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
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
Number of congenital cardiac defects related to
period of intrauterine life.
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
Istituto di Anatomia
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-
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,
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.