Activity of gemcitabine in patients with non-small cell lung cancer : A multicentre, extended phase II study

NARCIS (Netherlands)

Gatzemeier, U; Shepherd, FA; LeChevalier, T; Weynants, P; Cottier, B; Groen, HJM; Rosso, R; Mattson, K; CortesFunes, H; Tonato, M; Burkes, RL; Gottfried, M; Voi, M

Gemcitabine is a novel nucleoside analogue with activity in solid tumours. This study assessed the objective response rate to gemcitabine given weekly intravenously at a dose of 1250 mg/m(2) for 3 weeks followed by 1 week of rest (one cycle) in chemonaive patients with inoperable non-small cell lung

Vorinostat Combined with High-Dose Gemcitabine, Busulfan, and Melphalan with Autologous Stem Cell Transplantation in Patients with Refractory Lymphomas.

Science.gov (United States)

Nieto, Yago; Valdez, Benigno C; Thall, Peter F; Ahmed, Sairah; Jones, Roy B; Hosing, Chitra; Popat, Uday; Shpall, Elizabeth J; Qazilbash, Muzaffar; Gulbis, Alison; Anderlini, Paolo; Alousi, Amin; Shah, Nina; Bashir, Qaiser; Liu, Yan; Oki, Yasuhiro; Hagemeister, Frederick; Fanale, Michelle; Dabaja, Bouthaina; Pinnix, Chelsea; Champlin, Richard; Andersson, Borje S

2015-11-01

More active high-dose regimens are needed for refractory/poor-risk relapsed lymphomas. We previously developed a regimen of infusional gemcitabine/busulfan/melphalan, exploiting the synergistic interaction. Its encouraging activity in refractory lymphomas led us to further enhance its use as a platform for epigenetic modulation. We previously observed increased cytotoxicity in refractory lymphoma cell lines when the histone deacetylase inhibitor vorinostat was added to gemcitabine/busulfan/melphalan, which prompted us to clinically study this four-drug combination. Patients ages 12 to 65 with refractory diffuse large B cell lymphoma (DLCL), Hodgkin (HL), or T lymphoma were eligible. Vorinostat was given at 200 mg/day to 1000 mg/day (days -8 to -3). Gemcitabine was infused continuously at 10 mg/m(2)/minute over 4.5 hours (days -8 and -3). Busulfan dosing targeted 4000 μM-minute/day (days -8 to -5). Melphalan was infused at 60 mg/m(2)/day (days -3 and -2). Patients with CD20(+) tumors received rituximab (375 mg/m(2), days +1 and +8). We enrolled 78 patients: 52 DLCL, 20 HL, and 6 T lymphoma; median age 44 years (range, 15 to 65); median 3 prior chemotherapy lines (range, 2 to 7); and 48% of patients had positron emission tomography-positive tumors at high-dose chemotherapy (29% unresponsive). The vorinostat dose was safely escalated up to 1000 mg/day, with no treatment-related deaths. Toxicities included mucositis and dermatitis. Neutrophils and platelets engrafted promptly. At median follow-up of 25 (range, 16 to 41) months, event-free and overall survival were 61.5% and 73%, respectively (DLCL) and 45% and 80%, respectively (HL). In conclusion, vorinostat/gemcitabine/busulfan/melphalan is safe and highly active in refractory/poor-risk relapsed lymphomas, warranting further evaluation. This trial was registered at ClinicalTrials.gov (NCI-2011-02891). Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights

Phase II trial of weekly 24-hour infusion of gemcitabine in patients with advanced gallbladder and biliary tract carcinoma

International Nuclear Information System (INIS)

Delius, Stefan von; Lersch, Christian; Schulte-Frohlinde, Ewert; Mayr, Martina; Schmid, Roland M; Eckel, Florian

2005-01-01

Patients with advanced gallbladder and biliary tract carcinoma face a dismal prognosis, as no effective palliative chemotherapy exists. The antitumor effect of gemcitabine is schedule-dependent rather than dose-dependent. We evaluated the activity of a prolonged infusion of gemcitabine in advanced gallbladder and biliary tract carcinomas. Nineteen consecutive eligible patients were enrolled. All patients were required to have histologically confirmed diagnosis and measurable disease. Gemcitabine was infused over 24 hours at a dose of 100 mg/m 2 on days 1, 8, and 15. Treatment was repeated every 28 days until progression of disease or limiting toxicity. Tumor response was evaluated every second course by computed tomography (CT) scans. Eighteen patients were evaluable for response. A total of 89 cycles of therapy were administered. One partial response was observed (6%; 95% confidence interval (CI): 0–27%) and ten additional patients had stable disease for at least two months (disease control rate 61%; 95% CI: 36–83%). The therapy was well tolerated, with moderate myelosuppression as the main toxicity. The median time to tumor progression and median overall survival was 3.6 months (95% CI 2.6–4.6 months) and 7.5 months (95% CI 6.5–8.5 months), respectively. Weekly 24-hour gemcitabine at a dose of 100 mg/m 2 is well tolerated. There was a relatively high rate of disease control for a median duration of 5.3 months (range 2.8–18.8 months). However, the objective response rate of this regimen in gallbladder and biliary tract carcinomas was limited

Phase I trial of nanoparticle albumin-bound paclitaxel in combination with gemcitabine in patients with thoracic malignancies.

Science.gov (United States)

Stinchcombe, Thomas E; Socinski, Mark A; Lee, Carrie B; Hayes, D Neil; Moore, Dominic T; Goldberg, Richard M; Dees, E Claire

2008-05-01

Nab-paclitaxel has a different toxicity profile than solvent-based paclitaxel including a lower rate of severe neutropenia. This trial was designed to determine the maximum tolerated dose and dose limiting toxicities (DLT) of nab-paclitaxel in combination with gemcitabine. Patients were required to have a performance status of 0 to 1, < or = three prior cytotoxic chemotherapy regimens, and preserved renal, hepatic, and bone marrow function. Patients received gemcitabine 1000 mg/m on days 1, 8 in all cohorts, and nab-paclitaxel at doses of 260, 300, 340 mg/m every 21 days depending on the treatment cohort (1 cycle = 21 days). DLT were assessed after the first cycle, and doses were escalated in cohorts of 3 to 6 patients. Eighteen patients were consented and 15 patients are evaluable [median age 62 years (range, 35-75); median number of prior treatments 3 (range, 1-4); tumor types: non-small cell lung cancer (NSCLC) (n = 8), small cell lung cancer (SCLC) (n = 6), and esophageal cancer (n = 1)]. At a nab-paclitaxel dose of 300 mg/m, 1 of 6 pts experienced a DLT (omission of day 8 gemcitabine due to absolute neutrophil count < 500), and at an nab-paclitaxel dose of 340 mg/m 2 of 3 patients experienced a DLT (1 pt grade 3 rash and pruritus; 1 pt grade 3 fatigue and anorexia). Responses were observed in NSCLC and SCLC. The maximum tolerated dose of nab-paclitaxel is 300 mg/m in combination with gemcitabine 1000 mg/m on days 1, 8 every 21 days. This combination demonstrated activity in previously treated NSCLC and SCLC patients.

A phase II study of gemcitabine in the treatment of non small cell lung cancer

NARCIS (Netherlands)

LeChevalier, T; Gottfried, M; Gatzemeier, U; Shepherd, F; Weynants, P; Cottier, B; Groen, HJM; Rosso, R; Mattson, K; CortesFunes, H; Tonato, M; Burkes, RL; Voi, M; Ponzio, A

Gemcitabine is a novel pyrimidine nucleoside whose activity has been demonstrated on solid tumors. We report here the results of a multicentre phase II trial of gemcitabine in chemonaive patients with inoperable non small cell lung cancer (NSCLC). Gemcitabine was given weekly at a dose of 1,250

Phase I study of twice-weekly gemcitabine and concomitant external-beam radiotherapy in patients with adenocarcinoma of the pancreas

International Nuclear Information System (INIS)

Pipas, J. Marc; Mitchell, Sandra E.; Barth, Richard J.; Vera-Gimon, Raul; Rathmann, Joerg; Meyer, Louise P.; Wagman, Richard S.; Lewis, Lionel D.; McDonnell, Carol; Colacchio, Thomas A.; Perez, Raymond P.

2001-01-01

Purpose: To determine the maximum tolerated dose and dose-limiting toxicity associated with twice-weekly gemcitabine and concomitant external-beam radiotherapy in patients with adenocarcinoma of the pancreas. Methods and Materials: Twenty-one patients with biopsy-proven adenocarcinoma of the pancreas were treated with external-beam radiotherapy to a dose of 50.4 Gy in 28 fractions, concurrent with gemcitabine, infused over 30 min before irradiation on a Monday and Thursday schedule. The dose of gemcitabine was escalated in 5 cohorts of 3-6 patients each. Initial gemcitabine dose was 10 mg/m 2 , with dose escalation until dose-limiting toxicity was observed. Results: The maximum tolerated dose of gemcitabine was 50 mg/m 2 , when given in a twice-weekly schedule with radiation. Dose-limiting toxicity was seen in 2 patients at 60 mg/m 2 , and consisted of severe upper gastrointestinal bleeding approximately 1 month after completion of treatment. Six patients had radiographic evidence of response to treatment, and 5 of these underwent complete surgical resection. Three patients who underwent complete resection had been deemed to have unresectable tumors before enrollment on trial. Four patients are alive, including 2 without evidence of disease more than 1 year after resection. Conclusion: The combination of external-beam radiation and twice-weekly gemcitabine at a dose of 50 mg/m 2 is well tolerated and shows promising activity for the treatment of pancreatic cancer. Our data suggest a higher maximum tolerated dose and different dose-limiting toxicity than previously reported. Further investigation of this regimen is warranted

A phase I study of imexon plus gemcitabine as first-line therapy for advanced pancreatic cancer.

Science.gov (United States)

Cohen, Steven J; Zalupski, Mark M; Modiano, Manuel R; Conkling, Paul; Patt, Yehuda Z; Davis, Peg; Dorr, Robert T; Boytim, Michelle L; Hersh, Evan M

2010-07-01

Imexon is an aziridine-derived iminopyrrolidone which has synergy with gemcitabine in pancreatic cancer cell lines. Gemcitabine is a standard therapy for pancreatic cancer. We performed a phase I trial of imexon and gemcitabine to evaluate safety, dose-limiting toxicity (DLT), and maximum tolerated dose (MTD) in patients with advanced pancreatic cancer. Patients with untreated locally advanced or metastatic pancreatic adenocarcinoma received therapy in sequential cohorts on regimen A (n = 19; imexon 200 or 280 mg/m(2) intravenously (IV) over 30 min days 1-5, 15-19 and gemcitabine 800 or 1,000 mg/m(2) IV over 30 min on days 1,8,15 every 28 days) or regimen B (n = 86; imexon 280-1,300 mg/m(2) IV over 30-60 min days 1, 8, and 15 and gemcitabine 1,000 mg/m(2) IV over 30 min on days 1, 8, and 15 every 28 days). One hundred five patients received 340 treatment cycles (median 2, range 1-16). median age 63, 61% male, ECOG PS 0/1 50%/50%, 93% metastatic. DLT was abdominal cramping and pain, often with transient, acute diarrhea. Best response was confirmed partial response (PR) in 11.4%, 8.9% unconfirmed PR, and 48.1% with stable disease. There was a dose proportional increase in imexon AUC across the doses tested with terminal half life 69 min at the MTD and no alteration of gemcitabine pharmacokinetics. The recommended phase II dose of imexon is 875 mg/m(2) with gemcitabine 1,000 mg/m(2). DLT was acute abdominal pain and cramping. Encouraging antitumor responses support further evaluation of this combination in advanced pancreatic cancer.

Synergistic combination of gemcitabine and dietary molecule induces apoptosis in pancreatic cancer cells and down regulates PKM2 expression.

Directory of Open Access Journals (Sweden)

Archana Pandita

Full Text Available Gemcitabine, an effective agent in treatment of cancer of pancreas, has undergone failures in many instances after multiple cycles of therapy due to emergence of drug resistance. Combination of dietary compounds with clinically validated drugs has emerged as an effective therapeutic approach to treat pancreatic tumors, refractory to gemcitabine therapy. In order to optimize a possible synergistic combination of Gemcitabine (GCB with dietary molecules, Betuilnic acid (BA and Thymoquinone (TQ, stand-alone IC50 dose of GCB, BA and TQ was calculated for pancreatic cancer cell lines. Fixed IC50 dose ratio of the dietary molecules in combination with reduced IC50 dose of GCB was tested on GCB resistant PANC-1 and sensitive MIA PaCa-2 cells for synergism, additive response and antagonism, using calcusyn. Combination index (CI revealed that pre-treatment of BA and TQ along with GCB synergistically inhibited the cancer cell proliferation in in-vitro experiments. Pyruvate kinase (PK M2 isoform, a promising target involved in cancer cell metabolism, showed down-regulation in presence of TQ or BA in combination with GCB. GCB with BA acted preferentially on tumor mitochondria and triggered mitochondrial permeability transition. Pre-exposure of the cell lines, MIA PaCa-2 and PANC-1, to TQ in combination with GCB induced apoptosis. Thus, the effectiveness of BA or TQ in combination with GCB to inhibit cell proliferation, induce apoptosis and down-regulate the expression of PKM2, reflects promise in pancreatic cancer treatment.

Inhibitory effect of ginsenoside Rg3 combined with gemcitabine on angiogenesis and growth of lung cancer in mice

International Nuclear Information System (INIS)

Liu, Tai-Guo; Huang, Ying; Cui, Dan-Dan; Huang, Xiao-Bing; Mao, Shu-Hua; Ji, Ling-Ling; Song, Hai-Bo; Yi, Cheng

2009-01-01

Ginsenoside Rg3, a saponin extracted from ginseng, inhibits angiogenesis. The combination of low-dose chemotherapy and anti-angiogenic inhibitors suppresses growth of experimental tumors more effectively than conventional therapy or anti-angiogenic agent alone. The present study was designed to evaluate the efficacy of low-dose gemcitabine combined with ginsenoside Rg3 on angiogenesis and growth of established Lewis lung carcinoma in mice. C57L/6 mice implanted with Lewis lung carcinoma were randomized into the control, ginsenoside Rg3, gemcitabine and combination group. The quality of life and survival of mice were recorded. Tumor volume, inhibitive rate and necrosis rate were estimated. Necrosis of tumor and signals of blood flow as well as dynamic parameters of arterial blood flow in tumors such as peak systolic velocity (PSV) and resistive index (RI) were detected by color Doppler ultrasound. In addition, expression of vascular endothelial cell growth factor (VEGF) and CD31 were observed by immunohistochemstry, and microvessel density (MVD) of the tumor tissues was assessed by CD31 immunohistochemical analysis. Quality of life of mice in the ginsenoside Rg3 and combination group were better than in the control and gemcitabine group. Combined therapy with ginsenoside Rg3 and gemcitabine not only enhanced efficacy on suppression of tumor growth and prolongation of the survival, but also increased necrosis rate of tumor significantly. In addition, the combination treatment could obviously decrease VEGF expression and MVD as well as signals of blood flow and PSV in tumors. Ginsenoside Rg3 combined with gemcitabine may significantly inhibit angiogenesis and growth of lung cancer and improve survival and quality of life of tumor-bearing mice. The combination of chemotherapy and anti-angiogenic drugs may be an innovative and promising therapeutic strategy in the experimental treatment of human lung cancer

Inhibition of SIRT1 combined with gemcitabine therapy for pancreatic carcinoma

Directory of Open Access Journals (Sweden)

Gong DJ

2013-07-01

Full Text Available Dao-Jun Gong,1 Jia-Min Zhang,1 Min Yu,1 Bo Zhuang,1 Qing-Qu Guo21Department of Hepatobiliary-Pancreatic Surgery, Jinhua Hospital of Zhejiang University, Jinhua, People's Republic of China; 2Department of Surgery, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of ChinaBackground: Pancreatic carcinoma possesses one of the highest lethality rates, highest drug-resistance, and highest incidence rates. The objective of this research was to enhance the efficacy and drug-resistance for pancreatic carcinoma by using inhibition of SIRT1 combined with gemcitabine therapy methods.Methods: Three pancreatic carcinoma cells (PANC-1 cells, BxPC-3 cells, and SW1990 cells received treatment with physiological saline, inhibition of SIRT1, gemcitabine, and combination therapy with inhibition of SIRT1 and gemcitabine in vitro; then BxPC-3 pancreatic cancer xenogeneic mice also received treatment with physiological saline, inhibition of SIRT1, gemcitabine, and combination therapy with inhibition of SIRT1 and gemcitabine in vivo.Results: The cleaved poly ADP ribose polymerase (PARP-1 effect of drug in pancreatic carcinoma cells was significantly different (P < 0.05 and the efficacy in descending order was the combination therapy with inhibition of SIRT1 and gemcitabine, inhibition of SIRT1, and gemcitabine. The BxPC-3 pancreatic cancer xenogeneic mice model received treatment with physiological saline, inhibition of SIRT1, gemcitabine, and combination therapy with inhibition of SIRT1 and gemcitabine in vivo and the results showed that the tumor volumes decreased and the survival rate within 45 days increased according to the order of the given drugs and the difference was significant (P < 0.05.Conclusion: Combination therapy with inhibition of SIRT1 and gemcitabine could improve efficacy and survival time in a BxPC-3 pancreatic cancer xenogeneic mice model, compared with single inhibition of SIRT1, or single

Phase I study of combination of vorinostat, carboplatin, and gemcitabine in women with recurrent, platinum-sensitive epithelial ovarian, fallopian tube, or peritoneal cancer.

Science.gov (United States)

Matulonis, Ursula; Berlin, Suzanne; Lee, Hang; Whalen, Christin; Obermayer, Elizabeth; Penson, Richard; Liu, Joyce; Campos, Susana; Krasner, Carolyn; Horowitz, Neil

2015-08-01

Combining histone deacetylase inhibitors and chemotherapy is synergistic. This phase I study combined escalating vorinostat doses with constant doses of carboplatin and gemcitabine for the treatment of recurrent platinum-sensitive ovarian cancer. The objectives of this study were to determine the maximally tolerated dose of this combination; secondary objectives included preliminary response rate of this regimen and toxicity profile. Fifteen patients with relapsed ovarian cancer were enrolled into this phase I study. Doses of carboplatin and gemcitabine were AUC 4 on day 1 and 1000 mg/m(2) on days 1 and 8, respectively; cycles were administered every 21 days. Vorinostat was tested using four different schedules. The first dose level (DL A) tested vorinostat as daily oral dosing from days 1 to 14. DL B tested twice daily (BID) vorinostat dosing on days 1-3 and 8-10. DL C tested BID vorinostat dosing on days 1, 2, 8, and 9, starting vorinostat 1 day prior to initiation of carboplatin and gemcitabine, and DL D tested vorinostat on days 1 and 2 with chemotherapy starting on day 2. All four DLs tested resulted in dose-limiting toxicities, and no MTD was determined. Toxicities were mostly hematologic. Seven patients were evaluable for RECIST assessment, and six of them had partial responses (PR) via RECIST. Combination of carboplatin, gemcitabine, and vorinostat has activity in relapsed platinum-sensitive ovarian cancer, but was difficult to combine because of hematologic toxicities in this phase I study. No maximally tolerated dose was found, and the study was terminated early.

Bayesian estimation of dose rate effectiveness

International Nuclear Information System (INIS)

Arnish, J.J.; Groer, P.G.

2000-01-01

A Bayesian statistical method was used to quantify the effectiveness of high dose rate 137 Cs gamma radiation at inducing fatal mammary tumours and increasing the overall mortality rate in BALB/c female mice. The Bayesian approach considers both the temporal and dose dependence of radiation carcinogenesis and total mortality. This paper provides the first direct estimation of dose rate effectiveness using Bayesian statistics. This statistical approach provides a quantitative description of the uncertainty of the factor characterising the dose rate in terms of a probability density function. The results show that a fixed dose from 137 Cs gamma radiation delivered at a high dose rate is more effective at inducing fatal mammary tumours and increasing the overall mortality rate in BALB/c female mice than the same dose delivered at a low dose rate. (author)

Long-Term Results of Fixed High-Dose I-131 Treatment for Toxic Nodular Goiter: Higher Euthyroidism Rates in Geriatric Patients

Directory of Open Access Journals (Sweden)

Gül Ege Aktaş

2015-10-01

Full Text Available Objective: Geriatric patient population has special importance due to particular challenges. In addition to the increase in incidence of toxic nodular goiter (TNG with age, it has a high incidence in the regions of low-medium iodine intake such as in our country. The aim of this study was to evaluate the overall outcome of high fixed dose radioiodine (RAI therapy, and investigate the particular differences in the geriatric patient population. Methods: One hundred and three TNG patients treated with high dose I-131 (370-740 MBq were retrospectively reviewed. The baseline characteristics; age, gender, scintigraphic patterns and thyroid function tests before and after treatment, as well as follow-up, duration of antithyroid drug (ATD medication and achievement of euthyroid or hypothyroid state were evaluated. The patient population was divided into two groups as those=>65 years and those who were younger, in order to assess the effect of age. Results: Treatment success was 90% with single dose RAI therapy. Hyperthyroidism was treated in 7±7, 2 months after RAI administration. At the end of the first year, overall hypothyroidism rate was 30% and euthyroid state was achieved in 70% of patients. Age was found to be the only statistically significant variable effecting outcome. A higher ratio of euthyroidism was achieved in the geriatric patient population. Conclusion: High fixed dose I-131 treatment should be preferred in geriatric TNG patients in order to treat persistent hyperthyroidism rapidly. The result of this study suggests that high fixed dose RAI therapy is a successful modality in treating TNG, and high rates of euthyroidism can be achieved in geriatric patients.

Phase I study of conformal radiotherapy with concurrent gemcitabine in locally advanced bladder cancer

International Nuclear Information System (INIS)

Sangar, Vijay K.; McBain, Catherine A.; Lyons, Jeanette; Ramani, Vijay; Logue, John; Wylie, James; Clarke, Noel W.; Cowan, Richard A.

2005-01-01

Purpose: A prospective phase I trial was conducted to determine the maximal tolerated dose of gemcitabine given once weekly during hypofractionated conformal radiotherapy to patients with locally advanced transitional cell carcinoma of the bladder. Eight male patients, median age 69 years, with Stage T2 (n = 4) or T3 (n = 4) N0M0, were enrolled in cohorts of 3. Treatment comprised conformal radiotherapy (52.5 Gy in 20 fractions) within 4 weeks, with concurrent gemcitabine once weekly for four cycles. The weekly gemcitabine dose was escalated from 100 mg/m 2 in increments of 50 mg/m 2 per cohort. Dose-limiting toxicity was defined as any acute Radiation Therapy Oncology Group (RTOG) toxicity Grade 3 or greater arising in >1 of 3 patients in each cohort. Tumor response was assessed cystoscopically and radiologically at 3 months. Results: All 8 patients completed radiotherapy, and 6 of 8 completed chemoradiotherapy. No acute toxicity greater than RTOG Grade 1 was seen with gemcitabine at 100 mg/m 2 . Dose-limiting toxicity was observed at 150 mg/m 2 with Grade 3 toxicity seen in 2 of 2 patients (one bladder, one bowel). An additional 3 patients received 100 mg/m 2 with minimal toxicity. No hematologic toxicity was encountered. A complete response was seen in 7 (87.5%) of 8 patients, all of whom were disease free at a median follow-up of 19.5 months (range, 14-23 months). No late toxicity (greater than RTOG Grade 0) has been observed. Conclusion: The maximal tolerated dose for gemcitabine given once weekly with concurrent hypofractionated conformal bladder radiotherapy was 150 mg/m 2 , with a maximal recommended dose of 100 mg/m 2 . This dose regimen has now entered Phase II clinical trials

Weekly Gemcitabine and Cisplatin in Combination With Radiotherapy in Patients With Locally Advanced Head-and-Neck Cancer: Phase I Study

Energy Technology Data Exchange (ETDEWEB)

Arruda Viani, Gustavo, E-mail: gusviani@gmail.com [Radiation Oncology Department, Faculty of Medicine of Marilia, Sao Paulo (Brazil); Afonso, Sergio Luis [Clinical Oncology Department, Faculty of Medicine of Marilia, Sao Paulo (Brazil); Cardoso Tavares, Vivian [Head and Neck Oncology Department, Faculty of Medicine of Marilia, Sao Paulo (Brazil); Bernardes Godoi da Silva, Lucas; Stefano, Eduardo Jose [Radiation Oncology Department, Faculty of Medicine of Marilia, Sao Paulo (Brazil)

2011-11-15

Purpose: To define the maximum tolerated dose by describing the dose-limiting toxicity (DLT) of weekly gemcitabine and cisplatin in patients with locally advanced head-and-neck (LAHN) cancer concomitant to irradiation. Methods and Materials: Patients with LAHN cancer were enrolled in a prospective, dose-escalation Phase I study. Toxicity was graded according to the Common Toxicity Criteria score. Maximum tolerated dose was defined when DLT developed in 2 of 6 patients. The starting dose of cisplatin was 20 mg/m{sup 2} and that of gemcitabine was 10 mg/m{sup 2} in 3 patients, with a subsequent dose escalation of 10 mg/m{sup 2} of cisplatin only for 3 new patients. In the next levels, only a dose escalation of gemcitabine with 10 mg/m{sup 2} for each new cohort was used (Level 1, 10 mg/m{sup 2} of gemcitabine and 20 mg/m{sup 2} of cisplatin; Level 2, 10 mg/m{sup 2} of gemcitabine and 30 mg/m{sup 2} of cisplatin; and Level 3, 20 mg/m{sup 2} of gemcitabine and 30 mg/m{sup 2} of cisplatin). Radiation therapy was administered by use of a conformal technique over a period of 6 to 7 weeks in 2.0-Gy daily fractions for 5 consecutive days per week to a total dose of 70 Gy. Results: From 2008 to 2009, 12 patients completing 3 dose levels were included in the study. At Dose Level 3, 1 of 3 patients had DLT with Grade 3 mucositis. Of the next 3 required patients, 2 showed DLT with Grade 3 dermatitis. At a follow-up of 3 months, 10 of 12 evaluable patients (83.3%) obtained a complete response and 1 patient (8.3%) obtained a partial response. Among the complete responders, at a median follow-up of 10 months (range, 6-14 months), 9 patients are alive and disease free. Conclusion: Gemcitabine at low doses combined with cisplatin is a potent radiosensitizer effective in patients with LAHN cancer. The recommended Phase II dose is 10 mg/m{sup 2} of gemcitabine and 30 mg/m{sup 2} of cisplatin with an acceptable tolerability profile.

Evaluation of the Basedow disease treatment by a iodine 131 fixed dose; Evaluation du traitement de la maladie de Basedow par une dose fixe d'iode 131

Energy Technology Data Exchange (ETDEWEB)

El Ajmi, W.; Slim, I; Rmadi, S.; Yeddes, I.; Krimi, S.; Ltaief, B.; Mhiri, A.; Ben Slimene, M.F. [Service de medecine nucleaire, institut Salah Azeiz, Tunis, (Tunisia)

2009-05-15

The treatment of the basedow disease by iodine 131 is more and more used. however, the doses used stay variable. In order to reduce the treatment failure, we chose a protocol with strong fix doses of iodine 131. We give our preliminary results for 63 patients. The treatment by strong fix dose of iodine 131 is simple, safe and efficient for the control of hyperthyroidism in the Basedow disease. This protocol has for advantage to be simpler comparatively to these ones using adjusted doses according the weight of the thyroid and its fixation rate. (N.C.)

Gemcitabine: Selective cytotoxicity, induction of inflammation and effects on urothelial function

Energy Technology Data Exchange (ETDEWEB)

Farr, Stefanie E; Chess-Williams, Russ; McDermott, Catherine M, E-mail: camcderm@bond.edu.au

2017-02-01

Intravesical gemcitabine has recently been introduced for the treatment of superficial bladder cancer and has a favourable efficacy and toxicity profile in comparison to mitomycin c (MMC), the most commonly used chemotherapeutic agent. The aim of this study was to assess the cytotoxic potency of gemcitabine in comparison to MMC in urothelial cell lines derived from non-malignant (UROtsa) and malignant (RT4 and T24) tissues to assess selectivity. Cells were treated with gemcitabine or mitomycin C at concentrations up to the clinical doses for 1 or 2 h respectively (clinical duration). Treatment combined with hyperthermia was also examined. Cell viability, ROS formation, urothelial function (ATP, acetylcholine and PGE2 release) and secretion of inflammatory cytokines were assessed. Gemcitabine displayed a high cytotoxic selectivity for the two malignant cell lines (RT4, T24) compared to the non-malignant urothelial cells (UROtsa, proliferative and non-proliferative). In contrast, the cytotoxic effects of MMC were non-selective with equivalent potency in each of the cell lines. The cytotoxic effect of gemcitabine in the malignant cell lines was associated with an elevation in free radical formation and was significantly decreased in the presence of an equilibrative nucleoside transporter inhibitor. Transient changes in urothelial ATP and PGE{sub 2} release were observed, with significant increase in release of interleukin-6, interleukin-8 and interleukin-1β from urothelial cells treated with gemcitabine. The selectivity of gemcitabine for malignant urothelial cells may account for the less frequent adverse urological effects with comparison to other commonly used chemotherapeutic agents. - Highlights: • Intravesical gemcitabine has recently been introduced to treat bladder cancer. • Gemcitabine is selectively toxic for malignant urothelial cells. • Urothelial ATP, PGE{sub 2} and inflammatory cytokines were altered by gemcitabine. • Selectivity of gemcitabine

Phase 1 trial evaluating cisplatin, gemcitabine, and veliparib in 2 patient cohorts: Germline BRCA mutation carriers and wild-type BRCA pancreatic ductal adenocarcinoma.

Science.gov (United States)

O'Reilly, Eileen M; Lee, Jonathan W; Lowery, Maeve A; Capanu, Marinela; Stadler, Zsofia K; Moore, Malcolm J; Dhani, Neesha; Kindler, Hedy L; Estrella, Hayley; Maynard, Hannah; Golan, Talia; Segal, Amiel; Salo-Mullen, Erin E; Yu, Kenneth H; Epstein, Andrew S; Segal, Michal; Brenner, Robin; Do, Richard K; Chen, Alice P; Tang, Laura H; Kelsen, David P

2018-04-01

A phase 1 trial was used to evaluate a combination of cisplatin, gemcitabine, and escalating doses of veliparib in patients with untreated advanced pancreatic ductal adenocarcinoma (PDAC) in 2 cohorts: a germline BRCA1/2-mutated (BRCA+) cohort and a wild-type BRCA (BRCA-) cohort. The aims were to determine the safety, dose-limiting toxicities (DLTs), maximum tolerated dose, and recommended phase 2 dose (RP2D) of veliparib combined with cisplatin and gemcitabine and to assess the antitumor efficacy (Response Evaluation Criteria in Solid Tumors, version 1.1) and overall survival. Gemcitabine and cisplatin were dosed at 600 and 25 mg/m 2 , respectively, over 30 minutes on days 3 and 10 of a 21-day cycle. Four dose levels of veliparib were evaluated: 20 (dose level 0), 40 (dose level 1), and 80 mg (dose level 2) given orally twice daily on days 1 to 12 and 80 mg given twice daily on days 1 to 21 (dose level 2A [DL2A]). Seventeen patients were enrolled: 9 BRCA+ patients, 7 BRCA- patients, and 1 patient with an unknown status. DLTs were reached at DL2A (80 mg twice daily on days 1 to 21). Two of the 5 patients in this cohort (40%) experienced grade 4 neutropenia and thrombocytopenia. Two grade 5 events occurred on protocol. The objective response rate in the BRCA+ cohort was 7 of 9 (77.8%). The median overall survival for BRCA+ patients was 23.3 months (95% confidence interval [CI], 3.8-30.2 months). The median overall survival for BRCA- patients was 11 months (95% CI, 1.5-12.1 months). The RP2D of veliparib was 80 mg by mouth twice daily on days 1 to 12 in combination with cisplatin and gemcitabine; the DLT was myelosuppression. Substantial antitumor activity was seen in BRCA+ PDAC. A randomized phase 2 trial is currently evaluating cisplatin and gemcitabine with and without veliparib for BRCA+ PDAC (NCT01585805). Cancer 2018;124:1374-82. © 2018 American Cancer Society. © 2018 American Cancer Society.

131-I treatment in patients with hyperthyroidism using low fixed dose regimen

International Nuclear Information System (INIS)

Bochev, P.; Klisarova, A.; Chaushev, B.; Hristozov, K.; Tsvetanova, B.

2007-01-01

Treatment of hyperthyroidism is one of the major problems in thyroidology. The well known and widely exploited treatment modalities in patients with hyperthyroidism are antithyroid drugs, radioiodine treatment and thyroid surgery, the latter two being considered definitive. Radioiodine treatment is effective and well tolerated treating modality, which major disadvantage is the impossibility of exact calculation of the dose needed. Lots of dosage regimens are approved, including empirically chosen fixed dose regimen. The aim of the study is to define the overall success rate in patients with hyperthyroidism in subgroups Grave's disease and toxic nodular goiter treated with fixed dose 185MBq regimen. Of all treated patients a low fixed dose regimen was chosen in 43. All the patients were followed up clinically, with ultrasonography and hormone levels for a period of minimum 1 year. Part of the patients with persistent hyperthyroidism 6 months after the initial treatment receive a second dose of 185MBq 131-1. The overall success rate in the subgroup with Grave's disease was 87% by the time of the study, compared to a considerably lower success of 62% in patients with toxic nodular goiter. (authors)

Combined Chemoradiation Therapy With Twice-Weekly Gemcitabine and Cisplatin for Organ Preservation in Muscle-Invasive Bladder Cancer: Long-Term Results of a Phase 1 Trial

Energy Technology Data Exchange (ETDEWEB)

Azria, David, E-mail: david.azria@icm.unicancer.fr [Department of Radiation Oncology and Radiophysics Unit, Montpellier Cancer Institute (ICM), Montpellier (France); INSERM, U896, IRCM, Montpellier (France); Riou, Olivier [Department of Radiation Oncology and Radiophysics Unit, Montpellier Cancer Institute (ICM), Montpellier (France); Rebillard, Xavier [Department of Urology, Clinique Beausoleil, Montpellier (France); Thezenas, Simon [Biostatistics Unit, Montpellier Cancer Institute, Montpellier (France); Thuret, Rodolphe [Department of Urology, Montpellier University Hospital, Montpellier (France); Fenoglietto, Pascal [Department of Radiation Oncology and Radiophysics Unit, Montpellier Cancer Institute (ICM), Montpellier (France); Pouessel, Damien; Culine, Stephane [Department of Medical Oncology, AP-HP Saint-Louis, Paris (France)

2014-03-15

Purpose: Concomitant treatment with radiation therapy and cisplatin (CDDP) remains the gold standard for bladder preservation in the treatment of muscle-invasive bladder cancer (MIBC). We present the long-term results of a phase 1 clinical trial to assess the association of twice-weekly gemcitabine with CDDP and radiation therapy in this setting. Methods and Materials: Patients with pT2-pT4N0M0 MIBC without hydronephrosis or diffuse carcinoma in situ were enrolled in this study. After maximal transurethral resection of the bladder tumor, patients received concomitant radiation therapy (63 Gy in 1.8 fractions) and chemotherapy (CDDP 20 mg/m²/day over 4 days every 21 days and gemcitabine twice a week). The starting dose of gemcitabine was 15 mg/m² with dose escalation to 20, 25, and 30 mg/m². The primary endpoint was the maximum tolerated dose (MTD). Secondary endpoints included toxicity and tumor control. Results: Fourteen patients were enrolled. Dose-limiting toxicity occurred in 2 patients treated with 30 mg/m² gemcitabine (grade 4 thrombocytopenia and severe impairment of World Health Organization performance status, respectively). Nine patients received the complete chemoradiation therapy protocol. The recommended dose of gemcitabine was 25 mg/m². The median follow-up time was 53 months, and the overall and disease-specific 5-year survival rates were 62% and 77%, respectively. Among the patients who received the complete treatment, bladder-intact survival was 76% at 5 years, and the median overall survival was 69.6 months. Conclusions: This regimen was well tolerated. The gemcitabine MTD was 25 mg/m². Bladder preservation and disease control were promising. A multicenter phase 2 randomized trial is ongoing.

Radiochemotherapy with gemcitabine and cisplatin in pancreatic cancer - feasible and effective

International Nuclear Information System (INIS)

Wilkowski, R.; Thoma, M.; Duehmke, E.; Heinemann, V.; Rau, H.G.; Wagner, A.; Stoffregen, C.

2003-01-01

Background: Concomittant radiotherapy and chemotherapy with gemcitabine appears to be a promising tool for the treatment of pancreatic cancer since gemcitabine - applied as single or combination therapy - proved to have better efficacy in pancreatic cancer than 5-FU containing schemes and furthermore offers radiosensitizing potential. In the present paper our pilot data of concomittant and sequential chemoradiation with gemcitabine and cisplatin are presented. Patients and Methods: A total of 57 patients (f/m 23/34) with pancreatic cancer was treated, of whom 33 patients had irresectable tumors, 19 patients following resection (R1 and/or pN+) and five patients with local recurrent disease. Radiotherapy was delivered in 25 fractions up to a total dose of 45.0 Gy specified according to ICRU reference point (50 patients, 1.8 Gy/fraction) respectively 50.0 Gy to gross tumor volume (seven patients; 45.0 Gy in locoregional lymphatic pathways; 2.0/ 1.8 Gy/fraction). Concomittant with radiotherapy cisplatin (30 mg/m 2 ) and gemcitabine (300 mg/m 2 ) were applied on days 1, 8, 22 and 29. After simultaneous chemoradiation two sequential cycles gemcitabine and cisplatin (1000 mg/m 2 and 50 mg/m 2 d 1, 15) were applied. Results: With a median follow-up of 8.2 months the median survival time was 14.8 months (irresectable patients: 10.3 months, postoperative patients 15.1 months). Within 33 irresectable patients 19 and four partial and complete remissions, respectively, were observed. In 14 patients a secondary resection was possible. Using leveled antiemetics with ondansetron and dexamethasone no gastrointestinal toxicities grade III or IV were observed. Hematologic toxicities were the most grave side effects (leukocytopenia III/IV in 29/Five patients and thrombocytopenia III/IV in 21/eight patients), however with minor clinical relevancy (one neutropenic infection, one thrombopenic epistaxis). Conclusion: The presented treatment scheme using concomittant and sequential

Phase I trial of gefitinib with concurrent radiotherapy and fixed 2-h gemcitabine infusion, in locally advanced pancreatic cancer

International Nuclear Information System (INIS)

Maurel, Joan; Martin-Richard, Marta; Conill, Carlos; Sanchez, Marcelo; Petriz, Lourdes; Gines, Angels; Miquel, Rosa; Gallego, Rosa; Cajal, Rosana; Ayuso, Carmen; Navarro, Salvador; Marmol, Maribel; Nadal, Cristina; Auge, Josep Maria; Fernandez-Cruz, Laureano; Gascon, Pere

2006-01-01

Purpose: Pancreatic cancers are resistant to radiotherapy (RT) and current chemotherapy agents. Epidermal growth factor receptor is overexpressed in pancreatic cancer, and in vitro studies have shown that epidermal growth factor receptor inhibitors can overcome radio- and chemoresistance. The aim of the study was to determine whether the addition of gefitinib to RT and gemcitabine for patients with locally advanced pancreatic carcinoma (LAPC) was feasible and safe. Methods and Materials: Eighteen patients with pathologically proven LAPC, based on major vascular invasion based on helical computed tomography (CT) and endoscopic ultrasound, were entered into the study. The targeted irradiated volume included the tumor and 2-cm margin. Prophylactic irradiation of regional nodes was not allowed. Patients with >500 cm 3 of planning tumor volume were excluded. An initial cohort of 6 patients was treated with RT (45 Gy/25 fractions/5 weeks) plus concomitant gefitinib (250 mg/day). Successive cohorts of patients received 100, 150, and 200 mg/m 2 /day of gemcitabine in a 2-h infusion over Weeks 1, 2, 3, 4, and 5 with gefitinib (250 mg/day) and RT. Gefitinib was continued after RT until progression. A pharmacodynamic study of angiogenic markers was also performed to evaluate a possible antiangiogenic effect. Results: There were no dose-limiting toxicities. Common toxicities were mild neutropenia, asthenia, diarrhea, cutaneous rash and nausea/vomiting. The median (95% confidence interval [CI]) progression-free survival was 3.7 (95% CI = 1.9-5.5) months, and the median overall survival was 7.5 (95% CI 5.2-9.9) months. No significant reduction of vascular endothelial growth factor and interleukin-8 was observed after treatment. Conclusion: Our results support that the combination of gefitinib, RT, and gemcitabine has an acceptable toxicity but with modest activity in LAPC

Phase I trial of strictly time-scheduled gemcitabine and cisplatin with concurrent radiotherapy in patients with locally advanced pancreatic cancer

International Nuclear Information System (INIS)

Brunner, Thomas B.; Grabenbauer, Gerhard G.; Klein, Peter; Baum, Ulrich; Papadopoulos, Thomas; Bautz, Werner; Hohenberger, Werner; Sauer, Rolf

2003-01-01

Purpose: Maximal therapeutic gain in xenograft sarcoma and toxicity for jejunal mucosa is time dependent for concurrent gemcitabine and radiotherapy (RT). We used a time-dependent schedule to determine the maximal-tolerated dose and dose-limiting toxicities (DLTs; Grade 4 hematologic or Grade 3 other toxicity). Methods and Materials: Patients with pancreatic cancer (n=33), periampullary carcinoma (n=1), or bile duct cancer (n=2) were treated with 3-day conformal RT with 50.4 Gy (tumor, lymphatics) plus a 5.4-Gy boost. Concurrent cisplatin (20 mg/m 2 /d on Days 1-5 and 29-33) and gemcitabine (initially 600 mg/m 2 , weekly on Fridays 68 h before RT) were administered. Because of DLT, the doses were reduced to 500 mg/m 2 weekly and then 500, 400, or 300 mg/m 2 on Days 2, 5, 26, 33. Results: DLT occurred at all dose levels of gemcitabine >300 mg/m 2 . Fourteen patients were treated at the recommended Phase II dose of gemcitabine (300 mg/m 2 ) without DLT. The response to chemoradiation allowed 10 of 30 initially unresectable patients with primary pancreatic carcinoma to undergo radical surgery, including a complete response in 2 cases. Conclusions: At the recommended Phase II dose, chemoradiation with gemcitabine and cisplatin can be administered safely in pancreatic carcinoma. However, at higher dose levels, toxicity is severe and frequent. Patients with a chance for conversion to resection could benefit from this schedule

Gemcitabine and S-1 Combination Chemotherapy in Patients with Advanced Biliary Tract Cancer:A Retrospective Study

Directory of Open Access Journals (Sweden)

Kazuhito Mita

2010-12-01

Full Text Available Background:The aim of this study was to investigate the efficacy and safety of gemcitabine and S-1 combination chemotherapy in patients with advanced biliary tract cancer. Patients and Methods: A retrospective study was performed on 15 consecutive patients. Gemcitabine was administered intravenously at 1,000 mg/m2 on days 8 and 15. Oral S-1 (60 mg/m2 in 2 divided doses was given daily for the first 2 weeks, followed by 1 week of rest. This 3-week course of treatment was repeated. The primary endpoint was response rate, and the secondary endpoints were overall survival, progression-free survival, and safety. Results: The overall response rate was 26.7%, and the disease control rate was 73.4%. The overall survival was 12.0 months (95% CI, 9.5–14.5 months, and the progression-free survival was 8.0 months (95% CI, 4.3–11.7 months. Adverse events of grade 3 or 4 occurred in 33.3%, and the major grade 3/4 toxicities were anemia (20.0%, leukopenia (13.3%, and anorexia (13.3%. Conclusion:Gemcitabine and S-1 combination chemotherapy is effective and safe in patients with advanced biliary tract cancer.

Dose-finding and pharmacokinetic study of cisplatin, gemcitabine, and SU5416 in patients with solid tumors

NARCIS (Netherlands)

Kuenen, Bart C.; Rosen, Lee; Smit, Egbert F.; Parson, Mandy R. N.; Levi, Marcel; Ruijter, Rita; Huisman, Holger; Kedde, Marc A.; Noordhuis, Paul; van der Vijgh, Wim J. F.; Peters, Godefridus J.; Cropp, Gillian F.; Scigalla, Paul; Hoekman, Klaus; Pinedo, Herbert M.; Giaccone, Giuseppe

2002-01-01

Purpose: To investigate the feasibility and pharmacokinetics of the combination cisplatin, gemcitabine, and SU5416. Patients and Methods: Patients received cisplatin 80 mg/m(2) on day 1, gemcitabine 1,250 mg/m(2) on days 1 and 8, repeated every 3 weeks, and SU5416 (85 and 145 mg/m(2)) intravenously

A phase I dose escalation trial of AXP107-11, a novel multi-component crystalline form of genistein, in combination with gemcitabine in chemotherapy-naive patients with unresectable pancreatic cancer.

Science.gov (United States)

Löhr, Johannes-Matthias; Karimi, Masoud; Omazic, Brigitta; Kartalis, Nikolaos; Verbeke, Caroline Sabine; Berkenstam, Anders; Frödin, Jan-Erik

2016-01-01

AXP107-11 is a novel, multi-component crystalline form of the naturally occurring compound genistein. AXP107-11 has improved physiochemical properties and oral bioavailability compared to the natural form of genistein, and it is possible that combining AXP107-11 with chemotherapy may increase the effect and reduce chemoresistance. The purpose of this dose escalation phase Ib study was to assess the safety, maximum tolerated dose (MTD) and pharmacokinetics (PK) of AXP107-11 in combination with gemcitabine in treatment-naïve patients with inoperable pancreatic carcinoma. AXP107-11 was given orally in escalating doses (400 mg-1600 mg daily) in combination with standard gemcitabine treatment (1000 mg/m(2)/week) for the first seven of eight weeks and thereafter for a maximum of four × four-week treatment cycles. PK, safety, MTD and efficacy of AXP107-11 in combination with gemcitabine were evaluated. Sixteen patients were enrolled and received AXP107-11. The maximum concentration in serum of unconjugated (free) genistein was 1 μM. Neither dose-limiting toxicities (DLTs) nor signs of hematological or non-hematological toxicities related to AXP107-11 were observed over a period ranging from 0.7 to 13.2 months. The median overall survival time was 4.9 months (range 1.5-19.5 months). Seven patients (44%) survived longer than six months and 19% were alive at the one-year follow-up. Treatment of pancreatic cancer patients with AXP107-11 in combination with gemcitabine resulted in a favorable PK-profile with high serum levels without signs of either hematological or non-hematological toxicity. Accordingly, we suggest further studies with AXP107-11 in pancreatic cancer patients. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Fixed-dose lercanidipine/enalapril for hypertension.

Science.gov (United States)

Menne, Jan; Haller, Hermann

2008-04-01

The dihydropyridine calcium channel blocker lercanidipine and the ACE inhibitor enalapril are frequently used in the treatment of hypertensive patients. In April 2007, a fixed-dose combination of the two drugs was approved in Germany for the treatment of patients not responding to monotherapy. It is expected that the drug will soon be available in the other European Union markets. In this review the present literature is summarized. Two doses will be available with 10 mg lercanidipine each and 10 or 20 mg enalapril. The medication should be taken once daily, optimally =15 minutes before a meal and the consumption of grapefruit juice should be avoided. The fixed-dose combination of the two drugs has a stronger blood pressure-lowering effect than monotherapy with 20 mg enalapril or 10 mg lercanidipine. The combination is well tolerated and few patients stopped the treatment because of side effects. As expected, the most common side effects reported are cough, peripheral edema, flushing, dizziness and vertigo, occurring in 1-5% of patients. This new fixed-dose combination is a useful adjunct to the present treatment and should increase compliance and help reduce hypertension-related costs. 2008 Prous Science, S.A.U. or its licensors

Alterations in Pharmacokinetics of Gemcitabine and Erlotinib by Concurrent Administration of Hyangsayukgunja-Tang, a Gastroprotective Herbal Medicine.

Science.gov (United States)

Kim, Tae Hwan; Shin, Soyoung; Kim, Sarah; Bulitta, Jürgen B; Weon, Kwon-Yeon; Joo, Sang Hoon; Ma, Eunsook; Yoo, Sun Dong; Park, Gi-Young; Kwon, Dong Rak; Jeong, Seok Won; Lee, Da Young; Shin, Beom Soo

2017-09-10

Gemcitabine and erlotinib are the chemotherapeutic agents used in the treatment of various cancers and their combination is being accepted as a first-line treatment of advanced pancreatic cancer. Hyangsayukgunja-tang (HYT) is a traditional oriental medicine used in various digestive disorders and potentially helpful to treat gastrointestinal adverse effects related to chemotherapy. The present study was aimed to evaluate the effect of HYT on the pharmacokinetics of gemcitabine and erlotinib given simultaneously in rats. Rats were pretreated with HYT at an oral dose of 1200 mg/kg/day once daily for a single day or 14 consecutive days. Immediately after pretreatment with HYT, gemcitabine and erlotinib were administered by intravenous injection (10 mg/kg) and oral administration (20 mg/kg), respectively. The effects of HYT on pharmacokinetics of the two drugs were estimated by non-compartmental analysis and pharmacokinetic modeling. The pharmacokinetics of gemcitabine and erlotinib were not altered by single dose HYT pretreatment. However, the plasma levels of OSI-420 and OSI-413, active metabolites of erlotinib, were significantly decreased in the multiple dose HYT pretreatment group. The pharmacokinetic model estimated increased systemic clearances of OSI-420 and OSI-413 by multiple doses of HYT. These data suggest that HYT may affect the elimination of OSI-420 and OSI-413.

Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

Energy Technology Data Exchange (ETDEWEB)

Knecht, Wolfgang [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Mikkelsen, Nils Egil [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Clausen, Anders Ranegaard [Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden); Willer, Mette [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Eklund, Hans [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Gojkovic, Zoran [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Piskur, Jure, E-mail: Jure.Piskur@cob.lu.se [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden)

2009-05-01

Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 A resolution structure of Dm-dNK in complex with gemcitabine shows that the residues Tyr70 and Arg105 play a crucial role in the firm positioning of gemcitabine by extra interactions made by the fluoride atoms. This explains why gemcitabine is a good substrate for Dm-dNK.

Cisplatin, Gemcitabine, and Lapatinib as Neoadjuvant Therapy for Muscle-Invasive Bladder Cancer.

Science.gov (United States)

Narayan, Vivek; Mamtani, Ronac; Keefe, Stephen; Guzzo, Thomas; Malkowicz, S Bruce; Vaughn, David J

2016-07-01

We sought to investigate the safety and efficacy of gemcitabine, cisplatin, and lapatinib (GCL) as neoadjuvant therapy in patients with muscle-invasive bladder cancer (MIBC) planned for radical cystectomy. Four cycles of GCL were administered as neoadjuvant therapy for patients with MIBC. Although initially designed as a phase II efficacy study with a primary endpoint of pathologic complete response at the time of radical cystectomy, the dose selected for investigation proved excessively toxic. A total of six patients were enrolled. The initial four patients received gemcitabine 1,000 mg/m(2) intravenously on days 1 and 8 and cisplatin 70 mg/m(2) intravenously on day 1 of each 21-day treatment cycle. Lapatinib was administered as 1,000 mg orally daily starting one week prior to the initiation of cycle 1 of gemcitabine and cisplatin (GC) and continuing until the completion of cycle 4 of GC. These initial doses were poorly tolerated, and the final two enrolled patients received a reduced lapatinib dose of 750 mg orally daily. However, reduction of the lapatinib dose did not result in improved tolerance or drug-delivery, and the trial was terminated early due to excessive toxicity. Grade 3/4 toxicities included diarrhea (33%), nausea/vomiting (33%), and thrombocytopenia (33%). The addition of lapatinib to GC as neoadjuvant therapy for MIBC was limited by excessive treatment-related toxicity. These findings highlight the importance of thorough dose-escalation investigation of combination therapies prior to evaluation in the neoadjuvant setting, as well as the limitations of determination of maximum tolerated dose for novel targeted combination regimens.

Nab-Paclitaxel plus gemcitabine in patients with metastatic pancreatic adenocarcinoma: experience of use

Directory of Open Access Journals (Sweden)

Elena Ferris Villanueva

2015-02-01

Full Text Available Objective: To evaluate the results obtained with the combined use of nab-paclitaxel and gemcitabine in the treatment of patients with metastatic pancreatic adenocarcinoma. Materials and methods: Retrospective observational study. Patients treated with nab-paclitaxel and gemcitabine between January of 2013 and January of 2014 were selected. Demographical and clinical data were gathered. Results: 15 patients (mean age 59,4 ± 10,3 years were included. All patients received the combination of nab-paclitaxel and gemcitabine in first-line metastatic disease. Nine received adjuvant treatment before the disease was metastatic. The median progression-free survival rate with combined nab-paclitaxel and gemcitabine was 5,6 months (95% CI: 4,44 - 8,03. In two patients the treatment was stopped due to toxicity. Conclusions: The treatment with nab-paclitaxel and gemcitabine in our patients resulted in progression-free survival rates similar to those published in clinical trials with good treatment tolerability

Radiochemotherapy with gemcitabine and cisplatin in pancreatic cancer - feasible and effective; Radiochemotherapie mit Gemcitabin und Cisplatin bei Pankreaskarzinom - durchfuehrbar und effektiv

Energy Technology Data Exchange (ETDEWEB)

Wilkowski, R.; Thoma, M.; Duehmke, E. [Klinik und Poliklinik fuer Strahlentherapie, Klinikum Grosshadern, Ludwig-Maximilians-Univ. Muenchen (Germany); Heinemann, V. [Medizinische Klinik III, Klinikum Grosshadern, Ludwig-Maximilians-Univ. Muenchen (Germany); Rau, H.G. [Abt. fuer Viszeralchirurgie, Klinikum Dachau (Germany); Wagner, A. [Medizinische Klinik II, Klinikum Grosshadern, Ludwig-Maximilians-Univ. Muenchen (Germany); Stoffregen, C. [Lilly Deutschland GmbH, Bad Homburg (Germany)

2003-02-01

Background: Concomittant radiotherapy and chemotherapy with gemcitabine appears to be a promising tool for the treatment of pancreatic cancer since gemcitabine - applied as single or combination therapy - proved to have better efficacy in pancreatic cancer than 5-FU containing schemes and furthermore offers radiosensitizing potential. In the present paper our pilot data of concomittant and sequential chemoradiation with gemcitabine and cisplatin are presented. Patients and Methods: A total of 57 patients (f/m 23/34) with pancreatic cancer was treated, of whom 33 patients had irresectable tumors, 19 patients following resection (R1 and/or pN+) and five patients with local recurrent disease. Radiotherapy was delivered in 25 fractions up to a total dose of 45.0 Gy specified according to ICRU reference point (50 patients, 1.8 Gy/fraction) respectively 50.0 Gy to gross tumor volume (seven patients; 45.0 Gy in locoregional lymphatic pathways; 2.0/ 1.8 Gy/fraction). Concomittant with radiotherapy cisplatin (30 mg/m{sup 2}) and gemcitabine (300 mg/m{sup 2}) were applied on days 1, 8, 22 and 29. After simultaneous chemoradiation two sequential cycles gemcitabine and cisplatin (1000 mg/m{sup 2} and 50 mg/m{sup 2} d 1, 15) were applied. Results: With a median follow-up of 8.2 months the median survival time was 14.8 months (irresectable patients: 10.3 months, postoperative patients 15.1 months). Within 33 irresectable patients 19 and four partial and complete remissions, respectively, were observed. In 14 patients a secondary resection was possible. Using leveled antiemetics with ondansetron and dexamethasone no gastrointestinal toxicities grade III or IV were observed. Hematologic toxicities were the most grave side effects (leukocytopenia III/IV in 29/Five patients and thrombocytopenia III/IV in 21/eight patients), however with minor clinical relevancy (one neutropenic infection, one thrombopenic epistaxis). Conclusion: The presented treatment scheme using concomittant and

Optimizing a single fixed dose of Iodine-131 in Graves' Disease (An Experience)

International Nuclear Information System (INIS)

Khan, S.H.

2007-01-01

Full text: Kashmir is a Himalayan mountain state of India enclosed by high snow capped ridges of Pir Panjal Mountains at an average height of 4000-5000 meters above the sea level. For most of the 4 million inhabitants in this land locked valley, agriculture horticulture and handcrafts are the main source of income. Due to long and severe winters the terraced farming on the mountain slopes yield just a single crop of rice which is barely sufficient to meet the local needs of this staple diet. People are relatively poor with low annual per capita income. Goiter is endemic in the Valley of Kashmir. In a published report the overall prevalence of goiter among the school going children in Kashmir between the ages of 5 years is 45.2% (+ SEM) with urinary iodine excretion of 49 + 3.55 μg per gram of creatinine. The extremely shy people of Kashmir are casual towards the aesthetic aspects of their goiters but nevertheless seek medical advice when associated with physical symptoms. In a published study of 203 patients of thyrotoxicosis from Kashmir, Graves' disease was the commonest cause, accounting for 63% of patients. One hundred and twentyone patients of Graves' disease were prospectively studied for their response to a single fixed dose of I-131. Patients were randomly treated with two different fixed doses of I- 131. Sixty four patients belonging to Group-I received a fixed dose of 185 MBq (Low Dose) and 57 patients belonging to Group -2 received 370 MBq (High Dose) of I- 131. Following therapy all patients were evaluated at 3 months. Patients with normal or reduced thyroid hormone levels were termed as responders and those with persistently elevated levels of thyroid hormone were termed as non responders. The response rates among the two groups were analyzed for their statistical significance. Patients treated with the high fixed dose of 370 MBq revealed good response to therapy achieving a rate of 91.22%, while the response rate in the group of patients treated with

Randomized Phase II Trial of Gemcitabine Plus TH-302 Versus Gemcitabine in Patients With Advanced Pancreatic Cancer.

Science.gov (United States)

Borad, Mitesh J; Reddy, Shantan G; Bahary, Nathan; Uronis, Hope E; Sigal, Darren; Cohn, Allen L; Schelman, William R; Stephenson, Joe; Chiorean, E Gabriela; Rosen, Peter J; Ulrich, Brian; Dragovich, Tomislav; Del Prete, Salvatore A; Rarick, Mark; Eng, Clarence; Kroll, Stew; Ryan, David P

2015-05-01

TH-302 is an investigational hypoxia-activated prodrug that releases the DNA alkylator bromo-isophosphoramide mustard in hypoxic settings. This phase II study (NCT01144455) evaluated gemcitabine plus TH-302 in patients with previously untreated, locally advanced or metastatic pancreatic cancer. Patients were randomly assigned 1:1:1 to gemcitabine (1,000 mg/m(2)), gemcitabine plus TH-302 240 mg/m(2) (G+T240), or gemcitabine plus TH-302 340 mg/m(2) (G+T340). Randomized crossover after progression on gemcitabine was allowed. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), tumor response, CA 19-9 response, and safety. Two hundred fourteen patients (77% with metastatic disease) were enrolled between June 2010 and July 2011. PFS was significantly longer with gemcitabine plus TH-302 (pooled combination arms) compared with gemcitabine alone (median PFS, 5.6 v 3.6 months, respectively; hazard ratio, 0.61; 95% CI, 0.43 to 0.87; P = .005; median PFS for metastatic disease, 5.1 v 3.4 months, respectively). Median PFS times for G+T240 and G+T340 were 5.6 and 6.0 months, respectively. Tumor response was 12%, 17%, and 26% in the gemcitabine, G+T240, and G+T340 arms, respectively (G+T340 v gemcitabine, P = .04). CA 19-9 decrease was greater with G+T340 versus gemcitabine (-5,398 v -549 U/mL, respectively; P = .008). Median OS times for gemcitabine, G+T240, and G+T340 were 6.9, 8.7, and 9.2 months, respectively (P = not significant). The most common adverse events (AEs) were fatigue, nausea, and peripheral edema (frequencies similar across arms). Skin and mucosal toxicities (2% grade 3) and myelosuppression (55% grade 3 or 4) were the most common TH-302-related AEs but were not associated with treatment discontinuation. PFS, tumor response, and CA 19-9 response were significantly improved with G+TH-302. G+T340 is being investigated further in the phase III MAESTRO study (NCT01746979). © 2014 by American Society of

The effect of the second dose 131I in patients with Grave's disease, treated with 185 MBq low-fixed dose regimen

International Nuclear Information System (INIS)

Bochev, P.; Klissarova, A.; Hristozov, H.; Chaushev, B.; Cvetanova, B.

2006-01-01

Full text: The aim of the study was to evaluate the success rate after application of a second dose 131 I in patients with Grave's disease, treated with a fixed dose 185 MBq 131 I and still hyperthyroid. 27 patients with Grave's disease, treated with 185 MBq 131 I. Each patient was followed up by physical exam, ultrasonography and hormone levels for a period of at least one year. On the sixth month after the initial treatment 14 patients (52%) were still hyperthyroid. Based on hormone levels and reduction of gland size a decision for applying a second dose 131 I was taken for 8 patients. The remaining six patients with persistent hyperthyroidism were treated with antithyroid drugs till the end of the first year. By the time of the study 12.5% of the patients being treated with a second dose are still hyperthyroid, 37.5% - euthyroid and 50% -hypothyroid with total success rate (hypo+euthyroid) of 87%. In comparison 16 % of the patients treated with antithyroid drugs are euthyroid. The use of a second dose 131 I in patients with Graves disease being treated with low-fixed dose regimen and still hyperthyroid by the sixth month after the initial treatment leads to a high overall success rate in one year

Radiosensitizing potential of gemcitabine (2',2'-difluoro-2'-deoxycytidine) within the cell cycle in vitro

International Nuclear Information System (INIS)

Latz, Detlev; Fleckenstein, Katharina; Eble, Michael; Blatter, Johannes; Wannenmacher, Michael; Weber, Klaus J.

1998-01-01

Purpose: Gemcitabine (2',2'-difluorodeoxycytidine; dFdCyd) is a new deoxycitidine analog which exhibits substantial activity against solid tumors and radiosensitizing properties in vitro. To examine cell cycle-specific effects of a combined treatment with gemcitabine and radiation, the in vitro clonogenic survival of two different cell lines was measured for cells from log-phase culture, G1 and S-phase cells. Methods and Materials: Chinese hamster (V79) and human colon carcinoma (Widr) cells were exposed to different radiation doses and for different points of time relative to gemcitabine treatment (2 h). Experiments were also carried out with different cell-cycle populations obtained after mitotic selection (V79) or after serum stimulation of plateau-phase cells (Widr). The resulting survival curves were analyzed according to the LQ model, and mean inactivation doses (MID) and the cell cycle-specific enhancement ratios (ER) were calculated from the survival curve parameters. Results: Effectiveness of combined treatment of log-phase cells was greatest when cells were irradiated at the end of the gemcitabine exposure [ER: 1.28 (V79), 1.24 (Widr)]. For later times after the removal of the drug, radiosensitization declined, approaching independent toxicity. From the time course of interactive-type damage decay half-life values of 75 min (V79) and 92 min (Widr) were derived. Gemcitabine did not radiosensitize G1 Widr cells or V79 cells from the G1/S border, but substantial radiosensitization was observed for the S-phase cell preparations [ER: 1.45 (V79-lateS), 1.57 (Widr)]. Conclusions: Treatment of cells with gemcitabine immediately before irradiation eliminates, or at least greatly reduces, the variation in radiosensitivity during the cell cycle that is manifested by radioresistance during S phase. This reversal of S-phase radioresistance could imply that gemcitabine interferes with the potentially lethal damage repair/fixation pathway. Other approaches have been

Gemcitabine intercellular diffusion mediated by gap junctions: new implications for cancer therapy

Directory of Open Access Journals (Sweden)

Caruso Manuel

2010-06-01

Full Text Available Abstract Background Solid tumors are often poorly vascularized, with cells that can be 100 μm away from blood vessels. These distant cells get less oxygen and nutrients and are exposed to lower doses of chemotherapeutic agents. As gap junctions allow the passage of small molecules between cells, we tested the possibility that the chemotherapeutic agent gemcitabine can diffuse through gap junctions in solid tumors. Results We first showed with a dye transfer assay that the glioblastoma and the osteosarcoma cells used in this study have functional gap junctions. These cells were genetically engineered to express the herpes simplex virus thymidine kinase (TK, and induced a "bystander effect" as demonstrated by the killing of TK-negative cells in presence of the nucleoside analogue ganciclovir (GCV. The ability of gemcitabine to induce a similar bystander effect was then tested by mixing cells treated with 3 μM gemcitabine for 24 hours with untreated cells at different ratios. In all cell lines tested, bystander cells were killed with ratios containing as low as 5% treated cells, and this toxic effect was reduced in presence of α-glycyrrhetinic acid (AGA, a specific gap junction inhibitor. We also showed that a 2- or a 24-hour gemcitabine treatment was more efficient to inhibit the growth of spheroids with functional gap junctions as compared to the same treatment made in presence of AGA. Finally, after a 24-hour gemcitabine treatment, the cell viability in spheroids was reduced by 92% as opposed to 51% in presence of AGA. Conclusion These results indicate that gemcitabine-mediated toxicity can diffuse through gap junctions, and they suggest that gemcitabine treatment could be more efficient for treating solid tumors that display gap junctions. The presence of these cellular channels could be used to predict the responsiveness to this nucleoside analogue therapy.

