The effect of acetazolamide (Az) on exercise performance and muscle mass in acclimatised subjects at an altitude of 4846 m was assessed in 11 subjects and compared with the effect of placebo on 10 other subjects. Exercise performance at 85% maximum heart rate fell by 37% in the Az group and by 45% in controls (p less than 0.05). Weight loss was greater in the placebo group at high altitude (p less than 0.01) and this correlated with the fall in exercise performance (p less than 0.001). During the expedition anterior quadriceps muscle thickness fell by 12.9% in the control group and 8.5% in the Az group (p less than 0.001), while biceps muscle thickness fell by 8.6% in controls and 2.3% in the Az group (p less than 0.001). Measurements of skin-fold thickness indicated a loss of 18% of total body fat in the placebo group and 5% in the Az group by the end of the expedition (p less than 0.001). Calorie intakes at altitudes above 3000 m were low and similar for the two groups. The Az group had fewer symptoms of acute mountain sickness but differences between the two groups were not statistically significant. Acetazolamide is therefore useful for climbers and trekkers who are acclimatised to high altitudes. It could be most useful at extreme altitudes, where maintenance of exercise performance and muscle mass are important.

In a double-blind, placebo-controlled study, 252 prepubertal boys with 301 undescended testes were treated with luteinising-hormone-releasing-hormone (LHRH), 1.2 mg/day intranasally. After the 8-week double-blind period 10 placebo-treated (8%) and 14 LHRH-treated (9%) testes had completely descended. After a second LHRH course, involving all the subjects in an open study, 48 testes (18%) had descended completely. The lowest success rate (7%) occurred in the youngest age group (1-2 years). Of the successfully treated testes, 75% could be manipulated at least to the scrotal entrance before treatment. In comparison with age-matched controls, the cryptorchid boys' responses to LHRH and human chorionic gonadotropin before treatment did not suggest a deficient hypothalamo-pituitary-gonadal axis or deficient Leydig cell function. After treatment there was no evidence of stimulation of the hypothalamo-pituitary-gonadal axis; serum testosterone did not increase. Surgery was required in 170 patients (196 testes) revealing various anatomical anomalies.

Enalapril, atenolol, and hydrochlorothiazide were compared in a double-blind randomised parallel study in general practice. 436 patients with mild to moderate hypertension were included at 76 centres. A two-week placebo run-in period was followed by 16 weeks of monotherapy. The initial doses were: enalapril 20 mg; atenolol 50 mg; and hydrochlorothiazide 25 mg. These were doubled if treatment was not effective after 4 weeks. Adverse reactions were the main reason for withdrawal from the study (9 on enalapril, 19 on atenolol, and 8 on hydrochlorothiazide). Systolic and diastolic blood pressures were significantly reduced in all three groups. The reduction in systolic blood pressure was greater on enalapril than on atenolol. Serum potassium was reduced and uric acid increased on hydrochlorothiazide. Fasting blood sugar rose on atenolol but fell on enalapril. The frequency of adverse reactions was acceptable in all three groups. After 16 weeks on treatment significantly more adverse reactions were recorded in the atenolol group than in the enalapril group. Enalapril is effective and well tolerated in patients with mild to moderate hypertension.

In a randomised controlled evaluation of multifactorial prevention of coronary heart disease (CHD) among 60 881 men employed in 80 factories in Belgium, Italy, Poland, and the UK intervention was associated with reductions of 10.2% in total CHD, 6.9% in fatal CHD, 14.8% in non-fatal myocardial infarction, and 5.3% in total deaths, with a neutral result for non-CHD deaths. Benefit was significantly related to the extent of risk factor change. The observed reduction in total CHD was 62% of that predicted by means of a multiple logistic function summary of risk factor changes. Advice on risk factor reduction in middle-aged men is effective to the extent that it is accepted and it appears to be safe.

