Randomized controlled trial of two cigarette quit programmes in coronary care patients after acute myocardial infarction

Background: Tobacco cessation after acute myocardial infarction (AMI) substantially improves outcome but how effective individual programmes are needs to be established. To date, few studies have examined this factor. Aims: To assess the outcome of two smoking cessation programmes after AMI. Methods: One hundred and ninety-eight current smokers admitted to coronary care with an AMI participated in a randomized controlled study comparing two outpatient tobacco interventions, the Stanford Heart Attack Staying Free (SF) programme and a Usual Care (UC) programme. Results: Log-rank analyses revealed that patients in the SF programme were retained longer (P < 0.001) and had higher cotinine validated abstinence rates (P < 0.001) compared with patients in the UC programme. Twelve months after intervention, 39% of the SF programme compared with 2% of the UC programme demonstrated cotinine validated tobacco cessation, representing a significant reduced relapse rate in the SF programme (chi (2), P < 0.001). Conclusions: The SF smoking cessation programme initiated in hospital can significantly reduce smoking rates at 12 months after myocardial infarction. Although superior to the UC quit programme, Australian outcomes were lower than the American programme originators' published outcomes.

Promoters for pregenomic RNA of banana streak badnavirus are active for transgene expression in monocot and dicot plants

Two putative promoters from Australian banana streak badnavirus (BSV) isolates were analysed for activity in different plant species. In transient expression systems the My (2105 bp) and Cv (1322 bp) fragments were both shown to have promoter activity in a wide range of plant species including monocots (maize, barley, banana, millet, wheat, sorghum), dicots (tobacco, canola, sunflower, Nicotiana benthamiana, tipu tree), gymnosperm (Pinus radiata) and fern (Nephrolepis cordifolia). Evaluation of the My and Cv promoters in transgenic sugarcane, banana and tobacco plants demonstrated that these promoters could drive high-level expression of either the green fluorescent protein (GFP) or the beta -glucuronidase (GUS) reporter gene (uidA) in vegetative plant cells. In transgenic sugarcane plants harbouring the Cv promoter, GFP expression levels were comparable or higher (up to 1.06% of total soluble leaf protein as GFP) than those of plants containing the maize ubiquitin promoter (up to 0.34% of total soluble leaf protein). GUS activities in transgenic in vitro-grown banana plants containing the My promoter were up to seven-fold stronger in leaf tissue and up to four-fold stronger in root and corm tissue than in plants harbouring the maize ubiquitin promoter. The Cv promoter showed activities that were similar to the maize ubiquitin promoter in in vitro-grown banana plants, but was significantly reduced in larger glasshouse-grown plants. In transgenic in vitro-grown tobacco plants, the My promoter reached activities close to those of the 35S promoter of cauliflower mosaic virus (CaMV), while the Cv promoter was about half as active as the CaMV 35S promoter. The BSV promoters for pregenomic RNA represent useful tools for the high-level expression of foreign genes in transgenic monocots.

Isolation of a novel G-protein gamma-subunit from Arabidopsis thaliana and its interaction with G beta

There is increasing evidence that heterotrimeric G-proteins (G-proteins) are involved in many plant processes including phytohormone response, pathogen defence and stomatal control. In animal systems, each of the three G-protein subunits belong to large multigene families; however, few subunits have been isolated from plants. Here we report the cloning of a second plant G-protein γ-subunit (AGG2) from Arabidopsis thaliana. The predicted AGG2 protein sequence shows 48% identity to the first identified Arabidopsis Gγ-subunit, AGG1. Furthermore, AGG2 contains all of the conserved characteristics of γ-subunits including a small size (100 amino acids, 11.1 kDa), C-terminal CAAX box and a N-terminal α-helix region capable of forming a coiled-coil interaction with the β-subunit. A strong interaction between AGG2 and both the tobacco (TGB1) and Arabidopsis (AGB1) β-subunits was observed in vivo using the yeast two-hybrid system. The strong association between AGG2 and AGB1 was confirmed in vitro. Southern and Northern analyses showed that AGG2 is a single copy gene in Arabidopsis producing two transcripts that are present in all tissues tested. The isolation of a second γ-subunit from A. thaliana indicates that plant G-proteins, like their mammalian counterparts, may form different heterotrimer combinations that presumably regulate multiple signal transduction pathways.

