Evaluation of three indices for biofilm accumulation on complete dentures

doi:10.1111/j.1741‐2358.2009.00285.x
Evaluation of three indices for biofilm accumulation on complete dentures Objectives: The objective of this study was to evaluate the accuracy and reproducibility of three complete denture biofilm indices (Prosthesis Hygiene Index; Jeganathan et al. Index; Budtz‐Jørgensen Index) by means of a computerised comparison method. Background: Clinical studies into denture hygiene have employed a large number of biofilm indices among their outcome variables. However, the knowledge about the validity of these indices is still scarce. Materials and methods: Sixty‐two complete denture wearers were selected. The internal surfaces of the upper complete dentures were stained (5% erythrosine) and photographed. The slides were projected on paper, and the biofilm indices were applied over the photos by means of a scoring method. For the computerised method, the areas (total and biofilm‐covered) were measured by dedicated software (Image Tool). In addition, to compare the results of the computerised method and Prosthetic Hygiene Index, a new scoring scale (including four and five graded) was introduced. For the Jeganathan et al. and Budtz‐Jørgensen indices, the original scales were used. Values for each index were compared with the computerised method by the Friedman test. Their reproducibility was measured by means of weighed κ. Significance for both tests was set at 0.05. Results: The indices tested provided similar mean measures but they tended to overestimate biofilm coverage when compared with the computerised method (p < 0.001). Agreement between the Prosthesis Hygiene Index and the computerised method was not significant, regardless of the scale used. Jeghanathan et al. Index showed weak agreement, and consistent results were found for Budtz‐Jorgensen Index (κ = 0.19 and 0.39 respectively). Conclusion: Assessment of accuracy for the biofilm indices showed instrument bias that was similar among the tested methods. Weak inter‐instrument reproducibility was found for the indices, except for the Budtz‐Jørgensen Index. This should be the method of choice for clinical studies when more sophisticated approaches are not possible.     

Polymorphism of Microsatellite Markers in Papaya (<Emphasis Type="Italic">Carica papaya</Emphasis> L.)

A set of 81 new microsatellite markers for Carica papaya L. previously identified by data mining using freely available sequence information from Genbank were tested for polymorphism using 30 germplasm accessions from the Papaya Germplasm Bank (PGM) at Embrapa Mandioca e Fruticultura Tropical (CNPMF) and 18 landraces. The data were used to estimate pairwise genetic distances between the genotypes. A neighbor-joining based dendrogram was used to define clusters and infer possible genetic structuring of the collection. Most microsatellites were polymorphic (73%), with an observed number of alleles per locus ranging from one to eleven. The levels of observed and expected heterozygosity for 51 polymorphic loci varied from 0.00 to 0.85 and from 0.08 to 0.82, averaging 0.19 and 0.59, respectively. Forty-four percent of microsatellites showed polymorphism information content (PIC) higher than 0.50. The compound microsatellites seem to be more informative than dinucleotide and trinucleotide repeats in average alleles per locus and PIC. Among dinucleotides, AG/TC or GA/CT repeat motifs exhibited more informativeness than TA/AT, GT/CA and TG/AC repeat motifs. The neighbor-joining analysis based on shared allele distance could differentiate all the papaya accessions and landraces as well as differences in their genetic structure. This set of markers will be useful for examining parentage, inbreeding and population structure in papaya.     

The cluster-randomized Quality Initiative in Rectal Cancer trial: evaluating a quality-improvement strategy in surgery

Background

Following surgery for rectal cancer, two unfortunate outcomes for patients are permanent colostomy and local recurrence of cancer. We tested whether a quality-improvement strategy to change surgical practice would improve these outcomes.

Methods

Sixteen hospitals were cluster-randomized to the intervention (Quality Initiative in Rectal Cancer strategy) or control (normal practice) arm. Consecutive patients with primary rectal cancer were accrued from May 2002 to December 2004. Surgeons at hospitals in the intervention arm could voluntarily participate by attending workshops, using opinion leaders, inviting a study team surgeon to demonstrate optimal techniques of total mesorectal excision, completing postoperative questionnaires, and receiving audits and feedback. Main outcome measures were hospital rates of permanent colostomy and local recurrence of cancer.

