bluuebunny/crossref_metadata_2025 huggingface dataset:
A Critical Review on Using the Rorschach Method in Somatic Illnesses
Authors: Sultan Serge , Porcelli Piero
Published: April 2008

The Rorschach Inkblot Method is widely used in psychological assessment. Is it valid and clinically useful in the specific context of somatic illness? The goal of this article is to give synthetic arguments for deciding which Rorschach-derived measures to adopt in assessing individuals. Therefore, we reviewed three research directions in which this instrument has been applied and discuss methodological issues: (1) content scoring procedures of ego solidity and dependency, (2) the assessment of alexithymia, and (3) the prediction of self-care behaviors. This review identifies the main issues in using Rorschach in this field as being construct and discriminant validity. Future validation research should be developed and emphasize prevalidated external criteria and longitudinal designs.
Perception of Reality and Norm: A Study of the Popular Responses to Rorschach’s Psychodiagnostis in Brazil
Authors: Lelé Álvaro José
Published: April 2008

The objective of this present study was to delimit a list of popular responses in Rorschach’s Psychodiagnosis protocols of adult subjects in the state of Minas Gerais (Brazil). The popular response is a common, frequent response, given within a certain population group, determining the adaptation of the subjects to their social and cultural environment. The variety of criteria utilized to classify the Rorschach responses presents a problem for professionals in the area of psychological evaluations. A total of 100 volunteer subjects of both genders, without critical psychiatric or psychological history, of different ages (between 18 and 36) took part. The Rorschach Psychodiagnostic was given and studied in compliance with the French School system. The global profile of the subjects’ performance in relation to productivity has shown quantitative characteristics (R = 20.48 SD = 8.24 and mean = 18), which are within the mean profiles typically used as current reference in the Brazilian samples studied. From a total of 2.048 responses, 18 have been identified as popular (P) from which 8 were classified as specific popular responses (Ps) and 10 as popular regrouped responses (Pr). These results reinforce the need to carry out further studies on the criteria in establishing lists of popular responses in the Rorschach Psychodiagnostic.
From Ambiguity in Chinese Painting to Rorschach's Inkblots
Authors: Guinzbourg de Braude Mónica
Published: April 2008

Rorschach defines his method as a testing instrument based on the perception of ink blots, on the basis of which the subject finds meaning out of an associative integration of preexistent engrams (mnemonic images) with recent sense complexes. The more ambiguous the visual stimulus is, the more it requires an integrative effort to be decoded, therefore increasing the subject's mental activity and allowing his/her personality resources to be perceived more clearly. The subjects' responses to the stimuli of blots produced in this way would explain how the “mental equipment” organizes and processes stimuli on the basis of the construction of perception processes influenced by early registers in the archives of memory. The blots trigger these constructions, whose “thresholds” account for the potential readiness to tap on thoughts and emotions in processes of adapting to real life. Rorschach might have reached to his own knowledge on the process of construction that underlies the visual image. Most probably inspired by Chinese painting tradition – which exerted great influence on early 20th-century art movements, and relied on image overlapping, vacuum dynamics, shading, light and dark and ambiguity techniques – he constructed “accidental blots” as ideal stimuli to the “guided projection.” Thus, from the Chinese painting Rorschach would have also taken the role played by the spectator, who stimulated by an essentially ambiguous image (act of perception) is supposed to “complete” it in his mind (act of projection). In creating his method, then, Rorschach favored certain types of stimuli, integrating at the same time both his scientific and artistic sides.
The Rorschach and the Inventory of Interpersonal Problems
Authors: Schneider Robert B. , Huprich Steven K. , Fuller Kristi M.
Published: April 2008

The purpose of this study was to evaluate the relationship between a self-report (explicit) measure of interpersonal difficulties – the Inventory of Interpersonal Problems (IIP; Horowitz et al., 2000 ) – and the Rorschach, which includes implicit measures of self-perception and interpersonal relatedness. Seventeen a priori predictions were made regarding the face-valid associations (i.e., correlations) between the IIP and selected Rorschach variables. A sample of 62 undergraduates were administered the Rorschach and IIP. Their IIP scores were slightly higher than the normative sample reported by Horowitz et al. (1988) . Nonetheless, seven predicted relationships were statistically significant and included the following Rorschach variables: Intellectualization Index, AG, FM, S, T, Y, and MOR. These results remained significant when they were controlled for response productivity. Five of the predicted correlations approached statistical significance and included the following Rorschach variables: T, Food, Egocentricity Index, and M%. Most of the correlations were observed in the submissive hemisphere of the interpersonal circumplex. Nonsignificant results were partially explained to be the result of “heteromethod inversion” ( Bornstein, 2002 ) in which defensiveness in admitting difficulties in some interpersonal domains leads to apparent inconsistencies in explicit and implicit measures of a given trait or quality.
The Development of the Rorschach in Japan
Authors: Sorai Kenzo , Ohnuki Keiichi
Published: April 2008

