Reproducibility of Histologic Assessment in Porto-sinusoidal Vascular Disease Liver Biopsies

Introduction/Objective

Variable histologic findings that may be seen in porto-sinusoidal vascular disease (PSVD) liver biopsies are subject to high interobserver variability, requiring correlation with clinical history of portal hypertension (traditionally interpreted as non-cirrhotic portal hypertension NCPH). We investigated which histologic features are reproducible in PSVD biopsies.

Methods

Archived liver biopsies (n=38) from patients with NCPH (n=14) and without NCPH (n=21) were reviewed. Static H&E images of lobules (L, x100, NCPH=27, non-NCPH=23) and portal tracts (P, x200, NCPH=23, non- NCPH=27) were distributed among 9 gastrointestinal pathologists blinded to clinical history. Each pathologist answered multiple choice questions based on the presence (Q2) or absence (Q1) of portal hypertension clinically. The choice selected by 6 pathologists or more was considered consensus answer for the image. The interpretation of the image was considered reproducible when consensus was reached on both Q1 and Q2.

Results

The interpretations of 27 (54%; 17L, 10P) images from NCPH and 21 (42%; 10L, 11P) from non-NCPH were reproducible. In NCPH, the interpretations of normal (n=10, 4L, 6P), sinusoidal dilatation (n=7), and increased parenchymal draining vessels (n=3) were reproducible, while there was no consensus on the diagnoses of nodular regeneration and increased number of portal vessels. In non-NCPH, the interpretations of normal (n=8, 2L, 6P), sinusoidal dilatation (n=6), and paraportal shunting vessel(s) (n=4) were reproducible, whereas no consensus was reached on the diagnoses of nodular regeneration, incomplete fibrous septa, and increased number of portal vessels.

Conclusion

Histologic assessment of normal L and P as well as sinusoidal dilatation appears to be reproducible independent of clinical history. The findings of increased parenchymal draining vessels in NCPH group and paraportal shunting vessels in non-NCPH group may be consistently diagnosed to a certain extent. The assessment for nodular regeneration without reticulin stain, incomplete fibrous septa, or increased number of portal vessels appears to be unreliable.

Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV

We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200  GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200  GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.

Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Higher moments of net proton multiplicity distributions at RHIC

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

System-size independence of directed flow measured at the BNL relativistic heavy-ion collider

We measure directed flow (v_{1}) for charged particles in Au+Au and Cu+Cu collisions at sqrt[s_{NN}]=200 and 62.4 GeV, as a function of pseudorapidity (eta), transverse momentum (p_{t}), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to v_{1} in different collision systems, and investigate possible explanations for the observed sign change in v_{1}(p_{t}).

Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV

We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.

Comparative genomic hybridization study of nasal-type NK/T-cell lymphoma

BACKGROUND

Nasal-type NK/T-cell lymphoma is a rare type of non-Hodgkin's lymphoma. The genetic changes associated with pathogenesis have not been well defined. This study investigates the nonrandom genetic alteration of nasal-type NK/T-cell lymphoma.

METHODS

Nine cases were studied. Comparative genomic hybridization (CGH) was carried out using fresh tumor tissues of seven nasal-type NK/T-cell lymphomas. To complement the data by CGH, loss of heterozygosity (LOH) of chromosomes 6q, 1p, and 17p using polymorphic markers and p53 gene mutation by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) were analyzed.

RESULTS

The DNA copy number changes of seven nasal-type NK/T-cell lymphomas were gains on chromosomes 2q(5), 13q(4), 10q(3), 21q(2), 3q(2), 5q(2), and 17q(2), and losses involving chromosomes 1p(4), 17p(4), 12q(3), 13q(2), and 6q(1). One of six cases informative for at least two markers for chromosome 6q showed LOH at D6S300, D6S1639, D6S261, D6S407, and D6S292. Two cases showing loss of 1p and 17q by CGH revealed LOH at D1S214, D1S503, and D17S559. P53 mutation was detected in exon 8 in one of nine cases.

