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Biomedical subjects

S C Grant

Publications and source records attributed to S C Grant.

At least 37 records · Page 2Linked to original sources
PubMed1998

Contributions of proprioception to navigation in virtual environments.

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.

Adolescent↗
PubMed1997

Second primary cancers related to smoking and treatment of small-cell lung cancer. Lung Cancer Working Cadre.

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.

Actuarial Analysis↗
PubMed1997

Cytokine gene polymorphism and heart transplant rejection.

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.

Cytokines↗
PubMed1997

Phase II trial of chloroquinoxaline sulfonamide (CQS) in patients with stage III and IV non-small-cell lung cancer.

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.

Adult↗
PubMed1997

Phase II study of the combination of the novel bioreductive agent, tirapazamine, with cisplatin in patients with advanced non-small-cell lung cancer.

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.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Expression of cytokine messenger RNA after heart transplantation: relationship with rejection and serum cytokines.

Different groups of cytokines may initiate or inhibit the rejection process. We used the polymerase chain reaction to study the expression of cytokine mRNA for interleukin (IL)-2, -4, -6 and -10, tumor necrosis factor-alpha, and interferon-gamma in 187 biopsy specimens from 24 human cardiac transplant recipients 5-555 days after transplantation. Cytokine levels in the serum were also measured. Cytokine mRNA was detected in 38.5% of biopsy specimens. IL-10 mRNA was detected more frequently with mild or absent rejection (11.6% in grades 0 and 1 - vs. 1.4% in grades 2 and 3, P=0.01). Up to 90 days after transplantation, IL-2 mRNA was detected more frequently with moderate rejection (13% in grades 2 and 3 vs. 0% in grades 0 and 1, P=0.076), and IL-4 mRNA was detected more frequently with mild or absent rejection (16% in grades 0 and 1 - vs. 0% in grades 2 and 3, P=0.061). More than 90 days after transplantation, IL-2 mRNA was detected more frequently with mild or absent rejection (10% in grades 0 and 1 vs. 0% in grades 2 and 3, P=0.078). Serum IL-4 levels corresponding to biopsy specimens positive for IL-4 mRNA were higher than those corresponding to specimens negative for IL-4 mRNA (59 pg/ml vs. 32 pg/ml medians, P=0.028). Our results suggest that IL-10 and possibly IL-4 (T helper 2 cytokines) may suppress graft rejection, whereas IL-2 (T helper 1 cytokine) may promote cellular rejection. In addition, cytokine profiles may change with length of time after transplantation. The association of elevated serum levels of IL-4 with increased expression of intragraft IL-4 mRNA may suggest release of this cytokine from the graft into the circulation.

Adolescent↗
PubMed1996

Serum cytokines in human heart transplant recipients. Is there a relationship to rejection?

Cytokines are important in the pathogenesis of allograft rejection. Some studies have suggested a positive relationship between serum levels of cytokines and rejection, so this study was designed to investigate the presence of a range of cytokines in a large cohort of cardiac transplant recipients. We used enzyme linked immunosorbent assays (ELISA) to examine sequential serum samples from 28 consecutive heart transplant recipients; length of follow up varied between 2 and 566 days (median 357 days). Serum levels of IL-2, 4, 6, 10, TNF-alpha, and IFN-gamma were measured. We compared these results with detailed data on patients' clinical courses, including histological rejection, infection, and therapeutic use of antithymocyte globulin (ATG). No significant relationship was found between rejection and serum cytokine levels for samples taken more than 30 days after transplantation. Prior to this cytokine levels were significantly disturbed by the use of cytolytic therapy for induction immunosuppression. Serum cytokine levels sometimes showed peaks that appeared to be related to rejection, or occasionally to infection, but these relationships were not consistent. Serum TNF-alpha and IL-6 were consistently elevated within a few days of administration of ATG. We conclude that there is no systematic relationship between serum cytokine levels and histological rejection or infection in cardiac transplant recipients.

