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The Industrial Injuries Advisory Council has reaffirmed the view that simple pneumoconiosis does not produce disability or shorten life. This is often true but, without overlooking the importance of chronic bronchitis, such conclusions are wrong in many instances.Chronic bronchitis is probably commoner in miners without pneumoconiosis than in those with it, and an uneven distribution of bronchitis may mask the effects of pneumoconiosis. Cough and sputum in a miner with pneumoconiosis are not always due to chronic bronchitis. Disability is usually judged on measurement of vital capacity and forced expiratory volume, factors which cannot be expected to be significantly altered by simple pneumoconiosis alone. Other tests may show abnormalities which lead to ventilation and perfusion inequalities and to an increase in the ventilatory cost of exercise. Focal emphysema, often a consequence of simple pneumoconiosis, develops slowly and its influence on disability is delayed.Disagreements arise because epidemiologists expect all lungs with simple pneumoconiosis react in the same way, and they want a quantitative relation between simple pneumoconiosis and emphysema before attributing one to the other.There are major difficulties in assessing disability but there is little justification for the regular application of the rule that if the results of ventilatory tests are normal disability is not present and if they are abnormal this is due to something other than simple pneumoconiosis.

A total of 178 patients with obstructive airways disease were studied between 1966 and 1972, a period which followed a substantial fall in atmospheric pollution in Sheffield. Compared with patients from an earlier study of the same age and smoking habits they had less productive cough, fewer winter illnesses, less severe breathlessness, and only one-third of the rate of decline of forced expiratory volume (FEV). The analysis of the change in the annual loss of FEV was complicated. There were virtually no sudden steep falls of respiratory function, and patients with very low values of FEV survived for long periods. The predominant cause of death was cor pulmonale. Chronic hypoxia may be more of a problem in the next few years than bronchial infection. I believe that the clean air policy has effected an improvement and that the nature of chronic bronchitis with severe obstructive airways disease is changing, but further studies will be needed to confirm this.

The modes of presentation and the management of acute respiratory failure in 11 infants with severe lower respiratory tract infections (due to respiratory syncytial virus in eight) are described. Progressive respiratory difficulties leading to exhaustion, peripheral circulatory collapse, recurrent apnoeic attacks, or generalized convulsions were the main clinical presentations resulting in severe ventilatory failure. In nine infants preventilation carbon dioxide tensions exceeded 65 mm Hg. It seems likely that the use of intermittent positive-pressure ventilation in these patients contributed to the low mortality rate, less than 0·5%, from such illnesses during the 15-month study period.

Widespread fibrotic scarring occurs as a final stage of healing in many different types of tissue damaging injury to the lung. In some cases the acute stage may be short-lived; in others the active process may continue alongside the fibrosing response over prolonged periods. In either event the resulting fibrosis progressively impairs lung performance and often leads to premature death. At first sight it may, therefore, appear to be a somewhat nihilistic exercise to focus upon the scar tissue stage of disease when control and treatment of the earlier processes are of so much greater importance. The topic is justified on simple clinical grounds. Patients are seen regularly presenting with far advanced widespread fibrosis of the lungs with gross venti latory and circulatory impairment, in whom at this stage no form of treatment can alter their relentless downhill progress. The lack of appreciation of the hazards of allowing the more acute widespread changes to continue is understandable be cause, owing to the great ventilatory reserves of the lung, symp toms may be absent or relatively slight. Even when the potential dangers are recognized, the best methods to monitor progress or regression of disease in the aknost asymptomatic patient are not yet fully known. Nevertheless, even with this limitation, all too often little or no systematic attempt is made to supervise these patients, even with the techniques which are readily available. Serial assessment of lung performance at rest is in any case a relatively crude yardstick, and is often measured only at irregular intervals; standardized exercise tests are rarely used, and all too often too much reliance is placed on the chest radiograph, which also reflects only relatively gross changes. In any case chest x-ray films are but shadows, and the extent to which they can indicate the presence of fibrosis as distinct from more acute reversible inflammatory lesions is, with a few notable exceptions, limited. This lecture will emphasize the great variety of entirely distinct processes which may initiate widespread fibrosis in the lungs, will examine the intriguing problem of its selective distribution-favouring characteristically the upper lobes in somediseases and the lower lobes in others-and will consider the known factors which influence the rate of progression of these lesions.

