involved 90 people, aged 15–35 years, who were randomly assigned to CBT in addition to treatment as usual or to treatment as usual only. The findings showed that changes in DSH were partially mediated by changes in emotion‐regulation difficulties, particularly difficulties with impulse control and goal‐directed behaviours. In addition, the potential mediating role of symptoms of depression, anxiety and suicidal cognitions was examined. Although the CBT intervention significantly reduced depression, anxiety and suicidal cognitions, these measures of symptom severity did not play a mediating role. These findings suggest that interventions for DSH should not primarily focus on mental disorders associated with DSH, but should be DSH‐specific and should target specific emotion‐regulation difficulties. Copyright © 2008 John Wiley & Sons, Ltd.
Is therapist alliance or whole group cohesion more influential in group psychotherapy outcomes?
Authors: Crowe Trevor P. , Grenyer Brin F. S.
Published: August 2008

This study examined the differential ability of early in treatment measures of therapeutic alliance (Working Alliance Inventory), group cohesion (California Psychotherapy Alliance Scale for Group) and group climate (Group Climate Questionnaire) to predict outcome in a 16‐session dynamic group psychotherapy for adults with major depression. Six successful therapy groups with 30 patients receiving psychodynamic group therapy were studied. Patient perceptions of the therapist alliance was not related to outcome, however, perceptions of levels of conflict and group members' ability to work actively and purposefully in treatment did predict outcome. Future research should further investigate how patients' perceptions of the whole group influence their clinical improvement. Copyright © 2008 John Wiley & Sons, Ltd.
A time‐dominated TCP congestion control over heterogeneous networks
Authors: Lee Jongmin , Cha Hojung , Ha Rhan
Published: August 2008

The traditional transmission control protocol (TCP) suffers from performance problems such as throughput bias against flows with longer packet roundtrip time (RTT), which leads to burst traffic flows producing high packet loss, long delays, and high delay jitter. This paper proposes a TCP congestion control mechanism, TD‐TCP, that the sender increases the congestion window according to time rather than receipt of acknowledgement. Since this mechanism spaces out data sent into the network, data are not sent in bursts. In addition, the proposed mechanism reduces throughput bias because all flows increase the congestion window at the same rate regardless of their packet RTT. The implementation of the mechanism affects only the protocol stack at the sender; hence, neither the receiver nor the routers need modifications. The mechanism has been implemented in the Linux platform and tested in conjunction with various TCP variants in real environments. The experimental result shows that the proposed mechanism improves transmission performance, especially in networks with congestion and/or high packet loss rates. Experiments in real commercial wireless networks have also been conducted to support the proposed mechanism's practical use. Copyright © 2008 John Wiley & Sons, Ltd.
The role of twist during palate development
Authors: Yu Wenli , Kamara Harold , Svoboda Kathy K. H.
Published: August 2008

In palatogenesis, the MEE (Medial Edge Epithelium) cells disappear when palates fuse. We hypothesize that the MEE cells undergo EMT (Epithelial‐Mesenchymal Transition) to achieve mesenchyme confluence. Twist has an important role in EMT for tumor metastasis. The purpose of this study was to analyze Twist function during palatal fusion. Twist protein was expressed in palatal shelves and MEE both in vivo and in vitro just prior to fusion. Twist mRNA increased in chicken palates 3 and 6 hr after TGFβ3 treatment. Palatal fusion was decreased when cultured palatal shelves were treated with 200 nM Twist siRNA and the subcellular localization of β‐catenin was altered. Twist mRNA decreased in palatal shelves treated with TGFβ3 neutralizing antibody or LY294002, a specific phosphatidylinositol‐3 kinase (PI‐3K) inhibitor. In summary, Twist is downstream of TGFβ3 and PI‐3K pathways during palatal fusion. However, decreasing Twist with siRNA did not completely block palate fusion, indicating that the function of Twist may be duplicated by other transcription factors. Developmental Dynamics 237:2716–2725, 2008. © 2008 Wiley‐Liss, Inc.
Cellular nonmuscle myosins NMHC‐IIA and NMHC‐IIB and vertebrate heart looping
Authors: Lu Wenge , Seeholzer Steven H. , Han Mingda , Arnold Anne‐Sophie , Serrano Maria , Garita Barbara , Philp Nancy J. , Farthing Cassandra , Steele Peter , Chen Jizhen , Linask Kersti K.
Published: August 2008

