bluuebunny/crossref_metadata_2025 huggingface dataset:
The Arabidopsis thaliana Dihydroxyacetone Phosphate Reductase Gene SUPPRESSOR OF FATTY ACID DESATURASE DEFICIENCY1 Is Required for Glycerolipid Metabolism and for the Activation of Systemic Acquired Resistance[W]
Authors: Nandi Ashis , Welti Ruth , Shah Jyoti
Published: February 2004

Systemic acquired resistance (SAR) is a broad-spectrum resistance mechanism in plants that is activated in naive organs after exposure of another organ to a necrotizing pathogen. The organs manifesting SAR exhibit an increase in levels of salicylic acid (SA) and expression of the PATHOGENESIS-RELATED1 (PR1) gene. SA signaling is required for the manifestation of SAR. We demonstrate here that the Arabidopsis thaliana suppressor of fatty acid desaturase deficiency1 (sfd1) mutation compromises the SAR-conferred enhanced resistance to Pseudomonas syringae pv maculicola. In addition, the sfd1 mutation diminished the SAR-associated accumulation of elevated levels of SA and PR1 gene transcript in the distal leaves of plants previously exposed to an avirulent pathogen. However, the basal resistance to virulent and avirulent strains of P. syringae and the accumulation of elevated levels of SA and PR1 gene transcript in the pathogen-inoculated leaves of sfd1 were not compromised. Furthermore, the application of the SA functional analog benzothiadiazole enhanced disease resistance in the sfd1 mutant plants. SFD1 encodes a putative dihydroxyacetone phosphate (DHAP) reductase, which complemented the glycerol-3-phosphate auxotrophy of the DHAP reductase–deficient Escherichia coli gpsA mutant. Plastid glycerolipid composition was altered in the sfd1 mutant plant, suggesting that SFD1 is involved in lipid metabolism and that an SFD1 product lipid(s) is important for the activation of SAR.
The WRKY70 Transcription Factor: A Node of Convergence for Jasmonate-Mediated and Salicylate-Mediated Signals in Plant Defense[W]
Authors: Li Jing , Brader Günter , Palva E. Tapio
Published: February 2004

Cross talk between salicylic acid (SA)– and jasmonic acid (JA)–dependent defense signaling has been well documented in plants, but how this cross talk is executed and the components involved remain to be elucidated. We demonstrate that the plant-specific transcription factor WRKY70 is a common component in SA- and JA-mediated signal pathways. Expression of WRKY70 is activated by SA and repressed by JA. The early induction of WRKY70 by SA is NPR1-independent, but functional NPR1 is required for full-scale induction. Epistasis analysis suggested that WRKY70 is downstream of NPR1 in an SA-dependent signal pathway. Modulation of WRKY70 transcript levels by constitutive overexpression increases resistance to virulent pathogens and results in constitutive expression of SA-induced pathogenesis-related genes. Conversely, antisense suppression of WRKY70 activates JA-responsive/COI1-dependent genes. The effect of WRKY70 is not caused by subsequent changes in SA or JA levels. We suggest that WRKY70 acts as an activator of SA-induced genes and a repressor of JA-responsive genes, integrating signals from these mutually antagonistic pathways.
TheArabidopsis thaliana ABSCISIC ACID-INSENSITIVE8Locus Encodes a Novel Protein Mediating Abscisic Acid and Sugar Responses Essential for Growth[W]
Authors: Brocard-Gifford Inès , Lynch Tim J. , Garcia M. Emily , Malhotra Bhupinder , Finkelstein Ruth R.
Published: February 2004

Abscisic acid (ABA) regulates many aspects of plant growth and development, yet many ABA response mutants present only subtle phenotypic defects, especially in the absence of stress. By contrast, the ABA-insensitive8 (abi8) mutant, isolated on the basis of ABA-resistant germination, also displays severely stunted growth, defective stomatal regulation, altered ABA-responsive gene expression, delayed flowering, and male sterility. The stunted growth of the mutant is not rescued by gibberellin, brassinosteroid, or indoleacetic acid application and is not attributable to excessive ethylene response, but supplementing the medium with Glc improves viability and root growth. In addition to exhibiting Glc-dependent growth, reflecting decreased expression of sugar-mobilizing enzymes, abi8 mutants are resistant to Glc levels that induce developmental arrest of wild-type seedlings. Studies of genetic interactions demonstrate that ABA hypersensitivity conferred by the ABA-hypersensitive1 mutation or overexpression of ABI3 or ABI5 does not suppress the dwarfing and Glc dependence caused by abi8 but partially suppresses ABA-resistant germination. By contrast, the ABA-resistant germination of abi8 is epistatic to the hypersensitivity caused by ethylene-insensitive2 (ein2) and ein3 mutations, yet ABI8 appears to act in a distinct Glc response pathway from these EIN loci. ABI8 encodes a protein with no domains of known function but belongs to a small plant-specific protein family. Database searches indicate that it is allelic to two dwarf mutants, elongation defective1 and kobito1, previously shown to disrupt cell elongation, cellulose synthesis, vascular differentiation, and root meristem maintenance. The cell wall defects appear to be a secondary effect of the mutations because Glc treatment restores root growth and vascular differentiation but not cell elongation. Although the ABI8 transcript accumulates in all tested plant organs in both wild-type and ABA response mutants, an ABI8-β-glucuronidase fusion protein is localized primarily to the elongation zone of roots, suggesting substantial post-transcriptional regulation of ABI8 accumulation. This localization pattern is sufficient to complement the mutation, indicating that ABI8 acts either at very low concentrations or over long distances within the plant body.
A classification of mobile business models and its applications
Authors: Seong Leem Choon , Sik Suh Hyung , Seong Kim Dae
Published: February 2004

