Cross-Sectional Hardness of Enamel from Human Teeth at Different Posteruptive Ages

This study evaluated, by cross-sectional hardness (CSH), enamel maturation at different depths in sound human teeth at different posteruptive ages (12 per age group): unerupted (molars; control), 2-3 years (premolars), 4-10 years (premolars) and >10 years (molars). Cross-sectional Knoop hardness was measured at 10, 30, 50, 70, 90, 110, 220 and 330 mu m depth from the surface. The data were subjected to two-way ANOVA followed by Bonferroni`s pairwise tests (alpha = 0.05). The CSH significantly increased with posteruptive age, indicating that the time of exposure in the oral cavity might result in deep enamel maturation. Copyright (C) 2009 S. Karger AG, Basel

Cupped lesions of early onset dental erosion in young southeast Queensland adults

Background: Dental erosion manifests as cupped lesions on cusp apices and in fissures of teeth in patients from southeast Queensland referred with excessive tooth wear When found in young adults, these lesions may indicate early onset of active dental erosion. If the numbers and extent of cupped lesions increase with age, erosion may be a slow cumulative process. Methods: This cross-sectional study recorded the presence or absence and the relative sizes of cupped lesions from all cusps and occlusal fissures on premolar and permanent molar teeth from study models by image analysis. Type-specimens of cupped lesions were examined. Results: The Incidence by tooth reflected time in the mouth, post-tooth emergence. A linear increase in lesion number and size, with age, was found. However, cupped lesions occurred on mandibular first molar cusp apices as often, and attained greater extent, in adults under 27 years compared with older subjects. Conclusion: Marked differences were found between lesion number and size, between maxillary and mandibular molar sites that reflect differences in salivary protection against dental erosion. The significance of this study is that the mandibular first permanent molar indicates the age of onset and severity of dental erosion.

Ross River virus transmission, infection, and disease: a cross-disciplinary review

Ross River virus (RRV) is a fascinating, important arbovirus that is endemic and enzootic in Australia and Papua New Guinea and was epidemic in the South Pacific in 1979 and 1980. Infection with RRV may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. RRV disease notificatïons in Australia average 5,000 per year. The first well-described outbreak occurred in 1928. During World War II there were more outbreaks, and the name epidemic polyarthritis was applied. During a 1956 outbreak, epidemic polyarthritis was linked serologically to a group A arbovirus (Alphavirus). The virus was subsequently isolated from Aedes vigilax mosquitoes in 1963 and then from epidemic polyarthritis patients. We review the literature on the evolutionary biology of RRV, immune response to infection, pathogenesis, serologic diagnosis, disease manifestations, the extraordinary variety of vertebrate hosts, mosquito vectors, and transmission cycles, antibody prevalence, epidemiology of asymptomatic and symptomatic human infection, infection risks, and public health impact. RRV arthritis is due to joint infection, and treatment is currently based on empirical anti-inflammatory regimens. Further research on pathogenesis may improve understanding of the natural history of this disease and lead to new treatment strategies. The burden of morbidity is considerable, and the virus could spread to other countries. To justify and design preventive programs, we need accurate data on economic costs and better understanding of transmission and behavioral and environmental risks.

Diversity and commonality in national identities: an exploratory analysis of cross-national patterns

Issues of boundary maintenance are implicit in all studies of national identity. By definition, national communities consist of those who are included but surrounded (literally or metaphorically) by those who are excluded. Most extant research on national identity explores criteria for national membership largely in terms of official or public definitions described, for example, in citizenship and immigration laws or in texts of popular culture. We know much less about how ordinary people in various nations reason about these issues. An analysis of cross-national (N = 23) survey data from the 1995 International Social Science Program reveals a core pattern in most of the countries studied. Respondents were asked how important various criteria were in being 'truly' a member of a particular nation. Exploratory factor analysis shows that these items cluster in terms of two underlying dimensions. Ascriptive/objectivist criteria relating to birth, religion and residence can be distinguished from civic/voluntarist criteria relating to subjective feelings of membership and belief in core institutions. In most nations the ascriptive/objectivist dimension of national identity was more prominent than the subjective civic/voluntarist dimension. Taken overall, these findings suggest an unanticipated homogeneity in the ways that citizens around the world think about national identity. To the extent that these dimensions also mirror the well-known distinction between ethnic and civic national identification, they suggest that the former remains robust despite globalization, mass migration and cultural pluralism. Throughout the world official definitions of national identification have tended to shift towards a civic model. Yet citizens remain remarkably traditional in outlook. A task for future research is to investigate the macrosociological forces that produce both commonality and difference in the core patterns we have identified.