In 1925, a Japanese psychologist named Yuzaburo Uchida accidentally discovered a copy of Psychodiagnostik. His encounter with Psychodiagnostik marks the beginning of Rorschach studies in Japan. The Rorschach became more widely used after the Klopfer and Beck Systems were introduced. However, researchers questioned whether such systems could be applied to Japanese subjects. The systems were modified gradually and more Japanese systems were established. The major examples were the Nagoya University System and the Osaka University System. Yasufumi Kataguchi created his original system through modifications of the Klopfer System in 1956. The Kataguchi system became the one most often used in Japan. In 1958 the Rorschachiana Japonica was published and it became central to the study of Rorschach in Japan over the past few decades and stimulated various other aspects of study. Hirosi Motoaki translated The Rorschach Systems in 1972. Later, a number of researchers began the study of the Comprehensive System. Currently, the Rorschach Test is widely used in Japan. The future challenge of the Rorschach in Japan is to establish a standard based upon Japanese data and how Japanese studies will compare to other countries' research.
The History of the Rorschach in the United Kingdom
Authors: McCarthy Woods Justine
Published: April 2008

This article provides a brief outline of the history of the Rorschach in the United Kingdom (UK) from 1933, when it was “discovered” by Theodora Alcock and her colleagues, to the present day. It describes the professional group established to ensure the maintenance of high standards in the use of the Rorschach and other projective tests; the contribution made by the both the Tavistock Clinic and the Tavistock Institute for Human Relations (TIHR) in London to the teaching, training, and supervision in the Rorschach; the early use made of the Rorschach in clinical practice; the international links, which included the British Rorschach Forum acting as host for the International Rorschach Society (IRS) Congress in London in 1968; and the decline in the use of the Rorschach, followed by a recent resurgence of interest.
In a Working Mood?
Authors: Reinecke Leonard , Trepte Sabine
Published: April 2008

Abstract. This quasi-experimental study examined the effects of exposure to a computer game on arousal and subsequent task performance. After inducing a state of low arousal, participants were assigned to experimental or control conditions via self-selection. Members of the experimental group played a computer game for five minutes; subjects in the control group spent the same amount of time awaiting further instructions. Participants who were exposed to the computer game showed significantly higher levels of arousal and performed significantly better on a subsequent cognitive task. The pattern of results was not influenced by the participants' prior experience with the game. The findings indicate that mood-management processes associated with personal media use at the workplace go beyond the alteration of arousal and affect subsequent cognitive performance.
Instrument Development for Esthetic Perception Assessment
Authors: Rowold Jens
Published: April 2008

Abstract. Esthetic perception theories postulate several psychological dimensions, such as emotional, cognitive, and self-congruent processes, in the reception of visual arts stimuli. A diagnostic instrument, the Survey for the Assessment of Aesthetic Perception (SAAP), was developed in the German language to empirically assess these dimensions. Subsequently, the SAAP was implemented in two empirical studies, drawing on paintings and sculptures as visual arts stimuli. These studies provided evidence for construct validity, specifically factorial validity; the three esthetic processes of cognition, emotion, and self-congruency were distinguished. Also, internal consistency and test-retest reliability showed the SAAP to be strongly reliable. In sum, these results provide initial support toward the adequacy of the SAAP's psychometric properties.
Assessing influence of diagenetic carbonate dissolution on planktonic foraminiferal Mg/Ca in the southeastern Arabian Sea over the past 450 ka: Comparison between Globigerinoides ruber and Globigerinoides sacculifer
Authors: Tachikawa Kazuyo , Sépulcre Sophie , Toyofuku Takashi , Bard Edouard
Published: April 2008

The influence of supralysoclinal calcite dissolution on the Mg/Ca thermometer over the last 450 ka is assessed using Globigerinoides ruber and Globigerinoides sacculifer from a core site in the eastern Arabian Sea. The studied site is characterized by precession‐cycled paleoproductivity changes that have induced calcite dissolution in the sediments, although the core still contains 40–80% CaCO3. During high‐productivity periods, the narrow‐sized test weights of both foraminiferal species tend to decrease with increasing Mn/Ca ratio, indicating corrosive pore water conditions. Scanning electron microscope observations show that G. sacculifer maintains a better preserved test ultrastructure than G. ruber. Microprobe mapping reveals that Mg‐rich bands in G. ruber chamber walls are preserved despite reduced Ca content. Assuming that the low test weight and offset in Mg/Ca temperature between G. sacculifer and G. ruber are exclusively produced by calcite dissolution, the bias in Mg/Ca temperature determination can be estimated at around 1°C, comparable to uncertainty of this thermometry. Despite the evidence for test dissolution, foraminiferal Mg/Ca seems to preserve initial temperature signals under the studied conditions.
The Odden ice feature of the Greenland Sea and its association with atmospheric pressure, wind, and surface flux variability from reanalyses
Authors: Rogers Jeffrey C. , Hung Meng‐Pai
Published: April 2008

The Odden sea ice feature of the Greenland Sea is identified in a rotated principal component analysis of Hadley Center winter sea ice concentration data extending from 1951–2005. Time series of the Odden ice extent are evaluated in the context of sea level pressure, surface wind, air temperature, cloud, and energy flux variations using NCEP‐NCAR reanalyses. Odden was a recurring feature in winters 1966–1972, during the Great Salinity Anomaly (GSA), and appeared occasionally in the 1980s and 1990s but has occurred rarely since 2000. Odden formation is associated with northernmost Atlantic high pressure, a negative North Atlantic Oscillation, and anomalous westerly winds. Its formation is most highly correlated, however, to air temperature and fluxes of sensible/latent heat, and downward longwave radiation. Air temperature and downward longwave flux anomalies in the preceding autumn are also unusually low in advance of a winter Odden ice cover while heat fluxes are weakly positive. All parameters, including the ice cover anomaly, exhibit significant winter to winter persistence over time.
Circulation in the Ona Basin, southern Drake Passage
Authors: Barré Nicolas , Provost Christine , Sennechael Nathalie , Lee Jae Hak
Published: April 2008