Acute anuric renal failure complicating systemic lupus erythematosus does not usually respond to treatment with corticosteroids and immunosuppressive agents. We describe four cases treated by dialysis, corticosteroids, and heparin in anticoagulant doses in which there was remarkable improvement in renal function after prolonged anuria. One patient died later from a gastric haemorrhage. The other three were alive and well 55, 54, and 30 months from the onset of anuria. In two cases a second renal biopsy showed a striking improvement in the lesions. Large doses of corticosteroid and heparin may be the best treatment in acute anuric lupus nephritis.

A prospective study of 358 medical and 234 postoperative patients with clinical evidence of secondary chest infection showed that previous administration of antimicrobial agents greatly reduced the chance of obtaining a clear-cut laboratory report. In patients with radiographical evidence of pneumonia this led to a fourfold decrease in the overall rate of isolation of potential pathogens. Furthermore, 81 diverse “coliforms” were isolated from 258 medical and surgical patients who had received previous antimicrobial therapy while only four coliforms (all Escherichia coli) were isolated from 334 untreated patients. Thus the general hospital environment on its own seemed to have a negligible influence in promoting the growth of coliform flora in sputum. Any unique effect of underlying disease in this regard was masked by that of previous therapy. Finally, the results raised the possibility that previous antimicrobial therapy might have increased the risk of secondary pneumonia in hospital patients.

Tests measuring ithe levels of thyroid hormone in the blood stream are now being used increasingly in the diagnosis of thyroid disorders. Correspondin,gly, less emphasis is placed on in vivo tests of thyroid -uptake. The proliferation of in vitro tests of thyroid function has led to such confusion of nomen clature ithat many doctors do not know what they are asking for, much less the limiita-tions of the particular investigation in question. As tests of thyroid function are being sought wih increasing frequency and with fewer indications, it is hardly surprising that many erroneous diagnoses are made. Two important points need emphasi7ing to begin with: the first is that clinical criteria may be a better guide to the diagnosis of thyrotoxicosis and of hypothyroidism than any laboratory investigation, particularly in the younger patient. A detailed medical history and a fuRl physical examination are mandatory, and will lead to many fewer diagnostic errors than asking for a variety of itests af-ter a few hasty observations in the clinic. The second point is that doctors tend to have a naive faith in the validity of laboratory reponts. Laboratory workers are human and are subject to the same errs as are clinicians; furthermore, errors may also be contributed by the methods used. Even when investigations are carried out in the best laboratories values outside the normal range occur in at least 5% of euthyroid people.' In adition, abe tests themselves are subject to limitatons, which are of-ten not appreciated by those asking for them. Laboratory tests are liable to interference by many factors unrelated to the thyroid gland and are just as subject to misin,terpretation as the clinical findings.

Different groups of patients in a general practice have been under close observation by defined methods to assess the extent of their adherence to drug schedules. Patients taking antibiotics, admitted to a short drug trial and prescribed long-term treatments, proved in most cases to be compliant. Antenatal patients taking a once-daily dosage of prophylactic iron were more co-operative than those taking divided dosages. Socially isolated patients and those of low social class were particularly likely to neglect their drugs. It is suggested that the significance and extent of the problem have been largely ignored and that all drug trials undertaken on outpatients should incorporate methods of detecting defaulters.

The system of detection of unwanted side effects in new drugs distributed to the general public is described with several specific drugs cited including reference to the effects of oral contraceptives (OCs) and the manner in which their connection to thromboembolic phenomena was established. Attempts to estimate the incidence of thromboembolism by women using OCs from reports to the Committee on Safety of Drugs proved unsatisfactory. 3 separate studies however were found to give evidence in support of the relationship. 1 study interviewed young women recorded in the diagnostic index as having attended for a new episode of vascular pulmonary embolism or venous cerebral or coronary thrombosis of women who had no predisposing cause for the disease. In the 3rd study prepared for the Committee on Safety of Drugs all the deaths that had occurred in England Wales and Northern Ireland during 1966 in women 20-44 years old in which thrombosis or embolism of the pulmonary cerebral or coronary vessels was referred to on the death certificate were enumerated. The results showed the risks of developing deep vein thrombosis pulmonary embolism or cerebral thrombosis in the OC user 8 times that of the nonuser and the risks of developing phlebitis 3 times as great in the OC user. Pharmacological experience and knowledge of the mechanisms by which drugs act should enable many effects to be predicted. A system of medical intelligence such as mortality statistics can provide information on trends. It is suggested that a system of record linkage by computer is needed and that early warning system of the effect of new drugs should be limited to unusual or severe effects. Another suggestion encompasses use of the practitioners prescription as a method of monitoring the patients at risk from a new drug.

