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J J Strain

Publications and source records attributed to J J Strain.

At least 91 records · Page 5Linked to original sources
PubMed2000

Response of putative indices of copper status to copper supplementation in human subjects.

No sensitive functional index is currently available to assess Cu status in healthy human populations. This study evaluated the effect of Cu supplementation on putative indices of Cu status in twelve women and twelve men, aged between 22 and 45 years, who participated in a double-blind placebo controlled crossover study. The study consisted of three 6-week supplementation regimens of 3 mg CuSO4, 3 mg Cu-glycine chelate and 6 mg Cu-glycine chelate, each separated by placebo periods of equal length. Women had significantly higher caeruloplasmin oxidase activity (P < 0.001), caeruloplasmin protein concentration (P < 0.05), and serum diamine oxidase activity (P < 0.01) at baseline than men. Erythrocyte and leucocyte superoxide dismutase activity, leucocyte cytochrome c oxidase activity, and erythrocyte glutathione peroxidase activity did not respond to Cu supplementation. Platelet cytochrome c oxidase activity was significantly higher (P < 0.01), after supplementation with 6 mg Cu-glycine chelate in the total group and in women but did not change in men. Caeruloplasmin oxidase activity was significantly higher (P < 0.05), in men after supplementation with 3 mg Cu-glycine chelate, while caeruloplasmin protein concentration was significantly lower in men after supplementation with 6 mg Cu-glycine chelate (P < 0.05). Serum diamine oxidase activity was significantly higher after all supplementation regimens in the total group and in both men and women (P < 0.01). These results indicate that serum diamine oxidase activity is sensitive to changes in dietary Cu intakes and may also have the potential to evaluate changes in Cu status in healthy adult human subjects.

Adult↗
PubMed2000

Tracking of nutrient intakes in adolescence: the experiences of the Young Hearts Project, Northern Ireland.

This study evaluated the tracking of energy and nutrient intakes, assessed by diet history, in a random sample of adolescents (boys n 225, girls n 230) at baseline (age 12 years), and subsequently at age 15 years. Median energy (MJ/d) and macronutrient (g/d) intakes increased significantly (all P < 0.001) with increasing age in the boys. The girls' reported energy intake (MJ/d) remained stable over time, despite significant increases in BMI, weight and % body fat. Age-related changes in the girls' macronutrient intakes were inconsistent. When expressed in terms of nutrient density, the diets of both sexes became significantly richer, over time, in total folate (both sexes, P < 0.01), but poorer in Ca (boys P < 0.01, girls P < 0.001) and riboflavin (both sexes P < 0.001). Vitamin B6 (P < 0.001) and Fe (P < 0.05) densities increased in the boys, while the thiamin density of the girls' diets decreased (P < 0.001). Tracking, defined as maintenance of rank over time, was summarised using weighted kappa statistics (kappa). There were some significant changes in intakes at the group level; however, tracking of energy and nutrients in both sexes was only poor to fair (kappa < 0.40), indicating substantial drift of individuals between classes of intake over time. Particularly poor tracking was evident for % energy from sugars (kappa 0.09) and total fat (kappa 0.09) in the girls' diets. In conclusion, the poor to fair tracking observed in this cohort suggests that individual dietary patterns exhibited at 12 years of age are unlikely to be predictive of energy and nutrient intake at age 15 years.

Adolescent↗
PubMed1999

Oxidative stress and iron are implicated in fragmenting vacuoles of Saccharomyces cerevisiae lacking Cu,Zn-superoxide dismutase.