Vitamins C and K3 sensitize human urothelial tumors to gemcitabine.

Science.gov (United States)

Kassouf, Wassim; Highshaw, Ralph; Nelkin, Gina M; Dinney, Colin P; Kamat, Ashish M

2006-10-01

We evaluated the antitumor effects of vitamins C and K3 for human urothelial carcinoma and the potential use of the combination of vitamins C plus K3 as a sensitizing agent for conventional chemotherapy for urothelial carcinoma. The antiproliferative and apoptotic effects of vitamin C alone, vitamin K3 alone, vitamins C plus K3, gemcitabine alone and gemcitabine plus vitamins C plus K3 were assessed in vitro by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, propidium iodide staining and flow cytometry. For in vivo studies we implanted UMUC-14 tumorigenic urothelial carcinoma cells into the subcutis of nude mice. One week later we treated 10 mice each with saline (control), vitamins C plus K3, gemcitabine or gemcitabine plus vitamins C plus K3. Treatment was continued for 4 weeks, followed by necropsy. Tumor volume was measured and tumor kinetics were established. Apoptosis and proliferation were evaluated in tumor sections using immunohistochemistry and TUNEL assay. Vitamins C plus K3 induced cytostasis and caused apoptosis to a greater degree than either vitamin alone (p Vitamins C plus K3 also substantially augmented the effects of gemcitabine in vitro. There were 32.3% apoptosis with gemcitabine plus vitamins C plus K3, 5.3% with gemcitabine alone and 15.8% with vitamins C plus K3 alone (p vitamins C plus K3 compared with that in the control or for either agent alone. Mean tumor weight and growth rate in the gemcitabine plus vitamins C plus K3 group (237 mg and 11.3 mm3 daily) were decreased compared with those in the control (530 mg and 34.3 mm3 daily), and those for vitamins C plus K3 alone (490 mg and 25.2 mm3 daily) and gemcitabine alone (400 mg and 21.3 mm3 daily) (p Vitamins C and K3 have significant antiproliferative and apoptotic effects when used in combination. This combination enhances the efficacy of gemcitabine against bladder cancer in vivo.

Gemcitabine Chemotherapy and Single-Fraction Stereotactic Body Radiotherapy for Locally Advanced Pancreatic Cancer

International Nuclear Information System (INIS)

Schellenberg, Devin; Goodman, Karyn A.; Lee, Florence; Chang, Stephanie; Kuo, Timothy; Ford, James M.; Fisher, George A.; Quon, Andrew; Desser, Terry S.; Norton, Jeffrey; Greco, Ralph; Yang, George P.; Koong, Albert C.

2008-01-01

Purpose: Fractionated radiotherapy and chemotherapy for locally advanced pancreatic cancer achieves only modest local control. This prospective trial evaluated the efficacy of a single fraction of 25 Gy stereotactic body radiotherapy (SBRT) delivered between Cycle 1 and 2 of gemcitabine chemotherapy. Methods and Materials: A total of 16 patients with locally advanced, nonmetastatic, pancreatic adenocarcinoma received gemcitabine with SBRT delivered 2 weeks after completion of the first cycle. Gemcitabine was resumed 2 weeks after SBRT and was continued until progression or dose-limiting toxicity. The gross tumor volume, with a 2-3-mm margin, was treated in a single 25-Gy fraction by Cyberknife. Patients were evaluated at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT. Results: All 16 patients completed SBRT. A median of four cycles (range one to nine) of chemotherapy was delivered. Three patients (19%) developed local disease progression at 14, 16, and 21 months after SBRT. The median survival was 11.4 months, with 50% of patients alive at 1 year. Patients with normal carbohydrate antigen (CA)19-9 levels either at diagnosis or after Cyberknife SBRT had longer survival (p <0.01). Acute gastrointestinal toxicity was mild, with 2 cases of Grade 2 (13%) and 1 of Grade 3 (6%) toxicity. Late gastrointestinal toxicity was more common, with five ulcers (Grade 2), one duodenal stenosis (Grade 3), and one duodenal perforation (Grade 4). A trend toward increased duodenal volumes radiated was observed in those experiencing late effects (p = 0.13). Conclusion: SBRT with gemcitabine resulted in comparable survival to conventional chemoradiotherapy and good local control. However, the rate of duodenal ulcer development was significant

NCCAM/NCI Phase 1 Study of Mistletoe Extract and Gemcitabine in Patients with Advanced Solid Tumors

Directory of Open Access Journals (Sweden)

Patrick J. Mansky

2013-01-01

Full Text Available Purpose. European Mistletoe (Viscum album L. extracts (mistletoe are commonly used for cancer treatment in Europe. This phase I study of gemcitabine (GEM and mistletoe in advanced solid cancers (ASC evaluated: (1 safety, toxicity, and maximum tolerated dose (MTD, (2 absolute neutrophil count (ANC recovery, (3 formation of mistletoe lectin antibodies (ML ab, (4 cytokine plasma concentrations, (5 clinical response, and (6 pharmacokinetics of GEM. Methods. Design: increasing mistletoe and fixed GEM dose in stage I and increasing doses of GEM with a fixed dose of mistletoe in stage II. Dose limiting toxicities (DLT were grade (G 3 nonhematologic and G4 hematologic events; MTD was reached with 2 DLTs in one dosage level. Response in stage IV ASC was assessed with descriptive statistics. Statistical analyses examined clinical response/survival and ANC recovery. Results. DLTs were G4 neutropenia, G4 thrombocytopenia, G4 acute renal failure, and G3 cellulitis, attributed to mistletoe. GEM 1380 mg/m2 and mistletoe 250 mg combined were the MTD. Of 44 patients, 24 developed nonneutropenic fever and flu-like syndrome. GEM pharmacokinetics were unaffected by mistletoe. All patients developed ML3 IgG antibodies. ANC showed a trend to increase between baseline and cycle 2 in stage I dose escalation. 6% of patients showed partial response, 42% stable disease. Median survival was 200 days. Compliance with mistletoe injections was high. Conclusion. GEM plus mistletoe is well tolerated. No botanical/drug interactions were observed. Clinical response is similar to GEM alone.

Synergistic activity of troxacitabine (Troxatyl™ and gemcitabine in pancreatic cancer

Directory of Open Access Journals (Sweden)

Leblond Lorraine

2007-07-01

troxacitabine when cells were exposed at equal drug concentrations, there was no effect on phosphorylated pools at drug combinations that were synergistic. The amount of troxacitabine incorporated into DNA was also not affected by the presence of gemcitabine. In vivo testing against a human pancreatic (AsPC-1 xenograft mouse tumor model indicated that both drugs were more than additive at well-tolerated doses and schedule. The biological basis for this synergy is unclear as we did not observe changes in apoptosis, DNA repair, troxacitabine incorporation into DNA or troxacitabine metabolism in the presence of gemcitabine. Conclusion These data, together with phase I clinical data showing tolerability of both agents when combined, suggest combination therapy with troxacitabine and gemcitabine warrants further evaluation in advanced pancreatic cancer patients.

Synergistic activity of troxacitabine (Troxatyl™) and gemcitabine in pancreatic cancer

International Nuclear Information System (INIS)

Damaraju, Vijaya L; Bouffard, David Y; Wong, Clarence KW; Clarke, Marilyn L; Mackey, John R; Leblond, Lorraine; Cass, Carol E; Grey, Mike; Gourdeau, Henriette

2007-01-01

concentrations, there was no effect on phosphorylated pools at drug combinations that were synergistic. The amount of troxacitabine incorporated into DNA was also not affected by the presence of gemcitabine. In vivo testing against a human pancreatic (AsPC-1) xenograft mouse tumor model indicated that both drugs were more than additive at well-tolerated doses and schedule. The biological basis for this synergy is unclear as we did not observe changes in apoptosis, DNA repair, troxacitabine incorporation into DNA or troxacitabine metabolism in the presence of gemcitabine. These data, together with phase I clinical data showing tolerability of both agents when combined, suggest combination therapy with troxacitabine and gemcitabine warrants further evaluation in advanced pancreatic cancer patients

Phase I trial of S-1 every other day in combination with gemcitabine/cisplatin for inoperable biliary tract cancer.

Science.gov (United States)

Uwagawa, Tadashi; Sakamoto, Taro; Abe, Kyohei; Okui, Norimitsu; Hata, Daigo; Shiba, Hiroaki; Futagawa, Yasuro; Aiba, Keisuke; Yanaga, Katsuhiko

2015-01-01

To date, gemcitabine-based or fluoropyrimidine-based regimens are recommended for unresectable advanced biliary tract cancer. Then, we conducted a phase I study of gemcitabine/cisplatin and S-1 that is an oral fluoropyrimidine. The aim of this study was to determine the dose-limiting toxicity (DLT), maximum-tolerated dose, and a recommended phase II dose of S-1. Response was assessed as a secondary endpoint. Patients who have been diagnosed with unresectable or postoperative recurrent biliary tract cancer received cisplatin (25 mg/m² i.v. for 120 min) followed by gemcitabine (1,000 mg/m² i.v. for 30 min) on days 1 and 8, and oral S-1 on alternate days; this regimen was repeated at 21-day intervals. A standard '3 + 3' phase I dose-escalation design was adopted. This study was registered with University hospital Medical Information Network (UMIN) Center in Japan, number UMIN000008415. Twelve patients were evaluable in this study. No patients developed DLTs. Recommended dose of S-1 was 80 (day. One patient could achieve conversion to curative surgery. This phase I study was performed safely and demonstrated encouraging response.

A Meta-Analysis of Platinum Plus Gemcitabine or Vinorelbine for Advanced Non-small Cell Lung Cancer

Directory of Open Access Journals (Sweden)

Guanghui GAO

2009-01-01

Full Text Available Background and objective Platinum plus the third-generation agent doublet chemotherapy is the standard regimens and first line chemotherapy for advanced non-small cell lung cancer (NSCLC. The aim of this study is to determine the benefits and harms of platinum plus gemcitabine or vinorelbine for advanced NSCLC. Methods Thedatabases PubMed, CENTRAL, EMBASE and Chinese Biomedical Literature database were retrieved by using the key words "non small cell lung cancer" or "Carcinoma, Non Small Cell Lung" so as to search the studies about the randomized controlled clinical trials (RCT that had compared the gemcitabine plus platinum versus vinorelbine plus platinum for advanced NSCLC. A meta-analysis was conducted. Results Nine randomized controlled trials, with total 2 186 patients,were included. The overall response rate and one-year survival rate of the gemcitabine group were not significantly different from that of vinorelbine regimen (RR=0.91, 95%CI: 0.81-1.03, P =0.15; RR=1.06, 95%CI: 0.96-1.18, P =0.27, respectively. The incidence rate of grade 3-4 netropenia, constipation, phlebitis and grade 1-4 neuropathy were higher in vinorelbine group, just like higher incidence rate of grade 3-4 thrombocytopenia in the gemcitabine group. Conclusion The curative effects of the gemcitabine or vinorelbine plus platinum regimens are similar. The choice of gemcitabine or vinorelbine depends on the toxicity of the drugs and patients' tolerance.

Gemcitabine and cisplatin in a concomitant alternating chemoradiotherapy program for locally advanced head-and-neck cancer: A pharmacology-guided schedule

International Nuclear Information System (INIS)

Numico, Gianmauro; Russi, Elvio G.; Vitiello, Raffele; Sorrentino, Raffaele; Colantonio, Ida; Cipolat, Marco; Taglianti, Riccardo Vigna; Pelissero, Antonio; Fea, Elena; Granetto, Cristina; Di Costanzo, Gianna; Gasco, Milena; Garrone, Ornella; Occelli, Marcella; Merlano, Marco

2006-01-01

Purpose: Administration of gemcitabine together with cisplatin at cytotoxic doses in a chemoradiotherapy regimen is hampered by a high degree of local toxicity. Using the pharmacologic properties of the drug we designed a modified schedule aimed at reducing toxicity while preserving activity. Methods and Materials: Patients with squamous cell carcinomas of the oral cavity, pharynx and larynx, bulky T4, and/or N2 to N3 were eligible. Gemcitabine was administered at a dose of 800 mg/m 2 on Days 1 and 12 and cisplatin at a dose of 20 mg/m 2 on Days 2 to 5, every 21 days for 3 courses. Radiotherapy, delivered with standard fractionation, was given on Days 8 to 12 and 15 to 19 and was repeated 3 times up to a total dose of ≥60 Gy. Results: A total of 28 patients were selected. Grade 3 to 4 stomatitis was recorded in 25 patients (89%). Thirteen patients (46%) experienced Grade 3 to 4 neutropenia. Febrile neutropenia occurred in 8 patients (29%) and in 2 was complicated by infection and death. The overall complete response rate was 79%. At a median follow up of 71 months, 11 patients had a locoregional relapse (3-year locoregional control, 64%); 6 patients had distant metastases, among whom only 2 were without locoregional recurrence. The 3-year progression-free survival is 39% and 3-year overall survival has been 43%. Conclusion: The schedule modification did not attenuate local toxicity. Moreover, infections and especially pneumonia, were a major problem. The high activity of gemcitabine when combined with radiotherapy would most likely be better exploited in the context of modified radiation schemes

Mechanistic Distinctions between CHK1 and WEE1 Inhibition Guide the Scheduling of Triple Therapy with Gemcitabine.

Science.gov (United States)

Koh, Siang-Boon; Wallez, Yann; Dunlop, Charles R; Bernaldo de Quirós Fernández, Sandra; Bapiro, Tashinga E; Richards, Frances M; Jodrell, Duncan I

2018-06-01

Combination of cytotoxic therapy with emerging DNA damage response inhibitors (DDRi) has been limited by tolerability issues. However, the goal of most combination trials has been to administer DDRi with standard-of-care doses of chemotherapy. We hypothesized that mechanism-guided treatment scheduling could reduce the incidence of dose-limiting toxicities and enable tolerable multitherapeutic regimens. Integrative analyses of mathematical modeling and single-cell assays distinguished the synergy kinetics of WEE1 inhibitor (WEE1i) from CHEK1 inhibitor (CHK1i) by potency, spatiotemporal perturbation, and mitotic effects when combined with gemcitabine. These divergent properties collectively supported a triple-agent strategy, whereby a pulse of gemcitabine and CHK1i followed by WEE1i durably suppressed tumor cell growth. In xenografts, CHK1i exaggerated replication stress without mitotic CDK hyperactivation, enriching a geminin-positive subpopulation and intratumoral gemcitabine metabolite. Without overt toxicity, addition of WEE1i to low-dose gemcitabine and CHK1i was most effective in tumor control compared with single and double agents. Overall, our work provides quantitative insights into the mechanisms of DDRi chemosensitization, leading to the rational development of a tolerable multitherapeutic regimen. Significance: Multiple lines of mechanistic insight regarding DNA damage response inhibitors rationally guide the preclinical development of a tolerable multitherapeutic regimen. Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/11/3054/F1.large.jpg Cancer Res; 78(11); 3054-66. ©2018 AACR . ©2018 American Association for Cancer Research.

A PHASE II STUDY OF GEMCITABINE AND CAPECITABINE IN PATIENTS WITH ADVANCED RENAL CELL CANCER (RCC): SOUTHWEST ONCOLOGY GROUP STUDY S0312

Science.gov (United States)

Van Veldhuizen, Peter J.; Hussey, Michael; Lara, Primo N.; Mack, Philip C.; Gandour-Edwards, Regina; Clark, Joseph I.; Lange, Marianne K.; Crawford, E. David

2010-01-01

Background Gemcitabine plus capecitabine has modest efficacy in patients with advanced RCC but has considerable toxicity. We evaluated the efficacy and toxicity of a modified dose-schedule of this doublet in patients with advanced unresectable or metastatic RCC. Methods Chemotherapy-naïve patients were treated with gemcitabine at 900mg/m2 on days 1,8,15 and capecitabine at 625mg/m2 twice daily on days 1 through 21, every 28 days. Eligible patients must have adequate performance status and end-organ function. The primary endpoint was tumor response rate (RR). No further evaluation of this regimen would be pursued if the RR was ≤ 5%. In an exploratory manner using archival specimens, we also evaluated potential markers of prognosis and treatment response including thymidylate synthase (TS) gene polymorphisms and tumor expression of p53, PTEN, pAKT, pmTOR, and ERCC1. Results Of 43 patients registered, 1 was ineligible and 2 were not analyzable. There was 1 confirmed complete response (CR) and three unconfirmed partial responses (PR), for an overall response rate of 10% (95% CI: 3, 24). Nineteen patients (48%) had stable disease (SD). The six-month freedom-from-treatment-failure and overall survival rates were 20% (95% CI: 8, 32) and 75% (95% CI: 62, 88), respectively. Median survival time was 23 months (95% CI: 10, 37). One patient each experienced Grade 4 neutropenia, fatigue, thrombocytopenia and hemolysis with renal failure. The most common Grade 3 toxicities were neutropenia (12 patients), fatigue (5), and leucopenia (4). Patients with a best response of stable disease or better were more likely to have a decrease in expression of PTEN and an increased expression of pmTOR. Conclusions Gemcitabine plus capecitabine at this reduced dose-schedule benefits a small percentage of patients with RCC with an acceptable toxicity profile. The combination of gemcitabine and capecitabine may serve as a base regimen for combination therapy with targeted agents in select RCC

Carboxylic acid-functionalized SBA-15 nanorods for gemcitabine delivery

International Nuclear Information System (INIS)

Bahrami, Zohreh; Badiei, Alireza; Ziarani, Ghodsi Mohammadi

2015-01-01

The present study deals with the functionalization of mesoporous silica nanoparticles as drug delivery systems. Mono, di, and tri amino-functionalized SBA-15 nanorods were synthesized by post-grafting method using (3-aminopropyl) triethoxysilane, N-(2-aminoethyl-)3- aminopropyltrimethoxysilane, and 3-[2-(2-aminoethylamino) ethylamino] propyl trimethoxysilane, respectively. The carboxylic acid derivatives of the amino-functionalized samples were obtained using succinic anhydride. Tminopropyltrimethoxysilanehe obtained modified materials were investigated as matrixes for the anticancer drug (gemcitabine) delivery. The prepared samples were characterized by SAXS, N 2 adsorption/desorption, SEM, transmission electron microscopy, thermogravimetric analysis, and FTIR and UV spectroscopies. The adsorption and release properties of all samples were studied. It was revealed that the adsorption capacity and release behavior of gemcitabine were highly dependent on the type of the introduced functional groups. The carboxylic acid-modified samples have higher loading content, due to the strong interaction with gemcitabine. The maximum content of deposited drug in the modified SBA-15 nanorods is close to 40 wt%. It was found that the surface functionalization leads toward significant decrease of the drug release rate. The carboxylic acid-functionalized samples have slower release rate in contrast with the amino-functionalized samples

Population Pharmacokinetics of Gemcitabine and dFdU in Pancreatic Cancer Patients Using an Optimal Design, Sparse Sampling Approach.

Science.gov (United States)

Serdjebi, Cindy; Gattacceca, Florence; Seitz, Jean-François; Fein, Francine; Gagnière, Johan; François, Eric; Abakar-Mahamat, Abakar; Deplanque, Gael; Rachid, Madani; Lacarelle, Bruno; Ciccolini, Joseph; Dahan, Laetitia

2017-06-01

Gemcitabine remains a pillar in pancreatic cancer treatment. However, toxicities are frequently observed. Dose adjustment based on therapeutic drug monitoring might help decrease the occurrence of toxicities. In this context, this work aims at describing the pharmacokinetics (PK) of gemcitabine and its metabolite dFdU in pancreatic cancer patients and at identifying the main sources of their PK variability using a population PK approach, despite a sparse sampled-population and heterogeneous administration and sampling protocols. Data from 38 patients were included in the analysis. The 3 optimal sampling times were determined using KineticPro and the population PK analysis was performed on Monolix. Available patient characteristics, including cytidine deaminase (CDA) status, were tested as covariates. Correlation between PK parameters and occurrence of severe hematological toxicities was also investigated. A two-compartment model best fitted the gemcitabine and dFdU PK data (volume of distribution and clearance for gemcitabine: V1 = 45 L and CL1 = 4.03 L/min; for dFdU: V2 = 36 L and CL2 = 0.226 L/min). Renal function was found to influence gemcitabine clearance, and body surface area to impact the volume of distribution of dFdU. However, neither CDA status nor the occurrence of toxicities was correlated to PK parameters. Despite sparse sampling and heterogeneous administration and sampling protocols, population and individual PK parameters of gemcitabine and dFdU were successfully estimated using Monolix population PK software. The estimated parameters were consistent with previously published results. Surprisingly, CDA activity did not influence gemcitabine PK, which was explained by the absence of CDA-deficient patients enrolled in the study. This work suggests that even sparse data are valuable to estimate population and individual PK parameters in patients, which will be usable to individualize the dose for an optimized benefit to risk ratio.

Randomized Phase II trial of paclitaxel and carboplatin followed by gemcitabine switch-maintenance therapy versus gemcitabine and carboplatin followed by gemcitabine continuation-maintenance therapy in previously untreated advanced non-small cell lung cancer

Directory of Open Access Journals (Sweden)

Minami Seigo

2013-01-01

Full Text Available Abstract Background In recent years, maintenance chemotherapy is increasingly being recognized as a new treatment strategy to improve the outcome of advanced non-small cell lung cancer (NSCLC. However, the optimal maintenance strategy is still controversial. Gemcitabine is a promising candidate for single-agent maintenance therapy because of little toxicity and good tolerability. We have conducted a randomized phase II study to evaluate the validity of single-agent maintenance chemotherapy of gemcitabine and to compare continuation- and switch-maintenance. Methods Chemonaïve patients with stage IIIB/IV NSCLC were randomly assigned 1:1 to either arm A or B. Patients received paclitaxel (200 mg/m2, day 1 plus carboplatin (AUC 6 mg/mL/min, day 1 every 3 weeks in arm A, or gemcitabine (1000 mg/m2, days 1 and 8 plus carboplatin (AUC 5 mg/mL/min, day1 every 3 weeks in arm B. Non-progressive patients following 3 cycles of induction chemotherapy received maintenance gemcitabine (1000 mg/m2, days 1 and 8 every 3 weeks. (Trial registration: UMIN000008252 Results The study was stopped because of delayed accrual at interim analysis. Of the randomly assigned 50 patients, 49 except for one in arm B were evaluable. Median progression-free survival (PFS was 4.6 months for arm A vs. 3.5 months for arm B (HR = 1.03; 95% CI, 0.45–2.27; p = 0.95 and median overall survival (OS was 15.0 months for arm A vs. 14.8 months for arm B (HR = 0.79; 95% CI, 0.40–1.51; p = 0.60, showing no difference between the two arms. The response rate, disease control rate, and the transit rate to maintenance phase were 36.0% (9/25, 64.0% (16/25, and 48% (12/25 for arm A vs. 16.7% (4/24, 50.0% (12/24, and 33% (8/24 for arm B, which were also statistically similar between the two arms (p = 0.13, p = 0.32, and p = 0.30, respectively. Both induction regimens were tolerable, except that more patients experienced peripheral neuropathy in arm A. Toxicities during

Air dose rate in Aichi Prefecture

International Nuclear Information System (INIS)

Ohnuma, Shoko; Chaya, Kunio; Tomita, Banichi; Aoyama, Kan; Yamada, Naoki; Yamada, Masuo; Hamamura, Norikatsu

1985-01-01

We have carried out the observations of air dose rate during 1964--1983 at the fixed points of Aichi Prefecture and investigated the distribution of air dose rate in this prefecture during 1979--1983. The results of these researches are as follows. 1) The apparent half time of radiation dose from the earth and the atmosphere during the last 20 years was about 9.7 years and it was longer than the apparent half time of fallout total β radioactivity in every rainfall that was about 3.2 years. 2) The influence of nuclear explosion test in China on the measurements of air does rate did not existed directly during the latter half of 20 years, not so as during the former and it was keeping decreasing. It was expected that the air dose rate would begin to indicate the natural radiation dose from the earth and the atmosphere in the near future. 3) The distribution of air dose rate in this prefecture depended strongly on the geology. The maximum value was 5.6 μR/hr (except cosmic rays) in Fujioka Cho, the minimum value was 1.9 μR/hr (except cosmic rays) in Tahara Cho and the average in the whole prefecture was 3.5+-0.7 μR/hr (except cosmic rays). 4) It was estimated that the radiation dose which the inhabitants received from the earth and the atmosphere was 17--52 m rem a year and the average was 31 m rem a year. (author)

Air dose rate in Aichi Prefecture

Energy Technology Data Exchange (ETDEWEB)

Ohnuma, Shoko; Chaya, Kunio; Tomita, Banichi; Aoyama, Kan; Yamada, Naoki; Yamada, Masuo; Hamamura, Norikatsu

1985-03-01

We have carried out the observations of air dose rate during 1964-1983 at the fixed points of Aichi Prefecture and investigated the distribution of air dose rate in this prefecture during 1979-1983. The results of these researches are as follows. 1) The apparent half time of radiation dose from the earth and the atmosphere during the last 20 years was about 9.7 years and it was longer than the apparent half time of fallout total ..beta.. radioactivity in every rainfall that was about 3.2 years. 2) The influence of nuclear explosion test in China on the measurements of air does rate did not existed directly during the latter half of 20 years, not so as during the former and it was keeping decreasing. It was expected that the air dose rate would begin to indicate the natural radiation dose from the earth and the atmosphere in the near future. 3) The distribution of air dose rate in this prefecture depended strongly on the geology. The maximum value was 5.6 ..mu..R/hr (except cosmic rays) in Fujioka Cho, the minimum value was 1.9 ..mu..R/hr (except cosmic rays) in Tahara Cho and the average in the whole prefecture was 3.5 +- 0.7 ..mu..R/hr (except cosmic rays). 4) It was estimated that the radiation dose which the inhabitants received from the earth and the atmosphere was 17-52 m rem a year and the average was 31 m rem a year.

Tissue distribution of crizotinib and gemcitabine combination in a patient-derived orthotopic mouse model of pancreatic cancer

Directory of Open Access Journals (Sweden)

Richard J. Honeywell

2016-12-01

Full Text Available Pharmacokinetics focuses on the question whether a drug actually reaches its target in therapeutic concentrations or accumulates elsewhere, potentially causing toxicological or unpredictable side effects. We determined tissue distribution of gemcitabine, an antimetabolite, and crizotinib, a tyrosine-kinase inhibitor targeted against the anaplastic lymphoma kinase (ALK and mesenchymal-epithelial transition factor (c-Met receptors, in a validated orthotopic mouse model for pancreatic cancer. Mice with pancreatic cancer were treated with either oral crizotinib at 25 mg/kg, gemcitabine at 100 mg/kg or with their combination. Two hours after the last gemcitabine dose mice were sacrificed and all available blood/organs/tissues were sampled. Tissue was subsequently analyzed for drug concentrations using a validated liquid chromatography-mass spectrometry (LC-MS/MS technique. In whole blood gemcitabine was about 1.0 µM and crizotinib 2.4 µM in the single treatment, whereas in the combination crizotinib increased the levels of gemcitabine. Crizotinib was found in all major tissues, being highest in the intestine. Comparison of crizotinib alone to the gemcitabine-crizotinib combination showed that crizotinib tissue concentrations were 3-6 fold lower in liver, lung, kidney and spleen, 30-fold lower in the skin, heart and pancreas and 200-fold lower in the brain. Tissue gemcitabine was highest in spleen and skin, being about 5-10 fold higher than in the other tissues, including brain, which still had a relatively high accumulation. In conclusion, both gemcitabine and crizotinib accumulate at clinically active but variable levels in tissues, possibly relating to the effects exerted by these drugs.

Total dose and dose-rate effects on start-up current in anti-fuse FPGA

International Nuclear Information System (INIS)

Wang, J.; Wong, W.; McCollum, J.; Cronquist, B.; Katz, R.; Kleyner, I.; Kleyner, F.

1999-01-01

Radiation enhanced start-up current (RESC) in an anti-fuse FPGA, A1280A, is thoroughly investigated and a comprehensive transistor-level mechanism is proposed. Low dose-rate testing, appropriate for civilian space applications, and annealing at room temperature shows RESC to be negligible for the lot of parts tested with a fixed power supply slew rate. (authors)

Pathologic response and toxicity assessment of chemoradiotherapy with cisplatin versus cisplatin plus gemcitabine in cervical cancer: A randomized Phase II study

International Nuclear Information System (INIS)

Duenas-Gonzalez, Alfonso; Cetina-Perez, Lucely; Lopez-Graniel, Carlos; Gonzalez-Enciso, Aaron; Gomez-Gonzalez, Ernesto; Rivera-Rubi, Lesbia; Montalvo-Esquivel, Gonzalo; Munoz-Gonzalez, David; Robles-Flores, Juan; Vazquez-Govea, Elisa; Garza, Jaime de la; Mohar, Alejandro

2005-01-01

Purpose: To compare gemcitabine and cisplatin (GC) with cisplatin (C) concurrent with radiotherapy in International Federation of Gynecology and Obstetrics Stage IB2, IIA, and IIB cervical carcinoma in a preoperative setting. The main endpoints were the pathologic response rate and toxicity. Methods and materials: A total of 83 patients were randomized to either C or GC. Treatment consisted of six doses of cisplatin at 40 mg/m 2 every week for Arm 1 (C) and six doses of gemcitabine at 125 mg/m 2 plus cisplatin at 40 mg/m 2 every week for or Arm 2 (GC) Both regimens were administered concurrent with 50 Gy of external beam radiotherapy in 2-Gy fractions for 5 weeks. After chemoradiotherapy, patients underwent radical hysterectomy. Results: All 83 patients were studied for toxicity and 80 for response. The complete pathologic response rate in the C arm and GC arm was 55% (95% confidence interval, 35.5-73%) and 77.5% (95% confidence interval, 57-90%; p = 0.0201). Among those with a partial response, 7 patients each had high and intermediate-high risk factors for recurrence in their surgical specimens in the C arm vs. 2 and 3 patients, respectively, with these characteristics in the CG arm. The number of weekly doses and the dose intensity of GC were lower than for C. The time to complete external beam radiotherapy also favored the C arm. The CG combination produced greater GI and hematologic toxicity. Conclusion: The radiosensitizing combination of GC achieved a greater pathologic response rate than C in the treatment of cervical cancer

Mass spectrometry-based metabolic profiling of gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cells.

Science.gov (United States)

Fujimura, Yoshinori; Ikenaga, Naoki; Ohuchida, Kenoki; Setoyama, Daiki; Irie, Miho; Miura, Daisuke; Wariishi, Hiroyuki; Murata, Masaharu; Mizumoto, Kazuhiro; Hashizume, Makoto; Tanaka, Masao

2014-03-01

Gemcitabine resistance (GR) is one of the critical issues for therapy for pancreatic cancer, but the mechanism still remains unclear. Our aim was to increase the understanding of GR by metabolic profiling approach. To establish GR cells, 2 human pancreatic cancer cell lines, SUIT-2 and CAPAN-1, were exposed to increasing concentration of gemcitabine. Both parental and chemoresistant cells obtained by this treatment were subjected to metabolic profiling based on liquid chromatography-mass spectrometry. Multivariate statistical analyses, both principal component analysis and orthogonal partial least squares discriminant analysis, distinguished metabolic signature of responsiveness and resistance to gemcitabine in both SUIT-2 and CAPAN-1 cells. Among significantly different (P metabolic pathways such as amino acid, nucleotide, energy, cofactor, and vitamin pathways. Decreases in glutamine and proline levels as well as increases in aspartate, hydroxyproline, creatine, and creatinine levels were observed in chemoresistant cells from both cell lines. These results suggest that metabolic profiling can isolate distinct features of pancreatic cancer in the metabolome of gemcitabine-sensitive and GR cells. These findings may contribute to the biomarker discovery and an enhanced understanding of GR in pancreatic cancer.

PR-104 a bioreductive pre-prodrug combined with gemcitabine or docetaxel in a phase Ib study of patients with advanced solid tumours

Directory of Open Access Journals (Sweden)

McKeage Mark J

2012-10-01

Full Text Available Abstract Background The purpose of this phase Ib clinical trial was to determine the maximum tolerated dose (MTD of PR-104 a bioreductive pre-prodrug given in combination with gemcitabine or docetaxel in patients with advanced solid tumours. Methods PR-104 was administered as a one-hour intravenous infusion combined with docetaxel 60 to 75 mg/m2 on day one given with or without granulocyte colony stimulating factor (G-CSF on day two or administrated with gemcitabine 800 mg/m2 on days one and eight, of a 21-day treatment cycle. Patients were assigned to one of ten PR-104 dose-levels ranging from 140 to 1100 mg/m2 and to one of four combination groups. Pharmacokinetic studies were scheduled for cycle one day one and 18F fluoromisonidazole (FMISO positron emission tomography hypoxia imaging at baseline and after two treatment cycles. Results Forty two patients (23 females and 19 males were enrolled with ages ranging from 27 to 85 years and a wide range of advanced solid tumours. The MTD of PR-104 was 140 mg/m2 when combined with gemcitabine, 200 mg/m2 when combined with docetaxel 60 mg/m2, 770 mg/m2 when combined with docetaxel 60 mg/m2 plus G-CSF and ≥770 mg/m2 when combined with docetaxel 75 mg/m2 plus G-CSF. Dose-limiting toxicity (DLT across all four combination settings included thrombocytopenia, neutropenic fever and fatigue. Other common grade three or four toxicities included neutropenia, anaemia and leukopenia. Four patients had partial tumour response. Eleven of 17 patients undergoing FMISO scans showed tumour hypoxia at baseline. Plasma pharmacokinetics of PR-104, its metabolites (alcohol PR-104A, glucuronide PR-104G, hydroxylamine PR-104H, amine PR-104M and semi-mustard PR-104S1, docetaxel and gemcitabine were similar to that of their single agents. Conclusions Combination of PR-104 with docetaxel or gemcitabine caused dose-limiting and severe myelotoxicity, but prophylactic G-CSF allowed PR-104 dose escalation with docetaxel. Dose

PR-104 a bioreductive pre-prodrug combined with gemcitabine or docetaxel in a phase Ib study of patients with advanced solid tumours

International Nuclear Information System (INIS)

McKeage, Mark J; Jameson, Michael B; Ramanathan, Ramesh K; Rajendran, Joseph; Gu, Yongchuan; Wilson, William R; Melink, Teresa J; Tchekmedyian, N Simon

2012-01-01

The purpose of this phase Ib clinical trial was to determine the maximum tolerated dose (MTD) of PR-104 a bioreductive pre-prodrug given in combination with gemcitabine or docetaxel in patients with advanced solid tumours. PR-104 was administered as a one-hour intravenous infusion combined with docetaxel 60 to 75 mg/m 2 on day one given with or without granulocyte colony stimulating factor (G-CSF) on day two or administrated with gemcitabine 800 mg/m 2 on days one and eight, of a 21-day treatment cycle. Patients were assigned to one of ten PR-104 dose-levels ranging from 140 to 1100 mg/m 2 and to one of four combination groups. Pharmacokinetic studies were scheduled for cycle one day one and 18 F fluoromisonidazole (FMISO) positron emission tomography hypoxia imaging at baseline and after two treatment cycles. Forty two patients (23 females and 19 males) were enrolled with ages ranging from 27 to 85 years and a wide range of advanced solid tumours. The MTD of PR-104 was 140 mg/m 2 when combined with gemcitabine, 200 mg/m 2 when combined with docetaxel 60 mg/m 2 , 770 mg/m 2 when combined with docetaxel 60 mg/m 2 plus G-CSF and ≥770 mg/m 2 when combined with docetaxel 75 mg/m 2 plus G-CSF. Dose-limiting toxicity (DLT) across all four combination settings included thrombocytopenia, neutropenic fever and fatigue. Other common grade three or four toxicities included neutropenia, anaemia and leukopenia. Four patients had partial tumour response. Eleven of 17 patients undergoing FMISO scans showed tumour hypoxia at baseline. Plasma pharmacokinetics of PR-104, its metabolites (alcohol PR-104A, glucuronide PR-104G, hydroxylamine PR-104H, amine PR-104M and semi-mustard PR-104S1), docetaxel and gemcitabine were similar to that of their single agents. Combination of PR-104 with docetaxel or gemcitabine caused dose-limiting and severe myelotoxicity, but prophylactic G-CSF allowed PR-104 dose escalation with docetaxel. Dose-limiting thrombocytopenia prohibited further

Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

DEFF Research Database (Denmark)

Knecht, Wolfgang; Mikkelsen, N.E.; Clausen, A.R.

2009-01-01

Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 angstrom resolution...

Effects of 12-O-tetradecanoylphorbol-13-acetate in combination with gemcitabine on Panc-1 pancreatic cancer cells cultured in vitro or Panc-1 tumors grown in immunodeficient mice.

Science.gov (United States)

Zheng, Xi; Cui, Xiao-Xing; Gao, Zhi; Verano, Michael; Huang, Mou-Tuan; Liu, Yue; Rabson, Arnold B; Conney, Allan H

2012-12-01

In the present study, the effects of 12-O-tetra-decanoylphorbol-13-acetate (TPA) alone or in combination with gemcitabine on the growth of Panc-1 pancreatic cancer cells cultured in vitro or grown in NCr immunodeficient nude mice were investigated. Combinations of TPA and gemcitabine synergi-stically inhibited the growth and induced apoptosis in Panc-1 cells. The combination of TPA (0.16 nM) and gemcitabine (0.5 µM) induced a marked increase in phosphorylated c-Jun NH2-terminal kinase (JNK) in the Panc-1 cells. In animal experiments, NCr nude mice with established Panc-1 tumors received daily intraperitoneal (i.p.) injections of TPA (50 ng/g body weight/day) or gemcitabine (0.5 µg/g body weight/day) alone or in combination for 26 days. Treatment with daily i.p. injections of low doses of TPA or gemcitabine alone had a modest inhibitory effect on the growth of the tumors. However, the combination of low doses of TPA and gemcitabine more potently inhibited the growth of Panc-1 tumors than either agent used individually. Treatment with TPA or gemcitabine alone or in combination did not affect the body weight of the animals. Clinical trials with TPA alone or in combination with gemcitabine on patients with pancreatic cancer are warranted in order to confirm our results.

Transarterial infusion chemotherapy with a combination of gemcitabine and 5-fluorouracil in advanced pancreatic carcinoma

International Nuclear Information System (INIS)

Shi Haifeng; Jin Zhengyu; Yang Ning; Liu Wei; Pan Jie; Cai Lixing; Zhao Yupei; Zhou Zhiqiang

2002-01-01

Objective: To retrospectively analyze the effectiveness of transarterial infusion chemotherapy of gemcitabine and 5-fluorouracil in advanced pancreatic carcinoma. Methods: Twenty-two patients with advanced pancreatic carcinoma were treated with transarterial infusion chemotherapy. Gemcitabine and 5-fluorouracil was administered to the patients via an interarterial catheter. Then the tumor response rate and clinical benefit were observed. Results: A clinical benefit was obtained in 8 patients (36.4%). The tumor response rate was 13.6%. Median survival for all the patients was 6.1 months. Median time to tumor progression was 2.9 months. Conclusion: Transarterial infusion chemotherapy with a combination of gemcitabine and 5-fluorouracil appears to have good clinical benefit and may prolong the survival time of patients with advanced pancreatic carcinoma

Effects of gemcitabine on renal function in patients with non-small cell lung cancer

NARCIS (Netherlands)

Gietema, JA; Groen, HJM; Meijer, S; Smit, EF

Gemcitabine is a novel fluorine-substituted cytarabine (Ara-C) analogue with activity against a range of solid tumours. Besides dose-limiting haematological toxicity, renal side-effects were observed from phase I and II studies concerning elevations of serum creatinine, proteinuria and

Dose-rate and the reciprocity law: TL response of Ge-doped SiO2 optical fibers at therapeutic radiation doses

International Nuclear Information System (INIS)

Abdul Rahman, A.T.; Nisbet, A.; Bradley, D.A.

2011-01-01

An investigation has been made on commercially available Ge-doped SiO 2 optical fibers as a novel thermoluminescence system for radiotherapy dosimetry. This dosimeter has previously been shown by the group to provide sensitive dosimetry over a wide range of electron and photon dose, suitable for the needs of radiotherapy. In addition the optical fiber offers small physical size (125 μm diameter) and hence high spatial resolution. The reciprocity between thermoluminescence (TL) yield of Ge-doped SiO 2 optical fibers and dose has been investigated for fixed radiation dose for a range of photon and electron dose rates. For electron beams of nominal energies in the range of 9-20 MeV, we have investigated the TL response of these fibers for dose rates between 100 and 1000 cGy min -1 . For photon beams of nominal energies in the range of 6-15 MV, we have used dose rates of 100-600 cGy min -1 . Reproducibility and fading at fixed absorbed dose (3 Gy) and dose rate for the optical fibers were also investigated. At fixed dose rates, the TL optical fibers were found to produce a flat TL yield within 4% (1σ) and 3% (1σ) for electron and photon beams, respectively. The optical fibers demonstrated good reproducibility (±1.5%), low residual signal for a readout temperature of 300 o C and negligible fading. A weak dependence on dose-rate has been observed in the range of 3.4-3.9% for electrons (with an associated uncertainty of 4%) and 2.4-2.9% for photons (with an associated uncertainty of <4%). For electron and photon energies we note a consistent trend towards lower response in the TL yield of between 3.4-3.9% and 2.4-2.7%, respectively, at the higher dose rates in comparison with the response at lower dose rates. In addition we note an appreciable systematic energy dependence for both electron and photon beams. It is important to take such factors into account for providing precise and accurate radiotherapy dosimetry. It is also apparent that the optical fibers can be re

Induction Chemotherapy With Gemcitabine, Oxaliplatin, and 5-Fluorouracil/Leucovorin Followed by Concomitant Chemoradiotherapy in Patients With Locally Advanced Pancreatic Cancer: A Taiwan Cooperative Oncology Group Phase II Study

International Nuclear Information System (INIS)

Ch’ang, Hui-Ju; Lin, Yu-Lin; Wang, Hsiu-Po; Chiu, Yen-Feng; Chang, Ming-Chu; Hsu, Chih-Hung; Tien, Yu-Wen; Chen, Jen-Shi; Hsieh, Ruey-Kuen; Lin, Pin-Wen; Shan, Yan-Shen; Cheng, Ann-Lii; Chang, Jang-Yang; Whang-Peng, Jacqueline; Hwang, Tsann-Long

2011-01-01

Purpose: To evaluate the therapeutic efficacy of 3-month triplet induction chemotherapy (ICT) followed by concomitant chemoradiotherapy (CCRT) in patients with locally advanced pancreatic cancer (LAPC). Patients and Methods: Chemonaïve patients with measurable, histologically confirmed LAPC were eligible. The ICT consisted of biweekly gemcitabine (800 mg/m 2 ) infusion at a fixed dose rate (10 mg/m 2 /min), followed by 85 mg/m 2 oxaliplatin and 48-h infusion of 5-fluorouracil/leucovorin (3000/150 mg/m 2 ) for 6 cycles. Patients without disease progression 4 weeks after ICT would receive weekly 400 mg/m 2 gemcitabine and 5040 cGy radiation in 28 fractions. After CCRT, patients were subjected for surgical intervention and/or maintenance chemotherapy until progression or intolerable toxicity. Results: Between December 2004 and August 2008, 50 patients were enrolled. The best responses after ICT were partial response (PR) in 9, stable disease in 26, and progressive disease or not evaluable in 15. Among the former 35 patients, 2 had disease progression before CCRT, and 3 declined to have CCRT. Of the 30 patients receiving CCRT, an additional 4 and 1 patient(s) achieved PR at the end of CCRT and during maintenance chemotherapy, respectively. On intent-to-treat analysis, the overall best response was PR in 14 patients and stable disease in 21. The overall response rate and disease control rate were 28% (95% confidence interval [CI], 16.2–42.5%) and 70% (95% CI, 44.4–99.2%), respectively. The median time to progression and overall survival of the intent-to-treat population was 9.3 (95% CI, 5.8–12.8) months and 14.5 (95% CI, 11.9–17.1) months, respectively. One- and two-year survival rates were 68% (95% CI, 55.1–80.9%) and 20.6% (95% CI, 8.7–32.5%), respectively. Neutropenia was the most common Grade 3–4 toxicity of both ICT and CCRT, with a frequency of 28% and 26.7%, respectively. Significant sensory neuropathy occurred in 9 patients (18%). Conclusion

Induction Chemotherapy With Gemcitabine, Oxaliplatin, and 5-Fluorouracil/Leucovorin Followed by Concomitant Chemoradiotherapy in Patients With Locally Advanced Pancreatic Cancer: A Taiwan Cooperative Oncology Group Phase II Study

Energy Technology Data Exchange (ETDEWEB)

Ch' ang, Hui-Ju [National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan (China); Department of Radiation Oncology, National Cheng Kung University Hospital, Tainan, Taiwan (China); Lin, Yu-Lin [Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Wang, Hsiu-Po [Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Chiu, Yen-Feng [Institute of Public Health Sciences, National Health Research Institutes, Miaoli, Taiwan (China); Chang, Ming-Chu [Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Hsu, Chih-Hung [Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Tien, Yu-Wen [Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Jen-Shi [Department of Internal Medicine, Chang-Gung Memorial Hospital, Chang Gung University, College of Medicine, Tao-Yuan, Taiwan (China); Hsieh, Ruey-Kuen [Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan (China); Lin, Pin-Wen; Shan, Yan-Shen [Department of Surgery, National Cheng Kung University Hospital, Tainan, Taiwan (China); Cheng, Ann-Lii [Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chang, Jang-Yang [National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan (China); Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan (China); Whang-Peng, Jacqueline [National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan (China); Cancer Center Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan (China); Hwang, Tsann-Long, E-mail: hwangtl@adm.cgmh.org.tw [Department of Surgery, Chang-Gung Memorial Hospital, Chang Gung University, College of Medicine, Tao-Yuan, Taiwan (China); and others

2011-12-01

Purpose: To evaluate the therapeutic efficacy of 3-month triplet induction chemotherapy (ICT) followed by concomitant chemoradiotherapy (CCRT) in patients with locally advanced pancreatic cancer (LAPC). Patients and Methods: Chemonaieve patients with measurable, histologically confirmed LAPC were eligible. The ICT consisted of biweekly gemcitabine (800 mg/m{sup 2}) infusion at a fixed dose rate (10 mg/m{sup 2}/min), followed by 85 mg/m{sup 2} oxaliplatin and 48-h infusion of 5-fluorouracil/leucovorin (3000/150 mg/m{sup 2}) for 6 cycles. Patients without disease progression 4 weeks after ICT would receive weekly 400 mg/m{sup 2} gemcitabine and 5040 cGy radiation in 28 fractions. After CCRT, patients were subjected for surgical intervention and/or maintenance chemotherapy until progression or intolerable toxicity. Results: Between December 2004 and August 2008, 50 patients were enrolled. The best responses after ICT were partial response (PR) in 9, stable disease in 26, and progressive disease or not evaluable in 15. Among the former 35 patients, 2 had disease progression before CCRT, and 3 declined to have CCRT. Of the 30 patients receiving CCRT, an additional 4 and 1 patient(s) achieved PR at the end of CCRT and during maintenance chemotherapy, respectively. On intent-to-treat analysis, the overall best response was PR in 14 patients and stable disease in 21. The overall response rate and disease control rate were 28% (95% confidence interval [CI], 16.2-42.5%) and 70% (95% CI, 44.4-99.2%), respectively. The median time to progression and overall survival of the intent-to-treat population was 9.3 (95% CI, 5.8-12.8) months and 14.5 (95% CI, 11.9-17.1) months, respectively. One- and two-year survival rates were 68% (95% CI, 55.1-80.9%) and 20.6% (95% CI, 8.7-32.5%), respectively. Neutropenia was the most common Grade 3-4 toxicity of both ICT and CCRT, with a frequency of 28% and 26.7%, respectively. Significant sensory neuropathy occurred in 9 patients (18

Gemcitabine and irinotecan as first-line therapy for carcinoma of unknown primary: results of a multicenter phase II trial.

Directory of Open Access Journals (Sweden)

Shernan G Holtan

Full Text Available Metastatic carcinoma of unknown primary (CUP has a very poor prognosis, and no standard first-line therapy currently exists. Here, we report the results of a phase II study utilizing a combination of gemcitabine and irinotecan as first-line therapy. Treatment was with gemcitabine 1000 mg/m(2 and irinotecan 75 mg/m(2 weekly times four on a six week cycle (Cohort I. Due to excessive toxicity, the dose and schedule were modified as follows: gemcitabine 750 mg/m(2 and irinotecan 75 mg/m(2 given weekly times three on a four week cycle (Cohort II. The primary endpoint was the confirmed response rate (CR + PR. Secondary endpoints consisted of adverse events based upon the presence or absence of the UDP glucuronosyltransferase 1 family, polypeptide A1*28 (UGT1A1*28 polymorphism, time to progression, and overall survival. Thirty-one patients were enrolled with a median age of 63 (range: 38-94, and 26 patients were evaluable for efficacy. Significant toxicity was observed in Cohort 1, characterized by 50% (7/14 patients experiencing a grade 4+ adverse event, but not in cohort II. The confirmed response rate including patients from both cohorts was 12% (95% CI: 2-30%, which did not meet the criteria for continued enrollment. Overall median survival was 7.2 months (95% CI: 4.0 to 11.6 for the entire cohort but notably longer in cohort II than in cohort I (9.3 months (95% CI: 4.1 to 12.1 versus 4.0 months (95% CI: 2.2 to 15.6. Gemcitabine and irinotecan is not an active combination when used as first line therapy in patients with metastatic carcinoma of unknown primary. Efforts into developing novel diagnostic and therapeutic approaches remain important for improving the outlook for this heterogeneous group of patients.ClinicalTrials.gov NCT00066781.

Safety and effectiveness of gemcitabine in 260 patients with biliary tract cancer in a Japanese clinical practice based on post-marketing surveillance in Japan.

Science.gov (United States)

Okubo, Sumiko; Nishiuma, Shinichi; Kobayashi, Noriko; Taketsuna, Masanori; Taniai, Hisashi

2012-11-01

Gemcitabine was approved for the treatment of biliary tract cancer in 2006 in Japan. While biliary tract cancer is usually associated with patients 70 years of age or older and/or those who tend to have underlying liver dysfunction, data on this population were limited in the Japanese Phase II study of gemcitabine. Thus, further evaluation of safety and effectiveness in this population was planned. This special post-marketing surveillance was conducted as an observational study on the use of gemcitabine in a clinical practice setting. Gemcitabine-naïve patients with biliary tract cancer were enrolled from 2006 to 2008 and observed over 12 months; one or more doses of gemcitabine were administered during the period. Data such as patient background, treatment details, adverse events occurring during the observational period, laboratory values of liver enzyme and survival status were collected 3 and 12 months after the start of therapy. Of the 285 patients registered for the study, 260 were included in the analysis. The mean age was 66.9 years. There were 120 patients (46.2%) classified as elderly (70 years or older). Haematotoxicities were the most common adverse drug reactions. In the elderly and the non-elderly, adverse drug reactions (serious) occurred in 48.3% (20.8%) and 50.7% (12.9%), respectively. The overall estimated 1-year survival rate was 52.5% (95% confidence interval, 45.9-58.7%). In line with previous clinical and post-marketing studies conducted in Japan, the results of this study suggest that gemcitabine could be used safely and effectively for biliary tract cancer patients including the elderly.

PAM50 breast cancer intrinsic subtypes and effect of gemcitabine in advanced breast cancer patients

DEFF Research Database (Denmark)

Jørgensen, Charlotte Levin Tykjær; Nielsen, Torsten O; Bjerre, Karsten D

2014-01-01

BACKGROUND: In vitro studies suggest basal breast cancers are more sensitive to gemcitabine relative to other intrinsic subtypes. The main objective of this study was to use specimens from a randomized clinical trial to evaluate whether the basal-like subtype identifies patients with advanced...... breast cancer who benefit from gemcitabine plus docetaxel (GD) compared to single agent docetaxel (D). MATERIAL AND METHODS: From patients randomly assigned to GD or D, RNA was isolated from archival formalin-fixed, paraffin-embedded primary breast tumor tissue and used for PAM50 intrinsic subtyping...... chemotherapy were analyzed by the Kaplan-Meier method, and Cox proportional hazards regression models. Data analysis was performed independently by the Danish Breast Cancer Cooperative Group (DBCG) statistical core and all statistical tests were two-sided. RESULTS: RNA from 270 patients was evaluable; 84...

Transarterial chemoembolisation (TACE) with gemcitabine: Phase II study in patients with liver metastases of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Eichler, Katrin, E-mail: k.eichler@em.uni-frankfurt.de; Jakobi, Silke; Gruber-Rouh, Tatjana; Hammerstingl, Renate; Vogl, Thomas J.; Zangos, Stephan

2013-12-01

Objective: Evaluation of the efficacy and tolerability of transarterial chemoembolization with gemcitabine in patients with inoperable liver metastases of breast cancer. Materials and methods: Open-label, prospective non-randomized single-center study design; patients had previous chemotherapy including anthracyclines and/or taxanes in the metastatic setting, adequate bone marrow reserve, sufficient liver/renal function, no centralnervous system metastases, Karnovsky-performance-status >70%, and life expectancy >12 weeks. Forty-three patients were enrolled (median 58 years, range 48–71). A suspension of gemcitabine 1.200 mg/m{sup 2}, 2–10 ml/m{sup 2} of Lipiodol, and 5 ml of a degradable starch microsphere (Embocept) suspension, were administered intra-arterially up to 3 times with a 4-weaks-interval. Dose-limiting toxicit is defined as grade 4 thrombocytopenia, neutropenia, or nonhematologic toxicity > grade 3. Tumor response was evaluated by magnetic resonance (MRI) and computed tomography (CT) imaging. Results: All patients tolerated the treatment well; with no dose limiting toxicities. Imaging follow-up according to the RECIST-criteria (Response Evaluation Criteria in Solid Tumors) revealed a partial response in 3 patients, stable disease in 16 patients and progression in 22 patients. The progression free survival was 3.3 months. A significant correlation exists only with the factor vascularization: strongly vascularized tumors show a significantly lowered response. Patients with complete or partial response and the main fraction of the stable disease group showed in the MRI and angiography only a moderate vascularization. The resulting estimate of the total survival rate amounts to a median of 10.2 months. Conclusion: Transarterial chemoembolization with gemcitabine is well tolerated and provides an alternative treatment method for patients with liver metastases of breast cancer.

Bitter melon juice targets molecular mechanisms underlying gemcitabine resistance in pancreatic cancer cells

OpenAIRE

SOMASAGARA, RANGANATHA R.; DEEP, GAGAN; SHROTRIYA, SANGEETA; PATEL, MANISHA; AGARWAL, CHAPLA; AGARWAL, RAJESH

2015-01-01

Pancreatic cancer (PanC) is one of the most lethal malignancies, and resistance towards gemcitabine, the front-line chemotherapy, is the main cause for dismal rate of survival in PanC patients; overcoming this resistance remains a major challenge to treat this deadly malignancy. Whereas several molecular mechanisms are known for gemcitabine resistance in PanC cells, altered metabolism and bioenergetics are not yet studied. Here, we compared metabolic and bioenergetic functions between gemcita...

Dose-rate and the reciprocity law: TL response of Ge-doped SiO{sub 2} optical fibers at therapeutic radiation doses

Energy Technology Data Exchange (ETDEWEB)

Abdul Rahman, A.T., E-mail: a.t.abdulrahman@surrey.ac.uk [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey (United Kingdom); School of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi MARA Malaysia (UiTM), Campus of Negeri Sembilan, 72000 Kuala Pilah (Malaysia); Nisbet, A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey (United Kingdom); Departments of Medical Physics, the Royal Surrey County Hospital (RSCH) NHS Trust, Edgerton Road, Guildford GU2 7XX, Surrey (United Kingdom); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey (United Kingdom)

2011-10-01

An investigation has been made on commercially available Ge-doped SiO{sub 2} optical fibers as a novel thermoluminescence system for radiotherapy dosimetry. This dosimeter has previously been shown by the group to provide sensitive dosimetry over a wide range of electron and photon dose, suitable for the needs of radiotherapy. In addition the optical fiber offers small physical size (125 {mu}m diameter) and hence high spatial resolution. The reciprocity between thermoluminescence (TL) yield of Ge-doped SiO{sub 2} optical fibers and dose has been investigated for fixed radiation dose for a range of photon and electron dose rates. For electron beams of nominal energies in the range of 9-20 MeV, we have investigated the TL response of these fibers for dose rates between 100 and 1000 cGy min{sup -1}. For photon beams of nominal energies in the range of 6-15 MV, we have used dose rates of 100-600 cGy min{sup -1}. Reproducibility and fading at fixed absorbed dose (3 Gy) and dose rate for the optical fibers were also investigated. At fixed dose rates, the TL optical fibers were found to produce a flat TL yield within 4% (1{sigma}) and 3% (1{sigma}) for electron and photon beams, respectively. The optical fibers demonstrated good reproducibility ({+-}1.5%), low residual signal for a readout temperature of 300 {sup o}C and negligible fading. A weak dependence on dose-rate has been observed in the range of 3.4-3.9% for electrons (with an associated uncertainty of 4%) and 2.4-2.9% for photons (with an associated uncertainty of <4%). For electron and photon energies we note a consistent trend towards lower response in the TL yield of between 3.4-3.9% and 2.4-2.7%, respectively, at the higher dose rates in comparison with the response at lower dose rates. In addition we note an appreciable systematic energy dependence for both electron and photon beams. It is important to take such factors into account for providing precise and accurate radiotherapy dosimetry. It is also

The dipeptide monoester prodrugs of floxuridine and gemcitabine-feasibility of orally administrable nucleoside analogs.

Science.gov (United States)

Tsume, Yasuhiro; Borras Bermejo, Blanca; Amidon, Gordon L

2014-01-27

Dipeptide monoester prodrugs of floxuridine and gemcitabine were synthesized. Their chemical stability in buffers, enzymatic stability in cell homogenates, permeability in mouse intestinal membrane along with drug concentration in mouse plasma, and anti-proliferative activity in cancer cells were determined and compared to their parent drugs. Floxuridine prodrug was more enzymatically stable than floxuridine and the degradation from prodrug to parent drug works as the rate-limiting step. On the other hand, gemcitabine prodrug was less enzymatically stable than gemcitabine. Those dipeptide monoester prodrugs exhibited 2.4- to 48.7-fold higher uptake than their parent drugs in Caco-2, Panc-1, and AsPC-1 cells. Floxuridine and gemcitabine prodrugs showed superior permeability in mouse jejunum to their parent drugs and exhibited the higher drug concentration in plasma after in situ mouse perfusion. Cell proliferation assays in ductal pancreatic cancer cells, AsPC-1 and Panc-1, indicated that dipeptide prodrugs of floxuridine and gemcitabine were more potent than their parent drugs. The enhanced potency of nucleoside analogs was attributed to their improved membrane permeability. The prodrug forms of 5¢-L-phenylalanyl-l-tyrosyl-floxuridine and 5¢-L-phenylalanyl-L-tyrosyl-gemcitabine appeared in mouse plasma after the permeation of intestinal membrane and the first-pass effect, suggesting their potential for the development of oral dosage form for anti-cancer agents.

Gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency in populations of pulmonary adenocarcinoma (A549).

Science.gov (United States)

Coyne, Cody P; Narayanan, Lakshmi

2017-03-01

One molecular-based approach that increases potency and reduces dose-limited sequela is the implementation of selective 'targeted' delivery strategies for conventional small molecular weight chemotherapeutic agents. Descriptions of the molecular design and organic chemistry reactions that are applicable for synthesis of covalent gemcitabine-monophosphate immunochemotherapeutics have to date not been reported. The covalent immunopharmaceutical, gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R] was synthesized by reacting gemcitabine with a carbodiimide reagent to form a gemcitabine carbodiimide phosphate ester intermediate which was subsequently reacted with imidazole to create amine-reactive gemcitabine-(5'-phosphorylimidazolide) intermediate. Monoclonal anti-IGF-1R immunoglobulin was combined with gemcitabine-(5'-phosphorylimidazolide) resulting in the synthetic formation of gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R]. The gemcitabine molar incorporation index for gemcitabine-(5'-phosphoramidate)-[anti-IGF-R1] was 2.67:1. Cytotoxicity Analysis - dramatic increases in antineoplastic cytotoxicity were observed at and between the gemcitabine-equivalent concentrations of 10 -9  M and 10 -7  M where lethal cancer cell death increased from 0.0% to a 93.1% maximum (100.% to 6.93% residual survival), respectively. Advantages of the organic chemistry reactions in the multistage synthesis scheme for gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R] include their capacity to achieve high chemotherapeutic molar incorporation ratios; option of producing an amine-reactive chemotherapeutic intermediate that can be preserved for future synthesis applications; and non-dedicated organic chemistry reaction scheme that allows substitutions of either or both therapeutic moieties, and molecular delivery platforms. © 2016 The Authors Chemical Biology & Drug Design Published by John Wiley & Sons Ltd.

Nebivolol and valsartan as a fixed-dose combination for the treatment of hypertension.

Science.gov (United States)

Sander, Gary E; Giles, Thomas D

2015-04-01

The fixed-dose combination of nebivolol and valsartan drug has been clinically evaluated and demonstrated to represent a unique combination of nebivolol, a selective β1-adrenoceptor antagonist and a β3-adrenoceptor agonist; β3 receptor activation increases endothelial nitric oxide and produces vasodilation. Valsartan is highly selective angiotensin AT1 receptor blocker and exerts its major pharmacological effect by decreasing angiotensin II-induced vasoconstriction and production of aldosterone. The addition of nebivolol counteracts the effects of increased angiotensin II concentrations resulting from potent AT1 blockade. This review describes a recently completed trial establishing the efficacy of the nebivolol/valsartan combination. This review provides a literature search of pertinent pharmacological and clinical data that describes the mechanisms of both drugs individually and the results of a clinical trial comparing fixed-dose combinations of nebivolol with valsartan as compared with each drug as monotherapy. Fixed-dose combination drugs are intended to improve patient compliance and reduce drug costs, as well as to reduce long-term cardiovascular event rates and block counter-regulatory effects due to monotherapy. The vast majority of hypertensive patients will require at least two medications. We believe that the clinical evidence suggests that the combination of nebivolol with valsartan offers a definite clinical benefit, combining β1-adrenoceptor and angiotensin AT1 receptor blockade with β3 receptor activation and resultant increase in nitric oxide and vasodilation.

Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

CERN Document Server

Braby, L A; Reece, W D

2003-01-01

Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation exp...

