Biomedical subjects

G J Anders

Publications and source records attributed to G J Anders.

At least 19 recordsLinked to original sources

PubMed1991

Follow-up and pregnancy outcome after a diagnosis of mosaicism in CVS.

In 2103 consecutive diagnostic chorionic villus samples, examined in a 4-year period in our clinical genetics unit, 26 samples (1.2 per cent) presented chromosomal mosaicism in the direct and/or long-term culture preparations. Only once (46,XX/47,XX,+9) was the mosaicism confirmed in the fetus. In the cytogenetic follow-up studies of the remaining 25 pregnancies, in no cases could the aberration be confirmed in amniotic fluid or fetal tissue. One patient requested a termination after the CVS result. Of the remaining 24 pregnancies, four (16.7 per cent) ended in a spontaneous abortion. These findings suggest an association between placental mosaicism and fetal loss.

Abortion, Spontaneous↗

PubMed1990

The predictive value of cytogenetic diagnosis after CVS: 1500 cases.

The cytogenetic results of 1500 chorionic villus samples (CVS) are presented. In these 1500 samples, 23 samples (1.5 per cent) could not be provided with a diagnosis because of laboratory failure. This failure rate dropped from 3 per cent in the first 500 samples to 0.2 per cent in the last 500. In the remaining 1477 samples, 58 (3.9 per cent) chromosomal aberrations were found. Of these, 21 (36 per cent) proved not to represent the karyotype of the fetus proper. Predictive values of (different groups of) chromosomal aberrations in CVS are calculated. The impact of (differences between) the predictive value for some major chromosomal aberrations is discussed. A tissue- and chromosome-specific selection mechanism is postulated.

Chorionic Villi Sampling↗

PubMed1986

Acute nonlymphocytic leukemia 5 years after treatment with cisplatin, vinblastine, and bleomycin for disseminated testicular cancer.

The combination of cisplatin, vinblastine, and bleomycin (PVB) was used to treat a 25-year-old man for disseminated testicular germ cell cancer, leading to a complete remission. Acute nonlymphocytic leukemia (ANLL), resistant to chemotherapy, developed 5 years later. The secondary nature of this ANLL was corroborated by the detection of nonrandom chromosomal aberrations in bone marrow cells of chromosomes, 7, 5, and 3. This is one of the first reports of possible leukemogenic activity of PVB treatment when applied without additional irradiation or alkylating agents.

Acute Disease↗

PubMed1979

A comparison of constitutive heterochromatin staining methods in two cases of familial heterochromatin deficiencies.

Using DAPI staining after pretreatment with distamycin A we detected a familial deficiency of chromosome 16 heterochromatin. A distinct positively staining band, however, was seen after C-banding. Thus, by using these different heterochromatin staining methods, heterogeneity of the constitutive heterochromatin in the centromeric region of human chromosome 16 was indicated. The same C-banding procedure was also applied to a previously described familial deficiency of chromosome 9 heterochromatin evidenced using distamycin A/DAPI staining and G 11 staining (Buys et al., 1979). In this case a C-band appeared to be virtually absent on the relevant chromosome. These staining methods may be valuable tools in the study of chromosome polymorphisms.

Azure Stains↗

PubMed1979

Familial transmission of a translocation Y/14.

A translocation of heterochromatic material, brightly fluorescent after actinomycin D-DAPI staining, to the short arm of chromosome 14 was prenatally detected during cytogenetic examination of cells obtained by amniocentesis on the indication of advanced maternal age. Besides this abnormal chromosome, 43 autosomes and two X chromosomes were present. Silver staining made clear that an active nucleolus-organizing region was included in the translocation product. Both the intense fluorescence and the size of the translocated extra heterochromatic block were indicative of a Yq origin. Upon cytogenetic investigation of the parents, the mother appeared to carry the same t(Y;14) chromosome. Therefore, we expected a normal girl to be born. This was confirmed after birth.

Adult↗

PubMed1979

Age-dependent variability of ribosomal RNA-gene activity in man as determined from frequencies of silver staining nucleolus organizing regions on metaphase chromosomes of lymphocytes and fibroblasts.

Frequencies of silver staining nucleolus organizing regions (NORs) have been determined in lymphocytes and fibroblasts from very young and from aged persons. Since silver staining of NORs is associated with activity of ribosomal RNA-genes, we used this approach to investigate a possible inactivation of these genes during aging. Our lymphocyte data are based on a study per age-group of 220 metaphases from 10 subjects. Although in both age-groups modal numbers of silver staining chromosomes per metaphase had similar ranges over the subjects, the frequency of metaphases containing the maximal number of staining chromosomes was in the old age-group (80--89 years) significantly lower than in the young age-group (less than 1 year old). In fibroblasts, of which 75 metaphases from 4 subjects were included per age-group, differences were more pronounced. Modal numbers of silver staining chromosomes were for the aged persons (69--83 years) lower than for the young children (less than 1 year old). Highly significant differences were observed between both groups in frequency of metaphases containing the maximal number of positively reacting acrocentric chromosomes and, more in general, in frequencies of silver staining D- and G-group chromosomes, the lower frequencies being found in the old age-group. We propose the term NOR-junctions as distinct from satellite associations for arrangements of acrocentric chromosomes which after silver staining are visibly connected at their NORs. The number of acrocentric chromosomes involved in lymphocyte NOR-junctions of aged people was significantly higher than the number of joined acrocentrics in young children. The frequency of these NOR-junctions themselves, irrespective of the number of chromsomes involved, was higher for aged persons than for young children, although this difference appeared to be statistically not significantly higher than in fibroblasts. Also based on qualitative observations from our study we discuss tcehnical and biological problems of our approach to study cell aging in vivo by means of silver staining of NORs. We conclude that in man, reflected by the difference in frequencies of silver staining NORs between young and aged persons, a rather extensive loss of ribosomal RNA-gene activity may occur during aging.

