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B Rosenbusch

Publications and source records attributed to B Rosenbusch.

At least 19 recordsLinked to original sources
PubMed2006

The contradictory information on the distribution of non-disjunction and pre-division in female gametes.

Valuable information on the cytogenetic constitution of female gametes has been deduced from the direct, so-called conventional analysis of oocytes remaining unfertilized in programmes of assisted reproduction. Additional, indirect conclusions have become possible by PGD of the polar bodies. Both techniques provided evidence for the co-existence of two aneuploidy-causing mechanisms during first maternal meiosis; non-disjunction (ND) of bivalents results in the loss or gain of whole chromosomes in metaphase II complements, whereas a precocious division (pre-division, PD) of univalents leads to the loss or gain of single chromatids. As to the distribution of ND and PD, however, direct oocyte chromosome studies and PGD tell surprisingly different stories. Moreover, first and second polar body analyses contradict the data derived from DNA polymorphism studies concerning the distribution of first and second meiotic division errors. An increased awareness of these problems appears necessary because important decisions are made on the basis of PGD results.

Adult↗
PubMed2002

Cytogenetic analysis of giant oocytes and zygotes to assess their relevance for the development of digynic triploidy.

BACKGROUND: In order to assess the role of binucleate giant oocytes for generating digynic triploidy, we studied their frequency, maturation patterns and chromosomal complements at metaphase II (MII) or after fertilization. METHODS: Uncleaved, giant zygotes were incubated with podophyllotoxin and vinblastine, treated with hypotonic solution and fixed by a gradual fixation method. Giant MII oocytes were directly subjected to hypotonic treatment. The chromosomes were stained with Giemsa. RESULTS: A total of 7065 oocytes were collected during the study period, of which 18 (0.26%) were classified as giant cells. When considering only those patients in whom giant cells were identified (among other normal sized cells) a giant cell frequency of 18/237 (7.6%) was found. Nine cells underwent a union of the nuclei during maturation to MII and four of them became fertilized showing two pronuclei. Seven oocytes maintained the binucleate state to MII and one of them was fertilized showing three pronuclei. Ten unfertilized cells were available for cytogenetic analysis and proved to be diploid. All five giant zygotes revealed triploidy. CONCLUSIONS: The data suggest that giant oocytes may play an important, yet underestimated role in causing digynic triploidy. We recommend the exclusion of giant oocytes from IVF trials and that giant cells should be discarded, even if they carry the regular number of two pronuclei.

Adult↗
PubMed2001

Cytogenetic analysis of human zygotes displaying three pronuclei and one polar body after intracytoplasmic sperm injection.

BACKGROUND: Digynic zygotes with three pronuclei and one polar body obtained after intracytoplasmic sperm injection (ICSI) were studied cytogenetically to elucidate the frequency and origin of chromosomal abnormalities at the earliest stage of conception. METHODS: Uncleaved, single-cell zygotes were incubated with podophyllotoxin and vinblastine and fixed by a gradual fixation air drying method. The chromosomes were stained with Giemsa. RESULTS: Twenty-two (50%) out of 44 informative zygotes revealed cytogenetic alterations, including aneuploidy (six cells, 13.6%), structural aberrations (10 cells, 22.7%) and combinations of numerical and structural abnormalities (two cells, 4.5%). In one case (2.3%), double aneuploidy or an effect of chromosomal translocation could not be distinguished and one zygote (2.3%) turned out tetraploid due to injection of a diploid spermatozoon. Two zygotes (4.5%) showed an irregular chromatid segregation between the two maternal complements. In completely analysable cells, the sex chromosome ratio XXX:XXY was 17:15. CONCLUSIONS: Digynic ICSI zygotes carry a high rate of cytogenetic abnormalities that obviously have been transmitted by the participating oocytes and spermatozoa. We also confirmed the previously reported, possibly ICSI-induced irregular oocyte chromatid segregation. The results suggest that aneuploidy in the oocytes must have been caused by predivision instead of non-disjunction.

