Dietary Management of the Malabsorption Syndrome

The purpose of this report is to emphasize the importance of strict dietary control of patients suffering from the malabsorption syndrome and to announce the availability of a gluten-free bread-substitute, called “Unimix”, from the Scientific Development Committee, Room 14, Medical Building, University of Toronto. Science a gluten-free diet is difficult to follow because of the widespread use of wheat flour and other cereals in the production of many common foods, a suggested gluten-free meal pattern is presented, which conforms with Canada''s Food Guide and permits a number of choices of menu within certain limits.     

Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.     

Appraisal of environmental profiles of pasture-based milk production: a case study of dairy farms in the Waikato region,New Zealand

Purpose

Dairying is a relatively intensive livestock production system and contributes to a range of environmental impacts. In the southern hemisphere, dairy farming systems are based mainly on outdoor grazing of permanent pastures. The objectives of this study were to (i) assess environmental profiles and (ii) to identify environmental hotspots in a pasture-based dairy farming system.

Methods

A cradle-to-farm gate life cycle assessment of 53 dairy farms in the Waikato region, New Zealand, was carried out, using 1 kg of fat- and protein-corrected milk as the functional unit. Twelve environmental impact categories were assessed: climate change (CC), ozone depletion potential (ODP), cancer effects (Cancer), non-cancer effects (non-cancer), particulate matter (PM), ionizing radiation (IR), photochemical ozone formation potential (POFP), acidification potential (AP), terrestrial eutrophication potential (TEP), freshwater eutrophication potential (FEP), marine eutrophication potential (MEP) and ecotoxicity for aquatic freshwater (Ecotox). Contribution and sensitivity analyses were performed to determine key hotspots and investigate potential changes in results due to methodological choices.

Results and discussion

The on-farm stage contributed >50 % of the total result for 7 out of 12 indicators (CC, Non-cancer, PM, POFP, AP, TEP, MEP). The off-farm rearing of replacement animals contributed 11–20 % to the total result for all indicators. The production of brought-in (from off-farm) feeds for use on the dairy farms contributed >10 % to the indicator results for Non-cancer (25 %), FEP (15 %), MEP (12 %) and Ecotox (19 %). The manufacturing of agrichemicals for use on the dairy farms contributed >10 % to the indicator results for ODP (26 %), Cancer (26 %), PM (19 %), IR (46 %), FEP (25 %) and Ecotox (42 %). The transportation of off-farm inputs for use on the dairy farms contributed >10 % to the impacts on ODP (15 %), IR (21 %) and POFP (11 %). Sensitivity analysis demonstrated the influence of choices associated with data sources, inventories and impact assessment models on the results.

Conclusions

The off-farm activities together contributed >50 % to 5 out of 12 impact indicator results, >45 % to a further two impact indicator results and 32 % of the CC result. Therefore, environmental improvement options should focus on both on-farm and off-farm activities. A focus on just one impact category (such as CC) risks ignoring the environmental hotspots that are revealed in a more comprehensive environmental assessment.

     

Too late for the midwife toad: stress, variability and Hsp90.

In the 1940s and 1950s, Waddington put forward his theories of canalization and genetic assimilation. These provided a genetic basis to account for the inheritance of some apparently 'acquired' characters. Rutherford and Lindquist have now provided a molecular framework for these theories. Their results are also relevant to observations from the 1950s concerning homozygosity and variability, with a bearing on current views concerning the use of inbred strains.     

Genomic imprinting of the insulin-like growth factor 2 gene in sheep

A number of genes in the human and mouse genomes are subject to genomic imprinting, with selective inactivation of one allele of a gene in a parent-of-origin specific manner. One of the first imprinted genes identified was the Insulin-like Growth Factor 2 gene (IGF2), which promotes growth of the fetus and is expressed from only the paternal allele in most tissues in both the mouse and human. The aim of this study was to establish the imprinting status of IGF2 in sheep (Ovis aries). Sheep provide an interesting model to study imprinting, owing to differences in their placental development and the fact that they have been subject to strong artificial selection for various production traits. We report the identification of a length polymorphism in the transcribed 3′-untranslated region of the ovine IGF2 gene. This polymorphism was used to map IGF2 to sheep Chromosome (Chr) 21 and demonstrate that IGF2 is indeed imprinted in sheep, being expressed from the paternal allele. We also report that the developmental switch from imprinted IGF2 expression in the fetal liver to biallelic IGF2 expression in the adult liver, which occurs in the human but not mouse, also occurs in sheep. Differences in male- and female-specific recombination values reported around the IGF2 locus in the human were also observed around the ovine IGF2 locus. The techniques developed in this study will enable the imprinting status of IGF2 to be assessed in a variety of tissues and stages of development in normal sheep. Received: 3 October 1998 / Accepted 29 January 1999     

Quantitation of wall teichoic acid in Staphylococcus aureus by direct measurement of monomeric units using LC-MS/MS

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has created an urgent need for new therapeutic agents capable of combating this threat. We have previously reported on the discovery of novel inhibitors targeting enzymes involved in the biosynthesis of wall teichoic acid (WTA) and demonstrated that these agents can restore β-lactam efficacy against MRSA. In those previous reports pathway engagement of inhibitors was demonstrated by reduction in WTA levels measured by polyacrylamide gel electrophoresis. To enable a more rigorous analysis of these inhibitors we sought to develop a quantitative method for measuring whole-cell reductions in WTA. Herein we describe a robust methodology for hydrolyzing polymeric WTA to the monomeric component ribitol-N-acetylglucosamine coupled with measurement by LC-MS/MS. Critical elements of the protocol were found to include the time and temperature of hydrofluoric acid-mediated hydrolysis of polymeric WTA and optimization of these parameters is fully described. Most significantly, the assay enabled accurate and reproducible measurement of depletion EC_50s for tunicamycin and representatives from the novel class of TarO inhibitors, the tarocins. The method described can readily be adapted to quantifying levels of WTA in tissue homogenates from a murine model of infection, highlighting the applicability for both in vitro and in vivo characterizations.     

Consequential Life Cycle Assessment of Pasture‐based Milk Production: A Case Study in the Waikato Region,New Zealand

Farm intensification options in pasture‐based dairy systems are generally associated with increased stocking rates coupled with the increased use of off‐farm inputs to support the additional feed demand of animals. However, as well as increasing milk production per hectare, intensification can also exacerbate adverse impacts on the environment. The objective of the present study was to investigate environmental trade‐offs associated with potential intensification methods for pasture‐based dairy farming systems in the Waikato region, New Zealand. The intensification scenarios selected were (1) increased pasture utilization efficiency (PUE scenario), (2) increased use of nitrogen (N) fertilizer to boost on‐farm pasture production (N fertilizer scenario), and (3) increased use of brought‐in feed as maize silage (MS) (MS scenario). Twelve impact categories were assessed. The PUE scenario was the environmentally preferred intensification method, and the preferred choice between the N fertilizer and MS scenarios depended upon trade‐offs between different environmental impacts. Sensitivity analysis was carried out to test the effects of choice associated with: (1) the approaches used to account for indirect land‐use change (ILUC) and (2) the competing product systems (conventional beef systems) used to handle the co‐product dairy meat for the climate change (CC) indicator. Results showed that the magnitude of the CC indicator results was influenced by the ILUC accounting approaches and the choice associated with a global marginal beef mix, but the relative CC indicator results for the three intensification scenarios remained unchanged.