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Publications and source records attributed to S C Grant.
In this article we report on progress in high magnetic field MRI at the University of Florida in support of our new 750MHz wide bore and 11.7T/40cm MR instruments. The primary emphasis is on the associated rf technology required, particularly high frequency volume and phased array coils. Preliminary imaging results at 750MHz are presented. Our results imply that the pursuit of even higher fields seems warranted.
This study examines multicomponent diffusion in isolated single neurons and discusses the implications of the results for macroscopic water diffusion in tissues. L7 Aplysia neurons were isolated and analyzed using a 600 MHz Bruker wide-bore instrument with a magnetic susceptibility-matched radiofrequency microcoil. Using a biexponential fit, the apparent diffusion coefficients (ADCs) from the cytoplasm (with relative fraction) were 0.48 +/- 0.14 x 10(-3) mm2 x s(-1) (61 +/- 11%) for the fast component, and 0.034 +/- 0.017 x 10(-3) mm2 x s(-1) (32 +/- 11%) for the slow component (N = 10). Diffusion in the nucleus appears to be primarily monoexponential, but with biexponential analysis it yields 1.31 +/- 0.32 x 10(-3) mm2 x s(-1) (89 +/- 6%) for the fast component and 0.057 +/- 0.073 x 10(-3) mm2 x s(-1) (11 +/- 6%) for the slow (N = 5). The slow component in the nucleus may be explained by cytoplasmic volume averaging. These data demonstrate that water diffusion in the cytoplasm of isolated single Aplysia neurons supports a multiexponential model. The ADCs are consistent with previous measurements in the cytoplasm of single neurons and with the slow ADC measurement in perfused brain slices. These distributions may explain the multiple compartments observed in tissues, greatly aiding the development of quantitative models of MRI in whole tissues.
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The first spatially localized NMR spectra of osmolytes and metabolites from single isolated neurons have been obtained using a combination of high magnetic field strengths and NMR radio frequency (RF) microcoils. The proton spectra display peaks at high concentrations (100-300 mM) assigned to betaine and choline, and other metabolite resonances including lactate at lower concentrations in the order of 10s of millimoles. The volumes examined were approximately 10 nl, over two orders of magnitude less than previously possible. In these initial experiments; the cells were unperfused and the signal intensities of the osmolytes decrease with time, a phenomenon consistent with cell swelling. This work demonstrates the technical feasibility of NMR spectroscopy of single cells, further broadening the scope of NMR spectroscopy of living tissues from application to entire living organisms (man and animal models) and isolated tissues (perfused organs and cultured assemblies of cells) and now to single cells. Magn Reson Med 44:19-22, 2000.
The 10-deazaaminopterins are a new class of rationally designed antifolates demonstrating greater antitumor effects than methotrexate in murine tumor models and human tumor xenografts. Their design was aimed at improving membrane transport and polyglutamylation in tumor cells, resulting in increased intracellular accumulation and enhanced cytotoxicity. Compared with other 4-aminofolate analogues, 10-propargyl-10-deazaaminopterin (PDX) is the most efficient permeant for the RFC-1-mediated internalization and substrate for folylpolyglutamate synthetase. PDX demonstrates greater in vitro and in vivo antitumor efficacy than methotrexate or edatrexate. We undertook a Phase I study with PDX to identify the potential toxicities and define an optimal dose and schedule. Thirty-three patients were enrolled, all of whom had non-small cell lung cancer (NSCLC) and were treated previously with a median of two prior chemotherapy regimens. Initially, PDX was administered weekly for 3 weeks in a 4-week cycle. Mucositis requiring dose reduction and/or delay in the first cycle occurred in four of six patients treated at the initial dose level (30 mg/m2), making this the maximal tolerated dose for PDX given on this schedule. The treatment schedule was then modified to every 2 weeks. Twenty-seven patients were treated twice weekly with a total of 102 four-week cycles (median, 2 cycles/patient). Mucositis was the dose-limiting toxicity, with grade 3 and 4 mucositis occurring in the first two patients treated at the 170 mg/m2 dose level. Other toxicities were mild and reversible. No neutropenia was observed. The recommended Phase II dose is 150 mg/m2 biweekly. At that dose level, the mean area under the curve was 20.6 micromol x h, and the mean terminal half-life was 8 h. Two patients with stage IV NSCLC had major objective responses, and five patients had stable disease for 7 (two patients), 9 (one patient), 10 (one patient), and 13 months (one patient). PDX is a new antifolate with manageable toxicity and evidence of antitumor activity in NSCLC. A Phase II trial in NSCLC and a Phase I trial with paclitaxel are under way. These studies will also quantitate the expression of genes controlling internalization (RFC-1) and polyglutamylation of PDX in tumor cells as correlates of response.
