Developmental Defects of Enamel in Primary Teeth and Association with Early Life Course Events: A Study of 6--36 Month old Children in Manyara, Tanzania.

Children with low birth weight show an increased prevalence of developmental defects of enamel in the primary dentition that subsequently may predispose to early childhood caries (ECC).Focusing 6--36 months old, the purpose of this study was to assess the frequency of enamel defects in the primary dentition and identify influences of early life course factors; socio-demographics, birth weight, child's early illness episodes and mothers' perceived size of the child at birth, whilst controlling for more recent life course events in terms of current breastfeeding and oral hygiene. A cross-sectional study was conducted in the high fluoride area of Manyara, northern Tanzania including 1221 child-mother pairs who attended Reproductive and Child Health (RCH) clinics for immunization and/or growth monitoring. After the primary caregivers had completed face to face interviews at the health care facility, children underwent oral clinical examination whereby ECC and developmental defects of enamel were recorded using field criteria. All erupted teeth were examined and the enamel defects were assessed on buccal surfaces according to the modified DDE Index. The prevalence of enamel defects was 33.3%. Diffuse opacities were the most common defects identified (23.1%), followed by hypoplasia (7.6%) and demarcated opacities (5.0%). The most frequently affected teeth were the upper central incisors (29.0% - 30.5%), whereas lower central incisors (4.3% to 4.5%) were least frequently affected. Multiple logistic regression analysis, adjusting for confounding the factors revealed that having normal birth weight (equal or more than 2500 g) associated with lower odds of having enamel hypoplasia [OR 0.22 (95% CI 0.1-0.7)]. No statistically significant association occurred between birth weight and diffuse opacities, demarcated opacities or combined DDE. Children with the history of low birth weight were more likely than their normal birth weight counterparts to present with enamel hypoplasia. In view of the frequent occurrence of enamel defects and the fact that hypoplasia may constitute a risk factor for future ECC, enamel defects should be included as a dental health indicator in epidemiological studies of children in northern Tanzania

A comparison of photographic, replication and direct clinical examination methods for detecting developmental defects of enamel

Different methods have been used for detecting developmental defects of enamel (DDE). This study aimed to compare photographic and replication methods with the direct clinical examination method for detecting DDE in children's permanent incisors

Short-term acclimation in adults does not predict offspring acclimation potential to hypoxia

Abstract The prevalence of hypoxic areas in coastal waters is predicted to increase and lead to reduced biodiversity. While the adult stages of many estuarine invertebrates can cope with short periods of hypoxia, it remains unclear whether that ability is present if animals are bred and reared under chronic hypoxia. We firstly investigated the effect of moderate, short-term environmental hypoxia (40% air saturation for one week) on metabolic performance in adults of an estuarine amphipod, and the fitness consequences of prolonged exposure. We then reared the offspring of hypoxia-exposed parents under hypoxia, and assessed their oxyregulatory ability under declining oxygen tensions as juveniles and adults. Adults from the parental generation were able to acclimate their metabolism to hypoxia after one week, employing mechanisms typically associated with prolonged exposure. Their progeny, however, did not develop the adult pattern of respiratory regulation when reared under chronic hypoxia, but instead exhibited a poorer oxyregulatory ability than their parents. We conclude that species apparently hypoxia-tolerant when tested in short-term experiments, could be physiologically compromised as adults if they develop under hypoxia. Consequently, we propose that the increased prevalence of hypoxia in coastal regions will have marked effects in some species currently considered hypoxia tolerant

Microbial population and diversity on the exoskeletons of four insect species associated with gorse (Ulex europaeus L.)

Fungi and bacteria on the external surfaces of four gorse-associated insect species: gorse seed weevil Apion ulicis Förster (Coleoptera: Apionidae), light brown apple moth Epiphyas postvittana Walker (Lepidoptera: Tortricidae), gorse pod moth Cydia ulicetana Denis and Schiffermüller (Lepidoptera: Tortricidae) and gorse thrips Sericothrips staphylinus Haliday (Thysanoptera: Thripidae), were recov-ered by washing and plating techniques. The isolates were identified by morphology and polymerase chain reaction (PCR) restriction fragment length polymorphism and sequencing of internally tran-scribed spacer (ITS) and 16S rDNA. A culture-independent technique (direct PCR) was also used to assess fungal diversity by direct amplification of ITS sequences from the washings of the insects. All insect species carried Alternaria, Cladosporium, Corallomycetella, Penicillium, Phoma, Pseudozyma spp. and entomopathogens. Ninety-four per cent of the 178 cloned amplicons had ITS sequence similarity to Nectria mauritiicola (syn. Corallomycetella repens).E. postvittana carried the largest fungal spores (spore mean surface area of 126 μm 2) and the most fungal colony forming units per insect. Methylo-bacterium aquaticum and Pseudomonas lutea were isolated from all four insect species. P. fluorescens was the most abundant bacterium on the lepidopteran insects. This study presents the diversity of microbial taxa on insect exoskeletons, and provides the basis for developing a novel mycoherbicide delivery strategy for biological control of gorse using insects as vectors of a plant pathogen