bluuebunny/crossref_metadata_2025 huggingface dataset:
Clustering endothelial E-selectin in clathrin-coated pits and lipid rafts enhances leukocyte adhesion under flow
Authors: Setiadi Hendra , McEver Rodger P.
Published: November 2007

During inflammation, E-selectin expressed on cytokine-activated endothelial cells mediates leukocyte rolling under flow. E-selectin undergoes endocytosis and may associate with lipid rafts. We asked whether distribution of E-selectin in membrane domains affects its functions. E-selectin was internalized in transfected CHO cells or cytokine-activated human umbilical vein endothelial cells (HUVECs). Confocal microscopy demonstrated colocalization of E-selectin with α-adaptin, a clathrin-associated protein. Deleting the cytoplasmic domain of E-selectin or disrupting clathrin-coated pits with hypertonic medium blocked internalization of E-selectin, reduced colocalization of E-selectin with α-adaptin, and inhibited E-selectin-mediated neutrophil rolling under flow. Unlike CHO cells, HUVECs expressed a small percentage of E-selectin in lipid rafts. Even fewer neutrophils rolled on E-selectin in HUVECs treated with hypertonic medium and with methyl-β-cyclodextrin, which disrupts lipid rafts. These data demonstrate that E-selectin clusters in both clathrin-coated pits and lipid rafts of endothelial cells but is internalized in clathrin-coated pits. Distribution in both domains markedly enhances E-selectin's ability to mediate leukocyte rolling under flow.
The endogenous danger signal, crystalline uric acid, signals for enhanced antibody immunity
Authors: Behrens Marshall D. , Wagner Wolfgang M. , Krco Christopher J. , Erskine Courtney L. , Kalli Kimberly R. , Krempski James , Gad Ekram A. , Disis Mary L. , Knutson Keith L.
Published: November 2007

Studies have shown that the immune system can recognize self-antigens under conditions (eg, cell injury) in which the self-tissue might elaborate immune-activating endogenous danger signals. Uric acid (UA) is an endogenous danger signal recently identified to be released from dying cells. Prior work has shown that UA activates immune effectors of both the innate and adaptive immune system, including neutrophils and cytotoxic T-cell immunity. However, it was unclear whether UA could enhance antibody immunity, which was examined in this study. When added to dying tumor cells or with whole protein antigen, UA increased IgG1-based humoral immunity. Further, UA blocked growth of tumor in subsequent tumor challenge experiments, which depended on CD4, but not CD8, T cells. Sera derived from UA-treated animals enhanced tumor growth, suggesting it had little role in the antitumor response. UA did not signal for T-cell expansion or altered tumor-infiltrating leukocyte populations. Consistent with the lack of T-cell expansion, when applied to dendritic cells, UA suppressed T-cell growth factors but up-regulated B cell–activating cytokines. Understanding the nature of endogenous danger signals released from dying cells may aid in a better understanding of mechanisms of immune recognition of self.
Cost of diabetes care in out-patient clinics of Karachi, Pakistan
Authors: Khowaja Liaquat A , Khuwaja Ali K , Cosgrove Peter
Published: November 2007

Background

Diabetes Mellitus (DM) is a growing epidemic and the cost of treating diabetes is largely increasing. The objective of this study was to estimate the cost-of-illness of DM among attendees of out-patient clinics in Karachi, Pakistan. This is the first study conducted from a societal perspective to estimate the cost of managing diabetes in Pakistan.

Methods

A prevalence-based 'Cost-of-Illness' study for diabetes care was conducted in six different out-patient clinics of Karachi, Pakistan from July to September 2006. A pre-tested questionnaire was administered to collect the data from 345 randomly selected persons with diabetes.

Results

The annual mean direct cost for each person with diabetes was estimated to be Pakistani rupees 11,580 (US$ 197). Medicines accounted for the largest share of direct cost (46%), followed by laboratory investigations (32%). We found that increased age, the number of complications and longer duration of the disease significantly increase the burden of cost on society (p < 0.001). Comparing cost with family income it was found that the poorest segment of society is spending 18% of total family income on diabetes care.

Conclusion

This study concluded that substantial expenditure is incurred by people with diabetes; with the implication that resources could be saved by prevention, earlier detection and a reduction in diabetes co-morbidities and complications through improved diabetes care. Large scale and cost-effective prevention programs need to be initiated to maximise health gains and to reverse the advance of this epidemic.
Alterations of GPI transamidase subunits in head and neck squamous carcinoma
Authors: Jiang Wei-Wen , Zahurak Marianna , Zhou Zeng-Tong , Park Hannah Lui , Guo Zhong-Min , Wu Guo-Jun , Sidransky David , Trink Barry , Califano Joseph A
Published: November 2007

Background

GPI anchor attachment is catalyzed by the GPI transamidase (GPIT) complex.GAA1, PIG-TandPIG-Uare the three of five GPIT subunits. Previous studies demonstrated amplification and overexpression of GPIT subunits in bladder and breast cancer with oncogenic function. We performed an analysis of these subunits in head and neck squamous cell carcinoma (HNSCC).

Results

To evaluateGAA1, PIG-TandPIG-Uin HNSCC, we used quantitative PCR (QPCR) and quantitative RT-PCR (QRT-PCR) to determine the copy number of those genes in primary tumors and the matching lymphocytes in 28 patients with HNSCC and quantified RNA expression of those genes in 16 primary HNSCC patients and 4 normal control tissue samples.GAA1showed a significant increase in normalized mRNA expression, 2.11 (95% CI: 1.43, 2.79), in comparison to that of normal controls, 0.43 (95% CI: -0.76, 1.61), p = 0.014 (Mann-Whitney test). The mean genomic copy number ofGAA1was significantly increased in HNSCC, 0.59 (95% CI: 0.50, 0.79), in comparison to lymphocyte DNA, 0.35 (95% CI: 0.30, 0.50), p = 0.001(paired t-test).

