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Termination of the coronavirus pandemic by vaccination will be heralded as a triumph for science. Indeed, vaccines are an incredible intervention, freeing us from the harms caused by a swathe of diseases. A vaccine is a classical biomedical intervention, in this case targeted against a specific virus. The development of Koch’s postulates for determining whether a specific microorganism is the cause of a given disease, and the work of Louis Pasteur, were key elements in the development of the model, which didn’t just lay the basis for the development of vaccines, but also formed the bedrock of modern medicine. The biomedical approach relies on categorising patients through agreed, standardised criteria for diagnosis, thence providing a basis for the development of effective treatments. Infectious diseases and a wide range of other conditions have been classified …

Iodized salt and iodized oil are the main methods used to prevent iodine deficiency, but sometimes alternative approaches are needed. We tested the efficacy of various regimens for the intermittent administration of potassium iodide in Hwedza, Zimbabwe, an area of known severe iodine deficiency. We divided 304 schoolchildren aged 7-13 y into five equal groups that received iodine as a 10% solution of potassium iodide as follows: 8.7 mg every 2 wk (group A), 29.7 mg every month (group B), 148.2 mg every 3 mo (group C), 382 mg every 6 mo (group D), or 993 mg once (group E). The follow-up period was 13 mo. No adverse effects were encountered with any of these doses. After 6 mo, the median blood spot thyroglobulin concentration had decreased in all groups and had normalized in groups A and B to values found in iodine-sufficient populations. The number of children with elevated thyroid-stimulating hormone concentrations decreased in groups A-C, but the changes were not significant. Urine iodine concentration generally remained low in all groups but increased in group A. After 13 mo, mean thyroid volume measured by ultrasound had decreased in groups A and B to values comparable with those in iodine-sufficient areas, and was unchanged in the other groups. We conclude that oral potassium iodide is effective for the prophylaxis of iodine deficiency if given as a dose of 30 mg I monthly or 8 mg biweekly.

Chronic obstructive pulmonary disease (COPD) is a disease state characterised by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. Classically, it is thought to be a combination of emphysema and chronic bronchitis, although only one of these may be present in some people with COPD. The main risk factor for the development and deterioration of COPD is smoking.We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of maintenance drug treatment in stable COPD? What are the effects of smoking cessation interventions in people with stable COPD? What are the effects of non-drug interventions in people with stable COPD? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 119 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review, we present information relating to the effectiveness and safety of the following interventions: alpha(1) antitrypsin, antibiotics (prophylactic), anticholinergics (inhaled), beta(2) agonists (inhaled), corticosteroids (oral and inhaled), general physical activity enhancement, inspiratory muscle training, nutritional supplementation, mucolytics, oxygen treatment (long-term domiciliary treatment), peripheral muscle strength training, psychosocial and pharmacological interventions for smoking cessation, pulmonary rehabilitation, and theophylline.

Editor,--I would urge that donations of medical supplies to Third World countries should be chosen just as carefully as those to the former Yugoslavia.1 In Zimbabwe I worked at a mission hospital where some of the donations we received included lorazepam, drops for infant colic, and decongestant …

It has been shown in previous communications (Todd, 1930, a, b ) that the red blood corpuscle of the domestic fowl constitutes a “multiple antigen” of considerable complexity and of so high a degree of specificity that, in unrelated birds, the red cells of any particular fowl can be differentiated from those of any other individual of the same species, by means of a simple agglutination reaction carried out with suitably exhausted polyvalent iso-agglutinating sera. When the birds are closely related, however, this is not always possible, as the corpuscles of certain members of a family may show a very close resemblance. In the course of some earlier experiments, made in order to investigate the hereditary transmission of the characters of the red blood corpuscle, three separate couples of unrelated Plymouth Rock birds were mated, and the cells of parents and offspring in each of the three families examined in detail (Todd, 1930, b ). On reviewing the results obtained and com­paring the behaviour of the corpuscles of the individual members in anyone family, it was seen that the cells of no two chicks appeared to be exactly alike, but that there was always some degree of difference, varying from a close resemblance to a very marked contrast; suggesting that the red cells contain a number of different antigenic units, each of which behaves independently during the process of hereditary transmission.

