Seedling responses of three Australian tree species to toxic concentrations of zinc in solution culture

A frequently desired outcome when rehabilitating Zn toxic sites in Australia is to establish a self-sustaining native ecosystem. Hence, it is important to understand the tolerance of Australian native plants to high concentrations of Zn. Very little is known about the responses of Australian native plants, and trees in particular, to toxic concentrations of Zn. Acacia holosericea, Eucalyptus camaldulensis and Melaleuca leucadendra plants were grown in dilute solution culture for 10 weeks. The seedlings (42 days old) were exposed to six Zn treatments viz., 0.5, 5, 10, 25, 50 and 100 muM. The order of tolerance to toxic concentrations of Zn was E. camaldulensis > A. holosericea > M. leucadendra, the critical external concentrations being approximately 20, 12 and 1.5 muM, respectively. Tissue Zn concentrations increased as solution Zn increased for all species. Root tissue concentrations were higher than shoot tissue concentrations at all solution Zn concentrations. The critical tissue Zn concentrations were approximately 85 and 110 mug g(-1) DM for M. leucadendra, 115 and 155 mug g(-1) DM for A. holosericea and 415 and 370 mug g(-1) DM for E. camaldulensis for the youngest fully expanded leaf and total shoots, respectively. The results from this paper provide the first comprehensive combination of growth responses, critical external concentrations, critical tissue concentrations and plant toxicity symptoms for three important Australian genera, viz., Eucalyptus, Acacia and Melaleuca, for use in the rehabilitation of potentially Zn toxic sites.

Demography of bridled nailtail wallabies translocated to the edge of their former range from captive and wild stock

Despite numerous, generally unsuccessful attempts to reintroduce threatened Australian mammals, the factors leading to their failure have not been fully clarified, although predator control would appear to be of paramount importance. An experimental approach was taken in attempting to establish a population of bridled nailtail wallabies ih an area of apparently suitable habitat and low fox density, but on the edge of the species' former range. The 133 wallabies released since late 1996 comprised four groups captive-bred animals, wild caught from the single remaining wild population, animals that were captive bred and acclimatised at the translocation site in a 10 ha predator-proof enclosure, and animals which had been bred in the enclosure. Survival was highest in those bred in the enclosure and highly variable among captive-bred animals. Survival estimates for wild recruits suggested the population would maintain a positive rate of increase under prevailing environmental conditions. Spotlighting surveys suggested the population had increased to approximately 400 animals by late 1999. Above average rainfall during 1996-1999 and no apparent predation suggests caution in describing the translocation as a success. Ongoing monitoring is critical, because it A uncertain ho v the population will cope with drought and inevitable predation events, and whether the population will expand and persist outside of limited preferred habitat. (C) 2001 Elsevier Science Ltd. All rights reserved.

It's the first bites that count: Survival of first-instar monarchs on milkweeds

Mortality of first instars is generally very high, but variable, and is caused by many factors, including physical and chemical plant characters, weather and natural enemies. Here, a summary of detailed field-based studies of the early-stage survival of a specialist lepidopteran herbivore is presented. First-instar larvae of the monarch butterfly, Danaus plexippus, a milkweed specialist, generally grew faster and survived better on leaves when latex flow was reduced by partial severance of the leaf petiole. The outcome depended on milkweed species, and was related to the amount of latex produced, as well as other plant characters, such as leaf hairs, microclimate and concentration of secondary metabolites. Even for a so-called 'milkweed specialist', larval performance and survival appears to be related to the concentration of cardenolides produced by the plants (a potential chemical defence against herbivory). This case study of monarchs and milkweeds highlights the need for field-based experiments to assess the effect of plant characters on the usually poor survival of early instar phytophagous insects. Few similar studies concerning the performance and survival of first-instar, eucalypt-specific herbivores have been conducted, but this type of study is considered essential based on the findings obtained using D. plexippus.

