نتایج جستجو برای: dicentric y chromosome
تعداد نتایج: 603928 فیلتر نتایج به سال:
Although cancer development involves gradual step-wise mutational alterations, recent work has pointed to an additional contribution of episodic massive chromosome shattering phenomena, including chromoplexy and chromothripsis. How chromoplexy and chromothripsis are initiated is unknown. We hypothesize that chromosome shattering originates from end-to-end fused dicentric chromosomes, which occu...
background: microdeletions of the azoospermia factor locus of the long arm of y chromosome are an etiological factor of severe oligozoospermia or azoospermia. objective: the aim of this study was to investigate the prevalence of y-chromosome microdeletions in azf region and their role in infertility in pakistani population. materials and methods: the type of deletions in azf locus were detected...
A two year old girl with Down's syndrome (constitutional karyotype: 47 + 21), presenting with pancytopenia, developed acute megakaryoblastic leukaemia (AMKL). Her bone marrow contained an abnormal clone with a novel dicentric chromosome derived from chromosomes 5 and 7 (karyotype 46, XX, -5, -7, +dic (5;7) (p 13; p 11.2), +21. This case provides further evidence for a connection between chromos...
Three in vitro dose calibration curves for biodosimetry such as dicentric chromosome assay, fluorescence in situ hybridization (FISH) assay for translocation, and micronuclei (MNs) in binucleated cell assay were established after exposure to ionizing radiation. Peripheral blood lymphocyte samples obtained from healthy donors were irradiated with 60Co source at a dose rate of 0.5 Gy/min to doses...
Excess risk of leukemia and brain tumors after CT scans in children has been reported. We performed dicentric chromosome assay (DCAs) before and after CT scan to assess effects of low-dose ionizing radiation on chromosomes. Peripheral blood (PB) lymphocytes were collected from 10 patients before and after a CT scan. DCA was performed by analyzing either 1,000 or 2,000 metaphases using both Giem...
Homologous chromosome synapsis ("homosynapsis") and crossing over are well-conserved aspects of meiotic chromosome behavior. The long-standing assumption that these two processes are causally related has been challenged recently by observations in Saccharomyces cerevisiae of significant levels of crossing over (1) between small sequences at nonhomologous locations and (2) in mutants where synap...
Double-minute chromosomes (DMs) were observed in repeated samples in the leukocytes of a patient with a previous history of cervical carcinoma. The most interesting cytogenetic finding was the coexistence of DMs and a dicentric chromosome along with chromosome- and chromatid-type breaks and gaps. This observation suggests that DMs might originate through the breakage of existing chromosomes. Th...
We have utilized a dihydrofolate reductase (DHFR) probe in combination with selected probes from other positions along the 2q chromosome arm in a two-color fluorescence in situ hybridization analysis of early DHFR gene amplification events in CHO cells. These studies show clearly that the most frequent initiating event is the formation of a giant inverted duplication, resulting from chromosome ...
Background: Many advances have been made in reproductive medicine yet the spontaneous loss of a pregnancy remains the most common complication of pregnancy. The aetiology of spontaneous recurrent pregnancy loss (RPL) is multifactorial. Y chromosome microdeletions are found in approximately 7% of men with low sperm counts and, compared to the general population, a higher frequency of spontaneous...
background: wide range of disorders ranging from genetic disorders to coital difficulties can influence male fertility. in this regard, genetic factors are highlighted as the most frequent, contributed to 10-15%, of male infertility causes. objective: to investigate the influence of genetic abnormalities on semen quality and reproductive hormone levels of infertile men from northeast china. mat...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید