Effect of eating on plasma radical-trapping antioxidant activity (TRAP) in patients with cirrhosis

OBJECTIVES: To ascertain the effects of eating on plasma antioxidant capacity in patients with liver disease. DESIGN AND METHODS: Eighteen cirrhotic patients were compared to 18 age and sex-matched controls. TRAP was measured by a fluorometric assay after a 12 h fast, and 60, 120, and 180 min after the study participants had taken a drink formula food. RESULTS: In the fasting state, TRAP was higher in patients with alcoholic cirrhosis (847+/-39 micromol/L, mean +/- SEM) in comparison to patients with viral cirrhosis (653+/-41) and to controls (758+/-26) (p<0.005). In cirrhotic patients, TRAP did not change in the post-absorptive state. In controls, TRAP decreased progressively, to a value of 719+/-21 (p<0.02), and the AUC of the delta-values of TRAP and of plasma insulin showed an inverse correlation (r = -0.52, p<0.05). CONCLUSIONS: In normal subjects, but not in cirrhotics, TRAP decreases in the post-absorptive state, probably in relationship with the activation of metabolic pathways.     

Twin reversed arterial perfusion (TRAP) syndrome

Twin reversed arterial perfusion (TRAP) syndrome is an extremely rare manifestation of feto-fetal transfusion syndrome. This condition is seen in monozygotic twin pregnancies, where the affected twin is perfused retrogradely by the healthy twin. The affected twin presents with bizarre malformations such as acardia and acephalus. We present such a case, which was diagnosed prenatally. The pregnancy progressed uneventfully to term.     

运动健身与自由基研究现状和进展

目的:运动可以健身,但是运动方式和强度不当反而不利于健康。运动可以产生自由基可能是原因之一。从一次性急性有氧运动、一次性大强度无氧运动和不同强度运动后体内氧化和抗氧化系统变化规律进行综述,从自由基角度找出运动健身的最佳强度。资料来源:从www.ncbi.nlm.nih.gov/PubMed和www.ncki.net检索1978-01/2003-12的国内外期刊文献,逐一校对,检索词:自由基(freeradical),运动(exercise),强度(intensity)。资料选择:选择运动与自由基关系的文章100篇。排除非随机研究原著性文献,未排除非盲法研究原著的文献。资料提炼:在100篇文献中,内容呈不同程度重复的有24篇,给予删除;对76篇文献进行分类整理,用于综述,其中36篇选用为参考文献。资料综合:大量的文献是研究一次性运动后自由基的变化,缺乏运动中自由基变化的研究。另外缺乏连续递增强度运动与自由基关系的研究。结论:从自由基角度提出,应该把体内氧化和抗氧化系统失衡的强度作为运动健身的适宜强度。     

Tailored management of twin reversed arterial perfusion (TRAP) sequence.

OBJECTIVE: To describe our management of pregnancies complicated by twin reversed arterial perfusion (TRAP) sequence. METHODS: This was a retrospective study involving all cases of TRAP sequence referred to our fetal medicine unit in a 3-year period (2000-2002). Patients were routinely managed by repeat sonographic surveillance with sonographic anatomical evaluation and detailed echocardiography. Cases with signs of impending cardiac failure were treated by in-utero YAG-laser coagulation of the umbilical vessels of the acardiac twin. RESULTS: Six cases were studied. Three patients in whom there were no signs of deterioration in the status of the pump twin, and in whom the acardiac twin was smaller than the pump twin, were managed conservatively. However, one of these with monoamniotic twins ended in intrauterine fetal death of the pump twin. The other two cases presented with spontaneous cessation of blood flow in the umbilical artery of the acardiac twin. Both delivered at term normal neonates whose follow-up revealed no signs of neurological sequelae. One case of quadruplet pregnancy (with TRAP sequence and two dichorionic twins) was treated by selective termination of the monochorionic twins. Two cases with signs of impending cardiac failure were treated by in-utero YAG-laser occlusion of the vessels in the acardiac mass. Both interventions had a favorable outcome. CONCLUSIONS: Conservative treatment is suitable for milder cases of TRAP sequence in which the pump twin is the larger one. Cases in which the acardiac twin is larger have a poorer prognosis and should be treated by invasive intervention and cord occlusion.     

Total homocysteine, vitamin B(12), and total antioxidant status in vegetarians

BACKGROUND: Decreasing or eliminating animal products from the diet decreases the intake of some essential nutrients, such as vitamin B(12), which may lead to hyperhomocysteinemia. We investigated vitamin B(12)-dependent metabolism and oxidative stress in groups with various or no intake of meat or animal products. METHODS: We investigated 44 high meat eaters, 19 low meat eaters, 34 lacto-ovo/lacto vegetarians, and 7 vegan vegetarians. Homocysteine (HCY) was assayed by HPLC, methylmalonic acid (MMA) by capillary gas chromatography-mass spectrometry, serum folate and vitamin B(12) with a chemiluminescence immunoassay, and total antioxidant status (TAS) by a Randox method. RESULTS: The mean serum HCY concentration of vegetarians was significantly increased, and in vegans the median concentration exceeded 15 micromol/L. Vegetarians had a higher serum concentration of MMA but a lower TAS. Vitamin B(12) and folate did not differ significantly between vegetarian and omnivorous subjects. Overall, HCY and MMA were significantly correlated. Vitamin B(12) correlated negatively with MMA, HCY, and folate, whereas the correlation with TAS was positive. Backward regression analysis revealed an independent influence of MMA on HCY, of HCY and vitamin B(12) on MMA, and of vitamin B(12) on TAS. The increased MMA concentration suggested a 25% frequency of functional vitamin B(12) deficiency in all vegetarians. Serum vitamin B(12) was below the lower reference limit in only five subjects. CONCLUSIONS: Functional vitamin B(12) deficiency in vegetarians may contribute to hyperhomocysteinemia and decreased TAS, which may partly counteract the beneficial lifestyle of vegetarians. However, increased serum HCY is most likely not responsible for the lower TAS values in vegetarians. We recommend assaying of MMA and HCY to investigate functional vitamin B(12) status.     

Total antioxidant capacity and malondialdehyde in acute abdominal pain

Recent investigations suggest that oxidative stress markers are useful in the evaluation of some types of abdominal pathology. We hypothesized that the severity of abdominal pain is correlated with oxidative stress as quantified by total antioxidant capacity (TAC) and malondialdehyde (MDA). The objective of this study was to determine the plasma TAC and MDA levels in patients with acute abdominal pain and to examine their relation to abdominal emergency. We recruited 128 patients presenting with acute abdominal pain at the emergency department. Medical history, vital signs and laboratory data were collected on arrival. TAC and MDA levels were determined using serums obtained from the initial blood sampling. Patients with acute abdominal pain had lower levels of TAC and higher levels of MDA than normal control. When patients were grouped according to whether they were discharged early (less than 24 hours) or hospitalized longer than 24 hours, Patients with hospital stay > 24 hours had significantly elevated pulse rate, temperature, leukocyte count, and C reactive protein (CRP) and lower TAC. No significant difference was found in age, sex, temperature, respiratory rate, blood pressure, and MDA level. Multivariate logistic regression analysis revealed that CRP and TAC were significant indicators of quantitative variables for disposition. This study found a correlation exists between oxidative stress and disease severity in patients with abdominal pain. This suggests that TAC might be useful as a guide for patient disposition in the emergency department.     

MÜNCHAUSEN'S SYNDROME (HIV INFECTION): A TRAP FOR THE UNWARY

SUMMARY A case of Münchausen's syndrome with AIDS illustrates the need for a high index of caution when dealing with individuals whose histories are inconsistent and suspicious, particularly when they have moved area.     

Total antioxidant status in type 2 diabetic patients: experience at University College Hospital (UCH) Ibadan, Nigeria

Total antioxidant status (TAS) was measured in 20 Type 2 diabetic patients aged 40-60 years (mean 50 years). Patients were on diet and oral hypoglycemic drug therapy, with fasting plasma glucose (FPG) levels > 7.0 mmol/L. Similar measurements were carried out in 20 apparently healthy individuals within the same age range (mean 46 years) and with FPG levels < 6.1 mmol/L. FPG was measured by glucose oxidase method and TAS by a colourimetric method. Comparing the two groups, TAS was significantly reduced in the Type 2 diabetic patients (0.96 +/- 0.37 Vs 1.61 +/- 0.16 mmol/L) (P < 0.05). An inverse correlation between FPG and TAS suggested the existence of a lower antioxidant defense in poorly controlled Type 2 diabetics. Good control of FPG, could possibly help reduce free radical activity and probably minimize the chronic complications in diabetic patients.     