The absence of the antioxidant enzyme Cu,Zn-superoxide dismutase (SOD1) is shown here to cause vacuolar fragmentation in Saccharomyces cerevisiae. Wild-type yeast have 1-3 large vacuoles whereas the sod1Delta yeast have as many as 50 smaller vacuoles. Evidence that this fragmentation is oxygen-mediated includes the findings that aerobically (but not anaerobically) grown sod1Delta yeast exhibit aberrant vacuoles and genetic suppressors of other oxygen-dependent sod1 null phenotypes rescue the vacuole defect. Surprisingly, iron also is implicated in the fragmentation process as iron addition exacerbates the sod1Delta vacuole defect while iron starvation ameliorates it. Because the vacuole is reported to be a site of iron storage and iron reacts avidly with reactive oxygen species to generate toxic side products, we propose that vacuole damage in sod1Delta cells arises from an elevation of iron-mediated oxidation within the vacuole or from elevated pools of "free" iron that may bind nonproductively to vacuolar ligands. Furthermore, additional pleiotropic phenotypes of sod1Delta cells (including increased sensitivity to pH, nutrient deprivation, and metals) may be secondary to vacuolar compromise. Our findings support the hypothesis that oxidative stress alters cellular iron homeostasis which in turn increases oxidative damage. Thus, our findings may have medical relevance as both oxidative stress and alterations in iron homeostasis have been implicated in diverse human disease processes. Our findings suggest that strategies to decrease intracellular iron may significantly reduce oxidatively induced cellular damage.

Aerobiosis↗
PubMed1999

"Antioxidant" (reducing) efficiency of ascorbate in plasma is not affected by concentration.

Ascorbate (vitamin C), an important dietary derived antioxidant, reportedly shows decreasing "antioxidant efficiency" with increasing concentrations in indirect radical trapping methods of antioxidant capacity. This study investigated the effect of concentration on antioxidant efficiency of ascorbate using a direct test of antioxidant capacity, the ferric reducing/antioxidant power test (FRAP assay). Results showed that the antioxidant efficiency factor of ascorbate was 2 and was constant over a wide concentration range in both plasma and pure aqueous solution. However, the absolute amount of ascorbate lost per unit of time increased with concentration. Furthermore, ascorbate was less stable in plasma than in aqueous solutions of similar pH and less stable in ethylenediamine tetraacetic acid (EDTA) than in heparinized plasma. Results indicate that previously reported concentration-dependent changes in antioxidant efficiency of ascorbate may have been caused by loss of ascorbate prior to and during testing, and by methodologic characteristics of indirect peroxyl radical trapping tests of antioxidant capacity. Therefore, it is suggested that the premise that the antioxidant efficiency of ascorbate is concentration-dependent is largely methodologically derived and does not reflect the antioxidant behavior of ascorbate per se.

Journal Article↗
PubMed1999

Antioxidant enzymes, inflammatory indices and lifestyle factors in older men: a cohort analysis.

We examined the relationship between blood antioxidant enzyme activities, indices of inflammatory status and a number of lifestyle factors in the Caerphilly prospective cohort study of ischaemic heart disease. The study began in 1979 and is based on a representative male population sample. Initially 2512 men were seen in phase I, and followed-up every 5 years in phases II and III; they have recently been seen in phase IV. Data on social class, smoking habit, alcohol consumption were obtained by questionnaire, and body mass index was measured. Antioxidant enzyme activities and indices of inflammatory status were estimated by standard techniques. Significant associations were observed for: age with alpha-1-antichymotrypsin (p < 0.0001) and with caeruloplasmin, both protein and oxidase (p < 0.0001); smoking habit with alpha-1-antichymotrypsin (p < 0.0001), with caeruloplasmin, both protein and oxidase (p < 0.0001) and with glutathione peroxidose (GPX) (p < 0.0001); social class with alpha-1-antichymotrypsin (p < 0.0001), with caeruloplasmin both protein (p < 0.001) and oxidase (p < 0.01) and with GPX (p < 0.0001); body mass index with alpha-1-antichymotrypsin (p < 0.0001) and with caeruloplasmin protein (p < 0.001). There was no significant association between alcohol consumption and any of the blood enzymes measured. Factor analysis produced a three-factor model (explaining 65.9% of the variation in the data set) which appeared to indicate close inter-relationships among antioxidants.

