hFRUIT: An optimized agent for optical clearing of DiI-stained adult human brain tissue.

Here, we describe a new immersion-based clearing method suitable for optical clearing of thick adult human brain samples while preserving its lipids and lipophilic labels such as 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). This clearing procedure is simple, easy to implement, and allowed for clearing of 5 mm thick human brain tissue samples within 12 days. Furthermore, we show for the first time the advantageous effect of the Periodate-Lysine-Paraformaldehyde (PLP) fixation as compared to the more commonly used 4% paraformaldehyde (PFA) on clearing performance.

Induction of differentiation in erythroleukemic K562 cells by gamma-irradiation.

Various agents have been shown to induce differentiation in neoplastic cells. The present study aimed at investigating comparable phenomena induced by high doses of gamma-irradiation in the presence of physiological factors. The erythroleukemic K562 cells were gamma-irradiated or treated with cytosine-arabinoside (Ara-C), and examined for cell size, protein content, acetylcholinesterase (AChE)-activity and hemoglobin synthesis in relation to mitotic activity.

Long-term residual radiation effect in the murine hematopoietic stem cell compartment.

For the measurement of long-term residual radiation effect in the murine hematopoietic system a test system was developed that quantifies the proliferation ability of progeny of spleen repopulating cells by the proliferation factor (PF). The PF expresses the ratios of 125IUdR incorporation in the recipient spleens at days 3 and 5 following cell transfusion, thus measuring the relative increase in number of proliferating cells. Following 500 rad whole-body gamma irradiation, PF recovered up to 6 months and remained thereafter, on the average, at 80% of control.

An assay for the measurement of residual damage of murine hematopoietic stem cells.

The proliferation rate of murine hematopoietic cells in regenerating spleen was assayed by a novel technique that analyzes the integrity of stem cells irrespective of their number. It relies on the increment of incorporation of 5-(125I) iodo-2'-deoxyuridine (125IUdR) at day 3 and 5 after transfusion of syngeneic marrow cells in fatally irradiated recipients. A prerequisite of the assay is the linearity between in fatally irradiated recipients.