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McCarthy PM, Gillinov AM, Castle L, Chung M, Cosgrove D. The Cox-Maze procedure: the Cleveland Clinic experience. Semin Thorac Cardiovasc Surg 2000; 12:25-9. [PMID: 10746919 DOI: 10.1016/s1043-0679(00)70013-x] [Citation(s) in RCA: 197] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Cox-Maze procedure was designed to address the consequences of atrial fibrillation, tachycardia, hemodynamic impairment, and thromboembolism. From 1991 until June 1999, 100 patients underwent the Maze operation at the Cleveland Clinic Foundation. The group included 72 men with a mean age of 58 +/- 11 years (range, 23 to 78 years). Initially, the Maze-I procedure was performed primarily for patients with lone atrial fibrillation. However, since 1995, the Maze-III procedure has been performed exclusively, and it is typically combined with mitral valve repair. Twenty-three patients had only a Maze procedure, 60 patients had the Maze procedure/mitral valve repair, 10 patients had Maze procedure/coronary artery bypass, 6 had Maze procedure/mitral valve replacement, and 1 had Maze procedure/atrial septal defect repair. Chronic atrial fibrillation was present in 78% of patients for a mean of 8 +/- 9 years. There was a 1% perioperative mortality and 5% late mortality rate. Median hospital stay was 9 +/- 5 days. Six patients required new early permanent pacemaker insertion. With a mean follow-up of 3 years, 90.4% of patients are in sinus rhythm (or atrial pacing). Preoperative symptoms were reduced: 24% had preoperative syncope; none had syncope in follow-up; 14% of patients preoperatively had cerebral or systemic emboli; and there were no perioperative or late embolic events. The Maze procedure effectively addressed the major complications of atrial fibrillation and was associated with low perioperative and late morbidity rates.
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Jetten J, de Kruijf N, Castle L. Quality and safety aspects of reusable plastic food packaging materials: a European study to underpin future legislation. FOOD ADDITIVES AND CONTAMINANTS 1999; 16:25-36. [PMID: 11565572 DOI: 10.1080/026520399284299] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The objective of this study was to develop a comprehensive package of quality assurance criteria for use by industry and regulatory authorities for ensuring the quality and safety-in-use (sensory, microbiological and chemical) of reused plastics for food packaging. The study included thermal degradation effects, flavour carry-over caused by flavour and off-flavour substances, the influence of washing processes on the materials, and the efficiency of washing processes in removing off-flavour substances and surrogate substances representing misuse chemicals as might be put in bottles by consumers. The microbial safety of the refillable plastic articles in relation to commercial washing processes and the industrial procedures applied has also been investigated. Lastly, the suitability of laboratory procedures using strips of bottle material for predicting the sorption and washing properties of refillable plastic bottles has been studied. In general it is concluded that reuse of the articles does not significantly influence any of the properties investigated. Neither the chemical, physical nor surface properties seem to be significantly influenced by repeated washing. It can be concluded, however, that it is very likely that most of the articles investigated will cause flavour carry-over to a new filling if they are contaminated with strongly flavoured products. Finally it can be concluded that the procedures evaluated can serve as a basis for future legislation on refillable articles, but for several procedures (like quick predictive testing with strips) more investigation is required to create a more solid basis.
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van Lierop B, Castle L, Feigenbaum A, Ehlert K, Boenke A. Establishment of a reference collection of additives and an analytical handbook of reference data to support enforcement of EU regulations on food contact plastics. FOOD ADDITIVES AND CONTAMINANTS 1998; 15:855-60. [PMID: 10211194 DOI: 10.1080/02652039809374719] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A collection has been made of additives that are required as analytical standards for enforcement of European Union legislation on food contact plastics. The 100 additives have been characterized by mass spectrometry, infra-red spectroscopy and proton nuclear magnetic resonance spectroscopy to provide reference spectra. Gas chromatographic retention times have been recorded to facilitate identification by retention index. This information has been further supplemented by physico-chemical data. Finally, chromatographic methods have been used to indicate the presence of any impurities in the commercial chemicals. Samples of the reference substances are available on request and the collection of spectra and other information will be made available in printed format and on-line through the Internet. This paper gives an overview of the work done to establish the reference collection and the spectral atlas, which together will assist enforcement laboratories in the characterization of plastics and the selection of analytical methods for additives that may migrate.