Conclusion

An increased expression level and elevated copy number forGAA1suggest a role for this GPI anchor subunit in HNSCC.
Castleman's disease in the head of the pancreas: report of a rare clinical entity and current perspective on diagnosis, treatment, and outcome
Authors: Wang Hongbei , Wieczorek Rosemary L , Zenilman Michael E , Desoto-Lapaix Fidelina , Ghosh Bimal C , Bowne Wilbur B
Published: November 2007

Background

Castleman's disease of the pancreas is a very rare condition that may resemble more common disease entities as well as pancreatic cancer.

Case presentation

Here we report the case of a 58-year-old African American male with an incidentally discovered lesion in the head of the pancreas. The specimen from his pancreaticoduodectomy contained a protuberant, encapsulated mass, exhibiting microscopic features most consistent with localized/unicentric Castleman's disease. These included florid follicular hyperplasia with mantle/marginal zone hyperplasia along with focal progressive transformation of germinal centers admixed with involuted germinal centers.

Conclusion

To date, eight cases of Castleman's disease associated with the pancreas have been described in the world literature. We report the first case of unicentric disease situated within the head of the pancreas. In addition, we discuss the diagnostic dilemma Castleman's disease may present to the pancreatic surgeon and review current data on pathogenesis, treatment, and outcome.
Unbiased characterization of genotype-dependent metabolic regulations by metabolomic approach in Arabidopsis thaliana
Authors: Kusano Miyako , Fukushima Atsushi , Arita Masanori , Jonsson Pär , Moritz Thomas , Kobayashi Makoto , Hayashi Naomi , Tohge Takayuki , Saito Kazuki
Published: November 2007

Background

Metabolites are not only the catalytic products of enzymatic reactions but also the active regulators or the ultimate phenotype of metabolic homeostasis in highly complex cellular processes. The modes of regulation at the metabolome level can be revealed by metabolic networks. We investigated the metabolic network between wild-type and 2 mutant (methionine-over accumulation 1 [mto1] and transparent testa4 [tt4]) plants regarding the alteration of metabolite accumulation in Arabidopsis thaliana.

Results

In the GC-TOF/MS analysis, we acquired quantitative information regarding over 170 metabolites, which has been analyzed by a novel score (ZMC, z-score of metabolite correlation) describing a characteristic metabolite in terms of correlation. Although the 2 mutants revealed no apparent morphological abnormalities, the overall correlation values in mto1 were much lower than those of the wild-type and tt4 plants, indicating the loss of overall network stability due to the uncontrolled accumulation of methionine. In the tt4 mutant, a new correlation between malate and sinapate was observed although the levels of malate, sinapate, and sinapoylmalate remain unchanged, suggesting an adaptive reconfiguration of the network. Gene-expression correlations presumably responsible for these metabolic networks were determined using the metabolite correlations as clues.

Conclusion

Two Arabidopsis mutants, mto1 and tt4, exhibited the following changes in entire metabolome networks: the overall loss of metabolic stability (mto1) or the generation of a metabolic network of a backup pathway for the lost physiological functions (tt4). The expansion of metabolite correlation to gene-expression correlation provides detailed insights into the systemic understanding of the plant cellular process regarding metabolome and transcriptome.
Characterization of Thyroglobulin Epitopes in Patients with Autoimmune and Non-Autoimmune Thyroid Diseases Using Recombinant Human Monoclonal Thyroglobulin Autoantibodies
Authors: Latrofa Francesco , Ricci Debora , Grasso Lucia , Vitti Paolo , Masserini Lucio , Basolo Fulvio , Ugolini Clara , Mascia Giovanni , Lucacchini Antonio , Pinchera Aldo
Published: November 2007

Context: Thyroglobulin (Tg) epitopes of serum Tg autoantibodies (TgAb) have been characterized using inhibition of Tg binding by human monoclonal TgAb in autoimmune thyroid diseases (AITD) [Hashimoto’s thyroiditis (HT) and Graves’ disease (GD)] but not in non-AITD [nontoxic multinodular goiter (NTMG) and papillary thyroid carcinoma (PTC)].

Objective: Our objective was to compare Tg epitopes of serum TgAb from patients with AITD, non-AITD, and PTC associated with histological thyroiditis (PTC-T) using inhibition of Tg binding by four recombinant human TgAb-Fab (epitopic regions A–D).

Design: Inhibition of Tg binding of 24 HT, 25 GD, 19 NTMG, 15 PTC, and 25 PTC-T TgAb-positive sera by each TgAb-Fab was evaluated in ELISA. Inhibition by the pool of the four TgAb-Fab was evaluated using labeled Tg.

Results: Levels of inhibition were different for TgAb-Fab regions A (P = 0.001), B (0.007), and D (0.011). Inhibition by region A TgAb-Fab was significantly higher in HT, GD, and PTC-T than in NTMG and PTC patients. Inhibition levels by region B TgAb-Fab were significantly higher in HT compared with NTMG and PTC patients and in GD compared with NTMG patients. Inhibition by D region TgAb-Fab was significantly lower in NTMG than in the other groups. Inhibition by the pool ranged from 44% (NTMG) to 72% (GD).

