Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report the clinical evaluation of an improved DNA probe assay for the characteristic genetic marker of human CML, observed by cytogenetics and designated the Philadelphia chromosome (Ph1). The Ph1 chromosome results from the fusion of c-abl proto-oncogene sequences from chromosome 9 to phl gene sequence on chromosome 22. (The phl gene is often referred to as bcr. However, for clarity we prefer to reserve the designation "bcr" for the region within the phl gene in which translocation breakpoints have been found to occur. We also find it useful to distinguish between two such regions in phl, bcr-210 and bcr-190, named after the 210- and 190-kDa phl/abl fusion proteins resulting from translocations with breakpoints in the respective regions. We refer to the corresponding chromosomal translocations as Ph1(bcr-210) and Ph1(bcr-190).) DNA, extracted from peripheral blood (PB) or bone marrow (BM) and digested with restriction endonuclease BglII, is hybridized with a probe (phl/bcr-3) spanning a breakpoint cluster region within phl. Rearrangements are revealed by the presence of one or two novel junction fragments. Clinical specimens from leukemic patients with active disease were compared by cytogenetic and DNA probe analysis at seven centers in the United States and Europe. The probe assay identified the phl rearrangement in 190 of 191 cases of Ph1-positive CML, as well as in 12 of 27 clinically diagnosed CML specimens lacking a typical Ph1 chromosome. DNA rearrangements also were seen in two of six cases of Ph1-positive ALL. No false positive results were obtained among 93 non-leukemic controls. Mixing experiments showed that the DNA probe assay can detect as few as 1% leukemic cells in a specimen. A preliminary study of CML patients in remission after allogeneic BM transplantation revealed a small fraction of residual Ph1-positive leukemic cells in a significant number of such patients.
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PMID:Clinical evaluation of a DNA probe assay for the Philadelphia (Ph1) translocation in chronic myelogenous leukemia. 305 Feb 93

The Philadelphia (Ph) translocation [t(9;22)(q34;q11)] is the most common genetic abnormality in human leukemia; a transposition of the ABL gene to the major-breakpoint cluster region (M-BCR) is associated with the pathogenesis in Ph+ chronic myelogenous leukemia (Ph+ CML) and in some cases of Ph+ acute leukemia (Ph+ AL). Our current understanding of the methylation of human genomes allows us to consider the association between the epigenetic phenomenon and the control of differentiation and proliferation in mammalian cells. In order to determine whether the methylation status of the M-BCR is associated with breakpoint-localization in this region and with the lineage of hematopoietic cells, we have examined 28 patients with Ph+ leukemias, including nine with Ph+ AL, six patients with acute myeloblastic leukemia without Ph (Ph- AML), and five patients with Ph- acute lymphoblastic leukemia (Ph- ALL); using the restriction endonuclease isochizomers, MspI and HpaII. In CML patients in the chronic phase, the hypomethylated status within the normal M-BCR allele is heterogeneous. In contrast, patients with Ph+ CML in the lymphoid blast crisis phase exhibited a 2.5/2.7 kb band with a complete disappearance of the germline M-BCR fragment (type L). This pattern is consistently noted in Ph- ALL cells, and the pattern is quite different from that found in myeloid blast crisis or Ph- AML (type M). In patients with M-BCR-nonrearranged Ph+ ALL, it is suggested that the M-BCR methylation patterns are cell-lineage specific but some Ph+ ALL cells had a hypomethylation pattern that was identical to that observed in Ph- AML, suggesting a distinction of genetic diversity of leukemia cells with the Ph chromosome, especially Ph+ AL.
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PMID:The methylation status of the major breakpoint cluster region in human leukemia cells, including Philadelphia chromosome-positive cells, is linked to the lineage of hematopoietic cells. 850 75

A new rat cytomegalovirus (RCMV) isolated from the placenta/uterus of a house rat (Rattus rattus diardii) was found to productively infect rat embryo fibroblast (REF) cells. The virus produced typical herpesvirus-like cytopathic effects characterized by a lytic infection. The well-known herpesvirus morphology was confirmed by electron microscopy. Its slow growth in cell culture indicated that the virus is belonging to subfamily Betaherpesvirinae. Electron microscopy techniques and immunohistochemistry confirmed the presence of herpesviral inclusion bodies and virus related particles in the cytoplasm and nucleus of infected cells. Hyperimmune serum against the Maastricht strain of RCMV revealed the virus identity in neutralization test, immunoperoxidase and immunofluorescence techniques. Despite typical characteristics of CMV, the viral genome is significantly different from that of Maastricht, English, UPM/Sg and UPM/Kn strains. The dissimilarities, which have not been reported before, had been confirmed by mean of restriction endonuclease analysis. The new RCMV strain, a virus that infects placenta and uterus of rats, has been named as ALL-03.
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PMID:Characterization of a novel rat cytomegalovirus (RCMV) infecting placenta-uterus of Rattus rattus diardii. 1464 91