A prospective study was carried out of the frequency of thrombophlebitis and bacterial contamination of cannulas associated with four commonly used intravenous cannulas of differing length and chemical composition. For all cannulas the frequency of thrombophlebitis increased significantly with time. Long 'Teflon' cannulas were significantly more likely to be contaminated with bacteria and associated with thrombophlebitis than all other cannulas, while the low frequency of thrombophlebitis with butterfly stainless steel cannulas was shown to be due to their short duration of use. It is suggested that long teflon cannulas should be avoided and that infusion thrombophlebitis could be eliminated as a clinical problem by the use of intermittent short duration intravenous infusions.

34 hypertensive patients were assigned at random either to six weeks' treatment by yoga relaxation methods with bio-feedback or to placebo therapy (general relaxation). Both groups showed a reduction in blood-pressure (from 168/100 to 141/84 mm. Hg in the treated group and from 169/101 to 160/96 mm Hg in the control group). The difference was highly significant. The control group was then trained in yoga relaxation, and their blood-pressure fell to that of the other group (now used as controls).

In a double-blind randomised study, single intravenous doses of propranolol (0-1 mg. per kg.), practolol (1 mg. per kg.), acebutolol (1 mg. per kg.), or placebo were each administered at weekly intervals to six healthy volunteers. Forced expiratory volume in 1 second (F.E.V.1), resting and exercise heart-rate, and resting and exercise peak flow-rate (P.F.R.) were determined before and at 2, 3, 4, and 6 hours after each treatment. Venous blood-samples were also obtained at these times. Compared with placebo, resting heart-rate was reduced after all three drugs, but the corresponding differences in exercise heart-rate were much greater, more consistent, and of greater statistical significance. At 2, 3, and 4 hours when acebutolol and propranolol produced equivalent cardiac beta-blocking activity (judged by reductions in exercise heart-rate), their mean plasma concentratios were in the ratio of about 8/1; and at 2 hours when practolol and acebutolol gave rise to almost equivalent cardiac beta blockade, their mean plasma concentratio ration was 3/1. At times, reductions in F.E.V.1 and resting P.F.R. after propranolol (but not after practolol or acebutolol) were significantly greater than the corresponding changes after placebo. The reductions in exercies P.F.R. after propranolol (6 hours) and acebutolol (4 hours) (but not after practolol) were significantly greater than the changes after placebo. Changes in F.E.V.1, resting and exercise P.F.R. after propranolol, and the corresponding changes after practolol, were significantly different, all of which confirmed that practolol was more cardioselective than propranolo. In general, the reductions in F.E.V.1 and resting P.F.R. after acebutolol were slightly smaller than after propranolol, excepting at 6 hours when the difference between them was significant. The reductions in exercise P;F.R. after acebutolol and propranolol were of the same order, there being no significant differences between the two, whereas the reductions after acebutolol were clearly greater than the corresponding changes after practolol, the differences being significant at 2, 3, and 4 hours.

The efficacy of low-dose heparin in preventing fatal postoperative pulmonary embolism has been investigated in a multicentre prospective randomised trial. 4121 patients over the age of forty years undergoing a variety of elective major surgical procedures were included in the trial; 2076 of these were in the control group and 2045 patients received heparin. The two groups were well matched for age, sex, weight, blood-group, and other factors which could predispose to the development of venous thromboembolism. 180 (4-4 %) patients died during the postoperative period, 100 in the control and 80 in the heparin group: 72% of deaths in the control and 66% in the heparin group had necropsy examination. 16 patients in the control group and 2 in the heparin group were found at necropsy to have died due to acute massive pulmonary embolism (P smaller than 0-005). In addition, emboli found at necropsy in 6 patients in the control group and 3 in the heparin group were considered either contributory to death or an incidental finding since death in these patients was attributed to other causes. Taking all pulmonary emboli together, the findings were again significant (P smaller than 0-005). Of 1292 patients in whom the 125-I-fibrinogen test was performed to detect deep-vein thrombosis (D.V.T.) 667 were in the control group and 625 in the heparin group. The frequency of isotopic D.V.T. was reduced from 24-6% in the control group 7-7% in the heparin group (P smaller 0-005). In 30 patients D.V.T. was detected at necropsy; 24 in the control and 6 in the heparin group (P smaller 0-005). 32 patients in the control group and 11 in the heparin group developed clinically diagnosed D.V.T. which was confirmed by venography (P smaller than 0-005). In addition, 24 patients in the control and 8 in the heparin group were treated for clinically suspected pulmonary emoblism. The difference in the number of patients requiring treatment for D.V.T. and/or pulmonary embolism in the two groups was again significant (P smaller than 0-005). 9 patients were found at necropsy to have died from haemorrhage; 5 were in the control and 4 in the heparin group. A careful objective analysis of operative and postoperative bleeding in 1475 patients showed no statistically significant difference in the blood-transfusion requirements or in the fall in the postoperative haemoglobin level either in the individual operative groups or in the group as a whole. However, the difference in the number of patients who developed wound haematoma in the heparin and control groups was significant (P smaller 0-01). The results of the trial indicate that this form of prophylaxis can now be recommended for use on a large scale in "high-risk" patients undergoing major surgery.