Although there have been a lot of studies on mobile business, it is hard to find ones in which an integrated perspective of mobile business based on both customers’ and companies’ needs is suggested. This research develops a mobile business model classification scheme and applies it to analysis of current status in mobile business. In the first case study on 65 firms in Korea, mobile solutions are categorized based on the classification scheme in order to analyze an overall market environment of mobile business. In the second case study on mobile service trend analysis, a set of evaluation indices including four general indices, ten effectiveness indices and 13 measurement indices were developed to analyze mobile service environment in the perspective of B2C (business to customer). For the second case study, 200 mobile heavy users were questioned on the mobile service‐related issues.
Service failure and recovery: evidence from the hotel industry
Authors: Lewis Barbara R. , McCann Pamela
Published: February 2004

This paper is focused on service failure and recovery in the hotel industry in the UK. The objectives of the research were to: assess the types and magnitude of service failures experienced by hotel guests; evaluate the service recovery strategies used by hotels and their effectiveness; and discover whether or not there were differences in attitudes and behaviour between business and leisure guests. Data were collected from a sample of guests in a four‐star hotel. Discussion of the findings leads to some suggestions for improvements for hotel management.
Retarded protein folding of deficient human α1‐antitrypsin D256V and L41P variants
Authors: Jung Chan‐Hun , Na Yu‐Ran , Im Hana
Published: February 2004

α1‐Antitrypsin is the most abundant protease inhibitor in plasma and is the archetype of the serine protease inhibitor superfamily. Genetic variants of human α1‐antitrypsin are associated with early‐onset emphysema and liver cirrhosis. However, the detailed molecular mechanism for the pathogenicity of most variant α1‐antitrypsin molecules is not known. Here we examined the structural basis of a dozen deficient α1‐antitrypsin variants. Unlike most α1‐antitrypsin variants, which were unstable, D256V and L41P variants exhibited extremely retarded protein folding as compared with the wild‐type molecule. Once folded, however, the stability and inhibitory activity of these variant proteins were comparable to those of the wild‐type molecule. Retarded protein folding may promote protein aggregation by allowing the accumulation of aggregation‐prone folding intermediates. Repeated observations of retarded protein folding indicate that it is an important mechanism causing α1‐antitrypsin deficiency by variant molecules, which have to fold into the metastable native form to be functional.
Family Leave Policies and Labor Market Segregation in Germany: Reinvention or Reform of the Male Breadwinner Model?1
Authors: GOTTSCHALL KARIN , BIRD KATHERINE
Published: February 2004

abstract The historically dominant male breadwinner and female carer model in West Germany has resulted in comparably low female employment rates and a gender‐structured labor market. Since the 1970s, the decline of traditional patterns and sectors of male employment has been accompanied by the expansion of the female‐dominated service sector. Supplemented by women's higher educational attainment, a pluralism of household forms, and German unification, the result has been constant growth in female employment. With more working mothers, the question of combining work and family has provoked policy responses that, in West Germany, have mainly centered on family leave policies. In addressing the question of whether these policies have resulted in a more equitable sharing of paid and family work, this article presents longitudinal empirical data on the working patterns of women entitled to different forms of family leave. These show how changing regulations have led to the institutionalization of a “baby break” for younger women and to the promotion of labor market exclusion.
Women's and Men's Access to Employer‐Provided Benefits: An Assessment of Women's Acceptance as Breadwinners
Authors: BERGGREN HEIDI M.
Published: February 2004

abstractThis article asks whether the rising number of women in the paid labor force over the last half‐century has been accompanied by a parallel trend of increased recognition of a breadwinning status for women, or if traditional role conceptions have persisted in spite of women's changed economic and social circumstances. I theorize that employer‐provided benefits are a unique form of compensation that, by helping parents balance work and family, directly affect parents in their capacities as breadwinners. As such, assessing women's and men's access to these benefits over the period of women's rising labor force participation can be very revealing of the acceptance of women as breadwinners. To acquire a general picture of women's and men's access to employer‐provided benefits, I compare access to benefits from 1940 to 1990 in a modal women's occupation (“professional nurses”) to a modal men's occupation (“automobile mechanics and repairmen”). Through the studied time span, these occupations are the largest comparably sized women's and men's occupations that are also similar in pay level and extent of unionization. This allows me to control for pay level and unionization, important alternative explanations for women's restricted access to benefits. I hypothesize that nurses have had more restricted access to employer‐provided benefits than have auto mechanics. I find a disadvantage for nurses relative to auto mechanics through most of the time period, which nonetheless diminishes and then reverses slightly at the end. Taking into consideration subtleties, as well as patterns masked in the data as presented, these findings suggest at best a rather slow rate of acceptance of a breadwinning status for women, and at worst, a continuation of traditional gender norms.
Parasites in marine protected areas: success and specificity of monogeneans
Authors: Sasal P. , Desdevises Y. , Durieux E. , Lenfant P. , Romans P.
Published: February 2004