CONCLUSIONS

Frequent DNA losses at 1p, 17p, and 12q and gains at 2q, 13q, and 10q suggested that these regions could be targets for further molecular genetic analysis to investigate tumor suppressor genes or oncogenes associated with tumorigenesis of NK/T-cell lymphoma. Infrequent alteration of 6q contrary to previous studies raises doubt about an implication of 6q loss in the pathogenesis of early-stage NK/T-cell lymphoma. Further studies on more defined cases are required to verify their association.

Boron trifluoride etherate on silica-A modified Lewis acid reagent (VII). Antitumor activity of cannabigerol against human oral epitheloid carcinoma cells

Geraniol (1), olivetol (2), cannabinoids (3 and 4) and 5-fluorouracil (5) were tested for their growth inhibitory effects against human oral epitheloid carcinoma cell lines (KB) and NIH 3T3 fibroblasts using two different 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and sulforhodamine B protein (SRB) assay. Cannabigerol (3) exhibited the highest growth-inhibitory activity against the cancer cell lines.

Phase I clinical and pharmacologic study of intraperitoneal cisplatin and fluorouracil in patients with advanced intraabdominal cancer

Fluorouracil (5-FU) and cisplatin display marked therapeutic synergy in preclinical models and are effective in the treatment of a number of solid tumors when combined and administered intravenously (IV). Each drug has also been administered intraperitoneally (IP) and displays a favorable pharmacologic profile and acceptable clinical toxicity. We therefore undertook a phase I study to determine the feasibility and toxicity of combination IP chemotherapy with these agents. Thirty-one patients with histologically documented malignancy confined to the peritoneal space were treated with cisplatin 90 mg/m2 mixed with 5-FU in 2 L of lactated Ringer's solution and given IP for 4 hours every 28 days. Cohorts of at least three patients received starting 5-FU concentrations ranging from 5 mmol/L (1,300 mg in 2 L) to 20 mmol/L. The dose-limiting toxicity was neutropenia with a median granulocyte nadir of 156 cells per microliter occurring at a 5-FU dose of 20 mmol/L. Intrapatient escalation of the 5-FU dose was permitted and 15 cycles of chemotherapy were delivered at 5-FU concentrations greater than 20 mmol/L, the highest concentration being 30.7 mmol/L (8 g of 5-FU in 2L). Other toxicities included mild to moderate nausea during all cycles of therapy, vomiting in 54% of cycles, and diarrhea in 15% of cycles. Abdominal pain, renal dysfunction, peripheral neuropathy, and oral mucositis occurred infrequently and were not related to the 5-FU dose. Peritoneal fluid and plasma 5-FU concentrations were measured by high-performance liquid chromatography (HPLC) in selected patients. Mean peak plasma 5-FU concentrations ranged from 6.19 mumol/L to greater than 60 mumol/L, and peritoneal fluid to plasma 5-FU area under the curve (AUC) ratios ranged from 85 to 1,150. Nine of 15 patients with nonbulky disease had resolution of malignant ascites or at least a 50% reduction of peritoneal studding by tumor at repeat laparotomy. We conclude that combination IP chemotherapy with cisplatin and 5-FU is technically feasible and has acceptable clinical toxicity and a favorable pharmacologic profile. The recommended starting 5-FU dose for phase II trials is 3,900 mg mixed with 90 mg/m2 of cisplatin in 2 L of isotonic fluid.

