bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigen recognition induces phosphatidylserine exposure on the cell surface of human CD8+ T cells
Authors: Fischer Karin , Voelkl Simon , Berger Jana , Andreesen Reinhard , Pomorski Thomas , Mackensen Andreas
Published: August 2006

In eukaryotic cells the phospholipid phosphatidylserine (PS) is restricted to the inner plasma-membrane leaflet. This lipid asymmetry, which is maintained by the concerted action of phospholipid transport proteins, is mainly lost during apoptosis. Here, we demonstrate that primary human CD8+ cytotoxic T lymphocytes (CTLs) expose PS on T-cell receptor (TCR)–mediated antigen (Ag) recognition. In contrast to PS externalization on apoptotic cells, activation-induced PS exposure is less pronounced and reversible. Fluorescence microscopic analysis revealed that PS is distributed nonhomogenously over the plasma membrane and concentrated in membrane lipid raft domains at the immunologic synapse. By studying the activity of PS transport proteins using a fluorescence-labeled PS analogue, we found that activation of CTLs inhibited the flippase-mediated inward-directed PS transport without affecting the outward transport. Shielding of exposed PS by annexin V protein during Ag recognition diminished cytokine secretion, activation, and cell-to-cell clustering of Ag-specific CTLs. In summary, our data demonstrate for the first time that externalized PS on Ag-stimulated CTLs is linked to T-cell activation and probably involved in cell-to-cell contact formation at the immunologic synapse.
Histone deacetylase inhibitors increase virus gene expression but decrease CD8+ cell antiviral function in HTLV-1 infection
Authors: Mosley Angelina Jane , Meekings Kiran N. , McCarthy Corinna , Shepherd Dawn , Cerundolo Vincenzo , Mazitschek Ralph , Tanaka Yuetsu , Taylor Graham P. , Bangham Charles R.
Published: August 2006

The dynamics of human T-lymphotropic virus type-1 (HTLV-1) provirus expression in vivo are unknown. There is much evidence to suggest that HTLV-1 gene expression is restricted: this restricted gene expression may contribute to HTLV-1 persistence by limiting the ability of the HTLV-1–specific CD8+ cell immune response to clear infected cells. In this study, we tested the hypothesis that derepression of HTLV-1 gene expression would allow an increase in CD8+ cell–mediated lysis of HTLV-1–infected cells. Using histone deacetylase enzyme inhibitors (HDIs) to hyperacetylate histones and increase HTLV-1 gene expression, we found that HDIs doubled Tax expression in naturally infected lymphocytes after overnight culture. However, the rate of CD8+ cell–mediated lysis of Tax-expressing cells ex vivo was halved. HDIs appeared to inhibit the CD8+ cell–mediated lytic process itself, indicating a role for the microtubule-associated HDAC6 enzyme. These observations indicate that HDIs may reduce the efficiency of cytotoxic T-cell (CTL) surveillance of HTLV-1 in vivo. The impact of HDIs on HTLV-1 proviral load in vivo cannot be accurately predicted because of the widespread effects of these drugs on cellular processes; we therefore recommend caution in the use of HDIs in nonmalignant cases of HTLV-1 infection.
H-NS controls metabolism and stress tolerance in Escherichia coli O157:H7 that influence mouse passage
Authors: Erol Irfan , Jeong Kwang-Cheol , Baumler David J , Vykhodets Boris , Ho Choi Sang , Kaspar Charles W
Published: August 2006

Background

H-NS is a DNA-binding protein with central roles in gene regulation and nucleoid structuring in Escherichia coli. There are over 60 genes that are influenced by H-NS many of which are involved in metabolism. To determine the significance of H-NS-regulated genes in metabolism and stress tolerance, an hns mutant of E. coli O157:H7 was generated (hns::nptI, FRIK47001P) and its growth, metabolism, and gastrointestinal passage compared to the parent strain (43895) and strain FRIK47001P harboring pSC0061 which contains a functional hns and 90-bp upstream of the open-reading frame.

Results

The hns mutant grew slower and was non-motile in comparison to the parent strain. Carbon and nitrogen metabolism was significantly altered in the hns mutant, which was incapable of utilizing 42 carbon, and 19 nitrogen sources that the parent strain metabolized. Among the non-metabolized substrates were several amino acids, organic acids, and key metabolic intermediates (i.e., pyruvate) that limit carbon acquisition and energy generation. Growth studies determined that the parent strain grew in LB containing 14 to 15% bile or bile salts, while the hns mutant grew in 6.5 and 9% of these compounds, respectively. Conversely, log-phase cells of the hns mutant were significantly (p < 0.05) more acid tolerant than the parent strain and hns mutant complemented with pSC0061. In mouse passage studies, the parent strain was recovered at a higher frequency (p < 0.01) than the hns mutant regardless of whether log- or stationary-phase phase cells were orally administered.

Conclusion

These results demonstrate that H-NS is a powerful regulator of carbon and nitrogen metabolism as well as tolerance to bile salts. It is likely that the metabolic impairments and/or the reduced bile tolerance of the E. coli O157:H7 hns mutant decreased its ability to survive passage through mice. Collectively, these results expand the influence of H-NS on carbon and nitrogen metabolism and highlight its role in the ability of O157:H7 strains to respond to changing nutrients and conditions encountered in the environment and its hosts.
Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system
Authors: Mazzola Priscila G , Martins Alzira MS , Penna Thereza CV
Published: August 2006

Background

Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages), Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value) necessary to inactivate 90% of the initial bioburden (decimal reduction time) was experimentally determined.

Methods

Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild) bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H2O2) and 0.45% peracetic acid.

