bluuebunny/crossref_metadata_2025_split huggingface dataset:
Berchemins A and B: Novel Enzyme‐Inhibiting Dimeric Lignan Glycosides from Berchemia pakistanica
Authors: Mukhtar Naveen , Malik Abdul , Iqbal Kiran , Tareen Rasool Bakhsh , Khan Shamsun Nahar , Nawaz Sarfraz Ahmad , Choudhary M. Iqbal 
Published: August 2004

AbstractPhytochemical investigation of Berchemia pakistanica by extensive bioassay‐guided fractionation resulted in the isolation of two novel dimeric lignan glycosides, berchemin A (1) and berchemin B (2), and of the four known compounds β‐sitosterol, β‐sitosterol 3‐O‐β‐D‐glucoside, vavain, and daphnetin 8‐β‐D‐glucoside. The structures of 1 and 2 were elucidated with the help of modern spectroscopic techniques, and the known compounds were identified by comparing their spectral data with those reported in the literature. Berchemins A and B were found to inhibit lipoxygenase and α‐glucosidase enzymes in a concentration‐dependent fashion.
Natural p‐Menthene Monoterpenes: Synthesis of the Enantiomeric Forms of Wine Lactone, Epi‐wine Lactone, Dill Ether, and Epi‐dill Ether Starting from a Common Intermediate
Authors: Serra Stefano , Fuganti Claudio 
Published: August 2004

AbstractA concise synthesis of the enantiomeric forms of wine lactone (5), epi‐wine lactone (14), dill ether (6), and epi‐dill ether (15) was accomplished starting from the enantiomeric forms of p‐mentha‐1,8(10)‐diene‐3,9‐diol (8) (Scheme 3). The latter compounds were previously prepared in high optical purity by means of lipase‐mediated kinetic resolution, and they were the common building blocks for this divergent synthesis. The key steps were a number of chemo‐ and diastereoselective reactions of which the oxidation of 8 to the lactone 7 (see Table 1), the diastereoselective reduction of 7 to the lactones 14 and 5 (see Table 2), and the reduction of enol‐ether 16 to ether 15 were studied comprehensively. The effectiveness of this new synthetic approach allows the preparation of the title p‐menthane monoterpenes, which are of considerable interest to the perfume industry, in high yield and in a few simple experimental steps.
Expression of HYAL2 mRNA, hyaluronan and hyaluronidase in B‐cell non‐Hodgkin lymphoma: Relationship with tumor aggressiveness
Authors: Bertrand Philippe , Courel Marie‐Noëlle , Maingonnat Catherine , Jardin Fabrice , Tilly Hervé , Bastard Christian 
Published: August 2004

AbstractHyaluronidases and their substrate, hyaluronan (HA), were mainly explored in solid tumors but rarely in hematologic malignancies. While HA involvement was demonstrated in invasion and metastasis in most cases of solid tumors, the role of hyaluronidases in cancer progression remains controversial. One of the hyaluronidases, HYAL2, is suspected to be involved in the first step of HA degradation. In this work, HYAL2 mRNA, HA and total hyaluronidases expression were examined in lymphoma tissue extracts and correlated to the lymphoma subtype. Real‐time RT‐PCR was performed to evaluate HYAL2 mRNA. HA and hyaluronidase were assayed by enzyme‐linked sorbent assay. Our results showed that HYAL2 mRNA expression was correlated to lymphoma diagnosis (p = 6 × 10−3) and was significantly lower in high‐grade lymphoma, i.e., diffuse large B‐cell diffuse lymphomas (DLBCLs). Several forms of hyaluronidase were detected by zymography and total hyaluronidase activity detected in tissue extracts was not significantly different according to tumor grade. HA levels also correlated to lymphoma subtype (p = 1 × 10−5) and were higher in DLBCLs. Moreover, HYAL2 mRNA and HA expressions were inversely correlated (p = 0.035). HYAL2 gene is localized on chromosome 3p21, which contains candidates tumor suppressor genes. Our results suggest that HYAL2 may have a prognostic significance in lymphomas and an antioncogenic activity. Conversely, HA overexpression in high‐grade lymphomas is in favor of its involvement in tumor development and could provide a useful target for lymphoma therapy using HA‐binding peptides.
Seasonal Variation of the Macrozoobenthic Community Structure at Low Salinities in a Mediterranean Lagoon (Monolimni Lagoon, Northern Aegean)
Authors: Kevrekidis Theodoros 
Published: August 2004

