bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of provisioning in grey-headed albatrosses (Thalassarche chrysostoma): do adults respond to chick condition?
Authors: Phillips Richard A , Croxall John P
Published: February 2003

Recent studies have been equivocal in determining whether long-lived seabirds are able to respond to chick nutritional status and regulate provisioning rates accordingly. With some exceptions, albatrosses and petrels that feed their chicks every 13 days seem able to respond to variability in chick condition. In contrast, those with longer overall feeding periodicity and that frequently show a dual foraging strategy, mixing short trips (which most benefit the chick) with longer, pelagic feeding excursions (during which time adults recover lost condition), tend not to regulate provisioning. We used a combined observational and experimental approach to determine whether feeding rates in grey-headed albatrosses (Thalassarche chrysostoma) were determined by parental foraging proficiency and (or) offspring demand. The results indicated that both factors were important. Adults showed consistent differences in provisioning characteristics, but chick satiation and solicitation also influenced the mass of the meal delivered when adults returned. Given a provisioning schedule characterised by relatively frequent colony visits and with no means of assessing the feeding success of their partner in the interim, the adjustment of meal mass upon arrival appears to be a simple means of tailoring prey delivery to changing chick requirements and is likely to be as effective as alternative strategies suggested for other species of Procellariiform.
Determinants of social rank in female black-capped chickadees (Poecile atricapilla)
Authors: Ramsay Scott M , Ratcliffe Laurene M
Published: February 2003

Black-capped chickadees (Poecile atricapilla) mate assortatively by social rank. Previous field studies suggest that intrinsic characteristics of females may influence success at pairing with dominant males. Here we examined factors leading to dominance using dyads of captive unfamiliar females. The ownerintruder hypothesis predicts that prior residency determines dominantsubordinate relationships. The resource-value hypothesis suggests that social status is initially determined by need and the relationship persists through familiarity of the interactants. The resource holding potential hypothesis suggests that individuals win in dyadic contests because of intrinsic characteristics such as size or age. We tested the ownerintruder and resource-value hypotheses by allowing females prior residency in aviaries where dominance interactions subsequently occurred and by food depriving the intruders. Post-hoc comparisons of dominantsubordinate attributes tested the resource holding potential hypothesis. We found that owners were more likely to win interactions. Hungry individuals showed no competitive advantage. Dominants and subordinates did not differ in morphology or age. Our results agree with data from willow tits (Parus montanus) which show that captive females establish dominance independent of males and that prior residence plays a key role. These findings, together with field studies, suggest that assortative mating in chickadees results, at least in part, from intrasexual interactions among females.
Sensory impairment and mental health
Authors: du Feu Margaret , Fergusson Kenneth
Published: February 2003

Sensory impairment is often regarded from a medical/disability point of view and its effects on mental health can be poorly recognised. Communication is a key issue for deaf and deaf–blind people and difficulties here underlie developmental, psychological and emotional problems and delay or prevent appropriate assessment and treatment. Children may have additional problems associated with the cause of their sensory impairment and need early multi-disciplinary intervention. Emotional and practical support is needed for families to make fully informed choices. Those with and without sensory impairment need the same access to mental health services and this is particularly difficult to achieve for deaf and deaf–blind people. Local and specialist teams need to work together to implement the National Service Framework for this vulnerable patient group.
Cross-cultural differences in the epidemiology of unexplained fatigue syndromes in primary care
Authors: Skapinakis Petros , Lewis Glyn , Mavreas Venetsanos
Published: February 2003

Background

Unexplained fatigue has been extensively studied but most of the samples used were from Western countries.

Aims

To present international data on the prevalence of unexplained fatigue and fatigue as a presenting complaint in primary care.

Method

Secondary analysis of the World Health Organization study of psychological problems in general health care. A total of 5438 primary care attenders from 14 countries were assessed with the Composite International Diagnostic Interview.

Results

The prevalence of unexplained fatigue of 1-month duration differed across centres, with a range between 2.26 (95% CI 1.17–4.33) and 15.05 (95% CI 10.85–20.49). Subjects from more-developed countries were more likely to report unexplained fatigue but less likely to present with fatigue to physicians compared with subjects from less developed countries.

Conclusions

In less-developed countries fatigue might be an indicator of unmet psychiatric need, but in more-developed countries it is probably a symbol of psychosocial distress.
Diffusion of H2O in Smectite Gels: Obstruction Effects of Bound H2O Layers
Authors: Nakashima Yoshito
Published: February 2003

In water-rich smectite gels, bound or less mobile H2O layers exist near negatively-charged clay platelets. These bound H2O layers are obstacles to the diffusion of unbound H2O molecules in the porespace, and therefore reduce the H2O self-diffusion coefficient, D, in the gel system as a whole. In this study, the self-diffusion coefficients of H2O molecules in water-rich gels of Na-rich smectites (montmorillonite, stevensite and hectorite) were measured by pulsed-gradient spin-echo proton nuclear magnetic resonance (NMR) to evaluate the effects of obstruction on D. The NMR results were interpreted using random-walk computer simulations which show that unbound H2O diffuses in the gels while avoiding randomly-placed obstacles (clay platelets sandwiched in immobilized bound H2O layers). A ratio (volume of the clay platelets and immobilized H2O layers)/(volume of clay platelets) was estimated for each water-rich gel. The results showed that the ratio was 8.92, 16.9, 3.32, 3.73 and 3.92 for Wyoming montmorillonite (⩽ 5.74 wt.% clay), Tsukinuno montmorillonite (⩽ 3.73 wt.% clay), synthetic stevensite (⩽ 8.97 wt.% clay), and two synthetic hectorite samples (⩽ 11.0 wt.% clay), respectively. The ratios suggest that the thickness of the immobilized H2O layers in the gels is 4.0, 8.0, 1.2, 1.4 and 1.5 nm, respectively, assuming that each clay particle in the gels consists of a single 1 nm-thick platelet. The present study confirmed that the obstruction effects of immobilized H2O layers near the clay surfaces are important in restricting the self-diffusion of unbound H2O in water-rich smectite gels.
Exchangeable Ion and Thermal Treatment Effects on Basal Spacings of Al-Hydroxy Pillared Montmorillonites
Authors: Reis Aluísio Sousa , Ardisson José Domingos
Published: February 2003

