bluuebunny/crossref_metadata_2025 huggingface dataset:
Arachidonic acid release by cPLA2 may be causally related to NO‐induced apoptosis in vascular smooth muscle cells
Authors: Pilane Cyril M. , LaBelle Edward F.
Published: August 2002

Apoptosis has been shown to occur in vascular smooth muscle cells during the development of atherosclerosis. In order to investigate the possible role of arachidonic acid during apoptosis in vascular smooth muscle, we induced apoptosis in cultured rat aortal smooth muscle cells (SMCs) by treatment with either UV (ultraviolet) radiation, tumor necrosis factor‐α (TNF‐α) or NO donor drugs (sodium nitroprusside, or S‐nitroso‐N‐acetyl‐D‐penicillamine, SNAP). Apoptosis was detected by either DNA fragmentation analysis or by TUNEL analysis. UV radiation, TNF‐α and NO were observed to stimulate apoptosis in the cells as well as to stimulate arachidonate release from the cells. NO also increased levels of cPLA2 in the cells, which is an enzyme that is frequently activated in cells that release arachidonate. These agents stimulated arachidonate release somewhat earlier than they stimulated apoptosis in the cells. The inhibition of cPLA2 by arachidonyl trifluoromethyl ketone (AACOCF3) also led to the inhibition of arachidonate release from the cells as well as the inhibition of nitroprusside stimulated apoptosis. Arachidonic acid itself could induce apoptosis in the cultured cells. These observations provide evidence that arachidonate may be involved in apoptosis in vascular smooth muscle. J. Cell. Physiol. 191: 191–197, 2002. © 2002 Wiley‐Liss, Inc.
Effect of non‐ionic surfactants on elimination of polycyclic aromatic hydrocarbons (PAHs) in soil‐slurry by Phanerochaete chrysosporium
Authors: Zheng Zhongming , Obbard Jeffrey Philip
Published: August 2002

Surfactants can enhance bioremediation of soil contaminated with polycyclic aromatic hydrocarbons (PAHs) by increasing their bioavailability. The objective of this study was to evaluate the effect of non‐ionic polyoxyethylene (POE) surfactants on the elimination of nine PAHs in contaminated soil by the white rot fungus Phanerochaete chrysosporium. PAHs in both liquid and solid phases were extracted and then assayed using GC–MS. Fungal biomass concentration and the activity of extracellular ligninolytic enzymes were used to determine the toxicity of POE surfactants. Results indicated that 0.5% (w/v) of surfactant Tween 80 was not toxic to fungal growth and had little impact on extracellular ligninolytic enzyme synthesis. About 80% of low ring PAHs (ie acenaphthene and fluorene) could be efficiently catabolized by P chrysosporium without surfactants, while catabolism of others (ie phenanthrene, fluoranthene, pyrene, chrysene, benzo(a)pyrene, dibenz(ah)anthracene and benzo(ghi)perylene) was less than 30% over a 8‐day culture period. Elimination of four‐to six‐ring PAHs in contaminated soil was enhanced in P chrysosporium cultures with 0.4% (w/v) Tween 80 by 15–33% compared with those in cultures without Tween 80, while no obvious effect was observed in the elimination of three‐ring PAHs over the culture period. Investigations on PAH concentrations in aqueous phase during the culture period showed that Tween 80 increased PAH aqueous concentrations and the PAH oxidation rate in aqueous was rapid. Enhancement of soil PAH elimination in the presence of Tween 80 was due to the increased PAH bioavailability.

© 2001 Society of Chemical Industry
In vitro injury model for oligodendrocytes: Development, injury, and recovery
Authors: Espinosa De Los Monteros Araceli , Zhao Paul M. , De Vellis Jean
Published: August 2002

In this study we investigated the effects of severe hypothermia (cryoinjury) on oligodendrocyte (OL) cell marker expression and morphological features. We used a chemically defined cell culture medium, glial development medium (GDM), which favored the optimal expression of the OL phenotype in CG4 cells. Experiments using CG4 cells cultured in 2% serum or in GDM were conducted in parallel. After severe hypothermia, cells were reanimated at 37°C and 4.5% CO2 and cultured in either GDM or in medium supplemented with 2% serum. In either medium, around 70% of the total number of cells detached within 2 to 4 hours following reanimation. Oligodendroglial markers such as A2B5, O4, Tf, ferritin, tubulin, and MBP were examined by double and triple immunofluorescence. All of these markers except MBP re‐appeared at different times during the recovery period for up to 48 hours. Glial fibrillary acidic protein (GFAP) and heat shock protein 60 (HSP‐60) were used as injury markers. The presence of serum induced HSP‐60 expression, while GDM did not. All CG4 cells expressed HSP‐60 in response to hypothermia independently of the cell culture medium used. Cryoinjury induced a spectrum of morphological changes in CG4 cells. The expression of OL specific markers was also influenced by hypothermia. Moreover both, serum and cryoinjury induced the expression of HSP‐60 that colocalized with OL and myelin markers. The expression of GFAP by injured cells but not by normal cells corroborated the state of injury of CG4 cells. Microsc. Res. Tech. 52:719–730, 2001. © 2001 Wiley‐Liss, Inc.
Establishment of microglial cell cultures derived from postmortem human adult brain tissue: Immunophenotypical and functional characterization
Authors: De Groot C.J.A. , Hulshof S. , Hoozemans J.J.M. , Veerhuis R.
Published: August 2002

Cell cultures have become an integral part of the daily routine in most biological research laboratories. Because they are very dynamic and highly accessible, cell cultures permit direct experimental manipulations where cause‐effect relations can be more definitely assayed. We have developed cultures of microglial cells from rapid autopsies (range 3–10 hours) of non‐ demented elderly patients and Alzheimer's disease patients. Cultures were derived from the subcortical white matter, corpus callosum, and frontal, temporal, and occipital cortex. The adherent microglial cells were immunoreactive for CD68, CD45, CD11c, and major histocompatibility complex (MHC) class II markers, and were not immunoreactive for astrocyte or oligodendrocyte markers. In addition, some functional characteristics of the isolated microglial cells were also studied. Upon stimulation with lipopolysaccharide (LPS), microglial cells secreted pro‐ and anti‐inflammatory mediators, i.e., interleukin‐ (IL)‐6, prostaglandin E2 (PGE2), and IL‐10, indicating the functional capacity of cultured microglia. Microsc. Res. Tech. 54:34–39, 2001. © 2001 Wiley‐Liss, Inc.
Modulation of prey capture kinematics in the cheeklined wrasse Oxycheilinus digrammus (Teleostei: Labridae)
Authors: Ferry‐Graham Lara A. , Wainwright Peter C. , Westneat Mark W. , Bellwood David R.
Published: August 2002

The ability to modulate prey capture behaviors is of interest to organismal biologists as it suggests that predators can perceive features of the prey and select suitable behaviors from an available repertoire to successfully capture the item. Thus, behavior may be as important a trait as morphology in determining an organism’s diet. Using high‐speed video, we measured prey capture kinematics in three cheeklined wrasse, Oxycheilinus digrammus. We studied the effects of three experimental prey treatments: live fish, dead prawn suspended in the water column, and dead prawn pieces anchored to the substrate in a clip. Live prey elicited significantly more rapid strikes than dead prey suspended in the water column, and the head of the predator was expanded to significantly larger maxima. These changes in prey capture kinematics suggest the generation of more inertial suction. With greater expansion of the head, more water can be accelerated into the buccal cavity. The attached prey treatment elicited strikes as rapid as those on live prey. We suggest that the kinematics of rapid strikes on attached prey are indicative of attempts to use suction to detach the prey item. More rapid expansion of the buccal or mouth cavity should lead to higher velocities of water entering the mouth and therefore to enhanced suction. Further modulation in response to the attached prey item, such as clipping or wrenching behaviors, was not observed. J. Exp. Zool. 290:88–100, 2001. © 2001 Wiley‐Liss, Inc.
Sexual differentiation in the spiny softshell turtle (Apalone spinifera), a species with genetic sex determination
Authors: Greenbaum Eli , Carr John L.
Published: August 2002

It is hypothesized on the basis of sex determination theory that species exhibiting genetic sex determination (GSD) may undergo sexual differentiation earlier in development than species with environmental sex determination (ESD). Most turtle species exhibit a form of ESD known as temperature‐dependent sex determination (TSD), and in such species the chronology of sex differentiation is well studied.Apalone spiniferais a species of softshell turtle (Trionychidae) that exhibits GSD. We studied sexual differentiation in this species in order to facilitate comparison to TSD species. Eggs were incubated at two different temperatures and embryos were harvested at various stages of mid to late development. Gonad length was measured with image analysis software, then prepared histologically. Indifferent gonads have differentiated in stage 19 embryos. Histological details of gonadogenesis follow the same pattern as described for other reptiles. Regression of the male paramesonephric duct closely follows testicular differentiation. Gonad lengths are longer at the warmer incubation temperature, and ovaries are generally longer than testes at each stage and for each temperature. Although sexual differentiation takes place at about the same stage as in other turtles with TSD (18–20), inA. spiniferathis differentiation is irreversible at this stage, while in some of the TSD species sex is reversible until about stage 22. This immutable, definitive sexual differentiation may support the hypothesis of an accelerated chronology of sex differentiation for this species. We also note that sexual dichromatism at hatching is known in this species and may provide additional evidence of early differentiation.J. Exp. Zool. 290:190–200, 2001. © 2001 Wiley‐Liss, Inc.
Functional correction of episomal mutations withshort DNA fragments and RNA–DNA oligonucleotides
Authors: Thorpe P. H. , Stevenson B. J. , Porteous D. J.
Published: August 2002

Background

Gene correction is an alternative approach to replacement gene therapy. By correcting mutations within the genome, some of the barriers to effective gene therapy are avoided. Homologous nucleic acid sequences can correct mutations by inducing recombination or mismatch repair. Recently, encouraging data have been presented using both short DNAfragments (SDFs) and RNA–DNA oligonucleotides (RDOs) in experimental strategies to realize clinical gene correction.

Methods

The delivery of labelled SDFs and RDOs to a variety of cell lines was tested using both FACS analysis and confocal microscopy. A GFP‐based reporter system was constructed, containing a nonsense mutation, to allow quantitation of gene correction in living cells. This reporter was used to compare efficiencies of functional gene correction using SDFs and RDOs in arange of mammalian cell lines.

Results

The delivery experiments highlight the inefficient delivery of SDFs and RDOs to the nucleus using polyethylenimine (PEI) transfection. This study compared the episomal correction efficiency of the reporter plasmid mediated by SDFs and RDOs within different cell types; low levels of functional correction were detected in cell culture.

