Bladder irrigation with povidone-iodine in the prevention of urinary-tract infections after single or intermittent urethral catheterisation was investigated in a controlled study. In the control group (36 patients) the catheter was removed after urethral catheterisation and emptying of the bladder, and in the trial group (42 patients) 50 ml povidone-iodine 2% was instilled and allowed to drain immediately before removal of the catheter. The incidence of bacteriuria was 28% in the control group and 4% in the povidone-iodine group. After the introduction of bladder irrigation with povidone-iodine in the orthopaedic department of Leiden University Hospital the incidence of hospital-acquired bacteriuria fell from 6.9% to 3.7%.

The effects of atrial natriuretic peptide (ANP) were investigated in six healthy male volunteers taking a constant diet (120 mmol sodium and 60 mmol potassium daily). They were given an intravenous bolus of 100 micrograms human alpha-ANP on one day or placebo on another day 1-3 weeks apart in a double-blind randomised study. After ANP, urinary sodium excretion increased four-fold, and urine volume, calcium, magnesium, and phosphorus excretion doubled within 30 min of the injection. ANP induced an immediate fall in arterial pressure, followed by a longer vasodepressor phase which exceeded the duration of the effect on electrolyte excretion. There were no significant changes in plasma renin activity, aldosterone, antidiuretic hormone, or noradrenaline when compared with placebo.

76 selected overactive children were treated with an oligoantigenic diet, 62 improved, and a normal range of behaviour was achieved in 21 of these. Other symptoms, such as headaches, abdominal pain, and fits, also often improved. 28 of the children who improved completed a double-blind, crossover, placebo-controlled trial in which foods thought to provoke symptoms were reintroduced. Symptoms returned or were exacerbated much more often when patients were on active material than on placebo. 48 foods were incriminated. Artificial colorants and preservatives were the commonest provoking substances, but no child was sensitive to these alone.

240 patients were admitted to a double-blind study to determine the effect of long-term treatment with platelet-function inhibiting agents on occlusive arterial disease in the lower extremities. Patients were randomised into 1 of 3 treatment groups: aspirin 330 mg; dipyridamole 75 mg and aspirin 330 mg; or matching placebo 3 times daily. The duration of treatment was 2 years. Arteriography was carried out at the beginning of the study and 2 years later or before if deterioration was observed. 199 patients completed the study according to the trial protocol. The serial arteriograms were assessed in pairs qualitatively, by means of simple comparative viewing, and semiquantitatively with Bollinger's score system. Progression of the disease was most pronounced in the placebo-treated group, less so in the aspirin-treated group, and least of all in the dipyridamole-and-aspirin group. Patients who smoke and those with hypertension may benefit most from treatment with the 2 preparations under investigation.

Clinical trials carried out in Britain, Europe, and the United States have confirmed that between 80 and 90% of bacterial contaminants found in the wound after surgery come from colony forming units (cfu) present in the air of the operating theatre. When the numbers of cfu are reduced, there is a corresponding reduction in the incidence of would sepsis. The sources, concentration, and movement of airborne cfu during an operation are identified, and various ways of reducing their numbers are reviewed. Only reduction of cfu in the operating zone to less than 1/m3, by means of an exponentially curved flow of microbiologically clean air, together with a total body exhaust system worn by the members of the surgical team and the patient, provides aseptic conditions without imposing restrictions or changes in surgical procedure.

In a controlled trial of a home-care service available for the first 6 months after acute stroke, 440 patients received the new service and 417 patients were in the control group. The trial group used more hospital bed days, had a slightly higher admission rate, and did not show better emotional adjustment to stroke than the control group. There was no difference between the 2 groups in stress on relatives. Functional recovery was equal in the 2 groups. A quarter of patients managed at home in each group were severely disabled. Providing a new service does not necessarily alter clinical decisions in the short term, and care should be taken before expanding domiciliary services to reduce hospital use.

Mortality rates from colon cancer in the USA are highest in populations exposed to the least amounts of natural sunlight; differences in endogenous vitamin D production and calcium absorption could be responsible. To investigate this possibility, the association of dietary vitamin D and calcium with 19-year risk of colorectal cancer was examined in 1954 men who had completed detailed, 28-day dietary histories in the period 1957-59. Risk of colorectal cancer was inversely correlated with dietary vitamin D and calcium. In the quartiles of a combined index of dietary vitamin D and calcium, from lowest to highest, observed risks of colorectal cancer were 38.9, 24.5, 22.5, and 14.3/1000 population. This association remained significant after adjustment for age, daily cigarette consumption, body mass index, ethanol consumption, and percentage of calories obtained from fat.

In a study of 120 patients with chronic multiple sclerosis the effects of treatment with 100% oxygen at 2 atmospheres absolute for 90 min daily for a total of 20 exposures were compared with those of normal air at normal pressure for a similar length of time within the same compression chamber. No patient in either group showed any improvement on the Kurtzke disability status scale. 12 of 51 patients in the hyperbaric-oxygen group and 3 of 47 control patients improved on the Kurtzke functional systems scale on the subjective bowel/bladder parameter only. Such a degree of improvement can also be achieved with medication for urinary symptoms, but none of the patients in this study received such medication. The short-term results of this trial do not support the claims made for hyperbaric oxygen in the management of multiple sclerosis.

Five widely used neonatal face masks were tested on 44 babies for their efficiency in terms of degree of leakage and ease of cleaning. Leakage was measured indirectly. The mean peak pressure of ten breaths when babies were ventilated from a respirator via a mask was recorded; a low pressure was taken to indicate leakage. A triangular moulded rubber mask ('Rendell-Baker') leaked most and a circular silicone rubber mask ('Laerdal') leaked least. The ease of cleaning the masks was measured as the amount of bacteria removed from contaminated masks by wiping them with 70% ethanol. The Laerdal mask was significantly more effectively cleaned than the others. It is also the only one of the masks tested that can be boiled and autoclaved.