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J Jenderny

Publications and source records attributed to J Jenderny.

15 recordsLinked to original sources
PubMed1993

Analysis of a terminal Xp22.3 deletion in a patient with six monogenic disorders: implications for the mapping of X linked ocular albinism.

The molecular characterisation of chromosomal aberrations in Xp22.3 has established the map position of several genes with mutations resulting in diverse phenotypes such as short stature (SS), chondrodysplasia punctata (CDPX), mental retardation (MRX), ichthyosis (XLI), and Kallmann syndrome (KAL). We describe the clinical symptoms of a patient with a complex syndrome compatible with all these conditions plus ocular albinism (OA1). He has a terminal Xp deletion of at least 10 Mb of DNA. Both the mother and sister of the patient are carriers of the deletion and show a number of traits seen in Turner's syndrome. The diagnosis of ocular albinism was confirmed in the patient and his mother, who shows iris translucency, patches and streaks of hypopigmentation in the fundus, and macromelanosomes in epidermal melanocytes. By comparative deletion mapping we can define a deletion interval, which locates the OA1 gene proximal to DXS143 and distal to DXS85, with the breakpoints providing valuable starting points for cloning strategies.

Abnormalities, Multiple↗
PubMed1993

Transmission of a ring chromosome 18 from a mother with 46,XX/47,XX, + r(18) mosaicism to her daughter, resulting in a 46,XX,r(18) karyotype.

A 6 month old patient is reported with a ring chromosome 18 confirmed by cytogenetic studies and in situ hybridisation. Her clinical features were similar to previous cases of ring chromosome 18 syndrome. The ring chromosome was inherited from the phenotypically and mentally normal mother with a mos 46,XX/47,XX, + r(18) karyotype.

Abnormalities, Multiple↗
PubMed1992

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.

Chromosome Inversion↗
PubMed1988

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.

Aerosols↗
PubMed1987

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.

Chromosome Aberrations↗
PubMed1987

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.

Administration, Inhalation↗
PubMed1984

Control of meiosis by somatic cells in mice: inheritance of the meiosis I error 'diploidy' and nonexpression in sensitive NMRI/Han oocytes ovulated from chimeras.

NMRI mouse and Djungarian hamster females ovulate diploid and/or hyperploid oocytes with increased frequencies after gonadotrophin stimulation, suggesting that somatic cells are involved in the failures of endocrine control resulting in aneuploidy. To study the inheritance of gonadotrophin-induced aneuploidy as well as the fate of sensitive oocytes in a resistant somatic environment and vice versa, we analysed the frequency of diploid oocytes in NMRI/Han, C57BL/6J and their F1 hybrids (C57BL/6J X NMRI/Han), (NMRI/Han X C57BL/6J) as well as in NMRI/Han in equilibrium C57BL/6J chimeric females after gonadotrophin injections. Ovulated oocytes were analysed in all females for the appearance of diploidy, characterized as premature arrest of development at metaphase I. Our data suggest that the trait of induced diploidy is genetically determined and can be transmitted either maternally or paternally. A maternal effect modulated the expression of that trait. Several mechanisms acting on the feed-back control ovary-hypothalamus/pituitary, within the ovary or even within a chimeric follicle, may be responsible that 'sensitive' oocytes ovulated from chimeras are all normal haploid. These data suggest that not only oocyte maturation but also chromosome disjunction during meiosis I is controlled by somatic cells.

Aneuploidy↗
PubMed1983

The genetic basis of non-disjunction: increased incidence of hyperploidy in oocytes from F1 hybrid mice.

Oocytes from parental mice strains NMRI/Han, C57/bl and Balb/c and from F1 hybrid lines were analysed for aneuploidy due to non-disjunction after gonadotropin-stimulated ovulation. No hyperploid oocytes were present in five of the strains studied. F1 hybrids from crosses of NMRI/HanxC57/bl did ovulate, however, a significantly increased number of hyperploid oocytes, although females from their parental strains show a rather low incidence of non-disjunction. The evidence for a genetic basis for non-disjunction is assessed and possible causative factors are discussed.

Animals↗
PubMed1983

Low doses of X-rays decrease the risk of diploidy in mouse oocytes.

Females from the NMRI/Han mouse strain ovulate a high number of diploid oocytes (about 12%) after gonadotrophin-stimulated ovulation. These oocytes can be fertilized and develop into triploid embryos subsequently. The exposure of such gonadotrophin-primed females to X-ray doses of 0.05, 0.10, 0.20 or 0.40 Gy during the preovulatory period (2 h after the HCG dose) significantly decreased the percentage of diploid oocytes. After the highest dose used, i.e. 0.80 Gy, however, the incidence was on the level from unirradiated females, again. We suggest that the observed negative hump-shaped dose response of diploidy is not caused by secondary modifications induced by irradiation, such as a selective killing of diploid oocytes before ovulation, or a (compensatory) super-ovulation of only normal oocytes, but rather is caused by a direct radiobiological interference of low doses in protecting from gonadotrophin-induced aneuploidy.

Aneuploidy↗
PubMed1982

Nondisjunction and chromosome breakage in mouse oocytes after various x-ray doses.

The effect of varying X-ray doses (0.05-0.80 Gy) on preovulatory mouse oocytes was studied by measuring nondisjunction during the first meiotic division, as well as structural chromosome anomalies in ovulated oocytes at metaphase stage II. The incidence of nondisjunction (0.1% hyperploid oocytes) found in oocytes from nonirradiated NMRI-Han female mice was in accordance with the results previously obtained with the same strain. Significantly (P less than 0.05) more hyperploid oocytes (0.9%) were ovulated following irradiation with 0.8 Gy. There was no statistically significant increase of nondisjunction after low doses. Structural chromosome anomalies occurred, however, even after an irradiation dose as low as 0.05 Gy. The dose response for structural chromosome anomalies is altogether different from that of radiation-induced hyperploidy. We consider that irradiation of mature oocytes might well be less hazardous with regard to its potency for increasing nondisjunction during the first meiotic division when compared with the effect of chemical mutagens.

Animals↗
PubMedDate not supplied

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%.

Adult↗
PubMedDate not supplied

Sperm chromosome analysis of two males heterozygous for a t(2;17)(q35;p13) and t(3;8)(p13;p21) reciprocal translocation.

Sperm chromosome complements from two males, one heterozygous for the reciprocal translocation t(2;17)(q35;p13) (n = 18) and one for t(3;8) (p13;p21) (n = 73), were analyzed. Only 2:2 segregations were observed with t(2;17): alternate, 56%; adjacent-I, 33%; adjacent-II, 11%. Both 2:2 and 3:1 meiotic segregations occurred in t(3;8): alternate, 34.2%; adjacent-I, 43.8%; adjacent-II, 20.5% and 3:1, 1.4%. A significant excess of chromosomally normal versus balanced sperm complements was observed with both translocation heterozygotes. The frequencies of other chromosome aberrations unrelated to the translocations were 16.7% for t(2;17) and 8.2% for t(3;8). The ratio of X-bearing to Y-bearing sperm was not different from the theoretically expected ratio of 1:1.

Adult↗