The chemistry and biological effects of malondialdehyde-acetaldehyde adducts

This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Geoffrey M. Thiele and Simon Worrall. The presentations were (1) The chemistry of malondialdehyde-acetaldehyde (MAA) adducts, by Dean J. Tuma; (2) The formation and clearance of MAA adducts in ethanol-fed rats, by Simon Worrall; (3) Immune responses to MAA adducts may play a role in the development of alcoholic liver disease, by Lynell W. Klassen; (4) Unique biological responses to MAA-modifled proteins that may play a role in the development and/or progression of alcoholic liver disease, by Geoffrey M. Thiele; (5) MAA-adducted bovine serum albumin activates protein kinase C and stimulates interleukin-8 release in bovine bronchial epithelial cells, by Todd A. Wyatt; and (6) An enzyme immune assay for serum antiacetaldehyde adduct antibody using low-density lipoprotein-adduct and its significance in alcoholic liver injury and ALDH2 heterozygotes, by Naruhiko Nagata.

Adolescents' perceptions of social status: Development and evaluation of a new indicator

Objective. Eliminating health disparities, including those that are a result of socioeconomic status (SES), is one of the overarching goals of Healthy People 2010. This article reports on the development of a new, adolescent-specific measure of subjective social status (SSS) and on initial exploratory analyses of the relationship of SSS to adolescents' physical and psychological health. Methods. A cross-sectional study of 10 843 adolescents and a subsample of 166 paired adolescent/mother dyads who participated in the Growing Up Today Study was conducted. The newly developed MacArthur Scale of Subjective Social Status (10-point scale) was used to measure SSS. Paternal education was the measure of SES. Indicators of psychological and physical health included depressive symptoms and obesity, respectively. Linear regression analyses determined the association of SSS to depressive symptoms, and logistic regression determined the association of SSS to overweight and obesity, controlling for sociodemographic factors and SES. Results. Mean society ladder ranking, a subjective measure of SES, was 7.2 ± 1.3. Mean community ladder ranking, a measure of perceived placement in the school community, was 7.6 ± 1.7. Reliability of the instrument was excellent: the intraclass correlation coefficient was 0.73 for the society ladder and 0.79 for the community ladder. Adolescents had higher society ladder rankings than their mothers (µteen = 7.2 ± 1.3 vs µmom = 6.8 ± 1.2; P = .002). Older adolescents' perceptions of familial placement in society were more closely correlated with maternal subjective perceptions of placement than those of younger adolescents (Spearman's rhoteens

Extraction and purification of the zwitterions cylindrospermopsin and deoxycylindrospermopsin from Cylindrospermopsis raciborskii

The hepatotoxin cylindrospermopsin (CYN) has been isolated from the cyanobacterium Cylindrospermopsis raciborskii (C. raci.). Efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. It is usually extracted from lyophilized cells collected from a laboratory culture. Our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. We have therefore investigated the use of commercially available solid phase extraction sorbents to extract CYN from culture media in which C. raci. has been grown. A range of reverse phase and ion-exchange sorbents were tested across a range of pHs for their ability to retain CYN without success. Subsequently, graphitized carbon cartridges were found to retain CYN strongly. Elution with 5% formic acid in methanol allowed the CYN to be regained for final purification by HPLC. Deoxy-CYN, an analog of CYN can also be extracted using this procedure. (C) 2001 John Wiley & Sons, Inc.

The toxins of Lyngbya majuscula and their human and ecological health effects

Lyngbya majuscula is a benthic filamentous marine cyanobacterium, which in recent years appears to have been increasing in frequency and size of blooms in Moreton Bay, Queensland. It has a worldwide distribution throughout the tropics and subtropics in water to 30m. It has been found to contain a variety of chemicals that exert a range of biological effects, including skin, eye and respiratory irritation. The toxins lyngbyatoxin A and debromoaplysiatoxin appear to give the most widely witnessed biological effects in relation to humans, and experiments involving these two toxins show the formation of acute dermal lesions. Studies into the epidemiology of the dermatitic, respiratory and eye effects of the toxins of this organism are reviewed and show that Lyngbya induced dermatitis has occurred in a number of locations. The effects of aerosolised Lyngbya in relation to health outcomes were also reported. Differential effects of bathing behaviour after Lyngbya exposure were examined in relation to the severity of health outcomes. The potential for Lyngbya to exhibit differential toxicologies due to the presence of varying proportions of a range of toxins is also examined. This paper reviews the present state of knowledge on the effects of Lyngbya majuscula on human health, ecosystems and human populations during a toxic cyanobacterial bloom. The potential exists for toxins from Lyngbya majuscula affecting ecological health and in particular marine reptiles. (C) 2001 Elsevier Science Ltd. All rights reserved.