Adolescent↗
PubMed1996

Targeting of small-cell lung cancer using the anti-GD2 ganglioside monoclonal antibody 3F8: a pilot trial.

The present study evaluated the ability of the anti-GD2 ganglioside monoclonal antibody 3F8 to target tumor sites in patients with small-cell lung cancer (SCLC). Of 12 patients entered into the trial, ten received intravenous 3F8 labeled with 2 or 10 mCi iodine-131. The first five patients had recurrent or progressive disease after chemotherapy. Subsequent patients were studied before starting chemotherapy. Radionuclide scans were performed on days 1, 2, and 3 post-infusion and once between day 5 and day 7. Four patients underwent single-photon emission tomography (SPET) imaging. Radionuclide scans demonstrated localization to all known sites of disease, other than small brain metastases in one patient. SPET/CT scan fusion images confirmed precise localization. No significant toxicity was observed. Mean serum half-life was 64.2 h. Analysis of specimens from one patient who died of unrelated causes 6 days post-infusion confirmed the scan results. The present study demonstrates that 3F8 targets SCLC sites in patients. Further studies of anti-GD2 antibodies with higher doses of antibody and radionuclide are warranted to evaluate their role in SCLC.

Carcinoma, Small Cell↗
PubMed1996

High-dose edatrexate with oral leucovorin rescue: a phase I and clinical pharmacological study in adults with advanced cancer.

Our objective was to determine the maximum tolerated dose and toxicity of i.v. edatrexate with p.o. leucovorin. Thirty-one adults with advanced solid tumors received edatrexate as a 2-h infusion, once a week for 3 weeks, recycled every 28 days. p.o. leucovorin (10 mg/m2, every 6 h for 10 doses) began 24 h later. All had urinary alkalinization and p.o. hydration. Nine dosage levels ranging from 120 to 3750 mg/m2 were explored. Fatigue, epistaxis, nausea/emesis, mucositis, rash, myalgias, leukopenia, thrombocytopenia, and transient elevations of serum aspartate transferase were observed. Leukoencephalopathy with clinical manifestations occurred in two patients (one had prior cranial irradiation). Pharmacokinetic studies carried out at the 120- and 1080-mg/m2 dose levels revealed no significant difference in the elimination half-life at the two dose levels studied and no significant intrapatient variability between day 1 and day 8 edatrexate administration. Serum edatrexate levels measured using a dihydrofolate reductase inhibition assay correlated with those by high-performance liquid chromatography. Three major and two minor antitumor responses occurred. The maximum tolerated dose was 3750 mg/m2, with grade 3 or 4 leukopenia (one patient), stomatitis (one patient), and leukoencephalopathy (one patient). Because of the occurrence of leukoencephalopathy, further study of high-dose edatrexate with leucovorin rescue is not recommended.

Administration, Oral↗
PubMed1995

A genetic marker of high TNF-alpha production in heart transplant recipients.

The cytokine TNF-alpha has been implicated in the pathogenesis of both acute and chronic transplant rejection. Levels of the cytokine are known to vary in a normal population, leading to speculation that high responders may be at greater risk of rejection. Particular TNF region polymorphic markers have been associated with increased TNF-alpha levels and a biallelic polymorphism has been identified at position -308 of the TNF-alpha promoter that may contribute significantly to the interindividual variation in healthy persons. We describe here a new association between a polymorphic locus in the TNF gene region and increased production of TNF-alpha in heart transplant recipients. We studied two microsatellite markers that flank the TNFA gene, as well as a biallelic polymorphism at position -308 of the TNFA promoter, and found that the microsatellite allele TNFd3 was significantly associated with the capacity of leukocytes to produce TNF-alpha in vitro. No association was demonstrated for the promoter region polymorphism. Patients were receiving cyclosporine (CsA) and prednisolone (pred) at the time of sampling, which are known to interrupt 5' regulation of TNFA transcription in T cells and macrophages and may therefore negate the influence of the -308 polymorphism. Because of this we suggest that TNFd3 may be a marker for a 3' repressor region polymorphism that is of importance in immunosuppressed individuals.

