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Increasingly, physicians in emergency departments are seeing cases of injecting drug users (IDU) with dangerously high International Normalized Ratio (INR) results. Some of these patients have admitted to buying warfarin from a “street” source and taking the medication without INR monitoring. This group are known to be at significant risk of developing venous thrombo-embolic disease1 and have difficulties in …

Significant advances in water treatment over the last century have resulted in massive improvements in the microbiological safety of public drinking water supplies in the UK and the developed countries. Incidences of illness due to poor treatment or post-treatment contamination are rare, but when they occur tend to attract considerable media attention. A well managed water treatment works and supply system can provide high quality drinking water wherever in the world it is located. As a rule, throughout the world, private supplies tend to be of a poorer quality than public supplies, but poorly managed public supplies have the potential to make a large number of people ill and continued effort is needed to maintain and improve drinking water quality world-wide.

A doorless entry system has been designed for use in high-energy radiation therapy rooms. The doorless entry improves patient access, safety and throughput, increases the physical safety for the radiation therapists, and avoids the significant cost of heavy shielding doors. The design meets concerns relating to radiation safety, operational ease, and authorized entry. The new system is currently operating in one room housing a cobalt-60 unit and is to be employed in five additional rooms housing dual-energy accelerators (maximum energies of 10 and 18 MV). The doorless entry has received wide approval from the radiation therapists and no concerns have been expressed with respect to unauthorized entry or radiation safety.

Thirty-two patients with posterior fossa medulloblastoma underwent treatment with electron irradiation to the spinal field. The 5- and 10-year actuarial survival rates were 57% and 50%, respectively. Late complications observed in the 15 patients followed up for more than 5 years were short stature (six patients), decreased sitting-standing height ratio (four patients), scoliosis (two patients), poor school performance (seven patients), xerostomia (one patient), esophageal stricture (one patient), pituitary dysfunction (four patients), primary hypothyroidism (one patient), bilateral eighth-nerve deafness (one patient), and carcinoma of the thyroid (one patient). Complications following treatment with electrons to a spinal field are compared with reported complications following treatment with photons to the spinal field. Although short-term reactions were minimal, the authors found no difference in late complications. More sophisticated treatment planning may show such a long-term benefit in the future.

A statistical analysis has been made of ionometrically measured parameters related to the central‐axis output, the beam symmetry, the beam flatness, and the depth dose for the 6‐MV x‐ray beam from the Therac‐6 linear accelerator. The means and coefficients of variation of the measurements are determined on a monthly basis for each parameter. Mean coefficients of variation less than ± 1% have been determined and are useful in establishing the optimal limits of acceptance of these parameters. The results of this study indicate that the long‐term stability of the radiation parameters associated with this unit can be maintained within acceptable limits with a consistent quality‐assurance program.

Ionization chambers with wall materials of various electron densities have been employed to investigate the penumbral region of a cobalt-60 beam of side length 10 cm. Measurements were made in air with chambers of various inside diameters. The homogeneous walls of the ionization chambers were 0.5 g/cm2 in thickness. Extrapolation techniques to zero inside diameter and to infinite density were used, respectively, to eliminate the effect of the inside diameter of the chamber and to determine the penumbral photon-fluence distribution. The method also quantitates both the penumbral primary-dose profiles in water-equivalent media and the degradation of these profiles in media of low electron density.

The effect of dosemeter type and configuration on the measured penumbral distribution for Co‐60, 6‐MV, and 31‐MV x rays has been determined in air using equilibrium buildup caps for three commercial detection systems including a silicon diode and two ionization chambers. The diode is shown to be measuring a different parameter in the penumbral region than the ionization chambers. This fact in combination with the lateral spread of the secondary electrons and the difference in the inside diameters of the ionization chambers results in significant differences between the measured beam penumbra. The latter effect is studied in more detail with a series of specially designed ionization chambers of varying inside diameter from 0.3 to 1.4 cm. A theoretical model is described which resolves these differences, indicates a method to determine the true penumbral primary‐dose distribution and introduces the concept of an effective diameter for the ionometric measurement of high‐energy x‐ray penumbra. Recommendations are made concerning the dosemeters of choice for penumbral measurements over this range of photon energies.

Ionization chambers of varying inside diameter have been used to investigate the penumbral region of 6 0Co, 6‐MV, and 31‐MV x‐ray beams. Measurements were made in water at varying depths up to 25 cm for a square field of side length 10 cm. The dependence of the penumbral widths on both the inside diameter of the ionization chamber and the depth in water is established along with the asymmetry of the penumbral distributions about the 50% level. A standard correction is indicated to eliminate the dependence of the measured penumbral widths on the inside diameter of the ionization chamber.

An isotope scan using sucralphate labelled with technetium-99m has been compared with barium meal in the detection of peptic ulceration in 18 patients with endoscopically proven upper gastrointestinal lesions and eight controls. Gastric (75%) and duodenal (67%) ulcers were detected with identical frequency by isotope scan and barium meal but both were inferior to endoscopy. Structural, non-ulcerated lesions, were not identified by isotope scanning. The scan has potential value in duodenal ulcer disease, the serial assessment of ulcer healing and in paediatric gastroenterology.

