Search PubMed⌕ Search

Biomedical subjects

I Cooper

Publications and source records attributed to I Cooper.

At least 19 recordsLinked to original sources
PubMed2002

Survey of bisphenol A and bisphenol F in canned foods.

Bisphenol A (BPA) and bisphenol F (BPF) have been determined in a range of canned foods. Sixty-two different canned foods were purchased from retail outlets in the UK from January to November 2000 and the contents extracted and analysed by GC-MS for BPA and BPF isomers. The following canned products were analysed: fish in aqueous media, 10 samples; vegetables, 10; beverages, 11; soup, 10; desserts, five; fruit, two; infant formula, four; pasta, five; and meat products, five. BPF isomers were not detected in any of the canned foods with detection limits of 0.005 mg kg(-1) for the 2,2' and 2,4' isomers and 0.01 mg kg(-1) for the 4,4' isomer. BPA was detected in 38 samples with a detection limit of 0.002 mg kg(-1). Of these, BPA was quantified in 37 canned foods at levels from 0.007 mg kg(-1), with one sample of meat containing a mean level of 0.38 mg kg(-1). All other samples contained <0.07 mg kg(-1) BPA.

Benzhydryl Compounds↗
PubMed2002

Practical experience in the use of mathematical models to predict migration of additives from food-contact polymers.

To reduce the amount of compliance-specific migration testing for food-contact polymers, the use of migration modelling has been evaluated. The paper describes experimental work carried out on a range of plastics and compares measured migrations against predictions obtained using mathematical models. A large number of experimental migration data have been obtained and used to evaluate a Fickian-based migration model in the prediction of specific migration of additives into olive oil. All tests were conducted using olive oil, representing the most severe case for fatty foods with test conditions including 2h at 121 degrees C, 6h at 70 degrees C, 2h at 70 degrees C, 2h at 60 degrees C and 10 days at 40 degrees C, representing short-term exposures at high temperatures and room temperature storage. Predicted migrations were calculated by inputting the measured initial concentration of additive in the polymers (Cp,0) into the equations together with known variables such as additive molecular weight, temperature and exposure time. The results indicate the Piringer migration model, using the 'exact' calculations of the Migratest Lite program, predicted migrations into olive oil that were close to or in excess of the experimental results and gave an overestimation for > 95% of the migrations generated here.

Food Contamination↗
PubMed2001

Evaluation of human intestinal absorption data and subsequent derivation of a quantitative structure-activity relationship (QSAR) with the Abraham descriptors.

The human intestinal absorption of 241 drugs was evaluated. Three main methods were used to determine the human intestinal absorption: bioavailability, percentage of urinary excretion of drug-related material following oral administration, and the ratio of cumulative urinary excretion of drug-related material following oral and intravenous administration. The general solvation equation developed by Abraham's group was used to model the human intestinal absorption data of 169 drugs we considered to have reliable data. The model contains five Abraham descriptors calculated by the ABSOLV program. The results show that Abraham descriptors can successfully predict human intestinal absorption if the human absorption data is carefully classified based on solubility and administration dose to humans.

Administration, Oral↗
PubMed2001

Investigation of migration from paper and board into food--development of methods for rapid testing.

A range of paper and board materials including carton board, corrugated board, napkins and paper towels intended for contact with food have been solvent extracted and substances present at the highest levels identified and quantified by GC/MS. Dibutyl phthalate, and diisopropylnaphthalene (DIPN) were selected to study migration to food and potential food simulants with the aim of developing a simple quick test that will give an equivalent or higher result. Tenax was found to be a suitable food simulant for dry foods and dry 'fatty foods' such as pastry and cake and was also found to be a suitable simulant for pizza base tested at higher temperatures for short contact times. The percentage migration values from corrugated and carton boards were generally in the range 15-40%, with the highest percentage being 49% for rice using conditions representing ambient storage. Quick tests were developed using Tenax under accelerated conditions of 4 h at 80 degrees C to cover room temperature storage with dry foods and fatty dry foods. These tests are suitable for compliance testing of paperboard samples if migration limits are applied in future legislation. Migration from tissues, napkins and paper towels was found to be at very low or not detectable levels, even when the levels of DIPN and DBP were significant. It is strongly suspected that this finding is due to a combination of short contact time, low grammage and the fact that the tissues absorb fat and moisture from foods, thus minimizing extraction from the paper. In all cases, the results from migration experiments into food and Tenax indicate that for the substances found at highest concentrations in the paper, currently accepted safety limits were not exceeded where they exist in EU legislation or in working documents applying to plastics.

