bluuebunny/crossref_metadata_2025 huggingface dataset:
The Inhibitory Effects of Insulin on Hepatic Glucose Production Are Both Direct and Indirect
Authors: Girard Jean
Published: December 2006

Previous studies suggest that insulin can inhibit hepatic glucose production by both direct and indirect actions. The indirect effects include inhibition of glucagon secretion, reduction in plasma nonesterified fatty acid levels, reduction of the amount of gluconeogenic precursor supplied to the liver, and change in neural input to the liver. There is a controversy concerning the fact that the dominant action of insulin on hepatic glucose production is direct, as suggested by studies in fed dogs, or indirect, via the hypothalamus, as suggested by studies in rodents. A possible explanation for this discrepancy will be proposed involving the relative importance of glycogenolysis and gluconeogenesis in hepatic glucose production in dogs and rodents. Finally, the relative importance of direct and/or indirect effects of insulin on hepatic glucose production for the treatment of diabetes will be discussed.
Signaling Mechanisms Underlying the Release of Glucagon-Like Peptide 1
Authors: Reimann Frank , Ward Patrick S. , Gribble Fiona M.
Published: December 2006

Glucagon-like peptide-1 (GLP-1) is released from intestinal L-cells in response to a range of nutrients, hormones, and neurotransmitters. Its potency as an insulin secretagogue has led to pharmaceutical interest in developing strategies to enhance GLP-1 receptor activation in type 2 diabetes. A complementary approach, to stimulate endogenous release of GLP-1, would be facilitated by a better understanding of L-cell physiology. Using GLP-1–secreting cell lines such as GLUTag and STC-1, mechanisms underlying GLP-1 release have been identified at a single-cell level. A number of stimuli, including glucose and certain amino acids, result in membrane depolarization and Ca2+ entry through voltage-gated Ca2+ channels. Glucose triggers membrane depolarization both by closing ATP-sensitive potassium channels and because of its uptake by Na+-coupled glucose transporters. Whereas glutamine also triggers depolarization by Na+-coupled uptake, glycine opens Cl− channels on the surface membrane. A number of agents, including fatty acids and hormones, enhance GLP-1 secretion by acting at stages downstream of depolarization. Some of these target G protein–coupled receptors, triggering elevation of cAMP or release of Ca2+ from intracellular stores. Understanding these different pathways and how they could be targeted to maximize GLP-1 secretion may be a step toward developing therapeutic GLP-1 secretagogues.
Distinct Classes of Central GLUT2-Dependent Sensors Control Counterregulation and Feeding
Authors: Marty Nell , Bady Isabelle , Thorens Bernard
Published: December 2006

The pancreatic β-cell paradigm for glucose sensing has been proposed to apply to brain glucose sensors controlling counterregulation to hypoglycemia and feeding behavior. Over recent years, we tested this model in mice by first showing that inactivation of the GLUT2 gene suppressed glucose sensing and correctly regulated insulin secretion by pancreatic β-cells. Then, we restored the function of the β-cell in GLUT2-null mice by transgenic expression of a glucose transporter under the control of the rat insulin promoter. Using these rescued mice, we showed that GLUT2-dependent sensors are present in several anatomical sites, including the hepatoportal vein and the central nervous system. When these extrapancreatic glucose sensors are inactivated, the mice display loss of first-phase insulin secretion and hyperglucagonemia in the fed state, and they eat more than control mice—defects characteristic of developing obesity/diabetes. By gene complementation experiments, we further showed that glucose sensors controlling glucagon secretion require GLUT2 expression in glial cells. However, transgenic expression of GLUT2 in astrocytes or neurons failed to restore the normal control of feeding, indicating that different classes of glucose sensors control the response to hypoglycemia and food intake.
Role of Neuronal Glucosensing in the Regulation of Energy Homeostasis
Authors: Levin Barry E. , Kang Ling , Sanders Nicole M. , Dunn-Meynell Ambrose A.
Published: December 2006

Glucosensing is a property of specialized neurons in the brain that regulate their membrane potential and firing rate as a function of ambient glucose levels. These neurons have several similarities to β- and α-cells in the pancreas, which are also responsive to ambient glucose levels. Many use glucokinase as a rate-limiting step in the production of ATP and its effects on membrane potential and ion channel function to sense glucose. Glucosensing neurons are organized in an interconnected distributed network throughout the brain that also receives afferent neural input from glucosensors in the liver, carotid body, and small intestines. In addition to glucose, glucosensing neurons can use other metabolic substrates, hormones, and peptides to regulate their firing rate. Consequently, the output of these “metabolic sensing” neurons represents their integrated response to all of these simultaneous inputs. The efferents of these neurons regulate feeding, neuroendocrine and autonomic function, and thereby energy expenditure and storage. Thus, glucosensing neurons play a critical role in the regulation of energy homeostasis. Defects in the ability to sense glucose and regulatory hormones like leptin and insulin may underlie the predisposition of some individuals to develop diet-induced obesity.
Fatty Acid Signaling in the Hypothalamus and the Neural Control of Insulin Secretion
Authors: Migrenne Stéphanie , Cruciani-Guglielmacci Céline , Kang Ling , Wang Ruokun , Rouch Claude , Lefèvre Anne-Laure , Ktorza Alain , Routh Vanessa H. , Levin Barry E. , Magnan Christophe
Published: December 2006