Alleles↗
PubMed1995

Antithymocyte globulin preparations after heart transplantation. Cytokine responses in vivo and in vitro.

It is accepted that antithymocyte globulin (ATG) preparations vary in their bioactivity and side effects. However, this is poorly documented in the literature. We compared the clinical course and cytokine response of heart transplant patients who had received either Merieux or Stanford ATG preparations. The serum cytokine response (interleukin [IL]-6, tumor necrosis factor [TNF]-alpha, IL-4, and IL-10) of 28 consecutive heart transplant recipients was measured for 14 days after surgery using ELISAs. The effect of various ATG preparations on cytokine stimulation of whole blood in vitro was also evaluated. There was a much greater in vivo IL-6 and TNF-alpha response to Merieux than to Stanford ATG (P < 0.0005). There was little IL-4 or IL-10 response with either preparation. No side effects could be attributed to either treatment. No significant difference was seen in the frequency of rejection at 30, 90, or 365 days. More infection episodes occurred in the group treated with Stanford ATG at 30 days (0.5 compared with 0.2 episodes/patient; P = 0.097), 90 days (1.2 compared with 0.5 episodes/patient; P = 0.17), and 365 days (2.8 compared with 1.8; P = 0.59), although none of these differences were statistically significant. When tested in vitro for cytokine stimulation, the in vivo pattern was confirmed, with Merieux ATG producing greater levels of TNF-alpha and IL-6 than Stanford ATG. The differences in cytokine stimulation may be reflected in different immunosuppressive activities. Further research to elucidate the important components of immunosuppressive activity while excluding potentially detrimental effects is important.

Adolescent↗
PubMed1995

Phase II trial of a 75-mg/m2 dose of docetaxel with prednisone premedication for patients with advanced non-small cell lung cancer.

BACKGROUND: A prior Phase II study of a 100-mg/m2 dose of docetaxel conducted at the Memorial Sloan-Kettering Cancer Center (New York, NY) demonstrated a 38% response rate with grade 3 or 4 neutropenia in 76% of the patients and a grade 2 or greater rash or infusion-related reaction in 41% and 34% of the patients, respectively. The current Phase II study sought to determine the activity of a 75-mg/m2 dose of docetaxel to establish whether this lower dose, combined with prednisone, ameliorates toxicity. METHODS: Twenty untreated patients with advanced non-small cell lung cancer (NSCLC) received a 1-hour 75-mg/m2 dose of docetaxel every 21 days. Fifty milligrams of prednisone were administered twice the day before chemotherapy and once each of the next 3 days. Patients' disease-related symptoms were assessed prospectively using the Lung Cancer Symptom Scale (LCSS). RESULTS: All patients were assessable for response and toxicity. Five patients had a major objective response (25%; 95% confidence interval, 11-50%). The median duration of response was 9.1 months. The projected 1-year survival was 71%. Grade 3 or 4 neutropenia occurred in 70% of the patients. Grade 2 or greater rash and infusion-related reactions decreased to 25% each. Analysis of the LCSS measurements found that six of nine component symptoms improved on Day 22, and all improved when baseline measurements were compared with the best value for each patient during the study. CONCLUSIONS: Docetaxel administered at a dose of 75 mg/m2 every 21 days shows significant antitumor activity in untreated patients with NSCLC: Neutropenia is comparable with that observed at a 100-mg/m2 dose. The number of infusional reactions and rash decreased when docetaxel at this dose was administered with prednisone. Based on response rates observed in trials using a 100-mg/m2 dose with similar degrees of neutropenia, a 100-mg/m2 dose with steroid pretreatment is recommended future trials.

