- Email: [email protected]
FIBRINOLYTIC ACTIVITY OF SKIN SURFACE LIPIDS
193
suggestion that it involves a granulomatous type of reaction following absorption of macromolecular substances. It is for this reason that we believe the guineapig lesion would not serve adequately as a model for the study of human ulcerative colitis.
any
British Industrial Biological Research
Association, Carshalton, Surrey.
M. SHARRATT P. GRASSO F. CARPANINI S. D. GANGOLLI.
FIBRINOLYTIC ACTIVITY OF SKIN SURFACE LIPIDS
SIR,-Skin surface lipids contain
a factor which prothe formation of a fibrin clot.! In whole blood, the potential for laying down fibrin is balanced by the fibrinolytic system. The fibrinolytic system also plays an important part in inflammation and subsequent wound healing. We have therefore investigated the fibrinolytic activity of skin surface lipids using a fibrin-plate method.
motes
plates were made by mixing 6 ml. bovine fibrinogen Plasma Fraction I, Armour—1% in veronal buffer) and 0.1 ml. bovine thrombin. Surface lipids were collected from the forehead by a modification of the method described by Cunliffe and Shuster.’ Five sheets of absorbent paper were placed on the forehead, covered with gauze, and held in position by a rubber band 5 cm. wide; after 10 minutes the band was released and the
were incubated at 37 °C for 4 hours: (a) surface lipid; (b) absorbent paper containing lipid purified immediately after removal from the forehead; (c) unwashed scalp-hair shafts; and (d) a control consisting of paper soaked in ether. To test for inhibitors of fibrinolysis, lipidcontaining paper and ether-extracted lipid were applied to a fibrin plate together with urokinase (2-5 u per ml. solution). The accompanying figure shows that skin surface lipids contain a factor which activates fibrinolysis. No activity could be demonstrated on the heated plate. The normal bacterial flora cultured from the forehead showed We found no evidence of any fibrinolytic no activity. inhibitors in surface lipids. We suggest, that in conjunction with the clot-promoting effect of surface lipids, fibrinolytic activity is important in reconstituting the skin surface following injury. St. John’s Hospital for Diseases of R. P. R. DAWBER the Skin, London W.C.2, K. NISHIOKA and Institute of Dermatology, T. J. RYAN. London E.9.
at
80 °C, and
Fibrin
(Bovine
POSSIBLE HAPTEN FUNCTION OF INTRINSIC FACTOR IN THE AUTOIMMUNISATION PROCESS to gastric intrinsic factor (l.F.) are found in pernicious anxmia. Far the commonest type of Of. autoantibodies is the so-called blocking antibody or type-1 antibody, which specifically inhibits the binding of vitamin B12 to LF.1 By inhibiting a primary biological activity of I.F., the binding of vitamin B12, the antibody may play a role in the pathogenesis of pernicious ansemia. Blocking antibody does not react with the l.F. in complex with Bl2 2; thus, it is distinctly directed to a well-defined site of the i.F.-i.e., the B12-binding site. Because of steric hindrance, probably not more than one antigen-combining site of the antibody could be bound at the one time to this small part of the molecule. This would imply a hapten function of Of, in the autoimmunisation
SIR,-Autoantibodies
almost
exclusively
process. The I.F. in the parietal cell (the secretor of Of. in man 3) may normally be shielded from the immune apparatus. On the other hand, there is some evidence that immune tolerance exists to a form of I.F. absorbed from the intestine in complex with B12,4 although the quantitative importance of such an absorbed I.F.JBI2 complex is unknown. This idea is consistent with the facts that, unlike I.F. alone, the I.F.JBI2 complex is stable in the presence of gastrointestinal proteolytic enzymes5 and that I.F.JBI2 complex is bound to
specific intestinal receptor in preference to I.F. alone.s Furthermore, patients on replacement therapy with hog-l.F. often develop a refractory state, which is specifically directed against the heterologous I.F.7 In such patients, antibodies reactive with hog-i.F. but non-reactive with
a
Part of fibrin
plate showing fibrinolytic activity
of skin surface
lipids.
