The Dental Amalgam Phasedown in New Zealand: A 20-year Trend.

BACKGROUND AND OBJECTIVES: Information on the choice of material and performance of restorations placed in a dental practice annually is limited. The Minamata Convention on Mercury is likely to affect the use of amalgam worldwide. The objective of this research was to investigate the use of restorative materials at the University of Otago Faculty of Dentistry in New Zealand from 1998 to 2017. METHODS: Data from the Faculty of Dentistry's database from the years of interest were compiled. These data included information on the characteristics of restorations, including information on the material used and number of surfaces involved for each restoration. The tooth in which each restoration was placed was categorized by arch, tooth type, and deciduous or permanent dentition. RESULTS: Records identified 227,514 permanent restorations placed from January 1998 to December 2017, of which 91.7% were direct restorations. Among direct restorations, composite resin was the most commonly used material, followed by amalgam, glass ionomer, and compomer. The use of amalgam for direct restorations decreased from 52.3% of direct restorations in 1998 to 7.1% in 2017. A corresponding increase was observed in the use of tooth-colored direct restorations, particularly composites. Among indirect restorations, porcelain fused to metal, gold, and stainless steel (in pediatric applications) were the materials most frequently used. CONCLUSIONS: Despite having no official policy on reducing the use of dental amalgam, the Faculty of Dentistry is following the global trend in reducing its use, with composite resin now well established as the predominant restorative material used. If the current rate of decline persists unchecked, the Faculty of Dentistry could transition to being amalgam free by 2020, although it seems likely that the characteristics and principles of use of the material (and its removal) will be taught for some time to come. This knowledge is important to planning curriculum changes needed to prepare graduates for clinical practice.

Dental implant use in New Zealand: A 10-year update.

OBJECTIVE: The aim of this study was to explore changes in dentists' promotion and use of implants in New Zealand over the past 10 years. METHODS: A postal survey was conducted of a random sample of 807 New Zealand registered dentists, using a 23-item questionnaire adapted from one used in a similar survey in 2004. RESULTS: The participation rate was 54.3%. In the past 10 years, the percentage of dentists providing an implant service has increased from 49.4% to 68.0%, with an equal proportion of females now providing this service. Single missing teeth (56.9%) and trauma (51.5%) are the most common clinical situations in which implants are provided. Patient enquiries about implants have slightly increased. A need for continuing education, particularly in the area of implant prosthetic procedures, was noted by 76.5%. Despite more proprietary implant systems now being available, the most commonly used system has remained unchanged. Cost is still the primary barrier to implementing implant treatment. CONCLUSIONS: Although dental implant use in New Zealand has increased, it appears that a need exists for continuing education, particularly for implant prosthetic procedures. The perceived expense of treatment continues to hinder optimal utilisation.

Use of information and communication technology amongst New Zealand dental students.

Although international studies have shown an increasing use of information and communication technology (ICT) amongst dental students, there are no published studies specific to New Zealand (NZ). The aim of this research was to identify device ownership and academic utilisation patterns amongst New Zealand dental students, including preferences and perceptions, and barriers to use. All currently enrolled dental students (322) were invited to complete a 15-item questionnaire. Data were statistically analysed in SPSS version 20.0. Qualitative data were analysed using a general inductive technique. The participation rate was 78.6% (N = 253 of 322). The majority of respondents personally owned laptop computers (98%) and smartphones (80.2%). A total of 10.8% of participants used a desktop computer everyday for academic purposes, whilst 78.7% used a laptop computer daily, and 54.7% a smartphone. New Zealand dental students demonstrated a high usage of ICT for their coursework with varied use of different online resources. The most frequently used online resources were search engines, social networking sites and lecture slides provided on Blackboard(®) . A high perceived value was placed on both audio podcasts and video podcasts despite the high value also placed on the traditional lectures. Although most participants (84.5%) felt that their ICT knowledge was adequate to meet academic requirements, a small number (1.6%) did not agree.

Biological characterization of a novel class of toll-like receptor 7 agonists designed to have reduced systemic activity.