Premenstrual syndrome: The condition, the therapy and the pharmacist.

The following aspects of premenstrual syndrome are discussed: classification, common symptoms, aetiology, pharmacological treatment, other therapies, role of the pharmacist. (non-author abstract)

Crystallization and preliminary diffraction studies of native and selenomethionine CcmG (CycY, DsbE)

t Disulfide-bond (Dsb) proteins are a family of redox proteins containing a Cys-X-X-Cys motif. They are essential for disulfide-bond exchange in the bacterial periplasm and are necessary for the correct folding and function of many secreted proteins. CcmG (DsbE) is a reducing Dsb protein required for cytochrome c maturation. Crystals of Bradyrhizobium japonicum CcmG have been obtained that diffract X-rays to 1.14 Angstrom resolution. The crystals are orthorhombic, space group P2(1)2(1)2(1), with unit-cell parameters a = 35.1, b = 48.2, c = 90.2 Angstrom. Selenomethionine CcmG was expressed without using a methionine auxotroph or methionine-pathway inhibition and was purified without reducing agents.

First report of the cyanotoxins cylindrospermopsin and deoxycylindrospermopsin from Raphidiopsis curvata (Cyantobacteria)

A strain of Raphidiopsis (Cyanobacteria) isolated from a fish pond in Wuhan, P. R. China was examined for its taxonomy and production of the alkaloidal hepatotoxins cylindrospermopsin (CYN) and deoxy-cylindrospermopsin (deoxy-CYN). Strain HB1 was identified as R. curvata Fritsch et Rich based on morphological examination of the laboratory culture. HB1 produced mainly deoxy-CYN at a concentration of 1.3 mg(.)g(-1) (dry ut cells) by HPLC and HPLC-MS/MS. CYN was also detected in trace amounts (0.56 mug(.)g(-1)). A mouse bioassay did not show lethal toxicity when tested at doses up to 1500 mg dry weight cells(.)kg(-1) body weight within 96 h, demonstrating that production of primarily deoxy CYN does not lead to significant mouse toxicity by strain BB I. The presence of deoxy-CYN and CYN in R curvata suggests that Raphidiopsis belongs to the Nostocaceae, but this requires confirmation by molecular systematic studies. Production of these cyanotoxins by Raphidiopsis adds another genus, in addition to Cylindrospemopsis, Aphanizomenon, and Umezakia, now known to produce this group of hepatotoxic cyanotoxins. This is also the first report from China of a CYN and deoxy-CYN producing cyanobacterium.

Isolation and identification of the toxic peptides from Lophyrotoma zonalis (Pergidae) sawfly larvae

The broad-leaved paper bark tree Melaleuca quinquenervia (Cav) (Myrtaceae) was introduced into Florida (USA) early in this century it has proliferated to such an extent that urgent measures are now required to control it. The sawfly Lophyrotoma zonalis (Pergidae) has been introduced as a possible biological control agent due to its ability to defoliate M. quinquenervia. Because toxic D-amino acid- containing peptides have been isolated from some sawfly species, L. zonalis larvae were processed using the previously reported method for the recovery of these compounds. The toxins lophyrotomin (as the free C-terminal acid) and a mixture of pergidin and Val(4)-pergidin were isolated at 0.36 and 0.43% yield of the dried larvae, respectively. Both compounds when dosed intraperitoneally to C57/B16 male mice were hepatotoxic with lowest lethal doses of 8 and 32 mg/kg, respectively. The pathology of the liver was different for each compound, with the lophyrotomin free acid causing a periportal haemorrhagic necrosis and the pergidin causing a periacinar coagulative necrosis. (C) 2001 Elsevier Science Ltd. All rights reserved.