(A) a disc of filter paper containing ether extracted lipids; (B) absorbent paper removed from the forehead containing surface lipids; (C) unwashed hair shafts; (D) control consisting of filter paper soaked in ether. paper in contact with the forehead was removed. This procedure was repeated on 1-4 occasions at 10-minute intervals until, when the paper was held to the light, lipid was seen only at points corresponding to follicular orifices. The papers used for collecting the lipids (4-5 sheets) were then applied to the forehead for several hours. The surface lipids were extracted from the paper with ether and purified by Folch’s method.3
The following specimens were applied to (1) a fibrin plate, and (2) a fibrin plate previously heated for 30 minutes 1. 2. 3.
Ogston, D., Ogston, C. M., Ratnaff, O. D. J. Lab. clin. Med. 1969, 73, 70. Cunliffe, W. J., Shuster, S. Br. J. Derm. 1969, 81, 697. Folch, J., Ascoli, I., Lees, M., Meath, J. A., LeBaron, F. N. J. biol. Chem. 1951, 191, 833.
human i.F., are demonstrable.4 These antibodies are directed to determinants remote from the B12-binding site of I.F.8 Unlike I.F. autoantibodies, the antibodies against oral hog-I.F. are not confined to pernicious-anaemia patients. There is so far no evidence that immunisation to orally Abels, J., Bouma, W., Jansz, A., Woldring, M. G., Bakker, A., Niewig, H. O. J. Lab. clin. Med. 1963, 61, 893. 2. Garrido-Pinson, G. C., Turner, M. D., Crookston, J. H., Samloff, I. M., Miller, L. L., Segal, H. L. J. Immun. 1966, 97, 897. 3. Hoedemaeker, P. J., Abels, J., Wachters, J. J., Arends, A., Niewig, H. O. Lab. Invest. 1966, 15, 1163. 4. Gullberg, R. Acta med. scand. 1966, suppl. 463. 5. Gräsbeck, R. Progress in Hematology; vol. VI, p. 233. New York, 1.
1969. R. M., Mackenzie, I. L., Trier, J. S. J. clin. Invest. 1967, 46, 1215. 7. Schwartz, M. Vitamin B12 und Intrinsic Factor (edited by H. C. Heinrich); p. 613. Stuttgart, 1962. 8. Gullberg, R. Clin. exp. Immun. 1970, 7, 453.
6.
Donaldson,
suggestion that it involves a granulomatous type of reaction following absorption of macromolecular substances. It is for this reason that we believe the guineapig lesion would not serve adequately as a model for the study of human ulcerative colitis.
any
British Industrial Biological Research
Association, Carshalton, Surrey.
M. SHARRATT P. GRASSO F. CARPANINI S. D. GANGOLLI.
FIBRINOLYTIC ACTIVITY OF SKIN SURFACE LIPIDS
SIR,-Skin surface lipids contain
a factor which prothe formation of a fibrin clot.! In whole blood, the potential for laying down fibrin is balanced by the fibrinolytic system. The fibrinolytic system also plays an important part in inflammation and subsequent wound healing. We have therefore investigated the fibrinolytic activity of skin surface lipids using a fibrin-plate method.
motes
plates were made by mixing 6 ml. bovine fibrinogen Plasma Fraction I, Armour—1% in veronal buffer) and 0.1 ml. bovine thrombin. Surface lipids were collected from the forehead by a modification of the method described by Cunliffe and Shuster.’ Five sheets of absorbent paper were placed on the forehead, covered with gauze, and held in position by a rubber band 5 cm. wide; after 10 minutes the band was released and the
were incubated at 37 °C for 4 hours: (a) surface lipid; (b) absorbent paper containing lipid purified immediately after removal from the forehead; (c) unwashed scalp-hair shafts; and (d) a control consisting of paper soaked in ether. To test for inhibitors of fibrinolysis, lipidcontaining paper and ether-extracted lipid were applied to a fibrin plate together with urokinase (2-5 u per ml. solution). The accompanying figure shows that skin surface lipids contain a factor which activates fibrinolysis. No activity could be demonstrated on the heated plate. The normal bacterial flora cultured from the forehead showed We found no evidence of any fibrinolytic no activity. inhibitors in surface lipids. We suggest, that in conjunction with the clot-promoting effect of surface lipids, fibrinolytic activity is important in reconstituting the skin surface following injury. St. John’s Hospital for Diseases of R. P. R. DAWBER the Skin, London W.C.2, K. NISHIOKA and Institute of Dermatology, T. J. RYAN. London E.9.