Acute-Phase Proteins↗
PubMed1999

Effect of cholesterol feeding on DNA damage in male and female Syrian hamsters.

Cholesterol oxides are cytotoxic and have been implicated in many disease processes; however, it has been proposed that cholesterol oxides result from cholesterol acting as a sacrificial antioxidant. In this study, the effect of dietary cholesterol on DNA damage, assessed by the alkaline comet assay, was examined in male and female Syrian hamsters. Animals were fed ad libitum a modified AIN-76 diet (control) or a diet with 0.5% cholesterol for 10 weeks. Following the 10-week feeding period, there was no significant difference in body weight between cholesterol-fed and control animals. Cholesterol feeding resulted in significant liver hypertrophy, and increased plasma total and HDL cholesterol in both male and female animals compared with controls. There was no difference in liver cell DNA damage levels as measured by the comet assay. Heart cells from cholesterol-fed hamsters, however, showed a significant decrease in tail DNA (p = 0.050) indicating decreased damage compared with controls and a possible protective effect of cholesterol against DNA damage.

Animals↗
PubMed1999

Consumption of green tea causes rapid increase in plasma antioxidant power in humans.

Green tea contains polyphenolic antioxidants that have shown anticarcinogenic properties in animal and in vitro experimental studies. Current data regarding absorption and bioavailability of tea antioxidants in humans, however, are conflicting. In this study, plasma and urine antioxidant power after ingestion of green tea was measured using the ferric reducing/antioxidant power (FRAP) assay (US patent pending) to assess absorption, systemic distribution, and renal excretion of green tea antioxidants in healthy adults. Results showed that absorption of green tea antioxidants was rapid, with peak increase in plasma FRAP of around 4% at 40 minutes after ingestion: mean increase was 44 +/- 9 (SE) mumol/l. Excretion of polyphenolic antioxidants was also fast, peaking at 60-90 minutes, with significant correlation between urinary FRAP values and urinary total phenolic concentrations (r = 0.845, p < 0.001). In control studies, no increase in plasma or urine FRAP values was seen after intake of water. Although the amount of antioxidants absorbed was relatively small and the increase in plasma antioxidant power was of short duration, results demonstrate that some potentially anticarcinogenic polyphenolic antioxidants in green tea enter the systemic circulation soon after ingestion and cause a significant increase in plasma antioxidant status. This increase may, in turn, lower oxidative damage to DNA and so decrease risk of cancer.

Adult↗
PubMed1999

Dietary antioxidant supplementation and DNA damage in smokers and nonsmokers.

Deficiencies of antioxidant nutrients have been implicated in the etiology of lung and other cancers. However, most intervention trials with antioxidant nutrients have not shown beneficial effects, and some have indicated that beta-carotene may be deleterious. This randomized, double-blind, placebo-controlled study evaluated the effects of five short-term (4-wk) antioxidant nutrient supplement regimens [ascorbic acid (350 mg), RRR-alpha-tocopherol (250 mg), beta-carotene (60 mg), selenium (80 micrograms as sodium selenite), ascorbic acid (350 mg) + RRR-alpha-tocopherol (250 mg)] on plasma antioxidants and mononuclear leukocyte DNA damage in male smokers (n = 9) and nonsmokers (n = 12). Plasma concentrations of ascorbic acid and tocopherol were significantly increased by supplementation, but there was no significant change in plasma beta-carotene or blood glutathione peroxidase activity after supplementation with beta-carotene or selenium. DNA damage in mononuclear leukocytes, as assessed by comet assay, was not affected by any supplementation regimen. DNA damage, as assessed by 8-hydroxydeoxyguanosine in mononuclear leukocytes, was not influenced by ascorbic acid, alpha-tocopherol, or selenium supplementation in smokers or nonsmokers, but beta-carotene supplementation resulted in significant differences between smokers and nonsmokers in the level of oxidative DNA damage, with decreases in smokers and increases in smokers. This is a further indication of the differential effects of supplemental beta-carotene in smokers and nonsmokers.