AbstractThe macrozoobenthic community structure and dynamics at low salinities (0.3–6 psu) in a Mediterranean lagoon (Monolimni lagoon) were investigated. Samples were collected monthly from February 1998 to February 1999 at two sampling stations. Community structure was analyzed by means of uni‐ and multivariate methods. 21 taxa were collected; the amphipod Corophium orientale and the gastropod Ventrosia maritima dominated the assemblages. Total abundance peaked (50,000–60,000 individuals m–2) in mid or late autumn. Community structure showed an almost even seasonal periodicity; seasonal changes were mainly derived from the intense variation in abundance of most species and the non–occurrence of a few ones (e.g. Corophium insidiosum, Polydora ciliata) in spring and summer. Non– occurrence, which led to a depression of the most diversity indices, was possibly the only direct impact of the extremely low salinities (~0.3 psu) on community structure. The main structuring factors of the community in the deeper outer part of the lagoon were water temperature and depth, and in the innermost part, where a Ruppia maritima meadow occurred, were water temperature and predation pressure by crabs (Carcinus aestuarii) and gobies (Knipowitchia caucasica). A temporary decline in total abundance in summer followed an increase in abundance of these predators. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptations of an Emergence Trap for Use in Tropical Streams
Authors: Freitag Hendrik 
Published: August 2004

AbstractAn emergence trap based on the MPI Schlitz model was designed for use in the tropics and it was tested over one year in Palawan, the Philippines. Instructions for construction and use are given here. Only commonly available materials were used, except for the collection assembly made of UV‐light permeable acrylic glass. Heavy and bulky assemblies were avoided to enable easy transportation in the field. A special modification allows a fast and easy replacement of the screen when damaged by flooding, as is often required when traps are used downstream of headwaters. This type of trap also allows sampling of a wide littoral strip. Problems concerning the use of emergence traps in the humid tropics are discussed based on experience at different longitudinal stream sections in Palawan. The results presented here suggest that this trap should be used especially for qualitative or semi‐quantitative approaches. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Composition and Longitudinal Patterns of Aquatic Insect Emergence in Small Rivers of Palawan Island, the Philippines
Authors: Freitag Hendrik 
Published: August 2004

AbstractThis study presents the first emergence trap samples from streams in the Philippines and Greater Sunda. Aquatic insect emergence from two small rivers and longitudinal patterns including estuaries are compared. A decline of total emergence towards estuaries was observed, affecting all major orders. Diptera, namely Chironomidae, dominated all sites. High abundances in Ceratopogonidae, Odonata, and Coleoptera were found, compared to other emergence studies from tropical and temperate latitudes. Ephemeroptera displayed a highly variable contribution to the emergence from Palawan as well as in other comparative studies either supported by the appropriate conditions for certain functional groups or limited by environmental variables such as pH. Trichoptera are likely to tolerate a wider range of environmental conditions and they are consequently able to fill further niches where Ephemeroptera are under‐represented. Except for scarce abundances of Plecoptera observed in this and other studies from the tropics, no substantial differences in emergence composition at order level existed between temperate and tropical rivers, however, with a remarkable local variation. Components of riparian and non‐aquatic insects and non‐emergent fauna contributing to the collections are discussed based on trap features. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spatial Analysis of Twaite Shad, Alosa fallax (Lacepède, 1803), in the Southern North Sea: Application of Non‐Linear Geostatistics as a Tool to Search for Special Areas of Conservation
Authors: Stelzenmüller Vanessa , Maynou Francesc , Ehrich Siegfried , Zauke Gerd‐Peter 
Published: August 2004

