Biomedical subjects

E Reed

Publications and source records attributed to E Reed.

260 records · Page 15Linked to original sources

PubMedDate not supplied

Proteasome inhibition suppresses cisplatin-dependent ERCC-1 mRNA expression in human ovarian tumor cells.

One of the major problems with ovarian cancer treatment is the clinical development of resistance to cisplatin. Considerable efforts have been directed toward the identification of biological and pharmacological agents that would reverse drug resistance to cisplatin. ALLnL is an inhibitor of the proteasome that can inhibit the ubiquitin-proteasome pathway, which plays an essential role in many processes in cell life. We have recently shown that ALLnL, at concentrations that do not appear harmful, has significantly enhanced DNA platination and decreased DNA repair of cisplatin-DNA adducts in human A2780/CP70 ovarian carcinoma cells. These activities of proteasome inhibition were also associated with substantially increased cisplatin toxicity in these cells. In this communication, we demonstrate that treatment of A2780/CP70 cells with ALLnL blocks cisplatin-induced ERCC-1 mRNA expression in a concentration- and time-dependent manner, as measured by Northern blot analysis. In addition, we showed that the cisplatin-dependent increase in steady-state levels of ERCC-1 mRNA was prevented by pretreatment with lactacystin, a potent and specific inhibitor of proteasome. These results suggest that the effect of proteasome inhibition on cisplatin cytotoxicity, DNA platination, and DNA repair of cisplatin adducts in ovarian cancer cells may be through down-regulating ERCC-1 expression.

Acetylcysteine↗

PubMedDate not supplied

Vascular (humoral) rejection in human cardiac allograft biopsies: relation to circulating anti-HLA antibodies.

Vascular or humoral rejection (as defined by linear deposits of immunoglobulin and complement in myocardial capillaries) and the presence of circulating lymphocytotoxic anti-HLA antibodies are each associated with reduced long-term graft or patient survival. The relationship between these two factors has not been determined. We used immunofluorescent techniques to study 46 cardiac biopsy specimens in 16 patients from 15 to 412 days after transplantation. Biopsy specimens were selected from the first 2 months, and at approximately 6 and 12 months after transplantation and did not include episodes of acute cellular rejection. Each specimen studied was compared to a serum sample drawn an average of 1.8 days (range, 0 to 9 days) from the time of biopsy to assay for circulating anti-HLA antibodies. Of the specimens obtained at or near a positive anti-HLA antibody test, 90% (27 of 30) were found to have linear deposits of immunoglobulin (not necessarily with complement) versus 75% (12 of 16) of specimens obtained at the time of a negative test. Twenty-one cases of vascular rejection were documented. Both immunoglobulin M and immunoglobulin G were deposited along with complement in 13 instances; immunoglobulin M and complement were deposited in eight cases; no case had only immunoglobulin G and complement. The presence of circulating anti-HLA antibody in the serum was associated with 14 of the 21 cases of vascular rejection. Linear deposits of immunoglobulin in the capillaries of myocardium were frequently observed when anti-HLA antibodies were present in the serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Relationship between patient response in ovarian and breast cancer and platinum drug-DNA adduct formation.

Nucleated blood cell DNA samples from ovarian (n = 27) and breast (n = 25) cancer patients receiving either cis-diamminedichloroplatinum II (cisplatin) and/or diamminecyclobutanecarboxylatoplatinum II were examined for the presence of platinum drug bound to DNA during several cycles of therapy. Platinum-DNA adducts were quantitated by cisplatin-DNA enzyme-linked immunosorbent assay (ELISA) and atomic absorbance spectroscopy, techniques that measure either a fraction of the intrastrand cis-diammineplatinum-d(ApG) and -d(GpG) adducts (ELISA) or the total platinum bound to DNA (atomic absorbance spectroscopy), respectively. For either the complete study, or for samples obtained during the early cycles, individuals with progressive disease had severalfold lower overall cisplatin-DNA ELISA-measurable adduct levels than the individuals with more favorable clinical responses (complete response, partial response, or stable disease), who were grouped together and termed nonprogressive disease. In the case of the ovarian cancer patients, who experienced a 59% rate of complete and partial response, the correlation of high adduct values with disease response was statistically significant by the Wilcoxon rank-sum test (P = 0.028). In contrast, the breast cancer patients achieved only an 11.5% rate of complete and partial response, and the correlation of high adduct formation with disease response was not statistically significant. Levels of total DNA-bound platinum, measured by atomic absorbance spectroscopy, showed no correlation with disease response for either cancer by any analysis. The study supports previous observations demonstrating a consistent correlation between high cisplatin-DNA ELISA measurements and positive clinical outcome in ovarian cancer patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Assay↗