Locally advanced unresectable pancreatic cancer: Induction chemoradiotherapy followed by maintenance gemcitabine versus gemcitabine alone: Definitive results of the 2000-2001 FFCD/SFRO phase III trial; Cancer du pancreas localement evolue non resecable: chimioradiotherapie d'induction suivie de chimiotherapie par gemcitabine contre chimiotherapie exclusive par gemcitabine: resultats definitifs de l'etude de phase III 2000-2001de la FFCD et de la SFRO

Energy Technology Data Exchange (ETDEWEB)

Barhoumi, M.; Mornex, F. [EA 3738, departement de radiotherapie-oncologie, centre hospitalier Lyon-Sud, 165, chemin du Grand-Revoyet, 69310 Pierre-Benite (France); Bonnetain, F. [EA 4184, unite de biostatistiques et d' epidemiologie, centre Georges-Francois-Leclerc, 21034 Dijon cedex (France); Inserm UMR 866, faculte de medecine, 21078 Dijon cedex (France); Universite de Bourgogne, BP 27877, 21078 Dijon cedex (France); Rougier, P. [Service d' hepato-gastro-enterologie oncologie digestive, centre hospitalier Ambroise-Pare, 9, avenue Charles-de-Gaulle, 92100 Boulogne-Billancourt (France); Mariette, C. [Service de chirurgie digestive et generale, rez-de-jardin-aile-ouest, hopital Claude-Huriez, 59037 Lille cedex (France); Bouche, O. [CHU, 51092 Reims cedex (France); Bosset, J.F. [Service de radiotherapie, CHU de Besancon, 25030 Besancon cedex (France); Aparicio, T. [Service de gastroenterologie, hopital Avicenne, AP-HP, 93000 Bobigny (France); Mineur, L. [Service de radiotherapie oncologie digestive, institut Sainte-Catherine, 84082 Avignon cedex 2 (France); Azzedine, A. [Centre hospitalier Henri-Duffaut, 84902 Avignon (France); Hammel, P. [Service de gastroenterologie pancreatologie, hopital Beaujon, 92110 Clichy (France); Butel, J. [Hopital d' Abbeville, 80142 Abbeville (France); Stremsdoerfer, N. [Service d' hepatogastroenterologie, centre hospitalier Pierre-Oudot, 38317 Bourgoin-Jallieu (France); Maingon, P. [Departement de radiotherapie, centre Georges-Francois-Leclerc, 21079 Dijon cedex (France); Bedenne, L. [Inserm UMR 866, faculte de medecine, 21078 Dijon cedex (France); Universite de Bourgogne, 21078 Dijon cedex (France); Service d' hepatogastroenterologie, CHU Le-Bocage, 21034 Dijon cedex (France); Chauffert, B. [Inserm UMR 866, faculte de medecine, 21078 Dijon cedex (France); Universite de Bourgogne, 21078 Dijon cedex (France); Departement d' oncologie medicale, centre Georges-Francois-Leclerc, 21079 Dijon cedex (France)

2011-06-15

Purpose. - To compare chemo-radiation with systemic chemotherapy to chemotherapy alone in locally advanced pancreatic cancer. Patients and methods. - One hundred and nineteen patients with locally advanced pancreatic cancer, with World Health Organization performance status of zero to two were randomly assigned to either the induction chemo-radiation group (60 Gy, 2 Gy/fraction; concomitant 5-fluoro-uracil infusion, 300 mg/m{sup 2} per day, days 1-5 for 6 weeks; cisplatin, 20 mg/m{sup 2} per day, days 1-5 during weeks 1 and 5) or the induction gemcitabine group (GEM: 1000 mg/m{sup 2} weekly for 7 weeks). Maintenance gemcitabine (1000 mg/m{sup 2} weekly, 3/4 weeks) was given in both arms until disease progression or toxicity. Results. - Overall survival was shorter in the chemo-radiation than in the gemcitabine arm (median survival 8.6 [99% confidence interval 7.1-11.4] and 13 months [8,9,9-18], p = 0.03). One-year survival was, respectively, 32 and 53%. These results were confirmed in a per-protocol analysis for patients who received 75% or more of the planned dose of radiotherapy. More overall grades 3-4 toxic effects were recorded in the chemo-radiation arm, both during induction (36 versus 22%) and maintenance (32 versus 18%). Conclusion. - This intensive induction schedule of chemo-radiation was more toxic and less effective than gemcitabine alone. (authors)

12 CFR 619.9170 - Fixed interest rate.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Fixed interest rate. 619.9170 Section 619.9170 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9170 Fixed interest rate. The rate of interest specified in the note or loan document which will prevail as the maximum...

Fixed-dose combination therapy for the prevention of cardiovascular disease

Science.gov (United States)

de Cates, Angharad N; Farr, Matthew RB; Rees, Karen; Casas, Juan P; Huffman, Mark

2014-01-01

This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the effectiveness of fixed-dose combination therapy on optimising CVD risk factors and reducing CVD fatal and non-fatal events for both primary and secondary prevention of CVD. Details of CVD events and risk factors included are listed in the methods. We will also determine any adverse events associated with taking fixed-dose combination therapy. This will include studies conducted in both developed and developing regions of the world. PMID:25267903

Ku70 inhibits gemcitabine-induced DNA damage and pancreatic cancer cell apoptosis

International Nuclear Information System (INIS)

Ma, Jiali; Hui, Pingping; Meng, Wenying; Wang, Na; Xiang, Shihao

2017-01-01

The current study focused on the role of Ku70, a DNA-dependent protein kinase (DNA-PK) complex protein, in pancreatic cancer cell resistance to gemcitabine. In both established cell lines (Mia-PaCa-2 and PANC-1) and primary human pancreatic cancer cells, shRNA/siRNA-mediated knockdown of Ku70 significantly sensitized gemcitabine-induced cell death and proliferation inhibition. Meanwhile, gemcitabine-induced DNA damage and subsequent pancreatic cancer cell apoptosis were also potentiated with Ku70 knockdown. On the other hand, exogenous overexpression of Ku70 in Mia-PaCa-2 cells suppressed gemcitabine-induced DNA damage and subsequent cell apoptosis. In a severe combined immune deficient (SCID) mice Mia-PaCa-2 xenograft model, gemcitabine-induced anti-tumor activity was remarkably pontificated when combined with Ku70 shRNA knockdown in the xenografts. The results of this preclinical study imply that Ku70 might be a primary resistance factor of gemcitabine, and Ku70 silence could significantly chemo-sensitize gemcitabine in pancreatic cancer cells. - Highlights: • Ku70 knockdown sensitizes gemcitabine-induced killing of pancreatic cancer cells. • Ku70 knockdown facilitates gemcitabine-induced DNA damage and cell apoptosis. • Ku70 overexpression deceases gemcitabine's sensitivity in pancreatic cancer cells. • Ku70 knockdown sensitizes gemcitabine-induced anti-tumor activity in vivo.

A phase 1/1B trial of ADI-PEG 20 plus nab-paclitaxel and gemcitabine in patients with advanced pancreatic adenocarcinoma.

Science.gov (United States)

Lowery, Maeve A; Yu, Kenneth H; Kelsen, David Paul; Harding, James J; Bomalaski, John S; Glassman, Danielle C; Covington, Christina M; Brenner, Robin; Hollywood, Ellen; Barba, Adalberto; Johnston, Amanda; Liu, Kay Chia-Wei; Feng, Xiaoxing; Capanu, Marinela; Abou-Alfa, Ghassan K; O'Reilly, Eileen M

2017-12-01

ADI-PEG 20 is a pegylated form of the arginine-depleting enzyme arginine deiminase. Normal cells synthesize arginine with the enzyme argininosuccinate synthetase (ASS1); ADI-PEG 20 selectively targets malignant cells, which lack ASS1. A single-arm, nonrandomized, open-label, phase 1/1B, standard 3 + 3 dose escalation with an expansion cohort of 9 patients at the recommended phase 2 dose (RP2D) was conducted. Patients who had metastatic pancreatic cancer, up to 1 line of prior treatment (the dose-escalation cohort) or no prior treatment (the expansion cohort), and an Eastern Cooperative Oncology Group performance status of 0 to 1 were included. Patients received both gemcitabine (1000 mg/m 2 ) and nab-paclitaxel (125 mg/m 2 ) for 3 of 4 weeks and intramuscular ADI-PEG 20 at 18 mg/m 2 weekly (cohort 1) or at 36 mg/m 2 weekly (cohort 2 and the expansion cohort).The primary endpoint was to determine the maximum tolerated dose and RP2D of ADI-PEG 20 in combination with nab-paclitaxel and gemcitabine. Eighteen patients were enrolled. No dose-limiting toxicities (DLTs) were observed in cohort 1; cohort 2 was expanded to 6 patients because of 1 DLT occurrence (a grade 3 elevation in bilirubin, aspartate aminotransferase, and alanine aminotransferase). The most frequent adverse events (AEs) of any grade were neutropenia, thrombocytopenia, leukopenia, anemia, peripheral neuropathy, and fatigue; all 18 patients experienced grade 3/4 AEs. The most frequent grade 3/4 toxicities, regardless of the relation with any drugs, included neutropenia (12 patients or 67%), leukopenia (10 patients or 56%), anemia (8 patients or 44%), and lymphopenia (6 patients or 33%). The RP2D for ADI-PEG 20 was 36 mg/m 2 weekly in combination with standard-dose gemcitabine and nab-paclitaxel. The overall response rate among patients treated at the RP2D in the first-line setting was 45.5% (5 of 11).The median progression-free survival time for these patients treated at the RP2D was 6.1 months (95

Fixed-Rate Compressed Floating-Point Arrays.

Science.gov (United States)

Lindstrom, Peter

2014-12-01

Current compression schemes for floating-point data commonly take fixed-precision values and compress them to a variable-length bit stream, complicating memory management and random access. We present a fixed-rate, near-lossless compression scheme that maps small blocks of 4(d) values in d dimensions to a fixed, user-specified number of bits per block, thereby allowing read and write random access to compressed floating-point data at block granularity. Our approach is inspired by fixed-rate texture compression methods widely adopted in graphics hardware, but has been tailored to the high dynamic range and precision demands of scientific applications. Our compressor is based on a new, lifted, orthogonal block transform and embedded coding, allowing each per-block bit stream to be truncated at any point if desired, thus facilitating bit rate selection using a single compression scheme. To avoid compression or decompression upon every data access, we employ a software write-back cache of uncompressed blocks. Our compressor has been designed with computational simplicity and speed in mind to allow for the possibility of a hardware implementation, and uses only a small number of fixed-point arithmetic operations per compressed value. We demonstrate the viability and benefits of lossy compression in several applications, including visualization, quantitative data analysis, and numerical simulation.

Evidence-Based Design of Fixed-Dose Combinations: Principles and Application to Pediatric Anti-Tuberculosis Therapy.

Science.gov (United States)

Svensson, Elin M; Yngman, Gunnar; Denti, Paolo; McIlleron, Helen; Kjellsson, Maria C; Karlsson, Mats O

2018-05-01

Fixed-dose combination formulations where several drugs are included in one tablet are important for the implementation of many long-term multidrug therapies. The selection of optimal dose ratios and tablet content of a fixed-dose combination and the design of individualized dosing regimens is a complex task, requiring multiple simultaneous considerations. In this work, a methodology for the rational design of a fixed-dose combination was developed and applied to the case of a three-drug pediatric anti-tuberculosis formulation individualized on body weight. The optimization methodology synthesizes information about the intended use population, the pharmacokinetic properties of the drugs, therapeutic targets, and practical constraints. A utility function is included to penalize deviations from the targets; a sequential estimation procedure was developed for stable estimation of break-points for individualized dosing. The suggested optimized pediatric anti-tuberculosis fixed-dose combination was compared with the recently launched World Health Organization-endorsed formulation. The optimized fixed-dose combination included 15, 36, and 16% higher amounts of rifampicin, isoniazid, and pyrazinamide, respectively. The optimized fixed-dose combination is expected to result in overall less deviation from the therapeutic targets based on adult exposure and substantially fewer children with underexposure (below half the target). The development of this design tool can aid the implementation of evidence-based formulations, integrating available knowledge and practical considerations, to optimize drug exposures and thereby treatment outcomes.

Phase 1 Pharmacogenetic and Pharmacodynamic Study of Sorafenib With Concurrent Radiation Therapy and Gemcitabine in Locally Advanced Unresectable Pancreatic Cancer

Energy Technology Data Exchange (ETDEWEB)

Chiorean, E. Gabriela, E-mail: gchiorea@uw.edu [Department of Medicine, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, Indiana (United States); Department of Medicine, University of Washington, Seattle, Washington (United States); Schneider, Bryan P. [Department of Medicine, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, Indiana (United States); Akisik, Fatih M. [Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Perkins, Susan M. [Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana (United States); Anderson, Stephen [Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana (United States); Johnson, Cynthia S. [Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana (United States); DeWitt, John [Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana (United States); Helft, Paul; Clark, Romnee; Johnston, Erica L.; Spittler, A. John [Department of Medicine, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, Indiana (United States); Deluca, Jill [Department of Radiation Oncology, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, Indiana (United States); Bu, Guixue [Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Shahda, Safi; Loehrer, Patrick J. [Department of Medicine, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, Indiana (United States); Sandrasegaran, Kumar [Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Cardenes, Higinia R. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana (United States)

2014-06-01

Purpose: To define the safety, efficacy, and pharmacogenetic and pharmacodynamic effects of sorafenib with gemcitabine-based chemoradiotherapy (CRT) in locally advanced pancreatic cancer. Methods and Materials: Patients received gemcitabine 1000 mg/m{sup 2} intravenously weekly × 3 every 4 weeks per cycle for 1 cycle before CRT and continued for up to 4 cycles after CRT. Weekly gemcitabine 600 mg/m{sup 2} intravenously was given during concurrent intensity modulated radiation therapy of 50 Gy to gross tumor volume in 25 fractions. Sorafenib was dosed orally 400 mg twice daily until progression, except during CRT when it was escalated from 200 mg to 400 mg daily, and 400 mg twice daily. The maximum tolerated dose cohort was expanded to 15 patients. Correlative studies included dynamic contrast-enhanced MRI and angiogenesis genes polymorphisms (VEGF-A and VEGF-R2 single nucleotide polymorphisms). Results: Twenty-seven patients were enrolled. No dose-limiting toxicity occurred during induction gemcitabine/sorafenib followed by concurrent CRT. The most common grade 3/4 toxicities were fatigue, hematologic, and gastrointestinal. The maximum tolerated dose was sorafenib 400 mg twice daily. The median progression-free survival and overall survival for 25 evaluable patients were 10.6 and 12.6 months, respectively. The median overall survival for patients with VEGF-A -2578 AA, -1498 CC, and -1154 AA versus alternate genotypes was 21.6 versus 14.7 months. Dynamic contrast-enhanced MRI demonstrated higher baseline K{sup trans} in responding patients. Conclusions: Concurrent sorafenib with CRT had modest clinical activity with increased gastrointestinal toxicity in localized unresectable pancreatic cancer. Select VEGF-A/VEGF-R2 genotypes were associated with favorable survival.

Phase 1 Pharmacogenetic and Pharmacodynamic Study of Sorafenib With Concurrent Radiation Therapy and Gemcitabine in Locally Advanced Unresectable Pancreatic Cancer

International Nuclear Information System (INIS)

Chiorean, E. Gabriela; Schneider, Bryan P.; Akisik, Fatih M.; Perkins, Susan M.; Anderson, Stephen; Johnson, Cynthia S.; DeWitt, John; Helft, Paul; Clark, Romnee; Johnston, Erica L.; Spittler, A. John; Deluca, Jill; Bu, Guixue; Shahda, Safi; Loehrer, Patrick J.; Sandrasegaran, Kumar; Cardenes, Higinia R.

2014-01-01

Purpose: To define the safety, efficacy, and pharmacogenetic and pharmacodynamic effects of sorafenib with gemcitabine-based chemoradiotherapy (CRT) in locally advanced pancreatic cancer. Methods and Materials: Patients received gemcitabine 1000 mg/m 2 intravenously weekly × 3 every 4 weeks per cycle for 1 cycle before CRT and continued for up to 4 cycles after CRT. Weekly gemcitabine 600 mg/m 2 intravenously was given during concurrent intensity modulated radiation therapy of 50 Gy to gross tumor volume in 25 fractions. Sorafenib was dosed orally 400 mg twice daily until progression, except during CRT when it was escalated from 200 mg to 400 mg daily, and 400 mg twice daily. The maximum tolerated dose cohort was expanded to 15 patients. Correlative studies included dynamic contrast-enhanced MRI and angiogenesis genes polymorphisms (VEGF-A and VEGF-R2 single nucleotide polymorphisms). Results: Twenty-seven patients were enrolled. No dose-limiting toxicity occurred during induction gemcitabine/sorafenib followed by concurrent CRT. The most common grade 3/4 toxicities were fatigue, hematologic, and gastrointestinal. The maximum tolerated dose was sorafenib 400 mg twice daily. The median progression-free survival and overall survival for 25 evaluable patients were 10.6 and 12.6 months, respectively. The median overall survival for patients with VEGF-A -2578 AA, -1498 CC, and -1154 AA versus alternate genotypes was 21.6 versus 14.7 months. Dynamic contrast-enhanced MRI demonstrated higher baseline K trans in responding patients. Conclusions: Concurrent sorafenib with CRT had modest clinical activity with increased gastrointestinal toxicity in localized unresectable pancreatic cancer. Select VEGF-A/VEGF-R2 genotypes were associated with favorable survival

A randomized phase II trial of first-line treatment with gemcitabine, erlotinib, or gemcitabine and erlotinib in elderly patients (age ≥70 years) with stage IIIB/IV non-small cell lung cancer.

Science.gov (United States)

Stinchcombe, Thomas E; Peterman, Amy H; Lee, Carrie B; Moore, Dominic T; Beaumont, Jennifer L; Bradford, Daniel S; Bakri, Kamal; Taylor, Mark; Crane, Jeffrey M; Schwartz, Garry; Hensing, Thomas A; McElroy, Edwin; Niell, Harvey B; Harper, Harry D; Pal, Sridhar; Socinski, Mark A

2011-09-01

Single-agent gemcitabine is a standard of care for elderly patients with advanced non-small cell lung cancer, but novel therapies are needed for this patient population. We performed a noncomparative randomized phase II trial of gemcitabine, erlotinib, or the combination in elderly patients (age ≥70 years) with stage IIIB or IV non-small cell lung cancer. Patients were randomized to arms: A (gemcitabine 1200 mg/m on days 1 and 8 every 21 days), B (erlotinib 150 mg daily), or C (gemcitabine 1000 mg/m on days 1 and 8 every 21 days and erlotinib 100 mg daily). Arms B and C were considered investigational; the primary objective was 6-month progression-free survival. Between March 2006 and May 2010, 146 eligible patients received protocol therapy. The majority of the patients (82%) had stage IV disease, 64% reported adenocarcinoma histology, 90% reported current or previous tobacco use, and 28% had a performance status of 2. The 6-month progression-free survival rate observed in arms A, B, and C was 22% (95% confidence interval [CI] 11-35), 24% (95% CI 13-36), and 25% (95% CI 15-38), respectively; the median overall survival observed was 6.8 months (95% CI 4.8-8.5), 5.8 months (95% CI 3.0-8.3), and 5.6 months (95% CI 3.5-8.4), respectively. The rate of grade ≥3 hematological and nonhematological toxicity observed was similar in all three arms. The best overall health-related quality of life response did not differ between treatment arms. Erlotinib or erlotinib and gemcitabine do not warrant further investigation in an unselected elderly patient population.

Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

International Nuclear Information System (INIS)

Song, Yao; Baba, Tomohisa; Li, Ying-Yi; Furukawa, Kaoru; Tanabe, Yamato; Matsugo, Seiichi; Sasaki, Soichiro; Mukaida, Naofumi

2015-01-01

Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization. - Highlights: • Gemcitabine induced CXCL8 expression in human pancreatic cancer cells. • CXCL8 expression required ROS generation and NF-κB activation. • CXCL8 did not affect in vitro proliferation of human pancreatic cancer cells. • CXCL8 in vivo counteracted gemcitabine by inducing neovascularization

Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

Energy Technology Data Exchange (ETDEWEB)

Song, Yao; Baba, Tomohisa [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); Li, Ying-Yi [Cancer Research Institute, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Furukawa, Kaoru; Tanabe, Yamato [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); School of Natural System Bioengineering Course, College of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa (Japan); Matsugo, Seiichi [School of Natural System Bioengineering Course, College of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa (Japan); Sasaki, Soichiro [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); Mukaida, Naofumi, E-mail: mukaida@staff.kanazawa-u.ac.jp [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan)

2015-03-06

Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization. - Highlights: • Gemcitabine induced CXCL8 expression in human pancreatic cancer cells. • CXCL8 expression required ROS generation and NF-κB activation. • CXCL8 did not affect in vitro proliferation of human pancreatic cancer cells. • CXCL8 in vivo counteracted gemcitabine by inducing neovascularization.

Mechanistic studies of Gemcitabine-loaded nanoplatforms in resistant pancreatic cancer cells

International Nuclear Information System (INIS)

Papa, Anne-Laure; Basu, Sudipta; Sengupta, Poulomi; Banerjee, Deboshri; Sengupta, Shiladitya; Harfouche, Rania

2012-01-01

Pancreatic cancer remains the deadliest of all cancers, with a mortality rate of 91%. Gemcitabine is considered the gold chemotherapeutic standard, but only marginally improves life-span due to its chemical instability and low cell penetrance. A new paradigm to improve Gemcitabine’s therapeutic index is to administer it in nanoparticles, which favour its delivery to cells when under 500 nm in diameter. Although promising, this approach still suffers from major limitations, as the choice of nanovector used as well as its effects on Gemcitabine intracellular trafficking inside pancreatic cancer cells remain unknown. A proper elucidation of these mechanisms would allow for the elaboration of better strategies to engineer more potent Gemcitabine nanotherapeutics against pancreatic cancer. Gemcitabine was encapsulated in two types of commonly used nanovectors, namely poly(lactic-co-glycolic acid) (PLGA) and cholesterol-based liposomes, and their physico-chemical parameters assessed in vitro. Their mechanisms of action in human pancreatic cells were compared with those of the free drug, and with each others, using cytotoxity, apoptosis and ultrastructural analyses. Physico-chemical analyses of both drugs showed high loading efficiencies and sizes of less than 200 nm, as assessed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), with a drug release profile of at least one week. These profiles translated to significant cytotoxicity and apoptosis, as well as distinct intracellular trafficking mechanisms, which were most pronounced in the case of PLGem showing significant mitochondrial, cytosolic and endoplasmic reticulum stresses. Our study demonstrates how the choice of nanovector affects the mechanisms of drug action and is a crucial determinant of Gemcitabine intracellular trafficking and potency in pancreatic cancer settings

Treatment of hyperthyroidism with fixed dose form Iodine 131

International Nuclear Information System (INIS)

Pacheco Torres, P.; Cerquera, A.M.; Acosta, F.; Sierra, M.

2007-01-01

Full text: Objective: Evaluation of the response to therapy with fixed dose of Iodine-131 in patients with hyperthyroidism. One hundred seventeen patients with hyperthyroidism were tested and sent for treatment with Iodine-131. The dose of the therapy was calculated according to the pathology (Diffuser goiter (DG): Multinodular goiter (MNG) and Single toxic nodule (NST). Values of TSH confirmed hyperthyroidism by laboratory methods. The thyroid-blocking agents were discontinued: methimazole for five days and propylthiouracil two days prior to therapy. The pregnancy tests were routinely conducted in females of reproductive age group. Patients reported fasting for therapy. The doses were administered in capsule form after obtaining informed consent from the patients. The patients were normally instructed to eat only after two hours after administration of iodine to promote gastric absorption of the radionuclide. Normally a post therapy thyroid scan is performed four days after treatment. Patients are usually followed up by the endocrinologists. A three- month post therapy evaluation is done by the nuclear medicine physician by telephone. The demographic data of our patients treated are as follows: Total number of patients: 117 Female: 88 (75.21%) Male: 29 (24.79%) Age average: 45 years. Diffuse Goiter= 94 (80.34%), Multinodular Goiter= 17 (14.52%) and Toxic Adenoma (NST) = 6 (5.12%). The average administered dose was 22.5 mCi to DG, 41.8 mCi to MNG and 37.5 mCi to NST. 102 (87.14%) patients at the control at 2 years after treatment presented stable response to therapy, 15 (12.86%) required a second therapy, 11 (11.70%) with BD and 4 (23.52%) with BMN; and any patient with NST required a second therapy. 83 (88.29%) of the patients with BD; 13 (76.48%) with BMN and 6 (100%) with NST the therapy was successful. Conclusion: Fixed dose of I-131 in hyperthyroidism is useful in patients with DG (11.70%). In patients with MNG whom a fixed dose is supplied, 23.52% require a

PEG Grafted-Nanodiamonds for the Delivery of Gemcitabine.

Science.gov (United States)

Lu, Mingxia; Wang, Yu-Kai; Zhao, Jiacheng; Lu, Hongxu; Stenzel, Martina H; Xiao, Pu

2016-12-01

Carboxyl end-functionalized poly[poly(ethylene glycol) methyl ether methacrylate] [P(PEGMEMA)] and its block copolymer with gemcitabine substituted poly(N-hydroxysuccinimide methacrylate) [PGem-block-P(PEGMEMA)] are synthesized via reversible addition-fragmentation transfer (RAFT) polymerization. Then, two polymers are grafted onto the surface of amine-functionalized nanodiamonds to obtain [P(PEGMEMA)]-grafted nanodiamonds (ND-PEG) and [PGem-block-P(PEGMEMA)]-grafted nanodiamonds (ND-PF). Gemcitabine is physically absorbed to ND-PEG to produce ND-PEG (Gem). Two polymer-grafted nanodiamonds (i.e., with physically absorbed gemcitabine ND-PEG (Gem) and with chemically conjugated gemcitabine ND-PF) are characterized using attenuated total reflectance infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis. The drug release, cytotoxicity (to seed human pancreatic carcinoma AsPC-1 cells), and cellular uptake of ND-PEG (Gem) and ND-PF are also investigated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu; Magae, Junji

2008-01-01

Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

In vitro evaluation of photon and raster-scanned carbon ion radiotherapy in combination with gemcitabine in pancreatic cancer cell lines

International Nuclear Information System (INIS)

Shafie, Rami A. El; Habermehl, Daniel; Rieken, Stefan

2013-01-01

Pancreatic cancer is the fourth leading cause of cancer deaths, being responsible for 6% of all cancer-related deaths. Conventional radiotherapy with or without additional chemotherapy has been applied in the past in the context of neoadjuvant or adjuvant therapy concepts with only modest results, however new radiation modalities, such as particle therapy with promising physical and biological characteristics, present an alternative treatment option for patients with pancreatic cancer. Up until now the raster scanning technique employed at our institution for the application of carbon ions has been unique, and no radiobiological data using pancreatic cancer cells has been available yet. The aim of this study was to evaluate cytotoxic effects that can be achieved by treating pancreatic cancer cell lines with combinations of X-rays and gemcitabine, or alternatively with carbon ion irradiation and gemcitabine, respectively. Human pancreatic cancer cell lines AsPC-1, BxPC-3 and Panc-1 were irradiated with photons and carbon ions at various doses and treated with gemcitabine. Photon irradiation was applied with a biological cabin X-ray irradiator, and carbon ion irradiation was applied with an extended Bragg peak (linear energy transfer (LET) 103 keV/μm) using the raster scanning technique at the Heidelberg Ion Therapy Center (HIT). Responsiveness of pancreatic cancer cells to the treatment was measured by clonogenic survival. Clonogenic survival curves were then compared to predicted curves that were calculated employing the local effect model (LEM). Cell survival curves were calculated from the surviving fractions of each combination experiment and compared to a drug control that was only irradiated with X-rays or carbon ions, without application of gemcitabine. In terms of cytotoxicity, additive effects were achieved for the cell lines Panc-1 and BxPC-3, and a slight radiosensitizing effect was observed for AsPC-1. Relative biological effectiveness (RBE) of carbon

Tramadol/paracetamol fixed-dose combination in the treatment of moderate to severe pain

Science.gov (United States)

Pergolizzi, Joseph V; van de Laar, Mart; Langford, Richard; Mellinghoff, Hans-Ulrich; Merchante, Ignacio Morón; Nalamachu, Srinivas; O’Brien, Joanne; Perrot, Serge; Raffa, Robert B

2012-01-01

Pain is the most common reason patients seek medical attention and pain relief has been put forward as an ethical obligation of clinicians and a fundamental human right. However, pain management is challenging because the pathophysiology of pain is complex and not completely understood. Widely used analgesics such as nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol (acetaminophen) have been associated with adverse events. Adverse event rates are of concern, especially in long-term treatment or at high doses. Paracetamol and NSAIDs are available by prescription, over the counter, and in combination preparations. Patients may be unaware of the risk associated with high dosages or long-term use of paracetamol and NSAIDs. Clinicians should encourage patients to disclose all medications they take in a “do ask, do tell” approach that includes patient education about the risks and benefits of common pain relievers. The ideal pain reliever would have few risks and enhanced analgesic efficacy. Fixed-dose combination analgesics with two or more agents may offer additive or synergistic benefits to treat the multiple mechanisms of pain. Therefore, pain may be effectively treated while toxicity is reduced due to lower doses. One recent fixed-dose combination analgesic product combines tramadol, a centrally acting weak opioid analgesic, with low-dose paracetamol. Evidence-based guidelines recognize the potential value of combination analgesics in specific situations. The current guideline-based paradigm for pain treatment recommends NSAIDs for ongoing use with analgesics such as opioids to manage flares. However, the treatment model should evolve how to use low-dose combination products to manage pain with occasional use of NSAIDs for flares to avoid long-term and high-dose treatment with these analgesics. A next step in pain management guidelines should be targeted therapy when possible, or low-dose combination therapy or both, to achieve maximal efficacy with

Maximal safe dose therapy of I-131 after failure of standard fixed dose therapy in patients with differentiated thyroid carcinoma

International Nuclear Information System (INIS)

Lee, Jong Jin; Seok, Ju Won; Uh, Jae Sun

2005-01-01

In patients with recurrent or metastatic differentiated thyroid carcinoma, residual disease despite repetitive fixed dose I-131 therapy presents an awkward situation in terms of treatment decision making. Maximal safe dose (MSD) administration base on bone marrow radiation allows the delivery of a large amount I-131 to thyroid cancer tissue within the safety margin. We investigated the efficacy of MSD in differentiated thyroid cancers, which had persisted after conventional fixed dose therapy. Forty-six patients with differentiated thyroid carcinoma who had non-responsible residual disease despite repetitive fixed dose I-131 therapy were enrolled in this study. The postoperative pathology consisted of 43 papillary carcinomas and 3 follicular carcinomas. MSD was calculated according the Memorial Sloan Kettering Cancer Center protocol using blood samples. MSDs were administered at intervals of at least 6 months. Treatment responses were evaluated using I-131 whole body scan (WBS) and serum thyroglobulin measurements. Mean calculated MSD was 12.5±2.1 GBq. Of the 46 patients, 6 (13.0%) showed complete remission, 15 (32.6%) partial response, 19 (41.3%) stable disease, and 6 (13.0%) disease progression. Thus, about a half of the patients showed complete or partial remission, and of these patients, 14 (67%) showed response after a single MSD administration and 6 (29%) showed response after the second dose of MSD administrations. Twenty-nine patients (63%) experienced transient cytopenia after therapy, and recovered spontaneously with the exception of one. MSD administration is an effective method even in the patients who failed to be treated by conventional fixed dose therapy. MSD therapy of I-131 can be considered in the patients who failed by fixed dose therapy

Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

International Nuclear Information System (INIS)

Braby, L. A.; Reece, W. D.; Hsu, W. H.

2003-01-01

Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation experiments. We have also developed 4.3 mm diameter ion chambers with both tissue equivalent and carbon walls for the purpose of measuring dose mean lineal energy due to all radiations and due to all radiations except neutrons, respectively. By adjusting the gas pressure in the ion chamber, it can be made to simulate tissue volumes from a few nanometers to a few millimeters in diameter. The charge is integrated for 0.1 seconds, and the resulting pulse height is recorded by a multi channel analyzer. The system has been used in a variety of photon and neutron radiation fields, and measured values of dose and dose mean lineal energy are consistent with values extrapolated from measurements made by other techniques at much lower dose rates. It is expected that this technique will prove to be much more reliable than extrapolations from measurements made at low dose rates because these low dose rate exposures generally do not accurately reproduce the attenuation and

Maximal safe dose of I-131 after failure of standard fixed dose therapy in patients with differentiated thyroid carcinoma

International Nuclear Information System (INIS)

Lee, Jong-Jin; Chung, June-Key; Kim, Sung-Eun; Kang, Won-Jun; Park, Do-Joon; Lee, Dong-Soo; Cho, Bo-Youn; Lee, Myung-Chul

2008-01-01

The maximal safe dose (MSD) on the basis of bone marrow irradiation levels allows the delivery of a large amount of I-131 to thyroid cancer tissue. The efficacy of MSD therapy in differentiated metastatic thyroid cancers that persisted after conventional fixed dose therapy is investigated. Forty-seven differentiated thyroid carcinoma patients with non-responsive residual disease despite repetitive fixed dose I-131 therapy were enrolled in this study. Their postoperative pathologies were 43 papillary carcinomas and 4 follicular carcinomas. The MSD was calculated with the Memorial Sloan-Kettering Cancer Center protocol using serial blood samples. The MSDs were administered at intervals of 6 months. Treatment responses were evaluated using I-131 whole-body scans and serum thyroglobulin measurements. The mean calculated MSD was 12.5±2.1 GBq (339.6±57.5 mCi). Of the 46 patients, 7 (14.9%) showed complete remission, 15 (31.9%) partial remission, 19 (40.4%) stable disease, and 6 (12.8%) disease progression. Of the patients who showed complete or partial remission, 15 (65%) showed response after the first MSD session and 6 (26%) showed response after the second session. Twenty-nine patients (62%) experienced transient cytopenia after therapy, but three did not recover to the baseline level. The maximal safe dose provides an effective means of treatment in patients who failed to respond adequately to conventional fixed dose therapy. I-131 MSD therapy can be considered in patients who fail fixed dose therapy. (author)

Interdependence of Gemcitabine Treatment, Transporter Expression, and Resistance in Human Pancreatic Carcinoma Cells

Directory of Open Access Journals (Sweden)

Wolfgang Hagmann

2010-09-01

Full Text Available Gemcitabine is widely used as first-line chemotherapeutic drug in the treatment of pancreatic cancer. Our previous experimental chemotherapy studies have shown that treatment of human pancreatic carcinoma cells with 5-fluorouracil (5-FU alters the cellular transporter expression profile and that modulation of the expression of multidrug resistance protein 5 (MRP5; ABCC5 influences the chemoresistance of these tumor cells. Here, we studied the influence of acute and chronic gemcitabine treatment on the expression of relevant uptake and export transporters in pancreatic carcinoma cells by reverse transcription-polymerase chain reaction (RT-PCR, quantitative RT-PCR, and immunoblot analyses. The specific role of MRP5 in cellular gemcitabine sensitivity was studied by cytotoxicity assays using MRP5-overexpressing and MRP5-silenced cells. Exposure to gemcitabine (12 nM for 3 days did not alter the messenger RNA (mRNA expression of MRP1, MRP3, MRP5, and equilibrative nucleoside transporter 1 (ENT1, whereas high dosages of the drug (20 µM for 1 hour elicited up-regulation of these transporters in most cell lines studied. In cells with acquired gemcitabine resistance (up to 160 nM gemcitabine, the mRNA or protein expression of the gemcitabine transporters MRP5 and ENT1 was upregulated in several cell lines. Combined treatment with 5-FU and gemcitabine caused a 5- to 40-fold increase in MRP5 and ENT1 expressions. Cytotoxicity assays using either MRP5-overexpressing (HEK and PANC-1 or MRP5-silenced (PANC1/shMRP5 cells indicated that MRP5 contributes to gemcitabine resistance. Thus, our novel data not only on drug-induced alterations of transporter expression relevant for gemcitabine uptake and export but also on the link between gemcitabine sensitivity and MRP5 expression may lead to improved strategies of future chemotherapy regimens using gemcitabine in pancreatic carcinoma patients.

Phase 2, multicenter, open-label study of tigatuzumab (CS-1008), a humanized monoclonal antibody targeting death receptor 5, in combination with gemcitabine in chemotherapy-naive patients with unresectable or metastatic pancreatic cancer

International Nuclear Information System (INIS)

Forero-Torres, Andres; Infante, Jeffrey R; Waterhouse, David; Wong, Lucas; Vickers, Selwyn; Arrowsmith, Edward; He, Aiwu Ruth; Hart, Lowell; Trent, David; Wade, James; Jin, Xiaoping; Wang, Qiang; Austin, TaShara; Rosen, Michael; Beckman, Robert; Roemeling, Reinhard von; Greenberg, Jonathan; Saleh, Mansoor

2013-01-01

Tigatuzumab is the humanized version of the agonistic murine monoclonal antibody TRA-8 that binds to the death receptor 5 and induces apoptosis of human cancer cell lines via the caspase cascade. The combination of tigatuzumab and gemcitabine inhibits tumor growth in murine pancreatic xenografts. This phase 2 trial evaluated the efficacy of tigatuzumab combined with gemcitabine in 62 chemotherapy-naive patients with histologically or cytologically confirmed unresectable or metastatic pancreatic cancer. Patients received intravenous tigatuzumab (8 mg/kg loading dose followed by 3 mg/kg weekly) and gemcitabine (1000 mg/m 2 once weekly for 3 weeks followed by 1 week of rest) until progressive disease (PD) or unacceptable toxicity occurred. The primary end point was progression-free survival (PFS) at 16 weeks. Secondary end points included objective response rate (ORR) (complete responses plus partial responses), duration of response, and overall survival (OS). Safety of the combination was also evaluated. Mean duration of treatment was 18.48 weeks for tigatuzumab and 17.73 weeks for gemcitabine. The PFS rate at 16 weeks was 52.5% (95% confidence interval [CI], 39.3–64.1%). The ORR was 13.1%; 28 (45.9%) patients had stable disease and 14 (23%) patients had PD. Median PFS was 3.9 months (95% CI, 2.2–5.4 months). Median OS was 8.2 months (95% CI, 5.1–9.6 months). The most common adverse events related to tigatuzumab were nausea (35.5%), fatigue (32.3%), and peripheral edema (19.4%). Tigatuzumab combined with gemcitabine was well tolerated and may be clinically active for the treatment of chemotherapy-naive patients with unresectable or metastatic pancreatic cancer

Phase III study of iniparib plus gemcitabine and carboplatin versus gemcitabine and carboplatin in patients with metastatic triple-negative breast cancer.

Science.gov (United States)

O'Shaughnessy, Joyce; Schwartzberg, Lee; Danso, Michael A; Miller, Kathy D; Rugo, Hope S; Neubauer, Marcus; Robert, Nicholas; Hellerstedt, Beth; Saleh, Mansoor; Richards, Paul; Specht, Jennifer M; Yardley, Denise A; Carlson, Robert W; Finn, Richard S; Charpentier, Eric; Garcia-Ribas, Ignacio; Winer, Eric P

2014-12-01

There is a lack of treatments providing survival benefit for patients with metastatic triple-negative breast cancer (mTNBC), with no standard of care. A randomized phase II trial showed significant benefit for gemcitabine, carboplatin, and iniparib (GCI) over gemcitabine and carboplatin (GC) in clinical benefit rate, response rate, progression-free survival (PFS), and overall survival (OS). Here, we formally compare the efficacy of these regimens in a phase III trial. Patients with stage IV/locally recurrent TNBC who had received no more than two previous chemotherapy regimens for mTNBC were randomly allocated to gemcitabine 1,000 mg/m(2) and carboplatin area under the curve 2 (days 1 and 8) alone or GC plus iniparib 5.6 mg/kg (days 1, 4, 8, and 11) every 3 weeks. Random assignment was stratified by the number of prior chemotherapies. The coprimary end points were OS and PFS. Patients receiving GC could cross over to iniparib on progression. Five hundred nineteen patients were randomly assigned (261 GCI; 258 GC). In the primary analysis, no statistically significant difference was observed for OS (hazard ratio [HR] = 0.88; 95% CI, 0.69 to 1.12; P = .28) nor PFS (HR = 0.79; 95% CI, 0.65 to 0.98; P = .027). An exploratory analysis showed that patients in the second-/third-line had improved OS (HR = 0.65; 95% CI, 0.46 to 0.91) and PFS (HR = 0.68; 95% CI, 0.50 to 0.92) with GCI. The safety profile for GCI was similar to GC. The trial did not meet the prespecified criteria for the coprimary end points of PFS and OS in the ITT population. The potential benefit with iniparib observed in second-/third-line subgroup warrants further evaluation. © 2014 by American Society of Clinical Oncology.

A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance.

Science.gov (United States)

Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

2017-01-30

Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells. Three pancreatic cancer-cell lines were used to evaluate the antitumor effect of CG200745 combined with gemcitabine/erlotinib. CG200745 induced the expression of apoptotic proteins (PARP and caspase-3) and increased the levels of acetylated histone H3. CG200745 with gemcitabine/erlotinib showed significant growth inhibition and synergistic antitumor effects in vitro. In vivo, gemcitabine/erlotinib and CG200745 reduced tumor size up to 50%. CG200745 enhanced the sensitivity of gemcitabine-resistant pancreatic cancer cells to gemcitabine, and decreased the level of ATP-binding cassette-transporter genes, especially multidrug resistance protein 3 (MRP3) and MRP4. The novel HDAC inhibitor, CG200745, with gemcitabine/erlotinib had a synergistic anti-tumor effect on pancreatic cancer cells. CG200745 significantly improved pancreatic cancer sensitivity to gemcitabine, with a prominent antitumor effect on gemcitabine-resistant pancreatic cancer cells. Therefore, improved clinical outcome is expected in the future.

Randomized, phase III study of gemcitabine or erlotinib maintenance therapy versus observation, with predefined second-line treatment, after cisplatin-gemcitabine induction chemotherapy in advanced non-small-cell lung cancer.

Science.gov (United States)

Pérol, Maurice; Chouaid, Christos; Pérol, David; Barlési, Fabrice; Gervais, Radj; Westeel, Virginie; Crequit, Jacky; Léna, Hervé; Vergnenègre, Alain; Zalcman, Gérard; Monnet, Isabelle; Le Caer, Hervé; Fournel, Pierre; Falchero, Lionel; Poudenx, Michel; Vaylet, Fabien; Ségura-Ferlay, Céline; Devouassoux-Shisheboran, Mojgan; Taron, Miquel; Milleron, Bernard

2012-10-01

This phase III study investigated whether continuation maintenance with gemcitabine or switch maintenance with erlotinib improves clinical outcome compared with observation in patients with advanced non-small-cell lung cancer (NSCLC) whose disease was controlled after cisplatin-gemcitabine induction chemotherapy. Four hundred sixty-four patients with stage IIIB/IV NSCLC without tumor progression after four cycles of cisplatin-gemcitabine were randomly assigned to observation or to gemcitabine (1,250 mg/m(2) days 1 and 8 of a 3-week cycle) or daily erlotinib (150 mg/day) study arms. On disease progression, patients in all three arms received pemetrexed (500 mg/m(2) once every 21 days) as predefined second-line therapy. The primary end point was progression-free survival (PFS). PFS was significantly prolonged by gemcitabine (median, 3.8 v 1.9 months; hazard ratio [HR], 0.56; 95% CI, 0.44 to 0.72; log-rank P benefit was consistent across all clinical subgroups. Both maintenance strategies resulted in a nonsignificant improvement in overall survival (OS); patients who received second-line pemetrexed or with a performance status of 0 appeared to derive greater benefit. Exploratory analysis showed that magnitude of response to induction chemotherapy may affect the OS benefit as a result of gemcitabine maintenance. Maintenance gemcitabine and erlotinib were well tolerated with no unexpected adverse events. Gemcitabine continuation maintenance or erlotinib switch maintenance significantly reduces disease progression in patients with advanced NSCLC treated with cisplatin-gemcitabine as first-line chemotherapy. Response to induction chemotherapy may affect OS only for continuation maintenance.

Efficiency of radioiodine therapy with a fix dose of I-131 in toxic thyroid adenoma

International Nuclear Information System (INIS)

Petrovski, Z

2004-01-01

Purpose: The aim of this study was to estimate the results obtained using a fix dose of I-131 in the treatment of the solitary toxic thyroid adenoma. Material and Methods: We have performed radioiodine therapy m 64 patients, 49 female (50+ 1 7 yrs) and 15 male (43+-15 yrs) with solitary toxic thyroid adenoma. 45 patients received fix dose I-131 of 850 MBq, while 19 patients were treated with calculated (MBq/gr) dose 555-1100 MBq Previously 39(64%) patients were clinically hyperthyreotic and received thyreostatic meditication which were interruptecf one week before the administration of I-131. Those patients who were euthyreotic, TSH was suppressed(<0.25 MU/m1). 61(95.3%) patients received a single dose, while 3(4, 7%) patients needed two doses. Resulting thyroid matabolism and volume of nodules were evaluated 6-48 months after treatment. Results: From 45 radioiodine treated patients with fix dose 6(9, 8%) became hypothyroidism, 36(85, 3%) euthyroidism and 3(4, 9%) recurrent hyperthyroidism, in comparison with 19 treated patients with calculated I-131 dose: 2(10, 5%) hypothyroidism, 16(84, 3%) euthyroidism and 1(5, 2%) recurrent hyperthyroidism. The size of the nodules became unpalpable m 17(26, 2%), decreased evidently in 33(52, 5%) and remained unchanged in 14(21, 3%) of the treated patients. Conclusion: A fix dose of I-131 is simple, safe and efficient in the treatment of solitary toxic thyroid adenoma. There was not significant different in incidence of late follow-up results of hypothyroidism and recurrent hyperthyroidism between fix dose and calculated MBq/gr dose. (authors)

Chitosan and glyceryl monooleate nanostructures containing gemcitabine: potential delivery system for pancreatic cancer treatment.

Science.gov (United States)

Trickler, William J; Khurana, Jatin; Nagvekar, Ankita A; Dash, Alekha K

2010-03-01

The objectives of this study are to enhance cellular accumulation of gemcitabine with chitosan/glyceryl monooleate (GMO) nanostructures, and to provide significant increase in cell death of human pancreatic cancer cells in vitro. The delivery system was prepared by a multiple emulsion solvent evaporation method. The nanostructure topography, size, and surface charge were determined by atomic force microscopy (AFM), and a zetameter. The cellular accumulation, cellular internalization and cytotoxicity of the nanostructures were evaluated by HPLC, confocal microscopy, or MTT assay in Mia PaCa-2 and BxPC-3 cells. The average particle diameter for 2% and 4% (w/w) drug loaded delivery system were 382.3 +/- 28.6 nm, and 385.2 +/- 16.1 nm, respectively with a surface charge of +21.94 +/- 4.37 and +21.23 +/- 1.46 mV. The MTT cytotoxicity dose-response studies revealed the placebo at/or below 1 mg/ml has no effect on MIA PaCa-2 or BxPC-3 cells. The delivery system demonstrated a significant decrease in the IC50 (3 to 4 log unit shift) in cell survival for gemcitabine nanostructures at 72 and 96 h post-treatment when compared with a solution of gemcitabine alone. The nanostructure reported here can be resuspended in an aqueous medium that demonstrate increased effective treatment compared with gemcitabine treatment alone in an in vitro model of human pancreatic cancer. The drug delivery system demonstrates capability to entrap both hydrophilic and hydrophobic compounds to potentially provide an effective treatment option in human pancreatic cancer.

Dose rate constants for new dose quantities

International Nuclear Information System (INIS)

Tschurlovits, M.; Daverda, G.; Leitner, A.

1992-01-01

Conceptual changes and new quantities made is necessary to reassess dose rate quantities. Calculations of the dose rate constant were done for air kerma, ambient dose equivalent and directional dose equivalent. The number of radionuclides is more than 200. The threshold energy is selected as 20 keV for the dose equivalent constants. The dose rate constant for the photon equivalent dose as used mainly in German speaking countries as a temporary quantity is also included. (Author)

Gemcitabine-Based Combination Chemotherapy Followed by Radiation With Capecitabine as Adjuvant Therapy for Resected Pancreas Cancer

International Nuclear Information System (INIS)

Desai, Sameer; Ben-Josef, Edgar; Griffith, Kent A.; Simeone, Diane; Greenson, Joel K.; Francis, Isaac R.; Hampton, Janet; Colletti, Lisa; Chang, Alfred E.; Lawrence, Theodore S.; Zalupski, Mark M.

2009-01-01

Purpose: To report outcomes for patients with resected pancreas cancer treated with an adjuvant regimen consisting of gemcitabine-based combination chemotherapy followed by capecitabine and radiation. Patients and Methods: We performed a retrospective review of a series of patients treated at a single institution with a common postoperative adjuvant program. Between January 2002 and August 2006, 43 resected pancreas cancer patients were offered treatment consisting of 4, 21-day cycles of gemcitabine 1 g/m 2 intravenously over 30 min on Days 1 and 8, with either cisplatin 35 mg/m 2 intravenously on Days 1 and 8 or capecitabine 1500 mg/m 2 orally in divided doses on Days 1-14. After completion of combination chemotherapy, patients received a course of radiotherapy (54 Gy) with concurrent capecitabine (1330 mg/m 2 orally in divided doses) day 1 to treatment completion. Results: Forty-one patients were treated. Median progression-free survival for the entire group was 21.7 months (95% confidence interval 13.9-34.5 months), and median overall survival was 45.9 months. In multivariate analysis a postoperative CA 19-9 level of ≥180 U/mL predicted relapse and death. Toxicity was mild, with only two hospitalizations during adjuvant therapy. Conclusions: A postoperative adjuvant program using combination chemotherapy with gemcitabine and either cisplatin or capecitabine followed by radiotherapy with capecitabine is tolerable and efficacious and should be considered for Phase III testing in this group of patients.

A phase II trial of Cremorphor EL-free paclitaxel (Genexol-PM) and gemcitabine in patients with advanced non-small cell lung cancer.

Science.gov (United States)

Ahn, Hee Kyung; Jung, Minkyu; Sym, Sun Jin; Shin, Dong Bok; Kang, Shin Myung; Kyung, Sun Young; Park, Jeong-Woong; Jeong, Sung Hwan; Cho, Eun Kyung

2014-08-01

Genexol-PM is a Cremorphor EL (CrEL)-free polymeric micelle formulation of paclitaxel that allows higher-dose administration with less hypersensitivity. This study was designed to evaluate the efficacy and safety of Genexol-PM and gemcitabine combination in advanced non-small cell lung cancer patients as a first-line treatment. This is a prospective, single-arm, single-center phase II study. Patients with advanced NSCLC received Genexol-PM at 230 mg/m(2) on day 1 and gemcitabine 1,000 mg/m(2) on day 1 and day 8 of a 3-week cycle. Six cycles of chemotherapy were planned unless there was disease progression. The primary endpoint was overall response rate. Forty-three patients received the study drugs with a median of 4 cycles per patient (range 1-6). The overall response rate was 46.5%. The median progression-free survival was 4.0 months (95% CI 2.0-6.0 months), and median overall survival was 14.8 months (95% CI 9.1-20.5 months). The most common toxicities were anemia (n = 29, 67%), asthenia (n = 17, 40%), myalgia (n = 16, 37%), peripheral neuropathy (n = 15, 35 %), and diarrhea (n = 12, 30%). The most common grade 3/4 adverse events were neutropenia (n = 7, 16%) and pneumonia (n = 5, 12%). Two patients died of pneumonia and dyspnea. CrEL-free paclitaxel in combination with gemcitabine demonstrated favorable antitumor activity with little emetogenicities in non-small cell lung cancer patients. However, frequent grade 3/4 toxicities were observed, and safety should be evaluated thoroughly in future studies.

Fixed Dose Combination for TB treatment

Directory of Open Access Journals (Sweden)

Tjandra Y. Aditama

2003-06-01

Full Text Available According to the World Health Organization, a third of the world’s population is infected with tuberculosis. The disease is responsible for nearly 2 million deaths each year and over 8 million were developing active diseases. Moreover, according to WHO (2000, tuberculosis deaths are estimated to increase to 35 million between 2000-2020. The majority of tuberculosis patients worldwide are still treated with single drugs, or with 2-drug fixed-dose combinations (FDCs. To improve tuberculosis treatment, 2- and 3-drug FDCs were recommended by the World Health Organization (WHO as part of the DOTS strategy. Since 1999 a 4-drug FDC was included on the WHO Model List of Essential Drugs. Today, FDCs are important tools to further improve the quality of care for people with TB, and accelerate DOTS expansion to reach the global TB control targets. Fixed dose combination TB drugs could simplifies both treatment and management of drug supply, and may prevent the emergence of drug resistance .Prevention of drug resistance is just one of the potential benefits of the use of FDCs. FDCs simplify administration of drugs by reducing the number of pills a patient takes each day and decreasing the risk of incorrect prescriptions. Most tuberculosis patients need only take 3–4 FDCs tablets per day during the intensive phase of treatment, instead of the 15–16 tablets per day that is common with single-drug formulations It is much simpler to explain to patients that they need to take four tablets of the same type and colour, rather than a mixture of tablets of different shapes, colours and sizes. Also, the chance of taking an incomplete combination of drugs is eliminated, since the four essential drugs are combined into one tablet. FDCs are also simpler for care-givers as they minimize the risk of confusion. Finally, drug procurement, in all its components (stock management, shipping, distribution, is simplified by FDCs. Adverse reactions to drugs are not more

Concurrent chemoradiotherapy with gemcitabine and cisplatin for pancreatic cancer: from the laboratory to the clinic

International Nuclear Information System (INIS)

Symon, Zvi; Davis, Mary; McGinn, Cornelius J.; Zalupski, Mark M.; Lawrence, Theodore S.

2002-01-01

Purpose: We have reported that gemcitabine and concurrent radiation is a promising therapy for patients with pancreatic cancer. We investigated whether the addition of cisplatin, which may increase the systemic efficacy of gemcitabine, would be synergistic with gemcitabine and/or radiation in human pancreatic cancer cell lines. Methods and Materials: BxPc3 and Panc-1 human pancreatic cancer cells were treated with three different schedules before radiation: (A) a sequential incubation of gemcitabine for 2 h followed by cisplatin for 2 h, (B) gemcitabine for 2 h, followed by washout of drug, replenishment of media for a 24-h incubation, followed by cisplatin for 2 h, and (C) gemcitabine for 24 h with a concurrent incubation of cisplatin for the last 2 h. Cells were assessed for clonogenic survival using a standard assay. Synergism was evaluated by the median effect analysis. Results: The schedule shown to be maximally synergistic for both cell lines was the consecutive 2-h gemcitabine, 2-h cisplatin exposure, particularly at surviving fractions of <0.5. Cisplatin did not produce radiosensitization nor did it affect gemcitabine-mediated radiosensitization. Conclusion: Cisplatin produces synergistic cytotoxicity with gemcitabine without compromising gemcitabine-mediated radiosensitization. On the basis of these laboratory and previous clinical observations, we have initiated a Phase I trial of cisplatin plus gemcitabine and radiotherapy in patients with unresectable pancreatic cancer

Concurrent chemoradiotherapy with gemcitabine plus regional hyperthermia for locally advanced pancreatic carcinoma. Initial experience

International Nuclear Information System (INIS)

Ohguri, Takayuki; Imada, Hajime; Yahara, Katsuya; Morioka, Tomoaki; Nakano, Keita; Korogi, Yukunori; Narisada, Hiroyuki

2008-01-01

The aim of this study was to evaluate the efficacy and toxicity of concurrent chemoradiotherapy (CRT) with gemcitabine plus regional hyperthermia (HT) for locally advanced pancreatic carcinoma (LAPC). A total of 29 patients with LAPC treated with concurrent CRT using gemcitabine were retrospectively analyzed. Radiotherapy was administered with a median total dose of 61.2 Gy. Of the 29 patients, 20 (69%) also underwent regional HT during CRT (CRHT group). The remaining 9 patients did not receive regional HT (CRT group) because of a common bile duct stent placement, patient refusal, older age, or obesity. The efficacy and toxicity of the treatments and the predictors of good outcome were evaluated. The median disease progression-free and overall survival times were significantly better for the CRHT group than for the CRT group (8.8 vs. 4.9 months, P=0.02, and 18.6 vs. 9.6 months, P=0.01), respectively. Grade 3-4 hematological toxicities for the CRHT group were detected in eight patients (40%) and grade 3 nonhematologic toxicity in one (diarrhea). Concurrent CRT using gemcitabine with regional HT may be a feasible and promising regimen for LAPC, and the results justified further evaluation in a large number of patients to confirm its definite benefit. (author)

Comparison of fixed low dose versus high dose radioactive iodine for the treatment of hyperthyroidism: retrospective multifactorial analysis impacting the outcome of therapy

International Nuclear Information System (INIS)

Suresh Kumar, A.C.; Malhotra, G.; Basu, S.; Asopa, R.V.

2010-01-01

Full text: Radioactive iodine ( 131 I) as a fixed dose protocol is widely used for treatment of hyperthyroidism. However, there is no consensus on the best optimum dose for an individual patient. The objectives of this study were to observe the outcome of 131 I therapy in patients of primary hyperthyroidism in relation to fixed low dose versus high dose regimen, impact of antithyroid drugs and influence of thyroid gland size on therapy outcome. Materials and Methods: Study design: Retrospective analysis. Study group included 287 diagnosed patients of primary hyperthyroidism who had undergone 131 I therapy for the first time (68 M, 219 F; Mean age ± S.D.: 43.84 ± 12.53). All patients with low RAIU, thyrocardiac disease were excluded. Details of antithyroid (ATD) drug treatment were recorded. Analysis was done from 2002 till patients became euthyroid/hypothyroid or until January 2010. Each patient's response was evaluated initially at 6 weeks and thereafter every three months. Appropriate statistical tests were applied to compare treatment response between the groups. A P value<0.05 was considered significant. Results: Of 287 patients, 209 patients had been administered low dose (Mean ± S.D.: 4.68 ± 0.62 mCi) while 78 patients had received high dose (Mean ± S.D.: 9.15 ± 1.05 mCi) of radioiodine. 57.9% (121/ 209) patients in the low dose group responded as compared to 75.6% (59/78) in high dose group after a follow up of more than 36 months. Similarly, among patients with and without antithyroid drug treatment, grade II and above goiters the response rates were significantly higher for high dose group as compared to low dose group. Conclusion: We suggest that high dose radioiodine treatment with 8 to 10 mCi is effective in treating hyperthyroidism in patients with a better success rate than the low dose treatment with 3 to 5 mCi. This is also likely to be helpful in patients who have not received antithyroid drugs. It appears that clinically relevant

Safety and pharmacokinetics of motesanib in combination with gemcitabine and erlotinib for the treatment of solid tumors: a phase 1b study

Directory of Open Access Journals (Sweden)

Sun Yu-Nien

2011-07-01

Full Text Available Abstract Background This phase 1b study assessed the maximum tolerated dose (MTD, safety, and pharmacokinetics of motesanib (a small-molecule antagonist of VEGF receptors 1, 2, and 3; platelet-derived growth factor receptor; and Kit administered once daily (QD or twice daily (BID in combination with erlotinib and gemcitabine in patients with solid tumors. Methods Patients received weekly intravenous gemcitabine (1000 mg/m2 and erlotinib (100 mg QD alone (control cohort or in combination with motesanib (50 mg QD, 75 mg BID, 125 mg QD, or 100 mg QD; cohorts 1-4; or erlotinib (150 mg QD in combination with motesanib (100 or 125 mg QD; cohorts 5 and 6. Results Fifty-six patients were enrolled and received protocol-specified treatment. Dose-limiting toxicities occurred in 11 patients in cohorts 1 (n = 2, 2 (n = 4, 3 (n = 3, and 6 (n = 2. The MTD of motesanib in combination with gemcitabine and erlotinib was 100 mg QD. Motesanib 125 mg QD was tolerable only in combination with erlotinib alone. Frequently occurring motesanib-related adverse events included diarrhea (n = 19, nausea (n = 18, vomiting (n = 13, and fatigue (n = 12, which were mostly of worst grade Conclusions Treatment with motesanib 100 mg QD plus erlotinib and gemcitabine was tolerable. Motesanib 125 mg QD was tolerable only in combination with erlotinib alone. Trial Registration ClinicalTrials.gov NCT01235416

Total effective dose equivalent associated with fixed uranium surface contamination

International Nuclear Information System (INIS)

Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

1997-04-01

This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm 2 and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels

A prospective randomized study of gemcitabine with doxifluridine versus paclitaxel with doxifluridine in concurrent chemoradiotherapy for locally advanced pancreatic cancer

International Nuclear Information System (INIS)

Chung, Hye Won; Bang, Seung Min; Park, Seung Woo; Chung, Jae Bock; Kang, Jin Kyung; Kim, Ju Won; Seong, Jin Sil; Lee, Woo Jung; Song, Si Young

2004-01-01

Purpose: The objective of this study was to compare the efficacy and toxicity of gemcitabine-based concurrent chemoradiotherapy (CCRT) with paclitaxel-based CCRT in patients with locally advanced pancreatic cancer. Methods and materials: A total of 48 patients who had received no prior therapy were enrolled. The patients were treated with 4500 cGy radiation in 25 fractions over 5 weeks concomitant with gemcitabine 1000 mg/m 2 /week/intravenously (IV) and doxifluridine 600 mg/m 2 /day/by mouth (PO), or paclitaxel 50 mg/m 2 /week/IV and doxifluridine 600 mg/m 2 /day/PO. After a 4-week rest, the responses were evaluated and maintenance therapies (operation or chemotherapy) (gemcitabine 1000 mg/m 2 /week/IV and doxifluridine 600 mg/m 2 /day/PO) were conducted. Results: The median survival was 12 months in the gemcitabine group vs. 14 months in the paclitaxel group. The response rate was 13.6% vs. 25%, and the median time to progression was 12 months vs. 12.5 months, respectively. The positive rate of the clinical benefit response was 59.1% vs. 41.7%, respectively. Toxicities were acceptable in both groups. Conclusion: In this trial, we demonstrated that the gemcitabine-based CCRT and the paclitaxel-based CCRT in combination of doxifluridine are clearly acceptable treatment strategy, and appear more effective than the 5 fluorouracil-based CCRT for locally advanced pancreatic cancer with comparable tolerability. Furthermore, the paclitaxel-based CCRT showed similar efficacy and toxicities to the gemcitabine-based treatment when it was combined with 5-fluorouracil

Toxicoderma by gemcitabine: About a case

Directory of Open Access Journals (Sweden)

Flora López-López

2018-02-01

Full Text Available Skin reactions are often related with drugs, particularly with chemotherapy. Several types of cutaneous involvement have been described from pruritus alone to generalized eruptions not always but generally related with hypersensitivity or inflammatory reactions that usually are independent of primary tumor location. Gemcitabine is a widely used chemotherapy drug that may typically produce a mild skin rash. Herein, we show a case of uncommon and severe direct skin toxicity because of gemcitabine in context of thrombocytopenia. We have also performed a review of the literature showing that this may be the first case of such toxicity.

Circular RNA Signature Predicts Gemcitabine Resistance of Pancreatic Ductal Adenocarcinoma

Directory of Open Access Journals (Sweden)

Feng Shao

2018-06-01

Full Text Available Gemcitabine resistance is currently the main problem of chemotherapy for advanced pancreatic cancer patients. The resistance is thought to be caused by altered drug metabolism or reduced apoptosis of cancer cells. However, the underlying mechanism of Gemcitabine resistance in pancreatic cancer remains unclear. In this study, we established Gemcitabine resistant PANC-1 (PANC-1-GR cell lines and compared the circular RNAs (circRNAs profiles between PANC-1 cells and PANC-1-GR cells by RNA sequencing. Differentially expressed circRNAs were demonstrated using scatter plot and cluster heatmap analysis. Gene ontology and pathway analysis were performed to systemically map the genes which are functionally associated to those differentially expressed circRNAs identified from our data. The expression of the differentially expressed circRNAs picked up by RNAseq in PANC-1-GR cells was further validated by qRT-PCR and two circRNAs were eventually identified as the most distinct targets. Consistently, by analyzing plasma samples form pancreatic ductal adenocarcinoma (PDAC patients, the two circRNAs showed more significant expression in the Gemcitabine non-responsive patients than the responsive ones. In addition, we found that silencing of the two circRNAs could restore the sensitivity of PANC-1-GR cells to Gemcitabine treatment, while over-expression of them could increase the resistance of normal PANC-1 and MIA PACA-2 cells, suggesting that they might serve as drug targets for Gemcitabine resistance. Furthermore, the miRNA interaction networks were also explored based on the correlation analysis of the target microRNAs of these two circRNAs. In conclusion, we successfully established new PANC-1-GR cells, systemically characterized the circRNA and miRNA profiles, and identified two circRNAs as novel biomarkers and potential therapeutic targets for Gemcitabine non-responsive PDAC patients.

Phase II study of neoadjuvant gemcitabine, pegylated liposomal doxorubicin, and docetaxel in locally advanced breast cancer.

Science.gov (United States)

Artioli, Grazia; Grazia, Artioli; Mocellin, Simone; Simone, Mocellin; Borgato, Lucia; Lucia, Borgato; Cappetta, Alessandro; Alessandro, Cappetta; Bozza, Fernando; Fernando, Bozza; Zavagno, Giorgio; Giorgio, Zavagno; Zovato, Stefania; Stefania, Zovato; Marchet, Alberto; Alberto, Marchet; Pastorelli, Davide; Davide, Pastorelli

2010-09-01

This was a phase II study to assess the activity of a novel neoadjuvant regimen in locally-advanced breast cancer. Fifty patients with histological confirmation of locally advanced breast cancer received treatment with gemcitabine 1000 mg/m(2) (day 1) followed by gemcitabine 800 mg/m(2) plus docetaxel 75 mg/m(2) plus pegylated liposomal doxorubicin (PLD) 30 mg/m(2) (day 8) every 3 weeks for at least 4 cycles, plus a final 2 additional cycles. Tumour size was T1 (n=2), T2 (n=32), T3 (n=14), T4 (n=2). All 50 patients underwent surgery. Clinical complete, partial and no response were observed in 13 (26%), 24 (48%) and 11 (22%) patients, respectively (overall response rate: 74%). The number of chemotherapy cycles was found to be an independent predictor of a pathologic complete response. The combination of gemcitabine-docetaxel-PLD can yield high tumour response rates in patients with locally-advanced breast cancer who undergo a full treatment of 6 cycles.

Phase I/II study on docetaxel, gemcitabine and prednisone in castrate refractory metastatic prostate cancer

DEFF Research Database (Denmark)

Buch-Hansen, Trine Zeeberg; Bentzen, Lise Nørgaard; Hansen, Steinbjoern

2010-01-01

DGP, maximum of eight courses, until progression or unacceptable toxicity. Docetaxel 75 mg/m(2) was administered intravenously day 1, gemcitabine was given day 1 and 8 in doses increasing from 600 to 1,000 mg/m(2) every third week. Patients had castrate refractory metastatic prostate cancer (CRMPC......), adequate function of liver, kidney and bone marrow; ECOG performance status...