In a previous communication (Perdrau and Todd, 1933), dealing with the photodynamic action of methylene blue on bacteriophage, we have recorded the results of experiments confirming the observations of Clifton (1931), both as regards the part played by visible light in bringing about the reaction and also as regards the necessity for the presence of free oxygen. In the course of these experiments it was found that while the free phage is highly sensitive to the photodynamic action of methylene blue, it becomes very much more resistant to the dye in the presence of the corresponding living bacterium. This protection of the phage is only exercised by living bacteria, killed organisms being without effect. It is, moreover, not a strictly specific phenomenon, as protection is in some cases brought about by bacteria other than those for which the phage has been prepared. In view of the many similarities of behaviour shown by the bacteriophage and the ultramicroscopic viruses, it seemed not improbable that some of the latter might be susceptible to the photodynamic action of methylene blue, and tests were accordingly made with such viruses as we had at our disposal.

The term “Isolysin” was first employed by Ehrlich and Morgenroth in the third of their now classical series of papers entitled “Studies on Haemolysis(1).” It had been shown by Bordet that if the red blood corpuscles of an animal A are injected into another animal B, of a different species, the serum of B develops a haemolysin for the corpuscles of A. This haemolysin being produced in a different species of animal from that yielding the corpuscles, is termed, according to Ehrlich's nomenclature, a heterolysin.

The following is a brief account of some results obtained during the course of an investigation in to the artificially produced hæmolytic isolysins of the ox. The peculiar interest attaching to this class of bodies was first pointed out by Ehrlich and Morgenroth in their classical studies on hæmolytic, where they showed by the treatment of goats with large quantities of laked goats’ blood, that hæmolytic isolysins were formed in the blood of the immunised animals. Their investigations were made with sera prepared in this way.

It is now generally assumed by the majority of workers in the field of virus diseases that the term “ virus ” should be limited to those small organisms, either approaching or below the limit of ordinary microscopic visibility, which are incapable of multiplication in vitro except in the presence of living animal or vegetable cells. This limitation is obviously only provisional, as with a fuller knowledge of the conditions obtaining in the living cell it may at some time become possible to simulate these sufficiently closely to allow of the growth of the virus in a cell-free medium. Until this is accomplished, however, the presence of the living cell must be regarded as essential, and we are faced with the problem of elucidating its role in the multiplication of the virus.

Many deaths occur every year in Egypt as the result of scorpion sting. These deaths are practically confined to Cairo and Upper Egypt, and are almost entirely among children. Unfortunately, owing to local conditions, it is almost impossible to obtain really accurate figures for this mortality, but some idea may be formed from the statistics given below of some of the larger towns.

In a paper published last year the authors described a method by which it is possible to recognise the red blood corpuscles of any individual ox and to differentiate them from those of any other member of the same species. The method depends upon the fact that if a highly polyvalent isohæmolytic serum is treated repeatedly with the red blood corpuscles of any individual of the species for which the serum has been made, it entirely loses its hæmolytic action for the corpuscles of all other individuals of the same species. Such a serum therefore constitutes, so to speak, a specific reagent for the corpuscles of the individual for which it has been prepared, and by its means one is enabled to follow up and to identify these corpuscles even in the presence of corpuscles of other individuals.

In the course of some work on the trypsin susceptibility of two races of staphylococcus bacteriophage, Schultz and Krueger (1928) made the observation that these two phages were remarkably sensitive to the action of methylene blue─being completely inactivated within 6 to 12 hours by concentrations of the dye as low as 0.002 per cent. So far as their tests went, the susceptibility to methylene blue appeared to be peculiar to the two races of staphylococcus bacteriophage, as eight phages for other organisms were entirely unaffected by the dye. Moreover, of a considerable number of dyes used, methylene blue was the only one showing this action. Clifton and Lawler (1930) and Burnet and McKie (1930) repeated these experiments with methylene blue and other dyes on several strains of bacteriophage, but they were then unaware of the role played by light in these reactions. A new aspect of the mechanism of the reaction was opened up by Clifton (1931), who found that no inactivation took place when the dye and the phage were mixed, incubated and tested in the dark ; but that an exposure of 5 minutes, or even less, to indirect sunlight before incubation resulted in complete inactivation of the bacteriophage. He also showed that the presence of oxygen was necessary for the process, as inactivation did not occur in vacuo or in an atmosphere of nitrogen, and was inhibited by reducing agents such as cysteine hydrochloride. He therefore concluded that the inactivation of the staphylococcus phage by methylene blue is due to an oxidation of the phage by photosensitized methylene blue in the presence of oxygen.

