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Biomedical subjects

N A Green

Publications and source records attributed to N A Green.

At least 19 recordsLinked to original sources
PubMed1999

Degradation of 4-fluorobiphenyl in soil investigated by 19F NMR spectroscopy and 14C radiolabelling analysis.

The incubation of the model pollutant [U-14C]'-4-fluorobiphenyl (4FBP) in soil, in the presence and absence of biphenyl (a co-substrate), was carried out in order to study the qualitative disposition and fate of the compound using 14C-HPLC and 19F NMR spectroscopy. Components accounted for using the radiolabel were volatilization, CO2 evolution, organic solvent extractable and bound residue. Quantitative analysis of these data gave a complete mass balance. After sample preparation. 14C-HPLC was used to establish the number of 4FBP related components present in the organic solvent extract. 19F NMR was also used to quantify the organic extracts and to identify the components of the extract. Both approaches showed that the composition of the solvent extractable fractions comprised only parent compound with no metabolites present. As the 14C radiolabel was found to be incorporated into the soil organic matter this indicates that metabolites were being generated, but were highly transitory as incorporation into the SOM was rapid. The inclusion of the co-substrate biphenyl was to increase the overall rate of degradation of 4FBP in soil. The kinetics of disappearance of parent from the soil using the data obtained were investigated from both techniques. This is the first report describing the degradation of a fluorinated biphenyl in soil.

Biodegradation, Environmental↗
PubMed1999

Degradation of 4-fluorobiphenyl by mycorrhizal fungi as determined by (19)F nuclear magnetic resonance spectroscopy and (14)C radiolabelling analysis.

The pathways of biotransformation of 4-fluorobiphenyl (4FBP) by the ectomycorrhizal fungus Tylospora fibrilosa and several other mycorrhizal fungi were investigated by using (19)F nuclear magnetic resonance (NMR) spectroscopy in combination with (14)C radioisotope-detected high-performance liquid chromatography ((14)C-HPLC). Under the conditions used in this study T. fibrillosa and some other species degraded 4FBP. (14)C-HPLC profiles indicated that there were four major biotransformation products, whereas (19)F NMR showed that there were six major fluorine-containing products. We confirmed that 4-fluorobiphen-4'-ol and 4-fluorobiphen-3'-ol were two of the major products formed, but no other products were conclusively identified. There was no evidence for the expected biotransformation pathway (namely, meta cleavage of the less halogenated ring), as none of the expected products of this route were found. To the best of our knowledge, this is the first report describing intermediates formed during mycorrhizal degradation of halogenated biphenyls.

Basidiomycota↗
PubMed1989

Iron overload and the predisposition of cells to antioxidant consumption and peroxidative damage.

We have investigated the effects of iron overload in vivo on the tocopherol levels and the extent of lipid peroxidation in rat liver microsomes and their response to subsequent oxidative stress in vitro. The results demonstrate a direct correlation between consumption of antioxidant defences and the induction and extent of malondialdehyde production in microsomes prepared from iron-loaded rats. The data are consistent with the requirement for iron (II)/iron (III) ratios in lipid peroxidation in control microsomes.

Animals↗
PubMed1983

Is cervical spondylosis an occupational hazard for urologists?

Amongst 248 urologists who spend a substantial amount of their operative work performing endoscopic procedures and who were surveyed with reference to symptoms of cervical spondylosis, 118 admitted that they were, or had been, troubled by such symptoms (47.6%). A control group of 113 General Practitioners matched for age at qualification had no significantly fewer symptoms (43.4%). Similar numbers in each group had a history of neck injury, often of a sporting nature, and also had similar incidences of symptoms including pain down the arm. Significantly more urologists have current severe symptoms and more frequent attacks of trouble. Urologists offered a variety of advice on how to ameliorate these symptoms, which included attention to posture, the need for self-controlled motorised endoscopic tables, an endoscopic stool with wheels and the limitation of the number of transurethral prostatectomies per operating list.

Adult↗
PubMed1983

Distigmine bromide and post-prostatectomy voiding.

Distigmine bromide (Ubretid) is a long-acting anticholinesterase which is thought to improve detrusor function, restoring normal voiding patterns which may have been disturbed by autonomic overactivity, particularly after surgery. Ninety-three patients entered a double-blind study of the effect of distigmine bromide versus placebo on voiding after prostatectomy. The results demonstrated that there was a trend towards improvement but no statistically significant increase in post-operative flow rates, in reduction in bladder volume, and in the incidence of re-catheterisation in the patients treated with distigmine bromide.

Aged↗
PubMed1982

Blood loss during transurethral resection of the prostate.

Blood loss during operation was measured in 106 patients undergoing transurethral resection of the prostate, using a colorimetric technique. The total blood loss was related to the length of operation and the weight of prostate resected. There was no relationship between blood pressure and the blood loss during operation. However there was a significant reduction in blood loss if the patient received a regional rather than a general anaesthetic. Blood loss was lower in those patients undergoing prostatectomy for carcinomatous disease.

Aged↗
PubMed1981

A controlled trial of single dose intravesical adriamycin in superficial bladder tumours.

Sixty patients with recurrent superficial bladder tumours (Ta or T1) entered an open controlled trial of single dose Adriamycin. After transurethral resection of tumor recurrences, patients were alternately allocated to the control group or to the Adriamycin group, who received an instillation of 50 mg of Adriamycin in 50 ml of saline for 30 min. Six months later all patients were readmitted for endoscopy. In the Adriamycin group significantly more patients showed a decrease in the number of recurrent papillomas (72%) than in the control group (39%). This study shows that the use of adjuvant chemotherapy in the form of single dose Adriamycin is effective in reducing tumour recurrence.

Aged↗