Al-hydroxy intercalated clays (ALHICs) obtained from different parent clays were used to investigate the interactions between oligomers and clay surface layers.

The thermal stability of ALHICs obtained from natural, Cs-, Ca-, Ba-, Fe-, Cu- or Ce-montmorillonites has been investigated by studying the relationship between basal spacing and calcination temperature. X-ray diffraction has shown that the basal spacing of ALHICs obtained from Cu-montmorillonite calcined at 550°C is 13.4 Å, different from basal spacings of ALHICs obtained from Fe-montmorillonite (16.0 Å) and other parent clays (16.7 Å). Thermograms for AlHICs obtained from natural, Fe- and Ce-montmorillonites displayed distinct steps at 225 and 650°C, attributed to the dehydration of Al13 oligomers, and the dehydroxylation of the surface layer, respectively. By contrast, thermograms of ALHICs obtained from Cu-montmorillonite displayed one step between 250 and 700°C for both dehydration and dehydroxylation. Mössbauer parameters showed that Fe3+ octahedra in octahedral sheets are distorted in pillared interlayered clay (PILC) obtained from Cu-montmorillonite and undistorted in that obtained from Fe-montmorillonite. The difference in thermal stability for the various ALHICs is attributed to the retention of some of the original cations after intercalation with Al13 oligomers, which induces several interactions between the oligomers and the clay surface layers.
Preparation and Characterization of Ti-Pillared Clays Using Ti Alkoxides. Influence of the Synthesis Parameters
Authors: Valverde José Luis , Sánchez Paula , Dorado Fernando , Asencio Isaac , Romero Amaya
Published: February 2003

Titanium was introduced into the clay structure by cation exchange with polymeric Ti cations which were formed by partial hydrolysis of Ti alkoxide in HCl. X-ray diffraction, N2 adsorption-desorption, chemical analysis, thermogravimetric analysis, differential thermal analysis, temperature-programmed desorption of ammonia and temperature-programmed reduction were used to characterize the resulting Ti-pillared clays (Ti-PILCs). Titanium methoxide allows the synthesis of a solid with a large basal spacing (26 Å), a large surface area (360 m2/g), a significant amount of micropore surface area (90%), and notable acidity. Moreover, Ti-PILCs obtained from methoxide were found to be thermally stable up to 500°C. A correlation between the increase in acidity and the increases in both microporosity and Ti content was observed. The surface area, the micropore volume, the acidity and the d001 peak intensity all increased upon increasing the amount of Ti added to the preparation (up to ∼15 mmoles of Ti/g clay). The use of an aqueous suspension of 0.13 wt.% of clay yielded the best structural and textural properties in terms of subsequent use of the clay as a catalyst.
Loss of K-Bearing Clay Minerals in Flood-Irrigated, Rice-Growing Soils in Jiangxi Province, China
Authors: Li Zhongpei , Velde B. , Li Decheng
Published: February 2003

The loss of K-bearing clay minerals has been observed over an 80 y cultivation period in Chinese rice paddies despite the use of NKP fertilizers. Clay mineral determinations were made in flood-irrigated paddies cultivated for 3, 10, 15, 30 and 80 y in clayey (45 wt.%), red soils derived from red Quaternary sediments. Three clay minerals are initially present in these soils: illite-mica, magnesian chlorite and an interstratified mica-aluminous chlorite mineral. This last phase was identified using computer simulations. The K-bearing phases (discrete mica and illite as well as interstratified mica layers) are to a large extent lost while the Fe content decreases in the soil as a whole and increases in the chlorite. The mica component in the mixed-layer mineral decreases also. These changes in clay mineralogy and relative abundance suggest a loss of potassic minerals and an increase in the formation of less siliceous, more ferro-magnesian chlorite. These changes occur over 30 y or less, a rather rapid, irreversible transformation of soil clay minerals. Such loss of potassic minerals renders the cultivation more dependent on fertilizer amendment.
Does the cognitive interview help children to resist the effects of suggestive questioning?
Authors: Milne Rebecca , Bull Ray
Published: February 2003

Purpose. The first set of aims of the present study concerned event recall and examined; (1) whether the cognitive interview (CI) would enhance event recall when used with children, (2) which category(ies) of event recall might be affected, and (3) where in the interview any CI effect emanates from. The second set of aims concerned suggestibility issues and set out to determine whether (1) the CI increased the resistance of children to suggestive questions, and (2) whether scripts had a role in susceptibility to suggestion.

