Biomedical subjects
D I Thurnham
Publications and source records attributed to D I Thurnham.
Carotenoids: functions and fallacies.
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beta-Carotene, are we misreading the signals in risk groups? Some analogies with vitamin C.
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Free radical scavenging of lutein in vitro.
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Vitamin A, iron, and haemopoiesis.
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Micronutrients: how important in old age?
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Further evidence of lipid peroxidation in post-enteropathic haemolytic-uraemic syndrome.
Lipid peroxidation may play a role in the pathogenesis of the haemolytic-uraemic syndrome (HUS). Thirteen children with the post-enteropathic form of HUS were studied using conjugated diene lipids as markers of in vivo lipid peroxidation. Levels of total conjugated diene lipids and 9,11-linoleic acid, the principal conjugated diene in human plasma, were greater in the acute phase of this disorder than in controls. The ratio of plasma vitamin E to lipid was lower than that in children with other renal diseases, and the expected positive correlation between vitamin E and lipids did not hold for HUS patients. These data provide further evidence of lipid peroxidation in HUS and a disturbance in the metabolism of the principal lipid-bound anti-oxidant vitamin E.
Plasma ferritin concentration in relation to vitamin A and E status of children with severe oedematous malnutrition.
The association between plasma ferritin concentration and vitamin A and E status was studied in 17 children aged 15-72 months with severe oedematous malnutrition. The controls were 10 children of similar age who were apparently well and with no obvious signs of clinical malnutrition. Plasma ferritin concentration in the patients was significantly higher than that in the control children. Conversely, the plasma concentrations of beta-carotene, alpha-tocopherol and retinol in patients were significantly lower than those in plasma of control children. The median (interquartile range) plasma alpha-tocopherol concentration of patients, 6.03 (5.29-9.50) mumol/l, is below the threshold of vitamin E deficiency (11.6 mumol/l). Fifteen of 17 (88%) malnourished patients were found to have plasma tocopherol concentrations below the normal threshold. However, all the patients had a tocopherol: cholesterol ratio greater than 2.22, indicating adequate vitamin E status for the level of cholesterol present in plasma. Twelve of 17 patients (70.5%) had plasma retinol concentration less than 0.70 mumol/l, indicative of marginal vitamin A status, while 3 patients had plasma retinol concentrations less than 0.35 mumol/l, indicating vitamin A deficiency. The median (interquartile range) plasma retinol concentration of patients, 0.51 (0.41-0.93) mumol/l, is significantly less than that of control children, 0.96 (0.74-1.09) mumol/l; p less than 0.01 Mann Whitney U test. Furthermore, anaemia (Hb less than 110 g/l) was widespread in the patients. The results also indicate no significant correlation between elevated ferritin concentration and the concentrations of beta-carotene, retinol and alpha-tocopherol in the patients' plasma.(ABSTRACT TRUNCATED AT 250 WORDS)
Human requirements for riboflavin.
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Chain breaking antioxidant status in rheumatoid arthritis: clinical and laboratory correlates.
The ability of fresh sera to resist attack by peroxyl radicals (TRAP) was found to be significantly lower in 20 patients with rheumatoid arthritis (RA) than in 20 healthy controls, consistent with the existence of a redox stress in RA imposed by inflammation. TRAP values in RA varied inversely with a combination of visual analogue pain scale, duration of early morning stiffness, grip strength, and articular index (reflecting inflammatory activity) using multiple linear regression analysis. The concentration of the antioxidant vitamin ascorbic acid was lower in RA plasma and the oxidation-reduction equilibrium of ascorbic acid was disturbed, giving further support to the existence of a redox stress. The major determinant of TRAP in vitro was found to be serum uric acid in RA and serum vitamin E in controls. Serum urate concentration in RA correlated inversely with oxidative changes in serum albumin and IgG. It is suggested that serum urate might have an antioxidant role under certain conditions by limiting free radical induced oxidative changes to protein during inflammation.
Epidemiological study of precursor lesions of oesophageal cancer among young persons in Huixian, China.
A total of 538 subjects (354 males, 184 females) were investigated in a high-risk area for oesophageal cancer in China to provide large-scale data on the prevalence of chronic oesophagitis among persons below 25 years of age. The survey included an oesophagoscopy with guided biopsies and cytology, a physical examination, an interview and collection of a 10-ml blood sample and overnight urine. Histologically confirmed oesophagitis was found in 43.5% of male and 35.6% of female subjects. Mild and moderate oesophagitis was associated positively with consumption of burning hot beverages, family history of oesophageal cancer, frequent consumption of cottonseed oil, cigarette smoking, a clinical diagnosis of oral leukoplakia and seborrhoeic dermatitis; negative associations were seen with frequent consumption of fresh fruit, meat and eggs. A significantly higher level of urinary nitrate was found in the diseased group, but no difference was seen with regard to any of the N-nitrosamino acids measured.
Thiamine and sudden death in South-East Asians.
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An epidemiological study of precursor lesions of esophageal cancer among young persons in a high-risk population in Huixian, China.
