Meiotic abnormalities and spermatogenic parameters in severe oligoasthenozoospermia.
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The incidence of meiotic abnormalities and their relationship with different spermatogenic parameters was assessed in 103 male patients with presumably idiopathic severe oligoasthenozoospermia (motile sperm concentration < or = 1.5 x 10(6)/ml). Meiosis on testicular biopsies was independently evaluated by two observers. Meiotic patterns included normal meiosis and two meiotic abnormalities, i.e. severe arrest and synaptic anomalies. A normal pattern was found in 64 (62.1%), severe arrest in 21 (20.4%) and synaptic anomalies in 18 (17.5%). The overall rate of meiotic abnormalities was 37.9%. Most (66.7%) meiotic abnormalities occurred in patients with a sperm concentration < or = 1 x 10(6)/ml. In this group, total meiotic abnormalities were found in 57.8% of the patients; of these, 26.7% had synaptic anomalies. When the sperm concentration was < or = 0.5 x 10(6)/ml, synaptic anomalies were detected in 40% of the patients. In patients with increased follicle stimulating hormone (FSH) concentrations, total meiotic abnormalities occurred in 54.8% (synaptic anomalies in 22.6%). There were statistically significant differences among the three meiotic patterns in relation to sperm concentration (P < 0.001) and serum FSH concentration (P < 0.05). In the multivariate analysis, sperm concentration < or = 1 x 10(6)/ml and/or FSH concentration > 10 IU/l were the only predictors of meiotic abnormalities. (+info)
Rapid visualization of metaphase chromosomes in single human blastomeres after fusion with in-vitro matured bovine eggs.
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The present study was aimed to facilitate karyotyping of human blastomeres using the metaphase-inducing factors present in unfertilized eggs. A rapid technique for karyotyping would have wide application in the field of preimplantation genetic diagnosis. When cryopreserved in-vitro matured bovine oocytes were fused with human blastomeres, the transferred human nuclei were forced into metaphase within a few hours. Eighty-seven human blastomeres from abnormal or arrested embryos were fused with bovine oocytes in a preclinical study. Fusion efficiency was 100%. In 21 of the hybrid cells, no trace of human chromatin was found. Of the remaining 66, 64 (97%) yielded chromosomes suitable for analysis. The method was used to karyotype embryos from two patients with maternal translocations. One embryo which was judged to be karyotypically normal was replaced in the first patient, resulting in one pregnancy with a normal fetus. None of the second patient's embryos was diagnosed as normal, and hence none was transferred. The results of the present study demonstrated that the ooplasmic factors which induce and maintain metaphase in bovine oocytes can force transferred human blastomere nuclei into premature metaphase, providing the basis for a rapid method of karyotyping blastomeres from preimplantation embryos and, by implication, cells from other sources. (+info)
Analysis and dynamics of the chromosomal complements of wild sparkling-wine yeast strains.
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We isolated Saccharomyces cerevisiae yeast strains that are able to carry out the second fermentation of sparkling wine from spontaneously fermenting musts in El Penedes (Spain) by specifically designed selection protocols. All of them (26 strains) showed one of two very similar mitochondrial DNA (mtDNA) restriction patterns, whereas their karyotypes differed. These strains showed high rates of karyotype instability, which were dependent on both the medium and the strain, during vegetative growth. In all cases, the mtDNA restriction pattern was conserved in strains kept under the same conditions. Analysis of different repetitive sequences in their genomes suggested that ribosomal DNA repeats play an important role in the changes in size observed in chromosome XII, whereas SUC genes or Ty elements did not show amplification or transposition processes that could be related to rearrangements of the chromosomes showing these sequences. Karyotype changes also occurred in monosporidic diploid derivatives. We propose that these changes originated mainly from ectopic recombination between repeated sequences interspersed in the genome. None of the rearranged karyotypes provided a selective advantage strong enough to allow the strains to displace the parental strains. The nature and frequency of these changes suggest that they may play an important role in the establishment and maintenance of the genetic diversity observed in S. cerevisiae wild populations. (+info)
Severe mental retardation in a boy with partial trisomy 10q and partial monosomy 2q.