The effect of a marine protected area on the Lamellodiscus spp. monogenean community was tested by comparing the communities of parasites of Diplodus sargus inside and outside of the area. A total of 104 D. sargus were dissected harbouring 1280 monogeneans from the genus Lamellodiscus and belonging to 11 species. No modification in the global parasite community linked with the protection of the host populations was revealed. The most abundant and less specific parasite species, Lamellodiscus elegans, however, increased its abundance in the protected area. A significant relationship was found between parasite host range and the percentage of infected hosts. A significant relationship also occurred between epidemiological and genetic distances for the parasite species found. The results are discussed in term of parasite success and specificity and the importance of taking into account parasitism in the biological conservation of hosts.
Ovarian morphology of the Japanese eel in Mikawa Bay
Authors: Utoh T. , Mikawa N. , Okamura A. , Yamada Y. , Tanaka S. , Horie N. , Akazawa A. , Oka H. P.
Published: February 2004

Annual changes in gonadal maturation of female Japanese eel Anguilla japonica in sea water were investigated histologically over 5 years in the Mikawa Bay, Japan, where they occurred throughout the year except in March. Almost all immature Japanese eels (yellow eels) occurred mainly from April to September, and they were rare after November. In contrast, maturing Japanese eels (silver eels) occurred from October to February. The gonado‐somatic index (IG) and oocyte diameters of yellow eels were <1·0 and 150 μm, respectively, and oocytes were at the peri‐nucleolus or the oil droplet stages. The IG and oocyte diameters of silver eels were greater than those of yellow eels and most oocytes developed to the primary yolk globule stage. The numbers of silver eels lacking oocytes at the primary yolk globule stage increased after January in Mikawa Bay, although IG and oocyte diameters remained unchanged. In contrast, silver eels caught at the mouth of the bay in January possessed oocytes that had advanced to the secondary yolk globule stage. These observations indicate that oocyte development changes seasonally, especially after winter in Mikawa Bay.
Distribution and morphology of the sea lamprey from the Balkan coast of the Adriatic Sea
Authors: Holčík J. , Delić A. , Kučinić M. , Bukvić V. , Vater M.
Published: February 2004

In contrast to the Apennine Peninsula coast, the relatively rare occurrence of sea lampreys Petromyzon marinus in the Balkan Peninsula (eastern coast of the Adriatic Sea) is probably due to the closeness of the steep mountains causing unsuitable hydrological conditions of streams and impeded access to the coast. Most specimens are probably represented by invaders carried from the Mediterranean and other regions of the Adriatic Sea. Morphology was similar to that recorded for the sea lampreys from other geographical regions.
Read All About It! Understanding the Role of Media in Economic Development
Authors: Coyne Christopher J. , Leeson Peter T.
Published: February 2004

This paper explores the role of media in economic development. In particular, we seek to outline the conditions under which the media contributes to the successful adoption of policies aimed at economic progress. Our core thesis is that successful economic development requires the coordination of efforts by politicians with the interests of the populace on policies that bring about economic growth. However, the nature of the relationship between political actors in charge of reform is characterized by a conflict of interests. The role of media as a key mechanism for transforming these situations of conflict into situations of coordination between politicians and the populace is analyzed. Specifically, we consider four factors — media autonomy, legal structure, quality of the media and consumer demand — and how they impact media as a coordination‐enhancing mechanism.

Historical examples of the media in developing countries provide further insight into the circumstances necessary for media to be an effective coordination‐enhancing mechanism. We consider the impact of a free media in cases where successful economic development has occurred — Hungary and Poland. We also consider the Ukraine as a case where media has failed to overcome the conflict characterizing the reform process, and Bulgaria as a situation where politicians and the populace have failed to coordinate around ‘good’ reforms despite having a free media. Our paper concludes with some policy recommendations regarding the achievement of a free and effective media.
The Institutional Determinants of Bilateral Trade Patterns
Authors: De Groot Henri L. F. , Linders Gert‐Jan , Rietveld Piet , Subramanian Uma
Published: February 2004

This paper studies the effect of institutions on trade flows, using a gravity model approach. Standard gravity equations incorporate factors such as geographical proximity, language, trade policy and common history as explanatory factors for variation in bilateral trade that reflect the costs of trade across geographical and cultural distance. We extend this type of analysis by focusing on the relevance of the quality of governance and the extent of familiarity with the resulting framework of rules and norms in explaining variation in bilateral trade patterns. More specifically, we test whether institutional homogeneity and institutional quality have an independent impact on the trade volume between pairs of countries. We find that having a similar institutional framework promotes bilateral trade by 13%, on average. Furthermore, a better quality of formal institutions tends to coincide with more trade. Depending on being either importer or exporter, an increase in overall institutional quality of one standard deviation from the mean leads to an estimated increase of 30–44% in bilateral trade.
Migration, Self‐Selection and Income Inequality: An International Analysis
Authors: Liebig Thomas , Sousa‐Poza Alfonso
Published: February 2004

