Genetically engineered human umbilical cord-derived mesenchymal stem cells expressing human interleukin-12 and in vitro growth inhibition against lung adenocarcinoma cells.

INTRODUCTION: Mesenchymal stromal cells (MSCs) are promising vehicles for cancer therapy due to their homing ability and potency to be genetically manipulated through either viral or non-viral methods. Interleukin-12 (IL-12) is one of the key immunomodulatory cytokines which has anti-tumour effect. However, systemic administration of the cytokine at therapeutic dosage can cause serious toxicity in the host system due to the high systemic level of interferon-γ (IFN-γ) induced. OBJECTIVES: This study aimed to investigate the in vitro growth inhibition of genetically engineered human umbilical cord-derived mesenchymal stromal cells (hUCMSC) expressing IL-12 on H1975 human lung adenocarcinoma cells. MATERIALS AND METHODS: Both adenoviral method and electroporation which used to generate hUCMSC-IL12 were compared. The method with better outcome was selected to generate hUCMSC-IL12 for the co-culture experiment with H1975 or MRC-5 cells. Characterisation of hUCMSC and hUCMSC-IL12 was performed. RESULTS: Adenoviral method showed superior results in transfection efficiency (63.6%), post-transfection cell viability (82.6%) and hIL-12 protein expression (1.2 x 107 pg/ml) and thus was selected for the downstream experiments. Subsequently, hUCMSC-IL12 showed significant inhibition effect on H1975 cells after 5 days of co-culture. No significant difference was observed for all other co-culture groups, indicating that the inhibition effect was because of hIL-12. Lastly, the integrity of hUCMSC-IL12 remained unaffected by the transduction through examination of their surface markers and differentiation properties. CONCLUSION: This study provided proof of concept that hUCMSC can be genetically engineered to express hIL-12 which exerts direct growth inhibition effect on human lung adenocarcinoma cells.

Exploring the role of antibiotics and steroids in managing respiratory diseases.

Respiratory diseases (RDs), such as chronic obstructive pulmonary disease, cystic fibrosis, asthma, and pneumonia, are associated with significant morbidity and mortality. Treatment usually consists of antibiotics and steroids. Relevant published literature reviews, studies, and clinical trials were accessed from institutional and electronic databases. The keywords used were respiratory diseases, steroids, antibiotics, and combination of steroids and antibiotics. Selected articles and literature were carefully reviewed. Antibiotics are often prescribed as the standard therapy to manage RDs. Types of causative respiratory pathogens, spectrum of antibiotics activity, route of administration, and course of therapy determine the type of antibiotics that are prescribed. Despite being associated with good clinical outcome, treatment failure and recurrence rate are still high. In addition, antibiotic resistance has been widely reported due to bacterial mutations in response to the use of antibiotics, which render them ineffective. Nevertheless, there has been a growing demand for corticosteroids (CS) and antibiotics to treat a wide variety of diseases, including various airway diseases, due to their immunosuppressive and anti-inflammatory properties. The use of CS is well established and there are different formulations based on the diseases, such as topical administration, tablets, intravenous injections, and inhaled preparations. Both antibiotics and CS possess similar properties in terms of their anti-inflammatory effects, especially regulating cytokine release. Thus, the current review examines and discusses the different applications of antibiotics, CS, and their combination in managing various RDs. Drawbacks of these interventions are also discussed.

Reprogramming human dermal fibroblast into induced pluripotent stem cells using nonintegrative Sendai virus for transduction.