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Freire MT, Castle L, Reyes FG, Damant AP. Thermal stability of polyethylene terephthalate food contact materials: formation of volatiles from retain samples and implications for recycling. FOOD ADDITIVES AND CONTAMINANTS 1998; 15:473-80. [PMID: 9764218 DOI: 10.1080/02652039809374668] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PET packaging materials have been tested for volatile content after exposure to high temperatures. Samples included laminates, bottles, and roasting bags, and were heated at 120 degrees C, 150 degrees C and 230 degrees C for 50 min, according to sample type. Volatiles released from the material were trapped on Tenax, identified by GC-MS and assessed against a 10 micrograms/kg migration threshold limit. Few volatiles were found for samples composed only of PET. Volatiles from laminates varied according to the sample structure, but the main substances identified were not related to PET, but probably came from printing inks and adhesives. It is concluded that the migration potential of PET in high temperature applications is very low and that the formation of volatiles during use is unlikely to cause any special problems in polymer recovery in recycling schemes, provided that other packaging residues are removed effectively.
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Chen L, Cheng JC, Castle L, Sung ZR. EMF genes regulate Arabidopsis inflorescence development. THE PLANT CELL 1997; 9:2011-24. [PMID: 9401124 PMCID: PMC157054 DOI: 10.1105/tpc.9.11.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Mutations in EMBRYONIC FLOWER (EMF) genes EMF1 and EMF2 abolish rosette development, and the mutants produce either a much reduced inflorescence or a transformed flower. These mutant characteristics suggest a repressive effect of EMF activities on reproductive development. To investigate the role of EMF genes in regulating reproductive development, we studied the relationship between EMF genes and the genes regulating inflorescence and flower development. We found that APETALA1 and AGAMOUS promoters were activated in germinating emf seedlings, suggesting that these genes may normally be suppressed in wild-type seedlings in which EMF activities are high. The phenotype of double mutants combining emf1-2 and apetala1, apetala2, leafy1, apetala1 cauliflower, and terminal flower1 showed that emf1-2 is epistatic in all cases, suggesting that EMF genes act downstream from these genes in mediating the inflorescence-to-flower transition. Constitutive expression of LEAFY in weak emf1, but not emf2, mutants increased the severity of the emf phenotype, indicating an inhibition of EMF activity by LEAFY, as was deduced from double mutant analysis. These results suggest that a mechanism involving a reciprocal negative regulation between the EMF genes and the floral genes regulates Arabidopsis inflorescence development.
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Philo MR, Fordham PJ, Damant AP, Castle L. Measurement of styrene oxide in polystyrenes, estimation of migration to foods, and reaction kinetics and products in food simulants. Food Chem Toxicol 1997; 35:821-6. [PMID: 9350227 DOI: 10.1016/s0278-6915(97)00054-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The concentration of styrene-7,8-oxide has been measured in nine base resins and 16 samples of polystyrene articles intended for food contact. The epoxide was not detected in the resins (limit of detection 0.5 mg/kg) but was found in 11 of the 16 packaging samples at up to 2.9 mg/kg. Assuming that the propensity of styrene oxide to migrate is the same as styrene monomer, and using existing survey data for styrene monomer in packaging and foods, the migration levels expected for styrene oxide were calculated. Estimates were from 0.002 to 0.15 microgram/kg styrene oxide in foods. The stability of styrene oxide in the four standard EU food simulants was studied at 40, 100, 150 and 175 degrees C, to establish the transformation products to be expected following migration testing. The half-life at 40 degrees C in distilled water, 15% aqueous ethanol, 3% aqueous acetic acid and olive oil was 15, 23, < 1, > 2000 hr, respectively. The principal product was the diol from hydrolysis of the epoxide group. Ring opening in aqueous ethanol simulant gave the diol and also the glycol monoethyl ether. It is concluded that this instability of styrene oxide will reduce concentrations in foods, from an already low migration level to even lower levels with the formation of hydrolysis products that are less toxic than the parent epoxide.