The incidence of ventricular arrhythmias after myocardial infarction has been compared in a controlled study of procainamide, mexiletine, and placebo. Sixty male patients who has sustained a myocardial infarction and had received lignocaine for ventricular tachycardia or ventricular ectopic beats which were R-on-T, multiform, or close-coupled took part. The efficacy of the drugs was evaluated by continuous 24-hour recordings of the electrocardiogram on the 4th and 10th days after admission to the study. Procainamide was given as 500 mg. 4-hourly and mexiletine as 250 mg. 8-hourly with corresponding placebo regimens for 12 days. 77% of patients receiving placebo showed serious ventricular rhythm disorders compared with 33% receiving antiarrhythmic therapy (p smaller than 0.05). Although only 35% of patients receiving procainamide achieved accepted therapeutic plasma concentrations compared with 95% of those receiving mexiletine, both drugs were equally effective antiarrhythmically. The only major adverse effect of therapy noted was development of a positive antinuclear factor in a procainamide-treated patient. These results demonstrate the efficacy of oral antiarrhythmic agents in the management of ventricular arrhythmias after acute myocardial infarction. Mexiletine has the advantage of less frequent administration and lower toxicity.

230 Canadian steelworkers with hypertension took part in a randomised trial to see if compliance with antihypertensive drug regimens could be improved. For care and follow-up these men were randomly allocated to see either their own family doctors outside working-hours or industrial physicians during work shifts; the same men were randomly allocated to receive or not receive an educational programme aimed at instructing them about hypertension and its treatment. Surprisingly, the convenience of follow-up at work had no effect upon these men's compliance with antihypertensive drug regimens. Similarly, although men receiving health education learned a lot about hypertension, they were not more likely to take their medicine.

39 patients with carcinoma of the uterine cervix who were treated with radium and required repeated general anaesthetics were randomised to halothane and control groups. Their serum-alanine-aminotransferase (S.G.P.T.) levels were measured before each general anaesthetic, and those patients whose S.G.P.T. levels rose above 100 I.U. per litre were freed from the restriction determined by the initial allocation and treated as indicated clinically. None of the 21 patients in the control group had S.G.P.T. levels rising above 100 I.U. per litre. 4 out of 18 patients in the halothane group developed S.G.P.T. levels above 100 i.u. per litre before their third radium treatment. None of these had any symptoms or alteration in other liver-function tests, but liver biopsies in 2 of these patients showed changes characteristic of Hepatitis. Arbitrary selection of 18 out of the 39 patients would only give rise to the degree of abnormality observed in the halothane-treated group with a probability of about 0-02. In the patients studied who required repeated general anaesthetics at short time intervals, the monitoring of S.G.P.T. levels before each operation was useful screen for liver damage and may have reduced postoperative hepatic necrosis by preventing further anaesthetics with halothane when the liver was already damaged.

Patients who had received halothane within a periof of one year and who required another anaesthetic were allocated at random to be given halothane or a control anaesthetic, the control being fiben using halothane-free apparatus. There were 76 patients entries in each group. Serum-glutamic-oxaloacetic-transaminase (S.G.O.T.) levels were measured before the anaesthetics and serially postoperatively for two to three weeks. The S.G.O.T. levels in the halothane group were significantly higher than in the controls. High levels were confined to patients who had had less than four previous halothane anaesthetics, increases above normal in the remainder and in the controls being rate. 1 patient in the halothane group had an S.G.O.T. of 440 I.U. per litre and hepatocellular necrosis on liver biopsy. 2 patients in the halothane group whose S.G.O.T.s rose to more than twice normal showed a similar reaction to re-exposure to halothane, although they had not shown a reaction to an intervening control anaesthetic.

In a prospective, randomised trial, 111 obstetrically normal pregnant women, who had elective induction of labour performed between 39 and 40 weeks, were compared with 117 controls who were managed expectantly until 41 weeks. Compared with the controls, the patients who had elective induction of labour had significantly less meconium staining in labour and a smaller blood-loss after delivery. The mean length of labour, the amount of pethidine used, and the Apgar scores at 1 minute were similar in the two groups. In the electively induced group, the caesarean-section rate was lower and the use of epidural analgesia more common than in the controls, but the differences were mot statistically signficant. The hour of delivery was similar in the two groups, suggesting that convenience to medical and nursing staff would not be greatly changed by elective induction of labour. There was no evidence that the hazards to mother and child were increased by elective induction, and its use might improve perinatal mortality by reducing the number of unexplained mature stillbirths.

Infants have been fed with teats whose end-holes varied in shape and size. Two types of feeding-bottles were used. With conventional feeding-bottles, variations of teat-hole shape and size did not significantly alter the volumes of milk obtained at each suck. However, when an infant feeding-bottle was used which contained a valve, then variations in teat-hole shape and size did alter the volumes of milk obtained. The volume of milk obtained from a standard teat under such circumstances was the same as the volume previously calculated for breast-feeding.

The role of mycoplasmas in infertility was studied in 120 couples. During the twelve months of the study 27 couples (22-5%) conceived. T mycoplasmas were isolated from 63% of these couples, and Mycoplasma hominis from 18%, compared with 56% and 13%, respectively, in those who did not conceive. 88, with primary infertility of unascertained cause, took part in a controlled trial with doxycycline. The couples in the trial were allocated randomly to three groups: 30 received doxycycline, 28 received a placebo, and 30 couples were untreated. Although a twenty-eight-day course of doxycycline eradicated M. hominis and T-strain mycoplasmas from 27 (96%) of the 28 couples harbouring them, the rate of conception was no higher in those treated with the drug than in control groups. It is concluded that mycoplasmas are not associated with primary infertility and that, although doxycycline eradicates them, this drug is of no benefit in the treatment of primary infertility of unascertained cause.

Healthy medical students were divided into two groups. One group was given double the normal fibre intake of their diet as a high-fibre-containing breakfast cereal; the other group (control) was given a breakfast cereal containing negligible amounts of dietary fibre. Otherwise the nutrient intake of the two groups was maintained constant. No differences in the serum-cholesterol, serum-triglyceride, serum-calcium levels were found between the two groups during or at the end of the study. The addition of a tolerable amount of dietary fibre to the diet does not affect serum-lipids.

The results of a randomised trial of irradiation of the knee (synoviorthése), by intra-articular injection of yttrium-90, and surgical synovectomy have been compared in twenty knees in seventeen patients. The mean length of follow-up was 2 years. Relapse occurred in three out of ten irradiated knees, and in 2 out of 10 operated knees. Fewer irradiated knees were involved when generalised exacerbations of polyarthritis occurred. Irradiation carries a lower risk of complications than does synovectomy, it is more acceptable to patients, requires fewer days in hospital, and is cheaper; it would seem to be the treatment of choice in the older patient.

Sixty-three girls with covert bacteriuria were included in a controlled trial of therapy. Recurrent infection in the treated group was common and was not significantly different from the rate of persistent infection in the untreated control group. Two children in each group developed clinical pyelonephritis; the others have remained healthy and all of them have a normal rate of growth. 2 years after diagnosis three of the thirty-four children in the control group and one of twenty-six children in the treated group have radiological evidence of new scars of pyelonephritis. These changes were relatively minor and in both groups of children renal growth was similar to that in normal children. It is suggested that for most of these children therapy is not essential, and that when renal changes occur they are of little or no significance. Prescriptive screening for cobert bacteriuria of childhood cannot be recommended at present.

The effect of lowering raised plasma-free-fatty acids (F.F.A.) on the incidence of serious ventricular arrhythmias after myocardial infarction was assessed by a double-blind trial in eighty-one patients. A nicotinic-acid analogue (N.A.A.) with very slight haemodynamic effects was given within 12 hours of the onset of myocardial infarction to lower plasma-F.F.A. When treatment with N.A.A. was started within 5 hours of the onset of symptoms, the numbers of patients with ventricular symptoms, the numbers of patients with ventricular tachycardia were significantly reduced, provided elevated plasma-F.F.A. levels were rapidly lowered and maintained in the normal range throughout the treatment period. The incidence of R-on-apex T ventricular premature beats and beats in which the ectopic R wave interrupted the apex of the T wave of a previous ventricular premature beat was also reduced in patients receiving N.A.A within 5 hours of the onset of symptoms. Plasma-total-catecholamines and serum-creatine-kinase levels were similar in the N.A.A.-treated and placebo groups. N.A.A. rarely caused skin flushing, but vomiting occurred in some patients after many hours of treatment. These findings suggest that treatment directed towards stabilsing the matabolism of the ischaemic myocardium can be of therapeutic value and lead to fewer serious ventricular arrhythmias.

A prospective, randomised trial compared polygycolic-acid subcuticular skin closure with interrupted silk skin closure in 152 patients. There was no significant difference in the incidence of wound infection. The use of polyglycolic acid was associated with economic advantages.

Rubella-specific immunoglobulin responses in sera and nasopharyngeal secretions were compared in groups of adult females who had experienced naturally acquired rubella or infection induced by Cendehill, HPV77.DE-5, RA27/3 (subcutaneously and intranasally), and To-336 vaccines. Serum IgG and IgA and nasopharyngeal IgA responses after vaccination by RA27/3 intranasally most closely resembled those induced by naturally acquired infection. However, the other vaccines failed to induce a persistent local IgA response. Levels of local antibody induced by HPV77.DE-5 were especially poor. Virus-specific IgM was detected for prolonged periods. The highest levels and the most persistent response followed vaccination by HPV77.DE-5, four of five volunteers still having rubella-specific IgM at 1 year. Virus-specific IgM persisted for 6 months in seventeen of twenty-five (68%) and for a year in nine of twenty-four (38%) vaccinees. It was still present in four of nine (44%) naturally infected patients at a year.