- Email: [email protected]
VACTERL CONGENITAL MALFORMATIONS AND THE MALE FETUS
981 indicates that the inethod is adequate for preserving myocardial function in the majority of complicated, openheart-surgery cases in which the operation can be completed within this time limit. Cardiothoracic Department,
Hippokrateion Hospital, Vas. Sofias 114,
Ambelokipoi, Athens, Greece.
D. J. VISKOS
CONGENITAL-HEART-DISEASE RISK DURING PREGNANCY
SIR,-We observed in a series of 6145 necropsies carried out our Institute from Jan. 1, 1965, to Oct. 31, 1973., that the prevalence of congenital heart-disease (c.H.D.) WAS 5% (307 cases).’ We subdivided these cases into 32 classes of congenital in
defects listed in chronological order according to the probable period of intrauterine life 2when they are determined, following Van Mierop and Gessner.2 The 307 cases of C.H.D. were made up of 661 defects, of
Cd BANDING OF HUMAN CHROMOSOMES OBSERVED IN THE C-BANDING PROCEDURE
SIR,-Eibergreported a new banding technique, demonstrating two identical dots at the centromere region. This is termed " Cd staining ". He suggested that these dots may be composed of a family of repetitive D.N.A.S located in the centromeric region, representing organelles associated with the spindle fibres. We have obtained similar results, using the C-staining method of Sumner. Cultures are prepared from peripheral blood by the usual method. After hypotonic treatment with O’075M KCI for 5 minutes, the cells
are
fixed in several
Human metaphase chromosomes (A) from normal subject and (B) from a patient with chronic myeloid leukaemia.
Two identical dots
observed at the centromeric region. The secondary constrictions of chromosomes 1, 9, and 16 are sometimes stained.
of methanol/acetic acid and dried in warm air The next procedure is identical with Sumner’s method, except that the cells are treated with barium hydroxide for only 60 seconds at 53 °C. The dots are located in the centromere regions (see figure). One-day-old slides give the best results for this experiment. The procedure is highly reproducible, and we obtained the same results in malignant cells. When they were treated with barium hydroxide for more than 2 minutes, a typical C-banding
changes (70°C).
pattern
Number of congenital cardiac defects related to
period of intrauterine life.
are
appeared.
Unlike Eiberg’s method, the present technique could also stain the secondary constriction of chromosomes 1, 9, and 16. Compared with the figure revealed by the original method, the dots showed less clearly delineated morphology, and in some chromosomes two dots united to form a typical C band. The finding may be regarded as a reflection of the differential annealing of pericentric heterochromatin which comprises several kinds of repetitive D.N.A.S. Department of Preventive Medicine, Kyoto Prefectural University of Medicine, 602 Kyoto, Kamigyoku, Japan.
TATSUO ABE MASUJI MORITA KEIICHI KAWAI.
which 581 (87.9%) had been determined from the 5th to 6th week of embryonal life (see accompanying figure). It is clear that exposure to risk of C.H.D. is maximum during these weeks, while it is slight for the others. The prognostic and prophylactic significance of this observation is evident in view of the various exogenous factors (viral, radiation, hypoxic, traumatic, toxic, pharmacological) that may affect women
during pregnancy.
Istituto di Anatomia
Patologica,
Università di Padova, 35100 Padova, Italy.
V. TERRIBILE G. PERTILE
VACTERL CONGENITAL MALFORMATIONS AND THE MALE FETUS
SIR,-Previous reports34 have drawn attention
to a com-
bination of
multiple congenital anomalies involving skeletal, cardiovascular, renal, and gastrointestinal structures described by the acronym VACTERL (vertebral, anal, cardiac, tracheal, esophageal, renal, limb). Having recently attended the delivery of a baby with vertebral anomalies, limb defects, renal agenesis, and an imperforate anus we were prompted to review the incidence of this syndrome in this hospital. Out of the last 18 500 total births in this maternity depart1. Terribile, V., Pertile, G. Riv. Anat. Patol. Oncol. 1975, 40, 100. 2. Van Mierop, L. H. S., Gessner, I. H. Prog. cardiovasc. Dis. 1972,
1. 2.
Eiberg, H. Nature, Lond. 1974, 248, 55. Sumner, A. T. Exp. Cell Res. 1972, 75, 304.
3. Nora, J. J., Nora, A. H. Lancet, 1973, i, 941. 4. Kaufman, R. L. bid. p. 1396.
15,
67.
