Variation in groundwater manganese in Finland.

Increasing evidence has emerged that Mn derived from drinking water could be a health risk, especially for children. This study aimed to provide more information on the variation in Mn concentrations in well water and factors that affect manganese concentrations in groundwater in the natural environment. The geochemical data consisted of analyses of single water samples (n = 5311) that were taken only once and data from monitoring sites where water samples (n = 4607) were repeatedly taken and analyzed annually from the same wells. In addition, the well-specific results from six wells at monitoring sites were described in detail. We obtained the data on water samples from the groundwater database of Geological Survey of Finland. In single samples, Mn concentrations varied from < 0.02 µg/l to 5800 µg/l in bedrock well waters and up to 6560 µg/l in Quaternary deposit well waters. Results from single water samples from bedrock wells and Quaternary deposit wells indicated that the dissolved oxygen content has an inverse association with the Mn concentration. When the dissolved oxygen O2 levels were lower, the Mn concentrations were higher. No clear association was found between the Mn concentration and the pH or depth of the well for single samples. Part of Mn was particle bound, because total Mn was higher than soluble Mn in most measured samples. In the monitoring survey, large variation in Mn concentrations was found in bedrock well water in Kemijärvi, 114-352 µg/l, and in dug well water in Hämeenkoski, 8.77-2640 µg/l. Seasonal and spatial variability in Mn concentrations in water samples from two bedrock wells was large at monitoring sites in northern Finland. Variability in the Mn concentrations in groundwater can be large, even in the same area. These data suggest that single measurements of the Mn concentration from a water source may not reveal the Mn status, and measurement of both the total and soluble Mn concentrations may be recommended.

Climate-induced warming imposes a threat to north European spring ecosystems.

Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate-related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater-dependent ecosystems (GDEs) remains poorly known. Here we report long-term water temperature trends in 66 northern European cold-water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968-2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high-emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67 °C (RCP2.6) to 5.94 °C (RCP8.5) by 2086. According to the worst-case scenario, water temperature of these originally cold-water ecosystems (regional mean in the late 1970s: 4.7 °C) may exceed 12 °C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring-fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold-stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1 °C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring-fed streams. Climate change-induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems.

Children with Down syndrome: oral development and morphology after use of palatal plates between 6 and 48 months of age.

OBJECTIVE: The aim of this study was to describe the number of erupted teeth, sucking habits, tongue morphology, facial expression and speech in children with Down syndrome (DS) aged 48 +/- 6 months and treated from 6 months of age with palatal plates in combination with speech and language therapy. METHODS: The research took the form of a multicentre, multidisciplinary, longitudinal study of children with DS followed from the age of 6 months. A total of 37 children with DS were included. One child could not cooperate at all and was excluded from the evaluations. In combination with speech and language intervention provided by speech and language therapists, the children used palatal plates provided by dentists from 6 months of age. In the evaluation, the children in the sample (n = 36) were compared with two similarly aged control groups: one group of children with DS who never had used palatal plates (n = 31) and one group of children with normal development (n = 36). The evaluation of oral parameters was performed by dentists after calibration. Registration of facial expression and speech was done by a speech and language therapist, and the evaluation was done by two speech and language therapists and one phonetician who were calibrated in joint discussions. RESULTS: In contrast to the children with DS in the control group, the subjects in the study were found to have as many erupted teeth as the children with normal development. The prevalence of sucking habits did not differ between the three groups. Only children with DS sucked their tongue, a toy or other things in addition to a thumb or dummy. The prevalence of tongue diastase in the study group with DS was of the same magnitude as in the evaluation at the age of 18 +/- 3 months. The palatal plates were used by 57-65% of the children without any larger problems. In the study sample, the possible beneficial effects of palatal plate therapy were a lower prevalence of posterior cross-bite, a higher prevalence of frontal cusp-to-cusp relation and a lower prevalence of frontal open bite. Evaluation of facial expression and speech showed a higher score for facial expression and a better communicative capacity in the children in the study group than in the control children with DS. CONCLUSIONS: In children with DS, palatal plate therapy between 6 and 48 months of age in connection with speech and language intervention had a positive effect on occlusion, oral motor function, facial expression and speech. No harmful effects were observed. Although this is a valuable method, however, it must be emphasized that palatal plate therapy puts additional demands on already burdened children and their caretakers.