AbstractThis study aims to evaluate the suitability of non‐linear geostatistics and indicator kriging (IK) as a tool in environmental impact assessment and nature conservation, in particular to search for potential Special Areas of Conservation (SAC) for the endangered fish species twaite shad, Alosa fallax (Lacepède, 1803) within the German Exclusive Economical Zone (EEZ) of the North Sea. To analyse the spatial distribution of this fish species, data on standardised biomass index (catch per unit effort, c.p.u.e., kg × 30 min–1) from 1996 to 2001 were used, regarding the third and fourth quarters of each year, respectively. Thereby we assume that the spatial distribution can be described as a time‐invariant process. This assumption is supported by information on annual sampling effort, allocation of hauls and spatial distribution of the positive catches. All indicator variograms obtained for different c.p.u.e. cut‐off values displayed distinct spatial structures, clearly indicating that the indicator variables were spatially autocorrelated. Gaussian models were fitted by least‐squares methods and were evaluated with a goodness‐of‐fit statistic. Subsequently, IK was employed to estimate the probability of exceeding the c.p.u.e. cut‐off values for the twaite shad in the investigation area. These were highest in the Weser‐ and Elbe‐estuary, probably because of migrations of twaite shad to and from estuaries at the time of investigation due to spawning, while within the German EEZ of the North Sea no such areas with increased probabilities could be discerned. Thus, although available data did not allow to identify and implement any SAC in the German EEZ, the methods employed here can be regarded as a promising management tool in biological conservation issues. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Heliodiaptomus phuthaiorum n. sp., a New Freshwater Copepod (Calanoida, Diaptomidae) from Temporary Ponds in Northeast Thailand
Authors: Sanoamuang La‐orsri 
Published: August 2004

AbstractAn illustrated description of a new species, Heliodiaptomus phuthaiorum n. sp., from nine of the 456 sampled localities in northeast Thailand, is presented. Morphologically, it is closely related to the Indian H. pulcher (Gurney, 1907). The new species is characterized in the male by the prominent, spinulose knob on the inner margin of the right basis; the finely serrated inner margin of the right second exopodite‐segment; and the extraordinary large, tongue‐like projection on proximal inner margin of the left basis. In the female, the genital somite is unusually long, much longer than the other two urosomites combined. This new species is rare and has been found only in temporary ponds in Nakhon Pranom and Nong Khai Provinces. It usually co‐occurs with 1–5 other diaptomids; the most frequently co‐occurring species are Neodiaptomus blachei (Brehm, 1951), N. yangtsekiangensis Mashiko, 1951 and Eodiaptomus phuphanensis Sanoamuang, 2001. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The acrosomal vesicle of mouse sperm is a calcium store
Authors: Herrick Scott B. , Schweissinger Daniel L. , Kim Soo‐Woo , Bayan Keith R. , Mann Steven , Cardullo Richard A. 
Published: August 2004

AbstractSubsequent to binding to the zona pellucida, mammalian sperm undergo a regulated sequence of events that ultimately lead to acrosomal exocytosis. Like most regulated exocytotic processes, a rise in intracellular calcium is sufficient to trigger this event although the precise mechanism of how this is achieved is still unclear. Numerous studies on mouse sperm have indicated that a voltage‐operated Ca2+ channel plays some immediate role following sperm binding to the zona pellucida glycoprotein ZP3. However, there is also evidence that the mammalian sperm acrosome contains a high density of IP3 receptors, suggesting that the exocytotic event involves the release of Ca2+ from the acrosome. The release of Ca2+ from the acrosome may directly trigger exocytosis or may activate store‐operated Ca2+ channels in the plasma membrane. To test the hypothesis that the acrosome is an intracellular store we loaded mammalian sperm with the membrane permeant forms of three Ca2+‐sensitive fluorescent indicator dyes: fura‐2, indo‐1, and Calcium Green‐5N. Fluorescence microscopy revealed that the sperm were labeled in all intracellular compartments. When fura‐2 labeled sperm were treated with 150 μM MnCl2 to quench all fluorescence in the cytosol, or when the sperm were labeled with the low affinity dye Calcium Green‐5N, there was a large Ca2+ signal in the acrosome. Consistent with the acrosome serving as an intracellular Ca2+ reservoir, the addition of 20 μM thapsigargin, a potent inhibitor of the smooth endoplasmic reticular Ca2+‐ATPase (SERCA), to populations of capacitated sperm resulted in nearly 100% acrosomal exocytosis within 60 min (τ1/2 ∼ 10 min), in the absence of extracellular Ca2+. Additionally, treatment of sperm with 100 μM thimerosal, an IP3 receptor agonist, also resulted in acrosomal exocytosis. Taken together, these data suggest that the mouse sperm acrosome is a Ca2+ store that regulates its own exocytosis through an IP3 Ca2+ mobilization pathway. © 2004 Wiley‐Liss, Inc.
Developmental transcription factor slug is required for effective re‐epithelialization by adult keratinocytes
Authors: Savagner Pierre , Kusewitt Donna F. , Carver Ethan A. , Magnino Fabrice , Choi Chagsun , Gridley Thomas , Hudson Laurie G. 
Published: August 2004

