Biomedical subjects

T Ohtsu

Publications and source records attributed to T Ohtsu.

At least 19 recordsLinked to original sources

PubMed2004

A phase II study of single-agent docetaxel in patients with metastatic esophageal cancer.

BACKGROUND: To evaluate the activity and toxicity of docetaxel in patients with metastatic esophageal cancer. PATIENTS AND METHODS: Eligible patients had histologically confirmed carcinoma of the esophagus with measurable metastatic sites according to Response Evaluation Criteria in Solid Tumors (RECIST). Patients were either chemotherapy-naïve or previously treated with one regimen of chemotherapy. Docetaxel 70 mg/m(2) was administered intravenously over 1-2 h, every 21 days. RESULTS: Of 52 patients enrolled in this study, three were excluded because they did not receive docetaxel due to worsening condition after enrollment. Thirty-six patients had received prior platinum-based chemotherapy. The majority of patients (94%) had squamous cell carcinoma. Ten of 49 evaluable patients [20%; 95% confidence interval (CI) 10-34%] showed a partial response. Of the 10 partial responses, six patients had received prior platinum-based chemotherapy. Grade 3 or 4 neutropenia was noted in 43 of 49 patients (88%), and nine of 49 patients (18%) developed febrile neutropenia. Twenty-eight of 49 patients (57%) required lenograstim. Grade 3 anorexia and fatigue occurred in nine (18%) and six (12%) patients, respectively. Median survival time was 8.1 months (95% CI 6.6-11.3) and the 1-year survival rate was 35% (95% CI 21-48%). CONCLUSIONS: Docetaxel as a single agent is effective in esophageal cancer, but careful management of neutropenia is needed.

Adenocarcinoma↗

PubMed2002

Factors affecting toxicity, response and progression-free survival in relapsed patients with indolent B-cell lymphoma and mantle cell lymphoma treated with rituximab: a Japanese phase II study.

BACKGROUND: The aim of the study was to determine factors affecting the toxicity and efficacy of rituximab monotherapy in relapsed patients with indolent B-cell lymphoma and mantle cell lymphoma (MCL). PATIENTS AND METHODS: A total of 90 patients were enrolled and treated with rituximab infusions at 375 mg/m2 once weekly for 4 weeks. Central pathology review revealed that histologically, 81 patients had indolent B-cell lymphoma or MCL: 59 with follicular lymphoma, 17 with MCL, four with marginal zone lymphoma and one with lymphoplasmacytoid lymphoma. Of these, four were ineligible due to violation of other eligibility criteria. Pre-treatment variables affecting toxicities were analyzed for all 90 patients, and those affecting response and progression-free survival (PFS) were analyzed for 77 eligible patients with confirmed indolent B-cell lymphoma or MCL. The relationship between serum rituximab levels and efficacy was also analyzed for 66 eligible patients. RESULTS: Hematological toxicities (grade > or =3) occurred more frequently in females (P <0.05), and thrombocytopenia and leukopenia were more frequent in patients with high lactate dehydrogenase (LDH) levels (P <0.05). Non-hematological toxicities (grade > or =2) were more frequent in patients with extranodal disease or bone marrow involvement. The overall response rate (ORR) in patients receiving one prior chemotherapy regimen was higher than those receiving two or more regimens (P <0.05). The median PFS was shorter in MCL patients, in those with extranodal disease, or in those receiving two or more prior chemotherapy regimens (P <0.01). The PFS intervals of patients with higher serum rituximab levels (> or =70 microg/ml) immediately before the third infusion were longer than in other patients (P <0.01). CONCLUSIONS: Several prognostic factors and serum rituximab levels are useful for predicting the toxicity and efficacy of rituximab monotherapy.

Adult↗

PubMed2002

Randomized phase II study of biweekly CHOP and dose-escalated CHOP with prophylactic use of lenograstim (glycosylated G-CSF) in aggressive non-Hodgkin's lymphoma: Japan Clinical Oncology Group Study 9505.

