1240 Dr Stehbens’ suggestion that " the effect on serumlipids of the sloughing of much lipid-rich atheromatous debris to the bloodstream has been completely ignored " is a subcategory of the frequently stated hypothesis that hyperlipideemia might be a consequence of atherosclerosis rather than the reverse. Dr Stehbens’ suggestion surely does not apply to non-ulcerated atheromatous disease; in any event the burden of proof of such a hypothesis, which is susceptible to test, should rest with him who poses it. V.A. Wadsworth Hospital Center, Los Angeles, SEYMOUR DAYTON. California 90073, U.S.A.
ONION
AND GARLIC IN EXPERIMENTAL
less atherosclerotic involvement than the other cholesterolfed groups (see table). A fair degree of correlation between biochemical and histopathological findings was noted. Higher levels of serum-cholesterol and more severe atherosclerotic lesions were seen in groups 11 and III, whereas lower levels of serum-cholesterol and less extensive atherosclerotic involvement was found in group iv. Group-! animals, which were fed only a basic diet without any supplementation, showed normal serum-lipids and .no atherosclerosis. Thus, administration of onion to cholesterol-fed rabbits did not lower cholesterol levels or inhibit the development of atherosclerosis. However, supplementation of garlic to the rabbits fed with cholesterol resulted in significantly lower cholesterol levels and less atherosclerosis. Department of Pathology, University of Benghazi, Benghazi, Libya.
ATHEROSCLEROSIS
SIR,-Onion and garlic are said to possess hypoglycaemic and hypolipsemic activities and may have an inhibitory effect on atherosclerosis. 1-12 The present study investigates the role of onion and garlic in cholesterol-induced atherosclerosis in rabbits. 40 male albino rabbits weighing 1-1-5 kg. were divided into 4 groups of 10. Group I received stock diet (green vegetables, green grass, bengal gram, milk powder, and green feeder) and served as controls. Groups II, III, and iv were fed with stock diet plus 0-5 g. cholesterol in 5 ml. of olive oil. In addition, group III were given 10 ml. of juice from raw onion bulbs, and group iv had 10 ml. of garlic juice, both in distilled water. The cholesterol suspension and the onion and garlic juices were fed through an intragastric tube for 16 weeks. Total serumcholesterol was estimated by the method of Kim and Goldberg " in all the animals before and after the experiment. All the animals were killed after 16 weeks. At necropsy gross examination was made for visible lesions of the heart, aorta, and liver. EFFECT OF ONION AND GARLIC ON TOTAL SERUM-CHOLESTEROL AND GRADING OF EXPERIMENTAL AORTIC ATHEROSCLEROSIS IN RABBITS
R. C.
JAIN.
ELECTRICAL HAZARDS OF DISPOSABLE MONITORING ELECTRODES
SiR,—The use of resistors in series with monitoring electrode leads has been proposed by Mr Bond.l Although a worth-while measure which is likely to reduce the risk of . burns at the sites of monitoring electrodes, the idea is by no means new.
The incorporation of 10 Kohm resistors in the patient leads of E.c.G.s used by the Medical Service of the Royal Air Force was specified some ten years ago after an earlier investigation into the safety aspects of diathermy, as a result of which the use of radiofrequency chokes in monitoring leads was recommended.2 More recently protective resistors have been required in Department of Health and Social Security specifications for monitoring equipment.3,4 Reporting an investigation on nine patients with burns at the sites of E.C.G. electrodes, Becker et al.5 proposed the use of chokes, while the use of 10 Kohm resistors in series with monitoring leads is advised in a B.S.I. draft standard on
Sections of the
ascending arch, thoracic arch, abdominal arch, region of the heart, and liver were fixed in formol saline, and paraffin sections were stained with hsematoxylin and eosin and Verhoeff’s iron hxmatoxylin. At necropsy, the severity of aortic atherosclerosis was graded grossly on a scale of 0 to 4+, according to the technique of Horlick and Duff.13 Grade 0 represents no or very minute macroscopically visible lesions, and is arbitrarily considered to represent involvement not exceeding 2 % of the total surface of the aortic intima. Grade 1 represents an average involvement of about 10%, grade 2 about 20%, grade 3 about 40%, and grade 4 about 80%. The group-i rabbits showed no atherosclerosis (grade 0), and the garlic-fed animals (group iv) showed Jain, R. C. M.D. thesis, University of Rajasthan, India, 1968. Jain, R. C., Andleigh, H. S. Br. med. J. 1969, i, 514. Jain, R. C. J. Ass. Physns Ind. 1971, 19, 305. Jain, R. C. ibid. p. 301. 5. Jain, R. C. ibid. 1973, 21, 357. 6. Jain, R. C. Ind. J. med. Sci. 1971, 25, 601. 7. Jain, R. C. ibid. p. 598. 8. Jain, R. C. ibid. p. 236. 9. Jain, R. C., Sachdev, K. N. J. med. Prof. Ind. 1971, 27, 7991. 10. Jain, R. C., Sachdev, K. N. Curr. med. Pract. 1971, 15, 274. 11. Jain, R. C., Vyas, C. R. Lancet, 1973, ii, 1491. 12. Jain, R. C., Vyas, C. R. Br. med. J. 1974, i, 730. 13. Horlick, L., Duff, G. L. Archs Path. 1954, 57, 417. 14. Kim, E., Goldberg, M. Clin. Chem. 1962, 15, 1172. 1. 2. 3. 4.
