bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and Biochemical Characterization of Two Novel Metagenome-Derived Esterases
Authors: Elend C. , Schmeisser C. , Leggewie C. , Babiak P. , Carballeira J. D. , Steele H. L. , Reymond J.-L. , Jaeger K.-E. , Streit W. R. 
Published: May 2006

ABSTRACT
The metagenomes of uncultured microbial communities are rich sources for novel biocatalysts. In this study, esterase EstA3 was derived from a drinking water metagenome, and esterase EstCE1 was derived from a soil metagenome. Both esterases are approximately 380 amino acids in size and show similarity to β-lactamases, indicating that they belong to family VIII of the lipases/esterases. EstA3 had a temperature optimum at 50°C and a pH optimum at pH 9.0. It was remarkably active and very stable in the presence of solvents and over a wide temperature and pH range. It is active in a multimeric form and displayed a high level of activity against a wide range of substrates including one secondary ester, 7-[3-octylcarboxy-(3-hydroxy-3-methyl-butyloxy)]-coumarin, which is normally unreactive. EstCE1 was active in the monomeric form and had a temperature optimum at 47°C and a pH optimum at pH 10. It exhibited the same level of stability as EstA3 over wide temperature and pH ranges and in the presence of dimethyl sulfoxide, isopropanol, and methanol. EstCE1 was highly enantioselective for (+)-menthylacetate. These enzymes display remarkable characteristics that cannot be related to the original environment from which they were derived. The high level of stability of these enzymes together with their unique substrate specificities make them highly useful for biotechnological applications.
Melatonin in Alzheimer's disease and other neurodegenerative disorders
Authors: Srinivasan V , Pandi-Perumal SR , Cardinali DP , Poeggeler B , Hardeland R 
Published: May 2006

Abstract
Increased oxidative stress and mitochondrial dysfunction have been identified as common pathophysiological phenomena associated with neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). As the age-related decline in the production of melatonin may contribute to increased levels of oxidative stress in the elderly, the role of this neuroprotective agent is attracting increasing attention. Melatonin has multiple actions as a regulator of antioxidant and prooxidant enzymes, radical scavenger and antagonist of mitochondrial radical formation. The ability of melatonin and its kynuramine metabolites to interact directly with the electron transport chain by increasing the electron flow and reducing electron leakage are unique features by which melatonin is able to increase the survival of neurons under enhanced oxidative stress. Moreover, antifibrillogenic actions have been demonstrated in vitro, also in the presence of profibrillogenic apoE4 or apoE3, and in vivo, in a transgenic mouse model. Amyloid-β toxicity is antagonized by melatonin and one of its kynuramine metabolites. Cytoskeletal disorganization and protein hyperphosphorylation, as induced in several cell-line models, have been attenuated by melatonin, effects comprising stress kinase downregulation and extending to neurotrophin expression. Various experimental models of AD, PD and HD indicate the usefulness of melatonin in antagonizing disease progression and/or mitigating some of the symptoms. Melatonin secretion has been found to be altered in AD and PD. Attempts to compensate for age- and disease-dependent melatonin deficiency have shown that administration of this compound can improve sleep efficiency in AD and PD and, to some extent, cognitive function in AD patients. Exogenous melatonin has also been reported to alleviate behavioral symptoms such as sundowning. Taken together, these findings suggest that melatonin, its analogues and kynuric metabolites may have potential value in prevention and treatment of AD and other neurodegenerative disorders.
Early intervention for relapse in schizophrenia: Impact of cognitive behavioural therapy on negative beliefs about psychosis and self‐esteem
Authors: Gumley Andrew , Karatzias Athanasios , Power Kevin , Reilly James , McNay Lisa , O'Grady Margaret 
Published: May 2006