Five Argo floats trapped in the Ona Basin, in the southern Drake Passage, provided unprecedented information on the water masses and the circulation present in all the seasons from March 2002 to April 2006. Their profiles recorded evidence of deep‐penetrating eddies, interleaving of water masses, and branching of the Southern Front of the Antarctic Circumpolar Current as it meets the Shackleton Fracture Zone. Ten‐day mean‐velocity estimates at the float parking depth (2000 db) often exceeded 15 cm s−1, revealing the intensity of the mesoscale field. Satellite data showed that the trapping period of the floats corresponded to the presence of an anticyclonic meander of the polar front over a depression in the topography to the northwest of the Ona Basin. The presence of this meander seems to be linked to low‐frequency modes of variability in sea surface height in the Yaghan Basin.
Analyzing signatures of aerosol‐cloud interactions from satellite retrievals and the GISS GCM to constrain the aerosol indirect effect
Authors: Menon Surabi , Del Genio Anthony D. , Kaufman Yoram , Bennartz Ralf , Koch Dorothy , Loeb Norman , Orlikowski Daniel
Published: April 2008

Evidence of aerosol‐cloud interactions is evaluated using satellite data from MODIS, CERES, and AMSR‐E; reanalysis data from NCEP; and data from the NASA Goddard Institute for Space Studies climate model. We evaluate a series of model simulations: (1) Exp N, aerosol direct radiative effects; (2) Exp C, like Exp N but with aerosol effects on liquid‐phase cumulus and stratus clouds; and (3) Exp CN, like Exp C but with model wind fields nudged to reanalysis data. Comparison between satellite‐retrieved data and model simulations for June to August 2002 over the Atlantic Ocean indicate the following: a negative correlation between aerosol optical thickness (AOT) and cloud droplet effective radius (Reff) for all cases and satellite data, except for Exp N, a weak but negative correlation between liquid water path (LWP) and AOT for MODIS and CERES, and a robust increase in cloud cover with AOT for both MODIS and CERES. In all simulations, there is a positive correlation between AOT and both cloud cover and LWP (except in the case of LWP‐AOT for Exp CN). The largest slopes are obtained for Exp N, implying that meteorological variability may be an important factor. On the basis of NCEP data, warmer temperatures and increased subsidence were found for less clean cases (AOT > 0.06) that were not well captured by the model. Simulated cloud fields compared with an enhanced data product from MODIS and AMSR‐E indicate that model cloud thickness is overpredicted and cloud droplet number is within retrieval uncertainties. Since LWP fields are comparable, this implies an underprediction of Reff and thus an overprediction of the indirect effect.
Metal impacts on microbial biomass in the anoxic sediments of a contaminated lake
Authors: Gough Heidi L. , Dahl Amy L. , Nolan Melissa A. , Gaillard Jean‐François , Stahl David A.
Published: April 2008

Little is known about the long‐term impacts of metal contamination on the microbiota of anoxic lake sediments. In this study, we examined microbial biomass and metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, and zinc) in the sediments of Lake DePue, a backwater lake located near a former zinc smelter. Sediment core samples were examined using two independent measures for microbial biomass (total microscopic counts and total phospholipid phosphate concentrations) and for various fractions of each metal (pore water extracts, sequential extractions, and total extracts of all studied metals and zinc speciation by X‐ray absorption fine structure). Zinc concentrations were up to 1000 times higher than reported for sediments in the adjacent Illinois River and ranged from 21,400 mg/kg near the source to 1,680 mg/kg near the river. However, solid metal fractions were not well correlated with pore water concentrations and were not good predictors of biomass concentrations. Instead, biomass, which varied among sites by as much as 2 times, was inversely correlated with concentrations of pore water zinc and arsenic as established by multiple linear regression. Monitoring of other parameters known to naturally influence biomass in sediments (e.g., organic carbon concentrations, nitrogen concentrations, pH, sediment texture, and macrophytes) revealed no differences that could explain observed biomass trends. This study provides strong support for control of microbial abundance by pore water metal concentrations in contaminated freshwater sediments.
Radio tomography of the ionosphere: Analysis of an underdetermined, ill‐posed inverse problem, and regional application
Authors: Garcia R. , Crespon F.
Published: April 2008

After analysing the forward and inverse problems of radio tomography, a time varying three‐dimensional imaging method of the ionosphere from GPS slant TEC data is described and applied at regional scale. Our approach is based on local basis parametrisation of electron density, and constrained by NeQuick ionosphere model and its spatial gradients. Our inversion scheme is fundamentally different from the data assimilation approach because it is not based on a physical ionosphere model. Preliminary results obtained with European GPS receiver data validate the stability of our method which is able to retrieve small‐scale ionosphere features in properly resolved volumes. Many improvements are still possible on the algorithm, and a careful validation of inverted models by independent data is still necessary. However, our inversion algorithm is shown to improve the determination of the small‐scale features of a coarse a priori ionosphere model.
Impacts of future climate change and emissions reductions on nitrogen and sulfur deposition over the United States
Authors: Tagaris Efthimios , Liao Kuo‐Jen , Manomaiphiboon Kasemsan , Woo Jung‐Hun , He Shan , Amar Praveen , Russell Armistead G.
Published: April 2008

