No abstract available.
P-Glycoprotein* ; Stomach Neoplasms*

Extranodal NK/T-cell lymphoma (ENKL) is a rare subtype of NHL (Non-Hodgkin lymphoma]. It occurs mostly in the nasal and paranal areas. Most of the cases are presented stage I/II. International prognostic index (IPI) can predict the outcome. However, better prognostic model is available such as NKIPI. Because of high expression of p-glycoprotein, ENKL is refractory to chemotherapy. Early stage disease can be bestly treated with concurrent chemoradiation. For advanced stage disease, new clinical trials are now being conducted.
Lymphoma ; P-Glycoprotein

No abstract available.
Breast* ; DNA* ; P-Glycoprotein*

No abstract available.
Leukemia, Monocytic, Acute* ; P-Glycoprotein*

OBJECTIVE: We determined the influence of 3-OMD in the protein binding of levodopa to estimate the effect of 3-OMD on the penetration of levodopa into brain. METHOD: P-glycoprotein in the brain may serve to limit drug penetration into the brain. Because it is not available as an experimental substance, but has similar binding properties with alpha 1 acid glycoprotein(AGP), we used AGP in this study. Additionally, we used blood plasma to see the affinity of plasma binding of levodopa. The final concentration of chemicals used in this study were 125, 250, 500, 1000, 2000, 4000 microgram/l for levodopa and 0, 1250, 5000, 10,000 microgram/l for 3-OMD, 1 mg/l for AGP. The free fraction of levodopa in blood plasma and AGP were separated by ultrafiltration method and determined by beta-counter, respectively. RESULTS: We found that levodopa did not bind with AGP, but only 22-24% from 125 microgram/l to 4000 microgram/l of it bound with blood plasma. The addition of 3-OMD to the blood plasma did not significantly change the binding of levodopa. CONCLUSIONS: We can conclude that 3-OMD does not influence the penetration of levodopa into brain. These small amount of the binding does not expect to influence to other drugs on the binding with plasma.
Brain ; Drug Interactions ; Levodopa* ; P-Glycoprotein ; Plasma* ; Protein Binding ; Ultrafiltration

Oseltamivir is a substrate of P-glycoprotein, an efflux drug transporter encoded by ABCB1. The objective of this study was to assess the role of ABCB1 (c.1236C>T, c.2677G>T/A, and c.3435C>T) polymorphisms in the pharmacokinetics of oseltamivir and its active metabolite, oseltamivir carboxylate in humans. Nineteen healthy male subjects were enrolled, and their ABCB1 polymorphisms were evaluated. After the oral administration of 75 mg oseltamivir, the plasma concentrations of oseltamivir and oseltamivir carboxylate were measured. Pharmacokinetic analysis was carried out. Systemic exposure to oseltamivir and oseltamivir carboxylate was higher in the mutant group than in the wild-type and heterozygous groups. We suggest that ABCB1 polymorphisms affect the pharmacokinetics of oseltamivir in humans. Further studies in a large population are necessary to validate the results of this preliminary study (Clinical Trial Registration Information [CRIS] registry: http://cris.nih.go.kr, No. KCT0001903).
Administration, Oral ; Humans* ; Male ; Oseltamivir* ; P-Glycoprotein ; Pharmacokinetics* ; Plasma

No abstract available.
Carcinoma, Transitional Cell* ; Humans* ; P-Glycoprotein* ; Urinary Bladder*

