Reducing greenhouse gas emissions through genetic selection in the Australian dairy industry.

This research explores possible options to reduce greenhouse gas (GHG) emissions in the Australian dairy industry by (1) including an environmental component in the national breeding program and (2) estimating the economic and environmental impacts of implementation of the subsequent indexes. A total of 12 possible selection indexes were considered. These indexes were developed to predict changes in gross per-animal methane production (using 3 scenarios depending on availability and efficacy of a direct methane trait breeding value prediction) with 4 different carbon prices, integrating them into an augmentation of the current conventional national selection index. Although some economic response is lost with inclusion of the GHG subindexes in the Balanced Performance Index, options do exist where this loss is marginal and, even in scenarios where all selection pressure is based on the environmental weighting, economic progress is still made in all cases. When including environmental traits within an index, if a relatively low percentage of economic gain or index progression is sacrificed, then approximately 40 to 50% of the maximum possible reductions in emissions may be achieved. This concurrent selection of estimated breeding values that have a correlated favorable response in emissions in addition to direct selection on a residual methane trait allows a high level of methane reduction to be achieved with a realized cost to farmers that is far lower than the economic value placed on carbon. By implementing a GHG subindex in the national breeding program, we can achieve up to a 7.9% decrease in residual methane and 9 times the reduction in gross emissions in 10 yr, compared with the current breeding program, with little to no cost to farmers. By 2050, selection based on one of the more moderate index scenarios at a carbon price of AUD$250/t (AUD$1 = US$0.71), or opportunity cost to farmers of AUD$87.22, will reduce gross emissions by 8.23% and emissions intensity by 21.25%, therefore offering a mitigation strategy that will be effective at reducing emissions with little compromise to profit.

Prediction of effects of dairy selection indexes on methane emissions.

Global warming caused by greenhouse gas emissions is a threat to the survival of humans and other organisms living on Earth. The greenhouse gases released from the dairy sector of New Zealand accounted for 18.2 Mt of carbon dioxide equivalent (CO2-eq) in 2016, mainly from methane generated by enteric fermentation in the rumen of milking cows and their replacement stock. A productivity commission established by the New Zealand government in 2018 estimated that methane emissions from livestock needed to be reduced from 2016 levels by 10 to 22% by 2050 (i.e., 2.8 to 6.1 million t lower), so as to restrict future increases in global temperature to less than 2°C. In this study, we evaluated genetic effects of 8 traits included in the New Zealand national dairy breeding objective, on 3 types of methane emissions metrics: gross methane emissions per dairy cow per year (E), methane emissions per hectare (EH), and methane emissions intensity per milk protein equivalents (EI), as carbon dioxide equivalents. These effects were then aligned with recent genetic changes in these traits brought about by breeding schemes, so that the overall genetic trend for each metric into the future was estimated. The results showed that EH and EI are currently being reduced at rates of -2.31 kg of CO2-eq per hectare per cow per year (current average is 6,915 kg of CO2-eq/ha per cow per year) and -0.04 kg of CO2-eq per kg of milk protein equivalents per cow per year, respectively (current average is 9.7 kg of CO2-eq/milk protein-eq per cow per year). These improvements directly reflect increased production efficiency through selection for farm profitability. If the pastureland area in New Zealand remains the same, at the same productivity and with no increase in supplementation rates from external land sources, in 20 years gross emissions would be reduced by only 0.6%, or 89 Mt. Increased production efficiency will likely result in corresponding changes to the stocking rate, to fully utilize the pasture resource available, and might further encourage a greater rate of intensification via supplementary feeding. Both consequences of current genetic selection could negate any benefits for the national greenhouse gas inventory. New selection criteria for reduced methane production are needed to help achieve New Zealand's national methane reduction targets.

Eastern Canadian Colorectal Cancer Consensus Conference: standards of care for the treatment of patients with rectal, pancreatic, and gastrointestinal stromal tumours and pancreatic neuroendocrine tumours.