Objectives. The study aimed to test two hypotheses. Firstly, that participants who relapsed during the 12‐month follow‐up period of our randomized controlled trial, would show increased negative beliefs about their illness and reduced self‐esteem, in comparison to the non‐relapsed participants. Secondly, that cognitive behavioural therapy (CBT) for early signs of relapse would result in a reduction in negative beliefs about psychosis and an improvement in self‐esteem at 12 months.Design and methods. A total of 144 participants with schizophrenia or a related disorder were randomized to receive either treatment as usual (TAU; N=72) or CBT (N=72). Participants completed the Personal Beliefs about Illness Questionnaire (PBIQ; Birchwood, Mason, MacMillan, & Healy, 1993) and the Rosenberg Self‐Esteem Scale (RSES; Rosenberg, 1965) at entry, 3 months, 6 months, and 12 months.Results. At 12 months, relapsers showed greater increase in scores for PBIQ entrapment compared with non‐relapsers. In addition, after controlling for baseline covariates (treatment group and PBIQ self versus illness), relapsers also showed greater increase in scores for PBIQ self versus illness at 12 months. Furthermore, in comparison to treatment as usual, participants who received CBT showed greater improvement in PBIQ loss and in Rosenberg self‐esteem.Conclusions. The study provides evidence that relapse is associated with the development of negative appraisals of entrapment and self‐blame (self vs. illness). In addition, this is the first study to show that CBT reduces negative appraisals of loss arising from psychosis and improvements in self‐esteem. Implications for future research and treatment are discussed.
Risk factors for psychological distress following injury
Authors: Mason S. , Turpin G. , Woods D. , Wardrope J. , Rowlands A. 
Published: May 2006

Objectives.To identify predictors of psychological morbidity among injured patients admitted to an Emergency Department (ED).Design.A prospective cohort study.Participants.Participants were consecutive male ED attenders. 210 (97.7%) patients consented to participate. At one month, 128 (61.0%) responded, at six months, 114 (54.3%), at eighteen months 96 (45.7%).Main outcome measures.Measures immediately following injury were the Hospital Anxiety and Depression Scale, the Eysenck Personality Questionnaire and the McGill pain questionnaire. Recovery at one month was recorded using the SF‐36 Health Survey, COPE scale, Perceived Stress Scale and Revised Impact of Events Scale. At six and eighteen months outcome was measured using the General Health Questionnaire (28 items) and Revised Impact of Events Scale. Multivariate analysis identified pre‐morbid, accident‐related and recovery factors influencing outcome at six and eighteen months.Results.The strongest predictors of outcome were initial levels of anxiety and depression, prior history of mental health problems, early PTSD symptoms and involvement in litigation. These factors predicted between 40–60% of the variance at six months (p<0.001), and 50–60% of the variance in psychological distress at eighteen months (p<0.001).Conclusion.Factors identifying individuals at‐risk from psychological distress following injury include those related to the immediate response and the recovery phases of injury. Further development is needed to convert identified predictors into a comprehensive screening tool for clinical use.
Thermal transitions in polyimide transfer under sliding against steel, investigated by Raman spectroscopy and thermal analysis
Authors: Samyn P. , De Baets P. , Van Craenenbroeck J. , Verpoort F. , Schoukens G. 
Published: May 2006

AbstractPolyimides (PI) are known for their extremely high thermal stability and lack of a glass transition temperature below their decomposition point. Therefore, they are frequently used in high‐demanding tribological applications. The tribological characteristics of sintered polyimide (SP‐1) are presently investigated as a function of the sliding temperature that is artificially varied between 60°C and 260°C under fixed load in counterformal contact with a steel plate. For obtaining low friction and wear, a transfer film needs to develop onto the sliding counterface, induced by viscous polymer flow. As surface plastification is more difficult for high‐performance materials, for example, polyimide, a transition towards low friction and stabilized wear rates is observed at temperatures higher than 180°C in accordance with the occurrence of plate‐like transfer particles, while high friction and no transfer was observed at lower temperatures. This transition is correlated to a peak value in both friction and wear at 180°C and is further explained by Raman spectroscopy performed on the worn polymer surfaces and temperature‐modulated differential scanning calorimetry. It is concluded that the intensity of C‐N‐C related absorption bands is minimal at 180°C and is complementary to the intensity of the CC phenylene structure that is maximal at 180°C. The orientation of the C‐O‐C structure slightly decreases relative to the sliding surface at higher bulk temperatures. The amount of CO functional groups is the lowest at 140°C, while its orientation progressively enhances at higher bulk temperatures. At 140°C also, the lowest wear rates were measured. The 180°C transition temperature with a peak value in both friction and wear corresponds to a secondary transition measured in the specific complex heat capacity, pointing out that the overall bulk temperature is presently more important than local flash temperatures for causing transitions in tribological behavior. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1407–1425, 2006
Development of the upper lip: Morphogenetic and molecular mechanisms
Authors: Jiang Rulang , Bush Jeffrey O. , Lidral Andrew C. 
Published: May 2006

