216 INCIDENCE OF RETROLENTAL FIBROPLASIA
by a common pharmacological mechanism, possibly via dopaminergic blockade. If so, the data indicate that neuroleptics affect two functionally different systems in analogous ways, and that spinal-reflex excitability testing can provide another convenient means of monitoring dopaminergic effects in vivo. Department of Psychiatry, University of Chicago, Chicago, Illinois 60637, U.S.A
SIR,-Retrolental fibroplasia (R.L.F.) is a persistent problem in preterm infants despite strict attention to monitoring of oxygen therapy in the neonatal period. We have noted, as have others, that the incidence of R.L.F. appears to be increasing’ once more. This increase may be due to the increased survival of very small premature infants at risk of R.L.F., to increased recognition or diagnosis of the disease, and/or to an increase in the capacity to improve oxygenation (e.g., mechanical ventilation, distending airway pressure, and blood-transfusions). To test the first two possibilities, follow-up studies were done on the 90 surviving infants with birth-weights between 500 and 1000 g referred to the neonatal intensive-care unit of the Montreal Children’s Hospital for two time periods, 1962-71 and 1972-76. The results of the ophthalmological examinations are shown in the table.
JOHN W. CRAYTON CAROL A. TAMMINGA
CHROMOSOME ABERRATIONS IN CHRONIC ALCOHOLICS
SiR,-Little work has been done on the effect of alcohol on human chromosomes and the results have been contradictory.I-4 The controversy prompted the following cytogenetic analysis of a group of chronic alcoholics. Ten men aged 31-60 (mean 42) with a blood-ethanol of at least 90 mmol/1 (4-14 mg/ml) on admission to hospital were selected. All fulfilled the criteria of gamma alcoholics.5 Blood for chromosome analysis was taken before any treatment. The controls were ten healthy men aged 29-59 (mean 42). Lymphocyte cultures were set up6 and chromosome preparations were made 72 h later. All blood-samples were coded, mixed, and analysed blind. Agreement between two independent observers was required for scoring the cells as normal or abnormal. 200 metaphases were analysed from each individual. The results are given in the table, which summarises the chromosome data from 4000 cells, pooled for the two groups. In the table "breaks plus exchanges" includes chromatid breaks, chromatid interchanges, acentric fragments, ring chromosomes, dicentric chromosomes, and pericentric inversions. "Gaps" refer to both chromatid and isochromatid gaps. An aberration was recorded as a break only when there was a clear misalignment of one or both chromatids. Chromosome aberration was significantly more common in the chronic alcoholics. This is true for all variables studied. Environmental factors other than alcohol may have influenced the increased frequency of chromosome aberration in the alcoholics ; part, at least, of the increase was probably caused by the excessive intake of alcohol. Ethanol is mutagenic in plants’ and animals,g and mutagenicity cannot be ruled out in man. Department of Clinical Genetics, Lund University Hospital, S-221 85 Lund, Sweden
FELIX MITELMAN
Alcohol Clinic, Malmö General
JAN WADSTEIN
Hospital
SURVIVAL AND OPHTHALMOLOGICAL OUTCOME OF CHILDREN OF
500-1000 g
BIRTH-WEIGHT
*Of those with eye exam < 1 year of age.
The numbers of children with cicatricial R.L.F. in the two time periods are shown, in relation to severity, in the figure. The increase in R.L.F. in the period 1972-76 was due mainly to an increase in the number of children with less severe diseases. There were 2 patients with grade 5 R.L.F. in the first tenyear period and 1 in the second (five year) period. The rare child blinded by R.L.F. represents only a small proportion of those affected. It is possible that the increasing experience of and interest in R.L.F. led to a better diagnostic recognition of the less severe forms of the disease. Indirect ophthalmoscopy in the neonatal intensive-care unit and follow-up after discharge of all preterm infants who had received oxygen was not routine before 1969. An attempt to repeat fundoscopic examinations on the children born before 1969 was unsuccessful: even if it had been successful, underdiagnosis would still have been likely since 90-95% of cases of grade 1 and 2 R.L.F. regress spon-
taneously.2 1. 2.
A. A. E.M.S. Newsletter, 1971, 4, 35.
Bregman, Obe, G., Herha, J. Humangenetik, 1975, 29, 191. 3. Chan, I. S., Antley, R. M., Klein, C. I., Melin, I. R., Roberts, L., Reed, D. Mammal. Chrom. Newsletter, 1975, 16, 69. 4. Cadotte, M., Allard, S., Verdy, M. Ann. Génét. 1973, 16, 55. 5. Jellinek, E. M. The Disease Concept of Alcoholism. New Haven, 1969. 6. Mitleman, F., Hartley-Asp, B., Ursing, B. Lancet, 1976, ii, 802. 7. Rieger, R., Michaelis, A., Schubert, I., Döbel, P., Jank, H.-W. Mutat. Res. 1975, 27, 69. 8. Badr, F. M., Badr, R. S. Nature, 1975, 253, 134.
The clinical significance of early recognition of less severe lies in the higher incidence of severe refractive errors (high myopia) in the small preterm survivor with mild R.L.F. compared with those without.3,4 This often develops in the first year of life and corrective lenses are required. R.L.F.