BACKGROUND: CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) is accepted as the best available standard treatment for first-line chemotherapy in aggressive non-Hodgkin's lymphoma (NHL). However, the therapeutic efficacy of CHOP remains unsatisfactory, particularly in high-intermediate risk and high risk patients, and a new strategy is warranted in this patient population. The aim of the present study was to explore a suitable therapeutic-intensified regimen for the treatment of aggressive NHL. PATIENTS AND METHODS: Between May 1995 and July 1998, a total of 70 patients with high-intermediate risk or high risk aggressive NHL, according to the International Prognostic Index, were enrolled and randomly assigned to receive either eight cycles of standard CHOP (cyclophosphamide 750 mg/m(2), doxorubicin 50 mg/m(2), vincristine 1.4 mg/m(2) and prednisolone 100 mg for 5 days) every 2 weeks, or six cycles of dose-escalated CHOP (cyclophosphamide 1500 mg/m(2), doxorubicin 70 mg/m(2), vincristine 1.4 mg/m(2) and prednisolone 100 mg for 5 days) every 3 weeks. Lenograstim (glycosylated rHuG-CSF), at a dose of 2 micro g/kg/day s.c., was administered daily from day 3 until day 13 with biweekly CHOP and until day 20 with the dose-escalated CHOP. The primary endpoint was complete response rate. RESULTS: The complete response rate was 60% [21 of 35; 95% confidence interval (CI) 42% to 76%] with biweekly CHOP and 51% (18 of 35; 95% CI 34% to 69%) with dose-escalated CHOP. The major toxicity was grade 4 neutropenia and was more frequent in the dose-escalated CHOP arm (86%) than in the biweekly CHOP arm (50%). Grade 4 thrombocytopenia was also more frequent in the dose-escalated CHOP arm (20%) than the biweekly CHOP arm (3%). Non-hematological toxicities were acceptable in both arms. One treatment-related death (due to cardiac arrhythmia) was observed in a dose-escalated CHOP patient. Progression-free survival at 3 years was 43% (95% CI 27% to 59%) in the biweekly CHOP arm and 31% (95% CI 16% to 47%) in the dose-escalated CHOP arm. Although seven patients were deemed ineligible by central review of the pathological diagnosis, the results for both eligible and all enrolled patients were similar. CONCLUSIONS: Similar complete response rates and progression-free survival rates, but lower toxicity, indicated that biweekly CHOP was superior to dose-escalated CHOP in the treatment of aggressive NHL. Based on these results, the Lymphoma Study Group of the Japan Clinical Oncology Group is conducting a randomized phase III study comparing biweekly CHOP with standard CHOP in newly diagnosed patients with advanced-stage aggressive NHL.

Adult↗

PubMed2001

Re-treatment of relapsed indolent B-cell lymphoma with rituximab.

The purpose of this study was to investigate the toxicity and the efficacy of re-treatment with rituximab, a chimeric mouse human anti-CD20 monoclonal antibody, in relapsed patients with indolent B-cell non-Hodgkin's lymphoma (NHL) who responded to rituximab in the previous phase I or phase II study. Thirteen patients with relapsed B-cell NHL, each of whom was confirmed to have Revised European-American Lymphoma Classification type II, 1-6 histology (indolent B-NHL), enrolled in this re-treatment study. All were re-treated with rituximab at 375 mg/m2 weekly for 4 consecutive weeks. Rituximab re-treatment was well tolerated with no grade 3/4 nonhematological toxicities, similar to that of the initial treatment. No patients developed detectable human anti-chimeric antibody. Partial responses were observed in 5 of 13 patients (38%; 95% confidence interval [CI], 14% to 68%); 6 patients showed stable disease and 2 showed progressive disease. Overall survival rate was 93% at 19 months of median follow-up after rituximab re-treatment. Median progression-free survival (PFS) after the re-treatment was 5.1 months (95% CI, 4.1 to 5.6 months), and the median PFS after the initial treatment was 8.2 months (95%CI, 5.9 to 11.3 months). Although rituximab re-treatment induced prolonged depletion of normal peripheral blood B cells in all patients, no significant decrease in serum immunoglobulin or complement level was observed. In conclusion, rituximab re-treatment was well tolerated, and it may produce a prolonged PFS in some patients with indolent B-cell NHL who showed initial response to rituximab.

Adult↗

PubMed2001

Factors affecting the pharmacokinetics of CPT-11: the body mass index, age and sex are independent predictors of pharmacokinetic parameters of CPT-11.