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Mountfort KA, Kelly J, Jickells SM, Castle L. Investigations into the potential degradation of polycarbonate baby bottles during sterilization with consequent release of bisphenol A. FOOD ADDITIVES AND CONTAMINANTS 1997; 14:737-40. [PMID: 9373536 DOI: 10.1080/02652039709374584] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Twenty-four brands of plastic baby feeding bottles were purchased and all were found to be made of polycarbonate. Taking a batch of one representative sample, the polymer was tested for stability and possible release of bisphenol A following domestic practice of sterilization. Sterilization was by alkaline hypochlorite, steam, or washing in an automatic dishwasher at 65 degrees C with detergent. A total of 20 cycles of sterilization and subsequent food use were performed for each of the three procedures. Bisphenol A migration was in all cases not detectable in infant feed using a very sensitive method of liquid chromatography with fluorescence detection with a 0.03 mg/kg detection limit.
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Nielsen T, Damant AP, Castle L. Validation studies of a quick test for predicting the sorption and washing properties of refillable plastic bottles. FOOD ADDITIVES AND CONTAMINANTS 1997; 14:685-93. [PMID: 9373532 DOI: 10.1080/02652039709374580] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Quick tests are proposed in the literature as alternatives to the large scale contamination and washing studies performed to date to assess the acceptability of plastic beverage bottles for refilling. These tests use small plastic specimens ('strips') in place of bottles and use mixtures of surrogate contaminants to model the myriad of chemicals that could in principle contaminate returned bottles because of consumer mis-use. The work reported here has measured the sorption and wash performance using the quick test protocol with PET (polyethyleneterephthalate) strips and laboratory washing and compared the results with tests using actual bottles and a commercial washing process. The comparison indicates that the quick test satisfactorily simulated contamination and commercial washing of intact bottles. The results also show that repeated washing of PET bottles does not cause higher sorption of contaminants.
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Castle L, Offen CP, Baxter MJ, Gilbert J. Migration studies from paper and board food packaging materials. 1. Compositional analysis. FOOD ADDITIVES AND CONTAMINANTS 1997; 14:35-44. [PMID: 9059581 DOI: 10.1080/02652039709374495] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A survey of 32 paper and board materials intended for food contact has been undertaken. Sample composition was analysed to identify chemicals with a potential to migrate to foods. Representative materials covering a range of uses such as aqueous and fatty foods, and use at ambient and elevated temperatures, were obtained from industry. The samples were examined in their unfinished state, even where the final form would have included lamination to plastics, printing, or other treatments. A comprehensive and systematic analytical approach was applied which included determination of volatiles by headspace GC-MS, extraction using water, ethanol and chloroform with subsequent analysis by GC-MS and HPLC, and multi-element screening by ICP-MS. The solvent extracts were also weighed to determine the total amount of material available for migration. A large number of volatile substances were identified with alkyl and aryl aldehydes predominating in the majority of samples. Substances identified in solvent extracts included 2,6-di-tert-butyl-4-hydroxytoluene (BHT), di-tert-butylphenol, benzophenone, 4,4'-bis(dimethyl amino) benzophenone (Michler's ketone), triphenyl methane, bicyclohexylphenylphenanthrene carboxylic acid (and its methyl ester) and abietic acid. Levels of these substances were however generally below 1 mg/kg paper. Of the inorganic elements, arsenic and mercury were not detected above the limits of determination of 1.8 and 0.4 mg/kg respectively in any of the 10 samples examined. Cadmium was detected in teabag tissue and in unbleached Kraft paper at 0.3 mg/kg. Chromium was present in seven samples at 1.1-7.8 mg/kg, whilst lead was present in nine of the 10 samples at levels ranging from 0.3 to 5.9 mg/kg.
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Philo MR, Damant AP, Castle L. Reactions of epoxide monomers in food simulants used to test plastics for migration. FOOD ADDITIVES AND CONTAMINANTS 1997; 14:75-82. [PMID: 9059585 DOI: 10.1080/02652039709374499] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The reactions of four epoxides used as monomers for food contact plastics were studied in the food simulants distilled water, 15% aqueous ethanol, 3% aqueous acetic acid and olive oil. Loss of the parent substance and formation of products was monitored to establish the transformation products to be expected in each simulant following migration testing of plastics. Each epoxide was stable in olive oil but suffered extensive loss in the three aqueous simulants. Reaction half-lives were from < 1 to 10 h in aqueous acetic acid, 25-63 h in distilled water, and 33-87 h in aqueous ethanol simulant. Hydrolysis to the diol was the main reaction pathway. Epoxide ring opening in aqueous ethanol simulant gave the diol and also the diol monoethyl ether. It is concluded that, for aqueous simulants and by implication for most foods, testing plastics against specific migration limits for epoxides is not likely to give reliable results due to their reactivity. The present EC mode of control for these reactive monomers, via compositional limits in food contact plastics, is more practical since the hydrolysis products are less toxic than the parent epoxide.