31 CFR 359.10 - What is the fixed rate of return?

Science.gov (United States)

2010-07-01

.... The composite rate is composed of both the fixed rate and a semiannual inflation rate, which could... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What is the fixed rate of return? 359... BONDS, SERIES I General Information § 359.10 What is the fixed rate of return? The Secretary, or the...

Dose rate correction in medium dose rate brachytherapy for carcinoma cervix

International Nuclear Information System (INIS)

Patel, F.D.; Negi, P.S.; Sharma, S.C.; Kapoor, R.; Singh, D.P.; Ghoshal, S.

1998-01-01

Purpose: To establish the magnitude of brachytherapy dose reduction required for stage IIB and III carcinoma cervix patients treated by external radiation and medium dose rate (MDR) brachytherapy at a dose rate of 220±10 cGy/h at point A.Materials and methods: In study-I, at the time of MDR brachytherapy application at a dose rate of 220±10 cGy/h at point A, patients received either 3060 cGy, a 12.5% dose reduction (MDR-12.5), or 2450 cGy, a 30% dose reduction (MDR-30), to point A and they were compared to a group of previously treated LDR patients who received 3500 cGy to point A at a dose rate of 55-65 cGy/h. Study-II was a prospective randomized trial and patients received either 2450 cGy, a 30% dose reduction (MDR-II (30)) or 2800 cGy, a 20% dose reduction (MDR-II (20)), at point A. Patients were evaluated for local control of disease and morbidity. Results: In study-I the 5-year actuarial local control rate in the MDR-30 and MDR-12.5 groups was 71.7±10% and 70.5±10%, respectively, compared to 63.4±10% in the LDR group. However, the actuarial morbidity (all grades) in the MDR-12.5 group was 58.5±14% as against 34.9±9% in the LDR group (P 3 developed complication as against 62.5% of those receiving a rectal BED of (140 3 (χ 2 =46.43; P<0.001). Conclusion: We suggest that at a dose rate of 220±10 cGy/h at point A the brachytherapy dose reduction factor should be around 30%, as suggested by radiobiological data, to keep the morbidity as low as possible without compromising the local control rates. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

nab-Paclitaxel plus gemcitabine for metastatic pancreatic cancer: a subgroup analysis of the Western European cohort of the MPACT trial

Directory of Open Access Journals (Sweden)

Tabernero J

2017-02-01

Full Text Available Josep Tabernero,1 Volker Kunzmann,2 Werner Scheithauer,3 Michele Reni,4 Jack Shiansong Li,5 Stefano Ferrara,6 Kamel Djazouli7 1Medical Oncology Department, Vall d’Hebron University Hospital, Barcelona, Spain; 2Medizinische Klinik und Poliklinik II, University of Würzburg, Würzburg, Germany; 3Medizinische Universität Wien, Wien, Austria; 4San Raffaele Scientific Institute, Milan, Italy; 5Celgene Corporation, Summit, NJ, USA; 6Celgene Corporation, Boudry, Switzerland; 7Celgene Corporation, Paris, France Purpose: The global Phase III MPACT trial demonstrated superior efficacy of nab-paclitaxel plus gemcitabine over gemcitabine alone as first-line treatment for metastatic pancreatic cancer. Region was a randomization stratification factor in the MPACT trial. This subgroup analysis of MPACT examined efficacy and safety of patients treated in Western Europe.Patients and methods: Patients received nab-paclitaxel plus gemcitabine or gemcitabine alone as first-line treatment for metastatic pancreatic cancer as previously described. A total of 76 patients were included in this analysis (n=38 for each arm.Results: Differences between the overall Western European cohort and the intention-to-treat population included lower percentages of male patients (46% and 58%, respectively and patients with biliary stents (8% and 17%, and higher percentages of patients with Karnofsky performance status of 90–100 (78% and 60% and primary tumors in the body of the pancreas (48% and 31%. The median overall survival was 10.7 months with nab-paclitaxel plus gemcitabine vs 6.9 months with gemcitabine alone (hazard ratio [HR]: 0.82 [95% confidence interval (CI: 0.48–1.40]; P=0.471. Median progression-free survival was 5.3 vs 3.7 months, respectively (HR: 0.70 [95% CI: 0.37–1.33]; P=0.277. The independently assessed overall response rate was 18% vs 5% (response rate ratio, 3.50 [95% CI: 0.78–15.78]; P=0.076. The most common grade ≥3 adverse events with nab

Radioiodine treatment for complicated hyperthyroidism using a fixed dose regime

International Nuclear Information System (INIS)

Paul, A.K.; Rahman, S.H.; Ansari, S.M.

2005-01-01

Full text: Hyperthyroidism in the elderly and all those with cardiovascular and psychiatric problem has increased mortality and morbidity rate. These patients need special care to cure the disease promptly and permanently for avoidance of complications. Radioactive I-131 is one of the accepted forms of treatment for hyperthyroidism and increasingly being considered for the patients in whom rapid and permanent control of disease is desirable. To evaluate the success of I-131 to cure disease in-patients with complicated hyperthyroidism, we prospectively studied the outcome of radioiodine therapy using a fixed dose regime. Ninety-three patients with toxic diffuse goitre (65 female, 28 male) age ranging from 29-67 years (mean ? SD 41.35 ? 11.02 years) were evaluated. The subjects included 71 cases with cardiovascular problem, 13 elderly patients, 5 with poor drug compliance and 4 with associated psychiatric disease. The individual was excluded from the study who had autonomous toxic nodule. Every patient was pre-treated with antithyroid drugs for 4 weeks and the drug was discontinued for 3 days before administering I-131. No patients had post-treatment antithyroid drugs. All the patients were treated with a fixed oral dose of 15 mCi I-131 sodium iodide. Post-treatment follow-up examinations were done at 6 weeks without biochemical tests, at 3 months, 6 months, 9 months and 1 year and then annually with biochemical tests. Patients were classified as cured if the biochemical status was either euthyroid or hypothyroid at one year without further treatment by antithyroid drugs or radioiodine. Of the 93 cases, 82 patients became euthyroid or hypothyroid requiring no further treatment for hyperthyroidism with an overall cure of 88.17%. Hypothyroidism was developed in 49 (52.69%) patients at one year of whom 39 became hypothyroid within 6 months and another 10 patients within 1 year. 4 patients were subclinical hyperthyroid at 6 months and still hyperthyroid at 9 months. 7

Quantitative analysis of biological responses to low dose-rate γ-radiation, including dose, irradiation time, and dose-rate

International Nuclear Information System (INIS)

Magae, J.; Furukawa, C.; Kawakami, Y.; Hoshi, Y.; Ogata, H.

2003-01-01

Full text: Because biological responses to radiation are complex processes dependent on irradiation time as well as total dose, it is necessary to include dose, dose-rate and irradiation time simultaneously to predict the risk of low dose-rate irradiation. In this study, we analyzed quantitative relationship among dose, irradiation time and dose-rate, using chromosomal breakage and proliferation inhibition of human cells. For evaluation of chromosome breakage we assessed micronuclei induced by radiation. U2OS cells, a human osteosarcoma cell line, were exposed to gamma-ray in irradiation room bearing 50,000 Ci 60 Co. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, cytoplasm and nucleus were stained with DAPI and propidium iodide, and the number of binuclear cells bearing micronuclei was determined by fluorescent microscopy. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [3H] thymidine was pulsed for 4 h before harvesting. Dose-rate in the irradiation room was measured with photoluminescence dosimeter. While irradiation time less than 24 h did not affect dose-response curves for both biological responses, they were remarkably attenuated as exposure time increased to more than 7 days. These biological responses were dependent on dose-rate rather than dose when cells were irradiated for 30 days. Moreover, percentage of micronucleus-forming cells cultured continuously for more than 60 days at the constant dose-rate, was gradually decreased in spite of the total dose accumulation. These results suggest that biological responses at low dose-rate, are remarkably affected by exposure time, that they are dependent on dose-rate rather than total dose in the case of long-term irradiation, and that cells are getting resistant to radiation after the continuous irradiation for 2 months. It is necessary to include effect of irradiation time and dose-rate sufficiently to evaluate risk

Safety and efficacy of fixed-dose 10 mg daily isotretinoin treatment for acne vulgaris in Malaysia.

Science.gov (United States)

Yap, Felix Boon-Bin

2017-09-01

Low-dose isotretinoin is used to reduce side effects albeit higher relapse. This study aimed to determine the efficacy and safety of fixed-dose 10 mg daily isotretinoin for the treatment of acne. This prospective study was performed between 2011 and 2015. All 150 patients were given 10 mg daily isotretinoin until a cumulative dose of 90-110 mg/kg. The mean age was 26.6 years with 64.7% moderate acne, 29.3% severe, and 6% very severe. The mean cumulative dose was 98.8 ± 6.05 mg/kg. All 150 patients had total clearance with a mean time to clearance of 24.0 weeks. Patients with severe/very severe acne had higher cumulative dosage (102.1 vs. 97.0, P < 0.001) and longer duration to clearance (32.9 weeks vs. 19.1 weeks, P < 0.001). Mild relapse was seen in 4%. The mean time to relapse was 32.3 weeks. Lip dryness was the commonest side effects (100%). Mild transient elevation of liver enzymes was detected in 3.3% and a slight increase of serum lipid in 2.7% with no treatment discontinuation. Fixed-dose 10 mg daily treatment with isotretinoin until a cumulative dose of 90-110 mg/kg is safe with low relapse rate. © 2016 Wiley Periodicals, Inc.

Modulation of the ribonucleotide reductase M1-gemcitabine interaction in vivo by N-ethylmaleimide

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhengming; Zhou, Jun; Zhang, Yingtao [Developmental Therapeutics Program, Karmanos Cancer Institute, Detroit, MI (United States); Bepler, Gerold, E-mail: beplerg@karmanos.org [Developmental Therapeutics Program, Karmanos Cancer Institute, Detroit, MI (United States)

2011-09-23

Highlights: {yields} Gemcitabine induces a RRM1 conformational change in tumor cell lines and xenografts. {yields} The 110 kDa RRM1 is unique to gemcitabine interaction among 12 cytotoxic agents. {yields} The 110 kDa RRM1 can be stabilized by the thiol alkylator N-ethylmaleimide. {yields} C218A, C429A, and E431A mutations in RRM1 abolished the conformational change. {yields} The 110 kDa RRM1 may be a specific biomarker of gemcitabine's therapeutic efficacy. -- Abstract: Ribonucleotide reductase M1 (RRM1) is the regulatory subunit of the holoenzyme that catalyzes the conversion of ribonucleotides to 2'-deoxyribonucleotides. Its function is indispensible in cell proliferation and DNA repair. It also serves as a biomarker of therapeutic efficacy of the antimetabolite drug gemcitabine (2',2'-difluoro-2'-deoxycytidine) in various malignancies. However, a mechanistic explanation remains to be determined. This study investigated how the alkylating agent N-ethylmaleimide (NEM) interacts with the inhibitory activity of gemcitabine on its target protein RRM1 in vivo. We found, when cells were treated with gemcitabine in the presence of NEM, a novel 110 kDa band, along with the 90 kDa native RRM1 band, appeared in immunoblots. This 110 kDa band was identified as RRM1 by mass spectrometry (LC-MS/MS) and represented a conformational change resulting from covalent labeling by gemcitabine. It is specific to gemcitabine/NEM, among 11 other chemotherapy drugs tested. It was also detectable in human tumor xenografts in mice treated with gemcitabine. Among mutations of seven residues essential for RRM1 function, C218A, C429A, and E431A abolished the conformational change, while N427A, C787A, and C790A diminished it. C444A was unique since it was able to alter the conformation even in absence of gemcitabine treatment. We conclude that the thiol alkylator NEM can stabilize the gemcitabine-induced conformational change of RRM1, and this stabilized RRM1

Modulation of the ribonucleotide reductase M1-gemcitabine interaction in vivo by N-ethylmaleimide

International Nuclear Information System (INIS)

Chen, Zhengming; Zhou, Jun; Zhang, Yingtao; Bepler, Gerold

2011-01-01

Highlights: → Gemcitabine induces a RRM1 conformational change in tumor cell lines and xenografts. → The 110 kDa RRM1 is unique to gemcitabine interaction among 12 cytotoxic agents. → The 110 kDa RRM1 can be stabilized by the thiol alkylator N-ethylmaleimide. → C218A, C429A, and E431A mutations in RRM1 abolished the conformational change. → The 110 kDa RRM1 may be a specific biomarker of gemcitabine's therapeutic efficacy. -- Abstract: Ribonucleotide reductase M1 (RRM1) is the regulatory subunit of the holoenzyme that catalyzes the conversion of ribonucleotides to 2'-deoxyribonucleotides. Its function is indispensible in cell proliferation and DNA repair. It also serves as a biomarker of therapeutic efficacy of the antimetabolite drug gemcitabine (2',2'-difluoro-2'-deoxycytidine) in various malignancies. However, a mechanistic explanation remains to be determined. This study investigated how the alkylating agent N-ethylmaleimide (NEM) interacts with the inhibitory activity of gemcitabine on its target protein RRM1 in vivo. We found, when cells were treated with gemcitabine in the presence of NEM, a novel 110 kDa band, along with the 90 kDa native RRM1 band, appeared in immunoblots. This 110 kDa band was identified as RRM1 by mass spectrometry (LC-MS/MS) and represented a conformational change resulting from covalent labeling by gemcitabine. It is specific to gemcitabine/NEM, among 11 other chemotherapy drugs tested. It was also detectable in human tumor xenografts in mice treated with gemcitabine. Among mutations of seven residues essential for RRM1 function, C218A, C429A, and E431A abolished the conformational change, while N427A, C787A, and C790A diminished it. C444A was unique since it was able to alter the conformation even in absence of gemcitabine treatment. We conclude that the thiol alkylator NEM can stabilize the gemcitabine-induced conformational change of RRM1, and this stabilized RRM1 conformation has the potential to serve as a specific

Targeting the Warburg effect with a novel glucose transporter inhibitor to overcome gemcitabine resistance in pancreatic cancer cells

Science.gov (United States)

Lai, I-Lu; Chou, Chih-Chien; Lai, Po-Ting; Fang, Chun-Sheng; Shirley, Lawrence A.; Yan, Ribai; Mo, Xiaokui; Bloomston, Mark; Kulp, Samuel K.; Bekaii-Saab, Tanios; Chen, Ching-Shih

2014-01-01

Gemcitabine resistance remains a significant clinical challenge. Here, we used a novel glucose transporter (Glut) inhibitor, CG-5, as a proof-of-concept compound to investigate the therapeutic utility of targeting the Warburg effect to overcome gemcitabine resistance in pancreatic cancer. The effects of gemcitabine and/or CG-5 on viability, survival, glucose uptake and DNA damage were evaluated in gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cell lines. Mechanistic studies were conducted to determine the molecular basis of gemcitabine resistance and the mechanism of CG-5-induced sensitization to gemcitabine. The effects of CG-5 on gemcitabine sensitivity were investigated in a xenograft tumor model of gemcitabine-resistant pancreatic cancer. In contrast to gemcitabine-sensitive pancreatic cancer cells, the resistant Panc-1 and Panc-1GemR cells responded to gemcitabine by increasing the expression of ribonucleotide reductase M2 catalytic subunit (RRM2) through E2F1-mediated transcriptional activation. Acting as a pan-Glut inhibitor, CG-5 abrogated this gemcitabine-induced upregulation of RRM2 through decreased E2F1 expression, thereby enhancing gemcitabine-induced DNA damage and inhibition of cell survival. This CG-5-induced inhibition of E2F1 expression was mediated by the induction of a previously unreported E2F1-targeted microRNA, miR-520f. The addition of oral CG-5 to gemcitabine therapy caused greater suppression of Panc-1GemR xenograft tumor growth in vivo than either drug alone. Glut inhibition may be an effective strategy to enhance gemcitabine activity for the treatment of pancreatic cancer. PMID:24879635

Comparison of Measured and Estimated CT Organ Doses for Modulated and Fixed Tube Current:: A Human Cadaver Study.

Science.gov (United States)

Padole, Atul; Deedar Ali Khawaja, Ranish; Otrakji, Alexi; Zhang, Da; Liu, Bob; Xu, X George; Kalra, Mannudeep K

2016-05-01

The aim of this study was to compare the directly measured and the estimated computed tomography (CT) organ doses obtained from commercial radiation dose-tracking (RDT) software for CT performed with modulated tube current or automatic exposure control (AEC) technique and fixed tube current (mAs). With the institutional review board (IRB) approval, the ionization chambers were surgically implanted in a human cadaver (88 years old, male, 68 kg) in six locations such as liver, stomach, colon, left kidney, small intestine, and urinary bladder. The cadaver was scanned with routine abdomen pelvis protocol on a 128-slice, dual-source multidetector computed tomography (MDCT) scanner using both AEC and fixed mAs. The effective and quality reference mAs of 100, 200, and 300 were used for AEC and fixed mAs, respectively. Scanning was repeated three times for each setting, and measured and estimated organ doses (from RDT software) were recorded (N = 3*3*2 = 18). Mean CTDIvol for AEC and fixed mAs were 4, 8, 13 mGy and 7, 14, 21 mGy, respectively. The most estimated organ doses were significantly greater (P < 0.01) than the measured organ doses for both AEC and fixed mAs. At AEC, the mean estimated organ doses (for six organs) were 14.7 mGy compared to mean measured organ doses of 12.3 mGy. Similarly, at fixed mAs, the mean estimated organ doses (for six organs) were 24 mGy compared to measured organ doses of 22.3 mGy. The differences among the measured and estimated organ doses were higher for AEC technique compared to the fixed mAs for most organs (P < 0.01). The most CT organ doses estimated from RDT software are greater compared to directly measured organ doses, particularly when AEC technique is used for CT scanning. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance

OpenAIRE

Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

2017-01-01

Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resis...

Phase I evaluation of intravenous ascorbic acid in combination with gemcitabine and erlotinib in patients with metastatic pancreatic cancer.

Directory of Open Access Journals (Sweden)

Daniel A Monti

Full Text Available Preclinical data support further investigation of ascorbic acid in pancreatic cancer. There are currently insufficient safety data in human subjects, particularly when ascorbic acid is combined with chemotherapy.14 subjects with metastatic stage IV pancreatic cancer were recruited to receive an eight week cycle of intravenous ascorbic acid (three infusions per week, using a dose escalation design, along with standard treatment of gemcitabine and erlotinib. Of 14 recruited subjects enrolled, nine completed the study (three in each dosage tier. There were fifteen non-serious adverse events and eight serious adverse events, all likely related to progression of disease or treatment with gemcitabine or erlotinib. Applying RECIST 1.0 criteria, seven of the nine subjects had stable disease while the other two had progressive disease.These initial safety data do not reveal increased toxicity with the addition of ascorbic acid to gemcitabine and erlotinib in pancreatic cancer patients. This, combined with the observed response to treatment, suggests the need for a phase II study of longer duration.Clinicaltrials.gov NCT00954525.

Comparative evaluation of the two fixed dose methods of radioiodine therapy (185 MBq and 370 MBq) for the treatment of Graves' disease

International Nuclear Information System (INIS)

Esfahani, A.F.; Fallahi, B.; Kakhki, V.R.D.; Eftekhari, M.; Beiki, D.; Saghari, M.

2005-01-01

Full text: Radioiodine therapy is the safest, simplest, least expensive and most effective method for treatment of Graves' disease. But optimal method for determining iodine-131 treatment doses for Graves' hyperthyroidism is unknown, and techniques have varied from a fixed dose to more elaborate calculations based upon gland size, iodine uptake, and iodine turnover. Due to difficulties in previous methods for dose determination, fixed dose method of I-131 is now considered the best practical method for I-131 therapy in Graves' disease, but there is no consensus on the dose. We compared two routinely recommended fixed doses of 185 and 370 MBq for this purpose. Methods and Materials: Patients with Graves' hyperthyroidism (n = 59) who had not been previously treated with radioactive iodine were randomized in two groups of 185 MBq (5 Ci) and 370 MBq (10 mCi). l patients were followed for two years, with 6-month intervals for following clinical outcomes: hyperthyroid requiring further radioiodine, and hypothyroid requiring life-long replacement therapy. Euthyroid and hypothyroid states were considered successful therapy (cure) and hyperthyroid state was considered failure (no response or relapse). Results: Totally, among 59 patients treated with I-131, 20 (33.9%) patients became euthyroid and 19(32.2%) became hypothyroid, while failed therapy was noticed in 20 patients (33.9%). In the group treated by 185 MBq (33 patients), 10(30.3%) were euthyroid, 6(18.2%) were hypothyroid (overall cure rate of 48.5%), while 17(51.5%) remained hyperthyroid by the end of the follow-up period. From the 26 patients treated with 370 MBq, the euthyroid and hypothyroid states were observed in 10(38.5%) and 13(50%) patients, respectively (overall cure rate of 88.5%), and hyperthyroid state in 3(11.5%). No relationship was noted between the outcome and age, sex, size of the thyroid gland and thyroid uptake, but the relationship between the disease outcome and the amount of administered

Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

International Nuclear Information System (INIS)

Turesson, I.

1990-01-01

The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

Phase II study of gemcitabine plus cisplatin chemotherapy combined with intensity modulated radiotherapy in locoregionally advanced nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Ou Dan; He Xiayun; Hu Chaosu; Ying Hongmei; Zhu Guopei

2012-01-01

Objective: To evaluate the efficacy and toxicity of gemcitabine plus cisplatin (GP) chemotherapy combined with intensity-modulated radiation therapy (IMRT) in locoregionally advanced nasopharyngeal carcinoma (NPC). Methods: 71 patients (Stage III: 41, Stage IV A : 30) with locoregionally advanced NPC were entered this study. Neoadjuvant chemotherapy was consisted of cisplatin 25 mg/m 2 intravenously on d1-3 and gemcitabine 1000 mg/m 2 in 30 minutes intravenous infusion on days 1 and 8, every 3 weeks for 2 cycles. Adjuvant chemotherapy consisted of 2 cycles of the same GP regimen was given at 28 days after the end of radiotherapy. The prescription doses was 66.0-70.4 Gy to the gross tumor volume, 66 Gy to positive neck nodes, 60 Gy to the high-risk clinical target volume, 54 Gy to the low-risk clinical target volume. Results: The overall response rate to neoadjuvant chemotherapy was 91.2%, acute toxicity was mainly grade 1-2 myleosuppression. All patients completed IMRT. The median follow-up duration was 38 months. The 3-year nasopharyngeal local control, regional control, distant metastasis-free survival rate and overall survival rate were 93%, 99%, 91%, 90%, respectively. Severe late toxicities included grade 3 trismus in 1 patient, grade 3 hearing impairment in 2 patients and cranial nerve palsy in 2 patients, respectively. No grade 4 late toxicities were observed. Conclusions: The combination of GP chemotherapy and IMRT for locoregionally advanced nasopharyngeal carcinoma is well-tolerated, convenient, effective, and warrants further studies of more proper cycles of GP regimen. (authors)

Gemcitabine and treatment of diffuse large B-cell lymphoma in relapsed or refractory elderly patients: A prospective randomized trial in Algeria

Directory of Open Access Journals (Sweden)

Aribi Mourad

2010-01-01

Full Text Available Context: Support for non-Hodgkin′s lymphoma (NHL with large cells that is refractory or relapsed after first-line chemotherapy poses a greater therapeutic problem with bone marrow transplant therapy or when old age is a contra-indication for high-dose chemotherapy, especially among developing countries such as Algeria. Aim: To show that the regimen, including gemcitabine, could be more effective in treating elderly patients with diffuse large B-cell lymphoma (DLBCL in relapse / refractory, without complete remission, when compared with the ESHAP (etoposide, cisplatine, solumedrol, aracytine regimen. Materials and Methods: Ninety-six patients in the age group of 60-70 years were volunteers for a prospective randomized single-blind study, carried out for three years. Patients were divided into two groups by the drawing of lots. The first group (GA, n = 48, relapse; n = 27 [56.3%], refractory; n = 21 [43.7%] received treatment with ESHAP protocol and the second one (GB, n = 48, relapse; n = 28 [58%], refractory; n = 20 [42%] with GPD (gemcitabine, dexamethasone, cisplatine protocol. Results: The overall response rates and mean survival at three years were significantly higher among patients subjected to GPD treatment compared with those subjected to ESHAP treatment (63% vs. 55%, P = 0.01 and 20.5% [95% CI 16.5-24.5] vs. 11.8% [8.9-14.6], respectively. Additionally, three-year progression-free and event-free survival rates were 20.5% (16.3-24 and 19.7% (15.9-23.5, respectively, for the GPD regimen and 10.9% (8.2-13.7 and 11.1% (95% CI 8.5-13.7, respectively, for the ESHAP regimen. Moreover, the GPD regimen was associated with improving overall survival (RR=2.02, 95% CI 1.59-2.56; P = 0.000, event-free survival (2.03, 1.64-2.52; P < 0.001 and progression-free survival (1.86, 1.46-2.37; P < 0.001. Conclusion: In cases of contra-indication for high-dose chemotherapy for elderly patients with DLBCL, without complete remission, the Gemcitabine

Glycogen synthase kinase-3 inhibition disrupts nuclear factor-kappaB activity in pancreatic cancer, but fails to sensitize to gemcitabine chemotherapy

Directory of Open Access Journals (Sweden)

Mamaghani Shadi

2009-04-01

Full Text Available Abstract Background Aberrant activation NF-kappaB has been proposed as a mechanism of drug resistance in pancreatic cancer. Recently, inhibition of glycogen synthase kinase-3 has been shown to exert anti-tumor effects on pancreatic cancer cells by suppressing NF-kappaB. Consequently, we investigated whether inhibition of GSK-3 sensitizes pancreatic cancer cells to the chemotherapeutic agent gemcitabine. Methods GSK-3 inhibition was achieved using the pharmacological agent AR-A014418 or siRNA against GSK-3 alpha and beta isoforms. Cytotoxicity was measured using a Sulphorhodamine B assay and clonogenic survival following exposure of six different pancreatic cancer cell lines to a range of doses of either gemcitabine, AR-A014418 or both for 24, 48 and 72 h. We measured protein expression levels by immunoblotting. Basal and TNF-alpha induced activity of NF-kappaB was assessed using a luciferase reporter assay in the presence or absence of GSK-3 inhibition. Results GSK-3 inhibition reduced both basal and TNF-alpha induced NF-kappaB luciferase activity. Knockdown of GSK-3 beta reduced nuclear factor kappa B luciferase activity to a greater extent than GSK-3 alpha, and the greatest effect was seen with dual knockdown of both GSK-3 isoforms. GSK-3 inhibition also resulted in reduction of the NF-kappaB target proteins XIAP, Bcl-XL, and cyclin D1, associated with growth inhibition and decreased clonogenic survival. In all cell lines, treatment with either AR-A014418, or gemcitabine led to growth inhibition in a dose- and time-dependent manner. However, with the exception of PANC-1 where drug synergy occurred with some dose schedules, the inhibitory effect of combined drug treatment was additive, sub-additive, or even antagonistic. Conclusion GSK-3 inhibition has anticancer effects against pancreatic cancer cells with a range of genetic backgrounds associated with disruption of NF-kappaB, but does not significantly sensitize these cells to the standard

Glycogen synthase kinase-3 inhibition disrupts nuclear factor-kappaB activity in pancreatic cancer, but fails to sensitize to gemcitabine chemotherapy

International Nuclear Information System (INIS)

Mamaghani, Shadi; Patel, Satish; Hedley, David W

2009-01-01

Aberrant activation NF-kappaB has been proposed as a mechanism of drug resistance in pancreatic cancer. Recently, inhibition of glycogen synthase kinase-3 has been shown to exert anti-tumor effects on pancreatic cancer cells by suppressing NF-kappaB. Consequently, we investigated whether inhibition of GSK-3 sensitizes pancreatic cancer cells to the chemotherapeutic agent gemcitabine. GSK-3 inhibition was achieved using the pharmacological agent AR-A014418 or siRNA against GSK-3 alpha and beta isoforms. Cytotoxicity was measured using a Sulphorhodamine B assay and clonogenic survival following exposure of six different pancreatic cancer cell lines to a range of doses of either gemcitabine, AR-A014418 or both for 24, 48 and 72 h. We measured protein expression levels by immunoblotting. Basal and TNF-alpha induced activity of NF-kappaB was assessed using a luciferase reporter assay in the presence or absence of GSK-3 inhibition. GSK-3 inhibition reduced both basal and TNF-alpha induced NF-kappaB luciferase activity. Knockdown of GSK-3 beta reduced nuclear factor kappa B luciferase activity to a greater extent than GSK-3 alpha, and the greatest effect was seen with dual knockdown of both GSK-3 isoforms. GSK-3 inhibition also resulted in reduction of the NF-kappaB target proteins XIAP, Bcl-X L , and cyclin D1, associated with growth inhibition and decreased clonogenic survival. In all cell lines, treatment with either AR-A014418, or gemcitabine led to growth inhibition in a dose- and time-dependent manner. However, with the exception of PANC-1 where drug synergy occurred with some dose schedules, the inhibitory effect of combined drug treatment was additive, sub-additive, or even antagonistic. GSK-3 inhibition has anticancer effects against pancreatic cancer cells with a range of genetic backgrounds associated with disruption of NF-kappaB, but does not significantly sensitize these cells to the standard chemotherapy agent gemcitabine. This lack of synergy might be

Regulatory requirements for marketing fixed dose combinations

Directory of Open Access Journals (Sweden)

B G Jayasheel

2010-01-01

Full Text Available The development of fixed-dose combinations (FDCs is becoming increasingly important from a public health perspective. FDCs have advantages when there is an identifiable patient population for whom treatment with a particular combination of actives in a fixed ratio is safe and effective and when all of the actives contribute to the overall therapeutic effect. Such combinations of drugs are particularly useful in the management of chronic diseases. In addition, there can be real clinical benefits in the form of increased efficacy and/or a reduced incidence of adverse effects. Additional advantages of FDCs are potentially lower costs of manufacturing compared to the costs of producing separate products administered concurrently, simpler logistics of distribution and reduced development of resistance in the case of antimicrobials. Above all, FDC therapy reduces pill burden and improves medication compliance. Although, FDCs seem to be ideal under certain pre-defined circumstances, if a dosing adjustment is warranted, there may not be an FDC available in the most appropriate strength for the patient and if an adverse drug reaction occurs from using an FDC, it may be difficult to identify the active ingredient responsible for causing the reaction. Appendix VI of Schedule Y (Drugs & Cosmetics Rules 1945, India states the requirements for marketing approval of various types of FDCs. The same is further elaborated in this article to provide a detailed guidance including the clinical trial requirements. However, the heterogeneity of the therapeutic field makes it difficult to develop a standard guidance document.

The Deceptive Resilience of Fixed Exchange Rates

OpenAIRE

Mushin, Jerry

2004-01-01

This paper is an examination of the experience of exchange-rate systems since 1978. Despite the accelerating trend in favour of floating exchange rates, a substantial minority of IMF members have continued to fix the value of their currencies. The recent incidence of each of the principal types of exchange-rate peg is described.

Histone deacetylase inhibitor trichostatin A resensitizes gemcitabine resistant urothelial carcinoma cells via suppression of TG-interacting factor

Energy Technology Data Exchange (ETDEWEB)

Yeh, Bi-Wen [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Li, Wei-Ming [Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Li, Ching-Chia [Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Kang, Wan-Yi [Department of Pathology, Kuo General Hospital, Tainan 701, Taiwan (China); Huang, Chun-Nung [Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Hour, Tzyh-Chyuan [Institute of Biochemistry, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Liu, Zi-Miao [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); and others

2016-01-01

Gemcitabine and cisplatin (GC) has been widely used for advanced and metastatic urothelial carcinoma (UC). However, resistance to this remedy has been noticed. We have demonstrated that increase of TG-interacting factor (TGIF) in specimens is associated with worse prognosis of upper tract UC (UTUC) patients. The roles of TGIF in the gemcitabine resistance of UC were explored. Specimens of 23 locally advanced/advanced stage UTUC patients who received GC systemic chemotherapy after radical nephroureterectomy were collected to evaluate the alterations of TGIF in the resistance to the remedy by using immunohistochemistry. In vitro characterizations of mechanisms mediating TGIF in gemcitabine resistance were conducted by analyzing NTUB1 cells and their gemcitabine-resistant subline, NGR cells. Our results show that increased TGIF is significantly associated with chemo-resistance, poor progression-free survival, and higher cancer-related deaths of UTUC patients. Higher increases of TGIF, p-AKT{sup Ser473} and invasive ability were demonstrated in NGR cells. Overexpression of TGIF in NTUB1 cells upregulated p-AKT{sup Ser473} activation, enhanced migration ability, and attenuated cellular sensitivity to gemcitabine. Knockdown of TGIF in NGR cells downregulated p-AKT{sup Ser473} activation, declined migration ability, and enhanced cellular sensitivity to gemcitabine. In addition, histone deacetylases inhibitor trichostatin A (TSA) inhibited TGIF, p-AKT{sup Ser473} expression and migration ability. Synergistic effects of gemcitabine and TSA on NGR cells were also demonstrated. Collectively, TGIF contributes to the gemcitabine resistance of UC via AKT activation. Combined treatment with gemcitabine and TSA might be a promising therapeutic remedy to improve the gemcitabine resistance of UC. - Highlights: • TGIF expression in UC cells is associated with chemoresistance to gemcitabine. • TGIF-regulated AKT activation contributes to the gemcitabine resistance. • Increased

Histone deacetylase inhibitor trichostatin A resensitizes gemcitabine resistant urothelial carcinoma cells via suppression of TG-interacting factor

International Nuclear Information System (INIS)

Yeh, Bi-Wen; Li, Wei-Ming; Li, Ching-Chia; Kang, Wan-Yi; Huang, Chun-Nung; Hour, Tzyh-Chyuan; Liu, Zi-Miao

2016-01-01

Gemcitabine and cisplatin (GC) has been widely used for advanced and metastatic urothelial carcinoma (UC). However, resistance to this remedy has been noticed. We have demonstrated that increase of TG-interacting factor (TGIF) in specimens is associated with worse prognosis of upper tract UC (UTUC) patients. The roles of TGIF in the gemcitabine resistance of UC were explored. Specimens of 23 locally advanced/advanced stage UTUC patients who received GC systemic chemotherapy after radical nephroureterectomy were collected to evaluate the alterations of TGIF in the resistance to the remedy by using immunohistochemistry. In vitro characterizations of mechanisms mediating TGIF in gemcitabine resistance were conducted by analyzing NTUB1 cells and their gemcitabine-resistant subline, NGR cells. Our results show that increased TGIF is significantly associated with chemo-resistance, poor progression-free survival, and higher cancer-related deaths of UTUC patients. Higher increases of TGIF, p-AKT Ser473 and invasive ability were demonstrated in NGR cells. Overexpression of TGIF in NTUB1 cells upregulated p-AKT Ser473 activation, enhanced migration ability, and attenuated cellular sensitivity to gemcitabine. Knockdown of TGIF in NGR cells downregulated p-AKT Ser473 activation, declined migration ability, and enhanced cellular sensitivity to gemcitabine. In addition, histone deacetylases inhibitor trichostatin A (TSA) inhibited TGIF, p-AKT Ser473 expression and migration ability. Synergistic effects of gemcitabine and TSA on NGR cells were also demonstrated. Collectively, TGIF contributes to the gemcitabine resistance of UC via AKT activation. Combined treatment with gemcitabine and TSA might be a promising therapeutic remedy to improve the gemcitabine resistance of UC. - Highlights: • TGIF expression in UC cells is associated with chemoresistance to gemcitabine. • TGIF-regulated AKT activation contributes to the gemcitabine resistance. • Increased TGIF is significantly

Gemcitabine, cisplatin, and hyperfractionated accelerated radiotherapy for locally advanced non-small cell lung cancer.

Science.gov (United States)

Zwitter, Matjaz; Kovac, Viljem; Smrdel, Uros; Strojan, Primoz

2006-09-01

Due to potent radiosensitization and potential serious or fatal toxicity, concurrent gemcitabine and irradiation should only be applied within clinical trials. We here present experience from a phase I-II clinical trial for patients with locally advanced non-small cell lung cancer (NSCLC) treated with hyperfractionated accelerated radiotherapy and concurrent low-dose gemcitabine. Eligible patients had locally advanced inoperable NSCLC without pleural effusion, Eastern Cooperative Oncology Group performance status 0-1, were chemotherapy naïve and had no previous radiotherapy to the chest, and had adequate hematopoietic, liver, and kidney function. Routine brain computed tomography was not performed, and positron emission tomography/computed tomography was not available. Treatment consisted of three parts: induction chemotherapy with gemcitabine and cisplatin in standard doses, local treatment with concurrent chemotherapy and radiotherapy, and consolidation chemotherapy. Patients were irradiated with opposed AP-PA and oblique fields, using 2.5-D treatment planning. Although corrections for inhomogeneous tissue were made, volume of total lung receiving > or =20 Gy (V20) could not be determined. The trial started as phase I, aimed to determine the dose-limiting toxicity and maximal tolerated dose (MTD) for concurrent hyperfractionated radiotherapy (1.4 Gy twice daily) and gemcitabine 55 mg/m twice weekly as a radiosensitizer. Phase II of the trial then continued at the level of MTD. Twenty-eight patients with NSCLC, nine patients with stage IIIA, 16 patients with IIIB, and three patients with an inoperable recurrence after previous surgery, entered the trial. The first 12 patients entered Phase I of the trial at the initial level of 42 Gy in 30 fractions in 3 weeks. Dose-limiting toxicity was acute esophagitis; 47.6 Gy in 34 fractions in 3.5 weeks was the MTD for this regimen of concurrent chemotherapy and radiotherapy. In phase II of the trial, this dose was applied

Prognostic Significance of Carbohydrate Antigen 19-9 in Unresectable Locally Advanced Pancreatic Cancer Treated With Dose-Escalated Intensity Modulated Radiation Therapy and Concurrent Full-Dose Gemcitabine: Analysis of a Prospective Phase 1/2 Dose Escalation Study

International Nuclear Information System (INIS)

Vainshtein, Jeffrey M.; Schipper, Matthew; Zalupski, Mark M.; Lawrence, Theodore S.; Abrams, Ross; Francis, Isaac R.; Khan, Gazala; Leslie, William; Ben-Josef, Edgar

2013-01-01

Purpose: Although established in the postresection setting, the prognostic value of carbohydrate antigen 19-9 (CA19-9) in unresectable locally advanced pancreatic cancer (LAPC) is less clear. We examined the prognostic utility of CA19-9 in patients with unresectable LAPC treated on a prospective trial of intensity modulated radiation therapy (IMRT) dose escalation with concurrent gemcitabine. Methods and Materials: Forty-six patients with unresectable LAPC were treated at the University of Michigan on a phase 1/2 trial of IMRT dose escalation with concurrent gemcitabine. CA19-9 was obtained at baseline and during routine follow-up. Cox models were used to assess the effect of baseline factors on freedom from local progression (FFLP), distant progression (FFDP), progression-free survival (PFS), and overall survival (OS). Stepwise forward regression was used to build multivariate predictive models for each endpoint. Results: Thirty-eight patients were eligible for the present analysis. On univariate analysis, baseline CA19-9 and age predicted OS, CA19-9 at baseline and 3 months predicted PFS, gross tumor volume (GTV) and black race predicted FFLP, and CA19-9 at 3 months predicted FFDP. On stepwise multivariate regression modeling, baseline CA19-9, age, and female sex predicted OS; baseline CA19-9 and female sex predicted both PFS and FFDP; and GTV predicted FFLP. Patients with baseline CA19-9 ≤90 U/mL had improved OS (median 23.0 vs 11.1 months, HR 2.88, P<.01) and PFS (14.4 vs 7.0 months, HR 3.61, P=.001). CA19-9 progression over 90 U/mL was prognostic for both OS (HR 3.65, P=.001) and PFS (HR 3.04, P=.001), and it was a stronger predictor of death than either local progression (HR 1.46, P=.42) or distant progression (HR 3.31, P=.004). Conclusions: In patients with unresectable LAPC undergoing definitive chemoradiation therapy, baseline CA19-9 was independently prognostic even after established prognostic factors were controlled for, whereas CA19-9 progression

Prognostic Significance of Carbohydrate Antigen 19-9 in Unresectable Locally Advanced Pancreatic Cancer Treated With Dose-Escalated Intensity Modulated Radiation Therapy and Concurrent Full-Dose Gemcitabine: Analysis of a Prospective Phase 1/2 Dose Escalation Study

Energy Technology Data Exchange (ETDEWEB)

Vainshtein, Jeffrey M., E-mail: jvainsh@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Matthew [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Zalupski, Mark M. [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Abrams, Ross [Department of Radiation Oncology, Rush Medical Center, Chicago, Illinois (United States); Francis, Isaac R. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Khan, Gazala [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States); Leslie, William [Division of Hematology Oncology, Department of Internal Medicine, Rush Medical Center, Chicago, Illinois (United States); Ben-Josef, Edgar [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

2013-05-01

Purpose: Although established in the postresection setting, the prognostic value of carbohydrate antigen 19-9 (CA19-9) in unresectable locally advanced pancreatic cancer (LAPC) is less clear. We examined the prognostic utility of CA19-9 in patients with unresectable LAPC treated on a prospective trial of intensity modulated radiation therapy (IMRT) dose escalation with concurrent gemcitabine. Methods and Materials: Forty-six patients with unresectable LAPC were treated at the University of Michigan on a phase 1/2 trial of IMRT dose escalation with concurrent gemcitabine. CA19-9 was obtained at baseline and during routine follow-up. Cox models were used to assess the effect of baseline factors on freedom from local progression (FFLP), distant progression (FFDP), progression-free survival (PFS), and overall survival (OS). Stepwise forward regression was used to build multivariate predictive models for each endpoint. Results: Thirty-eight patients were eligible for the present analysis. On univariate analysis, baseline CA19-9 and age predicted OS, CA19-9 at baseline and 3 months predicted PFS, gross tumor volume (GTV) and black race predicted FFLP, and CA19-9 at 3 months predicted FFDP. On stepwise multivariate regression modeling, baseline CA19-9, age, and female sex predicted OS; baseline CA19-9 and female sex predicted both PFS and FFDP; and GTV predicted FFLP. Patients with baseline CA19-9 ≤90 U/mL had improved OS (median 23.0 vs 11.1 months, HR 2.88, P<.01) and PFS (14.4 vs 7.0 months, HR 3.61, P=.001). CA19-9 progression over 90 U/mL was prognostic for both OS (HR 3.65, P=.001) and PFS (HR 3.04, P=.001), and it was a stronger predictor of death than either local progression (HR 1.46, P=.42) or distant progression (HR 3.31, P=.004). Conclusions: In patients with unresectable LAPC undergoing definitive chemoradiation therapy, baseline CA19-9 was independently prognostic even after established prognostic factors were controlled for, whereas CA19-9 progression

Effect of fixed-dose combinations of ezetimibe plus rosuvastatin in patients with primary hypercholesterolemia: MRS-ROZE (Multicenter Randomized Study of ROsuvastatin and eZEtimibe).

Science.gov (United States)

Kim, Kyung-Jin; Kim, Sang-Hyun; Yoon, Young Won; Rha, Seung-Woon; Hong, Soon-Jun; Kwak, Choong-Hwan; Kim, Weon; Nam, Chang-Wook; Rhee, Moo-Yong; Park, Tae-Ho; Hong, Taek-Jong; Park, Sungha; Ahn, Youngkeun; Lee, Namho; Jeon, Hui-Kyung; Jeon, Dong-Woon; Han, Kyoo-Rok; Moon, Keon-Woong; Chae, In-Ho; Kim, Hyo-Soo

2016-10-01

We aimed to compare the effects of fixed-dose combinations of ezetimibe plus rosuvastatin to rosuvastatin alone in patients with primary hypercholesterolemia, including a subgroup analysis of patients with diabetes mellitus (DM) or metabolic syndrome (MetS). This multicenter eight-week randomized double-blind phase III study evaluated the safety and efficacy of fixed-dose combinations of ezetimibe 10 mg plus rosuvastatin, compared with rosuvastatin alone in patients with primary hypercholesterolemia. Four hundred and seven patients with primary hypercholesterolemia who required lipid-lowering treatment according to the ATP III guideline were randomized to one of the following six treatments for 8 weeks: fixed-dose combinations with ezetimibe 10 mg daily plus rosuvastatin (5, 10, or 20 mg daily) or rosuvastatin alone (5, 10, or 20 mg daily). Fixed-dose combination of ezetimibe plus rosuvastatin significantly reduced LDL cholesterol, total cholesterol, and triglyceride levels compared with rosuvastatin alone. Depending on the rosuvastatin dose, these fixed-dose combinations of ezetimibe plus rosuvastatin provided LDL cholesterol, total cholesterol, and triglyceride reductions of 56%-63%, 37%-43%, and 19%-24%, respectively. Moreover, the effect of combination treatment on cholesterol levels was more pronounced in patients with DM or MetS than in non-DM or non-MetS patients, respectively, whereas the effect of rosuvastatin alone did not differ between DM vs non-DM or MetS vs non-MetS patients. Fixed-dose combinations of ezetimibe and rosuvastatin provided significantly superior efficacy to rosuvastatin alone in lowering LDL cholesterol, total cholesterol, and triglyceride levels. Moreover, the reduction rate was greater in patients with DM or MetS. © 2016 The Authors Cardiovascular Therapeutics Published by John Wiley & Sons Ltd.

Dimethylaminoparthenolide and gemcitabine: a survival study using a genetically engineered mouse model of pancreatic cancer

International Nuclear Information System (INIS)

Yip-Schneider, Michele T; Wu, Huangbing; Stantz, Keith; Agaram, Narasimhan; Crooks, Peter A; Schmidt, C Max

2013-01-01

Pancreatic cancer remains one of the deadliest cancers due to lack of early detection and absence of effective treatments. Gemcitabine, the current standard-of-care chemotherapy for pancreatic cancer, has limited clinical benefit. Treatment of pancreatic cancer cells with gemcitabine has been shown to induce the activity of the transcription factor nuclear factor-kappaB (NF-κB) which regulates the expression of genes involved in the inflammatory response and tumorigenesis. It has therefore been proposed that gemcitabine-induced NF-κB activation may result in chemoresistance. We hypothesize that NF-κB suppression by the novel inhibitor dimethylaminoparthenolide (DMAPT) may enhance the effect of gemcitabine in pancreatic cancer. The efficacy of DMAPT and gemcitabine was evaluated in a chemoprevention trial using the mutant Kras and p53-expressing LSL-Kras G12D/+ ; LSL-Trp53 R172H ; Pdx-1-Cre mouse model of pancreatic cancer. Mice were randomized to treatment groups (placebo, DMAPT [40 mg/kg/day], gemcitabine [50 mg/kg twice weekly], and the combination DMAPT/gemcitabine). Treatment was continued until mice showed signs of ill health at which time they were sacrificed. Plasma cytokine levels were determined using a Bio-Plex immunoassay. Statistical tests used included log-rank test, ANOVA with Dunnett’s post-test, Student’s t-test, and Fisher exact test. Gemcitabine or the combination DMAPT/gemcitabine significantly increased median survival and decreased the incidence and multiplicity of pancreatic adenocarcinomas. The DMAPT/gemcitabine combination also significantly decreased tumor size and the incidence of metastasis to the liver. No significant differences in the percentages of normal pancreatic ducts or premalignant pancreatic lesions were observed between the treatment groups. Pancreata in which no tumors formed were analyzed to determine the extent of pre-neoplasia; mostly normal ducts or low grade pancreatic lesions were observed, suggesting prevention

The development of orally administrable gemcitabine prodrugs with D-enantiomer amino acids: enhanced membrane permeability and enzymatic stability.

Science.gov (United States)

Tsume, Yasuhiro; Incecayir, Tuba; Song, Xueqin; Hilfinger, John M; Amidon, Gordon L

2014-04-01

Gemcitabine prodrugs with D- and L-configuration amino acids were synthesized and their chemical stability in buffers, resistance to glycosidic bond metabolism, enzymatic activation, permeability in Caco-2 cells and mouse intestinal membrane, anti-proliferation activity in cancer cell were determined and compared to that of parent drug, gemcitabine. Prodrugs containing D-configuration amino acids were enzymatically more stable than ones with L-configuration amino acids. The activation of all gemcitabine prodrugs was 1.3-17.6-fold faster in cancer cell homogenate than their hydrolysis in buffer, suggesting enzymatic action. The enzymatic activation of amino acid monoester prodrugs containing D-configuration amino acids in cell homogenates was 2.2-10.9-fold slower than one of amino acid monoester prodrugs with L-configuration amino acids. All prodrugs exhibited enhanced resistance to glycosidic bond metabolism by thymidine phosphorylase compared to parent gemcitabine. Gemcitabine prodrugs showed superior the effective permeability in mouse jejunum to gemcitabine. More importantly, the high plasma concentration of d-amino acid gemcitabine prodrugs was observed more than one of L-amino acid gemcitabine prodrugs. In general, the 5'-mono-amino acid monoester gemcitabine prodrugs exhibited higher permeability and uptake than their parent drug, gemcitabine. Cell proliferation assays in AsPC-1 pancreatic ductal cell line indicated that gemcitabine prodrugs were more potent than their parent drug, gemcitabine. The transport and enzymatic profiles of 5'-D-valyl-gemcitabine and 5'-D-phenylalanyl-gemcitabine suggest their potential for increased oral uptake and delayed enzymatic bioconversion as well as enhanced uptake and cytotoxic activity in cancer cells, would facilitate the development of oral dosage form for anti-cancer agents and, hence, improve the quality of life for the cancer patients. Copyright © 2014. Published by Elsevier B.V.

Dose and dose rate monitor

International Nuclear Information System (INIS)

Novakova, O.; Ryba, J.; Slezak, V.; Svobodova, B.; Viererbl, L.

1984-10-01

The methods are discussea of measuring dose rate or dose using a scintillation counte. A plastic scintillator based on polystyrene with PBD and POPOP activators and coated with ZnS(Ag) was chosen for the projected monitor. The scintillators were cylindrical and spherical in shape and of different sizes; black polypropylene tubes were chosen as the best case for the probs. For the counter with different plastic scintillators, the statistical error 2σ for natural background was determined. For determining the suitable thickness of the ZnS(Ag) layer the energy dependence of the counter was measured. Radioisotopes 137 Cs, 241 Am and 109 Cd were chosen as radiation sources. The best suited ZnS(Ag) thickness was found to be 0.5 μm. Experiments were carried out to determine the directional dependence of the detector response and the signal to noise ratio. The temperature dependence of the detector response and its compensation were studied, as were the time stability and fatigue manifestations of the photomultiplier. The design of a laboratory prototype of a dose rate and dose monitor is described. Block diagrams are given of the various functional parts of the instrument. The designed instrument is easiiy portable, battery powered, measures dose rates from natural background in the range of five orders, i.e., 10 -2 to 10 3 nGy/s, and allows to determine a dose of up to 10 mGy. Accouracy of measurement in the energy range of 50 keV to 1 MeV is better than +-20%. (E.S.)

A meta-analysis of gemcitabine containing chemotherapy for locally advanced and metastatic pancreatic adenocarcinoma

Directory of Open Access Journals (Sweden)

Ma Yue

2011-03-01

Full Text Available Abstract Background The objectives of the present study are to investigate the efficacy and safety profile of gemcitabine-based combinations in the treatment of locally advanced and metastatic pancreatic adenocarcinoma (LA/MPC. Methods We performed a computerized search using combinations of the following keywords: "chemotherapy", "gemcitabine", "trial", and "pancreatic cancer". Results Thirty-five trials were included in the present analysis, with a total of 9,979 patients accrued. The analysis showed that the gemcitabine-based combination therapy was associated with significantly better overall survival (OS (ORs, 1.15; p = 0.011, progression-free survival (PFS (ORs, 1.27; p Conclusions Gemcitabine in combination with capecitabine or oxaliplatin was associated with enhanced OS and ORR as compared with gemcitabine in monotherapy, which are likely to become the preferred standard first-line treatment of LA/MPC.

Image-Guided Stereotactic Radiosurgery Using a Specially Designed High-Dose-Rate Linac

International Nuclear Information System (INIS)

Bayouth, John E.; Kaiser, Heather S.; Smith, Mark C.; Pennington, Edward C.; Anderson, Kathleen M. C.; Ryken, Timothy C.; Buatti, John M.

2007-01-01

Stereotactic radiosurgery and image-guided radiotherapy (IGRT) place enhanced demands on treatment delivery machines. In this study, we describe a high-dose-rate output accelerator as a part of our stereotactic IGRT delivery system. The linac is a Siemens Oncor without a flattening filter, and enables dose rates to reach 1000 monitor units (MUs) per minute. Even at this high-dose-rate, the linac dosimetry system remains robust; constancy, linearity, and beam energy remain within 1% for 3 to 1000 MU. Dose profiles for larger field sizes are not flat, but they are radially symmetric and, as such, able to be modeled by a treatment planning system. Target localization is performed via optical guidance utilizing a 3-dimensional (3D) ultrasound probe coupled to an array of 4 infrared light-emitting diodes. These diodes are identified by a fixed infrared camera system that determines diode position and, by extension, all objects imaged in the room coordinate system. This system provides sub-millimeter localization accuracy for cranial applications and better than 1.5 mm for extracranial applications. Because stereotactic IGRT can require significantly longer times for treatment delivery, the advantages of the high-dose-rate design and its direct impact on IGRT are discussed

4. Evaluation of the quality of fixed dose combination anti ...

African Journals Online (AJOL)

Esem

Methodology: This was a cross sectional study whose objective was to determine the quality of 3 types of fixed dose combination (FDC) anti TB drugs namely 4FDC, 3FDC and 2FDC tablets available in Lusaka District by assessing the presence of active ingredients and the percentage content of these active ingredients ...

Description of the local dose rate measuring system for the Angra 2 nuclear power plant

International Nuclear Information System (INIS)

Costa, Lilian Rose Sobral da; Souza Mendes, Jorge Eduardo de

1995-01-01

The equipment used and the measured value processing involved in the Local Dose Rate Measuring System is described including the installation points for the measuring equipment in the reactor building, the auxiliary building and at the main gate of Angra 2 Nuclear Power Plant. Under normal operating conditions protecting of the personnel is ensured by measuring the local dose rate at those points which are generally accessible. In some cases , fixed sensors are not suitable so that mobile equipment is used. (author). 2 refs., 1 fig

Investigation of the dose rate dependency of the PAGAT gel dosimeter at low dose rates

International Nuclear Information System (INIS)

Zehtabian, M.; Faghihi, R.; Zahmatkesh, M.H.; Meigooni, A.S.; Mosleh-Shirazi, M.A.; Mehdizadeh, S.; Sina, S.; Bagheri, S.

2012-01-01

Medical physicists need dosimeters such as gel dosimeters capable of determining three-dimensional dose distributions with high spatial resolution. To date, in combination with magnetic resonance imaging (MRI), polyacrylamide gel (PAG) polymers are the most promising gel dosimetry systems. The purpose of this work was to investigate the dose rate dependency of the PAGAT gel dosimeter at low dose rates. The gel dosimeter was used for measurement of the dose distribution around a Cs-137 source from a brachytherapy LDR source to have a range of dose rates from 0.97 Gy h −1 to 0.06 Gy h −1 . After irradiation of the PAGAT gel, it was observed that the dose measured by gel dosimetry was almost the same at different distances (different dose rates) from the source, although the points nearer the source had been expected to receive greater doses. Therefore, it was suspected that the PAGAT gel is dose rate dependent at low dose rates. To test this further, three other sets of measurements were performed by placing vials containing gel at different distances from a Cs-137 source. In the first two measurements, several plastic vials were exposed to equal doses at different dose rates. An ionization chamber was used to measure the dose rate at each distance. In addition, three TLD chips were simultaneously irradiated in order to verify the dose to each vial. In the third measurement, to test the oxygen diffusion through plastic vials, the experiment was repeated again using plastic vials in a nitrogen box and glass vials. The study indicates that oxygen diffusion through plastic vials for dose rates lower than 2 Gy h −1 would affect the gel dosimeter response and it is suggested that the plastic vials or (phantoms) in an oxygen free environment or glass vials should be used for the dosimetry of low dose rate sources using PAGAT gel to avoid oxygen diffusion through the vials.

[The possibility of local control of cancer by neoadjuvant chemoradiation therapy with gemcitabine and surgical resection for advanced cholangiocarcinoma].

Science.gov (United States)

Nakagawa, Kei; Katayose, Yu; Rikiyama, Toshiki; Okaue, Adoru; Unno, Michiaki

2009-11-01

Surgical resection is the gold standard of treatment for cholangiocarcinoma. However, there are also many recurrences after operation, because of the anatomical background and the tendency of invasion. We thought that eliminating the remnant of the cancer could yield a better prognosis. Therefore, an introduction of the neoadjuvant chemoradiation therapy with gemcitabine and surgical resection for advanced cholangiocarcinoma patient (NACRAC) was planned. The safety of NACRAC was confirmed by a pilot study. The recommended dose of gemcitabine (600 mg/m2) was determined by a phase I study. A phase II study is now being performed for evaluating the effectiveness and safety. NACRAC may control the frontal part of the tumor with difficult distinctions made by MDCT, and abolishing the cancer remnant is expected. The possibility of extended prognosis by NACRAC can be considered.

Potential Development of Tumor-Targeted Oral Anti-Cancer Prodrugs: Amino Acid and Dipeptide Monoester Prodrugs of Gemcitabine.

Science.gov (United States)

Tsume, Yasuhiro; Drelich, Adam J; Smith, David E; Amidon, Gordon L

2017-08-10

One of the main obstacles for cancer therapies is to deliver medicines effectively to target sites. Since stroma cells are developed around tumors, chemotherapeutic agents have to go through stroma cells in order to reach tumors. As a method to improve drug delivery to the tumor site, a prodrug approach for gemcitabine was adopted. Amino acid and dipeptide monoester prodrugs of gemcitabine were synthesized and their chemical stability in buffers, resistance to thymidine phosphorylase and cytidine deaminase, antiproliferative activity, and uptake/permeability in HFF cells as a surrogate to stroma cells were determined and compared to their parent drug, gemcitabine. The activation of all gemcitabine prodrugs was faster in pancreatic cell homogenates than their hydrolysis in buffer, suggesting enzymatic action. All prodrugs exhibited great stability in HFF cell homogenate, enhanced resistance to glycosidic bond metabolism by thymidine phosphorylase, and deamination by cytidine deaminase compared to their parent drug. All gemcitabine prodrugs exhibited higher uptake in HFF cells and better permeability across HFF monolayers than gemcitabine, suggesting a better delivery to tumor sites. Cell antiproliferative assays in Panc-1 and Capan-2 pancreatic ductal cell lines indicated that the gemcitabine prodrugs were more potent than their parent drug gemcitabine. The transport and enzymatic profiles of gemcitabine prodrugs suggest their potential for delayed enzymatic bioconversion and enhanced resistance to metabolic enzymes, as well as for enhanced drug delivery to tumor sites, and cytotoxic activity in cancer cells. These attributes would facilitate the prolonged systemic circulation and improved therapeutic efficacy of gemcitabine prodrugs.

Fixed dose of I-131 therapy for the treatment of Graves' hyperthyroidism

International Nuclear Information System (INIS)

Li Lin; Lee, K.

2004-01-01

Objectives: To evaluate short-term (6 month) efficacy of fixed-dose (555 MBq, 15 mCi) approach in the treatment of Graves' hyperthyroidism and analyze the relationship between clinical outcome (hyperthyroidism, hypothyroidism, and euthyroidism) and variances (patient age, thyroid weight, absorbed activity per gram of thyroid tissue, and radioactive iodine uptake value). Methods: 38 patients of Graves' hyperthyroidism were treated with 555MBq of radioactive iodine (in the form of capsule). Follow-up was done 3 and 6 months post therapy and the following clinical outcome was monitored: persistent hyperthyroidism, hypothyroidism, and euthyroidism. Statistical analysis was performed with SPSS software (version 11.5). P<0.05 was taken as indicating a statistically significant effect. Results: Of the 38 subjects, 14 (36.8%) were identified as euthyroidism, 18 (47.4%) hypothyroidism, and 6 (15.8%) hyperthyroidism. Cure rate (euthyroidism+hypothyroidism) was 84.2%. Statistical analysis revealed that there is a statistically significant difference of absorbed activity per gram of thyroid tissue and thyroid weight (F=17.639, P=0.000; F=28.453, P=0.000), but there is no statistically significant difference in terms of patient age and RAIU (F=1.375, P-0.266; F=2.453, P=0.101) among euthyroidism, hypothyroidism, and hyperthyroidism patients. Conclusion: We concluded that fixed-dose approach is very effective in the quickly restoration of thyroid function. There is a statistically significant difference of absorbed activity per gram of thyroid tissue and thyroid weight, but there is no statistically significant difference in terms of patient age and RAIU among euthyroidism, hypothyroidism, and hyperthyroidism patients. (authors)

An EORTC-IDBBC phase I study of gemcitabine and continuous infusion 5-fluorouracil in patients with metastatic breast cancer resistant to anthracyclines or pre-treated with both anthracyclines and taxanes.

NARCIS (Netherlands)

Awada, A.; Biganzoli, L.; Cufer, T.; Beex, L.V.A.M.; Lohrisch, C.; Batter, V.; Hamilton, A.; Nooij, M.A.; Piccart, M.

2002-01-01

The aim of this study was to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), and potential activity of combined gemcitabine and continuous infusion 5-fluorouracil (5-FU) in metastatic breast cancer (MBC) patients that are resistant to anthracyclines or have been

State estimation for networked control systems using fixed data rates

Science.gov (United States)

Liu, Qing-Quan; Jin, Fang

2017-07-01

This paper investigates state estimation for linear time-invariant systems where sensors and controllers are geographically separated and connected via a bandwidth-limited and errorless communication channel with the fixed data rate. All plant states are quantised, coded and converted together into a codeword in our quantisation and coding scheme. We present necessary and sufficient conditions on the fixed data rate for observability of such systems, and further develop the data-rate theorem. It is shown in our results that there exists a quantisation and coding scheme to ensure observability of the system if the fixed data rate is larger than the lower bound given, which is less conservative than the one in the literature. Furthermore, we also examine the role that the disturbances have on the state estimation problem in the case with data-rate limitations. Illustrative examples are given to demonstrate the effectiveness of the proposed method.

[Gemcitabine-induced thrombotic microangiopathy: Can we improve screening and treatment?

Science.gov (United States)

Charmetant, Xavier; Jolivot, Anne; Fournier, Thomas; Puthet, Jean-Charles; Cassier, Philippe; Lemoine, Sandrine; Juillard, Laurent

2017-06-01

Thrombotic microangiopathy is a rare but severe complication of treatment with gemcitabine. Its prevalence increases because gemcitabine's indications are growing. We report four cases, which presented with common clinical and biological manifestations, i.e. high blood pressure, proteinuria and increasing plasmatic creatinine level. However, severity was not similar, hemodialysis was inconstant. There is no consensus on treatment for this condition. Stopping gemcitabine is essential. Treatment was dispensed considering the severity of the presentation: plasma exchange therapy of variable outcome, and eculizumab, which was efficient when used. It's important to note that this syndrome includes common and frequent signs in patients receiving chemotherapies. But they must encourage the research of most specific signs, such as hypertension, mechanic hemolysis signs, proteinuria or hematuria, in order to recognize thrombotic microangiopathy as early as possible to treat it precociously, and to prevent additional gemcitabine injections. Copyright © 2017 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.