982 ment, 5 babies without chromosomal aberrations have exhibited a combination of three or more of the major anomalies that characterise the VACTERL group. 4 of the babies have been male. Nora and Nora’found significant fetal exposure to exogenous female sex hormones in their series, and Kaufman4 in his case-report also emphasised the possible pertinent association of oestrogen-progestogen supportive therapy given to the mother early in her pregnancy. Investigation into possible prenatal exposure to exogenous hormones is being conducted in our own cases, and so far no definite conclusions can be advanced. From the maternal case-records there is no evidence of hormones having been administered during the vulnerable period of embryogenesis, but, as Nora and Nora’ have emphasised, no valid conclusions can be reached from a retrospective review of routine maternal case-notes that do not include specific teratogenic histories. The feature of interest in our small series is the preponderance of males, which supports the disproportionate male sex incidence in this syndrome reported by Nora and Nora.3 R. CORCORAN G. D. ENTWISTLE
St. Catherine’s Hospital, Birkenhead L42 0LQ.
STERILISATION
SiR,—The article by Dr Neil and others (Oct. 11, p. 699) recommends that it should be the male who, after full counselling, should be sterilised and that if the woman is operated on then diathermy and division of the fallopian tubes should be replaced by an approach which causes less disruption of the utero-ovarian blood-supply. These are indeed striking recommendations, following the study of such a small group of patients 90% of whom, having undergone sterilisation, professed to be entirely satisfied. The operation of laparoscopic sterilisation demands a high degree of technical skill and in this article we are given no information about the experience or status of the operator. Although the trial is referred to as a controlled study, the comparison group are wives of men who have undergone vasectomy. Surely, although their symptoms will be different the group to study are the men who have undergone the vasectomies ! I have in my own mind doubt, neither about the advantages of female sterilisation over vasectomy in correctly selected cases, nor of the advantage of laparoscopic sterilisation over open sterilisation. It is tragic that articles of this nature, supported by so little information, throw doubt on the validity of this procedure. 1 The Quadrant, Wonford Road, Exeter EX2 4LE.
*
We showed this letter
to our
contributors whose
lows.-ED.L. SIR,-On behalf of the group,
we
should like
to
reply folmake the
following comments: (1) We refute the implication that the study groups are small, since the degree of significance would not have been apparent unless the numbers were adequate. (2) We should not be complacent if 90% are satisfied when our study indicates a disturbing incidence of late sequelae. Since the study terminated one year ago, we are now aware of 20 women who have come to hysterectomy. Of these, 15 were sterilised by laparoscopic techniques, 4 by abdominal ligation, and 1 in the control group. As stated in our article, no woman with abnormal menstrual symptoms was accepted for laparoscopic sterilisation. (3) We agree that the operation of laparoscopic sterilisation demands a high degree of technical skill and for this reason we 5. Nora,
J. J., Nora, A. H. New Engl.J. Med. 1974, 291, 731.
operation to consultants and carefully supervised gynaecological registrars. At the time of the study our unit carried out 400 laparoscopic sterilisations per annum. (4) The difficulties of finding a suitable control group exercised us considerably; we could think of no better group than the wives of vasectomised men. It is interesting to note that have restricted the
without the control group
our
results would appear
more
strik-
ing. (5) We do not believe that the male should be pressurised into accepting vasectomy, but in the female we believe that techniques should be used that result in minimum tissue disruption. We think the future will lie with the mini-laparotomy, or Hulka-Clemens clips applied under laparoscopic vision. Royal Hampshire County Hospital, Winchester.
