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PLASMA-CORTISOL AND VASOPRESSIN
1301
niques and patterns of behaviour that are no longer applicable today, however valuable they may have been in the past. Health
Department, Darlington.
JOSEPH V. WALKER.
THE DIGITAL COMPUTER SIR,-It is difficult to believe that in a properly programmed computer the range of stored information and the efficiency of its retrieval and correlation will not be greater than in the recollected experience of the wisest of doctors. If this is so, the computer has an assured future in medicine. Its chief value may not be in diagnosis, but if properly used-and adequate and intelligent programming will always be the kernel of the problem-it may be in just Sir Robert Platt’s Pasbaltod (" patients already seen by at least three other doctors ") type of syndrome (Nov. 27) that help will be given. A manifest lacuna in the evidence may imply the need to search for the unobserved sign or symptom. When the computer has become another invaluable handmaiden to medicine, we may wonder why this was allowed to take so long. Department of Neurology, Radcliffe Infirmary, Oxford.
C. W. M. WHITTY.
INDUCED ALLERGIC ENCEPHALOMYELITIS SIR,-We have shown1 increased monoamine-oxidase (M.A.O.) activity in the brain and spinal cord of animals with experimental allergic encephalomyelitis (E.A.E.). To clarify the role played by this enzyme, particularly in the pathogenesis of E.A.E. and generally in hypersensitivity reactions, we studied the influence of M.A.O. inhibitors on E.A.E. induced in guineapigs, weighing 250-300 g., by a intradermal injection of heterologous brain homosingle genate, emulsified as previously described,2 in Freund’s complete adjuvant. The animals were examined daily for a month before the inoculation and were fed according to a standard diet. The M.A.o. inhibitor we used was nialamide (’Niamid ’, Pfizer). 45 mg. per kg. of the drug was injected
increase of lipase and protease activity in E.A.E.3 Reserpine suppresses E.A.E. in rats, acting upon the thymus,4 but hasat least in some animals-an action contrary to nialamide. There may be differences in the role played by M.A.O. in the pathogenesis of E.A.E. and by M.A.O. inhibitors in inhibiting this disease in various species; in chickens, reserpine has a less suppressive effect.4 The similarity between E.A.E. and multiple sclerosis suggests the use of M.A.O. inhibitors in the treatment of the latter disease. The part played by M.A.O. inhibitors in other manifestations of delayed-type hypersensitivity (autoimmune disease and homograft rejection) should be investigated. MARCEL SARAGEA Department of Pathological Physiology, ADRIAN VLĂDUTIU. Institute of Medicine, Bucharest.
PLASMA-CORTISOL AND VASOPRESSIN
SIR,-The work reported by Dr. Landon and his colleagues (Dec. 4) further establishes the value of vasopressin in the assessment of pituitary function. It seems from our experience in patients admitted to the endocrine unit of the London Hospital that for practical purposes measurement of the rise in plasma-cortisol level, an hour after the intramuscular injection of 10 pressor units of aqueous pitressin, gives a good indication of pituitary-adrenal responsiveness.5 This test can conveniently be combined with measurement of diurnal variation in plasmacortisol levels by taking blood-samples at midnight and 8.30 A.M., then giving vasopressin, and taking a final blood-sample an hour later. The degree of diurnal variation gives additional evidence of pituitary activity; and if, as appears likely, this variation is dependent on hypothalamic integrity, such a simple test should also help to differentiate between hypothalamic and pituitary causes of deficient corticotrophin production.
E.A.E. was
daily, intraperitoneally. Two groups of 15 guineapigs were inoculated with encephalitogenic emulsion. The first group (control) was injected daily with saline, while the second group was injected daily with nialamide, starting from the day of encephalitogenic inoculation. The animals were examined daily, and those with obvious symptoms of E.A.E. (paresis or paralysis) were killed on the day of onset of symptoms. All the surviving animals were killed on the 21st day after inoculation with encephalitogenic emulsion, and the brains
were
removed for
Hospital, London, E.1.
The following results indicate that nialamide inhibits E.A.E. guineapigs-animals which are very susceptible to this disease, and in which E.A.E. may be readily produced by a single intracutaneous injection of encephalitogenic emulsion (waterin-oil emulsion of whole central-nervous-system tissue and killed mycobacteria): in
The mechanism by which nialamide inhibits E.A.E. is closely related to the role of M.A.O. in the pathogenesis of this disease. The increase of M.A.O. activity seems to be subordinate to serotonin release, but may also be a primary feature, like the Saragea, M., Rotaru, N., Negru, T., Vlădutiu, A. Nature, Lond. 1965, 206, 306. 2. Saragea, M., Vlădutiu, A., Negru, T., Rotaru, N. Spitalul, 1965, 18, 22.