Callus induction and plant regeneration from broccoli (Brassica oleracea var. italica) for transformation

We evaluated the efficiency of callus induction and plantlet regeneration from hypocotyl explants of broccoli (Brassica oleracea var. italica). The cultivars were ‘Marathon’, ‘Greenbelt’, and ‘Shogun’. Transformation success was not affected by the presence of tobacco feeder-cell layers on the culture media. The frequency of shoot regeneration was greater from 10-d-old hypocotyls than from 14-d-old hypocotyls. Both ‘Marathon’ and ‘Greenbelt’ had higher potentials for tissue regeneration than did ‘Shogun’. We found that for transformation selection, the optimum concentration was either 50 mg/L kanamycin or 100 mg/L genetkin.

Structure and function of plant toxins (with emphasis on cystine knot toxins)

Plant toxins are substances produced and secreted by plants to defend themselves against predators. In a broad sense, this includes all substances that have a toxic effect on targeted organisms, whether they are microbes, other plants, insects, or higher animals. Plant toxins have a diverse range of structures, from small organic molecules through to proteins. This review gives an overview of the various classes of plant toxins but focuses on an interesting class of protein-based plant toxins containing a cystine knot motif. This structural motif confers exceptional stability on proteins containing it and is associated with a wide range of biological activities. The biological activities and structural stability offer many potential applications in the pharmaceutical and agricultural fields. One particularly exciting prospect is in the use of protein-based plant toxins as molecular scaffolds for displaying pharmaceutically important bioactivities. Future applications of plant toxins are likely to involve genetic engineering techniques and molecular pharming approaches.

A critique of evaluated adolescent smoking cessation programmes

Rates of adolescent smoking appear to be on the increase, with a number of authors documenting increases in the 1990's. However, the issue of prevention rather than cessation has received greater attention in tobacco control programmes among youth. This review provides details of published school based and other tobacco cessation programmes for adolescents and compares their efficacy. Variations in outcome measures were noted with the programmes. Environmental risk factors such as economic deprivation, concurrent use of alcohol and illicit substances and a minority ethnic background have been associated with greater smoking rates among youth. It is suggested that tobacco cessation initiatives need to be considered in the context of improving adolescents lifestyle choices. Specific cessation programmes should also address issues such as appropriate follow-up and validation. (C) 2002 The Association for Professionals in Services for Adolescents. Published by Elsevier Science Ltd. All rights reserved.

Enhanced quantitative resistance to Leptosphaeria maculans conferred by expression of a novel antimicrobial peptide in canola (Brassica napus L.)

The novel antimicrobial peptide MiAMP1, originally isolated from the seeds of Macadamia integrifolia, was constitutively expressed in transgenic tobacco and canola plants to test its effect on disease resistance. Analysis of plants transformed with 35S-MiAMP1 construct by northern and western blot analyses demonstrated the presence of MiAMP1 mRNA and the mature peptide in the transgenic plants. The MiAMP1 purified from the leaves of transgenic plants was biologically active with the same in vitro antifungal activity as native MiAMP1 purified from the seeds of macadamia. The effect of MiAMP1 expression on the economically important canola pathogen Leptosphaeria maculans (causal agent of blackleg disease) was evaluated in comparison with an untransformed control line and an azygous segregant derived from one of the transgenic lines. Lesion development on the cotyledons of the inoculated canola seedlings was significantly reduced in the T-2 progeny of seven independently transformed transgenic lines. These results suggested that, transgenic canola expressing MiAMP1 may be useful for the management of blackleg disease.

A synthetic xylanase as a novel reporter in plants

Transient gene expression assays are often used to screen promoters before stable transformation. Current transient quantification methods have several problems, including a lack of reporter gene stability and expense. Here we report a synthetic, codon-optimised xylanase gene (sXynA) as a reporter gene for quantitative transient analyses in plants. Azurine-crosslinked xylan (AZCL-xylan) was used as a substrate for assaying xylanase activity. The enzymatic nature of the protein allows for sensitive assays at the low levels of transgene protein found in transiently transformed tissue extracts. The xylanase (XYN) protein is stable, activity slopes are linear over long time periods and assays are cost-effective. Coupled with the GUSPlus reporter gene, the XYN reporter allows sensitive and accurate quantification of gene control sequences in transient expression systems.