AbstractA sample of gene expression patterns in mouse craniofacial development. Show (starting upper left and proceeding clockwise) are Wnt9b, Fgf8, Bmp4 and Msx2. See Jiang et al., Developmental Dynamics, 235:1152–1166. © 2006 Wiley‐Liss, Inc.
CHLORORESPIRATORY REDUCTION 6 Is a Novel Factor Required for Accumulation of the Chloroplast NAD(P)H Dehydrogenase Complex in Arabidopsis
Authors: Munshi M. Kamruzzaman , Kobayashi Yoshichika , Shikanai Toshiharu 
Published: April 2006

Abstract
The chloroplast NAD(P)H dehydrogenase (NDH) complex is involved in photosystem I cyclic electron transport and chlororespiration in higher plants. An Arabidopsis (Arabidopsis thaliana) chlororespiratory reduction 6 (crr6) mutant lacking NDH activity was identified by means of chlorophyll fluorescence imaging. Accumulation of the NDH complex was impaired in crr6. Physiological characterization of photosynthetic electron transport indicated the specific defect of the NDH complex in crr6. In contrast to the CRR7 protein that was recently identified as a potential novel subunit of the NDH complex by means of the same screening, the CRR6 protein was stable under the crr2 mutant background in which the NDH complex does not accumulate. The CRR6 gene (At2g47910) encodes a novel protein without any known motif. Although CRR6 does not have any transmembrane domains, it is localized in the thylakoid membrane fraction of the chloroplast. CRR6 is conserved in phototrophs, including cyanobacteria, from which the chloroplast NDH complex has evolutionally originated, but not in Chlamydomonas reinhardtii, in which the NDH complex is absent. We believe that CRR6 is a novel specific factor for the assembly or stabilization of the NDH complex.
PetuniaPhospholipase C1 Is Involved in Pollen Tube Growth
Authors: Dowd Peter E. , Coursol Sylvie , Skirpan Andrea L. , Kao Teh-hui , Gilroy Simon 
Published: April 2006

AbstractAlthough pollen tube growth is essential for plant fertilization and reproductive success, the regulators of the actin-related growth machinery and the cytosolic Ca2+ gradient thought to determine how these cells elongate remain poorly defined. Phospholipases, their substrates, and their phospholipid turnover products have been proposed as such regulators; however, the relevant phospholipase(s) have not been characterized. Therefore, we cloned cDNA for a pollen-expressed phosphatidylinositol 4,5-bisphosphate (PtdInsP2)–cleaving phospholipase C (PLC) from Petunia inflata, named Pet PLC1. Expressing a catalytically inactive form of Pet PLC1 in pollen tubes caused expansion of the apical Ca2+ gradient, disruption of the organization of the actin cytoskeleton, and delocalization of growth at the tube tip. These phenotypes were suppressed by depolymerizing actin with low concentrations of latrunculin B, suggesting that a critical site of action of Pet PLC1 is in regulating actin structure at the growing tip. A green fluorescent protein (GFP) fusion to Pet PLC1 caused enrichment in regions of the apical plasma membrane not undergoing rapid expansion, whereas a GFP fusion to the PtdInsP2 binding domain of mammalian PLC Δ1 caused enrichment in apical regions depleted in PLC. Thus, Pet PLC1 appears to be involved in the machinery that restricts growth to the very apex of the elongating pollen tube, likely through its regulatory action on PtdInsP2 distribution within the cell.
Responses of apple leaf stomata: a model for single leaves and a whole tree
Authors: THORPE M. R. , WARRIT B. , LANDSBERG J. J. 
Published: April 2006

