Synthetic and naturally occurring COX-2 inhibitors suppress proliferation in a human oesophageal adenocarcinoma cell line (OE33) by inducing apoptosis and cell cycle arrest

Epidemiological studies suggest that the use of NSAIDs and/or a high intake of fruit and vegetables reduce the risk of oesophageal adenocarcinoma. Since COX-2 is up-regulated in Barrett's oesophageal carcinogenesis, the protective effect of NSAIDs and natural food components might reflect COX-2 inhibition. We explored the effects of quercetin, a natural flavonoid with a potent COX-2 inhibitory activity, and two commercially available selective COX-2 inhibitors (NS-398 and nimesulide) on cell proliferation, apoptosis, PGE2 production and COX-2 mRNA expression in a human oesophageal adenocarcinoma cell line (OE33). Changes in the relative numbers of adherent and floating cells were quantified and apoptotic cells were identified using ethidium bromide and acridine orange staining under fluorescence microscopy. Flow cytometric analysis of adherent and floating cells was used to quantify apoptosis and to examine the effects of the agents on the cell cycle. After 48 h exposure at concentrations of > or =1 microM both COX-2 inhibitors and quercetin suppressed cell proliferation (P < 0.01) and increased the fraction of floating apoptotic cells. At higher concentrations (50 microM) and longer exposure (48 h) the effects of quercetin were significantly greater than those of the selective COX-2 inhibitors (P < 0.01). Cell cycle analyses showed that quercetin blocked cells in S phase, while the selective COX-2 inhibitors blocked cells in G1/S interphase. COX-2 mRNA expression was suppressed by quercetin and the synthetic COX-2 inhibitors in a time- and dose-dependent manner. Quercetin and the synthetic COX-2 inhibitors (10 microM) suppressed PGE2 production by approximately 70% after 24 h exposure (P < 0.001). We conclude that OE33 is a useful model for the study of COX-2 expression and associated phenomena in human adenocarcinoma cells. Synthetic COX-2 inhibitors and the food-borne flavonoid quercetin suppress proliferation, induce apoptosis and cell cycle block in human oesophageal adenocarcinoma cells in vitro, and future studies should assess their effects in vivo.     

Phase I study of Doxil and vinorelbine in patients with advanced malignancies

Introduction. This study was designed to define the maximum tolerated dose of pegylated liposomal doxorubicin (Doxil®) and multiday vinorelbine (VNB), without and with prophylactic filgrastim, and to identify antineoplastic effect. Patients and Methods: Patients with resistant cancers were treated with Doxil 50 mg/m² every four weeks, and with VNB 15 mg/m² on the same day. The VNB dose escalations were accomplished in subsequent patient cohorts by adding VNB doses on consecutive days. When the maximum tolerated dose (MTD) of VNB with Doxil was defined, prophylactic filgrastim was added to define a second MTD. Results. Of 29 patients entered, two had early adverse events, and 27 received at least one full cycle with at least one month follow-up. The MTD of VNB, combined with Doxil 50 mg/m², was 15 mg/m² on day 1, with neutropenia as the dose-limiting toxicity. With prophylactic filgrastim, the MTD was15 mg/m² daily for two days, with neutropenia and stomatitis as dose-limiting toxicities. Palmar plantar erythrodysesthesia occurred frequently, usually after the third cycle. Objective responses were documented in six patients, all of whom received multiday VNB. Conclusion. Doxil 50 mg/m² on day 1 of a 28-day cycle can be safely combined with VNB 15 mg/m2 day 1, or with VNB 15 mg/m² days 1 and 2 with filgrastim prophylaxis. Antineoplastic activity was observed in this heavily pretreated population. Future studies of Doxil 35-40 mg/m² with multiday VNB may be worthwhile, especially in metastatic breast cancer.     

Supramolecular Behavior of the Amphiphilic Drug (2<Emphasis Type="Italic">R</Emphasis>)-2-Ethylchromane-2-Carboxylic Acid Arginine Salt (a Novel PPARα/γ Dual Agonist)

Purpose This study was conducted to evaluate the aggregation properties of an amphiphilic drug.Methods Aggregation of the drug was studied by various methods including phase-contrast and polarized microscopy, spectrophotometry, surface tensiometry, atomic force microscopy, and dynamic light scattering. Lymph-cannulated rats were used to assess fractions of drug that were absorbed into lymphatics.Results During the pharmaceutical development of an α/γ dual PPAR agonist, a derivative of a chromane-2-carboxylic acid (compound 1), it was discovered that the compound was able to form various aggregates in aqueous media from pH 6.5 to 7.1, whereas aggregating predominantly into micelles at higher pH values. Critical micelle concentrations seemed to be quite low, about 0.25 mM (0.17 mg/mL) in deionized water as determined by spectrophotometric (dye) and surface tensiometry (du Nuoy) methods. Aggregation of compound 1 into large supramolecular aggregates was visualized via phase-contrast microscopy and atomic force microscopy. The observed aggregates ranged from 250 nm to greater than 10 μm in size. Formation of liquid crystalline phases was observed by polarized microscopy as the material was gradually hydrated with water. Lymph studies in rats indicated that up to 6.9% of the orally administered dose of compound 1 in pH 6.5 buffer appeared in lymph, suggesting that supramolecular aggregation may also occur in vivo leading to partitioning between the portal and the lymph routes.Conclusions The aforementioned supramolecular aggregation was found to have a profound effect on the pharmaceutical development of the drug and potentially on in vivo absorption of the drug.     