Conclusions

Whilst delivery of PEI‐complexed SDFs or RDOs to the cell is highly effective, nuclear entry appears to be a limiting factor. SDFs elicited episomal GFP correction across a range of cell lines, whereas RDOs only corrected the reporter in a cell line that overexpresses RAD51. Copyright © 2002 John Wiley & Sons, Ltd.
The development of the skull in Acrochordus granulatus (Schneider) (Reptilia: Serpentes), with special consideration of the otico‐occipital complex
Authors: Rieppel Olivier , Zaher Hussam
Published: August 2002

The skull of Acrochordus has been characterized by the absence of a crista circumfenestralis (a synapomorphy shared by all snakes), and by the absence of a recessus scalae tympani that in other squamates forms by subdivision of the embryonic metotic fissure. These traits have variably been identified as either plesiomorphic or paedomorphic. The study of the development of the osteocranium in a series of cleared and stained embryos of Acrochordus shows a close correspondence to the development of the skull in other snakes. The exception is the formation of the postorbital from two ossification centers. The significance of this observation, which might suggest the embryonic fusion of a postfrontal with a postorbital, remains enigmatic, as it is based on one side only of the skull of a single specimen. By contrast, a rudimentary and modified crista circumfenestralis can be identified in the skull of Acrochordus. Furthermore, absence of a recessus scalae tympani is not due to an undivided fissura metotica, but results from the obliteration of the anterior part of the metotic fissure instead. With respect to this character, Acrochordus is neither plesiomorphic, nor paedomorphic, but autapomorphic. This interpretation of the skull of Acrochordus is compatible with the sister‐group relationships this genus shares with colubroid snakes. J. Morphol. 249:252–266, 2001. © 2001 Wiley‐Liss, Inc.
MRA of the lower extremities in patients with pulmonary embolism using a blood pool contrast agent: Initial experience
Authors: Hoffmann Udo , Loewe Christian , Bernhard Christoph , Weber Michael , Cejna Manfred , Herold Christian J. , Schima Wolfgang
Published: August 2002

Purpose

To evaluate the feasibility of blood pool contrast‐enhanced magnetic resonance angiography (MRA) to visualize the arterial and venous vessel tree and to detect deep venous thrombosis (DVT) of the lower extremities.

Materials and Methods

Nine consecutive patients with pulmonary embolism (mean age = 46 ± 9) were randomized to various doses of NC100150 (between 0.75 and 6 mg of Fe/kg of body weight). A T1‐weighted (T1W) 3D gradient recalled echo (GRE) sequence (TE = 2.0 msec, TR = 5.0 msec) was used. Two observers blinded to the dose of contrast agent assessed image quality, contrast attenuation, and appearance of thrombi.

Results

Qualitative assessment of overall MRA image quality and semiquantitative vessel scoring revealed good to excellent delineation of venous and arterial vessel segments independent of the dose of NC100150. However, quantitative region of interest analysis revealed a significantly higher signal‐to‐noise ratio (SNR) in the high‐dose group than in the mid‐ and low‐dose groups of NC100150 (P < 0.01). Between dose groups, the SNR was independent of vessel type (artery or vein) and vessel segment localization (proximal or distal). All seven venous thrombi (mean length = 7.2 ± 0.95cm) were characterized by a very low signal intensity (SI), which was only 16.6 ± 7% of the SI in adjacent venous segments (P < 0.0001).

Conclusion

High‐quality MR angiograms of the lower extremities can be obtained using low concentrations of NC100150 in combination with a strong T1W 3D GRE sequence. The obvious delineation of venous thrombi suggests that this technique may be potentially used as a noninvasive “one‐stop shopping” tool in the evaluation of thromboembolic disease. J. Magn. Reson. Imaging 2002;15:429–437. © 2002 Wiley‐Liss, Inc.
Gadobenate dimeglumine‐enhanced magnetic resonance imaging of intracranial metastases: Effect of dose on lesion detection and delineation
Authors: Schneider Günther , Kirchin Miles A. , Pirovano Gianpaolo , Colosimo Cesare , Ruscalleda Jordi , Korves Mathias , Salerio Isabella , La Noce Anna , Spinazzi Alberto
Published: August 2002

Seventy‐four patients with one to eight proven intraaxial metastatic lesions to the brain received a total gadobenate dimeglumine dose of 0.3 mmol/kg of body weight, administered as three sequential bolus injections of 0.1 mmol/kg, at 10‐minute intervals over a 20‐minute period. Quantitative and qualitative assessments of efficacy were performed after each injection and a full evaluation of safety was conducted. Cumulative dosing produced significant (P < 0.01) dose‐related increases in lesion‐to‐brain (L/B) ratio and lesion signal intensity (SI) enhancement. Two independent, blinded assessors noted additional lesions, compared to unenhanced images in 31% and 33%, 49% and 42%, and 50% and 48% of patients after each cumulative dose, respectively. Significantly more lesions were noted after the first injection, compared to unenhanced images (P = 0.002 and P < 0.001; assessors 1 and 2, respectively), and after a second injection, compared to the first (P < 0.001 and P = 0.039; assessors 1 and 2, respectively). Neither assessor noted significantly more lesions after the third injection. For patients with just one lesion observed on unenhanced T1‐ and T2‐weighted images, additional lesions were noted by assessors 1 and 2 for 27% and 26%, 48% and 35%, and 42% and 41% of patients, respectively, following each injection. Contemporaneously, diagnostic confidence was increased and lesion conspicuity improved over unenhanced magnetic resonance imaging (MRI). For patients with one lesion observed after 0.1 mmol/kg of gadobenate dimeglumine, additional lesions were noted for 24% and 17% of patients (assessors 1 and 2, respectively) following a second 0.1 mmol/kg injection. Only assessor 2 noted additional lesions following the third 0.1 mmol/kg injection. The findings of on‐site investigators concurred with those of the two off‐site assessors. No safety concerns were apparent. J. Magn. Reson. Imaging 2001;14:525–539. © 2001 Wiley‐Liss, Inc.
Quantitation of cyclosporin A in whole blood by liquid chromatography/stable isotope dilution electrospray ionization mass spectrometry
Authors: Magni F. , Pereira S. , Leoni M. , Grisenti G. , Galli Kienle M.
Published: August 2002