BACKGROUND: Cisplatin-based induction chemotherapy before surgery or irradiation has improved the survival of patients with Stage III nonsmall cell lung carcinoma (NSCLC). Encouraged by earlier results with preoperative MVP (cisplatin [120 mg/m(2) or 25 mg/m(2)/week], vinblastine, and mitomycin) for Stage IIIA patients with clinically apparent mediastinal (N2) disease, the authors conducted a Phase II trial of the safety and efficacy of induction MVP400 with the dose intensity of cisplatin doubled from 25 to 50 mg/m(2) per week. METHODS: From October 1992 to March 1996, 37 patients with Stage IIIA (26) or Stage IIIB (11) NSCLC began the MVP400 induction chemotherapy program. Four doses of cisplatin (100 mg/m(2)), 7 doses of vinblastine, and 2 doses of mitomycin were given over 9 weeks. Patients received either surgery or irradiation after induction treatment. RESULTS: Overall, the response rate was 65% (95% confidence interval, 49-81%) with a complete resection rate of 67%. The median survival was 17 months, with 66% of patients alive at 1 year. Complete resection and Stage IIIA involvement were favorable prognostic indicators for survival. No Stage IIIB patients underwent a complete resection. Myelosuppression was the most common side effect. There were no treatment-related deaths. CONCLUSIONS: Although high response and complete resection rates were again demonstrated, results with the MVP400 regimen were not improved over those achieved with MVP regimen tested earlier with Stage IIIA (N2) patients. The authors continue to recommend MVP as an induction chemotherapy regimen for clinical trials.
Although combination antiemetics prevent vomiting during the initial 24 h after high-dose (> or =100 mg/m2) cisplatin, many patients experience delayed emesis 24-120 h afterwards despite receiving prophylactic dexamethasone and metoclopramide during this time. Cisapride is a prokinetic agent, which stimulates propulsive motility throughout the gastrointestinal tract without causing extrapyramidal effects. In this phase II trial, we tested the ability of cisapride to prevent delayed emesis following cisplatin. Twenty patients receiving initial cisplatin >100 mg/m2 were entered. All patients received intravenous dexamethasone with either metoclopramide or ondansetron to prevent acute emesis 0-24 h after receiving cisplatin. Patients who had experienced two or fewer acute vomiting episodes then received cisapride 20 mg orally four times daily for 4 days (24-120 h after cisplatin). Cisapride prevented delayed emesis in 2 patients (10%) during the entire 4-day period (95% confidence interval, 1-32%). Abdominal cramping and pain occurred in 35%. At the dose and schedule tested, oral cisapride prevented delayed emesis in only 10% of patients receiving cisplatin >100 mg/m2 and caused abdominal cramping in 35%. Since in prior trials among similar patients, placebo prevented delayed emesis in 11%, further study of cisapride and dose escalation for this indication are not recommended.