In vitro anticandidal and antioxidant potential of Mezoneuron benthamianum

ObjectiveTo investigate the preliminary phytochemical screening and antioxidant properties of the methanolic extract of Mezoneuron benthamianum (M. benthamianum).MethodThe anti-candidal potential and minimum inhibition concentration (MIC) were evaluated on fresh isolates of Candida species using disc diffusion method. While the lipophilic free radical scavenging activity was examined using the spectrophotometric assay on the reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and compared with standard antioxidant, α-tocopherol.ResultThe anti-candidal activities of M. benthamianum root and leaf revealed zones of inhibition (ZI) against Candida glabrata as (13.6±1.00) mm and (13.7±1.00) mm respectively while, Candida krusei ZI against root (13.7±1.00) mm and leaf (11.8±0.80) mm as the most significant among other candida species (Candida stellatoidea, Candida albicans and Candida torulopsis). Phytochemicals present in the plant extracts includes saponin, anthracquinones, flavonoids and tannins. The antioxidant potential of the plant was significant and dose dependent at the concentrations tested. The extract has IC₅₀ values of 781 μg/mL while the standard, α-tocopherol has 222.3 μg/mL.ConclusionsThe result from this research suggests that M. benthamianum is a potent anti-candida and antioxidant plant and may be a potential anti-candida plant for future prospect in drug development.     

Influence of exercise intensity on systemic oxidative stress and antioxidant capacity

The aim of the current study was to examine the influence of exercise intensity on systemic oxidative stress (OS) and endogenous antioxidant capacity. Non‐smoking, sedentary healthy adult males (n = 14) participated in two exercise sessions using an electronically braked cycle ergometer. The first session consisted of a graded exercise test to determine maximal power output and oxygen consumption (VO_2max). One week later, participants undertook 5‐min cycling bouts at 40%, 55%, 70%, 85% and 100% of VO_2max, with passive 12‐min rest between stages. Measures of systemic OS reactive oxygen metabolites (dROM), biological antioxidant potential (BAP), heart rate (HR), VO₂, blood lactate and rating of perceived exertion were assessed at rest and immediately following each exercise stage. Significant (P<0·05) differences between exercise bouts were examined via repeated measures ANOVA and post hoc pairwise comparisons with Bonferroni correction. Increasing exercise intensity significantly augmented HR (P<0·001), VO₂ (P<0·001), blood lactate (P<0·001) and perceived exertion (P<0·001) with no significant effect on dROM levels compared with resting values. In contrast, increasing exercise intensity resulted in significantly (P<0·01) greater BAP at 70% (2427 ± 106), 85% (2625 ± 121) and 100% (2651 ± 92) of VO_2max compared with resting levels (2105 ± 57 μmol Fe²⁺/L). The current results indicate that brief, moderate‐to‐high‐intensity exercise significantly elevates endogenous antioxidant defences, possibly to counteract increased levels of exercise‐induced reactive oxygen species. Regular moderate‐to‐high‐intensity exercise may protect against chronic OS associated diseases via activation, and subsequent upregulation of the endogenous antioxidant defence system.     

The antioxidant potential of peptides obtained from the spotted babylon snail (Babylonia areolata) in treating human colon adenocarcinoma (Caco-2) cells

This research study investigated the free radical-scavenging activities of peptides which were obtained from the protein hydrolysates of the spotted babylon snail using a combination of pepsin and pancreatin proteolysis which can replicate the conditions of gastrointestinal digestion. In this study, spotted babylon protein hydrolysate (SPH) derived from a sequential 3 hour digestion, first with pepsin and then with pancreatin, was examined. SPH was fractionated using molecular weight cut-off membranes for 10 kDa, 5 kDa, 3 kDa, and 0.65 kDa. It was found that the MW < 0.65 kDa fraction provided the greatest levels of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazl (DPPH), and nitric oxide (NO) radical scavenging activity. Three subfractions of the MW < 0.65 kDa fraction were then generated via RP-HPLC. The subfraction which subsequently demonstrated the greatest free radical scavenging activity was F₃, which was accordingly chosen for further investigation commencing with quadrupole-time-of-flight-electron spin induction-mass spectrometry-based de novo peptide sequencing. This resulted in the identification of a pair of novel peptides: His–Thr–Tyr–His–Glu–Val–Thr–Lys–His (HTYHEVTKH), and Trp–Pro–Val–Leu–Ala–Tyr–His–Phe–Thr (WPVLAYHF). The WPVLAYHF peptide exhibited greater antioxidant activity. The study also confirmed that the F₃ sub-fraction was able to prevent hydroxyl radicals from causing DNA damage by conducting tests which involved the pKS, pUC19, and pBR322 plasmids using the Fenton reaction. In addition, cellular antioxidant activity was demonstrated by two synthetic peptides toward the human adenocarcinoma colon (Caco-2) cell line, with the potency of the activity dependent upon the peptide concentration.