This study was conducted to describe the relationship between pharmacokinetics of CPT-11 and its active metabolite SN-38, and clinical values with special emphasis on the influence of relative weight referring to the appropriateness of a conventional dose adjustment method by body surface area (BSA). Thirty-six patients received 100 mg/m2 of CPT-11 intravenously over 90 min. Body Mass Index (BMI) was used as a measure of relative weight which is calculated from the equation: BMI=weight(kg)/[height(m)]2. The area under the concentration-time curve (AUC) of CPT-11 was significantly correlated with sex, age, poorer creatinine clearance and indocyanine green retention test (ICG). The peak plasma concentration (Cmax) of CPT-11 was significantly correlated with sex a larger BMI, BSA and age. The AUC of SN-38 was significantly correlated with ICG. The volume of distribution at steady state of CPT-11 inversely correlated with BMI. Multiple regression analysis revealed that the best fitting model with significant independent predictors for AUC of CPT-11 included age and sex (F=6.93, R2=0.29). That of Cmax of CPT-11 included sex and BMI (F=8.96, R2=0.35). The only independent predictor of AUC of SN-38 was ICG (F=7.75, R2=0.19). These results indicated that several factors affect pharmacological behaviors of CPT-11 even in patients with normal organ functions. The dose modification method based solely on BSA is not sufficient to reduce interpatient variability of cancer chemotherapy. The influence of relative weight, sex and age on pharmacokinetics/pharmacodynamics should be taken into consideration in every pharmacological approach to establish the ideal dose modification method.

Adult↗

PubMed2001

Phase I study of intravenous PSC-833 and doxorubicin: reversal of multidrug resistance.

PSC-833 reverses multidrug resistance by P-glycoprotein at concentrations < or = 1000 ng / ml. A phase I study of PSC-833 and doxorubicin was conducted to determine the maximum tolerated dose and to investigate pharmacokinetics. PSC-833 was intravenously infused as a 2-h loading dose (LD) and a subsequent 24-h continuous dose (CD). Doxorubicin was infused over 5 min, 1 h after the LD. The starting dose was 1 mg / kg for both LD and CD with 30 mg / m(2) doxorubicin; these dosages were increased to 2 and 10 mg / kg and 50 mg / m(2), respectively. Thirty-one patients were treated. Nausea / vomiting was controllable with granisetron and dexamethasone. Neutropenia and ataxia were dose limiting. Steady-state concentrations of PSC-833 > 1000 ng / ml were achieved at a 2 mg / kg LD and a 10 mg / kg CD. Ex-vivo bioassay revealed that activity in serum for reversing multidrug resistance was achieved in all patients; IC(50) of P-glycoprotein expressing 8226 / Dox(6) in patients' serum was decreased from 5.9 to 1.3 microg / ml (P < 0.0001) by PSC-833 administration. Doxorubicin clearance was 24.3 +/- 13.7 (mean +/- SD) liter / h/m(2), which was lower than the 49.0 +/- 16.9 liter / h/m(2) without PSC-833 (P < 0.0001). The relationship between doxorubicin exposure and neutropenia did not differ between patients treated and not treated with PSC-833. The recommended phase II dose of PSC-833 was 2 and 10 mg / kg for LD and CD, respectively, which achieved a sufficient concentration in serum to reverse drug resistance, as confirmed by bioassay. The dose of doxorubicin should be reduced to 40 mg / m(2), not because of the pharmacodynamic interaction between PSC-833 and doxorubicin affecting hematopoiesis, but because of pharmacokinetic interaction.

Adult↗

PubMed2000

The super anti-apoptotic factor Bcl-xFNK constructed by disturbing intramolecular polar interactions in rat Bcl-xL.