Conclusions: The pattern of Tg recognition is similar when HT patients are compared to GD and NTMG to PTC patients and differs when AITD are compared with non-AITD patients. In PTC-T patients, it is similar to that of AITD patients.
Assessment of the Magnitude of Growth Hormone Hypersecretion in Active Acromegaly: Reliability of Different Sampling Models
Authors: Bajuk Studen Katica , Barkan Ariel
Published: November 2007

Context: The pulsatility of GH secretion in acromegaly poses difficulty in ascertaining true daily GH milieu in patients with this disease. Intensive GH sampling [every 10–20 (Q10–20) min for 24 h] is not practical in clinical practice.

Objective: Our objective was to ascertain reliability of abbreviated sampling protocols to reflect true 24-h mean GH concentrations in patients with acromegaly.

Design: An analysis of previously obtained plasma GH profiles was performed.

Setting: The analysis was performed at the General Clinical Research Center at the University of Michigan.

Patients: A total of 115 GH profiles obtained in 94 patients with active acromegaly were examined.

Intervention: Frequent blood sampling, i.e. Q10–20 min for 24 h, was performed.

Main Outcome Measures: Concordance of 24-h mean GH concentrations derived from Q10- to 20-min samplings with abbreviated GH sampling schedules was performed. The study was planned after data collection.

Results: All abbreviated schedules of GH sampling correlated well with the true 24-h plasma GH means (i.e. Q10- to 20-min sampling) (R = 0.93–0.98; P < 0.0001 for all). In the GH range more than 20 μg/liter, only 5 and 9-h means had R values more than 0.9. Single GH concentrations less than 1 μg/liter had a positive predictive value of only 0.29, and those with less than 2.5 μg/liter had a positive predictive value of 0.67 vs. their corresponding 24-h mean GH values of the same magnitude.

Conclusions: The intensity of GH sampling in patients with acromegaly may vary depending on the nature of the required information. Investigators and clinicians should be aware of the limitations of the abbreviated GH sampling protocols in acromegaly.
Mitochondrial electron-transport-chain inhibitors of complexes I and II induce autophagic cell death mediated by reactive oxygen species
Authors: Chen Yongqiang , McMillan-Ward Eileen , Kong Jiming , Israels Sara J. , Gibson Spencer B.
Published: November 2007

Autophagy is a self-digestion process important for cell survival during starvation. It has also been described as a form of programmed cell death. Mitochondria are important regulators of autophagy-induced cell death and damaged mitochondria are often degraded by autophagosomes. Inhibition of the mitochondrial electron transport chain (mETC) induces cell death through generating reactive oxygen species (ROS). The role of mETC inhibitors in autophagy-induced cell death is unknown. Herein, we determined that inhibitors of complex I (rotenone) and complex II (TTFA) induce cell death and autophagy in the transformed cell line HEK 293, and in cancer cell lines U87 and HeLa. Blocking the expression of autophagic genes (beclin 1 and ATG5) by siRNAs or using the autophagy inhibitor 3-methyladenine (3-MA) decreased cell death that was induced by rotenone or TTFA. Rotenone and TTFA induce ROS production, and the ROS scavenger tiron decreased autophagy and cell death induced by rotenone and TTFA. Overexpression of manganese-superoxide dismutase (SOD2) in HeLa cells decreased autophagy and cell death induced by rotenone and TTFA. Furthermore, blocking SOD2 expression by siRNA in HeLa cells increased ROS generation, autophagy and cell death induced by rotenone and TTFA. Rotenone- and TTFA-induced ROS generation was not affected by 3-MA, or by beclin 1 and ATG5 siRNAs. By contrast, treatment of non-transformed primary mouse astrocytes with rotenone or TTFA failed to significantly increase levels of ROS or autophagy. These results indicate that targeting mETC complex I and II selectively induces autophagic cell death through a ROS-mediated mechanism.
Compensatory signalling induced in the yolk sac vasculature by deletion of TGFβ receptors in mice
Authors: Carvalho Rita L. C. , Itoh Fumiko , Goumans Marie-Jose , Lebrin Franck , Kato Mitsuyasu , Takahashi Satoru , Ema Masatsugu , Itoh Susumu , van Rooijen Marga , Bertolino Philippe , ten Dijke Peter , Mummery Christine L.
Published: November 2007

Vascular development depends on transforming growth factor β (TGFβ), but whether signalling of this protein is required for the development of endothelial cells (ECs), vascular smooth muscle cells (VSMCs) or both is unclear. To address this, we selectively deleted the type I (ALK5, TGFBR1) and type II (TβRII, TGFBR2) receptors in mice. Absence of either receptor in ECs resulted in vascular defects in the yolk sac, as seen in mice lacking receptors in all cells, causing embryonic lethality at embryonic day (E)10.5. Deletion of TβRII specifically in VSMCs also resulted in vascular defects in the yolk sac; however, these were observed at later stages of development, allowing the embryo to survive to E12.5. Because TGFβ can also signal in ECs via ALK1 (ACVRL1), we replaced ALK5 by a mutant defective in SMAD2 and SMAD3 (SMAD2/3) activation that retained the ability to transactivate ALK1. This again caused defects in the yolk sac vasculature with embryonic lethality at E10.5, demonstrating that TGFβ/ALK1 signalling in ECs cannot compensate for the lack of TGFβ/ALK5-induced SMAD2/3 signalling in vivo. Unexpectedly, SMAD2 phosphorylation and α-smooth muscle actin (SMAα, ACTA2) expression occurred in the yolk sacs of ALK5–/– embryos and ALK5–/– embryonic stem cells undergoing vasculogenesis, and these processes could be blocked by an ALK4 (ACVR1B)/ALK5 inhibitor. Together, the data show that ALK5 is required in ECs and VSMCs for yolk sac vasculogenesis; in the absence of ALK5, ALK4 mediates SMAD2 phosphorylation and consequently SMAα expression.
Myosin VI and its interacting protein LMTK2 regulate tubule formation and transport to the endocytic recycling compartment
Authors: Chibalina Margarita V. , Seaman Matthew N. J. , Miller Christopher C. , Kendrick-Jones John , Buss Folma
Published: November 2007

