In situ nick translation of human chromosomes using Alu I: unmasking of recognition sites by proteinase K pretreatment.

Human chromosomes prepared according to routine methods were treated with the restriction endonuclease Alu I followed by staining with Giemsa solution or fluorescent dyes. This procedure results in a C-band-like appearance of the chromosomes due to removal of DNA from euchromatic chromosomal regions. The resistance of heterochromatic regions against cleavage by the enzyme has mainly been interpreted by the absence or rareness of recognition sites for this particular enzyme in these regions.

Relationship of cytogenetic subtypes of salivary gland pleomorphic adenomas with patient age and histologic type.

Sixty-nine salivary gland pleomorphic adenomas were fully karyotyped by G-banding including 40 tumors previously reported. The cytogenetic results allowed to distinguish between three major chromosomal subgroups characterized by either an apparently normal karyotype or by rearrangements of chromosome 8q12 or by rearrangements of chromosome 12q14-15. Significant correlations of these karyotypic groups with the age of the patients and histologic subgroups of the pleomorphic adenomas were found.

Retinitis pigmentosa, hearing loss and vitiligo: report of two patients.

In this report we describe the association of retinitis pigmentosa, hearing loss and vitiligo in two non-related patients. The second patient developed, in addition, an axonal polyneuritis after the age of 30. Previous reports dealing with this unusual combination of symptoms are discussed.

Cytogenetic findings on eight follicular thyroid adenomas including one with a t(10;19).

Eight follicular adenomas of the thyroid gland were cytogenetically investigated. Of these, only one showed a chromosomal abnormality, a translocation t(10;19)(q22;p13 or q13). The situation is compared with that of thyroid carcinomas and pleomorphic adenomas.

Translocation t(11;19)(q21;p13.1) as the sole chromosome abnormality in a cystadenolymphoma (Warthin's tumor) of the parotid gland.

Cytogenetic findings on a cystadenolymphoma (Warthin's tumor) of the parotid gland are reported. In the primary culture, a reciprocal balanced translocation t(11;19)(q21;p13.1) as the sole clonal abnormality was found in the majority of metaphases.

Identification of flow-sorted chromosomes by G-banding and in situ hybridization.

The identification of flow-sorted chromosomes is a very important tool for checking the purity of the fractions obtained. An easy and reproducible method for obtaining G-banded chromosomes with good resolution of bands is described. Also, we are able to show that the percentage of chromosomes which can be clearly distinguished by this procedure depends to a large extent on the duration of mitotic arrest.

Cytogenetic studies in 50 meningiomas.

In a series of 50 meningiomas, cytogenetic studies showed that almost half had a normal diploid karyotype. The remainder had monosomy 22, some with a normal diploid line also present. The initial monosomy was often followed by further chromosome loss, and occasionally by structural abnormalities, some with distinctive characteristics.

Plasma melatonin levels in patients suffering from colorectal carcinoma.

Plasma melatonin was determined in samples of patients with colorectal carcinoma and in controls using an iodinated radioimmunoassay. Both groups showed large individual variability in absolute melatonin levels. However, during the night, melatonin concentration in cancer patients was significantly lower than in controls.

The European Multiple Birth Study (EMBS).

The more that twin and other multiple pregnancies are investigated, the more it becomes mandatory that collaborative studies are set up in order to attain the critical number of cases needed to achieve meaningful and reliable results. The European Multiple Birth Study (EMBS) aims to study two aspects of twin and multiple pregnancy: 1) management of pregnancy and labour, with emphasis on the prevention of preterm delivery; 2) accurate determination of zygosity, a prerequisite for the proper use of the twin method in a variety of fields, eg, congenital malformations, genetics, clinical investigations, etc. The rationale, the methods and the organisation of the study are described and discussed.

Structural rearrangements of chromosome Nr 8 involving 8q12--a primary event in pleomorphic ademona of the parotid gland.

Nine pleomorphic adenomas of the human parotid gland were investigated. Within this series the group of cases having clonal aberrations of chromosome Nr 8 predominates. The occurrence of cases with trisomy-8 and cases with structural rearrangements involving a breakpoint in 8q11-8q13 allows a further subdivision of this group of tumors.

Rearrangements of chromosome region 12q13----q15 in pleomorphic adenomas of the human salivary gland (PSA).

Nine of 40 pleomorphic salivary gland adenomas (PSAs) showed clonal aberrations of chromosome 12, with a breakpoint at 12q13----q15. The cytogenetic findings in these cases and those of nine additional cases reported in the literature suggest that this type of aberration is a primary change directly involved in the genesis of PSA.