Potential impacts of global climate change and emissions on the total nitrogen and sulfur deposition over the US are investigated. Three future years' annual average deposition rates (i.e., 2049–2051) are compared with historic ones (i.e., 2000–2002) accounting for existing US and individual State's emission regulations and strategies. Impacts of global climate change alone on regional nitrogen and sulfur deposition are small compared to impacts from emission control‐related reductions for the projections used in this study. The combined effect of climate change and emission reductions is a decrease in the annual average nitrogen and sulfur deposition over the US. Reduced nitrogen species dominate oxidized nitrogen deposition in the future. Spatial distribution plots for both components show lower deposition rates in the future mainly in the middle and eastern States where reductions in NOx and SO2 emissions are more pronounced.
Quantification of new production during a winter Noctiluca scintillans bloom in the Arabian Sea
Authors: Prakash Satya , Ramesh R. , Sheshshayee M. S. , Dwivedi R. M. , Raman Mini
Published: April 2008

We present new data on the nitrate (new production), ammonium, urea uptake rates and f‐ratios for the eastern Arabian Sea (10° to 22°N) during the late winter (northeast) monsoon, 2004, including regions of green Noctilucascintillans bloom. A comparison of N‐uptake rates of the Noctiluca dominated northern zone to the southern non‐bloom zone indicates the presence of two biogeochemical regimes during the late winter monsoon: highly productive north and less productive south. The conservative estimates of photic zone‐integrated total N‐uptake and f‐ratio are high in the north (∼19 mmolNm−2d−1 and 0.82, respectively) during the bloom and low (∼5.5 mmolNm−2d−1 and 0.38 respectively) in the south. The present and earlier data imply persistence of high N‐uptake and f‐ratio during blooms year after year. This quantification of the enhanced seasonal sequestration of carbon is an important input to global biogeochemical models.
Site-directed mutagenesis of firefly luciferase: implication of conserved residue(s) in bioluminescence emission spectra among firefly luciferases
Authors: Tafreshi Narges Kh. , Sadeghizadeh Majid , Emamzadeh Rahman , Ranjbar Bijan , Naderi-Manesh Hossein , Hosseinkhani Saman
Published: April 2008

The bioluminescence colours of firefly luciferases are determined by assay conditions and luciferase structure. Owing to red light having lower energy than green light and being less absorbed by biological tissues, red-emitting luciferases have been considered as useful reporters in imaging technology. A set of red-emitting mutants of Lampyris turkestanicus (Iranian firefly) luciferase has been made by site-directed mutagenesis. Among different beetle luciferases, those from Phrixothrix (railroad worm) emit either green or red bioluminescence colours naturally. By substitution of three specific amino acids using site-specific mutagenesis in a green-emitting luciferase (from L. turkestanicus), the colour of emitted light was changed to red concomitant with decreasing decay rate. Different specific mutations (H245N, S284T and H431Y) led to changes in the bioluminescence colour. Meanwhile, the luciferase reaction took place with relative retention of its basic kinetic properties such as Km and relative activity. Structural comparison of the native and mutant luciferases using intrinsic fluorescence, far-UV CD spectra and homology modelling revealed a significant conformational change in mutant forms. A change in the colour of emitted light indicates the critical role of these conserved residues in bioluminescence colour determination among firefly luciferases. Relatively high specific activity and emission of red light might make these mutants suitable as reporters for the study of gene expression and bioluminescence imaging.
Quantitative analysis of the interactions between HIV-1 integrase and retroviral reverse transcriptases
Authors: Herschhorn Alon , Oz-Gleenberg Iris , Hizi Amnon
Published: April 2008

The RT (reverse transcriptase) of HIV-1 interacts with HIV-1 IN (integrase) and inhibits its enzymatic activities. However, the molecular mechanisms underling these interactions are not well understood. In order to study these mechanisms, we have analysed the interactions of HIV-1 IN with HIV-1 RT and with two other related RTs: those of HIV-2 and MLV (murine-leukaemia virus). All three RTs inhibited HIV-1 IN, albeit to a different extent, suggesting a common site of binding that could be slightly modified for each one of the studied RTs. Using surface plasmon resonance technology, which monitors direct protein–protein interactions, we performed kinetic analyses of the binding of HIV-1 IN to these three RTs and observed interesting binding patterns. The interaction of HIV-1 RT with HIV-1 IN was unique and followed a two-state reaction model. According to this model, the initial IN–RT complex formation was followed by a conformational change in the complex that led to an elevation of the total affinity between these two proteins. In contrast, HIV-2 and MLV RTs interacted with IN in a simple bi-molecular manner, without any apparent secondary conformational changes. Interestingly, HIV-1 and HIV-2 RTs were the most efficient inhibitors of HIV-1 IN activity, whereas HIV-1 and MLV RTs showed the highest affinity towards HIV-1 IN. These modes of direct protein interactions, along with the apparent rate constants calculated and the correlations of the interaction kinetics with the capacity of the RTs to inhibit IN activities, are all discussed.
Insulin exocytosis in Goto-Kakizaki rat β-cells subjected to long-term glinide or sulfonylurea treatment
Authors: Kawai Junko , Ohara-Imaizumi Mica , Nakamichi Yoko , Okamura Tadashi , Akimoto Yoshihiro , Matsushima Satsuki , Aoyagi Kyota , Kawakami Hayato , Watanabe Takashi , Watada Hirotaka , Kawamori Ryuzo , Nagamatsu Shinya
Published: April 2008

