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METALLIC SALTS AND HORMONES
390 be replaced with an extrapleural oleothorax. It is wise, as Dr. Rhodes points out, to allow an interval to elapse between the induction of the pneumothorax and its conversion into an oleothorax, to ensure a stiffening of the walls of the space. By such means is perforation of lung avoided. Two French observers, with similar opportunities of seeing the German work, have been proving the method at the Hopital Laennec and several Paris sanatoriums, reaching the same tentative conclusions.1 Because the extrapleural pneumothorax would seem to be a rational method of dealing with a certain group of cases that are denied collapse therapy at the present time ; because it is a less drastic and less mutilating procedure than thoracoplasty, and is, in no sense, a permanent collapse, we endorse Dr. Rhodes’s statement that it is a method deserving of more extended trial. can
hypoglycaemic action of insulin and have shown that the addition of zinc to the tannic-acid insulin complex still further prolongs the hypoglycsemia. Suspensions of tannic acid, insulin, and zinc with a tannic-acid insulin ratio of 2 to I have been shown to produce a hypoglycsemia as prolonged as that produced by suspensions of protamine, insulin, and zinc. The evidence certainly encourages a clinical trial of tannic acid and insulin in the ratio of 2 to 1 with the addition of 1 mg. of zinc to each 500 units of insulin. SILICOSIS HAZARDS AMONGST METAL POLISHERS
A STUDY of the silicosis hazards of metal polishers is recorded in the Industrial Bulletin for June, 1937 (p. 227), published by the Industrial Commissioner of New York State. Dr. Adelaide R. Siviter states that tripoli is the only siliceous substance to which polishers are exposed, and that in this industry it is METALLIC SALTS AND HORMONES so used, incorporated in a greasy medium, as to reduce SALTS of zinc are known to prolong the action of materially its dustiness ; and that the recent investigacertain hormones and other potent organic substances tions which indicate a slight silicosis risk amongst such as diphtheria toxin and histamine. In our last metal polishers appear quite consistent with issue Prof. E. C. Dodds and his co-workers showed the known facts. A group of 80 men were that the antidiuretic action of posterior pituitary examined, of whom 73 had been employed for over extract is also prolonged by salts of zinc, and still 5 years and 43 for over 15 years at metal polishing. more by salts of cadmium and nickel. The mechanism Out of the whole group " two, or 2-5 per cent., showed of this prolongation can hardly be a chemical union silicosis ... characterised by a fine type of mottling." with substances of such widely varied constitution ; Neither had worked at any other trade: 47 (58 per it is more likely, he thinks, that the metal alters cent.) showed " increased fibrosis " (12 of whom absorption from the site of injection. Investigations presented evidence of old healed tuberculous nodules). into the effect of zinc and allied metals in prolonging In all 16 per cent. of the whole group showed evidence insulin hypoglycaemia have been made in the pharmaof healed tuberculosis. Dr. Siviter quotes for comparicological laboratory of Boots Pure Drug Co. and were son a study of dust in a silverware plant, published reported by E. M. Bavin and W. A. Broom at the in a Public Health Bulletin (No. 208) in 1933, in which recent Liverpool meeting of the British Pharma70 per cent. of 51 men showed X ray evidence of ceutical Congress. The mammalian pancreas contains It would appear to us more increased fibrosis. small but definite amounts of zinc and this metal important to inquire into the causes and significance is an essential constituent of crystalline insulin. of the high proportion of men showing " increased Whereas small concentrations of zinc produce a pro- nbrosis " than to direct attention to the low incidence longation of hypoglycaemia, complete inhibition of the of frank silicosis in this occupation. It would be of normal insulin response results, it seems, if the amount interest to learn what grounds Dr. Siviter has for of metal present is increased. The prolongation of the opinion that the " rather high incidence of insulin hypoglycsemia caused by traces of certain increased fibrosis... is probably of little clinical metals is thus the initial stage of an inhibitory effect significance." Ought not its significance to be which becomes virtually complete with large con- related to the figures which she quotes earlier in her centrations. The mechanism of this inhibition is paper, where she points out that, according to figures discussed by the authors. Neglecting the theory that derived from statistics compiled by the Registrarthe metal may produce hyperglycsemia, which in the General, the mortality amongst metal polishers from case of zinc has been negatived, they suggest two tuberculosis and bronchitis is twice the standard possible explanations. In the first place, the metal rate for all occupied and retired males ? may attach itself to the active groups of the insulin "SABOTAGE" IN THE BACTERIOLOGICAL molecule and thus render it incapable of producing its normal response ; or the metals in the rather LABORATORY large concentrations used may exert a toxic effect THE careful bacteriologist when he finds some on some stage of carbohydrate metabolism and thus subculture which he has laid by with all precious inhibit the course of events which normally follows has become contaminated with moulds precautions the injection of insulin. The necessity for the presence must sometimes give way to the thought that some of zinc in the formation of crystalline insulin and its effect in increasing the action of protamine insulin perverse and mischievous agency has been at work. lend colour to the hypothesis that zinc can combine Dorothy Pease of the botany laboratory, Columbiai University, makes some interesting suggestions with the insulin molecule, and hence give support to as to how this contamination may sometimes come the first of the above suggestions. In such a case, it to the activities of mites such as however, it would be expected that, the smaller the about, ascribingSome of these mites may feed and tyroglyphidse. atomic weight of the metal used, the smaller would breed under the thick mycelium of moulds. They be the concentration necessary to produce inhibition, whereas a greater concentration of magnesium is will travel from culture to culture carrying conidia and bacteria on the surface of their bodies and leaving necessary than is the case with zinc. The same them in their wake. They can easily invade Petri the observation authors have confirmed of Bischoff dishes but they can also find their way through the and Gray that tannic acid also prolongs the cotton-wool plugs of culture tubes and they have 1 Hautefeuille, E., and Dreyfus-le Foyer, Presse méd. 1 June 9th, 1937, p. 859.