Flectin, a protein previously described to be expressed in a left‐dominant manner in the embryonic chick heart during looping, is a member of the nonmuscle myosin II (NMHC‐II) protein class. During looping, both NMHC‐IIA and NMHC‐IIB are expressed in the mouse heart on embryonic day 9.5. The patterns of localization of NMHC‐IIB, rather than NMHC‐IIA in the mouse looping heart and in neural crest cells, are equivalent to what we reported previously for flectin. Expression of full‐length human NMHC‐IIA and ‐IIB in 10 T1/2 cells demonstrated that flectin antibody recognizes both isoforms. Electron microscopy revealed that flectin antibody localizes in short cardiomyocyte cell processes extending from the basal layer of the cardiomyocytes into the cardiac jelly. Flectin antibody also recognizes stress fibrils in the cardiac jelly in the mouse and chick heart; while NMHC‐IIB antibody does not. Abnormally looping hearts of the NodalΔ 600 homozygous mouse embryos show decreased NMHC‐IIB expression on both the mRNA and protein levels. These results document the characterization of flectin and extend the importance of NMHC‐II and the cytoskeletal actomyosin complex to the mammalian heart and cardiac looping. Developmental Dynamics 237:3577–3590, 2008. © 2008 Wiley‐Liss, Inc.
Man1, an inner nuclear membrane protein, regulates left–right axis formation by controlling nodal signaling in a node‐independent manner
Authors: Ishimura Akihiko , Chida Shinsuke , Osada Shin‐Ichi
Published: August 2008

Man1, an inner nuclear membrane protein, regulates transforming growth factor β signaling by interacting with receptor‐associated Smads. In Man1‐deficient (Man1Δ/Δ) embryos, vascular remodeling is perturbed by misregulation of Smad activity. Here, we show that Man1Δ/Δ embryos exhibit abnormal heart morphogenesis including the looping abnormality. We searched for the molecular basis underlying the heart abnormalities and found that the left side‐specific genes responsible for left–right (LR) asymmetry, Nodal, Lefty2, and Pitx2, were expressed bilaterally in the lateral plate mesoderm and that their expression was enhanced significantly in mutants. Notably, Lefty1, a marker for the midline barrier, was maintained in Man1Δ/Δ mutants. Crossing Man1Δ/+ with Nodal hypomorphs (Nodalneo/+), in which Nodal signaling in the node is disrupted, to generate double homozygous embryos (Man1Δ/Δ; Nodalneo/neo) revealed that the bilateral Nodal was retained in Man1Δ/Δ; Nodalneo/neo embryos. These results suggest that Man1 regulates LR asymmetry by controlling Nodal signaling in a node‐independent manner. Developmental Dynamics 237:3565–3576, 2008. © 2008 Wiley‐Liss, Inc.
1‐(Pyridin‐2‐yl)methanamine‐Based Ruthenium Catalysts for Fast Transfer Hydrogenation of Carbonyl Compounds in 2‐Propanol
Authors: Baratta Walter , Rigo Pierluigi
Published: August 2008

This Microreview focuses on the development of novel ruthenium complexes displaying high performance in the catalytic asymmetric transfer hydrogenation of ketones with 2‐propanol, providing this procedure alternative to the hydrogenation with dihydrogen. The key role is played by 1‐(pyridin‐2‐yl)methanamine (Pyme) type ligands which in combination with appropriate phosphanes afforded ruthenium systems of unprecedented high catalytic activity and productivity for the reduction of ketones and aldehydes. For the pincer CNN complexes a mixed inner‐outer sphere mechanism involving Ru‐hydride and Ru‐alkoxide species is proposed. The excellent properties of these complexes are expected to have implications for the design of a new generation of catalysts.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Improved Preparation of 4,6,6‐Trimethyl‐1,3,2‐dioxaborinane and Its Use in a Simple [PdCl2(TPP)2]‐Catalyzed Borylation of Aryl Bromides and Iodides
Authors: PraveenGanesh Nageswaran , Chavant Pierre Yves
Published: August 2008

We describe a convenient preparation of 4,6,6‐trimethyl‐1,3,2‐dioxaborinane (MethylPentaneDiolBorane, MPBH) and demonstrate that it is an excellent reagent for the [PdCl2(PPh3)2]‐catalyzed borylation of aryl bromides and iodides. The corresponding boronic esters undergo rapid Suzuki coupling reactions in the presence of cesium fluoride. Thus, MPBH is an excellent alternative to pinacolborane for Pd‐catalyzed borylation and cross‐coupling reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A numerical model of infiltration processes for hysteretic flow coupled with mass conservation
Authors: Tan Yih‐Chi , Ma Kuo‐Chen , Chen Chu‐Hui , Ke Kai‐Yuan , Wang Ming‐Tsan
Published: August 2008