Assessing the Risk of Birth Defects Associated with Exposure to Fixed-Dose Combined Antituberculous Agents during Pregnancy in Rats

Directory of Open Access Journals (Sweden)

O. Awodele

2012-01-01

Full Text Available Due to the risks of disease progression and transmission to the newborn, treatment of tuberculosis is often pursued during pregnancy and fixed-dose combined antituberculous agents have been found to be beneficial. Unfortunately, there is paucity of data on the safety of the fixed-dose combined antituberculous drugs during pregnancy. This study intends to assess the teratogenic effect of fixed-dose combined antituberculous drugs on the organogenesis stage of fetal development and also investigate the possible roles of vitamin C in modulating the teratogenic effects of these agents on the fetus using animal model. Pregnant rats were divided into 3 groups with 12 animals per group: group 1 received distilled water (10 mL/kg orally; group 2 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents orally; group 3 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents plus vitamin C (10 mg/kg/day orally. Six rats in each group were randomly selected and sacrificed on day 20 by cervical dislocation prior to day 21 of gestation, and the foetuses were harvested through abdominal incision for physical examination. Blood samples were collected from the 1st filial rats of the remaining six animals for biochemical and hematological examination. The liver, kidney, heart, and brain of all the sacrificed animals were used for histopathological examination. There were significant (≤0.05 low birth weights of the foetuses of the animals that were treated with fixed-dose combined antituberculous agents. The haematological parameters also revealed a reduction in the platelets counts and neutrophiles at the first filial generation. Significant (≤0.05 elevations in the levels of aspartate aminotransferase (AST and alkaline phosphatase (ALP in the foetuses of the animals treated with fixed-dose combined antituberculous agents were also observed. However, the combination of vitamin C with fixed-dose combined antituberculous agents

Randomized Phase IIA Trial of Gemcitabine Compared With Bleomycin Plus Vincristine for Treatment of Kaposi’s Sarcoma in Patients on Combination Antiretroviral Therapy in Western Kenya

Directory of Open Access Journals (Sweden)

Naftali W. Busakhala

2018-01-01

Full Text Available Purpose: Kaposi’s sarcoma (KS is a spindle cell tumor resulting from growth dysregulation in the setting of infection with human herpes virus-8 (also called KS herpes virus. Advanced KS is characterized by poor responses to antiretroviral therapy and some of the chemotherapy readily accessible to patients in low-resource areas. Gemcitabine induced partial and complete regression of AIDS-associated KS (AIDS-KS in 11 of 24 patients in a pilot study. The current study compares the antimetabolite gemcitabine with the standard care bleomycin and vincristine (BV in the treatment of chemotherapy-naïve patients with AIDS-KS in a resource-limited setting. Patients and Methods: Patients with persistent or progressive KS despite treatment with combined antiretroviral therapy were randomly assigned to receive gemcitabine 1,000 mg/m2 or bleomycin 15 IU/ m2 and vincristine 1.4 mg/m2 given twice weekly. The main end point was objective response by bidirectional measurement, adverse events, and quality of life after three cycles of chemotherapy. Results: Of 70 participants enrolled, 36 received gemcitabine and 34 received BV. Complete response was achieved in 12 patients (33.3% in the gemcitabine arm and six (17.6% in the BV arm (P = .175. The partial response rate was 52.8% (n = 19 in the gemcitabine arm and 58.8% (n = 20 in the BV arm. Both study arms reported similar neurologic and hematologic adverse events; there was statistically significant baseline to post-treatment improvement in health-related quality-of-life scores. Conclusion: The results of this randomized, phase IIA trial demonstrate gemcitabine activity in chemotherapy-naïve patients with AIDS-KS, on the basis of response rates, adverse events, and health-related quality-of-life scores.

Low, fixed dose defibrotide in management of hepatic veno-occlusive disease post stem cell transplantation.

Science.gov (United States)

Bagal, Bhausaheb; Chandrasekharan, Arun; Chougle, Aliya; Khattry, Navin

2018-03-01

Hepatic veno-occlusive disease (VOD) is well recognized potentially serious regimen-related toxicity seen after stem cell transplantation. Severe VOD is associated with poor long-term outcomes with very high mortality. Besides supportive care, only defibrotide has been found to be effective in the management of VOD. The recommended dose of defibrotide is 25mg/kg/d but there has been no classical dose finding study done for this drug. A higher dose of defibrotide is associated with increased risk of bleeding and this drug is prohibitively expensive. We report our experience of using fixed low dose of defibrotide in patients with VOD. We retrospectively evaluated 511 patients who underwent stem cell transplant at our center from November 2007 and December 2015. All patients received ursodeoxycholic acid as VOD prophylaxis. Modified Seattle criterion was used for diagnosis and severity grading of VOD. Patients developing VOD were initially treated with furosemide and adequate analgesia. Defibrotide was started within 12 to 24 hours of diagnosis of VOD. All adult patients received defibrotide at a fixed dose of 200mg twice daily while two children were given dose of 100mg and 50mg twice daily. Nine (1.7%) of our patients developed VOD. Daily dose of defibrotide ranged from 5mg/kg/d to 20mg/kg/d till resolution of VOD. All patients had complete resolution of VOD. None of our patients required ventilator support or dialysis. No episodes of bleeding were observed. No dose response relationship was observed between defibrotide dose and time to resolution of VOD. Low fixed dose defibrotide initiated early seems to be effective and safe in treatment of VOD. This is relevant in a resource limited setting and warrants prospective evaluation. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

Gemcitabine radiosensitizes multiple myeloma cells to low let, but not high let, irradiation

International Nuclear Information System (INIS)

Supiot, Stephane; Thillays, Francois; Rio, Emmanuel; Gouard, Sebastien; Morgenstern, Alfred; Bruchertseifer, Frank; Mahe, Marc-Andre; Chatal, Jean-Francois; Davodeau, Francois; Cherel, Michel

2007-01-01

The radiosensitizing properties of gemcitabine in relation to low Linear Energy Transfer (LET) particles (Cobalt 60) and high-LET particles (alpha-RIT 213 Bi-radiolabeled CHX-DTPA-B-B4) were analyzed. Three multiple myeloma cell lines (LP1, RPMI 8226, U266) were irradiated with or without 10 nM gemcitabine 24 h prior to radiation. Gemcitabine led to radiosensitization of LP1 and U266 cells with low-LET (Radiation Enhancement Ratio: 1.55 and 1.49, respectively) but did not radiosensitize any cell line when combined with high-LET

Tank Z-361 dose rate calculations

International Nuclear Information System (INIS)

Richard, R.F.

1998-01-01

Neutron and gamma ray dose rates were calculated above and around the 6-inch riser of tank Z-361 located at the Plutonium Finishing Plant. Dose rates were also determined off of one side of the tank. The largest dose rate 0.029 mrem/h was a gamma ray dose and occurred 76.2 cm (30 in.) directly above the open riser. All other dose rates were negligible. The ANSI/ANS 1991 flux to dose conversion factor for neutrons and photons were used in this analysis. Dose rates are reported in units of mrem/h with the calculated uncertainty shown within the parentheses

Treatment of subclinical hypothyroidism in pregnancy using fixed thyroxine daily doses of 75 μg.

Science.gov (United States)

Penin, Manuel; Trigo, Cristina; López, Yolanda; Barragáns, María

2014-01-01

Treatment of hypothyroid pregnant women is usually calculated based on weight (1 μg/kg/day) and TSH levels. This study assessed the usefulness of treating these women with a fixed dose of 75 μg/day. All women with pregnancy diagnosed from January to August 2012 in the Vigo Health Area (Spain) without previous diagnosis of thyroid disease or thyroxine treatment and with TSH levels over 4,5 mUI/ml were enrolled by consecutive sampling. All 116 women in the sample were treated with a fixed daily dose of thyroxine 75 μg-thyroxine levels were measured at two, four, and six months, and thyroxine dose was modified if TSH level was lower than 0.3 or higher than 4.5 mUI/ml. A woman had a TSH level less than 0.3 mUI/ml in a test; reduction of thyroxine dose to 50 μg/day allowed for maintaining TSH level within the desired range until delivery. Six women had TSH levels over 4.5 mUI/ml in one test; in all of them, increase in thyroxine dose to 100 μg/day allowed for maintaining the level within the desired range until delivery. Fixed daily doses of thyroxine 75 μg allowed for achieving goal TSH levels in most of our pregnant women with subclinical hypothyroidism, irrespective of their weight and baseline TSH level. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

Gemcitabine-loaded liposomes: rationale, potentialities and future perspectives

Directory of Open Access Journals (Sweden)

Federico C

2012-11-01

Full Text Available Cinzia Federico, Valeria M Morittu, Domenico Britti, Elena Trapasso, Donato CoscoDepartment of Health Sciences, Building of BioSciences, University “Magna Græcia” of Catanzaro, Campus Universitario “S Venuta”, Germaneto, ItalyAbstract: This review describes the strategies used in recent years to improve the biopharmaceutical properties of gemcitabine, a nucleoside analog deoxycytidine antimetabolite characterized by activity against many kinds of tumors, by means of liposomal devices. The main limitation of using this active compound is the rapid inactivation of deoxycytidine deaminase following administration in vivo. Consequently, different strategies based on its encapsulation/complexation in innovative vesicular colloidal carriers have been investigated, with interesting results in terms of increased pharmacological activity, plasma half-life, and tumor localization, in addition to decreased side effects. This review focuses on the specific approaches used, based on the encapsulation of gemcitabine in liposomes, with particular attention to the results obtained during the last 5 years. These approaches represent a valid starting point in the attempt to obtain a novel, commercializable drug formulation as already achieved for liposomal doxorubicin (Doxil®, Caelyx®.Keywords: gemcitabine, liposomes, multidrug, poly(ethylene glycol, tumors

Randomized comparative study of intravenous infusion of three different fixed doses of milrinone in pediatric patients with pulmonary hypertension undergoing open heart surgery.

Science.gov (United States)

Barnwal, Neeraj Kumar; Umbarkar, Sanjeeta Rajendra; Sarkar, Manjula Sudeep; Dias, Raylene J

2017-01-01

Pulmonary hypertension secondary to congenital heart disease is a common problem in pediatric patients presenting for open heart surgery. Milrinone has been shown to reduce pulmonary vascular resistance and pulmonary artery pressure in pediatric patients and neonates postcardiac surgery. We aimed to evaluate the postoperative outcome in such patients with three different fixed maintenance doses of milrinone. Patients were randomized into three groups. All patients received fixed bolus dose of milrinone 50 μg/kg on pump during rewarming. Following this, patients in low-dose group received infusion of milrinone at the rate of 0.375 μg/kg/min, medium-dose group received 0.5 μg/kg/min, and high-dose group received 0.75 μg/kg/min over 24 h. Heart rate, mean arterial pressure (MAP), mean airway pressure (MaP), oxygenation index (OI), and central venous pressure (CVP) were compared at baseline and 24 h postoperatively. Dose of inotropic requirement, duration of ventilatory support and Intensive Care Unit (ICU) stay were noted. MAP, MaP, OI, and CVP were comparable in all three groups postoperatively. All patients in the low-dose group required low inotropic support while 70% of patients in the high-dose group needed high inotropic support to manage episodes of hypotension (P = 0.000). Duration of ventilatory support and ICU stay in all three groups was comparable (P = 0.412, P = 0.165). Low-dose infusions while having a clinical impact were more beneficial in avoiding adverse events and decreasing inotropic requirement without affecting duration of ventilatory support and duration of ICU stay.

Measurement of dose rates and Monte Carlo analysis of neutrons in a spent-fuel shipping vessel

International Nuclear Information System (INIS)

Ueki, K.; Namito, Y.; Fuse, T.

1986-01-01

On-board experiments were carried out in a spent-fuel shipping vessel, the Pacific Swan, in which 13 casks of TN-12A and Excellox 3 were loaded in five holds, and neutron and gamma-ray dose rates were measured on the hatch covers of the holds. Before shipping those casks, dose rates were also measured on the cask surfaces, one by one, to eliminate radiation from other casks. The Monte Carlo coupling technique was employed successfully to analyze the measured neutron dose rate distributions in the spent-fuel shipping vessel. Through this study, the Monte Carlo coupling code system, MORSE-CG/CASK-VESSEL, on which the MORSE-CG code was based, was established. The agreement between the measured and the calculated neutron dose rates on the TN-12A cask surface was quite satisfactory. The calculated neutron dose rates agreed with the measured values within a factor of 1.5 on the hold 3 hatch cover and within a factor of 2 on the hold 5 hatch cover in which the concrete shield was fixed in the Pacific Swan

Management strategy 3: fixed rate fertilizer applications

Science.gov (United States)

Previous chapters outlined management strategies for pond fertilization that take into account specific individual pond nutrient needs. Those methods would most likely be more ecologically efficient than a pre-determined fixed-rate nutrient addition strategy. However, the vast majority of available ...

Concurrent Radiotherapy and Gemcitabine for Unresectable Pancreatic Adenocarcinoma: Impact of Adjuvant Chemotherapy on Survival

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Kazuhiko, E-mail: kogawa@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, Okinawa (Japan); Ito, Yoshinori [Department of Radiation Oncology, National Cancer Center, Tokyo (Japan); Hirokawa, Naoki [Department of Radiology, Sapporo Medical University, Sapporo (Japan); Shibuya, Keiko [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto (Japan); Kokubo, Masaki [Department of Radiation Oncology, Institute of Biomedical Research and Innovation Hospital, Kobe (Japan); Ogo, Etsuyo [Department of Radiation Oncology, Kurume University, Kurume (Japan); Shibuya, Hitoshi [Department of Radiology, Tokyo Medical and Dental University, Tokyo (Japan); Saito, Tsutomu [Department of Radiation Oncology, Nihon University Itabashi Hospital, Tokyo (Japan); Onishi, Hiroshi [Department of Radiology, Yamanashi University, Yamanashi (Japan); Karasawa, Katsuyuki [Department of Radiation Oncology, Tokyo Metropolitan Komagome Hospital, Tokyo (Japan); Nemoto, Kenji [Department of Radiation Oncology, Yamagata University, Yamagata (Japan); Nishimura, Yasumasa [Department of Radiation Oncology, Kinki University School of Medicine, Osaka (Japan)

2012-06-01

Purpose: To retrospectively analyze results of concurrent chemoradiotherapy (CCRT) using gemcitabine (GEM) for unresectable pancreatic adenocarcinoma. Methods and Materials: Records of 108 patients treated with concurrent external beam radiotherapy (EBRT) and GEM were reviewed. The median dose of EBRT in all 108 patients was 50.4 Gy (range, 3.6-60.8 Gy), usually administered in conventional fractionations (1.8-2 Gy/day). During radiotherapy, most patients received GEM at a dosage of 250 to 350 mg/m{sup 2} intravenously weekly for approximately 6 weeks. After CCRT, 59 patients (54.6%) were treated with adjuvant chemotherapy (AC), mainly with GEM. The median follow-up for all 108 patients was 11.0 months (range, 0.4-37.9 months). Results: Initial responses after CCRT for 85 patients were partial response: 26 patients, no change: 51 patients and progressive disease: 8 patients. Local progression was observed in 35 patients (32.4%), and the 2-year local control (LC) rate in all patients was 41.9%. Patients treated with total doses of 50 Gy or more had significantly more favorable LC rates (2-year LC rate, 42.9%) than patients treated with total doses of less than 50 Gy (2-year LC rate, 29.6%). Regional lymph node recurrence was found in only 1 patient, and none of the 57 patients with clinical N0 disease had regional lymph node recurrence. The 2-year overall survival (OS) rate and the median survival time in all patients were 23.5% and 11.6 months, respectively. Patients treated with AC had significantly more favorable OS rates (2-year OS, 31.8%) than those treated without AC (2-year OS, 12.4%; p < 0.0001). On multivariate analysis, AC use and clinical T stage were significant prognostic factors for OS. Conclusions: CCRT using GEM yields a relatively favorable LC rate for unresectable pancreatic adenocarcinoma, and CCRT with AC conferred a survival benefit compared to CCRT without AC.

Clinical benefit of fixed-dose dual bronchodilation with glycopyrronium and indacaterol once daily in patients with chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Ulrik, Charlotte Suppli

2014-01-01

BACKGROUND AND AIM: Long-acting bronchodilators are the preferred option for maintenance therapy of patients with chronic obstructive pulmonary disease (COPD). The aim of this review is to provide an overview of the clinical studies evaluating the clinical efficacy of the once-daily fixed-dose du...... for chronic Obstructive Lung Disease [GOLD] spirometric criteria). Furthermore, a very recent study has shown that fixed-dose indacaterol/glycopyrronium improves exercise endurance time compared with placebo, although no significant difference was observed between fixed-dose indacaterol...

Dose/dose-rate responses of shrimp larvae to UV-B radiation

International Nuclear Information System (INIS)

Damkaer, D.M.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm -2 sub([DNA]) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm -2 sub([DNA]). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation. (orig.)

Dose/dose-rate responses of shrimp larvae to UV-B radiation

Energy Technology Data Exchange (ETDEWEB)

Damkaer, D.M.; Dey, D.B.; Heron, G.A.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm/sup -2/sub((DNA)) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm/sup -2/sub((DNA)). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation.

Measuring the absorbed dose in critical organs during low rate dose brachytherapy with 137 Cs using thermoluminescent dosemeters

International Nuclear Information System (INIS)

Torres, A.; Gonzalez, P.R.; Furetta, C.; Azorin, J.; Andres, U.; Mendez, G.

2003-01-01

Intracavitary Brachytherapy is one of the most used methods for the treatment of the cervical-uterine cancer. This treatment consists in the insertion of low rate dose 137 Cs sources into the patient. The most used system for the treatment dose planning is that of Manchester. This planning is based on sources, which are considered fixed during the treatment. However, the experience has shown that, during the treatment, the sources could be displaced from its initial position, changing the dose from that previously prescribed. For this reason, it is necessary to make measurements of the absorbed dose to the surrounding organs (mainly bladder and rectum). This paper presents the results of measuring the absorbed dose using home-made LiF: Mg, Cu, P + Ptfe thermoluminescent dosimeters (TLD). Measurements were carried out in-vivo during 20 minutes at the beginning and at the end of the treatments. Results showed that the absorbed dose to the critical organs vary significantly due to the movement of the patient during the treatment. (Author)

The colorimetric analysis of anti-tuberculosis fixed-dose combination tablets and capsules.

Science.gov (United States)

Ellard, G A

1999-11-01

The perceived need to demonstrate whether or not the actual amounts of rifampicin, isoniazid and pyrazinamide in fixed-dose combination tablets or capsules correspond to their stated drug contents. To adapt specific, robust and simple colorimetric methods that have been previously applied to measuring plasma and urinary rifampicin, isoniazid, pyrazinamide and ethambutol concentrations to estimate tablet and capsule drug contents. The methods were applied to the analysis of 14 commercially manufactured fixed-dose combinations: two capsule and three tablet formulations containing rifampicin and isoniazid; seven tablet formulations containing rifampicin, isoniazid and pyrazinamide; and two tablet formulations containing rifampicin, isoniazid, pyrazinamide and ethambutol. All the combined formulations contained near to their stated drug contents. Replicate analyses confirmed the excellent precision of the drug analyses. Such methods are not only rapid to perform but should be practical in many Third World situations with relatively modest laboratory facilities.

[Fixed-dose combination fluticasone propionate/formoterol for the treatment of asthma: a review of its pharmacology, efficacy and tolerability].

Science.gov (United States)

Quintano Jiménez, J A; Ginel Mendoza, L; Entrenas Costa, L M; Polo García, J

2016-02-01

The fixed-dose combination fluticasone propionate/formoterol (FPF) is a novel combination of a widely known and used inhaled glucocorticoid (IGC) and a long-acting β2-adrenergic agonist (LABA), available for the first time in a single device. This fixed-dose combination of FPF has a demonstrated efficacy and safety profile in clinical trials compared with its individual components and other fixed-dose combinations of IGC/LABA and is indicated for the treatment of persistent asthma in adults and adolescents. FPF is available in a wide range of doses that can adequately cover the therapeutic steps recommended by treatment guidelines, constituting a fixed-dose combination of GCI/LABA that is effective, rapid, well tolerated and with a reasonable acquisition cost. Various assessment agencies of the Spanish Autonomous Communities consider this combination to be an appropriate alternative therapy for asthma in the primary care setting. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Medicina Rural y Generalista (SEMERGEN). All rights reserved.

Effects of trapped proton flux anisotropy on dose rates in low Earth orbit

International Nuclear Information System (INIS)

Badhwar, G.D.; Kushin, V.V.; Akatov, Yu A.; Myltseva, V.A.

1999-01-01

Trapped protons in the South Atlantic Anomaly (SAA) have a rather narrow pitch angle distribution and exhibit east-west anisotropy. In low Earth orbits, the E-W effect results in different amounts of radiation dose received by different sections of the spacecraft. This effect is best studied on missions in which the spacecraft flies in a fixed orientation. The magnitude of the effect depends on the particle energy and altitude through the SAA. In this paper, we describe a clear example of this effect from measurements of radiation dose rates and linear energy transfer spectra made on Space Shuttle flight STS-94 (28.5 deg. inclination x 296 km altitude). The ratio of dose rates from the two directions at this location in the mid-deck was 2.7. As expected from model calculations, the spectra from the two directions are different, that is the ratio is energy dependent. The data can be used to distinguish the anisotropy models. The flight carried an active tissue equivalent proportional counter (TEPC), and passive thermoluminscent detectors (TLDs), and two types of nuclear emulsions. Using nuclear emulsions, charged particles and secondary neutron energy spectra were measured. The combined galactic cosmic radiation+trapped charged particle lineal energy spectra measured by the TEPC and the linear energy transfer spectrum measured by nuclear emulsions are in good agreement. The charged particle absorbed dose rates varied from 112 to 175 μGy/day, and dose equivalent rates from 264.3 to 413 μSv/day. Neutrons in the 1-10 MeV contributed a dose rate of 3.7 μGy/day and dose equivalent rate of 30.8 μSv/day, respectively

Effects of trapped proton flux anisotropy on dose rates in low Earth orbit.

Science.gov (United States)

Badhwar, G D; Kushin, V V; Akatov YuA; Myltseva, V A

1999-06-01

Trapped protons in the South Atlantic Anomaly (SAA) have a rather narrow pitch angle distribution and exhibit east-west anisotropy. In low Earth orbits, the E-W effect results in different amounts of radiation dose received by different sections of the spacecraft. This effect is best studied on missions in which the spacecraft flies in a fixed orientation. The magnitude of the effect depends on the particle energy and altitude through the SAA. In this paper, we describe a clear example of this effect from measurements of radiation dose rates and linear energy transfer spectra made on Space Shuttle flight STS-94 (28.5 degree inclination x 296 km altitude). The ratio of dose rates from the two directions at this location in the mid-deck was 2.7. As expected from model calculations, the spectra from the two directions are different, that is the ratio is energy dependent. The data can be used to distinguish the anisotropy models. The flight carried an active tissue equivalent proportional counter (TEPC), and passive thermoluminscent detectors (TLDs), and two types of nuclear emulsions. Using nuclear emulsions, charged particles and secondary neutron energy spectra were measured. The combined galactic cosmic radiation+trapped charged particle lineal energy spectra measured by the TEPC and the linear energy transfer spectrum measured by nuclear emulsions are in good agreement. The charged particle absorbed dose rates varied from 112 to 175 microGy/day, and dose equivalent rates from 264.3 to 413 microSv/day. Neutrons in the 1-10 MeV contributed a dose rate of 3.7 microGy/day and dose equivalent rate of 30.8 microSv/day, respectively.

Bretton Woods Fixed Exchange Rate System versus Floating Exchange Rate System

OpenAIRE

Geza, Paula; Giurca Vasilescu, Laura

2011-01-01

One of the most important issues of monetary policy is to find out whether the state should intervene among the exchange rates, taking into account the fact that changes in the exchange rates represent a significant transmission channel of the effects generated by the monetary policy. Taking into consideration the failure of fixed exchange rate regimes and the recent improvement of financial markets, the return in the near future to such a regime – as for example the Bretton Woods system –...

Global radiation damage at 300 and 260 K with dose rates approaching 1 MGy s{sup −1}

Energy Technology Data Exchange (ETDEWEB)

Warkentin, Matthew; Badeau, Ryan; Hopkins, Jesse B. [Cornell University, Ithaca, NY 14853 (United States); Mulichak, Anne M.; Keefe, Lisa J. [Argonne National Laboratory, Argonne, IL 60439 (United States); Thorne, Robert E., E-mail: ret6@cornell.edu [Cornell University, Ithaca, NY 14853 (United States)

2012-02-01

Approximately half of global radiation damage to thaumatin crystals can be outrun at 260 K if data are collected in less than 1 s. Global radiation damage to 19 thaumatin crystals has been measured using dose rates from 3 to 680 kGy s{sup −1}. At room temperature damage per unit dose appears to be roughly independent of dose rate, suggesting that the timescales for important damage processes are less than ∼1 s. However, at T = 260 K approximately half of the global damage manifested at dose rates of ∼10 kGy s{sup −1} can be outrun by collecting data at 680 kGy s{sup −1}. Appreciable sample-to-sample variability in global radiation sensitivity at fixed dose rate is observed. This variability cannot be accounted for by errors in dose calculation, crystal slippage or the size of the data sets in the assay.

SL-01, an oral derivative of gemcitabine, inhibited human breast cancer growth through induction of apoptosis

International Nuclear Information System (INIS)

Li, Yuan-Yuan; Qin, Yi-Zhuo; Wang, Rui-Qi; Li, Wen-Bao; Qu, Xian-Jun

2013-01-01

Highlights: •SL-01 is an oral derivative of gemcitabine. •SL-01 possessed activity against human breast cancer growth via apoptotic induction. •SL-01’s activity was more potently than that of gemcitabine. •SL-01 inhibited cancer growth without toxicity to mice. -- Abstract: SL-01 is an oral derivative of gemcitabine that was synthesized by introducing the moiety of 3-(dodecyloxycarbonyl) pyrazine-2-carbonyl at N4-position on cytidine ring of gemcitabine. We aimed to evaluate the efficacy of SL-01 on human breast cancer growth. SL-01 significantly inhibited MCF-7 proliferation as estimated by colorimetric assay. Flow cytometry assay indicated the apoptotic induction and cell cycle arrest in G1 phase. SL-01 modulated the expressions of p-ATM, p53 and p21 and decrease of cyclin D1 in MCF-7 cells. Further experiments were performed in a MCF-7 xenografts mouse model. SL-01 by oral administration strongly inhibited MCF-7 xenografts growth. This effect of SL-01 might arise from its roles in the induction of apoptosis. Immunohistochemistry assay showed the increase of TUNEL staining cells. Western blotting indicated the modulation of apoptotic proteins in SL-01-treated xenografts. During the course of study, there was no evidence of toxicity to mice. In contrast, the decrease of neutrophil cells in peripheral and increase of AST and ALT levels in serum were observed in the gemcitabine-treated mice. Conclusion: SL-01 possessed similar activity against human breast cancer growth with gemcitabine, whereas, with lower toxicity to gemcitabine. SL-01 is a potent oral agent that may supplant the use of gemcitabine

Management of advanced pancreatic cancer with gemcitabine plus erlotinib: efficacy and safety results in clinical practice.

Science.gov (United States)

Diaz Beveridge, Robert; Alcolea, Vicent; Aparicio, Jorge; Segura, Ángel; García, Jose; Corbellas, Miguel; Fonfría, María; Giménez, Alejandra; Montalar, Joaquin

2014-01-10

The combination of gemcitabine and erlotinib is a standard first-line treatment for unresectable, locally advanced or metastatic pancreatic cancer. We reviewed our single centre experience to assess its efficacy and toxicity in clinical practice. Clinical records of patients with unresectable, locally advanced or metastatic pancreatic cancer who were treated with the combination of gemcitabine and erlotinib were reviewed. Univariate survival analysis and multivariate analysis were carried out to indentify independent predictors factors of overall survival. Our series included 55 patients. Overall disease control rate was 47%: 5% of patients presented complete response, 20% partial response and 22% stable disease. Median overall survival was 8.3 months). Cox regression analysis indicated that performance status and locally advanced versus metastatic disease were independent factors of overall survival. Patients who developed acne-like rash toxicity, related to erlotinib administration, presented a higher survival than those patients who did not develop this toxicity. Gemcitabine plus erlotinib doublet is active in our series of patients with advanced pancreatic cancer. This study provides efficacy and safety results similar to those of the pivotal phase III clinical trial that tested the same combination.

Randomized comparative study of intravenous infusion of three different fixed doses of milrinone in pediatric patients with pulmonary hypertension undergoing open heart surgery

Directory of Open Access Journals (Sweden)

Neeraj Kumar Barnwal

2017-01-01

Full Text Available Background: Pulmonary hypertension secondary to congenital heart disease is a common problem in pediatric patients presenting for open heart surgery. Milrinone has been shown to reduce pulmonary vascular resistance and pulmonary artery pressure in pediatric patients and neonates postcardiac surgery. We aimed to evaluate the postoperative outcome in such patients with three different fixed maintenance doses of milrinone. Methodology: Patients were randomized into three groups. All patients received fixed bolus dose of milrinone 50 μg/kg on pump during rewarming. Following this, patients in low-dose group received infusion of milrinone at the rate of 0.375 μg/kg/min, medium-dose group received 0.5 μg/kg/min, and high-dose group received 0.75 μg/kg/min over 24 h. Heart rate, mean arterial pressure (MAP, mean airway pressure (MaP, oxygenation index (OI, and central venous pressure (CVP were compared at baseline and 24 h postoperatively. Dose of inotropic requirement, duration of ventilatory support and Intensive Care Unit (ICU stay were noted. Results: MAP, MaP, OI, and CVP were comparable in all three groups postoperatively. All patients in the low-dose group required low inotropic support while 70% of patients in the high-dose group needed high inotropic support to manage episodes of hypotension (P = 0.000. Duration of ventilatory support and ICU stay in all three groups was comparable (P = 0.412, P = 0.165. Conclusion: Low-dose infusions while having a clinical impact were more beneficial in avoiding adverse events and decreasing inotropic requirement without affecting duration of ventilatory support and duration of ICU stay.

ADAM15 is involved in MICB shedding and mediates the effects of gemcitabine on MICB shedding in PANC-1 pancreatic cancer cells.

Science.gov (United States)

Duan, Xiaohui; Mao, Xianhai; Sun, Weijia

2013-03-01

The aim of this study was to investigate the role of ADAM15 in MHC class I polypeptide-related sequence B (MICB) protein ectodomain shedding and observe whether or not gemcitabine affects MICB shedding from PANC-1 cells. In this study, immunohistochemistry of MICB and ADAM15 were performed on tumor samples obtained from 93 patients with pancreatic ductal adenocarcinoma (PDAC). The expression of MICB and ADAM15 in the PDAC tissues was significantly higher compared with that in the normal tissues of the pancreas. Statistical analysis showed a significant correlation between the expression of MICB and certain classic clinicopathological characteristics (i.e., histological grade and TNM stage). ADAM15 expression was found to correlate with lymph node metastasis and TNM stage. The Spearman's rank test suggested that the expression of MICB was inversely correlated with that of ADAM15 in PDAC tissues. Knockdown of ADAM15 in PANC-1 cells clearly upregulated MICB expression on the cellular surface and downregulated soluble MICB (sMICB) levels in the culture supernatants. A non-toxic dose of 0.5 µmol/l gemcitabine suppresses ADAM15 expression leading, at the same time, to an increase in MICB expression and a decrease in sMICB production in PANC-1 cells. The mRNA levels of MICB did not change following PANC-1 exposure to gemcitabine. Further study suggests that the suppressive effect of gemcitabine on MICB shedding in PANC-1 cells is mediated by ADAM15 downregulation. In conclusion, the results of the present study support the hypothesis that ADAM15 is involved in MICB shedding of PANC-1 cells and that gemcitabine inhibits MICB ectodomain shedding through the suppression of ADAM15.

Outdoor γ-ray dose rate in Shariki Village and environmental factors affecting outdoor γ-ray dose rate in IES

International Nuclear Information System (INIS)

Iyogi, Takashi; Hisamatsu, Shun'ichi; Inaba, Jiro

2000-01-01

Previously, we surveyed the outdoor γ-ray dose rate throughout Aomori Prefecture from 1992 to 1995, and found an annual mean dose rate of 51 nGy h -1 . Relatively high dose rates were also observed in several areas (municipalities) of the survey locations. In this study, we examined the detailed distribution of the γ-ray dose rate in one such high dose rate area, Shariki Village. Glass dosemeters were used for the monitoring of cumulative γ-ray dose rate at 10 locations in the village. The dose rate from each radioactive nuclide in the ground at the monitoring locations was measured by using an in situ γ-ray spectrometer with a Ge detector. The results obtained with the glass dosemeters showed that the γ-ray dose rates in Shariki Village varied from 49 to 55 nGy h -1 . Although the dose rates were generally higher than the mean dose in Aomori Prefecture (1992-1995), the rates were lower than other high dose rate areas which had already been measured. The in situ γ-ray spectrometry revealed that these relatively high dose rates were mainly caused by 40 K and Th series radionuclides in the village. The effect of meteorological conditions on the γ-ray dose rate was studied at a monitoring station in the IES site. The dose rate was continuously recorded by a DBM NaI(Tl) scintillation detector system. The mean dose rate obtained when precipitation was sensed was 27 nGy h -1 and higher than when no precipitation was sensed (25 nGy h -1 ). (author)

Outdoor γ-ray dose rate in Mutsu city and environmental factors affecting outdoor γ-ray dose rate in IES

International Nuclear Information System (INIS)

Iyogi, Takashi; Hisamatsu, Shun'ichi; Inaba, Jiro

2001-01-01

Previously, we surveyed outdoor γ-ray dose rates throughout Aomori Prefecture from 1992 to 1995, and found a mean annual dose rate of 28 nGy h -1 . Relatively high dose rates were also observed in several areas (municipalities) of the survey locations. In this study, we examined the detailed distribution of the γ-ray dose rate in one such high dose rate area, Mutsu City. Glass dosemeters were used for the monitoring of cumulative γ-ray dose rate at 10 locations in the city. The dose rate from each radioactive nuclide in the ground at the monitoring locations was measured by using an in situ γ-ray spectrometer with a Ge detector. The results obtained with the glass dosemeters showed that the γ-ray dose rates in Mutsu City varied from 17 to 32 nGy h -1 . Although the dose rates were almost the same as the mean dose in Aomori Prefecture (1992-1995), the rates were lower than other high dose rate areas which had already been measured. The in situ γ-ray spectrometry revealed that these relatively high dose rates were mainly caused by 40 K and Th series radionuclides in the local ground. The effect of meteorological conditions on the γ-ray dose rate was studied at a monitoring station in the IES site. The dose rate was continuously recorded by a DBM NaI(Tl) scintillation detector system. The mean dose rate obtained when precipitation was sensed was 26 nGy h -1 and higher than when no precipitation was sensed (24 nGy h -1 ). (author)

Spontaneous mutation rates and the rate-doubling dose

International Nuclear Information System (INIS)

Von Borstel, R.C.; Moustaccki, E.; Latarjet, R.

1978-01-01

The amount of radiation required to double the frequency of mutations or tumours over the rate of those that occur spontaneously is called the rate-doubling dose. An equivalent concept has been proposed for exposure to other environmental mutagens. The doubling dose concept is predicated on the assumption that all human populations have the same spontaneous mutation rate, and that this spontaneous mutation rate is known. It is now established for prokaryotes and lower eukaryotes that numerous genes control the spontaneous mutation rate, and it is likely that the same is true for human cells as well. Given that the accepted mode of evolution of human populatons is from small, isolated groups of individuals, it seems likely that each population would have a different spontaneous mutation rate. Given that a minimum of twenty genes control or affect the spontaneous mutation rate, and that each of these in turn is susceptible to spontaneously arising or environmentally induced mutations, it seems likely that every individual within a population (except for siblings from identical multiple births) will have a unique spontaneous mutation rate. If each individual in a population does have a different spontaneous mutation rate, the doubling dose concept, in rigorous terms, is fallacious. Therefore, as with other concepts of risk evaluation, the doubling dose concept is subject to criticism. Nevertheless, until we know individual spontaneous mutation rates with precision, and can evaluate risks based on this information, the doubling dose concept has a heuristic value and is needed for practical assessment of risks for defined populations. (author)

Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice

International Nuclear Information System (INIS)

Ware, J.H.; Rusek, A.; Sanzari, J.; Avery, S.; Sayers, C.; Krigsfeld, G.; Nuth, M.; Wan, X.S.; Kennedy, A.R.

2010-01-01

The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice.

Science.gov (United States)

Ware, J H; Sanzari, J; Avery, S; Sayers, C; Krigsfeld, G; Nuth, M; Wan, X S; Rusek, A; Kennedy, A R

2010-09-01

The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

Comparison of the bronchodilatation produced by inhalation of ipratropium bromide and salbutamol sequentially and in fixed dose combination in stable bronchial asthma patients

Directory of Open Access Journals (Sweden)

Mohan A

2006-01-01

Full Text Available Objectives : The combination of a 43-2 agonist and an anticholinergic agent is of-ten used to manage bronchial asthma. However, it is unclear whether these drugs should be given separately in sequence or in a fixed dose combination for maximum effect. Methods : 27 patients with stable bronchial asthma were given the above two drugs in two separate sessions one week apart. In one session they were given the above two drugs as a fixed dose combination and in the other session, they were given se-quentially with salbutamol following ipratropium after 30 minutes. Spirometry was performed at baseline and 15, 30 and 60 minutes after inhaling the second drug. Results : Both groups showed significant improvement in forced vital capacity (FVC, forced expiratory time in one second (FEV 1 , peak expiratory flow rate (PEFR and forced expiratory flow (FEF 25-75 from baseline upto one hour. FVC increased initially and then stabilized; however, the increase was more sustained in the group getting combination treatment. This group also showed a higher rise in FEV 1 (p=0.02. Both FEV 1 and FEF 25-75 decreased after 30 minutes in the group that received sequential therapy. PEFR increased continuously till 60 minutes in both groups and there was no significant difference between them (p=0.98. Interpretation and Conclusion: Both methods of drug dosing produce equivalent bronchodilation. Fixed dose combinations produced a more sustained rise in FVC and higher increase in FEV 1 . Hence fixed dose combinations are more effective short-term bronchodilators and give an added advantage of reducing the number of inhalers required, thus improv-ing compliance.

Surface applicators for high dose rate brachytherapy in AIDS-related kaposi's sarcoma

International Nuclear Information System (INIS)

Evans, Michael D.C.; Yassa, Mariam; Podgorsak, Ervin B.; Roman, Ted N.; Schreiner, L. John; Souhami, Luis

1997-01-01

Purpose: The development of commercially available surface applicators using high dose rate remote afterloading devices has enabled radiotherapy centers to treat selected superficial lesions using a remote afterloading brachytherapy unit. The dosimetric parameters of these applicators, the clinical implementation of this technique, and a review of the initial patient treatment regimes are presented. Methods and Materials: A set of six fixed-diameter (1, 2, and 3 cm), tungsten/steel surface applicators is available for use with a single stepping-source (Ir-192, 370 GBq) high dose rate afterloader. The source can be positioned either in a parallel or perpendicular orientation to the treatment plane at the center of a conical aperture that sits at an SSD of approximately 15 mm and is used with a 1-mm thick removable plastic cap. The surface dose rates, percent depth dose, and off-axis ratios were measured. A custom-built, ceiling-mounted immobilization device secures the applicator on the surface of the patient's lesion during treatment. Results: Between November 1994, and September 1996, 16 AIDS-related Kaposi's sarcoma patients having a total of 120 lesions have been treated with palliative intent. Treatment sites were distributed between the head and neck, extremity, and torso. Doses ranged from 8 to 20 Gy, with a median dose of 10 Gy delivered in a single fraction. Treatments were well tolerated with minimal skin reaction, except for patients with lesions treated to 20 Gy who developed moderate/severe desquamation. Conclusion: Radiotherapy centers equipped with a high dose rate remote afterloading unit may treat small selected surface lesions with commercially available surface applicators. These surface applicators must be used with a protective cap to eliminate electron contamination. The optimal surface dose appears to be either 10 or 15 Gy depending upon the height of the lesion

Synergistic interaction between cisplatin and gemcitabine in neuroblastoma cell lines and multicellular tumor spheroids

NARCIS (Netherlands)

Besançon, Odette G.; Tytgat, Godelieve A. M.; Meinsma, Rutger; Leen, René; Hoebink, Jerry; Kalayda, Ganna V.; Jaehde, Ulrich; Caron, Huib N.; van Kuilenburg, André B. P.

2012-01-01

The efficacy and mechanism of action of cisplatin and gemcitabine were investigated in a panel of neuroblastoma cell lines and multicellular tumor spheroids. In neuroblastoma spheroids, the combination of cisplatin and gemcitabine induced a complete cytostasis at clinical relevant concentrations. A

Determination of carcinogenic threshold limit values using the tumorigenic dose rate 50% (TD50)

International Nuclear Information System (INIS)

Bonvalot, Y.; Oudiz, A.; Hubert, P.; Abenhaim, L.

1989-01-01

The objective of the present study is to propose a simple procedure for the determination of Occupational Limit Values (OLVs) based on the TD 50 concept (Tumorigenic Dose Rate 50%). The TD 50 concept was introduced by Peto R. and al. to help classify chemical substances according to their carcinogenic potency. The TD 50 is that dose rate (in mg/KXg body weight/day) which, if administered chronically for the standard lifespan of the species will halve the probability of remaining tumorless throughout that period. Using TD 50 values available for 776 substances, the procedure presented here allows one to determine OLVs corresponding to a fixed excess risk. It is based on a mathematical high-to-low doses extrapolation of the TD 50 . OLVs obtained with this procedure are compared with currently available TLVs and other occupational guidelines. (author)

Efficacy and Tolerability of Fixed-Dose Combination of Dexketoprofen and Dicyclomine Injection in Acute Renal Colic

Directory of Open Access Journals (Sweden)

A. Porwal

2012-01-01

Full Text Available Objective. To evaluate the efficacy and tolerability of a fixed-dose combination of dexketoprofen and dicyclomine (DXD injection in patients with acute renal colic. Patients and Methods. Two hundred and seventeen patients were randomized to receive either DXD (n=109 or fixed-dose combination of diclofenac and dicyclomine injection (DLD; n=108, intramuscularly. Pain intensity (PI was self-evaluated by patients on visual analogue scale (VAS at baseline and at 1, 2, 4, 6, and 8 hours. Efficacy parameters were proportion of responders, difference in PI (PID at 8 hours, and sum of analogue of pain intensity differences (SAPID. Tolerability was assessed by patients and physicians. Results. DXD showed superior efficacy in terms of proportion of responders (98.17% versus 81.48; P<0.0001, PID at 8 hours (P=0.002, and SAPID0–8 hours (P=0.004. The clinical global impression for change in pain was significantly better for DXD than DLD. The incidence of adverse events was comparable in both groups. However, global assessment of tolerability was rated significantly better for DXD. Conclusion. DXD showed superior efficacy and tolerability than DLD in patients clinically diagnosed to be suffering from acute renal colic.

Efficacy and Tolerability of Fixed-Dose Combination of Dexketoprofen and Dicyclomine Injection in Acute Renal Colic

Science.gov (United States)

Porwal, A.; Mahajan, A. D.; Oswal, D. S.; Erram, S. S.; Sheth, D. N.; Balamurugan, S.; Kamat, V.; Enadle, R. P.; Badadare, A.; Bhatnagar, S. K.; Walvekar, R. S.; Dhorepatil, S.; Naik, R. C.; Basu, I.; Kshirsagar, S. N.; Keny, J. V.; Sengupta, S.

2012-01-01

Objective. To evaluate the efficacy and tolerability of a fixed-dose combination of dexketoprofen and dicyclomine (DXD) injection in patients with acute renal colic. Patients and Methods. Two hundred and seventeen patients were randomized to receive either DXD (n = 109) or fixed-dose combination of diclofenac and dicyclomine injection (DLD; n = 108), intramuscularly. Pain intensity (PI) was self-evaluated by patients on visual analogue scale (VAS) at baseline and at 1, 2, 4, 6, and 8 hours. Efficacy parameters were proportion of responders, difference in PI (PID) at 8 hours, and sum of analogue of pain intensity differences (SAPID). Tolerability was assessed by patients and physicians. Results. DXD showed superior efficacy in terms of proportion of responders (98.17% versus 81.48; P < 0.0001), PID at 8 hours (P = 0.002), and SAPID0–8 hours (P = 0.004). The clinical global impression for change in pain was significantly better for DXD than DLD. The incidence of adverse events was comparable in both groups. However, global assessment of tolerability was rated significantly better for DXD. Conclusion. DXD showed superior efficacy and tolerability than DLD in patients clinically diagnosed to be suffering from acute renal colic. PMID:22577544

Spillover adherence effects of fixed-dose combination HIV therapy

Directory of Open Access Journals (Sweden)

Kauf TL

2012-02-01

Full Text Available Teresa L Kauf1, Keith L Davis2, Stephanie R Earnshaw2, E Anne Davis31Department of Pharmaceutical Outcomes and Policy, College of Pharmacy, University of Florida, Gainesville, FL, 2RTI Health Solutions, Research Triangle Park, NC, 3Independent consultant, Pittsboro, NC, USAAbstract: The impact of fixed-dose combination (FDC products on adherence to other, non-fixed regimen components has not been examined. We compared adherence to a third antiretroviral (ART component among patients receiving a nucleoside reverse transcriptase inhibitor (NRTI backbone consisting of the FDC Epzicom®, GlaxoSmithKline Inc, Research Triangle Park, NC (abacavir sulfate 600 mg + lamivudine 300 mg; FDC group versus NRTI combinations taken as two separate pills (NRTI Combo group using data from a national sample of 30 health plans covering approximately 38 million lives from 1997 to 2005. Adherence was measured as the medication possession ratio (MPR. Multivariate logistic regression compared treatment groups based on the likelihood of achieving ≥95% adherence, with sensitivity analyses using alternative thresholds. MPR was assessed as a continuous variable using multivariate linear regression. Covariates included age, gender, insurance payer type, year of study drug initiation, presence of mental health and substance abuse disorders, and third agent class. The study sample consisted of 650 FDC and 1947 NRTI Combo patients. Unadjusted mean adherence to the third agent was higher in the FDC group than the NRTI Combo group (0.92 vs 0.85; P < 0.0001. In regression analyses, FDC patients were 48% and 39% more likely to achieve 95% and 90% third agent adherence, respectively (P ≤ 0.03. None of the other MPR specifications achieved comparable results. Among managed care patients, use of an FDC appears to substantially improve adherence to a third regimen component and thus the likelihood of achieving the accepted standard for adherence to HIV therapy of 95%.Keywords

Is the fixed-dose combination of telmisartan and hydrochlorothiazide a good approach to treat hypertension?

Directory of Open Access Journals (Sweden)

Marc P Maillard

2007-07-01

Full Text Available Marc P Maillard, Michel BurnierService of Nephrology, Department of Internal Medicine, Lausanne University Hospital, SwitzerlandAbstract: Blockade of the renin-angiotensin system with selective AT1 receptor antagonists is recognized as an effective mean to lower blood pressure in hypertensive patients. Among the class of AT1 receptor antagonists, telmisartan offers the advantage of a very long half-life. This enables blood pressure control over 24 hours using once-daily administration. The combination of telmisartan with hydrochlorothiazide is a logical step because numerous previous studies have demonstrated that sodium depletion enhances the antihypertensive efficacy of drugs interfering with the activity of the renin-angiotensin system (RAS. In accordance with past experience using similar compounds blocking the RAS, several controlled studies have now demonstrated that the fixed-dose combination of telmisartan/hydrochlorothiazide is superior in lowering blood pressure than either telmisartan or hydrochlorothiazide alone. Of clinical interest also is the observation that the excellent clinical tolerance of the angiotensin II receptor antagonist is not affected by the association of the low-dose thiazide. Thus telmisartan/hydrochlorothiazide is an effective and well-tolerated antihypertensive combination. Finally, the development of fixed-dose combinations should improve drug adherence because of the one-pill-a-day regimen.Keywords: telmisartan, hydrochlorothiazide, fixed-dose combinations, antihypertensive agent, safety, compliance

Sensitization of Tumor to 212Pb Radioimmunotherapy by Gemcitabine Involves Initial Abrogation of G2 Arrest and Blocked DNA Damage Repair by Interference With Rad51

International Nuclear Information System (INIS)

Yong, Kwon Joong; Milenic, Diane E.; Baidoo, Kwamena E.; Brechbiel, Martin W.

2013-01-01

Purpose: To elucidate the mechanism of the therapeutic efficacy of targeted α-particle radiation therapy using 212 Pb-TCMC-trastuzumab together with gemcitabine for treatment of disseminated peritoneal cancers. Methods and Materials: Mice bearing human colon cancer LS-174T intraperitoneal xenografts were pretreated with gemcitabine, followed by 212 Pb-TCMC-trastuzumab and compared with controls. Results: Treatment with 212 Pb-TCMC-trastuzumab increased the apoptotic rate in the S-phase-arrested tumors induced by gemcitabine at earlier time points (6 to 24 hours). 212 Pb-TCMC-trastuzumab after gemcitabine pretreatment abrogated G2/M arrest at the same time points, which may be associated with the inhibition of Chk1 phosphorylation and, in turn, cell cycle perturbation, resulting in apoptosis. 212 Pb-TCMC-trastuzumab treatment after gemcitabine pretreatment caused depression of DNA synthesis, DNA double-strand breaks, accumulation of unrepaired DNA, and down-regulation of Rad51 protein, indicating that DNA damage repair was blocked. In addition, modification in the chromatin structure of p21 may be associated with transcriptionally repressed chromatin states, indicating that the open structure was delayed at earlier time points. Conclusion: These findings suggest that the cell-killing efficacy of 212 Pb-TCMC-trastuzumab after gemcitabine pretreatment may be associated with abrogation of the G2/M checkpoint, inhibition of DNA damage repair, and chromatin remodeling

Hardness, function, emotional well-being, satisfaction and the overall sexual experience in men using 100-mg fixed-dose or flexible-dose sildenafil citrate.

Science.gov (United States)

Ströberg, P; Kaminetsky, J C; Park, N C; Goldfischer, E R; Creanga, D L; Stecher, V J

2010-01-01

The prescribing information for sildenafil citrate (VIAGRA, Pfizer, New York, NY, USA) recommends flexible dosing (50 mg initially, adjusted to 100 or 25 mg based on effectiveness and tolerability) in most men with erectile dysfunction (ED). In many men, however, 100 mg may be the most appropriate initial dose because it would reduce the need for titration and could prevent discouragement and treatment abandonment should 50 mg be insufficient. Results of two previously published double-blind, placebo-controlled sildenafil trials of similar design except for a fixed-dose vs flexible-dose regimen were analyzed. Relative to the flexible-dose, approximately one-third more men were satisfied with an initial and fixed dose of 100 mg. In addition, tolerability was similar, and improvements from baseline in outcomes on validated, ED-specific, patient-reported questionnaires were either similar (erectile function and the percentage of completely hard and fully rigid erections) or greater (emotional well-being and the overall sexual experience). The similarity in outcomes is not surprising given that almost 90% of the men in the flexible-dose trial titrated to 100 mg after 2 weeks. These data suggest prescription of an initial dose of 100 mg for men with ED, except in those for whom it is inappropriate.

A case of progressive hypertension preceding gemcitabine-associated thrombotic microangiopathy complicated by acute kidney injury and stroke.

LENUS (Irish Health Repository)

Phelan, Paul J

2009-01-01

Gemcitabine-associated thrombotic microangiopathy is being increasingly recognized as a serious complication of treatment. We report a normotensive patient who developed progressive hypertension after commencing gemcitabine therapy. She also developed subtle changes in her platelet count and serum creatinine months before her emergent presentation. Clinicians should be aware of new onset or worsening hypertension and \\'mild\\' biochemical changes in gemcitabine-treated patients.

Zero-Outage Cellular Downlink with Fixed-Rate D2D Underlay

DEFF Research Database (Denmark)

Kiilerich Pratas, Nuno; Popovski, Petar

2015-01-01

. D2D connections can be instrumental in localized aggregation of uplink M2M traffic to a more capable cellular device, before being finally delivered to the Base Station (BS). In this paper we show that a fixed M2M rate is an enabler of efficient Machine-Type D2D underlay operation taking place......, but not the interfering channels from the MTDs to U, we prove that there is a positive downlink rate that can always be decoded by U, leading to zero-outage of the downlink signal. This is a rather surprising consequence of the features of the multiple access channel and the fixed rate RM. We also consider the case...... of a simpler, single-user decoder at U with successive interference cancellation. However, with single-user decoder, a positive zero-outage rate exists only when NM = 1 and is zero when NM > 1. This implies that joint decoding is instrumental in enabling fixed-rate underlay operation....

High dose rate (HDR) and low dose rate (LDR) interstitial irradiation (IRT) of the rat spinal cord

International Nuclear Information System (INIS)

Pop, Lucas A.M.; Plas, Mirjam van der; Skwarchuk, Mark W.; Hanssen, Alex E.J.; Kogel, Albert J. van der

1997-01-01

Purpose: To describe a newly developed technique to study radiation tolerance of rat spinal cord to continuous interstitial irradiation (IRT) at different dose rates. Material and methods: Two parallel catheters are inserted just laterally on each side of the vertebral bodies from the level of Th 10 to L 4 . These catheters are afterloaded with two 192 Ir wires of 4 cm length each (activity 1-2.3 mCi/cm) for the low dose rate (LDR) IRT or connected to the HDR micro-Selectron for the high dose rate (HDR) IRT. Spinal cord target volume is located at the level of Th 12 -L 2 . Due to the rapid dose fall-off around the implanted sources, a dose inhomogeneity across the spinal cord thickness is obtained in the dorso-ventral direction. Using the 100% reference dose (rate) at the ventral side of the spinal cord to prescribe the dose, experiments have been carried out to obtain complete dose response curves at average dose rates of 0.49, 0.96 and 120 Gy/h. Paralysis of the hind-legs after 5-6 months and histopathological examination of the spinal cord of each irradiated rat are used as experimental endpoints. Results: The histopathological damage seen after irradiation is clearly reflected the inhomogeneous dose distribution around the implanted catheters, with the damage predominantly located in the dorsal tract of the cord or dorsal roots. With each reduction in average dose rate, spinal cord radiation tolerance is significantly increased. When the dose is prescribed at the 100% reference dose rate, the ED 50 (induction of paresis in 50% of the animals) for the HDR-IRT is 17.3 Gy. If the average dose rate is reduced from 120 Gy/h to 0.96 or 0.49 Gy/h, a 2.9- or 4.7-fold increase in the ED 50 values to 50.3 Gy and 80.9 Gy is observed; for the dose prescribed at the 150% reference dose rate (dorsal side of cord) ED 50 values are 26.0, 75.5 and 121.4 Gy, respectively. Using different types of analysis and in dependence of the dose prescription and reference dose rate, the �

Gamma dose rate effect on JFET transistors

International Nuclear Information System (INIS)

Assaf, J.

2011-04-01

The effect of Gamma dose rate on JFET transistors is presented. The irradiation was accomplished at the following available dose rates: 1, 2.38, 5, 10 , 17 and 19 kGy/h at a constant dose of 600 kGy. A non proportional relationship between the noise and dose rate in the medium range (between 2.38 and 5 kGy/h) was observed. While in the low and high ranges, the noise was proportional to the dose rate as the case of the dose effect. This may be explained as follows: the obtained result is considered as the yield of a competition between many reactions and events which are dependent on the dose rate. At a given values of that events parameters, a proportional or a non proportional dose rate effects are generated. No dependence effects between the dose rate and thermal annealing recovery after irradiation was observed . (author)

DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells.

Science.gov (United States)

Hu, Hao; Gu, Yuanlong; Qian, Yi; Hu, Benshun; Zhu, Congyuan; Wang, Gaohe; Li, Jianping

2014-09-12

Pancreatic cancer is one of the most aggressive human malignancies with extremely poor prognosis. The moderate activity of the current standard gemcitabine and gemcitabine-based regimens was due to pre-existing or acquired chemo-resistance of pancreatic cancer cells. In this study, we explored the potential role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in gemcitabine resistance, and studied the underlying mechanisms. We found that NU-7026 and NU-7441, two DNA-PKcs inhibitors, enhanced gemcitabine-induced cytotoxicity and apoptosis in PANC-1 pancreatic cancer cells. Meanwhile, PANC-1 cells with siRNA-knockdown of DNA-PKcs were more sensitive to gemcitabine than control PANC-1 cells. Through the co-immunoprecipitation (Co-IP) assay, we found that DNA-PKcs formed a complex with SIN1, the latter is an indispensable component of mammalian target of rapamycin (mTOR) complex 2 (mTORC2). DNA-PKcs-SIN1 complexation was required for Akt activation in PANC-1 cells, while inhibition of this complex by siRNA knockdown of DNA-PKcs/SIN1, or by DNA-PKcs inhibitors, prevented Akt phosphorylation in PANC-1 cells. Further, SIN1 siRNA-knockdown also facilitated gemcitabine-induced apoptosis in PANC-1 cells. Finally, DNA-PKcs and p-Akt expression was significantly higher in human pancreatic cancer tissues than surrounding normal tissues. Together, these results show that DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Gemcitabine enhances cell invasion via activating HAb18G/CD147-EGFR-pSTAT3 signaling.

Science.gov (United States)

Xu, Bao-Qing; Fu, Zhi-Guang; Meng, Yao; Wu, Xiao-Qing; Wu, Bo; Xu, Liang; Jiang, Jian-Li; Li, Ling; Chen, Zhi-Nan

2016-09-20

Pancreatic cancer, one of the most lethal cancers, has very poor 5-year survival partly due to gemcitabine resistance. Recently, it was reported that chemotherapeutic agents may act as stressors to induce adaptive responses and to promote chemoresistance in cancer cells. During long-term drug treatment, the minority of cancer cells survive and acquire an epithelial-mesenchymal transition phenotype with increased chemo-resistance and metastasis. However, the short-term response of most cancer cells remains unclear. This study aimed to investigate the short-term response of pancreatic cancer cells to gemcitabine stress and to explore the corresponding mechanism. Our results showed that gemcitabine treatment for 24 hours enhanced pancreatic cancer cell invasion. In gemcitabine-treated cells, HAb18G/CD147 was up-regulated; and HAb18G/CD147 down-regulation or inhibition attenuated gemcitabine-enhanced invasion. Mechanistically, HAb18G/CD147 promoted gemcitabine-enhanced invasion by activating the EGFR (epidermal growth factor receptor)-STAT3 (signal transducer and activator of transcription 3) signaling pathway. Inhibition of EGFR-STAT3 signaling counteracted gemcitabine-enhanced invasion, and which relied on HAb18G/CD147 levels. In pancreatic cancer tissues, EGFR was highly expressed and positively correlated with HAb18G/CD147. These data indicate that pancreatic cancer cells enhance cell invasion via activating HAb18G/CD147-EGFR-pSTAT3 signaling. Our findings suggest that inhibiting HAb18G/CD147 is a potential strategy for overcoming drug stress-associated resistance in pancreatic cancer.

Biological influence from low dose and low-dose rate radiation

International Nuclear Information System (INIS)

Magae, Junji

2007-01-01

Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

Dose rate measuring device and dose rate measuring method using the same

International Nuclear Information System (INIS)

Urata, Megumu; Matsushita, Takashi; Hanazawa, Sadao; Konno, Takahiro; Chiba, Yoshinori; Yumitate, Tadahiro

1998-01-01

The device of the present invention comprises a scintillation fiber scope having a shape elongated in the direction of the height of a pressure vessel and emitting light by incident of radiation to detect radiation, a radioactivity measuring device for measuring a dose rate based on the detection of the fiber scope and a reel means for dispensing and taking up the fiber scope, and it constituted such that the dose rate of the pressure vessel and that of a shroud are determined independently. Then, when the taken out shroud is contained in an container, excessive shielding is not necessary, in addition, this device can reliably be inserted to or withdrawn from complicated places between the pressure vessel and the shroud, and further, the dose rate of the pressure vessel and that of the shroud can be measured approximately accurately even when the thickness of them is different greatly. (N.H.)

Dose rate measuring device and dose rate measuring method using the same

Energy Technology Data Exchange (ETDEWEB)

Urata, Megumu; Matsushita, Takashi; Hanazawa, Sadao; Konno, Takahiro; Chiba, Yoshinori; Yumitate, Tadahiro

1998-11-13

The device of the present invention comprises a scintillation fiber scope having a shape elongated in the direction of the height of a pressure vessel and emitting light by incident of radiation to detect radiation, a radioactivity measuring device for measuring a dose rate based on the detection of the fiber scope and a reel means for dispensing and taking up the fiber scope, and it constituted such that the dose rate of the pressure vessel and that of a shroud are determined independently. Then, when the taken out shroud is contained in an container, excessive shielding is not necessary, in addition, this device can reliably be inserted to or withdrawn from complicated places between the pressure vessel and the shroud, and further, the dose rate of the pressure vessel and that of the shroud can be measured approximately accurately even when the thickness of them is different greatly. (N.H.)

Co-extrusion as a processing technique to manufacture a dual sustained release fixed-dose combination product.

Science.gov (United States)

Vynckier, An-Katrien; Voorspoels, Jody; Remon, Jean Paul; Vervaet, Chris

2016-05-01

This study aimed to design a fixed-dose combination dosage form which provides a sustained release profile for both the freely water-soluble metformin HCl and the poorly soluble gliclazide, two antidiabetic compounds used to treat diabetes mellitus. Hot-melt co-extrusion was used as an innovative manufacturing technique for a pharmaceutical fixed-dose combination product. In this way, a matrix formulation that sustained metformin release could be developed, despite the high drug load in the formulation and the freely soluble nature of the drug. It was clear that co-extrusion was perfectly suited to produce a fixed-dose combination product with adequate properties for each of the incorporated APIs. A coat layer, containing at least 30% CAPA(®) 6506 as a hydrophobic polymer, was necessary to adequately sustain the release of the highly dosed freely soluble drug from the 70% metformin HCl-loaded CAPA(®) 6506 core of the co-extrudate. To obtain a complete gliclazide release over 24-h solubilization in Kollidon(®) VA, added as a second polymer to the CAPA(®) 6506 in the coat, was needed. Both active pharmaceutical ingredients (APIs), which have different physicochemical characteristics, were formulated in a single dosage form, using co-extrusion. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

Simultaneous Estimation of Gemcitabine Hydrochloride and Capecitabine Hydrochloride in Combined Tablet Dosage Form by RP-HPLC Method

Directory of Open Access Journals (Sweden)

V. Rajesh

2011-01-01

Full Text Available A new reverse phase high performance liquid chromatography (RP-HPLC method has been developed for the simultaneous estimation of gemcitabine hydrochloride and capecitabine hydrochloride in combined tablet dosage form. An inertsil ODS-3 C-18 column having dimensions of 250×4.6 mm and particle size of 5 µm, with mobile phase containing a mixture of acetonitrile : water : triethyelamine in the ratio of (70 : 28 : 2v/v was used. The pH of mobile phase was adjusted to 4.0 with ortho-phosphoric acid. The flow rate was 1 mL/min and the column effluents were monitored at 260 nm. The retention time for gemcitabine hydrochloride and capecitabine hydrochloride was found to be 2.76 and 2.3 min respectively. The proposed method was validated in terms of linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The method was found to be linear in the range of 10-50 µg/mL and 4-24 µg/mL for gemcitabine hydrochloride and capecitabine hydrochloride, with regression coefficient r = 0.999 and r = 0.999, respectively.

