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Biomedical subjects

J Greaves

Publications and source records attributed to J Greaves.

At least 19 recordsLinked to original sources
PubMed1994

Healthcare and the environment.

There are many reasons why you should be concerned about the environment, particularly if you are a healthcare professional. Every environmental pollutant is also associated with a human health risk. So improving the environment will mean better healthcare. In addition we should make sure all our actions are such as not to impair the development of future generations. National governments and, in particular, the European Commission have recognised this public concern and have generated a large amount of environmental legislation in order to change the way we behave. A summary of this legislation is provided along with more detailed discussions on waste legislation.

Environmental Health↗
PubMed1993

Accumulation of polychlorinated terphenyls in aquatic biota of an estuarine creek.

Aroclor 5432, a mixture of polychlorinated terphenyls (PCT), was detected in several biological compartments including saltmarsh cordgrass (Spartina alterniflora), American oysters (Crassostrea virginica), red-jointed fiddler crabs (Uca minax), wharf crabs (Sesarma reticulatum), and mummichogs (Fundulus heteroclitus) collected from Tabbs Creek. This tidal creek is located in the southern Chesapeake Bay region and contains sediments with high concentrations of PCT. Samples were collected at four sites, ranging from a suspected outfall near the head of the creek, to its mouth, approximately 2.5 river kilometers downstream. Species from several phyla were selected in order to examine PCT accumulation in physiologically and ecologically different organisms. PCT concentrations in sediment, saltmarsh cordgrass, native oysters, and fiddler crabs decreased with distance downstream. Residues in transplanted oysters and mummichogs showed a more variable trend with distance downstream. The organism with the highest mean concentration (18,300 micrograms/kg dry wt) was the native oyster, a benthic filter feeder.

Animals↗
PubMed1992

Methods for the analysis of persistent chlorinated hydrocarbons in tissues.

Chlorinated hydrocarbons bioaccumulate in tissues and may have severe health consequences. These compounds occur individually, in small groups or as complex mixtures; examples of each category include aldrin, hexachlorocyclohexane and the polychlorinated biphenyls. Tissue extraction and purification schemes have been established, although new approaches such as supercritical fluid extraction are promising. Analyses often require the resolving power of capillary gas chromatography, in combination with the sensitivity and selectivity of electron-capture detection, electrolytic conductivity detection and mass spectrometry. Difficulties arise in quantitating chlorinated hydrocarbons in tissues, due to the number of components present and the fact that individual constituents may be reduced or enhanced in concentration in tissues, compared with the original formulation. Congener specific analysis and computer-assisted identification techniques have been applied to the problem.

Chromatography↗
PubMed1992

APL: a corporate strategy.

This paper is based on, and summarises, papers read at the second annual international conference of Nurse Education Tomorrow held at the University of Durham (UK) September 1991. To this end this paper will offer: Some Accreditation of Prior Learning (APL) definition and process as reflected in the literature available. A distinction will be made between APL and Accreditation of Prior Experiential Learning (APEL) although the procedures and processes for assessing them will be shown to be the same. A brief outline of corporate strategy, as it applies to APL, will be given to form the basis for logical demonstration of how Derbyshire Institute of Health and Community Studies has employed such a corporate strategy. Insights developed and gained from APL research currently being undertaken through the college of nursing and midwifery will be used to inform the development and nature of corporate strategy. A flowchart of the operationalisation of the corporate strategy is offered as an integrative summary of how all the APL ideas have had a positive cumulative effect. The paper finishes by highlighting the possible strengths and limitations of APL corporate strategy.

Accreditation↗
PubMed1992

Occupational reintegration of long-term cancer survivors.

To determine the long-term psychosocial consequences of cancer related to work, a postal survey was conducted among 849 long-term survivors of cancer in the southwest Netherlands. Forty-four percent of the responders who worked at the time of the diagnosis of cancer returned to their job, 24% of them part-time. Fourteen percent experienced impediments at work after return. Absenteeism in this group does not differ from that in the year prior to the moment of diagnosis. There is a small decrease in promotional and financial prospects.

