1301 in ampoules both with and without water. However, it should be pointed out that when the small amount of water (0.5 ml.) is converted to steam and mixed with the air which is also sealed in the tube, a very poor sterilising mixture occurs. While this mixture quickly’changes the markings on the tape, it does not approach the saturated (almost wet) steam required for efficient sterilisation. We submit that while both the glass-tube-type controls and the Bowie-Dick test are useful for pointing out certain types of mechanical malfunction and human error, even the combination of tests does not prove " sterilisation ". There seems to be a tendency in some hospitals to place too much reliance on various devices and too little reliance on adequate training of steriliser operators and thorough maintenance of equipment. An extrapolation of Morris and Everall’s experiment can be used as an excellent training device for autoclave operators. A Diack tube is wrapped in a few layers of cloth, then placed in an ordinary drinking tumbler which is, in turn, placed upright in an ordinary downward displacement steriliser. After processing through a normal cycle, the tube is examined and the pellet found to be unaffected. This illustrates air entrapment even though the top of the tumbler is unsealed. If a small amount of water is added, or if the tumbler is turned on its side before autoclaving, the pellet will melt as it should. This dramatically illustrates the danger of the common error of attempting to sterilise closed containers in an upright position, a frequent mistake. Smith and Underwood Laboratories,
for the local hospitals (8 deaths and 1 other relapse among 14) indicates that although the two groups had similar overall relapse-rates, the death-rate for the special centres was significantly lower than for the others. Given the small numbers, the limited extent of the analysis by outcome, and the discrepancy between the death and other relapse rates, the data as they stand can hardly be said either to strengthen or to weaken the case for centralising the treatment of childhood leukaemia. Regional Cancer Epidemiology Unit, Christie Hospital and Holt Radium Institute,
IAN LECK.
Manchester M20 9BX.
DEANOL IN SPONTANEOUS AND INDUCED DYSKINESIAS SIR,-In the hope of controlling abnormal movements in Huntington’s chorea, the levodopa-induced dyskinesias, and the late dyskinesias provoked by phenothiazines, some authors l,2 have used a presumed precursor of acetylcholine, 2-dimethylaminoethanol (deanol), which crosses the blood-brain barrier. Results with 300-900 mg. daily were so interesting that they prompted us to give the drug to 25 patients with dyskinesias of various kinds. Tablets of 75 mg. of dimethylaminoethanol-p-acetylaminobenzoate were used and the number of tablets was gradually increased from 3 to 12, in three equal doses a day. In the senile
1023 Troy
Court, Troy, Michigan 48084, U.S.A.
EFFECT OF DEANOL ON DYSKINESIAS
ROBERT F. SMITH.
MIXED VENOUS AND ARTERIAL
PCO2
of the rebreathing method SIR,-In on 100 consecutive patients the venoarterial CO2 tension difference was measured on paired venous and arterial blood-samples as reported by Lesh et al.l Results were in close accord with a new formula Paco2=0-8 PvC02 given by McEvoy et al.2 I prefer blood-gas analysis to the rebreathing method. One need only use arm venous blood to obtain a fairly accurate arterial PCo2 value. a
recent assessment
+ improvement. 0 no effect.
25 Lon Derw,
Abergele, Clwyd LL22 7EA.
WALTER LESH.
-
aggravation.
and
MEDICAL CARE OF CHILDHOOD LEUKÆMIA
SIR,-Dr McCarthy’s paper (May 17, p. 1128) comparing the results achieved by special centres and district general hospitals in treating childhood leukaemia is to be welcomed as an attempt to provide objective data of the kind on which the regional planning of cancer services should be based; but he goes beyond the evidence of his data on survival when he concludes that the policy in childhood leukaemia should be " to improve treatment regimens at local hospitals rather than attempt to concentrate care at a few centres ". The one objective finding cited in support of this view was that " the survival of children given optimal regimens at local hospitals was equivalent to thatof two of the three special centres ". However, among the children with acute lymphatic leukaemia in this series (who included all the survivors) only 10 were treated at these two centres; the 10 did not differ significantly in terms of survival or relapse from those treated at the third special centre; and a comparison between the figures for all three centres combined (4 deaths and 13 other relapses among 27 cases) and those 1. Lesh, W., Portwood, W. E., Morrison, J. B. Lancet, 1967, ii, 891. 2. McEvoy, J. D. S., Jones, N. L., Campbell, E. J. M. Br. med. J. 1974, iv, 687.
degenerative (Huntington) dyskinesias, the drug was given only after other therapy had been stopped. Treatment was continued for two weeks after the maximum dose was reached. The results are shown in the accompanying table. Evaluation was carried out at a dosage of 225 mg. per day and at 450-900 mg. per day. Transient improvement was observed in 6 patients; it persisted only in 1 patient. 7 patients became worse (6 with Huntington’s chorea and 1 with tardive dyskinesia); these patients had been previously treated successfully with tetrabenazine, and deterioration with deanol must be considered as a return to the pre-tetrabenazine state. In the 12 cases of levodopa-induced dyskinesias, deanol was a complete failure. Besides certain positive effects, such as an increase in alertness - in 8 patients, unpleasant side-effects were noted: gastrointestinal upset in 4 patients, asthma and tachycardia in 1 patient, and hypomania in 3 patients.