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Din N, Bartle KD, Clifford AA, McCormack A, Castle L. Supercritical fluid extraction of sulphamethazine and its metabolites from meat tissues. J Chromatogr Sci 1997; 35:31-7. [PMID: 8989870 DOI: 10.1093/chromsci/35.1.31] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An investigation is reported of factors affecting the supercritical fluid extraction of sulphamethazine and five of its metabolites from spiked meat (swine liver and kidney). The addition of the polar modifier methanol to the carbon dioxide extracting fluid was found to generally enhance recoveries under subcritical and supercritical conditions. Recoveries of the ionic metabolites were increased by up to 72% when employing tetramethylammonium hydroxide for ion pairing in situ with the supercritical fluid extraction. Extraction efficiency is demonstrated to be dependent on the matrix. Extractions of the less polar compounds from the kidney are more successful than from the liver, which corresponds to their partitioning into the supercritical fluid and/or the greater fraction of highly extractable fatty materials. The kidney was more retentive than liver for the relatively more polar compounds, which suggests that the liver offers a less polar environment under the same extraction conditions.
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Castle L, Damant AP, Honeybone CA, Johns SM, Jickells SM, Sharman M, Gilbert J. Migration studies from paper and board food packaging materials. Part 2. Survey for residues of dialkylamino benzophenone UV-cure ink photoinitiators. FOOD ADDITIVES AND CONTAMINANTS 1997; 14:45-52. [PMID: 9059582 DOI: 10.1080/02652039709374496] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A survey of retail samples was conducted in two phases with 50 general paper and board food contact materials and articles analysed in 1992, and 121 samples, specifically of printed cartonboard, analysed in 1995. Packaging samples were extracted with ethanol containing 0.4% triethylamine. The extracts were analysed using high performance liquid chromatography (HPLC) and the presence of 4,4'-bis (dimethylamino) benzophenone (Michler's ketone, MK) and 4,4'-bis (diethylamino)-benzophenone (DEAB) confirmed using gas chromatography coupled to mass spectroscopy (GC-MS). The limits of detection for MK and DEAB in packaging were 0.05 mg/kg and 0.1-0.2 mg/kg respectively. In the first phase, MK was detected in 24% of the 50 samples at concentrations of 0.06-3.9 mg/kg paper. DEAB was detected in 12% of samples (0.1-0.2 mg/kg). In the second phase, 26% of the 121 cartonboard samples contained detectable MK (0.1-1.6 mg/kg) and 4% contained DEAB (0.2-0.7 mg/kg). Residues of the monoamine 4-(dimethylamino)benzophenone (DMAB) were found in 10% of the 1992 samples (0.1-0.6 mg/ kg). DMAB was not surveyed in 1995. These levels are too low to indicate the use of these cure agents for printing the packages. Rather, the most likely origin is from the use of recycled fibres. For three samples where the highest concentration of MK was detected, the food was analysed by GC-MS after extraction and clean-up. There was no measurable migration of MK at a detection limit of 2 micrograms/kg food. It is concluded, therefore, that the concentrations of MK present in the packaging samples analysed are unlikely to pose a risk to human health.
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Castle L, Price D, Dawkins JV. Oligomers in plastics packaging. Part 1: Migration tests for vinyl chloride tetramer. FOOD ADDITIVES AND CONTAMINANTS 1996; 13:307-14. [PMID: 8718745 DOI: 10.1080/02652039609374412] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Vinyl chloride (VC) tetramer has been studied as a representative oligomer that has the potential for migration from plastics packaging. Poly(vinyl chloride) (PVC) bottles for retail beverages were analysed by a process of dissolution followed by gas chromatography. Tetramer levels ranged from 70 to 190 mg/kg in the plastic. When these bottles were tested for migration into the simulants distilled water, 3% acetic acid, 15% ethanol and olive oil, no tetramer migration was detected at a limit of 5-10 micrograms/kg. Since, of the low molecular weight oligomers, the tetramer had the highest concentration in the PVC plastics, it is concluded that the other VC oligomers of higher molecular weight, would not migrate above this limit of detection either.
