Xiaodong Tan

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PER genes are essential for the biogenesis of peroxisomes in the yeast Pichia pastoris. Here we describe the cloning of PER3 and functional characterization of its product Per3p. The PER3 sequence predicts that Per3p is a 713-amino acid (81-kDa) hydrophobic protein with at least three potential membrane-spanning domains. We show that Per3p is a membrane(More)
The objective of this study was to assess students' knowledge, attitudes and practices on HIV and AIDS. A questionnaire was administered to a cross section of 259 Chinese undergraduates. Respondents were asked to provide information about knowledge and attitudes about HIV/AIDS. Study results indicated that the majority of undergraduates had a moderate level(More)
We previously described the isolation of mutants of the methylotrophic yeast Hansenula polymorpha that are defective in peroxisome biogenesis. Here, we describe the characterization of one of these mutants, per8, and the cloning of the PER8 gene. In either methanol or methylamine medium, conditions that normally induce the organelles, per8 cells contain no(More)
We describe a rapid and efficient screen for peroxisome-deficient (per) mutants in the yeast Pichia pastoris. The screen relies on the unusual ability of P. pastoris to grow on two carbon sources, methanol and oleic acid, both of which absolutely require peroxisomes to be metabolized. A collection of 280 methanol utilization-defective (Mut-) P. pastoris(More)
Recombinant methioninase (rMETase) is a homotetrameric pyridoxal 5'-phosphate enzyme of 172-kda molecular mass derived from Pseudomonas putida and cloned in Escherichia coli. rMETase has been found previously to be an effective, anti-tumor agent in vitro and in vivo. The enzyme targets the elevated minimal methionine requirement seen in all tumor types. In(More)
The product of the retinoblastoma susceptibility gene, RB, is a negative regulator of cell proliferation. Inactivation of RB does not interfere with embryonic growth or differentiation. However, Rb-deficient embryos show abnormal degeneration of neurons and lens fiber cells through apoptosis, suggesting that RB may protect against programmed cell death.(More)
Execution of the cell-death programme requires the activation of a family of cysteine proteases known as caspases. Specific cellular proteins are cleaved by caspases during apoptosis, including the retinoblastoma tumour-suppressor protein (RB1). A caspase-resistant RB1 can attenuate the death response to tumour necrosis factor alpha. The cleavage of RB1(More)
The goal of the next generation of cancer chemotherapy is effective tumor-selectivity. A tumor-selective target with high therapeutic potential is the elevated methionine requirement of tumor cells relative to normal cells. We have termed the elevated requirement for methionine in tumors methionine dependence. To selectively target the methionine dependence(More)
Tumor necrosis factor-alpha (TNF) has been shown to induce intestinal necrosis in animals. Moreover, plasma TNF levels are elevated in patients with necrotizing enterocolitis. Thus, it is possible that TNF plays a role in the pathogenesis of NEC. In the present study we used in situ hybridization (with human TNF riboprobes) to localize TNF transcripts in(More)
Millions of incidents of hand, foot and mouth disease occur annually in China, with EVA71 and CVA16 as two major causative pathogens. A provincial surveillance system has been implemented in Guangdong for almost 5 years to analyze the aetiological spectrum and epidemic changes. An unusual enterovirus type, CVA6, was identified as the predominant serotype(More)