Cell Nucleus↗
PubMed1998

Maturation of a binuclear oocyte from the germinal vesicle stage to metaphase II: formation of two polar bodies and two haploid chromosome sets.

We report on a binuclear human oocyte that underwent maturation in vitro from germinal vesicle stage to metaphase II. Following extrusion of two polar bodies, the oocyte was processed for cytogenetic analysis which revealed two separate haploid chromosome sets accompanied by the corresponding polar body chromatin. Tentatively established karyotypes were 23,X and 23,X,ace, respectively. This condition could have resulted in a tripronuclear digynic zygote after monospermic fertilization.

Adult↗
PubMed1998

Chromosomal analysis of multipronuclear zygotes obtained after partial zona dissection of the oocytes.

We have attempted to analyse the chromosome constitution of multipronuclear 1-cell zygotes obtained after partial zona dissection (PZD) of the oocytes. Six cells with three pronuclei could not be evaluated whereas another one was characterized by the presence of a normal haploid and two uninterpretable metaphases. Complete karyotypes were established for 21 tripronuclear cells, taking the varying arrangement of the chromosome sets into consideration. Of the zygotes, 10 showed three separated haploid metaphases (distribution pattern n/n/n), eight zygotes had one haploid and one diploid chromosome set (n/2n) and in three cells the individual sets were not distinguishable (3n). The sex chromosome ratio XXX:XXY:XYY was 7:9:5. Chromosome abnormalities were found in eight of the completely or partially analysable tripronuclear zygotes (36.4%) and included numerical (4 cells), structural (2 cells) as well as combinations of numerical and structural alterations (2 cells). Three out of 11 zygotes with four pronuclei could not be evaluated at all. In three cases, only two chromosome sets were analysable and another cell displayed one uninterpretable set. Three out of eight completely or partially analysable zygotes with four pronuclei (37.5%) had chromosomal abnormalities. Excluding the four cells with one or two uninterpretable metaphases, the sex chromosome distribution XXXX:XXXY:XXYY:XYYY in the zygotes with four pronuclei was 0:1:1:2. Compared with previously analysed multipronuclear zygotes obtained after conventional in-vitro fertilization (IVF), the rate of aberrant zygotes as well as the incidence of aberrant (male + female) chromosome sets were not significantly changed after PZD.

Adult↗
PubMed1997

The chromosomal constitution of multipronuclear zygotes resulting from in-vitro fertilization.

We have attempted to analyse the chromosome constitution of 77 multipronuclear uncleaved zygotes obtained from our in-vitro fertilization programme. Complete karyotypes could be established for 51 tripronuclear cells and eight zygotes with four pronuclei. When compiling the results, the varying arrangement of the chromosome sets was taken into consideration. Eighteen tripronuclear zygotes showed three separate haploid metaphases (distribution pattern n/n/n), 16 cells had one haploid and one diploid chromosome set (n/2n), and in 15 zygotes the individual sets were not distinguishable (3n). Two zygotes were in fact tetraploid, the distribution of metaphases on the slide being n/3n and n/n/2n, respectively. In tripronuclear zygotes the sex chromosome ratio XXX:XXY:XYY was 14:16:18, excluding the two tetraploid cells and one zygote with a 23,X/23,X/22,-C or -Y karyotype. Chromosome abnormalities were found in 16 zygotes (31.4%) and included numerical (six cells), structural (four cells) as well as combinations of numerical and structural alterations (six cells). Four of the zygotes with four pronuclei (50%) had numerical and/or structural chromosome aberrations. Excluding two cells with one uninterpretable metaphase and a 22,-C or -Y karyotype, respectively, the sex chromosome distribution XXXX:XXXY:XXYY:XYYY was 1:1:2:1 in zygotes with four pronuclei. Another zygote was found to be pentaploid after fixation. These results suggest that analysis of multipronuclear zygotes yields valuable information about cytogenetic abnormalities occurring at the earliest stage of conception.

Adult↗
PubMed1997

Triploidy caused by endoreduplication in a human zygote obtained after in-vitro fertilization.