The isolation and subsequent identification of the two novel antioxidant peptides, HTYHEVTKH, and WPVLAYHF from the spotted babylon snail was achieved. In the Caco-2 cell line, two synthetic peptides produced a dose-dependent response on antioxidant activity.     

Total antioxidant status and coronary artery calcification in type 1 diabetes

OBJECTIVE: Type 1 diabetes is associated with a high risk of coronary heart disease (CHD), despite the absence of dyslipidemia. Oxidative modification may render LDLs more atherogenic. We aimed to assess antioxidant status in type 1 diabetes and its association with coronary artery calcification (CAC). RESEARCH DESIGN AND METHODS: Total antioxidant status (TAS) of serum was measured using the Trolox equivalent antioxidant capacity assay in 48 type 1 diabetic and 25 nondiabetic subjects. The presence of CAC was assessed in the diabetic subjects using electron beam computed tomography. RESULTS: TAS was reduced in type 1 diabetic subjects compared with nondiabetic subjects (Mann-Whitney U test, P < 0.0001). There were associations between TAS and HbA(1c) (r = -0.43; P = 0.0026) and duration of diabetes (r = -0.35; P = 0.0157). Significant CAC was considered present if the Agatston score was >10. The diabetic subjects with significant CAC were older (P < 0.0001); had longer duration of diabetes (P = 0.0002); were more likely to have high blood pressure (P = 0.040); had higher total cholesterol concentration (P = 0.039), serum creatinine concentration (P = 0.003), and urinary albumin-to-creatinine ratio (P = 0.022); and had lower serum TAS (P = 0.018) compared with those without significant calcification. In logistic regression with CAC as the dependent variable, TAS was entered as a predictor, and the effects on its predictive value of adding other explanatory variables in bivariate analyses were assessed. The power of TAS to predict CAC was independent of many of the traditional CHD risk factors. Whereas TAS as a predictor was no longer statistically significant when age or duration of diabetes were entered into the model, the odds ratio for a TAS concentration above the median value predicting significant CAC only increased from 0.19 to 0.26 and 0.32, respectively. CONCLUSIONS: TAS is reduced in type 1 diabetes and is associated with the presence of CAC.     

Changes in free radical generation and antioxidant capacity during ultramarathon foot race

Background Exhaustive exercise has been implicated in the generation of reactive oxygen species, resulting in oxidative stress. We studied the effect of a long‐distance, endurance exercise on oxidative stress parameters in athletes who participated in the ultramarathon race Spartathlon (246 km). Materials and methods This study included 18 runners (16 men and 2 women) aged 42·8 ± 1·4 years. Blood samples were obtained 24 h before (prerace), at the end (postrace) and 48 h after the end of the race (48 h postrace). We measured oxidative stress indices, including red cell glutathione, malonyldialdehyde and 8‐iso‐prostaglandin F_2a, as well as the total antioxidant capacity. Results 8‐Iso‐prostaglandin F_2a level increased significantly at the end of the race, compared to prerace levels (up to 914·7 ± 61·4 pg mL^?1 from 197·6 ± 8·4 pg mL^?1), and remained 2·5‐fold increased over the baseline 48 h after the race (532·0 ± 54·2 pg mL^?1, P < 0·000). The total antioxidant capacity of the athletes increased from a baseline of 289·6 ± 9·0 µmol L^?1 to 358·7 ± 11·0 µmol L^?1 immediately after the race and remained elevated 48 h later (350·6 ± 7·6 µmol L^?1) (P < 0·001). Conclusions Prolonged exercise induces a marked response of oxidative stress biomarkers, which in part is compensated by serum ability to scavenge free radicals. Whether these changes have long‐term negative effects in the organism needs further investigation.     

