Hospital and community acquired infection and the built environment--design and testing of infection control rooms.

Negative-pressure isolation rooms are required to house patients infected with agents transmissible by the aerosol route in order to minimise exposure of healthcare workers and other patients. Housing patients in a separate room provides a barrier which minimises any physical contact with other patients. An isolation room held at negative pressure to reduce aerosol escape and a high air-change rate to allow rapid removal of aerosols can eliminate transmission of infectious aerosols to those outside the room. However, badly designed and/or incorrectly operating isolation rooms have been shown to place healthcare workers and other patients at risk from airborne diseases such as tuberculosis. Few standards are available for the design of isolation rooms and no pressure differential or air-change rates are specified. Techniques such as aerosol particle tracer sampling and computational fluid dynamics can be applied to study the performance of negative-pressure rooms and to assess how design variables can affect their performance. This should allow cost-effective designs for isolation rooms to be developed. Healthcare staff should be trained to understand how these rooms operate and there should be systems in place to ensure they are functioning correctly.

Challenges and opportunities in evaluating a digital sexual health intervention in a clinic setting: Staff and patient views.

OBJECTIVES: The aim of the study was to gather the views of sexual health clinic staff and male clinic users regarding digital sexual health promotion and online trial procedures. METHODS: The Men's Safer Sex website was offered on tablet computers to men in the waiting rooms of three sexual health clinics, in a feasibility online randomised controlled trial (RCT). Interviews were conducted with 11 men who had participated in the trial and with nine clinic staff, to explore their views of the website and views of the online trial. Interviews were audio-recorded and transcribed, and we conducted a thematic analysis of interviews and of 281 free text comments from the online RCT outcome questionnaires. RESULTS: Clinic users and staff felt that digital interventions such as the Men's Safer Sex website are useful, especially if NHS endorsed. Pre-appointment waiting time presents a good opportunity for intervention but clinic users and staff felt that a website should supplement rather than replace face-to-face healthcare. The RCT procedures fitted well around clinical activities, but men did not self-direct to the tablet computers. Staff were more concerned about consent and confidentiality than clinic users, and staff and patients were frustrated by multiple technical problems. The trial outcome questionnaire was thought-provoking and could constitute an intervention in itself. Participants felt that clinics would need to promote a digital intervention and/or offer the site routinely to promote engagement. CONCLUSION: Digital interventions could usefully supplement in-person sexual health care, but there are important obstacles in terms of IT access in NHS settings, and in promoting engagement.

The international validation of a fixed-dose procedure as an alternative to the classical LD50 test.

In an international study involving 33 laboratories in 11 countries, the acute oral toxicity to the rat of 20 substances and preparations was evaluated using a fixed-dose procedure and the results compared with those obtained for the test materials using the classical LD50 test. The study has shown that the fixed-dose approach to acute oral toxicity testing: (1) produces consistent results that are not substantially affected by inter-laboratory variations; (2) provides adequate information for risk assessment purposes on signs of toxicity, including their nature, time to onset, duration and outcome; (3) uses fewer animals than the current internationally agreed OECD procedure (Guideline 401-revised); (4) subjects animals to less pain and distress than the classical LD50 test and causes less compound-related mortality; and (5) enables substances and preparations to be ranked according to the EEC classification system on the basis of their acute oral toxicity, such ranking being compatible with that allocated by the results of classical LD50 studies.

The EC novel foods Regulation--a UK perspective.

On 15 May 1997 the EC novel foods Regulation came into effect introducing a statutory pre-market approval system for novel foods across the whole of the European Union. A novel food is defined as a food which has not been consumed to a significant degree and includes foods containing or obtained from genetically modified organisms. The Regulation envisages an initial safety assessment at Member State level, although centralized procedures are available to resolve any objections between Member States. The most controversial aspect of the Regulation relates to the provisions for labelling genetically modified foods. Within the framework of the Regulation there is scope for labelling to be considered on a case by case basis, although the UK is pressing for all foods which may contain genetically modified material to be clearly labelled. To ensure that all Member States follow a consistent approach to the safety assessment of novel foods, the Commission has published a series of guidelines to accompany the regulation. The UK already has a well-developed system for assessing the safety of novel foods dating back to the approval of the first novel food in the UK in 1983.

The Conquest Hospital picture archiving and communications system development, 1992 to 1999.

Conquest Hospital was a UK regional development site for a pre-Digital Imaging and Communications in Medicine (DICOM) picture archiving and communication system (PACS). The initial system was installed in mid 1992. Identification has been made of data transfer, ergonomic and single point of failure issues in the original PACS, which was called "iLAN." This has informed respecification of a DICOM/HTML PACS, the first stages of which have been hospital renetworking and installation of new DICOM 3.0 computed radiography/fluorography and computed tomography/magnetic resonance imaging segments. Final PACS elements are at contract stage. Plans are being completed for linkage of PACS to a clinical information system to create a comprehensive electronic patient record system.

Cardiac flow measurement by ultrafast CT: validation of continuous and pulsatile flow.

To gauge the accuracy of ultrafast CT in measuring cardiac output and myocardial perfusion in humans, measurements of continuous and pulsatile flow were made in a large asymmetrical phantom. The variation in the relationship between Hounsfield number and contrast concentration was assessed in a human thorax phantom. Radiopaque contrast medium was injected during perfusion of the phantom at a range of flow rates between 1.5 and 8 L/min. The phantom was scanned in two modes (50 and 100 ms) during continuous and pulsatile flow and with the phantom surrounded by air and by water. Flow in the tubes was calculated using indicator dilution theory, and flow in the tissue-equivalent chamber was calculated by applying first-pass distribution principles. The standard deviation of the difference between calculated and measured flow varied from 0.2 to 0.6 L/min, giving 95% limits of agreement from 0.4 to 1.2 L/min. The constant (K) relating Hounsfield unit number to iodine concentration varied widely both in different locations within the phantom and under different scan conditions (17.2-27.6 HU/mg I). Within a human thorax phantom, K varied from 14.15 to 23.18 HU/mg I and was dependent on location within the thorax phantom, the scan mode, and the cross-sectional diameter of the phantom. These data suggest that though the ultrafast CT scanner can measure continuous and pulsatile flow accurately in tubes, precise measurements of cardiac output in humans will require K to be assessed for each subject. Measurements of flow in tissue should be possible.