- Email: [email protected]
DRUGS AGAINST VIRUSES
675
lymphocyte comparable to that in patients with sarcoidosis,5 Sjogren’s syndrome,6 or ataxia-telangiectasia. This is supported by the failure to find in-vivo evidence of impaired delayed hypersensitivity in M.S.8 A serum-factor inhibiting lymphocyte stimulation has been demonstrated in patients with active tuberculosis,9 and may be comparable to the factor found in M.S. serum. In view of our new findings the suggestion4 that cellular impairment in patients with M.S. might be due to lymphocytes infected with virus, as in
unlikely. The mechanism by which inhibitory
rubella,lo
We wish to thank the neurologists of the Royal Victoria Infirmary and Newcastle General Hospital for permission to study their patients; and Mr. E. A. Caspary for assistance with scintillation techniques. M.S. is in receipt of a Wellcome Trust research fellowship. Medical Research Council Diseases Unit. Newcastle upon Tyne 2.
Demyelinating
MICHAEL SAUNDERS MALCOLM KNOWLES E. J. FIELD.
CANNABIS AND CHROMOSOMES
SIR,-The letter from Miss Martin (Feb. 15, p. 370) prompts describe some of our present studies on the possible effects on cultures of human leucocytes in vitro. Isbell et al.15 have shown that the euphoric and psychotomimetic activities of Cannabis sativa are due to the tetrahydrocannabinol (T.H.C.) fraction of the resin produced by the plant. We made leucocyte cultures from four healthy adult subjects (3 men and 1 woman) with normal karyotypes, and added (-)-trans-A8-T.H.c. during the last 24 hours of the culturing period to give final concentrations of 20, 30, 35, and 40 (.Lg. per ml. Absolute ethanol was used as the solvent for T.H.C. Earlier control experiments had shown that these amounts of ethanol used in leucocyte cultures did not inhibit mitosis or cause any chromosomal aberrations. Control cultures were set up containing the same amount of ethanol as was present in each of the A8-T.H.C. cultures. Thirty metaphases were examined from each culture. Fewer metaphases were available for analysis in cultures with the higher A8-T.H.C. concentrations because of a decreased mitotic index. No more than 5% of the metaphases in the control cultures and in those cultures exposed to 8-T.H.C. had gaps or breaks. This represents no more chromosomal us to
8-tetrahydrocannabinol
5.
Buckley, C. E., Nagaya, H., Sieker, H. O. Ann. intern. Med. 1966, 64,
6. 7. 8.
Leventhal, B. G., Waldorf, D. S., Talal, N. J. clin. Invest. 1967, 46, 1338. Leikin, S. L., Bazilon, N. M., Park, K. I. J. Pediat. 1966, 68, 477. Johnson, R. T., Miller, H. G. J. Neurol. Neurosurg. Psychiat. 1963, 26,
9.
Heilman, D. H., Macfarland, W. Int. Archs Allergy appl. Immun. 1966, 30, 58. Olson, G. B., Dent, P. B., Rawls, W. E., South, M. A., Montgomery, J. R., Melnik, J. L., Good, R. A. J. exp. Med. 1968, 128, 47. Michalowsky, A., Jasinska, J., Brzosko, W. J., Nowoslawski, A. Expl. Cell Res. 1964, 34, 417. Razavi, L. Nature, Lond. 1966, 210, 444. Rieke, W. O. Lymphocyte Workshop. Washington, 1965. Field, E. J., Green, C. A., Miller, H. G. J. Neurol. Neurosurg. Psychiat. 1961, 24, 78. Isbell, H., Gorodetzsky, C. W., Jasinski, D., Claussen, U., von Spulak, F., Korte, F. Psychopharmacologia, 1967, 11, 184.
508.
151.
10. 11. 12. 13. 14. 15.
are
observed in cultures from normal, healthy changes other than the few gaps and
breaks
were
found.