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Halifax, Nova Scotia, October 20-22, 2011. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of rectal cancer, including pathology reporting, neoadjuvant systemic and radiation therapy, surgical techniques, and palliative care of rectal cancer patients. Other topics discussed include multidisciplinary cancer conferences, treatment of gastrointestinal stromal tumours and pancreatic neuroendocrine tumours, the use of folfirinox in pancreatic cancer, and treatment of stage ii colon cancer.

Genetic analysis of survival and fitness in turkeys with multiple-trait animal models.

Genetic parameters for production, survival, and structural fitness traits recorded in pedigreed turkey sire and dam parental lines from a nucleus breeding program were estimated with multiple-trait animal models. Survival and conformation traits were scored in binary terms of health, where 0 = died or affected, and 1 = survived or healthy. Walking ability at 20 wk was subjectively scored from 1 (poor) to 6 (excellent). Body weights and egg production displayed moderate heritability (h(2) = 0.18 to 0.35). Early survival (to 3 wk) displayed low heritability (h(2) = 0.02 and 0.04 for the dam and sire lines, respectively). Late survival (3 to 23 wk) and longevity (age at death or cull) had low to moderate heritability (h(2) = 0.12 to 0.14). Walking ability had moderate heritability (h(2) = 0.26, 0.25). Leg structure health displayed low heritability (h(2) = 0.08), as did hip structure, foot, and skin health (h(2) ≤ 0.02). Crop health displayed moderate heritability (h(2) = 0.12). Walking ability, hip and leg structures, footpad, and breast skin health had negative genetic correlations with BW (r(G) = -0.50 to -0.23). Egg production had moderate positive genetic correlation with late survival (r(G) = 0.61). Genetic correlations between early and late survival were close to zero (r(G) = 0.10 and 0.03 for the dam and sire lines, respectively). Walking ability had high positive genetic correlations with late survival, longevity, hip structure, and leg structure in both lines (r(G) = 0.51 to 0.91). These genetic parameters indicate that unchecked selection for growth could decrease survival, walking ability, and hip, leg, footpad, and skin health in turkeys. However, index selection should be effective at improving fitness, survival, and growth simultaneously in commercial turkey lines. Walking ability should be a good indicator trait for selection to improve overall late survival and hip and leg health in turkeys.

Herd-level versus animal-level variation in methane emission prediction in grazing dairy cattle.

In response to the increased concern over agriculture's contribution to greenhouse gas (GHG) emissions, more detailed assessments of current methane emissions and their variation, within and across individual dairy farms and cattle, are of interest for research and policy development. This assessment will provide insights into possible changes needed to reduce GHG emissions, the nature and direction of these changes, ways to influence farmer behavior and areas to maximize the adoption of emerging mitigation technologies. The objectives of this study were to (1) quantify the variation in enteric fermentation methane emissions within and among seasonal calving dairy farms with the majority of nutritional requirements met through grazed pasture; (2) use this variation to assess the potential of new individual animal emission monitoring technologies and their impact on mitigation policy. We used a large database of cow performance records for milk production and survival from 2 398 herds in New Zealand, and simulation to account for unobserved variation in feed efficiency and methane emissions per unit of feed. Results showed an average of 120 ± 31.4 kg predicted methane (CH4) per cow per year after accounting for replacement costs, ranging 8.9-323 kg CH4/cow per year. Whereas milk production, survival and predicted live weight were reasonably effective at predicting both individual and herd average levels of per cow feed intake, substantial within animal variation in emissions per unit of feed reduced the ability of these variables to predict variation in per animal methane output. Animal-level measurement technologies predicting only feed intake but not emissions per unit of feed are unlikely to be effective for advancing national policy goals of reducing dairy farming enteric methane output. This is because farmers seek to profitably utilize all farm feed resources available, so improvements in feed efficiency will not result in the reduction in feed utilization required to reduce methane emissions. At a herd level, average per cow milk production and live weight could form the basis of assigning a farm-level point of obligation for methane emissions. In conclusion, a comprehensive national database infrastructure that was tightly linked to animal identification and movement systems, and captured live weight data from existing farm-level recording systems, would be required to make this effective. Additional policy and incentivization mechanisms would still be required to encourage farmer uptake of mitigation interventions, such as novel feed supplements or vaccines that reduce methane emissions per unit of feed.