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MacDonald S, Castle L. A UK retail survey of aflatoxins in herbs and spices and their fate during cooking. FOOD ADDITIVES AND CONTAMINANTS 1996; 13:121-8. [PMID: 8647302 DOI: 10.1080/02652039609374387] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A survey of aflatoxins in herbs and spices has been carried out and cooking experiments conducted to assess the stability of aflatoxin in spice sauces. Of 157 retail samples which included curry powders, pepper, cayenne pepper, chilli, paprika, ginger, cinnamon and coriander, nearly 95% of samples contained below 10 micrograms/kg total aflatoxins and only nine samples had higher levels. The highest concentration in a retail sample was 48 micrograms/kg in a chilli powder. In addition to retail sampling, 14 consignments of whole chilli and chilli powder were sampled at the port of entry. Only two samples, both chilli powder, were above 10 micrograms/kg; containing 35 and 51 micrograms/kg total aflatoxins. Cooking experiments showed that aflatoxin levels in spiced sauces are not reduced by domestic cooking with either microwave or conventional gas oven heating.
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Sharman M, Honeybone CA, Jickells SM, Castle L. Detection of residues of the epoxy adhesive component bisphenol A diglycidyl ether (BADGE) in microwave susceptors and its migration into food. FOOD ADDITIVES AND CONTAMINANTS 1995; 12:779-87. [PMID: 8608852 DOI: 10.1080/02652039509374370] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Susceptors are an example of one of the many new products being introduced into food packaging. They are used to achieve local areas of high temperature; this has the effect of browning the food during microwave cooking. Previous work by Begley et al. had suggested that one particular cold cure adhesive component, bisphenol A diglycidyl ether (BADGE), might be present in some susceptor products but gave little indication as to the retail use of these products. As a result an investigation of UK retail samples was carried out in January 1992. Most of the susceptors tested contained no detectable BADGE ( < 0.1 mg/kg), however, two brands of pizza were found to be packaged with susceptors containing BADGE at between 700 and 800 mg/kg (1.8-2.0 mg/dm2). Migration of BADGE into the pizzas in question was 0.1-0.7 mg/kg when they were cooked in their packaging according to on-pack instructions. Further tests undertaken in June 1992 confirmed earlier findings when from a total of 54 samples purchased covering seven manufacturers, nine samples of susceptors used in one brand contained BADGE at concentrations between 1900 and 3200 mg/kg. The manufacturer of this brand has stopped supplying further products to the retail market using this particular type of susceptor. A third set of tests was undertaken in November 1992 to ensure that these products were no longer on sale in the UK. Of 44 susceptors analysed, only one contained BADGE above 0.1 mg/kg; this appeared to be old stock pre-dating the manufacturers' action.
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Fordham PJ, Gramshaw JW, Crews HM, Castle L. Element residues in food contact plastics and their migration into food simulants, measured by inductively-coupled plasma-mass spectrometry. FOOD ADDITIVES AND CONTAMINANTS 1995; 12:651-69. [PMID: 8522030 DOI: 10.1080/02652039509374354] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Polymers intended for food contact use have been analysed for inorganic residues which can be attributed to a range of substances employed as polymerization aids (e.g. catalysts), or to additives incorporated into the polymer to fulfil a specific task (e.g. lubricants). The migration of these residues into food simulants was studied. Residues were determined by using the multi-element capability of Inductively-Coupled Plasma-Mass Spectrometry (ICP-MS). Semi-quantitative analysis was carried out on acid digests of polymer materials, obtained by microwave heating in sealed Teflon containers. Limits of detection in the polymer were generally less than 1 mg/kg. Migration experiments were carried out with three food simulants and under two sets of conditions. Analysis for element residues was performed directly or, in the case of olive oil, on an emulsion of the simulant. Migration of certain elements into aqueous simulants was observed: Zr from polystyrene (650 micrograms/kg), Sb from polyethylene terephthalate (4 micrograms/kg) and Mg from acrylonitrile/butadiene/styrene copolymer (50 micrograms/kg). In all cases, where limits of detection permit, the levels which migrated from polymer to stimulant were less than proposed limits on migration.