Methods. Eighty‐four 8‐10‐year‐old children were shown a video recording of a magic show. A day later they were interviewed individually using either the CI or a structured interview. A pre‐set list of suggestive questions was also given to the children either before or after being interviewed.

Results. Those children interviewed using the CI recalled significantly more correct details pertaining to persons and actions, with no increase in the reporting of erroneous information. These effects were found to emanate from the questioning phase of the CI. In addition, those children interviewed with the CI were more resistant to subsequently asked suggestive questions, especially misleading script‐consistent questions.

Conclusions. The CI has been found to be a reliable interviewing technique which not only enhances recall but helps to inoculate children against the effects of misleading questions.
Personality traits, personality disorders and sensational interests in mentally disordered offenders
Authors: Egan Vincent , Austin Elizabeth , Elliot Debbie , Patel Darshana , Charlesworth Phillip
Published: February 2003

Purpose. Sensational interests (e.g. an interest in the occult or the methods of violence) in mentally disordered offenders are claimed to signify greater risk of psychopathology, but evidence to support this view is slight.

Methods. The relationships between self‐reported DSM‐IV personality disorder (PD), general personality traits and sensational interests were examined in 155 of 167 consecutively referred offenders to a forensic psychology service. The subscales of the PD and personality trait measures were reduced to the four basic PD/trait dimensions (asocial, antisocial, anxious and anankastic) using confirmatory factor analysis.

Results. Those high on the ‘antisocial’ factor (which was primarily defined by low Agreeableness, low Conscientiousness, and substantial elements of Paranoid, Antisocial and Borderline PD) were more interested in ‘violent‐occult’ and militaristic topics.

Conclusions. The aspects of the antisocial factor primarily associated with an interest in sensational and potentially violent topics cover a wide range of putative disorders. However, the factors reflecting asocial, anxious or anankastic disorders do not show a reliable association with measures of sensational interests. These results suggest that the personality dimensions reflecting an interest in ‘sensational’ topics in mentally disordered offenders are relatively specific.
Measuring the real impact of accredited offending behaviour programmes
Authors: Friendship Caroline , Falshaw Louise , Beech Anthony R.
Published: February 2003

Purpose. This paper describes an integrated model for the evaluation of offending behaviour programmes in order to assess their real impact.

Arguments. To date there has been an over‐reliance on reconviction data as the sole measure of treatment efficacy. Reconviction has a fundamental role to play but cannot be considered in isolation from other empirically related treatment and re‐settlement factors. A rigorous reconviction study requires an adequate comparison group but few papers describe with transparency how this has been achieved. There is also the assumption that participation in treatment renders an individual offender as treated. A treated profile is contingent upon the treatment climate, the quality of programme delivery and how the individual responds to treatment. The influence of life‐style or dynamic risk factors must also be acknowledged in terms of their effect on reconviction.

Conclusions. It is recommended that researchers use an integrated approach to the evaluation of accredited offending behaviour programmes. In order to establish a broad balance of treatment outcomes, a shift away from reconviction rates is needed. This paper presents an integrated model for the evaluation of offending behaviour programmes.
Two new species of Mycobilimbia from Spain
Authors: Sarrión Francisco José , Aragón Gregorio , Hafellner Josef , Rico Victor J. , Burgaz Ana Rosa
Published: February 2003

Two new species of Mycobilimbia are described from Spain. Mycobilimbia olwacea has a minutely squamulose and olivaceous thalli and dark reddish brown apothecia, colourless inside; it has been found at middle to high altitudes (from 900 to 1750 m), growing on humid tree bases of Pinus nigra and lignum of Quercus pyrenaica. Mycobilimbia parvilobulosa is closely related to M. berengeriana, but differs markedly by its squamulose thalli, with crenate to subdigitiform margins, dark reddish brown excipulum and colourless epithecium. It grows on moss-covered old trunks of fagaceous trees. The new taxa are compared with M. berengeriana, M. hypnorum and M. sanguineoatra and their main distinguishing characters are tabulated.
Heparin‐like dextran derivatives as well as glycosaminoglycans inhibit the enzymatic activity of human cathepsin G
Authors: Ledoux Dominique , Merciris Didier , Barritault Denis , Caruelle Jean-Pierre
Published: February 2003

Some synthetic dextran derivatives that mimic the action of heparin/heparan sulfate were previously shown to inhibit neutrophil elastase and plasmin. Here we report that these derivatized dextrans also inhibit cathepsin G (CatG). Dextran containing carboxymethyl and benzylamide groups (RG1150) as well as those containing carboxymethyl, sulfate and benzylamide groups (RG1192), were the most efficient inhibitors of CatG activity. RG1192 and RG1150 bind CatG with a K
i of 0.11 and 0.17 nM, respectively, while carboxymethylated sulfated dextran (RG1503) as well as heparin, heparan sulfate and dermatan sulfate bind CatG with a 7‐ to 30‐fold lower affinity. Variation of K
i with ionic strength indicates that ionic interactions account for 26% of the RG1503–CatG binding energy, while binding of RG1192 or RG1150 to CatG is mainly governed by non‐electrostatic interactions. This, together with the fact that these compounds both protect fibronectin and laminin against CatG‐mediated degradation, suggest that specific dextran derivatives can contribute to the regulation of CatG activity.
Identification of key regions within the Escherichia coli TatAB subunits
Authors: Barrett Claire M.L. , Mathers Joanne E. , Robinson Colin
Published: February 2003