Low dose rate and high dose rate intracavitary treatment for cervical cancer

International Nuclear Information System (INIS)

Hareyama, Masato; Oouchi, Atsushi; Shidou, Mitsuo

1997-01-01

From 1984 through 1993, 144 previous untreated patients with carcinoma of uterine cervix were treated with either low dose rate 137 Cs therapy (LDR) or high dose rate 60 Co therapy (HDR). The local failure rates for more than 2-years for the primary lesions were 11.8% (8 of 63 patients) for LDR and 18.0% (11 of 61 patients). Rectal complication rates were significantly lower for HDR versus LDR (14.3% VS. 32.8%. p<0.01). Also, bladder complication rates were significantly lower for HDR versus LDR (0% VS. 10.4%, p<0.005). Treatment results in term of local control were equivalent for HDR and LDR treatment. However, the incidence of complications was higher for the LDR group than for the HDR group. (author)

Usefulness of chemotherapy with gemcitabine for unresectable advanced pancreatic carcinoma

International Nuclear Information System (INIS)

Kawaguchi, Yoshiaki; Mine, Tetsuya

2007-01-01

We evaluated the usefulness of chemotherapy with gemcitabine for unresectable advanced pancreatic carcinoma. We examined 121 cases with unresectable advanced pancreatic carcinoma. They consisted of 65 locally advanced cases with no distant metastasis (Stage IVa) and 56 cases with distant metastasis (Stage IVb). Seventy-three cases were treated by chemotherapy with only gemcitabine (GEM) alone. Forty cases were not treated. Eight cases received chemoradiotherapy (CRT) combined with GEM. Their survival curves were compared. The survival curve of the GEM group was significantly longer than that of the no therapy group. In the locally advanced and distant metastasis groups, the survival curve of the GEM group was significantly longer than that of the no therapy group. And in the GEM group, the survival curve of the locally advanced group was significantly longer than that of the distant metastasis group. The survival curve of the CRT group was significantly longer than that of GEM group. Chemotherapy with gemcitabine for unresectable advanced pancreatic carcinoma was useful but the prognosis remained poor. (author)

Profile of a fixed-dose combination of tiotropium/olodaterol and its potential in the treatment of COPD

Directory of Open Access Journals (Sweden)

Muruganandan S

2015-06-01

Full Text Available Sanjeevan Muruganandan,1 Lata Jayaram2,3 1Department of Respiratory and Sleep Medicine, Austin Health, 2Department of Respiratory and Sleep Medicine, Western Health, 3University of Melbourne, Melbourne, Victoria, Australia Abstract: Chronic obstructive pulmonary disease (COPD is a progressive, debilitating disorder that results in frequent exacerbations and impacts quality of life. It represents a growing burden of health care cost, both from societal and economic perspectives. Short- and long-acting bronchodilators remain the mainstay of therapy in COPD patients. New fixed-dose combination inhalers with novel pharmacological combinations of long-acting β2-agonists and muscarinic antagonists and delivered once-daily through a variety of devices are currently being developed and licensed for the treatment of COPD. There is mounting research suggesting that combining a fixed dose of a β2-agonist and a muscarinic antagonist achieves better bronchodilation and clinical outcomes compared with either agent alone. These once-daily dosing inhalers are anticipated to impact favorably on patient preference and compliance. This review examines the fixed-dose combination of tiotropium bromide and olodaterol delivered by a Respimat® Soft Mist™ inhaler at doses of 2.5/5 µg and 5/5 µg in moderate-to-very-severe COPD, and its potential role in COPD compared with other long-acting β2-agonist with long-acting muscarinic antagonist combinations and delivery devices. Keywords: fixed-dose combination inhalers, olodaterol, tiotropium bromide, COPD treatment, long-acting β2-agonists, long-acting muscarinic antagonist

Sensitization of Tumor to {sup 212}Pb Radioimmunotherapy by Gemcitabine Involves Initial Abrogation of G2 Arrest and Blocked DNA Damage Repair by Interference With Rad51

Energy Technology Data Exchange (ETDEWEB)

Yong, Kwon Joong; Milenic, Diane E.; Baidoo, Kwamena E. [Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Brechbiel, Martin W., E-mail: martinwb@mail.nih.gov [Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)

2013-03-15

Purpose: To elucidate the mechanism of the therapeutic efficacy of targeted α-particle radiation therapy using {sup 212}Pb-TCMC-trastuzumab together with gemcitabine for treatment of disseminated peritoneal cancers. Methods and Materials: Mice bearing human colon cancer LS-174T intraperitoneal xenografts were pretreated with gemcitabine, followed by {sup 212}Pb-TCMC-trastuzumab and compared with controls. Results: Treatment with {sup 212}Pb-TCMC-trastuzumab increased the apoptotic rate in the S-phase-arrested tumors induced by gemcitabine at earlier time points (6 to 24 hours). {sup 212}Pb-TCMC-trastuzumab after gemcitabine pretreatment abrogated G2/M arrest at the same time points, which may be associated with the inhibition of Chk1 phosphorylation and, in turn, cell cycle perturbation, resulting in apoptosis. {sup 212}Pb-TCMC-trastuzumab treatment after gemcitabine pretreatment caused depression of DNA synthesis, DNA double-strand breaks, accumulation of unrepaired DNA, and down-regulation of Rad51 protein, indicating that DNA damage repair was blocked. In addition, modification in the chromatin structure of p21 may be associated with transcriptionally repressed chromatin states, indicating that the open structure was delayed at earlier time points. Conclusion: These findings suggest that the cell-killing efficacy of {sup 212}Pb-TCMC-trastuzumab after gemcitabine pretreatment may be associated with abrogation of the G2/M checkpoint, inhibition of DNA damage repair, and chromatin remodeling.

Fixed-dose combinations of drugs versus single-drug formulations for treating pulmonary tuberculosis

Science.gov (United States)

Gallardo, Carmen R; Rigau Comas, David; Valderrama Rodríguez, Angélica; Roqué i Figuls, Marta; Parker, Lucy Anne; Caylà, Joan; Bonfill Cosp, Xavier

2016-01-01

Background People who are newly diagnosed with pulmonary tuberculosis (TB) typically receive a standard first-line treatment regimen that consists of two months of isoniazid, rifampicin, pyrazinamide, and ethambutol followed by four months of isoniazid and rifampicin. Fixed-dose combinations (FDCs) of these drugs are widely recommended. Objectives To compare the efficacy, safety, and acceptability of anti-tuberculosis regimens given as fixed-dose combinations compared to single-drug formulations for treating people with newly diagnosed pulmonary tuberculosis. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL, published in the Cochrane Library, Issue 11 2015); MEDLINE (1966 to 20 November 2015); EMBASE (1980 to 20 November 2015); LILACS (1982 to 20 November 2015); the metaRegister of Controlled Trials; and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), without language restrictions, up to 20 November 2015. Selection criteria Randomized controlled trials that compared the use of FDCs with single-drug formulations in adults (aged 15 years or more) newly diagnosed with pulmonary TB. Data collection and analysis Two review authors independently assessed studies for inclusion, and assessed the risk of bias and extracted data from the included trials. We used risk ratios (RRs) for dichotomous data and mean differences (MDs) for continuous data with 95% confidence intervals (CIs). We attempted to assess the effect of treatment for time-to-event measures with hazard ratios and their 95% CIs. We used the Cochrane 'Risk of bias' assessment tool to determine the risk of bias in included trials. We used the fixed-effect model when there was little heterogeneity and the random-effects model with moderate heterogeneity. We used an I² statistic value of 75% or greater to denote significant heterogeneity, in which case we did not perform a

Dependence of total dose response of bipolar linear microcircuits on applied dose rate

International Nuclear Information System (INIS)

McClure, S.; Will, W.; Perry, G.; Pease, R.L.

1994-01-01

The effect of dose rate on the total dose radiation hardness of three commercial bipolar linear microcircuits is investigated. Total dose tests of linear bipolar microcircuits show larger degradation at 0.167 rad/s than at 90 rad/s even after the high dose rate test is followed by a room temperature plus a 100 C anneal. No systematic correlation could be found for degradation at low dose rate versus high dose rate and anneal. Comparison of the low dose rate with the high dose rate anneal data indicates that MIL-STD-883, method 1019.4 is not a worst-case test method when applied to bipolar microcircuits for low dose rate space applications

In vitro and in vivo studies of pharmacokinetics and antitumor efficacy of D07001-F4, an oral gemcitabine formulation.

Science.gov (United States)

Hao, Wei-Hua; Wang, Jong-Jing; Hsueh, Shu-Ping; Hsu, Pei-Jing; Chang, Li-Chien; Hsu, Chang-Shan; Hsu, Kuang-Yang

2013-02-01

The chemotherapy agent gemcitabine is currently administered intravenously because the drug has poor oral bioavailability. In order to assess the pharmacokinetics and antitumor activity of D07001-F4, a new self-microemulsifying oral drug delivery system preparation of gemcitabine, this study was performed to compare the effect of D07001-F4 with administered gemcitabine in vitro and in vivo. D07001-F4 pharmacokinetics was examined by evaluation of in vitro deamination of D07001-F4 and gemcitabine hydrochloride by recombinant human cytidine deaminase (rhCDA) and in vivo evaluation of D07001-F4 pharmacokinetics in mice. Antitumor activity was evaluated by comparing the effect of D07001-F4 and gemcitabine hydrochloride in inhibiting growth in nine cancer cell lines and by examining the effect of D07001-F4 and gemcitabine in two xenograft tumor models in mice. In vitro deamination of D07001-F4 by rhCDA was 3.3-fold slower than deamination of gemcitabine hydrochloride. Growth inhibition by D07001-F4 of 7 of the 8 cancer cell lines was increased compared with that seen with gemcitabine hydrochloride, and D07001-F4 inhibited the growth of pancreatic and colon cancer xenografts. In vivo pharmacokinetics showed the oral bioavailability of D07001-F4 to be 34%. D07001-F4 was effective against several cancer types, was metabolized more slowly than gemcitabine hydrochloride, and exhibited enhanced oral bioavailability.

Hardness, function, emotional well-being, satisfaction and the overall sexual experience in men using 100-mg fixed-dose or flexible-dose sildenafil citrate

Science.gov (United States)

Ströberg, P; Kaminetsky, J C; Park, N C; Goldfischer, E R; Creanga, D L; Stecher, V J

2010-01-01

The prescribing information for sildenafil citrate (VIAGRA, Pfizer, New York, NY, USA) recommends flexible dosing (50 mg initially, adjusted to 100 or 25 mg based on effectiveness and tolerability) in most men with erectile dysfunction (ED). In many men, however, 100 mg may be the most appropriate initial dose because it would reduce the need for titration and could prevent discouragement and treatment abandonment should 50 mg be insufficient. Results of two previously published double-blind, placebo-controlled sildenafil trials of similar design except for a fixed-dose vs flexible-dose regimen were analyzed. Relative to the flexible-dose, approximately one-third more men were satisfied with an initial and fixed dose of 100 mg. In addition, tolerability was similar, and improvements from baseline in outcomes on validated, ED-specific, patient-reported questionnaires were either similar (erectile function and the percentage of completely hard and fully rigid erections) or greater (emotional well-being and the overall sexual experience). The similarity in outcomes is not surprising given that almost 90% of the men in the flexible-dose trial titrated to 100 mg after 2 weeks. These data suggest prescription of an initial dose of 100 mg for men with ED, except in those for whom it is inappropriate. PMID:20596083

Apoptosis and changes in glucose transport early after treatment of Morris hepatoma with gemcitabine

International Nuclear Information System (INIS)

Haberkorn, U.; Bellemann, M.E.; Brix, G.; Kamencic, H.; Traut, U.; Kinscherf, R.; Doll, J.; Blatter, J.

2001-01-01

Apoptosis has been described as an energy-consuming process. This combined in vivo/in vitro study investigated the effects of the antineoplastic agent gemcitabine on tumour metabolism and on the induction of apoptosis. Dynamic positron emission tomography (PET) measurements of fluorine-18 fluorodeoxyglucose (FDG) uptake were done in rats bearing Morris hepatoma prior to and after therapy with 90 mg gemcitabine/kg b.w. Furthermore, thymidine (TdR) incorporation into the DNA of these tumours was determined. In vitro measurements of FDG and TdR uptake were performed immediately and 24 h after the end of gemcitabine treatment, and the amount of apoptotic cells was determined using the TUNEL reaction. In vivo an increase in FDG transport and phosphorylation occurred early after gemcitabine treatment, although TdR incorporation into the DNA of the tumours declined. In vitro, an enhanced glucose transport, an increase in TdR uptake in the cytoplasm and a decrease in TdR incorporation in the nucleic acid fraction early after treatment occurred. Inhibition of glucose transport caused an increase in the amount of apoptotic cells. The increase in glucose uptake and TdR metabolism early after therapy is interpreted as a stress reaction of the tumour cells, protecting the cells from apoptosis during this early period after exposure to cytotoxic drugs like gemcitabine. (orig.)

Apoptosis and changes in glucose transport early after treatment of Morris hepatoma with gemcitabine

Energy Technology Data Exchange (ETDEWEB)

Haberkorn, U. [Heidelberg Univ. (Germany). Abt. fuer Klinische Nuklearmedizin; Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Bellemann, M.E. [Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany); Brix, G. [Department of Medical Radiation Hygiene, Federal Office for Radiation Protection, Neuherberg (Germany); Kamencic, H.; Traut, U.; Kinscherf, R. [Heidelberg Univ. (Germany). Inst. fuer Anatomie und Zellbiologie; Morr, I.; Altmann, A. [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Doll, J. [Dept. of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Blatter, J. [Lilly GmbH Germany, Bad Homburg (Germany)

2001-04-01

Apoptosis has been described as an energy-consuming process. This combined in vivo/in vitro study investigated the effects of the antineoplastic agent gemcitabine on tumour metabolism and on the induction of apoptosis. Dynamic positron emission tomography (PET) measurements of fluorine-18 fluorodeoxyglucose (FDG) uptake were done in rats bearing Morris hepatoma prior to and after therapy with 90 mg gemcitabine/kg b.w. Furthermore, thymidine (TdR) incorporation into the DNA of these tumours was determined. In vitro measurements of FDG and TdR uptake were performed immediately and 24 h after the end of gemcitabine treatment, and the amount of apoptotic cells was determined using the TUNEL reaction. In vivo an increase in FDG transport and phosphorylation occurred early after gemcitabine treatment, although TdR incorporation into the DNA of the tumours declined. In vitro, an enhanced glucose transport, an increase in TdR uptake in the cytoplasm and a decrease in TdR incorporation in the nucleic acid fraction early after treatment occurred. Inhibition of glucose transport caused an increase in the amount of apoptotic cells. The increase in glucose uptake and TdR metabolism early after therapy is interpreted as a stress reaction of the tumour cells, protecting the cells from apoptosis during this early period after exposure to cytotoxic drugs like gemcitabine. (orig.)

Brachytherapy for early oral tongue cancer. Low dose rate to high dose rate

International Nuclear Information System (INIS)

Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Inoue, Toshihiko; Furukawa, Souhei; Kakimoto, Naoya

2003-01-01

To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n=341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer. (author)

Single fixed-dose oral dexketoprofen plus tramadol for acute postoperative pain in adults.

Science.gov (United States)

Derry, Sheena; Cooper, Tess E; Phillips, Tudor

2016-09-22

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. A new combination of dexketoprofen (a nonsteroidal anti-inflammatory drug) plus tramadol (an opioid) has been tested in acute postoperative pain conditions. It is not yet licensed for use. This review is one of a series on oral analgesics for acute postoperative pain. Individual reviews have been brought together in two overviews to provide information about the relative efficacy and harm of the different interventions. To assess the analgesic efficacy and adverse effects of a single fixed-dose of oral dexketoprofen plus tramadol, compared with placebo, for moderate to severe postoperative pain in adults, using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes. A secondary objective was to compare the combination with the individual analgesics alone. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via CRSO, MEDLINE via Ovid, and Embase via Ovid from inception to 31 May 2016. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries. Randomised, double-blind trials of oral dexketoprofen plus tramadol administered as a single oral dose, for the relief of acute postoperative pain in adults, and compared to placebo. Two review authors independently considered trials for inclusion in the review, examined issues of study quality and potential bias, and extracted data. For dichotomous outcomes, we calculated risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) for dexketoprofen plus tramadol, compared with placebo with 95% confidence intervals (CI). We collected information on the number of participants with at least 50% of

Fasting cycles potentiate the efficacy of gemcitabine treatment in in vitro and in vivo pancreatic cancer models

Science.gov (United States)

Mazza, Tommaso; Panebianco, Concetta; Saracino, Chiara; Pereira, Stephen P.; Graziano, Paolo; Pazienza, Valerio

2015-01-01

Background/aims Pancreatic cancer (PC) is ranked as the fourth leading cause of cancer-related deaths worldwide. Despite recent advances in treatment options, a modest impact on the outcome of the disease is observed so far. Short-term fasting cycles have been shown to potentiate the efficacy of chemotherapy against glioma. The aim of this study was to assess the effect of fasting cycles on the efficacy of gemcitabine, a standard treatment for PC patients, in vitro and in an in vivo pancreatic cancer mouse xenograft model. Materials and Methods BxPC-3, MiaPaca-2 and Panc-1 cells were cultured in standard and fasting mimicking culturing condition to evaluate the effects of gemcitabine. Pancreatic cancer xenograft mice were subjected to 24h starvation prior to gemcitabine injection to assess the tumor volume and weight as compared to mice fed ad libitum. Results Fasted pancreatic cancer cells showed increased levels of equilibrative nucleoside transporter (hENT1), the transporter of gemcitabine across the cell membrane, and decreased ribonucleotide reductase M1 (RRM1) levels as compared to those cultured in standard medium. Gemcitabine was more effective in inducing cell death on fasted cells as compared to controls. Consistently, xenograft pancreatic cancer mice subjected to fasting cycles prior to gemcitabine injection displayed a decrease of more than 40% in tumor growth. Conclusion Fasting cycles enhance gemcitabine effect in vitro and in the in vivo PC xenograft mouse model. These results suggest that restrictive dietary interventions could enhance the efficacy of existing cancer treatments in pancreatic cancer patients. PMID:26176887

DW-MRI as a biomarker to compare therapeutic outcomes in radiotherapy regimens incorporating temozolomide or gemcitabine in glioblastoma.

Directory of Open Access Journals (Sweden)

Stefanie Galbán

Full Text Available The effectiveness of the radiosensitizer gemcitabine (GEM was evaluated in a mouse glioma along with the imaging biomarker diffusion-weighted magnetic resonance imaging (DW-MRI for early detection of treatment effects. A genetically engineered murine GBM model [Ink4a-Arf(-/- Pten(loxP/loxP/Ntv-a RCAS/PDGF(+/Cre(+] was treated with gemcitabine (GEM, temozolomide (TMZ +/- ionizing radiation (IR. Therapeutic efficacy was quantified by contrast-enhanced MRI and DW-MRI for growth rate and tumor cellularity, respectively. Mice treated with GEM, TMZ and radiation showed a significant reduction in growth rates as early as three days post-treatment initiation. Both combination treatments (GEM/IR and TMZ/IR resulted in improved survival over single therapies. Tumor diffusion values increased prior to detectable changes in tumor volume growth rates following administration of therapies. Concomitant GEM/IR and TMZ/IR was active and well tolerated in this GBM model and similarly prolonged median survival of tumor bearing mice. DW-MRI provided early changes to radiosensitization treatment warranting evaluation of this imaging biomarker in clinical trials.

Fixed dose 131-I treatment in Basedow patients

International Nuclear Information System (INIS)

Klisarova, A; Bochev, P.; Hristosov, K.

2003-01-01

The choice of a treatment for Basedow patients is still unsolved problem. The treatment with 131-I has certain advantages but the determination of the individual therapeutic dose is impossible. The aim of the study is to assess the efficiency of the treatment with a fixed dose. 23 patient have been treated, 30 women and 3 men, age between 48 and 78. All patients are with chronic disease with relapses (1 to 4 relapses). 5 of the patients are with a thyrotoxic heart, 3 - with ophtalmopatia, 2 - with toxic medicamentous hepatitis and 2 with allergies to thyreostatics. Before the treatment with 131-I all patients have been in euthyroid state with normal levels of the peripheral hormones. All patients have received initial doses of 5 mCi 131-I. The hormone levels have been followed on 3rd, 6th, 12th and 24th month after the uptake. From a total of 23 patients, in 3 cases a transitional hypothyroidism has been found between 3th and 6th month, in 3 patients - permanent hypothyroidism. In 5 patients after the 6th month an additional dose of 5 mCi 131-I is given (in one woman a permanent hypothyroidism is reached). Four of the patients have been with a significant thyroid hyperplasia with volume above 60 ml. In three patients in the period between 6th and 12th month a slight hyperthyroidism is registered, which have been suppressed by a low dose thyreostatic. A year after the treatment they have been found euthyroid. The decision for giving a second dose have been based on the evident heptahydrate symptomatic s and the persisting increased thyroid volume. In one case it is observed an acute thyrotoxicosis for 3-5 days after the 131 I uptake. No cases of worsening of the eye symptoms are observed. In conclusion, the treatment with 131 I is a appropriate method for patients with cardiovascular complications, contraindication for surgery or side effects of the thyreostatic treatment. the dose od 5 mCi is sufficient for patients with mild to medium form of Basedow disease and a

Gemcitabine-Based Chemogene Therapy for Pancreatic Cancer Using Ad-dCK::UMK GDEPT and TS/RR siRNA Strategies

Directory of Open Access Journals (Sweden)

Soukaina Réjiba

2009-07-01

Full Text Available Gemcitabine is a first-line agent for advanced pancreatic cancer therapy. However, its efficacy is often limited by its poor intracellular metabolism and chemoresistance. To exert its antitumor activity, gemcitabine requires to be converted to its active triphosphate form. Thus, our aim was to improve gemcitabine activation using gene-directed enzyme prodrug therapy based on gemcitabine association with the deoxycytidine kinase::uridine monophosphate kinase fusion gene (dCK::UMK and small interference RNA directed against ribonucleotide reductase (RRM2 and thymidylate synthase (TS. In vitro, cytotoxicity was assessed by 3-[4,5-dimethylthiazol-2-yl]-3,5-diphenyl tetrazolium bromide and [3H]thymidine assays. Apoptosis-related gene expression and activity were analyzed by reverse transcription-polymerase chain reaction, Western blot, and ELISA. For in vivo studies, the treatment efficacy was evaluated on subcutaneous and orthotopic pancreatic tumor models. Our data indicated that cell exposure to gemcitabine induced a down-regulation of dCK expression and up-regulation of TS and RR expression in Panc1-resistant cells when compared with BxPc3- and HA-hpc2-sensitive cells. The combination of TS/RRM2 small interference RNA with Ad-dCK::UMK induced a 40-fold decrease of gemcitabine IC50 in Panc1 cells. This strong sensitization was associated to apoptosis induction with a remarkable increase in TRAIL expression and a diminution of gemcitabine-induced nuclear factor-κB activity. In vivo, the gemcitabine-based tritherapy strongly reduced tumor volumes and significantly prolonged mice survival. Moreover, we observed an obvious increase of apoptosis and decrease of cell proliferation in tumors receiving the tritherapy regimens. Together, these findings suggest that simultaneous TS/RRM2-gene silencing and dCK::UMK gene overexpression markedly improved gemcitabine's therapeutic activity. Clearly, this combined strategy warrants further investigation.

Dose Rate Effects in Linear Bipolar Transistors

Science.gov (United States)

Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

2011-01-01

Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

Fixed-dose combinations of antimicrobials: A need for special attention

Directory of Open Access Journals (Sweden)

N Shafiq

2016-01-01

Full Text Available Objective: To highlight the issue of freely available fixed-dose combinations (FDCs of antimicrobials. Methods: A critique of two such antimicrobial FDCs was undertaken wherein the following aspects were assessed - rational and regulatory issues and justification for clinical use. Available in vitro, in vivo (animals and humans evidence from published literature was analysed. Conclusions: There are several inadequately addressed aspects of the considered FDCs which are available in Indian market. In view of the growing problem of antimicrobial resistance, this issue must get the required attention.

Dose rate visualization of radioisotope thermoelectric generators

International Nuclear Information System (INIS)

Schwarz, R.A.; Kessler, S.F.; Tomaszewski, T.A.

1995-09-01

Advanced visualization techniques can be used to investigate gamma ray and neutron dose rates around complex dose rate intensive operations. A method has been developed where thousands of dose points are calculated using the MCNP(Monte Carlo N-Particle) computer code and then displayed to create color contour plots of the dose rate for complex geometries. Once these contour plots are created, they are sequenced together creating an animation to dynamically show how the dose rate changes with changes in the geometry or source over time

Biological responses to low dose rate gamma radiation

International Nuclear Information System (INIS)

Magae, Junji; Ogata, Hiromitsu

2003-01-01

Linear non-threshold (LNT) theory is a basic theory for radioprotection. While LNT dose not consider irradiation time or dose-rate, biological responses to radiation are complex processes dependent on irradiation time as well as total dose. Moreover, experimental and epidemiological studies that can evaluate LNT at low dose/low dose-rate are not sufficiently accumulated. Here we analyzed quantitative relationship among dose, dose-rate and irradiation time using chromosomal breakage and proliferation inhibition of human cells as indicators of biological responses. We also acquired quantitative data at low doses that can evaluate adaptability of LNT with statistically sufficient accuracy. Our results demonstrate that biological responses at low dose-rate are remarkably affected by exposure time, and they are dependent on dose-rate rather than total dose in long-term irradiation. We also found that change of biological responses at low dose was not linearly correlated to dose. These results suggest that it is necessary for us to create a new model which sufficiently includes dose-rate effect and correctly fits of actual experimental and epidemiological results to evaluate risk of radiation at low dose/low dose-rate. (author)

Review of low dose-rate epidemiological studies and biological mechanisms of dose-rate effects on radiation induced carcinogenesis

International Nuclear Information System (INIS)

Iwasaki, Toshiyasu; Otsuka, Kensuke; Yoshida, Kazuo

2015-01-01

Radiation protection system adopts the linear non-threshold model with using dose and dose-rate effectiveness factor (DDREF). The dose-rate range where DDREF is applied is below 100 mGy per hour, and it is regarded that there are no dose-rate effects at very low dose rate, less than of the order of 10 mGy per year, even from the biological risk evaluation model based on cellular and molecular level mechanisms for maintenance of genetic integrity. Among low dose-rate epidemiological studies, studies of residents in high natural background areas showed no increase of cancer risks at less than about 10 mGy per year. On the other hand, some studies include a study of the Techa River cohort suggested the increase of cancer risks to the similar degree of Atomic bomb survivor data. The difference of those results was supposed due to the difference of dose rate. In 2014, International Commission on Radiological Protection opened a draft report on stem cell biology for public consultations. The report proposed a hypothesis based on the new idea of stem cell competition as a tissue level quality control mechanism, and suggested that it could explain the dose-rate effects around a few milligray per year. To verify this hypothesis, it would be needed to clarify the existence and the lowest dose of radiation-induced stem cell competition, and to elucidate the rate of stem cell turnover and radiation effects on it. As for the turnover, replenishment of damaged stem cells would be the important biological process. It would be meaningful to collect the information to show the difference of dose rates where the competition and the replenishment would be the predominant processes. (author)

Gemcitabine treatment induces endoplasmic reticular (ER) stress and subsequently upregulates urokinase plasminogen activator (uPA) to block mitochondrial-dependent apoptosis in Panc-1 cancer stem-like cells (CSCs).

Science.gov (United States)

Wang, Li; Zhang, Yi; Wang, Weiguo; Zhu, Yunjie; Chen, Yang; Tian, Bole

2017-01-01

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with poor survival rates. The presence of cancer stem-like cells (CSCs) is believed to be among the underlying reasons for the aggressiveness of PDAC, which contributes to chemoresistance and recurrence. However, the mechanisms that induce chemoresistance and inhibit apoptosis remain largely unknown. We used serum-free medium to enrich CSCs from panc-1 human pancreatic cancer cells and performed sphere formation testing, flow cytometry, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and semi-quantitative western blotting to confirm the stemness of panc-1 CSCs. Hallmarks of endoplasmic reticulum (ER) stress, including IRE1, PERK, ATF4, ATF6α, GRP78 and uPA expression, were detected after gemcitabine treatment. Effects of gemcitabine-induced uPA expression on cell invasion, sphere formation, colony formation and gemcitabine sensitivity were detected. Electrophoretic mobility shift assays (EMSAs) and RNA-immunoprecipitation (RIP) were performed to detect interaction between the uPA mRNA 3'-UTR and mutant p53-R273H expressed by panc-1 CSCs. The effects of upregulated uPA by gemcitabine on apoptosis were detected by Annexin V-FITC/PI staining, and the impact of uPA on small molecule CP-31398-restored mutant p53 transcriptional activity was measured by a luciferase reporter assay. Enriched panc-1 CSCs expressing high levels of CD44 and CD133 also produced significantly higher amounts of Oct4 and Nanog. Compared with panc-1 cells, panc-1 CSCs presented chemoresistance to gemcitabine. ER stress gene detections demonstrated effects of gemcitabine-induced ER stress on both the pro-apoptotic and pro-survival branches. ER stress-induced ATF6α upregulated level of uPA by transcriptionally activating GRP78. Gemcitabine-induced uPA promoted invasion, sphere formation and colony formation and attenuated apoptosis induced by gemcitabine in panc-1 CSCs, depending on interaction with mutant p53

Dose rate visualization of radioisotope thermoelectric generators

International Nuclear Information System (INIS)

Schwarz, R.A.; Kessler, S.F.; Tomaszewski, T.A.

1996-01-01

Advanced visualization techniques can be used to investigate gamma ray and neutron dose rates around complex dose rate intensive operations. A method has been developed where thousands of dose points are calculated using the MCNP (Monte Carlo N-Particle) computer code (Briesmeister 1993) and then displayed to create color contour plots of the dose rate for complex geometries. Once these contour plots are created, they are sequenced together creating an animation to dynamically show how the dose rate changes with changes in the geometry or source over time. copyright 1996 American Institute of Physics

Fixed-dose combinations at the front line of multimodal pain management: perspective of the nurse-prescriber

Directory of Open Access Journals (Sweden)

O'Brien J

2013-02-01

Full Text Available Joanne O’Brien,1 Joseph V Pergolizzi Jr,2 Mart van de Laar3, Hans-Ulrich Mellinghoff,4 Ignacio Morón Merchante,5 Srinivas Nalamachu,6 Serge Perrot,7 Robert B Raffa81Department of Pain Medicine, Beaumont Hospital, Beaumont, Dublin, Ireland; 2Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD; Association of Chronic Pain Patients, Houston, TX; Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA; 3Arthritis Center Twente, Enschede, The Netherlands; 4Department of Endocrinology, Diabetology and Osteology, Kantonsspital St Gallen, Switzerland; 5Centro de Salud Universitario Goya, Madrid, Spain; 6Kansas University Medical Center, Kansas City, and International Clinic Research, Leawood, KS, USA; 7Service de Médecine Interne et Consultation de la Douleur, Hôpital Hotel Dieu, Paris Descartes University, Paris, France; 8Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia PA, USAAbstract: Pain should be treated promptly and effectively to restore the patient to full function, avoid pain chronification, and preserve quality of life. A recent pain specialists' meeting discussed the use of different pharmacological treatment options, such as topical analgesics, nonopioid agents (such as paracetamol and nonsteroidal anti-inflammatory drugs, weak and strong opioids, and fixed-dose combination products in the management of moderate to severe pain from different etiologies. One of the topics discussed in, and subsequent to, this meeting was the role of fixed-dose combination products for nurse-prescribers who are in many ways at the front line of managing both acute and chronic pain syndromes. The panel agreed that proper product selection should take into account the patient's age, condition, type of pain, and comorbidities, as well as balance safety with effectiveness. Although nurse-prescribers need to be aware of cumulative paracetamol dosing, fixed-dose

The pharmacokinetic profile of a novel fixed-dose combination tablet of ibuprofen and paracetamol

OpenAIRE

Tanner, Trevor; Aspley, Sue; Munn, Andrew; Thomas, Tracy

2010-01-01

Background Ibuprofen and paracetamol differ in their mode of action and related therapeutic effects, suggesting that combined administration may offer improved analgesia. Reported here are the results of two studies on the pharmacokinetic properties of a novel ibuprofen (200 mg) and paracetamol (500 mg) fixed-dose combination tablet. Methods Both studies were open-label, randomised studies in healthy volunteers: Study 1 was a four-way crossover, single-dose study; Study 2 was a two-way cross-...

Serum thyroxine concentrations following fixed-dose radioactive iodine treatment in hyperthyroid cats: 62 cases (1986-1989)

International Nuclear Information System (INIS)

Meric, S.M.; Rubin, S.I.

1990-01-01

The medical records of 62 hyperthyroid cats treated with a fixed dose of 4 mCi of radioactive iodine (131I) were reviewed. In 60 cats, serum thyroxine concentrations were determined after treatment, allowing evaluation of treatment success. Eighty-four percent of the cats had normal serum thyroxine concentrations after treatment. Five of the 60 cats (8%) remained hyperthyroxinemic after treatment. Five cats (8%) were hypothyroxinemic when evaluated within 60 days of treatment. Three of these cats had normal serum thyroxine concentrations 6 months after treatment, and none had clinical signs of hypothyroidism. The administration of a fixed dose of 4 mCi of 131I was determined to be an effective treatment for feline hyperthyroidism

Asthma Control Can Be Maintained after Fixed-Dose, Budesonide/Formoterol Combination Inhaler Therapy is Stepped Down from Medium to Low Dose

Directory of Open Access Journals (Sweden)

Masayuki Hojo

2013-01-01

Conclusions: If complete control of asthma, not only of clinical symptoms but also airway inflammation, is achieved by 3-6 months of fixed-dose budesonide/formoterol 4 puffs/day, it should be possible to safely perform step-down to 2 puffs/day.

SU-E-T-628: Effect of Dose Rate and Leakage Correction for Dosimetric Leaf Gap Measurement

Energy Technology Data Exchange (ETDEWEB)

Feng, W [New York Presbyterian Hospital, Tenafly, NJ (United States); Chu, A [Yale New Haven Hospital, New Haven, CT (United States); Chi, Y [Winter Park Cancer Center, Winter Park, FL (United States); Hu, J [Wayne State University, Detroit, MI (United States)

2014-06-15

Purpose: To study the dose rate response of Mapcheck and quantify/correct dose rate/leakage effect on IMRT QA. Evaluate the dose rate/leakage effect on dosimetric leaf gap (DLG) measurement. Methods: Varian Truebeam Linac with HD120 MLC was used for all measurement, it is capable to adjust dose rate from 600MU/min to 5MU/min. Fluke Advanced Therapy Doisemter and PTW 30013 Farmer chamber for chamber measurement; SunNuclear Mapcheck2 with 5cm total buildup for diode measurement. DLG was measured with both chamber and diode.Diode response was measured by varies dose rate, while fixed mapcheck setup and total MU. MLC Leakage was measured with both chamber and diode. Mapcheck measurement was saved as movie file (mcm file), which include measurement updated every 50mSec. The difference between intervals can be converted to dose and dose rate and leakage response correction can be applied to them. Results: DLG measurement results with chamber and diode were showed as follows, the DLG value is 0.36 vs. 0.24mm respectively. Diode dose rate response drops from 100% at 600MU/min to 95.5% at 5MU/min as follows. MLC Leakage measured with diode is 1.021%, which is 9% smaller than 1.112% from chamber measurement. By apply the dose rate and leakage correction, the residue error reduced 2/3. Conclusions: Diode has lower response at lower dose rate, as low as 4.5% for 5MU/min; diode has lower energy response for low energy too, 5% lower for Co-60 than 6MV. It partially explains the leakage difference of 9% between chamber and diode. Lower DLG with diode is because of the lower response at narrower gap, in Eclipse however DLG need to increase to makeup lower response, which is over correction for chamber though. Correction can reduce error by 2/3, the rest 1/3 can be corrected by scatter effect, which is under study.

Amlodipine and valsartan as components of a rational and effective fixed-dose combination

Directory of Open Access Journals (Sweden)

Bernard Waeber

2009-03-01

Full Text Available Bernard Waeber1, Luis M Ruilope21Division of Clinical Pathophysiology, University Hospital, Faculty of Biology and Medicine, University of Lausanne, Switzerland; 2Hypertension Unit, Hospital 12 de Octubre, Madrid, SpainAbstract: Pharmacological treatment of hypertension is effective in preventing cardiovascular and renal complications. Calcium antagonists and blockers of the renin-angiotensin system are widely used today to initiate antihypertensive therapy but, when given as monotherapy, do not suffice in most patients to normalize blood pressure. Combining the two types of agents considerably increases the antihypertensive efficacy, but not at the expense of a deterioration of tolerability. This is exemplified by the experience accumulated with the recently developed fixed dose combination containing the AT1-receptor blocker valsartan (160 mg and the dihydropyridine amlodipine (5 or 10 mg. In a randomized trial, an 8-week treatment normalized blood pressure (<140/90 mmHg within 8 weeks in a large fraction of hypertensive patients (78.4% and 85.2% using the 5/160 [n = 371] and 10/160 mg [n = 377] dosage, respectively. Like all AT1-receptor blockers valsartan has a placebo-like tolerability. Valsartan prevents to a large extent the occurrence amlodipine-induced peripheral edema. Both amlodipine and valsartan have beneficial effects on cardiovascular morbidity and mortality, as well as protective effects on renal function. The co-administration of these two agents is therefore very attractive, as it enables a rapid and sustained blood pressure control in hypertensive patients. The availability of a fixed-dose combination based on amlodipine and valsartan is expected therefore to facilitate the management of hypertension, to improve long-term adherence with antihypertensive therapy and, ultimately, to have a positive impact on cardiovascular and renal outcomes.Keywords: antihypertensive therapy, fixed-dose combination, calcium antagonists

Original article Intravesical Gemcitabine for Treatment of Super ...

African Journals Online (AJOL)

mn

and prophylaxis in superficial bladder cancer (SBC) as it reduces tumor recurrence and disease progression. About one-third of patients ... Key Words: Superficial bladder cancer, BCG, gemcitabine, intravesical. Corresponding Author: Dr. Mohamed .... immunotherapy has become the standard treatment for high-risk SBC, ...

Self-Delivery Nanoparticles of Amphiphilic Methotrexate-Gemcitabine Prodrug for Synergistic Combination Chemotherapy via Effect of Deoxyribonucleotide Pools.

Science.gov (United States)

Wang, Yao; Huang, Ping; Hu, Minxi; Huang, Wei; Zhu, Xinyuan; Yan, Deyue

2016-11-16

The distinct and complementary biochemical mechanisms of folic acid analog methotrexate (MTX) and cytidine analog gemcitabine (GEM) make their synergistic combination effective. Unfortunately, such a combination faces severe pharmacokinetic problems and several transportation barriers. To overcome these problems, a new strategy of amphiphilic small molecule prodrug (ASMP) is developed to improve their synergistic combination effect. The ASMP was prepared by the amidation of the hydrophilic GEM with the hydrophobic MTX at a fixed ratio. Owing to its inherent amphiphilicity, the MTX-GEM ASMP self-assembled into stable nanoparticles (ASMP-NPs) with high drug loading capacity (100%), in which the MTX and GEM could self-deliver without any carriers and release synchronously in cancer cells. In vitro studies showed that the MTX-GEM ASMP-NPs could greatly improve the synergistic combination effects by the reason of arresting more S phase of the cell cycle and reducing levels of deoxythymidine triphosphate (dTTP), deoxyadenosine triphosphate (dATP), and deoxycytidine triphosphate (dCTP). The stronger synergistic effects caused the higher cell cytotoxicity and apoptotic ratio, and circumvented the multidrug resistance (MDR) of tumor cells. Additionally, MTX-GEM ASMP-NPs could achieve the same anticancer effect with the greatly reduced dosage compared with the free drugs according to the dose-reduction index (DRI) values of MTX and GEM in MTX-GEM ASMP-NPs, which may be beneficial for reducing the side effects.

Dose-rate dependence of thermoluminescence response

International Nuclear Information System (INIS)

McKeever, S.W.S.; Chen, R.; Groom, P.J.; Durrani, S.A.

1980-01-01

The previously observed dose-rate effect of thermoluminescence in quartz at high dose-rates is given at theoretical formulation. Computer calculations simulating the experimental conditions yield similar results to the experimental ones. (orig.)

Twice-daily reirradiation for recurrent and second primary head-and-neck cancer with gemcitabine, paclitaxel, and 5-fluorouracil chemotherapy

International Nuclear Information System (INIS)

Milano, Michael T.; Vokes, Everett E.; Salama, Joseph K.; Stenson, Kerstin M.; Kao, Johnny; Witt, Mary-Ellyn; Mittal, Bharat B.; Argiris, Athanassios; Weichselbaum, Ralph R.; Haraf, Daniel J.

2005-01-01

Purpose: We previously demonstrated the efficacy of concurrent gemcitabine, paclitaxel, and 5-fluorouracil in conjunction with twice-daily (1.5-Gy) radiotherapy delivered on alternating weeks (TFGX 2 ) in locally advanced head-and-neck cancer. Here, we report the clinical outcome and late toxicity of TFGX 2 in a subset of patients previously irradiated to the head and neck. Methods and materials: Twenty-nine previously irradiated patients, presenting with recurrent or second primary head-and-neck cancer, underwent TFGX 2 . Twelve patients underwent attempted surgical resection before chemoradiotherapy, 10 of whom were left with no measurable disease. Patients with measurable disease received a median radiation dose of 72 Gy; those with no measurable disease received a median dose of 61 Gy. The cumulative dose ranged from 74.4 to 156.4 Gy (mean, 125.7 Gy; median, 131.0 Gy). Results: The median follow-up was 19.1 months (50.9 months for living patients). The 5-year overall survival rate was 34.5%, and the locoregional control rate was 54.5%. In patients with measurable disease at treatment, the 5-year overall survival and locoregional control rate was 26.3% and 45.1%, respectively, compared with 50.0% (p = 0.14) and 70% (p = 0.31), respectively, for those with no measurable disease. Measurable disease and radiation dose were highly statistically significant for overall survival and locoregional control on multivariate analysis. Of 14 patients assessable for late toxicity, 3 developed Grade 4-5, 8 Grade 2-3, and 3 Grade 0-1 toxicity. Conclusion: Aggressive reirradiation with chemotherapy in locally advanced head-and-neck cancer provides a chance for long-term cure at the expense of toxicity. Attempted surgical resection before chemoradiotherapy improved disease control and survival

Gemcitabine-loaded albumin nanospheres (GEM-ANPs) inhibit PANC-1 cells in vitro and in vivo

Science.gov (United States)

Li, Ji; Di, Yang; Jin, Chen; Fu, Deliang; Yang, Feng; Jiang, Yongjian; Yao, Lie; Hao, Sijie; Wang, Xiaoyi; Subedi, Sabin; Ni, Quanxing

2013-04-01

With the development of nanotechnology, special attention has been given to the nanomaterial application in tumor treatment. Here, a modified desolvation-cross-linking method was successfully applied to fabricate gemcitabine-loaded albumin nanospheres (GEM-ANPs), with 110 and 406 nm of mean diameter, respectively. The aim of this study was to assess the drug distribution, side effects, and antitumor activity of GEM-ANPs in vivo. The metabolic viability and flow cytometry analysis revealed that both GEM-ANPs, especially 406-nm GEM-ANPs, could effectively inhibit the metabolism and proliferation and promote the apoptosis of human pancreatic carcinoma (PANC-1) in vitro. Intravenous injection of 406-nm GEM-ANPs exhibited a significant increase of gemcitabine in the pancreas, liver, and spleen of Sprague-Dawley rats ( p PANC-1-induced tumor mice, intravenous injection of 406-nm GEM-ANPs also could effectively reduce the tumor volume by comparison with free gemcitabine. With these findings, albumin nanosphere-loading approach might be efficacious to improve the antitumor activity of gemcitabine, and the efficacy is associated with the size of GEM-ANPs.

Genomic signatures for paclitaxel and gemcitabine resistance in breast cancer derived by machine learning.

Science.gov (United States)

Dorman, Stephanie N; Baranova, Katherina; Knoll, Joan H M; Urquhart, Brad L; Mariani, Gabriella; Carcangiu, Maria Luisa; Rogan, Peter K

2016-01-01

Increasingly, the effectiveness of adjuvant chemotherapy agents for breast cancer has been related to changes in the genomic profile of tumors. We investigated correspondence between growth inhibitory concentrations of paclitaxel and gemcitabine (GI50) and gene copy number, mutation, and expression first in breast cancer cell lines and then in patients. Genes encoding direct targets of these drugs, metabolizing enzymes, transporters, and those previously associated with chemoresistance to paclitaxel (n = 31 genes) or gemcitabine (n = 18) were analyzed. A multi-factorial, principal component analysis (MFA) indicated expression was the strongest indicator of sensitivity for paclitaxel, and copy number and expression were informative for gemcitabine. The factors were combined using support vector machines (SVM). Expression of 15 genes (ABCC10, BCL2, BCL2L1, BIRC5, BMF, FGF2, FN1, MAP4, MAPT, NFKB2, SLCO1B3, TLR6, TMEM243, TWIST1, and CSAG2) predicted cell line sensitivity to paclitaxel with 82% accuracy. Copy number profiles of 3 genes (ABCC10, NT5C, TYMS) together with expression of 7 genes (ABCB1, ABCC10, CMPK1, DCTD, NME1, RRM1, RRM2B), predicted gemcitabine response with 85% accuracy. Expression and copy number studies of two independent sets of patients with known responses were then analyzed with these models. These included tumor blocks from 21 patients that were treated with both paclitaxel and gemcitabine, and 319 patients on paclitaxel and anthracycline therapy. A new paclitaxel SVM was derived from an 11-gene subset since data for 4 of the original genes was unavailable. The accuracy of this SVM was similar in cell lines and tumor blocks (70-71%). The gemcitabine SVM exhibited 62% prediction accuracy for the tumor blocks due to the presence of samples with poor nucleic acid integrity. Nevertheless, the paclitaxel SVM predicted sensitivity in 84% of patients with no or minimal residual disease. Copyright © 2015 Federation of European Biochemical Societies

External dose-rate conversion factors for calculation of dose to the public

Energy Technology Data Exchange (ETDEWEB)

1988-07-01

This report presents a tabulation of dose-rate conversion factors for external exposure to photons and electrons emitted by radionuclides in the environment. This report was prepared in conjunction with criteria for limiting dose equivalents to members of the public from operations of the US Department of Energy (DOE). The dose-rate conversion factors are provided for use by the DOE and its contractors in performing calculations of external dose equivalents to members of the public. The dose-rate conversion factors for external exposure to photons and electrons presented in this report are based on a methodology developed at Oak Ridge National Laboratory. However, some adjustments of the previously documented methodology have been made in obtaining the dose-rate conversion factors in this report. 42 refs., 1 fig., 4 tabs.

Radiobiological modelling of dose-gradient effects in low dose rate, high dose rate and pulsed brachytherapy

International Nuclear Information System (INIS)

Armpilia, C; Dale, R G; Sandilos, P; Vlachos, L

2006-01-01

This paper presents a generalization of a previously published methodology which quantified the radiobiological consequences of dose-gradient effects in brachytherapy applications. The methodology uses the linear-quadratic (LQ) formulation to identify an equivalent biologically effective dose (BED eq ) which, if applied uniformly to a specified tissue volume, would produce the same net cell survival as that achieved by a given non-uniform brachytherapy application. Multiplying factors (MFs), which enable the equivalent BED for an enclosed volume to be estimated from the BED calculated at the dose reference surface, have been calculated and tabulated for both spherical and cylindrical geometries. The main types of brachytherapy (high dose rate (HDR), low dose rate (LDR) and pulsed (PB)) have been examined for a range of radiobiological parameters/dimensions. Equivalent BEDs are consistently higher than the BEDs calculated at the reference surface by an amount which depends on the treatment prescription (magnitude of the prescribed dose) at the reference point. MFs are closely related to the numerical BED values, irrespective of how the original BED was attained (e.g., via HDR, LDR or PB). Thus, an average MF can be used for a given prescribed BED as it will be largely independent of the assumed radiobiological parameters (radiosensitivity and α/β) and standardized look-up tables may be applicable to all types of brachytherapy treatment. This analysis opens the way to more systematic approaches for correlating physical and biological effects in several types of brachytherapy and for the improved quantitative assessment and ranking of clinical treatments which involve a brachytherapy component

Comparison of evening and morning dosing of travoprost 0.004%/timolol 0.5% fixed combination in 6 month period.

Science.gov (United States)

Suić, Smiljka Popović; Laus, Katia Novak; Dosen, Vukosava Maricic; Ekert, Miroslav; Mandić, Zdravko; Bojić, Lovro

2010-09-01

An open label, multi-center, 6 months observational study of new fixed combination (travoprost 0.004%/timolol 0.5%), in order to evaluate both efficacy (intraocular pressure lowering) and tolerability (patient and investigator satisfaction) of two dosing regimens--evening (PM) and morning (AM). After screening for enrollment, to 40 patients (79 eyes with primary open angle glaucoma or ocular hypertension), new fixed combination travoprost 0.004%/timolol 0.5% was prescribed once a day in the evening (PM). Patients were enrolled according to each investigator decision on indication for travoprost 0.004%/timolol 0.5% fixed combination once a day, without washout period after previous medication. Intraocular pressure was measured at 9 AM at all time control points: at baseline, after 1 month, after 3 months and after 6 month. After 1 month, screening for nonresponders (criteria: 20% intraocular pressure lowering) and subjects with major side effects was performed. At second control visit, after 3 months PM dosing, intraocular pressure was measured and patients were instructed to continue once a day the same medication, but in the morning (AM) for consequent 3 months. After 1 month, reduction in mean intraocular pressure value was 21.66%. At the visit after 3 month, the mean intraocular pressure was 15.67 +/- 2.17 mm Hg (reduction 21.14%). 3 month after dosing regimen changed to AM (6 month after beginning of travoprost 0.004%/timolol 0.5% combination therapy), reduction in intraocular pressure value was 19.86%. The differences (mean +/- standard deviation) in intraocular pressure values after 1, 3 and 6 month were all highly statistically significant compared to baseline values. The tolerability was evaluated in five steps (Likert scale) ranging from unsatisfactory to excellent by both patient and investigator--taken at 3 and 6 month control visit. 95% of patients and 100% of investigators were satisfied with the possibility of choosing dosing regimen for travoprost 0

Pulsed dose rate and fractionated high dose rate brachytherapy: choice of brachytherapy schedules to replace low dose rate treatments

International Nuclear Information System (INIS)

Visser, Andries G.; Aardweg, Gerard J.M.J. van den; Levendag, Peter C.

1996-01-01

Purpose: Pulsed dose rate (PDR) brachytherapy is a new type of afterloading brachytherapy (BT) in which a continuous low dose rate (LDR) treatment is simulated by a series of 'pulses,' i.e., fractions of short duration (less than 0.5 h) with intervals between fractions of 1 to a few hours. At the Dr. Daniel den Hoed Cancer Center, the term 'PDR brachytherapy' is used for treatment schedules with a large number of fractions (at least four per day), while the term 'fractionated high dose rate (HDR) brachytherapy' is used for treatment schedules with just one or two brachytherapy fractions per day. Both treatments can be applied as alternatives for LDR BT. This article deals with the choice between PDR and fractionated HDR schedules and proposes possible fractionation schedules. Methods and Materials: To calculate HDR and PDR fractionation schedules with the intention of being equivalent to LDR BT, the linear-quadratic (LQ) model has been used in an incomplete repair formulation as given by Brenner and Hall, and by Thames. In contrast to earlier applications of this model, both the total physical dose and the overall time were not kept identical for LDR and HDR/PDR schedules. A range of possible PDR treatment schedules is presented, both for booster applications (in combination with external radiotherapy (ERT) and for BT applications as a single treatment. Because the knowledge of both α/β values and the half time for repair of sublethal damage (T (1(2)) ), which are required for these calculations, is quite limited, calculations regarding the equivalence of LDR and PDR treatments have been performed for a wide range of values of α/β and T (1(2)) . The results are presented graphically as PDR/LDR dose ratios and as ratios of the PDR/LDR tumor control probabilities. Results: If the condition that total physical dose and overall time of a PDR treatment must be exactly identical to the values for the corresponding LDR treatment regimen is not applied, there appears

Dose rate effect on low-dose hyper-radiosensitivity with cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Kim, Geon-Min; Kim, Eun-Hee [Seoul National University, Seoul (Korea, Republic of)

2016-10-15

Low-dose hyper-radiosensitivity (HRS) is the phenomenon that mammalian cells exhibit higher sensitivity to radiation at low doses (< 0.5 Gy) than expected by the linear-quadratic model. At doses above 0.5Gy, the cellular response is recovered to the level expected by the linear-quadratic model. This transition is called the increased radio-resistance (IRR). HRS was first verified using Chinese hamster V79 cells in vitro by Marples and has been confirmed in studies with other cell lines including human normal and tumor cells. HRS is known to be induced by inactivation of ataxia telangiectasia-mutated (ATM), which plays a key role in repairing DNA damages. Considering the connection between ATM and HRS, one can infer that dose rate may affect cellular response regarding HRS at low doses. In this study, we quantitated the effect of dose rate on HRS by clonogenic assay with normal and tumor cells. The HRS of cells at low dose exposures is a phenomenon already known. In this study, we observed HRS of rat normal diencephalon cells and rat gliosarcoma cells at doses below 1 Gy. In addition, we found that dose rate mattered. HRS occurred at low doses, but only when total dose was delivered at a rate below certain level.

Safety and pharmacokinetic profile of fixed-dose ivermectin with an innovative 18mg tablet in healthy adult volunteers.

Directory of Open Access Journals (Sweden)

Jose Muñoz

2018-01-01

Full Text Available Ivermectin is a pivotal drug for the control of onchocerciasis and lymphatic filariasis, which is increasingly identified as a useful drug for the control of other Neglected Tropical Diseases. Its role in the treatment of soil transmitted helminthiasis through improved efficacy against Trichuris trichiura in combination with other anthelmintics might accelerate the progress towards breaking transmission. Ivermectin is a derivative of Avermectin B1, and consists of an 80:20 mixture of the equipotent homologous 22,23 dehydro B1a and B1b. Pharmacokinetic characteristics and safety profile of ivermectin allow to explore innovative uses to further expand its utilization through mass drug administration campaigns to improve coverage rates. We conducted a phase I clinical trial with 54 healthy adult volunteers who sequentially received 2 experimental treatments using a new 18 mg ivermectin tablet in a fixed-dose strategy of 18 and 36 mg single dose regimens, compared to the standard, weight based 150–200 μg/kg, regimen. Volunteers were recruited in 3 groups based on body weight. Plasma concentrations of ivermectin were measured through HPLC up to 168 hours post treatment. Safety data showed no significant differences between groups and no serious adverse events: headache was the most frequent adverse event in all treatment groups, none of them severe. Pharmacokinetic parameters showed a half-life between 81 and 91 h in the different treatment groups. When comparing the systemic bioavailability (AUC0t and Cmax of the reference product (WA-ref with the other two study groups using fixed doses, we observed an overall increase in AUC0t and Cmax for the two experimental treatments of 18 mg and 36 mg. Body mass index (BMI and weight were associated with t1/2 and V/F, probably reflecting the high liposolubility of IVM with longer retention times proportional to the presence of more adipose tissue. Systemic exposure to ivermectin (AUC0t or Cmax was not

A randomized phase II study of weekly nab-paclitaxel plus gemcitabine or simplified LV5FU2 as first-line therapy in patients with metastatic pancreatic cancer: the AFUGEM GERCOR trial.

Science.gov (United States)

Bachet, Jean-Baptiste; Chibaudel, Benoist; Bonnetain, Franck; Validire, Pierre; Hammel, Pascal; André, Thierry; Louvet, Christophe

2015-10-06

Metastatic pancreatic adenocarcinoma (PAC) prognosis remains dismal and gemcitabine monotherapy has been the standard treatment over the last decade. Currently, two first-line regimens are used in this setting: FOLFIRINOX and nab-paclitaxel plus gemcitabine. Increasing translational data on the predictive value of hENT1 for determining gemcitabine efficacy suggest that a non-gemcitabine-based regimen is favored in about 60 % of patients with PAC due to high resistance of PAC to this cytotoxic drug. This study aims to evaluate the efficacy of weekly nab-paclitaxel combined with gemcitabine or a simplified (s) LV5FU2 regimen in patients with previously untreated metastatic PAC. AFUGEM is a two-stage, open-label, randomized, multicenter, phase II trial. Patients with PAC who meet the inclusion criteria and provide written informed consent will be randomized in a 1:2 ratio to either nab-paclitaxel (125 mg/m(2)) plus gemcitabine (1000 mg/m(2)) given on days 1, 8, and 15 every 28 days or nab-paclitaxel (125 mg/m(2)) plus sLV5FU2 (leucovorin 400 mg/m(2) followed by bolus 400 mg/m(2) 5-fluorouracil and by 5-fluorouracil 2400 mg/m(2) as an 46-h intravenous infusion) given on days 1 and 15 every 28 days. A total of 114 patients will be randomized to one of the treatment arms. The primary endpoint is progression-free survival at 4 months. Secondary outcomes are rate and duration of response, disease control, overall survival, safety, and quality of life. Potential biomarkers of gemcitabine (hENT1, dCK) and 5-fluorouracil (TS) efficacy will be assessed. The AFUGEM trial is designed to provide valuable information regarding efficacy and tolerability of nab-paclitaxel plus gemcitabine and nab-paclitaxel plus sLV5FU2 regimens. Identification of potential predictive biomarkers of gemcitabine and 5-fluorouracil is likely to drive therapeutic decisions in patients with metastatic PAC. AFUGEM is registered at Clinicaltrials.gov: NCT01964534 , October 15, 2013.

Clinical utility of fixed-dose combinations in hypertension: evidence for the potential of nebivolol/valsartan

Directory of Open Access Journals (Sweden)

Varagic J

2014-11-01

Full Text Available Jasmina Varagic,1–3 Henry Punzi,4,5 Carlos M Ferrario2,3,61Hypertension and Vascular Research Center, 2Division of Surgical Sciences, 3Department of Physiology and Pharmacology, Wake Forest University, Winston-Salem, NC USA; 4Trinity Hypertension and Diagnostic Research Center, Carrollton, TX, USA; 5Department of Family and Community Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; 6Department of Internal Medicine and Nephrology, Wake Forest University, Winston-Salem, NC, USAAbstract: Despite significant advances in pharmacologic approaches to treat hypertension during the last decades, hypertension- and hypertension-related organ damage are still a high health and economic burden because a large proportion of patients with hypertension do not achieve optimal blood pressure control. There is now general agreement that combination therapy with two or more antihypertensive drugs is required for targeted blood pressure accomplishment and reduction of global cardiovascular risk. The goals of combination therapies are to reduce long-term cardiovascular events by targeting different mechanism underlying hypertension and target organ disease, to block the counterregulatory pathways activated by monotherapies, to improve tolerability and decrease the adverse effects of up-titrated single agents, and to increase persistence and adherence with antihypertensive therapy. Multiple clinical trials provide evidence that fixed-dose combinations in a single pill offer several advantages when compared with loose-dose combinations. This review discusses the advances in hypertension control and associated cardiovascular disease as they relate to the prospect of combination therapy targeting a third-generation beta (β 1-adrenergic receptor (nebivolol and an angiotensin II receptor blocker (valsartan in fixed-dose single-pill formulations.Keywords: blood pressure control, hypertension, β1-adrenergic receptor, renin angiotensin system

Dose rate and dose fractionation studies in total body irradiation of dogs

International Nuclear Information System (INIS)

Kolb, H.J.; Netzel, B.; Schaffer, E.; Kolb, H.

1979-01-01

Total body irradiation (TBI) with 800-900 rads and allogeneic bone marrow transplantation according to the regimen designated by the Seattle group has induced remissions in patients with otherwise refractory acute leukemias. Relapse of leukemia after bone marrow transplantation remains the major problem, when the Seattle set up of two opposing 60 Co-sources and a low dose rate is used in TBI. Studies in dogs with TBI at various dose rates confirmed observations in mice that gastrointestinal toxicity is unlike toxicity against hemopoietic stem cells and possibly also leukemic stem cells depending on the dose rate. However, following very high single doses (2400 R) and marrow infusion acute gastrointestinal toxicity was not prevented by the lowest dose rate studied (0.5 R/min). Fractionated TBI with fractions of 600 R in addition to 1200 R (1000 rads) permitted the application of total doses up to 300 R followed by marrow infusion without irreversible toxicity. 26 dogs given 2400-3000 R have been observed for presently up to 2 years with regard to delayed radiation toxicity. This toxicity was mild in dogs given single doses at a low dose rate or fractionated TBI. Fractionated TBI is presently evaluated with allogeneic transplants in the dog before being applied to leukemic patients

Assessment of bioequivalence of rifampicin, isoniazid and pyrazinamide in a four drug fixed dose combination with separate formulations at the same dose levels.

Science.gov (United States)

Agrawal, Shrutidevi; Kaur, Kanwal Jit; Singh, Inderjit; Bhade, Shantaram R; Kaul, Chaman Lal; Panchagnula, Ramesh

2002-02-21

Tuberculosis (TB) needs treatment with three to five different drugs simultaneously, depending on the patient category. These drugs can be given as single drug preparations or fixed dose combinations (FDCs) of two more drugs in a single formulation. World Health Organization and International Union against Tuberculosis and Lung Disease (IUATLD) recommend FDCs only of proven bioavailability. The relative bioavailability of rifampicin (RIF), isoniazid (INH) and pyrazinamide (PYZ) was assessed on a group of 13 healthy male subjects from a four drug FDC versus separate formulations at the same dose levels. The study was designed to be an open, crossover experiment. A total of nine blood samples each of 3 ml volume were collected over a period of 24-h. The concentrations of RIF, its main metabolite desacetyl RIF (DRIF), INH and PYZ in plasma were assessed by HPLC analysis. Pharmacokinetic parameters namely AUC(0-24), AUC(0-inf), C(max), T(max), were calculated and subjected to different statistical tests (Hauschke analysis, two way ANOVA, normal and log transformed confidence interval) at 90% confidence interval. In addition, elimination rate constant (K(el)) and absorption efficiencies for each drug were also calculated. It was concluded that four drugs FDC tablet is bioequivalent for RIF, INH and PYZ to separate formulation at the same dose levels.

Cytotoxicity of Gemcitabine-Loaded-Microemulsions in Breast and ...

African Journals Online (AJOL)

Purpose: To evaluate the antitumor activity of gemcitabine (GEM), incorporated in microemulsions with varying surfactant-to-oil (S/O) ratio, against MCF-7 breast cancer cells and HCT 116 colon cancer cells. Methods: The microemulsion formulations consisted of Tween 80, Span 20, isopropyl myristate (IPM) and aqueous ...

Enzalutamide inhibits proliferation of gemcitabine-resistant bladder cancer cells with increased androgen receptor expression.

Science.gov (United States)

Kameyama, Koji; Horie, Kengo; Mizutani, Kosuke; Kato, Taku; Fujita, Yasunori; Kawakami, Kyojiro; Kojima, Toshio; Miyazaki, Tatsuhiko; Deguchi, Takashi; Ito, Masafumi

2017-01-01

Advanced bladder cancer is treated mainly with gemcitabine and cisplatin, but most patients eventually become resistance. Androgen receptor (AR) signaling has been implicated in bladder cancer as well as other types of cancer including prostate cancer. In this study, we investigated the expression and role of AR in gemcitabine-resistant bladder cancer cells and also the potential of enzalutamide, an AR inhibitor, as a therapeutic for the chemoresistance. First of all, we established gemcitabine-resistant T24 cells (T24GR) from T24 bladder cancer cells and performed gene expression profiling. Microarray analysis revealed upregulation of AR expression in T24GR cells compared with T24 cells. AR mRNA and protein expression was confirmed to be increased in T24GR cells, respectively, by quantitative RT-PCR and western blot analysis, which was associated with more potent AR transcriptional activity as measured by luciferase reporter assay. The copy number of AR gene in T24GR cells determined by PCR was twice as many as that of T24 cells. AR silencing by siRNA transfection resulted in inhibition of proliferation of T24GR cells. Cell culture in charcoal-stripped serum and treatment with enzalutamide inhibited growth of T24GR cells, which was accompanied by cell cycle arrest. AR transcriptional activity was found to be reduced in T24GR cells by enzalutamide treatment. Lastly, enzalutamide also inhibited cell proliferation of HTB5 bladder cancer cells that express AR and possess intrinsic resistance to gemcitabine. Our results suggest that enzalutamide may have the potential to treat patients with advanced gemcitabine-resistant bladder cancer with increased AR expression.

Dosimetric systems of high dose, dose rate and dose uniformity in food and medical products

International Nuclear Information System (INIS)

Vargas, J.; Vivanco, M.; Castro, E.

2014-08-01

In the Instituto Peruano de Energia Nuclear (IPEN) we use the chemical dosimetry Astm-E-1026 Fricke as a standard dosimetric system of reference and different routine dosimetric systems of high doses, according to the applied doses to obtain the desired effects in the treated products and the doses range determined for each type of dosimeter. Fricke dosimetry is a chemical dosimeter in aqueous solution indicating the absorbed dose by means an increase in absorbance at a specific wavelength. A calibrated spectrophotometer with controlled temperature is used to measure absorbance. The adsorbed dose range should cover from 20 to 400 Gy, the Fricke solution is extremely sensitive to organic impurities, to traces of metal ions, in preparing chemical products of reactive grade must be used and the water purity is very important. Using the referential standard dosimetric system Fricke, was determined to March 5, 2013, using the referential standard dosimetric system Astm-1026 Fricke, were irradiated in triplicate Fricke dosimeters, to 5 irradiation times (20; 30; 40; 50 and 60 seconds) and by linear regression, the dose rate of 5.400648 kGy /h was determined in the central point of the irradiation chamber (irradiator Gamma cell 220 Excel), applying the decay formula, was compared with the obtained results by manufacturers by means the same dosimetric system in the year of its manufacture, being this to the date 5.44691 kGy /h, with an error rate of 0.85. After considering that the dosimetric solution responds to the results, we proceeded to the irradiation of a sample of 200 g of cereal instant food, 2 dosimeters were placed at the lateral ends of the central position to maximum dose and 2 dosimeters in upper and lower ends as minimum dose, they were applied same irradiation times; for statistical analysis, the maximum dose rate was 6.1006 kGy /h and the minimum dose rate of 5.2185 kGy /h; with a dose uniformity of 1.16. In medical material of micro pulverized bone for

Dose-Response Analysis of RNA-Seq Profiles in Archival Formalin-Fixed Paraffin-Embedded (FFPE) Samples.

Science.gov (United States)

Use of archival resources has been limited to date by inconsistent methods for genomic profiling of degraded RNA from formalin-fixed paraffin-embedded (FFPE) samples. RNA-sequencing offers a promising way to address this problem. Here we evaluated transcriptomic dose responses us...

Self-assembled gemcitabine-gadolinium nanoparticles for magnetic resonance imaging and cancer therapy.