We
were
thus unable
to
confirm the benefits
reported
by other workers.3.4 Service de Neurologie-
Neurochirurgie, Université de Louvain,
Louvain, Belgium. 1. 2. 3. 4.
Walker, J. Miller, E. Miller, E. Casey, D.
E. CHRISTIAN LATERRE ERNEST FORTEMPS.
E., Hoehn, M., Sears, E., Lewis, J. Lancet, 1973, i, 1512. M. Neurology, 1974, 24, 116. M. New Engl. J. Med. 1974, 291, 796. E., Denney, D. ibid. p. 797.
for the local hospitals (8 deaths and 1 other relapse among 14) indicates that although the two groups had similar overall relapse-rates, the death-rate for the special centres was significantly lower than for the others. Given the small numbers, the limited extent of the analysis by outcome, and the discrepancy between the death and other relapse rates, the data as they stand can hardly be said either to strengthen or to weaken the case for centralising the treatment of childhood leukaemia. Regional Cancer Epidemiology Unit, Christie Hospital and Holt Radium Institute,
IAN LECK.
Manchester M20 9BX.
DEANOL IN SPONTANEOUS AND INDUCED DYSKINESIAS SIR,-In the hope of controlling abnormal movements in Huntington’s chorea, the levodopa-induced dyskinesias, and the late dyskinesias provoked by phenothiazines, some authors l,2 have used a presumed precursor of acetylcholine, 2-dimethylaminoethanol (deanol), which crosses the blood-brain barrier. Results with 300-900 mg. daily were so interesting that they prompted us to give the drug to 25 patients with dyskinesias of various kinds. Tablets of 75 mg. of dimethylaminoethanol-p-acetylaminobenzoate were used and the number of tablets was gradually increased from 3 to 12, in three equal doses a day. In the senile
1023 Troy
Court, Troy, Michigan 48084, U.S.A.
EFFECT OF DEANOL ON DYSKINESIAS
ROBERT F. SMITH.
MIXED VENOUS AND ARTERIAL
PCO2
of the rebreathing method SIR,-In on 100 consecutive patients the venoarterial CO2 tension difference was measured on paired venous and arterial blood-samples as reported by Lesh et al.l Results were in close accord with a new formula Paco2=0-8 PvC02 given by McEvoy et al.2 I prefer blood-gas analysis to the rebreathing method. One need only use arm venous blood to obtain a fairly accurate arterial PCo2 value. a
recent assessment
+ improvement. 0 no effect.
25 Lon Derw,
Abergele, Clwyd LL22 7EA.
WALTER LESH.
-
aggravation.
and
MEDICAL CARE OF CHILDHOOD LEUKÆMIA
SIR,-Dr McCarthy’s paper (May 17, p. 1128) comparing the results achieved by special centres and district general hospitals in treating childhood leukaemia is to be welcomed as an attempt to provide objective data of the kind on which the regional planning of cancer services should be based; but he goes beyond the evidence of his data on survival when he concludes that the policy in childhood leukaemia should be " to improve treatment regimens at local hospitals rather than attempt to concentrate care at a few centres ". The one objective finding cited in support of this view was that " the survival of children given optimal regimens at local hospitals was equivalent to thatof two of the three special centres ". However, among the children with acute lymphatic leukaemia in this series (who included all the survivors) only 10 were treated at these two centres; the 10 did not differ significantly in terms of survival or relapse from those treated at the third special centre; and a comparison between the figures for all three centres combined (4 deaths and 13 other relapses among 27 cases) and those 1. Lesh, W., Portwood, W. E., Morrison, J. B. Lancet, 1967, ii, 891. 2. McEvoy, J. D. S., Jones, N. L., Campbell, E. J. M. Br. med. J. 1974, iv, 687.
degenerative (Huntington) dyskinesias, the drug was given only after other therapy had been stopped. Treatment was continued for two weeks after the maximum dose was reached. The results are shown in the accompanying table. Evaluation was carried out at a dosage of 225 mg. per day and at 450-900 mg. per day. Transient improvement was observed in 6 patients; it persisted only in 1 patient. 7 patients became worse (6 with Huntington’s chorea and 1 with tardive dyskinesia); these patients had been previously treated successfully with tetrabenazine, and deterioration with deanol must be considered as a return to the pre-tetrabenazine state. In the 12 cases of levodopa-induced dyskinesias, deanol was a complete failure. Besides certain positive effects, such as an increase in alertness - in 8 patients, unpleasant side-effects were noted: gastrointestinal upset in 4 patients, asthma and tachycardia in 1 patient, and hypomania in 3 patients.
We
were
thus unable
to
confirm the benefits
reported
by other workers.3.4 Service de Neurologie-
Neurochirurgie, Université de Louvain,
Louvain, Belgium. 1. 2. 3. 4.
Walker, J. Miller, E. Miller, E. Casey, D.
E. CHRISTIAN LATERRE ERNEST FORTEMPS.
E., Hoehn, M., Sears, E., Lewis, J. Lancet, 1973, i, 1512. M. Neurology, 1974, 24, 116. M. New Engl. J. Med. 1974, 291, 796. E., Denney, D. ibid. p. 797.