The twin‐arginine translocation (Tat) system catalyzes the transport of folded proteins across the bacterial plasma membrane or the chloroplast thylakoid membrane. In Escherichia coli and most other species, three important tat genes have been identified but the structure and mechanism of this system are poorly understood; the role and location of TatA are particularly unclear. In this report we have used site‐specific mutagenesis to probe the significance of conserved features of the related TatA/B subunits. We find that an apparent ‘hinge’ region between the transmembrane (TM) span and an adjacent amphipathic region is important in both proteins, in that substitution of turn‐inducing residues inhibits the export of a natural Tat substrate. Surprisingly, large‐scale mutagenesis of the conserved amphipathic regions of TatA and TatB leads only to minor effects on Tat‐dependent export suggesting that this particular feature is not central to the translocation mechanism. This domain is, however, critical for the translocation process and we identify Gly/Pro residues in these regions of TatA/B that are essential for efficient export.
The pp60c‐Src inhibitor PP1 is non‐competitive against ATP
Authors: Karni Rotem , Mizrachi Sarit , Reiss-Sklan Ella , Gazit Aviv , Livnah Oded , Levitzki Alexander
Published: February 2003

Glutathione‐S‐transferase (GST)‐pp60c‐Src (GST‐Src) expressed in Escherichia coli is as catalytically active as purified, activated pp60c‐Src protein derived from human platelets. We utilized the bacterially expressed enzyme, together with information about the structures of Src family kinases in complex with their inhibitors PP1 and PP2, to modify PP1 in a quest for improved inhibitors. Despite the detailed structural information on Hck‐PP1 and Lck‐PP2 complexes, which shows that PP1 and PP2 bind to the adenosine triphosphate (ATP) pocket, we were unable to improve the affinity between modified PP1 and Src. Puzzled, we examined in detail the mechanism by which PP1 inhibits the kinase activity of Src. Here we report that PP1 is non‐competitive with ATP for the inhibition of Src, at variance with what is currently accepted, and is a ‘mixed competitive inhibitor’ vis‐à‐vis the substrate. These findings shed new light on the mechanism whereby PP1‐like molecules inhibit Src. Examination of the homology between the kinase domain of Src and those of Hck and Lck reveals significant differences outside the ATP binding pocket, whereas they are identical within the ATP binding domain. These results suggest that PP1 may be a leading compound for ATP non‐competitive inhibitors of Src family kinases. Since Src in its active form is the hallmark of numerous cancers, understanding how PP1 inhibits activated Src will aid in the discovery of potent and selective Src kinase inhibitors.
Oxidized glutathione stimulated the amyloid formation of α‐synuclein
Authors: Paik Seung R. , Lee Daekyun , Cho Hyun-Ju , Lee Eui-Nam , Chang Chung-Soon
Published: February 2003

α‐Synuclein is the major filamentous constituent of Lewy bodies found in Parkinson's disease (PD). The amyloid formation of α‐synuclein was significantly facilitated by oxidized glutathione (GSSG) as the lag period of the aggregation kinetics was shortened by 2.5‐fold from its absence. Reduced glutathione (GSH), on the other hand, did not influence the lag phase although it increased the final amyloid formation. The GSSG stimulation was specific for not only α‐synuclein but also its intactness. The preferred GSSG interaction of α‐synuclein to GSH was also demonstrated with dissociation constants of 0.53 and 43.5 mM, respectively. It is suggested that the oxidative stress favoring the GSSG generation from GSH could result in the augmented amyloid formation of α‐synuclein, which ought to be related to the pathogenesis of PD.
Crystal structure of GGA2 VHS domain and its implication in plasticity in the ligand binding pocket
Authors: Zhu Guangyu , He Xiangyuan , Zhai Peng , Terzyan Simon , Tang Jordan , Zhang Xuejun C.
Published: February 2003

Golgi‐localized, γ‐ear‐containing, ARF binding (GGA) proteins regulate intracellular vesicle transport by recognizing sorting signals on the cargo surface in the initial step of the budding process. The VHS (VPS27, Hrs, and STAM) domain of GGA binds with the signal peptides. Here, a crystal structure of the VHS domain of GGA2 is reported at 2.2 Å resolution, which permits a direct comparison with that of homologous proteins, GGA1 and GGA3. Significant structural difference is present in the loop between helices 6 and 7, which forms part of the ligand binding pocket. Intrinsic fluorescence spectroscopic study indicates that this loop undergoes a conformational change upon ligand binding. Thus, the current structure suggests that a conformational change induced by ligand binding occurs in this part of the ligand pocket.
Concurrent increase of cholesterol, sphingomyelin and glucosylceramide in the spleen from non‐neurologic Niemann–Pick type C patients but also patients possibly affected with other lipid trafficking disorders
Authors: Harzer Klaus , Massenkeil Gero , Fröhlich Eckhart
Published: February 2003