This study was aided by grants AM-02504, Tl-AM-5277, and 5-TO-2-CH-1081 from the National Institutes of Health, United States Public Health Service. H. 0. P. is a postdoctoral trainee of the National Institute of Arthritis and Metabolic Diseases. The T.H.C. used in this experiment was obtained through the courtesy of Dr. John A. Scigliano of the National Institute of Mental Health
(batch ADL-15886-17, 99-0±0-2% 8-T.H.C.).
seems
serum-factors impair the action of P.H.A. is unknown. Studies on cell localisation of P.H.A. have been inconclusive. Most workers have demonstrated its presence in the cell-either in the nucleus,"’ or in the cytoplasm.12 On the other hand Rieke 13 found that P.H.A. was localised to cell membranes and to a lesser extent within the cytoplasm. Inhibitory serum-factor could act by preventing P.H.A. binding to non-specific cell-membrane sites, or impeding entry into the cell itself. The presence of a serum-factor able to damp down the account for reduced antibody activity of lymphocytes might 14 in M.S. and production patients might interfere with defence a viral A longitudinal study to infection. against persistent find out whether the degree of inhibitory activity of serum is correlated with clinical activation of the disease would be of interest.
of
aberrations than
persons. No structural
Genetic and Endocrine Unit, Department of Pediatrics, State University of New York, Upstate Medical Center, Syracuse, New York 13210.
RICHARD L. NEU HAROLD O. POWERS SADDIE KING LYTT I. GARDNER.
DRUGS AGAINST VIRUSES question the statement"in your leading article (March 15, p. 559) that idoxuridine is too toxic for systemic use." In a recent paper1 this agent was employed in a case of congenital cytomegalovirus infection in a total dose of 600 mg. per kg. of body-weight. There was a transient depression of the white-cell and platelet counts and no hepatic damage on assessment by standard liver-function tests. There was a striking and sustained decrease in the excretion of virus. At the present stage of our knowledge it would seem a pity not to consider using this drug in severe and life-threatening D.N.A.virus infections. Doncaster Royal Infirmary, ALAN F. CONCHIE. Yorks.
SIR,-I
must
WHERE ARE THE TEACHERS OF COMMUNITY
MEDICINE ? SIR,-Many of them have gone to North America. Gibson2 counted 28 British and Irish graduates holding full-time or part-time academic positions in U.S.A. or Canada in July, 1965. Since then the brain-drain in this specialty has continued. To my knowledge at least 5 other very able teachers of community medicine have gone to North America in the past four years. At Sept. 30, 1967, there were 13 incumbents of chairs of social
medicine, public health, epidemiology, preventive medicine, and industrial health in Great Britain.3 The British-trained teachers of preventive medicine and related subjects personally known to me who hold full chairs in North America number 14. I doubt whether any other academic discipline can match this record. The position seems to me unlikely to improve unless terms and conditions of appointment and opportunities for promotion to senior oositions are reaooraised in Britain. University Department of Social Medicine, J. M. LAST. Edinburgh 9.
SIR,-Not the least of the objections to the term " community is that it is ungrammatical, since the word com-
medicine
"
"
and not an adjective. A more important number of adequate terms already exist. " Social medicine " is the generally accepted British term for the branch of medical science that is concerned with the investigation of the determinants of the health of populations, while " public health " is the internationally recognised term for the branch of medical practice that is concerned with the maintenance and promotion of the health of populations. If an internationally acceptable term is required to embrace both practical and investigational activities in this field then the term " public health " would surely be the best choice. University Department of Social and Preventive Medicine, ALWYN SMITH. Manchester M13 OJJ.
munity " is objection is
1. 2. 3.
a noun
that
a
Conchie, A. F., Barton, B. W., Tobin, J. O’H. Br. med. J. 1968, iv, 162 Gibson, T. C. Br. med. J. 1967, i, 688. Royal Commission on Medical Education, 19656-8: Report, H.M Stationery Office, 1968.