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6
surgical diathermy equipment.
cannot agree with Mr Bond’s second recommendation which involves the use of a saline-soaked sheet under the patient. A conventional diathermy plate electrode properly applied has an impedance of about 4 ohms only, and its area of approximately 400 sq.cm.-600 sq.cm. (depending on type) allows for the passage of the largest r.f. currents used in surgery with a large safety factor. My colleague, Dobbie 7,has reported on the production of " burns " due to the use of saline-soaked material in contact with the patient. There are a number of technical inaccuracies in Mr Bond’s letter which in the interest of brevity I cannot discuss in detail. Suffice it that:
However, I
coronary artery, middle
I
(1) Plate electrodes of diathermy equipment must not be connected directly to earth, since this practice considerably increases the risk of electric shock should other equipment connected to the patient become defective.9 References to the " earth contact " when discussing diathermy plate electrodes are therefore to be deprecated. 1. Bond, W. H. Lancet, April 12, 1975, p. 852. 2. Brennand, R. Technical Repair and Development Section 248MU, report No. 47, Royal Air Force, Chessington. 1954. 3. Department of Health and Social Security. Specification for a General Purpose ECG Monitor, TSS/EM/10002, 1970. 4. Department of Health and Social Security. Specification for Patient Monitoring Equipment for Intensive Therapy Units, TSS EM 100021, 1972. 5. Becker, C. M., et al. Anesthesiology, 1973, 38, 106. 6. British Standards Institute. Draft British Standard Specification for Surgical Diathermy Equipment, 73/6266, 1973. 7. Dobbie, A. K. D. Natnews, 1974, 11, 10. 8. Dobbie, A. K. D. Biomed. Engng, 1969, 5, 206. 9. Hospital Technical Memorandum no. 8, 1969. H.M. Stationery Office.
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ONION
AND GARLIC IN EXPERIMENTAL
less atherosclerotic involvement than the other cholesterolfed groups (see table). A fair degree of correlation between biochemical and histopathological findings was noted. Higher levels of serum-cholesterol and more severe atherosclerotic lesions were seen in groups 11 and III, whereas lower levels of serum-cholesterol and less extensive atherosclerotic involvement was found in group iv. Group-! animals, which were fed only a basic diet without any supplementation, showed normal serum-lipids and .no atherosclerosis. Thus, administration of onion to cholesterol-fed rabbits did not lower cholesterol levels or inhibit the development of atherosclerosis. However, supplementation of garlic to the rabbits fed with cholesterol resulted in significantly lower cholesterol levels and less atherosclerosis. Department of Pathology, University of Benghazi, Benghazi, Libya.
ATHEROSCLEROSIS
SIR,-Onion and garlic are said to possess hypoglycaemic and hypolipsemic activities and may have an inhibitory effect on atherosclerosis. 1-12 The present study investigates the role of onion and garlic in cholesterol-induced atherosclerosis in rabbits. 40 male albino rabbits weighing 1-1-5 kg. were divided into 4 groups of 10. Group I received stock diet (green vegetables, green grass, bengal gram, milk powder, and green feeder) and served as controls. Groups II, III, and iv were fed with stock diet plus 0-5 g. cholesterol in 5 ml. of olive oil. In addition, group III were given 10 ml. of juice from raw onion bulbs, and group iv had 10 ml. of garlic juice, both in distilled water. The cholesterol suspension and the onion and garlic juices were fed through an intragastric tube for 16 weeks. Total serumcholesterol was estimated by the method of Kim and Goldberg " in all the animals before and after the experiment. All the animals were killed after 16 weeks. At necropsy gross examination was made for visible lesions of the heart, aorta, and liver. EFFECT OF ONION AND GARLIC ON TOTAL SERUM-CHOLESTEROL AND GRADING OF EXPERIMENTAL AORTIC ATHEROSCLEROSIS IN RABBITS
R. C.
JAIN.
