bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of psilocybin on time perception and temporal control of behaviour in humans
Authors: Wittmann Marc , Carter Olivia , Hasler Felix , Cahn B. Rael , Grimberg Ulrike , Spring Philipp , Hell Daniel , Flohr Hans , Vollenweider Franz X.
Published: May 2006

Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo. To control for cognitive and subjective changes, we assessed spatial working memory and conscious experience. Twelve healthy human volunteers were tested under placebo, medium (115μg/kg), and high (250μg/kg) dose conditions, in a double-blind experimental design. Psilocybin was found to significantly impair subjects’ ability to (1) reproduce interval durations longer than 2.5 sec, (2) to synchronize to inter-beat intervals longer than 2 sec and (3) caused subjects to be slower in their preferred tapping rate. These objective effects on timing performance were accompanied by working-memory deficits and subjective changes in conscious state, namely increased reports of ‘depersonalization’ and ‘derealization’ phenomena including disturbances in subjective ‘time sense.’ Our study is the first to systematically assess the impact of psilocybin on timing performance on standardized measures of temporal processing. Results indicate that the serotonin system is selectively involved in duration processing of intervals longer than 2 to 3 seconds and in the voluntary control of the speed of movement. We speculate that psilocybin’s selective disruption of longer intervals is likely to be a product of interactions with cognitive dimensions of temporal processing -presumably via 5-HT2A receptor stimulation.
Implications of mechanism-based inhibition of CYP2D6 for the pharmacokinetics and toxicity of MDMA
Authors: Yang Jiansong , Jamei Masoud , Heydari Amir , Yeo Karen R. , de la Torre Rafael , Farré Magí , Tucker Geoffrey T. , Rostami-Hodjegan Amin
Published: May 2006

The aim of this study was to model the in vivo kinetic consequences of mechanism-based inhibition (MBI) of CYP2D6 by 3,4 methylenedioxymethamphetamine (MDMA, ecstasy). A model with physiologically-based components of drug metabolism was developed, taking account of change in the hepatic content of active CYP2D6 due to MBI by MDMA. Based on the in vitro information, plasma concentration time profiles of MDMA after various doses were computed and compared with reported observations. The analysis suggested that a typical recreational MDMA dose could inactivate most hepatic CYP2D6 within an hour, and the return to a basal level of CYP2D6 could take at least 10 days. Thus, the genetic polymorphism of CYP2D6 and coadministration of CYP2D6 inhibitors may have less impact on MDMA pharmacokinetics and the risk of acute toxicity than previously thought. This is consistent with clinical observations that indicate no obvious link between inherited CYP2D6 deficiency and acute MDMA intoxication.
The Effects of Maltreatment Recurrence and Child Welfare Services on Dimensions of Delinquency
Authors: Lemmon John H.
Published: May 2006

The study examines the relationship between maltreatment recurrence and various dimensions of delinquency among a cohort of at-risk youths. The results indicate that maltreatment recurrence is a significant predictor of the initiation, continuation, and severity of delinquency. The relationship continues to exist in the presence of other delinquency risk factors. Within the maltreatment subgroup, a curvilinear pattern is observed. This pattern suggests that child welfare placement services reduce the effects of maltreatment recurrence on chronic and violent offending. The maltreatment recurrence-delinquency relationship follows a linear pattern among youths receiving in-home services and a curvilinear pattern among those receiving placement services.
Environmental Justice and the Role of Criminology
Authors: Zilney Lisa Anne , McGurrin Danielle , Zahran Sammy
Published: May 2006

An increasing number of scholars and activists have begun to tackle a variety of issues relevant to environmental justice studies. This study attempts to address the role of criminologists in this domain. The authors examine 425 environmental justice articles in 204 academic journals, representing 18 programs/departments between 1970 and 2003. First, they measure the environmental justice contributions in the literature by academic department or activist affiliation. Second, they identify the major themes in the literature as they have developed and reveal the current and future directions of environmental justice studies. Such themes include the spatial distribution of hazards, social movements, law and public policy, and environmental discrimination. Finally, the authors seek to call attention to the evident linkages between accepted areas of criminological scholarship and environmental justice. From this latter objective, the authors seek to demonstrate how criminology and criminal justice can advance this critical dialogue and social movement.
A Simple Model of the Treloar—Kearsley Instability
Authors: Steigmann David J.
Published: May 2006

The Treloar—Kearsley instability is studied in the framework of membrane theory. The phenomenon considered is the bifurcation of an equibiaxial stretch of a thin square elastic sheet, in equilibrium under equibiaxial dead loads, to a rectangle at a critical value of the load. The membrane setting, in which the sheet is regarded as an elastic surface, leads to sharper results on the stability of equilibria than those delivered by conventional elasticity theory. Further, definite conclusions can be drawn under weaker constitutive hypotheses. These are illustrated through the use of a particular strain-energy function which renders the analysis nearly trivial.
Single and multiple material constraints in thermoelasticity
Authors: Negahban Mehrdad
Published: May 2006