lymphocyte comparable to that in patients with sarcoidosis,5 Sjogren’s syndrome,6 or ataxia-telangiectasia. This is supported by the failure to find in-vivo evidence of impaired delayed hypersensitivity in M.S.8 A serum-factor inhibiting lymphocyte stimulation has been demonstrated in patients with active tuberculosis,9 and may be comparable to the factor found in M.S. serum. In view of our new findings the suggestion4 that cellular impairment in patients with M.S. might be due to lymphocytes infected with virus, as in
unlikely. The mechanism by which inhibitory
rubella,lo
We wish to thank the neurologists of the Royal Victoria Infirmary and Newcastle General Hospital for permission to study their patients; and Mr. E. A. Caspary for assistance with scintillation techniques. M.S. is in receipt of a Wellcome Trust research fellowship. Medical Research Council Diseases Unit. Newcastle upon Tyne 2.
Demyelinating
MICHAEL SAUNDERS MALCOLM KNOWLES E. J. FIELD.
CANNABIS AND CHROMOSOMES
SIR,-The letter from Miss Martin (Feb. 15, p. 370) prompts describe some of our present studies on the possible effects on cultures of human leucocytes in vitro. Isbell et al.15 have shown that the euphoric and psychotomimetic activities of Cannabis sativa are due to the tetrahydrocannabinol (T.H.C.) fraction of the resin produced by the plant. We made leucocyte cultures from four healthy adult subjects (3 men and 1 woman) with normal karyotypes, and added (-)-trans-A8-T.H.c. during the last 24 hours of the culturing period to give final concentrations of 20, 30, 35, and 40 (.Lg. per ml. Absolute ethanol was used as the solvent for T.H.C. Earlier control experiments had shown that these amounts of ethanol used in leucocyte cultures did not inhibit mitosis or cause any chromosomal aberrations. Control cultures were set up containing the same amount of ethanol as was present in each of the A8-T.H.C. cultures. Thirty metaphases were examined from each culture. Fewer metaphases were available for analysis in cultures with the higher A8-T.H.C. concentrations because of a decreased mitotic index. No more than 5% of the metaphases in the control cultures and in those cultures exposed to 8-T.H.C. had gaps or breaks. This represents no more chromosomal us to
8-tetrahydrocannabinol
5.
Buckley, C. E., Nagaya, H., Sieker, H. O. Ann. intern. Med. 1966, 64,
6. 7. 8.
Leventhal, B. G., Waldorf, D. S., Talal, N. J. clin. Invest. 1967, 46, 1338. Leikin, S. L., Bazilon, N. M., Park, K. I. J. Pediat. 1966, 68, 477. Johnson, R. T., Miller, H. G. J. Neurol. Neurosurg. Psychiat. 1963, 26,
9.
Heilman, D. H., Macfarland, W. Int. Archs Allergy appl. Immun. 1966, 30, 58. Olson, G. B., Dent, P. B., Rawls, W. E., South, M. A., Montgomery, J. R., Melnik, J. L., Good, R. A. J. exp. Med. 1968, 128, 47. Michalowsky, A., Jasinska, J., Brzosko, W. J., Nowoslawski, A. Expl. Cell Res. 1964, 34, 417. Razavi, L. Nature, Lond. 1966, 210, 444. Rieke, W. O. Lymphocyte Workshop. Washington, 1965. Field, E. J., Green, C. A., Miller, H. G. J. Neurol. Neurosurg. Psychiat. 1961, 24, 78. Isbell, H., Gorodetzsky, C. W., Jasinski, D., Claussen, U., von Spulak, F., Korte, F. Psychopharmacologia, 1967, 11, 184.
508.
151.
10. 11. 12. 13. 14. 15.
are
observed in cultures from normal, healthy changes other than the few gaps and
breaks
were
found.
