Recovery of cell nuclei from 15,000 years old mammoth tissues and its injection into mouse enucleated matured oocytes.

Here, we report the recovery of cell nuclei from 14,000-15,000 years old mammoth tissues and the injection of those nuclei into mouse enucleated matured oocytes by somatic cell nuclear transfer (SCNT). From both skin and muscle tissues, cell nucleus-like structures were successfully recovered. Those nuclei were then injected into enucleated oocytes and more than half of the oocytes were able to survive. Injected nuclei were not taken apart and remained its nuclear structure. Those oocytes did not show disappearance of nuclear membrane or premature chromosome condensation (PCC) at 1 hour after injection and did not form pronuclear-like structures at 7 hours after injection. As half of the oocytes injected with nuclei derived from frozen-thawed mouse bone marrow cells were able to form pronuclear-like structures, it might be possible to promote the cell cycle of nuclei from ancient animal tissues by suitable pre-treatment in SCNT. This is the first report of SCNT with nuclei derived from mammoth tissues.

[Validation of a method for discrimination of formaldehyde processing in textile products].

It is important to investigate a cause of formaldehyde contamination exceeding a regulation limit value in a textile product. If formaldehyde was released from a textile product itself by treatment or processing with formaldehyde, an administrative guidance is given to a manufacture. On the other hand, when the formaldehyde migrated from other textile products or a furniture stand during displaying, an improvement instruction is performed to the store. Iwama et al. [Ann. Rep. Nagoya City Public Res. Inst., 42, 11-16 (1996)] developed a method for distinguishing fabric processing and migration by additional hydrolytic extraction using hydrochloric acid solution. This study was to confirm the reliability and stability of the method for knowing formaldehyde processing on textiles. Five laboratories evaluated three samples: unprocessed textile, processed textile and unprocessed but formaldehyde-migrated textile. For a processed textile sample, amounts of formaldehyde increased by additional extractions with acidic solution, so all laboratories judged that the sample had been treated with formaldehyde. In the cases of the other two samples, such increases were not observed in the extracts using acidic solution. All laboratories reported that these samples were not processed using formaldehyde but had absorbed a different level of formaldehyde by migration. In a series of experiments, the judgement about the existence of formaldehyde processing or migration is comparatively consistent among all laboratories. This validation study concluded that the distinguishing method adopting additional extractions with acidic solution is useful to find formaldehyde processing of textile, and to deal with processing and migration separately as a cause of formaldehyde contamination.

[Determination of sucralose in foods by liquid chromatography/tandem mass spectrometry].

A simple method for the determination of sucralose in various foods using liquid chromatography-electrospray ionization tandem mass spectrometry (LC/MS/MS) was developed. Sucralose was extracted with water or methanol, and the extract was cleaned up on a C18 cartridge, and diluted with water for injection into the LC/MS/MS. The LC separation was performed with a reversed-phase gradient on an ODS column, and the mass spectral acquisition was done in the negative ion mode by applying selected reaction monitoring (SRM). The recoveries of sucralose from various kinds of foods fortified at 100 micrograms/g and 5 micrograms/g were 88.1-96.7% and 92.7-98.5%, respectively. The lower limits of quantification were 0.5 microgram/g in beverage, low-malt beer, yogurt and chocolate and 2.5 micrograms/g in other foods. Forty-three commercial foods containing sucralose were analyzed by this method. Sucralose was detected in all samples at levels of 3.8-481 micrograms/g.