Early toxicity from preoperative radiotherapy with continuous infusion 5-fluorouracil for resectable adenocarcinoma of the rectum: A phase II trial for the Trans-Tasman Radiation Oncology Group

Purpose: To assess the toxicity and the efficacy of preoperative radiotherapy with continuous infusion 5-fluorouracil (5-FU) for locally advanced adenocarcinoma of the rectum. Methods and Materials: Eligible patients had newly diagnosed localized adenocarcinoma of the rectum within 12 cm of the anal verge, Stage T3-4, and were suitable for curative resection. Eighty-two patients were treated with radiotherapy-50.4 Gy in 28 fractions in 5.6 weeks, given concurrently with continuous infusion 5-FU, using either 96-h/week infusion at 300 mg/m(2)/day or 7-days/week infusion at 225 mg/m(2)/day. Results: The median age was 59 years (range, 27-87), and 67% of patients were male. Pretreatment stages of the rectal cancer were T3, 89% and resectable T4, 11%, with endorectal ultrasound confirmation in 67% of patients. Grade 3 acute toxicity occurred in 5 of 82 patients (6%; 95% confidence interval [CI], 2-14%). Types of surgical resection were anterior resection, 61%; abdominoperineal resection, 35%; and other procedures, 4%. There was no operative mortality. Anastomotic leakage after low anterior resection occurred in 3 of 50 patients (6%; 95% CI, 1-17%). The pathologic complete response rate was 16% (95% CI, 9-26%). Pathologic Stages T2 or less occurred in 51%. Conclusion: Preoperative radiotherapy with continuous infusion 5-FU for locally advanced rectal cancer is a safe regimen, with a significant downstaging effect. It does not seem to lead to a significant increase in serious surgical complications. (C) 2001 Elsevier Science Inc.

Leptospiral antibodies in Flying Foxes in Australia

The sera of 271 pteropid bats (or flying foxes) collected from Queensland, New South Wales, Western Australia, and the Northern Territory were screened against it reference panel of 21 Leptospira spp. using the microscopic agglutination test (MAT). Sera were collected from December 1997 through August 1999. The MAT panel represented those serovars previously isolated in Australia. as well as exotic serovar found in neighboring countries. Leptospiral antibodies were detected in 75 (28%) of the sera and represented seven serovars, one of which. L. interrogans serovar cynopteri has been regarded as exotic to Australia. Sixty sera were reactive to one serovar, 12 sera were reactive to two serovars, and three sera were reactive to three serovars. The L. kirschneri serovar australis was most frequently identified (60.2%). The findings suggest a previously unrecognized role of pteropid bats in the natural history of leptospirosis. The potential exists for establishment of infection in new host species, the transmission of new serovars to known host species, and for changes in virulence of leptospires as a result of passage through these species.

Identifying the origin of single corneal cells by DNA fingerprinting - Part I - Implications for corneal limbal allografting

Purpose. To demonstrate that the combination of impression cytology and single cell DNA fingerprinting represents a powerful tool that is suitable for detecting transplanted cells after corneal limbal allografting. Methods, Fifty single cells were obtained by corneal impression cytology from 12 patients undergoing cataract surgery. Individual cells were isolated from samples by micromanipulation. Polymerase chain reaction and short tandem repeat profiling was used to obtain forensic standard DNA fingerprints from single cells. Blood samples taken at the time of impression cytology provided control fingerprints. Results, informative DNA fingerprints were obtained from all corneal samples and 66% (33 of 50 cells) of isolated single cells, Of all fingerprints obtained, most (91%, 30 of 33 fingerprints) corneal fingerprints matched corresponding blond sample fingerprints. At least one corneal fingerprint matched the corresponding blood sample fingerprint in 83% (10 of 12 patients) of the patients in the study, Conclusions. This extremely specific single cell DNA fingerprinting system permits accurate identification of individual corneal epithelial cells, allowing very reliable determination of their origin, which will enable host and donor cells to be distinguished from each other after keratolimbal allografting procedures. even if the host and donor are the same sex or siblings. These DNA fingerprinting methods allow assessment of quality and quantity of donor cell survival, as well as survival time. The extreme sensitivity and accuracy of the technique means that should contamination occur, it would be identified, thus ensuring meaningful results.

How different is Mediterranean Caulerpa taxifolia (Caulerpales : Chlorophyta) to other populations of the species?