Niemann–Pick type C disease (NPC) is a neurovisceral (or, extremely rarely, only visceral) lipidosis caused by mutations in the NPC1 gene or, in a few patients, the HE1 gene, which encode sterol regulating proteins. NPC is characterised by a complex lipid anomaly including a disturbed cellular trafficking of cholesterol but also multi‐lipid storage in visceral organs and brain. Lipids were studied using conventional methods in enlarged spleens that had been removed from five patients for different therapeutic and diagnostic reasons and found to have microscopic signs of lysosomal storage disease not suspected clinically. The spleen lipid findings with a concurrent accumulation of cholesterol, sphingomyelin and glucosylceramide (Acc‐CSG) allowed us to suggest NPC diagnoses for these patients, who were free of neurologic symptoms. From two patients no material for confirmatory studies was available, but in two other patients NPC diagnoses could be confirmed with the filipin cytochemical cholesterol assay and NPC1 gene analysis, respectively. However, these tests and also HE1 gene analysis were negative in a third patient. Since the Acc‐CSG lipid pattern seems to indicate a multi‐lipid trafficking defect rather than being highly specific for NPC, this patient, if not affected with very atypical NPC, may be a candidate for a different lipid trafficking disorder. The Acc‐CSG pattern was considered to be similar to the lipid pattern known for the lipid rafts, these functional cell structures being probably disorganised and accumulated in late endosomes and lysosomes of NPC cells.
Proteomic identification of divalent metal cation binding proteins in plant mitochondria
Authors: Herald V.L. , Heazlewood J.L. , Day D.A. , Millar A.H.
Published: February 2003

Divalent metal binding proteins in the Arabidopsis mitochondrial proteome were analysed by mobility shifts in the presence of divalent cations during two‐dimensional diagonal sodium dodecyl sulphate–polyacrylamide gel electrophoresis. Tandem mass spectrometry and searches of the predicted Arabidopsis protein dataset were used in an attempt to identify 34 of the proteins which shifted. This analysis identified a total of 23 distinct protein spots as the products of at least 11 different Arabidopsis genes. A series of proteins known to be divalent cation‐binding proteins, or to catalyse divalent cation‐dependent reactions, were identified. These included: succinyl CoA ligase β subunit, Mn‐superoxide dismutase (SOD), an Fe–S centred component of complex I and the REISKE iron–sulphur protein of the b/c1 complex. A further set of four proteins of known function but without known divalent binding properties were also identified: the Vb subunit of cytochrome c oxidase, a subunit of ATP synthase (orfB), the acyl carrier protein, and the translocase of the outer membrane (TOM20). Three other proteins, of unknown function, were also found to shift in the presence of divalent cations. This approach has broad application for the identification of sub‐proteomes based on the metal interaction of polypeptides.
Further enhancement of baculovirus insecticidal efficacy with scorpion toxins that interact cooperatively
Authors: Regev Avital , Rivkin Hadassah , Inceoglu Bora , Gershburg Eduard , Hammock Bruce D. , Gurevitz Michael , Chejanovsky Nor
Published: February 2003

We have studied whether the cooperative insecticidal effect of certain scorpion toxin pairs, namely either a combination of excitatory and depressant, or alpha and depressant scorpion toxins, would improve the efficacy of Autographa californica nucleopolyhedrovirus (AcMNPV) over a virus expressing only a single toxin, towards Heliothis virescens, Helicoverpa armigera, and Spodoptera littoralis larvae. The best result was achieved by combined expression of the excitatory toxin, LqhIT1, and the depressant toxin, LqhIT2, that provided an ET50 value of 46.9 h on H. virescens neonates, an improvement of 40% over the efficacy of wild‐type AcMNPV, and of 18% and 22% over baculoviruses that express each of the toxins independently. These results demonstrate that significant improvement in efficacy of recombinant baculoviruses is obtainable with toxins that exhibit a cooperative effect, and may contribute to employ baculoviruses to replace hazardous chemicals in insect control.
Perturbation of protein kinase CK2 uncouples executive part of phosphate maintenance pathway from cyclin‐CDK control1
Authors: Barz Thomas , Ackermann Karin , Pyerin Walter
Published: February 2003

The budding yeast Saccharomyces cerevisiae encounters phosphate starvation by the transcription‐regulated PHO pathway. We find that genetic perturbation of protein kinase CK2, a conserved tetrameric Ser/Thr phosphotransferase with links to cell cycle and transcription, affects expression of PHO pathway genes in a subunit‐ and isoform‐specific manner. Remarkably, the genes encoding phosphate supplying phosphatases and transporters are significantly repressed, while the genes encoding components of the central pathway regulator complex, a cyclin‐dependent kinase (CDK), a cyclin, and a CDK inhibitor, remain unaltered. Thus, perturbation of CK2 uncouples the executive part of the PHO pathway from its cyclin‐CDK control complex.
Preproinsulin mRNA engineering and its application to the regulation of insulin secretion from human hepatomas
Authors: Tang Shiue-Cheng , Sambanis Athanassios
Published: February 2003

Cell‐based therapies for treating insulin‐dependent diabetes (IDD) can provide a more physiologic regulation of blood glucose levels in a less invasive fashion than daily insulin injections. Promising cells include non‐β cells genetically engineered to secrete insulin in response to physiologic cues; responsiveness can be introduced at the transcriptional level to regulate preproinsulin (PPI) mRNA biosynthesis. However, these cells exhibit sluggish secretion dynamics, which is not appropriate for achieving euglycemia in higher animals and, eventually, humans. In this work, we have engineered the PPI mRNA so as to destabilize it through nonsense‐mediated mRNA decay (NMD). When expressed under transcriptional regulation in HepG2 hepatomas, the engineered PPI mRNA level and of the insulin secretion rate declined faster upon switching off transcription, compared to the one‐copy non‐engineered control. Our work provides a simple and straightforward method to improve the dynamics of transcriptionally regulated insulin secretion, which can be a useful tool in developing cell‐based therapies for IDD.
Endocytosis and intracellular transport of ricin: recent discoveries
Authors: Sandvig Kirsten , van Deurs Bo
Published: February 2003