Myosin VI is an actin-based retrograde motor protein that plays a crucial role in both endocytic and secretory membrane trafficking pathways. Myosin VI's targeting to and function in these intracellular pathways is mediated by a number of specific binding partners. In this paper we have identified a new myosin-VI-binding partner, lemur tyrosine kinase 2 (LMTK2), which is the first transmembrane protein and kinase that directly binds to myosin VI. LMTK2 binds to the WWY site in the C-terminal myosin VI tail, the same site as the endocytic adaptor protein Dab2. When either myosin VI or LMTK2 is depleted by siRNAs, the transferrin receptor (TfR) is trapped in swollen endosomes and tubule formation in the endocytic recycling pathway is dramatically reduced, showing that both proteins are required for the transport of cargo, such as the TfR, from early endosomes to the endocytic recycling compartment.
MAP-kinase activity necessary for TGFβ1-stimulated mesangial cell type I collagen expression requires adhesion-dependent phosphorylation of FAK tyrosine 397
Authors: Hayashida Tomoko , Wu Ming-Hua , Pierce Amy , Poncelet Anne-Christine , Varga John , Schnaper H. William
Published: November 2007

The signals mediating transforming growth factor β (TGFβ)-stimulated kidney fibrogenesis are poorly understood. We previously reported TGFβ-stimulated, Smad-mediated collagen production by human kidney mesangial cells, and that ERK MAP kinase activity optimizes collagen expression and enhances phosphorylation of the Smad3 linker region. Furthermore, we showed that disrupting cytoskeletal integrity decreases type I collagen production. Focal adhesion kinase (FAK, PTK2) activity could integrate these findings. Adhesion-dependent FAK Y397 phosphorylation was detected basally, whereas FAK Y925 phosphorylation was TGFβ1-dependent. By immunocytochemistry, TGFβ1 stimulated the merging of phosphorylated FAK with the ends of thickening stress fibers. Cells cultured on poly-L-lysine (pLL) to promote integrin-independent attachment spread less than those on control substrate and failed to demonstrate focal adhesion (FA) engagement with F-actin. FAK Y397 phosphorylation and ERK activity were also decreased under these conditions. In cells with decreased FAK Y397 phosphorylation from either plating on pLL or overexpressing a FAK Y397F point mutant, serine phosphorylation of the Smad linker region, but not of the C-terminus, was reduced. Y397F and Y925F FAK point mutants inhibited TGFβ-induced Elk-Gal activity, but only the Y397F mutant inhibited TGFβ-stimulated collagen-promoter activity. The inhibition by the Y397F mutant or by culture on pLL was prevented by co-transfection of constitutively active ERK MAP kinase kinase (MEK), suggesting that FAK Y397 phosphorylation promotes collagen expression via ERK MAP kinase activity. Finally, Y397 FAK phosphorylation, and both C-terminal and linker-region Smad3 phosphorylation were detected in murine TGFβ-dependent kidney fibrosis. Together, these data demonstrate adhesion-dependent FAK phosphorylation promoting TGFβ-induced responses to regulate collagen production.
Supported gold nanoparticles for aerobic, solventless oxidation of allylic alcohols
Authors: Abad Alberto , Corma Avelino , García Hermenegildo
Published: November 2007

After giving some general considerations about the specific properties of nanoparticles below 20 nm, procedures for size stabilization, and the importance of developing green alcohol oxidation reactions, catalytic data are presented showing that gold nanoparticles (3-7 nm) supported on nanoparticulated ceria (4 nm) are far more chemoselective than related palladium catalysts for the aerobic oxidation of allylic alcohols. Using palladium catalysts, in addition to minor oxidation of the alcohol functional group, we have also observed polymerization, 1-2 hydrogen shift, and hydrogenation. In contrast, ceria-supported gold nanoparticles exhibit a remarkable chemoselectivity (in many cases, almost complete) to the alcohol oxidation.
Green approaches to highly selective processes: Reactions of dimethyl carbonate over both zeolites and base catalysts
Authors: Selva Maurizio
Published: November 2007

Nowadays available by clean industrial processes, dimethyl carbonate (DMC) possesses properties of nontoxicity and biodegradability which make it a true green reagent/solvent to devise syntheses that prevent pollution at the source. In particular, the versatile reactivity of DMC allows both methylation and carboxymethylation protocols that can replace conventional and highly noxious reagents such as methyl halides (and dimethyl sulfate, DMS) and phosgene. In the field of DMC-mediated methylations, representative examples are the reactions of DMC with CH2-active compounds and primary aromatic amines. In the presence of organic/inorganic bases or zeolites (faujasites) catalysts, these processes proceed with unprecedented selectivity (up to 99 %, at complete conversion) toward the corresponding mono-C- and mono-N-methyl derivatives, a result hitherto not possible with conventional alkylation reagents. In the case of ambident amines (e.g., aminophenols, aminobenzyl alcohols, aminobenzoic acids, and aminobenzamides), the unique combination of DMC and zeolites allows not only a very high mono-N-methyl selectivity, but also a complete chemoselectivity toward the amino group. The other nucleophilic functionalities (OH, CO2H, CH2OH, CONH2) are fully preserved from alkylation and/or transesterification reactions, usually observed over basic catalysts.
Organic solvent-free synthesis of phosphorus-containing polymers
Authors: Iliescu Smaranda , Ilia Gheorghe , Pascariu Aurelia , Popa Adriana , Plesu Nicoleta
Published: November 2007