Results

A total of 56 surgeons (n = 558 patients) participated in the intervention arm and 49 surgeons (n = 457 patients) in the control arm. The median follow-up of patients was 3.6 years. In the intervention arm, 70% of surgeons participated in workshops, 70% in intraoperative demonstrations and 71% in postoperative questionnaires. Surgeons who had an intraoperative demonstration provided care to 86% of the patients in the intervention arm. The rates of permanent colostomy were 39% in the intervention arm and 41% in the control arm (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.63–1.48). The rates of local recurrence were 7% in the intervention arm and 6% in the control arm (OR 1.06, 95% CI 0.68–1.64).

Interpretation

Despite good participation by surgeons, the resource-intense quality-improvement strategy did not reduce hospital rates of permanent colostomy or local recurrence compared with usual practice. (ClinicalTrials.gov trial register no. {"type":"clinical-trial","attrs":{"text":"NCT00182130","term_id":"NCT00182130"}}NCT00182130.)Following surgery for rectal cancer, two unfortunate outcomes for patients are permanent colostomy and local recurrence of the cancer. Local recurrence is especially feared, because it is usually inoperable and patients can suffer a slow, painful death.¹ The use of total mesorectal excision, which involves dissection of the lymph node-bearing portion of the rectum,² has resulted in improved outcomes, with local recurrence rates as low as 1%–5% and rates of permanent colostomy of 10%–15%.^3–6 Population-based rates of local recurrence are unavailable for any North American jurisdiction, although a Canadian hospital series found that rates varied from 10% to 45% based on the practice volume and training of surgeons.⁷ A surgical report on health regions in the province of Ontario (population 13 million) found that rates of permanent colostomy varied from 31% to 41%.⁸ This geographic variation in outcomes, together with rates of inferior outcomes as compared to outcomes specific to total mesorectal excision, suggest that gaps exist in the quality of rectal surgery provided to patients with rectal cancer.Quality-improvement strategies for encouraging physicians to change practice include continuing medical education, the use of opinion leaders, and audit and feedback.^9–11 As well, improvement may be enhanced by using a participatory and supportive approach that focuses on the system and not on individual practitioners.^12,13 The small number of studies that have evaluated changes in surgeons’ practices often have targeted process measures, such as preoperative ordering of antibiotics, rather than patient outcomes, such as recurrence of cancer.^14,15We tested whether use of a surgeon-directed quality-improvement strategy would improve hospital rates of permanent colostomy and local recurrence of cancer among patients undergoing surgery for rectal cancer. We used the Quality Initiative in Rectal Cancer (QIRC) strategy, which integrates quality-improvement interventions and principles to encourage surgeons to provide optimal total mesorectal excision to patients with rectal cancer.¹⁶     

Differential leaf traits of a neotropical tree Cariniana legalis (Mart.) Kuntze (Lecythidaceae): comparing saplings and emergent trees

Cariniana legalis is an emergent tree that reaches the upper canopy in Brazilian Semideciduous Forest. Spatial contrasts in microclimatic conditions between the upper canopy and understorey in a forest may affect morpho-physiological leaf traits. In order to test the hypothesis that the upper canopy is more stressful to leaves than a gap environment we compared emergent trees of C. legalis, 28–29 m in height to gap saplings, 6–9 m in height, for the following parameters: leaf area, leaf mass area (LMA the dry weight:leaf area ratio), leaf thickness, leaf anatomical parameters, stomata conductance, and chlorophyll a fluorescence. Leaves from emergent trees had smaller leaf areas but greater LMA compared to saplings. Leaf thickness, palisade layer thickness, and stomatal density were higher for emergent trees than for saplings. The opposite pattern was observed for spongy layer thickness and spongy/palisade ratio. Stomatal conductance was also higher for emergent tree leaves than for sapling leaves, but the magnitude of depression on stomatal conductance near midday was more pronounced in emergent trees. The potential quantum yield of photosystem II, as determined by the F _v/F _m ratio was lower for leaves from saplings. The lower values of stomatal conductance, indicating restriction in CO₂ diffusion into the mesophyll can be related to higher photoinhibition observed in the saplings. Leaves from emergent trees and saplings exhibited similar values for apparent electron transport rates and non-photochemical quenching. Our results suggest that changes in leaf traits could be associated to dry conditions at the upper canopy as well as to the ontogenetic transition between sapling/emergent tree life stages.     

