Development of a quality control material for the measurement of 8-oxo-7,8-dihydro-2'-deoxyguanosine, an in vivo marker of oxidative stress, and comparison of results from different laboratories

The measurement of 8-oxo-7,8-dihydro-2'-deoxyguanosine is an increasingly popular marker of in vivo oxidative damage to DNA. A random-sequence 21-mer oligonucleotide 5'-TCA GXC GTA CGT GAT CTC AGT-3' in which X was 8-oxo-guanine (8-oxo-G) was purified and accurate determination of the oxidised base was confirmed by a 32P-end labelling strategy. The lyophilised material was analysed for its absolute content of 8-oxo-dG by several major laboratories in Europe and one in Japan. Most laboratories using HPLC-ECD underestimated, while GC-MS-SIM overestimated the level of the lesion. HPLC-ECD measured the target value with greatest accuracy. The results also suggest that none of the procedures can accurately quantitate levels of 1 in 10(6) 8-oxo-(d)G in DNA.

Quality control of pharmaceutical ingredients:developing a caking test for industry

Objectives - Powdered and granulated particulate materials make up most of the ingredients of pharmaceuticals and are often at risk of undergoing unwanted agglomeration, or caking, during transport or storage. This is particularly acute when bulk powders are exposed to extreme swings in temperature and relative humidity, which is now common as drugs are produced and administered in increasingly hostile climates and are stored for longer periods of time prior to use. This study explores the possibility of using a uniaxial unconfined compression test to compare the strength of caked agglomerates exposed to different temperatures and relative humidities. This is part of a longer-term study to construct a protocol to predict the caking tendency of a new bulk material from individual particle properties. The main challenge is to develop techniques that provide repeatable results yet are presented simply enough to be useful to a wide range of industries. Methods - Powdered sucrose, a major pharmaceutical ingredient, was poured into a split die and exposed to high and low relative humidity cycles at room temperature. The typical ranges were 20–30% for the lower value and 70–80% for the higher value. The outer die casing was then removed and the resultant agglomerate was subjected to an unconfined compression test using a plunger fitted to a Zwick compression tester. The force against displacement was logged so that the dynamics of failure as well as the failure load of the sample could be recorded. The experimental matrix included varying the number of cycles, the amount between the maximum and minimum relative humidity, the height and diameters of the samples, the number of cycles and the particle size. Results - Trends showed that the tensile strength of the agglomerates increased with the number of cycles and also with the more extreme swings in relative humidity. This agrees with previous work on alternative methods of measuring the tensile strength of sugar agglomerates formed from humidity cycling (Leaper et al 2003). Conclusions - The results show that at the very least the uniaxial tester is a good comparative tester to examine the caking tendency of powdered materials, with a simple arrangement and operation that are compatible with the requirements of industry. However, further work is required to continue to optimize the height/ diameter ratio during tests.

Quality control of high throughput screening

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Quality control of high throughput screening

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Quality control in Midland industry

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Medical error:a discussion of the medical construction of error and suggestions for reforms of medical education to decrease error

Introduction: There is a growing public perception that serious medical error is commonplace and largely tolerated by the medical profession. The Government and medical establishment's response to this perceived epidemic of error has included tighter controls over practising doctors and individual stick-and-carrot reforms of medical practice. Discussion: This paper critically reviews the literature on medical error, professional socialization and medical student education, and suggests that common themes such as uncertainty, necessary fallibility, exclusivity of professional judgement and extensive use of medical networks find their genesis, in part, in aspects of medical education and socialization into medicine. The nature and comparative failure of recent reforms of medical practice and the tension between the individualistic nature of the reforms and the collegiate nature of the medical profession are discussed. Conclusion: A more theoretically informed and longitudinal approach to decreasing medical error might be to address the genesis of medical thinking about error through reforms to the aspects of medical education and professional socialization that help to create and perpetuate the existence of avoidable error, and reinforce medical collusion concerning error. Further changes in the curriculum to emphasize team working, communication skills, evidence-based practice and strategies for managing uncertainty are therefore potentially key components in helping tomorrow's doctors to discuss, cope with and commit fewer medical errors.

VGI quality control

This paper presents a framework for considering quality control of volunteered geographic information (VGI). Different issues need to be considered during the conception, acquisition and post-acquisition phases of VGI creation. This includes items such as collecting metadata on the volunteer, providing suitable training, giving corrective feedback during the mapping process and use of control data, among others. Two examples of VGI data collection are then considered with respect to this quality control framework, i.e. VGI data collection by National Mapping Agencies and by the most recent Geo-Wiki tool, a game called Cropland Capture. Although good practices are beginning to emerge, there is still the need for the development and sharing of best practice, especially if VGI is to be integrated with authoritative map products or used for calibration and/or validation of land cover in the future.