Aged↗

PubMed1979

Micromethod for chromosome preparations from Chinese hamster lymphocytes.

Chromosome preparations from Chinese hamster lymphocytes were made by culturing for 2 to 6 days 50,000 to 800,000 lymphocytes in flat-bottomed Cooke microtiter plates in 0.1 or 0.2 ml Roswell Park Memorial Institute-1640 medium (RPMI-1640) supplemented with 5--40 microliters PHA/ml, 20% fetal calf serum (FCS), and 40 microns 2-mercaptoethanol. Depending on blood volume and cell concentrations used, it was possible to obtain up to 1400 well-spread metaphases from one venepuncture.

Animals↗

PubMed1978

Rapid identification of chromosomes carrying silver-stained nucleolus-organizing regions: application to case of 21/21 Robertsonian translocation.

The use of a combination of transmitted light and epiluminescence after silver and fluorescent staining of chromosome preparations makes it possible to achieve simultaneous visualization of silver-stained NORs and flourescent chromosomes. This technique permits exact localization of silver precipitates on normal and BrdU-substituted chromosomes. After previous silver impregnation, fluorescent staining by actinomycin-daunomycin-DAPI was used to induce a banding pattern that enables identification of specific chromosomes while observing silver-stained NORs at the same time. Application of this method to a Down's syndrome patient revealed a 21/21 Robertsonian translocation with NOR'S eliminated.

Cell Nucleolus↗

PubMed1978

Time and cell systems as variables in fusion experiments with polyethylene glycol.

Cell hybridization was done between a monolayer of B14-150 Chinese hamster cells and a suspension of either mouse leukemia cells or normal human lymphocytes. Cell contact was obtained by centrifugation of the suspension cells onto the monolayer cells in a culture plate. Cell fusion was done by means of polyethylene glycol (PEG). The optimum time for PEG exposure as well as the yield of hybrid cells differed markedly with the different combinations.

Animals↗

PubMed1978

Should we screen all newborns for cystic fibrosis?

To assess the value of detecting albumin in meconium as a screening procedure for cystic fibrosis [CF] 68,000 meconium samples were examined by BM Meconium Test, single radial immunodiffusion and benzidine reaction. The specificity and sensitivity of this combination of tests were 99.67% and 78.57% respectively. The prevalence of CF at birth was confirmed as 1:3600 in this country. This low prevalence resulted in a relatively high number of false positives. Therefore, a positive test result has a low predictive value [3.39%] and this is a serious drawback of the method. The experiences and opinions of 37 local paediatricians about the screening programme were evaluated by a simple questionnaire. Gold's decision rule was applied. The least relative cost of misclassification justifying a mass-screening programme was 3 times higher than the actual relative cost as suggested by the aggregate opinion of paediatricians in the region. These results support the view that with the methods used screening may have more disadvantages than not screening.

Albumins↗

PubMed1977

The influence of the serum/PHA ratio, microplate well shape and 2-mercaptoethanol on the stimulation of different numbers of cells in lymphocyte cultures from the chinese hamster.

Conditions for microculture of Chinese hamster lymphocytes are described which allow measurement of thymidine uptake with 6000 to 1000 lymphocytes per culture. The relationship between degree of cell stimulation, PHA concentration culture surface and cell concentration is described, as well as the influence of addition of 2-mercaptoethanol to the cultures.

Animals↗

PubMed1976

Chromosome preparations from microplate cultures of man, dog, rat, and mouse.

A simple method for making chromosomal preparations from 10(5) leukocytes from man, dog, mouse, and rat and from 0.01 ml total human and dog blood is developed. The leukocytes and the peripheral blood are cultured in Cooke microtiter plates in a culture volume of 0.1 ml. The culture medium is R.P.M.I. 1640 supplemented with serum and phytohemagglutinin. The culture time is 72 or 96 h.

Animals↗

PubMed1976

Short-term microcultures of lymphocytes from Chinese hamster peripheral blood.

A microtechnique for the culture of Chinese Hamster lymphocytes is described using Cooke microtiter plates with 100,000 leucocytes in a culture volume of 0.1 ml and a culture time of three days. The culture media used were RPMI 1640 and Trowell T8 supplemented with 20% foetal calf serum (FCS) and 2 mu PHA. The cells were harvested with a Skatron cell culture harvester using glass fibre filters. Various technical aspects of the lymphocyte cultures from the Chinese Hamster are described. The relevance of changes in culture conditions to the variability of culture results was analysed for PHA and FCS concentrations, different culture media, cell concentration, vessel shape and culture duration.

Animals↗

PubMed1973