PubMedDate not supplied

The pharmacokinetics of TNP-470, a new angiogenesis inhibitor.

STUDY OBJECTIVE: To characterize the pharmacokinetic profile of TNP-470, a synthetic analog of fumagillin that is a potent inhibitor of angiogenesis and inhibits neovascularization in several solid tumor models. DESIGN: A dose-escalation phase I clinical trial. SETTING: The National Institutes of Health. PATIENTS: Patients with human immunodeficiency virus-associated Kaposi's sarcoma. INTERVENTIONS: The TNP-470 dosage was increased in 13 sequential cohorts using a modified Fibonacci escalation scheme (4.6, 9.3, 15.4, 23.2, and 43.1 mg/m2). The drug was administered as a 1-hour intravenous infusion. Serial blood samples were collected and assayed by reverse-phase high-performance liquid chromatography and the pharmacokinetics were characterized. MEASUREMENTS AND MAIN RESULTS: There was a linear relationship between the dose of TNP-470 and both area under the curve to infinity (AUC[inf]) and time to maximum concentration (Cmax). The Cmax ranged between 6.6 ng/ml at the lowest dosage (4.6 mg/m2) and 597.1 ng/ml at the highest dosage (43.1 mg/m2). The agent was rapidly cleared from the circulation with a short terminal half-life (0.88 +/- 2.5 hr), which is consistent with preclinical data. Peak plasma concentrations of AGM-1883, an active metabolite, ranged between 0.4 and 158.1 ng/ml. CONCLUSION: Concentrations of TNP-470 that have in vitro activity were achievable in vivo. The drug was rapidly cleared from the circulation after a single 1-hour infusion. There was considerable interpatient variability in the clearance, but no evidence of saturable elimination. If more prolonged exposure is necessary for activity, administration of TNP-470 by continuous infusion may be suitable.

Adult↗

PubMedDate not supplied

Continuous hyperthermic peritoneal perfusion with cisplatin for the treatment of peritoneal mesothelioma.

PURPOSE: Peritoneal mesothelioma remains a difficult therapeutic challenge. Aggressive debulking combined with continuous hyperthermic peritoneal perfusion (CHPP) using cisplatin (CDDP) is a novel strategy for the treatment of peritoneal mesothelioma, allowing high regional delivery of chemotherapeutics and hyperthermia while minimizing systemic toxicity. PATIENTS AND METHODS: From June 1993 to May 1996, 10 patients with peritoneal mesothelioma (six men, four women; mean age 40 years, range 15-57) underwent tumor debulking followed by a 90-minute CHPP. CHPP parameters included mean initial CDDP of 120 micrograms/mL (range 81-166), perfusate volume 5.2 L (range 4-7), flow 1.5 L/min, intraperitoneal temperature at three locations-41.5 degrees C, 40.5 degrees C, 41.1 degrees C, and core temperature 38.4 degrees C (range 37.2 degrees C-39.5 degrees C). Nine of 10 patients had malignant peritoneal mesothelioma, eight with associated ascites, while the tenth had a symptomatic, multiply recurrent benign peritoneal mesothelioma. Nine of 10 patients were optimally debulked. Pharmacokinetics were performed on blood and perfusate samples on nine patients; CDDP levels were quantitated by atomic absorption spectroscopy. RESULTS: Total perfusate cisplatin AUC was a mean of 21-fold higher (range 2- to 116-fold) than total serum cisplatin AUC, and serum CDDP behaved similarly to systemically administered CDDP. Median follow-up after CHPP is 10 months (range 2-32), with no treatment-related mortality. In eight optimally debulked patients there is no evidence of recurrent disease clinically or by CT or MRI. Seven patients with symptomatic ascites have been completely palliated. CONCLUSIONS: CHPP with CDDP is well tolerated with no significant regional toxicity. Because favorable CDDP pharmacokinetics suggest the potential for enhanced CDDP tumoricidal effect during CHPP, tumor debulking and CHPP may represent an effective strategy for the treatment of peritoneal mesothelioma.

