Analysis of a de novo complex chromosome rearrangement involving chromosomes 4, 11, 12 and 13 and eight breakpoints by conventional cytogenetic, fluorescence in situ hybridization and spectral karyotyping.

A complex chromosome rearrangement (CCR) with eight breakpoints resulting in four derivative chromosomes (4, 11, 12 and 13) was detected prenatally in a male fetus of a twin pregnancy. The karyotype of the female second fetus was normal. The apparently balanced de novo CCR was identified by classical cytogenetic methods and fluorescence in situ hybridization (FISH). We compared these findings with results from spectral karyotyping (SKY).

Type and frequency of chromosome aberrations in 781 couples undergoing intracytoplasmic sperm injection.

Cytogenetic investigations were performed in 781 couples prior to intracytoplasmic sperm injection (ICSI) because of severe male infertility or fertilization failures in previous in-vitro fertilization attempts. Out of these 1562 patients, 1012 had a normal karyotype without any aberrations (64.8%), 204 patients had an abnormal karyotypes (13.1%). These chromosome aberrations included constitutional aberrations (4.4%), fragile sites of autosomes (3.0%), low level mosaicism of sex chromosomes (4.0%) and secondary structural chromosome aberrations (4.2%). Combinations of different types of abnormalities were stated. Another 346 patients (22.1%) showed single cell aberrations; the significance of these is unclear at the moment. Constitutional chromosome aberrations were detected in 69 patients. The following chromosome aberrations were observed: 35 sex chromosomal aberrations (comprising hyperploidies of X or Y chromosomes, mosaicisms and derivative X and Y chromosomes), 34 autosomal aberrations including 14 reciprocal translocations, five Robertsonian translocations, six inversions, one marker chromosome, one trisomy 18 mosaicism and seven other structural aberrations. Three autosomal regions showed fragile sites: 6q13 in 2.9% of the patients, 17p12 and 10q24 in 0.05% each. In conclusion, our data show that a high number of infertile couples in an ICSI programme are affected by chromosome aberrations which occur in both sexes. It is suggested that a chromosomal analysis should be performed on both partners before ICSI treatment is initiated.

Combined cytogenetic and Y chromosome microdeletion screening in males undergoing intracytoplasmic sperm injection.

We evaluated the frequency of chromosomal aberrations and microdeletions of the Y chromosome in a sample of 204 patients included in an intracytoplasmic sperm injection (ICSI) programme. The prevalence of Y chromosome deletions in males with severely or only moderately reduced sparm counts is mainly unknown, so that patients were chosen with sperm counts ranging from mild oligozoospermia to azoospermia. While six out of 158 (3.8%) patients showed constitutional chromosomal aberrations, only two out of 204 (0.98%) patients were diagnosed with a microdeletion of Yq11. One had a terminal deletion in subinterval 6 of Yq11.23 which included the DAZ gene and a corresponding sperm count < 0.1 x 10(6) spermatozoa/ml. The second patient had an isolated deletion of marker Y6PH54c, a more proximal site in subinterval 5 on Yq11.23, but repeatedly showed sperm counts of 3-8 x 10(8) spermatozoa/ml. Thus, of the 158 patients who underwent a combined cytogenetic and Y-microdeletion screening, eight patients (5.1%) showed chromosomal abnormalities, either at the cytogenatic (n = 6) or the molecular level (n = 2). In conclusion, although rare in number, microdeletions of the Y chromosome can also be observed in patients with moderately reduced sperm counts. A more proximal site of the deletion breakpoint does not necessarily imply a more severe impairment of spermatogenesis than a distal deletion site. In our sample, the overall frequency of constitutional chromosomal aberrations exceeded the incidence of microdeletions of the Y chromosome even in patients with idiopathic azoo- or severe oligozoospermia.

A comparison of thermal enhancement of cis-diamminedichloroplatinum (II) induced renal and intestinal toxicities by whole body hyperthermia in the rat.

Thermal enhancement of cis-diamminedichloroplatinum (II) (DDP) induced renal and intestinal toxicities by whole body hyperthermia (WBH) were compared using a F344 rat model. Thermal enhancement ratios (TER) for DDP-induced nephrotoxicity were calculated using renal functional assays and morphological techniques. TER values for gastrointestinal (G.I.) toxicity were calculated using "severity of diarrhea" and jejunal crypt cell survival as assays. TER's for renal damage varied between 3 and 3.4, whereas the TER measured for G.I.-toxicity was 1.8. Physiological changes caused by WBH or intrinsic differences in the sensitivities of normal tissues to DDP +/- WBH may be responsible for the differences in thermal enhancement of DDP-induced renal and intestinal toxicities.