It is now clearly demonstrated that fatty acids (FAs) may modulate neural control of energy homeostasis and specifically affect both insulin secretion and action. Indeed, pancreatic β-cells receive rich neural innervation and FAs induce important changes in autonomic nervous activity. We previously reported that chronic infusion of lipids decreased sympathetic nervous system activity and led to exaggerated glucose-induced insulin secretion (GIIS), as would be expected from the known inhibitory effect of sympathetic splanchnic nerve activity on insulin secretion. Intracarotid infusion of lipids that do not change plasma FA concentrations also lead to increased GIIS. This effect of FAs on GIIS was prevented by inhibition of β-oxidation. It is noteworthy that a single intracarotid injection of oleic acid also induced a transient increase in plasma insulin without any change in plasma glucose, suggesting that FAs per se can regulate neural control of insulin secretion. Finally, using whole cell current clamp recordings in hypothalamic slices and calcium imaging in dissociated hypothalamic neurons, we identified a hypothalamic subpopulation of neurons either excited (13%) or inhibited (6%) by FAs. Thus, FAs per se or their metabolites modulate neuronal activity, as a means of directly monitoring ongoing fuel availability by central nervous system nutrient-sensing neurons involved in the regulation of insulin secretion.
Brain Adipocytokine Action and Metabolic Regulation
Authors: Ahima Rexford S. , Qi Yong , Singhal Neel S. , Jackson Malaka B. , Scherer Philipp E.
Published: December 2006

Adipose tissue secretes factors that control various physiological systems. The fall in leptin during fasting mediates hyperphagia and suppresses thermogenesis, thyroid and reproductive hormones, and immune system. On the other hand, rising leptin levels in the fed state stimulate fatty acid oxidation, decrease appetite, and limit weight gain. These divergent effects of leptin occur through neuronal circuits in the hypothalamus and other brain areas. Leptin also regulates the activities of enzymes involved in lipid metabolism, e.g., AMP-activated protein kinase and stearoyl-CoA desaturase-1, and also interacts with insulin signaling in the brain. Adiponectin enhances fatty acid oxidation and insulin sensitivity, in part by stimulating AMP-activated protein kinase phosphorylation and activity in liver and muscle. Moreover, adiponectin decreases body fat by increasing energy expenditure and lipid catabolism. These effects involve peripheral and possibly central mechanisms. Adipose tissue mediates interconversion of steroid hormones and secretes proinflammatory cytokines, vasoactive peptides, and coagulation and complement proteins. Understanding the actions of these “adipocytokines” will provide insight into the pathogenesis and treatment of obesity and related diseases.
Glucagon-Like Peptide 1 Secretion by the L-Cell
Authors: Lim Gareth E. , Brubaker Patricia L.
Published: December 2006

Glucagon-like peptide 1 (GLP-1) is a gut-derived peptide secreted from intestinal L-cells after a meal. GLP-1 has numerous physiological actions, including potentiation of glucose-stimulated insulin secretion, enhancement of β-cell growth and survival, and inhibition of glucagon release, gastric emptying, and food intake. These antidiabetic effects of GLP-1 have led to intense interest in the use of this peptide for the treatment of patients with type 2 diabetes. Oral nutrients such as glucose and fat are potent physiological regulators of GLP-1 secretion, but non-nutrient stimulators of GLP-1 release have also been identified, including the neuromodulators acetylcholine and gastrin-releasing peptide. Peripheral hormones that participate in energy homeostasis, such as leptin, have also been implicated in the regulation of GLP-1 release. Recent studies have begun to elucidate the intracellular signaling pathways that mediate the effects of GLP-1 secretagogues on the intestinal L-cell. The purpose of this review is to summarize the known signaling mechanisms of GLP-1 secretagogues based on the available literature. A better understanding of the pathways underlying GLP-1 secretion may lead to novel approaches by which the levels of this important insulinotropic hormone can be enhanced in patients with type 2 diabetes.
Translocable Glucose Transporters in the Brain
Authors: Alquier Thierry , Leloup Corinne , Lorsignol Anne , Pénicaud Luc
Published: December 2006

The discovery of the brain expression of the translocable glucose transporters, GLUT4 then GLUT8, led to the question of their putative role in the central nervous system, particularly in relation to insulin effect. The anatomical, cellular, and subcellular localization of these transporters has been described in detail. It has been shown that, as in peripheral tissues, these transporters are localized both in an intracellular pool and at the plasma membrane. This is coherent with a translocation phenomenon, but the data reporting the effect of insulin on that property of GLUT4 and GLUT8 remains very controversial. Glucose and insulin have been shown to modulate GLUT4 expression. Based on their anatomical features, different hypotheses have been proposed. Because of the colocalization with the insulin receptors, insulin might regulate glucose uptake in specific brain areas. A role in nutrient sensing has also been proposed, since both insulin and GLUT4 are expressed in gluco-excited neurons of the hypothalamus. Some studies suggest a role for GLUT8 in the endoplasmic reticulum stress. Whereas much has been learned about their cellular features in the central nervous system, many questions remain unanswered concerning their physiological functions. Gene knockout strategy specifically in the brain and even more in specific nuclei or type of cells should provide new clues to the physiological role of both transporters in the central nervous system.
Displayed emotions and witness credibility: a comparison of judgements by individuals and mock juries
Authors: Dahl Janne , Enemo Ida , Drevland Guri C. B. , Wessel Ellen , Eilertsen Dag Erik , Magnussen Svein
Published: December 2006