Constraints on the possible forms of material response, such as incompressibility or inextensibility, have long been used to simplify constitutive response models, and have resulted in substantial progress in fields such as fluid mechanics and the mechanics of composite materials. A method of imposing these constraints for thermoelastic materials is considered that follows steps that remove the need for assuming an additive term resulting from the constraint. In the process, three methods are considered for the separation of the constitutively prescribed part of the response from the part that is in reaction to the constraints. Both the case of single and multiple constraints are considered with extensive examples including special considerations for including effects associated with isotropic or anisotropic thermal expansion.
Boundary-Value Problems for Hyperbolic Equations Related to Steady Granular Flow
Authors: Schaeffer David G. , Shearer Michael , Witelski Thomas P.
Published: May 2006

Boundary value problems for steady-state flow in elastoplasticity are a topic of mathematical and physical interest. In particular, the underlying PDE may be hyperbolic, and uncertainties surround the choice of physically appropriate stress and velocity boundary conditions. The analysis and numerical simulations of this paper address this issue for a model problem, a system of equations describing antiplane shearing of an elastoplastic material. This system retains the relevant mathematical structure of elastoplastic planar flow. Even if the flow rule is associative, two significant phenomena appear: (i) For boundary conditions suggestive of granular flow in a hopper, in which it seems physically natural to specify the velocity everywhere along a portion of the boundary, no such solutions of the equations exist; rather, we construct a solution with a shear band (velocity jump) along part of the boundary, and an appropriate relaxed boundary condition is satisfied there. (ii) Rigid zones appear inside deforming regions of the flow, and the stress field in such a zone is not uniquely determined. For a nonassociative flow rule, an extreme form of nonuniqueness—both velocity and stress—is encountered.
Long-term clearance from small airways in subjects with ciliary dysfunction
Authors: Lindström Maria , Falk Rolf , Hjelte Lena , Philipson Klas , Svartengren Magnus
Published: May 2006

The objective of this study was to investigate if long-term clearance from small airways is dependent on normal ciliary function.

Six young adults with primary ciliary dyskinesia (PCD) inhaled111Indium labelled Teflon particles of 4.2 μm geometric and 6.2 μm aerodynamic diameter with an extremely slow inhalation flow, 0.05 L/s. The inhalation method deposits particles mainly in the small conducting airways. Lung retention was measured immediately after inhalation and at four occasions up to 21 days after inhalation. Results were compared with data from ten healthy controls. For additional comparison three of the PCD subjects also inhaled the test particles with normal inhalation flow, 0.5 L/s, providing a more central deposition. The lung retention at 24 h in % of lung deposition (Ret24) was higher (p < 0.001) in the PCD subjects, 79 % (95% Confidence Interval, 67.6;90.6), compared to 49 % (42.3;55.5) in the healthy controls. There was a significant clearance after 24 h both in the PCD subjects and in the healthy controls with equivalent clearance. The mean Ret24with slow inhalation flow was 73.9 ± 1.9 % compared to 68.9 ± 7.5 % with normal inhalation flow in the three PCD subjects exposed twice. During day 7–21 the three PCD subjects exposed twice cleared 9 % with normal flow, probably representing predominantly alveolar clearance, compared to 19 % with slow inhalation flow, probably representing mainly small airway clearance.

This study shows that despite ciliary dysfunction, clearance continues in the small airways beyond 24 h. There are apparently additional clearance mechanisms present in the small airways.
Predicting DNA-binding sites of proteins from amino acid sequence
Authors: Yan Changhui , Terribilini Michael , Wu Feihong , Jernigan Robert L , Dobbs Drena , Honavar Vasant
Published: May 2006

Background

Understanding the molecular details of protein-DNA interactions is critical for deciphering the mechanisms of gene regulation. We present a machine learning approach for the identification of amino acid residues involved in protein-DNA interactions.

Results

We start with a Naïve Bayes classifier trained to predict whether a given amino acid residue is a DNA-binding residue based on its identity and the identities of its sequence neighbors. The input to the classifier consists of the identities of the target residue and 4 sequence neighbors on each side of the target residue. The classifier is trained and evaluated (using leave-one-out cross-validation) on a non-redundant set of 171 proteins. Our results indicate the feasibility of identifying interface residues based on local sequence information. The classifier achieves 71% overall accuracy with a correlation coefficient of 0.24, 35% specificity and 53% sensitivity in identifying interface residues as evaluated by leave-one-out cross-validation. We show that the performance of the classifier is improved by using sequence entropy of the target residue (the entropy of the corresponding column in multiple alignment obtained by aligning the target sequence with its sequence homologs) as additional input. The classifier achieves 78% overall accuracy with a correlation coefficient of 0.28, 44% specificity and 41% sensitivity in identifying interface residues. Examination of the predictions in the context of 3-dimensional structures of proteins demonstrates the effectiveness of this method in identifying DNA-binding sites from sequence information. In 33% (56 out of 171) of the proteins, the classifier identifies the interaction sites by correctly recognizing at least half of the interface residues. In 87% (149 out of 171) of the proteins, the classifier correctly identifies at least 20% of the interface residues. This suggests the possibility of using such classifiers to identify potential DNA-binding motifs and to gain potentially useful insights into sequence correlates of protein-DNA interactions.

Conclusion

Naïve Bayes classifiers trained to identify DNA-binding residues using sequence information offer a computationally efficient approach to identifying putative DNA-binding sites in DNA-binding proteins and recognizing potential DNA-binding motifs.
Prognostic significance of cyclooxygenase-2 (COX-2) expression in patients with surgically resectable adenocarcinoma of the oesophagus
Authors: Bhandari Pradeep , Bateman Adrian C , Mehta Raj L , Stacey Bernard SF , Johnson Penny , Cree Ian A , Di Nicolantonio Federica , Patel Praful
Published: May 2006

Background

COX-2 expression in tumour cells has been associated with poor prognosis in gastrointestinal and non-gastrointestinal cancers. The aim of our study was to test the hypothesis that higher levels of COX-2 expression are prognostically related to poor clinico-pathologic features in adenocarcinoma of the oesophagus.

