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VITAMIN C AND HEALING
130
ANNOTATIONS
cells.
The
retrogressive changes are but they are less obvious. It appears that all these crucial chemical and morphological comparisons have been made on long-grafted tumours, which probably means that there has been considerable selection from the original -tumour-cell population, with the result that the most rapidly growing elements have predominated. It might be valuable to know how the cells of primary malignant tumours compare with those that are conditional or dependent on the one hand, and with both normal embryonic and adult cells on the other. G. C. Easty and E. J. Ambrose have made a start, and they find that the methionine content of aestrogen-induced, dependent kidney tumours of hamsters is considerably less than that of normal kidney.
aqueous humour of non-inflamed aphakic eyes has indeed the same vitamin-C content as that of normal eyes.7 8 The reduced levels found in Boyd’s experiment may therefore be no more than an indication that the inflammation resulting from the lens extraction was more persistent than that resulting from the sham operation. It is at least as justifiable to attribute the observed delay in healing to the persistent inflammation as to the difference in ascorbic-acid levels. That is to say, delay in healing and reduction in the vitamin concentration are not necessarily causally related, as Boyd suggests, but both may be the result of the greater degree of inflammation induced by the true as compared with the sham
VITAMIN C AND HEALING Bourne1 has suggested that the formation of collagen in healing wounds is unlikely to be influenced by supplements of vitamin C if the diet is already adequate. The failure of local applications of the vitamin to increase the rate of healing in well-nourished laboratory animals accords with this view.23 . Since contrary findings have
OuR knowledge of cerebral vascular disorders is Potter 9 has broken new pathetically incomplete. in of his ground study angiomatous lesions, other than neoplasms. Perhaps his most important conclusion is that in all of these the essential abnormality is an
malignant
to be found in
same
embryonic cells,
been reported-by Saitta,4for example-the problem has been reinvestigated. In order to vary the local concentration of the vitamin in healing wounds, Boyd5 has made use of the considerable reduction in the ascorbic-acid content of the aqueous humour that follows extraction of the lens.6 In a trial series of 10 guineapigs he found that the mean concentration of ascorbic acid in the aqueous humour fell from 22-16 mg. per 100 ml. to 11-60 mg. per 100 ml.-a highly significant difference. For his main experiment he used 20 guineapigs in which the lens had been removed from the left eye, and the right eye had been subjected to a similar but sham operation. Ten days later a standard injury of each cornea was produced by an electrically heated wire loop. Healing of this injury was then assessed by watching the gradual disappearance of fluorescence from the injured site when it was viewed in ultraviolet light after the local application of fluorescein. Owing to the frequent relapses, especially on the aphakic side, healing was not regarded as complete until fluorescence was absent on four consecutive occasions. The mean of the healing time so determined was 17-3 days for the aphakic eyes and 10.8 days for the shamoperated controls. The ascorbic acid in the cornea and in the aqueous humour one week after completion of healing was significantly less in the aphakic than in the control eyes. Boyd rightly emphasises that even in the aphakic eyes the mean corneal ascorbic-acid level of 32-09 mg. per 100 g. was many times higher than in normal connective tissue ; yet healing was delayed compared with the control eyes, which had a mean corneal ascorbic-acid content of 47-29 mg. per 100 g. It is, however, questionable whether the difference in the rate of healing was in fact due to this difference in the local concentration of the vitamin. The amount of trauma suffered by the control eye was indubitably less, and probably much less, than that suffered by the eye undergoing extraction of the lens. The observed difference in the ascorbic-acid levels of aqueous humour and cornea of the two eyes was most’ probably the result of different degrees of injury. The fall in ascorbic-acid content of the aqueous humour of inflamed eyes was presumably caused by dilution with exudate from the relatively vitamin-poor plasma. The 1. Bourne, G. H. Lancet, 1942, ii, 661. Proto, M. Ann. ital. Chir. 1936, 15, 31. Galloway, N. M., Garry, R. C., Hitchin, A. D. Brit. J. Nutr. 1948, 2, 228. 4. Saitta, S. Scr. biol. Castaldi, 1929, 4, 301. 5. Boyd, T. A. S. Brit. J. Ophthal. 1955, 39, 204. 6. Muller, H. K., Buschke, W. Arch. Augenheilk. 1934, 108, 368. 2. 3.