P. CANNON.
DETECTION OF RENOVASCULAR HYPERTENSION Dr. A. C. KENNEDY and Mr. W. BARR STIRLING
(University
Department of Medicine, Royal Infirmary, Glasgow) write: With reference to our article (Nov. 13), we wish to record the help given by members of staff of the hypertension unit of the department of cardiology in the referral of a considerable "
number of patients."-ED. L.
Public Health
microscopic examination.
In the control group 11 animals showed symptoms of E.A.E. between the 12th and the 18th day after inoculation. In the nialamide-treated group 2 guineapigs exhibited signs of encephalomyelitis, and 2 died without symptoms of E.A.E., but with characteristic lesions in the brain.
1.
London
Movements in Population
FIGURES, taken from the 1961 Census of England and Wales, on movements in the population have now been published. Part I of the Migration National Summary Tables6 reveals that, at the time of the Census, 11 % of the population sample had lived at their current residence for less than a year; this group were " migrants " as defined in the Census. At the other end of the scale, 20% had lived in the same home for more than fifteen years. Part 11 analyses the 11% migrant group in terms of direction of migration within England and Wales. In general the balance of migration is small compared with the gross movements-e.g., there were 58,000 migrants to the Midland region while 59,000 people left this region. The most notable changes were in the London and South Eastern region with a net loss of 59,000 and the Eastern and Southern regions with net gains of 45,000 and 28,000 3. 4.
Benetato, G., Gabrielescu, E., Boros, I. Studii. Cerc. fiziol. 1964, 9, 87. Janković, B. D., Drăskoci, M., Paunovic, D., Popesković, L. Nature, Lond. 204, 1101. 5. Gwinup, G. Lancet, Sept. 18, 1965, p. 572. 6. Census 1961 England and Wales. Migration National Summary Tables: part I, pp. 34, 4s. 6d.; part II, pp. 59, 4s. H.M. Stationery Office, 1965.
niques and patterns of behaviour that are no longer applicable today, however valuable they may have been in the past. Health
Department, Darlington.
JOSEPH V. WALKER.
THE DIGITAL COMPUTER SIR,-It is difficult to believe that in a properly programmed computer the range of stored information and the efficiency of its retrieval and correlation will not be greater than in the recollected experience of the wisest of doctors. If this is so, the computer has an assured future in medicine. Its chief value may not be in diagnosis, but if properly used-and adequate and intelligent programming will always be the kernel of the problem-it may be in just Sir Robert Platt’s Pasbaltod (" patients already seen by at least three other doctors ") type of syndrome (Nov. 27) that help will be given. A manifest lacuna in the evidence may imply the need to search for the unobserved sign or symptom. When the computer has become another invaluable handmaiden to medicine, we may wonder why this was allowed to take so long. Department of Neurology, Radcliffe Infirmary, Oxford.
C. W. M. WHITTY.
INDUCED ALLERGIC ENCEPHALOMYELITIS SIR,-We have shown1 increased monoamine-oxidase (M.A.O.) activity in the brain and spinal cord of animals with experimental allergic encephalomyelitis (E.A.E.). To clarify the role played by this enzyme, particularly in the pathogenesis of E.A.E. and generally in hypersensitivity reactions, we studied the influence of M.A.O. inhibitors on E.A.E. induced in guineapigs, weighing 250-300 g., by a intradermal injection of heterologous brain homosingle genate, emulsified as previously described,2 in Freund’s complete adjuvant. The animals were examined daily for a month before the inoculation and were fed according to a standard diet. The M.A.o. inhibitor we used was nialamide (’Niamid ’, Pfizer). 45 mg. per kg. of the drug was injected
increase of lipase and protease activity in E.A.E.3 Reserpine suppresses E.A.E. in rats, acting upon the thymus,4 but hasat least in some animals-an action contrary to nialamide. There may be differences in the role played by M.A.O. in the pathogenesis of E.A.E. and by M.A.O. inhibitors in inhibiting this disease in various species; in chickens, reserpine has a less suppressive effect.4 The similarity between E.A.E. and multiple sclerosis suggests the use of M.A.O. inhibitors in the treatment of the latter disease. The part played by M.A.O. inhibitors in other manifestations of delayed-type hypersensitivity (autoimmune disease and homograft rejection) should be investigated. MARCEL SARAGEA Department of Pathological Physiology, ADRIAN VLĂDUTIU. Institute of Medicine, Bucharest.