Science.gov (United States)

Li, Lele; Tong, Rong; Li, Mengyuan; Kohane, Daniel S

2016-03-01

Nanoparticles with combined diagnostic and therapeutic functions are promising tools for cancer diagnosis and treatment. Here, we demonstrate a theranostic nanoparticle that integrates an active gemcitabine metabolite and a gadolinium-based magnetic resonance imaging agent via a facile supramolecular self-assembly synthesis, where the anti-cancer drug gemcitabine-5'-monophosphate (a phosphorylated active metabolite of the anti-cancer drug gemcitabine) was used to coordinate with Gd(III) to self-assemble into theranostic nanoparticles. The formulation exhibits a strong T1 contrast signal for magnetic resonance imaging of tumors in vivo, with enhanced retention time. Furthermore, the nanoparticles did not require other inert nanocarriers or excipients and thus had an exceptionally high drug loading (55 wt%), resulting in the inhibition of MDA-MB-231 tumor growth in mice. Recent advances in nanoparticle-based drug delivery systems have spurred the development of "theranostic" multifunctional nanoparticles, which combine therapeutic and diagnostic functionalities in a single formulation. Developing simple and efficient synthetic strategies for the construction of nanotheranostics with high drug loading remains a challenge. Here, we demonstrate a theranostic nanoparticle that integrates high loadings of an active gemcitabine metabolite and a gadolinium-based magnetic resonance imaging agent via a facile synthesis. The nanoparticles were better T1 contrast agents than currently used Gd-DTPA and had prolonged retention in tumor. Moreover they exhibited enhanced in vivo antitumor activity compared to free drug in a breast cancer xenograft mouse model. The strategy provides a scalable way to fabricate nanoparticles that enables enhancement of both therapeutic and diagnostic capabilities. Published by Elsevier Ltd.

Stochastic Discount Factor Approach to International Risk-Sharing: Evidence from Fixed Exchange Rate Episodes

NARCIS (Netherlands)

Hadzi-Vaskov, M.; Kool, C.J.M.

2007-01-01

This paper presents evidence of the stochastic discount factor approach to international risk-sharing applied to fixed exchange rate regimes. We calculate risk-sharing indices for two episodes of fixed or very rigid exchange rates: the Eurozone before and after the introduction of the Euro, and

Analysis of factors affecting the outcome of Graves disease patients treated with two regimens of fixed Iodine-131 doses (10 mCi and 15 mCi)

International Nuclear Information System (INIS)

Machado, Ana C.B.; Santos, Roberto B.; Chaves, Fatima R.; Romaldini, Joao H.; Ward, Laura S.

2005-01-01

Full text: The use of fixed doses of radioiodine ( 131 I) simplifies the approach to treatment for Graves' disease (GD) patients with potential cost savings. In order to evaluate factors that may affect the outcome of 2 different regimens of 131 I, we prospectively examined 128 patients with overt thyrotoxicosis from GD, as confirmed by suppressed serum TSH, presence of TRAb, increased serum T 3 and FT 4 values. Group 1 comprised 76 patients who received a fixed dose of 10 mCi and Group 2=52 patients who received a fixed dose of 15 mCi. 36 patients did not use any antithyroid drugs and 92 patients used methimazole that was withdrawn at least 5 days before radioiodine administration. Antithyroid drugs treatment was restarted at least 7 days following 131 I therapy when needed. Baseline serum TSH and FT 4 levels were measured at 3, 6, 9 and 12 months after treatment. The groups were similar concerning age, gender, smoke, eye disease, goiter size, serum T 3 , FT 4 , TRAb, anti-Tg and anti-TPO levels as well as 24-hour 131 I or Tec-uptake values and thyroid scan. Clinical outcome was evaluated at the end of 1-year follow-up and cure of hyperthyroidism was defined as clinical and laboratory evidence of either euthyroidism or hypothyroidism in the absence of antithyroid drugs. The cure rate obtained was similar in groups 1 and 2: 73.7% and 80.8%, respectively (p=0.35). Hypothyroidism was diagnosed in 56.5% and 71.15% of the patients from groups 1 and 2, respectively (p=0.13). There was no correlation between clinical features, thyroid uptake, antibodies, serum hormones and outcome. However, logistic regression analysis demonstrated that patients with larger thyroids (weight >60 g) that, consequently, received a lower dose of radioiodine in MBq/g, had 2.4 times less chance to cure (95% Cl=1.18-4.96). The use of fixed doses of radioiodine ( 131 I) simplifies the approach to treatment for Graves' disease (GD) patients with potential cost savings. In order to evaluate

miR-34 increases in vitro PANC-1 cell sensitivity to gemcitabine via targeting Slug/PUMA.

Science.gov (United States)

Zhang, Qing-An; Yang, Xu-Hai; Chen, Dong; Yan, Xiang; Jing, Fu-Chun; Liu, Hong-Qian; Zhang, Ronghua

2018-01-01

miR-34 was deregulated in tumor tissues compared with corresponding noncancerous tissue samples. Furthermore, miR-34 may contribute to cancer-stromal interaction associated with cancer progression. However, whether miR-34 could decrease chemoresistance of cancer cells to chemotherapeutic agent remains unclear. In our study, we examined whether overexpression of miR-34 could sensitize gemcitabine -mediated apoptosis in human pancreatic cancer PANC-1 cells. We found that miR-34 markedly induced gemcitabine -mediated apoptosis in PANC-1 cells. miR-34 induced down-regulation of Slug expression and upregulation of p53 up-regulated modulator of apoptosis (PUMA) expression. The over-expression of Slug or downregulation of PUMA by Slug cDNA or PUMA siRNA transfection markedly blocked miR-34-induced gemcitabine sensitization. Furthermore, miR-34 induced PUMA expression by downregulation of Slug. Taken together, our study demonstrates that miR-34 enhances sensitization against gemcitabine-mediated apoptosis through the down-regulation of Slug expression, and up-regulation of Slug-dependent PUMA expression.

Advances of Drug Resistance Marker of Gemcitabine for Non-small Cell Lung Cancer

Directory of Open Access Journals (Sweden)

Baorui LIU

2011-05-01

Full Text Available With the development of pharmacogenomics and pharmacogenetics, personal therapy based on genes has become one of the most effective ways to enhance chemotherapeutic effect on non-small cell lung cancer (NSCLC patients. Much attention has been paid to validate the predictive biomarkers of chemotherapy in order to guide chemotherapy and enhance effect in general. Gemcitabine is one of the common agents treating NSCLC recently. This review is mainly about the recent reports on potential biomarkers of Gemcitabine in tailored therapy of NSCLC.

Dose-rate effects in external beam radiotherapy redux

International Nuclear Information System (INIS)

Ling, C. Clifton; Gerweck, Leo E.; Zaider, Marco; Yorke, Ellen

2010-01-01

Recent developments in external beam radiotherapy, both in technical advances and in clinical approaches, have prompted renewed discussions on the potential influence of dose-rate on radio-response in certain treatment scenarios. We consider the multiple factors that influence the dose-rate effect, e.g. radical recombination, the kinetics of sublethal damage repair for tumors and normal tissues, the difference in α/β ratio for early and late reacting tissues, and perform a comprehensive literature review. Based on radiobiological considerations and the linear-quadratic (LQ) model we estimate the influence of overall treatment time on radio-response for specific clinical situations. As the influence of dose-rate applies to both the tumor and normal tissues, in oligo-fractionated treatment using large doses per fraction, the influence of delivery prolongation is likely important, with late reacting normal tissues being generally more sensitive to the dose-rate effect than tumors and early reacting tissues. In conventional fractionated treatment using 1.8-2 Gy per fraction and treatment times of 2-10 min, the influence of dose-rate is relatively small. Lastly, the dose-rate effect in external beam radiotherapy is governed by the overall beam-on-time, not by the average linac dose-rate, nor by the instantaneous dose-rate within individual linac pulses which could be as high as 3 x 10 6 MU/min.

The system for automatic dose rate measurements by mobile groups in field

International Nuclear Information System (INIS)

Drabova, D.; Filgas, R.; Cespirova, I.; Ejemova, M.

1998-01-01

The comparison of characteristics between a pressurized ionization chamber, plastic scintillator and proportional counter is given. Based on requirements and comparison of properties of various probes, the system for automatic dose rate measurement and integration of geographic co-ordinates in field was designed and tested.The system consists of proportional counter. This is so-called intelligent probe can be easily connected to a personal computer. The probe measures in the energy range 30 keV - 1.3 MeV with reasonable energy and angular response, it can measure the dose rate in the range 50 nSv/h - 1 Sv/h with the typical efficiency 9.5 imp/s/μSv/h. The probe is fixed in the holder placed on the front mask of a car. For the simultaneous determination of geographical co-ordinates the personal GPS navigator Garmin 95 is used. Both devices are controlled by a notebook via two serial ports. The second serial port that is not quite common in notebook can be easily realised by a PCMCIA card. The notebook is used in the field by a mobile group can be transmitted to the assessment centre by the cellular GSM phone. The system Nokia 2110 connected to notebook by PCMCIA card is used. The whole system is powered up from the car battery. The system is controlled by specially developed software. The software was developed in the FoxPro 2.5 environment and works under MS-DOS 6.22. It has no problems to work in Windows 95 DOS window. The results of dose rate measurements obtained during route monitoring are stored in files. They can be displayed on a graphic screen, presenting the geographical distribution of the dose rate values colour coded on a map and the time sequence of the measured data. (authors)

Optimal bank portfolio choice under fixed-rate deposit insurance

OpenAIRE

Anlong Li

1991-01-01

An analysis of the investment decisions of a bank whose deposits are fully insured under fixed-rate insurance, showing how banks dynamically adjust their investment portfolios in response to market information and how this flexibility affects both investment decisions and the fair cost of deposit insurance.

Dose-rate effects and chronological changes of chromosome aberration rates in spleen cells from mice that are chronically exposed to gamma-ray at low dose rates

International Nuclear Information System (INIS)

Tanaka, Kimio; Kohda, Atsushi; Ichinohe, Kazuaki; Matsumoto, Tsuneya; Oghiso, Yoichi

2006-01-01

Dose-rate effects have not been examined in the low dose-rate regions of less than 60-600 mGy/h. Mice were chronically exposed to gamma-ray at 20 mGy/day (approximately 1 mGy/h) up to 700 days and at 1 mGy/day (approximately 0.05 mGy/h) for 500 days under SPF conditions. Chronological changes of chromosome aberration rates in spleen cells were observed along with accumulated doses at both low dose-rates. Unstable aberrations increased in a biphasic manner within 0-2 Gy and 4-14 Gy in 20 mGy/day irradiation. They slightly increased up to 0.5 Gy in 1 mGy/day irradiation. Chromosome aberration rates at 20 mGy/day and 1 mGy/day were compared at the same total doses of 0.5 Gy and 0.25 Gy. They were 2.0 vs. 0.53, and 1.0 vs. 0.47 respectively. Thus, dose-rate effects were observed in these low dose-rate regions. (author)

Absorbed dose rate meter for β-ray

International Nuclear Information System (INIS)

Bingo, K.

1977-01-01

The absorbed dose of β-ray depends on the energy of β-rays and the epidermal thickness of tissue in interest. In order to measure the absorbed dose rate at the interested tissue directly, the ratio of counting rate to absorbed dose should be constant independent of β-ray energy. In this purpose, a thin plastic scintillator was used as a detector with a single channel analyzer. The pulse height distribution, obtained using the scintillator whose thickness is less than the range of β-rays, shows a peak at a particular pulse height depending on the thickness of scintillator used. This means an increase of the number of pulses at lower pulse height. The lower level of discrimination and window width of the single channel analyzer are chosen according to the epidermal thickness of the tissue. In the experiment, scintillators of 0.5, 1, 2, 3, 5 and 10 mm thick were tested. It was found that desirable pulse height distribution, to obtain a constant dose sensitivity, could be obtained using the 2 mm thick scintillator. The sensitivity of the absorbed dose rate meter is constant within +-15% for β-ray with maximum energy from 0.4 to 3.5 MeV, when the absorbed dose rate for skin (epidermal thickness 7mg/cm 2 ) is measured. In order to measure the dose rate for a hand (epithermal thickness 40mg/cm 2 ) the lower level of discrimination is changed to be higher and at the same time the window width is also changed. Combining these techniques, one can get an absorbed dose rate meter for the tissue dose of various thickness, which has the constant dose sensitivity within +-15% for β-rays with maximum energy from 0.4 to 3.5 MeV

Multi-institutional phase I study of low-dose ultra-fractionated radiotherapy as a chemosensitizer for gemcitabine and erlotinib in patients with locally advanced or limited metastatic pancreatic cancer

International Nuclear Information System (INIS)

Konski, Andre; Meyer, Joshua E.; Joiner, Michael; Hall, Michael J.; Philip, Philip; Shields, Anthony; McSpadden, Erin; Choi, Minsig; Adaire, Beth; Duncan, Gail; Meropol, Neal J.; Cescon, Terrence P.; Cohen, Steven J.

2014-01-01

Purpose: Gemcitabine (G) has been shown to sensitize pancreatic cancer to radiotherapy but requires lower doses of G and thus delays aggressive systemic treatment, potentially leading to distant failure. We initiated a phase I trial combining ultra-fractionated low-dose radiotherapy with full dose G and erlotinib in the treatment of patients with advanced pancreatic cancer. Methods: Patients with locally advanced or metastatic pancreatic cancer confined to the abdomen and an ECOG performance status (PS) of 0–1 who had received 0–1 prior regimens (without G or E) and no prior radiotherapy were eligible. Patients were treated in 21 day cycles with G IV days 1 and 8, E once PO QD, and twice daily RT fractions separated by at least 4 h on days 1, 2, 8, and 9. Whole abdominal RT fields were used. Primary endpoint was to define dose limiting toxicity (DLT) and the maximum tolerated dose (MTD). Results: 27 patients (median age 64 years and 15 male) were enrolled between 11/24/08 and 4/12/12. 1 patient withdrew consent prior to receiving any protocol therapy. 17 patients had a PS of 1. The majority of patients were stage IV. One DLT was noted out of 7 patients at dose level (DL) 1. Subsequently no DLTs were noted in 3 patients each enrolled at DL2-4 or 11 patients in the expansion cohort. The majority of grade 3 toxicities were hematologic with 1 grade 5 bowel perforation in dose level 1 in cycle 4. Best response in 24 evaluable patients: PR (8), stable (15), PD 1. Median survival for the entire group was 9.1 months. Conclusion: This phase I study combining low-dose ultra-fractionated RT as a sensitizer to full dose G plus E was well tolerated with encouraging efficacy. This represents a novel strategy worthy of further investigation in advanced pancreatic cancer patients

A graphical review of radiogenic animal cancer data using the 'dose and dose-rate map'

International Nuclear Information System (INIS)

Yoshida, Kazuo; Hoshi, Yuko; Sakai, Kazuo

2008-01-01

We have been investigating the effects of low dose or low dose rate irradiation on mice, using our low dose-rate irradiation facilities. In these studies, we found that the effects were highly dependent on both total dose and dose rate. To show this visually, we proposed the 'dose/dose rate map', and plotted the results of our laboratory and our co-workers. The map demonstrated that dose/dose rate plane could be divided into three areas; 1) An area where harmful effects are observed, 2) An area where no harmful effects are observed, and 3) Another area, between previous two areas, where certain protective functions are enhanced. As this map would be a powerful tool to find some trend among the vast numbers of data relating the biological effects of ionizing radiation, we have developed a computer program which plots the collected data on the dose/dose rate map sorting by experimental conditions. In this study, we graphically reviewed and analyzed the data relating to the lifespan studies of animals with a view to determining the relationships between doses and dose rates of ionizing radiation and cancer incidence. The data contains about 800 sets of experiments, which concerns 187,000 animals exposed to gamma ray or X-ray and their 112,000 controls, and total of about 30,000 cancers in exposed animals and 14,000 cancers in controls. About 800 points of data were plotted on the dose/dose rate map. The plot showed that 1) The divided three areas in the dose/dose rate map were generally confirmed by these 800 points of data, and 2) In some particular conditions, e.g. sarcoma by X-rays, the biologically effective area is extended to relatively high dose/dose rate area. (author)

Radiation recall gastritis secondary to combination of gemcitabine and erlotinib in pancreatic cancer and response to PPI - a case report.

Science.gov (United States)

Choi, Seong Ji; Kim, Hyo Jung; Kim, Jae Seon; Bak, Young-Tae; Kim, Jun Suk

2016-08-02

Radiation recall gastritis is rare but can be induced after concurrent chemoradiation for pancreatic cancer. We report a patient with pancreatic cancer who developed radiation-recall gastritis related to a combination of gemcitabine and erlotinib. A 54-year-old female with unresectable pancreatic cancer received gemcitabine in combination with radiation therapy followed by chemotherapy with gemcitabine and erlotinib. After completing 2 cycles of chemotherapy, the patient had epigastric pain, nausea, and vomiting. Abdominal computed tomography (CT) scan revealed diffuse wall thickening of the stomach, and esophagogastroduodenoscopy (EGD) showed multiple gastric ulcers. The patient was treated with proton pump inhibitors (PPI) and was continued on maintenance chemotherapy. Two months later, the patient presented with the similar symptoms and persistent gastric ulcers were observed during subsequent EGD. Nevertheless, the patient's symptom had resolved with PPI therapy. Thus, the patient underwent maintenance chemotherapy with gemcitabine and erlotinib for additional 4 cycles. Eventually, follow-up abdominal CT Scan and EGD at 6 months demonstrated resolution of the gastric ulcers. Physicians should be aware of the possibility of radiation recall gastritis associated with a combination of gemcitabine and erlotinib. Administration of PPIs may mitigate the adverse effects of gemcitabine and erlotinib in the presence of radiation recall gastritis; however further studies are warranted.

Radiation recall gastritis secondary to combination of gemcitabine and erlotinib in pancreatic cancer and response to PPI - a case report

International Nuclear Information System (INIS)

Choi, Seong Ji; Kim, Hyo Jung; Kim, Jae Seon; Bak, Young-Tae; Kim, Jun Suk

2016-01-01

Radiation recall gastritis is rare but can be induced after concurrent chemoradiation for pancreatic cancer. We report a patient with pancreatic cancer who developed radiation-recall gastritis related to a combination of gemcitabine and erlotinib. A 54-year-old female with unresectable pancreatic cancer received gemcitabine in combination with radiation therapy followed by chemotherapy with gemcitabine and erlotinib. After completing 2 cycles of chemotherapy, the patient had epigastric pain, nausea, and vomiting. Abdominal computed tomography (CT) scan revealed diffuse wall thickening of the stomach, and esophagogastroduodenoscopy (EGD) showed multiple gastric ulcers. The patient was treated with proton pump inhibitors (PPI) and was continued on maintenance chemotherapy. Two months later, the patient presented with the similar symptoms and persistent gastric ulcers were observed during subsequent EGD. Nevertheless, the patient’s symptom had resolved with PPI therapy. Thus, the patient underwent maintenance chemotherapy with gemcitabine and erlotinib for additional 4 cycles. Eventually, follow-up abdominal CT Scan and EGD at 6 months demonstrated resolution of the gastric ulcers. Physicians should be aware of the possibility of radiation recall gastritis associated with a combination of gemcitabine and erlotinib. Administration of PPIs may mitigate the adverse effects of gemcitabine and erlotinib in the presence of radiation recall gastritis; however further studies are warranted

13 CFR 120.213 - What fixed interest rates may a Lender charge?

Science.gov (United States)

2010-01-01

... Lender charge? 120.213 Section 120.213 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... have a reasonable fixed interest rate. SBA periodically publishes the maximum allowable rate in the... government determines the interest rate on direct loans. SBA publishes the rate periodically in the Federal...

TM4SF1 Promotes Gemcitabine Resistance of Pancreatic Cancer In Vitro and In Vivo.

Directory of Open Access Journals (Sweden)

Jia Cao

Full Text Available TM4SF1 is overexpressed in pancreatic ductal adenocarcinoma (PDAC and affects the development of this cancer. Also, multidrug resistance (MDR is generally associated with tumor chemoresistance in pancreatic cancer. However, the correlation between TM4SF1 and MDR remains unknown. This research aims to investigate the effect of TM4SF1 on gemcitabine resistance in PDAC and explore the possible molecular mechanism between TM4SF1 and MDR.The expression of TM4SF1 was evaluated in pancreatic cancer cell lines and human pancreatic duct epithelial (HPDE cell lines by quantitative RT-PCR. TM4SF1 siRNA transfection was carried out using Hiperfect transfection reagent to knock down TM4SF1. The transcripts were analyzed by quantitative RT-PCR, RT-PCR and western blotting for further study. The cell proliferation and apoptosis were obtained to investigate the sensitivity to gemcitabine of pancreatic cancer cells after silencing TM4SF1 in vitro. We demonstrated that cell signaling of TM4SF1 mediated chemoresistance in cancer cells by assessing the expression of multidrug resistance (MDR genes using quantitative RT-PCR. In vivo, we used orthotopic pancreatic tumor models to investigate the effect of proliferation after silencing TM4SF1 by a lentivirus-mediated shRNA in MIA PaCa-2 cell lines.The mRNA expression of TM4SF1 was higher in seven pancreatic cancer cell lines than in HPDE cell lines. In three gemcitabine-sensitive cell lines (L3.6pl, BxPC-3, SU86.86, the expression of TM4SF1 was lower than that in four gemcitabine-resistant cell lines (MIA PaCa-2, PANC-1, Hs766T, AsPC-1. We evaluated that TM4SF1 was a putative target for gemcitabine resistance in pancreatic cancer cells. Using AsPC-1, MIA PaCa-2 and PANC-1, we investigated that TM4SF1 silencing affected cell proliferation and increased the percentages of cell apoptosis mediated by treatment with gemcitabine compared with cells which were treated with negative control. This resistance was associated

Efficacy and safety of sorafenib in combination with gemcitabine in patients with advanced hepatocellular carcinoma: a multicenter, open-label, single-arm phase II study.

Science.gov (United States)

Srimuninnimit, Vichien; Sriuranpong, Virote; Suwanvecho, Suthida

2014-09-01

Currently, the only standard systemic treatment for advanced hepatocellular carcinoma is sorafenib monotherapy. The study was conducted to assess the efficacy and safety of the novel combination of sorafenib and gemcitabine in the treatment of advanced hepatocellular carcinoma. Between March 2008 and October 2010, patients with advanced pathologically proven hepatocellular carcinoma who had not received previous systemic therapy and had Child-Pugh liver function class A or B received sorafenib plus gemcitabine. Treatment included 4-week cycle of gemcitabine (1000 mg/m(2) days 1, 8, 15) to the maximum of six cycles together with sorafenib (400 mg twice daily). Patient continued sorafenib until disease progression or withdrawal from other reasons. The primary end point is progression-free survival. Forty-five patients were enrolled in this study. The median progression-free survival was 3.7 months (95% CI 3.5-3.8). The overall response rate was 4% with no complete responses and the disease control rate was 66%. The median overall survival (OS) was 11.6 months (95% CI 7.4-15.9). The median time to progression was 3.6 months (95% CI 3.4-3.7). The most frequently reported grade 3/4 treatment-related adverse events included thrombocytopenia 33%, neutropenia 16% and hand-foot skin reaction 13%. The study regimen was well tolerated. The combination of sorafenib and gemcitabine in advanced hepatocellular carcinoma is generally well tolerated and has modest clinical efficacy. The median OS is up to 1 year. However, well-designed randomized controlled trials with a sorafenib alone comparator arm are needed to confirm this finding. © 2014 Wiley Publishing Asia Pty Ltd.

Biology of dose rate in brachytherapy

International Nuclear Information System (INIS)

Brenner, David J.

1995-01-01

Purpose: This course is designed for practitioners and beginners in brachytherapy. The aim is to review biological principles underlying brachytherapy, to understand why current treatment regimes are the way they are, and to discuss what the future may hold in store. Brachytherapy has a long history. It was suggested as long ago as 1903 by Alexander Graham Bell, and the optimal application of this technique has been a subject of debate ever since. 'Brachy' means 'short', and the essential features of conventional brachytherapy are: positioning of the source a short distance from, or in, the tumor, allowing good dose distributions; short overall treatment times, to counter tumor repopulation; low dose rate, enabling a good therapeutic advantage between tumor control and damage to late-responding tissue. The advantages of good dose distributions speak for themselves; in some situations, as we shall see, computer-based dose optimization can be used to improve them still further. The advantages of short overall times stem from the fact that accelerated repopulation of the tumor typically begins a few weeks after the start of a radiation treatment. If all the radiation can be crammed in before that time, the risks of tumor repopulation can be considerably reduced. In fact even external-beam radiotherapy is moving in this direction, with the use of highly accelerated protocols. The advantages of low dose rate stem from the differential response to fractionation of early- and late-responding tissues. Essentially, lowering the dose rate spares late-responding tissue more than it does early-responding tissue such as tumors. We shall also discuss some recent innovations in the context of the general principles that have been outlined. For example, High dose rate brachytherapy, particularly for the uterine cervix: Does it work? If so, when and why? Use of Ir-192 sources, with a half life of 70 days: Should corrections be made for changing biological effectiveness as the dose

High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

Energy Technology Data Exchange (ETDEWEB)

Ghadjar, Pirus, E-mail: pirus.ghadjar@insel.ch [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Bojaxhiu, Beat [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Simcock, Mathew [Swiss Group for Clinical Cancer Research Coordinating Center, Bern (Switzerland); Terribilini, Dario; Isaak, Bernhard [Division of Medical Radiation Physics, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Gut, Philipp; Wolfensberger, Patrick; Broemme, Jens O.; Geretschlaeger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M. [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland)

2012-07-15

Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3-23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

Concurrent chemoradiotherapy for advanced pancreatic cancer. 1,000 mg/m{sup 2} gemcitabine can be administered using limited-field radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Yamazaki, Hideya [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Radiation Oncology; National Hospital Organization, Osaka National Hospital, Osaka (Japan). Dept. of Radiology; Nishiyama, Kinji; Koizumi, Masahiko; Tanaka, Eiichi [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Radiation Oncology; Ioka, Tatsuya; Uehara, Hiroyuki; Iishi, Hiroyasu; Nakaizumi, Akihiko [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Internal Medicine; Ohigashi, Hiroaki; Ishikawa, Osamu [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Surgery

2007-06-15

Purpose: To examine the feasibility of concurrent use of full-dose gemcitabine (GEM) and radiotherapy for advanced pancreatic cancer. Patient and Methods: 22 patients with advanced pancreatic cancer were subjected to concurrent chemoradiotherapy (GEM 1,000 mg/m2 weekly, three times during 4 weeks). They received limited-field irradiation by three-dimensional radiotherapy planning. Results: Of the 22 patients, 16 (72%) completed the treatment (50 Gy irradiation and at least three times concurrent administration of 1 g/m{sup 2} GEM). One patient with unresectable tail cancer showed peritonitis carcinomatosa and both chemotherapy and radiotherapy had to be stopped. Dose reduction or omission of GEM was necessary in another four patients. In addition, radiotherapy was discontinued in one patient for fatigue. Grade 3 hematologic toxicity was detected in eight patients (36%), and grade 3 nonhematologic toxicity (anorexia) in one patient (5%). In total, the response rate amounted to 32% (seven partial responses), and the median survival time (MST) was 16 months. Among the twelve patients who received preoperative chemoradiotherapy, nine underwent surgery and showed a survival rate of 78% at 1 year. Another 13 patients without surgery showed 14 months of MST. No regional lymph node failure has appeared so far. Conclusion: Limited-field radiotherapy enables the safe concurrent administration of 1,000 mg/m{sup 2} GEM.

Gemcitabine/cisplatin versus 5-fluorouracil/mitomycin C chemoradiotherapy in locally advanced pancreatic cancer: a retrospective analysis of 93 patients

Directory of Open Access Journals (Sweden)

Sauer Rolf

2011-07-01

Full Text Available Abstract Background Despite of a growing number of gemcitabine based chemoradiotherapy studies in locally advanced pancreatic cancer (LAPC, 5-fluorouracil based regimens are still regarded to be standard and the debate of superiority between the two drugs is going on. The aim of this retrospective analysis was to evaluate the effect of two concurrent chemoradiotherapy regimens using 5-fluorouracil or gemcitabine to compare their effect and tolerance. Methods We have performed a single centre retrospective analysis of 93 patients treated with conventionally fractionated radiotherapy of 55.8 Gray using either concurrent 5-fluorouracil, 1 g/m² on days 1-5 and 29-33 of radiotherapy and 10 mg/m² of mitomycin C on day 1, 29 of radiotherapy (FM group, 35 patients versus gemcitabine (300 mg/m² and cisplatin, (30 mg/m² on days 1, 8, 22, and 29 (GC group, 58 patients. Primary endpoint was the median overall survival (OS rate. Results The median OS rate was 12.7 months in the GC group and 9.7 months in the FM group. The 1-year OS rate was 53% versus 40%, respectively (p = 0.009. GC led to more grade 3 leukocytopenia and thrombocytopenia than FM, but not to more grade 4 myelosuppression. Thrombocytopenia was the most frequently observed grade 4 toxicity in both groups (11% after FM versus 12% after GC. No grade 3/4 febrile neutropenia was observed. Grade 3 nausea was more common in the FM group (20% versus 9% and grade 4 nausea was observed in one patient per group only. Conclusions GC was superior to FM for overall survival and both regimens were similar in terms of tolerance. We conclude that GC leads to encouraging results and that the use of FM for chemoradiotherapy in LAPC cannot be recommended without concerns.

A phase I/II study of gemcitabine-concurrent proton radiotherapy for locally advanced pancreatic cancer without distant metastasis

International Nuclear Information System (INIS)

Terashima, Kazuki; Demizu, Yusuke; Hashimoto, Naoki; Jin, Dongcun; Mima, Masayuki; Fujii, Osamu; Niwa, Yasue; Takatori, Kento; Kitajima, Naoto; Sirakawa, Sachiyo; Yonson, Ku; Hishikawa, Yoshio; Abe, Mitsuyuki; Sasaki, Ryohei; Sugimura, Kazuro; Murakami, Masao

2012-01-01

Purpose: We conducted the study to assess the feasibility and efficacy of gemcitabine-concurrent proton radiotherapy (GPT) for locally advanced pancreatic cancer (LAPC). Materials and methods: Of all 50 patients who participated in the study, 5 patients with gastrointestinal (GI)-adjacent LAPC were enrolled in P-1 (50 Gy equivalent [GyE] in 25 fractions) and 5 patients with non-GI-adjacent LAPC in P-2 (70.2 GyE in 26 fractions), and 40 patients with LAPC regardless of GI-adjacency in P-3 (67.5 GyE in 25 fractions using the field-within-a-field technique). In every protocol, gemcitabine (800 mg/m 2 /week for 3 weeks) was administered concurrently. Every patient received adjuvant chemotherapy including gemcitabine after GPT within the tolerable limit. Results: The median follow-up period was 12.5 months. The scheduled GPT was feasible for all except 6 patients (12%) due to acute hematologic or GI toxicities. Grade 3 or greater late gastric ulcer and hemorrhage were seen in 5 patients (10%) in P-2 and P-3. The one-year freedom from local-progression, progression-free, and overall survival rates were 81.7%, 64.3%, and 76.8%, respectively. Conclusion: GPT was feasible and showed high efficacy. Although the number of patients and the follow-up periods are insufficient, the clinical results seem very encouraging.

Dose Response Model of Biological Reaction to Low Dose Rate Gamma Radiation

International Nuclear Information System (INIS)

Magae, J.; Furikawa, C.; Hoshi, Y.; Kawakami, Y.; Ogata, H.

2004-01-01

It is necessary to use reproducible and stable indicators to evaluate biological responses to long term irradiation at low dose-rate. They should be simple and quantitative enough to produce the results statistically accurate, because we have to analyze the subtle changes of biological responses around background level at low dose. For these purposes we chose micronucleus formation of U2OS, a human osteosarcoma cell line, as indicators of biological responses. Cells were exposed to gamma ray in irradiation rom bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide, respectively. the number of binuclear cells bearing micronuclei was counted under a fluorescence microscope. Dose rate in the irradiation room was measured with PLD. Dose response of PLD is linear between 1 mGy to 10 Gy, and standard deviation of triplicate count was several percent of mean value. We fitted statistically dose response curves to the data, and they were plotted on the coordinate of linearly scale response and dose. The results followed to the straight line passing through the origin of the coordinate axes between 0.1-5 Gy, and dose and does rate effectiveness factor (DDREF) was less than 2 when cells were irradiated for 1-10 min. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose above 0.1 Gy when 5,000 binuclear cells were analyzed. In contrast, dose response curves never followed LNT, when cells were irradiated for 7 to 124 days. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose below 6 Gy, when cells were continuously irradiated for 124 days. These results suggest that dose response curve of biological reaction is remarkably affected by exposure

On determining dose rate constants spectroscopically

International Nuclear Information System (INIS)

Rodriguez, M.; Rogers, D. W. O.

2013-01-01

Purpose: To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of 125 I and 103 Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089–6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated 125 I and 103 Pd sources. Methods: Spectra generated by 14 125 I and 6 103 Pd seeds were calculated in vacuo at 10 cm from the source in a 2.7 × 2.7 × 0.05 cm 3 voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the 125 I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for 103 Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were ⩽0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. Results: The ratio of the intensity of the 31 keV line relative to that of the main peak in 125 I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The 103 Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when calculated with the TG-43U1 rather than the NNDC(2000) initial spectrum. The measured values from three different

Late effects of low doses and dose rates

International Nuclear Information System (INIS)

Paretzke, H.G.

1980-01-01

This paper outlines the spectrum of problems and approaches used in work on the derivation of quantitative prognoses of late effects in man of low doses and dose rates. The origins of principal problems encountered in radiation risks assessments, definitions and explanations of useful quantities, methods of deriving risk factors from biological and epidemiological data, and concepts of risk evaluation and problems of acceptance are individually discussed

Cost-utility analysis of the fixed-dose combination of dolutegravir/abacavir/lamivudine as initial treatment of HIV+ patients in Spain

Directory of Open Access Journals (Sweden)

Santiago Moreno Guillen

2017-09-01

Full Text Available Objective: Fixed-dose combinations of antiretroviral drugs have meant an important step forward in simplifying treatment and improving compliance and has led to an increased effectiveness of therapy, a viral load decrease and improving the quality of life of patients. The single-table formulation of dolutegravir with abacavir and lamivudine (DTG/ABC/3TC is a highly efficacious and well-tolerated once-daily regimen for HIV-infected patients. The objective of the study was to assess the incremental cost-utility ratio of the fixed-dose combination of (DTG/ABC/3TC versus the combinations emtricitabine/tenofovir/efavirenz (FTC/TDF/EFV, and darunavir/r (DRV/r or raltegravir (RAL with emtricitabine/tenofovir (FTC/TDF or abacavir/lamivudine (ABC/3TC as initial antiretroviral therapy in patients infected with HIV-1 from the perspective of the Spanish National Health System. Method: The ARAMIS model, which uses a microsimulation approach to simulate the individual changes in each patient from the start of treatment to death through a Markov chain of descriptive health states of the disease, was adapted to Spain. The alternatives used for comparison were the fixed-dose combination of emtricitabine/tenofovir/efavirenz (FTC/TDF/EFV, and the fixed- dose combinations of emtricitabine/tenofovir (FTC/TDF or abacavir/lamivudine (ABC/3TC with darunavir/r (DRV/r or raltegravir (RAL. The probability of achieving virological suppression by the treatments included in the model was obtained from clinical trials SINGLE, SPRING-2 and FLAMINGO and the costs were expressed in € (2015. The model use the perspective of the Spanish National Health System, with a lifetime horizon and a discount rate of 3% was applied to cost and effectiveness. Results: Treatment initiation with DTG/ABC/3TC was dominant when it was compared with treatment initiation with all the comparators: vs. FTC/TDF/EFV (-67 210.71€/QALY, vs. DRV/r + FTC/TDF or ABC/3TC (-1 787 341.44€/QALY, and vs

Quality control of 192Ir high dose rate after loading brachytherapy dose veracity

International Nuclear Information System (INIS)

Feng Zhongsu; Xu Xiao; Liu Fen

2008-01-01

Recently, 192 Ir high dose rate (HDR) afterloading are widely used in brachytherapy. The advantage of using HDR systems over low dose rate systems are shorter treatment time and higher fraction dose. To guarantee the veracity of the delivery dose, several quality control methods are deseribed in this work. With these we can improve the position precision, time precision and dose precision of the brachytherapy. (authors)

48 CFR 3452.216-71 - Negotiated overhead rates-fixed.

Science.gov (United States)

2010-10-01

... acceptability of cost allocation methods shall be determined in accordance with part 31 of the Federal... different period, for which the rates apply, and (4) the specific items treated as direct costs or any changes in the items previously agreed to be direct costs. (e) Pending establishment of fixed overhead...

Synergistic antiviral activity of gemcitabine and ribavirin against enteroviruses

NARCIS (Netherlands)

Kang, Hyunju; Kim, Chonsaeng; Kim, Dong-Eun; Song, Jae-Hyoung; Choi, Miri; Choi, Kwangman; Kang, Mingu; Lee, Kyungjin; Kim, Hae Soo; Shin, Jin Soo; Kim, Janghwan; Han, Sang-Bae; Lee, Mi-Young; Lee, Su Ui; Lee, Chong-Kyo; Kim, Meehyein; Ko, Hyun-Jeong; van Kuppeveld, Frank J M; Cho, Sungchan

2015-01-01

Enteroviruses are major causative agents of various human diseases, and some of them are currently considered to be an enormous threat to public health. However, no effective therapy is currently available for the treatment of these infections. We identified gemcitabine, a nucleoside-analog drug

Randomize Trial of Cisplatin plus Gemcitabine with either Sorafenib or Placebo as First-line Therapy for Non-small Cell Lung Cancer

Directory of Open Access Journals (Sweden)

Yan WANG

2011-03-01

Full Text Available Background and objective Platinum-based chemotherapy doublets reached an efficacy plateau in nonsmall-cell lung cancer (NSCLC. This randomized controlled study prospectively assessed the efficacy and safety of cisplatin plus gemcitabine with either Sorafenib or placebo as first-line therapy for NSCLC. Methods Thirty patients, which were confirmed advanced NSCLC histologically or cytologically, were randomly assigned to receive up to six cycles of cisplatin plus gemcitabine with sorafenib or placebo. The maintenance of sorafenib or placebo after chemotherapy will continued in patients with response or stable disease until disease progression or unacceptable adverse events. Results Overall demographics were balanced between experimental group (sorafenib+chemotherapy and controlled group (chemotherapy only. Overall response (OS rate was 55.6% and 41.7% in experimental arm and controlled arm, respectively (P=0.905. Median progressivefree survival (PFS and median overall survial were similar (5 months vs 4 months, P=0.75; 18 months vs 18 months, P=0.68. Adverse events were tolerable, though the risk of hypertension and diarrhea was increase in experimental arm. Since patients with ECOG PS 0, stage IIIb, no liver metastasis and tyrasine kinasis inhibitor treatment after study had longer survive, these factors seemed to be predictive factors favor of survival in Cox regression analyses. Conclusion No additional benefit of response rate, PFS or OS were observed from adding targeted agent-sorafenib to regular cisplatin plus gemcitabine chemotherapy. Selecting aproper patients is needed in further study.

[Randomize trial of cisplatin plus gemcitabine with either sorafenib or placebo as first-line therapy for non-small cell lung cancer].

Science.gov (United States)

Wang, Yan; Wang, Lin; Liu, Yutao; Yu, Shufei; Zhang, Xiangru; Shi, Yuankai; Sun, Yan

2011-03-01

Platinum-based chemotherapy doublets reached an efficacy plateau in nonsmall-cell lung cancer (NSCLC). This randomized controlled study prospectively assessed the efficacy and safety of cisplatin plus gemcitabine with either Sorafenib or placebo as first-line therapy for NSCLC. Thirty patients, which were confirmed advanced NSCLC histologically or cytologically, were randomly assigned to receive up to six cycles of cisplatin plus gemcitabine with sorafenib or placebo. The maintenance of sorafenib or placebo after chemotherapy will continued in patients with response or stable disease until disease progression or unacceptable adverse events. Overall demographics were balanced between experimental group (sorafenib+chemotherapy) and controlled group (chemotherapy only). Overall response (OS) rate was 55.6% and 41.7% in experimental arm and controlled arm, respectively (P=0.905). Median progressive-free survival (PFS) and median overall survival were similar (5 months vs 4 months, P=0.75; 18 months vs 18 months, P=0.68). Adverse events were tolerable, though the risk of hypertension and diarrhea was increase in experimental arm. Since patients with ECOG PS 0, stage IIIb, no liver metastasis and tyrasine kinasis inhibitor treatment after study had longer survive, these factors seemed to be predictive factors favor of survival in Cox regression analyses. No additional benefit of response rate, PFS or OS were observed from adding targeted agent-sorafenib to regular cisplatin plus gemcitabine chemotherapy. Selecting aproper patients is needed in further study.

Carcinogenesis in mice after low doses and dose rates

International Nuclear Information System (INIS)

Ullrich, R.L.

1979-01-01

The results from the experimental systems reported here indicate that the dose-response curves for tumor induction in various tissues cannot be described by a single model. Furthermore, although the understanding of the mechanisms involved in different systems is incomplete, it is clear that very different mechanisms for induction are involved. For some tumors the mechanism of carcinogenesis may be mainly a result of direct effects on the target cell, perhaps involving one or more mutations. While induction may occur, in many instances, through such direct effects, the eventual expression of the tumor can be influenced by a variety of host factors including endocrine status, competence of the immune system, and kinetics of target and interacting cell populations. In other tumors, indirect effects may play a major role in the initiation or expression of tumors. Some of the hormone-modulated tumors would fall into this class. Despite the complexities of the experimental systems and the lack of understanding of the types of mechanisms involved, in nearly every example the tumorigenic effectiveness per rad of low-LET radiation tends to decrease with decreasing dose rate. For some tumor types the differences may be small or may appear only with very low dose rates, while for others the dose-rate effects may be large

Radiation dose rate meter

International Nuclear Information System (INIS)

Kronenberg, S.; Siebentritt, C.R.

1981-01-01

A combined dose rate meter and charger unit therefor which does not require the use of batteries but on the other hand produces a charging potential by means of a piezoelectric cylinder which is struck by a manually triggered hammer mechanism. A tubular type electrometer is mounted in a portable housing which additionally includes a geiger-muller (Gm) counter tube and electronic circuitry coupled to the electrometer for providing multi-mode operation. In one mode of operation, an rc circuit of predetermined time constant is connected to a storage capacitor which serves as a timed power source for the gm tube, providing a measurement in terms of dose rate which is indicated by the electrometer. In another mode, the electrometer indicates individual counts

Combination therapy versus gemcitabine monotherapy in the treatment of elderly pancreatic cancer: a meta-analysis of randomized controlled trials

Directory of Open Access Journals (Sweden)

Jin JM

2018-03-01

Full Text Available Jiamin Jin, Chunbo Teng, Tao Li College of Life Science, Northeast Forestry University, Harbin, China Purpose: We aimed to compare the efficacy of combination therapy versus gemcitabine monotherapy in the treatment of elderly pancreatic cancer (PC by using a meta-analysis.Materials and methods: Databases were searched to identify relevant clinical trials. Hazard ratios (HRs were used to estimate overall survival (OS and progression-free survival (PFS. Statistical analyses were conducted by using Comprehensive Meta Analysis software (version 2.0.Results: A total of 3,401 elderly PC patients from six randomized controlled trials were included for analysis. In comparison with gemcitabine alone, combination therapy in elderly PC patients did not significantly improve OS (HR 0.93, 95% CI: 0.82–1.06, p=0.29. Sub-group analysis according to treatment regimens showed that combined chemotherapy significantly improved OS in comparison with gemcitabine alone (HR 0.73, 95% CI: 0.56–0.94, p=0.016, while gemcitabine plus targeted agents did not improve OS (HR 1.02, 95% CI: 0.87–1.19, p=0.83. Additionally, gemcitabine plus nab-paclitaxel significantly improved PFS in elderly PC patients (HR 0.69, 95% CI: 0.52–0.91, p=0.009 in comparison with gemcitabine alone. No publication bias was detected by Begg’s and Egger’s tests for OS.Conclusion: The findings of this study suggest that combined chemotherapy, but not for gemcitabine plus targeted agents, could be recommended for elderly PC patients due to its survival benefits. Further studies are still needed to assess the treatment tolerance of combination chemotherapy in these patient populations. Keywords: pancreatic cancer, elderly, randomized controlled trials, meta-analysis, targeted agents

Effect of gemcitabine chemotherapy on immune function and VEGF in patients with middle and advanced liver cancer

Directory of Open Access Journals (Sweden)

Ling Zuo

2016-09-01

Full Text Available Objective: To observe the effect of gemcitabine chemotherapy on the immune function and VEGF in patients with middle and advanced liver cancer. Methods: A total of 90 patients with middle and advanced liver cancer who were admitted in our hospital from June, 2014 to July, 2015 were included in the study and randomized into the observation group and the control group with 45 cases in each group. The patients in the control group were given adriamycin, and the patients in the observation group were given gemcitabine chemotherapy. The efficacy, immunological function indicators, VEGF level, and the occurrence of adverse reactions in the two groups were compared. Results: IL-6 and TNF-毩 levels after treatment in the two groups were significantly elevated, and the increased degree in the observation group was significantly greater than that in the control group (P0.05. VEGF level after treatment in the two groups was significantly reduced, and the reduced degree in the observation group was significantly greater than that in the control group (P<0.05. The improvement of T cell subsets after treatment in the observation group was significantly superior to that in the control group (P<0.05. The occurrence rate of adverse reactions in the observation group was significantly lower than that in the control group (P<0.05. Conclusions: Gemcitabine chemotherapy on patients with middle and advanced liver cancer can effectively improve the immunological function, and enhance the efficacy, with a higher safety.

A study on gamma dose rate in Seoul (I)

International Nuclear Information System (INIS)

Kim, You Hyun; Kim, Chang Kyun; Choi, Jong Hak; Kim, Jeong Min

2001-01-01

This study was conducted to find out gamma dose rate in Seoul, from January to December in 2000, and the following results were achieved : The annual gamma dose rate in Seoul was 17.24 μR/hr as average. The annual gamma dose rate in subway of Seoul was 14.96 μR/hr as average. The highest annual gamma dose rate was Dong-daemon ku. Annual gamma dose rate in Seoul was higher autumn than winter

Fisetin Enhances the Cytotoxicity of Gemcitabine by Down-regulating ERK-MYC in MiaPaca-2 Human Pancreatic Cancer Cells.

Science.gov (United States)

Kim, Nayoung; Kang, Min-Jung; Lee, Sang Hyub; Son, Jun Hyuk; Lee, Ji Eun; Paik, Woo Hyun; Ryu, Ji Kon; Kim, Yong-Tae

2018-06-01

Pancreatic cancer is a highly lethal malignancy with a poor prognosis. This study was set up to investigate the combined effect of gemcitabine and fisetin, a natural flavonoid from plants, on human pancreatic cancer cells. Meterials and Methods: Cytotoxic effect of fisetin in combination with gemcitabine on MiaPaca-2 cells was evaluated by the MTT assay, caspase 3/7 assay and propidium iodide/Annexin V. Extracellular signal-regulated kinase (ERK)-v-myc avian myelocytomatosis viral oncogene homolog (MYC) pathway was investigated by western blotting and quantitative real-time polymerase chain reaction. Combination treatment with fisetin and gemcitabine inhibited the proliferation of pancreatic cancer cells within 72 h and induced apoptosis, as indicated by activation of caspase 3/7. Fisetin down-regulated ERK at the protein and mRNA levels, and reduced ERK-induced MYC instability at the protein level. Fisetin sensitized human pancreatic cancer cells to gemcitabine-induced cytotoxicity through inhibition of ERK-MYC signaling. These results suggest that the combination of fisetin and gemcitabine could be developed as a novel potent therapeutic. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Radioactivities (dose rates) of rocks in Japan

International Nuclear Information System (INIS)

Matsuda, Hideharu; Minato, Susumu

1995-01-01

The radioactive distribution (radiation doses) of major rocks in Japan was monitored to clarify the factors influencing terrestrial gamma-ray absorbed dose rates. The rock samples were reduced to powder and analyzed by well-type NaI(Tl) scintillation detector and pulse height analyzer. Terrestrial gamma-ray dose rates were estimated in terms of gamma radiation dose rate 1 m above the ground. The radioactivity concentration was highest in acidic rock which contains much SiO 2 among igneous rock, followed by neutral rock, basic rock, and ultrabasic rock. The radioactive concentration was 30-40% lower in acidic and clastic rocks than those of the world average concentration. Higher radioactive concentration was observed in soils than the parent rocks of sedimentary rock and metamorphic rock. The gamma radiation dose rate was in proportion to the radioactive concentration of the rocks. To clarify the radioactive effect in the change course of rocks into soils, comparative measurement of outcrop and soil radioactive concentrations is important. (S.Y.)

Low doses effects and gamma radiations low dose rates

International Nuclear Information System (INIS)

Averbeck, D.

1999-01-01

This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

Ageing effects of polymers at very low dose-rates

International Nuclear Information System (INIS)

Chenion, J.; Armand, X.; Berthet, J.; Carlin, F.; Gaussens, G.; Le Meur, M.

1987-10-01

The equipment irradiation dose-rate into the containment is variable from 10 -6 to 10 -4 gray per second for the most exposed materials. During qualification, safety equipments are submitted in France to dose-rates around 0.28 gray per second. This study purpose is to now if a so large irradiation dose-rate increase is reasonable. Three elastomeric materials used in electrical cables, o'rings seals and connectors, are exposed to a very large dose-rates scale between 2.1.10 -4 and 1.4 gray per second, to 49 KGy dose. This work was carried out during 3.5 years. Oxygen consumption measurement of the air in contact with polymer materials, as mechanical properties measurement show that: - at very low dose-rate, oxygen consumption is maximum at the same time (1.4 year) for the three elastomeric samples. Also, mechanical properties simultaneously change with oxygen consumption. At very low dose-rate, for the low irradiation doses, oxygen consumption is at least 10 times more important that it is showed when irradiation is carried out with usual material qualification dose-rate. At very low dose-rate, oxygen consumption decreases when absorbed irradiation dose by samples increases. The polymer samples irradiation dose is not still sufficient (49 KGy) to certainly determine, for the three chosen polymer materials, the reasonable irradiation acceleration boundary during nuclear qualification tests [fr

Evaluation of radioiodine therapy with fixed doses of 10 and 15 mCi in patients with Graves disease

International Nuclear Information System (INIS)

Canadas, Viviane; Vilar, Lucio; Moura, Eliane; Brito, Ana; Castellar, Enio

2007-01-01

The treatment options for the hyperthyroidism of Graves' disease are antithyroid drugs, surgery and radioiodine, none of which is considered ideal, as they do not act directly on the etiopathogenesis of the disease. Radioiodine has been increasingly used as the treatment of choice because it is a safe and definitive therapy whose administration is very easy. Some authors prefer to administer higher doses in order to deliberately induce hypothyroidism, while others recommend lower doses that result in a lower incidence of hypothyroidism and a greater incidence of euthyroidism. There is no consensus for the optimal regimen of fixed doses to be used and this is the main focus of the present study, where doses of 10 and 15 mCi of 131 I were compared. Among the 164 patients analyzed, 61 (37.2%) were submitted to 10 mCi and 103 (62.8%) to 15 mCi. In the longitudinal analysis it was observed that remission of the hyperthyroidism was statistically different in the sixth month (p 131 I brought about a similar remission of the hyperthyroidism after 12 months of treatment. Moreover, the remission rate of the hyperthyroidism had no association with age, sex or previous therapy with antithyroid drugs. (author)

Recommended de minimis radiation dose rates for Canada

International Nuclear Information System (INIS)

1990-07-01

A de minimis dose or dose rate as used in this report represents a level of risk which is generally accepted as being of no significance to an individual, or in the case of a population, of no significance to society. The doses corresponding to these levels of risk are based on current scientific knowledge. Dose rates recommended in this report are as follows: a de minimis individual dose rate of 10 μSv a -1 , based on a risk level that would generally be regarded as negligible in comparison with other risks; and a de minimis collective dose rate of 1 person-Sv a -1 , based on an imperceptible increase above the normal incidences of cancer and genetic defects in the exposed population. The concept of de minimis is to be distinguished from 'exempt from regulation' (below regulatory concern). The latter involves broader social and economic factors which encompass but are not limited to the purely risk-based factors addressed by the de minimis dose. De minimis is one of the factors that determine the exemption of sources or practices that may result in doses below or above the de minimis level. Although these de minimis dose rates should be considered in developing criteria and guidelines for deriving quantities and concentrations of radioactive substances that may be exempted from regulation, this document is only concerned with establishing de minimis dose rates, not with exempting sources and practices

The calculation of dose rates from rectangular sources

International Nuclear Information System (INIS)

Hartley, B.M.

1998-01-01

A common problem in radiation protection is the calculation of dose rates from extended sources and irregular shapes. Dose rates are proportional to the solid angle subtended by the source at the point of measurement. Simple methods of calculating solid angles would assist in estimating dose rates from large area sources and therefore improve predictive dose estimates when planning work near such sources. The estimation of dose rates is of particular interest to producers of radioactive ores but other users of bulk radioactive materials may have similar interest. The use of spherical trigonometry can assist in determination of solid angles and a simple equation is derived here for the determination of the dose at any distance from a rectangular surface. The solid angle subtended by complex shapes can be determined by modelling the area as a patchwork of rectangular areas and summing the solid angles from each rectangle. The dose rates from bags of thorium bearing ores is of particular interest in Western Australia and measured dose rates from bags and containers of monazite are compared with theoretical estimates based on calculations of solid angle. The agreement is fair but more detailed measurements would be needed to confirm the agreement with theory. (author)

Evaluation of radioiodine therapy with fixed doses of 10 and 15 mCi in patients with Graves disease; Avaliacao da radioiodoterapia com doses fixas de 10 e 15 mCi em pacientes com doenca de Graves

Energy Technology Data Exchange (ETDEWEB)

Canadas, Viviane; Vilar, Lucio; Moura, Eliane; Brito, Ana; Castellar, Enio [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Hospital das Clinicas. Servico de Endocrinologia]. E-mail: vivi2207@ig.com.br

2007-10-15

The treatment options for the hyperthyroidism of Graves' disease are antithyroid drugs, surgery and radioiodine, none of which is considered ideal, as they do not act directly on the etiopathogenesis of the disease. Radioiodine has been increasingly used as the treatment of choice because it is a safe and definitive therapy whose administration is very easy. Some authors prefer to administer higher doses in order to deliberately induce hypothyroidism, while others recommend lower doses that result in a lower incidence of hypothyroidism and a greater incidence of euthyroidism. There is no consensus for the optimal regimen of fixed doses to be used and this is the main focus of the present study, where doses of 10 and 15 mCi of {sup 131}I were compared. Among the 164 patients analyzed, 61 (37.2%) were submitted to 10 mCi and 103 (62.8%) to 15 mCi. In the longitudinal analysis it was observed that remission of the hyperthyroidism was statistically different in the sixth month (p < 0.001), being higher in the group that used the dose of 15 mCi, but similar in both groups at 12 and 24 months. It may be concluded that the administration of fixed doses of 10 and 15 mCi of {sup 131}I brought about a similar remission of the hyperthyroidism after 12 months of treatment. Moreover, the remission rate of the hyperthyroidism had no association with age, sex or previous therapy with antithyroid drugs. (author)

Estimation of dose from chromosome aberration rate

International Nuclear Information System (INIS)

Li Deping

1990-01-01

The methods and skills of evaluating dose from correctly scored shromsome aberration rate are presented, and supplemented with corresponding BASIC computer code. The possibility and preventive measures of excessive probability of missing score of the aberrations in some of the current routine score methods are discussed. The use of dose-effect relationship with exposure time correction factor G in evaluating doses and their confidence intervals, dose estimation in mixed n-γ exposure, and identification of high by nonuniform acute exposure to low LET radiation and its dose estimation are discussed in more detail. The difference of estimated dose due to whether the interaction between subleisoms produced by n and γ have been taken into account is examined. In fitting the standard dose-aberration rate curve, proper weighing of experiment points and comparison with commonly accepted values are emphasised, and the coefficient of variation σ y √y of the aberration rate y as a function of dose and exposure time is given. In appendix I and II, the dose-aberration rate formula is derived from dual action theory, and the time variation of subleisom is illustrated and in appendix III, the estimation of dose from scores of two different types of aberrations (of other related score) is illustrated. Two computer codes are given in appendix IV, one is a simple code, the other a complete code, including the fitting of standard curve. the skills of using compressed data storage, and the production of simulated 'data ' for testing the curve fitting procedure are also given

High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

International Nuclear Information System (INIS)

Ghadjar, Pirus; Bojaxhiu, Beat; Simcock, Mathew; Terribilini, Dario; Isaak, Bernhard; Gut, Philipp; Wolfensberger, Patrick; Brömme, Jens O.; Geretschläger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M.

2012-01-01

Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3–23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

Radiobiological responses for two cell lines following continuous low dose-rate (CLDR) and pulsed dose rate (PDR) brachytherapy

International Nuclear Information System (INIS)

Hanisch, Per Henrik; Furre, Torbjoern; Olsen, Dag Rune; Pettersen, Erik O.

2007-01-01

The iso-effective irradiation of continuous low-dose-rate (CLDR) irradiation was compared with that of various schedules of pulsed dose rate (PDR) irradiation for cells of two established human lines, T-47D and NHIK 3025. Complete single-dose response curves were obtained for determination of parameters α and β by fitting of the linear quadratic formula. Sublethal damage repair constants μ and T 1/2 were determined by split-dose recovery experiments. On basis of the acquired parameters of each cell type the relative effectiveness of the two regimens of irradiation (CLDR and PDR) was calculated by use of Fowler's radiobiological model for iso-effect irradiation for repeated fractions of dose delivered at medium dose rates. For both cell types the predicted and observed relative effectiveness was compared at low and high iso-effect levels. The results indicate that the effect of PDR irradiation predicted by Fowler's model is equal to that of CLDR irradiation for both small and large doses with T-47D cells. With NHIK 3025 cells PDR irradiation induces a larger effect than predicted by the model for small doses, while it induces the predicted effect for high doses. The underlying cause of this difference is unclear, but cell-cycle parameters, like G2-accumulation is tested and found to be the same for the two cell lines

Efficacy and safety of a therapeutic interchange from high-dose calcium channel blockers to a fixed-dose combination of amlodipine/benazepril in patients with moderate-to-severe hypertension.

Science.gov (United States)

Hilleman, D E; Reyes, A P; Wurdeman, R L; Faulkner, M

2001-08-01

Recent hypertension trials have demonstrated the importance of achieving goal blood pressures to reduce the risk of target organ damage. In patients with moderate to severe hypertension, the use of high-dose monotherapy and/or combinations of drugs are necessary to achieve these goals. Fixed-dose combination products may be useful in these patients by reducing the number of daily doses required to control blood pressure. The objective of the present study was to evaluate the efficacy and safety of a therapeutic interchange between high-dose calcium channel blocker therapy and a fixed-dose combination of amlodipine/ benazepril (Lotrel; Novartis Pharmaceuticals, USA) in patients with moderate to severe hypertension. A total of 75 patients were switched from amlodipine (n = 25), felodipine (n = 25), and nifedipine-GITS (n = 25) to amlodipine/benazepril. Twenty-eight of the 75 patients (37%) were taking either a beta-blocker or a diuretic in addition to the high-dose calcium channel blocker prior to the switch. Blood pressure control, side effects and the cost of the therapeutic interchange were evaluated in the year following the therapeutic interchange. Sixty-six of the 75 (88%) patients were successfully switched with maintenance of blood pressure control and without the development of new dose-limiting side effects. Reasons for treatment failure after the therapeutic interchange included loss of blood pressure control in five patients and the development of new dose-limiting side effects in four patients. These side effects included cough in three patients and rash in one patient. After accounting for differences in drug acquisition cost and costs related to the switch (clinic and emergency room and laboratory tests), a cost savings of $16030 for all 75 patients was realised in the first year. The per patient-per year cost savings was $214. Our data indicate that a therapeutic interchange from selected high-dose calcium channel blockers to a fixed-dose combination

Dose and dose rate effects of whole-body gamma-irradiation: I. Lymphocytes and lymphoid organs

Science.gov (United States)

Pecaut, M. J.; Nelson, G. A.; Gridley, D. S.

2001-01-01

The major goal of part I of this study was to compare varying doses and dose rates of whole-body gamma-radiation on lymphoid cells and organs. C57BL/6 mice (n = 75) were exposed to 0, 0.5, 1.5, and 3.0 Gy gamma-rays (60Co) at 1 cGy/min (low-dose rate, LDR) and 80 cGy/min (high-dose rate, HDR) and euthanized 4 days later. A significant dose-dependent loss of spleen mass was observed with both LDR and HDR irradiation; for the thymus this was true only with HDR. Decreasing leukocyte and lymphocyte numbers occurred with increasing dose in blood and spleen at both dose rates. The numbers (not percentages) of CD3+ T lymphocytes decreased in the blood in a dose-dependent manner at both HDR and LDR. Splenic T cell counts decreased with dose only in HDR groups; percentages increased with dose at both dose rates. Dose-dependent decreases occurred in CD4+ T helper and CD8+ T cytotoxic cell counts at HDR and LDR. In the blood the percentages of CD4+ cells increased with increasing dose at both dose rates, whereas in the spleen the counts decreased only in the HDR groups. The percentages of the CD8+ population remained stable in both blood and spleen. CD19+ B cell counts and percentages in both compartments declined markedly with increasing HDR and LDR radiation. NK1.1+ natural killer cell numbers and proportions remained relatively stable. Overall, these data indicate that the observed changes were highly dependent on the dose, but not dose rate, and that cells in the spleen are more affected by dose rate than those in blood. The results also suggest that the response of lymphocytes in different body compartments may be variable.

Cocaine tolerance: acute versus chronic effects as dependent upon fixed-ratio size.

OpenAIRE

Hoffman, S H; Branch, M N; Sizemore, G M

1987-01-01

The effects of cocaine on operant behavior were studied by examining fixed-ratio value as a factor in the development of tolerance. Pigeons pecked a response key under a three-component multiple schedule, with each bird being exposed to fixed-ratio values that were categorized as small, medium, or large. Administered acutely, cocaine (1.0 to 10.0 mg/kg) produced dose-related decreases in overall rate of responding. Responding maintained by the largest ratio was decreased by lower doses than t...

MONTEC, an interactive fortran program to simulate radiation dose and dose-rate responses of populations

International Nuclear Information System (INIS)

Perry, K.A.; Szekely, J.G.

1983-09-01

The computer program MONTEC was written to simulate the distribution of responses in a population whose members are exposed to multiple radiation doses at variable dose rates. These doses and dose rates are randomly selected from lognormal distributions. The individual radiation responses are calculated from three equations, which include dose and dose-rate terms. Other response-dose/rate relationships or distributions can be incorporated by the user as the need arises. The purpose of this documentation is to provide a complete operating manual for the program. This version is written in FORTRAN-10 for the DEC system PDP-10

The limiting dose rate and its importance in radiation protection

International Nuclear Information System (INIS)

Bakkiam, D.; Sonwani, Swetha; Arul Ananthakumar, A.; Mohankumar, Mary N.

2012-01-01

The concept of defining a low dose of ionizing radiation still remains unclear. Before attempting to define a low dose, it is more important to define a low-dose rate since effects at low dose-rates are different from those observed at higher dose-rates. Hence, it follows that low dose-rates rather than a low dose is an important criteria to determine radio-biological effects and risk factors i.e. stochastic health effects. Chromosomal aberrations induced by ionizing radiations are well fitted by quadratic model Y= áD + âD 2 + C with the linear coefficient of dose predominating for high LET radiations and low doses of low LET. At higher doses and dose rates of sparsely ionizing radiation, break pairs produced by inter-track action leads to the formation of exchange type aberrations and is dependent on dose rate. Whereas at lower doses and dose rates, intra-track action produces break pairs and resulting aberrations are in direct proportion to absorbed dose and independent of dose rate. The dose rate at which inter-track ceases to be observable and where intra-track action effectively becomes the sole contributor of lesion-pair formation is referred to as limiting dose rate (LDR). Once the LDR is reached further reduction in dose rates will not affect the slope of DR since breaks produced by independent charged particle tracks are widely separated in time to interact with each other for aberration yield. This linear dependency is also noticed for acute exposures at very low doses. Existing reports emphasizes the existence of LDR likely to be e6.3cGyh -1 . However no systematic studies have been conducted so far to determine LDR. In the present investigation DR curves were constructed for the dose rates 0.002 and 0.003 Gy/min and to define LDR at which a coefficient approaches zero. Extrapolation of limiting low dose rate data can be used to predict low dose effects regardless of dose rate and its definition ought to serve as a useful index for studies pertaining

Nebivolol/valsartan: Fixed-dose combination for treatment of hypertension.

Science.gov (United States)

Paton, D M

2017-01-01

Clinical trials demonstrated that a fixed-dose combination (FDC) of the beta-blocker nebivolol (5 mg) and the angiotensin II antagonist valsartan (80 mg) produced a significant reduction of both diastolic and systolic blood pressure in patients with hypertension. Both nebivolol and valsartan contributed to this effect, partial additivity of 86.6% and 82.2% being observed for diastolic and systolic blood pressure, respectively. These values are very similar to the additivity ratios of other recently approved FDCs for hypertension. Use of the FDC nebivolol 5 mg/valsartan 80 mg formulation was associated with a low incidence of treatment-related adverse effects and of serious adverse effects. There was no evidence of adverse effects due to beta2-adrenoceptor blockade. The FDC (Byvalson) was approved and launched in 2016 in the U.S. for the treatment of hypertension. Copyright 2017 Clarivate Analytics.