The study presents a numerical infiltration model of a hysteretic flow coupled with general mass conservation for practical application to unsaturated soil. In unsaturated soil, hysteresis is an important phenomenon in the complicated hydrological processes, and it is usually ignored when simulating the relationship of soil water content. The governing equation of unsaturated flow is the Richards equation, and it is difficult to obtain the analytic solutions because of the variation of temporal boundary conditions and the dynamics of change of soil water content in the vadose zone. The numerical solution is solved by the finite difference method technique with the Picard iteration scheme combined with the hysteresis model derived by Huang et al. (2005) and the mass conservation control within simulation domain. The results showed that the mixed form had better mass conservation. The present numerical solutions with the hysteresis model were verified by Gillham's experimental data of 1979. The results of the present mixed form numerical approximations with hysteresis effect are better than without hysteresis. In order to raise the accuracy of the soil water relationship numerical model, hysteresis and mass conservation are important factors in infiltration processes. Copyright © 2008 John Wiley & Sons, Ltd.
Hypoxia and oxidation levels of DNA and lipids in humans and animal experimental models
Authors: Møller Peter , Risom Lotte , Lundby Carsten , Mikkelsen Lone , Loft Steffen
Published: August 2008

The objective of this review was to evaluate the association between hypoxia and oxidative damage to DNA and lipids. Evaluation criteria encompassed specificity and validation status of the biomarkers, study design, strength of the association, dose‐response relationship, biological plausibility, analogous exposures, and effect modification by intervention. The collective interpretation indicates persuasive evidence from the studies in humans for an association between hypoxia and elevated levels of oxidative damage to DNA and lipids. The levels of oxidatively generated DNA lesions and lipid peroxidation products depend on both the duration and severity of the exposure to hypoxia. Largest effects are observed with exposure to hypoxia at high altitude, but other factors, including ultraviolet light, exercise, exertion, and low intake of antioxidants, might contribute to the effect observed in subjects at high altitude. Most of the animal experimental models should be interpreted with caution because the assays for assessment of lipid peroxidation products have suboptimal validity. © 2008 IUBMB IUBMB Life, 60(11): 707–723, 2008
Biomaterial and antibiotic strategies for peri‐implantitis: A review
Authors: Norowski P. Andrew , Bumgardner Joel D.
Published: August 2008

Dental implants have 89% plus survival rates at 10–15 years, but peri‐implantitis or dental implant infections may be as high as 14%. Peri‐implantitis can limit clinical success and impose health and financial burdens to patients and health providers. The pathogenic species associated with periodontitis (e.g., Fusobacterium ssp, A. actinomycetemcomitans, P. gingivalis) are also associated with peri‐implantitis. Incidence of peri‐implantitis is highest within the first 12 months after implantation, and is higher in patients who smoke or have poor oral health as well as with calcium‐phosphate‐coated or surface‐roughened implants. Biomaterial therapies using fibers, gels, and beads to deliver antibiotics have been used in the treatment of Peri‐implantitis though clinical efficacy is not well documented. Guided tissue regeneration membranes (e.g., collagen, poly‐lactic/glycolic acid, chitosan, ePTFE) loaded with antimicrobials have shown success in reosseointegrating infected implants in animal models but have not been proven in humans. Experimental approaches include the development of anti‐bioadhesion coatings, coating surfaces with antimicrobial agents (e.g., vancomycin, Ag, Zn) or antimicrobial releasing coatings (e.g., calcium phosphate, polylactic acid, chitosan). Future strategies include the development of surfaces that become antibacterial in response to infection, and improvements in the permucosal seal. Research is still needed to identify strategies to prevent bacterial attachment and enhance normal cell/tissue attachment to implant surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Multinozzle low‐temperature deposition system for construction of gradient tissue engineering scaffolds
Authors: Liu Li , Xiong Zhuo , Yan Yongnian , Zhang Renji , Wang Xiaohong , Jin Le
Published: August 2008