Abstract. An empirical model of stomatal response to environmental factors was developed from measurements of stomatal conductance (gs) made in a leaf chamber under controlled conditions. Results presented in a companion paper (Warrit, Landsberg & Thorpe, 1980) indicated that the model could be written in terms of only two factors, photon flux density (Qp) and leaf to air vapour pressure gradient (D). The response of Qp was hyperbolic and that to D linear; combining these the equation of the model is

image

where gr is a reference conductance, α is the slope of the response to D and β indicates the sensitivity of gs response to Qp. Values of α were 0.20 and 0.30 kPa−1 in June and August; the corresponding values of β were 59 and 79 μmol m−2 s−1.The model was tested against mean values of gs obtained with a porometer in the field, using environmental measurements as inputs. Correspondence between measured and calculated values was good. Transpiration rates were calculated from the Penman‐Monteith equation, with stomatal resistance values calculated from the model, and compared with gravimetric measurements of tree water use. It was shown that transpiration could be calculated with acceptable accuracy. The effects of variations in stomatal resistance on transpiration rates under a range of conditions were explored using the model and the Penman‐ Monteith equation.
Root nodule anatomy, type of export product and evolutionary origin in some Leguminosae
Authors: SPRENT J. I. , EMBRAPA  
Published: April 2006

Abstract. The tribe Phaseoleae, of the sub‐family Papi‐lionoideae of the Leguminosae shows distinct differences from the tribes Vicieae and Trifolieae in nodule morphology and anatomy. Nodules of the Phaseoleae have determinate growth as, at maturity, the vascular strands fuse at the apex forming, effectively, a closed loop of the root stele. Nodules of the Vicieae and Trifolieae have an apical meristem, hence indeterminate growth; one or more branches of the root stele enter and dichotomise within the nodule, new elements are differentiated in relation to nodule growth, and the fine branches are free at the apical end of the nodule. Nodules of the Vicieae and Trifolieae additionally have vascular transfer cells and vacuolate infected cells, and the rhizobial bacteroids are pleomorphic.The principal export products of nitrogen fixing nodules of the Phaseoleae are the ureides allantoin and allantoic acid, whilst those of the Vicieae and Trifolieae are amides and amino acids, especially glutamine and asparagine. The advantages and disadvantages of these export products are discussed in the light of nodular vascular anatomy and in respect of the tropical/subtropical origin of the Phaseoleae and the temperate origin of the Vicieae and Trifolieae.
Relationship of dehydration rate to drought avoidance, dehydration tolerance and dehydration avoidance of cabbage leaves, and to their acclimation during drought‐induced water stress*
Authors: LEVITT J. 
Published: April 2006

Abstract. Drought avoidance due to cuticular control increases with leaf number to a maximum in the intermediate leaves, decreasing to a minimum in the upper leaves. Dehydrated intermediate leaves do not rehydrate detectably when floated on water for several days. Excision of their petioles when submerged, permits full rehydration, presumably via the xylem. Stressing the plant by withholding water for 1–3 weeks fails to increase this already high resistance to water movement through the leaf surface. It does, however, markedly decrease the loss of water from the fully rehydrated (100% RWC) leaves during the first hour of dehydration, presumably due to a more rapid stomatal closure than in the non‐stressed leaves.Dehydration tolerance increases with leaf number, without an intermediate maximum. The intermediate and upper leaves were markedly more tolerant of dehydration after drought‐induced stress than when non‐stressed. Dehydration tolerance in some cases, was inversely proportional to dehydration rate. It was possible, however, to equalize the rates of dehydration of drought‐stressed and non‐drought‐stressed leaves without affecting the greater tolerance of the drought‐stressed leaves.Dehydration avoidance by osmotic adjustment was markedly developed in the slowly dehydrated attached leaves of drought‐stressed plants, but not in the rapidly dehydrated excised leaves. This is evidence of drought acclimation. It must, therefore, be concluded that the slow dehydration of the drought‐stressed plants also leads to the increase in dehydration tolerance by permitting drought‐induced acclimation.The overall drought resistance of cabbage leaves depends on the three components: drought avoidance, dehydration avoidance and dehydration tolerance. The latter two increase during acclimation but the cuticular control of drought avoidance does not.
The evolution of educational inequalities in smoking: a changing relationship and a cross‐over effect among German birth cohorts of 1921–70
Authors: Schulze Alexander , Mons Ute 
Published: May 2006