Estimating the environmental impact of dairy cattle breeding programs through emission intensity.

A recently developed methodological approach for determining the greenhouse gas emissions impact of national breeding programs was applied to measure the effects of current and future breeding goals on the emission intensity (EI) of the Canadian dairy industry. Emission intensity is the ratio of greenhouse gas outputted in comparison to the product generated. Traits under investigation affected EI by either decreasing the direct emissions yield (i.e. increasing feed performance), changing herd structure (i.e. prolonging herd life) or through the dilution effect of increased production (i.e. increasing fat yield). The intensity value (IV) of each trait, defined as the change in emissions' intensity per unit change in each trait, was calculated for each of the investigated traits. The IV trend of these traits was compared for the current and prospective selection index, as well as for a system with and without quota (the supply management policy designed to prevent overproduction). The overall EI of the average genetic merit Canadian dairy herd per breeding female was 5.07 kg CO2eq/kg protein equivalent output. The annual reduction in EI due to the improvement of production traits was -0.027, -0.018 and -0.006 for fat, protein and milk other solids, respectively. The functional traits, herd life and mastitis resistance, had more modest effects (-0.008 and -0.001, respectively). These results are consistent with international studies that identified traits related to production, survival, health and fertility as having the largest impact on the environmental footprint of dairy cattle. Overall, the dairy industry is becoming more efficient by reducing its EI through selection of environmentally favorable traits, with a 1% annual reduction of EI in Canada.

Determining the economic value of daily dry matter intake and associated methane emissions in dairy cattle.

Feed represents a substantial proportion of production costs in the dairy industry and is a useful target for improving overall system efficiency and sustainability. The objective of this study was to develop methodology to estimate the economic value for a feed efficiency trait and the associated methane production relevant to Canada. The approach quantifies the level of economic savings achieved by selecting animals that convert consumed feed into product while minimizing the feed energy used for inefficient metabolism, maintenance and digestion. We define a selection criterion trait called Feed Performance (FP) as a 1 kg increase in more efficiently used feed in a first parity lactating cow. The impact of a change in this trait on the total lifetime value of more efficiently used feed via correlated selection responses in other life stages is then quantified. The resulting improved conversion of feed was also applied to determine the resulting reduction in output of emissions (and their relative value based on a national emissions value) under an assumption of constant methane yield, where methane yield is defined as kg methane/kg dry matter intake (DMI). Overall, increasing the FP estimated breeding value by one unit (i.e. 1 kg of more efficiently converted DMI during the cow's first lactation) translates to a total lifetime saving of 3.23 kg in DMI and 0.055 kg in methane with the economic values of CAD $0.82 and CAD $0.07, respectively. Therefore, the estimated total economic value for FP is CAD $0.89/unit. The proposed model is robust and could also be applied to determine the economic value for feed efficiency traits within a selection index in other production systems and countries.

A methodology framework for weighting genetic traits that impact greenhouse gas emission intensities in selection indexes.

A methodological framework was presented for deriving weightings to be applied in selection indexes to account for the impact genetic change in traits will have on greenhouse gas emissions intensities (EIs). Although the emission component of the breeding goal was defined as the ratio of total emissions relative to a weighted combination of farm outputs, the resulting trait-weighting factors can be applied as linear weightings in a way that augments any existing breeding objective before consideration of EI. Calculus was used to define the parameters and assumptions required to link each trait change to the expected changes in EI for an animal production system. Four key components were identified. The potential impact of the trait on relative numbers of emitting animals per breeding female first has a direct effect on emission output but, second, also has a dilution effect from the extra output associated with the extra animals. Third, each genetic trait can potentially change the amount of emissions generated per animal and, finally, the potential impact of the trait on product output is accounted for. Emission intensity weightings derived from this equation require further modifications to integrate them into an existing breeding objective. These include accounting for different timing and frequency of trait expressions as well as a weighting factor to determine the degree of selection emphasis that is diverted away from improving farm profitability in order to achieve gains in EI. The methodology was demonstrated using a simple application to dairy cattle breeding in Ireland to quantify gains in EI reduction from existing genetic trends in milk production as well as in fertility and survival traits. Most gains were identified as coming through the dilution effect of genetic increases in milk protein per cow, although gains from genetic improvements in survival by reducing emissions from herd replacements were also significant. Emission intensities in the Irish dairy industry were estimated to be reduced by ~5% in the last 10 years because of genetic trends in production, fertility and survival traits, and a further 15% reduction was projected over the next 15 years because of an observed acceleration of genetic trends.

