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G Cuthbert

Publications and source records attributed to G Cuthbert.

8 recordsLinked to original sources

Sensitivity of FISH in detection of MLL translocations.

Fluorescence in situ hybridisation (FISH) detection of MLL translocations is now commonplace in cytogenetics laboratories. One of the most widely used probes is the Oncor MLL probe (Oncor, Gaithersburg, MD) that theoretically demonstrates the presence of an MLL rearrangement by a splitting of the FISH signal between the two derivative chromosomes generated by a translocation. Recently, another commercial probe has been made available from Vysis (Vysis, Downers Grove, IL) that uses a dual colour system. We examined material from 29 patients and 4 cell lines, all with recognised MLL translocations by G-banding, that were confirmed using Southern blot analysis of the MLL breakpoint cluster region. Both Oncor and Vysis MLL FISH probes were applied to these cases to compare their performance in detection of the MLL translocations. Thirty of the 33 cases demonstrated a clear splitting of Oncor MLL FISH signal in concordance with the Southern blot analysis and cytogenetics. Three cases failed to demonstrate a split MLL FISH signal. Therefore, we conclude that the Oncor MLL FISH probe has a 9.1% false negative rate, i.e., 90.9% sensitivity in detection of classic MLL translocations. Vysis MLL FISH detected the rearrangement in all 33 cases.

Blotting, Southern↗

MLL amplification in acute leukaemia: a United Kingdom Cancer Cytogenetics Group (UKCCG) study.

The MLL gene, located at 11q23, is frequently rearranged in acute leukaemia as either chimaeric fusion genes or partial tandem duplications. We report a series of 12 acute leukaemia cases with apparent amplification of the MLL gene ascertained using fluorescence in situ hybridisation (FISH). Seven cases showed intrachromosomal amplification of MLL, four cases showed extrachromosomal amplification as double minute chromosomes (dmin) and one case had separate subclones with dmin and homogenously staining region (hsr). Southern blot analysis of the MLL gene showed MLL gene rearrangement in three of the 10 successful cases. These cases do not naturally fall into either of the two recognised categories of MLL rearrangement and may represent a third variety of MLL gene abnormalities.

Acute Disease↗

Jumping translocation at 11q23 with MLL gene rearrangement and interstitial telomeric sequences.

myeloid leukemia of acute myeloid leukemia (AML) M5a showing a jumping translocation with a breakpoint at 11q23. Fluorescence in situ hybridization (FISH) demonstrated triplication of the MLL gene and the presence of interstitial telomeric sequences, supporting the role of repetitive sequences in the mechanism of jumping translocations. Southern blot analysis of the MLL breakpoint cluster region showed the presence of an MLL gene rearrangement. Jumping translocation with MLL gene rearrangement is a previously unreported phenomenon in leukemia cytogenetics.

Aged↗

Frequency and pattern of radionuclide administration to medical patients in a general hospital.

As part of a drug surveillance programme details of nuclide administration were recorded for 5288 consecutive patients admitted to the medical wards of a large general hospital. Overall use of nuclides amongst this group was found to be low, and multiple exposure to radiation as a result of nuclide administration is not a major hazard when compared to the diagnostic information provided.

Hospitals, General↗