Neonatal ethanol exposure reduces AMPA but not NMDA receptor levels in the rat neocortex

Fetal alcohol syndrome (FAS) is the leading cause of mental retardation in western society. We investigated possible changes in glutamate receptor levels in neonatal animals following ethanol exposure using radioligand binding and western blot analysis. We used a vapor chamber to administer ethanol to neonatal Wistar rats 3 h a day from postnatal day (PND) 4-9. A separation control group was separated from their mothers for the same time and duration as the vapor treatment, while a normal control group was left to develop normally. Daily ethanol administrations resulted in decreased brain weight and body weight, as well as microencephaly (decreased brain:body weight ratio). Neither the affinity nor maximum binding of [H-3]MK-801 (dizoclipine maleate) in the cortex of PND10 rats differed between treatment groups. Western blot analysis also failed to reveal any changes in NMDAR1, NMDAR2A, or NMDAR2B receptor levels. In contrast, the AMPA receptor subunit GluR1 was greatly reduced in vapor-treated pups compared with control pups, as revealed by western blot analysis. A similar reduction was found in westerns with an antibody recognizing the GluR2 and 4 subunits. These results indicate that ethanol reduces AMPA rather than NMDA receptors in the developing neocortex, possibly by blocking NMDA receptors during development. (C) 2002 Elsevier Science B.V. All rights reserved.

Behaviour of caregivers to protect their infants from exposure to the sun in Queensland, Australia.

Exposure to the sun by infants has been demonstrated to increase the risk of the development of melanoma and other skin cancers later in life. A cohort of 508 women who delivered healthy Caucasian babies were followed up at 1 year to determine their knowledge, attitudes and practices regarding sun protection towards themselves and their child. In addition, the 1-year-old infants were assessed by a trained nurse for the number of nevi they had on their skin. Results indicate caregivers reported a high level of sun-protection practices towards their child, with 93% of the caregivers reporting usually or always placing the child in the shade when going outside. Further, 81% of the caregivers reported usually or always placing a hat on the child, while 64% reported usually or always applying sunscreen to the child's exposed skin. Interestingly, only 61% of the caregivers reported that they stayed in the shade to reduce sun exposure and only 42% wore a hat when out in the sun. Mother's own personal sun-protection methods predicted the method of sun protection that she would most likely use for the child. While children appear to be reasonably protected from the sun, they are influenced by their mother's own behaviors.

A field study conducted at Kidston Gold Mine, to evaluate the impact of arsenic and zinc from mine tailing to grazing cattle

The grazing trial at Kidston Gold Mine, North Queensland, was aimed specifically to assess the uptake of metals from the tailing and the potential for unacceptable contamination of saleable meat. Further aims included estimating metal dose rates and identifying potential exposure pathways including plant uptake of heavy metals, mine tailings adhered to plants and direct ingestion of mine tailing. It was found that of the 11 metals analysed (As, Zn, Co, Cd, Cr, Sn, Pb, Sb, Hg, Se and Ni) in the animal's liver, muscle and blood during the 8-month trial period, only accumulation of arsenic and zinc occurred. A risk assessment including these two metals was conducted to determine the potential for chronic metal toxicity and long-term contamination, using the estimates of metal dose rate. It was concluded that no toxicity or long-term contamination in cattle was likely at this site. Management procedures were therefore not required at this site; however, the results highlight percent ground cover and standing dry matter (DM) as important factors in decreasing metal exposure from direct ingestion of tailings and dust adhered to plants. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

Porphyrins as early biomarkers for arsenic exposure in animals and humans

We studied the effect of arsenic exposure on the haem biosynthetic pathway in the rat and humans. Significant increases in protoporphyrin IX, coproporphyrin III, coproporphyrin I were observed in the blood, liver and kidney, and in the urine of rats after a single dose of arsenic. The level of increase was dependent on the arsenic species present. Most of porphyrin concentrations in the tissues increased within 24 hr and urinary excretion elevated within 48 hr. In the human study, we collected urine samples from 113 people who live in Xing Ren of Guizhou Province, a coal-borne arsenicosis endemic area in southwest of PR China and from 30 people who live in Xing Yi (about 80 km southwest of Xing Ren) where arsenicosis is not prevalent. We analyzed the urinary porphyrins using HPLC. Results indicate that all urinary porphyrins were higher in the arsenic exposed group than those in the control group. Women, children and older age people spend much of their time indoors, they had greater increases of urinary arsenic and porphyrins. They were the higher risk groups among the study subjects. A positive correlation between the urinary arsenic levels and porphyrin concentrations demonstrated the effect of arsenic on haem biosynthesis. Significant alteration in the porphyrin excretion profiles of the younger age (