The green macroalgal species Caulerpa taxifolia is indigenous to tropical/subtropical Australia, ranging as far south as 28degrees and 29degrees 15' S on the Australian mainland east and west coasts, respectively. The origin of disjunct populations of the species, discovered in 2000 on the Australian mainland east coast at localities to 35degrees S remains unknown, variously attributed to introduced exotic strains or range extensions from other eastern Australian populations. Some naturally occurring Australian populations of C. taxifolia are similar to Mediterranean C. taxifolia. In Australia, large broad forms of the species, which have been known in the region since 1860, grow luxuriantly in sheltered seagrass meadows, with some of these populations tolerating minimum surface seawater temperatures in winter of 12.5 to 14.5degreesC. Accordingly, the contention that the Mediterranean has been invaded by a genetically-modified, large, cold-adapted strain of C. taxifolia may be incorrect. It is crucial that genetic markers (DNA fingerprinting, microsatellites) sensitive at the population level are used to accurately determine the genetic relatedness of C. taxifolia populations.

History of the events leading to the formulation of the apoptosis concept

Histological studies of ischaemic liver injury performed between 1962 and 1964 distinguished two types of cell death: classical necrosis, and a process involving conversion of scattered cells into small round masses of cytoplasm that often contained specks of condensed nuclear chromatin. Enzyme histochemistry demonstrated rupture of lysosomes in the former, but preservation of lysosomes in the latter. Similar small round masses were also observed sparsely in normal liver. Electron microscopy showed that the small round bodies resulted from cellular condensation and budding, that they were bounded by membranes and contained intact organelles, and that they were phagocytosed and digested by resident tissue cells, including epithelial cells. In work done in association with Jeffrey Searle, the process was found to occur spontaneously in a variety of malignant tumours and to be enhanced in squamous cell carcinomas of skin responding to radiotherapy. During 1971-1972, I collaborated with Andrew Wyllie and Alastair Currie while on sabbatical leave in Scotland. The newly defined type of cell death was shown to be regulated by hormones in the adrenal cortex and in breast carcinomas. Further, review of published electron micrographs of the cell death known to play an essential role in normal development revealed the same morphological pattern. We proposed that this distinctive phenomenon subserves a general homoeostatic function and suggested it be called apoptosis. © 2002 Elsevier Science Ireland Ltd. All rights reserved.

Alterations in Plasmodium falciparum genotypes during sequential infections suggest the presence of strain specific immunity

Many of the asexual stage Plasmodium falciparum proteins that are the targets of host protective responses are markedly polymorphic. The full repertoire of diversity is not defined for any antigen. Most studies have focused on the genes encoding merozoite surface proteins 1 and 2 (MSP1, MSP2). We explored the extent of diversity of some of the less studied merozoite surface antigens and analyzed the degree of complexity of malaria field isolates by deriving nucleotide sequences of several antigens. We have determined the genotype of apical membrane antigen 1 (AMA1) in a group of 30 field samples, collected over 29 months, from individuals living in an area of intense malaria transmission in Irian Jaya, identifying 14 different alleles. AMA1 genotyping was combined with previously determined MSP2 typing. AMA1 had the greatest power in distinguishing between isolates but methodological problems, especially when mixed infections are present, suggest it is not an ideal typing target. MSP1, MSP3, and glutamate-rich protein genotypes were also determined from a smaller group of samples, and all results were combined to derive an extended antigenic haplotype. Within this subset of 10 patients, nine different genotypes could be discerned; however, five patients were all infected with the same strain. This strain was present in individuals from two separate villages and was still present 12 months later. This strain was predominant at the first time point but had disappeared at the fourth time point. This significant change in malaria genotypes could be due to strain-specific immunity developing in this population.