Mock juries of 5–7 jurors viewed one of three video‐recorded versions of a rape victim's testimony, role‐played by a professional actress. The statement was given in a free‐recall manner with one of three kinds of emotions displayed, termed congruent, neutral and incongruent emotional expressions. The juries were requested to reach a decision on items in a short questionnaire, probing the perceived credibility of the witness and judgements of the probability of a guilty verdict. The jurors were then asked to complete the questionnaire a second time, individually and anonymously. A control group filled out the questionnaire individually without preceding jury deliberations. When participants judged credibility and guilt independently, without a preceding jury discussion, the displayed emotions strongly influenced the judgements. However, discussions in the context of the jury strongly attenuated the effect of displayed emotion, with judgements converging on the credibility of a neutral emotional expression as judged by independent participants, and the attenuating effect outlasted the jury‐situation. The results are consistent with research within social psychology showing that social stereotypes and prejudices are often neutralised by group discussions. Copyright © 2006 John Wiley & Sons, Ltd.
Confidentiality versus duty to inform—An empirical study on attitudes towards the handling of genetic information
Authors: Wolff Katharina , Brun Wibecke , Kvale Gerd , Nordin Karin
Published: December 2006

We set out to investigate whether potential relatives want to be informed about the existence of hereditary conditions within their family and under which conditions they want healthcare providers to breach confidentiality to inform them. We hypothesized that the willingness to be informed about a hereditary condition in the family would be influenced by characteristics of the disease and by individual characteristics. Surveys were administered to a Norwegian random sample (N = 2,400) to a Swedish random sample (N = 1,200), and to a Norwegian student sample (n = 607). Eight different disease scenarios were constructed, systematically varying three disease characteristics: fatality, penetrance, and availability of treatment. Results show that a majority of participants wished to be informed about the existence of a hereditary disease within their family. The desire to be informed and the acceptability of breaches of confidentiality were predicted by the treatability of the disease, uncertainty avoidance, and age, but not by self‐efficacy or worry. © 2006 Wiley‐Liss, Inc.
No association between the Ser9Gly polymorphism of the dopamine D3 receptor gene and schizophrenia in a Spanish sample
Authors: Lorenzo C. Vaquero , Baca‐Garcia E. , Hernandez M. Diaz , Martin C. Botillo , Perez‐Rodriguez M.M. , Saiz‐Gonzalez M.D. , Fernández P. , Gutierrez F.J. Quintero , Saiz‐Ruiz J. , Piqueras J. Fernandez , de Rivera J.L. Gonzalez , de Leon J.
Published: December 2006

This study aims to further evaluate the controversial association between the Ser9Gly polymorphism in codon 9 of the D3 dopamine receptor gene (DRD3) and schizophrenia in psychiatric inpatients acutely hospitalized in two general hospitals in Madrid, Spain. The Ser9Gly polymorphism of the DRD3 was examined in 178 schizophrenic patients, 286 patients with other psychiatric diagnoses, and 132 controls recruited. Genotype frequencies were in Hardy‐Weinberg equilibrium. No association was found between schizophrenia and the Ser9Gly polymorphism of the D3 dopamine receptor gene. © 2006 Wiley‐Liss, Inc.
Association between the 120‐bp duplication of the dopamine D4 receptor gene and attention deficit hyperactivity disorder: Genetic and molecular analyses
Authors: Kereszturi Eva , Kiraly Orsolya , Csapo Zsolt , Tarnok Zsanett , Gadoros Julia , Sasvari‐Szekely Maria , Nemoda Zsofia
Published: December 2006

Abnormalities of the dopamine neurotransmission have been hypothesized to play an important role in the pathophysiology of attention deficit hyperactivity disorder (ADHD). Promoter variants of the dopamine D4 receptor gene (DRD4) have attracted particular interest due to their possible role in regulation of gene transcription. Here we describe the haplotype analysis of the 120 base pair duplication (120‐bp dup) and three SNPs (−616C/G, −615A/G, −521C/T) in the 5′ region of the DRD4 gene among children with ADHD. We observed a trend (χ2 = 14.905, df = 9, P = 0.093) in the four‐locus haplotype distribution between ADHD probands (N = 173) and controls (N = 284). The homozygote genotype of the 1‐repeat form of the 120‐bp dup (1–1) had a significantly higher frequency among ADHD children than in controls (8.1% vs. 3.2%, χ2 = 5.526, df = 1, P = 0.019, Odds Ratio = 2.71). In addition, a novel, 4‐repeat allele was identified among ADHD patients. This particular allele has been cloned to the luciferase expression vector and its transcriptional activity has been compared to the 1‐ and 2‐repeat allele. The number of repeats of the 120‐bp dup was found to have an effect on transcriptional activity in both neuroblastoma and retinoblastoma cell lines in a dose‐dependent manner (1‐repeat > 2‐repeat > 4‐repeat). These results suggest that the 1‐repeat form of the 120‐bp dup might be a risk factor of ADHD, especially in the homozygous form and/or in the context of certain haplotypes. © 2006 Wiley‐Liss, Inc.
Evaluation of association of SNPs in the TNF alpha gene region with schizophrenia
Authors: Morar B. , Schwab S.G. , Albus M. , Maier W. , Lerer B. , Wildenauer D.B.
Published: December 2006