Tissue engineering is a technology that enables us to construct complicated hominine organs composed of many different types of cells. One of the key points to achieve this goal is to control the material composition and porous structure of the scaffold accurately. A disposable syringe based volume‐driven injecting (VDI) nozzle was proposed and designed to extrude both natural derived and synthetic polymers. A multinozzle low‐temperature deposition and manufacturing (M‐LDM) system is proposed to fabricate scaffolds with heterogeneous materials and gradient hierarchical porous structures. PLGA, collagen, gelatin, chitosan can be extruded without leaking to form hierarchical porous scaffolds for primary study. Composite scaffolds with two kinds of materials were fabricated via two different nozzles to get both hydrophilic and mechanical properties. The results from scanning electron microscopy (SEM) demonstrated that the natural‐derived biomaterials were strongly absorbed onto the synthetic biomaterials to form a stable network. Several gradient PLGA/TCP scaffolds were also fabricated to supply several samples. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Characterization of saccharides and phenolic acids in the Chinese herb Tanshen by ESI‐FT‐ICR‐MS and HPLC
Authors: Li Huilin , Song Fengrui , Zheng Zhong , Liu Zhiqiang , Liu Shuying
Published: August 2008

This study sought to determine the main components (saccharides and phenolic acids) in crude extract of the Chinese herb Tanshen by electrospray ionization Fourier transform ion cyclotron resonant mass spectrometry (ESI‐FT‐ICR‐MS) in negative‐ion mode. Eleven compounds were identified as phenolic acids by exact mass measurement and further confirmed by sustained off‐resonance irradiation (SORI) CID data. In addition, monosaccharides and oligosaccharides (n = 2 ∼ 5) and a serial of corresponding anionic adducts of saccharide were observed without adding any anions additionally to the extract solution, and the anionic components were unambiguously identified as H2O, HCl, HCOOH, HNO3, C3H6O2, H2SO4 and C5H7NO3 according to the exact mass measurement results. Furthermore, the saccharide types in Tanshen extract were identified as raffitrinose, saccharose, glucose, galactose and fructose with HPLC by comparing standards. Copyright © 2008 John Wiley & Sons, Ltd.
A fast screening MALDI method for the detection of cocaine and its metabolites in hair
Authors: Vogliardi Susanna , Favretto Donata , Frison Giampietro , Ferrara Santo Davide , Seraglia Roberta , Traldi Pietro
Published: August 2008

Matrix‐assisted laser desorption/ionisation (MALDI) mass spectrometry was used for the rapid detection of cocaine, benzoylecgonine and cocaethylene in hair. Different MALDI sample preparation procedures have been tested and the employment of a multi‐layer ‘graphite–sample–electrosprayed α‐cyano‐4‐hydroxycinnamic acid (HCCA)’ yielded the best results for standard solutions of the target analytes. The same approach was subsequently applied to hair samples that were known to contain cocaine, benzoylecgonine and cocaethylene, as determined by a classical GC‐MS method. It was however necessary to extract hair samples by incubating them in methanol/trifluoroacetic acid for a short time (15 min) at 45 °C; 1 µl of the obtained supernatant was deposed on a metal surface treated with graphite, and HCCA was electrosprayed on it. This procedure successfully suppressed matrix peaks and was effective in detecting all the target analytes as their protonated species. The results obtained give further confirmation of the effectiveness of the MALDI for detecting drugs and their metabolites in complex biological matrices. The method can be useful as a fast screening procedure to detect the presence of cocaine and metabolites in hair samples. Copyright © 2008 John Wiley & Sons, Ltd.
Co‐oxidation of ammonia and ethanol in supercritical water, part 2: Modeling demonstrates the importance ofH2NNOx
Authors: Ploeger Jason M. , Green William H. , Tester Jefferson W.
Published: August 2008

A co‐oxidation model was constructed from available submechanisms for ammonia and ethanol oxidation. The ammonia submechanism validated for combustion at atmospheric pressure conditions was modified for the higher densities and lower temperatures (655–700°C) of supercritical water. The ethanol submechanism had previously been tested and validated at supercritical water conditions. The initial model poorly reproduced experimental ammonia conversion data and was not able to consistently match nitrous oxide production as a function of temperature over a range from 655–700°C at 246 bar. To improve model predictions, the low‐pressure NH2+ NOxsubmechanism was replaced with a submechanism that included the H2NNOxadduct species that are expected to be stabilized in the high‐pressure supercritical water environment. Thermochemical and kinetic parameters for the adduct species were estimated with quantum chemical calculations using Gaussian 98 with the CBS‐Q method. The explicit treatment of the H2NNOxadducts resulted in nitrous oxide yield predictions that correctly reproduced experimental trends. This work represents a vital first step in improving the understanding of ammonia oxidation in supercritical water. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 653–662, 2008
Rate coefficients for the OH + acetaldehyde (CH3CHO) reaction between 204 and 373 K
Authors: Zhu Lei , Talukdar Ranajit K. , Burkholder James B. , Ravishankara A. R.
Published: August 2008