Rapid sexual maturity and short life span in the blue-legged frog and the rainbow frog from the arid Isalo Massif, southern-central Madagascar

Longevity and age at sexual maturity were estimated in two anurans from the arid Isalo Massif (southern-central Madagascar), the blue-legged frog (Mantella expectata) and the rainbow frog (Scaphiophryne gottlebei). Phalanges from 69 individuals of M. expectata and 38 individuals of S. gottlebei were analyzed, using the skeletochronological method, in samples collected during two periods: January-February and November-December 2004. The male gonads of both species were also analyzed in order to better correlate reproductive activity with phenology. The phalangeal diaphysis in adults of both species was composed of two concentric bone layers: an innermost endosteal bone, which was less developed or sometimes lacking in S. gottlebei, and an outermost and broader layer of periosteal bone. Lines of arrested growth (LAGs) were observed in both species, although their recognition was more problematic and their distinctiveness much less evident in S. gottlebei. The results presented here indicate that M. expectata and S. gottlebei have a short life span and attain sexual maturity within the first active season after metamorphosis. Maximum longevity was 3 years in M. expectata and 2 years in S. gottlebei. In S. gottlebei the adult body size is likely attained during the same season in which metamorphosis occurs, but then breeding occurs only after the first latency period. Thus, mature individuals have only one LAG, corresponding to 1 year. The low number of individuals with two LAGs suggests that most animals die before the second latency period.     

Spectroscopic and metal-binding properties of DF3: an artificial protein able to accommodate different metal ions

The design, synthesis, and metal-binding properties of DF3, a new de novo designed di-iron protein model are described (“DF” represents due ferri, Italian for “two iron,” “di-iron”). DF3 is the latest member of the DF family of synthetic proteins. They consist of helix–loop–helix hairpins, designed to dimerize and form an antiparallel four-helix bundle that encompasses a metal-binding site similar to those of non-heme carboxylate-bridged di-iron proteins. Unlike previous DF proteins, DF3 is highly soluble in water (up to 3 mM) and forms stable complexes with several metal ions (Zn, Co, and Mn), with the desired secondary structure and the expected stoichiometry of two ions per protein. UV–vis studies of Co(II) and Fe(III) complexes confirm a metal-binding environment similar to previous di-Co(II)- and di-Fe(III)-DF proteins, including the presence of a μ-oxo-di-Fe(III) unit. Interestingly, UV–vis, EPR, and resonance Raman studies suggest the interaction of a tyrosine adjacent to the di-Fe(III) center. The design of DF3 was aimed at increasing the accessibility of small molecules to the active site of the four-helix bundle. Indeed, binding of azide to the di-Fe(III) site demonstrates a more accessible metal site compared with previous DFs. In fact, fitting of the binding curve to the Hill equation allows us to quantify a 150% accessibility enhancement, with respect to DF2. All these results represent a significant step towards the development of a functional synthetic DF metalloprotein.     

