Walter Vormittag

Cytogenetic and dermatoglyphic findings in a familial case of hypomelanosis of Ito (incontinentia pigmenti achromians).

Cytogenetic and dermatoglyphic investigations were performed in a mother (M.B.) and her daughter (D.B.), who were both suffering from hypomelanosis of Ito (incontinentia pigmenti achromians; HI). Whereas quite normal chromosomal results could be obtained after culture of peripheral lymphocytes, a diploid/tetraploid mosaicism (46,XX/92,XXXX) was found in cultured skin‐fibroblasts derived from a hypopigmented skin area of M.B., with a slowly decreasing tetraploidy rate in the course of passaging: #2 23%, #5 11%, #11 and #14 6% and #18 and #21 2%. In cultures of normally pigmented skin, only single tetraploid cells could be detected. Dermatoglyphic examinations in both patients showed single transverse creases, a high number of secondary creases and a longitudinal alignment of the main line A bilaterally, and there was a tricentric fingertip pattern on the right digit III of M.B., i.e. a pattern which occurs very seldom in human beings. The results are discussed in respect to the clinical‐diagnostic overlap of HI and incontinentia pigmenti Bloch‐Sulz‐berger.

As to the clastogenic-, sister-chromatid exchange inducing-and cytotoxic activity of inosine triphosphate in cultures of human peripheral lymphocytes

The influence of commercial inosine triphosphate (ITP) on the chromosome aberration rate, the mitotic rate, sister-chromatid exchange (SCE) frequency, and the proportion of first (X1), second (X2) and third (X3) division metaphases was investigated in 72h cultures of human peripheral lymphocytes. The blood donors had mild inactive arthrosis and a normal health check-up. All cultures of each volunteer were set-up simultaneously. In contrast to a previous report [Arch. Biochem. Biophys. 278 (1990) 238-244], it was demonstrated in two preliminary studies (number of subjects, n=5 each) that ITP at a final concentration of 100 microM does not induce chromosomal aberrations and, furthermore, that not ITP concentrations higher than 100 microM but ITP doses higher than 3.8mM prohibit culture growth. Based on these results, cultures with a final ITP concentration of 3.6mM (max.) and 1.8mM (max./2) were compared with control cultures (number of subjects n=10; three males and seven females, mean age x=57.6 years). Whereas no increase in the chromosomal breakage rate was observed in cultures with an ITP concentration of 1.8mM and only a marginally significant one (P=0.048) for 3.6mM ITP cultures, a highly significant induction of SCEs, not only at an ITP concentration of 3.6mM (P<0.0001) but also at 1.8mM (P<0.0001) was seen. The increase in the SCE frequency was not linear, but steeper from 0 to 1.8mM than from 1.8 to 3.6mM. Nevertheless, the difference between 1.8 and 3.6mM cultures was significant (P=0.027). The distribution of the number of SCEs per metaphase as well as the distribution of SCEs per chromosome correspond to the expected Poisson values. The investigation of the cytotoxic effect of the studied ITP concentrations revealed a highly significant reduction of the mitotic rate from 0 to 1.8mM as well as from 1.8 to 3.6mM in the aberration studies (all P values are equal to smallest possible one for a sample size of 10, namely, 0.002), and in the SCE studies there is a significant decrease in the X3 frequency when ITP is increased (0-1.8mM: P=0.0061 and 1.8-3.6mM: P<0.0001). The proportion of X1 within all X1 and X2 metaphases changes significantly only at the second dose step (0-1.8mM ITP: P=0.22 and 1.8-3.6mM ITP: P<0.0001). The results are discussed.

Hypoplasia of the corpus callosum and growth hormone deficiency in a boy with the XXXXY syndrome

Sirs, We report on new radiological and endocrine findings in a 3.6-year-old boy with the XXXXY syndrome. He demonstrated the typical clinical signs reviewed by Terheggen et al. (1973), which are retarded psychomotor development, brachycephaly, dysmorphic ears, hypoplasia of genitalia, clinodactyly, valgus deformity of the knees and minor malformation of inner organs (mild pulmonary stenosis, unilateral kidney hypoplasia). In addition, speech development was severely retarded, as described by Sheridan et al. (1990), height was below the 3rd percentile, and bone age retarded (1.8 “years”). MRI of the brain was performed by T1weighted, single-echo imaging in the saggital and coronal planes and by TZweighted sequence in the axial plane. We found hypoplasia of the corpus callosum which was quantified by means of reduced thickness and length and reduced corpus callosum/ brain ratio when compared to an agematched, healthy control (Fig. 1). Additional focal hypoplasia involved the posterior body and the rostrum of the corpus callosum (arrows); the ventricular system was enlarged due to a marked atrophy of the cerebral cortex. Because of bilateral undescended testes, orchidopexy was done and a biopsy of the

Effect of Donor Age on Inter- and Intrachromosomal Distribution of Sister Chromatid Exchanges in Cultured Human Lymphocytes

The distribution of sister chromatid exchange (SCE) points has been analyzed in cultured lymphocytes from three age-groups of 30 females (n = 10; young: 13-20, middle-aged: 30-55, old: 75-84 years). The observed interchromosomal SCE distribution is in good agreement with the results of previous workers, significant age-dependent differences could not be established. It has only to be mentioned that chromosome E16 showed a relative SCE deficiency in young females, a result which has to be affirmed by further studies. Analysis of intrachromosomal SCE distribution revealed a surplus in the midarm section of most chromatid arms. Besides very similar distribution patterns in all three age-groups, there were some, mostly insignificant differences which had to be verified by further investigation.

Age-related influence of piracetam on mitotic index and number of silver-stained nucleolus organizer regions

Mitotic indices and the number of silver-positive nucleolus organizer regions (AgNORs) were scored in phytohemagglutinin-stimulated cultures of peripheral lymphocytes from two age groups of females (mean = 23.1 and 84.0 yr, respectively) under the influence of Piracetam (2-oxo-pyrrolidine-1-acetamid; Nootropil, Reg. No. 17051) and in simultaneously set up control cultures without Piracetam addition. Piracetam concentrations of 10, 14 and 16 mg/ml culture medium produced a highly significant, decreasing effect on both parameters tested, without an age-related difference. Lower Piracetam concentrations (2 and 4 mg/ml culture medium) showed a depressant effect on some of the cultures only; but, on average, there was a rather equal, significant, dose-dependent, linear decrease of the mitotic indices of both age groups, whereas the suppressive effect on the number of AgNORs was significant in cultures from the young females only.

Reduction of main line C.

Fifteen hundred palmar prints of normal persons and patients suffering from various diseases were studied and classified as to dermal ridge configurations at the base of digit IV, after the exclusion of main line C courses with endings at one of the palmar marginal regions. This classification scheme, based on the three classical reduction forms of line C (O,X(8),x), resulted in the differentiation of three main groups, A, B, and C. Within these main groups, pattern types with strong similarity were combined to subgroups allowing an easier documentation. Twin and family data were used to test whether the described pattern types, besides the classical abortive states O,X and x of line C (called special and intermediate forms), are heritable and for which of them a remarkable reduction tendency could be established. The results allow us to confirm the main grouping and the assumed reduction tendency of the special forms of group A.