A powerful artificial anti-apoptotic factor will be useful for medical applications of the future therapies for many diseases by prolonging survival of sick cells. For constructing it, we designed the super anti-apoptotic factor by disturbing three intramolecular polar interactions among alpha-helix structures of Bcl-x(L). The resultant mutant Bcl-x(L), named Bcl-xFNK, was expected to make the pore-forming domain more mobile and flexible than the wild-type. When overexpressed in Jurkat cells, Bcl-xFNK was markedly more potent in prolonging survival following apoptosis-inducing treatment with a kind of cell death cytokines (anti-Fas), a protein kinase inhibitor (staurosporine), cell cycle inhibitors (TN-16, camptothecin, hydroxyurea, and trichostatin A), or oxidative stress (hydrogen peroxide and paraquat) than wild-type Bcl-x(L). Furthermore, the transfectants of bcl-xFNK became more resistant against a calcium ionophore and even a heat treatment than wild-type Bcl-x(L). In addition, Bcl-xFNK showed marked anti-apoptotic activity in Chinese hamster ovary and Jurkat cells deprived of serum. Thus, Bcl-xFNK may be the first mutant generated by site-directed mutagenesis of Bcl-x(L) with a gain-of-function phenotype. Interestingly, Bcl-xFNK was found to allow interleukin-3-dependent FDC-P1 to grow without interleukin-3, but not BaF/3. In Bcl-xFNK transfectants of FDC-P1 and Jurkat, the p42/p44 mitogen-activated protein kinase was activated by 2 to 5 times, but not in those of BaF/3 and Chinese hamster ovary. Bcl-xFNK might gain a new function to activate the mitogen-activated protein kinase in a cell-type specific manner. The findings of this study suggest that the central alpha5-alpha6 pore-forming region of anti-apoptotic factor Bcl-x(L) has a pivotal role in suppressing apoptosis.

Animals↗

PubMed2000

Atomic Force Microscopy Study of Ultrafine Particles Prepared in Reverse Micelles.

The imaging of ultrafine Au, Pd, CdS, and ZnS particles prepared in reverse micelles has been studied by atomic force microscopy (AFM). Mica substrates, derivatized with a monolayer of amine or thiol-terminated silanes, were used to immobilize the particles. The substrates were exposed to reverse micellar solutions containing the particles and were then immersed in appropriate solvent media to remove surfactants. This resulted in a partial coating of the surfaces by the particles. The particle size was estimated as the height of protrusion, shown on the AFM images. The size values for the Pd and CdS particles, thus obtained, were found to be almost identical to those obtained by transmission electron microscopy (TEM), whereas those for the Au and ZnS particles were larger than those obtained by TEM. Scanning electron microscopy showed that the Au particles tended to aggregate on the surfaces, while Pd particles were isolated from one another. Copyright 2000 Academic Press.

Journal Article↗

PubMed2000

Effects of perceived job stress on mental health. A longitudinal survey in a Japanese electronics company.

We conducted a cohort study for 2 years to examine the causal relationship between perceived job stress and mental health. Questionnaire surveys, including a 30-item General Health Questionnaire (GHQ) and a questionnaire on perceived job stress were carried out every 6 months for 2 years. To clarify the causal relationship between job stress and mental health, we followed a group of workers who initially had a GHQ score < or = 7. Out of 462 workers who were thought to be in a healthy mental state, 282 were successfully followed for 2 years. We considered subjects who developed unhealthy mental health states (GHQ score > or = 8) as hazardous cases. To control potential confounding factors, proportional hazard analysis was done. The overall proportion hazardous cases detected in the development of an unhealthy mental health state over two years was 55.7%. Using Cox's proportional hazard model, workers who complained of perceived job stress had a greater hazard than those without job stress. In particular, the item 'poor relationship with superior' showed the largest adjusted hazard ratio [95% confidence interval (CI)] of 1.51 (1.06-2.15). The item 'too much trouble at work' also had a significant hazardous effect on mental health with an adjusted hazard ratio (95% CI) of 1.43 (1.00-2.04). Some specific items of perceived job stress could cause mental ill health in workers.

Cohort Studies↗

PubMed2000

Dose-escalation study of CHOP with or without prophylactic G-CSF in aggressive non-Hodgkin's lymphoma.