The association of the tumor necrosis factor alpha (TNFα) −G308A promoter polymorphism with schizophrenia has complemented clinical findings of increased levels of the TNFα cytokine in schizophrenic patients, with some support for a functional consequence of the variant. Our previous studies of genetic causes in schizophrenia supported findings of linkage to the major histocompatibility complex (MHC) region where the TNFα gene is located as well as association with the −G308A promoter polymorphism. While the common G‐allele shows association in our sample, association with the A‐allele has been reported by other groups. This suggests linkage disequilibrium (LD) rather than direct involvement in the disorder. In order to define LD of DNA variants with the disorder in this area, we analyzed 36 SNPs in a 165‐kb region around this polymorphism. We detected nominally significant associations (P < 0.05) of three markers (including the −G308A promoter polymorphism) and multiple haplotypes with schizophrenia in our sample of 204 families (79 sib‐pairs and 125 trios). The association is largely restricted to a 30 kb high LD region/block and should assist in the identification of a schizophrenia susceptibility gene within the block or elsewhere in the MHC. © 2006 Wiley‐Liss, Inc.
Perinatal size and maturation of the olfactory and vomeronasal neuroepithelia in lorisoids and lemuroids
Authors: Smith Timothy D. , Alport Laura J. , Burrows Anne M. , Bhatnagar Kunwar P. , Dennis John C. , Tuladhar Praphul , Morrison Edward E.
Published: December 2006

Explanations for the chemosensory abilities of newborn mammals focus primarily on food (milk) acquisition and communication (e.g., maternal–infant bonding). However, the relative importance of the main and accessory (vomeronasal) olfactory systems is hypothesized to differ at birth between altricial and precocial mammals. Strepsirrhines (lemurs and lorises) possess main and accessory olfactory systems, and vary in life‐history traits related to infant dependency and maturation. Accordingly, this study examines the size and maturational characteristics of vomeronasal (VNNE) and olfactory (OE) neuroepithelia in strepsirrhines. Serially sectioned heads of 18 infant cadavers were examined microscopically for neuroepithelial distribution. Measurements were taken on the length of the nasal fossa on one side that was occupied by VNNE and OE. The data were corrected for body size using the cranial length or body mass, and were then examined for correlation with several life‐history variables, as well as activity pattern. In addition, immunohistochemistry was used to identify cells in the VNNE and OE that express olfactory marker protein (OMP), a marker of mature olfactory neurons. Relative OE extent was not significantly correlated with any of the life‐history variables. Relative VNNE length was negatively correlated with relative gestation length and relative neonatal mass (P<0.05). However, when we corrected for phylogenetic relationships, we found no significant correlations between either of the neuroepithelial measurements and life‐history variables. Immunohistochemical findings suggest that OE has more OMP‐reactive cells than VNNE in all species. OMP‐reactive cells appear to be less numerous in diurnal species compared to most nocturnal species. These results indicate that the VNNE may be relatively longer at birth in altricial species. However, it remains uncertain how phylogeny and/or ontogeny may explain these findings. Am. J. Primatol. 69:74–85, 2007. © 2006 Wiley‐Liss, Inc.
Not all lorises are slow: rapid arboreal locomotion in Loris tardigradus of Southwestern Sri Lanka
Authors: Nekaris K.A.I. , Stevens N.J.
Published: December 2006

The unique slow‐climbing quadrupedalism of Asian lorises has been the subject of numerous studies; however, qualitative observations of more rapid locomotion have occasionally been reported. Field studies of the red slender loris have revealed the habitual use of unexpectedly high‐speed locomotion by the so‐called “sloth of the primate world.” Novel video footage permitted the first quantitative kinematic analysis of rapid quadrupedalism in wild lorises. Observations revealed that this previously unexplored behavior is far from infrequent, with 26% of red slender loris locomotor activity being dedicated to high‐velocity arboreal quadrupedalism. This locomotor pattern may represent a primitive retention of the rapid, scrambling quadrupedalism that is observed in other strepsirhines, or it may constitute a more recent specialization of this smallest loris taxon. Am. J. Primatol. 69:112–120, 2007. © 2006 Wiley‐Liss, Inc.
Interference of tributyltin(IV)chloride on the vascular plant cells
Authors: Caratozzolo R. , Bellini E. , Melati M. R. , Pellerito C. , Fiore T. , D'Agati P. , Scopelliti M. , Pellerito L.
Published: December 2006