Sulfonylurea and glinide drugs display different effects on insulin granule motion in single β-cells in vitro. We therefore investigated the different effects that these drugs manifest towards insulin release in an in vivo long-term treatment model. Diabetic GK (Goto-Kakizaki) rats were treated with nateglinide, glibenclamide or insulin for 6 weeks. Insulin granule motion in single β-cells and the expression of SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) proteins were then analysed. Perifusion studies showed that decreased first-phase insulin release was partially recovered when GK rats were treated with nateglinide or insulin for 6 weeks, whereas no first-phase release occurred with glibenclamide treatment. In accord with the perifusion results, TIRF (total internal reflection fluorescence) imaging of insulin exocytosis showed restoration of the decreased number of docked insulin granules and the fusion events from them during first-phase release for nateglinide or insulin, but not glibenclamide, treatment; electron microscopy results confirmed the TIRF microscopy data. Relative to vehicle-treated GK β-cells, an increased number of SNARE clusters were evident in nateglinide- or insulin-treated cells; a lesser increase was observed in glibenclamide-treated cells. Immunostaining for insulin showed that nateglinide treatment better preserved pancreatic islet morphology than did glibenclamide treatment. However, direct exposure of GK β-cells to these drugs could not restore the decreased first-phase insulin release nor the reduced numbers of docked insulin granules. We conclude that treatment of GK rats with nateglinide and glibenclamide varies in long-term effects on β-cell functions; nateglinide treatment appears overall to be more beneficial.
Endoplasmic reticulum Ca2+ measurements reveal that the cardiac ryanodine receptor mutations linked to cardiac arrhythmia and sudden death alter the threshold for store-overload-induced Ca2+ release
Authors: Jones Peter P. , Jiang Dawei , Bolstad Jeff , Hunt Donald J. , Zhang Lin , Demaurex Nicolas , Chen S. R. Wayne
Published: April 2008

A number of RyR2 (cardiac ryanodine receptor) mutations linked to ventricular arrhythmia and sudden death are located within the last C-terminal ∼500 amino acid residues, which is believed to constitute the ion-conducting pore and gating domain of the channel. We have previously shown that mutations located near the C-terminal end of the predicted TM (transmembrane) segment 10, the inner pore helix, can either increase or decrease the propensity for SOICR (store-overload-induced Ca2+ release), also known as spontaneous Ca2+ release. In the present study, we have characterized an RyR2 mutation, V4653F, located in the loop between the predicted TM 6 and TM 7a, using an ER (endoplasmic reticulum)-targeted Ca2+-indicator protein (D1ER). We directly demonstrated that SOICR occurs at a reduced luminal Ca2+ threshold in HEK-293 cells (human embryonic kidney cells) expressing the V4653F mutant as compared with cells expressing the RyR2 wild-type. Single-channel analyses revealed that the V4653F mutation increased the sensitivity of RyR2 to activation by luminal Ca2+. In contrast with previous reports, the V4653 mutation did not alter FKBP12.6 (FK506-binding protein 12.6 kDa; F506 is an immunosuppressant macrolide)–RyR2 interaction. Luminal Ca2+ measurements also showed that the mutations R176Q/T2504M, S2246L and Q4201R, located in different regions of the channel, reduced the threshold for SOICR, whereas the A4860G mutation, located within the inner pore helix, increased the SOICR threshold. We conclude that the cytosolic loop between TM 6 and TM 7a plays an important role in determining the SOICR threshold and that the alteration of the threshold for SOICR is a common mechanism for RyR2-associated ventricular arrhythmia.
Generation of an agonistic binding site for blockers of the M3 muscarinic acetylcholine receptor
Authors: Thor Doreen , Schulz Angela , Hermsdorf Thomas , Schöneberg Torsten
Published: April 2008

GPCRs (G-protein-coupled receptors) exist in a spontaneous equilibrium between active and inactive conformations that are stabilized by agonists and inverse agonists respectively. Because ligand binding of agonists and inverse agonists often occurs in a competitive manner, one can assume an overlap between both binding sites. Only a few studies report mutations in GPCRs that convert receptor blockers into agonists by unknown mechanisms. Taking advantage of a genetically modified yeast strain, we screened libraries of mutant M3Rs {M3 mAChRs [muscarinic ACh (acetylcholine) receptors)]} and identified 13 mutants which could be activated by atropine (EC50 0.3–10 μM), an inverse agonist on wild-type M3R. Many of the mutations sensitizing M3R to atropine activation were located at the junction of intracellular loop 3 and helix 6, a region known to be involved in G-protein coupling. In addition to atropine, the pharmacological switch was found for other M3R blockers such as scopolamine, pirenzepine and oxybutynine. However, atropine functions as an agonist on the mutant M3R only when expressed in yeast, but not in mammalian COS-7 cells, although high-affinity ligand binding was comparable in both expression systems. Interestingly, we found that atropine still blocks carbachol-induced activation of the M3R mutants in the yeast expression system by binding at the high-affinity-binding site (Ki ∼10 nM). Our results indicate that blocker-to-agonist converting mutations enable atropine to function as both agonist and antagonist by interaction with two functionally distinct binding sites.
Neurobin/TMPRSS11c, a novel type II transmembrane serine protease that cleaves fibroblast growth factor-2 in vitro
Authors: Stallmach Robert , Gloor Sergio M.
Published: April 2008

