19 research outputs found
Sales Loss Determination in Food Contamination Incidents: An Application to Milk Bans in Hawaii
This article presents a procedure for estimating sales loss following a food contamination incident with application to the case of heptachlor contamination of fresh fluid milk in Oahu, Hawaii in 1982. A major finding is that media coverage following the incident had a significant impact on milk purchases and that negative coverage had a larger effect than positive coverage. This conclusion implies that public statements by producers or government to assure the public of safe food supplies may be ineffective in restoring consumer confidence following the discovery of a food safety problem. American Journal of Agricultural Economics, August, 1988.food contamination, food safety policy, milk demand, Food Consumption/Nutrition/Food Safety,
Malignant melanoma and bone resorption
The cellular and humoral mechanisms accounting for osteolysis in skeletal metastases of malignant melanoma are uncertain. Osteoclasts, the specialised multinucleated cells that carry out bone resorption, are derived from monocyte/macrophage precursors. We isolated tumour-associated macrophages (TAMs) from metastatic (lymph node/skin) melanomas and cultured them in the presence and absence of osteoclastogenic cytokines and growth factors. The effect of tumour-derived fibroblasts and melanoma cells on osteoclast formation and resorption was also analysed. Melanoma TAMs (CD14+/CD51−) differentiated into osteoclasts (CD14−/CD51+) in the presence of receptor activator for nuclear factor κB ligand (RANKL) and macrophage-colony stimulating factor. Tumour-associated macrophage-osteoclast differentiation also occurred via a RANKL-independent pathway when TAMs were cultured with tumour necrosis factor-α and interleukin (IL)-1α. RT–PCR showed that fibroblasts isolated from metastatic melanomas expressed RANKL messenger RNA and the conditioned medium of cultured melanoma fibroblasts was found to be capable of inducing osteoclast formation in the absence of RANKL; this effect was inhibited by the addition of osteoprotegerin (OPG). We also found that cultured human SK-Mel-29 melanoma cells produce a soluble factor that induces osteoclast differentiation; this effect was not inhibited by OPG. Our findings indicate that TAMs in metastatic melanomas can differentiate into osteoclasts and that melanoma fibroblasts and melanoma tumour cells can induce osteoclast formation by RANKL-dependent and RANKL-independent mechanisms, respectively
Sales Loss Determination in Food Contamination Incidents: An Application to Milk Bans in Hawaii
This article presents a procedure for estimating sales loss following a food
contamination incident with application to the case of heptachlor contamination of fresh
fluid milk in Oahu, Hawaii in 1982. A major finding is that media coverage following the
incident had a significant impact on milk purchases and that negative coverage had a
larger effect than positive coverage. This conclusion implies that public statements by
producers or government to assure the public of safe food supplies may be ineffective in
restoring consumer confidence following the discovery of a food safety problem.
American Journal of Agricultural Economics, August, 1988
Determination of pharmacologically active compounds in root extracts of Cassia alata L. by use of high performance liquid chromatography
A simple high performance liquid chromatography (HPLC) method was developed and validated for the determination of six phenolic compounds, five anthraquinones (rhein, aloe-emodin, emodin, chrysophanol and physcion) and a flavonoid (kaempferol), in root extracts from Cassia alata L. Solid-phase extraction, using C18 cartridges, was used to remove interfering substances from the root extracts. The extracts were analyzed on a C18 column using an isocratic mobile phase which consisted of acetonitrile, methanol, and 10 mM aqueous ammonium acetate (25:55:20, v/v). Identification of the analytes was performed by use of standards and on-line mass spectrometric detection using atmospheric pressure chemical ionization. The concentration of the phenolic compounds in the root extracts was determined using HPLC with ultraviolet detection at 260 nm. The limits of detection obtained for the anlytes were in the range of 0.23-4.61 ppm. The overall R.S.D. precision values (intra- and inter-day) for the retention times and peak-areas were lower than 0.16 and 2.10%, respectively. In addition, the recovery of the developed method for the analysis of these phenolic compounds was determined, and ranged from 81.2 ± 4.3 to 106 ± 2%. © 2007 Elsevier B.V. All rights reserved