Therapy with cyclosporin A (CsA) for immunosuppression after organ transplantation requires monitoring of its levels in blood owing to the narrow therapeutic index of the drug and to the high inter‐individual variability of the drug absorption and metabolism. We describe the preparation of CsA labelled with stable isotopes (13C and 2H) with an isotopic enrichment of about 99% using labelled glucose and its use as internal standard for quantification of CsA blood levels by isotope dilution/electrospray ionization mass spectrometry. The method was found to be linear in the tested range (1–1000 ng) with and without the matrix. The accuracy of the bracketting calibration curves prepared using 100 ng ml−1 labelled CsA was within ±1.7% (bias). The results confirmed the usefulness of the procedure as a reference method for the external quality assessment of the field methods for the evaluation of CsA blood concentration, the imprecision (relative standard deviation) and accuracy (bias) being <2%. Copyright © 2001 John Wiley & Sons, Ltd.
Direct assay of Aplysia tissues and cells with laser desorption/ionization mass spectrometry on porous silicon
Authors: Kruse Rebecca A. , Rubakhin Stanislav S. , Romanova Elena V. , Bohn Paul W. , Sweedler Jonathan V.
Published: August 2002

Desorption/ionization on porous silicon (DIOS) is a form of laser desorption mass spectrometry that allows for the direct mass analysis of a variety of analytes without the addition of organic matrix. Protocols are described for the direct analysis of exocrine tissue and single neurons using DIOS‐MS. The atrial gland of Aplysia californica was blotted on to porous silicon and analyzed with DIOS‐MS in the range m/z 1000–4000. The ability to culture invertebrate neurons directly on porous silicon is also presented. Isolated bag cells regenerated neuronal processes in culture on porous silicon. DIOS‐MS allowed the direct detection of the peptides contained in individual cultured neurons indicating that with appropriate protocols, DIOS can be used with biological samples with considerable thickness. Copyright © 2001 John Wiley & Sons, Ltd.
Preischemic hyperglycemia‐aggravated damage: Evidence that lactate utilization is beneficial and glucose‐induced corticosterone release is detrimental
Authors: Schurr Avital , Payne Ralphiel S. , Miller James J. , Tseng Michael T.
Published: August 2002

Aerobic lactate utilization is crucial for recovery of neuronal function posthypoxia in vitro. In vivo models of cerebral ischemia pose a conceptual challenge when compared to in vitro models. First, the glucose paradox of cerebral ischemia, namely, the aggravation of delayed neuronal damage by preischemic hyperglycemia, cannot be reproduced in vitro. Second, in vitro elevated glucose levels protect against ischemic (hypoxic) damage, an outcome that has seldom been reproduced in vivo. Employing a rat model of cardiac‐arrest‐induced transient global cerebral ischemia (TGI), we found that hyperglycemic conditions, when induced 120–240 min pre‐TGI, significantly reduced post‐TGI neuronal damage as compared to normoglycemic conditions. In contrast, hyperglycemia, when induced 15–60 min pre‐TGI, significantly aggravated post‐TGI neuronal damage. Brain lactate levels in rats loaded with glucose either 15 min or 120 min pre‐TGI were significantly and equally higher than those of control, saline‐injected rats. The beneficial effect of 120 min pre‐TGI glucose loading was abolished by lactate transport inhibition. A significant increase in blood corticosterone (CT) levels was observed upon glucose loading that peaked at 15–30 min and returned to baseline levels by 60–120 min. When rats loaded with glucose 15 min pre‐TGI were treated with metyrapone, a CT synthesis inhibitor, a significantly lower degree of delayed neuronal damage in comparison to both untreated, 15 min glucose‐loaded rats and normoglycemic, control rats was observed. Thus, although elevated levels of brain lactate cannot explain the glucose paradox of cerebral ischemia, hyperglycemia‐induced, short‐lived elevation in CT blood levels could. More importantly, lactate appears to play a crucial role in improving postischemic outcome. © 2001 Wiley‐Liss, Inc.
Endogenous IGF1 enhances cell survival in the postnatal dentate gyrus
Authors: Cheng Clara M. , Cohen Matt , Tseng Victor , Bondy Carolyn A.
Published: August 2002

The dentate gyrus is selectively reduced in size in the insulin‐like growth factor 1 (IGF1) null mouse brain. The purpose of this study was to determine whether this defect is due to reduced granule cell numbers, and if so, to determine whether altered cell proliferation, survival, or both contribute to attenuation of dentate gyrus size. At postnatal day 10 (P10), granule cell numbers were not significantly different in IGF1 null and littermate wildtype (WT) dentate gyri. The subgranular zone cell population, however, was relatively increased, and the granule cell layer population relatively decreased in the IGF1 null dentate gyrus. By P50, total dentate cell numbers were decreased by 20% (P = 0.01) in the IGF1 null mouse, although IGF1 null subgranular zone progenitor cells remained relatively increased compared with WT (38%, P < 0.05). IGF1 null dentate cell proliferation, assessed by thymidine analogue incorporation, was actually increased at P10 (33%, P < 0.05) and P50 (167%, P = 0.001). Dentate granule cell death, assessed by the appearance of pycnotic cells and DNA fragmentation, was also significantly increased in the IGF1 null dentate (61%, P < 0.05 and 101%, P = 0.03). These data suggest that endogenous IGF1 serves an important role in dentate granule cell survival during the course of postnatal brain development. In addition, this work suggests the potential of a compensatory mechanism promoting increased dentate cell proliferation in the face of impaired cell survival during postnatal neurogenesis. J. Neurosci. Res. 64:341–347, 2001. Published 2001 Wiley‐Liss, Inc.
Regulation of olfactory neurogenesis by amidated neuropeptides
Authors: Hansel Donna E. , Eipper Betty A. , Ronnett Gabriele V.
Published: August 2002