TTSPs [type II TMPRSSs (transmembrane serine proteases)] are a growing family of trypsin-like enzymes with, in some cases, restricted tissue distribution. To investigate the expression of TTSPs in the nervous system, we performed a PCR-based screening approach with P10 (postnatal day 10) mouse spinal cord mRNA. We detected the expression of five known TTSPs and identified a novel TTSP, which we designated neurobin. Neurobin consists of 431 amino acids. In the extracellular part, neurobin contains a single SEA (sea-urchin sperm protein, enterokinase and agrin) domain and a C-terminal serine protease domain. RT–PCR (reverse transcription–PCR) analysis indicated the expression of neurobin in spinal cord and cerebellum. Histochemical analysis of brain sections revealed distinct staining of Purkinje neurons of the cerebellum. Transiently overexpressed neurobin was autocatalytically processed and inserted into the plasma membrane. Autocatalytic activation could be suppressed by mutating Ser381 in the catalytic pocket to an alanine residue. The protease domain of neurobin, produced in Escherichia coli and refolded from inclusion bodies, cleaved chromogenic peptides with an arginine residue in position P1. Serine protease inhibitors effectively suppressed the proteolytic activity of recombinant neurobin. Ca2+ or Na+ ions did not significantly modulate the catalytic activity of the protease. Recombinant neurobin processed 17-kDa FGF-2 (fibroblast growth factor-2) at several P1 lysine and arginine positions to distinct fragments, in a heparin-inhibitable manner, but did not cleave FGF-7, laminin or fibronectin. These results indicate that neurobin is an authentic TTSP with trypsin-like activity and is able to process FGF-2 in vitro.
Prostaglandin E1 inhibits IL-6-induced MCP-1 expression by interfering specifically in IL-6-dependent ERK1/2, but not STAT3, activation
Authors: Sobota Radoslaw M. , Müller Pia J. , Heinrich Peter C. , Schaper Fred
Published: April 2008

IL (interleukin)-6 exerts pro- as well as anti-inflammatory activities. Beside many other activities, IL-6 is the major inducer of acute phase proteins in the liver, acts as a differentiation factor for blood cells, as migration factor for T-cells and is a potent inducer of the chemokine MCP-1 (monocyte chemoattractant protein-1). Recent studies have focused on the negative regulation of IL-6 signal transduction through the IL-6-induced feedback inhibitors SOCS (suppressor of cytokine signalling) 1 and SOCS3 or the protein tyrosine phosphatases SHP-2 (Src homology 2 domain-containing protein tyrosine phosphatase 2) and TcPTP (T-cell protein tyrosine phosphatase). Studies on the cross-talk between pro-inflammatory mediators (IL-1, tumour necrosis factor, lipopolysaccharide) and IL-6 elucidated further regulatory mechanisms. Less is known about the regulation of IL-6 signal transduction by hormone/cytokine signalling through G-protein-coupled receptors. This is particularly surprising since many of these hormones (such as prostaglandins and chemokines) play an important role in inflammatory processes. In the present study, we have investigated the inhibitory activity of PGE1 (prostaglandin E1) on IL-6-induced MCP-1 expression and have elucidated the underlying molecular mechanism. Surprisingly, PGE1 does not affect IL-6-induced STAT (signal transducer and activator of transcription) 3 activation, but does affect ERK (extracellular-signal-regulated kinase) 1/2 activation which is crucial for IL-6-dependent expression of MCP-1. In summary, we have discovered a specific cross-talk between the adenylate cyclase cascade and the IL-6-induced MAPK (mitogen-activated protein kinase) cascade and have investigated its impact on IL-6-dependent gene expression.
Lysophosphatidic acid-induced transactivation of epidermal growth factor receptor regulates cyclo-oxygenase-2 expression and prostaglandin E2 release via C/EBPβ in human bronchial epithelial cells
Authors: He Donghong , Natarajan Viswanathan , Stern Randi , Gorshkova Irina A. , Solway Julian , Spannhake Ernst Wm. , Zhao Yutong
Published: April 2008