Results

The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log10) population (n cycles). To kill 90% of the initial population (or one log10 cycle), the necessary time (D-value) was for P. aeruginosa into: (i) 0.5% citric acid, D = 3.8 min; (ii) 0.5% hydrochloric acid, D = 6.9 min; (iii) 70% ethanol, D = 9.7 min; (iv) 0.5% sodium bisulfite, D = 5.3 min; (v) 0.4% sodium hydroxide, D = 14.2 min; (vi) 0.5% sodium hypochlorite, D = 7.9 min; (vii) mixture of hydrogen peroxide (2.2%) plus peracetic acid (0.45%), D = 5.5 min.

Conclusion

The contact time of 180 min of the system with the mixture of H2O2+ peracetic acid, a total theoretical reduction of 6 log10 cycles was attained in the water purified storage tank and distribution loop. The contact time between the water purification system (WPS) and the sanitary agents should be reviewed to reach sufficient bioburden reduction (over 6 log10).
Increased mRNA expression levels of ERCC1, OGG1 and RAIin colorectal adenomas and carcinomas
Authors: Sæbø Mona , Skjelbred Camilla Furu , Nexø Bjørn Andersen , Wallin Håkan , Hansteen Inger-Lise , Vogel Ulla , Kure Elin H
Published: August 2006

Background

The majority of colorectal cancer (CRC) cases develop through the adenoma-carcinoma pathway. If an increase in DNA repair expression is detected in both early adenomas and carcinomas it may indicate that low repair capacity in the normal mucosa is a risk factor for adenoma formation.

Methods

We have examined mRNA expression of two DNA repair genes, ERCC1 and OGG1 as well as the putative apoptosis controlling gene RAI, in normal tissues and lesions from 36 cases with adenomas (mild/moderat n = 21 and severe n = 15, dysplasia) and 9 with carcinomas.

Results

Comparing expression levels of ERCC1, OGG1 and RAI between normal tissue and all lesions combined yielded higher expression levels in lesions, 3.3-fold higher (P = 0.005), 5.6-fold higher(P < 3·10-5) and 7.7-fold higher (P = 0.0005), respectively. The levels of ERCC1, OGG1 and RAI expressions when comparing lesions, did not differ between adenomas and CRC cases, P = 0.836, P = 0.341 and P = 0.909, respectively. When comparing expression levels in normal tissue, the levels for OGG1 and RAI from CRC cases were significantly lower compared to the cases with adenomas, P = 0.012 and P = 0.011, respectively.

Conclusion

Our results suggest that increased expression of defense genes is an early event in the progression of colorectal adenomas to carcinomas.
Interoceptive hypersensitivity and interoceptive exposure in patients with panic disorder: specificity and effectiveness
Authors: Lee Kiyoe , Noda Yumiko , Nakano Yumi , Ogawa Sei , Kinoshita Yoshihiro , Funayama Tadashi , Furukawa Toshiaki A
Published: August 2006

Background

Interoceptive exposure has been validated as an effective component of cognitive behavioral therapy (CBT) for the treatment of panic disorder but has hitherto received little research attention. We examined the effectiveness of various interoceptive exposure exercises using the Body Sensations Questionnaire (BSQ) (Chambless et al., 1984).

Methods

We first performed an exploratory principal factor analysis of all the items contained in the BSQ to obtain meaningful dimensions of interoceptive fears. Next, we examined the correlations between each interoceptive exposure task's degree of similarity to panic attacks and each BSQ factor and then examined whether the BSQ factor scores decreased in comparison with the baseline values when the corresponding exposure tasks were successfully completed by the subjects.

Results

The factor analyses revealed four factors, which we named "pseudoneurological fears", "gastrointestinal fears", "cardiorespiratory fears" and "fears of dissociative feelings." Among the nine interoceptive exposure tasks, 'hyperventilation', 'shaking head', 'holding breath' and 'chest breathing' were considered to reproduce pseudoneurological symptoms, 'breathing through a straw' was considered to reproduce gastrointestinal symptoms, and 'spinning' was considered to reproduce both pseudoneurological and dissociative symptoms; none of the interoceptive exercises were found to reproduce cardiorespiratory symptoms. Among each group of patients for whom 'hyperventilation', 'holding breath', 'spinning' or 'chest breathing' was effective, a significant improvement in the BSQ pseudoneurological fears factor scores was observed. On the other hand, no significant difference between the baseline and endpoint values of the BSQ gastrointestinal fears or the BSQ fears of dissociative feelings factor scores were observed among the patients for whom 'spinning' or 'breathing through a straw' was effective.

Conclusion

Several interoceptive exposure tasks were particularly effective in reducing pseudoneurological fears. New interoceptive tasks, especially tasks related to cardiorespiratory and dissociative feelings, are needed.
Phagocytic response to fully controlled plural stimulation of antigens on macrophage using on-chip microcultivation system
Authors: Matsumura Kazunori , Orita Kazuki , Wakamoto Yuichi , Yasuda Kenji
Published: August 2006

To understand the control mechanism of innate immune response in macrophages, a series of phagocytic responses to plural stimulation of antigens on identical cells was observed. Two zymosan particles, which were used as antigens, were put on different surfaces of a macrophage using optical tweezers in an on-chip single-cell cultivation system, which maintains isolated conditions of each macrophage during their cultivation. When the two zymosan particles were attached to the macrophage simultaneously, the macrophage responded and phagocytosed both of the antigens simultaneously. In contrast, when the second antigen was attached to the surface after the first phagocytosis had started, the macrophage did not respond to the second stimulation during the first phagocytosis; the second phagocytosis started only after the first process had finished. These results indicate that (i) phagocytosis in a macrophage is not an independent process when there are plural stimulations; (ii) the response of the macrophage to the second stimulation is related to the time" delay from the first stimulation. Stimulations that occur at short time intervals resulted in simultaneous phagocytosis, while a second stimulation that is delayed long enough might be neglected until the completion of the first phagocytic process.
Leader (L) and L* proteins of Theiler's murine encephalomyelitis virus (TMEV) and their regulation of the virus' biological activities
Authors: Takano-Maruyama Masumi , Ohara Yoshiro , Asakura Kunihiko , Okuwa Takako
Published: August 2006