In the context of an emerging focus on highly skilled migration throughout the OECD area, the question under which circumstances migrants can be expected to be relatively skilled is of particular importance. Borjas has analysed the relation between the income distribution and the skills of migrants. His self‐selection model predicts that immigrants from countries with a higher income inequality tend to be negatively selected (i.e., less skilled than the average worker in both host and source countries). According to other models based on the human capital theory of migration, however, migrants can be expected to be relatively skilled. Empirical tests of Borjas' much‐disputed negative self‐selection hypothesis generally rely on immigration data, particularly to the US, and may therefore be biased due to host‐country specifics such as network migration and the impact of migration policy. This paper analyses the relationship between country‐specific emigration propensities and each country's score on various indices of income inequality with a rich international microdata set. The main result is that highly‐skilled persons are more inclined to migrate, though a higher income inequality attenuates the positive selectivity.
When Grammar Instruction Undermines Cohesion in L2 Spanish Classroom Discourse
Authors: Toth Paul D.
Published: February 2004

This article compares ordinary conversational topics and targeted second language (L2) forms for their effectiveness in building and maintaining classroom discourse cohesion. In this study, 16 learners participated in 2 lessons, 1 with teacher turns determined by a grammatical object of instruction, and the other with turns determined by conversation topics. Based on research by Sperber and Wilson (1995) and Vuchinich (1977), extended latency gaps and remedy sequences in learner turns were taken as evidence of poor cohesion. Both lessons were videotaped, transcribed, and coded. Of the 16 learners, 5 volunteers viewed the videotapes and offered written explanations for their extended latencies. Longer latencies and more frequent remedy sequences occurred during the grammatically‐determined discourse, with volunteers likewise indicating greater difficulty understanding the instructor, than during the conversational lesson. It is argued that for grammar instruction to work effectively, a focus on form must be transparent as the instructional objective, and targeted L2 forms must themselves be properly treated as discourse topics.
Syntactic Transfer: Evidence from the Interlanguage of Hong Kong Chinese ESL Learners
Authors: Chan Alice Y. W.
Published: February 2004

This article presents evidence of syntactic transfer from Chinese to English based on data obtained from 710 Hong Kong Chinese ESL learners at different proficiency levels. Three methodologies were used: self‐reporting in individual interviews, translation (with and without prompts), and grammaticality judgment. The focus of the study was on 5 error types: (a) lack of control of the copula, (b) incorrect placement of adverbs, (c) inability to use the there be structure for expressing the existential or presentative function, (d) failure to use the relative clause, and (e) confusion in verb transitivity. The results showed that many Chinese ESL learners in Hong Kong tended to think in Chinese first before they wrote in English, and that the surface structures of many of the interlanguage strings produced by the participants were identical or very similar to the usual or normative sentence structures of the learners' first language (L1), Cantonese. The extent of syntactic transfer was particularly large for complex target structures and among learners of a lower proficiency level, though high‐proficiency learners may also have relied on the syntax and vocabulary of their previous linguistic repertoire, their L1, when finding it difficult to produce output in the target language.
Healthy improvement of ionic balance with industrial processing of vegetables
Authors: Martínez‐Tomé M. , Vera A.
Published: February 2004

The anion (chloride, nitrate, phosphate, sulphate and oxalate) composition of water used to wash spinach during processing (frozen and canned) was determined by Ion Chromatography (IC). The results showed the anions to increase in the water during washing of raw spinach and during the freezing and canning processes. Thus the anion content of the spinach itself was reduced. This observation has important health implications, particularly for people suffering with kidney stones for whom it is essential to seek ways of reducing oxalate intake. It is also important for improving quality and reducing the level of contaminants (such as nitrates) according to EU Commission proposed levels. The lower concentration of nitrates, oxalates and other toxic components is especially beneficial for those who follow the recommendation to eat five or more servings of a combination of vegetables and fruits, especially green and yellow vegetables and citrus fruits each day.
The accuracy of electronic working length determination
Authors: Hoer D. , Attin T.
Published: February 2004

Aim  To determine in vivo the accuracy of two impedance quotient apex locators under clinical conditions.

Methodology  Electronic working length determination was carried out before extraction in 79 human teeth with 93 root canals. In 51 root canals, the determination was performed using the apex locator Justy II® (Hager & Werken, Duisburg, Germany); in 42 canals, the apex locator Endy 5000® (Loser, Leverkusen, Germany) was used. A root canal instrument was fixed at working length with composite material prior to extraction followed by the exposure of a radiograph. After histological preparation of the apical region, the teeth were examined under a light microscope. The distance of the file tips to the target intervals ‘minor foramen – major foramen’ and ‘apical canal constriction’ was determined. These values were compared with the calculated working lengths, determined by radiographic assessment. The data were statistically analysed by a paired t‐test.

Results  For both apex locators and both target intervals, no significant differences between the electronic and radiographical assessments were recorded. The probability of determining the area between minor and major foramen was 82.4% for Justy II and 81% for Endy 5000. However, accurate determination of the apical constriction was only successful in 51% (Justy II) and 64.3% (Endy 5000) of canals. Variation of the inaccurate measurements was higher for Endy 5000 than for Justy II.

