Adipato bridged novel hexanuclear Cu(ii) and polymeric Co(ii) coordination compounds involving cooperative supramolecular assemblies and encapsulated guest water clusters in a square grid host: antiproliferative evaluation and theoretical studies.

Two new coordination compounds involving hexanuclear Cu(ii), viz., [Cu6(phen)6(µ4-adpt)4(H2O)2](NO3)4·10H2O (1) and polymeric Co(ii), viz., {[(µ2-adpt)4Co(µ2-H2O)2Co(H2O)4]·4H2O}n (2) (phen = 1,10-phenanthroline; adpt = adipate) have been synthesized and characterized using elemental analysis, TGA, spectroscopic (IR, electronic and ESR), PXRD and single crystal X-ray diffraction techniques. Discrete nitrate-water clusters involving the [(H2O)3NO3]- core in 1 and linear (H2O)4 core in 2 provide stability to the layered network of the structures of the compounds. Interestingly, the water clusters in polymer 2 are encapsulated as guests in the voids of the host square grid that extends in 2D architecture. Theoretical studies have revealed the presence of interesting energetically significant cooperativity effects of π-stacking contacts that are responsible for the hexanuclear structure of compound 1. Both complexes significantly inhibit cell viability by inducing apoptotic cell death in the DL cancer cell line with negligible cytotoxicity in normal cells (PBMC). An assessment of ROS (reactive oxygen species) level study revealed a rapid increase of ROS in DL cells indicating cytotoxicity of the compounds against the DL cells. A decrease in MMP (mitochondrial membrane potential) is associated with an opening of the mitochondrial permeability transition pores which corroborates the apoptotic features of 1 and 2. The mode of action of the cytotoxic activities of the compounds has been explored with respect to their in silico docking ability and further inhibition of antiapoptotic proteins as evidenced by western blot analysis. SAR analyses based on pharmacophore modelling reveal that the molecular features of the structures of the compounds play important roles in biological activities.

The influence of varying maxillary incisor shape on perceived smile aesthetics.

OBJECTIVES: This paper aims to determine the influence of varying the maxillary incisor shape of an individual on perceived smile aesthetics. METHODS: A photograph of a female smile displaying maxillary teeth only was digitally altered to produce five different incisor shapes. They consisted of three basic shapes: square (S), ovoid (O), triangular (T) and two variations, tapered-ovoid (TO) and square-tapering (ST). The images were ranked from the most to the least attractive by 30 dentists, 30 technicians and 30 patients. RESULTS: The TO maxillary incisor shape was perceived to be the most attractive smile overall (50%), and amongst dentists (70%), technicians (50%) and patients (30%). The O shape maxillary incisors were ranked the second most attractive overall (36.7%) and the most attractive amongst patients (56%). The S shape maxillary incisors were perceived as the least attractive overall (43.3%), and amongst dentists (47%), technicians (50%) and patients (33%). CONCLUSIONS: The tapered-ovoid incisor tooth form for females is preferred to the square form, which corresponds with the findings in the dental literature. However, the results also suggest that there is not one 'ideal' incisor shape and that dental professionals are more critical than patients with respect to the shapes of maxillary incisors. Dental professionals should take the individual variability in patient response into consideration during treatment planning, to produce an aesthetic outcome that is acceptable for the patient. CLINICAL SIGNIFICANCE: As a general rule, the tapered-ovoid tooth form is perceived to be more desirable than the square tooth form. The dental team should therefore keep this finding in mind and liaise with the patients accordingly, in order to help to produce desirable aesthetic clinical outcomes.

Are "universal" DNA primers really universal?

"Universal" DNA primers LCO 1490 and HCO 2198 were originally designed from three coding and six anticoding strands by comparing highly conserved regions of mitochondrial cytochrome c oxidase subunit I (COI) genes across 15 taxa. These primers have been successful in amplifying a 710-bp fragment of highly conserved regions of the COI gene for more than 80 invertebrate species from 11 phyla. In the present study, 130,843 variations were reviewed in the primer region of mitochondrial molecular markers by comparing 725 COI sequences from the kingdom Animalia. It was found that, for 177 invertebrate species, the forward primer (LCO 1490) showed only four conserved regions, compared to 12 in the original study. For ascidians, fungi and vertebrates, it showed approximately 50 % conserved regions, dropping to one conserved region for echinoderms. However, the reverse primer (HCO 2198) was highly conserved across 725 COI primer sequences. A similar pattern was observed in amino acid distributions. There was a significant difference in the means of base pair differences from the level of family, genus and species for LCO 1490 [analysis of variance (ANOVA), F 6,188 = 8.193, P < 0.001] and at the level of genus and species for HCO 2198 (ANOVA, F 6,77 = 2.538, P < 0.027). We conclude that, at different taxonomic levels, it is possible to design forward primers from reference sequences belonging to the level of order (maximum 5 bp differences), family (maximum 6 bp differences) or genus (maximum 1 bp difference). Reverse primers can be designed from the level of family (maximum 5 bp differences) or genus (maximum 2 bp differences).

Molecular approach to identify sibling species of the Ceriodaphnia cornuta complex (Cladocera: Daphniidae) from Australia with notes on the continental endemism of this group.

