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Biomedical subjects

T L Dormandy

Publications and source records attributed to T L Dormandy.

At least 37 records · Page 2Linked to original sources

Macrocytic anaemia due to copper deficiency in a patient with late onset hypogammaglobulinaemia.

Very few cases of acquired severe copper deficiency have been described. The principal effects are haematological, but the precise abnormalities are uncertain due to the possible association of other deficiencies. A case of isolated severe copper deficiency associated with late onset hypogammaglobulinaemia is reported in which the chief findings were macrocytic anaemia, neutropenia and a decrease in mean platelet volume. All these abnormalities resolved when copper therapy was instituted and recurred when the medication was stopped.

Agammaglobulinemia↗

Recognition of cervical neoplasia by the estimation of a free-radical reaction product (octadeca-9,11-dienoic acid) in exfoliated cells.

The molar ratio between a diene-conjugated linoleic-acid isomer (18:2(9,11)) and the parent linoleic acid (18:2(9,12)), both esterified as phospholipids, was significantly different in exfoliated cells from normal cervices and from cervices with colposcopic and cytological evidence of precancer. The measurement may provide a simple and perhaps improved alternative to cytological screening.

Biomarkers, Tumor↗

Ferroxidase II activity and serum cholesterol.

Ferroxidase II (Fox II) was developed in serum by acid incubation for 24 h. The resulting activity showed a strong positive correlation with the serum cholesterol concentration in normal subjects and patients with hyperlipidaemia. The potentiating effect of cholesterol on developed Fox II has been confirmed by the in-vitro addition of cholesterol to serum. There was no significant correlation between developed Fox II and caeruloplasmin (ferroxidase I) or between cholesterol and caeruloplasmin.

Ceruloplasmin↗

Free radicals in hypothermic rat heart preservation--prevention of damage by mannitol and desferrioxamine.

The free radical mediated oxidation of proteins in stored hypothermic rat hearts has been investigated by the estimation of fluorescence (Ex 360, Em 440-460 nm) believed to result from the oxidation of tryptophan residues. Damage occurring during ischaemia results in the release of oxidised proteins. This damage is significantly attenuated by mannitol and desferrioxamine although the mechanism of action of the two compounds may be different.

Animals↗

Increased free-radical activity during haemodialysis?

Free-radical activity was studied in patients on maintenance haemodialysis by measuring plasma octadeca-9, 11-dienoic acid (9,11-LA'), a diene-conjugated derivative of linoleic acid. Baseline values of 9,11-LA' (esterified as phospholipids and as free fatty acids) in 51 haemodialysis patients were similar to that of normal control subjects. However, during haemodialysis there was a highly significant (P less than 0.001) increase in 9,11-LA' in all 13 patients studied, which reached a peak 30 min after haemodialysis was started and then declined. The rise in plasma 9,11-LA' may be due to free radicals generated by activated neutrophils. Abnormal free-radical activity may be partly responsible for some haemodialysis-related complications, including pulmonary dysfunction in early haemodialysis.

Adult↗

Increased free-radical activity in alcoholics.

The identification of the main dieneconjugated "free-radical marker" in human serum led to a study of free-radical activity in chronic alcoholics. 66 patients were investigated immediately after alcohol withdrawal and over 1-4 weeks' follow-up. The control groups were 76 normal subjects, 78 patients with liver disease, 30 patients on long-term antiepileptic drug treatment, 9 pregnant women, and 99 unselected hospital patients. 82% of chronic alcoholics had a significantly higher than normal level of phospholipid-esterified 9,11 linoleicacid isomer in blood collected within 24 h of their last alcoholic drink. The levels fell to normal over the next 2-4 days but continued to decline within the normal range for 2-3 weeks. There was no rise in the level of the isomer in normal controls after an acute alcohol load. The results suggest that chronic alcoholism may induce a specific detoxifying mechanism which is activated by alcohol and which entails or depends on greatly increased free-radical activity.

Adolescent↗

A method for the measurement of a diene-conjugated derivative of linoleic acid, 18:2(9,11), in serum phospholipid, and possible origins.

A method is described for the measurement of a diene-conjugated derivative of linoleic acid, 18:2(9,11), in the phospholipid fraction of serum. The method is based on enzymatic hydrolysis, solid-phase sample preparation, and high-performance liquid chromatography (HPLC). Phospholipid esterified 18:2(9,11) can be detected in serum from normal individuals, and a provisional normal range is provided. The possible origins of 18:2(9,11) and the potential application of this method to the measurement of free radical damage to linoleic acid in vivo is discussed.

