Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts.

Gain of androgen receptor gene copies in primary prostate cancer due to X chromosome polysomy.

BACKGROUND: Prostate cancer is an androgen dependent tumor. In advanced prostate cancers androgen deprivation has proved to be an effective therapy, but 25% show no response. In this study prostatectomy specimens from patients without preoperative therapy were analyzed to determine the possible mechanism of primary antiandrogen resistance. METHODS: The number of androgen receptor (AR) gene copies and X-centromeres were investigated from 80 prostate cancer specimens by FISH analysis. RESULTS: In 9 out of 80 prostate cancers additional X-chromosomes with the corresponding AR gene could be detected. Polysomy of the X-chromosome correlates with pathological classification and tumor volume. CONCLUSIONS: Additional AR genes due to polysomy of the X-chromosome are present in a subgroup of primary prostate cancers prior to antiandrogen therapy. Because the growth of prostate cancers is androgen dependent, these specimens may have an advantage in low concentrations of androgens. This may be a factor for initial antiandrogen resistance.