Adolescent↗

PubMedDate not supplied

Peripheral blood progenitor cells: enabling outpatient transplantation.

Peripheral blood progenitor cells (PBPCs) are becoming the stem cell source of choice for rescuing patients from marrow aplasia after high-dose chemotherapy. Their advantages over bone marrow include avoidance of general anesthesia and more rapid hematologic recovery after transplantation. More rapid engraftment can reduce the risks associated with transplantation and shorten the hospital stay or, under certain circumstances, eliminate it. The cost reductions associated with a shorter stay have made PBPC transplantation cost-competitive with more conventional therapy. The move to outpatient transplantation requires increased patient and family involvement with posttransplantation care, as well as increased patient education and a multidisciplinary care team for the safe transition of patients between care sites. Improvements in outpatient transplantation may incorporate a cooperative care model with the intent of reducing readmission rates and extending this modality to most patients who undergo autologous transplantation.

Ambulatory Care↗

PubMedDate not supplied

Effect of interleukin-1 alpha and tumour necrosis factor-alpha on cisplatin-induced ERCC-1 mRNA expression in a human ovarian carcinoma cell line.

Enhanced expression of the human excision repair enzyme ERCC-1 is associated with cellular and clinical resistance to cisplatin in human ovarian cancer. High levels of expression of ERCC-1 appear to be associated with increased activity of the nucleotide excision repair pathway. We therefore began to examine the effect of some cisplatin resistance modulators on cisplatin-induced ERCC-1 mRNA expression in the human ovarian carcinoma cell line, A2780/CP70. Cisplatin exposure to A2780/CP70 cells in culture resulted in a four- to five-fold induction for steady-state ERCC-1 mRNA, that was dose- and time-dependent. The biological agents interleukin (IL)-1 alpha and tumour necrosis factor (TNF)-alpha have been shown to enhance cisplatin cytotoxicity in vitro. IL-1 alpha inhibited cisplatin induction of ERCC-1 mRNA levels in our system. The effect of IL-1 alpha was sequence dependent, in that the maximum inhibitory effect was observed with 24-hour pretreatment with IL-1 alpha. By contrast, TNF-alpha had little effect on ERCC-1 mRNA induction by cisplatin. Low-temperature hyperthermia (42 degrees C) almost completely suppressed ERCC-1 mRNA induction in these cells. These findings suggest that the enhancement effect of some agents on cisplatin sensitivity in ovarian tumour cells may be through downregulating ERCC-1 expression.

Cisplatin↗

PubMedDate not supplied

The measurement of cadmium in biological materials, using graphite furnace atomic absorption spectrometry with Zeeman background correction.

Cadmium (Cd), a toxic heavy metal and probable carcinogen in humans, appears to have potential anti-cancer activity in pre-clinical systems. This observation led us to develop a method for measuring cellular Cd and DNA-bound Cd following micromolar exposures to cadmium dichloride. Cultured human ovarian cancer cell lines were used. Following low level exposures to cadmium dichloride (CdCl2), atomic absorption spectrometry with Zeeman background correction was used to measure total cell associated Cd in wet-ashed cells, and the lower limits of detection was at 100 pg of Cd per 106 cells. In cellular DNA isolated by cesium chloride density gradient centrifugation, levels of 1.5 Cd lesions (Cd molecules) per 106 nucleotides were reproducibly detected. Standard curves with samples yielded 76.4 6.7% recovery when using picogram quantities of Cd. Manipulation of the total amount of biological material used, can further improve detection limits. Thus, this method is suitable for the detection of Cd in biological matrixes after low levels of Cd exposure, and shows good performance in terms of the level of sensitivity and reproducibility.

Cadmium↗