Methods

We reviewed the records of 100 consecutive patients undergoing resection for adenocarcinoma of the oesophagus to collect data on T-stage, N-stage, tumour recurrence and survival. T & N-stage was further confirmed by histological examination. COX-2 protein expression was assessed by immunohistochemistry in all patients and COX-2 m-RNA expression was measured by quantitative RT-PCR in a small group of patients.

Results

Higher levels of COX-2 expression were associated with higher T stage (p = 0.008), higher N stage (p = 0.049), increased risk of tumour recurrence (p = 0.01) and poor survival (p = <0.001). A COX-2 score of >200 was associated with a median survival of 10 months compared to 26 months with a score of <200 (p = <0.001).

Conclusion

Higher levels of COX-2 expression are associated with poor clinico-pathologic features and poor survival in patients with oesophageal adenocarcinoma.
Critical moments in the production of `rigorous' and `relevant' cultural economic geographies
Authors: James Al
Published: May 2006

While many commentators have recently argued forcefully for increased `rigour' and `relevance' within cultural economic geography, they have offered relatively less guidance on how we might achieve that in practice, according to criteria that are methodologically and epistemologically appropriate to the cultural turn. Within this context, I outline a series of feasible concrete strategies that researchers (especially those with limited resources of finance, status and power) might employ in the pursuit of these twin research ideals across five commonly experienced moments in the research process, namely: (i) development of research questions; (ii) research design and case study selection; (iii) data collection; (iv) empirical analysis and theory-building; and (v) write-up and communication.
Research on Chinese urban form: retrospect and prospect
Authors: Whitehand J. W.R. , Gu Kai
Published: May 2006

In the last 10 years, research on Chinese urban form has grown rapidly both in China itself and in other parts of the world. At the same time Chinese cities have undergone unprecedented growth and transformation, presenting great challenges for the comprehension and management of urban landscape change. In planning future urban morphological research during this period of exceptional flux, an important first step is to take stock of past research, especially that of the recent past. Hitherto research on Chinese urban form across a range of disciplines, including architectural history, urban planning, archaeology and urban geography, has tended to be descriptive and has contained scant comparison, either of findings or methods, with that on towns and cities in other parts of the world. Future research on Chinese urban form can benefit from exploring the efficacy of urban morphological concepts and methods that have been developed and applied elsewhere in the world, especially Europe.
Myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis in the common marmoset reflects the immunopathology of pattern II multiple sclerosis lesions
Authors: Merkler D , Schmelting B , Czéh B , Fuchs E , Stadelmann C , Brück W
Published: May 2006

Pathomorphological studies described pathological heterogeneity in patients with multiple sclerosis (MS). Different effector mechanisms might therefore be responsible for lesion formation in MS. The present report shows that myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in common marmoset monkeys reflects one specific lesional subtype of MS, namely MS pattern II lesions with antibody/complement-mediated damage. MOG-induced EAE in marmoset monkeys will, therefore, provide an ideal model for therapeutic approaches directed against B-cell/antibody/complement in MS.
Particulate delivery systems for vaccines: what can we expect?
Authors: Bramwell Vincent W , Perrie Yvonne
Published: May 2006

In our attempts to thwart the unwanted attentions of microbes by prophylactic and therapeutic vaccination, the knowledge of interactions at the molecular level may prove to be an invaluable asset. This article examines how particulate delivery systems such as liposomes and polymer micro-spheres can be applied in the light of recent advances in immunological understanding. Some of the biological interactions of these delivery systems are discussed with relevance for antigen trafficking and molecular pathways of immunogenicity and emphasis on the possible interaction of liposomal components. In particular, traditional concepts such as antigen protection, delivery to antigen presenting cells and depot formation remain important aspects, whilst the inclusion of selected co-adjuvants and enhanced delivery of these moieties in conjunction with antigen now has a firm rationale.
An investigation into the adjuvanticity and immunogenicity of zein microspheres being researched as drug and vaccine carriers
Authors: Hurtado-López Pepi , Murdan Sudaxshina
Published: May 2006

We have determined whether zein microspheres could act as vaccine adjuvants i.e. increase the immune responses to co-administered immunogens. Ovalbumin (model antigen)-loaded zein micro-spheres, blank zein microspheres and ovalbumin solution were intramuscularly administered to mice and the sera antibody levels were determined by ELISA. Another group of mice was orally dosed with blank zein microspheres, and serum and faecal antibody levels were determined. As expected, negligible antibody titres were obtained with the ovalbumin solution. Surprisingly, intramuscular administrations of blank zein microspheres elicited high levels of serum IgG which bound to the ovalbumin antigen coated on ELISA microtitre plates. This indicated that anti-zein antibodies had been elicited by blank zein microspheres and that these antibodies were cross-reacting with ovalbumin antigen coated onto ELISA plates. Such cross-reactivity inhibited the determination of the adjuvant activity of zein microspheres, if any. Additional ELISA assays, where zein was used as the coating antigen, confirmed the generation of anti-zein antibodies by blank zein microspheres i.e. zein microspheres were immunogenic following intramuscular administration. Upon oral administration of blank zein microspheres, serum IgG levels remained low but intestinal IgA levels increased following booster doses i.e. systemic tolerance, but not mucosal tolerance, to oral zein particles was achieved. Zein microspheres were immunogenic when administered intramuscularly and orally.
The preparation of liposomes using compressed carbon dioxide: strategies, important considerations and comparison with conventional techniques
Authors: Bridson R H , Santos R C D , Al-Duri B , McAllister S M , Robertson J , Alpar H O
Published: May 2006