BACKGROUND AND PURPOSE Toll-like receptor 7 (TLR7) agonists have potential in the treatment of allergic diseases. However, the therapeutic utility of current low molecular weight TLR7 agonists is limited by their systemic activity, resulting in unwanted side effects. We have developed a series of TLR7-selective 'antedrugs', including SM-324405 and AZ12441970, which contain an ester group rapidly cleaved in plasma to reduce systemic exposure. EXPERIMENTAL APPROACH Agonist activity at TLR7 of the parent ester and acid metabolite was assessed in vitro in reporter cells and primary cells from a number of species. Pharmacokinetics following a dose to the lungs was assessed in mice and efficacy evaluated in vivo with a mouse allergic airway model. KEY RESULTS Compounds were selective agonists for TLR7 with no crossover to TLR8 and were metabolically unstable in plasma with the acid metabolite showing substantially reduced activity in a number of assays. The compounds inhibited IL-5 production and induced IFN-α, which mediated the inhibition of IL-5. When dosed into the lung the compounds were rapidly metabolized and short-term exposure of the 'antedrug' was sufficient to activate the IFN pathway. AZ12441970 showed efficacy in a mouse allergic airway model with minimal induction of systemic IFN-α, consistent with the low plasma levels of compound. CONCLUSIONS AND IMPLICATIONS The biological and metabolic profiles of these TLR7-selective agonist 'antedrug' compounds are consistent with a new class of compound that could be administered locally for the treatment of allergic diseases, while reducing the risk of systemic side effects. LINKED ARTICLE This article is commented on by Kaufman and Jacoby, pp. 569-572 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01758.x.

Alpha male chimpanzee grooming patterns: implications for dominance "style".

In social primates, individuals use various tactics to compete for dominance rank. Grooming, displays and contact aggression are common components of a male chimpanzee's dominance repertoire. The optimal combination of these behaviors is likely to differ among males with individuals exhibiting a dominance "style" that reflects their tendency to use cooperative and/or agonistic dominance tactics. Here, we examine the grooming behavior of three alpha male chimpanzees at Gombe National Park, Tanzania. We found that (1) these males differed significantly in their tendency to groom with other males; (2) each male's grooming patterns remained consistent before, during and after his tenure as alpha, and (3) the three males tended to groom with high- middle- and low-ranking partners equally. We suggest that body mass may be one possible determinant of differences in grooming behavior. The largest male exhibited the lowest overall grooming rates, whereas the smallest male spent the most time grooming others. This is probably because large males are more effective at physically intimidating subordinates. To achieve alpha status, a small male may need to compensate for reduced size by investing more time and energy in grooming, thereby ensuring coalitionary support from others. Rates of contact aggression and charging displays conformed to this prediction, suggesting that each male exhibited a different dominance "style."

Inhaled allergen-driven CD1c up-regulation and enhanced antigen uptake by activated human respiratory-tract dendritic cells in atopic asthma.

BACKGROUND: Dendritic cells (DC) mediate inflammation in rodent models of allergic airway disease, but the role played by human respiratory-tract DC (hRTDC) in atopic asthma remains poorly defined. Recent data suggest that CD1 antigen presentation by hRTDC may contribute to asthma pathogenesis. OBJECTIVE: To investigate the influence of hRTDC on the balance between atopy and allergic asthma in human subjects and to determine whether CD1 expression by hRTDC is modulated during asthmatic inflammation. METHODS: Sputum cells were induced from steroid-naïve, allergen-challenged and allergen-naïve subjects (atopic asthmatics, atopic non-asthmatics and non-atopic controls). hRTDC were identified using monoclonal antibody labelling and analysis by flow cytometry. RESULTS: hRTDC stained HLA-DR(+) (negative for markers of other cell lineages) were predominantly myeloid and comprised approximately 0.5% of viable sputum cells. Sputum cells were potent stimulators of allogeneic CD4(+) naïve T cells and enrichment/depletion experiments correlated stimulatory potency with DC numbers. Sputum contained cells that exhibited typical dendritic morphology when analysed by electron microscopy. Myeloid hRTDC were endocytically active, but uptake of FITC-dextran was enhanced in cells from asthmatics (P<0.001). Despite their increased endocytic capacity, asthmatic myeloid hRTDC appeared mature and expressed increased levels of maturation markers (P<0.05-P<0.001), CD1c, CD1d and langerin (P<0.05). CD1c expression by asthmatic myeloid hRTDC was enhanced upon in vivo allergen challenge (three to ninefold within 24 h; P<0.05). CD11c(-)CD123(high) hRTDC were only detected in asthmatic sputum and were increased in number following allergen challenge. CONCLUSION: Despite limited cell numbers, it proved possible to analyse human RTDC in induced sputum, providing evidence that increased antigen uptake and enhanced CD1 presentation by activated hRTDC may contribute to allergic airway disease. CD1 presentation by hRTDC in atopic asthma may therefore constitute a novel target for future intervention strategies.