BACKGROUND: The antifolate edatrexate and the microtubule-stabilizing agent paclitaxel have both demonstrated single-agent activity in lung and breast cancer. In vitro, the sequential combination of edatrexate followed by paclitaxel produced synergistic antitumor effects. This trial was designed to find the maximum tolerated doses of edatrexate and paclitaxel when given every two weeks utilizing this sequential schedule. PATIENTS AND METHODS: Thirty-four patients with solid tumors received edatrexate intravenously on days 1 and 15 and paclitaxel intravenously as a three-hour infusion on days 2 and 16 of each 28-day cycle. Edatrexate was escalated from 40 to 120 mg/m2 and the paclitaxel dose fixed at 135 mg/m2. When the maximum-tolerated dose was not reached, edatrexate was fixed at 120 mg/m2 and paclitaxel escalated to 175 and 210 mg/m2. RESULTS: All 34 patients were assessable. The maximum tolerated doses were 120 mg/m2 of edatrexate and 210 mg/m2 of paclitaxel. Grade 3 myalgia, peripheral neuropathy, leukopenia, and an infusion-related reaction occurred. Eight patients with non-small-cell lung cancer and one with bladder cancer achieved major objective responses. CONCLUSIONS: The recommended phase II doses are 120 mg/m2 of edatrexate days 1 and 15 and 175 mg/m2 of paclitaxel as a three-hour infusion days 2 and 16 of a 28 day cycle. These results warrant phase II trials of the combination leading to phase III studies comparing the two drugs to a single agent to confirm the preclinical evidence of synergy.
Despite active therapies for small cell lung cancer (SCLC), most patients relapse and die of the disease. The present study evaluates immunization using the anti-idiotypic antibody BEC2, which mimics the ganglioside GD3 expressed on the surface of most SCLC tumors, combined with Bacillus Calmette-Guérin (BCG) as an immune adjuvant. We hypothesized that active immunization could alter the natural history of the disease. Fifteen patients who had completed standard therapy for SCLC received a series of five intradermal immunizations consisting of 2.5 mg of BEC2 plus BCG over a 10-week period. Blood was collected for serological analysis, and outcome was monitored. All patients developed anti-BEC2 antibodies, despite having received chemotherapy with or without thoracic radiation. We detected anti-GD3 antibodies in five patients, including those with the longest relapse-free survival. The median relapse-free survival for patients with extensive stage disease is 11 months and has not been reached for patients with limited stage disease (>47 months), with only one of seven patients having relapsed after a median follow-up of 47 months. Immunization of patients with SCLC after standard therapy using BEC2 plus BCG can induce anti-GD3 antibodies and is safe. The survival and relapse-free survival in this group of patients are substantially better than those observed in a prior group of similar patients. A Phase III trial is being conducted to evaluate BEC2 plus BCG as adjuvant therapy after chemotherapy and irradiation.
Although small cell lung cancer (SCLC) is highly responsive to chemotherapy, relapses are common, and most patients die within 2 years of diagnosis. After initial therapy, standard treatment is observation alone. We have been investigating immunization against selected gangliosides as adjuvant therapy directed against residual and presumably resistant disease persisting after chemotherapy and irradiation. Previously, we reported that the presence of anti-GM2 ganglioside antibodies is associated with a prolonged disease-free survival in patients with melanoma, and that SCLC patients immunized with BEC2, an anti-idiotypic monoclonal antibody that mimics the ganglioside GD3, had a prolonged survival compared with historical controls. In the present trial, fucosyl-alpha1-2Galbeta1-3GalNAcbeta1-4(NeuAcalpha2-3) Galbeta1-4Glcbeta1-1Cer (Fuc-GM1), a ganglioside expressed on the SCLC cell surface, was selected as a target for active immunotherapy. Fuc-GM1 is present on most SCLCs but on few normal tissues. SCLC patients achieving a major response to initial therapy were vaccinated s.c. on weeks 1, 2, 3, 4, 8, and 16 with Fuc-GM1 (30 microg) conjugated to the carrier protein keyhole limpet hemocyanin and mixed with the adjuvant QS-21. Ten patients received at least five vaccinations and are evaluable for response. All patients demonstrated a serological response, with induction of both IgM and IgG antibodies against Fuc-GM1, despite prior treatment with chemotherapy with or without radiation. Posttreatment flow cytometry demonstrated binding of antibodies from patients' sera to tumor cells expressing Fuc-GM1. In the majority of cases, sera were also capable of complement-mediated cytotoxicity. Mild transient erythema and induration at injection sites were the only consistent toxicities. The Fuc-GM1-KLH + QS-21 vaccine is safe and immunogenic in patients with SCLC. Continued study of this and other ganglioside vaccines is ongoing.