AbstractDuring re‐epithelialization of cutaneous wounds, keratinocytes recapitulate several aspects of the embryonic process of epithelial‐mesenchymal transition (EMT), including migratory activity and reduced intercellular adhesion. The transcription factor Slug modulates EMT in the embryo and controls desmosome number in adult epithelial cells, therefore, we investigated Slug expression and function during cutaneous wound re‐epithelialization. Slug expression was elevated in keratinocytes bordering cutaneous wounds in mice in vivo, in keratinocytes migrating from mouse skin explants ex vivo, and in human keratinocytes at wound margins in vitro. Expression of the related transcription factor Snail was not significantly modulated in keratinocytes during re‐epithelialization in vitro. Epithelial cell outgrowth from skin explants of Slug knockout mice was severely compromised, indicating a critical role for Slug in epithelial keratinocyte migration. Overexpression of Slug in cultured human keratinocytes caused increased cell spreading and desmosomal disruption, both of which were most pronounced at wound margins. Furthermore, in vitro wound healing was markedly accelerated in keratinocytes that ectopically expressed Slug. Taken together, these findings suggest that Slug plays an important role during wound re‐epithelialization in adult skin and indicate that Slug controls some aspects of epithleial cell behavior in adult tissues as well as during embryonic development. © 2004 Wiley‐Liss, Inc.
Film‐surface diffusion during the adsorption of acid dyes onto activated carbon
Authors: Choy KKH , Porter JF , McKay G 
Published: August 2004

AbstractA mass transport model has been developed and applied to the adsorption of three acid dyes onto activated carbon in three single component systems. The mass transfer model is based on two rate controlling mass transfer steps, namely external film mass transfer and homogeneous solid‐phase surface diffusion (HSD). Almost all previous film‐HSD models have been based on numerical solutions to the diffusion equation using orthogonal collocation or Crank–Nicolson finite difference solutions. However, in the present model a semi‐analytical solution to the solid surface diffusion equation is presented, yielding a sophisticated solution of the differential equations. The solutions provide a good correlation between the experimental concentration–time decay curves by incorporating the Langmuir equilibrium isotherm to describe the solid phase surface dye concentrations. However, the surface diffusivities show a dependence on the carbon particle surface coverage and these diffusivities have been correlated using a Darken relationship. Copyright © 2004 Society of Chemical Industry
Stability of horseradish peroxidase immobilized on different cinnamic carbohydrate esters
Authors: Rojas‐Melgarejo Francisco , Rodríguez‐López José Neptuno , García‐Cánovas Francisco , García‐Ruiz Pedro Antonio 
Published: August 2004

AbstractFour types of organic polymer were used to cover 3 mm diameter glass beads for subsequent use in immobilizing horseradish peroxidase (HRP). These supports were the totally cinnamoylated derivatives of D‐glucosone (GSOCN), D‐sorbitol (SOTCN), ethyl‐D‐glucopyranoside (EGSCN) or inuline (INCN). In some assays, a partially cinnamoylated derivative, 2,3,4,6‐tetracinnamoyl‐D‐glucopyranoside (GPSTCN) (obtained from the EGSCN derivative by hydrolysis in acidic medium) was used. Polymerization and cross‐linking of the derivatives obtained initially was carried out by irradiation in the ultraviolet region, where these polymers show the greatest degree of sensitivity. The enzyme was immobilized by adsorption to the support. Immobilized enzymatic activity varied with the incubation time used (2–21 h), depending on the chemical nature of the immobilization support. The affinity of HRP for H2O2 and 2,2′‐azinobis(3‐ethylbenzothiazolinesulfonic acid) (ABTS) was slightly lower in the case of the enzyme immobilized on the GSOCN, SOTCN and EGSCN derivatives than in the case of the soluble enzyme, as can be seen from the corresponding apparent kinetic constants ($K_{\rm m}^{\rm H_{2}O_{2}}$ and $K_{\rm m}^{\rm ABTS}$). However, the affinity of HRP immobilized on the INCN derivative for these substrates was higher than that shown by the enzyme in solution. In turn, the enzyme immobilized on all the supports was more resistant than the soluble form to inactivation by H2O2 and by heat at neutral pH. When the stability and durability of the immobilized HRP were analysed, the cinnamoylated derivatives prepared were seen to function as suitable supports for immobilizing peroxidase and to be suitable for industrial application of the enzyme. Copyright © 2004 Society of Chemical Industry
Extraction of citric acid from aqueous solutions with Alamine 336: equilibrium and kinetics
Authors: Nikhade Bhaurao P , Moulijn Jacob A , Pangarkar Vishwas G 
Published: August 2004