The plant toxin ricin has proven valuable as a membrane marker in studies of endocytosis as well as studies of different intracellular transport steps. The toxin, which consists of two polypeptide chains, binds by one chain (the B‐chain) to both glycolipids and glycoproteins with terminal galactose at the cell surface. The other chain (the A‐chain) enters the cytosol and inhibits protein synthesis enzymatically. After binding the toxin is endocytosed by different mechanisms, and it is transported via endosomes to the Golgi apparatus and the endoplasmic reticulum before translocation of the A‐chain to the cytosol. The different transport steps have been analyzed by studying trafficking of ricin as well as modified ricin molecules.
Mitochondrial assembly in yeast
Authors: Grivell Les A , Artal-Sanz Marta , Hakkaart Gertjan , de Jong Liesbeth , Nijtmans Leo G.J , van Oosterum Katinka , Siep Michel , van der Spek Hans
Published: February 2003

The yeast Saccharomyces cerevisiae is likely to be the first organism for which a complete inventory of mitochondrial proteins and their functions can be drawn up. A survey of the 340 or so proteins currently known to be localised in yeast mitochondria reveals the considerable investment required to maintain the organelle's own genetic system, which itself contributes seven key components of the electron transport chain. Translation and respiratory complex assembly are particularly expensive processes, together requiring around 150 of the proteins so far known. Recent developments in both areas are reviewed and approaches to the identification of novel mitochondrial proteins are discussed.
Nuclear RNA export in yeast
Authors: Sträßer Katja , Hurt Ed
Published: February 2003

Eukaryotic cells massively exchange macromolecules (proteins and RNAs) between the nucleus and cytoplasm through the nuclear pore complexes. Whereas a mechanistic picture emerges of how proteins are imported into and exported from the nucleus, less is known about nuclear exit of the different classes of RNAs. However, the yeast Saccharomyces cerevisiae offers an experimental system to study nuclear RNA export in vivo and thus to genetically dissect the different RNA export machineries. In this review, we summarize our current knowledge and recent progress in identifying components involved in nuclear RNA export in yeast.
Lipid signaling in CD95‐mediated apoptosis
Authors: Malisan Florence , Testi Roberto
Published: February 2003

Ceramides play an important role mediating different cell responses such as proliferation, differentiation, growth arrest and apoptosis. They are released upon sphingomyelin hydrolysis which occurs after triggering of a number of cell surface receptors including CD95. Ceramide generation also regulates glycosphingolipid and ganglioside metabolism. In particular, ganglioside GD3 biosynthesis represents an important event for the progression of apoptotic signals generated by CD95 and mediated by ceramide in hematopoietic cells.
Plant genomics
Authors: Terryn Nancy , Rouzé Pierre , Van Montagu Marc
Published: February 2003

The rapidity with which genomic sequences of the model plant Arabidopsis thaliana and soon of rice are becoming available has strongly boosted plant molecular biology research. Here, two main genomic fields will be discussed: the progress in different structural genome projects, such as mapping, sequencing, genome organization and comparative genomics, and the so‐called functional genomics approaches to analyze the genome using such molecular tools as transcript profiling, micro‐arrays, and insertional mutagenesis. In addition a section on bioinformatics is included.
First trimester sonographic diagnosis of holoprosencephaly
Authors: Tongsong T. , Wanapirak C. , Chanprapaph P. , Siriangkul S.
Published: February 2003

Objective: To describe our experience with sonographic diagnosis of fetal holoprosencephaly in first trimester. Subjects: A total of three fetuses with early prenatal diagnosis of holoprosencephaly were sonographically evaluated and followed up. Results: The study revealed that all showed monoventricular cavity, fused thalami, no falx and cavum septum pellucidum. All of them were correctly diagnosed sonographically in the first trimester. Extracranial anomalies had also been identified in all three fetuses and all of them had facial abnormalities. Cytogenetic studies were successfully carried out in only one case. No polyhydramnios was demonstrated in all cases. Conclusion: This small series indicates that holoprosencephaly can be diagnosed in the first trimester. The most valuable clue to the diagnosis is the demonstration of the single ventricle.
Preoperative ultrasound assessment of adnexal masses in premenopausal women
Authors: Milad M.P. , Cohen L.
Published: February 2003

Objectives: This study was undertaken to determine the accuracy of preoperative transvaginal ultrasound in predicting ovarian histopathology in premenopausal women. Methods: A retrospective cohort study was performed from reproductive‐age women that underwent removal of an ovarian cyst between May 1990 and April 1998. Results: Of the 120 consecutive patients identified, 19 did not meet inclusion criteria. Pathologic diagnosis confirmed endometriomas (n=55), mature teratoma (n=25), serous cystadenoma (n=18), persistent corpus luteum (n=7) and other (n=5). The primary preoperative transvaginal ultrasound impression was accurate in most cases (endometrioma: 85%, mature teratoma: 86%, serous cystadenoma: 80%). Conclusion: Endometriomas and mature cystic teratomas can be predicted with a moderate degree of accuracy by preoperative ultrasound.
Information processing biases among chronic pain patients and ankylosing spondylitis patients: the impact of diagnosis
Authors: Wells Heather J , Pincus Tamar , McWilliams Elaine
Published: February 2003