Theiler's murine encephalomyelitis virus (TMEV) is divided into two subgroups on the basis of their different biological activities. GDVII subgroup strains produce fatal poliomyelitis in mice without virus persistence or demyelination. In contrast, TO subgroup strains induce demyelinating disease with virus persistence in the spinal cords of weanling mice. Two proteins, whose open reading frames are located in the N-terminus of the polyprotein, recently have been reported to be important for TMEV biological activities. One is leader (L) protein and is processed from the most N-terminus of the polyprotein; its function is still unknown. Although the homology of capsid proteins between DA (a representative strain of TO subgroup) and GDVII strains is over 94% at the amino acid level, that of L shows only 85%. Therefore, L is thought to be a key protein for the subgroup-specific biological activities of TMEV. Various studies have demonstrated that L plays important roles in the escape of virus from host immune defenses in the early stage of infection. The second protein is a 17–18 kDa protein, L*, which is synthesized out-of-frame with the polyprotein. Only TO subgroup strains produce L* since GDVII subgroup strains have an ACG rather than AUG at the initiation site and therefore do not synthesize L*. 'Loss and gain of function' experiments demonstrate that L* is essential for virus growth in macrophages, a target cell for TMEV persistence. L* also has been demonstrated to be necessary for TMEV persistence and demyelination. Further analysis of L and L* will help elucidate the pathomechanism(s) of TMEV-induced demyelinating disease.
No advantage of laser-assisted over conventional intracytoplasmic sperm injection: a randomized controlled trial [NCT00114725]
Authors: Richter Kevin S , Davis Alana , Carter Jennifer , Greenhouse Stephen J , Mottla Gilbert L , Tucker Michael J
Published: August 2006

Background

Intracytoplasmic sperm injection (ICSI) is a component of infertility treatment often employed when conventional in vitro fertilization is unlikely to be successful. Despite good clinical results with ICSI, the procedure is typically associated with degeneration of a significant percentage (approximately 10%) of the treated oocytes. The cause of this degeneration remains unclear. Speculation that damage caused by oocyte compression during the injection procedure may be responsible has led to the development of a novel technique known as laser-assisted ICSI. This procedure involves drilling a small hole through the zona pellucida with a laser prior to sperm injection. Preliminary studies have suggested that laser-assisted ICSI may dramatically reduce oocyte degeneration rates. The objective of this study was to examine whether the reported benefits of laser-assisted ICSI could be verified on a larger, less-selected group of patients.

Methods

Oocytes retrieved from 59 patients scheduled for ICSI were randomly divided into equal treatment and control groups. Oocytes in the treatment group were inseminated by laser-assisted ICSI, while oocytes in the control group were inseminated by conventional ICSI. Outcome variables (oocyte fertilization and degeneration, embryo cell numbers and fragmentation on days 2 and 3, and compaction and blastocyst formation rates) were compared between treatment and control groups by paired-sample t-test. Subgroup analysis was performed according to zona pellucida and oolemma breakage patterns.

Results

No significant differences between treatment and control groups were observed for any of the measured outcome variables. However, fragile zonae pellucidae were associated with significantly poorer embryo quality, and fragile oolemmas that broke easily upon insertion of the injection needle were associated with a significantly higher oocyte degeneration rate. Nevertheless, there were also no between-treatment differences in clinical outcomes within these patient subpopulations.

Conclusion

Contrary to previous reports based on smaller sample sizes, the results of this study suggest that there is no benefit of laser-assisted ICSI, either for the general population of ICSI patients, or for patients prone to zona pellucida or oolemma fragility.
Associations of Early Growth and Adult Adiposity with Patterns of Salivary Cortisol in Adulthood
Authors: Power Chris , Li Leah , Hertzman Clyde
Published: August 2006

Context: Early growth and obesity are associated with adult chronic disease. A suspected mediator is the hypothalamic-pituitary-adrenal axis and cortisol regulation. Our prior hypothesis was that cortisol levels are affected by anthropometry at several life stages.

Objective: The objective of the study was to assess whether prenatal and postnatal growth and adiposity are associated with adult cortisol levels, and whether early growth and adiposity are related to later cortisol through adult body size.

Design: Weight, head circumference (birth), height, and body mass index (BMI) (7 yr); and height, BMI (33 yr), and waist-hip ratio (WHR) (45 yr) were measured in the 1958 British birth cohort.

Setting: All study subjects were born in England, Scotland, and Wales in 1 wk in March 1958.

Participants: A total of 6,470 participants with salivary cortisol were gathered from 12,069 invitees (54%) at 45 yr.

Main Outcome Measures: Two saliva samples on 1 d were collected: 45 min postwaking (t1) and 3 h later (t2). Three cortisol outcomes were measured: t1 level, area-under-curve, and abnormal t1–t2 pattern.

Results: WHR was associated with all cortisol measures: among men over the WHR range 0.81–1.05, t1 cortisol decreased by approximately 3 nmol/liter, and the risk of an abnormal t1–t2 pattern increased by 77%; for women, over the WHR range 0.69–0.93, the risk of an abnormal t1–t2 pattern increased by 74%. For childhood measures, among males, increasing 7-yr BMI was associated with decreased t1 cortisol and increased risk of an abnormal t1–t2 pattern. Poorer prenatal growth in women, and postnatal growth in both sexes, was associated with increasing area-under-curve.