Spatial and temporal changes in multiple hormone groups during lateral bud release shortly following apex decapitation of chickpea (Cicer arietinum) seedlings

Although the co-ordination of promotive root-sourced cytokinin (CK) and inhibitory shoot apex-sourced auxin (IAA) is central to all current models on lateral bud dormancy release, control by those hormones alone has appeared inadequate in many studies. Thus it was hypothesized that the IAA : CK model is the central control but that it must be considered within the relevant timeframe leading to lateral bud release and against a backdrop of interactions with other hormone groups. Therefore, IAA and a wide survey of cytokinins (CKs), were examined along with abscisic acid (ABA) and polyamines (PAs) in released buds, tissue surrounding buds and xylem sap at 1 and 4 h after apex removal, when lateral buds of chickpea are known to break dormancy. Three potential lateral bud growth inhibitors, IAA, ABA and cis-zeatin 9-riboside (ZR), declined sharply in the released buds and xylem following decapitation. This is in contrast to potential dormancy breaking CKs like trans-ZR and trans-zeantin 9-riboside 5'phosphate (ZRMP), which represented the strongest correlative changes by increasing 3.5-fold in xylem sap and 22-fold in buds. PAs had not changed significantly in buds or other tissues after 4 h, so they were not directly involved in the breaking of bud dormancy. Results from the xylem and surrounding tissues indicated that bud CK increases resulted from a combination synthesis in the bud and selective loading of CK nucleotides into the xylem from the root.

The coincidence of thrips and dispersed pollen in PNRSV-infected stonefruit orchards - a precondition for thrips-mediated transmission via infected pollen

Recent laboratory studies have demonstrated that Prunus necrotic ringspot virus (PNRSV) (family Bromoviridae) can be readily transmitted when thrips and virus-bearing pollen are placed together on to test plants. For this transmission mechanism to result in stonefruit tree infection in the field, PNRSV-bearing pollen must be deposited onto surfaces of stonefruit trees on which thrips also occur. In a previous paper, we demonstrated that almost all pollen in a PNRSV-infected Japanese plum orchard in southeastern Queensland was deposited onto flowers, whereas few grains occurred on leaves and none on stems. Here, we present results of our investigation of thrips species composition, distribution and abundance on stonefruit trees in the same study area as our previous pollen deposition study. We collected a total of 2010 adult thrips from 13 orchards during the 1989, 1991 and 1992 flowering seasons of which all but 14 were in the suborder Terebrantia. Most (97.4%) terebrantian thrips were of three species, Thrips imaginis, Thrips australis and Thrips tabaci. Thrips tabaci as well as species mixtures that included T imaginis, T australis and T tabaci have been shown to transmit PNRSV via infected pollen in laboratory tests. Adult thrips were frequently collected from flowers but rarely from leaves and never from stems. Large and significant differences in numbers of T imaginis, T australis and T tabaci adults in flowers occurred among orchards and between seasons. No factor was conclusively related to thrips numbers but flowers of late-flowering stonefruit varieties tended to hold more thrips than those of early-flowering varieties. Our results indicate that the common thrips species present on stonefruit trees in the Granite Belt are also ones previously shown to transmit PNRSV via infected pollen in the laboratory and that these thrips are concentrated in stonefruit flowers where most stonefruit pollen is deposited. These results contribute to mounting circumstantial evidence that stonefruit flowers may be inoculated with PNRSV via an interaction of thrips with virus-bearing pollen and that this transmission mechanism may be an important cause of new tree infections in the field.

