Long range restriction map of the von Hippel-Lindau gene region on human chromosome 3p.

Von Hippel-Lindau disease is a heritable tumour syndrome caused by the loss of the function of a tumour suppressor gene on the short arm of human chromosome 3. The interval RAF1-D3S18 (3p25-3p26) has been identified by genetic linkage studies to harbour the von Hippel-Lindau gene. We have constructed a long range restriction map of this region and have succeeded in demonstrating the physical linkage of loci D3S726 (DNA probe LIB31-38), D3S18 (c-LIB-1, L162E5), D3S601 (LIB19-63) and D3S587 (LIB12-48). Since multipoint analysis has located D3S601 proximal to D3S726, the physical map should be oriented with D3S726 towards the telomere. The order and distances of probes within the von Hippel-Lindau gene region is as follows: telomere--LIB31-38--(< 280 kb)--c-LIB-1--(overlapping)--L162E5--(900-1600 kb)--(LIB19-63, LIB12-48)--centromere. In tissues that included blood, semen and Epstein-Barr-virus-transformed lymphocytes, we detected a putative CpG island flanking D3S18.

Chromosome aberrations in 450 sperm complements from eight controls and lack of increase after chemotherapy in two patients.

Four hundred fifty sperm complements from eight controls were analyzed. A conservative estimate of aneuploidy was 1.8% with a hyperhaploid rate of 0.9% (4/450). The overall frequency of structural aberrations was 8.9% (40/450). The proportion of X-bearing (47.5%) and Y-bearing (52.5%) sperm did not differ significantly. Sperm complements were analyzed from a cancer patient 9 months after polychemotherapy (n = 63) and from a patient being treated with Imurek (azathioprine) (n = 30). There was no significant increase in the incidence of numerical and structural chromosome aberrations in the sperm of either patient. The percentages of X-bearing and Y-bearing sperm were not significantly different from the expected 50%.

Sperm chromosome analysis of a man heterozygous for a pericentric inversion of chromosome 20.

The sperm chromosomes of a man heterozygous for inv(20)(p13q11.2) were analyzed. Twenty-six sperm chromosome complements were examined, of which fourteen contained the normal chromosome, and twelve the inverted chromosome. None of the sperm complements contained a recombinant chromosome 20. The frequency of structural chromosomal aberrations unrelated to the inversion was 11.5% (3/26). Numerical aberrations were not observed. The percentages of X- and Y-bearing sperm were 56% and 44%, respectively, which was similar to the expected 1:1 ratio.

Chromosomal abnormalities and sister-chromatid exchange in bone marrow cells of mice and Chinese hamsters after inhalation and intraperitoneal administration. II. Cyclophosphamide.

The genotoxic effects of cyclophosphamide (CPP), a human and animal carcinogen requiring metabolic activation, were studied in bone marrow cells of mice and Chinese hamsters, analyzing chromosome abnormalities (CA) and sister-chromatid exchange (SCE) after a 2-h inhalation or a single intraperitoneal administration. In order to compare the genotoxicity after the different routes of administration in the dose range of 10-110 mg CPP/kg body weight, the systemic dose obtained by inhalation was calculated from blood concentrations and the inhalation duration after an analysis of the CPP blood kinetics. In NMRI mice the frequency of bone marrow cells with chromosome abnormalities was higher after aerosol exposure than after intraperitoneal administration of comparable CPP doses. In Chinese hamsters the CA frequency was similar with both exposure routes. Inhaled CPP was found to induce a higher frequency of CA and SCE in the bone marrow cells of mice compared to those of Chinese hamsters. The findings suggest that for genotoxins requiring metabolic activation species differences exist with respect to the influence of the route of entry and the sensitivity of bone marrow cells.

[Partial deletion of the short arm of chromosome 13 as an indication of paternity in forensic assessment]. / Partielle Deletion am kurzen Arm eines Chromosoms 13 als Hinweis auf Vaterschaft im Rahmen eines Gutachtens.

We report a paternity testing case in which a decisive clue was a deletion of the short arm of chromosome 13 in the child and in his putative father.

Chromosomal abnormalities and sister-chromatid exchange in bone marrow cells of mice and Chinese hamsters after inhalation and intraperitoneal administration: I. Diepoxybutane.

Diepoxybutane (DEB), a direct-acting animal carcinogen, was found to increase the frequency of structural chromosomal abnormalities (CA) and sister-chromatid exchange (SCE) in bone marrow cells of mice and Chinese hamsters, when inhaled from an aerosol during a 2-h head-only exposure or administered as a single intraperitoneal injection. For the purpose of comparing the genotoxicity in the 2 species, both after inhalation and intraperitoneal administration, the systemic DEB dose obtained by inhalation was determined on the basis of blood concentrations and inhalation duration after the investigation of the blood kinetics. The bone marrow cells of male and female NMRI mice were found to be more sensitive than those of Chinese hamsters to the genotoxic activity of DEB.

Chromosome analysis of human sperm. I. First results with a modified method.

A modified technique has been developed for the visualization of the chromosomes in human sperm. The cytogenetic analysis of 129 G-banded human sperm metaphases of 6 normal donors showed an incidence of structural and numerical chromosome abnormalities of 7.8%. Two out of 129 spermatozoa were aneuploid (1.6%). The frequency of sperms with chromatid-type aberrations was 2.3% (3/129). Chromosome-type aberrations were found in 5 out of 129 (3.9%) spermatozoa. X to Y ratio did not differ significantly from the expected one-to-one ratio. Twenty-six sperm complements from a patient 18-20 months after testes exposure to 30 Gy were examined. A significant increase of numerical and structural chromosome abnormalities was not observed. Chromatid-type aberrations were found in two sperm complements (7.7%) and chromosome-type aberrations in one sperm complement (3.9%). The cytogenetic analysis of 15 human sperms from a cancer patient 26 months after chemotherapy showed an increased frequency of aberrant sperm complements (33.4%). One chromatid-type (6.7%), three chromosome-type aberrations (20.0%) and one (6.7%) hyperploid sperm complement could be observed. The sample size is still too small to answer the question whether chemical mutagens may increase the frequency of chromosomal abnormalities in human sperm.