Actions at GABA(A) receptors in the hippocampus may mediate some antiseizure effects of progestins

Progestins can have antiseizure effects; however, the mechanisms and sites of action of these effects are not well-understood. Whether progesterone's actions at GABA(A) receptors in the hippocampus are important for its antiseizure effects was investigated. In Experiment 1, ovariectomized rats were administered sesame oil vehicle or a regimen of progesterone (500 microg sc, which produces physiological concentrations in plasma and the hippocampus), followed 2.5 hours later by administration of saline vehicle or a regimen of bicuculline (1 mg/kg, sc), a GABA(A) receptor antagonist, which does not produce any intrinsic effects on seizures. Progesterone, compared with vehicle, significantly increased the latency to, and decreased the number of, pentylenetetrazole-induced tonic seizures and increased GABA-stimulated chloride flux. Co-administration of bicuculline attenuated progesterone's antiseizure effects and decreased GABA-stimulated chloride flux in the hippocampus. Bicuculline did not alter ictal behavior compared with vehicle. In Experiment 2, ovariectomized rats were subcutaneously administered sesame oil or progesterone (500 microg), followed 2.5 hours later by bilateral infusions of bicuculline (100 ng) or vehicle (saline) into the hippocampus. Infusion of bicuculline into the hippocampus of progesterone-primed rats significantly increased ictal activity, compared with that induced by progesterone administration alone, but alone did not alter seizures compared with that produced by saline infusions into the hippocampus. These data suggest that actions of progesterone at GABA(A) receptors in the hippocampus are important for progesterone's antiseizure effects.     

Effect of the dopamine D2 receptor T allele on response latency after mild traumatic brain injury

OBJECTIVE: The authors tested the hypothesis that the dopamine D2 receptor T allele (formerly described as the A1 allele) would be associated with poorer performance on memory and attention tasks following mild traumatic brain injury. METHOD: Thirty-nine patients with mild traumatic brain injury and 27 comparison subjects were genotyped. All subjects completed memory and attention tests, including the California Verbal Learning Test recognition task and the Continuous Performance Test. RESULTS: In both groups the T allele was associated with poorer performance on the California Verbal Learning Test recognition task. There was also a significant diagnosis-by-allele interaction on measures of response latency (Continuous Performance Test): the subjects with mild traumatic brain injury and the T allele had the worst performance. CONCLUSIONS: Genetic polymorphisms modulating central dopaminergic tone can affect cognitive outcome following mild traumatic brain injury.     

IGF-1 protects oligodendrocyte progenitor cells and improves neurological functions following cerebral hypoxia-ischemia in the neonatal rat

To investigate if insulin-like growth factor-1 (IGF-1) provides neuroprotection to oligodendrocyte progenitor cells (OPCs) following cerebral hypoxia-ischemia, a previously developed neonatal rat model of white matter damage was used in this study. Postnatal day 4 (P4) SD rat pups were subjected to bilateral common carotid artery ligation, followed by exposure to 8% oxygen for 10 min. IGF-1 (0.5 microg) or vehicle was injected into the left ventricle after artery ligation and before the hypoxic exposure. Cerebral hypoxia-ischemia caused death of O4+ late OPCs in the P5 rat brain and impaired myelination in the P9 and P21 rat brain. Caspase-3 activation was involved in the death of OPCs. Moreover, cerebral hypoxia-ischemia impaired neurobehavioral performance in juvenile rats. IGF-1 treatment attenuated damages to OPCs and improved neurological functions after cerebral hypoxia-ischemia. It reduced death of O4+ OPCs by 39% on P5 and enhanced myelination on P9 and P21. Bromodeoxyuridine uptake assay showed that cerebral hypoxia-ischemia inhibited proliferation of stem/progenitor cells in the subventricular zone and NG2+ early OPCs in the white matter area. IGF-1 treatment increased cell proliferation in the subventricular zone by 31% 1 day following hypoxic-ischemic insult. Proliferation of early and late OPCs in the IGF-1-treated group was 1.5- and 2.4-fold of that in the vehicle-treated group, respectively. In conclusion, IGF-1 provided potent neuroprotection to OPCs and improved neurological functions following cerebral hypoxia-ischemia in the neonatal rat. The neuroprotection of IGF-1 was associated with its antiapoptotic and mitogenic effects.     

Commercial portion-controlled foods in research studies: how accurate are label weights?

OBJECTIVE: The purpose of this study was to evaluate the reliability of label weights as surrogates for actual weights in commercial portion-controlled foods used in a research setting. DESIGN: Actual weights of replicate samples of 82 portion-controlled food items and 17 discrete units of food from larger packaging were determined over time. Comparison was made to the package label weights for the portion-controlled food items and the per-serving weights for the discrete units. SETTING: The study was conducted at the US Department of Agriculture's Beltsville Human Nutrition Research Center's Human Study Facility, which houses a metabolic kitchen and human nutrition research facility. MAIN OUTCOME MEASURES: The primary outcome measures were the actual and label weights of 99 food items consumed by human volunteers during controlled feeding studies. Statistical analyses performed The difference between label and actual weights was tested by the paired t test for those data that complied with the assumptions of normality. The Wilcoxon signed rank test was used for the remainder of the data. Compliance with federal guidelines for packaged weights was also assessed. RESULTS: There was no statistical difference between actual and label weights for only 37 food items. The actual weights of 15 portion-controlled food items were 1% or more less than label weights, making them potentially out of compliance with federal guidelines. CONCLUSIONS:With advance planning and continuous monitoring, well-controlled feeding studies could incorporate portion-controlled food items and discrete units, especially beverages and confectionery products. Dietetics professionals should encourage individuals with diabetes and others on strict dietary regimens to check actual weights of portion-controlled products carefully against package weights.