The aim of this research was to explore the impact that diagnostic status has on information processing biases among chronic pain (CP) and ankylosing spondylitis (AS) patients. AS patients, CP patients, and healthy hospital staff controls, completed a questionnaire and short computer task. During the computer task participants endorsed sensory, depression, illness, and neutral adjectives, following a cue question (which facilitated encoding of the adjectives in relation to the self). They were then asked to recall the adjectives in a surprise memory task. Diagnosed CP patients demonstrated a recall bias away from depression related stimuli, whilst the non‐diagnosed CP patients did not. The results also suggest an association between receipt of a diagnosis and better psychological outcome in terms of information processing biasing. It was questioned whether the presence of a diagnosis among CP patients who are not currently depressed may protect or ‘buffer’ them against cognitive biasing towards classic depression related stimuli. The diagnosed AS group showed a bias towards sensory stimuli, perhaps reflecting the presence of an enduring and over‐riding pain schema. The non‐pain control group also displayed a sensory bias, which was attributed to a frequency effect as a result of working in an environment where they were regularly exposed to sensory language. The results are discussed in relation to existing literature in this area and implications for clinical practice are provided.
Epidural ketamine potentiates epidural morphine but not fentanyl in acute nociception in rats
Authors: Hoffmann Vincent L.H , Baker Alexis K , Vercauteren Marcel P , Adriaensen Hugo F , Meert Theo F
Published: February 2003

Epidural opioids have been reported to provide superior analgesia in acute pain management. Despite the fact that the required doses are low, major side effects such as respiratory depression may still occur. In an effort to maximize analgesia and to minimize the rate of side effects, epidural NMDA receptor antagonists, especially ketamine, may be co‐administered with opioids. This study investigated whether ketamine had beneficial effects on fentanyl‐ or morphine‐induced antinociception in an acute pain model in rats.

In male Wistar rats, an epidural catheter was placed under general anaesthesia. After 1 week the animals were subjected to the tail withdrawal reaction (TWR) test. After determination of the basal reaction latencies, fentanyl, morphine, ketamine or combinations of an opioid with ketamine were administered epidurally. TWR latencies were measured for up to 2 h after treatment.

Both opioids showed a dose related antinociceptive effect. Fentanyl had a fast onset and a short duration of action whereas the reverse was true for morphine. Ketamine exhibited only limited antinociceptive properties. In the combinations, ketamine improved morphine‐induced antinociception both in terms of maximal possible effect (MPE) as well as in duration of action. The combination of fentanyl with ketamine did not result in any improvement, neither in terms of MPE nor in duration of action. Moreover, increasing doses of ketamine tended to decrease the MPE of various doses of fentanyl. These data confirm that ketamine, contrary to opioids, does not possess important antinociceptive properties in an acute test such as the TWR test. Furthermore, these data indicate that additive drugs such as ketamine may have different effects on different opioids.
Antinociceptive effect in mice of intraperitoneal N‐methyl‐d‐aspartate receptor antagonists in the formalin test
Authors: Berrino Liberato , Oliva Patrizia , Massimo Francesco , Aurilio Caterina , Maione Sabatino , Grella Antonio , Rossi Francesco
Published: February 2003

Although the antinociceptive effect of NMDA antagonists in the formalin test is well recognised, these compounds can induce adverse motor effects. The aim of this study was to identify the systemic doses of NMDA antagonists that induce analgesia without causing side effects. Male Swiss mice (30–40 g) received a subcutaneous (sc) injection of 1.25% formalin () in the dorsal surface of the right hind‐paw and, 15 min before or after formalin, an ip injection of one of the following NMDA receptor antagonists: MK 801 (0.01, 0.025, and 0.05 mg/kg), memantine (0.1, 0.5, and 1 mg/kg), ketamine (0.125, 0.25, and 0.5 mg/kg), dextromethorphan (5, 10, and 20 mg/kg), and CGP 37849 (4, 6, and 8 mg/kg). Pain‐related behaviour (licking, lifting, favouring, shaking, and flinching of the treated paw) was recorded at 5‐min intervals for 60 min. The NMDA receptor antagonists significantly (p<0.01) and dose‐dependently reduced, versus controls, nociceptive activity during the second phase of the formalin test (from the 20th to the 60th min): at the highest doses, 97.6±0.1% with MK 801; 90.4±0.2% with memantine; 74.7±0.3% with ketamine; 92.8±0.4% with dextromethorphan; and 80.7±0.3% with CGP 37849, without affecting coordination. The rank order potency of antinociceptive activity of NMDA antagonists was: . The NMDA antagonists administered after formalin (during the analgesic interval) did not affect the late phase of the formalin test. In conclusion, systemic administration of NMDA receptor antagonists decreases the nociception observed during the late phase of the formalin test.
Psychophysics of phasic and tonic heat pain stimuli by quantitative sensory testing in healthy subjects
Authors: Granot Michal , Sprecher Elliot , Yarnitsky David
Published: February 2003