Continuous infusion mitoxantrone in relapsed acute nonlymphocytic leukemia

Mitoxantrone is a substituted anthraquinone with considerable activity against human acute leukemia. The authors' goal was to treat patients with continuous infusion mitoxantrone in order to maintain cytotoxic steady state levels with acceptable toxicity and to assess the results. Daily mitoxantrone levels showed a mean steady state plasma level of 16.8 +/- 1.4 ng/ml (range, 9.1-25.1) with a systemic clearance of 519 +/- 47 ml/minute/m2. No drug accumulation occurred. Mitoxantrone was undetectable 24 hours postinfusion. All patients, including two patients with chronic myelogenous leukemia in blast phase, had greater than 90% reduction in leukemia cell mass (marrow cellularity X percent leukemia cells) by day 6. However, six patients received 3 days of etoposide at that point because of residual acute nonlymphocytic leukemia (ANLL). Overall four patients (36%) had a complete remission; one additional patient had a bone marrow remission but also had a persistent granulocytic sarcoma. Toxicities included severe but tolerable myelosuppression, mucositis, and hepatic dysfunction. There was no correlation between mitoxantrone levels, toxicity, or clinical response. Continuous infusion produces cytotoxic plasma mitoxantrone levels and rapid clearing of ANLL from bone marrow. Further dose escalation may be possible.

Pharmacokinetics and pharmacodynamics of long-term continuous-infusion doxorubicin

Steady-state plasma levels of doxorubicin and doxorubicinol were analyzed in 32 patients with advanced cancer, each of whom was given doxorubicin by long-term continuous infusion at progressively increasing infusion rates. Patients received doxorubicin for 2 to 50 weeks at rates of 0.2 to 6.1 mg/m2/day. Dose-limiting stomatitis and leukopenia were observed. The mean maximum steady-state doxorubicin concentration was 6.04 ng/ml at a mean maximum infusion rate of 3.92 mg/m2/day. Clearance mechanisms did not appear to be saturated at the durations or infusion rates used in this study. The maximum steady-state doxorubicin level and the ln (initial WBC) were significant correlates of the ln (nadir WBC) (p = 0.002 and 0.02, respectively). A model was constructed according to these two parameters that significantly describes ln (nadir WBC) (p = 0.001). Neither age, infusion rate, nor doxorubicinol level correlated with nadir WBC. Stomatitis did not correlate with any of these parameters. The demonstration of this pharmacodynamic relationship highlights the potential importance of pharmacologic data collection in ongoing attempts to predict the clinical effects of anticancer drugs.

Clinical pharmacology of the stereoisomers of leucovorin during repeated oral dosing

As part of a clinical trial of cisplatin, 5-fluorouracil (5-FU), and leucovorin (LV) for treatment of patients with advanced head and neck cancer, patients received 100 mg of LV (d,l-5-formyltetrahydrofolate) orally every 4 hours for 5 days. On days 2 and 4 of treatment, plasma samples were obtained 2 hours after (peak) and 30 minutes before (trough) a dose of LV. Total LV and 5-methyltetrahydrofolate (THF) concentrations were measured with high-performance liquid chromatography (HPLC) analysis. LV stereoisomer concentrations were determined by chiral HPLC on a bovine serum albumin-bonded silica column. Thus far, plasma folate levels have been analyzed for ten cycles of treatment administered to 7 patients (40 samples). Administration of LV in divided oral doses approximates a plasma steady state with no significant differences noted between peak and trough concentrations. Mean (+/- SD) plasma concentrations for all samples were (mumol): LV, 3.2 +/- 1.3; l-LV, 0.28 +/- 0.21; d-LV, 2.9 +/- 1.2; and THF, 4.25 +/- 2.5. Plasma levels of d-LV and THF tended to be approximately 10% higher on day 4 than day 2, although mean differences were not significantly different due to substantial interpatient variability. Of note was that the sum of THF and l-LV exceeds that of d-LV which was consistent with selective absorption of the l-isomer of LV. Mean ratios of d-LV/l-LV and d-LV/l-LV and THF were 13.7 +/- 10 and 0.88 +/- 0.68, respectively. The authors conclude that oral administration of LV in divided dose (1) simulates a continuous intravenous infusion; (2) produces plasma levels of l-reduced folates in a range known to potentiate 5-FU cytotoxicity; and (3) results in low ratios of d/l-reduced folates that may be important in maximizing the effectiveness of 5-FU-LV chemotherapy.