Dibutyl Phthalate↗
PubMed2001

Characterisation of the culturable heterotrophic bacterial community in a small eutrophic lake (Priest Pot).

The community composition and structure of planktonic heterotrophic bacteria (903 isolates) sampled from a small eutrophic lake in northern England (Priest Pot) was studied with respect to season (four samples) and depth (to 3.1 m). Bacteria (887) were isolated on tryptic soy broth agar and identified to 48 genera using fatty acid methyl ester analysis. The two most abundant genera isolated were Aeromonas and Pseudomonas which, respectively, dominated the middle to bottom depths in August and all depths in February. The structure of the sampled community was described using: species richness, Simpson's index and the Shannon-Wiener index. All three indices detected a number of significant differences with depth demonstrating stratification. The greatest stratification of the bacterial community was observed in August when bacterial counts correlated strongly and negatively with diversity. Using structural measures was found to be preferable to the use of species frequencies in the analysis of perturbation and succession in community structure. Insensitivity to one or more of eight antibiotics was observed in 71% (61/86) of the isolates tested particularly in Gram-negative genera. Bacteriocinogeny and lysogeny was observed in 36% (32/90) of isolates. Using sensitive indicator strains, two of 10 producing strains produced virus, while the others produced bacteriocins.

Journal Article↗
PubMed1999

Polymer additive migration to foods--a direct comparison of experimental data and values calculated from migration models for high density polyethylene (HDPE).

To reduce the amount of compliance testing for food contact polymers the use of migration modelling has been proposed. This study was conducted to provide valid data for the independent evaluation of two such diffusion-based models using a range of different high density polyethylene (HDPE) polymers and plastics additives. Seventy-two experimental migration data have been obtained in triplicate and used to evaluate two Fickian-based migration models in the prediction of specific migration of four HDPE additives into olive oil. All tests were conducted using olive oil, representing the most severe case for fatty foods with test conditions of 2 h at 70 degrees C, 6 h at 70 degrees C, 10 days at 40 degrees C representing short term exposures at high temperatures and room temperature storage. Predicted migration values were calculated by inserting the measured initial concentration of additive in the polymers (Cp,0) into the equations together with known variables such as additive molecular weight, temperature and exposure time. The results indicate that both models predict migration values into olive oil close to, or in excess of, the experimental results. The Piringer migration model, using the 'exact' calculations of the Migratest Lite program, gave an overestimation for 83% of the migration values generated in this study. The highest overestimation was 3.7 times the measured value. For all measurements, the predicted migration from the Migratest Lite program was greater than 50% of the observed value. The FDA model was found more accurately to predict migration in most situations but underestimated migration more frequently. Differences in the polymer specification had little effect on specific migration of the additives investigated.

Chemical Phenomena↗
PubMed1998

Specific migration testing with alternative fatty food simulants.

Many additives used in plastics materials and articles intended for food contact are expected to be assigned specific migration limits (SMLs) in a future amendment to EC Directive 90/128/EEC. In order to demonstrate compliance with these restrictions, specific migration tests will need to be performed on the finished plastics packaging using foods or the appropriate EC food simulants. Owing to the involatile and lipophilic nature of many of these additives, their analysis in the conventional fatty food simulant, olive oil, presents technical difficulties. One way of overcoming these difficulties would be to use a simple solvent alternative to olive oil as has been proposed for overall migration testing. The objective of this work is to compare specific migration data obtained using olive oil with alternative fat simulants iso-octane and 95% ethanol, to find out if similar results are obtained and identify the most appropriate alternative simulant to use for future testing. Good agreement with the olive oil migration data was obtained using 95% ethanol (equivalent exposure conditions) for both of the additives studied in polyolefins. For the polystyrene materials studied it is unlikely that the SMLs for the two additives would be exceeded, and in these cases iso-octane (1.5 h at 60 degrees C) could be used as a rapid 'alternative test'.

Adipates↗
PubMed1998

Survey of bisphenol a diglycidyl ether (BADGE) in canned foods.