When the heart ceases to meet the requirements of the body for oxygen, the sympathetic-adrenal system is activated. This occurs in people with a healthy heart when the demands for oxygen are excessive-for example, in heavy muscular work-and in subjects with a failing heart when the demands are normal or small. Eventually, when the heart is unable to meet even the ordinary requirements of everyday life, the sympathetic activity becomes more or less continuous. It may lessen during rest at night, but with a further failing of the heart its output may become inadequate even in complete rest.The sympathetically-medicated renal vasoconstriction, with reduction of the glomerular sodium load, redistribution of the blood flow in the renal cortex to the juxtamedullary glomeruli, and the mobilization of the renin-angiotensin-aldosterone system, is responsible for the salt and water retention which will ultimately become clinically manifest as oedema-especially when it is no longer counteracted by the tidal output of water and sodium at night. A by-product of this continuing dehydration reaction is a cumulative potassium loss which may lead to disastrous consequences if untreated.

It was Ford1 who first suggested that advantages and disad vantages, such as susceptibility to certain diseases, would be found to be associated with the human blood groups. Neverthe less, it was many years before practical work was started on the subject and only when Aird et al2 had shown that a signifi cantly high proportion of patients with cancer of the stomach belong to group A and of those with peptic ulcer to group O did the idea become widely accepted. Though of great theoretical interest, such associations between blood groups and disease are not of help to individual patients, and the purpose of this paper is to draw attention to other situations which do have medical (or veterinary) implications in particular cases and yet which also play a part in maintaining the polymorphisms. Such, for instance, are disorders due to interactions between the blood groups of mother and fetus which may result in the various types of haemolytic disease of the newborn, and, though this is more speculative, where blood group compatibility may influence the course of certain types of cancer. The keynote of haemolytic disease of the newborn, whether it be due to ABO or Rh incompatibility, is how ??frequently the fetus is affected compared with the chances of how often it might be. This is because there are several naturally occurring protective mechanisms, and it was one of these which led to a successful method of preventing rhesus haemolytic disease.

The need for carefully controlled continuous oxygen therapy for patients with chronic obstructive airways disease has been amply stated (Campbell, 1960 ; Hutchison et al., 1964). Further, it has been suggested that patients with cardiogenic shock require as high a concentration of oxygen as possible in the inspired air (MacKenzie et al., 1964). It is surprising, therefore, that, with the exception of the Ventimask, little or no information is provided by the manufacturers of the many devices at present available in regard to the concentrations of oxygen likely to be delivered to the patient. Few data have been published comparing the performance of these various pieces of equipment in an attempt to define which is the most appropriate to use in a given set of circumstances. Campbell (1960) pointed out the danger of intermittent oxygen therapy and the need for continuous administration, and it is not uncommon for a patient to be treated continuously with oxygen for several days. Clearly, then, the method used should be comfortable for the patient and should interfere with his activities and those of his attendants as little as possible. This aspect of oxygen therapy has been largely ignored by those writing on the subject. This paper describes the investigation of a number of methods of oxygen administration commonly employed. The aspects that have been particularly examined are: (1) how accurately the concentration of oxygen that each delivers can be predicted ; (2) to what extent rebreathing occurs ; and (3) how comfortable and convenient the methods are.

A simple apparatus which can deliver a painful electric shock to the subject for aversion therapy is described. It has advan tages over nausea-producing drugs, particularly in allowing the patient to treat himself even at home. The use of the apparatus is illustrated by cases of fetishism, obsessional rumi nations, smoking, writer's cramp, and alcoholism. Technical details are given of the components and their assembly which requires only the most rudimentary knowledge of electricity.

A study of the reasons for admission of 280 patients from their own homes to a geriatric unit in the East End of Glasgow showed that in two-thirds of cases patients were admitted primarily because they failed to receive adequate basic care at home (usually because of lack of relatives) or because their relatives suffered undue strain in caring for them. Neglect by relatives played a negligible part in the need for admission.