Sponge halogenated natural products found at parts-per-million levels in marine mammals

Several unknown, abundant brominated compounds (BCs) were recently detected in the blubber of dolphins and other marine mammals from Queensland (northeast Australia). The BC were interpreted as potential natural products due to the lack of anthropogenic sources for these compounds. This study investigated whether some of the BCs accumulated by diverse marine mammal species are identical with natural BCs previously isolated from sponges (Dysidea sp.) living in the same habitat. Isolates from sponges and mollusks (Asteronotus cespitosus) were compared with the signals detected in the mammals' tissue. Mass spectra and gas chromatography retention times on four different capillary columns of the isolates from sponges and mammals were identical in all respects. This proves that the chemical name of the compound previously labeled BC-2 is 4,6-dibromo-2-(2'-dibromo)phenoxyanisole and that the chemical name of BC-11 is 3,5-dibromo-2-(3',5'-dibromo-2'-methoxy)phenoxyanisole. Using a quantitative reference solution of BC-2, we established that the concentrations of the brominated metabolies found in the marine mammals are frequently >1 mg/kg. The highest concentration (3.8 mg/kg), found in a sample of pygmy sperm whale (Kogia breviceps), indicates that BC-2 is a bioaccumulative, natural organohalogen compound. This is supported by the concentrations of the BCs in our samples being equal to the highest concentrations of anthropogenic BCs in any environmental sample. The quantitative determination of BC-2 in blubber of marine mammals from Africa and the Antarctic suggests that BC-2 is wide-spread. These results are direct proof that marine biota can produce persistent organic chemicals that accumulate to substantial concentrations in higher trophic organisms.

Genotoxicity investigation of a cyanobacterial toxin, cylindrospermopsin

Cylindrospermopsin (CYN), a potent cyanobacterial hepatotoxin produced by Cylindrospermopsis raciborskii and other cyanobacteria, is regularly found in water supplies in many parts of the world, and has been associated with the intoxication of humans and livestock. In this study, Balb/c mice were injected via the intraperitoneal (IP) route with a single dose of 0.2 mg/kg CYN. Animals were sacrificed at 6, 12, 24, 48 and 72 It. DNA was isolated from the mouse livers, and examined for strand breakage by alkaline gel electrophoresis (pH 12). Significant DNA strand breakage was observed in the mouse liver exposed to CYN, suggesting that induction of DNA strand breakage is probably one of the key mechanisms for CYN genotoxicity. (C) 2002 Elsevier Science Ltd. All rights reserved.

Taxonomic theory and the ICF: Foundations for a unified disability athletics classification

Development of a unified classification system to replace four of the systems currently used in disability athletics (i.e., track and field) has been widely advocated. The definition and purpose of classification, underpinned by taxonomic principles and collectively endorsed by relevant disability sport organizations, have not been developed but are required for successful implementation of a unified system. It is posited that the International classification of functioning. disability, and health (ICF), published by the World Health Organization (2001), and current disability athletics systems are, fundamentally, classifications of the functioning and disability associated with health conditions and are highly interrelated. A rationale for basing a unified disability athletics system on ICF is established. Following taxonomic analysis of the current systems, the definition and purpose of a unified disability athletics classification are proposed and discussed. The proposed taxonomic framework and definitions have implications for other disability sport classification systems.

Age and gender differences in objectively measured physical activity in youth

TROST. S. G., R. R. PATE, J. F. SALLIS, P. S. FREEDSON, W. C. TAYLOR, M. DOWDA, and J. SIRARD. Age and gender differences in objectively measured physical activity in youth. Med. Sci. Sports Ererc., Vol. 34, No. 2, pp. 350-355, 2002. Purpose: The purpose of this study was to evaluate age and gender differences in objectively measured physical activity (PA) in a population-based sample of students in grades 1-12. Methods: Participants (185 male, 190 female) wore a CSA 7164 accelerometer for 7 consecutive days. To examine age-related trends. students were grouped as follows: grades 1-3 (N = 90), grades 4-6 (N = 91), grades 7-9 (N = 96). and grades 10-12 (N = 92). Bouts of PA and minutes spent in moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) were examined. Results: Daily MVPA and VPA exhibited a significant inverse relationship with grade level, with the largest differences occurring between grades 1d-3 and 4-6. Boys were more active than girls; however, for overall PA, the magnitudes of the gender differences were modest. Participation in continuous 20-min bouts of PA was low to nonexistent. Conclusion: Our results support the notion that PA declines rapidly during childhood and adolescence and that accelerometers are feasible alternatives to self-report methods in moderately sized population-level surveillance studies.

Arsenic inhibits the repair of DNA damage induced by benzo(a)pyrene

In order to study the effect of arsenic on DNA damage, Sprague-Dawley rats were dosed with sodium arsenite (10 mg/kg) with or without 800 mug of benzo(a)pyrene (BP) by intramammilary injection. The animals were sacrificed on day 1, 3, 5, 10 and 27 and the mammary gland tissues were collected for DNA adduct measurement using a P-32 post-labeling assay. Animals dosed with arsenic alone did not show any DNA adducts. DNA adduct levels in rats dosed with BP alone reached a maximum level by day 5, reducing to 13% of this level by day 27. Adduct levels in rats dosed with arsenic and BP also reached a maximum by day 5 but only 80% of the level observed in the BP group. However, 84% of this amount still remained by day 27. The First Nucleotide Change (FNC) technique was used for the screening of 115 samples of various tissues from mice that had been chronically exposed to sodium arsenate for over 2 years revealed that inorganic arsenic did not attack the two putative hotspots (codons 131 and 154) of the hOGG1 gene. These results support the hypothesis that arsenic exerts its biological activity through DNA repair inhibition. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

The Tampa decision : refugee rights versus the executive's power to detain and expel unlawful non-citizens

In Ruddock and Others v Vadarlis and Others the Federal Court had to balance two fundamental but competing rights, the right of the state to secure its frontiers and the rights of individuals not to be subjected to unlawful detention - Court's task was hampered by intense public debate over the illegal refugee crisis - in the wake of 11 September 2001 and the Tampa crisis, the Federal Government has rushed through several amendments to migration laws and border protection legislation.