Risk factors for oral health in young, urban, Aboriginal and Torres Strait Islander children.

BACKGROUND: The caries process follows a strong social gradient which can commence in the first years of life. Yet data on young children remain limited. This study reports the potential risk factors and indicators in urban, Aboriginal and Torres Strait Islander children aged less than 5 and estimates the prevalence of caries. METHODS: Demographic and risk factor and risk indicator data were collected at baseline in a cohort study of children attending a health clinic in north Brisbane. Dentulous children received a basic oral examination to explore the presence of decayed, missing and filled teeth (dmft). Descriptive analyses were performed. A backwards stepwise logistic regression model was performed to identify potential associations with dmft status. RESULTS: In this study, 180 children enrolled: 111 children received the oral examination, of whom 14 (12.6%) (mean age 35 months) were estimated to have dmft >0. There was a high prevalence of socio-economic, dietary and behavioural risk factors/indicators present for children. Due to the small sample size, planned regression was not performed. CONCLUSIONS: Overall, the prevalence of risk factors and risk indicators for caries in the study population is high. More culturally appropriate resources that support preventive care need to be invested before children are school aged.

Microencapsulation of islets within alginate/poly(ethylene glycol) gels cross-linked via Staudinger ligation.

Functionalized alginate and poly(ethylene glycol) (PEG) polymers were used to generate covalently linked alginate-PEG (XAlgPEG) microbeads of high stability. The cell-compatible Staudinger ligation scheme was used to cross-link phosphine-terminated PEG chemoselectively to azide-functionalized alginate, resulting in XAlgPEG hydrogels. XAlgPEG microbeads were formed by co-incubation of the two polymers, followed by ionic cross-linking of the alginate using barium ions. The enhanced stability and gel properties of the resulting XAlgPEG microbeads, as well as the compatibility of these polymers for the encapsulation of islets and beta cells lines, were investigated. The data show that XAlgPEG microbeads exhibit superior resistance to osmotic swelling compared with traditional barium cross-linked alginate (Ba-Alg) beads, with a five-fold reduction in observed swelling, as well as resistance to dissolution via chelation solution. Diffusion and porosity studies found XAlgPEG beads to exhibit properties comparable with standard Ba-Alg. XAlgPEG microbeads were found to be highly cell compatible with insulinoma cell lines, as well as rat and human pancreatic islets, where the viability and functional assessment of cells within XAlgPEG are comparable with Ba-Alg controls. The remarkable improved stability, as well as demonstrated cellular compatibility, of XAlgPEG hydrogels makes them an appealing option for a wide variety of tissue engineering applications.

A double-blind, placebo-controlled investigation of the efficacy of modafinil for sustaining the alertness and performance of aviators: a helicopter simulator study.

RATIONALE: In 1998, the FDA approved modafinil for treating excessive daytime sleepiness in narcoleptics, and this has raised questions about the appropriateness of this compound for enhancing alertness in sleep-deprived controls. This study explored the efficacy of modafinil for maintaining the performance of volunteers required to accomplish highly demanding tasks despite sleep loss. OBJECTIVE: The principal objective was to determine whether prophylactic doses of modafinil would attenuate decrements in aviator performance and arousal throughout 2 days and 1 night without sleep. METHODS: Six pilots were exposed to two 40-h periods of continuous wakefulness. In one, three 200-mg doses of modafinil were given and in the other, matching placebos were administered. Helicopter simulator flights, resting EEGs, and Profile of Mood States (POMS) questionnaires were evaluated. RESULTS: Modafinil attenuated sleep deprivation effects on four of six flight maneuvers, reduced slow-wave EEG activity, and lessened self-reported problems with mood and alertness in comparison to placebo. The most noticeable benefits occurred between 0330 and 1130 hours, when the combined impact of sleep loss and the circadian trough was most severe. The most frequently observed drug side effects were vertigo, nausea, and dizziness. These could have been related to: 1) the motion-based testing, 2) the use of a simulator rather than an actual aircraft (i.e., "simulator sickness"), and/or 3) the administration of more than 400 mg modafinil. CONCLUSIONS: Modafinil is a promising countermeasure for sleep loss in normals; however, additional studies aimed at reducing side effects are needed before it should be used in aviators.

The effects of body posture on resting electroencephalographic activity in sleep-deprived subjects.

OBJECTIVE: This study examined the effects of posture on the resting electroencephalographic (EEG) activity of sleep-deprived volunteers. METHODS: EEG data were collected under two conditions at 13 separate time points. Testing was performed while subjects remained in a normal seated position and then repeated while subjects stood upright. RESULTS: Results indicated that delta and theta activity progressively increased as a function of sleep loss, and that standing upright attenuated this effect. CONCLUSIONS: These results suggest that an upright posture increases EEG arousal and may be useful for counteracting fatigue in sleep-deprived individuals.