Taxonomy of the genus Ceriodaphnia Dana, 1853 (Cladocera: Daphniidae) has been uncertain for a long time, the species richness was often underestimated due to (1) a morphological similarity among the species and (2) their great morphological inter- and intra- populational variability. Support for this conclusion comes from the first analysis of three molecular markers for Australian representatives of this genus, two mitochondrial (COI and 16s) and one nuclear (28s) genes. Sequence analysis indicates the existence of three sibling Australian species belonging to the complex. Further work is required to establish species boundaries and investigate potential morphological diagnoses. Comparison of COI sequences with all other published sequences from the genus Ceriodaphnia revealed no common clades among continents pointing to the regional endemism within this group, which could suggest its Mesozoic differentiation.

Determining replacement teeth position for the implant-retained prosthesis in the edentulous patient.

A pleasing final appearance is vitally important for patients who undergo extensive oral rehabilitation. This applies equally to the fields of orthodontics, restorative, prosthetic, and implant dentistry. In the field of removable prostheses there are biometric guides that aid in the replacement of teeth especially when the anatomical ridges are severely resorbed. These guides should be considered when planning the appearance and function of prostheses. This paper suggests that in view of the fact that unfavourable placement of implant fixtures is not easily rectified, knowledge of biometric guides can be critical in the treatment planning of the implant supported prosthesis especially when there are large resorbed edentulous spans.

Implant supported fixed partial dentures survival rate high, but biological and technical complications common.

DATA SOURCES: PubMed (1966-April 2004) provided the primary data source along with the bibliographies from identified articles and reviews. Manual search of eight relevant journals (published 2001-2003) provided a further source of data. STUDY SELECTION: As there were no randomised controlled trials comparing implant therapy with conventional reconstructive dentistry, English language prospective and retrospective cohort studies were selected if; they had a mean follow-up of >/=5 years; included patients who were clinically examined at follow-up; reported details on suprastructures and described at least one-third of reconstructions as fixed partial dentures (FPDs). DATA EXTRACTION AND SYNTHESIS: Two independent reviewers screened articles for inclusion. Disagreements were resolved by discussion and agreement determined by kappa. Data were extracted on the survival proportions of the reconstructions and on biological and technical complications. Biological complications included disturbances in the function of the implant characterized by a biological process affecting the supporting tissues. Technical complications denoted mechanical damage of implants, implant components, or the suprastructures. The number of events for all categories was identified and the corresponding total exposure time of the reconstruction calculated. Failure and complication rates were calculated by dividing the number of events by the total exposure time. RESULTS: Twenty-one studies of implant supported FPDs, reporting on 16 patient cohorts were included. Of the studies, 16 were prospective and five retrospective. A total of 1336 FPDs supported by 3578 oral implants were involved. Meta-analyses gave an estimated implant survival of 95.4% (95% CI 93.9-96.5) after 5 years and 92.8% (95% CI 90-94.8) after 10 years. Implant failure rate was 48% lower (P=0.006) in the more recent studies. The estimated survival for the FPDs was 95% (95% CI 92.2-96.8) after 5 years and 86.7% (95% CI 82.8-89.8) after 10 years. Four studies provided information on the number of patients free from complications - after 5 years 61.3% (95% CI 55.3-66.8) had suffered no minor or major complications. A random effects Poisson model revealed the rate of biological complications for patients treated with implant supported FPDs to be 8.6% (95% CI 5.1-14.1) after 5 years. For technical complications the cumulative 5 year complication rate varied from 0.4% for implant fracture to 13.2% for veneer fracture. CONCLUSIONS: Although survival rate for implant supported FPDs is high, biological and technical complications are relatively common.

90% of fixed partial dentures survive 5 years. How long do conventional fixed partial dentures (FPDs) survive and how frequently do complications occur?

DATA SOURCES: PubMed (1966-April 2004) provided the primary data source along with the bibliographies from identified articles and reviews. STUDY SELECTION: As there were no randomised controlled trials, English language prospective and retrospective cohort studies were selected if they had a mean follow-up of >/=5 years, included patients who were clinically examined at follow-up, reported details on suprastructures and described at least one-third of reconstructions as fixed partial dentures (FPDs). DATA EXTRACTION AND SYNTHESIS: Two independent reviewers screened articles for inclusion. Disagreements were resolved by discussion and agreement determined by kappa. Three reviewers extracted data on the survival and success of the reconstructions and on biological and technical complications. Studies deemed sufficiently similar by design were pooled using negative binomial regression with robust standard errors. Ten-year survival risks were calculated using exp(-10 x failure rate) and 10-year failure risks using 1-S(10). RESULTS: 17 retrospective and two prospective cohort studies including 1764 patients with 3548 FPDs analyzed in total. Meta-analysis was undertaken and after exclusion of one outlier a 10-year FPD survival of 92% was estimated. Only four studies provided information on FPD success - pooled complication rate was 34.1/1000 FPD years (95% CI 16-74). Exclusion of one outlier resulted in an estimated 10-year success of 81.1%. Considering biological complications, the estimated 10-years risk for caries at abutments was 9.5% (95% CI 4.6-89.9) while that for FPD loss due to caries and periodontal disease were 2.6% (95% CI 1.6-4.2) and 0.5% (95% CI 0.1-2.2), respectively. Estimated 10-year risks for technical complications were: 6.4% (95% CI 3.9-10.4) for loss of retention; 2.1% (95% CI 1.4-3.2) for loss of FPD due to abutment fracture and 3.2% (95% CI 1.5-6.5) for material fractures. CONCLUSIONS: Estimated success and survival rates for conventional FPDs largely confirm those of previous reviews. Technical complications such as loss of retention, which have not been reviewed before, resulted in a greater risk of FPD loss than did biological complications.