We have demonstrated that LPA (lysophosphatidic acid)-induced IL (interleukin)-8 secretion was partly mediated via transactivation of EGFR [EGF (epidermal growth factor) receptor] in HBEpCs (human bronchial epithelial primary cells). The present study provides evidence that LPA-induced transactivation of EGFR regulates COX (cyclo-oxygenase)-2 expression and PGE2 [PG (prostaglandin) E2] release through the transcriptional factor, C/EBPβ (CCAAT/enhancer-binding protein β), in HBEpCs. Treatment with LPA (1 μM) stimulated COX-2 mRNA and protein expression and PGE2 release via Gαi-coupled LPARs (LPA receptors). Pretreatment with inhibitors of NF-κB (nuclear factor-κB), JNK (Jun N-terminal kinase), or down-regulation of c-Jun or C/EBPβ with specific siRNA (small interference RNA) attenuated LPA-induced COX-2 expression. Downregulation of EGFR by siRNA or pretreatment with the EGFR tyrosine kinase inhibitor, AG1478, partly attenuated LPA-induced COX-2 expression and phosphorylation of C/EBPβ; however, neither of these factors had an effect on the NF-κB and JNK pathways. Furthermore, LPA-induced EGFR transactivation, phosphorylation of C/EBPβ and COX-2 expression were attenuated by overexpression of a catalytically inactive mutant of PLD2 [PLD (phospholipase D) 2], PLD2-K758R, or by addition of myristoylated PKCζ [PKC (protein kinase C) ζ] peptide pseudosubstrate. Overexpression of the PLD2-K758R mutant also attenuated LPA-induced phosphorylation and activation of PKCζ. These results demonstrate that LPA induces COX-2 expression and PGE2 production through EGFR transactivation-independent activation of transcriptional factors NF-κB and c-Jun, and EGFR transactivation-dependent activation of C/EBPβ in HBEpCs. Since COX-2 and PGE2 have been shown to be anti-inflammatory in airway inflammation, the present data suggest a modulating and protective role of LPA in regulating innate immunity and remodelling of the airways.
N-glycosylation analysis of the human Tweety family of putative chloride ion channels supports a penta-spanning membrane arrangement: impact of N-glycosylation on cellular processing of Tweety homologue 2 (TTYH2)
Authors: He Yaowu , Ramsay Andrew J. , Hunt Melanie L. , Whitbread Astrid K. , Myers Stephen A. , Hooper John D.
Published: April 2008

The Tweety proteins are a family of recently identified putative Cl− channels predicted to be modified by N-glycosylation and, controversially, to contain five or six membrane-spanning domains, leading to the contentious proposal that members of this family do not share the same topology at the plasma membrane. In humans, three family members have been identified, designated TTYH1 (Tweety homologue 1), TTYH2 and TTYH3. To gain greater insight into the arrangement of membrane-spanning domains and cellular processing of Tweety proteins, in the present study we have examined the sequence homology, hydrophobicity and N-glycan content of members of this family and performed N-glycosylation site-mutagenesis studies on TTYH2 and TTYH3. Based on these observations we propose a structure for Tweety family proteins which incorporates five membrane-spanning domains with a topology at the cell surface in which the N-terminus is located extracellularly and the C-terminus cytoplasmically. Our results also suggest that N-glycosylation is important, but not essential, in the processing of members of the Tweety family with results indicating that, although incomplete N-glycosylation mediates reduced expression and increased ubiquitination of TTYH2, N-glycosylation is not the determining factor for TTYH2 trafficking to the plasma membrane. This information will be important for the characterization of Tweety family proteins in normal physiology and disease.
Energization-dependent endogenous activation of proton conductance in skeletal muscle mitochondria
Authors: Parker Nadeene , Affourtit Charles , Vidal-Puig Antonio , Brand Martin D.
Published: April 2008

Leak of protons into the mitochondrial matrix during substrate oxidation partially uncouples electron transport from phosphorylation of ADP, but the functions and source of basal and inducible proton leak in vivo remain controversial. In the present study we describe an endogenous activation of proton conductance in mitochondria isolated from rat and mouse skeletal muscle following addition of respiratory substrate. This endogenous activation increased with time, required a high membrane potential and was diminished by high concentrations of serum albumin. Inhibition of this endogenous activation by GDP [classically considered specific for UCPs (uncoupling proteins)], carboxyatractylate and bongkrekate (considered specific for the adenine nucleotide translocase) was examined in skeletal muscle mitochondria from wild-type and Ucp3-knockout mice. Proton conductance through endogenously activated UCP3 was calculated as the difference in leak between mitochondria from wild-type and Ucp3-knockout mice, and was found to be inhibited by carboxyatractylate and bongkrekate, but not GDP. Proton conductance in mitochondria from Ucp3-knockout mice was strongly inhibited by carboxyatractylate, bongkrekate and partially by GDP. We conclude the following: (i) at high protonmotive force, an endogenously generated activator stimulates proton conductance catalysed partly by UCP3 and partly by the adenine nucleotide translocase; (ii) GDP is not a specific inhibitor of UCP3, but also inhibits proton translocation by the adenine nucleotide translocase; and (iii) the inhibition of UCP3 by carboxyatractylate and bongkrekate is likely to be indirect, acting through the adenine nucleotide translocase.
Intracellular copper deficiency increases amyloid-β secretion by diverse mechanisms
Authors: Cater Michael A. , McInnes Kelly T. , Li Qiao-Xin , Volitakis Irene , La Fontaine Sharon , Mercer Julian F. B. , Bush Ashley I.
Published: April 2008