operation. CEREBRAL ANGIOMATA
arteriovenous communication ; the tortuous and dilated vessels around this, which form the specta,cular part of the visible lesion, are not the cause of the shunt, nor are they associated congenital defects of structure: they are the consequences of the fistula and occur wherever there is such a fistula. Holman 10 too, concluded from his work on experimental arteriovenous fistulae that, whenever there was a significant leak and a large deviation of blood, the veins and the artery became tortuous and dilated ; but the reason for this is obscure. Holman further showed that the vascular dilatation was not permanent but disappeared if the leak was controlled, whereas excision of redundant vessels without control of the leak was followed by dilatation of further veins. So in surgical treatment the essential step is to interrupt the anastomosis-not to excise the lesion or block entering vessels. Potter’s clinical observations are perhaps of greater immediate importance. With cerebral angiomata the risk of serious cerebral injury is always present, but his figures suggest that complications come early or not at all ; that haemorrhage, though very common (4 cases out of 5) occurs at a younger age than does haemorrhage from berry aneurysms, and is much more benign ; and that the risk of serious epilepsy or mental damage is slight. About 1 in 10 of the patients show mental impairment, sometimes as premature ageing. Finally Potter’s useful contribution draws attention to the possibilities of radiotherapy. THE U.S.S.R. RETURNS TO W.H.O. ON July 8 Mr. Kumykin announced in Geneva that his government now proposes to take an active part in the work of the World Health Organisation, to take up membership of the International Bureau of Education, and to contribute 2 million roubles to the United Nations children’s fund in the form of services and equipment for maternity and child centres. This decision will be warmly welcomed by all who regretted the withdrawal of the Soviet Union from W.H.O. in 1949. Dr. F. H. K. GREEN, principal medical officer on the headquarters staff of the Medical Research Council since 1949, has been appointed scientific secretary to the trustees of the will of the late Sir Henry Wellcome (the Wellcome Trust) from Oct. 1. 7. Kinsey, V. E. Amer. J. Ophthal. 1950, 33, 257. 8. Purcell, E. F., Lerner, L. H., Kinsey, V. E. Arch. Ophthal., Chicago, 1954, 51, 1. 9. Potter, J. M. Ann. R. Coll. Surg. Engl. 1955, 16, 227. 10. Holman, E. Arteriovenous Aneurysms. New York, 1937. 11. See Lancet, 1949, i, 355.
ANNOTATIONS
cells.
The
retrogressive changes are but they are less obvious. It appears that all these crucial chemical and morphological comparisons have been made on long-grafted tumours, which probably means that there has been considerable selection from the original -tumour-cell population, with the result that the most rapidly growing elements have predominated. It might be valuable to know how the cells of primary malignant tumours compare with those that are conditional or dependent on the one hand, and with both normal embryonic and adult cells on the other. G. C. Easty and E. J. Ambrose have made a start, and they find that the methionine content of aestrogen-induced, dependent kidney tumours of hamsters is considerably less than that of normal kidney.
aqueous humour of non-inflamed aphakic eyes has indeed the same vitamin-C content as that of normal eyes.7 8 The reduced levels found in Boyd’s experiment may therefore be no more than an indication that the inflammation resulting from the lens extraction was more persistent than that resulting from the sham operation. It is at least as justifiable to attribute the observed delay in healing to the persistent inflammation as to the difference in ascorbic-acid levels. That is to say, delay in healing and reduction in the vitamin concentration are not necessarily causally related, as Boyd suggests, but both may be the result of the greater degree of inflammation induced by the true as compared with the sham
VITAMIN C AND HEALING Bourne1 has suggested that the formation of collagen in healing wounds is unlikely to be influenced by supplements of vitamin C if the diet is already adequate. The failure of local applications of the vitamin to increase the rate of healing in well-nourished laboratory animals accords with this view.23 . Since contrary findings have
OuR knowledge of cerebral vascular disorders is Potter 9 has broken new pathetically incomplete. in of his ground study angiomatous lesions, other than neoplasms. Perhaps his most important conclusion is that in all of these the essential abnormality is an
malignant
to be found in
same
embryonic cells,