Direct, efficient, organic solvent- and catalyst-free synthesis of a series of polyphosphates was accomplished. The reaction involved a gas-liquid interfacial polycondensation between arylphosphoric dichlorides and bisphenol A. The polyphosphates were characterized by IR, 1H NMR, 31P NMR, inherent viscosity, thermal analysis, and molar mass. Yields in the range 70-90 % and inherent viscosities in the range 0.30-0.40 dl/g were obtained. The thermal stability of the polyphosphates was investigated by using thermogravimetry.
Heterogeneous catalysts and process for reductive dechlorination of polychlorinated hydrocarbons
Authors: Lokteva Ekaterina S. , Golubina Elena V. , Kachevsky Stanislav A. , Turakulova Anara O. , Lunin Valery V. , Tundo Pietro
Published: November 2007

The utilization and decomposition of chlorinated wastes without formation of dioxins are challenges of great environmental importance. In this work, the catalytic reductive methods of chlorinated organics processing are described, focusing on catalyst development. Pd-containing catalysts are improved by modification of supports [use of ultra dispersed diamond (UDD) or double oxides] or by dilution of Pd by not-noble metals (Fe, Ni, Cu). Both ways are effective for the processing of 1,3,5-trichlorobenzene (TCB) as a model of polychlorinated organics. The reasons for improvement of catalysts are discussed. The best catalysts were effectively used for hydrodechlorination (HDC) of hexachlorobenzene (HCB).
Photocatalysis and solar hydrogen production
Authors: Kudo Akihiko
Published: November 2007

Photocatalytic water splitting is a challenging reaction because it is an ultimate solution to energy and environmental issues. Recently, many new powdered photocatalysts for water splitting have been developed. For example, a NiO (0.2 wt %)/NaTaO3:La (2 %) photocatalyst with a 4.1-eV band gap showed high activity for water splitting into H2 and O2 with an apparent quantum yield of 56 % at 270 nm. Overall water splitting under visible light irradiation has been achieved by construction of a Z-scheme photocatalysis system employing visible-light-driven photocatalysts, Ru/SrTiO3:Rh and BiVO4 for H2 and O2 evolution, and an Fe3+/Fe2+ redox couple as an electron relay. Moreover, highly efficient sulfide photocatalysts for solar hydrogen production in the presence of electron donors were developed by making solid solutions of ZnS with AgInS2 and CuInS2 of narrow band gap semiconductors. Thus, the database of powdered photocatalysts for water splitting has become plentiful.
Photochemistry in synthesis: Where, when, and why
Authors: Protti Stefano , Dondi Daniele , Fagnoni Maurizio , Albini Angelo
Published: November 2007

A series of photochemical reactions are assessed under the environmental aspect by using Eissen and Metzger's EATOS (environmental assessment tool for organic syntheses) method and are compared with strictly analogous thermal processes. These include C-C bond-forming reactions (arylation and alkylation) and selective oxidation and reduction reactions. In most cases, the photochemical method is experimentally simpler and less expensive than the thermal alternative. A disadvantage is that photochemical reactions are carried out in rather dilute solution, and this factor gives by far the main contribution to the assessment. However, if the solvent is recovered, the photochemical reaction is more environment-friendly.
Recent progress on photoreactions in microreactors
Authors: Matsushita Yoshihisa , Ichimura Teijiro , Ohba Nobuko , Kumada Shinji , Sakeda Kosaku , Suzuki Tadashi , Tanibata Hideki , Murata Toshiaki
Published: November 2007

A microreaction system for organic photoreactions was developed, and the processes of diastereo-differentiating photosensitized reaction, photocatalytic oxidation and reduction of organic compounds, and amine N-alkylation were examined in microspace. These model reactions proceeded very rapidly with considerably large photonic efficiencies because of some distinct properties of microreactors for photoreactions, such as higher spatial illumination homogeneity and better light penetration through the entire reactor depth, and large surface-to-volume ratio in comparison with large-scale batch reactors. These results suggest feasibility of microreaction systems on organic photoreactions.
Industrial development and application of biobased oleochemicals
Authors: Hill Karlheinz
Published: November 2007

In concepts for new products, performance, product safety, and product economy criteria are equally important. They are taken into account already when the raw materials base for a new industrial product development is defined. Here, renewable resources gain-again after the earlier "green trend" in the 1980s-increasing attention as an alternative raw materials source compared to fossil feedstock. The industrial use of carbohydrates, proteins, and vegetable oils aligns perfectly with the principles of Responsible Care and is an important part of green chemistry and sustainability in general. Since the 1950s, oleochemistry has grown to a major research and technology area in several institutions and industries. A large variety of products based on fats and oils have been developed since then for different uses, such as specialties for polymer applications, biodegradable mineral oil replacements for lubricants, and surfactants and emulsifiers for the home and personal-care industries. However, at present it seems that the use of renewable resources, especially vegetable oils, has to compete more and more with the increasing demand for bioenergy, which could cause an unbalanced supply and demand in the future or even a threat for the increasing demand for food in certain areas of the world.
Controlled ring-opening polymerization of lactide by group 3 metal complexes
Authors: Amgoune Abderramane , Thomas Christophe M. , Carpentier Jean-François
Published: November 2007