Conclusions  Under clinical conditions, it is possible to determine the region between the minor and major apical foramen with electronic length measuring devices (ELD). However, use of these devices does not result in precise determination of the apical constriction.
The use of glass ionomer cements in both conventional and surgical endodontics
Authors: De Bruyne M. A. A. , De Moor R. J. G.
Published: February 2004

The capacity to bond to dental tissues, especially to dentine, their long‐term fluoride release and their biocompatibility make glass ionomer cements (GICs) advantageous for use in endodontics, as well as in restorative dentistry. This review provides information on the basic properties of GICs, such as adhesion, antimicrobial effects and biocompatibility, particularly as they relate to use in endodontics. Indications for the use of GICs in endodontics are orthograde root canal sealing, root‐end filling, repair of perforations and root resorption defects, treatment of vertical fractures and maintenance of the coronal seal. The paper includes a review on each of these indications. It is concluded that in spite of the critical handling characteristics and the inconclusive findings regarding sealing ability and antimicrobial activity, there is substantial evidence to confirm their satisfactory clinical performance. Both soft tissue and bone compatibility make them suitable for use during endodontic surgery.
Cytotoxicity of composite resins polymerized with different curing methods
Authors: Nalçacı A. , Öztan M. D. , Yılmaz Ş.
Published: February 2004

Aim  To compare the relative cytotoxicity of resin‐based composite materials polymerized with three different curing methods on L 929 cells over a period of 1 week.

Methodology  Ten discs of each material (Flowline®, P 60® and Z 250®) were cured from one side with either standard cure (Optilux 401®), soft‐start cure (Elipar Free Light®) or fast cure (Hilux Ultra Plus®). Then the samples were aged for 1, 2, 3, 5 and 7 days in Dulbecco's Modified Eagle Medium/Ham's F12 (DMEM/F12). After each ageing interval, cytotoxicity of the extracts to cultured fibroblasts (L 929) was measured by MTT assay. The degree of cytotoxicity for each sample was determined according to the reference value represented by the cells with a pure culture medium. Statistical significance was determined by one‐way analysis of variance (anova), followed by the Student's Newman–Keuls test.

Results  Exposure of L 929 cells to the test materials resulted in a high survival fraction at 1 and 7 days. Flowline® specimens, either cured with Optilux 401® or Elipar Free Light®, had no toxic effect on the cells, whereas the other groups were moderately toxic on the 2‐day interval. All experimental groups presented lower cell viability than the control at the 3‐ and 5‐day intervals.

Conclusions  The composite resins used in this study were cytotoxic after 48 h pre‐incubation, but this toxicity disappeared after pre‐incubation in a biological medium for 7 days. Curing did not have a significant effect on the cytotoxicity of the composite materials tested.
Interleukin‐4 Selectively Inhibits Interleukin‐2 Secretion by Lipopolysaccharide‐Activated Dendritic Cells
Authors: Sauma D. , Michea P. , Lennon‐Duménil A.‐M. , Fierro A. , Morales J. , Rosemblatt M. , Bono M. R.
Published: February 2004

Dendritic cells (DCs) generated in vitro from bone marrow precursors using granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) secrete interleukin‐2 (IL‐2) upon activation, an event probably associated to the initiation of adaptive immune responses. Additionally, they produce IL‐12, a cytokine related to T‐cell polarization. To analyse the effect of IL‐4 on DC differentiation and function, we assessed the capacity of murine bone marrow dendritic cells (BMDCs) differentiated with GM‐CSF in the presence or absence of IL‐4 to produce IL‐2 and IL‐12 upon lipopolysaccharide (LPS) activation. We found that although IL‐4 enhanced DC IL‐12p70 production, it strongly impaired IL‐2 secretion by BMDCs. This inhibition, which depends on the presence of IL‐4 during LPS activation, is DC specific, as IL‐4 did not affect IL‐2 secretion by T cells. Interestingly, inhibition of DC IL‐2 production did not prevent DC priming of T lymphocytes. These results illustrate a new putative role for IL‐4 on the regulation of the immune response and should help clarify the controversial reports on the effect of IL‐4 on DCs.
Comparative effectiveness of hand and ultrasonic instrumentations in root surface planing in vitro
Authors: Khosravi Mahmood , Bahrami Zahra Samadi , Atabaki Mahdi Saheb Jam , Shokrgozar Mohammad Ali , Shokri Fazel
Published: February 2004

Background/aims: A variety of techniques are employed for planing and scaling of the superficial root surfaces, of which hand and ultrasonic instrumentations have been preferentially used in routine periodontics clinics. This study was undertaken to compare the effectiveness of ultrasonic scalers and hand curettes in facilitating fibroblast attachment to the scaled root surfaces.

Materials and Methods: Sixteen patients with periodontally involved teeth and nine subjects without periodontal diseases (control subjects) were selected. Two single‐rooted teeth were extracted from each subject. Mesial and distal surfaces of teeth were selected in treated and untreated groups, respectively. The mesial surface of each tooth was randomly chosen to be treated either by hand curettes or ultrasonic instrumentation. The degree of cell attachment on the root surfaces of treated and untreated groups from control subjects and patients was then determined by the use of a gingival fibroblast line established and employed at early passages. The attachment and proliferation of gingival fibroblasts on the root surfaces were evaluated using neutral red assay and scanning electron microscopy (SEM).

Results: Fibroblast survival and proliferation on the surfaces of untreated periodontally involved roots were found to be significantly lower compared with control untreated surfaces (p<0.0001) or treated surfaces from patients (p<0.0001). No significant difference, however, was observed between root surfaces treated either by hand curettes or ultrasonic scalers.