Conclusions: Smaller head circumference, shorter stature, lower BMI, and WHR are associated with higher cortisol levels.
Serum Insulin-Like Growth Factor-I (IGF-I) and Growth in Children Born after Assisted Reproduction
Authors: Mau Kai Claudia , Main Katharina M. , Nyboe Andersen Anders , Loft Anne , Chellakooty Marla , Skakkebæk Niels E. , Juul Anders
Published: August 2006

Context: Concern has been raised about the safety of assisted reproduction techniques for the offspring.

Objectives: The objective of the study was to investigate postnatal growth and growth factors in children born after intra-cytoplasmatic sperm injection (ICSI) and in vitro fertilization (IVF).

Design: The study had two cohorts: a population-based longitudinal infant cohort 0–36 months [236 ICSI, 173 IVF, 1530 naturally conceived (NC)], and a cross-sectional child cohort at 5 yr (68 ICSI, 67 IVF, 70 NC).

Intervention: Anthropometrical measurements were made at birth, 3, 18, 36 (infant cohort), and 60 months (child cohort), and blood samples were collected at 3 or 60 months.

Main Outcome Measures: Serum IGF-I, IGFBP-3, height, weight, head and abdominal circumference, body mass index, and fat folds were the main outcome measures.

Results: Anthropometrical measurements showed no significant differences between ICSI and IVF children and controls in either cohort. However, singleton ICSI girls [3.4 (0.6) kg, P = 0.008] had a slightly lower birth weight than IVF [3.5 (0.5) kg] and NC girls [3.5 (0.5) kg]. Birth weights of singleton boys [3.6 (0.5) kg], twin boys [2.6 (0.6) kg], and twin girls [2.4 (0.5) kg] did not differ between types of conception. In the infant cohort in 3-month-old singletons, serum IGF-I was lower in ICSI [78 (26) ng/ml] than NC boys [94 (27) ng/ml, P < 0.001] and IVF [74 (34) ng/ml], compared with NC girls [93 (43) ng/ml, P = 0.011]. ICSI children were also smaller than their target height (sd score) at 3 yr of age [mean −0.91 (1.2)], compared with NC children [−0.61 (0.9), P = 0.033]. In the child cohort, target height attainment (sd score) and growth factors did not differ among the three groups.

Conclusions: The overall growth pattern of ICSI and IVF children in both cohorts was normal. Our findings of subtle differences in target height attainment and serum IGF-I levels between infants born after assisted reproduction techniques and controls may not be clinically significant. However, these observations indicate that further systematic follow-up of growth and puberty in these children is needed.
Divergent Phenotype of Two Siblings Human Leukocyte Antigen Identical, Affected by Nonclassical and Classical Congenital Adrenal Hyperplasia Caused by 21-Hydroxylase Deficiency
Authors: Porzio O. , Cunsolo V. , Malaponti M. , De Nisco E. , Acquafredda A. , Cavallo L. , Andreani M. , Giardina E. , Testi M. , Cappa M. , Federici G.
Published: August 2006

Context: Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders most often caused by enzyme 21-hydroxylase deficiency. Most mutations causing enzymatic deficiency are generated by recombinations between the active gene CYP21 and the pseudogene CYP21P. Only 1–2% of affected alleles result from spontaneous mutations. The phenotype of CAH varies greatly, usually classified as classical or nonclassical, depending on variable degree in 21-hydroxylase activity. Here we report a divergent phenotype of two human leukocyte antigen identical siblings, affected by nonclassical and classical CAH caused by 21-hydroxylase deficiency due to different genotype.

Patients and Methods: Using direct sequencing method and Southern blot, we studied two children (one male and one female), affected, respectively, by nonclassical and classical CAH and their parents.

Results: The mother was heterozygous for the Q318X mutation, and the father was heterozygous for the V281L mutation. The brother was a compound heterozygote for the mutations V281L and Q318X, whereas the proband was compound heterozygote for the Q318X mutation and a large conversion. The two children are human leukocyte antigen identical (A*02;B*14;DRB1*01/A*33;B*14;DRB1*03).

Conclusions: Different phenotype of the proband is the result of compound heterozygosity for the maternal mutation Q318X and a de novo large conversion.
Inactivation of MAPK in mature oocytes triggers progression into mitosis via a Ca2+-dependent pathway but without completion of S phase
Authors: Zhang Wen Ling , Huitorel Philippe , Geneviere Anne-Marie , Chiri Sandrine , Ciapa Brigitte
Published: August 2006

Unfertilized sea urchin eggs that are arrested at G1 phase after completion of meiosis contain a highly phosphorylated mitogen-activated protein (MAP) kinase (MAPK), the ERK-like protein (ERK-LP). Several data including our previous results show that ERK-LP is inactivated after fertilization, which agrees with results obtained in other species including Xenopus, starfish and mammals. The question is to elucidate the function of a high MAPK activity in sea urchin eggs. We report here that dephosphorylation of ERK-LP with very low concentrations of two MEK inhibitors, PD98059 or U0126, triggers entry into mitosis. Under these conditions, recurrent oscillations of the phosphorylation of ERK-LP and of a tyrosine residue in Cdc2 occur, and the intracellular Ca2+ level (Ca2+i) progressively and slowly increases. Nuclear envelope breakdown and all mitotic events initiated after dephosphorylation of ERK-LP are inhibited when changes in Ca2+i are prevented; however, they are independent of the intracellular pH. These results suggest that inactivation of a MEK-ERK pathway, normally induced after fertilization of sea urchin eggs, triggers entry into mitosis by altering Ca2+i but cannot trigger full DNA replication. We discuss the hypothesis that neither inactivation nor activation of a MEK-ERK pathway is required for S phase completion in sea urchin egg.
Solvational Behavior of Some Substituted Benzoic Acids in Ethanol–Water Mixtures at 298.15 K
Authors: Biswas P K , Lahiri S C , Dey B P
Published: August 2006