Numerous strategies are currently available for preparing liposomes, although no single method is ideal in every respect. Two methods for producing liposomes using compressed carbon dioxide in either its liquid or supercritical state were therefore investigated as possible alternatives to the conventional techniques currently used. The first technique used modified compressed carbon dioxide as a solvent system. The way in which changes in pressure, temperature, apparatus geometry and solvent flow rate affected the size distributions of the formulations was examined. In general, liposomes in the nano-size range with an average diameter of 200 nm could be produced, although some micron-sized vesicles were also present. Liposomes were characterized according to their hydrophobic drug-loading capacity and encapsulated aqueous volumes. The latter were found to be higher than in conventional techniques such as high-pressure homogenization. The second method used compressed carbon dioxide as an antisolvent to promote uniform precipitation of phospholipids from concentrated ethanolic solutions. Finely divided solvent-free phospholipid powders of saturated lipids could be prepared that were subsequently hydrated to produce liposomes with mean volume diameters of around 5 μm.
A comparative study of cationic liposome and niosome-based adjuvant systems for protein subunit vaccines: characterisation, environmental scanning electron microscopy and immunisation studies in mice
Authors: Vangala Anil , Kirby Daniel , Rosenkrands Ida , Agger Else Marie , Andersen Peter , Perrie Yvonne
Published: May 2006

Vesicular adjuvant systems composing dimethyldioctadecylammonium (DDA) can promote both cell-mediated and humoral immune responses to the tuberculosis vaccine fusion protein in mice. However, these DDA preparations were found to be physically unstable, forming aggregates under ambient storage conditions. Therefore there is a need to improve the stability of such systems without undermining their potent adjuvanticity. To this end, the effect of incorporating non-ionic surfactants, such as 1-monopalmitoyl glycerol (MP), in addition to cholesterol (Chol) and trehalose 6,60-dibehenate (TDB), on the stability and efficacy of these vaccine delivery systems was investigated. Differential scanning calorimetry revealed a reduction in the phase transition temperature (Tc) of DDA-based vesicles by ∼12°C when MP and cholesterol (1:1 molar ratio) were incorporated into the DDA system. Transmission electron microscopy (TEM) revealed the addition of MP to DDA vesicles resulted in the formation of multi-lamellar vesicles. Environmental scanning electron microscopy (ESEM) of MP-Chol-DDA-TDB (16:16:4:0.5 μmol) indicated that incorporation of antigen led to increased stability of the vesicles, perhaps as a result of the antigen embedding within the vesicle bilayers. At 4°C DDA liposomes showed significant vesicle aggregation after 28 days, although addition of MP-Chol or TDB was shown to inhibit this instability. Alternatively, at 25°C only the MP-based systems retained their original size. The presence of MP within the vesicle formulation was also shown to promote a sustained release of antigen in-vitro. The adjuvant activity of various systems was tested in mice against three subunit antigens, including mycobacterial fusion protein Ag85B-ESAT-6, and two malarial antigens (Merozoite surface protein 1, MSP1, and the glutamate rich protein, GLURP). The MP-and DDA-based systems induced antibody responses at comparable levels whereas the DDA-based systems induced more powerful cell-mediated immune responses.
Evaluation in melanoma-bearing mice of an etoposide derivative associated to a cholesterol-rich nanoemulsion
Authors: Prete Ana C Lo , Maria Durvanei A , Rodrigues Dé bora G , Valduga Claudete J , Ibañez Olga C M , Maranhão Raul C
Published: May 2006

A cholesterol-rich nanoemulsion (LDE) may be used as a vehicle to target antineoplastic drugs against cancer cells. The association of an etoposide derivative to LDE is stable and retains the cytotoxic activity of etoposide. We have evaluated the toxicity and antitumoral action of this new preparation in-vivo. Melanoma-bearing mice and control mice were administered LDE-etoposide oleate or commercial etoposide, either with or without radioactive labelling. The maximum tolerated dose (MTD), tissue distribution, plasma decay curves, pharmacokinetic parameters and antitumoral activity were determined. Association to LDE drastically reduced the drug toxicity, since MTD was approximately five-fold greater than in commercial etoposide. LDE-etoposide oleate was concentrated four-fold in the tumour compared with the normal adjacent tissues, was removed faster from plasma in tumour-bearing mice than in controls, and remained in the bloodstream longer than commercial etoposide. The tumour growth inhibition rate and survival were greater in animals treated with LDE-etoposide oleate compared with commercial etoposide. However, increasing the dose from 17 to 85 μM kg−1 did not result in further improvement of the antitumour action. The incorporation of etoposide oleate to LDE resulted in markedly reduced toxicity and superior antitumoral activity. LDE-etoposide oleate is a promising new weapon for cancer treatment.
Examination of the impact of a range of Pluronic surfactants on the in-vitro solubilisation behaviour and oral bioavailability of lipidic formulations of atovaquone
Authors: Sek Leab , Boyd Ben J , Charman William N , Porter Christopher J H
Published: May 2006