This study was aided by grants AM-02504, Tl-AM-5277, and 5-TO-2-CH-1081 from the National Institutes of Health, United States Public Health Service. H. 0. P. is a postdoctoral trainee of the National Institute of Arthritis and Metabolic Diseases. The T.H.C. used in this experiment was obtained through the courtesy of Dr. John A. Scigliano of the National Institute of Mental Health
(batch ADL-15886-17, 99-0±0-2% 8-T.H.C.).
seems
serum-factors impair the action of P.H.A. is unknown. Studies on cell localisation of P.H.A. have been inconclusive. Most workers have demonstrated its presence in the cell-either in the nucleus,"’ or in the cytoplasm.12 On the other hand Rieke 13 found that P.H.A. was localised to cell membranes and to a lesser extent within the cytoplasm. Inhibitory serum-factor could act by preventing P.H.A. binding to non-specific cell-membrane sites, or impeding entry into the cell itself. The presence of a serum-factor able to damp down the account for reduced antibody activity of lymphocytes might 14 in M.S. and production patients might interfere with defence a viral A longitudinal study to infection. against persistent find out whether the degree of inhibitory activity of serum is correlated with clinical activation of the disease would be of interest.
of
aberrations than
persons. No structural
Genetic and Endocrine Unit, Department of Pediatrics, State University of New York, Upstate Medical Center, Syracuse, New York 13210.
RICHARD L. NEU HAROLD O. POWERS SADDIE KING LYTT I. GARDNER.
DRUGS AGAINST VIRUSES question the statement"in your leading article (March 15, p. 559) that idoxuridine is too toxic for systemic use." In a recent paper1 this agent was employed in a case of congenital cytomegalovirus infection in a total dose of 600 mg. per kg. of body-weight. There was a transient depression of the white-cell and platelet counts and no hepatic damage on assessment by standard liver-function tests. There was a striking and sustained decrease in the excretion of virus. At the present stage of our knowledge it would seem a pity not to consider using this drug in severe and life-threatening D.N.A.virus infections. Doncaster Royal Infirmary, ALAN F. CONCHIE. Yorks.
SIR,-I
must
WHERE ARE THE TEACHERS OF COMMUNITY
MEDICINE ? SIR,-Many of them have gone to North America. Gibson2 counted 28 British and Irish graduates holding full-time or part-time academic positions in U.S.A. or Canada in July, 1965. Since then the brain-drain in this specialty has continued. To my knowledge at least 5 other very able teachers of community medicine have gone to North America in the past four years. At Sept. 30, 1967, there were 13 incumbents of chairs of social
medicine, public health, epidemiology, preventive medicine, and industrial health in Great Britain.3 The British-trained teachers of preventive medicine and related subjects personally known to me who hold full chairs in North America number 14. I doubt whether any other academic discipline can match this record. The position seems to me unlikely to improve unless terms and conditions of appointment and opportunities for promotion to senior oositions are reaooraised in Britain. University Department of Social Medicine, J. M. LAST. Edinburgh 9.
SIR,-Not the least of the objections to the term " community is that it is ungrammatical, since the word com-
medicine
"
"
and not an adjective. A more important number of adequate terms already exist. " Social medicine " is the generally accepted British term for the branch of medical science that is concerned with the investigation of the determinants of the health of populations, while " public health " is the internationally recognised term for the branch of medical practice that is concerned with the maintenance and promotion of the health of populations. If an internationally acceptable term is required to embrace both practical and investigational activities in this field then the term " public health " would surely be the best choice. University Department of Social and Preventive Medicine, ALWYN SMITH. Manchester M13 OJJ.
munity " is objection is
1. 2. 3.
a noun
that
a
Conchie, A. F., Barton, B. W., Tobin, J. O’H. Br. med. J. 1968, iv, 162 Gibson, T. C. Br. med. J. 1967, i, 688. Royal Commission on Medical Education, 19656-8: Report, H.M Stationery Office, 1968.