A. T. LETCHWORTH A. D. NOBLE L. RUSHTON.
THE METHYLFOLATE TRAP
SIR,-Professor Hoffbrand (June 21, p. 1880) provides strong support for the methylfolate-trap hypothesis.I do not intend to judge between the protagonists in the controversy in your columns which followed the letter by Dr Tisman (May 24, p. 1184) and your leader (April 12, p. 843), but I wish to indicate some complexities in the theoretical basis of the hypothesis which have been overlooked by your correspondents. The cornerstone of this theory is that the only pathway for the demethylation of the 5-methylfolate is the Bl2-dependent transmethylase, which leads to translocation of the methyl group from folate to homocysteine, leading to the production of methionine and the essential tetrahydrofolate. It has been suggested’ that the major function subserved by this reaction is the regeneration of tetrahydrofolate. The methylfolate-trap hypothesis supposes that the existence of B12 deficiency would lead to the continuous accumulation of the 5-methylfolate and a concomitant depletion of cellular tetrahydrofolate. Two comments should be made. Firstly, on the basis of available evidence concerning the regulation of the 5-methyltetrahydrofolic-acid synthetic pathway, the accumulation of the final product of this pathway would only occur if the Bl2-deficient condition corresponded with a methionine-deficient condition. Dietary methionine reduces or abolishes the folate effects of B12 deficiency in rats.2 This is explained by the observation that methionine, or in its activated form as S-adenosylmethionine, inhibits the reductase which is responsible for the final reaction in the pathway for
methyltetrahydrofolic-acid synthesis.34 Secondly, recent reports indicate that the transmethylation with homocysteine is not the only reaction enabling the demethylation of S-methyltetrahydrofolic acid. The first reports suggested a transmethylation reaction to biogenic amines.56 More recent reports indicated that a single methyl transfer is not occurring, but that a one-carbon transfer does occur.’-10 This would produce tetrahydrofolate as one of the products. While there has been no attempt to confirm that tetrahydrofolate is produced in the reaction, there is indirect evidence that it is a product," These two factors considerably weaken the theoretical back1. Eldford, H. L., Katzen, H. M., Rosenthal, S., Smith, L. C, Buchanan, J M. Transmethylation and Methionine Synthesis (edited by S K. Shapiro and R. F Schlenk); p. 157. Chicago, 1965. 2. Brown, D. D., Silva, O. L., Gardiner, R. C., Silverman, M. J biol Chem.
1960, 235, 2058. 3. Kutzbach, C., Stokstad, E. L. R. Biochim. biophys. Acta, 1967, 139, 217 4. Kutzbach, C., Stokstad, E. L. R. ibid. 1971, 251, 459. 5. Laduron, P. M., Gommeren, W. R., Leysen, J. E. Biochem Pharmac 1974,
23, 1599. J. E., Laduron, P. M. Adv. biochem. Psychopharmac 1974, 11, 65 E., Rosengarten, H., Friedhoff, A J., Stebbins, R. D, Silber, R Science, 1975, 187, 171. 8. Mandel, L. R., Rosegay, A., Walker, R. W., VandenHeuvel, W. J A, Rokach, J. Science, 1974, 186, 741. 9. Wyatt, R. J., Erdelyi, E. D., Amaral, J. R., Elliott, G. R., Renson, J. Barchas, J. D. ibid. 1975, 187, 853. 10. Boarder, M. R., Rodnight, R. (in the press). 11. Lin, R. C., Narasimhachari, N. Biochim. biophys. Acta, 1975, 385, 268. 6. Leysen, 7. Meller,
Hippokrateion Hospital, Vas. Sofias 114,
Ambelokipoi, Athens, Greece.
D. J. VISKOS
CONGENITAL-HEART-DISEASE RISK DURING PREGNANCY
SIR,-We observed in a series of 6145 necropsies carried out our Institute from Jan. 1, 1965, to Oct. 31, 1973., that the prevalence of congenital heart-disease (c.H.D.) WAS 5% (307 cases).’ We subdivided these cases into 32 classes of congenital in
defects listed in chronological order according to the probable period of intrauterine life 2when they are determined, following Van Mierop and Gessner.2 The 307 cases of C.H.D. were made up of 661 defects, of
Cd BANDING OF HUMAN CHROMOSOMES OBSERVED IN THE C-BANDING PROCEDURE
SIR,-Eibergreported a new banding technique, demonstrating two identical dots at the centromere region. This is termed " Cd staining ". He suggested that these dots may be composed of a family of repetitive D.N.A.S located in the centromeric region, representing organelles associated with the spindle fibres. We have obtained similar results, using the C-staining method of Sumner. Cultures are prepared from peripheral blood by the usual method. After hypotonic treatment with O’075M KCI for 5 minutes, the cells
are
fixed in several
Human metaphase chromosomes (A) from normal subject and (B) from a patient with chronic myeloid leukaemia.
Two identical dots
observed at the centromeric region. The secondary constrictions of chromosomes 1, 9, and 16 are sometimes stained.
of methanol/acetic acid and dried in warm air The next procedure is identical with Sumner’s method, except that the cells are treated with barium hydroxide for only 60 seconds at 53 °C. The dots are located in the centromere regions (see figure). One-day-old slides give the best results for this experiment. The procedure is highly reproducible, and we obtained the same results in malignant cells. When they were treated with barium hydroxide for more than 2 minutes, a typical C-banding
changes (70°C).
pattern
Number of congenital cardiac defects related to
period of intrauterine life.
are
appeared.