Exogenous surfactants are increasingly used to enhance the dispersion properties of lipid-based formulations of poorly water-soluble drugs, yet their possible effects on formulation digestion and oral bioavailability in-vivo are not well documented. In this study, in-vitro dispersion and digestion experiments were conducted using formulations comprising a blend of long-chain glycerides, ethanol, a model poorly water-soluble drug (atovaquone), and a series of surfactants including Cremophor EL and a range of Pluronic surfactants (Pluronics L121, L61, L72, L43 and F68). Inclusion of Cremophor EL, a surfactant with a high hydrophilic-lipophilic balance (HLB), promoted complete digestion of the formulation and effective dispersion and solubilisation of the lipolytic products and co-administered drug. Surprisingly, formulations containing the Pluronic (L121) with the lowest HLB (0.5) equally effectively promoted digestion and drug solubilisation and a trend towards decreased digestion and drug solubilisation was observed with Pluronics of increasing HLB values. All formulations effectively prevented drug precipitation, suggesting possible utility in-vivo, and no correlation was evident between the ability of the formulations to self-emulsify on dispersion and to promote drug solubilisation on digestion. Subsequent assessment of the oral bioavailability of atovaquone after administration of formulations containing Cremophor EL or Pluronic L121 or a simple solution of atovaquone in long-chain glycerides confirmed the utility of lipid-based formulations for enhancing the oral bioavailability of poorly water-soluble drugs such as atovaquone, but also indicated that in some cases microemulsion preconcentrate formulations may not provide additional bioavail-ability benefits beyond that achievable using simple lipid solutions.
Intestinal permeability and excretion into bile control the arrival of amlodipine into the systemic circulation after oral administration
Authors: Raušl Dragica , Fotaki Nikoletta , Zanoški Ružica , Vertzoni Maria , Cetina-Čižmek Biserka , Khan M Zahirul I , Reppas Christos
Published: May 2006

The objective of this study was to identify the factors controlling the arrival of amlodipine into the systemic circulation after oral administration in the fasting state. Dissolution data were collected with the rotating paddle and the flow-through apparatus. Caco-2 cell lines were used to assess the intestinal permeability characteristics. Actual in-vivo data were collected in 24 fasted healthy subjects after single-dose administration of the same amlodipine besylate tablet formulation used in the in-vitro dissolution studies. Regardless of the hydrodynamics, dissolution of amlodipine besylate tablets was rapid and complete in media simulating the contents of the upper gastrointestinal tract in the fasting state. Permeability of amlodipine through Caco-2 cell lines was lower than propranolol's and higher than ranitidine's, indicating that transport through the intestinal mucosa may be one process that limits the arrival into the systemic circulation. Indeed, the deconvoluted profile indicated that arrival into portal blood occurs at rates much slower than gastric emptying or dissolution rates. However, prediction of amlodipine's mean plasma profile after oral administration became possible only after additionally assuming excretion of amlodipine into the bile and a reasonable gastrointestinal residence time. Interestingly, in-vitro permeability data collected in this or in previous studies were inappropriate for simulating the mean actual plasma profile.
Sesquiterpene lactones from Lychnophora pohlii: neutrophil chemiluminescence inhibition and free radical scavenger activity
Authors: Kanashiro Alexandre , Kabeya Luciana M , Grael Cristiane F F , Jordão Christiane O , Azzolini Ana Elisa C S , Lopes João Luis C , Lucisano-Valim Yara M
Published: May 2006

Excessive production of reactive oxygen species (ROS) by polymorphonuclear leucocytes (PMNLs) is thought to contribute to the pathology of many inflammatory diseases. Sesquiterpene lactones (STLs) seem to be important contributors to the anti-inflammatory activity of many species of Lychnophora (Asteraceae), which have been widely used in Brazilian folk medicine because of this pharmacological property. In this study, the inhibitory effects of three STLs isolated from Lychnophora pohlii (lychnopholide, centratherin and goyazensolide) on rabbit PMNL oxidative burst were evaluated by the luminol-enhanced chemiluminescence (CL-lum) assay. All STLs tested showed concentration-dependent inhibitory activity on CL-lum but were not cytotoxic to PMNLs (evaluated by lactate dehydrogenase release) under the assessed conditions. Moreover, goyazensolide, the most active STL, had no free radical scavenger property, as assessed by 1,1-diphenyl-2-picrylhydrazyl radical assay, and had no inhibitory effect on the luminol-horseradish peroxidase-hydrogen peroxide chemiluminescence. Taken together, the results of this investigation suggest that the concomitant presence of methacrylate ester and hydroxyl groups contributes to a high inhibitory effect on PMNL oxidative metabolism. This effect was not mediated by free radical scavenger or cytotoxic effects, but probably by inhibition of enzymes involved in the signal transduction pathways of the ROS generation process.
Participation of epoxygenase activation in saikogenin D-induced inhibition of prostaglandin E2 synthesis
Authors: Toriniwa Yasufumi , Lv Xiaochuan , Kodama Yasuo , Ohizumi Yasushi , Yoshida Makoto , Nakahata Norimichi
Published: May 2006