In this review, attention is focused on the use of group 3 metal complexes for the ring-opening polymerization (ROP) of lactide to give polylactides (PLAs). Synthesis of PLAs has been studied intensively due to their biocompatible and biodegradable properties and their potential applications in medical and agricultural fields. ROP of lactide, a cyclic diester of lactic acid, provides PLA. This review includes our recent research results and implications in developing new amino-bis(phenolate) group 3 initiators for the synthesis of polyesters.
Extraction of novel sulfated polysaccharides from Aphanothece sacrum (Sur.) Okada, and its spectroscopic characterization
Authors: Okajima-Kaneko Maiko , Ono Masateru , Kabata Kiyotaka , Kaneko Tatsuo
Published: November 2007

We extracted polysaccharides (PS) from Aphanothece sacrum using a hot alkaline solution which degraded other biopolymers such as proteins and nucleotides. The spectroscopy and elemental analyses indicated the PS contain carboxyls and sulfate groups. The degree of sulfation was estimated as about 10 mol %. 1H NMR studies demonstrated that the PS of A. sacrum had a dimethylated fucose unit. The combination of sulfate group and fucose in the prokaryotic PS was first evidenced by the direct spectroscopic studies. The PS showed efficient gelation behavior, binding to metal ions abundant in soil, and the swelling volume of the gel was approximately 250 times the dry volume. These results imply that PS of A. sacrum, which has been mass cultivated in Japan for a long time, may have potential as an environmentally benign water absorbent.
Acylation of different amino derivatives with fatty acids on UL-MFI-type catalysts
Authors: Musteata Mariana , Musteata Vasile , Dinu Alina , Florea Mihaela , Hoang Vinh-Thang , Trong-On Do , Kaliaguine Serge , Pârvulescu Vasile I.
Published: November 2007

Acylation of different amino derivatives (ethanol amine, diethanol amine, N-aminoethylpiperazine) was carried out under green conditions with oleic acid or tail oil fatty acids. The experiments were carried out using as heterogeneous catalysts mesoporous Al-Meso and UL-ZSM-5 with Si/Al ratios between 100 and 20, in the range of the temperatures 80-180 °C without any solvent or in octane or water. The efficiency of the catalysts for the acylation of the investigated substrates appeared to be directly dependent on the Si/Al ratio and the size of the pores. The selectivity toward esters or amides was firstly controlled by temperature, and then by the Si/Al ratios. Additionally, both the conversion and selectivity were controlled by the solvent in which the reaction was carried out. The use of water led mostly to a mixture of esters and amides.
Diesel fuels from biomass
Authors: Casanave Dominique , Duplan Jean-Luc , Freund Edouard
Published: November 2007

The demand for transportation fuels - gasoline (for cars), diesel (for trucks and cars), and kerosene (for aircraft) - is predicted to increase. The fastest growth will be observed for kerosene, in competition with diesel, inducing constraints on diesel. At the same time, all of these fuels are derived mainly from oil (more than 95 %), thus generating growing, uncontrolled CO2 emissions. Therefore, production of diesel derived from biomass (the so-called biodiesel) appears as a major objective. In this paper, we describe the existing industrial processes, discuss the possible improvements, and present the new routes (the "second-generation" processes) under development that will allow biodiesel to gain a significant percentage of the diesel (and maybe of middle distillates) pool.
Enhanced Transmission at a Spinal Synapse TriggeredIn Vivoby an Injury Signal Independent of Altered Synaptic Activity
Authors: Bichler Edyta K. , Nakanishi Stan T. , Wang Qing-Bo , Pinter Martin J. , Rich Mark M. , Cope Timothy C.
Published: November 2007

Peripheral nerve crush initiates a robust increase in transmission strength at spinal synapses made by axotomized group IA primary sensory neurons. To study the injury signal that initiates synaptic enhancementin vivo, we designed experiments to manipulate the enlargement of EPSPs produced in spinal motoneurons (MNs) by IA afferents 3 d after nerve crush in anesthetized adult rats. If nerve crush initiates IA EPSP enlargement as proposed by reducing impulse-evoked transmission in crushed IA afferents, then restoring synaptic activity should eliminate enlargement. Daily electrical stimulation of the nerve proximal to the crush site did, in fact, eliminate enlargement but was, surprisingly, just as effective when the action potentials evoked in crushed afferents were prevented from propagating into the spinal cord. Consistent with its independence from altered synaptic activity, we found that IA EPSP enlargement was also eliminated by colchicine blockade of axon transport in the crushed nerve. Together with the observation that colchicine treatment of intact nerves had no short-term effect on IA EPSPs, we conclude that enhancement of IA-MN transmission is initiated by some yet to be identified positive injury signal generated independent of altered synaptic activity. The results establish a new set of criteria that constrain candidate signaling moleculesin vivoto ones that develop quickly at the peripheral injury site, move centrally by axon transport, and initiate enhanced transmission at the central synapses of crushed primary sensory afferents through a mechanism that can be modulated by action potential activity restricted to the axons of crushed afferents.
Uncoupling Proton Activation of Vanilloid Receptor TRPV1
Authors: Ryu Sujung , Liu Beiying , Yao Jing , Fu Qiang , Qin Feng
Published: November 2007