In the recent past years, interest in the environmental impact of organotin(IV) compounds has risen markedly. Considering that most data in the scientific literature refers to the animal kingdom and not to higher plants cells, we tested the effects of organotin compounds on vascular plant cells, by studying the interaction of tributyltin chloride (TBTCl) with Allium cepa, Solanun tuberosum and Solanum melongena, vascular plants that are directly involved in the human food chain. The TBTCl effects on mitotic metaphase plates, on pollen grains and on both microtubers and adult tuber parenchymatic cells were investigated and the concentrations of TBTCl inside the treated parenchymatic cells were determined through ICP‐mass spectrometry. Oxygen and chlorophyll productions were also determined. The obtained results showed that TBTCl influenced not only morphology, but also the physiology of the vegetable cells since, despite the low concentrations used, the stress the cells were submitted to was experimentally confirmed. Moreover, the increase in the tin concentration in the cells, with increasing incubation time, showed that TBTCl possesses a very high capacity to be bioaccumulated and, as a consequence, it is able to enter the food chain. Copyright © 2006 John Wiley & Sons, Ltd.
Osmium Complexes with Tridentate 6‐Pyrazol‐3‐yl 2,2′‐Bipyridine Ligands: Coarse Tuning of Phosphorescence from the Red to the Near‐Infrared Region
Authors: Chen Kellen , Cheng Yi‐Ming , Chi Yun , Ho Mei‐Lin , Lai Chin‐Hung , Chou Pi‐Tai , Peng Shie‐Ming , Lee Gene‐Hsiang
Published: December 2006

We have prepared and characterized a series of osmium complexes [Os2(CO)4(fpbpy)2] (1), [Os(CO)(fpbpy)2] (2), and [Os(fpbpy)2] (3) with tridentate 6‐pyrazol‐3‐yl 2,2′‐bipyridine chelating ligands. Upon the transformation of complex 2 into 3 through the elimination of the CO ligand, an extremely large change in the phosphorescence wavelength from 655 to 935 nm was observed. The results are rationalized qualitatively by the strong π‐accepting character of CO, which lowers the energy of the osmium dπ orbital, in combination with the lower degree of π conjugation in 2 owing to the absence of one possible pyridine‐binding site. As a result, the energy gap for both intraligand π–π* charge transfer (ILCT) and metal‐to‐ligand charge transfer (MLCT) is significantly greater in 2. Firm support for this explanation was also provided by the time‐dependent DFT approach, the results of which led to the conclusion that the S0→T1 transition mainly involves MLCT between the osmium center and bipyridine in combination with pyrazolate‐to‐bipyridine 3π–π* ILCT. The relatively weak near‐infrared emission can be rationalized tentatively by the energy‐gap law, according to which the radiationless deactivation may be governed by certain low‐frequency motions with a high density of states. The information provided should allow the successful design of other emissive tridentate metal complexes, the physical properties of which could be significantly different from those of complexes with only a bidentate chromophore.
Thermodynamic Parameters for the Association of Fluorinated Benzenesulfonamides with Bovine Carbonic Anhydrase II
Authors: Krishnamurthy Vijay M. , Bohall Brooks R. , Kim Chu‐Young , Moustakas Demetri T. , Christianson David W. , Whitesides George M.
Published: December 2006

This paper describes a calorimetric study of the association of a series of seven fluorinated benzenesulfonamide ligands (C6HnF5−nSO2NH2) with bovine carbonic anhydrase II (BCA). Quantitative structure–activity relationships between the free energy, enthalpy, and entropy of binding and pKa and log P of the ligands allowed the evaluation of the thermodynamic parameters in terms of the two independent effects of fluorination on the ligand: its electrostatic potential and its hydrophobicity. The parameters were partitioned to the three different structural interactions between the ligand and BCA: the ZnII cofactor–sulfonamide bond (≈65 % of the free energy of binding), the hydrogen bonds between the ligand and BCA (≈10 %), and the contacts between the phenyl ring of the ligand and BCA (≈25 %). Calorimetry revealed that all of the ligands studied bind in a 1:1 stoichiometry with BCA; this result was confirmed by 19F NMR spectroscopy and X‐ray crystallography (for complexes with human carbonic anhydrase II).
Covalent immobilization of redox enzyme on electrospun nonwoven poly(acrylonitrile‐co‐acrylic acid) nanofiber mesh filled with carbon nanotubes: A comprehensive study
Authors: Wang Zhen‐Gang , Ke Bei‐Bei , Xu Zhi‐Kang
Published: December 2006

In this work, novel conductive composite nanofiber mesh possessing reactive groups was electrospun from solutions containing poly(acrylonitrile‐co‐acrylic acid) (PANCAA) and multi‐walled carbon nanotubes (MWCNTs) for redoxase immobilization, assuming that the incorporated MWCNTs could behave as electrons transferor during enzyme catalysis. The covalent immobilization of catalase from bovine liver on the neat PANCAA nanofiber mesh or the composite one was processed in the presence of EDC/NHS. Results indicated that both the amount and activity retention of bound catalase on the composite nanofiber mesh were higher than those on the neat PANCAA nanofiber mesh, and the activity increased up to 42%. Kinetic parameters, Km and Vmax, for the catalases immobilized on the composite nanofiber mesh were lower and higher than those on the neat one, respectively. This enhanced activity might be ascribed to either promoted electron transfer through charge‐transfer complexes and the π system of carbon nanotubes or rendered biocompatibility by modified MWCNTs. Furthermore, the immobilized catalases revealed much more stability after MWCNTs were incorporated into the polymer nanofiber mesh. However, there was no significant difference in optimum pH value and temperature, thermal stability and operational stability between these two immobilized preparations, while the two ones appeared more advantageous than the free in these properties. The effect of MWCNTs incorporation on another redox enzyme, peroxidase, was also studied and it was found that the activity increased by 68% in comparison of composite one with neat preparation. Biotechnol. Bioeng. 2007;97: 708–720. © 2006 Wiley Periodicals, Inc.
Cysteine‐Specific, Covalent Anchoring of Transition Organometallic Complexes to the Protein Papain from Carica papaya
Authors: Haquette Pierre , Salmain Michèle , Svedlung Karolina , Martel Annie , Rudolf Bogna , Zakrzewski Janusz , Cordier Stéphane , Roisnel Thierry , Fosse Céline , Jaouen Gérard
Published: December 2006