Validation of a 21-locus autosomal SNP multiplex for forensic identification purposes.

A single nucleotide polymorphism (SNP) multiplex has been developed to analyse highly degraded and low copy number (LCN) DNA template, i.e. <100 pg, for scenarios including mass disaster identification. The multiplex consists of 20 autosomal non-coding loci plus Amelogenin for sex determination, amplified in a single tube PCR reaction and visualised on the Applied Biosystems 3100 capillary electrophoresis (CE) system. Allele-specific primers tailed with shared universal tag sequences were designed to speed multiplex design and balance the amplification efficiencies of all loci through the use of a single reverse and two differentially labelled allele denoting forward universal primers. As the multiplex is intended for use with samples too degraded for conventional profiling, a computer program was specifically developed to aid interpretation. Critical factors taken into account by the software include empirically determined extremes of heterozygous imbalance (Hb) and the drop-out threshold (Ht) defined as the maximum peak height of a surviving heterozygous allele, where its partner may have dropped out. The discrimination power of the system is estimated at 1 in 4.5 million, using a White Caucasian population database. Comparisons using artificially degraded samples profiled with both the SNP multiplex and AMPFISTR SGM plus (Applied Biosystems) demonstrated a greater likelihood of obtaining a profile using SNPs for certain sample types. Saliva stains degraded for 147 days generated an 81% complete SNP profile whilst short tandem repeats (STRs) were only 18% complete; similarly blood degraded for 243 days produced full SNP profiles but only 9% with STRs. Reproducibility studies showed concordance between SNP profiles for different sample types, such as blood, saliva, semen and hairs, for the same individual, both within and between different DNA extracts.

Structure-based focusing using pharmacophores derived from the active site of 17beta-hydroxysteroid dehydrogenase.

Structure-based focusing constitutes a powerful approach to design libraries of compounds with a given biological profile. Computers with special software can be used to analyse the large amount of data usually available for the compounds. Pharmacophores can be used to identify new compounds that present a specific arrangement of features responsible for a certain type of activity. When available, information about the 3D structure of a biological target can also be included in the building of pharmacophore models. These pharmacophores can then be used as queries to search and/or focus large compound libraries. Multiple pharmacophores were generated from the 3D structure 17beta-hydroxystreoid dehydrogenase type1 complexed with different inhibitors. The validity of these pharmacophores was assessed against a test database containing known active and inactive 17beta-hydroxystreoid dehydrogenase type1 inhibitors. The most selective models were then used to search commercial databases for new structural lead molecules. This approach has allowed us to identify a few new compounds possessing structural features common to flavonoids, a structural class of compounds known to contain good inhibitors of 17beta-hydroxystreoid dehydrogenase type1 enzyme. A structure-based focusing approach is demonstrated to be a meaningful and powerful technique for identifying new lead candidates, which can be taken into the lead optimization process.

Design of libraries to explore receptor sites.

Despite rapid progress in both combinatorial chemistry and high-throughput screening, the number of molecules that could potentially be made and tested for biological activity still far exceeds the capacity for synthesis or screening. Consequently, it is potentially valuable to select and synthesize sublibraries that contain rationally selected subsets. When the structure of the protein receptor site is known, this may be used to impose restrictions of the selection on molecules. This paper describes a method for rapid analysis of large virtual libraries to select a subset that can exhibit at least one conformer which wil interact strongly with the receptor and fit within the receptor site.

Interpersonal problem-solving skills training in the treatment of self-poisoning patients.