Adult↗
PubMed1999

No effect of copper supplementation on biochemical markers of bone metabolism in healthy adults.

The influence of Cu supplementation of the usual diet for 6 weeks on biochemical markers of bone turnover and on putative indices of Cu status was investigated in healthy adults (twelve male and twelve female) aged 22-46 years, who participated in a double-blind placebo-controlled repeated crossover study. The study consisted of three 6-week supplementation regimens of 3 mg CuSO4, 3 mg Cu-glycine chelate (CuGC), and 6 mg CuGC, each separated by placebo periods of equal length. During baseline and on the last day of each dietary period, fasting morning first-void urine and fasting blood serum, plasma and erythrocytes were collected. The habitual dietary Cu intakes in males and females were approximately 1.4 and 1.1 mg/d respectively. Females had significantly higher (50%) plasma caeruloplasmin (Cp) protein concentrations than males at baseline. Cu supplementation had no effect on erythrocyte superoxide dismutase (SOD, EC 1.15.1.1) activity or plasma Cp protein (putative indices of Cu status) in the total group. Similarly, serum osteocalcin (a marker of bone formation), urinary creatinine (Cr) concentration, urinary pyridinoline: Cr or deoxypyridinoline: Cr excretion (markers of bone resorption) were unaffected in either the total group or in males and females separately, by any Cu supplementation regimen. It is concluded that Cu supplementation of the usual diet in healthy adult males and females had no effect on biochemical markers of bone formation or bone resorption over 6-week periods.

Adult↗
PubMed1998

Chaperone-facilitated copper binding is a property common to several classes of familial amyotrophic lateral sclerosis-linked superoxide dismutase mutants.

Mutations in Cu, Zn superoxide dismutase (SOD1) cause the neurodegenerative disease familial amyotrophic lateral sclerosis from an as-yet-unidentified toxic property(ies). Analysis in Saccharomyces cerevisiae of a broad range of human familial amyotrophic lateral sclerosis-linked SOD1 mutants (A4V, G37R, G41D, H46R, H48Q, G85R, G93C, and I113T) reveals one property common to these mutants (including two at residues that coordinate the catalytic copper): Each does indeed bind copper and scavenge oxygen-free radicals in vivo. Neither decreased copper binding nor decreased superoxide scavenging activity is a property shared by all mutants. The demonstration that shows that all mutants tested do bind copper under physiologic conditions supports a mechanism of SOD1 mutant-mediated disease arising from aberrant copper-mediated chemistry catalyzed by less tightly folded (and hence less constrained) mutant enzymes. The mutant enzymes also are shown to acquire the catalytic copper in vivo through the action of CCS, a specific copper chaperone for SOD1, which in turn suggests that a search for inhibitors of this SOD1 copper chaperone may represent a therapeutic avenue.

Amyotrophic Lateral Sclerosis↗
PubMed1998

Adipose tissue omega-3 and omega-6 fatty acid content and breast cancer in the EURAMIC study. European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Breast Cancer.

The fatty acid content of adipose tissue in postmenopausal breast cancer cases and controls from five European countries in the European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Cancer (EURAMIC) breast cancer study (1991-1992) was used to explore the hypothesis that fatty acids of the omega-3 family inhibit breast cancer and that the degree of inhibition depends on background levels of omega-6 polyunsaturates. Considered in isolation, the level of omega-3 or omega-6 fat in adipose tissue displayed little consistent association with breast cancer across study centers. The ratio of long-chain omega-3 fatty acids to total omega-6 fat showed an inverse association with breast cancer in four of five centers. In Malaga, Spain, the odds ratio for the highest tertile relative to the lowest reached 0.32 (95% confidence interval 0.13-0.82). In this center, total omega-6 fatty acid was strongly associated with breast cancer. With all centers pooled, the odds ratio for long-chain omega-3 to total omega-6 reached 0.80 for the second tertile and 0.65 for the third tertile, a downward trend bordering on statistical significance (p for trend = 0.055). While not definitive, these results provide evidence for the hypothesis that the balance between omega-3 and omega-6 fat may play a role in breast cancer.