Site‐directed and covalent introduction of various transition metal–organic entities to the active site of the cysteine endoproteinase, papain, was achieved by treatment of this enzyme with a series of organometallic maleimide derivatives specially designed for the purpose. Kinetic studies made it clear that time‐dependent irreversible inactivation of papain occurred in the presence of these organometallic maleimides as a result of Michael addition of the sulfhydryl of Cys25. The rate and mechanism of inactivation were highly dependent on the structure of the organometallic entity attached to the maleimide group. Combined ESI‐MS and IR analysis indicated that all the resulting papain adducts contained one organometallic moiety per protein molecule. This confirmed that chemospecific introduction of the metal complexes was indeed achieved. Thus, three novel reagents for heavy‐atom derivatization of protein crystals, which include ruthenium, rhenium and tungsten, are now available for the introduction of electron‐dense scatterers for phasing of X‐ray crystallographic data.
The CAPTURE registry: Results of carotid stenting with embolic protection in the post approval setting
Authors: Gray William A. , Yadav Jay S. , Verta Patrick , Scicli Andrea , Fairman Ronald , Wholey Mark , Hopkins L. Nelson , Atkinson Richard , Raabe Rod , Barnwell Stanley , Green Richard
Published: December 2006

Background: Pivotal study data examining carotid stenting with embolic protection as a less invasive alternative to endarterectomy for high surgical risk patients have been acquired under controlled conditions with highly selected physicians and hospitals. This report examines outcomes of carotid stenting post‐approval after diffusion of this technology to a broader cross‐section of physicians and hospitals. Methods: The Carotid Acculink/Accunet Post‐Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi‐center registry to assess two important aspects of the post‐IDE experience: the safety of carotid stenting by physicians with varying levels of experience as a measure of the adequacy of physician training, and the identification of rare/unexpected device‐related complications. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30 days post‐procedure. Results: 3,500 patients were enrolled by 353 physicians at 144 sites. The 30‐day primary endpoint event rate was 6.3% (95% CI: 5.5–7.1%) and did not differ among the three operator experience levels (5.3%, 6.0%, and 7.4%; P = 0.31) from most to least experienced, respectively. There were no differences in outcomes among physician specialties when adjusted for case mix. There were no unanticipated device related adverse events. Conclusions: The results of the CAPTURE study compare favorably to those achieved in the predicate pivotal investigations, and suggest that the post‐approval transfer of this new therapy to the community practice setting via carotid stent training programs is effective in preparing physicians with varying experience levels and specialty training backgrounds. © 2006 Wiley‐Liss, Inc.
Experimental and Theoretical Studies on Oligomer Formation of N‐Confused Porphyrin–Zinc(II) Complexes
Authors: Toganoh Motoki , Harada Naoyuki , Morimoto Tatsuki , Furuta Hiroyuki
Published: December 2006

Dimer formation of the N‐confused porphyrin zinc(II), cadmium(II), and mercury(II) complexes was investigated experimentally as well as theoretically. The stable dimers were formed through coordination of the peripheral nitrogen atoms owing to flexible rotation of the confused pyrrole rings. The Z dimers were significantly more stable than the E dimers likely due to π–π interaction between the two confused pyrrole rings. The possible formation of higher oligomers such as trimers was suggested in the case of meso‐unsubstituted derivatives.
2,2′‐Biphosphinines and 2,2′‐Bipyridines in Homoleptic Dianionic Group 4 Complexes and Neutral 2,2′‐Biphosphinine Group 6 d6 Metal Complexes: Octahedral versus Trigonal‐Prismatic Geometries
Authors: Lesnard Hervé , Cantat Thibault , Le Floch Pascal , Demachy Isabelle , Jean Yves
Published: December 2006

The geometric and electronic structure of formally d6 tris‐biphosphinine [M(bp)3]q and tris‐bipyridine [M(bpy)3]q complexes were studied by means of DFT calculations with the B3LYP functional. In agreement with the available experimental data, Group 4 dianionic [M(bp)3]2− complexes (1P–3P for M=Ti, Zr, and Hf, respectively) adopt a trigonal‐prismatic (TP) structure, whereas the geometry of their nitrogen analogues [M(bpy)3]2− (1N–3N) is nearly octahedral (OC), although a secondary minimum was found for the TP structures (1N′–3N′). The electronic factors at work in these systems are discussed by means of an MO analysis of the minima, MO correlation diagrams, and thermodynamic cycles connecting the octahedral and trigonal‐prismatic limits. In all these complexes, pronounced electron transfer from the metal center to the lowest lying π* ligand orbitals makes the d6 electron count purely formal. However, it is shown that the bp and bpy ligands accommodate the release of electron density from the metal in different ways because of a change in the localization of the HOMO, which is a mainly metal‐centered orbital in bp complexes and a pure π* ligand orbital in bpy complexes. The energetic evolution of the HOMO allows a simple rationalization of the progressive change from the TP to the OC structure on successive oxidation of the [Zr(bp)3]2− complex, a trend in agreement with the experimental structure of the monoanionic complex. The geometry of Group 6 neutral complexes [M(bp)3] (4P and 5P for M=Mo and W, respectively) is found to be intermediate between the TP and OC limits, as previously shown experimentally for the tungsten complex. The electron transfer from the metal center to the lowest lying π* ligand orbitals is found to be significantly smaller than for the Group 4 dianionic analogues. The geometrical change between [Zr(bp)3]2− and [W(bp)3] is analyzed by means of a thermodynamic cycle and it is shown that a larger ligand–ligand repulsion plays an important role in favoring the distortion of the tungsten complex away from the TP structure.
Helical Complexes Containing Diamide‐Bridged Benzene‐o‐dithiolato/Catecholato Ligands
Authors: Schulze Isfort Christian , Kreickmann Thorsten , Pape Tania , Fröhlich Roland , Hahn F. Ekkehardt
Published: December 2006

