The effects of common matrices for assay standards on performance of ‘ultra sensitive’ immunometric assays for TSH: Report of a joint WHO/IFCC collaborative study

This report describes the results of a collaborative study organized by a joint working group of the IFCC and WHO and involving nine manufacturers of TSH immunometric assay kits. The study was designed to determine whether a calibrator with a common matrix gives better between-laboratory agreement for calibration of serum samples than the various kit calibrators, and to assess various materials for their suitability for use as common matrices. Kit calibrators, or calibrators consisting of the IRP for TSH made up in two common matrices: (a) serum from patients with untreated thyrotoxicosis or (b) serum taken from subjects treated with suppressive doses of triiodothyronine, gave similar results for the between-laboratory variation of estimates of TSH concentration for a range of serum samples. Dose-response curves for the two calibrators in ‘common’ matrices were similar to one another and to those for the kit calibrator. However, the occurrence of non-specific serum effects is shown by the comparison of results for these calibrators with results for calibrators made up in a third common matrix: serum treated with wheat germ lectin. Dose response curves for this calibrator were dissimilar to those for the other calibrators and between-laboratory variation for estimates in terms of this latter calibrator showed a substantial increase. Moreover, although the between-laboratory variances for estimates of the TSH concentration in terms of each of these calibrators (except those made up in serum treated with the wheat germ lectin) were similar for any one sample from five hyperthyroid patients, the variances were not consistent between samples, even for samples with similar mean TSH concentrations. These results suggest that a major factor in the between-laboratory variation, especially in the region near ‘zero dose’, is sample-related, and is caused by particular samples interacting differently with different assay systems.In general, it would appear that for the well-controlled ‘ultrasensitive’ TSH immunometric assay kits, included in this study, between-laboratory agreement of estimates of the TSH concentration in serum samples is not likely to be substantially improved by use of a common matrix for the standards.     

Early town planning in British South East Asia: 1910-1939

This article reviews attempts to introduce town planning in the Federated Malay States and Singapore in the 1920s, and the reasons for the failure of Reade and Richards to persuade the colonial authorities to implement their proposals. The analysis examines the legislation in some depth and uses original documents of the day to review the political opposition to their proposals which led to their withdrawal. It is argued that Reade and Richards failed because of insufficient consideraton of the likely consequences of implementing their proposals, and a personal inability to persuade the colonial communities of their value. It is suggested that the failure represents an early example of the perils of attempting town planning without developing sufficient community support and legitimation.     

Emissions of CO2 from road freight transport in London: Trends and policies for long run reductions

Freight transport has been receiving increasing attention in both literature and practice following the growing recognition of its importance in urban transport planning. This paper analyses historical and projected road freight CO₂ emissions in the city of London and explores the potential mitigation effect of a set of freight transport policies and logistics solutions. Findings indicate a range of policies with potential to reduce emissions in the period up to 2050. However, this reduction would appear to only be capable of partly counterbalancing the projected increase in freight traffic. More profound behavioural measures therefore appear to be necessary for London’s CO₂ emissions reduction targets to be met.     

Developing quality in agro‐food supply chains: A Welsh perspective

This paper describes the challenges facing the agro‐food sector in Wales as it searches for a more sustainable future than that provided by the productivist post‐war food regime. Growing concerns for food quality, coupled with the potential for wider regional spin‐offs from quality foods have highlighted the opportunities for Wales to exploit environmental quality in its food production. At present, however, Wales has a complex array of supply chains with a varying emphasis on quality. This paper compares and contrasts two models of supply chain development in Wales—mainstream meat commodity production and organic foods—for purposes of focusing questions on the development of quality agro‐food production. The paper concludes by identifying critical opportunities for and constraints upon the wider embodiment of quality in regional food supply chains.     

The dietary excitotoxins beta-N-methylamino-L-alanine and beta-N-oxalylamino-L-alanine induce necrotic- and apoptotic-like death of rat cerebellar granule cells

The neurotoxic properties of the dietary excitotoxins beta-N-methylamino-L-alanine and beta-N-oxalylamino-L-alanine have been studied in rat cerebellar granule cells and compared with those of glutamate. Glutamate caused dose-dependent death of cerebellar granule cells after a 30-min exposure when viability was assessed 24 h later. Beta-N-methylamino-L-alanine and beta-N-oxalylamino-L-alanine, however, were toxic only after 24 or 48 h of exposure. The neurotoxic effects of beta-N-methylamino-L-alanine were blocked by D(-)-2-amino-5-phosphonopentanoic acid, and those of beta-N-oxalylamino-L-alanine were blocked by kynurenic acid, which demonstrated that these excitotoxins caused cerebellar granule cell death through the activation of glutamate receptors. The features of this death were examined morphologically (fluorescent dyes, electron microscopy) and biochemically (conventional agarose gel electrophoresis, effect of aurintricarboxylic acid). Characteristics of apoptosis were identified by transferring cerebellar granule cells from a high K+ (30 mM)- to a low K+ (10 mM)-containing medium. In cerebellar granule cells exposed to beta-N-methylamino-L-alanine or beta-N-oxalylamino-L-alanine (3 mM), hallmarks of necrotic- and apoptotic-like death were observed at various time points over a 72-h period. Therefore, in cerebellar granule cells, beta-N-methylamino-L-alanine and beta-N-oxalylamino-L-alanine induce death over 12-72 h of exposure via a mechanism that involves both necrotic- and apoptotic-like cell death.     

A Digital Ratemeter Controlled by the Input Data Rate

Many radiation counter applications require the rapid response speed of a digital ratemeterl & 2, but if large changes in count rate are encountered, a conventional digital ratemeter must be set for a short counting period, producing an excessive number of individual measurements. An instrument is described which avoids this difficulty by automatically adjusting its time base as the count rate changes, the counting period always being such that a preset statistical accuracy is achieved. Further, data readout is inhibited if a measurement does not differ by a statistically significant amount from the last measurement allowed to transfer to the readout line, or if a sudden increase in rate occurs while a measurement is being taken. For applications in which a single digital ratemeter scans the output lines of a number of detectors, a preset time base limit is provided to prevent time being lost in making measurements of very low count rates or where a counter has failed. Among the display modes is a prediction mode which indicates the rate with increasing accuracy as the count is accumulated. The display utilizes scientific notation, which is very economical of display components and output lines, resulting in an instrument which has fewer parts than a scaler-timer of conventional design.     

Airborne monitoring of surface water pollutants by fluorescence spectroscopy

An airborne laserfluorosensor has been used to record fluorescence profiles of a controlled oil spill and of the river effluent from a pulp and paper mill. A pulsed ultraviolet laser is used as the excitation source in conjunction with a telescope receiver and photomultiplier detector. The complete system, including power supplies and monitoring and recording equipment, was installed and flown on a Canadian Forces DC-3 aircraft. The fluorescence profiles exhibited excellent signal-to-noise ratios and ground resolution, thereby providing for good discrimination between targets of different fluorescence quantum efficiency. By making a number of passes over a particular target area, it has been shown how the measured fluorescence profiles demonstrate the manner in which the target changes both in space and time. Information gained from these remote sensing measurements has provided data for use in the design of an advanced laserfluorosensor capable of recording fluorescence spectra and decay time data in addition to fluorescence profiles similar to those presented here.