Hydrolytic kinetic resolution of terminal mono- and bis-epoxides in the synthesis of insect pheromones: routes to (-)-(R)- and (+)-(S)-10-methyldodecyl acetate, (-)-(R)-10-methyl-2-tridecanone, (-)-(R)-(Z)-undec-6-en-2-ol (Nostrenol), (-)-(1R,7R)-1,7-dime

Hydrolytic kinetic resolution (HKR) of functionalised epoxides using (salen)Co(OAc) complexes provides enantiomerically enriched epoxides and diols, which have been transformed into important insect sex pheromones. In this general approach, (-)-(R)- and (+)-(S)-10-methyldodecyl acetates from the smaller tea tortrix moth were obtained, as was (-)-(R)-10-methyltridecan-2-one from the southern corn rootworm. The (S)-epoxide obtained from undec-1-en-6-yne was transformed to (-)-(R)-(Z)-undec-6-en-2-ol (Nostrenol) from ant-lions. HKR of appropriate bisepoxides was also investigated, and transformations of the resulting bisepoxides and epoxydiols provided (-)-(1R,7R)-1,7-dimethylnonylpropanoate from corn rootworms, (-)-(6R,12R)-6,12-dimethylpentadecan-2-one from the female banded cucumber beetle, and (-)-(2S,11S)-2,11-diacetoxytridecane and (+)-(2S,12S)-2,12-diacetoxytridecane from female pea-midges. (C) 2002 Elsevier Science Ltd. All rights reserved.

Detection of West Nile virus antigen in mosquitoes and avian tissues by a monoclonal antibody-based capture enzyme immunoassay

An antigen capture immunoassay to detect West Nile (WN) virus antigen in infected mosquitoes and avian tissues has been developed. With this assay purified WN virus was detected at a concentration of 32 pg/0.1 ml, and antigen in infected suckling mouse brain and laboratory-infected mosquito pools could be detected when the WN virus titer was 10(2.1) to 10(3.7) PFU/0.1 ml. In a blindly coded set of field-collected mosquito pools (n = 100), this assay detected WN virus antigen in 12 of 18 (66.7%) TaqMan-positive pools, whereas traditional reverse transcriptase PCR detected 10 of 18 (55.5%) positive pools. A sample set of 73 organ homogenates from naturally infected American crows was also examined by WN virus antigen capture immunoassay and TaqMan for the presence of WN virus. The antigen capture assay detected antigen in 30 of 34 (88.2%) TaqMan-positive tissues. Based upon a TaqMan-generated standard curve of infectious WN virus, the limit of detection in the antigen capture assay for avian tissue homogenates was approximately 10(3) PFU/0.1 ml. The recommended WN virus antigen capture protocol, which includes a capture assay followed by a confirmatory inhibition assay used to retest presumptive positive samples, could distinguish between the closely related WN and St. Louis encephalitis viruses in virus-infected mosquito pools and avian tissues. Therefore, this immunoassay demonstrates adequate sensitivity and specificity for surveillance of WN virus activity in mosquito vectors and avian hosts, and, in addition, it is easy to perform and relatively inexpensive compared with the TaqMan assay.

Attitudes of paediatric medical ward staff to a dog visitation programme

No previous studies regarding either structured, strictly controlled pet visitation programmes in paediatric hospital wards or hospital staff attitudes towards them have been conducted in Australia. Information regarding these is essential in order to minimize problems during implementation of such programmes. The aim of the study was to analyse hospital staff perceptions regarding the introduction of a pet visitation programme in an acute paediatric medical ward prior to and following implementation of the programme and to compare attitudes between the various professional groups. The study consisted of two cross-sectional surveys. A total of 224 anonymous questionnaires were distributed to administrators, doctors, nursing staff and therapists 6 weeks before and 195 were distributed 12 weeks after the introduction of a pet visitation programme. Responses were received from 115 respondents (before the programme introduction) and 45 respondents (after the programme introduction). Prior to the introduction of the dog visitation programme, there were high staff expectations that the programme would distract children from their illness, relax children and that it was a worthwhile project for the hospital to undertake. Following implementation of the programme these expectations were strongly endorsed, in addition to the perception that the ward was a happier place, the work environment was more interesting and that nurses accepted the dogs. After implementation staff were less concerned about the possibility of dog bites and dogs doing damage to equipment. Allied health staff and non-clinical staff were more positive about the programme with respect to ward climate and acceptance than were doctors and nurses. We conclude that well-planned dog visitation programmes result in positive anticipation among staff and high levels of satisfaction following programme impact.