BACKGROUND: CHOP is accepted as the gold standard for first line chemotherapy of aggressive non-Hodgkin's lymphoma (NHL). A dose-escalation study of CHOP was conducted to determine the maximal tolerated dose (MTD) and toxicity profile of CHOP at three-week intervals with or without prophylactic recombinant human granulocyte colony-stimulating factor (rHuG-CSF) in patients with aggressive NHL. PATIENTS AND METHODS: The doses of drugs were escalated from 50 mg/m2 to 70 mg/m2 for doxorubicin and from 750 mg/m2 to 2250 mg/m2 for cyclophosphamide, with conventional doses of vincristine and oral prednisolone. After the MTD was determined without rHuG-CSF, dose escalation was conducted with prophylactic rHuG-CSF. RESULTS: Thirty-three patients with NHL were enrolled into the study. The MTD without prophylactic rHuG-CSF was 70 mg/m2 of doxorubicin and 1250 mg/m2 of cyclophosphamide, with neutropenia as a dose-limiting toxicity. The MTD with prophylactic rHuG-CSF was 70 mg/m2 of doxorubicin and 2250 mg/m2 of cyclophosphamide. The overall response rate was 100% (76% complete response and 24% partial response). Progression-free survival and overall survival at five years were 45% and 66%, respectively. CONCLUSIONS: Significant dose escalation of doxorubicin and cyclophosphamide was feasible with prophylactic rHuG-CSF. The efficacy of dose-escalated CHOP should be compared with that of standard CHOP.

Adolescent↗

PubMed2000

Linear IgA disease with IgA antibodies directed against 200- and 280-kDa epidermal antigens.

We report an 80-year-old man with the lamina lucida type of linear IgA disease, with IgA autoantibodies reactive with 200-kDa and 280-kDa epidermal proteins. The patient presented with widespread bullous lesions on his trunk and extremities without mucosal involvement. Histopathology of lesional skin showed a subepidermal blister with papillary microabscesses of neutrophils and a few eosinophils. Direct immunofluorescence microscopy of perilesional skin showed linear deposits of IgA and C3 at the basement membrane zone. The patient's serum contained IgA autoantibodies that bound exclusively to the epidermal side of 1 mol L-1 NaCl split skin as determined by indirect immunofluorescence microscopy. Circulating IgA autoantibodies to 200- and 280-kDa antigens were detected in the patient's serum by immunoblot analysis using extracts from normal human epidermis and human epidermal keratinocytes. These two antibodies, eluted from individual nitrocellulose membranes, reacted with the epidermal side of 1 mol L-1 NaCl split skin on indirect immunofluorescence microscopy, and bound to hemidesmosomes as determined by immunoperoxidase electron microscopy. This observation suggests the presence of hitherto uncharacterized 200- and 280-kDa hemidesmosomal proteins distinct from BPAG1, BPAG2 and beta4 integrin as target antigens in linear IgA disease.

Aged↗

PubMed2000

Randomized comparison of mobilization kinetics of circulating CD34+ cells between biweekly CHOP and dose-escalated CHOP with the prophylactic use of lenograstim (glycosylated rHuG-CSF) in aggressive non-Hodgkin's lymphoma. The lenograstim/Lymphoma Study Group.

High-dose chemotherapy with autologous hematopoietic stem cell transplantation has been expected to result in a promising outcome in high risk aggressive non-Hodgkin's lymphoma (NHL). However, it remains unknown what type of initial chemotherapy is optimal, especially regarding progenitor cell mobilization. Sixty-three untreated patients with aggressive NHL in a high risk group were randomized to either a biweekly arm with 8 cycles of standard CHOP or 6 cycles of the dose-escalated CHOP arm with cyclophosphamide 1.5 g/m2 and doxorubicin 70 mg/m2. Lenograstim (glycosylated rHuG-CSF 2.0 microg/kg/day) was administered daily from day 3 to patients in both arms. The mobilization effect of the two regimens on circulating CD34+ cells was evaluated. Twenty-seven of 29 patients in the biweekly CHOP arm and 33 of 34 patients in the dose-escalated CHOP were assessable. Dose-escalated CHOP yielded a significantly higher number of circulating CD34+ cells in the first cycle compared with biweekly CHOP (p=0.05). The peak number of circulating CD34+ cells with biweekly CHOP did not significantly change from cycle to cycle; however, in dose-escalated CHOP, the peak number of circulating CD34+ cells mobilized after the fifth and sixth cycle was lower than after the first cycle (p=0.07 and 0.009, respectively). Routine conventional-dose chemotherapy and low-dose G-CSF can mobilize sufficient CD34+ cells in patients with aggressive NHL. The mobilization kinetics of circulating progenitor cells in patients with aggressive NHL is dependent on the dosage and schedule of CHOP.