Unlike Eiberg’s method, the present technique could also stain the secondary constriction of chromosomes 1, 9, and 16. Compared with the figure revealed by the original method, the dots showed less clearly delineated morphology, and in some chromosomes two dots united to form a typical C band. The finding may be regarded as a reflection of the differential annealing of pericentric heterochromatin which comprises several kinds of repetitive D.N.A.S. Department of Preventive Medicine, Kyoto Prefectural University of Medicine, 602 Kyoto, Kamigyoku, Japan.
TATSUO ABE MASUJI MORITA KEIICHI KAWAI.
which 581 (87.9%) had been determined from the 5th to 6th week of embryonal life (see accompanying figure). It is clear that exposure to risk of C.H.D. is maximum during these weeks, while it is slight for the others. The prognostic and prophylactic significance of this observation is evident in view of the various exogenous factors (viral, radiation, hypoxic, traumatic, toxic, pharmacological) that may affect women
during pregnancy.
Istituto di Anatomia
Patologica,
Università di Padova, 35100 Padova, Italy.
V. TERRIBILE G. PERTILE
VACTERL CONGENITAL MALFORMATIONS AND THE MALE FETUS
SIR,-Previous reports34 have drawn attention
to a com-
bination of
multiple congenital anomalies involving skeletal, cardiovascular, renal, and gastrointestinal structures described by the acronym VACTERL (vertebral, anal, cardiac, tracheal, esophageal, renal, limb). Having recently attended the delivery of a baby with vertebral anomalies, limb defects, renal agenesis, and an imperforate anus we were prompted to review the incidence of this syndrome in this hospital. Out of the last 18 500 total births in this maternity depart1. Terribile, V., Pertile, G. Riv. Anat. Patol. Oncol. 1975, 40, 100. 2. Van Mierop, L. H. S., Gessner, I. H. Prog. cardiovasc. Dis. 1972,
1. 2.
Eiberg, H. Nature, Lond. 1974, 248, 55. Sumner, A. T. Exp. Cell Res. 1972, 75, 304.
3. Nora, J. J., Nora, A. H. Lancet, 1973, i, 941. 4. Kaufman, R. L. bid. p. 1396.
15,
67.
982 ment, 5 babies without chromosomal aberrations have exhibited a combination of three or more of the major anomalies that characterise the VACTERL group. 4 of the babies have been male. Nora and Nora’found significant fetal exposure to exogenous female sex hormones in their series, and Kaufman4 in his case-report also emphasised the possible pertinent association of oestrogen-progestogen supportive therapy given to the mother early in her pregnancy. Investigation into possible prenatal exposure to exogenous hormones is being conducted in our own cases, and so far no definite conclusions can be advanced. From the maternal case-records there is no evidence of hormones having been administered during the vulnerable period of embryogenesis, but, as Nora and Nora’ have emphasised, no valid conclusions can be reached from a retrospective review of routine maternal case-notes that do not include specific teratogenic histories. The feature of interest in our small series is the preponderance of males, which supports the disproportionate male sex incidence in this syndrome reported by Nora and Nora.3 R. CORCORAN G. D. ENTWISTLE
St. Catherine’s Hospital, Birkenhead L42 0LQ.
STERILISATION
SiR,—The article by Dr Neil and others (Oct. 11, p. 699) recommends that it should be the male who, after full counselling, should be sterilised and that if the woman is operated on then diathermy and division of the fallopian tubes should be replaced by an approach which causes less disruption of the utero-ovarian blood-supply. These are indeed striking recommendations, following the study of such a small group of patients 90% of whom, having undergone sterilisation, professed to be entirely satisfied. The operation of laparoscopic sterilisation demands a high degree of technical skill and in this article we are given no information about the experience or status of the operator. Although the trial is referred to as a controlled study, the comparison group are wives of men who have undergone vasectomy. Surely, although their symptoms will be different the group to study are the men who have undergone the vasectomies ! I have in my own mind doubt, neither about the advantages of female sterilisation over vasectomy in correctly selected cases, nor of the advantage of laparoscopic sterilisation over open sterilisation. It is tragic that articles of this nature, supported by so little information, throw doubt on the validity of this procedure. 1 The Quadrant, Wonford Road, Exeter EX2 4LE.