In the last 25 years, treatment for small cell lung cancer (SCLC) has improved with advances in chemotherapy and radiotherapy. Standard chemotherapy regimens can yield 80% to 90% response rates and some cures when combined with thoracic irradiation in limited-stage patients. Nonetheless, small cell lung cancer has a high relapse rate due to drug resistance; this has resulted in poor survival for most patients. Attacking this problem requires a unique approach to eliminate resistant disease remaining after induction therapy. This review will focus on three potential strategies: high-dose chemotherapy with autologous bone marrow transplantation, matrix metalloproteinase inhibitors, and BEC2 plus BCG vaccination.
Topotecan (9-dimethylaminoethyl-10-hydroxycamptothecin) is a topoisomerase I inhibitor. Twenty-six patients with stage IIIB or IV non-small-cell lung cancer (NSCLC) who had received no prior chemotherapy were treated in a multicenter study with topotecan 0.6 mg/m2/day for 21 days by continuous intravenous infusion every 28 days; this starting dose was decreased to 0.5 mg/m2/day in the last 23 patients because of myelosuppression. There was one partial response, for a response rate of 4% (95% confidence interval, 0.1%-19.6%). Median survival was 9 months. One-year survival was 39%. Of the 58 lung cancer symptoms at baseline, 40% were resolved by the end of best response (all in the partial response patient, 62% in stable disease patients, 26% in progressive disease patients). Catheter-related infections complicated 19% of courses. Red-cell transfusions were given in 50% of courses. Toxicity included grade 4 neutropenia (4%), grade 3-4 anemia (19%), grade 4 thrombocytopenia (8%), and catheter-related infections (19% courses). Although the major objective response rate was only 4%, patients treated with topotecan given as a 21-day continuous intravenous infusion experienced a decrease in cancer-related symptoms and a 1-year survival of 39%.
Users immersed in virtual environments (VEs) are prone to disorientation and have difficulty transferring spatial knowledge to the real world. A single experiment investigated the contribution of inadequate proprioception to this problem by providing participants with interfaces to a virtual environment that either did (a walking interface) or did not (a joystick) afford proprioceptive feedback similar to that obtained during real walking. The 2 groups explored a large, complex building using a low-resolution head-mounted display. Later, their navigational abilities within the actual building were compared with those of control groups who either studied a map of the building, walked through the real building, or received no prior training. The walking interface conveyed no benefit on an orientation task performed during training in the VE, but it did benefit participants when they tried to find objects in the real world. Actual or potential applications include simulations of environments that are normally explored on foot but cannot be readily visited, such as infantry battlefields and facilities contaminated with chemical, biological, or radiological materials.
BACKGROUND: An increased risk of second primary cancers has been reported in patients who survive small-cell carcinoma of the lung. The treatment's contribution to the development of second cancers is difficult to assess, in part because the number of long-term survivors seen at any one institution is small. We designed a multi-institution study to investigate the risk among survivors of developing second primary cancers other than small-cell lung carcinoma. METHODS: Demographic, smoking, and treatment information were obtained from the medical records of 611 patients who had been cancer free for more than 2 years after therapy for histologically proven small-cell lung cancer, and person-years of follow-up were cumulated. Population-based rates of cancer incidence and mortality were used to estimate the expected number of cancers or deaths. The actuarial risk of second cancers was estimated by the Kaplan-Meier method. RESULTS: Relative to the general population, the risk of all second cancers among these patients (mostly non-small-cell cancers of the lung) was increased 3.5-fold. Second lung cancer risk was increased 13-fold among those who received chest irradiation in comparison to a sevenfold increase among nonirradiated patients. It was higher in those who continued smoking, with evidence of an interaction between chest irradiation and continued smoking (relative risk = 21). Patients treated with various forms of combination chemotherapy had comparable increases in risk (9.4- to 13-fold, overall), except for a 19-fold risk increase among those treated with alkylating agents who continued smoking. IMPLICATIONS: Because of their substantially increased risk, survivors should stop smoking and may consider entering trials of secondary chemoprevention.