We examined the effect of saikogenin D on arachidonic acid metabolism in C6 rat glioma cells to clarify its anti-inflammatory mechanism. Incubation of C6 cells with saikogenin D for 20min resulted in the inhibition of prostaglandin E2 production and the accumulation of an arachidonic acid metabolite that was found to be 11,12-dihydroxyeicosatrienoic acid, a metabolite of 11,12-epoxyei-cosatrienoic acid. C6 cells expressed rat epoxygenase mRNAs, CYP1A1, CYP2B1 and CYP2J3, which converted arachidonic acid to epoxyeicosatrienoic acids. 11,12-Epoxyeicosatrienoic acid inhibited A23187-induced prostaglandin E2 production and SKF-525A, an inhibitor of epoxygenase, attenuated the saikogenin D-induced inhibition of prostaglandin E2 production in C6 cells. Furthermore, 11,12-epoxyeicosatrienoic acid and 11,12-dihydroxyeicosatrienoic acid, but not saikogenin D, inhibited the activity of cyclooxygenase in a cell-free condition. These data suggest that saikogenin D activates epoxygenases that rapidly convert arachidonic acid to epoxyeicosanoids and dihydroxyeicosatrienoic acids, and then the metabolites secondarily inhibit prostaglandin E2 production.
Surfactin C inhibits platelet aggregation
Authors: Kim Sung Dae , Park Sun Kyu , Cho Jae Youl , Park Hwa Jin , Lim Jong Hwan , Yun Hyo In , Park Seung Chun , Lee Kyoung Youl , Kim Sang Keun , Rhee Man Hee
Published: May 2006

This study was designed to investigate the effect of surfactin C, which is derived from Bacillus subtilis, on platelet aggregation and homotypic leucocyte aggregation. Surfactin C strongly and dose-dependently inhibited platelet aggregation, which was stimulated both by thrombin (0.1 U mL−1), a potent agonist that activates the G protein-coupled protease receptor, and by collagen (5 μg mL−1), a potent ligand that activates αIIbβ3 with IC50 values (concentration inhibiting platelet aggregation by 50%) of 10.9 and 17.0 μM, respectively. Moreover, surfactin C significantly suppressed the intracellular Ca2+ mobilization in thrombin-activated platelets. Surfactin C, however, did not affect various integrin-mediated U937 cell aggregation, implying that the anti-platelet activity of surfactin C was not due to its detergent effect but by its action on the downstream signalling pathway. Therefore, the results suggest that surfactin C may have a beneficial therapeutic effect on aberrant platelet aggregation-mediated cardiovascular diseases.
ZERO COPULA IN THE EASTERN CARIBBEAN: EVIDENCE FROM BEQUIA
Authors: WALKER JAMES A. , MEYERHOFF MIRIAM
Published: May 2006

Zero copula is a feature of English-based creoles which has figured in the African American Vernacular English (AAVE) origins debate. While much attention has been paid to the effects of the following grammatical category, the lack of a comparative base highlights the need for more quantitative studies in the Caribbean. We analyze zero copula on the eastern Caribbean island of Bequia, where a mesolectal creole variety coexists with a nonstandard English variety. Our results show that the relative ordering of factors within the following grammatical category is parallel in the two varieties, but predicate adjectives are treated differently. We suggest reconsidering the inference of a creole origin for zero copula in AAVE on the basis of the following grammatical category and reevaluating the theoretical notion of the creole continuum.
The Mass Media, Political Parties, and Europessimism in Hungary
Authors: Hegedűs István
Published: May 2006

István Hegedűs is a former member of the Hungarian parliament (1990-94). In 1989 he served on the team that negotiated the country's transition to democracy.
Monodisperse Organosilica Microcapsules with Functional Groups by Self-catalysis
Authors: Fei Bin , Lu Haifeng , Wang Rong Hua , Xin John H
Published: May 2006

On the basis of the self-catalytic sol–gel reaction of methyl trimethoxysilane (MTMS) and 3-aminopropyl trimethoxysilane (ATMS) at oil/water interface, monodisperse organosilica microcapsules with functional groups were prepared in one step at room temperature, without any surfactant or mediating reagent.
Chemical Modification of SWCNT and VGCF by Radical Addition Reaction
Authors: Gunji Takahiro , Akazawa Minako , Arimitsu Koji , Abe Yoshimoto
Published: May 2006

Single wall carbon nanotubes (SWCNTs) and vapor growth carbon fibers (VGCFs) were chemically modified by radical reactions with 2,2′-azobis(isobutyronitrile) (AIBN) and 4,4′-azobis(4-cyanovaleric acid) (ACVA) in o-dichlorobenzene. The modification was monitored by infrared and Raman spectra and differential thermal gravimetry. These spectral and analytical data supported the chemical modification of SWCNTs and VGCFs by a simple and clean procedure. AIBN-modified SWCNTs and VGCFs were well dispersed in organic solvents such as methanol, tetrahydrofuran, and chloroform. In contrast, ACVA-modified SWCNTs and VGCFs were dispersed in water.
Organogel Formation by Self-assembly of Ag(I) and Mono-urea Derivatives Containing Pyridyl Group
Authors: Arai Sadao , Imazu Kanako , Kusuda Shiho , Yoshihama Isao , Tonegawa Masami , Nishimura Yukihiro , Kitahara Kei-ichi , Oishi Shigero , Takemura Tetsuo
Published: May 2006