The benzene‐o‐dithiol/catechol ligands H4‐2 and H4‐3 react with [TiO(acac)2] to give the dinuclear, double‐stranded anionic complexes [Ti2(L)2(μ‐OCH3)2]2− ([22]2−, L=24−; [23]2−, L=34−). NMR spectroscopic investigations reveal that the complex anion [Ti2(2)2(μ‐OCH3)2]2− is formed as a mixture of three of four possible isomers/pairs of enantiomers, whereas only one isomer of the complex anion [Ti2(3)2(μ‐OCH3)2]2− is obtained. The crystal structure analysis of (PNP)2[Ti2(3)2(μ‐OCH3)2] shows a parallel orientation of the ligand strands, whereas the structure determination for (AsPh4)2[Ti2(2)2(μ‐OCH3)2] does not yield conclusive results about the orientation of the ligand strands due the presence of different isomers in solution, the possible co‐crystallisation of different isomers and severe disorder in the crystal. NMR spectroscopy shows that ligand H4‐3 reacts at elevated temperature with [TiO(acac)2] to give the triple‐stranded helicate (PNP)4[Ti2(3)3] ((PNP)4[24]) as a mixture of two isomers, one with a parallel orientation of the ligand strands and one with an antiparallel orientation. Exclusively the triple‐stranded helicates [Ti2(L)3]4− ([25]4−, L=14−; [26]2−, L=44−) are formed in the reaction of ligands H4‐1 and H4‐4 with [TiO(acac)2]. The molecular structures of Na(PNP)3[Ti2(1)3]⋅CH3OH⋅H2O⋅Et2O (Na(PNP)3[25]⋅CH3OH⋅H2O⋅Et2O) and Na1.5(PNP)6.5[Ti2(4)3]2⋅3 DMF (Na1.5(PNP)6.5[26]2⋅3 DMF) reveal a parallel orientation of the ligand strands in both complexes, which is retained in solution. The sodium cations present in the crystal structures lead to two different kinds of aggregation in the solid state. Na‐[25]‐Na‐[25]‐Na polymeric chains are formed from compound Na(PNP)3[25], with the sodium cations coordinated by the carbonyl groups of two ligand strands from two different [Ti2(1)3]4− ions in addition to solvent molecules. In contrast to this, two [Ti2(4)3]4− ions are connected by a sodium cation that is coordinated by the three meta oxygen atoms of the catecholato groups of each complex tetraanion to form a central {NaO6} octahedron in the anionic pentanuclear complex {[26]‐Na‐[26]}7−.
Electrochemical, Pulsed‐Field‐Gradient Spin‐Echo NMR Spectroscopic, and ESR Spectroscopic Study of the Diffusivity of Molecular Probes inside Gel‐Type Cross‐Linked Polymers
Authors: Corain Benedetto , D'Archivio Angelo A. , Galantini Luciano , Lora Silvano , Isse Abdirisak A. , Maran Flavio
Published: December 2006