Adipose Tissue↗
PubMed1998

Fish oil supplementation with and without added vitamin E differentially modulates plasma antioxidant concentrations in healthy women.

The purpose of this study was to assess the effect of fish oil with or without vitamin E on plasma vitamin antioxidants. Thirty-three apparently healthy women aged 18-28 yr were recruited from the university environs, and 30 completed the double-blinded, parallel design supplementation trial. Blood samples were collected at baseline (week 0) and following 28 d of supplementation with three capsules/d (0.8 g x 3) of either fish oil (FO) or FO with vitamin E (3 IU/g) (FOE). An additional blood sample was taken at day 91 (washout). Plasma antioxidant vitamins, fatty acid composition, and lipid peroxides were measured. Plasma alpha-tocopherol concentrations were increased significantly in both groups postsupplementation FO (P = 0.018) and FOE (P = 0.003) compared with baseline and washout values. Plasma retinol concentration was significantly increased (P = 0.034) compared with baseline and washout values following supplementation with FOE but not FO, while plasma beta-carotene was significantly increased (P = 0.036), compared with baseline and washout values, following supplementation with FO but not FOE. There was a trend (P = 0.059) toward decreased plasma ascorbic acid following FO supplementation compared with baseline and washout. Plasma lipid peroxides did not change following either supplementation. Results suggest that low-dose FO feeding with and without vitamin E differentially modulates plasma antioxidant vitamins but has no significant effect on lipid peroxidation.

Adolescent↗
PubMed1998

Adjustment disorder: a multisite study of its utilization and interventions in the consultation-liaison psychiatry setting.

The consultation-liaison (C-L) psychiatry services of seven university teaching hospitals in the United States, Canada, and Australia (the MICRO-CARES Consortium) used a common clinical database to examine 1039 consecutive referrals. A diagnosis of adjustment disorder (AD) was made in 125 patients (12.0%); as the sole diagnosis, in 81 (7.8%); and comorbidly with other Axis I and II diagnoses in 44 (4.2%). It had been considered as a rule-out diagnosis in a further 110 (10.6%). AD with depressed mood, anxious mood, or mixed emotions were the commonest subcategories used. AD was diagnosed comorbidly most frequently with personality disorder and organic mental disorder. Sixty-seven patients (6.4%) were assigned a V code diagnosis only. Patients with AD were referred significantly more often for problems of anxiety, coping, and depression; had less past psychiatric illness; and were rated as functioning better--all consistent with the construct of AD as a maladaptation to a psychosocial stressor. Interventions were similar to those for other Axis I and II diagnoses, in particular, the prescription of antidepressants. Patients with AD required a similar amount of clinical time and resident supervision. It is concluded that AD is an important and time-consuming diagnostic category in C-L psychiatry practice.

Adjustment Disorders↗
PubMed1998

Plasma ascorbate and vitamin E levels in Hong Kong Chinese.