The existence of stem cells in the CNS raises issues concerning the ability of nervous tissues to regenerate in the adult mammal and provides new perspectives on the treatment of degenerative disease and traumatic injury of the nervous system. These cells have a relatively limited range of locations within the nervous system and include cells of the rostral migratory stream, hippocampus, retina, and olfactory epithelium. The olfactory epithelium has been studied as a model of adult neuronal regeneration, with neuronal precursor/basal cells serving as the olfactory “stem cells.” The identification of factors that promote neuronal proliferation or regeneration within the olfactory epithelium can provide clues to the process of adult mammalian nervous system repair and treatment. Multiple factors have been examined that appear to influence the proliferation and subsequent maturation of basal cells. These factors include nerve growth factor, fibroblast growth factor‐2, epidermal growth factor, and insulin/insulin‐like growth factor‐1. Recently, two amidated neuropeptides, neuropeptide Y (NPY) and pituitary adenylate cyclase‐activating polypeptide (PACAP38), identified in the olfactory epithelium have been shown to promote dramatically neuronal proliferation. The effects of NPY and PACAP suggest that amidated neuropeptides may serve a broad developmental and regenerative role in the mammalian olfactory epithelium. J. Neurosci. Res. 66:1–7, 2001. © 2001 Wiley‐Liss, Inc.
Effect of cyclic AMP on the expression of myelin basic protein species and myelin proteolipid protein in committed oligodendrocytes: Differential involvement of the transcription factor CREB
Authors: Afshari Fatemah S. , Chu Annie K. , Sato‐Bigbee Carmen
Published: August 2002

Our previous results support the idea that CREB (cyclic AMP‐response element binding protein) may be a mediator of neuroligand and growth factor signals that, coupled to different signal transduction pathways, play different roles at specific stages of oligodendrocyte development. In the early stages, when cells are immature precursors, CREB may play a role as a mediator of protein kinase C (PKC)/mitogen‐activated protein kinase (MAPK) pathways regulating cell proliferation. In contrast, at a later stage, when cells are already committed oligodendrocytes, CREB seems to play an important role as a mediator in the stimulation of myelin basic protein (MBP) expression by cyclic AMP (cAMP). In this study, we have investigated whether cAMP and CREB play a role in regulating the expression of all or on the other hand particular MBP isoforms. The results indicated that treatment of committed oligodendrocytes with the cAMP analogue db‐cAMP results in a pattern of expression of MBP‐related polypeptides that most closely resembles the pattern of MBPs observed in cerebra from adult animals. Experiments in which CREB expression was inhibited using a CREB antisense oligonucleotide, suggested that CREB is involved in the cAMP‐dependent stimulation of all the MBP isoforms. In contrast, we have found that db‐cAMP stimulates the expression of myelin proteolipid protein (PLP) in a process that occurs despite inhibition of CREB expression. These results support the idea that cAMP stimulates the maturation of oligodendrocytes and stress the fact multiple mechanisms may convey the action of this second messenger modulating oligodendrocyte differentiation and myelination. J. Neurosci. Res. 66:37–45, 2001. © 2001 Wiley‐Liss, Inc.
Comparison of two‐layer and single‐layer canopy models with Lagrangian and K‐theory approaches in modelling evaporation from forests
Authors: Wu A. , Black A. , Verseghy D.L. , Bailey W.G.
Published: August 2002

The near‐field effect on flux calculation was examined using two approaches: (1) The performance of a Lagrangian two‐layer canopy model was compared with a K‐theory two‐layer canopy model and a K‐theory single‐layer canopy model; and (2) the near‐field resistance was placed in series with aerodynamic resistance in the Canadian Land Surface Scheme (CLASS). The first approach was tested using flux data measured from a boreal aspen forest because it had a thick understorey canopy. The second approach was tested using the aspen forest and a Douglas fir forest. Results from both approaches confirmed that the difference between simulations from K‐theory and the Lagrangian evaporation models was small due to the strong control by stomatal conductance. Furthermore, the two‐layer canopy models were inferior to the single canopy model in the calculation of the sensible and latent heat fluxes above the forest. Copyright © 2001 Royal Meteorological Society
Diurnal and seasonal characteristics of precipitation at an upland site in Scotland
Authors: Svensson Cecilia , Jakob Dörte
Published: August 2002

The diurnal and seasonal characteristics of precipitation at Eskdalemuir, in southern Scotland, were studied by representing the hour of rainfall as a circular variable and applying statistical methods for directional data. Hourly precipitation data for 1970–86 were analysed for four different precipitation intensities. Concurrent observations of wind direction and speed were used to help in the interpretation of the results.

The occurrence of precipitation of light intensity, 0.1–0.4 mm h−1, has a bimodal distribution with early‐morning and afternoon maxima in both summer and winter. Heavier precipitation in summer is concentrated in the afternoon, presumably reflecting convective activity in response to the diurnal heating cycle. Very heavy precipitation (≥5.0 mm h−1) in winter occurs significantly more often in the early‐morning hours (02:00–08:00 GMT) than during the rest of the day. This is attributed to orographic enhancement of precipitation because of the associated wind direction. For both seasons, very heavy precipitation in the early‐morning hours occurs predominantly in airflow from the south or south–south‐east, i.e. roughly perpendicular to the topographical barrier formed by the Southern Uplands. In contrast, very heavy precipitation during the afternoon, especially in summer, is more associated with south–south‐westerly winds coming from the sea. Copyright © 2002 Royal Meteorological Society.
Steric contributions to CO binding in heme proteins: a density functional analysis of FeCO vibrations and deformability
Authors: KOZLOWSKI PAWEL M. , VOGEL KATHLEEN M. , ZGIERSKIA MAREK Z. , SPIRO THOMAS G.
Published: August 2002