The effect of substitution on the solubility and dissociation constants for the reaction

have been studied from the measurements of pH and solubilities of substituted benzoic acids in ethanol+water mixtures (0—100 wt%). The changes in the solubility values depend on the hydrophobic character and the dielectric constant of the solvent medium. The free energies of transfer for anions have been determined from the relation

using the previously determined values of ΔGt°(H+). The results are discussed in the light of solute-solvent interactions.
Catalytic Behaviors of the Heteropolytungstolanthanate (LnW10, Ln: Cerium, Neodymium, and Samarium) Anion on the Decomposition of Hydrogen Peroxide and Cyclohexanol Oxidation with H2O2 in a Homogeneous System
Authors: Shiozaki Ryuji , Goto Hideya , Kera Yoshiya
Published: August 2006

In the presence of the heteropolytungstolanthanate anion (Ce(IV)W10O36−8, Nd(III)W10O36−9, and Sm(III)W10O36−9; LnW10) the kinetic behaviors of hydrogen peroxide decomposition and cyclohexanol oxidation with H2O2 were investigated. In CeW10 the H2O2 decomposition rate tended to reach almost a limited value with increasing H2O2 concentration, while in NdW10 and SmW10 it decreased considerably after reaching the maximum value in high H2O2. The kinetic behavior of LnW10 was reasonably explained by a reaction scheme in which an intermediate species is initially formed (IS1) and then reacts further with H2O2 molecules to change the inactive species and, thus, to be removed from the catalytic cycle. Cyclohexanol was selectively oxidized with H2O2 to cyclohexanone according to the reaction order 0.6—0.8 on the H2O2 concentration until the high H2O2 region in the presence of all LnW10. The Arrhenius law concerning the overall rates of both reactions of H2O2 decomposition and cyclohexanol oxidation was maintained in any LnW10; further, a good compensation effect between the Arrhenius parameters, preexponential factor (log V0) and apparent activation energy (Eap), was found for both reactions in the series of LnW10. However, the empirical points concerning the log V0 vs. Eap plot in the oxidation alined in an inverse manner to those in H2O2 decomposition; that is, the order is CeW10 < SmW10 < NdW10 in the former and NdW10 < SmW10 < CeW10 in the latter. From this finding, both reactions were suggested to proceed via a common-intermediate species. Furthermore, it was elucidated that the more stable is the species, the more favorably are the alcohol molecules activated to the final products in the oxidation reaction.
Formation of Reversed Micelles and W/O Microemulsions of Butyldodecyldimethylammonium Bromide in Chlorobenzene
Authors: Kawai Takeshi , Hamada Kaoru , Kon-No Kijiro
Published: August 2006

The limiting amounts of water solubilized by butyldodecyldimethylammonium bromide (BDDAB) in chlorobenzene increased rapidly at 0.01 mol kg−1 surfactant concentration at 30 °C. Using 1H NMR, fluorescence, and near infrared spectroscopic techniques, the solubilized states of water in the region obtained above 0.01 mol kg−1 were examined as a function of Rw ( = [H2O]/[BDDAB]) at various concentrations of surfactant. It was found from these spectral features that three types of water exist in varying proportions in the interior of reversed micelles, i.e., below Rw = 4 water is bound directly to the ionic head groups of the surfactant, in the range of Rw = 4—10 the succeeded water is held together with the hydrated ionic groups by hydrogen bonds, and above Rw = 10 bulk-like water is built up. These types of water could be discussed in connection with the formation of reversed and swollen micelles or W/O microemulsions. Further, the minimum Rw required for the formation of swollen micelles and W/O microemulsion and the critical swollen micelles or W/O microemulsion concentration could be estimated.
Equilibrium and Kinetic Studies of the Binding of Monoanionic and Dianionic Ligands to Bovine Serum Albumin
Authors: Murakami Kiyofumi
Published: August 2006

The binding of monoanionic azo dyes (4-(2-hydroxy-1-naphtylazo)benzenesulfonate (Orange II) and 6-hydroxy-5-phenylazo-2-naphthalenesulfonate (Ponceau 4G)) and dianionic one (6-hydroxy-5-(4-sulfophenylazo)-2-naphthalenesulfonate (Sunset Yellow FCF)) to bovine serum albumin (BSA) at pH = 7.0 and 25 °C has been studied by equilibrium dialysis, spectrophotometry, and a temperature-jump method. The binding parameters for the monoanionic dyes were found to take quite similar values to each other. This shows that both of the dyes bind to BSA in essentially the same manner, irrespective of the difference in the position of the sulfonato group on the ligands. On the other hand, the data for the dianionic dye showed that the secondary sites, observed for the monoanionic dyes, almost completely disappeared, while the number and the binding constant for the primary sites were comparable. Kinetic data concerning the BSA–Sunset Yellow FCF system were found to be consistent with a scheme in which a bimolecular binding is followed by two isomerizations of the complex at the primary site. All of the equilibrium and rate constants for the scheme have been determined. A comparison of the results to those for other ligands has shown that the bimolecular association rate constant successively decreases with an increase in the number of anionic charges on the ligands. In the case of monoanionic dyes, however, the number of observed relaxations showed a tendency to increase with an increase in the number of bound dyes on the secondary sites. On the basis of these results, the detailed binding mechanism is discussed from the view point of the relation between the specificity of ligand-binding and the number of charges on the ligand.
Oxygen-17 Magnetic Resonance Study of the Oxygen Exchange of Methyl- and Butylarsonic Acids and Dimethylarsinic Acid with Solvent Water
Authors: Okumura Akiko , Fushimi Midori , Yamamoto Masako
Published: August 2006