The occurrence of chronic esophagitis, considered a precursor condition for esophageal cancer, among persons 15 to 26 yr of age and risk factors for the disease were investigated in Huixian, Henan Province, a high-risk area for esophageal cancer in the People's Republic of China. The 538 study subjects underwent an esophagoscopy with guided biopsies and cytology, a physical examination, an interview with a questionnaire including known and suspected risk factors for esophageal lesions, and collection of a 10-ml blood sample and overnight urine. One-third of the subjects was selected from households with a case of esophageal cancer in the past 6 yr and two-thirds came from control households. Histologically confirmed very mild, mild, and moderate esophagitis was observed in 31.6%, 10.7%, and 1.1% of 354 male and 30.4%, 4.3%, and 1.1% of 184 female subjects, respectively. In the multivariate case-control analysis of mile and moderate esophagitis compared with very mild esophagitis and normal subjects, the prevalence of mild and moderate disease was found to be positively associated with the consumption of burning hot beverages [odds ratio (OR) = 4.7], the prevalence of esophagitis among siblings (OR = 4.4), and family history of esophageal cancer (OR = 1.8) and negatively associated with the frequent consumption of fresh fruits (OR = 0.3) and wheat flour products (OR = 0.4). Weaker associations were seen for cigarette smoking and the use of cottonseed oil as the main cooking oil. Univariate associations seen with a clinical diagnosis of oral leukoplakia (OR = 2.7) and seborrheic dermatitis (OR = 3.7) are probably due to common risk factors such as smoking and nutritional deficiency. The present findings suggest that exposures early in life to environmental risk factors and nutritional deficiency may be responsible for inflammation and a weakened esophageal epithelium, resulting in a condition possibly more favorable for the development of esophageal cancer.
Influence of malaria infection on peroxyl-radical trapping capacity in plasma from rural and urban Thai adults.
Measurement of peroxyl-radical trapping capacity (TRAP) were made in plasma from patients with malaria from a rural and an urban Thai community. The results were compared with those from control subjects living in the same areas and chosen to match the patients closely. Measurements were also made of various antioxidants including nutritional indices vitamin C and alpha-tocopherol and the non-nutritional indices urate and protein-sulphydryl. Parasite counts, temperature on examination and the duration of illness were recorded together with measurements of plasma caeruloplasmin (EC 1.16.3.1), retinol and malondialdehyde (MDA). In general, most measurements made in the villagers were lower than those in the comparable urban groups. The exceptions were caeruloplasmin and MDA when the latter was expressed as MDA:cholesterol ratio. TRAP values were extremely low in 50% of the villagers and 25% of the urban patients with malaria and these results correlated with retinol and vitamin C and inversely with malonaldehyde. The results suggested that low TRAP values are associated with lipid peroxidation and that vitamin C and possibly retinol may be destroyed by the oxidative conditions present in the plasma in this disease.
Antioxidants and prooxidants in malnourished populations.
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Plasma ferritin concentrations in anemic children: relative importance of malaria, riboflavin deficiency, and other infections.
Anemia (hemoglobin less than 110 g/L) was documented in 36 children of both sexes aged 1-12 y who were divided into two groups: malaria and other infections. The control subjects were 10 children of similar age with no anemia and without any apparent infections. Plasma ferritin concentrations (median, range) were higher in the anemic patients (203 micrograms/L, 21-5000 micrograms/L) than in control children (52 micrograms/L, 25-239 micrograms/L) although ferritin concentrations in those with malaria were still within the normal range (99 micrograms/L, 21-205 micrograms/L). In the rest of the anemic group, five patients had plasma ferritin concentrations greater than 1000 micrograms/L. There was no difference in riboflavin status between control subjects and patients or between the two anemic groups. Severity of anemia was no different between the two anemic groups either. The data indicate that riboflavin deficiency makes no contribution to the infection-induced elevation in plasma ferritin and that the contribution of malaria is smaller than that of other unidentified factors.
Increased plasma lipid peroxidation in riboflavin-deficient, malaria-infected children.
Plasma lipid peroxides were measured as malonyldialdehyde (MDA) by the thiobarbituric acid (TBA) method in 75 children suffering from Plasmodium falciparum malaria. Their riboflavin status was assessed by measuring erythrocyte glutathione reductase activation coefficients (EGRACs), and values greater than 1.40 were regarded as indicating biochemical deficiency. Plasma MDA was higher (p less than 0.001) in patients than in control subjects; the concentrations were 3.65 +/- 0.70 and 1.77 +/- 0.45 mumol/L (means +/- SD), respectively. The riboflavin-deficient group had higher plasma MDA values (3.98 +/- 0.70 mumol/L) than did the nondeficient group (3.30 +/- 0.68 mumol/L, p less than 0.001). Plasma MDA concentrations correlated with EGRACs (r = 0.46, p less than 0.01) in the patients. It is proposed that riboflavin deficiency restricts regeneration of reduced glutathione making the parasitized erythrocytes more vulnerable to destructive lipid peroxidation and increasing plasma lipid hydroperoxides.