OBJECTIVE: To describe fasting plasma total- and lipid standardised-vitamin E and ascorbate concentrations in Hong Kong Chinese subjects, and to explore age-, diet- and sex-related differences. DESIGN: Observational study. SETTING: Hong Kong. SUBJECTS: One hundred and fifty randomly selected Chinese subjects. INTERVENTIONS: Fasting plasma concentrations of ascorbate, total vitamin E and lipid standardised vitamin E (Vit E(LS), expressed as micromol vitamin E/mmol total cholesterol plus triglycerides) were measured. RESULTS: Total vitamin E concentrations ranged from 6-53 micromol/l (mean 24; s.d. 8.5), and Vit ELS from 0.85-7.09 micromol/mmol (mean 3.61; s.d. 1.19). Plasma Vit E(LS) concentrations in women were higher (P = 0.02) than in men: mean (median) concentrations 3.82 (3.88) and 3.37 (3.28) micromol/mmol, respectively. Vit ELS concentrations in men decreased with age. Mean (s.d.) plasma ascorbate concentrations in men and women were 49.7 (14.0) and 51.6 (21.6) micromol/l respectively, and did not show the significant age- and sex- differences reportedly found in Western studies. CONCLUSIONS: The hypothesis that Hong Kong Chinese, with their low risk of CHD, might have high Vit E(LS) levels in fasting plasma is not supported by the results obtained. Moreover, results showed male female differences and, in men, a previously unreported age-related decrease in plasma Vit E(LS) concentration which cannot be accounted for by concomitant differences in dietary intake of vitamin E alone. Results also suggest that the age- and sex- differences in plasma ascorbate seen in Western populations can be avoided by increased vitamin C intake.

Adult↗
PubMed1998

Monocyte tissue factor-like activity in post myocardial infarction patients.

It is widely recognized that thrombosis is the major event in the evolution of stable vascular disease to unstable ischaemic syndromes including myocardial infarction and stroke. The purpose of this case-control study was to establish clinical and laboratory data on the possible relationship between specific components of the haemostatic system and coronary heart disease. The procoagulant activity (PCA) of peripheral monocytes and polymorphonuclear neutrophils was assessed in 21 males who had suffered a myocardial infarction (MI) and in age-matched controls. In addition, total factor VII activity, fibrinogen, tissue factor pathway inhibitor (TFPI). D-dimers, tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), tumour necrosis factor-alpha (TNF-alpha) and full blood counts were measured. Post MI patients had significantly higher monocyte PCA, higher plasma concentrations of TFPI, fibrinogen, t-PA, T/P100 and also higher total white blood cell and neutrophil counts compared to age-matched controls. This elevated procoagulant state in post MI patients could further exacerbate the disease process and increase the risk of subsequent acute ischaemic events.

Blood Cell Count↗
PubMed1998

Tissue stores of individual monounsaturated fatty acids and breast cancer: the EURAMIC study. European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Breast Cancer.

The strongest evidence that monunsaturated fat may influence breast cancer risk comes from studies of southern European populations, in whom intake of oleic acid sources, particularly olive oil, appears protective. No previous study has examined the relation of adipose tissue fatty acid content to breast cancer in such a population. We used adipose biopsies with diverse fat intake patterns gathered in 5 European centers, including southern Europe (Malaga, Spain), to test the hypothesis that stores of oleic acid or other monounsaturates are inversely associated with breast cancer. Gluteal fat aspirates were obtained from 291 postmenopausal incident breast cancer patients and 351 control subjects, frequency-matched for age and catchment area. Logistic regression was used to model breast cancer by monounsaturates, with established risk factors controlled for. Oleic acid showed a strong inverse association with breast cancer in the Spanish center. The odds ratio for the difference between 75th and 25th percentiles was 0.40 (95% CI: 0.28, 0.58) in Malaga and 1.27 (0.88, 1.85) in all other centers pooled, with a peak at 2.36 (1.01, 5.50) for Zeist. Palmitoleic and myristoleic acids showed evidence of an inverse association outside Spain, and cis-vaccenic acid showed a positive association in 3 centers. These data do not support the hypothesis that increasing tissue stores of oleic acid are protective against breast cancer in non-Spanish populations. This finding implies that the strong protective associations reported for olive oil intake in dietary studies may be due to some other protective components of the oil and not to the direct effect of oleic acid uptake. Alternatively, high olive oil intake may indicate some other protective aspect of the lifestyle of these women.

Adipose Tissue↗