The rates of the oxygen-exchange reactions of methyl- and butylarsonic acids and dimethylarsinic acid with solvent water were measured in the pH range below 6, and at temperatures between 50 and 90 °C, by using the 17O NMR line-broadening technique. For methylarsonic acid, the rate RMAA is expressed by the following rate law: RMAA = kh1[H+][H2A] + k1[H2A] + kh2[H+][H2A]2 + k2[H2A]2 + k3[H2A][HA−], where H2A and HA− designate CH3AsO3H2 and CH3AsO3H−, respectively. For butylarsonic acid, the rate law is expressed as: RBAA = kh1[H+][n–C4H9AsO3H2]. For dimethylarsinic acid, its conjugated acid is involved in the rate law as: RCAA = kh1′[(CH3)2AsO2H2+] + khh1′[H+][(CH3)2AsO2H2+]. The exchange rates of methyl- and butylarsonic acids and dimethylarsinic acid (50—90 °C) were analyzed in terms of the respective rate law to obtain the values of the rate constants involved in the rate laws. The activation parameters of these rate constants were obtained; for both the first- and second-order rate constants, the activation energies are characteristic of their small values (from 45 to 20 kJ mol−1), while the activation entropies have large negative values, which are found in the range between −92 and −145 J K−1 mol−1.
Crystal Structures of the Room-Temperature Phase of 4,4″-Difluoro-p-terphenyl and 4,4″′-Difluoro-p-quaterphenyl
Authors: Saitoh Hideki , Saito Kazuya , Yamamura Yasuhisa , Matsuyama Haruo , Kikuchi Koichi , Iyoda Masahiko , Ikemoto Isao
Published: August 2006

4,4″-Difluoro-p-terphenyl and 4,4″′-difluoro-p-quaterphenyl were synthesized and their crystal structures were determined at room temperature. These are isostructural to p-terphenyl and p-quaterphenyl, respectively. Some “disorder” in the inner benzene ring orientation was detected and resolved by the split-atom method. A rigid-body librational analysis of each benzene ring around the long molecular axis was performed. A rough estimate of the barrier height of the planar conformation for 4,4″-difluoro-p-terphenyl was obtained as being about 1 kJ mol−1. The results are compared with the properties of p-terphenyl and p-quaterphenyl, and the effect of fluorine-substitution on the molecular properties is discussed in relation to the low-temperature phase transitions.
Electrochemical Insertion of Hydrogen into Diniobium Pentaoxide
Authors: Komura Teruhisa , Nakanori Takahiro , Takahashi Koshin
Published: August 2006

The electrical behavior of the Nb2O5 electrode in Na2SO4 solutions was characterized by the impedance spectra. The pH dependence of the flat band potential could be explained in terms of the acid-dissociating equilibrium of hydroxyl groups on the oxide surface. The plot of equilibrium potential of the oxide vs. pH gave a straight line with a slope of −0.06 V. The equilibrium potential became monotonously more negative with increasing extent of the reduction of the oxide. The cyclic voltammograms and chronopotentiograms of the partially reduced oxide indicated that the diffusion of an electroactive species in the oxide controlled the rate of the electrode process. These results suggest that HxNbO2.5 or NbO2.5−x(OH)x can be formed by the reduction of the oxide. The conductivities of the oxide increased about two orders of magnitude by the insertion of a small amount of hydrogen. In conclusion, a blue coloration of the oxide can occur as a result of the diffusion of H+ from the electrolyte into the Nb2O5 lattice and a simultaneous injection of electrons to d-block bands of Nb in the energy band model.
Band Assignments of the Infrared Spectrum of 1-Methyl-2(1H)-pyridinimine
Authors: Inuzuka Kozo , Fujimoto Akira , Ito Hiroshi
Published: August 2006

The band assignments of the IR spectrum of 1-methyl-2(1H)-pyridinimine in solution were carried out with the normal coordinate treatment by the ab initio 6-31G method. The IR spectrum of the compound is characterized by three prominent strong absorption bands in the 1700 to 1500 cm−1 region. These three bands are mainly attributed to the stretching modes of the C=C bonds of the ring and the C=N group. All another bands are relatively weak compared with the intensities of these bands. The normal coordinate treatment suggests that 1-methyl-2(1H)-pyridinimine has three out-of-plane fundamental bands in the frequency region lower than the lowest fundamental band of pyridine. The calculated lowest fundamental band is near 129 cm−1. It was assigned to the twisting mode of the CH3 group. The second and third lowest bands correspond to the twisting vibration of the CH3 group and the out-of-plane bending vibration of the ring framework. This suggests that the ring framework of 1-methyl-2(1H)-pyridinimine may be more flexible than that of pyridine. The vibrational features of the IR spectrum of 1-methyl-2(1H)-pyridinimine are similar to that of 1-methyl-2-pyridone. In the liquid state, 1-methyl-2(1H)-pyridinimine forms an inter-molecular hydrogen bond between the imino groups.
Crystal Structures and Molecular Conformations of Isoprenaline Hydrochloride and (S)-Isoprenaline Hydrogen (2R,3R)-Tartrate
Authors: Kingsford-Adaboh Robert , Hayashi Eiichi , Haisa Masao , Kashino Setsuo
Published: August 2006

