Biomedical subjects

L Ding

Publications and source records attributed to L Ding.

183 records · Page 11Linked to original sources

PubMedDate not supplied

Combination preoperative radiation and endocavitary hyperthermia for rectal cancer: long-term results of 44 patients.

Long-term results of 122 patients with advanced rectal cancer who were randomly treated with three different methods from July 1984 to July 1986. Of 122 patients, 44 were treated with endocavitary 915 MHz microwave applicators combined with 10 MeV X-ray or 60CO followed by surgery (group A), 38 with preoperative radiation (group B) and 40 with surgery (group C) as a control group. The temperature on the surface of the applicator touching the middle of the caudad to cephaladic extent of disease was 45-50 degrees C for 45 min twice a week for 6-8 sessions. Radiation dose was 30 Gy or 40 Gy/4 weeks. Of cases with stages 0 and A, 45.5% (20/44) were in group A, 23.7% (9/38) in group B and 12.5% (5/40) in group C (chi 2 test p < 0.05 and p < 0.01, respectively). Five-year survival rate was 66.7% (24/36) in group A, 50% (14/28) in group B and 40.5% (15/37) in group C. Percentage of survival at 5 years was 73.7% (14/19) for 40 Gy plus heat, 57.1% (8/14) for 40 Gy alone, 58.8% (10/17) for 30 Gy plus heat, and 42.9% (6/14) for 30 Gy alone. Data suggest a survival advantage for patients treated with preoperative radiation combined with endocavitary hyperthermia.

Adenocarcinoma↗

PubMedDate not supplied

Proteasome inhibition suppresses cisplatin-dependent ERCC-1 mRNA expression in human ovarian tumor cells.

One of the major problems with ovarian cancer treatment is the clinical development of resistance to cisplatin. Considerable efforts have been directed toward the identification of biological and pharmacological agents that would reverse drug resistance to cisplatin. ALLnL is an inhibitor of the proteasome that can inhibit the ubiquitin-proteasome pathway, which plays an essential role in many processes in cell life. We have recently shown that ALLnL, at concentrations that do not appear harmful, has significantly enhanced DNA platination and decreased DNA repair of cisplatin-DNA adducts in human A2780/CP70 ovarian carcinoma cells. These activities of proteasome inhibition were also associated with substantially increased cisplatin toxicity in these cells. In this communication, we demonstrate that treatment of A2780/CP70 cells with ALLnL blocks cisplatin-induced ERCC-1 mRNA expression in a concentration- and time-dependent manner, as measured by Northern blot analysis. In addition, we showed that the cisplatin-dependent increase in steady-state levels of ERCC-1 mRNA was prevented by pretreatment with lactacystin, a potent and specific inhibitor of proteasome. These results suggest that the effect of proteasome inhibition on cisplatin cytotoxicity, DNA platination, and DNA repair of cisplatin adducts in ovarian cancer cells may be through down-regulating ERCC-1 expression.

Acetylcysteine↗

PubMedDate not supplied

Time and pressure dependence of sieving coefficients during membrane plasma fractionation.

The apparent sieving coefficient (S') of a membrane, defined as the ratio of permeate to feed concentration, is not an intrinsic property of the membrane, but depends upon operating conditions. The variation of albumin, IgG, and IgM sieving coefficients with time during dead-end filtration was investigated using human pooled plasma and two types of hollow fiber filters (cellulose acetate PF 100 and ethylene vinyl alcohol Eval 2A). For the same filtrate flux (3.6 10(-3) cm/min) the transmembrane pressure (TMP) rises faster with time for the Eval filter because of its smaller hydraulic permeability (0.26 10(-4) cm/min mmHg vs. 7.3 10(-4). The albumin S' of the PF 100 reaches 0.95 after 20 min of filtration but drops to 0.4 after 50 min, whereas the S' of the Eval filter, which never exceeds 0.6, remains at this level for at least 50 min. By varying the inlet flow rate the authors show that for a given membrane, the critical parameter that governs the S' is the TMP. These data suggest that it is essential to specify the TMP when quoting a value of S', and the most permeable membrane, with the highest maximum S', is not necessarily the one that maximizes the overall recovery over a long period.

Cell Membrane Permeability↗