Exposure to automotive pollution increases plasma susceptibility to oxidation

Low-density lipoprotein oxidation is implicated in the development of atherosclerosis. Plasma susceptibility to oxidation may be used as a marker of low-density lipoprotein oxidation and thus predict atherosclerotic risk. In this study the authors investigated the relationship between plasma susceptibility to oxidation and exposure to automotive pollution in a group of automobile mechanics (n = 16) exposed to high levels of automotive pollution, vs. matched controls (n = 13). The authors induced plasma oxidation by a free radical initiator and they determined susceptibility to oxidation by (1) change in absorbance at 234 nm, (2) lag time to conjugated diene formation, and (3) linear slope of the oxidation curve. Mechanics had significantly higher values (mean standard error) for change in absorbance (1.60 +/- 0.05 vs. 1.36 +/- 0.05; p < .002), and slope (1.6 x 10(-3) +/- 0.1 x 10(-3) vs. 1.3 x 10(-3) +/- 0.1 x 10(-3); p < .001), compared with controls. These results indicate that regular exposure to automotive pollutants increases plasma susceptibility to oxidation and may, in the long term, increase the risk of developing atherosclerosis.

Expectations of the effects of drinking on couple relationship functioning: An assessment of women in distressed relationships who consume alcohol at harmful levels

Based on a cognitive-social learning model of alcohol use, it was hypothesised that women with both alcohol and relationship problems would endorse more positive expectations of the effects of alcohol consumption on their relationship and would report lower relational efficacy than women without relationship or alcohol problems. Measures of relationship-referent alcohol expectancies and relational efficacy were completed by 174 married women with both alcohol and relationship problems (n = 20), alcohol problems alone (it = 26), relationship problems alone (n = 30), or neither problem (n = 98). Women without either alcohol or relationship problems strongly rejected expectations of enhanced relationship functioning (e.g., enhanced intimacy, increased emotional expression) following alcohol consumption, whereas women with both alcohol and relationship problems were ambivalent about these positive expectations. Women with both problems also reported lower relational efficacy than the other groups of women. Negative expectations about the effect of alcohol consumption on relationships in women with low relational efficacy may inhibit harmful drinking. (C) 2002 Elsevier Science Ltd. All rights reserved.

Comparison of tafenoquine (WR238605) and primaquine in the post-exposure (terminal) prophylaxis of vivax malaria) in Australian Defence Force personnel

On return from duty in North Solomons Province (including Bougainville Island), Papua New Guinea, 586 Australian Defence Force personnel received either primaquine (14-d) or tafenoquine (3-d) post-exposure malaria prophylaxis. Within 12 months, 6 of the 214 volunteers receiving primaquine and 7 of 378 receiving tafenoquine had developed vivax malaria. Overall, volunteers preferred the shorter course of tafenoquine.

Implications of missed opportunities for learning and assessment in design and technology education

Supporting student learning can be difficult, especially within open-ended or loosely structured activities, often seen as valuable for promoting student autonomy in many curriculum areas and contexts. This paper reports an investigation into the experiences of three teachers who implemented design and technology education ideas in their primary school classrooms for the first time. The teachers did not capitalise upon many of the opportunities for scaffolding their students' learning within the open-ended activities they implemented. Limitations of the teachers' conceptual and procedural knowledge of design and technology were elements that influenced their early experiences. The study has implications for professional developers planning programs in newly introduced areas of the curriculum to support teachers in supporting learning within open-ended and loosely structured problem solving activities. (C) 2001 Elsevier Science Ltd. All rights reserved.

Pulse-exposure effects of selected insecticides to juvenile Australian crimson-spotted rainbowfish (Melanotaenia duboulayi)

Laboratory toxicity studies were conducted in southeastern Queensland, Australia, to determine the acute lethal effects of a 1-h pulse exposure of selected insecticides to adult and juvenile (