2,2-Bis(4-hydroxyphenyl)propane bis(2,3-epoxypropyl) ether (BADGE) is used in the manufacture of lacquers for coating the inside of food and beverage cans. In June 1996 the EC Scientific Committee for Food temporarily increased the specific migration limit applying to BADGE to 1 mg/kg pending consideration of additional toxicological data. In order to find out if there is migration of BADGE from can coatings into foods, a 'worst case' sampling exercise has been conducted to survey those canned foods where the propensity for migration of BADGE was judged to be highest. The foods surveyed include canned fish in oil, meat and milk and, altogether, BADGE was determined in 181 retail samples. Analysis for BADGE was conducted, in duplicate, by HPLC with fluorescence detection with confirmation of BADGE identity by GC/MS analysis using selected ion monitoring. BADGE was found at levels exceeding 1 mg/kg in seven of the 15 canned anchovy samples and five of the 22 sardine samples purchased during the period September 1995-July 1996. Infrared analysis of the can coatings provided strong evidence that the higher BADGE levels found were associated with use of PVC organosol lacquers, although in some cases cans coated with organosols gave low BADGE results. For canned sardine samples found to contain greater than 0.5 mg/kg BADGE in the total contents, a replicate can was opened and separate analyses performed on the drained fish and the oil. The results clearly showed that BADGE concentrations in the oil were about 20 times higher than in the drained fish. Further samples of canned sardines and anchovies were purchased in June/July 1997 and, in all cases, BADGE levels were found to be below 1 mg/kg. In the other retail canned foods, BADGE was not detectable (DL = 0.02 mg/kg) or detected at concentrations well below the temporary SML of 1 mg/kg.

Animals↗
PubMed1997

Treatment of advanced Hodgkin's disease with chemotherapy--comparison of MOPP/ABV hybrid regimen with alternating courses of MOPP and ABVD: a report from the National Cancer Institute of Canada clinical trials group.

PURPOSE: This randomized, prospective trial compares outcomes for patients with advanced Hodgkin's disease treated with mechlorethamine, vincristine, procarbazine, and prednisone (MOPP)/doxorubicin, bleomycin, and vinblastine (ABV) hybrid regimen or alternating MOPP/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). METHODS: Three hundred one patients with advanced Hodgkin's disease were randomized to receive MOPP/ ABV hybrid regimen or alternating MOPP/ABVD after stratification for prior treatment, B symptoms, and treatment center. Eligible patients were either previously untreated and found to have stage IIIB, IVA, or IVB disease or previously treated with wide-field irradiation. Responding patients received a minimum of eight cycles of chemotherapy. Those with residual disease in a localized region received irradiation between the sixth and seventh cycle of treatment. RESULTS: Response rates to the two regimens were similar. Five-year overall survival rates were 81% and 83% for MOPP/ABV hybrid and alternating MOPP/ ABVD, respectively (P = .74; 95% confidence interval [CI] for the difference, -11% to 7%). Five-year failure-free survivals were 71% and 67% for MOPP/ABV hybrid and alternating MOPP/ABVD, respectively (P = .87; 95% CI for the difference, -9% to 17%). Significantly more episodes of febrile neutropenia and stomatitis were observed with the MOPP/ABV hybrid regimen; there was no significant difference in fatal toxicity. Patients with predefined, high-quality partial responses (PR-1s) had results similar to those with complete responses (CRs). Planned subset analysis showed no significant difference in outcome between the two arms of the trial for patients with newly diagnosed disease (5-year failure-free survival rates were 70% for MOPP/ABV hybrid and 59% for alternating MOPP/ABVD; P = .180), but superiority of alternating MOPP/ABVD for patients with prior irradiation (5-year failure-free survival 94% v 73%; P = .017). CONCLUSION: MOPP/ABV hybrid and alternating MOPP/ABVD regimens are equally effective for patients with advanced Hodgkin's disease.

Actuarial Analysis↗
PubMed1997

Prognostic value of cytogenetic abnormalities in previously untreated patients with non-Hodgkin's lymphoma.

In this study cytogenetic findings have been correlated with prognosis in 78 previously untreated patients with non-Hodgkin's lymphoma (NHL) presenting between 1983 and 1988. The median follow-up was 7 years (range 2-9 years). There was no significant difference in the duration of survival of 33 patients with only abnormal karyotypes, 35 patients with a mixture of normal and abnormal karyotypes (AN) and 10 patients with only normal karyotypes (NN). This was true for the entire group (p = 0.6) as well as for the subsets of diffuse lymphomas (DL) and follicular lymphomas (FL) (p = 0.6 and 0.4, respectively). Monosomy 14 was the only abnormality in the entire group of patients to be associated with a statistically significant difference in survival duration (p = 0.046). Among the FL patients, trisomy 7 (p = 0.046) and trisomy 12 (p = 0.010) were associated with shorter survival. Presence of t(14;18) did not influence survival in the entire group (p = 0.16), nor in any of the histological subgroups. Among the FL patients with t(14;18), presence of additional cytogenetic abnormalities was not associated with a worse outcome. The lack of consistency of results between various studies is likely to be due to several factors and the prognostic significance of karyotypic abnormalities can only be clarified by large prospective studies employing uniform treatment policies.