Plasma pharmacokinetics of high-dose oral melphalan in patients treated with trialkylator chemotherapy and autologous bone marrow reinfusion

The pharmacokinetics of melphalan following high-dose p.o. administration were determined in 17 patients with various malignancies for the purpose of assessing interpatient and intrapatient pharmacokinetic variability. All patients underwent bone marrow harvest on day -8 (relative to bone marrow reinfusion). On days -7, -6, and -5, melphalan was given p.o. and the dose was escalated on each cohort consisting of at least 3 patients (beginning at 0.75 mg/kg). On days -6, -4, and -2, cyclophosphamide at 2.5 g/m2 and thiotepa at 225 mg/m2 were given i.v. On day -7 the peak melphalan concentration was 1.64 +/- 0.89 (SD) microM with a terminal half-life of 1.56 +/- 0.86 h. The area under the plasma concentration time curve (AUC) and oral clearance were 217.9 +/- 115.1 microM/min and 30.2 +/- 14.2 ml/min/kg. There was only a moderate correlation between the melphalan dose and both the peak concentration (r = 0.50, P less than 0.05) and AUC (r = 0.64, P less than 0.01) over the dosage range of 0.75-2.5 mg/kg. There was a trend towards greater interpatient variability in peak concentration, AUC, and oral clearance observed at the higher doses of melphalan. Analysis of intrapatient pharmacokinetic variability in 8 patients showed a significant difference between the doses given on days -7 and -5 in the peak concentration (2.09 versus 1.07 microM, P = 0.02), AUC (264.9 versus 134.8 microM/min, P = 0.01), and oral clearance (25.1 versus 53.1 ml/min/kg, P = 0.05) but no significant difference in the time to peak and terminal half-life. We conclude that there is marked interpatient and intrapatient variability in melphalan pharmacokinetics following high-dose p.o. administration. The data are consistent with saturable absorptive pathways for melphalan, which might be especially sensitive to concurrent high-dose chemotherapy.

Adaptive control of etoposide administration: impact of interpatient pharmacodynamic variability

We sought to use a previously derived pharmacodynamic model for 72-hour etoposide infusions to adaptively control administration of this agent and to demonstrate that more predictable toxicity could be obtained with this dosing scheme. A randomized crossover study design was used to compare "standard" dosing (125 mg/m2/day) to adaptive control, with dose adjustment at 28 hours based on the 24-hour plasma level. A total of 31 patients received 86 cycles of chemotherapy, 36 by standard dosing and 50 by adaptive control. However, there was no demonstrable advantage to the adaptive control scheme, because of apparent bias of the previous model. A new model was proposed that also included serum albumin, performance status, and prior RBC transfusions as measures of interpatient pharmacodynamic variability. We conclude that adaptive control dosing of etoposide is feasible but that the therapy must be individualized for both pharmacokinetic and pharmacodynamic variability.

A randomized study of inpatient versus outpatient continuous infusion chemotherapy for patients with locally advanced head and neck cancer

This study was designed to evaluate the safety, reliability, and patient acceptance of outpatient continuous intravenous infusion (CVI) chemotherapy. Twenty-two patients with locally advanced head and neck cancer received induction chemotherapy with methotrexate, cisplatin and a 5-day CVI of 5-fluorouracil (5-FU). Patients were randomized to receive the 5-FU portion of cycle 1 either by a standard inpatient CVI chemotherapy delivery device (standard pump) or by the Infusor (Baxter Healthcare Corporation, Deerfield, IL), a portable chemotherapy delivery system that provides a constant flow of drug over a period of 24 hours. For cycle 2, patients crossed over to the alternative drug delivery method. Patients receiving chemotherapy via the Infusor could choose to be either inpatients or outpatients. Daily plasma concentrations of 5-FU were determined during the first two cycles of chemotherapy. There was no significant difference in the mean steady state plasma 5-FU levels achieved with either drug delivery method (329.7 +/- 95.8 ng/ml for infusor cycles vs. 352.8 +/- 114.9 ng/ml for standard pump cycles). Clinical toxicities consisted primarily of mucositis for both methods of drug delivery. Eight patients declined to receive CVI chemotherapy as outpatients citing as reasons fear of malfunction of the device, inconvenience of the frequent clinic visits necessitated by daily monitoring of plasma 5-FU concentrations, and restrictions in daily home activities. Eleven patients underwent CVI chemotherapy via Infusor as outpatients. All reported outpatient CVI chemotherapy as convenient and effective and, when eligible, chose it again in subsequent cycles. A comparison of estimated costs revealed reductions in daily costs of +366.00 (+2,200.00 per cycle) for outpatient chemotherapy. Outpatient CVI chemotherapy is a reliable drug delivery method that was accepted by a majority of patients in this study. These factors may help to establish outpatient CVI chemotherapy as a viable alternative to hospitalization.