The increased use of quantitative sensory testing in the study of pain raises the need to characterize various aspects of psychophysical response to noxious stimulation in healthy subjects. The present study aims to address several issues regarding the use of heat pain stimuli: (a) Are pain scores for short‐term repeated phasic stimuli consistent? (b) Does an exposure to tonic heat pain stimulus cause sensitization and change the scores for subsequent phasic stimuli? and (c) Are pain scores for phasic and tonic heat pain correlated? To address these questions, a series of four phasic heat pain stimuli of 47 °C were given to the forearms of 70 healthy volunteers, over the course of an hour. Pain scores by Visual Analog Scale (VAS) were obtained for each stimulus. In 50 subjects, a tonic heat pain of 70 s duration at 47.5 °C was given between the first and second phasic stimuli. Pain scores were obtained at four points along this tonic stimulus. Repeated measures ANOVA and a sensitive post hoc analysis indicated that, while the pain perception was reduced on the second, nearly immediate trial, subsequent VAS scores of pain perception were not different from the first (#1: 35.2±19.2; #2: 31.4±20.2, #3: 33.0±21.6; and #4: 33.2±20.1, respectively), with strong correlation among the phasic tests. The average tonic pain score was 53.7±23.1. Administration of tonic pain stimuli did not result in different VAS scores of subsequent phasic pain stimuli, compared to those subjects who did not receive tonic pain stimuli. Tonic and phasic pain were positively correlated (e.g., for the first phasic stimuli). However, no relation was found between the level of perceived pain, either for phasic or for tonic stimuli, and presence or absence of temporal summation during the tonic pain. In conclusion: (i) phasic pain scores assessments at 30′ and 60′ after baseline is consistent; (ii) tonic heat pain, despite relatively high VAS scores, does not cause a change in the scoring of subsequent phasic stimuli; and (iii) phasic and tonic pain scores correlate with each other. Thus, the normal pattern of pain perception is stable and not altered by single tonic pain stimulation.
A single gene that promotes interaction of a phytopathogenic bacterium with its insect vector, Drosophila melanogaster
Authors: Basset Alan , Tzou Phoebe , Lemaitre Bruno , Boccard Frédéric
Published: February 2003

Insects are major vectors of plant and animal disease, and bacterial phytopathogens are often disseminated by flies. We have previously reported that some isolates of the phytopathogenic bacterial species Erwinia carotovora infect Drosophila and activate an immune response. Using a genetic screen, we have now identified two genes that are required by E. carotovora to infect Drosophila. One of these genes has a regulatory role whereas the other, evf, confers an infectious phenotype: its transfer to non‐infectious Erwinia strains or to several enterobacteria improves survival in the gut and triggers the immune response. Overexpression of Erwinia virulence factor(evf) allowed bacteria to colonize the apical side of the gut epithelium and in some cases to spread to the body cavity. Our results demonstrate a specific interaction between plant pathogens and flies that promote their dissemination.
Identification of short ‘eukaryotic’ Okazaki fragments synthesized from a prokaryotic replication origin
Authors: Matsunaga Fujihiko , Norais Cédric , Forterre Patrick , Myllykallio Hannu
Published: February 2003

Although archaeal genomes encode proteins similar to eukaryotic replication factors, the hyperthermophilic archaeon Pyrococcus abyssi replicates its circular chromosome at a high rate from a single origin (oriC) as in Bacteria. In further elucidating the mechanism of archaeal DNA replication, we have studied the elongation step of DNA replication in vivo. We have detected, in two main archaeal phyla, short RNA‐primed replication intermediates whose structure and length are very similar to those of eukaryotic Okazaki fragments. Mapping of replication initiation points further showed that discontinuous DNA replication in P. abyssi starts at a well‐defined site within the oriC recently identified in this hyperthermophile. Short Okazaki fragments and a high replication speed imply a very efficient turnover of Okazaki fragments in Archaea. Archaea therefore have a unique replication system showing mechanistic similarities to both Bacteria and Eukarya.
Distinct macroscopic structures developed from solutions of chemical compounds and periodic proteins
Authors: Shiba Kiyotaka , Honma Takako , Minamisawa Tamiko , Nishiguchi Keiichi , Noda Tetsuo
Published: February 2003

By controlling the growth of inorganic crystals, macro‐biomolecules, including proteins, play pivotal roles in modulating biomineralization. Natural proteins that promote biomineralization are often composed of simple repeats of peptide sequences; however, the relationship between these repetitive structures and their functions remains largely unknown. Here we show that an artificial protein containing a repeated peptide sequence allows NaCl, KCl, CuSO4and sucrose to form a variety of macroscopic structures, as represented by their dendritic configurations. Mutational analyses revealed that the physicochemical characteristics of the protein, not the peptide sequenceper se, were responsible for formation of the dendritic structures. This suggests that proteins that modulate crystal growth may have evolved as repeat‐containing forms at a relatively high rate. These observations could serve as the basis for developing new genetic programming systems for creation of artificial proteins able to modulate crystal growth from inorganic compounds, and may thus provide a new tool for nano‐biotechnology.
Synchronization of time-continuous chaotic oscillators
Authors: Yanchuk Sergiy , Maistrenko Yuri , Mosekilde Erik
Published: February 2003

Considering a system of two coupled identical chaotic oscillators, the paper first establishes the conditions of transverse stability for the fully synchronized chaotic state. Periodic orbit threshold theory is applied to determine the bifurcations through which low-periodic orbits embedded in the fully synchronized state lose their transverse stability, and the appearance of globally and locally riddled basins of attraction is discussed, respectively, in terms of the subcritical, supercritical nature of the riddling bifurcations. We show how the introduction of a small parameter mismatch between the interacting chaotic oscillators causes a shift of the synchronization manifold. The presence of a coupling asymmetry is found to lead to further modifications of the destabilization process. Finally, the paper considers the problem of partial synchronization in a system of four coupled Rössler oscillators.