been reported-by Saitta,4for example-the problem has been reinvestigated. In order to vary the local concentration of the vitamin in healing wounds, Boyd5 has made use of the considerable reduction in the ascorbic-acid content of the aqueous humour that follows extraction of the lens.6 In a trial series of 10 guineapigs he found that the mean concentration of ascorbic acid in the aqueous humour fell from 22-16 mg. per 100 ml. to 11-60 mg. per 100 ml.-a highly significant difference. For his main experiment he used 20 guineapigs in which the lens had been removed from the left eye, and the right eye had been subjected to a similar but sham operation. Ten days later a standard injury of each cornea was produced by an electrically heated wire loop. Healing of this injury was then assessed by watching the gradual disappearance of fluorescence from the injured site when it was viewed in ultraviolet light after the local application of fluorescein. Owing to the frequent relapses, especially on the aphakic side, healing was not regarded as complete until fluorescence was absent on four consecutive occasions. The mean of the healing time so determined was 17-3 days for the aphakic eyes and 10.8 days for the shamoperated controls. The ascorbic acid in the cornea and in the aqueous humour one week after completion of healing was significantly less in the aphakic than in the control eyes. Boyd rightly emphasises that even in the aphakic eyes the mean corneal ascorbic-acid level of 32-09 mg. per 100 g. was many times higher than in normal connective tissue ; yet healing was delayed compared with the control eyes, which had a mean corneal ascorbic-acid content of 47-29 mg. per 100 g. It is, however, questionable whether the difference in the rate of healing was in fact due to this difference in the local concentration of the vitamin. The amount of trauma suffered by the control eye was indubitably less, and probably much less, than that suffered by the eye undergoing extraction of the lens. The observed difference in the ascorbic-acid levels of aqueous humour and cornea of the two eyes was most’ probably the result of different degrees of injury. The fall in ascorbic-acid content of the aqueous humour of inflamed eyes was presumably caused by dilution with exudate from the relatively vitamin-poor plasma. The 1. Bourne, G. H. Lancet, 1942, ii, 661. Proto, M. Ann. ital. Chir. 1936, 15, 31. Galloway, N. M., Garry, R. C., Hitchin, A. D. Brit. J. Nutr. 1948, 2, 228. 4. Saitta, S. Scr. biol. Castaldi, 1929, 4, 301. 5. Boyd, T. A. S. Brit. J. Ophthal. 1955, 39, 204. 6. Muller, H. K., Buschke, W. Arch. Augenheilk. 1934, 108, 368. 2. 3.
operation. CEREBRAL ANGIOMATA
arteriovenous communication ; the tortuous and dilated vessels around this, which form the specta,cular part of the visible lesion, are not the cause of the shunt, nor are they associated congenital defects of structure: they are the consequences of the fistula and occur wherever there is such a fistula. Holman 10 too, concluded from his work on experimental arteriovenous fistulae that, whenever there was a significant leak and a large deviation of blood, the veins and the artery became tortuous and dilated ; but the reason for this is obscure. Holman further showed that the vascular dilatation was not permanent but disappeared if the leak was controlled, whereas excision of redundant vessels without control of the leak was followed by dilatation of further veins. So in surgical treatment the essential step is to interrupt the anastomosis-not to excise the lesion or block entering vessels. Potter’s clinical observations are perhaps of greater immediate importance. With cerebral angiomata the risk of serious cerebral injury is always present, but his figures suggest that complications come early or not at all ; that haemorrhage, though very common (4 cases out of 5) occurs at a younger age than does haemorrhage from berry aneurysms, and is much more benign ; and that the risk of serious epilepsy or mental damage is slight. About 1 in 10 of the patients show mental impairment, sometimes as premature ageing. Finally Potter’s useful contribution draws attention to the possibilities of radiotherapy. THE U.S.S.R. RETURNS TO W.H.O. ON July 8 Mr. Kumykin announced in Geneva that his government now proposes to take an active part in the work of the World Health Organisation, to take up membership of the International Bureau of Education, and to contribute 2 million roubles to the United Nations children’s fund in the form of services and equipment for maternity and child centres. This decision will be warmly welcomed by all who regretted the withdrawal of the Soviet Union from W.H.O. in 1949. Dr. F. H. K. GREEN, principal medical officer on the headquarters staff of the Medical Research Council since 1949, has been appointed scientific secretary to the trustees of the will of the late Sir Henry Wellcome (the Wellcome Trust) from Oct. 1. 7. Kinsey, V. E. Amer. J. Ophthal. 1950, 33, 257. 8. Purcell, E. F., Lerner, L. H., Kinsey, V. E. Arch. Ophthal., Chicago, 1954, 51, 1. 9. Potter, J. M. Ann. R. Coll. Surg. Engl. 1955, 16, 227. 10. Holman, E. Arteriovenous Aneurysms. New York, 1937. 11. See Lancet, 1949, i, 355.