PURPOSE: Numerous non-invasive imaging methods for evaluating the chemotherapy response of breast cancer patients are currently being explored. The aim of present study was to investigate whether the washout rates (WRs) of 99mTc-MIBI could predict the response to chemotherapy in patients suffering with infiltrating ductal carcinoma using the expressions of multidrug resistance-related protein (MRP) and P-glycoprotein (Pgp). METHODS: From May 2002 and March 2004, the patients were randomly and consecutively selected according to the results of immunohistochemical analyses of breast carcinoma specimens before the administration of neoadjuvant chemotherapy. A total 45 infiltrating ductal carcinomas in 45 female patients were selected and they were separated into three groups: group A consisted of tumors with both negative Pgp and MRP expressions (n=15); group B consisted of the tumors that were positive for either a Pgp expression or a MRP expression (n=15); group C consisted of the tumors that were positive for both Pgp and MRP expressions (n=15). All the patients were referred for double phase 99mTc-MIBI mammoscintigraphy after the injection of 925 MBq of 99mTc-MIBI to calculate the WR. The tumor response was evaluated after completion of neoadjuvant chemotherapy. The tumor response was classified as a complete or partial response (the responder group) and stable or progression (the non-responder group). All the patients underwent surgery. RESULTS: The response rate of group C was lower than that of the other groups, but the difference was not statistically significant (p=0.283). The WR of non-responder group was lower than that of the responder group, although the difference was not statistically significant (p=0.674). The washout rates of group C was the highest than other groups and the difference was statistically significant (p=0.001). CONCLUSION: In conclusion, the WR of 99mTc-MIBI is helpful for in vivo determination of both the Pgp and MRP expressions for infiltrating ductal carcinoma of the breast.
Breast Neoplasms ; Breast* ; Carcinoma, Ductal* ; Drug Therapy* ; Female ; Humans ; P-Glycoprotein*

Some researchers tried to use Tc-99m MIBI scintigraphy for evaluating breast cancer patients Early reports revealed that Tc-99m MIBI breast scintigraphy is useful in distinguishing malignancies from benign masses in patients who have difficulty in mammographic evaluation. Further studies suggested that the functional imaging with Tc-99m MIBI in breast cancer seems to be correlated with levels of P-glycoprotein (Pgp) expression and angiogenesis in cancer tissues. So we evaluated whether there is an actually significant relationship between the pattern of Tc-99m MIBI uptake in tumor tissue and tumoric factors including Pgp expression and angiogenesis. Thirty one untreated breast cancer patients (pathologically proved to invasive ductal carcinoma later) were prospectively studied by both Tc-99m MIBI scintigraphy and immunohistochemical analysis of angiogenesis and Pgp expression on sugically removed tumor tissues. Both lateral and anterior planar images were obtained at 10 minutes and 3 hours after intravenous injection of 740 MBq Tc-99m MIBI. Tumor-to-normal breast ratio(T/N) and washout index (WI, early T/N minus late T/N divided by early T/N) were calcuated. The results were follows; A significant correlation was found between T/N at early and late images(r=0.54, p=0.002 on early images, r=0.47, p=0.008 on late images). T/N of early images were not different among different groups of Pgp expression(p=0.3696), while those of late images were significantly different among groups(p=0.0276). Even more significant difference of WI among the groups were noted (p=0.0015). A significant negative correlation was noted between T/N of late images and Pgp expression (p=0.00276). A even stronger correlation was found between WI and Pgp expression (r=0.68, p=0.001). In conclusion, the tumoral uptake and washout of Tc-99m MIBI can be used as a simple functional test for angiogenesis and P-glycoprotein expression in untreated breast cancer.
Breast Neoplasms* ; Breast* ; Carcinoma, Ductal ; Humans ; Injections, Intravenous ; P-Glycoprotein ; Population Characteristics* ; Prospective Studies ; Radionuclide Imaging*

OBJECTIVES: The purpose of this study was to evaluate expression of cyclooxygenase-2 (COX-2) and P-glycoprotein (P-gp) in ovarian epithelial carcinomas, to find out the correlations between their expression and clinicopathological parameters, and to evaluate the response to treatment and clinical outcome according to their expression. METHODS: Immunohistochemical studies of COX-2 and P-gp were carried out in 64 cases that were treated with ovarian epithelial carcinomas at Department of Obstetrics and Gynecology, Korea University Hospital, Korea University from 1996 to 2005. RESULTS: COX-2 over-expression was detected in 20 (31.2%) cases and was significantly higher in non-responder than responder to chemotherapy (56.2% versus 22.9%, respectively; P=0.012). The patients of COX-2 overexpression showed shorter overall survival (P<0.001). Over-expression of P-gp was detected in 15 (23.4%) cases was significantly higher in non-responder than responder to chemotherapy (56.2% versus 12.5%, respectively; P<0.001). The patients of P-gp overexpression showed shorter overall survival (P= 0.042). CONCLUSION: COX-2 and P-gp overexpression could provide additional information to identify ovarian carcinoma patients with poor chance of response to chemotherapy.
Cyclooxygenase 2* ; Drug Therapy ; Gynecology ; Humans ; Korea ; Obstetrics ; P-Glycoprotein* ; Prognosis