The new Enamel Defects Index: testing and expansion.

The Enamel Defects Index (EDI) was created based on three innovative principles: (i) a basic level of the three major categories of defects; (ii) more detailed subcategories of each major category; and (iii) each category scored independently as present [1] or absent [0], simplifying decision making. The aim of this investigation was to further test the index in a number of applications and to expand it to record defect subtype and treatment need. Testing was undertaken by operators with different levels of clinical experience. A computer-assisted learning (CAL) package was developed for operator training and calibration. The index was also used on clinical photographs and high-resolution digital images of exfoliated and extracted teeth. Scoring of photographs revealed substantial intra-operator agreement. Training using the CAL package resulted in significant improvement in index use. Intra-operator reproducibility was good to excellent, and interoperator reproducibility was good for buccal surfaces on digital images. Index expansion allowed information on defect subtype, location, and treatment need to be gathered readily. The EDI has high reproducibility and allows more rapid and accurate data collection from clinical and in vitro studies than the Fédération Dentaire Internationale Developmental Defects of Enamel index.

Comparison of methods for measurement of hypoplastic lesions.

Enamel hypoplasia is a quantitative defect of enamel thickness. Methods previously used for its measurement have limitations in clinical studies. The aim of this study was to investigate new methods of measurement using image analysis. Lesions on 8 teeth affected by enamel hypoplasia were quantified from study models and impression surfaces using an image-analysis system. The measurements made included lesion area and tooth surface area; from these the proportion of tooth surface area affected was calculated. For comparison, manual measurement was performed on impression surfaces and study models, using digital callipers. Images were also acquired of lesions on 12 exfoliated teeth, and the lesion area and total tooth area were calculated. For assessment of intra-operator reliability, the +/-repeatability coefficient was calculated. Measurement of the surface of lesions direct from the exfoliated teeth gave the best results overall, followed by direct image analysis of the silicone impression.

Exclusion of p63 as a candidate gene for autosomal-dominant amelogenesis imperfecta.

OBJECTIVE: Mutations within the p63 gene have been shown to cause ectodermal dysplasia syndromes affecting a spectrum of developmental abnormalities, including ectodermal appendages, e.g. enamel. The affected teeth have a similar phenotype as another dental disorder, amelogenesis imperfecta (AI), a disease of genetically determined abnormal enamel formation in the absence of systemic symptoms. The genetic basis of particular forms of AI has been found, although the gene(s) responsible for the most prevalent AI types has not been identified. MATERIAL AND METHODS: DNA samples of 41 individuals (25 affected and 16 unaffected) from 6 Swedish families with autosomal-dominant AI were screened for mutations (by partially denaturing HPLC) and sequenced. RESULTS: No mutation in p63 was found in these families. CONCLUSIONS: p63 is not responsible for different forms of autosomal-dominant AI in the Swedish families studied. The roles of p63 in tooth development and in the genetic etiology of AI remain to be identified.

A nonsense mutation in the enamelin gene causes local hypoplastic autosomal dominant amelogenesis imperfecta (AIH2).

Amelogenesis imperfecta (AI) is an inherited tooth disorder affecting tooth enamel formation only. A gene for autosomal dominant AI, the local hypoplastic form, has been localized to a 4 Mb region on chromosome 4q (AIH2). The enamelin gene (ENAM ), has been mapped to chromosome 4q21, to the same region as AIH2, and was recently shown to be mutated in patients with smooth and thin hypoplastic autosomal dominant AI (ADAI). In this study, we describe an ENAM mutation causing the local hypoplastic form of ADAI, a phenotype that accounts for 27% of the autosomally inherited cases in Northern Sweden. This nonsense mutation in the enamelin gene results in a truncated peptide of 52 amino acids as compared with 1142 amino acids of the normal protein. Our results show that while a splice site mutation is associated with smooth and thin hypoplastic AI, a base substitution resulting in a shorter peptide causes local hypoplasia of the enamel, a milder form of AI. These findings support ENAM as a disease gene, and shed new light on the molecular mechanism of the disease and to the function of the enamelin protein in enamel formation.