Adult↗

An approach to free radicals.

Free radicals have become a buzz word in experimental pathology and they are beginning to impinge on clinical practice.

Aging↗

The nature of diene conjugation in human serum, bile and duodenal juice.

Diene-conjugated lipids have been located by HPLC in serum, bile and duodenal juice. Whether esterified or not the same predominant fatty acid is responsible for most of the diene conjugation in all of these biological fluids. Initial attempts to generate this fatty acid in pure lipid by classical lipid peroxidation in vitro were unsuccessful. Ultraviolet irradiation of free fatty acids in the presence of protein produced diene-conjugated lipids similar to those found in vivo. The predominant diene-conjugated fatty acid in vivo is an isomerised C18:2 compound.

Bile↗

Lipid-peroxidation (free-radical-oxidation) products in bile from patients with pancreatic disease.

Serial samples of bile or duodenal or pancreatic secretions from patients with and without pancreatic disease were examined for lipid-peroxidation (free-radical-oxidation) products. Peroxidation products were found in the phospholipid fraction of bile and the free-fatty-acid fraction of duodenal juice but not in pancreatic juice. There was a highly significant difference in the concentration and excretion pattern of these products between the group of patients with pancreatic disease and the control group of patients with miscellaneous abdominal disorders.

Bile↗

Fluorescence changes in human gamma-globulin induced by free-radical activity.

Low-intensity ultraviolet irradiation was used to generate free-radical activity in lipid-free human gamma-globulin. The changes were monitored by fluorescence spectroscopy and gel filtration chromatography. The pattern and the effect of thiol compounds, free-radical scavengers and antioxidants point to a free-radical-mediated process. Initial energy uptake was probably in the region of aromatic amino acid residues, followed by complex intramolecular rearrangements. Irradiation led to the formation of molecular species and complexes whose fluorescence characteristics were different from those of native gamma-globulin and indistinguishable from those observed in inflammatory exudates.

Free Radicals↗

The effect of porta-systemic shunting on liver, brain and kidney zinc concentrations in the rat.

Patients with alcoholic cirrhosis have subnormal liver zinc concentrations, and excessive urinary zinc excretion. It has been suggested that diversion of dietary zinc into the systemic circulation through porta-systemic shunts may be a major factor influencing the organ distribution of zinc in these patients. To test this hypothesis, we randomized Sprague-Dawley rats into a sham-operated group, and a group subjected to partial portal-vein occlusion (PPVO), which induces the formation of extensive porta-systemic collaterals. Three months after the operation, liver, brain and kidney zinc concentrations were measured in 8 sham-operated and 8 PPVO rats. Mean liver zinc concentrations were significantly higher in the PPVO group when compared to sham-operated controls (P less than 0.05). Brain and kidney zinc concentrations were similar in the 2 groups. This short-term study indicates that liver zinc concentrations are maintained and even increased in rats with porta-systemic shunting, and that diversion of portal blood into the systemic circulation is not a major cause of the low liver zinc concentration observed in alcoholic cirrhosis.

Animals↗

Free-radical mediated aggregation of human gamma-globulin.

Ultra-violet irradiation of human gamma-globulin results in aggregation and the formation of fluorescent products. The fluorescence was inhibited by ascorbate and propyl gallate indicating the release of oxygen-free radicals.

Free Radicals↗

Lipid peroxidation in iron-overloaded spleens.

1. Iron-overloaded spleens from thalassaemic subjects showed a greatly increased susceptibility to free-radical oxidation (peroxidation) in vitro. 2. Iron content was the main but not the only variable governing susceptibility. Added ascorbate had a dose-dependent action either as an antioxidant or as a pro-oxidant, the direction of its effect depending mainly on the degree of iron overload. This has therapeutic implications.

Adolescent↗

Free radical oxidation (peroxidation)products in plasma in normal and abnormal pregnancy.

Using recently developed methods for measuring free-radical oxidation products in biological material, plasma extracts were studied in 24 women in the first two trimesters of pregnancy, in 124 women in the third trimester of pregnancy, in 20 women with pre-eclamptic toxaemia (PET), and in a control group. There was a significant progressive rise of two groups of free-radical oxidation products throughout pregnancy and a significantly greater rise in PET. In women whose diastolic blood pressure rose to above 70 mmHg there was a highly significant relation between two groups of free-radical reaction products and blood pressure.

Blood Pressure↗