The mono-urea derivative 3 derived from 4-(2-aminoethyl)pyridine and dodecyl isocyanate gelled aromatic solvents, such as p-xylene, tetralin, and benzene, in the presence of Ag(I). The complex formation by the coordination of two equivalents of mono-urea 3 to Ag(I) and the intermolecular hydrogen bonding between urea groups plays important roles for the fibrous self-assembly followed by the gelation.
Adsorption and Possible Luminescence Detection of Nonylphenol by Eu3+–Smectites
Authors: Okada Tomohiko , Ehara Yusuke , Ogawa Makoto
Published: May 2006

4-Nonylphenol was effectively adsorbed on Eu3+–smectites, which were prepared by cation exchange reactions of a natural montmorillonite and a synthetic saponite with Eu3+ chloride, from aqueous solutions. The appearance of luminescence bands of Eu3+ by the excitation of the adsorbed 4-nonylphenol was also observed.
A Route to Redox-active Nanoparticle-cored Dendrimers: Post-encapsulation of Ferrocene
Authors: Shon Young-Seok , Choi Daeock
Published: May 2006

Redox-active nanoparticle-cored dendrimers were synthesized by a stepwise reaction, in which synthesis of functionalized nanoparticles was followed by organic reactions to build dendritic architecture around a nanoparticle core. Incorporation of redox molecules on the surface of nanoparticles resulted in the formation of a redox-active nanoparticle-cored dendrimer.
Heating Effect of Plasma Catalytic Reaction on the CH4 Reforming of CO2 over Ni/γ-Al2O3 Catalyst in Dielectric-barrier Discharge Reactor
Authors: Lee Hwaung , Song Hyung Keun , Min Byoung Ryul
Published: May 2006

CH4 reforming of CO2 reaction for producing synthesis gas (syngas) was performed using dielectric-barrier discharge (DBD) with catalyst. Ni/γ-Al2O3 was used as a catalyst. To investigate the effect of reaction temperature, extra heating was applied outside of the plasma reactor. When supplied extra heating, pure syngas could be obtained only at 573 K. It is a noticeable result comparing with pure catalytic reaction or plasma reaction only.
A Series of Polymorphs with Different Colors in Fluorescent 2,5-Diamino-3,6-dicyanopyrazine Dyes
Authors: Matsumoto Shinya , Uchida Yoko , Yanagita Mitsuhiro
Published: May 2006

We found a series of polymorphs with different colors in 2,5-diamino-3,6-dicyanopyrazine dyes. Their color difference was found to be caused by conformational change in the crystals, not by exciton interactions.
Calf muscle pump failure in lower limb lymphoedema
Authors: Parmar J H , Aslam M , Standfield N J
Published: May 2006

Abnormal venous haemodynamics and poor calf muscle pump may play a role in lymphoedema by contributing to production of excess interstitial fluid. Using photoplethysmography (PPG), we compared haemodynamic characteristics between normal and lymphoedematous lower limbs. PPG was performed using an automated infrared-based system, while the patient performed 10 active dorsiflexions of the ankle. This gave values for venous refilling time and venous pump power. A total of 62 limbs (normal = 37; lymphoedematous = 25) were studied. Lymphoedematous limbs showed significantly decreased venous pump power and venous refilling time (s) than normal limbs (24.6±14.1 versus 45.4±16 and 23±15.2 versus >45, respectively; P<0.005 for all the results). The haemodynamic values measured in the normal group showed good consistency and reproducibility. These results were consistent with the previous literature and demonstrate an impaired venous system associated with the development of lymphoedema. Poor muscle pump power may reflect physical disability of the ankle joint to perform dorsiflexion. This factor should be considered when treating this incurable condition.
Comparative outcomes of radiofrequency endoluminal ablation, invagination stripping, and cryostripping in the treatment of great saphenous vein insufficiency
Authors: Stötter L , Schaaf I , Bockelbrink A
Published: May 2006

Objective: Prospective, randomized comparison of short-term and one-year postoperative outcomes after radiofrequency endoluminal ablation (REA) of the great saphenous vein (GSV), saphenofemoral junction (SFJ) ligation with extended tributary ligation and invagination GSV stripping, and SFJ ligation with extended tributary ligation and GSV cryostripping.

Methods: In all, 60 consenting patients were randomly allocated to three groups and treated contemporaneously over a nine-month period. Clinical, duplex Doppler, analogue scale pain scoring and activity impairment assessments were performed one day postoperatively, and after one, two, and six weeks, and then repeated after one year, adding patient satisfaction scoring and the CIVIQ 2 quality-of-life questionnaire, specifically designed for lower limb venous insufficiency.

Results: Immediate success was achieved in 19/20 REA limbs with one open segment that subsequently spontaneously closed, in 20/20 invagination stripping limbs, and in 18/20 cryostripped limbs, two having residual open segments. Cumulative up to six-week impairment scores, cumulative up to six-week pain scores, and time to return to full activity were all statistically superior for REA patients. At one year, segmental recanalization on less than 10 cm was detected in two REA patients, and for all REA patients the GSV trunk was sonographically no longer visible, beginning from 10 cm below the SFJ. REA patients continued to be significantly more satisfied with both their operative procedures and the cosmetic appearance of their treated lower extremity compared with patients in the two other treatment cohorts.