J. Bact. 1937, 33, 619.
hypoglycaemic action of insulin and have shown that the addition of zinc to the tannic-acid insulin complex still further prolongs the hypoglycsemia. Suspensions of tannic acid, insulin, and zinc with a tannic-acid insulin ratio of 2 to I have been shown to produce a hypoglycsemia as prolonged as that produced by suspensions of protamine, insulin, and zinc. The evidence certainly encourages a clinical trial of tannic acid and insulin in the ratio of 2 to 1 with the addition of 1 mg. of zinc to each 500 units of insulin. SILICOSIS HAZARDS AMONGST METAL POLISHERS
A STUDY of the silicosis hazards of metal polishers is recorded in the Industrial Bulletin for June, 1937 (p. 227), published by the Industrial Commissioner of New York State. Dr. Adelaide R. Siviter states that tripoli is the only siliceous substance to which polishers are exposed, and that in this industry it is METALLIC SALTS AND HORMONES so used, incorporated in a greasy medium, as to reduce SALTS of zinc are known to prolong the action of materially its dustiness ; and that the recent investigacertain hormones and other potent organic substances tions which indicate a slight silicosis risk amongst such as diphtheria toxin and histamine. In our last metal polishers appear quite consistent with issue Prof. E. C. Dodds and his co-workers showed the known facts. A group of 80 men were that the antidiuretic action of posterior pituitary examined, of whom 73 had been employed for over extract is also prolonged by salts of zinc, and still 5 years and 43 for over 15 years at metal polishing. more by salts of cadmium and nickel. The mechanism Out of the whole group " two, or 2-5 per cent., showed of this prolongation can hardly be a chemical union silicosis ... characterised by a fine type of mottling." with substances of such widely varied constitution ; Neither had worked at any other trade: 47 (58 per it is more likely, he thinks, that the metal alters cent.) showed " increased fibrosis " (12 of whom absorption from the site of injection. Investigations presented evidence of old healed tuberculous nodules). into the effect of zinc and allied metals in prolonging In all 16 per cent. of the whole group showed evidence insulin hypoglycaemia have been made in the pharmaof healed tuberculosis. Dr. Siviter quotes for comparicological laboratory of Boots Pure Drug Co. and were son a study of dust in a silverware plant, published reported by E. M. Bavin and W. A. Broom at the in a Public Health Bulletin (No. 208) in 1933, in which recent Liverpool meeting of the British Pharma70 per cent. of 51 men showed X ray evidence of ceutical Congress. The mammalian pancreas contains It would appear to us more increased fibrosis. small but definite amounts of zinc and this metal important to inquire into the causes and significance is an essential constituent of crystalline insulin. of the high proportion of men showing " increased Whereas small concentrations of zinc produce a pro- nbrosis " than to direct attention to the low incidence longation of hypoglycaemia, complete inhibition of the of frank silicosis in this occupation. It would be of normal insulin response results, it seems, if the amount interest to learn what grounds Dr. Siviter has for of metal present is increased. The prolongation of the opinion that the " rather high incidence of insulin hypoglycsemia caused by traces of certain increased fibrosis... is probably of little clinical metals is thus the initial stage of an inhibitory effect significance." Ought not its significance to be which becomes virtually complete with large con- related to the figures which she quotes earlier in her centrations. The mechanism of this inhibition is paper, where she points out that, according to figures discussed by the authors. Neglecting the theory that derived from statistics compiled by the Registrarthe metal may produce hyperglycsemia, which in the General, the mortality amongst metal polishers from case of zinc has been negatived, they suggest two tuberculosis and bronchitis is twice the standard possible explanations. In the first place, the metal rate for all occupied and retired males ? may attach itself to the active groups of the insulin "SABOTAGE" IN THE BACTERIOLOGICAL molecule and thus render it incapable of producing its normal response ; or the metals in the rather LABORATORY large concentrations used may exert a toxic effect THE careful bacteriologist when he finds some on some stage of carbohydrate metabolism and thus subculture which he has laid by with all precious inhibit the course of events which normally follows has become contaminated with moulds precautions the injection of insulin. The necessity for the presence must sometimes give way to the thought that some of zinc in the formation of crystalline insulin and its effect in increasing the action of protamine insulin perverse and mischievous agency has been at work. lend colour to the hypothesis that zinc can combine Dorothy Pease of the botany laboratory, Columbiai University, makes some interesting suggestions with the insulin molecule, and hence give support to as to how this contamination may sometimes come the first of the above suggestions. In such a case, it to the activities of mites such as however, it would be expected that, the smaller the about, ascribingSome of these mites may feed and tyroglyphidse. atomic weight of the metal used, the smaller would breed under the thick mycelium of moulds. They be the concentration necessary to produce inhibition, whereas a greater concentration of magnesium is will travel from culture to culture carrying conidia and bacteria on the surface of their bodies and leaving necessary than is the case with zinc. The same them in their wake. They can easily invade Petri the observation authors have confirmed of Bischoff dishes but they can also find their way through the and Gray that tannic acid also prolongs the cotton-wool plugs of culture tubes and they have 1 Hautefeuille, E., and Dreyfus-le Foyer, Presse méd. 1 June 9th, 1937, p. 859.
J. Bact. 1937, 33, 619.