The crystal structures of racemic form of isoprenaline hydrochloride (I) and (S)-isoprenaline hydrogen (2R,3R)-tartrate (II) were determined by X-ray diffraction method. Among the related compounds I has the least extended phenethylamine chain with a gauche–gauche conformation. The side chain of II has the usually observed perpendicular-trans conformation. The conformations observed for I and II are consistent with the intermolecular hydrogen bonding. The observed conformations are close to either a global or local minimum estimated by MMP2.
The Synthesis and X-Ray Crystal Structures of Bis(diethylenetriamine)rhodium(III), Bis(diethylenetriamine)iridium(III), and Bis[bis(3-aminopropyl)amine]rhodium(III) Complexes
Authors: Harada Kazumasa
Published: August 2006

Separations of geometrical isomers of the title complexes were carried out by a column chromatographic method. All three isomers of mer-, sym-fac-, and unsym-fac-[Rh(dien)2]3+ complexes were isolated. The only mer-isomer of the [Ir(dien)2]3+ complex was isolated, although trace fac-isomers were detected. Although the synthesis of a new [Rh(dpt)2]3+ (dpt = bis(3–aminopropyl)amine) complex was successful, that of [Ir(dpt)2]3+ was not. The only mer-[Rh(dpt)2]3+ isomer was obtained. These complexes were characterized by spectroscopic methods. In each case, the obtained unsym-fac- and mer-isomer were resolved in their antipodes. The crystal structures of three complexes were determined by an X-ray diffraction method. The crystal data are: for sym-fac-[Rh(dien)2]Br3, monoclinic, C2/c, a = 14.803(5), b = 9.102(3), c = 13.989(6) Å, β = 118.25(3)°, Z = 4, R = 0.0478; for mer-[Rh(dpt)2]Cl(ClO4)2, monoclinic, P21/a, a = 18.711(6), b = 12.942(5), c = 9.714(2) Å, β = 103.34(3)°, Z = 4, R = 0.0275; for mer-[Ir(dien)2] (ClO4)3·2H2O, orthorhombic, Aba2, a = 15.283(9), b = 14.736(4), c = 10.411(3) Å, Z = 4, R = 0.0341. The formation ratio of the isomers for the [Rh(dien)2]3+ complex is different from the known ratio for cobalt(III) analogs; this can be attributed to a difference in the M–N bond length based on a molecular mechanics calculation.
Mg2+-Promoted P–O vs. S–O Bond Cleavage in the Alcoholyses of Phenyl Phosphatosulfate
Authors: Eiki Toshio , Negishi Shin-ichi , Izumi Mitsunori , Ishida Naoko , Hada Hiroshi
Published: August 2006

In order to obtain insight into the selectivity of Mg2+ at the site of bond cleavage of P–O and S–O of the P–O–S linkage, metal ion-promoted alcoholyses of phenyl phosphatosulfate were studied. Mg2+ quantitatively promoted P–O bond cleavage in the methanolysis, but mixed cleavage of the P–O bond, which occurred partly due to hydrolysis by trace water and the S–O bond in the reaction of ethanol, 1- or 2-propanol. The ratio of the S–O bond cleavage against the mixed cleavage increased in a order EtOH (11.5%) < n–PrOH (13.3%) < i–PrOH (29.0%). On the other hand, Ca2+ and Zn2+ promoted selective P–O and S–O bond cleavage, respectively, in the reaction of 2-propanol as well as methanolysis.The medium-dependent change in the selectivity of Mg2+ at the site of bond cleavage was discussed.
Synthesis of Optically Active 4-Hydroxyalkanenitriles via an Enzymatic Reaction
Authors: Takagi Yumiko , Itoh Toshiyuki
Published: August 2006

Lipase-catalyzed enantioselective hydrolysis of esters of 4-hydroxyalkanenitriles was demonstrated for the first time. Efficient optical resolution was achieved when (±)-3-cyano-1-phenylpropyl 2-(phenylthio)acetate was hydrolyzed by lipase PS (Pseudomonas sp.).
Stabilization of Sugar-Boronic Esters of Indolylboronic Acid in Water via Sugar–Indole Interaction: A Notable Selectivity in Oligosaccharides
Authors: Nagai Yoshiro , Kobayashi Kenji , Toi Hiroo , Aoyama Yasuhiro
Published: August 2006

5-Indolylboronic acid (1) reversibly forms boronic esters with reducing sugars in water. The resulting boronates are stronger Lewis acids than the starting boronic acid in the deprotonation of water; pKa = 10 for 1 and < 7 for its sugar-boronates. Thus, at pH 9.0, there exists an experimentally-evaluable sugar-binding equilibrium between neutral trivalent acid 1 and anionic tetravalent ester thereof, which can be conveniently monitored by fluorescence or 11B NMR spectroscopy. A characteristic aspect of the present sugar-binding process is the notable selectivity of host 1 for oligosaccharides. The binding constants for maltodextrins (α-1,4-linked glucose oligomers) increase with increasing chain lengths or repetition numbers of the glucose unit. Such a chain length selectivity and those among stereoisomers and linkage isomers of disaccharides are discussed in terms of intracomplex oligosaccharide–indole interaction.
Photochemical Reaction of 2,3-Di[(E)-styryl]pyrazine Derivatives in the Crystalline State and in Solution
Authors: Takeuchi Atsuo , Komiya Hitoshi , Tsutsumi Takehiro , Hashimoto Yukihiko , Hasegawa Masaki , Iitaka Yoichi , Saigo Kazuhiko
Published: August 2006