Local tetrachlorodecaoxygen anion complex (TCDO) had three therapeutic effects in difficult wounds, substantiated on day 14 in a multicentre double-blind randomised clinical trial on 271 inpatients with 0.9% saline as control. Wound cleansing was intensified, the formation of new tissue (granulations, epithelium) was promoted, and, irrespective of the different wound types, wound surfaces decreased more quickly, by a factor of 2.4. A novel quantity (eta) was derived as an indicator of wound healing promotion. eta NaCl (= -0.14) did not differ among different wound diagnoses. eta TCDO values were significantly better in relation to wound diagnosis, to smear (detritus), and to epithelialisation. Local TCDO was well tolerated.

In a study of 272 consecutive patients with acute myeloblastic leukaemia admitted to 14 general hospitals in the Toronto region the complete remission rate ranged from 43.8% to 85.3% depending on the exclusion applied. The median duration of survival for all patients was 5 months, and for those who achieved complete remission it was 16.8 months. The first 130 patients received different treatments from the other 142, with the second group showing an improved remission rate. Differences in exclusion criteria might have affected considerably the comparison of these two consecutive groups. To aid in the comparative evaluation of drug regimens the population base from which the patients are drawn must be fully described. This would help haematologists explain prognosis to unselected and unreferred patients.

During the course of a prospective, randomised trial comparing dextran 40 with antithrombin III plus heparin as prophylaxis against thrombosis after total hip replacement, an unexpectedly low incidence of postoperative thromboembolic disease was found in patients receiving non-cemented (0 of 23) rather than cemented prostheses (4 of 13, 31%). Despite the small number of patients, the difference was significant and necessitated modification of the protocol. These preliminary findings suggest that the type of hip replacement used was more important than the type of antithrombotic medication in preventing venous thrombosis and pulmonary embolism.

A single-patient randomised clinical trial was used to determine optimum treatment for a patient with inflammation of her continent ileostomy. The trial proved to be feasible and acceptable to both patient and clinician. As a result, both the diagnosis of inflammation and the efficacy of metronidazole in treating it were confirmed. The trial design, in which multiple courses of active and control treatments are given to one patient, may be useful in other clinical situations to determine the most effective therapy in an individual case.

'InterVir-A' (IVA), an agent with in-vitro anti herpes-simplex-virus (HSV) activity was compared with a placebo (PBO) in the treatment of recurrent perianal, orofacial, and genital HSV I and II infection in a randomised double-blind trial. Samples from lesions of 69 patients seen within 48 h of the onset of prodromal symptoms were sent for culture. Patients were asked to apply IVA or PBO ointment every 2 h for 24 h, and 4 times daily for the remainder of the attack, during which period (mean 7 days) they visited the clinic 4 times. No adverse reactions were reported. Crusting times were faster for the IVA than the PBO group (4.5 days versus 6.4 days), as were healing times (7.4 days versus 9.9 days). Complete symptom relief was obtained within 30-60 min of first use in the IVA group, compared with a mean of 4 days in the PBO population (p less than 0.00005). IVA also reduced the frequency and severity of recurrences.

Entamoeba histolytica (EH) in homosexual men is generally considered to be pathogenic. To test this hypothesis, the generally accepted features of invasion (haematophagous trophozoites in faeces; high-titre serum antibody; moderate to severe acute inflammatory change; and presence of EH in the mucosa on rectal biopsy) and the zymodeme pattern of cultured trophozoites were assessed in twenty-three EH excretors and eleven control homosexual men. No trophozoites or antibody to EH were found in either group. When other pathogens were excluded, no patient in either group had severe, acute histopathological proctitis. Moderately severe change was seen in 38% of EH excretors and 18% of controls (not significant). All the zymodemes were non-pathogenic. Successful eradication of EH did not result in even a trend towards normalisation of the moderate inflammatory histopathology. There are, therefore, no data here to suggest that EH is a pathogen in homosexual men.

