Grant R. Sutherland

Chromosomal mosaicism in amniotic fluid cell cultures

Six cases of chromosomal mosaicism detected in amniotic fluid cultures are described. In five of these there was no evidence of fetal mosaicism. In one case fetal mosaicism was demonstrated but only by the study of fibroblasts since blood cultures showed only normal cells. The implications of amniotic fluid mosaicism are discussed and it is concluded that this usually does not indicate fetal mosaicism. The value of repeated amnio‐centesis in the diagnosis of fetal mosaicism was demonstrated by findings in three of the cases. It is recommended that amniotic fluid cultures be harvested in situ for chromosome studies and that cytogenetic results be expressed as number of colonies karyotyped rather than as number of cells analyzed.

Lysosomal enzymes of cultured amniotic fluid cells

Abstract 1. 1. The levels of some lysosomal enzymes in a minimum of 38 amniotic fluid cell strains cultured to the third passage were as follows (mean ± standard deviation): N- acetyl -β- d - glucosaminidase 52.1 ± 16.70 , acid phosphatase 7.73 ± 2.82, β-galactosidase 4.59 ± 1.97, β-glucuronidase 1.30 ± 0.52, β-glucosidase 0.072 ± 0.030, α-galactosidase 0.42 ± 0.15, α-arabinosidase 0.53 ± 0.25, α-glucosidase 0.38 ± 0.18 and α-mannosidase 0.65 ± 0.30 nmole 4-methylumbelliferone/min/mg protein. 2. 2. No correlation was observed between the levels of these enzymes and gestational age. 3. 3. The levels of these enzymes in uncultured cells tended to be lower than in the corresponding cultured cells. Occasionally, very low levels of certain of the enzymes were found in uncultured cells, although normal levels were found in the corresponding cultured cells.

Lysosomal enzyme levels in human amniotic fluid cells in tissue culture. I. α-glucosidase and β-glucosidase

Abstract A number of factors which may correlate with the levels of α-glucosidase and β-glucosidase in cultured amniotic fluid cells have been investigated. Fluctuations in enzyme activity occurred as passage numbers increased. Whereas α-glucosidase showed a consistently lower activity in the earlier passages compared to the later ones, the results for β-glucosidase were equivocal. Both enzymes showed an increase in activity correlated with the time taken by the cells to reach confluency in the third passage. When replicate cultures were assayed daily after subculture, neither enzyme showed any change correlated with time. When cultures were grown in parallel in Hams F10 and Eagles M.E.M. tissue culture media, the activity of both enzymes was unaffected. Cell strains cultured from serial samples of amniotic fluid from the same woman had differing enzyme levels unrelated to gestational age.

Effect of serum concentration, type of culture medium and pH on the lysosomal enzyme activity of cultured human amniotic fluid cells.

Abstract 1. 1. Possible changes in lysosomal enzyme activity of cultured amniotic fluid cells with serum concentration, type of medium and the pH of the medium were studied. 2. 2. Apart from a small, but significant, decrease in the activity of β-galactosidase, none of the enzymes changed with increasing serum concentration. 3. 3. No significant changes in enzyme activity were found between cells cultured in Hams F10 and Eagles MEM medium. 4. 4. Lysosomal enzyme levels were unaffected by culturing cells for up to 9 days at pH 7.0, 7.4 and 7.9.

Lysosomal enzyme variations in thirteen cell strains cultured from one amniotic fluid

Abstract Fifteen primary amniotic fluid cultures were established from a single sample of amniotic fluid. Three different methods were used to set up these cultures which yielded 13 cell strains. Nine lysosomal enzymes (acid phosphatase, β-glucuronidase, β-galactosidase, α-galactosidase, α-glucosidase, α-mannosidase, α-arabinosidase, N- acetyl -s- d - glucosaminidase and arylsulphatase A) were assayed in these 13 cell strains. The coefficients of variation of these enzyme levels were less than the coefficients for enzyme levels in cell strains grown from different samples of amniotic fluid but greater than those for the combined culture and assay system used. No assay values were found which could have suggested a possible enzyme deficiency disease.

Metaphase chromosomes from neonatal urine

SummanyTissue culture of the cells present in the urine of neonates has been demonstrated to be a suitable means of obtaining metaphase chromosomes whenever cytogenetic studies are required on cells other than blood lymphocytes. The advantages of this type of cell culture compared with the use of fibroblast culture from skin biopsy are discussed.ZusammenfassungEs konnte gezeigt werden, daß Gewebekulturen von Zellen aus dem Urin Neugeborener sich zur Gewinnung von Metaphasenchromosomen eignen, wenn cytogenetische Untersuchungen nicht allein an Blutlymphocyten durchgeführt werden sollen. Es werden die Vorteile diskutiert, die diese Art der Zellkultur gegenüber der Fibroblastenkultur aus Hautbiopsien bietet.

Lysosomal enzyme levels in human amniotic fluid cells in tissue culture: II. α-galactosidase, β-galactosidase and α-arabinosidase

Changes in the activities of α‐galactosidase, β‐galactosidase and a‐arabinosidase in amniotic fluid cells with time in culture were studied. Marked fluctuations in all three enzymes occurred with passage. In certain cell strains, β‐galactosidase showed a marked rise in activity correlated with passage. The activity of all three enzymes, in amniotic fluid cells at the third passage, was correlated with the total time taken to reach con‐fluency. There was no consistent pattern of enzyme activity associated with the time after subculture. Enzyme levels in cell strains derived from serial samples of amniotic fluid from several women showed large differences in activity unrelated to gestational age.

Chromosome studies in a mental deficiency hospital: Total ascertainment

Chromosome studies on individuals suffering from mental defects are common but the screening of the total population of a mental deficiency hospital has not, to our knowledge, been reported. Such a survey was recently completed at St. Nicholas Hospital, Carlton. This is a hospital of 150 beds for mentally defective children. Most of the children are severely or profoundly retarded. The age range is from 3 months to 16 years with the majority being in the 2 to 12 years range.

Six cases of the Cri-Du-Chat Syndrome

SummarySix cases of the cri-du-chat syndrome are presented. Brief case histories are given along with clinical description, cytogenetics and dermatoglyphics. The problem of diagnosing this syndrome in older children is discussed and it is pointed out that the ‘cat cry’ can persist into early adulthood. A case of Wolfs syndrome is also described so that comparison of these two cytogenetically similar syndromes can be made.

Lysosomal enzyme levels in human amniotic fluid cells in tissue culture:IV. %A N-acetyl-β-D-glucosaminidase

Total and % A hexosaminidase were similar for primary cultures and later passages of amniotic fluid cells. The culture variables ‐ through serial passage, within a passage and replicate primary cultures ‐ resulted in some variation in total hexosaminidase, but an insignificant change in % A hexosaminidase. They are unlikely to give rise to any problems in the antenatal diagnosis of Sandhoffs and Tay‐Sachs diseases.