Association mapping of germinability and seedling vigor in sorghum under controlled low-temperature conditions.

Sorghum is one of the world's most important food, feed, and fiber crops as well as a potential feedstock for lignocellulosic bioenergy. Early-season planting extends sorghum's growing season and increases yield in temperate regions. However, sorghum's sensitivity to low soil temperatures adversely impacts seed germination. In this study, we evaluated the 242 accessions of the ICRISAT sorghum mini core collection for seed germination and seedling vigor at 12 °C as a measure of cold tolerance. Genome-wide association analysis was performed with approximately 162,177 single nucleotide polymorphism markers. Only one marker locus (Locus 7-2) was significantly associated with low-temperature germination and none with vigor. The linkage of Locus 7-2 to low-temperature germination was supported by four lines of evidence: strong association in three independent experiments, co-localization with previously mapped cold tolerance quantitative trait loci (QTL) in sorghum, a candidate gene that increases cold tolerance and germination rate when its wheat homolog is overexpressed in tobacco, and its syntenic region in rice co-localized with two cold tolerance QTL in rice. This locus may be useful in developing tools for molecular breeding of sorghums with improved low-temperature germinability.

Genetic analyses of nickel tolerance in a North American serpentine endemic plant, Caulanthus amplexicaulis var. barbarae (Brassicaceae).

PREMISE OF THE STUDY: The evolution of metal tolerance in plants is an important model for studies of adaptation to environment, population genetics, and speciation. Here, we investigated nickel tolerance in the North American serpentine endemic Caulanthus amplexicaulis var. barbarae in comparison with its nonserpentine sister taxon C. amplexicaulis var. amplexicaulis. We hypothesized that the serpentine endemic would have a heritable growth advantage on nickel-containing substrates. METHODS: We employed an artificial growth assay to quantify biomass accumulation. Study plants were crossed to create an F(2:3) population that was used to determine the heritability of nickel tolerance and to map quantitative trait loci (QTL). Nickel accumulation in both laboratory populations and native specimens was examined using energy-dispersive x-ray fluorescence (EDXRF). KEY RESULTS: The serpentine endemic had a dramatic growth advantage at concentrations of nickel >30 µmol/L. Caulanthus amplexicaulis var. barbarae and its nonserpentine sister taxon both accumulated nickel to substantial levels. Nickel tolerance was highly heritable (h(2) = 0.59) and not associated with accumulation. The QTL analyses identified two major loci for nickel tolerance, on linkage group 2 (LG2) and linkage group 9 (LG9). CONCLUSIONS: In our study, nickel tolerance was determined by two major loci with large effects. At both loci, alleles from the serpentine parent conferred positive effects on nickel tolerance, suggesting that they are adaptive in the natural serpentine environment. The mechanism of nickel tolerance in the serpentine plant was not exclusion of nickel. Nickel tolerance may have an inducible component in C. amplexicaulis var. barbarae.

A pilot study to test the use of a checklist in a tertiary intensive care unit as a method of ensuring quality processes of care.

This pilot study aimed to test the use of a checklist as a method of ensuring that certain processes of care are performed routinely and systematically in a tertiary intensive care unit. The pilot involved the development of a process indicator checklist, its implementation and review. The checklist contained 16 items sourced from the literature or deemed important by local clinicians. Checklists were completed on the morning round for all adult patients admitted to the unit for approximately one month. Baseline and evaluation surveys were conducted with medical staff to assess both the benefits and shortcomings of using the checklist. Results demonstrated good compliance in completing the checklist (81%) and that when checked, certain aspects of care were not always delivered when appropriate. At the conclusion of the study the majority of medical staff believed that care in the intensive care unit actually improved with the use of the checklist, and all thought that it assisted in ensuring that good quality care was delivered. The checklist is a useful tool that can be readily applied to facilitate best practice and quality in everyday clinical care, ultimately leading to better health outcomes for patients.

Perductal electrolytic ablation of the porcine pancreas: a minimally invasive option-studies of morbidity and mortality.