Free/Total PSA (F/T ratio) kinetics in patients with clinically localized prostate cancer undergoing radical prostatectomy

BACKGROUND: In this paper we study the Free/Total PSA kinetics in patients with clinically localized prostate cancer undergoing radical prostatectomy. METHODS: Serum PSA, Free PSA and Free/Total Ratio were determined preoperatively, at the time of prostate removal (0 time) and then at 3, 6, 12, 24, 48, 72 and 168 h, from 9 patients with clinically localized prostate cancer who underwent radical retropubic prostatectomy. The elimination rates and half-lives of Total, Free PSA and F/T Ratio were studied applying one and two compartment models for pharmacokinetic analysis. RESULTS: Surgical manipulations of the prostate caused a mean 2.16-fold increase of PSA, 12-fold increase of free PSA and 4.2-fold increase of F/T PSA ratio. Removal of the prostate caused a rapid biphasic, biexponential elimination of Free PSA with a mean half-life of 0.8 h for the alpha (a) phase and 32.6 h for the beta (b) phase. PSA was eliminated following a rapid exponential (a) phase with a half-life of 1.15 h and a non-exponential (b) phase with a half-life of 71.96 h. Free/Total PSA followed a biphasic kinetic, with an initial exponential elimination phase and a mean half-life of 2.6 h and a second non-exponential increase phase with a doubling time of 130.8 h. Free/Total PSA reached its nadir very soon, at the first postoperative 24 h. CONCLUSIONS: Free/Total PSA kinetic after radical prostatectomy reflects the differences of Free and Total PSA elimination kinetics. Free/Total Ratio follows a biphasic kinetic, with an initial rapid exponential elimination phase, which is affected mainly by the rapid exponential (a) phase of Free PSA elimination and a second slow increase, which is affected mainly by the terminal non-exponential (b) phase of PSA elimination.     

Effect of 12-month statin therapy on antioxidant potential of LDL and serum antioxidant vitamin concentrations

BACKGROUND: Statins are known to cause short-term reduction in serum lipid-soluble antioxidant concentrations, but their long-term effects are not known. AIM: We randomised 104 subjects with CHD and hypercholesterolaemia to receive either atorvastatin or simvastatin treatment for 52 weeks and measured the antioxidant potential of LDL and serum antioxidant vitamin concentrations. METHOD: Initial daily dose for both statins was 20 mg. RESULTS: LDL antioxidant capacity and serum alpha-tocopherol, gamma-tocopherol and beta-carotene concentrations decreased by 22%-35% with both statins during the first 12 weeks' therapy (P < 0.01 for all). After 52 weeks' therapy, the concentrations of serum gamma-tocopherol in the simvastatin group and serum beta-carotene in both treatment groups returned to baseline levels, while the concentrations of serum gamma-tocopherol in the atorvastatin group and LDL anti-oxidant capacity and serum alpha-tocopherol in both treatment groups remained reduced (P < 0.001 for all). The LDL antioxidant capacity:LDL-cholesterol and the serum alpha-tocopherol:LDL-cholesterol ratios were significantly elevated with both statins after 12 and 52 weeks (P < 0.001 for all). Statistically significant increases were also observed for corresponding ratios of the less abundant vitamins gamma-tocopherol and beta-carotene. CONLUSIONS: Some of the decreases in serum lipid soluble antioxidant vitamins reported in short-term statin interventions may become attenuated when therapy continues longer. The relative antioxidant capacity of LDL particles increased during the 52-week treatment, suggesting that the oxidation resistance of LDL particles did not become impaired and that their atherogenicity did not increase.     

Comparative antioxidant potential of anaesthetics and perioperative drugs in vitro

We have investigated the comparative antioxidant capacity of a range of anaesthetics (inhaled and intravenous) and perioperative neurosurgical drugs (at clinically relevant concentrations) using different radical species and assay methods in vitro. The highest levels of antioxidant activity against the ABTS(.+) radical were obtained with propofol (100 mmol/LTE) and dopamine (1080 mmol/LTE), respectively. However, only dopamine (12 mmol/l) showed antioxidant activity in protecting proteins in normal brain tissue from oxidative damage (assessed via SDS-PAGE analysis) induced by OH(.) or O(2)(-.) generated radiolytically in vitro. Neither dopamine nor propofol showed antioxidant activity against O(2)(-.) generated chemically via reaction between xanthine and xanthine oxidase in vitro. From these data, together with data on the relative antioxidant properties of anaesthetics/drugs obtained by other research groups which we have reviewed, we conclude that the apparent antioxidant activity of a given compound may depend entirely on the free radical species and/or the method of generation or assay employed. Finally, we suggest that on the basis of data obtained showing protection of brain proteins from oxidative damage induced by OH(.), or O(2)(-.) in vitro, further investigation into the in vivo antioxidant therapeutic potential of dopamine (or its analogues) on neurosurgical patients may be warranted.