The present study evaluated the effectiveness of interpersonal problem-solving skills training (IPSST) for the treatment of self-poisoning patients. Thirty-nine self-poisoning patients were assigned randomly either to IPSST or to a control treatment condition (a brief problem-oriented approach). Both conditions were equally effective in reducing the number of presenting problems and in reducing hopelessness levels. However, the IPSST condition was significantly more effective than the control condition as determined by other outcome measures (measures of interpersonal cognitive problem solving, self-rated personal problem-solving ability, perceived ability to cope with ongoing problems, and self-perception). Follow-up studies showed maintenance of IPSST treatment gains at 6 months and a greater reduction of repetition of self-poisoning in the IPSST group at 1 year posttreatment.

A single photon emission computerised tomography study of regional brain function in elderly patients with major depression and with Alzheimer-type dementia.

The uptake, at rest, of 99mTc-exametazime into different brain regions was compared using SPECT for 20 elderly subjects with major depressive disorder, 20 with Alzheimer-type dementia, and 30 age-matched normal volunteers. Uptake was referred to calcarine-occipital cortex as a reference sensory area. Cross-sectional differences between the three groups were highly statistically significant, but reflected primarily the reductions in cortical uptake in the Alzheimer group. A detailed comparison of depressed patients and controls identified decrements in anterior cingulate, temporal and frontal cortex and in caudate and thalamus in men only. These decrements were correlated with impairment of performance on a trail-making task, but were also associated with continuing treatment with antidepressants or benzodiazepines. However, most depressed patients had quantitatively normal scans for posterior parietal association cortex, and this suggests that SPECT may find a limited role in the differential diagnosis of depression and dementia. The reduced brain function in some depressed patients may parallel the findings from studies of brain structure in elderly depressives; there was between good outcome at 6-18 months and increased tracer uptake in subcortical areas.

Prevalence of gastric lesions in foals without signs of gastric disease: an endoscopic survey.

Gastroendoscopic examinations were conducted on 75 Thoroughbred foals aged two to 85 days on seven breeding farms in England and Ireland. The foals showed no signs of gastric disease. There was no significant difference between lesion prevalence in foals in England (16 of 28 foals; 57 per cent) or Ireland (22 of 47 foals; 47 per cent). Neither was there any sex predilection (18 of 36 males; 20 of 39 females). Lesions were most prevalent in foals under 10 days old (8 of 9) and least prevalent in foals older than 70 days (3 of 10). Lesions occurred most frequently in the squamous mucosa immediately adjacent to the margo plicatus along the greater curvature (34 foals), whereas lesions in the squamous fundus, the glandular fundus, and the lesser curvature were observed in 11, six and three foals, respectively. Lesions were not observed in the squamous mucosa surrounding the cardia. Gastric lesions were more prevalent in foals with a previous disorder than in those without (68 vs 43 per cent) and particularly with a history of recent or concurrent diarrhoea (9 of 14).

Delayed response of the mouse uterus to progesterone and oestradiol.

The delayed response of the uterus of the ovariectomized mouse to progesterone (P) required the presence of a low dose of oestradiol-17 beta (E2) and was associated with a maintained level of uterine DNA, an increase in RNA:DNA ratio and in total tissue protein and a decreased level of uterine P. This last parameter was associated with an increased level of in vitro metabolism of P by the uterus. Changes in the level of receptors for P and E2 were temporally unrelated to the delayed response. Omission of oestradiol every second, third or fourth day inhibited development of the delayed response, which could also be obtained with the long acting progestogen, medroxy progesterone acetate, and E2 or oestradiol benzoate.

Interpersonal problem-solving deficits in self-poisoning patients.

Self-poisoning patients (n = 40) were compared with psychiatric patients (n = 40) and nonpatient controls (n = 20) on measures of interpersonal problem-solving skills and locus of control in an effort to determine the importance of these cognitive and personality variables in self-poisoning behavior. The psychiatric and self-poisoning groups showed deficits on measures assessing interpersonal problem solving when compared with nonpatient controls. The self-poisoning group performed below the level of the psychiatric patients on all except one test, on which they performed at the level of the psychiatric group. Locus of control did not differentiate self-poisoning patients from nonpatient controls, and it was concluded that this variable is not an important factor in self-poisoning behavior.