Adolescent↗
PubMed1996

Use of in-house studies of molecular epidemiology and full species identification for controlling spread of vancomycin-resistant Enterococcus faecalis isolates.

Infection with multidrug-resistant (MDR) organisms is a major clinical challenge, and few, if any, therapeutic options remain available. Increasingly, infection control measures have taken on greater importance in preventing the nosocomial transmission of MDR organisms. During December 1994 and January 1995, we identified a cluster of vancomycin-resistant Enterococcus faecalis isolates involving 16 patients situated in different areas of our university-affiliated teaching hospital. Initial review of laboratory requisition forms for the patients' locations revealed no common association, suggesting that the occurrence was not due to horizontal spread. However, using genomic DNA extraction, restriction enzyme analysis, and gel electrophoresis, we found that 12 patients were infected with isolates originating from a single clone, 2 other patients were infected with isolates from a different clone, and the remaining 2 patients were infected with unique strains. Because the typing data suggested nosocomial spread, chart review was undertaken to determine a possible common exposure source. With three exceptions, clonal isolates were linked to patient movement between surgical floors, intensive care units, and a rehabilitation unit. A detailed review of patient records revealing the association would not have been performed without realization of clonality. Thus, the data demonstrate the utility of genomic typing for epidemiological purposes. In turn, targeted infection control measures that halted the spread of the potentially lethal MDR pathogen were instituted.

Anti-Bacterial Agents↗
PubMed1995

Vancomycin-resistant Enterococcus faecium sepsis following persistent colonization.

Vancomycin-resistant enterococci have emerged as important nosocomial pathogens and represent a serious threat to patients with impaired host defenses. We describe a patient with leukemia who developed prolonged colonization with vancomycin-resistant Enterococcus faecium and ultimately died of sepsis due to this multidrug-resistant organism. This case report confirms that colonization with vancomycin-resistant enterococci may last indefinitely and that asymptomatic carriage can lead to invasive infection.

Adult↗
PubMed1995

Lymphocyte predominant Hodgkin's disease: a clinicopathologic comparative study of histologic and immunophenotypic subtypes.

PURPOSE: To compare the clinicopathologic features of the histologic and immunophenotypic subgroups of lymphocyte predominant Hodgkin's disease. METHODS AND MATERIALS: A retrospective review of 64 patients with lymphocyte predominant Hodgkin's disease treated at the Peter MacCallum Cancer Institute, Melbourne, was performed. Nodular and diffuse histological subtypes were confirmed by review of hematoxylin and eosin paraffin sections. Immunophenotyping with monoclonal antibodies L26 (B-cell origin) and Leu M1 (Hodgkin's phenotype) were available in 36 patients. RESULTS: The estimated freedom from progression and estimated overall survival at 10 years was 74% standard error (SE 5.8%) and 85% (SE 5.2%), non-Hodgkin's respectively. There were no significant differences in freedom from progression or overall survival when nodular and diffuse histology were compared. Similarly the presence of B-cell markers did not influence prognosis. There was only one case of secondary non-Hodgkin's lymphoma. CONCLUSION: Our results are consistent with major reported series displaying no differences between any of the subgroups of lymphocyte predominant Hodgkin's disease.

Adolescent↗
PubMed1995

Recovery of vancomycin-resistant enterococci on fingertips and environmental surfaces.