Non-local Density Functional Theory (DFT) is applied to the calculation of geometry and vibrational frequencies of FeII (porphine)(imidazole)(CO), a model for CO adducts of heme proteins. Bond distances and angles are in agreement with crystallographic data, and frequencies are correctly calculated for C–O and Fe–C stretching and for Fe–C - O bending. This last mode is actually the out-of-phase combination of Fe–C–O bending and Fe–C tilting coordinates, which are heavily mixed because of a large bend–tilt interaction force constant. The in-phase combination is predicted at a very low frequency, 73 cm-1, and to have a low infrared intensity; attempts to detect it in far-IR spectra via 13 C 18 O isotope sensitivity have been unsuccessful. The stretch–bend interaction lowers the energy required for FeCO distortion. A soft potential may account for the wide range of crystallographically determined Fe–C–O displacements and orientations in myoglobin ( Mb ). The minimum energy path for displacement of the O atom from the heme normal was calculated by relaxing the structure while constraining only the O atom displacement from the heme normal. Energies of 0.2 to 3.5 kcal mol-1 are required for the range of reported displacement, 0.3–1.3 Å. However, vibrational spectroscopy limits the allowable displacement to the low end of this range. The O atom displacement is computed via DFT to be 0.6 Å for a 7 ° angle of the C–O stretching IR dipole relative to the heme normal, the maximum value compatible with IR polarization measurements on MbCO . FeCO distortion is predicted to diminish both ν CO and ν FeC , thereby producing deviations from the well-established backbonding correlation; the scatter of the data permits a maximum displacement of 0.5 Å. This displacement would cost about 1.6 kcal mol-1 of steric energy. A small distortion energy is consistent with the CO affinity changes produced by mutations of the distal histidine residue in Mb . Taking the leucine mutant as reference, we estimate the 1.6 kcal mol-1 affinity loss in the wild-type protein to be the resultant of a 0.0–1.6 kcal steric inhibition, a 0.5 kcal mol-1 attraction of the distal histidine sidechain for the bound CO [weak H -bond], and a 0.5–2.1 kcal mol-1 attraction of the same side-chain for a water molecule in the deoxy protein. The observed 2.3 kcal mol-1 O 2 affinity increase in the wild-type protein relative to the leucine mutant then implies a 2.8–4.4 kcal mol-1 attraction of the histidine sidechain for bound O 2, consistent with a substantial H -bond interaction with the distal histidine. Thus steric inhibition can account for only a minor fraction of the discrimination factor against CO and in favor of O 2 which is produced by the heme–myoglobin interaction.
Photodynamic therapy using motexafin lutetium in allograft coronary artery disease
Authors: WOODBURN KATHRYN W. , RODRIGUEZ SHARI , ROBBINS ROBERT C. , KESSEL DAVID , YAMAGUCHI ATSUSHI
Published: August 2002

Graft coronary artery disease (GCAD) limits long-term patient survival following heart transplantation. There are few treatment options. Exploration into less invasive diagnostic techniques and attenuation of allograft coronary disease is warranted. The selectivity of Antrin®Injection (a motexafin lutetium sensitizer, Lu-Tex) and illumination with far-red light, approximately 732 nm, has been evaluated in several preclinical atherosclerosis models. Lu-Tex, using fluorescence microscopy, was found to partition into distinct punctate cytoplasmic compartments in cultured human bypass coronary smooth muscle cells (SMCs). Using specific organelle probes the chief subcellular localization sites were lysosomes and endoplasmic reticulum. The inhibitory effect of Lu-Tex-mediated photoactivation was demonstrated using SMCs; many cells died via an apoptotic pathway. Following illumination, fluorescence microscopy revealed sensitizer redistribution with fluorescence being observed in the mitochondria. The distribution of Lu-Tex was evaluated in a rat model of heterotopic cardiac allografts 60 days after transplantation. Lu-Tex was retained in the cardiac allograft, exhibiting a five-fold increase in retention between the allograft and native heart. These results encourage further exploration of Lu-Tex for diagnosis, and possible amelioration of chronic graft vascular disease using photodynamic therapy.
Third-order optical nonlinearity of chlorin derivatives
Authors: SINGH BHANU P. , VIJAYA R. , KUNDU T. , KANDASAMY K. , PUNTAMBEKAR P. N. , SHETTY SHANKAR J. , SRIVASTAVA T. S.
Published: August 2002

Second-order molecular hyperpolarizabilities (γ) of four tetraphenylchlorin derivatives were measured by the Z -scan technique at 784 nm in the off-resonant region and the enhancement in the hyperpolarizabilities of these derivatives in comparison to the regular porphyrins with the same external side-groups is explained on the basis of the difference in their Q-band oscillator strengths.
Phthalocyanine photophysics and photosensitizer efficiency on human embryonic lung fibroblasts
Authors: OWENS JOHN W. , ROBINS MARSHA
Published: August 2002

This study correlates the photophysical properties of aluminum phthalocyanine tetrasulfonate (AlPcTs), zinc phthalocyanine tetrasulfonate (ZnPcTs), and phthalocyanine tetrasulfonate (PcTs) with their ability to kill human embryonic lung (HEL) cells. Photofrin, a proven anti-cancer drug, was used for comparison. The photophysical properties include fluorescence emission spectra, fluorescence quantum yields, singlet state and radiative lifetimes, quantum yield for triplet formation, and fluorescence rate constants. Results indicate that photodynamic efficacy correlates inversely with fluorescence quantum yield and fluorescence lifetime and directly with quantum yield for triplet formation.
Ionically bound metalloporphyrin pairs on solid polymer support
Authors: VINODU MIKKI V. , PADMANABHAN M.
Published: August 2002