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Lafuse WP, Castle L, Brown D, Zwilling BS. The cytotoxic T lymphocyte gene FIBLP with homology to fibrinogen beta and gamma subunits is also induced in mouse macrophages by IFN-gamma. Cell Immunol 1995; 163:187-90. [PMID: 7606791 DOI: 10.1006/cimm.1995.1115] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To identify genes induced in mouse macrophages by IFN-gamma, a cDNA subtraction library of IFN-gamma-induced genes was screened. One of the clones, 36F2, was identified by DNA sequencing as the FIBLP gene. The FIBLP (fibrinogen-like protein) gene is a T-lymphocyte-specific gene that is expressed in mouse cytotoxic T lymphocytes but not in helper T lymphocytes or B lymphocytes. The protein sequence shows a high homology to fibrinogen beta and gamma subunits. The FIBLP gene is not expressed in unstimulated mouse peritoneal macrophages but is induced by IFN-gamma to high levels. FIBLP mRNA is detected by 1 hr after the addition of IFN-gamma and maximal levels are reached by 12 hr. Expression of FIBLP mRNA was not induced by IL-2, IL-4, IL-10, or TNF-alpha. Though the function of this gene is unknown, its expression in both cytotoxic T lymphocytes and activated macrophages suggests that FIBLP may play an as yet undefined role in the cytotoxic function of these cells.
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Damant AP, Jickells SM, Castle L. Liquid chromatographic determination of residual isocyanate monomers in plastics intended for food contact use. J AOAC Int 1995; 78:711-9. [PMID: 7756886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A liquid chromatographic (LC) method was developed for the analysis of 10 isocyanates in polyurethane articles and laminates intended for food use. Residual isocyanates are extracted by dichloromethane with concurrent derivatization by 9-(methylaminomethyl)anthracene. The resultant derivatives are analyzed by reversed-phase LC with fluorescence detection. Separation of the isocyanates was studied and optimized. Quantitation uses 1-naphthyl isocyanate as internal standard and standard addition to the food package. Validation demonstrated the method to have good precision (+/- 2-5%) and recovery (83-95%) for samples spiked with isocyanates at 0.1 mg/kg. The limit of detection was 0.03 mg/kg. Analysis of 19 commercial polyurethane or laminate food packages demonstrated that the method was not prone to interferences. Residues of diphenylmethane-4,4'-diisocyanate were detected in 5 packages and ranged from 0.14 to 1.08 mg/kg.
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Lafuse WP, Brown D, Castle L, Zwilling BS. IFN-gamma increases cathepsin H mRNA levels in mouse macrophages. J Leukoc Biol 1995; 57:663-9. [PMID: 7722423 DOI: 10.1002/jlb.57.4.663] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Expression of major histocompatibility complex (MHC) class II molecules and ability to present antigen to T lymphocytes is acquired upon activation of the macrophage by interferon-gamma (IFN-gamma). Little information is available concerning immune regulation of protease gene expression in mouse macrophages. We have isolated a cDNA clone for cathepsin H, a lysosomal cysteine proteinase from a cDNA subtraction library of mouse macrophage genes induced by IFN-gamma, and have characterized its expression. The level of cathepsin H mRNA increased in mouse peritoneal macrophages following addition of IFN-gamma. Cathepsin H mRNA levels began to increase 8 h after the addition of IFN-gamma and was maximal at 24-48 h. This increase was concordant in time with appearance of MHC class II E beta mRNA and Ia invariant chain mRNA. The increase in cathepsin H mRNA levels by IFN-gamma was dose dependent. Cycloheximide treatment of peritoneal macrophages inhibited the increase in cathepsin H mRNA levels induced by IFN-gamma, suggesting that the increase in cathepsin mRNA levels requires de novo protein synthesis. Lipopolysaccharide and cytokines interleukin-2 (IL-2), IL-4, IL-10, and tumor necrosis factor alpha were found to have no effect on cathepsin H mRNA levels in mouse peritoneal macrophages.