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A severely mentally subnormal child with many physical stigmata was shown to have the karyotype 46,XY,-2,+der(2),t(2;10)(q31;q24)pat. Full evaluation of this patient's karyotype depended on the family studies. It was shown that a balanced translocation t(2,10) was present in 4 normal males in 3 generations. (+info)
Clinical characteristics of CHARGE syndrome.
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CHARGE syndrome, first described by Pagon, was named for its six major clinical features. They are: coloboma of the eye, heart defects, atresia of the choanae, retarded growth and development including CNS anomalies, genital hypoplasia and/or urinary tract anomalies, and ear anomalies and/or hearing loss. We experienced three cases of CHARGE syndrome who displayed ocular coloboma, heart defects, retarded growth and development, and external ear anomalies, and we also review the previously reported literature concerning CHARGE syndrome. (+info)
Karyotypes on three species of Chinese mesogastropod snails, Semisulcospira libertina, S. dolichostoma and Viviparus rivularis.
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Three species of the families Viviparidae and Pleuroceridae, the first intermediate host of paragonimiasis, metagonimiasis and echinostomiasis were studied cytologically. The observed diploid chromosome number was as follows: Semisulcospira libertina 36, S. dolichostoma 34, and Viviparus rivularis 64. The mitotic chromosome complement of S. libertina has nine metacentric pairs and nine submetacentric pairs, and S. dolichostoma has three metacentric pairs and 14 submetacentric pairs of chromosomes. Viviparus rivularis showed two metacentric pairs and 30 submetacentric pairs of chromosomes. (+info)
Genomic instability and recurrent breakpoints are main cytogenetic findings in Hodgkin's disease.
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BACKGROUND AND OBJECTIVE: Successful cytogenetic studies in Hodgkin's disease (HD) are rare, and, except for hyperdiploidy, no chromosome changes typical for this disorder have been described. The purpose of this study was to collect cytogenetic information from a new series of lymphoid neoplasms diagnosed either as classical HD or as Hodgkin's-like anaplastic large cell lymphoma (HD-like ALCL), according to the REAL Classification. DESIGN AND METHODS: We studied 27 cases of HD and 10 cases of HD-like ALCL. Cytogenetic investigations were performed on lymph nodes (35 cases), bone marrow or pleural effusion. A large screening of slides was performed to detect abnormal metaphases despite the low mitotic index of Reed-Sternberg cells. In addition to ours, available published data were analyzed in detail to identify recurring cytogenetic events. RESULTS: Metaphases which could be analyzed were obtained in 86.5% of cases, with 59.4% showing abnormal clones. We found a peculiar kind of cytogenetic instability in which, despite variations in the type of structural rearrangements, chromosome breakpoints were non-randomly distributed. Moreover, from our data plus those collected from literature on HD (total 177 cases), the number of breakpoints was higher in patients in a more advanced clinical stage. INTERPRETATION AND CONCLUSIONS: Cytogenetic studies in HD are highly informative regarding clonality, provided large numbers of metaphases are examined. Based on karyotype, genetic changes in HD and HD-like ALCL are similar. Results are consistent with a high degree of chromosomal instability and predominance of hyperdiploid complex karyotypes. Chromosome breakpoints are non-randomly distributed and more numerous in advanced clinical stages. (+info)
New reciprocal translocation t(5;10)(q33;q22) associated with atypical chronic myeloid leukemia.
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We report a new chromosomal reciprocal translocation t(5;10)(q33;q22) in a 49-year-old man with atypical chronic myeloid leukemia (a-CML) and history of occupational exposure to petroleum products including benzene and other hydrocarbons. The t(5;10) (q33;q22) was found in 94% and 84% of metaphases in peripheral blood and bone marrow cells, respectively. Cytogenetic analysis of single colonies derived from granulocyte-macrophage (CFU-GM), and erythroid (BFU-E) hematopoietic progenitors showed that 88% and 40% of CFU-GM and BFU-E, respectively, had the t(5;10)(q33;q22). In contrast, peripheral blood T-lymphocytes, and cutaneous fibroblasts had normal 46,XY karyotype. Molecular analysis of the t(5;10)(q33;q22) translocation breakpoint is currently underway in order to identify genes located in this region which might provide insights into the pathogenesis of atypical myeloproliferative disorders. (+info)