Biomedical subjects

L L Chen

Publications and source records attributed to L L Chen.

112 records · Page 7Linked to original sources

PubMedDate not supplied

Telomerase antisense inhibition for the proliferation of endometrial cancer in vitro and in vivo.

The objective of this study was to investigate the antitumor effect of antisense telomerase oligodeoxynucleotides to endometrial cancer cells in vitro and in vivo. Antisense oligodeoxynucleotides (ODNs) against the human telomerase transcripatse (hTERT) synthesized to serve as telomerase inhibitors. Reverse transcription-polymerase chain reaction and 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide (MTT) assay were used to test the expression of hTERT messengerRNA (mRNA) and inhibition of cell proliferation in vitro. In vivo, antitumor effects of ODNs or combined with cisplatin were evaluated in endometrial cancer xenograft. Telomerase activity was tested by telomeric repeat amplification protocol. Antisense ODNs could inhibit proliferation of human endometrial cancer cells (HEC-1-A) in vitro, and downregulate the expression hTRET mRNA in a dose- and period-dependent manner. The tumor growth inhibitory rate of low- and high-dose ODNs were 34.20% and 89.21%, and combined group was 75.30%. Telomerase activity was downregulated to 87.32% compared to the control in the ODNs-treated xenograft tumors. Antisense oligonucleotides of hTERT effectively inhibit the growth of endometrial cancer cell line. Telomerase inhibitor might be a new strategy for chemotherapy or chemoprevention in endometrial cancer.

Animals↗

PubMedDate not supplied

Confirmation of persistent closure of surgically repaired macular hole in subsequent retinal detachment by optical coherence tomography.

Idiopathic macular holes have shown response to surgical intervention with vitrectomy, presumably because of glial cell proliferation in the reapproximated tissue. We describe a patient with postoperative closure of a macular hole who subsequently developed a retinal detachment involving the macular area. Despite the detachment, the macular hole remained closed as evidenced by biomicroscopy and optical coherence tomography (OCT). OCT provides accurate documentation and assessment of pre- and postoperative conditions in macular hole surgery.

Aged↗

PubMedDate not supplied

Early use of cyclic TPN prevents further deterioration of liver functions for the TPN patients with impaired liver function.

BACKGROUND/AIMS: Impaired liver function is frequently found in patients who need prolonged total parenteral nutrition. Cyclic total parenteral nutrition can minimize the adverse effects of long-term total parenteral nutrition, such as hepatic complication. The adequate timing to shift to use cyclic total parenteral nutrition for patients with impaired liver function may prevent further hepatic dysfunction. METHODOLOGY: A prospective study of 65 patients who need total parenteral nutrition and have impaired liver functions was performed. Cyclic total parenteral nutrition was used in different groups of patients, when their total bilirubin levels were just over 5 mg%, 10 mg%, or 20 mg% during the course of total parenteral nutrition. The patients of control groups received straight non-cyclic total parenteral nutrition. All the patients had stable vital signs without major stress, such as sepsis or acute bleeding. Ten patients (A2) in Group A were shifted to cyclic total parenteral nutrition when their total bilirubin was just over 5 mg%; the other 10 patients (A1) continued the non-cyclic total parenteral nutrition. Eleven patients (B2) in Group B were shifted to cyclic total parenteral nutrition when their total bilirubin was just over 10 mg%; the other 11 patients (B1) continued the non-cyclic total parenteral nutrition. Ten patients (C2) in Group C were shifted to cyclic total parenteral nutrition when their total bilirubin was just over 20 mg%; the other 13 patients (C1) continued the non-cyclic total parenteral nutrition. The average energy intake among 3 groups had no difference. Their liver functions were examined each week for 2 weeks. RESULTS: The results showed that the patients with non-cyclic total parenteral nutrition had significant increase of direct-total bilirubin and alkaline phosphatase (P < 0.05) in Group A and significant decrease of albumin accompanied with increase of GOT, GPT, direct/total bilirubin (P < 0.05) in Group B. The patients either using cyclic or non-cyclic total parenteral nutrition showed significant decrease of albumin and increase of direct/total bilirubin (P < 0.05) in Group C. CONCLUSIONS: We conclude that the early use of cyclic total parenteral nutrition may prevent deterioration of liver function for the patients with jaundice and need prolonged total parenteral nutrition.

Adolescent↗

PubMedDate not supplied

Pentose phosphate pathway alterations in multi-drug resistant leukemic T-cells: 31P NMR and enzymatic studies.

31P NMR studies were carried out on the parental drug-sensitive human T-lymphoblastoid cell line CCRI-CEM (CEM) and its multi-drug-resistant (MDR) CEM-VBL100 variants, to assess the role of the pentose phosphate (PP) in MDR expression. CEM and CEM-VBL100 were incubated in the presence of 2-deoxyglucose, as recently proposed by our group (Clin. Chim. Acta 208: 39, 1992). Accumulation of 2-deoxyglucose 6-phosphate was much lower in the drug-resistant than in sensitive cells, indicating PP shunt activation in the MDR variants. This result was confirmed by enzymatic analyses, which demonstrated that, with respect to the parental line, the MDR variant was characterized by a) unaltered hexokinase activity; b) higher glucose 6-phosphate dehydrogenase activity; c) increased levels of reduced glutathione and marked increase of glutathione peroxidase activity after cell exposure to an oxidizing agent (tert-butylhydroperoxide). These results support the view that cell detoxification mechanisms mediated by the pentose phosphate pathway may contribute to the expression of MDR in tumours.

ATP Binding Cassette Transporter, Subfamily B, Mem↗