Interspecific hybrids between the homothallic Phytophthora sojae and Phytophthora vignae

An interspecific cross was attempted between two homothallic species of Phytophthora, P. sojae and P. vignae. From 1640 single-oospore cultures isolated, DNA was extracted from 800, and two interspecific F-1 hybrids (F(1)1121 and F(1)1426) were putatively identified using RAPD markers. The true hybrid nature of these F-1 hybrids was confirmed using additional AFLP analysis. Single- zoospore cultures were generated for each F-1 hybrid and one single-zoospore culture of each was used in pathogenicity and virulence tests. Both F-1 hybrids were pathogenic to soybean and cowpea, causing symptoms including lesions, wilting and death of susceptible soybean and cowpea cultivars. However, the aggressiveness of the F-1 hybrids was reduced and was substantially more variable when compared with that of the parental isolates on their respective hosts. The F-1 hybrids were reisolated from infected seedlings and their hybrid nature confirmed using RAPD and AFLP analysis. These results provide a basis for further research aimed at obtaining an increased understanding of the genetics of host specificity in the Oomycetes.

Escalation of Drug Use in Early-Onset Cannabis Users vs Co-twin Controls

Context Previous studies have reported that early initiation of cannabis (marijuana) use is a significant risk factor for other drug use and drug-related problems. Objective To examine whether the association between early cannabis use and subsequent progression to use of other drugs and drug abuse/dependence persists after controlling for genetic and shared environmental influences. Design Cross-sectional survey conducted in 1996-2000 among an Australian national volunteer sample of 311 young adult (median age, 30 years) monozygotic and dizygotic same-sex twin pairs discordant for early cannabis use (before age 17 years). Main Outcome Measures Self-reported subsequent nonmedical use of prescription sedatives, hallucinogens, cocaine/other stimulants, and opioids; abuse or dependence on these drugs (including cannabis abuse/dependence); and alcohol dependence. Results Individuals who used cannabis by age 17 years had odds of other drug use, alcohol dependence, and drug abuse/dependence that were 2.1 to 5.2 times higher than those of their co-twin, who did not use cannabis before age 17 years. Controlling for known risk factors (early-onset alcohol or tobacco use, parental conflict/separation, childhood sexual abuse, conduct disorder, major depression, and social anxiety) had only negligible effects on these results. These associations did not differ significantly between monozygotic and dizygotic twins. Conclusions Associations between early cannabis use and later drug use and abuse/dependence cannot solely be explained by common predisposing genetic or shared environmental factors. The association may arise from the effects of the peer and social context within which cannabis is used and obtained. In particular, early access to and use of cannabis may reduce perceived barriers against the use of other illegal drugs and provide access to these drugs.

Respiratory health effects of cannabis: Position statement of the Thoracic Society of Australia and New Zealand

Both the gaseous and the particulate phases of tobacco and cannabis smoke contain a similar range of harmful chemicals. However, differing patterns of inhalation mean that smoking a 'joint' of cannabis results in exposure to significantly greater amounts of combusted material than with a tobacco cigarette. The histopathological effects of cannabis smoke exposure include changes consistent with acute and chronic bronchitis. Cellular dysplasia has also been observed, suggesting that, like tobacco smoke, cannabis exposure has the potential to cause malignancy. These features are consistent with the clinical presentation. Symptoms of cough and early morning sputum production are common (20-25%) even in young individuals who smoke cannabis alone. Almost all studies indicate that the effects of cannabis and tobacco smoking are additive and independent. Public health education should dispel the myth that cannabis smoking is relatively safe by highlighting that the adverse respiratory effects of smoking cannabis are similar to those of smoking tobacco, even although it remains to be confirmed that smoking cannabis alone leads to the development of chronic lung disease.

Expression analysis of four Pinus radiata male cone promoters in the heterologous host Arabidopsis

Four male cone-specific promoters were isolated from the genome of Pinus radiata D. Don, fused to the beta-glucuronidase (GUS) reporter gene and analysed in the heterologous host Arabidopsis thaliana (L.) Heynh. The temporal and spatial activities of the promoters PrCHS1, PrLTP2, PrMC2 and PrMALE1 during seven anther developmental stages are described in detail. The two promoters PrMC2 and PrMALE1 confer an identical GUS expression pattern on Arabidopsis anthers. DNA sequence analysis of the PrMC2 and PrMALE1 promoters revealed an 88% sequence identity over 276 bp and divergence further upstream (