Cytogenetic analysis of a presumably tripronuclear zygote revealed that triploidy was caused by an endoreduplicated 46,XX complement. The remaining chromosomes yielded a hyperhaploid karyotype of 28,Y, +2, +3C, +D. The origin of this chromosomal composition is obscure. Besides endoreduplication in a normal 23,X oocyte pronucleus and fertilization by a normal 23,Y spermatozoon, an additional female pronucleus might have been formed due to an irregular chromosome distribution during second meiotic division. On the other hand, penetration by a hyperhaploid spermatozoon cannot be excluded with certainty.

Adult↗
PubMed1996

Influence of smoking on fertility in women attending an in vitro fertilization program.

OBJECTIVE: To investigate the influence of cigarette smoking of women on the fertilization and pregnancy rates obtained by IVF treatment. PATIENTS: One hundred ninety-seven infertile, otherwise healthy women who entered an IVF program for the first time. SETTING: Fertility unit at the Women's University hospital of the University of Ulm, Ulm, Germany. INTERVENTIONS: The study population consisted of 197 women (23 to 39 years old) who were divided into the following groups: nonsmokers (n = 68), passive smokers (n = 26), and active smokers (n = 103) according to the cotinine concentration measured in follicular fluid. The reason for infertility was strictly a tubal factor with apparently normal ovulatory cycles. To guarantee an objective recording of tobacco smoke exposure, the smoking habit was not determined by questionnaires, but by cotinine, the principal metabolite of nicotine. RESULTS: There were no significant differences in fertilization and pregnancy rates between the different groups. The E2 serum levels were decreased significantly in women who smoked when compared with the results obtained from nonsmokers and passive smokers. Overall, a strong negative correlation of the cotinine and E2 levels was observed (r = -0.65). CONCLUSION: The results suggest that there is no clinically detectable impairment of fertilization potential due to female smoking and that there is a greater influence on the outcome of IVF by other factors.

Adult↗
PubMed1995

Predicting the success of in vitro fertilization: conventional semen analysis compared to the hamster ova penetration test.

In vitro fertilization has been advocated as a possible treatment for male factor infertility. Using data collected on 154 men, conventional semen analysis and the hamster ova penetration test are compared with respect to their power in predicting the success of assisted conception. As performing the hamster test is more expensive than the semen analysis, we also investigate a combined strategy. It performs better than the discrimination based solely on the semen parameters, but does not lead to an improvement over the overall discriminatory power obtained from the hamster test alone.

Adult↗
PubMed1995

[Idiopathic habitual abortion: experiences with active immunotherapy].

The effect of lymphocyte transfusions on the stabilisation and successful outcome of pregnancy was investigated in 30 women with recurrent abortions presumably caused by immunologic factors. Lymphocyte concentrates were obtained from stored whole blood of the husbands and transferred by intravenous injection. Exclusion criteria for this study were the presence of antipaternal lymphocytotoxic antibodies in the patient's serum (cross match) or an advanced pregnancy (> 12 weeks). After transfusion of paternal lymphocytes 19 (63%) women had uncomplicated and successful pregnancies whereas 11 (37%) suffered again from early pregnancy loss. Two out of these 11 patients aborted twice. The probability of a successful treatment decreased as soon as lymphocytotoxic antibodies appeared in the patient's serum (p < or = 0.021). Women with a lower number of abortions before treatment carried their pregnancies to full term more frequently (p < or = 0.03). The number of transfusions, the period between start of treatment and conception as well as the distribution of age within the two groups had no significant effect on the outcome of therapy. A lack of lymphocytotoxic antibodies or their late appearance during treatment give a positive prognosis for the progress of pregnancy. Compared with a fertile control group, couples with habitual abortions showed no significantly increased HLA sharing. Immunisation with paternal lymphocytes in cases of presumably habitual abortions due to immunologic factors appears as an effective therapy with only few side effects. Large, randomised, double-blind, and placebo-controlled trials are needed before drawing conclusions.

Abortion, Habitual↗