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ANTAGONISM BETWEEN CRANIAL IRRADIATION AND INTRATHECAL METHOTREXATE IN MENINGEAL LEUKÆMIA
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lymphatic and myeloid leukaemia seem to nature, 10, 11 no comparable information is available on acute leukaemia. The phenomenon described by Dr Pegrum and his colleagues may point not only to the clonal status of the acute leukaemias but more importantly to different pathogenetic mechanisms operative during the While chronic
be monoclonal in
preleukxmic stages of acute and Mayo Clinic, Rochester, Minnesota 55901, U.S.A
chronic leukxmia. T. F. C. S. WARNER.
ANTAGONISM BETWEEN CRANIAL IRRADIATION AND INTRATHECAL METHOTREXATE IN MENINGEAL LEUKÆMIA et al.12 demonstrated that in meningeal SIR,-Duttera teukxmia intrathecal methotrexate was more effective than intrathecal methotrexate and cranial irradiation. They propose two possible explanations for these unexpected results. Itdifficult to accept either one. Price and Johnson 13 have shown that perivascular leukoemic infiltrates in the arachnoid are relatively resistant to the effect of intrathecal cytostatic
drugs. If the radiotherapy did indeed
significant leakage of methotrexate into the systemic circulation, this would be more likely to increase the efficacy of the drug. The risk of systemic. toxicity of methotrexate can be minimised by folinic acid " rescue ", thus permitting administration of adequate intrathecal methotrexate. Furthermore, the median time required to achieve remission was identical at 18 days and the total dose of methotrexate cause a
intrauterine difficulties. Secondly, there is no evidence that a rise of intracranial venous pressure of the magnitude they measured causes intracranial hxmorrhage. Surely the pressures must rise higher than that with crying,
coughing,
or
stooling.
I agree that C.P.A.P. by any means should be applied with caution. If C.P.A.P. is to be applied by head chamber, the lowest pressure possible should be used, there should be an adequate leak between neck and collar to allow gas to escape from the hood, and the neck piece should be at least 1 cm. wide and of soft material, so that the least pressure possible can be applied. University of California, San Francisco, School of Medicine, Department of Anesthesia, San Francisco, California 94143, U.S.A.
GEORGE A. GREGORY.
PSEUDO-BECKWITH-WIEDEMANN SYNDROME: INTERACTION WITH MATERNAL DIABETES
SIR,-Professor Wiedemann (Sept. 15, p. 626) reviewed the main clinical features of the Beckwith-Wiedemann (B.-W.) syndrome: umbilical hernia, macroglossia, and macrosomia in an infant who is not a congenital cretin. A vertical crease in the ear lobes and hypoglycaemia early in life may also be
also identical at 75 mg. per sq.m. in both groups. If simultaneous radiotherapy had protected the leukaemic cells from the S-phase effect of methotrexate, one would have expected either delayed or less frequent remissions in this group. was
Cook County Hospital,
Chicago, Illinois 60612, U.S.A.
ASHOK R. PATEL PRABODH SHAH.
CONTINUOUS POSITIVE AIRWAY PRESSURE AND HYDROCEPHALUS
SIR,-With interest and concern I read the letter by Dr Vert and others (Aug. 11, p. 319). At least two things suggest the neck piece they used was too tight. First, they were able to develop a 10 cm. H2O chamber pressure with as little as 6 litres per minute gas flow. In our experience, unless there is a 10-20 litres per minute gas flow and some gas leak between the neck ccllar and neck the device is too tight. The second sign the cuff might be too tight was the presence of head and scalp cedema. Because two fingers could be inserted between the skin and neck piece is no assurance the neck piece is loose. I was able to accomplish this on myself when the sub-cuff pressure was 35 mm. Hg-many times that needed to treat sick infants. The short communique by Dr. Vert and others leaves a lot of unanswered questions and does not prove that C.P.A.P. by hood caused the hydrocephalus. It is unclear how they know the hydrocephalus was post-hsemorrhagic. It is even less clear how they know it occurred while C.P.A.P. was being applied. Intracranial bleeds are frequent in premature infants with or without C.P.A.P., especially those who have had asphyxia, before or after birth. Their table records that all 6 infants had abnormal deliveries or
Macrosomia and ear-lobe-crease anomaly.