Conclusion: These results indicate the beneficial effectiveness of both techniques in root treatment and planing.
Comparative clinical responses related to the use of various periodontal instrumentation
Authors: Obeid Patrick R. , D'hoore William , Bercy Pierre
Published: February 2004

Aim: The aim of this study was to evaluate in vivo the effectiveness of scaling and root planing of a power‐driven mechanism compared with hand instruments and ultrasonic insert alone with a split‐mouth design after 3 and 6 months.

Methods: Healing events after initial periodontal therapy were investigated in 20 patients with moderate‐to‐severe adult periodontitis. Plaque index (PlI), bleeding on probing (PBI), probing pocket depth (PPD), probing attachment level (PAL) and number of moderate and deep pockets (NMP, NDP) were recorded at baseline and 3 and 6 months after treatment. Oral hygiene instruction was provided for each patient. Randomly assigned quadrants per patient were scaled and root planed with hand instrumentation (curettes, hoes and files), with reciprocating power‐driven instruments, with ultrasonic scaler alone and with the combined use of ultrasonic scaler and power‐driven inserts. The Friedman test was applied to test the significance of difference between the various methods of root instrumentation. Repeated measures of analysis of variance (manova) were used to analyse the time effect on the different treatments.

Results: At the 6‐month evaluation, all groups in the scaling and root planing treatment presented with an improvement in the measured clinical parameters, as compared with baseline. No statistical differences (p>0.05) were observed in the assessed periodontal indices among the study sites between the four groups for either treatment.

Conclusions: Under our experimental conditions, this clinical study demonstrates that mechanized root planing with power‐driven instruments, as effective as the usual procedures (hand and sonic instruments), represents a satisfactory and alternative means of nonsurgical root therapy.
Clinical and microbiological effects of different restorative materials on the periodontal tissues adjacent to subgingival class V restorations
Authors: Paolantonio Michele , D'ercole Simonetta , Perinetti Giuseppe , Tripodi Domenico , Catamo Giovanni , Serra Emanuela , Bruè Claudia , Piccolomini Raffaele
Published: February 2004

Objectives:The relationship between subgingival dental restorations and periodontal health has been thoroughly investigated for many years. However, longitudinal data on the subgingival microflora features after the placement of well‐finished subgingival restorations are still lacking. Therefore, this study compares the short‐term clinical and microbiological features occurring in the gingiva after the completion of different subgingival restorations.

Material and Methods:Sixteen systemically healthy subjects, 10 males and six females (ages: 31.7–45.8 years; mean age 39.3±5.1 years), who were non‐smokers and were positive for the presence of three cervical abrasion/erosion defects to be restored in three different adjacent teeth were enrolled in this study. The cervical abrasion/erosion defects were each restored by using one of three different materials: amalgam, glass ionomer cement, or composite resin. Immediately before class V cavity preparations and restorations (baseline), clinical monitoring and subgingival plaque sampling were performed in the mid‐buccal aspect of each experimental restored tooth and in one adjacent sound, non‐treated, control tooth. These procedures were repeated every 4 months over the following 1 year.

Results:Throughout the study, the clinical parameters recorded did not change significantly in any of the experimental groups, and no differences were detected among them at each clinical session. Over this time, no significant changes in the composition of the subgingival microflora were observed in amalgam, glass ionomer cement, and control groups. Conversely, in the composite resin group, there was a significant increase in the total bacterial counts, and a significant (p<0.05) decrease in Gram‐positive, aerobic bacteria, which was associated with a significant (p<0.05) increase in the Gram‐negative, anaerobic microbiota.

Conclusions:Over a 1‐year observation period, amalgam, glass ionomer cement, and composite resin subgingival restorations do not significantly affect the clinical parameters recorded. However, composite resin restorations may have some negative effects on the quantity and quality of subgingival plaque.
Four‐year water degradation of a resin‐modified glass‐ionomer adhesive bonded to dentin
Authors: De Munck Jan , Van Meerbeek Bart , Yoshida Yasuhiro , Inoue Satoshi , Suzuki Kazuomi , Lambrechts Paul
Published: February 2004

Glass‐ionomers are auto‐adhesive to tooth tissue through combined micro‐mechanical and chemical bonding. How much each of the two bonding components contributes to the actual bonding effectiveness is, however, not known and there is not much information available on long‐term stability. The objective of this study was to assess the bonding effectiveness of a resin‐modified glass‐ionomer adhesive to dentin after 4 yr of water storage. Fuji Bond LC (GC) was applied without (i) and with pretreatment using (ii) a polyalkenoic acid conditioner and (iii) a 37.5% phosphoric acid etchant. The etchant was used to exclude any chemical interaction with hydroxyapatite. The micro‐tensile bond strength (µTBS) to dentin decreased significantly over the 4 yr period in all three experimental groups. After 24 h and 4 yr, the lowest µTBS was recorded when dentin was not pretreated. The highest µTBS was obtained following polyalkenoic acid pretreatment, although this was not significantly different from specimens that were pretreated using phosphoric acid. Pretreating dentin with phosphoric acid intensified micromechanical interlocking at the expense of chemical bonding potential to hydroxyapatite. Nevertheless, correlating the µTBS data with failure analysis through scanning electron microscopy and transmission electron microscopy indicated that combined micro‐mechanical and chemical bonding involving pretreatment with the polyalkenoic acid conditioner yielded the most durable bond.
Influence of orthodontic movement on root length of autotransplanted immature third molars
Authors: Bauss Oskar , Schwestka‐Polly Rainer , Hoy Ludwig , Kiliaridis Stavros
Published: February 2004