ABSTRACTAims  To investigate the evolution of the relationship between education and smoking behaviour (ever‐smoking and age of initiation) among German birth cohorts of 1921–70.Participants  A total of 5297 respondents to the German Federal Health Survey of 1998 were divided into 10‐year sex–birth–education cohorts.Measurements  Self‐reported smoking histories (ever‐smoking and the age of starting smoking). Findings  There was an inversion of the educational gradient around the birth cohorts of 1931–40 for men and 1941–50 for women. For men, the educational cross‐over in smoking was due to a stronger decrease of the ever‐smoking prevalence of the highly educated compared to the least educated. In women it was due to a stronger increase in ever‐smoking prevalence among the least educated compared to the highly educated. This educational cross‐over effect was also be detected for the average age of starting smoking, and involved the same cohorts. Additionally, in the youngest birth cohorts the differences between the least and highest educated of each gender were greater than the differences between the genders.Conclusions  The educational differences in smoking prevalence are stable in men but in women they are widening. Hence, socio‐economic inequalities in health due to smoking will rise in women in the next decades, while they will stabilize in men.
Review article: uncomplicated diverticular disease of the colon
Authors: PETRUZZIELLO L. , IACOPINI F. , BULAJIC M. , SHAH S. , COSTAMAGNA G. 
Published: April 2006

SummaryDiverticular disease of the colon is the fifth most important gastrointestinal disease in terms of direct and indirect healthcare costs in western countries. Uncomplicated diverticular disease is defined as the presence of diverticula in the absence of complications such as perforation, fistula, obstruction and/or bleeding. The distribution of diverticula along the colon varies worldwide being almost always left‐sided and directly related to age in western countries and right‐sided where diet is rich in fibre.The pathophysiology of diverticular disease is complex and relates to abnormal colonic motility, changes in the colonic wall, chronic mucosal low‐grade inflammation, imbalance in colonic microflora and visceral hypersensitivity. Moreover, there can be genetic factors involved in the development of colonic diverticula.The use of non‐absorbable antibiotics is the mainstay of therapy in patients with mild to moderate symptoms, and the effect of fibre‐supplementation alone does not appear to be significantly different from placebo, although no definite data are available.More recently, alternative treatments have been reported. Mesalazine acts as a local mucosal immunomodulator and has been shown to improve symptoms and prevent recurrence of diverticulitis. In addition, probiotics have also been shown to be beneficial by re‐establishing a normal gut microflora. In this study, the current literature on uncomplicated diverticular disease of the colon is reviewed.
Class switch recombination in selective IgA-deficient subjects
Authors: Hummelshoj L , Ryder L P , Nielsen L K , Nielsen C H , Poulsen L K 
Published: April 2006

SummarySelective IgA deficiency is a common immunodeficiency in Caucasians, but the molecular basis of the disorder remains elusive. To address this issue we examined the molecular events leading to IgA production. Naive IgD positive B cells were purified from four donors with IgA deficiency and four control donors, all Caucasians. Stimulation of B cells from IgA-deficient donors with the cytokines transforming growth factor (TGF)-β, interferon (IFN)-γ or interleukin (IL)-10 in the presence of anti-CD40 antibodies showed reduced expression of both activation-induced cytidine deaminase (AID) and α germline transcripts (GLT) compared to controls. It was possible, however, to induce AID and α GLT when stimulating the cells with anti-CD40 antibody and TGF-β in the combination with IL-10. Moreover, in anti-CD40 antibody-stimulated cultures, addition of IL-10 or IL-10 + TGF-β in combination, induced IgA production, albeit lower than found in B cells from controls. The B cells from the IgA-deficient subjects were less effective in differentiating into CD138+ X-box binding protein 1 (XBP-1)+ plasma cells when stimulated with TGF-β, IFN-γ or IL-10. Interestingly, when adding IL-4 to TGF-β alone or in combination with IL-10, the immunoglobulin production in B cells from IgA-deficient donors was comparable with those of normal controls. These data show that in healthy subjects in vitro IgA production can be up-regulated by addition of IL-10 to CD40-stimulated B cells, whereas a similar B cell differentiation does not occur in IgA-deficient subjects. Addition of IL-4, however, reverts this abnormality.