Conclusion: REA offers significant short-term, patient-oriented advantages over extended ligation and invagination or cryostripping through one year.
Audit of venous thromboembolic prophylaxis in emergency general surgical admissions
Authors: Sinha I , Galland R B
Published: May 2006

Objective: The aim was to audit venous thromboembolic disease (VTE) prophylaxis in emergency surgical admissions and, given the reducing number of available surgical beds, to compare protocol violation rates between surgical and outlying wards.

Method: Study 1: Prospective data collected on VTE prophylaxis in emergency surgical patients over a two-week period during or after the post-take ward round. Provisional diagnoses were recorded and drug charts were reviewed looking for prescription of standard unfractionated heparin 5000 IU and/or thromboembolic deterrent stockings. Following presentation at the governance meeting, departmental protocols were circulated to the emergency surgical unit and outlying wards that received emergency surgical patients. Study 2: Carried out two months later. Data on VTE prophylaxis collected over a two-week period in emergency surgical admissions in the same manner as study 1.

Results: Study 1: A total of 70 patients were studied, 42 of which were women. The median age of the group was 47 years (range 19–90). There were 36 patients (51.2%) who violated VTE prophylaxis protocol. Of the 60 patients admitted to surgical wards, 29 violated VTE protocol (48.3%). Of the 10 patients admitted to outlying wards, seven violated VTE protocol (70%). This difference was not statistically significant. Study 2: A total of 70 patients were studied, 40 of which were women. The median age was 46 years (range 17–101). Eleven patients (15.7%) violated VTE prophylaxis recommendations. This improvement was statistically significant, P<0.0001. Some 56 patients were admitted to general surgical wards; nine violated VTE protocol (16.1%). In the fourteen patients admitted to outlying wards, there were two protocol violations (14.3%). This difference was not statistically significant.

Conclusions: VTE is a potentially fatal complication of hospital admission. This audit highlighted that VTE prophylaxis rates in our emergency admissions were unacceptable at 51.2%, but were improved through audit and clinical governance. No significant difference in protocol violation was found between surgical and outlying wards. In the absence of national guidelines, VTE prophylaxis is the responsibility of individual general surgical departments and requires a documented, circulated departmental protocol, education of staff and regular audit to ensure appropriate compliance.
The morphology of the varicose short saphenous system
Authors: Fowkes L A , Darke S G
Published: May 2006

Objective: Surgery for the varicose short saphenous vein (SSV) remains unsatisfactory. Specific problems include locating the saphenopopliteal junction (SPJ) and whether the trunk should be stripped. Recurrence rates are high. The objective was to review the morphology of varicose SSV and to address these aspects.

Methods: Retrospective study of consecutive patients scheduled for SSV surgery based on initial continuous wave Doppler assessment. Detailed analysis of preoperative duplex ultrasound examinations with quantified reflux.

Results: A total of 56 limbs (unilateral) were studied, male to female ratio was 18:38 and mean age was 51 years. SPJ: severe reflux in 47, mean diameter 8.1 mm (all above the skin crease [mean 2.7 cm]). Reflux was 'focal', being confined to the peri-junctional area with normal sized and competent distal short saphenous trunks in 29. In the remainder, incompetence was 'complete' with dilatation and reflux of the entire system. In only one limb did varicosities arise distally from a proximally competent system. Long saphenous vein ( LSV): coexistent reflux in 17, with communications with the SSV in 11. Deep reflux: at least one segment of deep reflux was found in 24 limbs. In this small study, no significant association with other morphology was found apart from 'complete' SSV reflux.

Conclusion: The SPJ is usually severely incompetent, enlarged and sited above the skin crease. The morphology of the varicose SSV exhibits important differences from the LSV. In over half, incompetence is 'focal', confined to the peri-junctional vein and the distal trunk is competent suggesting a case for selective trunk stripping. Varicosities arising from a distally incompetent short saphenous trunk are uncommon.
Venous haemodynamic effects of anti-thromboembolism stockings
Authors: Tan J , Lockhart S , Smith A , Burnand K
Published: May 2006

Objective: The aim of this study was to assess the haemodynamic changes in the deep veins of 13 volunteers, following application of 13 made-to-measure graduated compression stockings all designed to exert different compression gradients along the limb.

Methods: The compression gradients were designed to apply pressures from 12–22 mmHg at the ankle to 9–20 mmHg at the calf and 5–10 mmHg at the thigh. These had been laboratory tested by the Hosiery Pressure Tester Mark II (HATRA). A medical stocking tester (MST) was subsequently used to measure the actual pressure measurements on the volunteers. A duplex scanner was used to measure the venous velocity in the deep veins at predetermined sites.

Results: The application of all the stockings increased the mean velocity in the popliteal vein by 38.7% (confidence interval [CI] 8–64%, P<0.01) but produced only a slight statistically insignificant increase in velocity in the femoral vein. No particular stocking profile gave significantly better results. A good correlation was found between the MST and HATRA tester measurements of the stocking pressures at the ankle and calf, but the MST method usually recorded higher pressures for the thigh measurements.

Conclusions: All profiles of graduated stockings appear to increase the velocity of blood in the deep veins above the knee, but only four pressure profiles (average 16.5, 14 and 6 mmHg) produced significant increases in velocity. There was no evidence to suggest that any one specific compression profile was superior to others at increasing the venous velocity in the popliteal vein.