The present work demonstrates a simple and elegant strategy by which synthetically simple porphyrins are grafted on solid polymer support to generate porphyrin pairs held together by strong coulombic forces. Metalloporphyrins of tetra(4-pyridyl)porphyrins (MTPyP) were reacted with chloromethylated polystyrene (PS) beads to get covalently bound monocationic porphyrins on the polymer support (PS–MTPyP+). These were then converted to their tetracationic species (PS–MTMe3PyP4+) by exhaustive quaternisation, using CH3I . These polymer-grafted cationic porphyrins were made to react with tetraanionic p-sulphonated phenylporphyrins (MTPPS4-) in aqueous conditions. Analysis showed that the PS–MTMe3PyP4+take up MTPPS4-in exactly 1:1 stoichiometry to form strongly bound (ionically) porphyrin pairs. A variety of homo- and hetero-porphyrin pairs involving central metal ions like Mn , Co , Cu , Zn and Ag and also free-base porphyrins are generated by this strategy.
5,15-Diaryl-β-substituted-porphyrinato-manganese(III) chlorides as probes for structure–activity relationships in porphyrin-based epoxidation catalysts
Authors: SOBRAL ABÍLIO J. F. N. , ROCHA GONSALVES ANTÓNIO M. D'A.
Published: August 2002

Manganese complexes of 5,15-diaryl-β-substituted-porphyrins were prepared and their behaviour as oxidation catalysts was studied. The role of the pyrrolic and meso-substituents on the activity and selectivity of these catalysts was studied to reveal new structure–activity relationships in these porphyrin-based epoxidation catalysts. The beneficial effect of the halogen atoms at the meso-phenyls is still observed with these catalysts but, for the first time, a strong dependence on the selectivity of the epoxide production was found to be dependent on the nature of the non-halogen substituents at the β-pyrrolic positions of the porphyrin.
Millennial‐scale variability in the oceans: an ocean modelling view
Authors: Bigg Grant R. , Wadley Martin R.
Published: August 2002

Climate and ocean‐only models have shown that the ocean will respond abruptly to significant perturbations in surface forcing. Centennial‐scale oscillation is a characteristic of circulation in large semi‐enclosed ocean basins such as the Arctic, whereas millennial‐scale adjustment to changes in surface forcing has been found in the global ocean component of climate models. We show that the millennial time‐scale in climate models is likely to be intrinsic to the ocean through its presence in an ocean‐only model. The strength of the thermohaline circulation is shown to be very sensitive to the magnitude of ice albedo and, to a lesser extent, perturbation in the surface freshwater flux. Modelled glacial ocean circulation, in contrast to present‐day simulations, requires an enhanced freshwater flux over the northern Atlantic, even in its non‐Heinrich state, to obtain realistic overturning in the North Atlantic. Copyright © 2001 John Wiley & Sons, Ltd.
Holocene variations of sea‐surface conditions in the southeastern Barents Sea, reconstructed from dinoflagellate cyst assemblages
Authors: Voronina Elena , Polyak Leonid , Vernal Anne De , Peyron Odile
Published: August 2002

Palynomorphs were analysed in two sediment cores from the southeastern Barents Sea representing the past 8.3 and 4.4 kyr. High dinocyst contents and species diversity enabled the application of the best analogue method to quantitatively reconstruct sea‐surface salinities, temperatures and ice cover using 677 modern reference sites from the North Atlantic and Arctic seas, including new data from the Barents Sea reported here. At the southern core site, where waters are affected by the Atlantic inflow, sea‐surface conditions were relatively warm and stable between ca. 8000 and 5000 calendar yr BP. In contrast, the past 5 kyr had periods with cooler temperatures and extended ice cover, fluctuating mostly at 1–1.5 kyr frequencies at both sites. Most pronounced coolings occurred around 8.1, 5, 3.5–3.2 and 2.5 ka. The northern site additionally shows younger cooling events, tentatively dated to 1.4, 0.3 and 0.1 ka. Identified variations in sea‐surface conditions indicate changes in Atlantic water inputs to the Barents Sea. Our results generally correlate to palaeoclimatic reconstructions from northwestern Eurasia, exemplified by palynological records from Karelia. This correlation suggests that sea‐surface variations in the Barents Sea reflect large‐scale changes in atmospheric and oceanic interactions between the North Atlantic and the Arctic. Copyright © 2001 John Wiley & Sons, Ltd.
E‐Change: Charting a path towards sustainable e‐strategies
Authors: Stace Doug , Holtham Clive , Courtney Nigel
Published: August 2002

This paper proposes that the E‐revolution constitutes a special case of disruptive innovation for organizations, demanding new responses by leaders, managers and change agents in successfully charting a course of change.

The greatest challenges in embedding E‐technologies are not necessarily strategic or technical. They relate to people, structure and culture—that is, to the critical issues of implementation and business innovation.

A typology of different kinds of E‐change strategies is developed, showing how different organizational forms and change processes will be necessary in different strategic contexts.

The approach used successfully by one organization may be completely inappropriate for another. A change‐mapping schema is then introduced to illustrate how these E‐strategies and associated change processes may alter over time.