The effects of field elongation on the central‐axis output at d max and on the depth‐dose curves for the 6‐MV x rays from the Therac 6 linear accelerator are considered. These parameters are independent of the collimator angle for both square and elongated fields. The exchange of collimator pairs results in significant output differences but has a negligible effect on the depth‐dose curves. Both the central‐axis output at d max and the depth‐dose curves agree satisfactorily with the predictions of the equivalent‐square technique. An alternative method of greater accuracy is also indicated for the prediction of central‐axis outputs at d max for elongated fields.

The distribution of radioactivity after the oral administration of sucralfate labelled with technetium-99m was studied in 33 patients with Crohn's disease (13 adults, 20 children), 10 with ulcerative colitis (four adults), and 29 controls (23 with upper intestinal disease, four irritable bowel, one hypolactasia, and one malrotation of the gut). Positive scans were obtained in all patients with ulcerative colitis and 29 of 31 with active Crohn's disease. The scans of two patients with inactive Crohn's disease were negative. There were two false negative scans in patients with Crohn's colitis and one false positive scan. Overall, sensitivity was 95% and specificity 97%. Comparison with radiology in 39 patients showed similar distribution of disease in 24 and more extensive disease in 12. The scan was inexpensive, simple to perform, well tolerated, allowed small and large bowel to be visualised simultaneously, and used a lower dose of radiation than barium studies. It may prove useful as a screening test for inflammatory bowel disease and in the serial assessment of disease activity.

Percentage depth doses for 34 MV betatron X-rays were measured ionometrically for a number of square fields of side 5-20 cm. Significant differences in the depth doses for different field sizes were found in the build-up region and in the depth of maximum dose. A systematic change with depth was also indicated in the exponential region of these curves. These differences are discussed in terms of the changes in the contributions of primary radiation and of scattered radiation from both the collimator and the phantom.

Prostaglandin synthetase activity in rectal biopsy specimens from patients with ulcerative colitis has been shown to fall on treatment with sulphasalazine, local steroids, and codeine phosphate. In vitro studies have shown that sulphasalazine is an inhibitor of prostaglandin synthetase, although less potent than indomethacin, whereas prednisolone and codeine phosphate were inactive. It is suggested that the therapeutic action of sulphasalazine may be related in part to its action in inhibiting prostaglandin biosynthesis.

A 22 year old woman presenting with recurrent intestinal pseudo-obstruction is reported. Jejunal biopsy showed subtotal villous atrophy which improved markedly during a period of total parenteral nutrition and with steroid treatment. It did not relapse on a gluten free diet. The reasons why this patient represents a case of coeliac disease with secondary pseudo-obstruction, rather than primary intestinal pseudo-obstruction with secondary bacterial overgrowth, is discussed.

An analysis of unscheduled downtime and of patient treatment data for a 6‐MV linear accelerator is presented for a 7‐yr period. Following the initial year of clinical use, the unscheduled downtime has averaged 2.4%, with a corresponding loss of 1.3% in patient treatments. The quality assurance, preventive maintenance, and repairs are handled in‐house, with an investment of approximately 500 man‐hours annually.

The tissue-maximum ratios for high-energy betatron x rays, measured at target-axis distances of 90, 110, and 130 cm, exhibit a strong dependence on the target-axis distance in the buildup region as well as a significant dependence in the exponential region. This dependence and the field-size dependence of the tissue-maximum ratios at a fixed target-axis distance are studied with the use of phantom and collimator scatter factors. The depth and field-size dependence of these scatter factors are determined experimentally. The measurements indicate that the collimator scatter factor is dependent on both the collimator opening and the targetaxis distance. These components are quantitated separately and are associated primarily with high-energy electron scatter from the collimating system. An equation involving these components of the collimator scatter factor is derived for the conversion of tissue-maximum ratios from one target-axis distance to another. With the use of this equation, the tissue-maximum ratios measured for one target-axis distance can be used to calculate within 1% those at other target-axis distances.

Une observation: un athlete pratiquant la course souffre depuis 3 ans de troubles de defecation: urgence et frequence (toutes les 30 mn lors de competitions). Les examens revelent que la cause peut etre une hypertrophie du psoas comprimant le colon; lors d'efforts continus ce «massage» peut provoquer une diarrhee

13 observations d'insuffisance hepatique aigue avec coma (12 cas dus au paracetamol, 1 a une hepatite virale non A-NON-B). Hypophosphatemie dans tous les cas. Correlation entre le degre d'hypophosphatemie et l'evolution. 6 des malades sont morts

Central axis depth doses for 34 MV X-rays have been measured ionometrically in a water phantom at a TSD of 110 cm. The variation with field size of the exponential portion of these curves is found to be minimal; however, significant differences are indicated in the build-up region and in the depth of maximum dose. The numerical scaling of the central axis curves for varying TSDs was discussed and TMRs were derived from the data. Measurements of off-axis ratios have also been made and a number of phenomena relating to these measurements were discussed including the depth dependence of OARs, the scaling of OARs with respect to both the depth and field size and the effect of field size on the beam penumbra.