The aim of this study was to investigate the influence of orthodontic extrusion or derotation on final root length and root length increment in 75 autotransplanted immature third molars. Depending on the condition of the recipient site and the root morphology, transplants had to be placed in extreme rotated or infra‐occluded position. Three to six months after transplantation, these transplants were derotated to a correct position in the dental arch (derotation group, n = 19) or extruded to the occlusal plane (extrusion group, n = 18). Thirty‐eight transplants with no orthodontic treatment need served as controls (control group). Transplants were followed clinically and radiologically for a mean period of 4.0 yr. No statistically significant differences were observed between the extrusion and the control groups or between the single‐rooted transplants in the different groups. In contrast, multi‐rooted transplants in the derotation group showed a statistically significantly shorter final root length than multi‐rooted transplants in the extrusion and the control groups. However, as these differences may be considered to be of minor clinical importance (<1 mm), it can be concluded that the effect of orthodontic movement on root development of transplanted immature third molars is of only negligible clinical significance.
Curing efficiency and heat generation of various resin composites cured with high‐intensity halogen lights
Authors: Kleverlaan Cornelis Johannes , De Gee Anton Johannes
Published: February 2004

The objective of this study was to assess the curing efficiency and heat generation of two high‐intensity halogen lamps, the Astralis 10 HIP (1100 mW cm−2), and Optilux 501 Boost (1000 mW cm−2) in curing three resin composites (InTen‐S, Tetric Ceram, and Filtek Z250). It was expected that the two lamps, having similar irradiance would give rise to the same curing efficiency and heat generation. The curing efficiency was evaluated by Vickers hardness and depth of cure measurements. Heat generation in the resin composites was studied in standardized restorations using a thermocouple. No significant differences were observed in curing efficiency between the two lamps for the three resin composites. The temperature rise in the composites during curing was between 11.2°C and 16.2°C. At subsequent irradiation, after the composites had been cured, the temperature rise was between 8.2°C and 12.1°C. The Optilux 501 generated, in all cases, less heat than the Astralis 10. This was not expected based on the irradiance, but could be accounted for by the differing spectra.
Chewing behavior and salivary secretion
Authors: Gavião Maria Beatriz D. , Engelen Lina , Van Der Bilt Andries
Published: February 2004

We determined the salivary flow rate in 16 healthy subjects in rest and while chewing artificial and natural foods (Parafilm, Melba toast with and without margarine, and three different volumes of breakfast cake and cheese). We also determined the duration of a chewing cycle, the number of chewing cycles until swallowing, and the time until swallowing. The physical characteristics of the foods were quantified from force‐deformation experiments. The flow rates of the saliva as obtained without stimulation, with Parafilm stimulation, and with chewing on the various foods were significantly correlated. An increase in chewing cycle duration, number of chewing cycles until swallowing, and time until swallowing was observed as a function of the volume of the food. More chewing cycles were required for Melba toast than for an equal volume of cake or cheese. This may be caused by the low water and fat percentage of the Melba toast. The number of chewing cycles and the time until swallowing significantly decreased when the Melba toast was buttered. The decrease may be caused by facilitation in bolus formation and lubrication of the food due to buttering the toast. The number of chewing cycles until swallowing was not correlated to the salivary flow rate.
A randomised, controlled study of peri‐operative low dose s(+)‐ketamine in combination with postoperative patient‐controlled s(+)‐ketamine and morphine after radical prostatectomy*
Authors: Snijdelaar D. G. , Cornelisse H. B. , Schmid R. L. , Katz J.
Published: February 2004

In a randomised, double‐blind prospective study we compared the effects on postoperative pain and analgesic consumption of intra‐operative s(+)‐ketamine (100 μg.kg−1 bolus and a continuous infusion of 2 μg.kg−1.min−1) followed by postoperative patient‐controlled analgesia with morphine (1 mg per bolus) plus s(+)‐ketamine (0.5 mg per bolus), or intra‐operative saline followed by postoperative patient‐controlled analgesia morphine (1 mg per bolus) alone. A total of 28 male patients undergoing radical prostatectomy were studied. Morphine consumption, pain scores, pressure algometry and adverse effects were recorded for 48 h after surgery. Cumulative morphine consumption was significantly lower in the ketamine/morphine group (47.9 ± 26.2 mg) than in the saline/morphine group (73.4 ± 34.8 mg; p = 0.049). Pain scores at rest were significantly lower in the ketamine/morphine group across the 48‐h study period (p = 0.01). No significant differences were found in pressure algometry measurements or the occurrence of adverse effects.
The effects of indomethacin on intracranial pressure and cerebral haemodynamics in patients undergoing craniotomy: A randomised prospective study
Authors: Rasmussen M. , Tankisi A. , Cold G. E.
Published: February 2004