Prediction of effects of beef selection indexes on greenhouse gas emissions.

Genetic improvement in production efficiency traits can also drive reduction in greenhouse gas emissions. This study used international 'best-practice' methodology to quantify the improvements in system-wide CO2 equivalent emissions per unit of genetic progress in the Irish Maternal Replacement (MR) and Terminal (T) beef cattle indexes. Effects of each index trait on system gross emissions (GE) and system emissions intensity (EI) were modelled by estimating effects of trait changes on per-animal feed consumption and associated methane production, per-animal meat production and numbers of animals in the system. Trait responses to index selection were predicted from linear regression of individual bull estimated breeding values for each index trait on their MR or T index value, and the resulting regression coefficients were used to calculate trait-wise responses in GE and EI from index selection. Summed over all trait responses, the MR index was predicted to reduce system GE by 0.810 kg CO2e/breeding cow per year per € index and system EI by 0.009 kg CO2e/kg meat per breeding cow per year per € index. These reductions were mainly driven by improvements in cow survival, reduced mature cow maintenance feed requirements, shorter calving interval and reduced offspring mortality. The T index was predicted to reduce system EI by 0.021 kg CO2e/kg meat per breeding cow per year per € index, driven by increased meat production from improvements in carcass weight, conformation and fat. Implications for incorporating an EI reduction index to the current production indexes and long-term projections for national breeding programs are discussed.

Long-term skeletodental stability of mandibular symphyseal distraction osteogenesis: Tooth-borne vs hybrid distraction appliances.

OBJECTIVE: To evaluate and compare the long-term skeletodental stability of mandibular symphyseal distraction osteogenesis (MSDO) achieved with the use of tooth-borne vs. hybrid distraction appliances. MATERIALS AND METHODS: Posttreatment and follow-up orthodontic records were collected for 33 patients. The 14 patients who underwent distraction with a tooth-borne appliance had a mean follow-up of 5.08 years. The 19 patients who underwent distraction with a hybrid appliance had a mean follow-up of 6.07 years. Records included intraoral photographs, study models, postero-anterior cephalometric radiographs, and lateral cephalometric radiographs. Total changes of 16 measurements were analyzed to compare patients who underwent the tooth-borne vs. the hybrid distraction. RESULTS: Both groups shared several similar and significant (P < .05) changes from posttreatment to follow-up records. Cast analysis showed a decrease in intercanine width and arch length and an increase in irregularity index. The postero-anterior cephalometric radiograph showed an increase in the width of the interincisal apices. The lateral cephalometric radiograph showed a decrease in the MP-L1 angle. The only statistically significant difference between the two appliances was the intercentral incisor contact point. CONCLUSION: Changes found are consistent with those found in untreated and orthodontically treated individuals over time. The long-term changes in the current patient sample can be determined to be expected and acceptable. MSDO is a viable treatment option with the use of either a hybrid or tooth-borne appliance.

Comparative analysis of genetic parameters and quantitative trait loci for growth traits in Fraser strain Arctic charr (Salvelinus alpinus) reared in freshwater and brackish water environments.