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Lafuse WP, Brown D, Castle L, Zwilling BS. Cloning and characterization of a novel cDNA that is IFN-gamma-induced in mouse peritoneal macrophages and encodes a putative GTP-binding protein. J Leukoc Biol 1995; 57:477-83. [PMID: 7884320 DOI: 10.1002/jlb.57.3.477] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Macrophage activation by IFN-gamma results in a cascade of gene expression. To identify genes activated in mouse peritoneal macrophages by IFN-gamma, we created a cDNA subtraction library of IFN-gamma-induced genes. We have isolated from this subtraction library a novel cDNA clone, called Mg21, whose mRNA is absent in unstimulated mouse peritoneal macrophages and is induced to high levels within 4 h following the addition of IFN-gamma. Induction of Mg21 mRNA by IFN-gamma occurred in the presence of cycloheximide, indicating that expression of Mg21 mRNA does not require protein synthesis. A small amount of Mg21 mRNA was also induced by LPS, but not by IL-2, IL-4, IL-10, or TNF-alpha. The DNA sequence of Mg21 is 1617 nucleotides and contains an open reading frame that codes for a protein of 415 amino acids with a predicted molecular weight of 47,106 Da. The predicted amino acid sequence lacks a signal sequence or transmembrane segments, indicating that the protein is an intracellular protein. Computer search of the GenBank and EMBL databases indicates that this cDNA clone is unique but has 57% sequence identity with IRG-47, which is a mouse gene induced by IFN-gamma in pre-B and B lymphocyte cell lines. IRG-47 encodes an intracellular protein that contains three conserved protein motifs present in GTP-binding proteins. Analysis of the protein sequence of Mg21 showed that these three conserved protein motifs are also present in Mg21.
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Jickells SM, Nichol J, Castle L. Migration of mineral hydrocarbons into foods. 6. Press lubricants used in food and beverage cans. FOOD ADDITIVES AND CONTAMINANTS 1994; 11:595-604. [PMID: 7835472 DOI: 10.1080/02652039409374259] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Unused food and beverage cans were supplied by manufacturers together with two typical samples of press lubricants used to facilitate stamping of can ends. The lubricants were based on mineral hydrocarbon fractions. The cans were of aluminium two-piece construction (two sizes) and tin-plate steel three-piece construction (two sizes) and of four representative types. Gas chromatographic analysis was used to distinguish the two press lubricants from one another by their n-alkane profiles. Analysis of solvent extracts of the cans indicated that one of the two press lubricants had been used in the manufacture of the three-piece cans and the other lubricant for the two-piece cans. Residual levels of hydrocarbons were between 0.05 and 1.1 mg per can. Based on the capacity of the cans and assuming all the mineral hydrocarbon transferred to the contents, maximum levels in foods and beverages could be between 0.1 and 4.4 mg/kg. A limited number of retail products were also analysed. For the 35 samples covering 18 retail brands of canned foods and beverages, press lubricants were considered to be present in 50% of the products at levels ranging from 0.05 to 1.0 mg per can, equivalent to 0.1 to 3.6 mg/kg of food. Additionally mineral oil of unknown origin was detected in 10 of the retail products at levels of 0.1 to 4.7 mg/kg. Analysis of a sparkling apple juice packed in a glass bottle showed mineral oil at 0.3 mg/kg compared with 0.7 mg/kg for the same canned product, indicating that although mineral oils may be used in can manufacture they may also be derived from other parts of the food processing chain.
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Sharman M, Read WA, Castle L, Gilbert J. Levels of di-(2-ethylhexyl)phthalate and total phthalate esters in milk, cream, butter and cheese. FOOD ADDITIVES AND CONTAMINANTS 1994; 11:375-85. [PMID: 7926171 DOI: 10.1080/02652039409374236] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Di-(2-ethylhexyl)phthalate (DEHP) and total phthalate ester plasticizer levels were determined in milk, cream, butter and cheese samples from a variety of sources from three European countries (UK, Norway and Spain). Samples of milk (from Norway) obtained at various stages during collection, transportation and packaging operations showed no apparent trends in phthalate contamination with total phthalate levels (expressed as DEHP equivalents) in the raw milk of between 0.12 and 0.28 mg/kg. On processing the DEHP was concentrated in the cream at levels up to 1.93 mg/kg, whereas low fat milk contained from < 0.01 to 0.07 mg/kg. Retail dairy products (from Spain) were contaminated with < 0.01-0.55 mg/kg DEHP with a maximum total phthalate level of 3.0 mg/kg in cream samples. UK pooled milk samples from doorstep delivery (obtained from different regions of the country) contained low levels of DEHP (< 0.01-0.09 mg/kg) and total phthalate (0.06-0.32 mg/kg). Retail UK samples of cheese, butter and other fatty products varied considerably in their levels of contamination, the highest being cheese samples containing 17 mg/kg of DEHP and 114 mg/kg total phthalate. However, the majority of samples contained 0.6-3.0 mg/kg DEHP and 4-20 mg/kg total phthalate. UK cream samples contained levels of 0.2-2.7 mg/kg DEHP and 1.8-19.0 mg/kg total phthalate. The level found in these products was too high to have resulted solely from milk by concentration in the fat phase and must therefore have arisen in other ways.