BACKGROUND: Pancreatic cancer has a dismal prognosis. Few patients are suitable for surgical resection, leaving the majority requiring symptom palliation. Current palliative techniques such as surgical bypass and endoscopic retrograde cholangiopancreatography (ERCP) are imperfect. A novel palliative therapy combining the symptom control of surgical bypass with the minimally invasive nature of ERCP is required. METHODS: Perductal electrolytic ablation of pancreatic tissue, in a porcine model, was performed. There were two survival groups of 2 weeks (n = 4) and 8 weeks (n = 4). Postoperatively, serum biochemistry, amylase and C-reactive protein (CRP) were assessed. Histological examination of the pancreas, lungs, and kidneys was performed to determine the presence of acute pancreatitis or systemic inflammatory response. RESULTS: An immediate transient increase in both amylase and CRP was seen. Although pancreatic histology demonstrated localised necrosis at the electrolytic site at 2 weeks, there was no evidence of generalized pancreatitis or a systemic inflammatory response at either 2 or 8 weeks. CONCLUSIONS: This study suggests that, although there is localized pancreatic necrosis and transient hyperamylasemia, perductal pancreatic electrolytic ablation is safe, with neither generalized pancreatitis nor a systemic inflammatory response, in the medium and long term. Although performed in normal porcine pancreas, because of the absence of a large-animal model of pancreatic cancer, this study suggests that electrolytic pancreatic ablation is safe. This technique may have a role in the palliation of pancreatic cancer, especially if delivered via a minimally, invasive approach, and warrants further investigation.

Palliation of pancreatic cancer using electrolytic ablation.

BACKGROUND: Inoperable pancreatic cancer has a dismal prognosis. Palliation involves either stenting or surgical bypass. Stenting does not relieve gastric outlet obstruction, and surgical bypass is a major procedure. A minimally invasive procedure is needed that relieves both gastric outlet and biliary obstruction, with the potential for relieving pain. METHODS: In an experimental model, pancreatic electrolysis was investigated. The pancreatic duct was cannulated via a transduodenal approach with an electrode catheter. In 6 animals an electrolytic "lesion" was created using a direct current generator. Six animals were controls. The local and systemic effects of electrolysis were assessed using histological and biochemical parameters. RESULTS: The pancreatic duct was cannulated in all animals and treatment was uneventful. Electrolytic lesions comprised a central area of necrosis with a sharp demarcation between necrotic and viable pancreas. All animals developed transient hyperamylasemia after electrolysis. There was no significant difference between treatment and controls. Importantly, no animal had clinical, biochemical, or histological evidence of pancreatitis. CONCLUSIONS: This experimental study suggested that electrolytic palliation of inoperable pancreatic cancer via the gastrointestinal tract is potentially safe. In patients, this treatment could be performed during endoscopic retrograde cholangiopancreatography and may have therapeutic advantages when compared to stenting or biliary bypass.

Cost effectiveness of treatment options in advanced breast cancer in the UK.

OBJECTIVE: To compare clinical and economic study data for docetaxel, paclitaxel and vinorelbine in the treatment of anthracycline-resistant advanced breast cancer. STUDY DESIGN AND METHODS: A Markov decision-analysis model to simulate the clinical course of a 'typical' patient with advanced breast cancer during salvage chemotherapy was updated with response rates and adverse effect rates from phase III clinical trial data for docetaxel, paclitaxel and vinorelbine. Costs were taken from UK national databases and hospitals. Utilities were estimated from 30 oncology nurses in the UK using the standard gamble method. PERSPECTIVE: National Health Service. RESULTS: When compared with other chemotherapeutic agents, docetaxel has been shown to increase response rate, time to progression and survival in patients with advanced breast cancer. In the base-case analysis, the incremental cost-utility ratio for docetaxel versus paclitaxel was pound1995 per quality-adjusted life year (QALY) gained (1998 values). The incremental cost-utility ratio for docetaxel versus vinorelbine was pound14 055 per QALY gained. In the comparison with vinorelbine, docetaxel provided the equivalent of an additional 92 days of perfect health. Sensitivity analyses confirmed the robustness of the model and the validity of the base-case analysis results. Even in the worst case scenarios, docetaxel remained cost effective compared with paclitaxel and vinorelbine. CONCLUSIONS: These findings support the use of the taxoids, notably docetaxel, in the management of advanced breast cancer.