Human plasma pharmacokinetics of thiotepa following administration of high-dose thiotepa and cyclophosphamide

Thiotepa is an established alkylating agent whose pharmacokinetics in standard doses are well defined. In order to ascertain whether dose-dependent variations in pharmacokinetics occur, we have undertaken an analysis of plasma thiotepa levels in 16 patients entered on a phase I-II study of bialkylator chemotherapy. High-dose thiotepa (1.8 to 7.0 mg/kg) and cyclophosphamide (2.5 g/m2) were administered intravenously (IV) on days -6, -4, and -2 followed by autologous marrow reinfusion on day 0. Plasma and urinary thiotepa was assayed by gas chromatography. Biexponential plasma decay curves were seen in ten patients, with a t 1/2 alpha of 10.0 +/- 6.4 minutes, a t 1/2 beta of 174 +/- 61 minutes and a total body clearance of 379 +/- 153 mL/h/kg (mean +/- SD). Six patients displayed monoexponential plasma decay curves with a terminal t 1/2 of 137 +/- 83 minutes and a total body clearance of 440 +/- 195 mL/h/kg. Although there was a trend toward reduced plasma clearance in the three patients treated at the highest dose level, the available data suggest that metabolic clearance mechanisms for thiotepa were not saturated with the doses used in this study. By stepwise regression analysis, linear functions using only 15-minute and four-hour postinfusion plasma levels were derived that correlated closely with area under the plasma concentration X time curves (AUC) (P less than .002). We conclude that high-dose thiotepa results in similar pharmacokinetic values to conventional doses with no apparent dose-dependent variation. The value of specific time points to predict AUC and clearance will require prospective evaluation.

Cisplatin, fluorouracil, and high-dose leucovorin for recurrent or metastatic head and neck cancer

We added high-dose oral leucovorin to the combination of cisplatin and fluorouracil (5-FU) to assess the efficacy of this regimen in the treatment of patients with head and neck cancer. Cisplatin, 100 mg/m2, was followed by a 5-FU continuous infusion at 600 mg/m2/d for five days. Leucovorin, 50 mg/m2, was administered at the start of cisplatin and every six hours throughout the duration of the 5-FU infusion. The dose of 5-FU was escalated to 800 mg/m2 and 1,000 mg/m2 according to observed toxicity. In a second phase of the study, the dose of leucovorin was escalated to 50 mg/m2 every four hours. A total of 25 patients were registered: 23 had recurrent disease after extensive prior treatment; and two had newly diagnosed metastatic disease. The maximally tolerated dose of 5-FU was 800 mg/m2/d with leucovorin administered every six hours. Toxicities at that level included mild to moderate myelosuppression and dose-limiting mucositis in the previously irradiated field. Identical toxicities were observed when administering 800 mg/m2/d of 5-FU with leucovorin every four hours. Eighteen patients were evaluated for response: one had a pathologic complete response; nine had a partial response (including four who received prior cisplatin and 5-FU as induction chemotherapy); and eight patients failed to respond. The mean peak and trough plasma leucovorin concentrations were 2.61 (+/- 1.07) mumol/L and 2.46 (+/- 0.95) mumol/L with administration of the drug every six hours, and 2.75 (+/- 2.15) mumol/L and 2.52 (+/- 1.48) mumol/L with administration every four hours. We conclude that the combination of cisplatin, 5-FU, and leucovorin has activity in the treatment of recurrent head and neck cancer. The maximally tolerated dose of 5-FU in this study was 800 mg/m2/d, with mucositis in previously irradiated sites being dose-limiting. Plasma leucovorin concentrations exceeding 1 mumol/L are achieved following oral administration of this drug.