BACKGROUND: Allograft rejection is mediated by cytokines. As polymorphism in cytokine genes can result in interindividual differences in cytokine production, we hypothesize that some patients may have an increased risk of rejection. METHODS: We have related polymorphisms that influence cytokine production in the tumor necrosis factor (TNF)-A and interleukin (IL)-10 genes to early graft rejection in 115 heart transplant recipients. RESULTS: Certain combinations of TNF-A and IL-10 gene polymorphisms are associated with rejection. Five of 19 patients who had high levels of rejection typed as high TNF-alpha/low IL-10 producers compared with 4 of 96 patients with lower levels of rejection (P<0.005). CONCLUSIONS: We have identified a particular cytokine genotype that may confer susceptibility to increased levels of early rejection. Patients with a worse prognosis may be able to be identified pretransplant by DNA analysis of TNF-A, IL-10, and other gene polymorphisms.
PURPOSE: Chloroquinoxaline sulfonamide (CQS) was one of the first agents identified by the human tumor colony-forming assay (HTCFA) as possessing antitumor activity in non-small-cell lung cancer (NSCLC). Prior phase I studies had suggested that plasma concentrations equivalent to those showing efficacy in the HTCFA could be reliably attained in humans. This phase II study assessed the antitumor activity of CQS while using an adaptive control pharmacokinetic modelling system to attain targeted plasma levels of this novel compound. METHODS: A group of 20 patients with stage III or IV NSCLC received CQS as a 1-h weekly infusion at an initial dose of 2 g/m2. In all patients, 24-h plasma concentrations of CQS were measured. Patients with levels < 100 micrograms/ml had dose increases determined by their 24-h levels and pharmacokinetic parameters obtained from two prior phase I trials of this agent. These individuals had 24-h CQS levels repeated after their second weeks' treatment and doses were readjusted if the target concentration was not reached. Antitumor response assessment was made every 6 weeks. RESULTS: Of the 20 patients, 18 attained the target plasma concentration, and 16 of these achieved this initially or with just one dose adjustment. No major objective antitumor responses were observed (major response rate 0%, 95% CI 0-17%). CQS was well tolerated with hypoglycemia being the most clinically significant toxicity. CONCLUSIONS: When given on this schedule CQS is inactive in NSCLC despite the fact that the target concentration was achieved in 90% of patients. The ability of the HTCFA to identify active agents remains unproved.
PURPOSE: Tirapazamine is a bioreductive compound synergistic with cisplatin in preclinical testing. This phase II study was conducted to evaluate the efficacy and toxicity of tirapazamine with cisplatin in patients with advanced non-small-cell lung cancer. PATIENTS AND METHODS: Twenty patients with unresectable stage III-B and IV non-small-cell lung cancer who had not received prior chemotherapy were given tirapazamine (390 mg/m2) intravenously (i.v.) over two hours followed one hour later by cisplatin (75 mg/m2) i.v. over one hour every 21 days. RESULTS: Five of 20 patients (25%) had major objective responses (95% confidence interval, 11%-50%). Median duration of response was eight months with a one-year survival of 40%. Toxicities included temporary hearing loss (25%), muscle cramping, diarrhea, skin rash and nausea/vomiting. No grade 3 or 4 hematologic or renal toxicity was observed. CONCLUSIONS: The combination of tirapazamine plus cisplatin appears to be safe and active in the treatment of advanced non-small lung cancer without a substantial increase in toxicity compared to cisplatin alone. A phase III randomized study compared the combination to cisplatin alone has completed accrual. Further evaluation of tirapazamine with other active agents and in multi-modality therapy is warranted.