The studies concerning clinical implications of TET2 mutation in patients with primary acute myeloid leukemia (AML) are scarce. We analyzed TET2 mutation in 486 adult patients with primary AML. TET2 mutation occurred in 13.2% of our patients and was closely associated with older age, higher white blood cell and blast counts, lower platelet numbers, normal karyotype, intermediate-risk cytogenetics, isolated trisomy 8, NPM1 mutation, and ASXL1 mutation but mutually exclusive with IDH mutation. TET2 mutation is an unfavorable prognostic factor in patients with intermediate-risk cytogenetics, and its negative impact was further enhanced when the mutation was combined with FLT3-ITD, NPM1-wild, or unfavorable genotypes (other than NPM1 ؉ /FLT3-ITD ؊ or CEBPA ؉ ). A scoring system integrating TET2 mutation with FLT3-ITD, NPM1, and CEBPA mutations could well separate AML patients with intermediate-risk cytogenetics into 4 groups with different prognoses (P < .0001). Sequential analysis revealed that TET2 mutation detected at diagnosis was frequently lost at relapse; rarely, the mutation was acquired at relapse in those without TET2 mutation at diagnosis. In conclusion, TET2 mutation is associated with poor prognosis in AML patients with intermediate-risk cytogenetics, especially when it is combined with other adverse molecular markers. TET2 mutation appeared to be unstable during disease evolution. (Blood. 2011;118(14): 3803-3810)

Lung stem/progenitor cells are potentially useful for regenerative therapy, for example in repairing damaged or lost lung tissue in patients. Several optical imaging methods and probes have been used to track how stem cells incorporate and regenerate themselves in vivo over time. However, these approaches are limited by photobleaching, toxicity and interference from background tissue autofluorescence. Here we show that fluorescent nanodiamonds, in combination with fluorescence-activated cell sorting, fluorescence lifetime imaging microscopy and immunostaining, can identify transplanted CD45(-)CD54(+)CD157(+) lung stem/progenitor cells in vivo, and track their engraftment and regenerative capabilities with single-cell resolution. Fluorescent nanodiamond labelling did not eliminate the cells' properties of self-renewal and differentiation into type I and type II pneumocytes. Time-gated fluorescence imaging of tissue sections of naphthalene-injured mice indicates that the fluorescent nanodiamond-labelled lung stem/progenitor cells preferentially reside at terminal bronchioles of the lungs for 7 days after intravenous transplantation.

A bunch of loners: Fluorescent nanodiamonds (FNDs) noncovalently conjugated with bovine serum albumin (BSA) or α‐lactalbumin exhibited good dispersibility in a buffer with only minor or no agglomeration. They are useful as photostable fluorescent markers in cells for superresolution imaging by STED (see confocal fluorescence image of an FND‐labeled cell (left) and STED image of single BSA‐conjugated FNDs (right)).

We report on SwissSPAD2, an image sensor with 512×512 photon-counting pixels, each comprising a single-photon avalanche diode (SPAD), a 1-bit memory, and a gating mechanism capable of turning the SPAD on and off, with a skew of 250ps and 344ps, respectively, for a minimum duration of 5.75ns. The sensor is designed to achieve a frame rate of up to 97,700 binary frames per second and sub-40ps gate shifts. By synchronizing it with a pulsed laser and using multiple successive overlapping gates, one can reconstruct a molecule’s fluorescent response with picosecond temporal resolution. Thanks to the sensor’s number of pixels (the largest to date) and the fully integrated gated operation, SwissSPAD2 enables widefield FLIM with an all-solid-state solution and at relatively high frame rates. This was demonstrated with preliminary results on organic dyes and semiconductor quantum dots using both decay fitting and phasor analysis. Furthermore, pixels with an exceptionally low dark count rate and high photon detection probability enable uniform and high quality imaging of biologically relevant fluorescent samples stained with multiple dyes. While future versions will feature the addition of microlenses and optimize firmware speed, our results open the way to low-cost alternatives to commercially available scientific time-resolved imagers.