To determine the potential for genetic improvement in Fraser strain Arctic charr (AC, Salvelinus alpinus), we calculated genetic parameters for BW and condition factor (K) and tested if previously identified QTL for these traits were detectable across a commercial broodstock reared in both freshwater (FRW) and brackish water (BRW). Individuals from 30 full-sib families were reared up to 29 mo of age in FRW and BRW tanks at a commercial facility. Heritability for BW and K was moderate in FRW (0.29 to 0.38) but lower in BRW (0.14 to 0.17). Genetic correlations for BW across environments were positive and moderate (0.33 to 0.67); however, equivalent K correlations were very weak (0.24 to 0.37). We identified a single BW QTL with experimentwide effects on linkage group AC-8, 4 BW QTL (AC-4, -13, -14, and -19), and 3 K QTL (AC-4, -5, and -20) with chromosomewide effects across families. Notably, the QTL on AC-8 had significant effects with BW at 3 out of 4 sampling dates in FRW and had significant allelic phase disequilibrium with BW across families, suggesting a tight coupling of the marker region to the QTL in this population. Body weight QTL were identified on AC-4 in both FRW and BRW environments and AC-4 was the only linkage group with a detectable QTL for both K and BW. Modest consistency of some QTL effects as well as moderate heritability in both environments suggests that there is some potential for genetic improvement of growth in this species even though gene × environment interactions are high.

Role of pemetrexed in advanced non-small-cell lung cancer: meta-analysis of randomized controlled trials, with histology subgroup analysis.

PURPOSE: Platinum-based regimens represent the standard first-line treatment for non-small-cell lung cancer (nsclc). However, newer data have established a role for pemetrexed in the treatment of this disease. Such data suggest that histology represents a determining factor in the selection of treatment. METHODS: We undertook a systematic review of the literature for randomized controlled trials that compared the efficacy of pemetrexed with that of other treatments in advanced nsclc. Data and study quality were assessed according to published guidelines. RESULTS: We identified five trials that compared pemetrexed with other treatments or with placebo. Overall survival for patients treated with pemetrexed was superior to that with other treatments: hazard ratio (hr): 0.89; 95% confidence interval (ci): 0.80 to 0.99. The survival benefit was limited to patients with non-squamous histology: hr: 0.82; 95% ci: 0.73 to 0.91. Pemetrexed was inferior to other chemotherapy options in patients with squamous histology: hr: 1.19; 95% ci: 0.99 to 1.43. CONCLUSIONS: Compared with other chemotherapy agents, pemetrexed is more effective for the treatment of nsclc in patients with non-squamous histology.

Quality and production trait genetics of farmed European whitefish, Coregonus lavaretus.

We present here phenotypic and genetic parameters for the major quality and production traits of farmed European whitefish. A total of 70 families were produced by mating each of 45 sires to an average of 1.6 dams and each of the 52 dams to an average of 1.3 sires. A total of 2,100 individuals were recorded for survival, and 507 individuals for growth and quality-related traits. The 4 major results were as follows: first, all traits exhibited nonzero heritabilities except for fillet gaping and fillet protein%. The heritabilities for the production traits were harvest weight (0.42 ± 0.10), gutted weight (0.40 ± 0.10), fillet weight (0.36 ± 0.09), maturity score (0.27 ± 0.11, on liability scale), survival (0.19 ± 0.05, on liability scale), carcass% (0.14 ± 0.07), and fillet% (0.11 ± 0.06). The heritabilities for the quality traits were condition factor (0.49 ± 0.10), fillet lipid% (0.37 ± 0.10), muscle texture (0.30 ± 0.09), Distell lipid reading (0.26 ± 0.09), fillet lightness (0.16 ± 0.07), fillet gaping (0.04 ± 0.06), and fillet protein% (0.04 ± 0.06). Second, the quality traits that were significantly genetically correlated with each other were all related to lipid deposition. Increasing fillet lipid% (an undesired change in whitefish) was genetically related to desired lighter fillet color [genetic correlation (r(G)) = 0.70 ± 0.22] and to undesired greater condition factor (0.39 ± 0.17). None of the other genetic correlations between condition factor, fillet lipid%, muscle texture, fillet lightness, fillet gaping, and fillet protein% were significant. Third, BW and gutted weight were genetically related to the quality traits that were genetically related to lipid deposition. Increasing harvest weight was genetically related to high fillet lipid% (r(G) = 0.59 ± 0.14), lighter fillet color (0.61 ± 0.25), and to greater condition factor (0.60 ± 0.12). All other genetic correlations of harvest weights with the quality traits were nonsignificant, indicating that rapid growth was not genetically related to gaping and softer flesh. Fourth, none of the genetic correlations of carcass%, fillet%, maturity, and survival with the quality traits were significant, implying weak genetic integration between the traits. Yet, marginally significant genetic correlations were found for fillet lipid% with maturity score (r(G) = -0.46 ± 0.24) and survival (0.36 ± 0.19). These results provide the genetic basis for assessing the potential to improve product quality via selective breeding.