Problems in continuous dose rate measurement

International Nuclear Information System (INIS)

Yoshioka, Mitsuo

1983-01-01

The system of continuous dose rate measurement in Fukui Prefecture is described. A telemeter system was constructed in October, 1976, and it has been operated since 1977. Observation has been made at 11 observation stations in the Prefecture. In addition to the continuous measurement of dose rate by using NaI(T1)-DBM systems, the ionization chambers for high dose rate were installed, and also meteorological data have been collected. The detectors are covered with 1 mm thick aluminum designed so that the absorption of external radiation is kept as small as possible. To keep the environmental temperature of the detectors constant, constant temperature wind blow is made. With these consideration, the measurement of Xe-133 is possible, and the standard deviation of yearly dose is around 0.4 mR/Y. By measuring DBM transmission rate, the contribution of Xe-133, which comes from the exhaust pumps in power plants, can be detected. The problems of this system are as follows. First of all, the characteristics of the system must meet the purpose of dose monitoring. The system must detect the dose less than the target value to be achieved. The second is the selection of measuring systems to be set. The system is still not unified, and it is difficult to exchange data between different stations. Finally, the method of data analysis is not yet unified. Manuals or guide-books for this purpose are necessary for the mutual comparison of the data from the stations in different districts. (Kato, T.)

Randomized phase III study comparing paclitaxel/cisplatin/gemcitabine and gemcitabine/cisplatin in patients with locally advanced or metastatic urothelial cancer without prior systemic therapy

DEFF Research Database (Denmark)

Bellmunt, Joaquim; von der Maase, Hans; Mead, Graham M

2012-01-01

The combination of gemcitabine plus cisplatin (GC) is a standard regimen in patients with locally advanced or metastatic urothelial cancer. A phase I/II study suggested that a three-drug regimen that included paclitaxel had greater antitumor activity and might improve survival....

Radiation shielding and dose rate distribution for the building of the high dose rate accelerator

International Nuclear Information System (INIS)

Matsuda, Koji; Takagaki, Torao; Nakase, Yoshiaki; Nakai, Yohta.

1984-03-01

A high dose rate electron accelerator was established at Osaka Laboratory for Radiation Chemistry, Takasaki Establishment, JAERI in the fiscal year of 1975. This report shows the fundamental concept for the radiation shielding of the accelerator building and the results of their calculations which were evaluated through the model experiments. After the construction of the building, the leak radiation was measured in order to evaluate the calculating method of radiation shielding. Dose rate distribution of X-rays was also measured in the whole area of the irradiation room as a data base. (author)

Clinical experience with fixed bimonthly aflibercept dosing in treatment-experienced patients with neovascular age-related macular degeneration

Directory of Open Access Journals (Sweden)

Khanani AM

2015-07-01

Full Text Available Arshad M Khanani Sierra Eye Associates, Reno, NV, USA Purpose: To evaluate the durability of fixed bimonthly dosing of intravitreal aflibercept for neovascular age-related macular degeneration.Methods: Records of 16 patients were retrospectively reviewed. Patients received three initial 2.0 mg monthly doses of aflibercept then 8-weekly doses according to the product label. Best-corrected visual acuity (Early Treatment Diabetic Retinopathy Study [ETDRS] letters, central macular thickness, fluid on optical coherence tomography, and pigment epithelial detachment (PED were measured.Results: Prior to starting aflibercept, 13 patients had subretinal fluid (SRF, five had intraretinal fluid (IRF, four had PED, and baseline visual acuity (VA was 62 approximate ETDRS letters. Following the monthly dosing, seven patients had no improvement or decreased VA, ten patients still had SRF/IRF, and PED had worsened in one patient. At Visit 4, an average of 6.8 weeks after Visit 3, VA had decreased in seven patients, SRF/IRF had increased in 12 patients, and PED had returned in all patients who initially responded. Based on the presence of fluid after the initial monthly injections, 12 patients could not be extended to fixed bimonthly dosing.Conclusion: This case series adds to the growing body of evidence on the need for flexible dosing schedules for the personalized treatment of neovascular age-related macular degeneration. Keywords: age-related macular degeneration, AMD, bimonthly, regimen, aflibercept, case studies, retinal fluid

Gemcitabine plus nedaplatin as salvage therapy is a favorable option for patients with progressive metastatic urothelial carcinoma after two lines of chemotherapy.

Science.gov (United States)

Matsumoto, Kazumasa; Mochizuki, Kohei; Hirayama, Takahiro; Ikeda, Masaomi; Nishi, Morihiro; Tabata, Ken-ichi; Okazaki, Miyoko; Fujita, Tetsuo; Taoka, Yoshinori; Iwamura, Masatsugu

2015-01-01

This study was conducted to evaluate the effectiveness of a combination of gemcitabine and nedaplatin therapy among patients with metastatic urothelial carcinoma previously treated with two lines of chemotherapy. Between February 2009 and August 2013, 30 patients were treated with gemcitabine and paclitaxel as a second-line chemotherapy. All had received a first-line chemotherapy consisting of methotrexate, vinblastine, doxorubicin and cisplatin. Ten patients who had measurable histologically proven advanced or metastatic urothelial carcinoma of the urinary bladder and upper urinary tract received gemcitabine 1,000 mg/m2 on days 1, 8 and 15 and nedaplatin 70 mg/m2 on day 2 as a third-line chemotherapy. Tumors were assessed by imaging every two cycles. The median number of treatment cycles was 3.5. One patient had partial response and three had stable disease. The disease-control rate was 40%, the median overall survival was 8.8 months and the median progression-free survival was 5.0 months. The median overall survival times for the first-line and second-line therapies were 29.1 and 13.9 months, respectively. Among disease-controlled patients (n=4), median overall survival was 14.2 months. Myelosuppression was the most common toxicity. There were no therapy-related deaths. Gemcitabine and nedaplatin chemotherapy is a favorable third-line chemotherapeutic option for patients with metastatic urothelial carcinoma. Given the safety and benefit profile seen in this study, further prospective trials are warranted given the implications of our results with regard to strategic chemotherapy for patients with advanced or metastatic urothelial carcinoma.

Use of gemcitabine and ginger extract infusion may improve the ...

African Journals Online (AJOL)

PRECIOUS

2009-12-15

Dec 15, 2009 ... Key words: Gemcitabine, ginger, chemotherapy, chemoprevention, cytotoxicity, cervical cancer. INTRODUCTION ... leading to side effects such as nausea and vomiting. (64%) ... indole- 3 -carbinol (I3C), curcumin, (-)-epigallocatechin- 3 ... kindly provided by Dr. K. Satyamoorthy (Manipal University, India).

Suppression of IL-6 Gene by shRNA Augments Gemcitabine Chemosensitization in Pancreatic Adenocarcinoma Cells

Directory of Open Access Journals (Sweden)

Hai-Bo Xing

2018-01-01

Full Text Available Pancreatic adenocarcinoma has an exceedingly poor prognosis, accounting for five-year survival of less than 5%. Presently, improving the efficacy of pancreatic adenocarcinoma treatment has been the focus of medical researchers worldwide. Recently, it has been suggested that deregulation of interleukin- (IL- 6 is caused by a key gene involved in the beginning and development of pancreatic adenocarcinoma. Herein, we investigated whether suppression of IL-6 could augment gemcitabine sensitivity in the PANC-1 cells. We found considerably higher expression of IL-6 in pancreatic adenocarcinoma tissues than that in the adjacent nontumorous tissues. Suppression of IL-6 by shRNA resulted in apoptosis as well as inhibition of cell proliferation and tumorigenicity. In addition, suppression of IL-6 remarkably promoted antitumor effect of gemcitabine, indicating that the combination of shRNA targeting IL-6 with gemcitabine may provide a potential clinical approach for pancreatic cancer therapy.

Evaluation of a UCMK/dCK fusion enzyme for gemcitabine-mediated cytotoxicity

International Nuclear Information System (INIS)

Johnson, Adam J.; Brown, Melissa N.; Black, Margaret E.

2011-01-01

Highlights: ► Goal was to enhance dFdC cytotoxicity by the creation of a UCMK/dCK fusion enzyme. ► The UCMK/dCK fusion enzyme possesses both native activities. ► The fusion renders cells equally sensitive to dFdC relative to dCK expression alone. ► Dual activities of fusion not sufficient to augment cell dFdC sensitivity in vitro. ► Data may warrant the implementation of UCMK mutagenesis studies. -- Abstract: While gemcitabine (2′-2′-difluoro-2′-deoxycytidine, dFdC) displays wide-ranging antineoplastic activity as a single agent, variable response rates and poor intracellular metabolism often limit its clinical efficacy. In an effort to enhance dFdC cytotoxicity and help normalize response rates, we created a bifunctional fusion enzyme that combines the enzymatic activities of deoxycytidine kinase (dCK) and uridine/cytidine monophosphate kinase (UCMK) in a single polypeptide. Our goal was to evaluate whether the created fusion could induce beneficial, functional changes toward dFdC, expedite dFdC conversion to its active antimetabolites and consequently amplify cell dFdC sensitivity. While kinetic analyses revealed the UCMK/dCK fusion enzyme to possess both native activities, the fusion rendered cells sensitive to the cytotoxic effects of dFdC at the same level as dCK expression alone. These results suggest that increased wild-type UCMK expression does not provide a significant enhancement in dFdC-mediated cytotoxicity and may warrant the implementation of studies aimed at engineering UCMK variants with improved activity toward gemcitabine monophosphate.

Wee1 inhibition by MK-1775 leads to tumor inhibition and enhances efficacy of gemcitabine in human sarcomas.

Directory of Open Access Journals (Sweden)

Jenny M Kreahling

Full Text Available Sarcomas are rare and heterogeneous mesenchymal tumors affecting both pediatric and adult populations with more than 70 recognized histologies. Doxorubicin and ifosfamide have been the main course of therapy for treatment of sarcomas; however, the response rate to these therapies is about 10-20% in metastatic setting. Toxicity with the drug combination is high, response rates remain low, and improvement in overall survival, especially in the metastatic disease, remains negligible and new agents are needed. Wee1 is a critical component of the G2/M cell cycle checkpoint control and mediates cell cycle arrest by regulating the phosphorylation of CDC2. Inhibition of Wee1 by MK1775 has been reported to enhance the cytotoxic effect of DNA damaging agents in different types of carcinomas. In this study we investigated the therapeutic efficacy of MK1775 in various sarcoma cell lines, patient-derived tumor explants ex vivo and in vivo both alone and in combination with gemcitabine, which is frequently used in the treatment of sarcomas. Our data demonstrate that MK1775 treatment as a single agent at clinically relevant concentrations leads to unscheduled entry into mitosis and initiation of apoptotic cell death in all sarcomas tested. Additionally, MK1775 significantly enhances the cytotoxic effect of gemcitabine in sarcoma cells lines with different p53 mutational status. In patient-derived bone and soft tissue sarcoma samples we showed that MK1775 alone and in combination with gemcitabine causes significant apoptotic cell death. Magnetic resonance imaging (MRI and histopathologic studies showed that MK1775 induces significant cell death and terminal differentiation in a patient-derived xenograft mouse model of osteosarcoma in vivo. Our results together with the high safety profile of MK1775 strongly suggest that this drug can be used as a potential therapeutic agent in the treatment of both adult as well as pediatric sarcoma patients.

Terrestrial gamma dose rate in Pahang state Malaysia

International Nuclear Information System (INIS)

Gabdo, H.T.; Federal College of Education, Yola; Ramli, A.T.; Sanusi, M.S.; Saleh, M.A.; Garba, N.N.; Ahmadu Bello University, Zaria

2014-01-01

Environmental terrestrial gamma radiations (TGR) were measured in Pahang state Malaysia between January and April 2013. The TGR dose rates ranged from 26 to 750 nGy h -1 . The measurements were done based on geology and soil types of the area. The mean TGR dose rate was found to be 176 ± 5 nGy h -1 . Few areas of relatively enhanced activity were located in Raub, Temerloh, Bentong and Rompin districts. These areas have external gamma dose rates of between 500 and 750 nGy h -1 . An Isodose map of the state was produced using ArcGIS9 software version 9.3. To evaluate the radiological hazard due to terrestrial gamma dose, the annual effective dose equivalent and the mean population weighted dose rate were calculated and found to be 0.22 mSv year -1 and 168 nGy h -1 respectively. (author)

Health effect of low dose/low dose rate radiation

International Nuclear Information System (INIS)

Kodama, Seiji

2012-01-01

The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

Efficacy and Factors Affecting Outcome of Gemcitabine Concurrent Chemoradiotherapy in Patients With Locally Advanced Pancreatic Cancer

International Nuclear Information System (INIS)

Huang, P.-I.; Chao, Yee; Li, C.-P.; Lee, R.-C.; Chi, K.-H.; Shiau, C.-Y.; Wang, L.-W.; Yen, S.-H.

2009-01-01

Purpose: To evaluate the efficacy and prognostic factors of gemcitabine (GEM) concurrent chemoradiotherapy (CCRT) in patients with locally advanced pancreatic cancer. Methods and Materials: Between January 2002 and December 2005, 55 patients with locally advanced pancreatic cancer treated with GEM (400 mg/m 2 /wk) concurrently with radiotherapy (median dose, 50.4 Gy; range, 26-61.2) at Taipei Veterans General Hospital were enrolled. GEM (1,000 mg/m 2 ) was continued after CCRT as maintenance therapy once weekly for 3 weeks and repeated every 4 weeks. The response, survival, toxicity, and prognostic factors were evaluated. Results: With a median follow-up of 10.8 months, the 1- and 2-year survival rate was 52% and 19%, respectively. The median overall survival (OS) and median time to progression (TTP) was 12.4 and 5.9 months, respectively. The response rate was 42% (2 complete responses and 21 partial responses). The major Grade 3-4 toxicities were neutropenia (22%) and anorexia (19%). The median OS and TTP was 15.8 and 9.5 months in the GEM CCRT responders compared with 7.5 and 3.5 months in the nonresponders, respectively (both p 2 /wk vs. 296 ± 15 mg/m 2 /wk, p = 0.02) than the nonresponders. KPS and serum carbohydrate antigen 19-9 were the most significant prognostic factors of OS and TTP. Conclusion: The results of our study have shown that GEM CCRT is effective and tolerable for patients with locally advanced pancreatic cancer. The KPS and GEM dose correlated with response. Also, the KPS and CA 19-9 level were the most important factors affecting OS and TTP

A model for inverse dose-rate effects - low dose-rate hyper-sensibility in response to targeted radionuclide therapy

International Nuclear Information System (INIS)

Murray, I.; Mather, S.J.

2015-01-01

Full text of publication follows. The aim of this work was to test the hypothesis that the Linear-Quadratic (LQ) model of cell survival, developed for external beam radiotherapy (EBRT), could be extended to targeted radionuclide therapy (TRT) in order to predict dose-response relationships in a cell line exhibiting low dose hypersensitivity (LDH). Methods: aliquots of the PC-3 cancer cell line were treated with either EBRT or an in-vitro model of TRT (Irradiation of cell culture with Y-90 EDTA over 24, 48, 72 or 96 hours). Dosimetry for the TRT was calculated using radiation transport simulations with the Monte Carlo PENELOPE code. Clonogenic as well as functional biological assays were used to assess cell response. An extension of the LQ model was developed which incorporated a dose-rate threshold for activation of repair mechanisms. Results: accurate dosimetry for in-vitro exposures of cell cultures to radioactivity was established. LQ parameters of cell survival were established for the PC-3 cell line in response to EBRT. The standard LQ model did not predict survival in PC-3 cells exposed to Y 90 irradiation over periods of up to 96 hours. In fact cells were more sensitive to the same dose when irradiation was carried out over 96 hours than 24 hours. I.e. at a lower dose-rate. Deviations from the LQ predictions were most pronounced below a threshold dose-rate of 0.5 Gy/hr. These results led to an extension of the LQ model based upon a dose-rate dependent sigmoid model of single strand DNA repair. This extension to the model resulted in predicted cell survival curves that closely matched the experimental data. Conclusion: the LQ model of cell survival to radiation has been shown to be largely predictive of response to low dose-rate irradiation. However, in cells displaying LDH, further adaptation of the model was required. (authors)

Conditioned instrumental behaviour in the rat: Effects of prenatal irradiation with various low dose-rate doses

International Nuclear Information System (INIS)

Klug, H.

1986-01-01

4 groups of rats of the Wistar-strain were subjected to γ-irradiation on the 16th day of gestation. 5 rats received 0,6 Gy low dose rate irradiation, 5 animals received 0,9 Gy low dose and 6 high dose irradiation, 3 females were shamirradiated. The male offspring of these 3 irradiation groups and 1 control group were tested for locomotor coordination on parallel bars and in a water maze. The female offspring were used in an operant conditioning test. The locomotor test showed slight impairment of locomotor coordination in those animals irradiated with 0,9 Gy high dose rate. Swimming ability was significantly impaired by irradiation with 0,9 Gy high dose rate. Performance in the operant conditioning task was improved by irradiation with 0,9 Gy both low and high dose rate. The 0,9 Gy high dose rate group learned faster than all the other groups. For the dose of 0,9 Gy a significant dose rate effect could be observed. For the dose of 0,6 Gy a similar tendency was observed, differences between 0,6 Gy high and low dose rate and controls not being significant. (orig./MG) [de

High dose rate versus low dose rate interstitial radiotherapy for carcinoma of the floor of mouth

International Nuclear Information System (INIS)

Inoue, Takehiro; Inoue, Toshihiko; Yamazaki, Hideya; Koizumi, Masahiko; Kagawa, Kazufumi; Yoshida, Ken; Shiomi, Hiroya; Imai, Atsushi; Shimizutani, Kimishige; Tanaka, Eichii; Nose, Takayuki; Teshima, Teruki; Furukawa, Souhei; Fuchihata, Hajime

1998-01-01

Purpose: Patients with cancer of the floor of mouth are treated with radiation because of functional and cosmetic reasons. We evaluate the treatment results of high dose rate (HDR) and low dose rate (LDR) interstitial radiation for cancer of the floor of mouth. Methods and Materials: From January 1980 through March 1996, 41 patients with cancer of the floor of mouth were treated with LDR interstitial radiation using 198 Au grains, and from April 1992 through March 1996 16 patients with HDR interstitial radiation. There were 26 T1 tumors, 30 T2 tumors, and 1 T3 tumor. For 21 patients treated with interstitial radiation alone, a total radiation dose of interstitial therapy was 60 Gy/10 fractions/6-7 days in HDR and 85 Gy within 1 week in LDR. For 36 patients treated with a combination therapy, a total dose of 30 to 40 Gy of external radiation and a total dose of 48 Gy/8 fractions/5-6 days in HDR or 65 Gy within 1 week in LDR were delivered. Results: Two- and 5-year local control rates of patients treated with HDR interstitial radiation were 94% and 94%, and those with LDR were 75% and 69%, respectively. Local control rate of patients treated with HDR brachytherapy was slightly higher than that with 198 Au grains (p = 0.113). For late complication, bone exposure or ulcer occurred in 6 of 16 (38%) patients treated with HDR and 13 of 41 (32%) patients treated with LDR. Conclusion: HDR fractionated interstitial brachytherapy can be an alternative to LDR brachytherapy for cancer of the floor of mouth and eliminate radiation exposure for the medical staff

Dose rate effect in food irradiation

International Nuclear Information System (INIS)

Singh, H.

1991-08-01

It has been suggested that the minor losses of nutrients associated with radiation processing may be further reduced by irradiating foods at the high dose rates generally associated with electron beams from accelerators, rather than at the low dose rates typical of gamma irradiation (e.g. 60 Co). This review briefly examines available comparative data on gamma and electron irradiation of foods to evaluate these suggestions. (137 refs., 27 tabs., 11 figs.)

Dose and Dose-Rate Effectiveness Factor (DDREF); Der Dosis- und Dosisleistungs-Effektivitaetsfaktor (DDREF)

Energy Technology Data Exchange (ETDEWEB)

Breckow, Joachim [Fachhochschule Giessen-Friedberg, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

2016-08-01

For practical radiation protection purposes it is supposed that stochastic radiation effects a determined by a proportional dose relation (LNT). Radiobiological and radiation epidemiological studies indicated that in the low dose range a dependence on dose rates might exist. This would trigger an overestimation of radiation risks based on the LNT model. OCRP had recommended a concept to combine all effects in a single factor DDREF (dose and dose-Rate effectiveness factor). There is still too low information on cellular mechanisms of low dose irradiation including possible repair and other processes. The Strahlenschutzkommission cannot identify a sufficient scientific justification for DDREF and recommends an adaption to the actual state of science.

The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate

International Nuclear Information System (INIS)

Sminia, Peter; Schneider, Christoph J.; Fowler, Jack F.

2002-01-01

Background and Purpose: Indications of the existence of long repair half-times on the order of 2-4 h for late-responding human normal tissues have been obtained from continuous hyperfractionated accelerated radiotherapy (CHART). Recently, these data were used to explain, on the basis of the biologically effective dose (BED), the potential superiority of fractionated high-dose rate (HDR) with large fraction sizes of 5-7 Gy over continuous low-dose rate (LDR) irradiation at 0.5 Gy/h in cervical carcinoma. We investigated the optimal fraction size in HDR brachytherapy and its dependency on treatment choices (overall treatment time, number of HDR fractions, and time interval between fractions) and treatment conditions (reference low-dose rate, tissue repair characteristics). Methods and Materials: Radiobiologic model calculations were performed using the linear-quadratic model for incomplete mono-exponential repair. An irradiation dose of 20 Gy was assumed to be applied either with HDR in 2-12 fractions or continuously with LDR for a range of dose rates. HDR and LDR treatment regimens were compared on the basis of the BED and BED ratio of normal tissue and tumor, assuming repair half-times between 1 h and 4 h. Results: With the assumption that the repair half-time of normal tissue was three times longer than that of the tumor, hypofractionation in HDR relative to LDR could result in relative normal tissue sparing if the optimum fraction size is selected. By dose reduction while keeping the tumor BED constant, absolute normal tissue sparing might therefore be achieved. This optimum HDR fraction size was found to be largely dependent on the LDR dose rate. On the basis of the BED NT/TUM ratio of HDR over LDR, 3 x 6.7 Gy would be the optimal HDR fractionation scheme for replacement of an LDR scheme of 20 Gy in 10-30 h (dose rate 2-0.67 Gy/h), while at a lower dose rate of 0.5 Gy/h, four fractions of 5 Gy would be preferential, still assuming large differences between tumor

Dose rate-dependent marrow toxicity of TBI in dogs and marrow sparing effect at high dose rate by dose fractionation.

Science.gov (United States)

Storb, R; Raff, R F; Graham, T; Appelbaum, F R; Deeg, H J; Schuening, F G; Sale, G; Seidel, K

1999-01-01

We evaluated the marrow toxicity of 200 and 300 cGy total-body irradiation (TBI) delivered at 10 and 60 cGy/min, respectively, in dogs not rescued by marrow transplant. Additionally, we compared toxicities after 300 cGy fractionated TBI (100 cGy fractions) to that after single-dose TBI at 10 and 60 cGy/min. Marrow toxicities were assessed on the basis of peripheral blood cell count changes and mortality from radiation-induced pancytopenia. TBI doses studied were just below the dose at which all dogs die despite optimal support. Specifically, 18 dogs were given single doses of 200 cGy TBI, delivered at either 10 (n=13) or 60 (n=5) cGy/min. Thirty-one dogs received 300 cGy TBI at 10 cGy/min, delivered as either single doses (n=21) or three fractions of 100 cGy each (n=10). Seventeen dogs were given 300 cGy TBI at 60 cGy/min, administered either as single doses (n=5) or three fractions of 100 cGy each (n=10). Within the limitations of the experimental design, three conclusions were drawn: 1) with 200 and 300 cGy single-dose TBI, an increase of dose rate from 10 to 60 cGy/min, respectively, caused significant increases in marrow toxicity; 2) at 60 cGy/min, dose fractionation resulted in a significant decrease in marrow toxicities, whereas such a protective effect was not seen at 10 cGy/min; and 3) with fractionated TBI, no significant differences in marrow toxicity were seen between dogs irradiated at 60 and 10 cGy/min. The reduced effectiveness of TBI when a dose of 300 cGy was divided into three fractions of 100 cGy or when dose rate was reduced from 60 cGy/min to 10 cGy/min was consistent with models of radiation toxicity that allow for repair of sublethal injury in DNA.

Dose and dose-rate effects of ionizing radiation: a discussion in the light of radiological protection

Energy Technology Data Exchange (ETDEWEB)

Ruehm, Werner [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Radiation Protection, Neuherberg (Germany); Woloschak, Gayle E. [Northwestern University, Department of Radiation Oncology, Feinberg School of Medicine, Chicago, IL (United States); Shore, Roy E. [Radiation Effects Research Foundation (RERF), Hiroshima City (Japan); Azizova, Tamara V. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region (Russian Federation); Grosche, Bernd [Federal Office for Radiation Protection, Oberschleissheim (Germany); Niwa, Ohtsura [Fukushima Medical University, Fukushima (Japan); Akiba, Suminori [Kagoshima University Graduate School of Medical and Dental Sciences, Department of Epidemiology and Preventive Medicine, Kagoshima City (Japan); Ono, Tetsuya [Institute for Environmental Sciences, Rokkasho, Aomori-ken (Japan); Suzuki, Keiji [Nagasaki University, Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki (Japan); Iwasaki, Toshiyasu [Central Research Institute of Electric Power Industry (CRIEPI), Radiation Safety Research Center, Nuclear Technology Research Laboratory, Tokyo (Japan); Ban, Nobuhiko [Tokyo Healthcare University, Faculty of Nursing, Tokyo (Japan); Kai, Michiaki [Oita University of Nursing and Health Sciences, Department of Environmental Health Science, Oita (Japan); Clement, Christopher H.; Hamada, Nobuyuki [International Commission on Radiological Protection (ICRP), PO Box 1046, Ottawa, ON (Canada); Bouffler, Simon [Public Health England (PHE), Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot (United Kingdom); Toma, Hideki [JAPAN NUS Co., Ltd. (JANUS), Tokyo (Japan)

2015-11-15

The biological effects on humans of low-dose and low-dose-rate exposures to ionizing radiation have always been of major interest. The most recent concept as suggested by the International Commission on Radiological Protection (ICRP) is to extrapolate existing epidemiological data at high doses and dose rates down to low doses and low dose rates relevant to radiological protection, using the so-called dose and dose-rate effectiveness factor (DDREF). The present paper summarizes what was presented and discussed by experts from ICRP and Japan at a dedicated workshop on this topic held in May 2015 in Kyoto, Japan. This paper describes the historical development of the DDREF concept in light of emerging scientific evidence on dose and dose-rate effects, summarizes the conclusions recently drawn by a number of international organizations (e.g., BEIR VII, ICRP, SSK, UNSCEAR, and WHO), mentions current scientific efforts to obtain more data on low-dose and low-dose-rate effects at molecular, cellular, animal and human levels, and discusses future options that could be useful to improve and optimize the DDREF concept for the purpose of radiological protection. (orig.)

Mathematical model for evaluation of dose-rate effect on biological responses to low dose γ-radiation

International Nuclear Information System (INIS)

Ogata, H.; Kawakami, Y.; Magae, J.

2003-01-01

Full text: To evaluate quantitative dose-response relationship on the biological response to radiation, it is necessary to consider a model including cumulative dose, dose-rate and irradiation time. In this study, we measured micronucleus formation and [ 3 H] thymidine uptake in human cells as indices of biological response to gamma radiation, and analyzed mathematically and statistically the data for quantitative evaluation of radiation risk at low dose/low dose-rate. Effective dose (ED x ) was mathematically estimated by fitting a general function of logistic model to the dose-response relationship. Assuming that biological response depends on not only cumulative dose but also dose-rate and irradiation time, a multiple logistic function was applied to express the relationship of the three variables. Moreover, to estimate the effect of radiation at very low dose, we proposed a modified exponential model. From the results of fitting curves to the inhibition of [ 3 H] thymidine uptake and micronucleus formation, it was obvious that ED 50 in proportion of inhibition of [ 3 H] thymidine uptake increased with longer irradiation time. As for the micronuclei, ED 30 also increased with longer irradiation times. These results suggest that the biological response depends on not only total dose but also irradiation time. The estimated response surface using the three variables showed that the biological response declined sharply when the dose-rate was less than 0.01 Gy/h. These results suggest that the response does not depend on total cumulative dose at very low dose-rates. Further, to investigate the effect of dose-rate within a wider range, we analyzed the relationship between ED x and dose-rate. Fitted curves indicated that ED x increased sharply when dose-rate was less than 10 -2 Gy/h. The increase of ED x signifies the decline of the response or the risk and suggests that the risk approaches to 0 at infinitely low dose-rate

Gemcitabine and carboplatin in advanced transitional cell carcinoma of the urinary tract: an alternative therapy.

Science.gov (United States)

Nogué-Aliguer, Miquel; Carles, Joan; Arrivi, Antonio; Juan, Oscar; Alonso, Lorenzo; Font, Albert; Mellado, Begoña; Garrido, Pilar; Sáenz, Alberto

2003-05-01

Cisplatin-based combinations are considered to be the standard treatment for advanced transitional cell carcinoma (TCC) of the urothelium. Many of the patients are elderly with concomitant diseases or impaired renal function. We studied the tolerance and activity of the gemcitabine/carboplatin combination as a therapeutic alternative. Patients with locally advanced or metastatic TCC of the urothelium were treated with gemcitabine 1000 mg/m(2) on Days 1 and 8 and carboplatin area under the concentration-time curve 5 on Day 1 every 21 days. Patients with creatinine clearance of 30 mL/min or above and Karnofsky performance status (KPS) scores 60 or above were enrolled. A total of 227 cycles were administered to 41 patients, with an average of 5.5 cycles per patient (range, 1-8 cycles). Creatinine clearance was below 60 mL/min in 54% of patients, KPS was 70 or below in 37% of patients, and 37% of patients were 70 years old or older. Hematologic toxicity was mainly Grade 3/4 neutropenia in 63%, Grade 3/4 thrombocytopenia in 32%, and Grade 3/4 anemia in 54% of patients. There were only three episodes of febrile neutropenia and one death from neutropenic sepsis. Nonhematologic toxicity was mild, with asthenia as the most frequently reported event. We obtained 6 complete and 17 partial responses, for an overall response rate of 56.1% (95% confidence interval [CI], 40.6-71.6%). Progression-free survival was 7.2 months (95% CI, 5.7-8.5) and median survival was 10.1 months (95% CI, 8.8-12.2). The combination of gemcitabine plus carboplatin achieves a similar result to doublets using cisplatin. It has an acceptable toxicity profile and enables patients with impaired renal function and/or poor performance status and elderly patients to be treated. Copyright 2003 American Cancer Society.DOI 10.1002/cncr.10990

Concrete spent fuel storage casks dose rates

International Nuclear Information System (INIS)

Bace, M.; Jecmenica, R.; Trontl, K.

1998-01-01

Our intention was to model a series of concrete storage casks based on TranStor system storage cask VSC-24, and calculate the dose rates at the surface of the casks as a function of extended burnup and a prolonged cooling time. All of the modeled casks have been filled with the original multi-assembly sealed basket. The thickness of the concrete shield has been varied. A series of dose rate calculations for different burnup and cooling time values have been performed. The results of the calculations show rather conservative original design of the VSC-24 system, considering only the dose rate values, and appropriate design considering heat rejection.(author)

Targeting EGFR/HER2 pathways enhances the antiproliferative effect of gemcitabine in biliary tract and gallbladder carcinomas

International Nuclear Information System (INIS)

Pignochino, Ymera; Bardelli, Alberto; Aglietta, Massimo; Leone, Francesco; Sarotto, Ivana; Peraldo-Neia, Caterina; Penachioni, Junia Y; Cavalloni, Giuliana; Migliardi, Giorgia; Casorzo, Laura; Chiorino, Giovanna; Risio, Mauro

2010-01-01

Advanced biliary tract carcinomas (BTCs) have poor prognosis and limited therapeutic options. Therefore, it is crucial to combine standard therapies with molecular targeting. In this study EGFR, HER2, and their molecular transducers were analysed in terms of mutations, amplifications and over-expression in a BTC case series. Furthermore, we tested the efficacy of drugs targeting these molecules, as single agents or in combination with gemcitabine, the standard therapeutic agent against BTC. Immunohistochemistry, FISH and mutational analysis were performed on 49 BTC samples of intrahepatic (ICCs), extrahepatic (ECCs), and gallbladder (GBCs) origin. The effect on cell proliferation of different EGFR/HER2 pathway inhibitors as single agents or in combination with gemcitabine was investigated on BTC cell lines. Western blot analyses were performed to investigate molecular mechanisms of targeted drugs. EGFR is expressed in 100% of ICCs, 52.6% of ECCs, and in 38.5% of GBCs. P-MAPK and p-Akt are highly expressed in ICCs (>58% of samples), and to a lower extent in ECCs and GBCs (<46%), indicating EGFR pathway activation. HER2 is overexpressed in 10% of GBCs (with genomic amplification), and 26.3% of ECCs (half of which has genomic amplification). EGFR or its signal transducers are mutated in 26.5% of cases: 4 samples bear mutations of PI3K (8.2%), 3 cases (6.1%) in K-RAS, 4 (8.2%) in B-RAF, and 2 cases (4.1%) in PTEN, but no loss of PTEN expression is detected. EGI-1 cell line is highly sensitive to gemcitabine, TFK1 and TGBC1-TKB cell lines are responsive and HuH28 cell line is resistant. In EGI-1 cells, combination with gefitinib further increases the antiproliferative effect of gemcitabine. In TFK1 and TGBC1-TKB cells, the efficacy of gemcitabine is increased with addiction of sorafenib and everolimus. In TGBC1-TKB cells, lapatinib also has a synergic effect with gemcitabine. HuH28 becomes responsive if treated in combination with erlotinib. Moreover, HuH28 cells are

Radiation dose rates from UF{sub 6} cylinders

Energy Technology Data Exchange (ETDEWEB)

Friend, P.J. [Urenco, Capenhurst (United Kingdom)

1991-12-31

This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer.

Science.gov (United States)

Martinez, Alvaro A; Gustafson, Gary; Gonzalez, José; Armour, Elwood; Mitchell, Chris; Edmundson, Gregory; Spencer, William; Stromberg, Jannifer; Huang, Raywin; Vicini, Frank

2002-06-01

To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed. Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level >or=10.0 ng/mL, Gleason score >or=7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose 93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure. The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%. Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause-specific survival with higher doses. These results, coupled with the low risk of complications, the advantage of not being radioactive after implantation, and the real-time interactive planning, define a new standard for treatment.

Efficacy and safety of benzalkonium chloride-free fixed-dose combination of latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension

Directory of Open Access Journals (Sweden)

Bhagat P

2014-06-01

concomitantly at all time points (mean IOP difference and 95% confidence interval within ±1.5 mmHg; P=0.4223 to P=0.9981. The fixed-dose combination of latanoprost/timolol demonstrated significantly better IOP-lowering efficacy than timolol monotherapy at all time points (P=0.001 to P<0.0001 and significantly better IOP-lowering efficacy than latanoprost monotherapy at all time points. Responder rates on at least one time point and on at least two time points with fixed-dose combination ­latanoprost/timolol were similar to those with concomitant latanoprost plus timolol (85.5% versus 82.1%, P=0.6360; 78.2% versus 75%, P=0.6923, but significantly better than either latanoprost or timolol monotherapy (68.5%, P=0.0355; 55.4%, P=0.0005; 57.4%, P=0.0202; and 46.4%, P=0.0006, respectively. No significant differences in ocular and nonocular treatment-emergent adverse events were found between the treatment groups. Conclusion: A BAK-free, fixed-dose combination of latanoprost 0.005%/timolol 0.5% was as effective and well tolerated as concomitant latanoprost and timolol for treatment of elevated IOP in patients with open-angle glaucoma or ocular hypertension. Keywords: open-angle glaucoma, ocular hypertension, pharmaceutical preservatives, benzalkonium chloride, latanoprost, timolol

Gemcitabine treatment causes resistance and malignancy of pancreatic cancer stem-like cells via induction of lncRNA HOTAIR

Science.gov (United States)

Wang, Li; Dong, Ping; Wang, Weiguo; Huang, Mingquan; Tian, Bole

2017-01-01

Gemcitabine is the first-line chemotherapeutic agent for advanced adenocarcinoma of the pancreas, despite the high risk of chemoresistance as a major disadvantage. In the past few years, significant advances have been made in the field of pancreatic cancer stem-like cells (CSCs) and their critical roles in drug resistance, invasion and metastasis, which are tightly regulated by long non-coding RNAs (lncRNAs). The present study demonstrated that HOX antisense intergenic RNA (HOTAIR) is not different between the pancreatic cancer cell line PANC-1 and its enriched CSC sub-population. However, after gemcitabine treatment, the expression levels of HOTAIR in CSCs were induced, but not in PANC-1 cells. HOTAIR induced by gemcitabine failed to cause chemoresistance, but promoted the clonogenicity, proliferation and migration of the cells. By introducing HOTAIR using lentivirus, chemoresistance was induced and the self-renewal capacity, proliferation and migration were significantly promoted. By contrast, HOTAIR knockdown in PANC-1 CSCs treated with or without gemcitabine decreased the cell proliferation, altered the cell cycle progression and induced apoptosis, demonstrating its critical roles in regulating the malignant character of PANC-1 CSCs. In conclusion, the present study demonstrated that HOTAIR may be induced by gemcitabine and acts as a tumor promoter by inhibiting the chemosensitivity, and promoting the self-renewal capacity, proliferation and migration of PANC-1 CSCs, which supports its potential application as a novel therapeutic approach for pancreatic cancer. PMID:29201179

Phase III study comparing cisplatin plus gemcitabine with cisplatin plus pemetrexed in chemotherapy-naive patients with advanced-stage non-small-cell lung cancer

DEFF Research Database (Denmark)

Scagliotti, G.V.; Parikh, P.; Pawel, J. von

2008-01-01

, in patients with squamous cell histology, there was a significant improvement in survival with cisplatin/ gemcitabine versus cisplatin/pemetrexed (n = 473; 10.8 v 9.4 months, respectively). For cisplatin/pemetrexed, rates of grade 3 or 4 neutropenia, anemia, and thrombocytopenia (P ... neutropenia (P = .002); and alopecia (P

The dose-rate effect

International Nuclear Information System (INIS)

Steel, G.G.

1989-01-01

This paper presents calculations that illustrate two conclusions; for any particular cell type there will be a critical radius at which tumor control breaks down, and the radius at which this occurs is strongly dependent upon the low-dose-rate radiosensitivity of the cells

Dose rate constant and energy spectrum of interstitial brachytherapy sources

International Nuclear Information System (INIS)

Chen Zhe; Nath, Ravinder

2001-01-01

In the past two years, several new manufacturers have begun to market low-energy interstitial brachytherapy seeds containing 125 I and 103 Pd. Parallel to this development, the National Institute of Standards and Technology (NIST) has implemented a modification to the air-kerma strength (S K ) standard for 125 I seeds and has also established an S K standard for 103 Pd seeds. These events have generated a considerable number of investigations on the determination of the dose rate constants (Λ) of interstitial brachytherapy seeds. The aim of this work is to study the general properties underlying the determination of Λ and to develop a simple method for a quick and accurate estimation of Λ. As the dose rate constant of clinical seeds is defined at a fixed reference point, we postulated that Λ may be calculated by treating the seed as an effective point source when the seed's source strength is specified in S K and its source characteristics are specified by the photon energy spectrum measured in air at the reference point. Using a semi-analytic approach, an analytic expression for Λ was derived for point sources with known photon energy spectra. This approach enabled a systematic study of Λ as a function of energy. Using the measured energy spectra, the calculated Λ for 125 I model 6711 and 6702 seeds and for 192 Ir seed agreed with the AAPM recommended values within ±1%. For the 103 Pd model 200 seed, the agreement was 5% with a recently measured value (within the ±7% experimental uncertainty) and was within 1% with the Monte Carlo simulations. The analytic expression for Λ proposed here can be evaluated using a programmable calculator or a simple spreadsheet and it provides an efficient method for checking the measured dose rate constant for any interstitial brachytherapy seed once the energy spectrum of the seed is known

A comparison of anti-tumor effects of high dose rate fractionated and low dose rate continuous irradiation in multicellular spheroids

International Nuclear Information System (INIS)

Kubota, Nobuo; Omura, Motoko; Matsubara, Sho.

1997-01-01

In a clinical experience, high dose rate (HDR) fractionated interstitial radiotherapy can be an alternative to traditional low dose rate (LDR) continuous interstitial radiotherapy for head and neck cancers. To investigate biological effect of HDR, compared to LDR, comparisons have been made using spheroids of human squamous carcinoma cells. Both LDR and HDR were delivered by 137 Cs at 37degC. Dose rate of LDR was 8 Gy/day and HDR irradiations of fraction size of 4, 5 or 6 Gy were applied twice a day with an interval time of more than 6 hr. We estimated HDR fractionated dose of 31 Gy with 4 Gy/fr to give the same biological effects of 38 Gy by continuous LDR for spheroids. The ratio of HDR/LDR doses to control 50% spheroids was 0.82. (author)

Gemcitabine and docetaxel in relapsed and unresectable high-grade osteosarcoma and spindle cell sarcoma of bone

OpenAIRE

Palmerini, E.; Jones, R. L.; Marchesi, E.; Paioli, A.; Cesari, M.; Longhi, A.; Meazza, C.; Coccoli, L.; Fagioli, F.; Asaftei, S.; Grignani, G.; Tamburini, A.; Pollack, S. M.; Picci, P.; Ferrari, S.

2016-01-01

Background Few new compounds are available for relapsed osteosarcoma. We retrospectively evaluated the activity of gemcitabine (G) plus docetaxel (D) in patients with relapsed high-grade osteosarcoma and high-grade spindle cell sarcoma of bone (HGS). Methods Patients receiving G 900?mg/m2 d 1, 8; D 75?mg/m2 d 8, every 21?days were eligible. Primary end-point: progression-free survival (PFS) at 4?months; secondary end-point: overall survival (OS) and response rate. Results Fifty-one patients w...

Icotinib plus gemcitabine for metastatic pancreatic cancer: a case report.

Science.gov (United States)

Zhao, Jing; Shen, Hong; Hu, Han-Guang; Huang, Jian-Jin

2015-03-21

A large majority of patients diagnosed with pancreatic cancer have advanced metastatic disease with unresectable malignancies. Despite treatment advances, the survival benefit from chemotherapeutic regimens and targeted drugs is limited. Moreover, their application is limited in China because of high toxicity and cost. Recently, inhibitors of epidermal growth factor receptor activity have shown promise for the treatment of solid cancers when used in combination with standard therapy. However, these drugs have not been evaluated extensively for the treatment of pancreatic cancer. Here, we report the treatment of a 64-year-old male with metastatic pancreatic cancer using a novel regimen of icotinib with gemcitabine. Marked shrinkage of the mass was observed after two treatment cycles, and partial remission was achieved. The abdominal pain was relieved. The adverse effects were tolerable and treatment cost was acceptable. This is the first reported case for the treatment of advanced pancreatic cancer with icotinib plus gemcitabine and demonstrates a promising therapeutic alternative.

Experimental study of radiation dose rate at different strategic points of the BAEC TRIGA Research Reactor.

Science.gov (United States)

Ajijul Hoq, M; Malek Soner, M A; Salam, M A; Haque, M M; Khanom, Salma; Fahad, S M

2017-12-01

The 3MW TRIGA Mark-II Research Reactor of Bangladesh Atomic Energy Commission (BAEC) has been under operation for about thirty years since its commissioning at 1986. In accordance with the demand of fundamental nuclear research works, the reactor has to operate at different power levels by utilizing a number of experimental facilities. Regarding the enquiry for safety of reactor operating personnel and radiation workers, it is necessary to know the radiation level at different strategic points of the reactor where they are often worked. In the present study, neutron, beta and gamma radiation dose rate at different strategic points of the reactor facility with reactor power level of 2.4MW was measured to estimate the rising level of radiation due to its operational activities. From the obtained results high radiation dose is observed at the measurement position of the piercing beam port which is caused by neutron leakage and accordingly, dose rate at the stated position with different reactor power levels was measured. This study also deals with the gamma dose rate measurements at a fixed position of the reactor pool top surface for different reactor power levels under both Natural Convection Cooling Mode (NCCM) and Forced Convection Cooling Mode (FCCM). Results show that, radiation dose rate is higher for NCCM in compared with FCCM and increasing with the increase of reactor power. Thus, concerning the radiological safety issues for working personnel and the general public, the radiation dose level monitoring and the experimental analysis performed within this paper is so much effective and the result of this work can be utilized for base line data and code verification of the nuclear reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dose Rate Determination from Airborne Gamma-ray Spectra

DEFF Research Database (Denmark)

Bargholz, Kim

1996-01-01

The standard method for determination of ground level dose rates from airborne gamma-ray is the integral count rate which for a constant flying altitude is assumed proportional to the dose rate. The method gives reasonably results for natural radioactivity which almost always has the same energy...

The impact of fixed-dose combination versus free-equivalent combination therapies on adherence for hypertension: a meta-analysis.

Science.gov (United States)

Du, Li-Ping; Cheng, Zhong-Wei; Zhang, Yu-Xuan; Li, Ying; Mei, Dan

2018-04-27

Nonadherence to antihypertensive medication is considered as a reason of inadequate control of blood pressure. This meta-analysis aimed to systemically evaluate the impact of fixed-dose combination (FDC) therapy on hypertensive medication adherence compared with free-equivalent combination therapies. Articles were retrieved from MEDLINE and Embase databases using a combination of terms "fixed-dose combinations" and "adherence or compliance or persistence" and "hypertension or antihypertensive" from January 2000 to June 2017 without any language restriction. A meta-analysis was performed to parallel compare the impact of FDC vs free-equivalent combination on medicine adherence or persistence. Studies were independently reviewed by two investigators. Data from eligible studies were extracted and a meta-analysis was performed using R version 3.1.0 software. A total of nine studies scored as six of nine to eight of nine for Newcastle-Ottawa rating with 62 481 patients with hypertension were finally included for analysis. Results showed that the mean difference of medication adherence for FDC vs free-equivalent combination therapies was 14.92% (95% confidence interval, 7.38%-22.46%). Patients in FDC group were more likely to persist with their antihypertensive treatment, with a risk ratio of 1.84 (95% confidence interval, 1.00-3.39). This meta-analysis confirmed that FDC therapy, compared with free-equivalent combinations, was associated with better medication adherence or persistence for patients with hypertension. It can be reasonable for physicians, pharmacists, and policy makers to facilitate the use of FDCs for patients who need to take two or more antihypertensive drugs. ©2018 Wiley Periodicals, Inc.

Dose-rate effects of low-dropout voltage regulator at various biases

International Nuclear Information System (INIS)

Wang Yiyuan; Zheng Yuzhan; Gao Bo; Chen Rui; Fei Wuxiong; Lu Wu; Ren Diyuan

2010-01-01

A low-dropout voltage regulator, LM2941, was irradiated by 60 Co γ-rays at various dose rates and biases for investigating the total dose and dose rate effects. The radiation responses show that the key electrical parameters, including its output and dropout voltage, and the maximum output current, are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias. The integrated circuits damage change with the dose rates and biases, and the dose-rate effects are relative to its electric field. (authors)

Risk of solid cancer in low dose-rate radiation epidemiological studies and the dose-rate effectiveness factor.

Science.gov (United States)

Shore, Roy; Walsh, Linda; Azizova, Tamara; Rühm, Werner

2017-10-01

Estimated radiation risks used for radiation protection purposes have been based primarily on the Life Span Study (LSS) of atomic bomb survivors who received brief exposures at high dose rates, many with high doses. Information is needed regarding radiation risks from low dose-rate (LDR) exposures to low linear-energy-transfer (low-LET) radiation. We conducted a meta-analysis of LDR epidemiologic studies that provide dose-response estimates of total solid cancer risk in adulthood in comparison to corresponding LSS risks, in order to estimate a dose rate effectiveness factor (DREF). We identified 22 LDR studies with dose-response risk estimates for solid cancer after minimizing information overlap. For each study, a parallel risk estimate was derived from the LSS risk model using matching values for sex, mean ages at first exposure and attained age, targeted cancer types, and accounting for type of dosimetric assessment. For each LDR study, a ratio of the excess relative risk per Gy (ERR Gy -1 ) to the matching LSS ERR risk estimate (LDR/LSS) was calculated, and a meta-analysis of the risk ratios was conducted. The reciprocal of the resultant risk ratio provided an estimate of the DREF. The meta-analysis showed a LDR/LSS risk ratio of 0.36 (95% confidence interval [CI] 0.14, 0.57) for the 19 studies of solid cancer mortality and 0.33 (95% CI 0.13, 0.54) when three cohorts with only incidence data also were added, implying a DREF with values around 3, but statistically compatible with 2. However, the analyses were highly dominated by the Mayak worker study. When the Mayak study was excluded the LDR/LSS risk ratios increased: 1.12 (95% CI 0.40, 1.84) for mortality and 0.54 (95% CI 0.09, 0.99) for mortality + incidence, implying a lower DREF in the range of 1-2. Meta-analyses that included only cohorts in which the mean dose was LDR data provide direct evidence regarding risk from exposures at low dose rates as an important complement to the LSS risk estimates used

Analysis of the spatial rates dose rates during dental panoramic radiography

Energy Technology Data Exchange (ETDEWEB)

Ko, Jong Kyung [Dept. of Radiation Safety Management Commission, Daegu Health College, Daegu (Korea, Republic of); Park, Myeong Hwan [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of); Kim, Yong Min [Dept. of Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

2016-12-15

A dental panoramic radiography which usually uses low level X-rays is subject to the Nuclear Safety Act when it is installed for the purpose of education. This paper measures radiation dose and spatial dose rate by usage and thereby aims to verify the effectiveness of radiation safety equipment and provide basic information for radiation safety of radiation workers and students. After glass dosimeter (GD-352M) is attached to direct exposure area, the teeth, and indirect exposure area, the eye lens and the thyroid, on the dental radiography head phantom, these exposure areas are measured. Then, after dividing the horizontal into a 45°, it is separated into seven directions which all includes 30, 60, 90, 120 cm distance. The paper shows that the spatial dose rate is the highest at 30 cm and declines as the distance increases. At 30 cm, the spatial dose rate around the starting area of rotation is 3,840 μSv/h, which is four times higher than the lowest level 778 μSv/h. Furthermore, the spatial dose rate was 408 μSv/h on average at the distance of 60 cm where radiation workers can be located. From a conservative point of view, It is possible to avoid needless exposure to radiation for the purpose of education. However, in case that an unintended exposure to radiation happens within a radiation controlled area, it is still necessary to educate radiation safety. But according to the current Medical Service Act, in medical institutions, even if they are not installed, the equipment such as interlock are obliged by the Nuclear Safety Law, considering that the spatial dose rate of the educational dental panoramic radiography room is low. It seems to be excessive regulation.

Limitations to very high rate wire chambers in fixed target geometries

International Nuclear Information System (INIS)

Spiegel, L.

1989-11-01

The task is to explore physical limitations to the operation of wire chambers in fixed target geometries at an interaction rate of 52 MHz (chosen as it corresponds to the FNAL accelerator rf rate.) That is, to see if there are physical limitations to the operation of gaseous wire chambers at such a high operating rate. A primary proton beam energy of 800 GeV has been assumed although modest increases in the primary energy should not affect the basic conclusion as secondary multiplicity increases logarithmically with center-of-momentum energy. By sustaining a 52 MHz interaction rate it is meant that results from a given interaction are electronically isolated from preceding and subsequent rf buckets, good wire plane efficiency is maintained throughout the active region of the chamber, and the chamber operates in a stable manner throughout the course of a typical fixed target run -- six months to a full year. Other working assumptions include the understanding that chamber electronics -- amplifiers, discriminators, delay elements, encoders -- will not suffer degradation at 52 MHz and that the intensely populated beam regions have been somehow excluded from the chambers. 7 refs., 2 figs

Effect of traditional Chinese medicine composit Guben Yiliu III combined with gemcitabine on human pancreatic cancer xenograft in nude mice%固本抑瘤Ⅲ号方联合吉西他滨对人胰腺癌裸鼠异位移植瘤的抑瘤作用

Institute of Scientific and Technical Information of China (English)

刘炬; 钱海利; 徐志坚; 张立生; 叶霈智; 田爱平; 杨宏丽

2014-01-01

目的：探讨固本抑瘤Ⅲ号方以及与吉西他滨联合治疗人胰腺癌裸鼠异位移植瘤的抑瘤作用。方法将40只荷瘤裸鼠随机分为对照组、吉西他滨组、固本抑瘤Ⅲ号联合吉西他滨组、固本抑瘤Ⅲ号组，每组10只。于接种后第8天开始给药，观察指标为瘤重、裸鼠体重、移植瘤体积。结果吉西他滨组、固本抑瘤Ⅲ号联合吉西他滨组、固本抑瘤Ⅲ号组的抑瘤率分别为49.2％、68.9％和28.0％。固本抑瘤Ⅲ号联合吉西他滨组较吉西他滨组抑瘤作用更强（ P＜0.05）。吉西他滨组、固本抑瘤Ⅲ号联合吉西他滨组、固本抑瘤Ⅲ号组移植瘤体积均较对照组明显降低，差异有显著性。固本抑瘤Ⅲ号联合吉西他滨组体重下降明显，体重较对照组、吉西他滨组及固本抑瘤Ⅲ号组明显下降，差异有显著性。结论固本抑瘤Ⅲ号方具有增加吉西他滨化疗治疗人胰腺癌裸鼠腋下移植瘤疗效的作用。%Objective To explore whether the Chinese medicine Guben Yiliu III can improve the effect of gemcit -abine on human pancreatic cancer xenograft in nude mice . Methods Nude mice with transplanted human pancreatic cancer were divided randomly into 4 groups: control group, gemcitabine treatment group , combined ( Guben Yiliu III +gemcitabine) group, and Guben Yiliu III group, 10 mice in each group.The gemcitabine group and combined group were treated with gemcitabine from the 8th day after transplantation in a dose of 100 mg/kg by i.p.injection, twice a week. Guben Yiliu III and combined groups were given the aqueous solution of Guben Yiliu III granules p .o.since the 8th day af-ter transplantation .Result The inhibition rate of transplanted tumor in the three treatment groups were 48.9% in the gemcitabine group , 68.9%in the combined group , and 28.0%in the Guben Yiliu III group .The combined group showed a significantly higher inhibition rate than the gemcitabine group (P<0

Retention of the In Vitro Radiosensitizing Potential of Gemcitabine Under Anoxic Conditions, in p53 Wild-Type and p53-Deficient Non-Small-Cell Lung Carcinoma Cells

International Nuclear Information System (INIS)

Wouters, An; Pauwels, Bea; Lambrechts, Hilde A.J.; Pattyn, Greet G.O.; Ides, Johan; Baay, Marc; Meijnders, Paul; Peeters, Marc; Vermorken, Jan B.; Lardon, Filip

2011-01-01

Purpose: Whereas radiosensitization by gemcitabine is well studied under normal oxygen conditions, little is known about its radiosensitizing potential under reduced oxygen conditions. Therefore, the present study evaluated the impact of anoxia on gemcitabine-mediated radiosensitization. Methods and Materials: The clonogenic assay was performed in three isogenic A549 cell lines differing in p53 status (24 h, 0-15 nM gemcitabine, 0-8 Gy irradiation, normoxia vs. anoxia). Using radiosensitizing conditions, cells were collected for cell cycle analysis and apoptosis detection. Results: Whereas wild-type p53 A549-LXSN cells were more sensitive to radiation than p53-deficient A549-E6 cells, both cell lines showed similar radiosensitization by gemcitabine under normoxia and anoxia. Independent of p53 functionality, gemcitabine was able to overcome anoxia-induced G 0/1 arrest and established an (early) S phase block in normoxic and anoxic cells. The percentage early and late apoptotic/necrotic cells increased with the gemcitabine/radiation combination, with a significant difference between A549-LXSN and A549-E6. Conclusions: This study is the first to show that gemcitabine retains its radiosensitizing potential under low oxygen conditions. Although radiosensitization was observed in both p53 wild-type and p53-deficient cells, p53 status might influence induction of apoptosis after gemcitabine/radiation treatment, whereas no effect on cell cycle progression was noticed.

Quality assurance of rifampicin-containing fixed-drug combinations in South Africa: dosing implications.

Science.gov (United States)

Court, R; Chirehwa, M T; Wiesner, L; Wright, B; Smythe, W; Kramer, N; McIlleron, H

2018-05-01

Rifampicin (RMP) drives treatment response in drug-susceptible tuberculosis. Low RMP concentrations increase the risk of poor outcomes, and drug quality needs to be excluded as a contributor to low RMP exposure. We performed an open-label, three-way cross-over study of three licensed RMP-containing formulations widely used in South Africa to evaluate the bioavailability of RMP in a two-drug fixed-dose combination tablet (2FDC) and a four-drug FDC (4FDC) against a single-drug reference. RMP dosed at 600 mg was administered 2 weeks apart in random sequence. Plasma RMP concentrations were measured pre-dose and 1, 2, 3, 4, 6, 8 and 12 h post-dose. The area under the concentration-time curve (AUC0-12) of the FDCs was compared to the single drug reference. Simulations were used to predict the impact of our findings. Twenty healthy volunteers (median age 22.8 years, body mass index 24.2 kg/m2) completed the study. The AUC0-12 of the 4FDC/reference (geometric mean ratio [GMR] 78%, 90%CI 69-89) indicated an average 20% reduction in RMP bioavailability in the 4FDC. The 2FDC/reference (GMR 104%, 90%CI 97-111) was bioequivalent. Simulations suggested dose adjustments to compensate for the poor bioavailability of RMP with the 4FDC, and revised weight-band doses to prevent systematic underdosing of low-weight patients. Post-marketing surveillance of in vivo bioavailability of RMP and improved weight band-based dosing are recommended.

LDR brachytherapy: can low dose rate hypersensitivity from the "inverse" dose rate effect cause excessive cell killing to peripherial connective tissues and organs?

Science.gov (United States)

Leonard, B E; Lucas, A C

2009-02-01

Examined here are the possible effects of the "inverse" dose rate effect (IDRE) on low dose rate (LDR) brachytherapy. The hyper-radiosensitivity and induced radioresistance (HRS/IRR) effect benefits cell killing in radiotherapy, and IDRE and HRS/IRR seem to be generated from the same radioprotective mechanisms. We have computed the IDRE excess cell killing experienced in LDR brachytherapy using permanent seed implants. We conclude, firstly, that IDRE is a dose rate-dependent manifestation of HRS/IRR. Secondly, the presence of HRS/IRR or IDRE in a cell species or tissue must be determined by direct dose-response measurements. Thirdly, a reasonable estimate is that 50-80% of human adjoining connective and organ tissues experience IDRE from permanent implanted LDR brachytherapy. If IDRE occurs for tissues at point A for cervical cancer, the excess cell killing will be about a factor of 3.5-4.0 if the initial dose rate is 50-70 cGy h(-1). It is greater for adjacent tissues at lower dose rates and higher for lower initial dose rates at point A. Finally, higher post-treatment complications are observed in LDR brachytherapy, often for unknown reasons. Some of these are probably a result of IDRE excess cell killing. Measurements of IDRE need be performed for connective and adjacent organ tissues, i.e. bladder, rectum, urinary tract and small bowels. The measured dose rate-dependent dose responses should extended to tissues and organs remain above IDRE thresholds).

Tramadol/Paracetamol Fixed-Dose Combination for Chronic Pain Management in Family Practice: A Clinical Review

Science.gov (United States)

Morón Merchante, Ignacio; Pergolizzi, Joseph V.; van de Laar, Mart; Mellinghoff, Hans-Ulrich; O'Brien, Joanne; Perrot, Serge; Raffa, Robert B.

2013-01-01

The family practitioner plays an important role in the prevention, diagnosis, and early management of chronic pain. He/she is generally the first to be consulted, the one most familiar with the patients and their medical history, and is likely the first to be alerted in case of inadequate pain control or safety and tolerability issues. The family practitioner should therefore be at the center of the multidisciplinary team involved in a patient's pain management. The most frequent indications associated with chronic pain in family practice are of musculoskeletal origin, and the pain is often multimechanistic. Fixed-dose combination analgesics combine compounds with different mechanisms of action; their broader analgesic spectrum and potentially synergistic analgesic efficacy and improved benefit/risk ratio might thus be useful. A pain specialist meeting held in November 2010 agreed that the fixed-dose combination tramadol/paracetamol might be a useful pharmacological option for chronic pain management in family practice. The combination is effective in a variety of pain conditions with generally good tolerability. Particularly in elderly patients, it might be considered as an alternative to conventional analgesics such as NSAIDs, which should be used rarely with caution in this population. PMID:24959571

Biological effect of Pulsed Dose Rate brachytherapy with stepping sources

International Nuclear Information System (INIS)

Limbergen, Erik F.M. van; Fowler, Jack F.

1996-01-01

Purpose: To explore the possible increase of radiation effect in tissues irradiated by pulsed brachytherapy (PDR), for local tissue dose-rates between those 'averaged over the whole pulse' and the instantaneous high dose rates close to the dwell positions. An earlier publication (Fowler and Mount 1992) had shown that, for dose rates (averaged for the duration of the pulse) up to 3 Gy/h, little change of isoeffect doses from continuous low dose rate (CLDR) are expected, unless larger doses per fraction than 1 Gy are used, and especially if components of very rapid repair are present with half-times of less than about 0.5 hours. However, local and transient dose rates close to stepping sources can be up to several Gy per minute. Methods: Calculations were done assuming the linear quadratic formula for radiation damage, in which only the dose-squared term is subject to repair, at a constant exponential rate. The formula developed by Dale for fractionated low-dose-rate radiotherapy was used. A constant overall time of 140 hours and constant total dose of 70 Gy were assumed throughout, the continuous low dose-rate of 0.5 Gy/h (CLDR) providing the unitary standard effects for each PDR condition. Effects of dose-rates ranging from 4 Gy/h to 120 Gy/h (HDR at 2 Gy/min) were studied, and T (1(2)) from 4 minutes to 1.5 hours. Results: Curves are presented relating the ratio of increased biological effect (proportional to log cell kill) calculated for PDR relative to CLDR. Ratios as high as 1.5 can be found for large doses per pulse (> 1 Gy) at high instantaneous dose-rates if T (1(2)) in tissues is as short as a few minutes. The major influences on effect are dose per pulse, half-time of repair in the tissue, and - when T (1(2)) is short - the instantaneous dose-rate. Maximum ratios of PDR/CLDR effect occur when the dose-rate is such that pulse duration is approximately equal to T (1(2)) of repair. Results are presented for late-responding tissues, the differences from CLDR

Dose response relationship for unstable-type chromosome aberration rate of spleen cells from mice continuously exposed to low-dose-rate gamma-rays

International Nuclear Information System (INIS)

Tanaka, Kimio; Khoda, Atsushi; Ichinohe, Kazuaki; Oghiso, Yoichi

2007-01-01

It has been reported that people who are chronically exposed to radiation such as nuclear facility workers and medical radiologists have slightly higher incidences of chromosome aberrations than non-exposed people. However, chronological changes of chromosome aberration rates related to accumulated doses and dose-rates for low dose-rate radiation exposures have not been well studied. Precise analyses of human populations are quite limited because confounding factors influence the results. For this reason, animal experiments are important for analyses. Mice were continuously exposed to gamma-rays at 400 mGy/22 hr/day for 10 days, 20 mGy/22 hr/day for about 400 days, and 1 mGy/22 hr/day for about 615 days under SPF conditions. Chronological changes of unstable-type chromosome aberration rates of spleen cells were observed along with accumulated doses at the middle dose rate and the two low-dose rates by conventional Giemsa-staining method. Aberrations such as dicentric chromosome, ring chromosome and fragment increased in a two-phase manner within 0-1.2 Gy and 2-8 Gy at 20 mGy/22 hr/day. They slightly increased up to 0.5 Gy at 1 mGy/22 hr/day. Aberration rates for 1, 2, 8 Gy at the 20 mGy/22 hr/day and for 0.5 Gy at 1 mGy/22 hr/day were 5.1, 9.6, 13.9 and 2.2 times higher than those of age-matched, non-irradiated control mice, respectively. Chromosome aberration rates at 400 mGy/22 hr/day were 2.7 times higher than that of 20 mGy/22 hr/day for the same total dose of 1.2 Gy. The results that unstable-type chromosome aberrations increased with accumulated dose of the low-dose rate radiation will be important to establish biological dosimetry for people who are chronically exposed to radiation. (author)