OBJECTIVE: To determine the recovery of vancomycin-resistant enterococci (VRE) on fingertips, gloved fingertips, and environmental surfaces commonly encountered in the healthcare setting, and to examine the importance of handwashing on the removal of these organisms. DESIGN: Two clinical isolates of VRE (Enterococcus faecalis and Enterococcus faecium) were inoculated onto the hands of healthy human volunteers and the following environmental surfaces: countertops, bedrails, telephones, and stethoscopes. Following inoculation, samples were obtained at various time intervals to determine rates of recovery of organisms. To evaluate the effects of handwashing on enterococcal recovery, two different soap preparations were tested. Hands were washed with water alone or with one of the soaps and water. The soap and water studies were performed with a 5-second and a 30-second wash. RESULTS: Both enterococcal strains survived for at least 60 minutes on gloved and ungloved fingertips. The E faecalis was recoverable from countertops for 5 days; the E faecium persisted for 7 days. For bedrails, both enterococcal species survived for 24 hours without significant reduction in colony counts. The bacteria persisted for 60 minutes on the telephone handpiece and for 30 minutes on the diaphragmatic surface of the stethoscope. A 5-second wash with water alone resulted in virtually no change in recovery of enterococci; a 30-second wash with water plus either soap was necessary to eradicate the bacteria from hands completely. CONCLUSION: VRE are capable of prolonged survival on hands, gloves, and environmental surfaces. Hands should be washed thoroughly and gloves removed following contact with patients infected or colonized with these multidrug-resistant bacteria. Finally, environmental surfaces may serve as potential reservoirs for nosocomial transmission of VRE and need to be considered when formulating institutional infection control policies.

Drug Resistance, Microbial↗
PubMed1995

Post-splenectomy lymphocytosis.

We describe post-splenectomy lymphocytosis (PSL) in 23 patients, a majority (20/23) of whom have undergone splenectomy as a staging procedure for Hodgkin's disease. The absolute lymphocyte count ranged from 4.0 to 8.7 x 10(9)/l. The lymphocytosis was noted 4-242 (median 70) months after splenectomy and persisted almost unchanged in most patients on prolonged follow up (median 50 months). Immunophenotyping of the lymphocytes revealed no monoclonal B cell population.

Adult↗
PubMed1994

Association of abnormalities of chromosome 11 with t(14;18) in diffuse non-Hodgkin's lymphoma.

Cytogenetic studies of non-Hodgkin's lymphomas (NHL) have revealed a nonrandom translocation, t(14;18)(q32;q21), to be strongly correlated with follicular histology. In our recent study of 149 cases of NHL, 68 cases had a t(14;18). Forty-four of these were follicular and 24 diffuse. In the majority of cases (90%) there were additional chromosome abnormalities, which were analyzed to determine whether any were specifically associated with diffuse histology. Chromosome 11 abnormalities occurring together with the t(14;18) were found to be present in 17/68 cases; 14/17 (82%) were diffuse and 3/17 (18%) were follicular NHL. Thus, 14/24 (58%) of all diffuse lymphomas with t(14;18) had an abnormality of chromosome 11 compared to only 3/44 (7%) of follicular lymphomas, suggesting that the addition of an abnormality of chromosome 11 to a t(14;18) karyotype is associated with diffuse histology.

Adult↗
PubMed1994

Selection of patients for randomised trials: a study based on the MACOP-B vs CHOP in NHL study.

BACKGROUND: Selection of patients for a clinical trial is affected by awareness of the existence of the trial, interest in the study question and clinical practices and views of the clinicians. AIMS: To investigate the selectivity that may have occurred at Peter MacCallum Cancer Institute (PMCI) during the ANZ Lymphoma Group trial of MACOP-B vs CHOP in non-Hodgkin's lymphoma (NHL). METHODS: NHL patients at PMCI in the study period were assessed against the trial's eligibility criteria. Comparisons were made between eligible (except for consent) non-trial patients and all patients actually randomised into the trial. RESULTS: Of 497 patients presenting during the trial period, 320 (64%) did not meet the specified eligibility criteria, 102 (21%) were unsuitable on other grounds (age and medical) and 75 (15%) were eligible. Of those eligible, 43 (57%) were entered into the trial and 32 (43%) were not. Four non-trial patients had inappropriate application of eligibility criteria and 13 unknown reason. Eligible non-trial patients were similar to trial patients in most patient and tumour characteristics and overall survival. Significantly more non-trial patients had higher stage disease (p = 0.02). More non-trial patients had lower grade histology, but this was not significant. CONCLUSIONS: Physician selectivity occurred with respect to patient entry, but trial and non-trial patients were similar in most characteristics. Eligibility criteria should specify that patients can withstand all trial drugs and patient availability for treatment and follow-up. PMCI trial accural could have been up to 33% greater. These results suggest the trial accrual period could have been 25% shorter. Patient entry into this trial by PMCI clinicians compared favourably with other centres.

Adult↗