In this outbreak of diphtheria certain individuals suffered from diphtheria, and others from sore throat probably diphtheritic. These individuals obtained their milk supply from two cows. Members of one household who did not drink milk, or who used it only after sterilisation, escaped infection. The cows yielding the milk were found to be suffering from an eruptive disease of the udder, and both from the lesions and from the milk cultures of virulent diphtheria bacilli were isolated. The pathological condition in the cows preceded, by a short interval, the onset of the disease in the patients. Having regard to Power's epidemiological investigations, and to Klein's experimental work, this observation was of the greatest interest and naturally suggested the hypothesis that the lesions were due, primarily, to a specific diphtheritic infection of the cow. Further investigations weakened this view, for it must be noted:—(1) That in a cow intentionally submitted to infection from the diseased cows and in which there occurred the eruptive condition of the udder, neither in the vesicular nor in the ulcerative stage of the disease could diphtheria bacilli be demonstrated.(2) That in calves infected with the eruptive disease no diphtheria bacilli could be demonstrated.(3) That in a calf, in spite of the fact that it had received 10, 000 units of diphtheria antitoxin, the vesicular eruption was experimentally produced. The last is probably the strongest point in support of the dual nature of the condition in the cows.It is conceivable that pathological lesions in the cow such as those described, if infected with the diphtheria bacillus, might form a suitable nidus for its growth and permit of the infection of large quantities of milk over a considerable period. Though we have as yet no evidence on the subject it is possible that a profound change in the virulence of the diphtheria bacillus for the human subject might be effected by such passage through the cow1.The disgusting habit the milkers in this part of England have, of spitting on their hands before milking, would easily account for the infection of the lesions, even in the absence of obvious diphtheria in the cowman; knowing, as we now do, that apparently healthy individuals are not uncommonly the hosts of the diphtheria bacillus.The experiments made with the view of ascertaining whether the eruptive condition was genuine cowpox, are opposed to that view; for two calves, and one cow successfully infected with the eruptive condition and subsequently vaccinated with vaccine lymph, developed a typical vaccinia.The somewhat limited time and material available have prevented us from investigating the matter so fully as we should have wished, or on a scale proportionate to its interest and practical importance. We hope at some future time to go further into the matter.Our best thanks are due to Mr Sidney Villar, F.R.C.V.S., for bringing the outbreak to our notice, and for his help in the veterinary side of the question; and to Dr Carson Smyth for his kindness in allowing us facilities for taking cultures from the throats of his patients.

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One of the most striking points in the pathology of Bacterial Dysentery is the fact that while the bacilli are found regularly in the mesenteric glands, they are not found in the spleen or other organs, and do not occur in the blood, urine, or milk. In this respect Lentz (p. 320) points out that the disease differs markedly from the septicaemic diseases, such as typhoid, and that it must be regarded as a local infection of the intestinal mucous membrane and corresponding lymphatic glands by the bacillus, the toxin alone passing into the circulation and giving rise to the typical clinical picture, which, as in the case of cholera, gives the impression of a severe poisoning or toxaemia.

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The outbreak of cattle plague in Egypt and the establishment of the Serum Institute at Abbassieh offered a suitable opportunity for investigating some points concerning the nature of the causal agent of the disease, and especially the important question whether the virus is, or is not, capable of traversing a filter candle. On this point the literature is strangely contradictory.

We have determined this item to be in the public domain according to US copyright law through information in the bibliographic record and/or US copyright renewal records. The digital version is available for all educational uses worldwide. Please contact HathiTrust staff at hathitrust-help@umich.edu with any questions about this item., (OCoLC)7666105., 2790137., Sdr-ia-srlf2790137., Http://hdl.handle.net/2027/uc2.ark:/13960/t2b859v8w.