Resolution of the stereoisomers of leucovorin and 5-methyltetrahydrofolate by chiral high-performance liquid chromatography

Leucovorin (5-formyltetrahydrofolate, LV) is a reduced folate that has been in clinical use for many years as a rescue agent following methotrexate (MTX) therapy. Commercially available LV is a 1:1 mixture of [6R]-and [6S]-isomers. Due to the lack of a specific method for directly separating and quantitating the stereoisomers of LV, it has been difficult to precisely define the pharmacokinetic and biological characteristics of each stereoisomer. We have now developed a novel HPLC method to completely separate [6S]-LV and [6S]-5-methyltetrahydrofolate (MeTHF) from their respective [6R]-isomers using bovine serum albumin (BSA)-bonded silica as the chiral stationary phase. Baseline separation was achieved using 5 and 25 mM sodium phosphate buffers (pH 7.4) as the mobile phase with resolution factors of 1.65 for LV and 2.31 for MeTHF, respectively. The purity of each isomer prepared by this HPLC method is greater than 99%. The stereoisomers were identified by examining their ability to protect CEM cells from MTX (0.04 microM)-induced inhibition of growth. In the LV chromatogram, the first eluted peak provided complete protection from MTX growth inhibition when LV concentrations of 0.1 microM and above were used, whereas the last eluted peak failed to reverse MTX toxicity at concentrations up to 1.0 microM. Chemically pure synthetic [6R]-and [6S]-LV standards confirmed that the first eluted, biologically active peak is the [6S]-isomer. For MeTHF, only the last eluted peak effectively protects cells from MTX growth inhibition and is therefore believed to be the [6S]-isomer. This new HPLC method will serve as a useful tool to elucidate the clinical and cellular pharmacology of the stereoisomers of LV and MeTHF.

High-performance liquid chromatographic assay for mitoxantrone in plasma using electrochemical detection

A sensitive and specific high-performance liquid chromatographic (HPLC) assay was developed for the quantitation of mitoxantrone in plasma using electrochemical detection. Bisantrene was chosen as the internal standard. A reversed-phase, 10-microns muBondapak C18 analytical column (30 cm X 3.9 mm) with an isocratic mobile phase of 28% acetonitrile in 80 mM sodium formate buffer (pH 3.0) was used. The eluent was monitored by both electrochemical detection at an applied potential of +0.75 V vs. Ag/AgCl and visible absorbance at 660 nm. Only electrochemical detection was able to quantitate the internal standard and provided ten times higher sensitivity than visible absorbance for mitoxantrone with a detection limit as low as 0.1 ng/ml. Calibration curves in the range 0.1-1000 ng/ml showed good linearity (r = 0.998) and precision (coefficient of variation less than 10%). This HPLC method utilized a reproducible and inexpensive liquid-liquid extraction procedure. Using methylene chloride, the extraction efficacy of mitoxantrone from plasma was 85.3% with a coefficient of variation less than 2.1%. This new assay was then applied to measure mitoxantrone concentrations in plasma obtained from two leukemic patients receiving 12 mg/m2 mitoxantrone as a 1-h infusion.