CHROMOSOME ABERRATIONS IN CHRONIC ALCOHOLICS
*p
by a common pharmacological mechanism, possibly via dopaminergic blockade. If so, the data indicate that neuroleptics affect two functionally different systems in analogous ways, and that spinal-reflex excitability testing can provide another convenient means of monitoring dopaminergic effects in vivo. Department of Psychiatry, University of Chicago, Chicago, Illinois 60637, U.S.A
SIR,-Retrolental fibroplasia (R.L.F.) is a persistent problem in preterm infants despite strict attention to monitoring of oxygen therapy in the neonatal period. We have noted, as have others, that the incidence of R.L.F. appears to be increasing’ once more. This increase may be due to the increased survival of very small premature infants at risk of R.L.F., to increased recognition or diagnosis of the disease, and/or to an increase in the capacity to improve oxygenation (e.g., mechanical ventilation, distending airway pressure, and blood-transfusions). To test the first two possibilities, follow-up studies were done on the 90 surviving infants with birth-weights between 500 and 1000 g referred to the neonatal intensive-care unit of the Montreal Children’s Hospital for two time periods, 1962-71 and 1972-76. The results of the ophthalmological examinations are shown in the table.
JOHN W. CRAYTON CAROL A. TAMMINGA
CHROMOSOME ABERRATIONS IN CHRONIC ALCOHOLICS
SiR,-Little work has been done on the effect of alcohol on human chromosomes and the results have been contradictory.I-4 The controversy prompted the following cytogenetic analysis of a group of chronic alcoholics. Ten men aged 31-60 (mean 42) with a blood-ethanol of at least 90 mmol/1 (4-14 mg/ml) on admission to hospital were selected. All fulfilled the criteria of gamma alcoholics.5 Blood for chromosome analysis was taken before any treatment. The controls were ten healthy men aged 29-59 (mean 42). Lymphocyte cultures were set up6 and chromosome preparations were made 72 h later. All blood-samples were coded, mixed, and analysed blind. Agreement between two independent observers was required for scoring the cells as normal or abnormal. 200 metaphases were analysed from each individual. The results are given in the table, which summarises the chromosome data from 4000 cells, pooled for the two groups. In the table "breaks plus exchanges" includes chromatid breaks, chromatid interchanges, acentric fragments, ring chromosomes, dicentric chromosomes, and pericentric inversions. "Gaps" refer to both chromatid and isochromatid gaps. An aberration was recorded as a break only when there was a clear misalignment of one or both chromatids. Chromosome aberration was significantly more common in the chronic alcoholics. This is true for all variables studied. Environmental factors other than alcohol may have influenced the increased frequency of chromosome aberration in the alcoholics ; part, at least, of the increase was probably caused by the excessive intake of alcohol. Ethanol is mutagenic in plants’ and animals,g and mutagenicity cannot be ruled out in man. Department of Clinical Genetics, Lund University Hospital, S-221 85 Lund, Sweden
FELIX MITELMAN
Alcohol Clinic, Malmö General
JAN WADSTEIN
Hospital
SURVIVAL AND OPHTHALMOLOGICAL OUTCOME OF CHILDREN OF
500-1000 g
BIRTH-WEIGHT
*Of those with eye exam < 1 year of age.
The numbers of children with cicatricial R.L.F. in the two time periods are shown, in relation to severity, in the figure. The increase in R.L.F. in the period 1972-76 was due mainly to an increase in the number of children with less severe diseases. There were 2 patients with grade 5 R.L.F. in the first tenyear period and 1 in the second (five year) period. The rare child blinded by R.L.F. represents only a small proportion of those affected. It is possible that the increasing experience of and interest in R.L.F. led to a better diagnostic recognition of the less severe forms of the disease. Indirect ophthalmoscopy in the neonatal intensive-care unit and follow-up after discharge of all preterm infants who had received oxygen was not routine before 1969. An attempt to repeat fundoscopic examinations on the children born before 1969 was unsuccessful: even if it had been successful, underdiagnosis would still have been likely since 90-95% of cases of grade 1 and 2 R.L.F. regress spon-
taneously.2 1. 2.
A. A. E.M.S. Newsletter, 1971, 4, 35.
Bregman, Obe, G., Herha, J. Humangenetik, 1975, 29, 191. 3. Chan, I. S., Antley, R. M., Klein, C. I., Melin, I. R., Roberts, L., Reed, D. Mammal. Chrom. Newsletter, 1975, 16, 69. 4. Cadotte, M., Allard, S., Verdy, M. Ann. Génét. 1973, 16, 55. 5. Jellinek, E. M. The Disease Concept of Alcoholism. New Haven, 1969. 6. Mitleman, F., Hartley-Asp, B., Ursing, B. Lancet, 1976, ii, 802. 7. Rieger, R., Michaelis, A., Schubert, I., Döbel, P., Jank, H.-W. Mutat. Res. 1975, 27, 69. 8. Badr, F. M., Badr, R. S. Nature, 1975, 253, 134.
The clinical significance of early recognition of less severe lies in the higher incidence of severe refractive errors (high myopia) in the small preterm survivor with mild R.L.F. compared with those without.3,4 This often develops in the first year of life and corrective lenses are required. R.L.F.
CHROMOSOME ABERRATIONS IN CHRONIC ALCOHOLICS
*p