In Alzheimer's disease there is abnormal brain copper distribution, with accumulation of copper in amyloid plaques and a deficiency of copper in neighbouring cells. Excess copper inhibits Aβ (amyloid β-peptide) production, but the effects of deficiency have not yet been determined. We therefore studied the effects of modulating intracellular copper levels on the processing of APP (amyloid precursor protein) and the production of Aβ. Human fibroblasts genetically disposed to copper accumulation secreted higher levels of sAPP (soluble APP ectodomain)α into their medium, whereas fibroblasts genetically manipulated to be profoundly copper deficient secreted predominantly sAPPβ and produced more amyloidogenic β-cleaved APP C-termini (C99). The level of Aβ secreted from copper-deficient fibroblasts was however regulated and limited by α-secretase cleavage. APP can be processed by both α- and β-secretase, as copper-deficient fibroblasts secreted sAPPβ exclusively, but produced primarily α-cleaved APP C-terminal fragments (C83). Copper deficiency also markedly reduced the steady-state level of APP mRNA whereas the APP protein level remained constant, indicating that copper deficiency may accelerate APP translation. Copper deficiency in human neuroblastoma cells significantly increased the level of Aβ secretion, but did not affect the cleavage of APP. Therefore copper deficiency markedly alters APP metabolism and can elevate Aβ secretion by either influencing APP cleavage or by inhibiting its degradation, with the mechanism dependent on cell type. Overall our results suggest that correcting brain copper imbalance represents a relevant therapeutic target for Alzheimer's disease.
Effect of sample size on deformation in amorphous metals
Authors: Volkert C. A. , Donohue A. , Spaepen F.
Published: April 2008

Uniaxial compression tests were performed on micron-sized columns of amorphous PdSi to investigate the effect of sample size on deformation behavior. Cylindrical columns with diameters between 8μm and 140nm were fabricated from sputtered amorphous Pd77Si23 films on Si substrates by focused ion beam machining and compression tests were performed with a nanoindenter outfitted with a flat diamond punch. The columns exhibited elastic behavior until they yielded by either shear band formation on a plane at 50° to the loading axis or by homogenous deformation. Shear band formation occurred only in columns with diameters larger than 400nm. The change in deformation mechanism from shear band formation to homogeneous deformation with decreasing column size is attributed to a required critical strained volume for shear band formation.
Electric field assisted dissolution of metal clusters in metal island films for photonic heterostructures
Authors: Sancho-Parramon J. , Janicki V. , Arbiol J. , Zorc H. , Peiro F.
Published: April 2008

The dissolution of metal clusters in metal island films by the simultaneous application of electric field and temperature is reported. The consequent fading of surface plasmon resonance greatly modifies the optical properties of the samples. The dissolution process is verified in island films of different metals, obtained under different conditions and covered by different dielectric materials, as well as on multilayer dielectric stacks showing interferential properties. The tailoring possibilities of the optical behavior of metal island films combined with the inexpensive technical requirements of this approach open up the possibility to produce low-cost photonic heterostructures.
Brownian dynamics simulations of polyelectrolyte adsorption in shear flow: Effects of solvent quality and charge patterning
Authors: Hoda Nazish , Kumar Satish
Published: April 2008

We probe the effects of solvent quality and charge patterning on polyelectrolyte adsorption in shear flow using Brownian dynamics simulations with hydrodynamic interaction (HI). The polyelectrolyte is modeled as a freely jointed bead-rod chain, and electrostatic and non-electrostatic interactions are accounted for by using screened Coulombic and Lennard-Jones potentials, respectively. In the absence of flow, the conformation of a polyelectrolyte molecule adsorbed onto a uniformly charged surface changes from flat to globular with an increase in bead-bead attraction (hydrophobicity), consistent with prior experimental observations. In the presence of flow, migration due to bead-wall HI and, as a consequence, desorption decrease with an increase in bead-bead attraction, implying that flow-induced desorption is more difficult under poor-solvent conditions. When bead-bead non-electrostatic attraction is strong, desorption can be enhanced by increasing bead-bead electrostatic repulsion. Analogous to the effect of bead-surface electrostatic attraction, an increase in the strength of bead-surface non-electrostatic attraction reduces desorption. We also study the effect of shear flow on the adsorption of a polyelectrolyte molecule onto surfaces decorated with periodic arrays of charged patches. An increase in patch periodicity increases desorption even when the effective surface charge density is kept the same. The results of this work suggest mechanisms for controlling the desorption of polyelectrolyte molecules in shear flows.
Study of the translational diffusion of the benzophenone ketyl radical in comparison with stable molecules in room temperature ionic liquids by transient grating spectroscopy
Authors: Nishiyama Y. , Fukuda M. , Terazima M. , Kimura Y.
Published: April 2008

Transient grating (TG) spectroscopy has been applied to the photoinduced hydrogen-abstraction reaction of benzophenone (BP) in various kinds of room temperature ionic liquids (RTILs). After the photoexcitation of BP in RTILs, the formation of a benzophenone ketyl radical (BPK) was confirmed by the transient absorption method, and the TG signal was analyzed to determine the diffusion coefficients of BPK and BP. For comparison, diffusion coefficients of carbon monoxide (CO), diphenylacetylene (DPA), and diphenylcyclopropenone (DPCP) in various RTILs were determined by the TG method using the photodissociation reaction of DPCP. While the diffusion coefficients of the stable molecules BP, DPA, and DPCP were always larger than those predicted by the Stokes–Einstein (SE) relation in RTILs, that of BPK was much smaller than those of the stable molecules and relatively close to that predicted by the SE relation in all solvents. For the smallest molecule CO, the deviation from the SE relation was evident. The diffusion coefficients of stable molecules are better represented by a power law of the inverse of the viscosity when the exponent was less than unity. The ratios of the diffusion coefficient of BP to that of BPK were larger in RTILs (2.7–4.0) than those (1.4–2.3) in conventional organic solvents. The slow diffusion of BPK in RTILs was discussed in terms of the fluctuation of the local electric field produced by the surrounding solvent ions.