Evaluation of leukapheresis and thrombocytapheresis in the horse.

Continuous-flow centrifugation leukapheresis techniques were used to collect 300-ml volumes of leukocyte-rich plasma from 5 nonmedicated horses and from 5 corticosteroid-stimulated horses. White blood cell counts and differential counts were performed on the horses before (base line) and up to 48 hours after leukapheresis. Systemic administration of hydrocortisone increased numbers of total WBC and neutrophils and improved harvest of these cells. Nonmedicated horses had a mean yield of 3.38 X 10(10) leukocytes in the 300-ml volume. Stimulated horses yielded a mean of 6.88 X 10(10) leukocytes. After leukapheresis, WBC counts decreased a mean of 38% in nonstimulated horses and decreased a mean of 30% in stimulated horses. By 6 hours after leukapheresis, circulating WBC counts of horses in both groups had returned to preleukapheresis values. The relationship between neutrophil yield and the 4 variables (preleukapheresis WBC count, preleukapheresis neutrophil count, preleukapheresis lymphocyte count, and the PCV of the leukocyte-rich plasma) were examined, using simple (pair-wise) correlation and multiple linear regression. A significant positive correlation was found between neutrophil yield and preleukapheresis WBC and neutrophil counts. Because sodium citrate was used in the collection system to prevent extracorporeal blood coagulation, ionized and total serum calcium concentrations were monitored before and after leukapheresis. Although total serum calcium concentrations remained unchanged, ionized calcium concentrations decreased approximately 33% from base-line values during the 2-hour leukapheresis procedures. Occasional mild muscle fasciculations were the only adverse clinical signs of citrate toxicity exhibited by the horses.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous-flow centrifugation hemapheresis in the horse.

In a continuous-flow centrifugation apheresis technique adapted for blood-component separation and collection in horses, hydroxyethyl starch was not required for erythrocyte sedimentation. The efficacy and separation characteristics of whole blood from 10 horses were evaluated at various gravitational forces (700 to 1,500 rpm), using a constant withdrawal rate (100 ml/min). Maximum leukocyte collection occurred at 700 rpm (P less than 0.01), and optimal neutrophil collection occurred at 700 to 750 rpm (P less than 0.01). Although neutrophil counts decreased and lymphocyte counts remained constant at higher rpm settings, an optimal rpm range could not be determined for lymphocyte collection. Peak platelet collection occurred at 1,500 rpm. The response of whole blood from 5 horses was evaluated at lower (500 to 700 rpm) and higher (1,400 to 2,200 rpm) centrifuge speeds. A constant whole blood withdrawal rate of 100 ml/min and a leukocyte collection rate of 3 ml/min were maintained. The optimal rpm settings were determined and compared with values obtained from the 10 horses. Significant differences (P less than 0.01) did not exist between maximum numbers of leukocytes collected at low and high speeds. There was a significant (P less than 0.01) decrease in neutrophils and a concomitant increase in the numbers of lymphocytes recovered at the higher rpm. Platelet yields increased as rpm was increased to 2,000.

Community-acquired bacteremic Achromobacter xylosoxidans type IIIa pneumonia in a patient with idiopathic IgM deficiency.

A man was hospitalized with bacteremic Achromobacter xylosoxidans type IIIa pneumonia. The authors are aware of no previously reported similar infections caused by this bacterium. A clinical cure was achieved with a combination of carbenicillin and kanamycin therapy. Microtiter susceptibility testing revealed that carbenicillin was the antibiotic to which A. xylosoxidans IIIa was most sensitive (minimal inhibitory concentration, 1.6 microgram/ml) and that synergy between carbenicillin and kanamycin existed. During the patient's hospitalization, deficiency of IgM (21 mg/dl) was found. Specific serum activity against A. xylosoxidans IIIa was detected by the agglutination method. Specific anti-A. xylosoxidans IIIa IgG, but not IgM, was detected by indirect immunofluorescence. It appears that a defect in immunologic recognition of A. xylosoxidans IIIa as an invasive bacterium, a defect in synthesis of specific IgM, or both, contributed to this patient's infection.