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Jickells SM, Nichol J, Castle L. Migration of mineral hydrocarbons into foods. 5. Miscellaneous applications of mineral hydrocarbons in food contact materials. FOOD ADDITIVES AND CONTAMINANTS 1994; 11:333-41. [PMID: 7926167 DOI: 10.1080/02652039409374232] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Polystyrene and acrylonitrile/butadiene/styrenes (ABS) containers for individual serving portions (80 samples of milk, cream, butter, margarine and spreads) used in the catering industry were found to contain 1-4% mineral oil. Levels of mineral oil migrating into the foods were generally low (< 5-15 mg/kg) except in one instance where levels of 45-85 mg/kg were detected in a low fat spread, and this was attributed to mineral hydrocarbon transfer from an adhesive used in the lidding. Analysis of wine bottle corks (105 samples from 11 different countries) indicated that 50% had been treated with mineral wax or mineral oil, although in all cases mineral hydrocarbon contamination of the wine was < 0.2 mg/l. Waxed paper discs sold for home-use for covering the surface of jams and preserves were found to be coated with 100 mg/dm2 of mineral hydrocarbons. However, in experiments with a variety of jams and preserves levels of migration were not significant, ranging from 0.15 to 1.2 mg/kg.
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Brown LS, Phillips RY, Brown CL, Knowlan D, Castle L, Moyer J. HIV/AIDS policies and sports: the National Football League. Med Sci Sports Exerc 1994; 26:403-7. [PMID: 8201893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
With the assistance of highly respected experts in the field of HIV/AIDS, the NFL has developed a comprehensive policy that should decrease the spread of HIV and any other blood-borne pathogens among its players and medical staff. Transmission of HIV infection is likely to be rare in the NFL. This is supported by the fact that in over 10 yr of the AIDS epidemic, the CDC has not attributed one AIDS case to athletic competition. Whatever the rate of HIV infection, on-the-field transmission is certainly less frequent than hepatitis B, which is manyfold more transmissible than HIV. Based on these facts, a player with HIV infection poses virtually no threat to others or himself by further athletic participation in the NFL. In addition, the relatively short average playing career of an NFL player and the extended period between HIV contraction and development of AIDS symptoms decrease the prospect that a player's HIV-positive status would affect his athletic performance. Consequently, HIV testing should remain voluntary, and continued participation in the NFL of HIV-infected players should remain a private decision between the player and his physician.
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Gilbert J, Castle L, Jickells SM, Sharman M. Current research on food contact materials undertaken by the UK Ministry of Agriculture, Fisheries and Food. FOOD ADDITIVES AND CONTAMINANTS 1994; 11:231-40. [PMID: 8039583 DOI: 10.1080/02652039409374221] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Recent research funded by the UK Ministry of Agriculture, Fisheries and Food (MAFF) in the area of migration from food contact materials is reviewed and set within a framework of surveillance; evaluation of new technology; support of current regulations; and anticipation of future controls. Recent surveillance projects monitoring foods for migration of monomeric plasticizers (in particular di-(2-ethylhexyl)adipate), polymeric additives and mineral hydrocarbons are highlighted. Development of high temperature testing conditions for food contact materials has been carried out in support of regulations and proposals are made for the control of susceptors by analysis of release of volatiles. Migration of benzophenone from the printing ink of a paper board sleeve during microwave heating of a pre-cooked meal is described as a recent example of a migration situation that would not easily have been anticipated. Finally, the approach being adopted for investigating paper and board food contact materials for inorganic constituents, for volatile organic and for solvent-extractable organic components is outlined as an example of work being carried out in anticipation of future regulatory controls.
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