Copyright © 2001 John Wiley & Sons, Ltd.
Combining high‐amylose and waxy starch mutations in barley
Authors: Swanston J Stuart , Ellis Roger P , Morrison Ian M , Mackay George R , Dale M Finlay B , Cooper Allison , Tiller Sarah A , Duffus Carol M , Cochrane M Patricia , Prentice R Derek M , Paterson Linda , Lynn Andrew
Published: August 2002

Inbred lines, from a cross between barleys carrying the waxy and high‐amylose genes respectively, were characterised by the presence of both, either or neither of the genes and grown under field conditions. Starch granule proteins were separated by SDS‐PAGE and lines carrying the waxy gene, with or without the high‐amylose gene, had greatly reduced intensities of the 60 kDa band associated with granule‐bound starch synthase. One representative sample of each starch type was also grown under two controlled environment (CE) regimes. Starch properties were assessed on field‐ and CE‐grown samples of these genotypes and large differences were observed among starch types. Growth conditions generally had comparatively little effect on the starch properties measured. The waxy and high‐amylose genes appeared to have additive effects, both in reducing modal granule size and in increasing gelatinisation temperature significantly above that observed when only one of the genes was present. The genotype with both mutations produced a starch with phosphorus content and blue value, after removal of lipid, slightly higher than those of the waxy type and with an RVA profile similar to that of the wild type, but with lower peak and final viscosities.

© 2001 Society of Chemical Industry
Detection of inverted beet sugar adulteration of honey by FTIR spectroscopy
Authors: Sivakesava S , Irudayaraj J
Published: August 2002

A combination of Fourier transform infrared (FTIR) spectroscopy and multivariate statistics as a screening tool for the determination of beet medium invert sugar adulteration in three different varieties of honey is discussed. Honey samples with different concentrations of beet invert sugar were scanned using the attenuated total reflectance (ATR) accessory of the Bio‐Rad FTS‐6000 Fourier transform spectrometer. The spectral wavenumber region between 950 and 1500 cm−1 was selected for partial least squares (PLS) regression to develop calibration models for beet invert sugar determination in honey samples. Results from the PLS (first derivative) models were slightly better than those obtained with other calibration models. Predictive models were also developed to classify beet sugar invert in three different varieties of honey samples using discriminant analysis. Spectral data were compressed using the principal component method, and linear discriminant and canonical variate analyses were used to detect the level of beet invert sugar in honey samples. The best predictive model for adulterated honey samples was achieved with canonical variate analysis, which successfully classified 88–94 per cent of the validation set. The present study demonstrated that Fourier transform infrared spectroscopy could be used for rapid detection of beet invert sugar adulteration in different varieties of honey.

© 2001 Society of Chemical Industry
Pathology and prognosis of mucinous gastric carcinoma
Authors: Yasuda Kazuhiro , Adachi Yosuke , Shiraishi Norio , Yamaguchi Kimio , Shiromizu Akio , Kitano Seigo
Published: August 2002

Background and Objectives

Clinicopathologic characteristics of mucinous gastric carcinoma (MGC) are unclear, and whether surgical results of MGC are unfavorable is controversial. Pathology and prognosis of patients with MGC were studied using multivariate analysis.

Methods

The study included 17 patients with MGC and 614 with nonmucinous gastric carcinoma (NGC). The tumor was defined as MGC when more than one half of tumor area had mucin pools. Patients were evaluated with regard to age, sex, tumor location, size, gross type, depth of wall invasion, lymph node metastasis, lymphatic and vascular permeations, stage of disease, and operative curability.

Results

MGC tumors, when compared with NGC tumors, were featured by the large size (9.0 vs. 5.2 cm), grossly infiltrative type (76 vs. 30%), T2 or more invasion (100 vs 53%), positive lymph node metastasis (88 vs. 32%), lymphatic permeation (94 vs. 55%), vascular permeation (47 vs. 25%), and stages III and IV (88 vs. 32%). On a multivariate analysis, mucinous histologic type was not an independent prognostic factor. Although 5‐year survival rate for all MGC patients was lower than that for all NGC patients, the survival rate was not different between the MGC and NGC patients when compared in the same category of tumor size, depth of wall invasion, lymph node metastasis, and stage.

Conclusions

MGC is rare and detected mostly in an advanced stage. Mucinous histologic type itself is not a prognostic significance in patients with gastric carcinoma, and the biologic behavior of MGC is similar to that of ordinary advanced gastric carcinoma. J. Surg. Oncol. 2001;76:272–277. © 2001 Wiley‐Liss, Inc.
Interleukin‐10 and interferon‐gamma levels within the peritoneal cavity of patients with gastric cancer
Authors: Majima Takashi , Ichikura Takashi , Seki Shuhji , Takayama Eiji , Hiraide Hoshio , Mochizuki Hidetaka
Published: August 2002

Background and Objectives:

Immune status in the peritoneal cavity of patients with gastric cancer remains largely unknown. To clarify the clinical significance of the host immune response within the peritoneal cavity, we examined the levels of interferon‐gamma (IFN‐γ), a type 1 cytokine, and interleukin‐10 (IL‐10), a type 2 cytokine, in peritoneal washings obtained from patients with gastric cancer.

Methods:

Both the concentrations of IFN‐γ and of IL‐10 in peritoneal washings obtained during surgery from 56 patients with gastric cancer were determined by an enzyme‐linked immunosorbent assay.

Results:

The IFN‐γ level was not correlated with the IL‐10 level. The IL‐10 level increased in a stage‐dependent manner. The high IL‐10 level correlated with an unfavorable outcome, whereas there was no relationship between the IFN‐γ level and survival rate. However, among the stage III–IV cancer patients, the high IFN‐γ level correlated with a favorable outcome, while there was no relationship between the IL‐10 level and survival rate.

Conclusion:

Although the IL‐10 level increases with tumor progression, the outcome of patients with advanced gastric cancer may be affected by the IFN‐γ level, but not by the IL‐10 level, in the peritoneal cavity. J. Surg. Oncol. 2001;78:124–130. © 2001 Wiley‐Liss, Inc.