Alterations of AP-1 and CREB protein DNA binding in rat supraoptic and paraventricular nuclei by acute and repeated hyperosmotic stress.

Electrophoretic mobility shift assays were used to analyze Fos and CREB protein-DNA-interactions in the rat hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. After intraperitoneal administration of normal saline, PVN (but not SON) extracts exhibited a significant 183% increase in binding to the activational protein-1 (AP-1) canonical DNA binding sequence. Hypertonic saline treatment resulted in a approximately 2.5-fold increase in binding by tissue samples from both regions. AP-1 binding by SON extracts after two hypertonic saline injections caused a 307% increase in binding that was significantly greater than binding by PVN extracts (207%). Fos binding was equal in the SON after one and two hypertonic saline injections, but the PVN exhibited less of an increase after two injections. Binding to the canonical cyclic adenosine monophosphate regulatory element (CRE), and phosphorylated CREB (pCREB) supershift binding, indicated pCREB is constitutively expressed. Any experimental treatment (handling and an injection) caused an elevation in binding in the PVN. AP-1 protein complex DNA binding was increased after osmotic stimulation, and SON and PVN exhibit differences in AP-1 DNA binding kinetics, after repeated hypertonic saline stress. Changes in PVN tissue samples were subtle, and may reflect the fact that magnocellular and parvocellular neurons mediate, respectively, fluid homeostasis and stress responses.

The determination of the flour improver potassium bromate in bread by gas chromatographic and ICP-MS methods.

The development and application of two methods for determining bromate in bread are described. A gas chromatographic (GC) method which relied on the formation of a volatile derivative of bromate gave a detection limit of 12 micrograms/kg. Duplicate analyses agreed well but recovery from breads spiked with bromate were low and averaged 30% for brown bread and 42% for white bread. Further studies indicated that this was caused by the derivatization reaction being suppressed by components of the sample and reagents used in their preparation. After taking both these factors into account, a recovery of 80% could be achieved. The GC method was used to carry out a survey of retail bread samples in 1989. Bromate was found in all six unwrapped breads analysed (median 35 micrograms/kg, range 17-317 micrograms/kg), whilst for 22 wrapped breads, seven were found to contain bromate (median < 12 micrograms/kg, range < 12-238 micrograms/kg). A second method of analysis employing inductively coupled plasma-mass spectrometry (ICP-MS) was developed which provided independent confirmation of the presence of bromate in these retail samples. The method gave a mean recovery of 71% from five spiked samples and a detection limit of 20 micrograms/kg. The GC and ICP-MS methods were compared by performing replicate analyses of a bread sample prepared with bromate-treated flour. Quantitative agreement between the two techniques was good. The precision of the ICP-MS technique (CV 12%) proved better than that found for the GC method (CV 18%). The Potassium Bromate (Prohibition as a Flour Improver) Regulation 1990 came into force on 1 April 1990 (Statutory Instrument 1990 Number 399).(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular dissection of mutations at the heterozygous thymidine kinase locus in mouse lymphoma cells.

The mouse lymphoma L5178Y TK+/- 3.7.2C cell line allows quantitation of induced TK(+/-)----TK-/- mutations at the heterozygous thymidine kinase (Tk) locus. TK-/- mutant colonies show a bimodal size distribution, reflecting a difference in the growth rates of the two size classes that is hypothesized to result from different degrees of genetic damage. The two homologous chromosomes 11 containing the alleles of the Tk gene in L5178Y 3.7.2C TK+/- cells are distinguishable at the cytogenetic level. We find, in addition, that the two alleles are distinguishable at the molecular level because of an Nco I restriction fragment length polymorphism at the 3' end of the gene. In a set of 51 large-colony and 48 small-colony TK-/- mutants induced by ionizing radiation or by chemical mutagens, we find that 78, including all except one of the small-colony mutants, have lost the Tk+ allele and that some of these have two to four copies of the remaining Tk- allele. Nineteen of the large-colony TK-/- mutants that do not show Tk+ allele loss show no other structural changes detectable at the level of Southern blot analysis. One shows a partial deletion. The variety of mutagenic lesions recorded at the heterozygous Tk locus may be representative of events observed in human malignancy and may include a wider range of mutagenic events than can be observed at hemizygous test loci.