Adjuvants, Immunologic↗

PubMed2000

Study of dose escalation and sequence switching of administration of the combination of docetaxel and doxorubicin in advanced breast cancer.

The objectives of the present study were to evaluate whether a schedule-dependent pharmacokinetic and/or pharmacodynamic interaction exists between two sequences of docetaxel and doxorubicin administration and to determine the maximal tolerated dose (MTD) of this combination. Patients with chemotherapy-naïve metastatic or recurrent advanced breast cancer were enrolled. In the crossover design, tandem dose escalation of docetaxel and doxorubicin was performed. Docetaxel, in doses ranging from 50-70 mg/m2, was administered for 1 h by drip infusion either just before or after a 5-min bolus i.v. injection of doxorubicin at dosages from 40-50 mg/ m2. The sequence of drug administration was switched after the first course in each patient, and the sequence of drug administration thereafter depended on the patient's choice. Twenty-five patients were initially assessable for toxicity. The MTD in the sequence of doxorubicin after docetaxel was 40 and 50 mg/m2, respectively, with the dose-limiting toxicity of neutropenia. On the other hand, the MTD of the sequence of docetaxel after doxorubicin was 70 and 50 mg/m2, respectively. The dose-limiting toxicities in this sequence were neutropenia and diarrhea. Duration of grade 4 neutropenia in the sequence of docetaxel followed by doxorubicin was significantly longer than that in the alternate sequence (P = 0.0062). However, there was no difference in pharmacokinetic parameters of docetaxel, doxorubicin, and doxorubicinol between the two sequences. The sequence of 50 mg/m2 doxorubicin followed by 60 mg/m2 docetaxel is recommended for subsequent clinical trials for practical reasons.

Adult↗

PubMed1999

Acute myocardial infarction following toxic epidermal necrolysis?

We describe a 29-year-old woman with rheumatoid arthritis who suffered an acute myocardial infarction 70 days after an initial presentation with toxic epidermal necrolysis (TEN). The trigger for the TEN was probably an over-the-counter anti-influenza treatment containing tipepidine hibenzate. Although the patient had familial hypercholesterolemia, we believe that thrombocytosis, induced by the inflammatory response and metabolic stress resulting from the TEN, may also have played a significant role in the pathogenesis of the myocardial infarction. Although TEN manifests itself principally as a skin disease, the potential for systemic morbidity, including cardiovascular abnormalities, should also be remembered.

Adult↗

PubMed1998

How Drosophila species acquire cold tolerance--qualitative changes of phospholipids.

Phospholipids of many cold-tolerant organisms have been reported to contain more unsaturated fatty acids than cold-susceptible organisms, a phenomenon known to maintain membrane fluidity at low temperature. However, we have obtained results to the contrary through a comparison of the membrane phospholipids of six temperate and subtropical species belonging to the Drosophila melanogaster species group. With enhancement of cold tolerance, the percentages of monoenoic acids increased but the percentages of dienoic acids decreased, that is, the number of double bonds in the phospholipid decreased without a marked variation in the percentages of unsaturated fatty acids. Concomitantly, the percentage of fatty acids containing 16 carbon atoms increased, while that of fatty acids with 18 carbon atoms decreased. Since phosphatidylethanolamine is a dominant phospholipid in Drosophila, these changes probably contribute to keeping the homeoviscosity of the cellular membranes in a manner different to that in phosphatidylcholine-rich membranes, thereby increasing cold tolerance.

Acclimatization↗

PubMed1998

Pharmacokinetic study of low- versus high-dose medroxyprogesterone acetate (MPA) in women.