PLASMA-CORTISOL AND VASOPRESSIN
SIR,-The work reported by Dr. Landon and his colleagues (Dec. 4) further establishes the value of vasopressin in the assessment of pituitary function. It seems from our experience in patients admitted to the endocrine unit of the London Hospital that for practical purposes measurement of the rise in plasma-cortisol level, an hour after the intramuscular injection of 10 pressor units of aqueous pitressin, gives a good indication of pituitary-adrenal responsiveness.5 This test can conveniently be combined with measurement of diurnal variation in plasmacortisol levels by taking blood-samples at midnight and 8.30 A.M., then giving vasopressin, and taking a final blood-sample an hour later. The degree of diurnal variation gives additional evidence of pituitary activity; and if, as appears likely, this variation is dependent on hypothalamic integrity, such a simple test should also help to differentiate between hypothalamic and pituitary causes of deficient corticotrophin production.
E.A.E. was
daily, intraperitoneally. Two groups of 15 guineapigs were inoculated with encephalitogenic emulsion. The first group (control) was injected daily with saline, while the second group was injected daily with nialamide, starting from the day of encephalitogenic inoculation. The animals were examined daily, and those with obvious symptoms of E.A.E. (paresis or paralysis) were killed on the day of onset of symptoms. All the surviving animals were killed on the 21st day after inoculation with encephalitogenic emulsion, and the brains
were
removed for
Hospital, London, E.1.
The following results indicate that nialamide inhibits E.A.E. guineapigs-animals which are very susceptible to this disease, and in which E.A.E. may be readily produced by a single intracutaneous injection of encephalitogenic emulsion (waterin-oil emulsion of whole central-nervous-system tissue and killed mycobacteria): in
The mechanism by which nialamide inhibits E.A.E. is closely related to the role of M.A.O. in the pathogenesis of this disease. The increase of M.A.O. activity seems to be subordinate to serotonin release, but may also be a primary feature, like the Saragea, M., Rotaru, N., Negru, T., Vlădutiu, A. Nature, Lond. 1965, 206, 306. 2. Saragea, M., Vlădutiu, A., Negru, T., Rotaru, N. Spitalul, 1965, 18, 22.
P. CANNON.
DETECTION OF RENOVASCULAR HYPERTENSION Dr. A. C. KENNEDY and Mr. W. BARR STIRLING
(University
Department of Medicine, Royal Infirmary, Glasgow) write: With reference to our article (Nov. 13), we wish to record the help given by members of staff of the hypertension unit of the department of cardiology in the referral of a considerable "
number of patients."-ED. L.
Public Health
microscopic examination.
In the control group 11 animals showed symptoms of E.A.E. between the 12th and the 18th day after inoculation. In the nialamide-treated group 2 guineapigs exhibited signs of encephalomyelitis, and 2 died without symptoms of E.A.E., but with characteristic lesions in the brain.
1.
London
Movements in Population
FIGURES, taken from the 1961 Census of England and Wales, on movements in the population have now been published. Part I of the Migration National Summary Tables6 reveals that, at the time of the Census, 11 % of the population sample had lived at their current residence for less than a year; this group were " migrants " as defined in the Census. At the other end of the scale, 20% had lived in the same home for more than fifteen years. Part 11 analyses the 11% migrant group in terms of direction of migration within England and Wales. In general the balance of migration is small compared with the gross movements-e.g., there were 58,000 migrants to the Midland region while 59,000 people left this region. The most notable changes were in the London and South Eastern region with a net loss of 59,000 and the Eastern and Southern regions with net gains of 45,000 and 28,000 3. 4.
Benetato, G., Gabrielescu, E., Boros, I. Studii. Cerc. fiziol. 1964, 9, 87. Janković, B. D., Drăskoci, M., Paunovic, D., Popesković, L. Nature, Lond. 204, 1101. 5. Gwinup, G. Lancet, Sept. 18, 1965, p. 572. 6. Census 1961 England and Wales. Migration National Summary Tables: part I, pp. 34, 4s. 6d.; part II, pp. 59, 4s. H.M. Stationery Office, 1965.