Lycopene prevents 7-ketocholesterol-induced oxidative stress,cell cycle arrest and apoptosis in human macrophages

The present study was undertaken to examine whether lycopene is able to counteract 7-ketocholesterol (7-KC)-induced oxidative stress and apoptosis in human macrophages. Human THP-1 macrophages were exposed to 7-KC (10–25 μM) alone and in combination with lycopene (0.5–2 μM), and we monitored changes in cell oxidative status [reactive oxygen species (ROS) production, NOX-4, hsp70 and hsp90 expressions, 8-OHdG formation] and in cell proliferation and apoptosis. After 24 h of treatment, lycopene significantly reduced the increase in ROS production and in 8-OHdG formation induced by the oxysterol in a dose-dependent manner. Moreover, the carotenoid strongly prevented the increase of NOX-4, hsp70 and hsp90 expressions as well as the phosphorylation of the redox-sensitive p38, JNK and ERK1/2 induced by the oxysterol. The attenuation of 7-KC-induced oxidative stress by lycopene coincided with a normalization of cell growth in human macrophages. Lycopene prevented the arrest in G0/G1 phase of cell cycle induced by the oxysterol and counteracted the increased expression of p53 and p21. Concomitantly, it inhibited 7-KC-induced apoptosis, by limiting caspase-3 activation and the modulatory effects of 7-KC on AKT, Bcl-2, Bcl-xL and Bax. Comparing the effects of lycopene, β-carotene and (5Z)-lycopene on ROS production, cell growth and apoptosis show that lycopene and its isomer were more effective than β-carotene in counteracting the dangerous effects of 7-KC in human macrophages. Our study suggests that lycopene may act as a potential antiatherogenic agent by preventing 7-KC-induced oxidative stress and apoptosis in human macrophages.     

Preliminary characterization of some Streptomyces species isolated from a composting process and their antimicrobial potential

The aim of this study was to screen Streptomycetes isolates with antimicrobial and antiviral activity, in a search for new metabolites. The isolates were obtained from a composting process, and identified based on morphological characteristics and molecular biological methods. The antimicrobial activity was determined using the double-layer agar method against 53 test organisms (bacteria, yeasts, and filamentous fungi). All isolates were grown in submerged culture, in mineral salts-starch-casein (SC) broth and ISP2 media, and the filtrate cultures were used in the assays for antibacterial and antiviral activity. Bovine Herpes virus (BoHV-I) was used for the antiviral activity. The morphological and molecular characteristics confirmed that all 25 isolates belonged to the genus Streptomyces. In the assay for antimicrobial activity, 80% of the Streptomyces isolates were able to inhibit at least one of the test organisms. Of these, 80% were active against bacteria and 45% against fungi. Eight of the isolates showed a broad spectrum of inhibitory activity; of these, the isolate Streptomyces spp. 1S was able to inhibit 46 of the test organisms, and, most importantly, the 16 Gram-negative strains were inhibited. Of the 25 isolates, 44.4% of the isolates were able to grow and produce bioactive metabolites when grown in submerged culture. Four extracts showed a cytopathic effect in 10 CCID₅₀ MDBK cell, even though no viricidal effect was observed. The results obtained with these isolates indicated good biotechnological potential of these Streptomyces strains.     

Indicators for biodiversity and ecosystem services: towards an improved framework for ecosystems assessment

Ecosystem assessment and monitoring requires the development and application of suitable indicators, i.e. they need to be (i) reliable and capable of simplifying complex relationships, (ii) quantifiable and transparent in order to enable an easy communication, and (iii) fit for the purpose of indication. These requirements are scarcely fulfilled in current ecosystem assessment and monitoring efforts to address the requirements of international biodiversity conventions. Here we present and test a set of seven criteria towards an improved framework for ecosystems indication with particular emphasis on the indication of biodiversity and ecosystem services: purpose of indication, indicator type according to the EEA’s Driver-Pressure-State-Impact-Response scheme, direct/indirect linkages to biodiversity and ecosystem services, spatial scale and scalability across scales, applicability of benchmarks/reference values, availability of data and protocols, and applicability of remote sensing. The criteria are tested using 24 indicators of ecosystem assessment and monitoring at the global, continental and regional scale. Based on the general trends revealed by our evaluation, we present recommendations to streamline and improve ecosystem indication with respect to international biodiversity conventions. The implementation of our recommendations does require concerted international effort, comparable, for instance, to the implementation of the Water Framework Directive in Europe.