The present study was conducted to compare the pharmacokinetics (PK) of low-dose versus high-dose medroxyprogesterone (MPA) as a once-daily oral administration. Of 32 patients, all women, enrolled in this PK study, 18 received 600 mg MPA daily and 14 received 1200 mg daily. Detailed PK data were obtained on day 1 and after more than 4 weeks of MPA treatment. In addition, multiple data for the minimum steady-state concentration (Css min) were analyzed. The MPA serum concentrations were measured by high-performance liquid chromatography. Wide interpatient variability was found in the PK parameters obtained both on day 1 and after more than 4 weeks. There were no clear relationships between the oral dose and the MPA peak concentration (Cmax), area under the time versus concentration curve (AUC), or mean Css min. Weight gains of 10% or more were demonstrated more frequently in the high-dose group (P < 0.01). Liver dysfunction (n = 5) did not influence the PK of MPA. Five patients demonstrated extremely low AUC and Cmax (< 10 ng/ml) values on day 1. Phenobarbital, dexamethasone and betamethasone were being taken concomitantly with the MPA each by one patient. The serum MPA concentrations were markedly increased after the discontinuation of phenobarbital in that patient, suggesting a drug interaction. At present we cannot recommend the high dose of MPA, except in clinical studies, from a PK or a pharmacodynamic points of view.

Adult↗

PubMed1998

Indirect-response model for the time course of leukopenia with anticancer drugs.

BACKGROUND: Because both the nadir count and the duration of leukopenia after chemotherapy with anticancer drugs are important, a pharmacodynamic model describing the entire time course of leukopenia is valuable. In this study, a pharmacodynamic model was developed to simulate leukopenia. METHODS: The model was developed with the 3-hour infusion data of paclitaxel. A concentration-time curve of paclitaxel for each patient estimated by a 3-compartment pharmacokinetic model was used as input to the model, which had 2 compartments corresponding to leukocytes in bone marrow and peripheral blood, respectively. Differentiation stages of myeloid cells sensitive to anticancer drugs were assumed, and exposure to a drug during their sensitive period as a function of time was used to inhibit the production of leukocytes in bone marrow. The model was validated by fitting the data of 24-hour infusion of paclitaxel or 14-day infusion of etoposide. RESULTS: Successful fitting of the leukopenia after a 3-hour infusion of paclitaxel was achieved. The following parameters were estimated: lag-time, 58 +/- 38 (mean +/- SD) hours before the leukocyte count started to decline; exposure giving 50% inhibition of leukocyte production (IC), 12.1 +/- 6.1 microg x h/mL; and sensitive period, 288 +/- 64 hours. These estimations were within physiologic ranges. In validation, leukopenia after 24-hour infusion of paclitaxel or 14-day infusion of etoposide was also explained by the model. Age was significantly negatively correlated with IC of paclitaxel (P = .039). CONCLUSIONS: This mechanistic model describes the time course of leukopenia and may provide a platform for pharmacodynamic analysis of anticancer drugs.

Adult↗

PubMed1998

Toxicity and efficacy of ifosfamide, carboplatin and etoposide (modified ICE) as a salvage chemotherapy in Japanese patients with relapsed or refractory aggressive non-Hodgkin's lymphoma.

The combination of ifosfamide, carboplatin and etoposide (modified ICE), was evaluated for its toxicity and activity in relapsed or refractory aggressive non-Hodgkin's lymphoma. Twenty patients, 14-69 years of age, with relapsed (19 cases) or refractory (one case) aggressive non-Hodgkin's lymphoma were treated with modified ICE therapy, consisting of ifosfamide 6 g/m2 (1.2 g/m2 day 1-5), carboplatin 400 mg/m2 (day 1) and etoposide 500 mg/m2 (100 mg/m2 day 1-5). The regimen was repeated at approximately 28-day intervals. All patients had undergone a doxorubicin-containing regimen before modified ICE therapy. Median total dose of previously received doxorubicin was 406 mg/m2 (range: 200-825 mg/m2). The median interval from diagnosis to modified ICE therapy was 9.4 months (range: 3.6-121 months). Two patients achieved CR and five achieved PR out of 16 patients with measurable lesions (response rate 43.8%; 95% confidence interval 19.0-68.6%). Median overall survival was 227 days (range: 41-552 days) from the start of modified ICE therapy. Myelosuppression was the most serious toxicity, namely 16 patients (80%) and 11 patients (55%) showed grade 4 neutropenia and grade 4 thrombocytopenia after the first course, respectively. Modified ICE therapy might be an active regimen with acceptable toxicity as a salvage chemotherapy in aggressive non-Hodgkin's lymphoma.

Adolescent↗