at
80 °C, and
Fibrin
(Bovine
POSSIBLE HAPTEN FUNCTION OF INTRINSIC FACTOR IN THE AUTOIMMUNISATION PROCESS to gastric intrinsic factor (l.F.) are found in pernicious anxmia. Far the commonest type of Of. autoantibodies is the so-called blocking antibody or type-1 antibody, which specifically inhibits the binding of vitamin B12 to LF.1 By inhibiting a primary biological activity of I.F., the binding of vitamin B12, the antibody may play a role in the pathogenesis of pernicious ansemia. Blocking antibody does not react with the l.F. in complex with Bl2 2; thus, it is distinctly directed to a well-defined site of the i.F.-i.e., the B12-binding site. Because of steric hindrance, probably not more than one antigen-combining site of the antibody could be bound at the one time to this small part of the molecule. This would imply a hapten function of Of, in the autoimmunisation
SIR,-Autoantibodies
almost
exclusively
process. The I.F. in the parietal cell (the secretor of Of. in man 3) may normally be shielded from the immune apparatus. On the other hand, there is some evidence that immune tolerance exists to a form of I.F. absorbed from the intestine in complex with B12,4 although the quantitative importance of such an absorbed I.F.JBI2 complex is unknown. This idea is consistent with the facts that, unlike I.F. alone, the I.F.JBI2 complex is stable in the presence of gastrointestinal proteolytic enzymes5 and that I.F.JBI2 complex is bound to
specific intestinal receptor in preference to I.F. alone.s Furthermore, patients on replacement therapy with hog-l.F. often develop a refractory state, which is specifically directed against the heterologous I.F.7 In such patients, antibodies reactive with hog-i.F. but non-reactive with
a
Part of fibrin
plate showing fibrinolytic activity
of skin surface
lipids.
(A) a disc of filter paper containing ether extracted lipids; (B) absorbent paper removed from the forehead containing surface lipids; (C) unwashed hair shafts; (D) control consisting of filter paper soaked in ether. paper in contact with the forehead was removed. This procedure was repeated on 1-4 occasions at 10-minute intervals until, when the paper was held to the light, lipid was seen only at points corresponding to follicular orifices. The papers used for collecting the lipids (4-5 sheets) were then applied to the forehead for several hours. The surface lipids were extracted from the paper with ether and purified by Folch’s method.3
The following specimens were applied to (1) a fibrin plate, and (2) a fibrin plate previously heated for 30 minutes 1. 2. 3.
Ogston, D., Ogston, C. M., Ratnaff, O. D. J. Lab. clin. Med. 1969, 73, 70. Cunliffe, W. J., Shuster, S. Br. J. Derm. 1969, 81, 697. Folch, J., Ascoli, I., Lees, M., Meath, J. A., LeBaron, F. N. J. biol. Chem. 1951, 191, 833.
human i.F., are demonstrable.4 These antibodies are directed to determinants remote from the B12-binding site of I.F.8 Unlike I.F. autoantibodies, the antibodies against oral hog-I.F. are not confined to pernicious-anaemia patients. There is so far no evidence that immunisation to orally Abels, J., Bouma, W., Jansz, A., Woldring, M. G., Bakker, A., Niewig, H. O. J. Lab. clin. Med. 1963, 61, 893. 2. Garrido-Pinson, G. C., Turner, M. D., Crookston, J. H., Samloff, I. M., Miller, L. L., Segal, H. L. J. Immun. 1966, 97, 897. 3. Hoedemaeker, P. J., Abels, J., Wachters, J. J., Arends, A., Niewig, H. O. Lab. Invest. 1966, 15, 1163. 4. Gullberg, R. Acta med. scand. 1966, suppl. 463. 5. Gräsbeck, R. Progress in Hematology; vol. VI, p. 233. New York, 1.
1969. R. M., Mackenzie, I. L., Trier, J. S. J. clin. Invest. 1967, 46, 1215. 7. Schwartz, M. Vitamin B12 und Intrinsic Factor (edited by H. C. Heinrich); p. 613. Stuttgart, 1962. 8. Gullberg, R. Clin. exp. Immun. 1970, 7, 453.
6.
Donaldson,