Toxicity and uptake mechanism of cylindrospermopsin and lophyrotomin in primary rat hepatocytes

The toxicities and uptake mechanisms of two hepatotoxins, namely cylindrospermopsin and lophyrotomin, were investigated on primary rat hepatocytes by using microcystin-LIZ (a well-known hepatotoxin produced by cyanobacteria) as a comparison. Isolated rat hepatocytes were incubated with different concentrations of hepatotoxins for 0, 24, 48 and 72 h. The cell viability was assayed by the tetrazolium-based (MTT) assay. Microcystin-LR, cylindrospermopsin and lophyrotomin all exhibited toxic effects on the primary rat hepatocytes with 72-h LC50 of 8, 40 and 560 ng/ml, respectively. The involvement of the bile acid transport system in the hepatotoxin-induced toxicities was tested in the presence of two bile acids, cholate and taurocholate. Results showed that the bile acid transport system was responsible for the uptake, and facilitated the subsequent toxicities of lophyrotomin on hepatocytes. This occurred to a much lesser extent with cylindrospermopsin. With its smaller molecular weight, passive diffusion might be one of the possible mechanisms for cylindrospermopsin uptake into hepatocytes. This was supported by incubating a permanent cell line, KB (devoid of bile acid transport system), with cylindrospermopsin which showed cytotoxic effects. No inhibition of protein phosphatase 2A by cylindrospermopsin or lophyrotomin was found. This indicated that other toxic mechanisms besides protein phosphatase inhibition were producing the toxicities of cylindrospermopsin and lophyrotomin, and that they were unlikely to be potential tumor promoters. (C) 2001 Elsevier Science Ltd. All rights reserved.

Perceived constraints and social support for active leisure among mothers with young children

Evidence suggests that women who are mothers of young children have lower levels of physical activity than women of similar age who do not have children (Brown, Lee, Mishra, & Bauman, 2000). The purposes of this study were to explore the factors that constrain mothers of young children from being more physically active, and the relationship between physical activity and levels of social support available to the women. The empirical basis for this examination was provided through a study of activity levels and barriers to physical activity experienced by a sample of 543 mothers of young children from differing socioeconomic backgrounds. The data indicate that: (a) more than two-thirds of the mothers were inadequately active in their leisure time for health benefit; (b) while the vast majority of mothers expressed a desire to be more active, they were inhibited in their ability to act out their leisure preferences by a combination of structural (e.g., lack of time, money, energy) and ideological influences (e.g., sense of commitment to others); (c) access to social support (from partners, family, and friends) was seen to place some women in a better position than others to negotiate constraints that inhibit leisure participation; and (d) within groups of varying socioeconomic status (SES) there was wide variation in the amount of time spent each week in active leisure.

Isolation and identification of the cyanotoxin cylindrospermopsin and deoxy-cylindrospermopsin from a Thailand strain of Cylindrospermopsis raciborskii (Cyanobacteria)

A strain of Cylindrospermopsis (Cyanobacteria) isolated from a fishpond in Thailand was examined for its taxonomy based upon morphology and 16S rRNA gene sequence. It was also examined for production of the hepatotoxic cyanotoxin called cylindrospermopsin (CYN) and deoxycylindrospermopsin (deoxy-CYN). The strain (CY-Thai) was identified as C. raciborskii (Woloszynska) Seenaya and Subba Raju based upon morphological examination which was confirmed by 16S rRNA gene sequences and phylogenetic comparisons based upon its 16S rRNA gene. The alkaloid heptatotoxin CYN was confirmed using mouse bioassay, HPLC and HPLC-MS/MS while deoxy-CYN was confirmed using HPLC-MS/MS. The mouse bioassay gave a minimum lethal dose at 250 mg dry weight cells/kg body weight within 24 h and 125 mg/kg at 72 h, with signs of poisoning the same as in literature reports for CYN. HPLC chromatographic comparison of the CY-Thai toxin with standard CYN gave the same retention time and an absorbance maximum at 262 nm. HPLC-MS/MS confirmed the presence of CYN (M + H 416) and deoxy-CYN (M + H 400). The CYN content in strain CY-Thai was estimated at 1.02 mg/g and approximately 1/10 of this amount for deoxy-CYN. This is the first report from Asia of a CYN, deoxy-CYN producing Cylindrospermopsis raciborskii. (C) 2001 Elsevier Science Ltd. All rights reserved.

Polychlorinated Dibenzodioxins and Dibenzofurans in Butter from Different States in Australia

Nine samples of butter from producers in various states of Australia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Detectable concentrations of 2,3,7,8-chlorine substituted PCDD/Fs were found in all samples. The mean PCDD/F concentration expressed as 2',3,7,8-TCDD equivalents (TEQs) was 0.19 pg TEQ g(-1) fat. The highest concentration (0.46 pg TEQ g(-1) fat) was observable in a sample from Victoria which is the most densely populated state. Overall the results indicate that PCDD/F concentrations in dairy products from Australia are low in comparison to the levels in dairy products of industrialized countries on the Northern Hemisphere. As expected, this study provides evidence that the environmental and consequently the human body burden of PCDD/ Fs to be relatively low in Australia.