Transplacental and direct exposure of mouse and marmoset to ethylnitrosourea: analysis of chromosome aberrations.

The effect of ethylnitrosourea (ENU) on chromosomes of mouse bone marrow cells and transplacentally exposed embryonic liver cells was investigated. Chromosome aberrations were found to be dose- and time-dependent. The maximum damage was seen 6 h after the exposure. Chromosome aberrations were also induced in bone marrow cells and lymphocytes of marmosets (Callithrix jacchus) directly exposed to ENU. Aberrations did not, however, occur in offspring whose mothers were treated with ENU before conception. Furthermore, chronic transplacentally exposed offspring have been analyzed. The frequency of chromosome aberrations was not increased in their lymphocytes and fibroblasts. The elimination of chromosome aberrations during embryogenesis is discussed.

In vitro testing of chlorpropamide with human lymphocyte cultures in the presence of liver microsome fraction S9 mix of rats.

The oral hypoglycaemic drug 1-(p-chloroben-zenesulfonyl)-3-propylurea (chlorpropamide) was examined for clastogenic properties using human lymphocytes with a microsomal (S9 mix) activation system. Lymphocytes, exposed to the S9 mix only as well as to the solvent DMSO, yielded chromosome aberration levels within the background range. The sensitivity of the S9 mix could be demonstrated using 2-[bis(2-chloroethyl)amino]tetrahydro(2H)-1,3,2-oxazaphosphorine 2-oxide (cyclophosphamide) as a positive control, which only displays clastogenic properties after metabolic activation. Chlorpropamide, however, did not induce structural chromosome aberrations under the in vivo conditions tested in this study.

Mutagenicity studies with 2,4,5-T on bacteria and mammalian germ cells.

The herbicide 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) was evaluated for potential mutagenicity by a Salmonella/mammalian-microsome test, a dominant lethal test on female rats, and by a cytogenetic assay on spermatogonia of Chinese hamster. In the Salmonella/mammalian-microsome test on four Salmonella typhimurium strains (TA 1535, TA 100, TA 1537, and TA 98), doses of up to and including 2500 micrograms/plate did not cause any mutagenic effects. In a dominant lethal test on female rats, 8-week dietary administration of 2,4,5-T at doses of up to and including 10 mg/kg/day did not cause any increase in preimplantation loss or the rate of dead implants, and did not have any effect on the fertilization quota. Cytogenetic analysis of the spermatogonia of male Chinese hamsters orally dosed five times at 24-hr intervals with 2,4,5-T at levels of up to and including 100 mg/kg did not provide any indication of 2,4,5-T having chromosome-damaging effects. Therefore, none of the three test systems provided any indication of 2,4,5-T having a mutagenic effect.

Lack of mutagenic effects of halothane in mammals in vivo.

Rodents were exposed in vivo to various clinical doses of halothane to observe structural chromosome aberrations, micronuclei, sister chromatid exchanges (SCEs), dominant lethal mutations, and interferences with phases of the cell cycle. The frequency of chromosome aberrations in bone marrow cells was not increased after exposing Chinese hamsters to 1 per cent halothane once for 3 h, twice for 3 h (exposures 24 h apart), or to 0.5 per cent for 24 h. The analysis of SCEs in bone marrow cells was also negative after exposing hamsters to 1 per cent halothane for 3 h, or to 0.5 per cent for 12 h. In halothane-exposed female mice (0.75 per cent for 16 h), oocyte maturation (meiotic stages) was delayed. Another group of exposed female mice (1 per cent for 5 h) were mated with untreated males. The number of dead implants was not increased as compared to controls. In liver cells of 16-day-old living embryos, neither monosomic nor trisomic cells were observed. Male mice were exposed to 1 per cent halothane for 1 h per day for 48 days. On the evening of the forty-eighth day, they were mated with untreated females. Dominant lethal mutations were not increased as compared to controls. In erythrocytes of these chronically exposed male mice, the frequency of micronuclei was not significantly enhanced. The authors conclude that halothane does not induce mutations under the in vivo conditions tested in this study.

Gene frequencies of transferrin (TfC) subtypes in Western Germany (Düsseldorf region).

Transferrin (Tf) subtypes were determined by isoelectric focusing and polyacrylamide gel electrophoresis on samples from 380 unrelated individuals. The following gene frequencies were observed: TfC1 0.7816, TfC2 0.1355, TfC3 0.0711, and TfB 0.0118.

Transformation of BHK 21/CL 13 cells by various polycyclic aromatic hydrocarbons using the method of Styles.

Nine polycyclic aromatic hydrocarbons (PAHs) were investigated by the cell-transformation assay method of Styles. Benzo(a)pyrene [B(a)P], chrysene (CH), 3-methylcholanthrene (3-MC), benz(a)anthracene (BA), benzo(b)fluoranthene [B(b)F], and dibenz(a,h)anthracene (DBA) were tested, including liver homogenate, and showed dose-effect relationships and a more than 2-fold increase of transformation rates at LC50. Due to variations of the test method our results differed quantitatively from the data published by Purchase and Styles. Discrimination between the known carcinogens listed above and the noncarcinogens, phenanthrene (PA) and anthracene (AC), lacking a dose-effect relationship was, however, possible. Benzo(e)pyrene [B(e)P] was regarded as positive although producing only a 2-fold increase in the number of transformed colonies.