In a controlled, randomised, double-blind study to see whether knowledge of left-ventricular ejection fraction (LVEF) could reduce the frequency of left-sided heart failure after acute myocardial infarction, LVEF was determined a few days before hospital discharge in a consecutive series of 60 patients. Subsequently, the patients were randomly assigned to two groups. The cardiologist responsible for their treatment was aware of the LVEF result in group I but not in group II. A month after hospital discharge there was no significant difference in the LVEF between the groups. 2 months after discharge there were no significant differences between the groups in clinical and radiological signs of left-ventricular heart failure or the use of drugs. The cardiologist's clinical estimate of the LVEF and the result of the radionuclide determination were significantly correlated. Thus, the use of LVEF did not change the clinical outcome. The need for randomised controlled studies in the evaluation of diagnostic methods is emphasised.

204 of 460 patients with upper gastrointestinal bleeding admitted to a busy district hospital were found to be bleeding from peptic ulcers or to have signs of recent haemorrhage at endoscopy within 24 h of admission. To determine if the small bipolar probe could stop bleeding or rebleeding, patients were allocated to electrocoagulation (101) or not (103); other aspects of treatment were identical. Groups were stratified by ulcer site to give similar numbers in each. To allow for differences in sex, age, initial haemoglobin, presence of other diseases, and shock, data were analysed by logistic regression. Fewer patients in the treated group (17) continued to bleed or rebled compared with controls (34). Rebleeding and mortality rates in the treated group were higher early in the trial, suggesting the need for experience in application of the probe. Further improvements in technology and technique may result in significant reductions in mortality.

Analysis of the results of United Kingdom Acute Lymphoblastic Leukaemia (UKALL) trials since 1972 showed that no improvement in remission or survival had been achieved over the 7 years up to 1979 for 1470 patients in trials UKALL II to VI. UKALL VII (1979-80) gave somewhat better results for a small group of good-prognosis patients. However, UKALL VIII, introduced in 1980, produced a 15-20% increase in 4-year disease-free survival compared with the best results of previous studies, despite a higher frequency of treatment-induced morbidity and mortality. Factors possibly contributing to this highly significant difference include the policy of continuing therapy without interruption during induction, a long course of intramuscular asparaginase over 3 weeks, full-dose mercaptopurine and co-trimoxazole during central-nervous-system prophylaxis, and the use of sustained maximum tolerated oral doses of mercaptopurine and methotrexate maintenance. An intensive sustained approach to chemotherapy in childhood ALL is needed, especially in the early stages of treatment.

In an unblinded trial of intravenous streptokinase (SK) in early acute myocardial infarction, 11 806 patients in one hundred and seventy-six coronary care units were enrolled over 17 months. Patients admitted within 12 h after the onset of symptoms and with no contraindications to SK were randomised to receive SK in addition to usual treatment and complete data were obtained in 11 712. At 21 days overall hospital mortality was 10.7% in SK recipients versus 13% in controls, an 18% reduction (p = 0.0002, relative risk 0.81). The extent of the beneficial effect appears to be a function of time from onset of pain to SK infusion (relative risks 0.74, 0.80, 0.87, and 1.19 for the 0-3, 3-6, 6-9, and 9-12 h subgroups). SK seems to be a safe drug for routine administration in acute myocardial infarction.

To test the effect of transplantation of T-cell-depleted bone marrow on recipient immune function the results of pre-transplantation immunisation with tetanus toxoid and hepatitis-B vaccine were studied in 38 donor-recipient pairs. Immunisation of the donor alone resulted in transfer of an antibody response to the recipient; immunisation of both donor and recipient resulted in potentiation of the antibody response in both magnitude and duration. These findings indicate that donor T-cell-depleted marrow can transfer humoral immunity to the recipient and that appropriate pre-transplant immunisation schedules may be of benefit to the recipient.

To compare antibiotic regimens for their effectiveness in preventing or treating wound sepsis, well-defined criteria for outcome are needed. A method of assessing wound healing has been devised that defines carefully the characteristics to be considered and how they are to be awarded points. Objective criteria are also included in the assessment. Points are given for the need for Additional treatment, the presence of Serous discharge, Erythema, Purulent exudate, and Separation of the deep tissues, the Isolation of bacteria, and the duration of inpatient Stay (ASEPSIS).