observed, associated with hyperinsulinxmia 1-3 and insulin hyperresponsiveness to glucose, glucagon, and tolbutamide.44 There is a poorly understood relationship between the classic B.-W. syndrome and the disturbances in carbohydrate metabolism in the infants of diabetic mothers. 4,5 The findings of islet-cell hyperplasia, hyperinsulinism, and macrosomia are common to both groups. Cohen et al.6 described maternal diabetes in the B.-W. syndrome.
Aisenberg, A.
C. Am. J. Med. 1973, 55, 184. Advanc. Cancer Res. 1972, 15, 199. 12 Duttera, M. J., Bleyer, W. A., Pomeroy, T. C., Leventhal, C. M. Leventhal, B. G. Lancet, Sept. 29, 1973, p. 703. 13 Price, R. A., Johnson, W. W. Cancer, 1973, 31, 520.
11 Fialkow, P. J.
of their
patients with
1. Beckwith, J. B. Transactions of the Western Society for Pediatric Research, Los Angeles, Nov. 11, 1963. 2. Coombs, J. T., Grunt, J. A., Brandt, I. K. New Engl. J. Med.
1966, 275, 236. Mariani, R., Unal, D., Spriet, A., Carcassonne, M., Bernard, R. Archs fr. Pédiat. 1969, 26, 337. 4. Schiff, D., Colle, E., Wells, D., Stern, L. J. Pediat. 1973, 82, 258. 5. Schiff, D., Colle, E. Un. méd. Can. 1971, 100, 501. 6. Cohen, M. M., Jr., Gorlin, R. J., Feingold, M., ten Bensel, R. W. Am. J. Dis. Child. 1971, 122, 515. 3.
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one
lymphatic and myeloid leukaemia seem to nature, 10, 11 no comparable information is available on acute leukaemia. The phenomenon described by Dr Pegrum and his colleagues may point not only to the clonal status of the acute leukaemias but more importantly to different pathogenetic mechanisms operative during the While chronic
be monoclonal in
preleukxmic stages of acute and Mayo Clinic, Rochester, Minnesota 55901, U.S.A
chronic leukxmia. T. F. C. S. WARNER.
ANTAGONISM BETWEEN CRANIAL IRRADIATION AND INTRATHECAL METHOTREXATE IN MENINGEAL LEUKÆMIA et al.12 demonstrated that in meningeal SIR,-Duttera teukxmia intrathecal methotrexate was more effective than intrathecal methotrexate and cranial irradiation. They propose two possible explanations for these unexpected results. Itdifficult to accept either one. Price and Johnson 13 have shown that perivascular leukoemic infiltrates in the arachnoid are relatively resistant to the effect of intrathecal cytostatic
drugs. If the radiotherapy did indeed
significant leakage of methotrexate into the systemic circulation, this would be more likely to increase the efficacy of the drug. The risk of systemic. toxicity of methotrexate can be minimised by folinic acid " rescue ", thus permitting administration of adequate intrathecal methotrexate. Furthermore, the median time required to achieve remission was identical at 18 days and the total dose of methotrexate cause a
intrauterine difficulties. Secondly, there is no evidence that a rise of intracranial venous pressure of the magnitude they measured causes intracranial hxmorrhage. Surely the pressures must rise higher than that with crying,
coughing,
or
stooling.
I agree that C.P.A.P. by any means should be applied with caution. If C.P.A.P. is to be applied by head chamber, the lowest pressure possible should be used, there should be an adequate leak between neck and collar to allow gas to escape from the hood, and the neck piece should be at least 1 cm. wide and of soft material, so that the least pressure possible can be applied. University of California, San Francisco, School of Medicine, Department of Anesthesia, San Francisco, California 94143, U.S.A.