Adult↗
PubMed1995

Effectiveness and toxicity of preoperative therapy in stage IIIA non-small cell lung cancer including the Memorial Sloan-Kettering experience with induction MVP in patients with bulky mediastinal lymph node metastases (Clinical N2).

The use of preoperative chemotherapy with mitomycin, vinblastine and cisplatin (MVP) has led to improved complete resection rates and survival in Stage IIIA non-small cell lung cancer with bulky, ipsilateral, mediastinal lymph node metastases (Clinical N2 disease). The addition of preoperative irradiation has also been explored with results not substantially different from preoperative cisplatin-based chemotherapy alone. While preoperative chemotherapy has been shown to be feasible, the toxicity of both the chemotherapy and the subsequent resection is of concern with an overall treatment-related mortality of nearly 8%. The careful selection of patients, swift management of neutropenia, and meticulous perioperative pulmonary care has the potential to reduce the mortality from multimodality therapy. Having shown survival benefit in multiple single-institution and randomized trials, induction chemotherapy followed by surgery or irradiation is now the treatment of choice for patients with Stage IIIA non-small cell lung cancer with mediastinal lymph node metastases.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Paclitaxel (Taxol) and docetaxel (Taxotere): active chemotherapeutic agents in lung cancer.

Paclitaxel (Taxol), the prototype of a new class of plant-derived antineoplastic compounds, is a natural product isolated from the Pacific yew. Docetaxel (Taxotere) is a hemisynthetic product derived from the European yew. These agents share a unique mechanism of cytotoxic action by promoting assembly of microtubules and rendering the microtubules resistant to depolymerization. In vitro studies suggest a possible role for radiation sensitization. In Phase I trials, the dose-limiting toxicity was neutropenia for both agents. Other toxicities include infusion-related hypersensitivity reactions, alopecia, neurotoxicity, mucositis, diarrhoea and myalgias. To prevent infusion-related reactions, routine premedication is recommended. Noncumulative cardiac toxicity has been observed with paclitaxel. Fluid retention and rash have been reported with docetaxel. In Phase II studies of paclitaxel in advanced non-small cell lung cancer, response rates of 21% and 24% were observed. In Phase II studies of docetaxel in similar patients, response rates ranging from 28-38% were reported, including patients previously treated with cisplatin. The most common toxicity in these studies was neutropenia. Combination studies with cisplatin and other agents are in progress. Paclitaxel and docetaxel are among the most active chemotherapeutic agents for non-small cell lung cancer patients. Their testing will dominate trials of new therapies in this disease for years to come.

Antineoplastic Agents, Phytogenic↗
PubMed1995

Ifosfamide plus high-dose cisplatin in patients with non-small cell lung cancer previously treated with chemotherapy.

This study determined the maximum tolerated dose (MTD) of ifosfamide that could be given with high-dose cisplatin to non-small cell lung cancer (NSCLC) patients previously treated with non-platin-containing chemotherapy and to assess the efficacy of this combination. Twenty-three patients with inoperable NSCLC treated with one prior chemotherapy regimen received continuous infusion ifosfamide 1.2 g/m2 per day with MESNA for 5 days every 35 days and cisplatin 120 mg/m2. After one patient who received cisplatin as a single dose developed grade 4 nephrotoxicity and myelosuppression, cisplatin was given in four divided doses (30 mg/m2 per day) and the ifosfamide dose was lowered to 1.0 g/m2 per day, infused over 4 days. Dose-limiting grades 3 and 4 leukopenia was seen in 43%. A major objective response rate of 9% was observed. The 1-year survival was 30%, with a median survival of 6.4 months. The MTD of ifosfamide administered with cisplatin (30 mg/m2 per day for 4 consecutive days) to this population of patients is 1.0 g/m2 daily for 4 days. This combination produced limited anticancer activity and significant toxicity. Excessive toxicity was observed when cisplatin was given as a single dose with ifosfamide, and this schedule should not be used.

Antineoplastic Combined Chemotherapy Protocols↗