Multimodal gating is an essential feature of many TRP ion channels, enabling them to respond to complex cellular environments. TRPV1, a pain receptor involved in nociception at the peripheral nerve terminals, can be activated by a range of physical and chemical stimuli (e.g., capsaicin, proton, and heat) and further sensitized by proinflammatory substances. How a single receptor achieves this multiplicity of functionality is poorly understood at the molecular level. Here, we investigated the structural basis of proton activation of TRPV1. Chimeric channels between rTRPV1 and the low pH-insensitive homolog TRPV2 were constructed by systematically exchanging the extracellular domains and were characterized using whole-cell recording in transiently transfected HEK293 cells. Two discrete domains, one involving the pore helix and the other the S3–S4 linker, were found crucial for direct activation of the channel by low pH. Single residue mutations in either domain (T633A/V538L) abrogated the proton-evoked current while preserving the capsaicin and heat responses and their potentiation by mildly acidic pH. Both residues exert a gating effect through hydrophobic interactions. Our results unravel novel information on the structural basis of channel function, and support the existence of discrete domains for multimodal gating of the channel. In view of the resemblance of the pore of TRPV1 to KcsA, our findings also provide evidence on the pore helix as an active component in channel gating in addition to its role in ion permeation.
Plasticity of Neuron-Glial Interactions Mediated by Astrocytic EphARs
Authors: Nestor Michael W. , Mok Lee-Peng , Tulapurkar Mohan E. , Thompson Scott M.
Published: November 2007

Ephrin (Eph) signaling via Eph receptors affects neuronal structure and function. We report here that exogenous ephrinAs (EphAs) induce outgrowth of filopodial processes from astrocytes within minutes in rat hippocampal slice cultures. Identical effects were induced by release of endogenous ephrinAs by cleavage of their glycosylphosphatidylinositol anchor. Reverse transcription-PCR and immunocytochemistry revealed the expression of multiple EphA receptors (EphARs) in astrocytes. Exogenous and endogenous ephrins did not induce process outgrowth from astrocytes transfected with a kinase-dead EphAR construct, indicating that the critical EphARs were located on glia. Concomitant with these morphological changes, ephrinA reduced the frequency of (S)-3,5-dihydroxyphenylglycine-evoked NMDA receptor-mediated inward currents in CA1 pyramidal cells, elicited by release of glutamate from glial cells. The sensitivity of CA1 cell synaptic or extrasynaptic NMDA receptors was unaffected by ephrinA, indicating that this effect was mediated by inhibition of glutamate release from glial cells. Finally, ephrinA application decreased the frequency and increased the duration of spontaneous oscillations of the intracellular [Ca2+] in astrocytes. We conclude that ephrinA–EphA signaling is a pluripotent regulator of neuron–astrocyte interactions mediating rapid structural and functional plasticity.
Reinforcement Learning Signals in the Human Striatum Distinguish Learners from Nonlearners during Reward-Based Decision Making
Authors: Schönberg Tom , Daw Nathaniel D. , Joel Daphna , O'Doherty John P.
Published: November 2007

The computational framework of reinforcement learning has been used to forward our understanding of the neural mechanisms underlying reward learning and decision-making behavior. It is known that humans vary widely in their performance in decision-making tasks. Here, we used a simple four-armed bandit task in which subjects are almost evenly split into two groups on the basis of their performance: those who do learn to favor choice of the optimal action and those who do not. Using models of reinforcement learning we sought to determine the neural basis of these intrinsic differences in performance by scanning both groups with functional magnetic resonance imaging. We scanned 29 subjects while they performed the reward-based decision-making task. Our results suggest that these two groups differ markedly in the degree to which reinforcement learning signals in the striatum are engaged during task performance. While the learners showed robust prediction error signals in both the ventral and dorsal striatum during learning, the nonlearner group showed a marked absence of such signals. Moreover, the magnitude of prediction error signals in a region of dorsal striatum correlated significantly with a measure of behavioral performance across all subjects. These findings support a crucial role of prediction error signals, likely originating from dopaminergic midbrain neurons, in enabling learning of action selection preferences on the basis of obtained rewards. Thus, spontaneously observed individual differences in decision making performance demonstrate the suggested dependence of this type of learning on the functional integrity of the dopaminergic striatal system in humans.
Can the Human Brain Predict the Consequences of Arm Movement Corrections When Transporting an Object? Hints from Grip Force Adjustments
Authors: Danion Frédéric , Sarlegna Fabrice R.
Published: November 2007

It is well established that motor prediction is crucial for many of our daily actions. However, it is still unclear whether the brain generates motor prediction in real time. To challenge this idea, grip force was monitored while subjects had to transport a hand-held object to a visual target that could move unexpectedly. In agreement with previous reports, subjects triggered fast arm movement corrections to bring the object to the new target location. In addition, we found that subjects initiated grip force adjustments before or in synchrony with arm movement corrections. Throughout the movement, grip force anticipated the mechanical consequences resulting from arm motion, even when it was substantially corrected. Moreover, the predictive control of grip force did not interfere with the on-line control of arm trajectory. Altogether, our results suggest that motor prediction is an automatic, real-time process operating during movement execution and correction.
In VivoAnalysis of Ascl1 Defined Progenitors Reveals Distinct Developmental Dynamics during Adult Neurogenesis and Gliogenesis
Authors: Kim Euiseok J. , Leung Cheuk T. , Reed Randall R. , Johnson Jane E.
Published: November 2007