The photoreaction of 2,3-di[(E)-styryl]pyrazine derivatives was carried out in the crystalline state and in solution. Among them, 2,3-di(p-chlorostyryl)pyrazine and 2,3-di(p-cyanostyryl)pyrazine were photoreactive in the crystalline state and gave, upon photoirradiation, [2.2]orthocyclophanes in 76 and 58% yields, respectively. Such a topochemical photo-behavior was interpreted on the basis of X-ray crystallographic analyses of the crystals. The photoirradiation of 2,3-distyrylpyrazine in solution gave [2.2]orthocyclophane and anti head-to-tail type monocyclic dimer as the major products. The yields of the products varied depending on the solvent; with decreasing the polarity of the solvent, the yield of the cyclophane decreased, whereas the yield of the monocyclic dimer increased. In a similar manner, the photoirradiation of the other 2,3-distyrylpyrazine derivatives in acetonitrile/chloroform (10/1) or acetonitrile gave the corresponding [2.2]orthocyclophanes and monocyclic dimers, respectively, as major products through two types of excimers.
Substituent Effect Studies of Aryl-Assisted Solvolyses. I. The Acetolysis of 2,2-Bis(substituted phenyl)ethyl p-Toluenesulfonates
Authors: Fujio Mizue , Maeda Yasuyuki , Goto Mutsuo , Saeki Yoshihiro , Mishima Masaaki , Tsuno Yuho
Published: August 2006

The substituent effect on the acetolysis of 2,2-bis(substituted phenyl)ethyl p-toluenesulfonates at 90.10 °C can be described accurately in terms of the Yukawa–Tsuno (LArSR) relationship, giving a ρ value of −4.44 and an r value of 0.53. The substituent effect correlation of this system carrying two aryls is quite comparable to that of the 2-methyl-2-phenylpropyl system carrying a single aryl group, suggesting the close similarity in the structure of the transition states between the systems. The results can be reasonably accounted for on the basis of the accepted mechanism of this reaction, involving a rate-determining aryl-assisted transition state where only one aryl group of the two β-aryl groups participates.
Studies on Nickel-Containing Ziegler-Type Catalysts. IV. Dimerization of Propylene to 2,3-Dimethylbutenes. Part-II
Authors: Sato Hiroshi , Tojima Hideto
Published: August 2006

A small amount of water was found to increase the activity of catalyst (A) for the selective dimerization of propylene to 2,3-dimethylbutenes (DMBS),

Ni(naph)2/AlEt3/PR3/Diene/Chlorinated phenol, (A)

where Ni(naph)2 denotes nickel naphthenate. The activity increased by about three to five times upon the addition of H2O in amounts of 0.2 to 0.8 mole per mole of AlEt3; the maximum activity was obtained at around 0.5 molar ratio of H2O to AlEt3. On the other hand, the reaction product between H2O and AlEt3 in a molar ratio of 0.5 was isolated and was identified to be μ-oxo-bis(diethylaluminum), the accelerating effect of which was also proved to be high. It is, therefore, concluded that the Lewis acidity of μ-oxo-bis(diethylaluminum) activates the Ni–H bond of the active species through coordination to the square-planer complex of nickel.
Infrared Study of Hydrogenation of Benzoic Acid to Benzaldehyde on ZrO2 Catalysts
Authors: Kondo Junko , Ding Nan , Maruya Ken-ichi , Domen Kazunari , Yokoyama Toshiharu , Fujita Naoko , Maki Takao
Published: August 2006

The selective hydrogenation of benzoic acid to benzaldehyde on ZrO2 and Cr2O3–ZrO2 at 523 K was studied by IR spectroscopy. An enhancement of the hydrogenation rate of benzoic acid by Cr2O3 doping to ZrO2 was observed. The main role of Cr2O3 was considered to be the step of activating hydrogen. An intermediate species was observed based on the IR bands during a transformation from the adsorbed benzaldehyde to the benzoate at lower temperatures. This is discussed in conjunction with the reaction mechanism of the hydrogenation. The intermediate species was regarded as being the chemisorbed benzaldehyde by an analysis of the observed IR bands.
Formation of Polystyrene Latex Thin Films by Micelle Disruption Method
Authors: Saji Tetsuo , Ebata Ken-ichi
Published: August 2006

Polystyrene latex thin films were prepared on an indium tin oxide electrode by controlled-potential electrolysis of an aqueous solution containing a nonionic surfactant with a ferrocenyl moiety and dispersed latex particles. Thermal treatment rendered the film more transparent, and made the ITO electrode covered with the film inert against electrochemical reaction of hexacyanoferrate(II) due to the disappearance of the intergranular space in the film.
Methanol Synthesis from CO2 and H2 over a ZnO Catalyst. Effect of the Pretreatment with CO–H2 upon the Reaction
Authors: Fujita Shin-ichiro , Ito Hiroto , Takezawa Nobutsune
Published: August 2006

Methanol Synthesis from CO2–H2 was carried out over a ZnO catalyst. Pretreatments with a CO–H2 mixture caused a transient increase of the methanol formation as Bowker et al. found. It was shown that methoxide species was formed in the course of the pretreatments, being readily hydrolyzed to methanol by water formed via the reverse water gas shift reaction.
Enzymatic Kinetic Resolution of 2-Cyclohexen-1-ol Derivatives
Authors: Hagiwara Hisahiro , Nakano Takashi , Uda Hisashi
Published: August 2006

Optically active (S)-2-cyclohexen-1-ol derivatives and their enantiomeric (R)-acetates have been obtained in high enantiomeric excesses by enzymatic kinetic acetylation catalyzed by lipase AK.
Theoretical Simulations on d(CGCGAATTCGCG)2 with cis-syn Thymine–Thymine Cyclobutane Dimer
Authors: Rao Shashidhar N , Kollman Peter A
Published: August 2006

We present molecular mechanics and molecular dynamics simulations on the dodecanucleotide d(CGCGAATTCGCG)2, incorporating a cis-syn thymine–thymine cyclobutane dimer, represented as T[]T, at the TT site using the all atom force field. Although the starting optimized structures were essentially kink-free, kinked models are observed during the molecular dynamics simulations. Most conformational changes are seen in the sugar puckering and phosphodiester conformations of residues in and around the site of photolesion.