The rate coefficient, k1, for the gas‐phase reaction OH + CH3CHO (acetaldehyde) → products, was measured over the temperature range 204–373 K using pulsed laser photolytic production of OH coupled with its detection via laser‐induced fluorescence. The CH3CHO concentration was measured using Fourier transform infrared spectroscopy, UV absorption at 184.9 nm and gas flow rates. The room temperature rate coefficient and Arrhenius expression obtained are k1(296 K) = (1.52 ± 0.15) × 10−11 cm3 molecule−1 s−1 and k1(T) = (5.32 ± 0.55) × 10−12 exp[(315 ± 40)/T] cm3 molecule−1 s−1. The rate coefficient for the reaction OH (ν = 1) + CH3CHO, k7(T) (where k7 is the rate coefficient for the overall removal of OH (ν = 1)), was determined over the temperature range 204–296 K and is given by k7(T) = (3.5 ± 1.4) × 10−12 exp[(500 ± 90)/T], where k7(296 K) = (1.9 ± 0.6) × 10−11 cm3 molecule−1 s−1. The quoted uncertainties are 2σ (95% confidence level). The preexponential term and the room temperature rate coefficient include estimated systematic errors. k7 is slightly larger than k1 over the range of temperatures included in this study. The results from this study were found to be in good agreement with previously reported values of k1(T) for temperatures <298 K. An expression for k1(T), suitable for use in atmospheric models, in the NASA/JPL and IUPAC format, was determined by combining the present results with previously reported values and was found to be k1(298 K) = 1.5 × 10−11 cm3 molecule−1 s−1, f(298 K) = 1.1, E/R = 340 K, and Δ E/R (or g) = 20 K over the temperature range relevant to the atmosphere. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 635–646, 2008
A shock tube study of cyclopentane and cyclohexane ignition at elevated pressures
Authors: Daley Shane M. , Berkowitz Andrew M. , Oehlschlaeger Matthew A.
Published: August 2008

Ignition delay times for cyclopentane/air and cyclohexane/air mixtures were measured in a shock tube at temperatures of 847–1379 K, pressures of 11–61 atm, and equivalence ratios of ϕ = 1.0, 0.5, and 0.25. Ignition times were determined using electronically excited OH emission monitored through the shock tube endwall and piezoelectric pressure measurements made in the shock tube sidewall. The dependence of ignition time on pressure, temperature, and equivalence ratio is quantified and correlations for ignition time formulated. Measured ignition times are compared to kinetic modeling predictions from four recently published mechanisms. The data presented provide a database for the validation of cycloalkane kinetic mechanisms at the elevated pressures found in practical combustion engines. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 624–634, 2008
Mechanical and Thermal Properties of Green Polylactide Composites with Natural Fillers
Authors: Lezak Emil , Kulinski Zbigniew , Masirek Robert , Piorkowska Ewa , Pracella Mariano , Gadzinowska Krystyna
Published: August 2008

Green composites of PLA with micropowders derived from agricultural by‐products such as oat husks, cocoa shells, and apple solids that remain after pressing have been prepared by melt mixing. The thermal and mechanical properties of the composites, including the effect of matrix crystallization and plasticization with poly(propylene glycol), have been studied. All fillers nucleated PLA crystallization and decreased the cold‐crystallization temperature. They also affected the mechanical properties of the compositions, increasing the modulus of elasticity but decreasing the elongation at break and tensile impact strength although with few exceptions. Plasticization of the PLA matrix improved the ductility of the composites.

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Tetronic–Oligolactide–Heparin Hydrogel as a Multi‐Functional Scaffold for Tissue Regeneration
Authors: Go Dong Hyun , Joung Yoon Ki , Lee Sang Young , Lee Myung Chul , Park Ki Dong
Published: August 2008

A novel cell‐supporting scaffold, Tetronic–oligolactide–heparin (TLH) hydrogel, was prepared by coupling heparin to polymerized Tetronic–oligolactide for use in improving tissue regeneration. Aqueous TLH solutions showed thermosensitive behavior, demonstrating potential for use as injectable hydrogels. The content and activity of conjugated heparin were determined to be 61 wt.‐% of total polymer and 67.2% of intact heparin activity, respectively. The basic fibroblast growth factor (bFGF) binding assay showed TLH hydrogel had a relatively high bFGF affinity, which indicates applicability for growth factor delivery. Chondrocyte culture on hydrogels revealed that the cell viability and the amount of synthesized glycosaminoglycan for TLH hydrogel were higher than those for alginate gel.

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