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Biomedical subjects

Qiuyun Liu

Publications and source records attributed to Qiuyun Liu.

4 recordsLinked to original sources

The Neurospora checkpoint kinase 2: a regulatory link between the circadian and cell cycles.

The clock gene period-4 (prd-4) in Neurospora was identified by a single allele displaying shortened circadian period and altered temperature compensation. Positional cloning followed by functional tests show that PRD-4 is an ortholog of mammalian checkpoint kinase 2 (Chk2). Expression of prd-4 is regulated by the circadian clock and, reciprocally, PRD-4 physically interacts with the clock component FRQ, promoting its phosphorylation. DNA-damaging agents can reset the clock in a manner that depends on time of day, and this resetting is dependent on PRD-4. Thus, prd-4, the Neurospora Chk2, identifies a molecular link that feeds back conditionally from circadian output to input and the cell cycle.

Amino Acid Sequence↗

A highly efficient polyethylene glycol-mediated transformation method for mushrooms.

A highly efficient transformation system mediated by polyethylene glycol was developed for the cultivated mushroom Pleurotus ostreatus. Eighty to 180 integrative and stable-resistant colonies appeared per mug of DNA per 10(7) viable protoplasts in a transformation experiment with the hygromycin B phosphotransferase gene (hph), which is about 40-1800 times higher than that previously reported in P. ostreatus. One hundred to 150 transformants emitting green fluorescence were observed per mug of DNA per 10(7) viable protoplasts in a transformation with the green fluorescent protein gene, but green fluorescence disappeared 30 h after transformation, suggesting that the green fluorescent protein gene was only transiently expressed in P. ostreatus. Plasmid pAN7-1 was also transferred into two important cultivated mushrooms, Ganoderma lucidum and Lentinus edodes, and 120-150 and 85-100 transformants per mug of DNA per 10(7) viable protoplasts were obtained, respectively, which is seven to 38 times and 24-28 times greater than previously reported. These data indicate that this new polyethylene glycol-mediated transformation procedure is highly efficient for mushrooms, and could be a useful tool in mushroom improvement by gene engineering.

Drug Resistance, Fungal↗

A comparative study on the close reduction of arytenoid dislocation under indirect and direct laryngoscope.

To assess the curative effects of different reduction techniques on the dislocation of cricoarytenoid joint caused by intubation, indirect laryngoscope (IL) and direct laryngoscope (DL) were utilized for the closed reduction of the displaced arytenoid under local anesthesia. 23 patients who underwent the reduction for dislocated arytenoid under IL or DL from January 1991 to June 2001 were reviewed. The data were collected on the duration of the laryngeal injury, times of receiving reduction, side-effects after the treatment and the period for voice to return to normal. The relationship between the duration of the laryngeal lesion and the period of the voice rehabilitation was examined. 13 patients received the reduction under IL and 10 patients under DL. Except the times of the reduction, which showed significant difference, no differences were found between IL group and DL group in the course and the period of voice rehabilitation, as well as sore throat after the manipulation. The patients' voice recovery was positively related to their course of disease in both IL and DL group. It is concluded that the recovery of normal voice is obviously affected by the duration of arytenoid dislocation. The reduction under IL is as effective as under DL in the treatment of arytenoid dislocation. Reduction by DL is better suit the patients with long time course of disease.

Adult↗