*
We showed this letter
to our
contributors whose
lows.-ED.L. SIR,-On behalf of the group,
we
should like
to
reply folmake the
following comments: (1) We refute the implication that the study groups are small, since the degree of significance would not have been apparent unless the numbers were adequate. (2) We should not be complacent if 90% are satisfied when our study indicates a disturbing incidence of late sequelae. Since the study terminated one year ago, we are now aware of 20 women who have come to hysterectomy. Of these, 15 were sterilised by laparoscopic techniques, 4 by abdominal ligation, and 1 in the control group. As stated in our article, no woman with abnormal menstrual symptoms was accepted for laparoscopic sterilisation. (3) We agree that the operation of laparoscopic sterilisation demands a high degree of technical skill and for this reason we 5. Nora,
J. J., Nora, A. H. New Engl.J. Med. 1974, 291, 731.
operation to consultants and carefully supervised gynaecological registrars. At the time of the study our unit carried out 400 laparoscopic sterilisations per annum. (4) The difficulties of finding a suitable control group exercised us considerably; we could think of no better group than the wives of vasectomised men. It is interesting to note that have restricted the
without the control group
our
results would appear
more
strik-
ing. (5) We do not believe that the male should be pressurised into accepting vasectomy, but in the female we believe that techniques should be used that result in minimum tissue disruption. We think the future will lie with the mini-laparotomy, or Hulka-Clemens clips applied under laparoscopic vision. Royal Hampshire County Hospital, Winchester.
A. T. LETCHWORTH A. D. NOBLE L. RUSHTON.
THE METHYLFOLATE TRAP
SIR,-Professor Hoffbrand (June 21, p. 1880) provides strong support for the methylfolate-trap hypothesis.I do not intend to judge between the protagonists in the controversy in your columns which followed the letter by Dr Tisman (May 24, p. 1184) and your leader (April 12, p. 843), but I wish to indicate some complexities in the theoretical basis of the hypothesis which have been overlooked by your correspondents. The cornerstone of this theory is that the only pathway for the demethylation of the 5-methylfolate is the Bl2-dependent transmethylase, which leads to translocation of the methyl group from folate to homocysteine, leading to the production of methionine and the essential tetrahydrofolate. It has been suggested’ that the major function subserved by this reaction is the regeneration of tetrahydrofolate. The methylfolate-trap hypothesis supposes that the existence of B12 deficiency would lead to the continuous accumulation of the 5-methylfolate and a concomitant depletion of cellular tetrahydrofolate. Two comments should be made. Firstly, on the basis of available evidence concerning the regulation of the 5-methyltetrahydrofolic-acid synthetic pathway, the accumulation of the final product of this pathway would only occur if the Bl2-deficient condition corresponded with a methionine-deficient condition. Dietary methionine reduces or abolishes the folate effects of B12 deficiency in rats.2 This is explained by the observation that methionine, or in its activated form as S-adenosylmethionine, inhibits the reductase which is responsible for the final reaction in the pathway for
methyltetrahydrofolic-acid synthesis.34 Secondly, recent reports indicate that the transmethylation with homocysteine is not the only reaction enabling the demethylation of S-methyltetrahydrofolic acid. The first reports suggested a transmethylation reaction to biogenic amines.56 More recent reports indicated that a single methyl transfer is not occurring, but that a one-carbon transfer does occur.’-10 This would produce tetrahydrofolate as one of the products. While there has been no attempt to confirm that tetrahydrofolate is produced in the reaction, there is indirect evidence that it is a product," These two factors considerably weaken the theoretical back1. Eldford, H. L., Katzen, H. M., Rosenthal, S., Smith, L. C, Buchanan, J M. Transmethylation and Methionine Synthesis (edited by S K. Shapiro and R. F Schlenk); p. 157. Chicago, 1965. 2. Brown, D. D., Silva, O. L., Gardiner, R. C., Silverman, M. J biol Chem.
1960, 235, 2058. 3. Kutzbach, C., Stokstad, E. L. R. Biochim. biophys. Acta, 1967, 139, 217 4. Kutzbach, C., Stokstad, E. L. R. ibid. 1971, 251, 459. 5. Laduron, P. M., Gommeren, W. R., Leysen, J. E. Biochem Pharmac 1974,
23, 1599. J. E., Laduron, P. M. Adv. biochem. Psychopharmac 1974, 11, 65 E., Rosengarten, H., Friedhoff, A J., Stebbins, R. D, Silber, R Science, 1975, 187, 171. 8. Mandel, L. R., Rosegay, A., Walker, R. W., VandenHeuvel, W. J A, Rokach, J. Science, 1974, 186, 741. 9. Wyatt, R. J., Erdelyi, E. D., Amaral, J. R., Elliott, G. R., Renson, J. Barchas, J. D. ibid. 1975, 187, 853. 10. Boarder, M. R., Rodnight, R. (in the press). 11. Lin, R. C., Narasimhachari, N. Biochim. biophys. Acta, 1975, 385, 268. 6. Leysen, 7. Meller,