ELECTRICAL HAZARDS OF DISPOSABLE MONITORING ELECTRODES
SiR,—The use of resistors in series with monitoring electrode leads has been proposed by Mr Bond.l Although a worth-while measure which is likely to reduce the risk of . burns at the sites of monitoring electrodes, the idea is by no means new.
The incorporation of 10 Kohm resistors in the patient leads of E.c.G.s used by the Medical Service of the Royal Air Force was specified some ten years ago after an earlier investigation into the safety aspects of diathermy, as a result of which the use of radiofrequency chokes in monitoring leads was recommended.2 More recently protective resistors have been required in Department of Health and Social Security specifications for monitoring equipment.3,4 Reporting an investigation on nine patients with burns at the sites of E.C.G. electrodes, Becker et al.5 proposed the use of chokes, while the use of 10 Kohm resistors in series with monitoring leads is advised in a B.S.I. draft standard on
Sections of the
ascending arch, thoracic arch, abdominal arch, region of the heart, and liver were fixed in formol saline, and paraffin sections were stained with hsematoxylin and eosin and Verhoeff’s iron hxmatoxylin. At necropsy, the severity of aortic atherosclerosis was graded grossly on a scale of 0 to 4+, according to the technique of Horlick and Duff.13 Grade 0 represents no or very minute macroscopically visible lesions, and is arbitrarily considered to represent involvement not exceeding 2 % of the total surface of the aortic intima. Grade 1 represents an average involvement of about 10%, grade 2 about 20%, grade 3 about 40%, and grade 4 about 80%. The group-i rabbits showed no atherosclerosis (grade 0), and the garlic-fed animals (group iv) showed Jain, R. C. M.D. thesis, University of Rajasthan, India, 1968. Jain, R. C., Andleigh, H. S. Br. med. J. 1969, i, 514. Jain, R. C. J. Ass. Physns Ind. 1971, 19, 305. Jain, R. C. ibid. p. 301. 5. Jain, R. C. ibid. 1973, 21, 357. 6. Jain, R. C. Ind. J. med. Sci. 1971, 25, 601. 7. Jain, R. C. ibid. p. 598. 8. Jain, R. C. ibid. p. 236. 9. Jain, R. C., Sachdev, K. N. J. med. Prof. Ind. 1971, 27, 7991. 10. Jain, R. C., Sachdev, K. N. Curr. med. Pract. 1971, 15, 274. 11. Jain, R. C., Vyas, C. R. Lancet, 1973, ii, 1491. 12. Jain, R. C., Vyas, C. R. Br. med. J. 1974, i, 730. 13. Horlick, L., Duff, G. L. Archs Path. 1954, 57, 417. 14. Kim, E., Goldberg, M. Clin. Chem. 1962, 15, 1172. 1. 2. 3. 4.
I I I
6
surgical diathermy equipment.
cannot agree with Mr Bond’s second recommendation which involves the use of a saline-soaked sheet under the patient. A conventional diathermy plate electrode properly applied has an impedance of about 4 ohms only, and its area of approximately 400 sq.cm.-600 sq.cm. (depending on type) allows for the passage of the largest r.f. currents used in surgery with a large safety factor. My colleague, Dobbie 7,has reported on the production of " burns " due to the use of saline-soaked material in contact with the patient. There are a number of technical inaccuracies in Mr Bond’s letter which in the interest of brevity I cannot discuss in detail. Suffice it that:
However, I
coronary artery, middle
I
(1) Plate electrodes of diathermy equipment must not be connected directly to earth, since this practice considerably increases the risk of electric shock should other equipment connected to the patient become defective.9 References to the " earth contact " when discussing diathermy plate electrodes are therefore to be deprecated. 1. Bond, W. H. Lancet, April 12, 1975, p. 852. 2. Brennand, R. Technical Repair and Development Section 248MU, report No. 47, Royal Air Force, Chessington. 1954. 3. Department of Health and Social Security. Specification for a General Purpose ECG Monitor, TSS/EM/10002, 1970. 4. Department of Health and Social Security. Specification for Patient Monitoring Equipment for Intensive Therapy Units, TSS EM 100021, 1972. 5. Becker, C. M., et al. Anesthesiology, 1973, 38, 106. 6. British Standards Institute. Draft British Standard Specification for Surgical Diathermy Equipment, 73/6266, 1973. 7. Dobbie, A. K. D. Natnews, 1974, 11, 10. 8. Dobbie, A. K. D. Biomed. Engng, 1969, 5, 206. 9. Hospital Technical Memorandum no. 8, 1969. H.M. Stationery Office.
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