We compared the effects of indomethacin (bolus of 0.2 mg.kg−1 followed by an infusion of 0.2 mg.kg−1.h−1) and placebo on intracranial pressure and cerebral haemodynamics in 30 patients undergoing craniotomy for supratentorial brain tumours under propofol and fentanyl anaesthesia. Indomethacin was given before induction of anaesthesia and the infusion was terminated after opening of the dura. Subdural intracranial pressure was measured through the first burr hole and before opening the dura. Cerebral blood flow velocity, cerebral perfusion pressure, jugular bulb oxygen saturation, arterio‐venous oxygen difference and carbon dioxide reactivity were measured; dural tension and the degree of brain swelling were estimated. Before induction of anaesthesia, indomethacin administration was associated with a significant decrease in cerebral blood flow velocity compared with placebo. After induction of anaesthesia, cerebral blood flow velocity and mean arterial blood pressure decreased significantly in both groups. Indomethacin was not associated with a decrease in intracranial pressure. There were no differences in cerebral perfusion pressure, dural tension or degree of brain swelling between the two groups. Carbon dioxide reactivity measured after induction of anaesthesia was significantly lower in the indomethacin group (p < 0.05). After removal of the bone flap, no significant difference in carbon dioxide reactivity was observed. We suggest that these findings are explained by propofol‐induced cerebral vasoconstriction.
The effect of positive airway pressure during pre‐oxygenation and induction of anaesthesia upon duration of non‐hypoxic apnoea
Authors: Herriger A. , Frascarolo Ph. , Spahn D. R. , Magnusson L.
Published: February 2004

Positive end‐expiratory pressure (PEEP) applied during induction of anaesthesia may prevent atelectasis formation in the lungs. This may increase the duration of non‐hypoxic apnoea by increasing the functional residual capacity. We studied the benefit of PEEP applied during the induction of anaesthesia on the duration of apnoea until the SpO2 reached 90%. Forty ASA I‐II patients were randomly allocated to one of two groups. In the PEEP group (n = 20) patients were pre‐oxygenated using 100% O2 administered using a CPAP device (6 cmH2O) for 5 min. Following induction of anaesthesia, patients were mechanically ventilated (PEEP 6 cm H2O) for a further 5 min. In the ZEEP group (n = 20), no CPAP or PEEP was used. The duration of apnoea until SpO2 reached 90% was measured. Non‐hypoxic apnoea duration was longer in the PEEP group compared to ZEEP group (599 ± 135 s vs. 470 ± 150 s, p = 0.007). We conclude that the application of positive airway pressure during induction of anaesthesia in adults prolongs the non‐hypoxic apnoea duration by > 2 min.
Phosphorylation and 14‐3‐3 binding of Arabidopsis 6‐phosphofructo‐2‐kinase/fructose‐2,6‐bisphosphatase
Authors: Kulma Anna , Villadsen Dorthe , Campbell David G. , Meek Sarah E. M. , E. Harthill Jean , Nielsen Tom H. , MacKintosh Carol
Published: February 2004

Fructose 2,6‐bisphosphate (fru‐2,6‐P2) is a signalling metabolite that regulates photosynthetic carbon partitioning in plants. The content of fru‐2,6‐P2 in Arabidopsis leaves varied in response to photosynthetic activity with an abrupt decrease at the start of the photoperiod, gradual increase through the day, and modest decrease at the start of the dark period. In Arabidopsis suspension cells, fru‐2,6‐P2 content increased in response to an unknown signal upon transfer to fresh culture medium. This increase was blocked by either 2‐deoxyglucose or the protein phosphatase inhibitor, calyculin A, and the effects of calyculin A were counteracted by the general protein kinase inhibitor K252a. The changes in fru‐2,6‐P2 at the start of dark period in leaves and in the cell experiments generally paralleled changes in nitrate reductase (NR) activity. NR is inhibited by protein phosphorylation and binding to 14‐3‐3 proteins, raising the question of whether fructose‐6‐phosphate,2‐kinase/fructose‐2,6‐bisphosphatase protein from Arabidopsis thaliana (AtF2KP), which both generates and hydrolyses fru‐2,6‐P2, is also regulated by phosphorylation and 14‐3‐3s. Consistent with this hypothesis, AtF2KP and NR from Arabidopsis cell extracts bound to a 14‐3‐3 column, and were eluted specifically by a synthetic 14‐3‐3‐binding phosphopeptide (ARAApSAPA). 14‐3‐3s co‐precipitated with recombinant glutathione S‐transferase (GST)‐AtF2KP that had been incubated with Arabidopsis cell extracts in the presence of Mg‐ATP. 14‐3‐3s bound directly to GST‐AtF2KP that had been phosphorylated on Ser220 (SLSASGpSFR) and Ser303 (RLVKSLpSASSF) by recombinant Arabidopsis calcium‐dependent protein kinase isoform 3 (CPK3), or on Ser303 by rat liver mammalian AMP‐activated protein kinase (AMPK; homologue of plant SNF‐1 related protein kinases (SnRKs)) or an Arabidopsis cell extract. We have failed to find any direct effect of 14‐3‐3s on the F2KP activity in vitro to date. Nevertheless, our findings indicate the possibility that 14‐3‐3 binding to SnRK1‐phosphorylated sites on NR and F2KP may regulate both nitrate assimilation and sucrose/starch partitioning in leaves.