Methotrexate bioavailability after oral and intramuscular administration in children

Although methotrexate is one of the most commonly used drugs for maintenance therapy in childhood acute lymphocytic leukemia (ALL), its oral absorption is highly variable and its intramuscular bioavailability at dosages used for ALL therapy has not been assessed in children. We therefore determined the absolute bioavailability of orally and intramuscularly administered methotrexate in 12 pediatric patients receiving 13 to 120 mg/m2 methotrexate every week as maintenance therapy for ALL. Mean bioavailability, as determined by comparing the area under the concentration-time curve after oral or intramuscular administration with that produced by the same dosage given intravenously, was 33% (range 13% to 76%) for oral (n = 11) and 76% (54% to 112%) for intramuscular (n = 7) administration (P less than 0.01). Median bioavailability (with orally administered dosages less than or equal to 40 mg/m2 (range 13 to 40 mg/m2) was 42% (19% to 76%); at dosages greater than 40 mg/m2 (43 to 76 mg/m2), bioavailability was significantly lower, 17.5% (12.7% to 22.3%, p less than 0.02). Conversely, there was no significant relationship between dosage and bioavailability with intramuscularly administered drug. The substantially higher bioavailability for intramuscularly injected methotrexate may warrant its consideration as an alternative to oral administration, especially for dosages greater than 40 mg/m2.

Phase I clinical and pharmacological study of 72-hour continuous infusion of etoposide in patients with advanced cancer

Etoposide (VP-16) is a semisynthetic epipodophyllotoxin that exhibits cell cycle phase specific cytotoxicity and enhanced effectiveness with increasing duration of drug exposure. We have therefore conducted a Phase I trial to determine the side effects, tolerable doses, and pharmacokinetic parameters of VP-16 given by continuous i.v. infusion to patients with advanced cancer. Eighteen patients were treated with varying dosages of VP-16 infused continuously for 72 consecutive hours every 28 days. Using this schedule, the maximally tolerated dosage of VP-16 was 150 mg/m2/day for patients with good performance status and 125 mg/m2/day for more debilitated cancer patients. Hematological toxicity was dose limiting with median granulocyte and platelet nadirs of 700/mm3 and 116,000/mm3, respectively, at a dose of 150 mg/m2/day. Other toxicities included only mild nausea, vomiting, and alopecia. Plasma and urine VP-16 concentrations were determined using a high-performance liquid chromatography assay. At a VP-16 dosage of 150 mg/m2/day, steady-state VP-16 concentrations were in the range of 2.1 to 7.0 micrograms/ml in all patients. Further pharmacokinetic analysis revealed that the plasma clearance of VP-16 was consistently near 25 ml/min/m2 (independent of dosage) and that renal clearance accounted for only 15% of VP-16 total plasma clearance. Patient age was found to be the most important factor correlating with plasma clearance of VP-16. Linear regression analysis also revealed that both the plasma VP-16 concentration at steady state and the concentration of VP-16 in plasma at 24 h from the start of the infusion correlated with hematological toxicity; no other patient characteristics correlated with hematological toxicity. The recommended VP-16 dose for Phase II trials of 72-h continuous infusion VP-16 is 150 mg/m2/day in patients with good performance status.

A clinical and pharmacokinetic study of mitoxantrone in acute nonlymphocytic leukemia

Twenty-two patients with relapsed or refractory acute leukemia received 31 treatment courses of mitoxantrone (10 to 12 mg/m2/d) as a one-hour infusion for five days. Seven of the 13 patients who had greater than or equal to 95% reduction in the leukemia cell mass, calculated using the bone marrow examination on day 6, achieved a complete remission (CR). These remissions lasted up to 14 months without additional therapy. There were no CRs among the 18 patients who had less than 95% cytoreduction by day 6. The sequential addition of 5-azacytidine (200 mg/m2/d) for three days in those patients with residual disease on day 6 provided little additional benefit. Nonhematological toxicity from mitoxantrone was mild, although fever and infection were common. A new high-performance liquid chromatography (HPLC) assay was used to describe the clinical pharmacokinetics of mitoxantrone. Neither clinical response nor toxicity was strongly correlated with the peak plasma mitoxantrone concentration on the first day (mean +/- SD, 510 +/- 206 ng/mL), nor the area under the concentration-time curve (484 +/- 229 ng X h/mL), nor the systemic clearance (405 +/- 124 mL/min/m2). Mitoxantrone causes rapid cytoreduction in acute nonlymphocytic leukemia (ANLL), but the optimal dose and schedule remain to be determined.