Surgical removal of a fish hook from the oesophagus of a turtle.

An adult male Macquarie turtle was presented for examination after swallowing a fish hook. Radiographs taken to determine the position of this foreign body within the gastrointestinal tract revealed the fish hook lodged in the turtle's oesophagus. Surgical removal of the fish hook involved an approach through the soft tissues of the lateral neck. The turtle recovered well and was returned to the wild.

Statistical confirmation that immunofluorescent detection of DNA repair in human fibroblasts by measurement of bromodeoxyuridine incorporation is stoichiometric and sensitive.

Diploid human fibroblasts (IMR-90 cells), grown to confluency and growth-arrested by serum starvation, were irradiated with a variety of doses of UV light (0.025-40 J/m2) or incubated with broad dose ranges of four direct-acting mutagens [ethyl methanesulfonate (EMS), ICR-170, methyl methanesulfonate (MMS), and 4-nitroquinoline oxide (4-NQO)] and pulsed with a thymidine analog, 5-bromodeoxyuridine (BrdUrd) to detect evidence of DNA repair. These cells and appropriate controls were immunochemically stained and subjected to flow cytometric analysis to quantify BrdUrd incorporation into DNA and simultaneously measure cellular DNA content. Since the maximal quantity of BrdUrd incorporated with repairing cells is profoundly less than the amount incorporated during replicative synthesis and flow cytometric analysis collects information on a cell-to-cell basis, data collection using linear histograms succeeded both in revealing repairing cellular populations and eliminating replicative cells from the analysis. Technical modifications necessary to achieve stoichiometry with UV-irradiated IMR-90 fibroblasts included a 48h repair (and pulse) period, followed by denaturing cellular DNA for 15 min at 90 degrees C. The limit of detection was equal to or below the lowest dose investigated (0.025 J/m2). DNA repair was also detected with cultures incubated with low doses of all chemicals and pulsed with BrdUrd for a 24 h period. The limits of detection were near or below 500 microM EMS, 5 microM MMS, 0.25 microM 4-NQO, and 0.1 microM ICR-170.