GEORGE A. GREGORY.
PSEUDO-BECKWITH-WIEDEMANN SYNDROME: INTERACTION WITH MATERNAL DIABETES
SIR,-Professor Wiedemann (Sept. 15, p. 626) reviewed the main clinical features of the Beckwith-Wiedemann (B.-W.) syndrome: umbilical hernia, macroglossia, and macrosomia in an infant who is not a congenital cretin. A vertical crease in the ear lobes and hypoglycaemia early in life may also be
also identical at 75 mg. per sq.m. in both groups. If simultaneous radiotherapy had protected the leukaemic cells from the S-phase effect of methotrexate, one would have expected either delayed or less frequent remissions in this group. was
Cook County Hospital,
Chicago, Illinois 60612, U.S.A.
ASHOK R. PATEL PRABODH SHAH.
CONTINUOUS POSITIVE AIRWAY PRESSURE AND HYDROCEPHALUS
SIR,-With interest and concern I read the letter by Dr Vert and others (Aug. 11, p. 319). At least two things suggest the neck piece they used was too tight. First, they were able to develop a 10 cm. H2O chamber pressure with as little as 6 litres per minute gas flow. In our experience, unless there is a 10-20 litres per minute gas flow and some gas leak between the neck ccllar and neck the device is too tight. The second sign the cuff might be too tight was the presence of head and scalp cedema. Because two fingers could be inserted between the skin and neck piece is no assurance the neck piece is loose. I was able to accomplish this on myself when the sub-cuff pressure was 35 mm. Hg-many times that needed to treat sick infants. The short communique by Dr. Vert and others leaves a lot of unanswered questions and does not prove that C.P.A.P. by hood caused the hydrocephalus. It is unclear how they know the hydrocephalus was post-hsemorrhagic. It is even less clear how they know it occurred while C.P.A.P. was being applied. Intracranial bleeds are frequent in premature infants with or without C.P.A.P., especially those who have had asphyxia, before or after birth. Their table records that all 6 infants had abnormal deliveries or
Macrosomia and ear-lobe-crease anomaly.
observed, associated with hyperinsulinxmia 1-3 and insulin hyperresponsiveness to glucose, glucagon, and tolbutamide.44 There is a poorly understood relationship between the classic B.-W. syndrome and the disturbances in carbohydrate metabolism in the infants of diabetic mothers. 4,5 The findings of islet-cell hyperplasia, hyperinsulinism, and macrosomia are common to both groups. Cohen et al.6 described maternal diabetes in the B.-W. syndrome.
Aisenberg, A.
C. Am. J. Med. 1973, 55, 184. Advanc. Cancer Res. 1972, 15, 199. 12 Duttera, M. J., Bleyer, W. A., Pomeroy, T. C., Leventhal, C. M. Leventhal, B. G. Lancet, Sept. 29, 1973, p. 703. 13 Price, R. A., Johnson, W. W. Cancer, 1973, 31, 520.
11 Fialkow, P. J.
of their
patients with
1. Beckwith, J. B. Transactions of the Western Society for Pediatric Research, Los Angeles, Nov. 11, 1963. 2. Coombs, J. T., Grunt, J. A., Brandt, I. K. New Engl. J. Med.
1966, 275, 236. Mariani, R., Unal, D., Spriet, A., Carcassonne, M., Bernard, R. Archs fr. Pédiat. 1969, 26, 337. 4. Schiff, D., Colle, E., Wells, D., Stern, L. J. Pediat. 1973, 82, 258. 5. Schiff, D., Colle, E. Un. méd. Can. 1971, 100, 501. 6. Cohen, M. M., Jr., Gorlin, R. J., Feingold, M., ten Bensel, R. W. Am. J. Dis. Child. 1971, 122, 515. 3.
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