In the adult mammalian brain, new neurons and glia are continuously generated but molecular factors regulating their differentiation and lineage relationships are largely unknown. We show that Ascl1, a bHLH (basic helix-loop-helix) transcription factor, transiently labels neuronal and oligodendrocyte precursors in the adult brain. Usingin vivolineage tracing with inducible Cre recombinase, we followed the maturation of these precursors in four distinct regions. In the hippocampus, Ascl1 mostly marks type-2a progenitor cells with some late stage type-1 stem cells. Thirty days after Ascl1 expression, although a majority of the cells matured to granule neurons, a few cells remained as immature progenitors. By 6 months, however, essentially all Ascl1 lineage cells were granule neurons. In contrast, in the olfactory bulb neuronal lineage, Ascl1 is restricted to transit amplifying cells, and by 30 d all cells matured into GABAergic interneurons. Ascl1 also broadly marks oligodendrocyte precursors in subcortical gray and white matter regions. In the corpus callosum, Ascl1 defines a ventral layer of early oligodendrocyte precursors that do not yet express other early markers of this lineage like PDGFRα and Olig2. By 30 d, most had transitioned to mature oligodendrocytes. In contrast, Ascl1 expressing oligodendrocyte precursors in gray matter already coexpressed the early oligodendrocyte markers, but by 30 d they mostly remained as precursors. Our results reveal that Ascl1 is a common molecular marker of early progenitors of both neurons and oligodendrocytes in the adult brain, and these Ascl1 defined progenitors mature with distinct dynamics in different brain regions.
Prostaglandin E2Acts on EP1Receptor and Amplifies Both Dopamine D1and D2Receptor Signaling in the Striatum
Authors: Kitaoka Shiho , Furuyashiki Tomoyuki , Nishi Akinori , Shuto Takahide , Koyasu Sho , Matsuoka Toshiyuki , Miyasaka Masayuki , Greengard Paul , Narumiya Shuh
Published: November 2007

Dopamine is involved in multiple neural functions including motor control, reward and motivational processing, learning and reinforcement, and cognitive attention. Dopamine binds to two distinct classes of receptors, namely D1and D2, to exert these functions. Various endogenous substances regulate dopamine signaling, although their physiological functions are not fully understood. Here, we examined the role of prostaglandin E2(PGE2) and one of its receptors, EP1, in dopaminergic function in the striatum. EP1was expressed in both preprodynorphin-containing D1and preproenkephalin-containing D2neurons, and PGE2was produced in striatal slices in response to both D1and D2dopamine receptor stimulation. EP1-deficient mice exhibited significant suppression of hyperlocomotion induced by cocaine or SKF81297 (6-chloro-2,3,4,5-tetrahydro-1-phenyl-1H-3-benzazepine hydrobromide), a D1agonist, and significant attenuation of catalepsy induced by raclopride, a D2antagonist. Despite these behavioral defects, the extracellular concentration of dopamine was not suppressed in the striatum of EP1-deficient mice, and the densities of D1and D2receptors in the striatum were not different between the two genotypes. Stimulation of the D1receptor induced phosphorylation of dopamine and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) at Thr34 in striatal slices, and the addition of indomethacin, a PG synthesis inhibitor, attenuated the D1agonist-induced increase in DARPP-32–Thr34 phosphorylation. The further addition of an EP1agonist restored the indomethacin-attenuated phosphorylation. Furthermore, both D1- and D2-mediated changes in the DARPP-32–Thr34 phosphorylation were attenuated in EP1−/−slices. These results suggest that PGE2is formed in response to dopamine receptor stimulation in the striatum and amplifies both D1and D2receptor signaling via EP1.
Non-Cell-Autonomous Regulation of GABAergic Neuron Development by Neurotrophins and the p75 Receptor
Authors: Lin Pao-Yen , Hinterneder Jeanine M. , Rollor Sarah R. , Birren Susan J.
Published: November 2007

Basal forebrain GABAergic and cholinergic circuits regulate the activity of cholinergic projections to the cortex and hippocampus. Because these projections influence cortical development and function, the development of basal forebrain excitatory and inhibitory neurons is critical for overall brain development. We show that the neurotransmitter phenotype of these neurons is developmentally regulated by neurotrophins and the p75 receptor. Neurotrophins (nerve growth factor and brain-derived neurotrophic factor) increased the number of both cholinergic and GABAergic neurons in neonatal basal forebrain neuron cultures from the region of the medial septum. However, the p75 receptor is required only for neurotrophin-dependent expansion of the GABAergic, not the cholinergic, population. Neurotrophin-induced GABAergic development can be rescued inp75−/−cultures by expression of a p75 rescue construct in neighboring cells or by treatment with medium collected from neurotrophin-treated wild-type cultures. Because p75 is not expressed in basal forebrain GABAergic neurons, this defines a new, non-cell-autonomous mechanism of p75 action in which ligand binding results in release of a soluble factor that modifies neurotrophin responses of nearby neurons. p75 is also required for the maintenance of basal forebrain GABAergic neuronsin vivo, demonstrating that p75-mediated interactions between cholinergic and GABAergic neurons regulate the balance of excitatory and inhibitory components of basal forebrain circuits.
Cortex Mediates Multisensory But Not Unisensory Integration in Superior Colliculus
Authors: Alvarado Juan Carlos , Stanford Terrence R. , Vaughan J. William , Stein Barry E.
Published: November 2007

Converging cortical influences from the anterior ectosylvian sulcus and the rostral lateral suprasylvian sulcus were shown to have a multisensory-specific role in the integration of sensory information in superior colliculus (SC) neurons. These observations were based on changes induced by cryogenic deactivation of these cortico-SC projections. Thus, although the results indicated that they played a critical role in integrating SC responses to stimuli derived from different senses (i.e., visual–auditory), they played no role in synthesizing its responses to stimuli derived from within the same sense (visual–visual). This was evident even in the same multisensory neurons. The results suggest that very different neural circuits have evolved to code combinations of cross-modal and within-modal stimuli in the SC, and that the differences in multisensory and unisensory integration are likely caused by differences in the configuration of each neuron's functional inputs rather than to any inherent differences among the neurons themselves. The specificity of these descending influences was also apparent in the very different ways in which they affected responses to the component cross-modal stimuli and their actual integration. Furthermore, they appeared to target only multisensory neurons and not their unisensory neighbors.