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Biomedical subjects

J Greaves

Publications and source records attributed to J Greaves.

15 recordsLinked to original sources
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

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↗
PubMed1979

A selected ion monitoring assay for primaquine in plasma and urine.

The antimalarial drug primaquine was analysed in plasma and urine by gas chromatography mass spectrometry, using a deuterated internal standard. After freeze-drying and extraction with trichloroethylene the sample plus internal standard was reacted with Tri Sil TBT (a 3:3:2 by volume mixture of trimethylsilylimidazole, N,O,-bis-(trimethylsilylacetamide and trimethylchlorosilane) and an aliquot injected into the gas chromatograph mass spectrometer. The gas chromatographic effluent was monitored at m/z 403 and m/z 406, the molecular ions of the bis-TMS ethers of primaquine and 6-trideuteromethoxy primaquine. Calibration curves were prepared from standards made up in plasma and urine. Data from the analysis of plasma and urine samples from a volunteer who ingested the equivalent of 45 mg primaquine are presented.

Adult↗
PubMed1978

Gas chromatography mass spectrometry studies on biologically important 8-aminoquinoline derivatives.

Several substituted 8-aminoquinolines related to known antimalarial drugs have been studied by gas chromatography mass spectrometry. 5,6-Dihydroxy-8-aminoquinoline, a possible metabolite of Primaquine, can be detected by single ion monitoring after conversion to a trimethylsilyl ether derivative. The mass spectra obtained in this study indicate that there are certain ions which are characteristic of the trimethylsilyl ethers of hydroxylated 8-aminoquinolines and 5,6-dimethoxy-8-aminoquinolines. These compounds should thus be amenable to analysis if they were produced during in vivo metabolism studies. Using selected ion monitoring the derivatized compounds can be detected at submicrogram levels.

Aminoquinolines↗