Determinants of hepato- and spleno-megaly in Hunan, China: cross-sectional survey data from areas endemic for schistosomiasis

In order to understand the determinants of schistosome-related hepato- and spleno-megaly better, 14 002 subjects aged 3-60 years (59% male; mean age =32 years) were randomly selected from 43 villages, all in Hunan province, China, where schistosomiasis caused by Schistosoma japonicum is endemic. The abdomen of each subject was examined along the mid-sternal (MSL) and mid-clavicular lines, for evidence of current hepato- and/or spleno-megaly, and a questionnaire was used to collect information on the medical history of each individual. Current infections with S. japonicum were detected by stool examination. Almost all (99.8%) of the subjects were ethnically Han by descent and most (77%) were engaged in farming. Although schistosomiasis appeared common (42% of the subjects claiming to have had the disease), only 45% of the subjects said they had received anti-schistosomiasis drugs. Overall, 1982 (14%) of the subjects had S. japonicum infections (as revealed by miracidium-hatching tests and/or Katon Katz smears) when examined and 22% had palpable hepatomegaly (i.e. enlargement of at least 3 cm along the MSL), although only 2.5% had any form of detectable splenomegaly (i.e. a Hackett's grade of at least 1). Multiple logistic regression revealed that male subjects, fishermen, farmers, subjects aged greater than or equal to 25 years, subjects with a history of schistosomiasis, and subjects who had had bloody stools in the previous 2 weeks were all at relatively high risk of hepato- and/or spleno-megaly. In areas moderately endemic for Schistosoma japonicum, occupational exposure and disease history appear to be good predictors of current disease status among older residents. These results reconfirm those reported earlier in the same region.

A study of the vacuum gamma-radiolysis of two aromatic polyimide fluoropolymers containing phenylphosphine oxide

The vacuum gamma -radiolysis of two fluorinated polyimides containing phenylphosphine oxide units, TOR-RC and TOR-RC ODPA, have been studied at 77 K and 300 K. The phenyl phosphine oxide units provide protection of the polymers towards oxidation by oxygen atoms and the bulky fluoromethyl groups reduce the colouration of the polymers by limiting donor-acceptor complex formation through the aromatic units. At 77 K the radicals formed were identified to be a mixture of neutral radicals (60%) and anion radicals. At 300 K only neutral radicals were found. The G-values for radical formation were found to be 0.50 and 0.42 at 77 K and 0.051 and 0.052 at 300 K for TOR-RC and TOR-RC ODPA, respectively. Little change was observed in the visible spectra of the polyimides following vacuum radiolysis at 300 K up to a dose of 3.3 MGy, and the polymers were shown to undergo net cross linking with a gel dose of 0.45 MGy.

Immunization with tumor-associated epitopes fused to an endoplasmic reticulum translocation signal sequence affords protection against tumors with down-regulated expression of MHC and peptide transporters

Treatment of human cancers with an inherent antigen-processing defect due to a loss of peptide transporters (TAP-1 and TAP-2) and/or MHC class I antigen expression remains a considerable challenge. There is now an increasing realization that tumor cells with down-regulated expression of TAP and/or MHC class I antigens display strong resistance to cytotoxic T lymphocyte (CTL)mediated immune control, and often fail to respond to the conventional immunotherapeutic protocols based on active immunization with tumor-associated epitopes (TAE) or adoptive transfer of tumor-specific T cells, In the present study, we describe a novel approach based on immunization with either genetically modified tumor cells or naked DNA vectors encoding TAE fused to an endoplasmic reticulum (ER) signal sequence (ER-TAE) which affords protection against challenge by melanoma cells with down-regulated expression of TAP-1/2 and MHC class I antigens. In contrast, animals immunized with a vaccine based on TAE alone showed no protection against tumor challenge. Although MHC-peptide tetramer analysis showed a similar frequency of antigen-specific CTL in both ER-TAE- and TAE-immunized mice, functional analysis revealed that CTL activated following immunization with ER-TAE displayed significantly higher avidity for TAE when compared to animals immunized with the TAE alone, These observations provide a new strategy in anti-cancer vaccine design that allows activation of a highly effective and well-defined CTL response against tumors with down-regulated expression of TAP and MHC class I antigens.