AbstractCitric acid is one of the organic acids for which the world market is growing every year. This article describes equilibria and kinetic studies for the extraction of citric acid by Alamine 336 with methyl‐iso‐butylketone (MIBK) as diluent. The theory of extraction accompanied by a chemical reaction has been used to obtain the intrinsic kinetics of extraction of citric acid by Alamine 336 in MIBK. The reaction has been found to be first order in both Alamine 336 and citric acid with a rate constant of 0.013 m3 kmol−1 s−1. Copyright © 2004 Society of Chemical Industry
Cytoskeletal protein 4.1G is a binding partner of the metabotropic glutamate receptor subtype 1α
Authors: Lu Dongcheng , Yan Henglin , Othman Timothy , Rivkees Scott A. 
Published: August 2004

AbstractRecent evidence suggests that cytoskeletal proteins play important roles in the clustering and anchoring of glutamate receptors to the cell surface membrane. To examine further this issue, we tested for direct interactions between the metabotropic glutamate receptor subtype 1α (mGlu1α) and 4.1G, which is a member of the erythrocyte membrane, cytoskeletal protein 4.1 family. First, co‐localization of 4.1G and mGlu1α was observed in cultured hippocampal neurons. Second, in transiently transfected HEK 293 cells and in whole rat brain tissue, direct interactions between mGlu1α and 4.1G were observed. Third, we were able to identify the C‐terminal tail of mGlu1α as an essential region for mGlu1α–4.1G interactions. Fourth, 4.1 G influences mGlu1α‐mediated cAMP accumulation. Finally, we found that 4.1G increases the ligand‐binding ability of mGlu1α and alters its cellular distribution. These observations identify 4.1G as a novel binding partner of mGlu1α that can regulate the action of mGlu1α. © 2004 Wiley‐Liss, Inc.
Calcineurin activation contributes to noise‐induced hearing loss
Authors: Minami Shujiro B. , Yamashita Daisuke , Schacht Jochen , Miller Josef M. 
Published: August 2004

AbstractAcoustic overstimulation increases Ca2+ concentration in auditory hair cells. Because calcineurin is known to activate cell death pathways and is controlled by Ca2+ and calmodulin, this study assessed the role of calcineurin in auditory hair cell death in guinea pigs after intense noise exposure. Immediately after noise exposure (4‐kHz octave band, 120 dB, for 5 hr), a population of hair cells exhibited calcineurin immunoreactivity at the cuticular plate, with a decreasing number of positive‐stained cells on Days 1–3. By Day 7, the levels of calcineurin immunoreactivity had diminished to near control, non‐noise exposed values, concomitant with an increasing loss of hair cells. Staining of hair cell nuclei with propidium iodide (PI), restricted to calcineurin‐immunopositive cells, indicated breakdown of cell membranes symptomatic of incipient cell death. The local application of the calcineurin inhibitors, FK506 and cyclosporin A, reduced the level of noise‐induced auditory brain stem response threshold shift and hair cell death, indicating that calcineurin is a factor in noise‐induced hearing loss. The results suggest that calcineurin inhibitors are of potential therapeutic value for long‐term protection of the morphologic integrity and function of the organ of Corti against noise trauma. © 2004 Wiley‐Liss, Inc.