The use of soluble African horse sickness viral protein 7 as an antigen delivery and presentation system.

We have investigated the use of soluble chimeric trimers of the major capsid protein VP7 of African horse sickness virus (AHSV) as a vaccine delivery system by targeting some of the natural hydrophilic loops on the VP7 top domain for the insertion of foreign peptides. Key to this trimer display strategy is the solubility of AHSV VP7 and how the solubility of this hydrophobic protein can be manipulated by inserting peptides into the top domain. To investigate, we generated different cloning vectors by inserting multiple cloning sites at three different positions in the VP7 gene. These modifications inserted six amino acids at the cloning sites and in some cases this converted VP7 to a largely soluble protein without affecting the ability of the modified proteins to form trimers. The vectors were used to generate a number of soluble VP7 fusion proteins including a fusion with a 36 amino acid insert that overlaps important immunological domains on protein VP1 of foot and mouth disease virus (FMDV) as well as a 110 amino acid peptide derived from AHSV VP2. Soluble trimers of these fusion proteins were able to elicit a good insert-specific immune response in guinea pigs. l-Arginine was found to reverse protein aggregation and was employed as an effective strategy to isolate relatively pure soluble chimeric VP7 trimers. Another factor that increased VP7 solubility in both wild-type VP7 and one of the VP7 vector proteins was the substitution of the leucine residue in position 345 of the VP7 C-terminus with a hydrophilic arginine residue.

Genetic relationships of body composition and feed utilization traits in European whitefish (Coregonus lavaretus L.) and implications for selective breeding in fishmeal- and soybean meal-based diet environments.

Body composition traits have potential use in fish breeding programs as indicator traits for selective improvement of feed efficiency. Moreover, feed companies are increasingly replacing traditional fish meal (FM) based ingredients in feeds for carnivorous farmed fish with plant protein ingredients. Therefore, genetic relationships of composition and feed utilization traits need to be quantified for both current FM-based and future plant-based aquaculture feeds. Individual whole-body lipid% and protein%, daily gain (DG), ADFI, and G:F (daily gain/daily feed intake) were measured on 1,505 European whitefish (Coregonus lavaretus) from 70 half/full-sib families reared in a split-family design with either a typical FM or a novel soybean meal (SBM) based diet. Diet-specific genetic parameters were estimated with multiple-trait animal models. Lipid% was significantly greater in the FM diet group than in the SBM group, even independent of final BW or total feed intake. In both diets, lipid% showed moderate heritability (0.12 to 0.22) and had positive phenotypic and genetic correlations with DG (0.37 to 0.82) and ADFI (0.36 to 0.88). Therefore, selection against lipid% can be used to indirectly select for lower feed intake. Protein% showed low heritability (0.05 to 0.07), and generally very weak or zero correlations with DG and ADFI. In contrast to many previous studies on terrestrial livestock, lipid% showed zero or very weak phenotypic and genetic correlations with G:F. However, selection index calculations demonstrated that simultaneous selection for high DG and reduced lipid% could be used to indirectly increase G:F; this strategy increased absolute genetic response in G:F by a factor of 1.5 to 1.6 compared with selection on DG alone. Lipid% and protein% were not greatly affected by genotype-diet environment interactions, and therefore, selection strategies for improving body composition within current FM diets should also improve populations for future SBM diets.

