Biomedical subjects

Dongjiu Ye

Publications and source records attributed to Dongjiu Ye.

5 recordsLinked to original sources

PubMed2006

Common bile duct MALT lymphoma: case report and review of the literature.

We report a rare case of common bile duct mucosa-associated lymphoid tissue (MALT) lymphoma treated with pancreatico-duodenectomy with a partial gastrectomy. MALT lymphoma involving the biliary tree is extremely rare. Diagnosis is difficult and treatment options are controversial. Even though Helicobacter pylori treatment is effective in the early stages of the disease, surgery is still helpful especially when obstruction, perforation, or bleeding is present.

Aged↗

PubMed2005

Sudden unexpected death in a 31-year-old man caused by arrhythmogenic right ventricular cardiomyopathy.

A 31-year-old white man collapsed suddenly at a graduation ceremony and was pronounced dead after attempted resuscitation. He had no pertinent medical or familial history. Postmortem toxicologic studies showed negative results. A complete autopsy revealed a cardiac cause of death. Grossly, the right ventricular chamber was moderately to markedly dilated, and its free wall showed extensive myocardial adiposity. Microscopically, the right ventricular free wall consisted predominantly of adipose tissue, with only small subendocardial islands of hypertrophied myocytes and interstitial fibrosis. These features are characteristic of arrhythmogenic right ventricular cardiomyopathy. Moreover, Purkinje-like cells were observed among right ventricular myocytes and may have increased the likelihood of developing an arrhythmia. To our knowledge, this finding has not been previously emphasized. Because arrhythmogenic right ventricular cardiomyopathy accounts for 10% of cases of sudden unexpected cardiac death, recognition of this disease by pathologists is important, especially in cases of otherwise unexplained death in young persons.

Adult↗

PubMed2002

Evaluating the specificity of antisense oligonucleotide conjugates. A DNA array analysis.

Antisense oligonucleotides are potentially powerful tools for selective control of cellular and viral gene expression. Crucial to successful application of this approach is the specificity of the oligonucleotide for the chosen RNA target. Here we apply DNA array technology to examine the specificity of antisense oligonucleotide treatments. The molecules used in these studies consisted of phosphorothioate oligomers linked to the Antennapedia (Ant) delivery peptide. The antisense oligonucleotide component was complementary to a site flanking the AUG of the MDR1 message, which codes for P-glycoprotein, a membrane ATPase associated with multidrug resistance in tumor cells. Using a DNA array of 2059 genes, we analyzed cellular responses to molecules comprised of Ant peptide-oligonucleotide conjugates, as well as to the Ant peptide alone. Besides the expected reduction in MDR1 message level, 37 other genes (approximately 2% of those tested) showed changes of comparable magnitude. The validity of the array results was confirmed for selected genes using Northern blots to assess messenger RNA levels. These results suggest that studies using antisense oligonucleotide technology to modulate gene expression need to be interpreted with caution.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2002

Evaluation of strategies for the intracellular delivery of proteins.

PURPOSE: The intracellular delivery of functionally active protein represents an important emerging strategy for laboratory investigation and therapeutic applications. Although a number of promising approaches for protein delivery have been developed, thus far there has been no attempt to compare the merits of the various deliver technologies. This issue is addressed in the current study. METHODS: In this study we utilize a sensitive luciferase reporter gene assay to provide unambiguous and quantitative evaluation of several strategies for the intracellular delivery of a biologically active protein comprised of the Gal4 DNA binding domain and the VP16 transactivating domain. RESULTS: Both a cationic lipid supramolecular complex and a poly meric complex were able to effectively deliver the chimeric transcription factor to cultured cells. In addition, protein chimeras containing the Tat cell penetrating peptide, but not those containing the VP22 peptide, were somewhat effective in delivery. CONCLUSIONS: Both supramolecular protein-carrier complexes and protein chimeras with certain cell penetrating peptides can support intracellular delivery of proteins. In the cell culture setting the supramolecular complexes are more effective, but their large size may present problems for in vivo applications.

Cell Line↗

PubMed2002

Selective inhibition of P-glycoprotein expression in multidrug-resistant tumor cells by a designed transcriptional regulator.

Selective inhibition of the multidrug resistance 1 (MDR1) gene and its product, the P-glycoprotein, a membrane transporter responsible for multidrug resistance, could be an important approach for enhancing cancer therapeutics. An emerging strategy for selective gene regulation involves designed zinc finger proteins that can recognize specific sequences in the promoter regions of disease-related genes. Herein, we investigate the behavior of clones of multidrug-resistant NCI/ADR-RES breast carcinoma cells displaying ponasterone-inducible expression of a designed transcriptional repressor targeted to the MDR1 promoter. The controlled production of this novel repressor resulted in major reductions in P-glycoprotein levels in these otherwise highly drug-resistant tumor cells. The regulated reduction of MDR1 expression in NCI/ADR-RES cells was accompanied by a marked increase in the rate of uptake of the P-glycoprotein substrate rhodamine 123. In addition, the cytotoxicity profile of the antitumor drug doxorubicin was dramatically altered in the induced cells compared with controls. The expression levels of other genes were examined both by a DNA array analysis of approximately 2000 genes and by biochemical techniques. Although some changes were observed in mRNA levels of nontargeted genes, the most dramatic effect by far was on MDR1, indicating that the action of the designed transcriptional repressor was quite selective. This study suggests that designed transcriptional regulators can be used to strongly and selectively influence expression of cancer-related genes, even under circumstances of extensive amplification of the target gene.

ATP Binding Cassette Transporter, Subfamily B↗