The permeability of five gel‐type synthetic resins, obtained by polymerization of 1‐vinylpyrrolidin‐2‐one cross‐linked withN,N′‐methylenebisacrylamide (1, 2, 3, 4, and 5 wt %) and swollen byN,N‐dimethylformamide (DMF), has been analyzed. The diffusion of 2,2,6,6‐tetramethyl‐4‐oxo‐1‐piperidinyloxyl (TEMPONE) was studied by ultramicroelectrode voltammetry. Similar measurements were performed for solutions of non‐cross‐linked poly(vinylpyrrolidone) in DMF. To provide information on the rotational mobility of TEMPONE and the translational mobility of DMF, electron spin resonance (ESR) spectroscopic and pulsed‐field‐gradient spin‐echo nuclear magnetic resonance (PGSE‐NMR) spectroscopic experiments, respectively, were carried out. Comparative analysis of the results obtained by electrochemical, ESR spectroscopic, and PGSE‐NMR spectroscopic measurements showed that diffusivity inside the polymer framework is significantly affected by the extent of cross‐linking, the size of the diffusing probe, and the presence of electrolytes.
The 1/1 and 2/1 Approximants in the Sc—Mg—Zn Quasicrystal System: Triacontahedral Clusters as Fundamental Building Blocks.
Authors: Lin Qisheng , Corbett John D.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Structure of the Ternary Compound DyAlSi.
Authors: He Wei , Zhang Jiliang , Zeng Lingmin
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and the Crystal and Electronic Structure of Hg4AsI5.
Authors: Oleneva O. S. , Shestimerova T. A. , Olenev A. V. , Dikarev E. V. , Shevelkov A. V.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Sm2NiSn4: The Intermediate Structure Type Between ZrSi2 and CeNiSi2.
Authors: Sun Zhong‐Ming , Pan Da‐Chun , Lei Xiao‐Wu , Mao Jiang‐Gao
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structure Property Relationships in the ATi2O4 (A: Na, Ca) Family of Reduced Titanates.
Authors: Geselbracht Margret J. , Erickson Ann S. , Rogge Matthew P. , Greedan John E. , Walton Richard I. , Stoltzfus Matthew W. , Eng Hank W. , Woodward Patrick M.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mechanosynthesis of the Ferroelectric Materials Ba2ANb5O15 (A: K, Na, Li).
Authors: Khachane M. , Moure A. , Elaatmani M. , Zegzouti A. , Daoud M. , Castro A.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
High Pressure Synthesis, Crystal, Magnetic Structure and Magnetotransport of SrFe0.5Co0.5O3‐δ.
Authors: Munoz A. , Alonso J. A. , Martinez‐Lope M. J. , de la Calle C. , Fernandez‐Diaz M. T.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Much Improved Upper Limit for the Rate Constant for the Reaction of O2+ with N2.
Authors: Viggiano A. A.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
One‐Step Synthesis of Dispersed Bimetallic Carbides and Nitrides from Transition Metals Hexamethylenetetramine Complexes.
Authors: Chouzier Sandra , Afanasiev Pavel , Vrinat Michel , Cseri Tivadar , Roy‐Auberger Magalie
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Characterization of a New Open‐Framework Fluorinated Gallium Phosphite with Three‐Dimensional Intersecting Channels.
Authors: Wang Li , Song Tianyou , Fan Yong , Tian Zhenfen , Wang Ying , Shi Suhua , Xu Jianing
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydrothermal Synthesis of a Luminescent Europium(III) Sulfate with Three‐Dimensional Chiral Framework Structure.
Authors: Wu Chuan‐De , Liu Zi‐Yang
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Synthesis of 2‐Substituted‐1,4‐diketones from (S)‐Mandelic Acid Enolate and α,β‐Enones.
Authors: Blay Gonzalo , Fernandez Isabel , Monje Belen , Munoz M. Carmen , Pedro Jose R. , Vila Carlos
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Highly Enantioselective Hydrogenation of Exocyclic Double Bond of N‐Tosyloxazolidinones Catalyzed by a Neutral Rhodium Complex and Its Synthetic Applications.
Authors: Shen Zengming , Lu Xiyan , Lei Aiwen
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Enantioselective Decarboxylative Protonation.
Authors: Mohr Justin T. , Nishimata Toyoki , Behenna Douglas C. , Stoltz Brian M.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Intramolecular [2 + 2 + 2] Cycloaddition of 1,4‐Diene‐ynes: A New Approach to the Construction of Quaternary Carbon Stereocenters.
Authors: Shibata Takanori , Tahara Yu‐ki
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Intermolecular [4 + 2] Cycloaddition of o‐Quinodimethanes Derived from Ene—Bis(sulfinylallenes).
Authors: Kitagaki Shinji , Katoh Kumiko , Ohdachi Kazuhiro , Takahashi Yuji , Shibata Daisuke , Mukai Chisato
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Baeyer—Villiger Oxidation in Supercritical CO2 with Potassium Peroxomonosulfate Supported on Acidic Silica Gel.
Authors: Gonzalez‐Nunez Maria E. , Mello Rossella , Olmos Andrea , Asensio Gregorio
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reactions of Propargylic Alcohols with Nitric Oxide.
Authors: Shen Ying‐Lin , Wu Wen‐Tao , Liu Qiang , Wu Guai‐Li , Wu Long‐Min
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Facile and Efficient Reduction of Nitroarenes with NiCl2×6H2O/Indium System.
Authors: Han Jung Hwa , Choi Jin Woo , Choi Kyung Il , Kim Joong Hyup , Yoo Byung Woo
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Mild and Convenient Reduction of Nitro Compounds with NaBH4/SbF3 System in Wet CH3CN.
Authors: Zeynizadeh Behzad , Ghasemi Hamed
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Aminolysis of Allyl Esters with Bislithium Aryl Amides.
Authors: Faler Catherine A. , Joullie Madeleine M.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Novel Synthesis, Reactivity, and Stereochemistry of Substituted 3‐Trifluoromethyl‐ and 3‐Perfluoroalkyl‐3‐phenoxyprop‐2‐enal.
Authors: El Kharrat Salem , Laurent Philippe , Blancou Hubert
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxidation of Aromatic Aldehydes with Tetrabutylammonium Fluoride: Competition with the Cannizzaro Reaction.
Authors: Chung Kyoo‐Hyun , Moon Byung‐Chul , Lim Choong Hwan , Kim Jin Pil , Lee Jae Hak , Chi Dae Yoon
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Scandium‐Catalyzed Vinylsilane Additions: A New Approach to the Synthesis of Enantiopure β,γ‐Unsaturated α‐Hydroxy Acid Derivatives.
Authors: Evans David A. , Aye Yimon
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.