Subtractive hybridization magnetic bead capture: a new technique for the recovery of full-length ORFs from the metagenome.

A new method for the recovery of full-length open reading frames from metagenomic nucleic acid samples is reported. This technique, based on subtractive hybridization magnetic bead capture technology, has the potential to access multiple gene variants from a single amplification reaction. It is now widely accepted that classical microbiological methods provide only limited access to the true microbial biodiversity (less than 1%). The desire to access a higher proportion of the metagenome has led to the development of efficient environmental nucleic acid extraction technologies and to a range of sequence-dependent and sequence-independent gene discovery techniques. These methods avoid many of the limitations of culture-dependent gene targeting.

One hundred cases of attempted suicide in the elderly.

BACKGROUND: Despite the high suicide rate in the elderly, there is a relative lack of information on the longer-term outcome of elderly people who have attempted suicide, particularly their psychiatric and physical morbidity and mortality. METHOD: Comprehensive demographic and psychiatric data were available on 100 consecutive referrals to a liaison psychiatric service of patients over 65 years of age who attempted suicide between 1989 and 1992. Detailed follow-up in 1994 included the interviewing of survivors using GMS-AGECAT. RESULTS: Of the 64 women and 36 men, with a mean age of 75.8 years, 42 subjects were dead at follow-up; 12 were suspected suicides, five having died as a delayed result of their index attempt. Twelve women made a further non-lethal suicide attempt. All five male repeat attempts proved fatal. CONCLUSIONS: Elderly people who attempt suicide have a high mortality both from completed suicide and death from other causes. The completed suicide rate is at least 1.5% per year, and the repetition rate is 5.4% per year. Those at risk of further self-harm are likely to be in contact with psychiatric services and to be suffering from persistent depression.

A randomized crossover trial of Quick Medical Reference (QMR) as a teaching tool for medical interns.

OBJECTIVE: To determine whether the addition of Quick Medical Reference (QMR) to usual educational tools improves an intern's performance in managing clinical cases that test diagnostic and investigative skills. DESIGN: Randomized, controlled, single-blinded crossover study. SETTING: Tertiary care teaching hospital. SUBJECTS: Comprehensive medical interns who are proficient in the use of QMR. INTERVENTION: A total of 16 interns trained in the use of QMR were randomized to work up a total of six diagnostically challenging cases, three using medical textbooks plus access to QMR and three using textbooks and no access to QMR. MEASUREMENTS: The interns provided their solutions to the cases, which consisted of the differential diagnosis and investigations. They were scored by comparing their answers with the consensus answers provided by subspecialty consultants. For each intern, the difference in mean total scores with and without QMR was calculated. RESULTS: The mean difference in total scores was 7.2% benefit (p < 0.05, 95% CI = 0.05 to 14.4) using QMR. The beneficial difference was driven mainly by improvement in diagnostic scores, with the mean difference being 11.6% (p = 0.01, 95% CI = 2.4 to 20.8). Regression analysis showed that the more difficult the case, the greater the benefit of QMR. CONCLUSIONS: Quick Medical Reference may be a useful adjunct to interns in formulating diagnostic strategies for difficult clinical cases. However, since optimal conditions were chosen for QMR benefit in this study design, the small benefit in test scores must be weighed against the time required to teach QMR to interns.

The evolution of renal osteodystrophy in patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

Since the introduction of continuous ambulatory peritoneal dialysis by Popovich et al [1] and the subsequent modification of the technique by Oreopoulos et al [2], an increasing number of patients with end-stage renal disease are maintained on this new treatment modality. To date, there has not been any report of the effect of CAPD on the evolution of renal osteodystrophy which is one of the major complications of chronic renal failure. In this report we will present the results of our radiological and biochemical studies of renal osteodystrophy in 28 patients who have been on CAPD from 6 to 23 months.