Absenteeism↗
PubMed1991

Problems at social re-integration of long-term cancer survivors.

To assess the long-term consequences of cancer for everyday life, a postal survey in the Netherlands was done among 849 ex-cancer patients. Almost all responders were self-supporting to a large extent. Compared with the period before diagnosis, the socioeconomic position had not changed in 62%. 28% of the responders who were employed at the time of diagnosis (10% of all responders), were now housekeepers (99% female). Absence from work at survey did not differ significantly from absence in the year before diagnosis. A history of cancer tended to have a negative impact on promotional prospects and income. Ex-cancer patients were often confronted with problems when they tried to take out insurance or to modify an existing policy. The psychological well-being of the responders was low, compared to the average Dutch population.

Activities of Daily Living↗
PubMed1991

'The Barn'.

An exciting new concept in operating theatre suite design is being pioneered at the Robert Jones and Agnes Hunt Orthopaedic Hospital. Jane Donnelly visited 'The Barn' in February and reports on how the work is progressing.

Humans↗
PubMed1989

Fast-atom bombardment mass spectrometry of conjugated benzo(a)pyrene metabolites.

Fast-atom bombardment mass spectrometry has been used to obtain spectra of conjugated benzo(a)pyrene (bap) metabolites using a 1:1, glycerol + thioglycerol matrix, bap Glucuronides give positive- and negative-ion spectra with peaks due to [M + H]+ and [M - H]- ions and a major fragment peak (base peak) at [bap-OH]+ and [bap-O]-. bap Sulfates (sodium salts) give similar negative-ion spectra with [M - Na]- and [bap-O]- peaks, but the positive-ion spectra are dominated by sodium and glycerol adducts of the bap sulfates.

Animals↗
PubMed1988

A selective ion monitoring assay for tributyltin and its degradation products.

Tributyltin (TBT) is a biocide which has been shown to enter the aquatic environment by release from antifouling paints. TBT is acutely toxic to some marine organisms at concentrations near 1 microgram l-1 and physiological changes may occur at low nanogram per liter concentrations. Gas chromatography/mass spectrometry (GC/MS) (methane chemical ionization) has been used for identification (full scanning) and quantification (selected ion monitoring) of TBT, dibutyltin (DBT) and monobutyltin (MBT). The butyltins were extracted from environmental water samples with hexane/0.2% tropolone and derivatized with hexyl magnesium bromide to form hexylbutyltins. Selected ion monitoring was at m/z 319 (TBT) and m/z 347 (DBT, MBT and tripentyltin, the internal standard). Calibration curves prepared in natural water were linear and detection limits were less than 2 ng l-1. GC/MS and GC with flame photometric detection were compared as quantification methods for environmental samples and were shown to give similar results at the low nanogram per liter levels.

Gas Chromatography-Mass Spectrometry↗
PubMed1987

Characterization of benzo(a)pyrene metabolites by high performance liquid chromatography-mass spectrometry with a direct liquid introduction interface and using negative chemical ionization.

Polynuclear aromatic hydrocarbons are ubiquitous pollutants that may become highly carcinogenic during their metabolism by organisms. Benzo(a)pyrene is an example of such a compound. Benzo(a)pyrene metabolite standards, which are labile, polar compounds, have been used to evaluate high performance liquid chromatography-mass spectrometry as an analytical technique for polynuclear aromatic hydrocarbon metabolites. The chromatography used microbore (1 mm i.d.) C18 columns with acetonitrile/water as the elution solvent which became the reagent/moderator gas. A direct liquid introduction interface was used and characteristic spectra were obtained in the negative chemical ionization mode. Molecular or pseudomolecular ions were obtained for five phenols (m/z 268 and m/z 267) and three trans-dihydrodiols (m/z 286, m/z 285, m/z 284). Useful spectra were also obtained for a tetrahydrotriol, four tetrahydrotetrols and three conjugated metabolites. Fragmentation usually involved loss of water and anions at m/z 284 and m/z 268 were common to most of the spectra. Variations in the source/desolvation chamber temperature between 175 degrees C and 275 degrees C caused significant alterations in the relative abundance of molecular and fragment ions. Dissociative electron capture was the dominant ionization process.

Benzo(a)pyrene↗
PubMed1985

Analytical and pharmacological studies on a new antineoplastic tripeptide, PTT.119.

The new synthetic tripeptide, p-fluoro-L-phenylalanyl-m-bis-(2-chloroethyl)-amino-L-phenylalanyl-methi onine ethylester hydrochloride, PTT.119, an alkylating agent, is currently undergoing preclinical trials as an antineoplastic agent. The molecular composition, C29H39N4O4SCl2F, was confirmed by desorption chemical ionization mass spectrometry with accurate mass measurement. A high-performance liquid chromatographic technique was developed for the quantification of PTT.119 in cell culture medium and serum. Incubation of 5 X 10(5) mammary tumor cells (MJY-alpha)/ml tissue culture medium with 25 micrograms PTT.119/ml for 60 min (37 degrees C) removed 68% of the tripeptide from the medium. This corresponds to an uptake of 51 fmol PTT.119/tumor cell. Cell death, assessed 5 days after treatment, was directly proportional to the time-dependent removal of PTT.119 from the cell culture medium.

Antineoplastic Agents↗
PubMed1985

Polybrominated biphenyls in model and environmentally contaminated human blood: protein binding and immunotoxicological studies.

A review and summary is given of analytical, biochemical, and immunological studies made following an immunodiagnostic investigation which revealed significant decreases in the numbers, and changes in the functional integrity, of both T-and B-lymphocytes in a group of Michigan dairy farmers exposed to polybrominated biphenyls (PBB) which had been inadvertently introduced into the food chain in 1973. A quantification technique based on selected ion monitoring of bromine anions, obtained in negative chemical ionization, permitted determination of 10-35 pg of individual PBB congener per mL serum, a 20-fold improvement over electron capture gas chromatography. An in vitro spiked system was established and shown to be a representative model of environmentally contaminated blood. Immunoprecipitation followed by mass spectrometric quantification determined that the distribution of PBB among plasma, erythrocytes, mononucleocytes and polymorphonucleocytes was 89:9:less than 1:less than 1. In plasma 80% of the PBB was bound to apolipoproteins B and A in a 3:1 ratio. No preferential absorption of PBB congeners was found in the blood compartments suggesting that changes in the relative abundances of PBB congeners observed in longitudinal studies on Michigan subjects reflect differences in excretion rates or metabolism. A repeat in 1981 of the immunodiagnostic tests conducted in 1976 revealed a virtually complete persistence of the immune dysfunctions in the Michigan farmers exposed to PBB a decade ago.

Agricultural Workers' Diseases↗
PubMed1985

Hyaluronic acid content of effusions as a diagnostic aid for malignant mesothelioma.

A high-performance liquid chromatographic technique, using a size exclusion column (TSK-5000PW), has been developed for the quantification of hyaluronic acid (HA) in pleural and peritoneal effusions. Sample preparation requires only a 100-fold dilution of the exudate with phosphate buffer prior to analysis. Chromatographic conditions are: 0.05 M phosphate buffer (pH, 5.0) mobile phase at a flow rate of 1.0 ml/min, ultraviolet absorbance detection at 200 nm. The method resolves HA from all other glycosaminoglycans. The presence of HA is confirmed by the removal of the HA peak (retention time, approx. 5.3 min) by incubation of a second sample aliquot with hyaluronidase. Effusions of 13 of 14 patients with confirmed malignant mesothelioma contained HA in the 0.3 to 11.1 mg/ml range. In only one case was no HA detected. None of the effusions from 56 control patients with various other primary tumors contained detectable HA, i.e., there were no false positives. An unidentified peak, not susceptible to hyaluronidase appeared in 11% (6 of 56) of the controls. A single mesothelioma case was correctly identified in a group of 10 coded samples. It is suggested that an effusion with an HA concentration greater than 0.25 mg/ml, confirmed by hyaluronidase susceptibility, is an indication of the presence of malignant mesothelioma. The test is simple and rapid, and it is recommended that any effusion of uncertain etiology be screened for the presence of HA.

Ascitic Fluid↗