INTRODUCTION: Induced pluripotent stem cells (iPSC) that exhibit embryonic stem cell-like properties with unlimited self-renewal and multilineage differentiation properties, are a potential cell source in regenerative medicine and cell-based therapy. Although retroviral and lentiviral transduction methods to generate iPSC are well established, the risk of mutagenesis limits the use of these products for therapeutic applications. MATERIALS AND METHODS: In this study, reprogramming of human dermal fibroblasts (NHDF) into iPSC was carried out using non-integrative Sendai virus for transduction. The iPSC clones were characterised based on the morphological changes, gene expression of pluripotency markers, and spontaneous and directed differentiation abilities into cells of different germ layers. RESULTS: On day 18-25 post-transduction, colonies with embryonic stem cell-like morphology were obtained. The iPSC generated were free of Sendai genome and transgene after passage 10, as confirmed by RT-PCR. NHDF-derived iPSC expressed multiple pluripotency markers in qRT-PCR and immunofluorescence staining. When cultured in suspension for 8 days, iPSC successfully formed embryoid body-like spheres. NHDF-derived iPSC also demonstrated the ability to undergo directed differentiation into ectoderm and endoderm. CONCLUSION: NHDF were successfully reprogrammed into iPSC using non-integrating Sendai virus for transduction.

Opinion diversity and community formation in adaptive networks.

It is interesting and of significant importance to investigate how network structures co-evolve with opinions. In this article, we show that, a simple model integrating consensus formation, link rewiring, and opinion change allows complex system dynamics to emerge, driving the system into a dynamic equilibrium with the co-existence of diversified opinions. Specifically, similar opinion holders may form into communities yet with no strict community consensus; and rather than being separated into disconnected communities, different communities are connected by a non-trivial proportion of inter-community links. More importantly, we show that the complex dynamics may lead to different numbers of communities at the steady state with a given tolerance between different opinion holders. We construct a framework for theoretically analyzing the co-evolution process. Theoretical analysis and extensive simulation results reveal some useful insights into the complex co-evolution process, including the formation of dynamic equilibrium, the transition between different steady states with different numbers of communities, and the dynamics between opinion distribution and network modularity.

Frequency of cancer events with saxagliptin in the SAVOR-TIMI 53 trial.

The Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR)-Thrombolysis in Myocardial Infarction (TIMI) 53 trial randomized trial of 16,492 patients (placebo, n = 8212; saxagliptin, n = 8280) treated and followed for a median of 2.1 years afforded an opportunity to explore whether there was any association with cancer reported as a serious adverse event. At least one cancer event was reported by 688 patients (4.1%): 362 (4.3%) and 326 (3.8%) in the placebo and saxagliptin arms, respectively (p = 0.13). There were 59 (0.6%) deaths adjudicated as malignancy deaths with placebo and 53 (0.6%) with saxagliptin. Stratification by gender, age, race and ethnicity, diabetes duration, baseline glycated haemoglobin and pharmacotherapy did not show any clinically meaningful differences between the two study arms. The overall number of cancer events and malignancy-associated mortality rates were generally balanced between the placebo and saxagliptin groups, suggesting a null relationship with saxagliptin use over the median follow-up of 2.1 years. Multivariable modelling showed that male gender, dyslipidaemia and current smoking were independent predictors of cancer. These randomized data with adequate numbers of cancer cases are reassuring but limited, by the short follow-up in a trial not designed to test this hypothesis.

BRCA1 gene therapy reduces systemic inflammatory response and multiple organ failure and improves survival in experimental sepsis.

Sepsis-related complications and mortality remain a major clinical problem. Increased cell death and unresolved cellular repair have been implicated as key upstream mediators of sepsis-induced organ dysfunction and death. We hypothesised that gene therapy with BRCA1, a critical regulator of DNA damage repair and cell survival, would attenuate the sequelae of sepsis and peritonitis in mice subjected to caecal ligation and perforation (CLP) and thioglycollate stimulation. C57Bl/6J mice underwent sham or CLP surgery 3 days following treatment with either human BRCA1 adenovirus (AdBRCA1) or the adeno-CMV-null vector (Adnull). The 24-h post-CLP mortality was 2.8% vs 17.9% (P<0.001) and the median post-CLP survival was 50.5 vs 33 h (P<0.05) for AdBRCA1- vs Adnull-treated mice, respectively. AdBRCA1 therapy blunted CLP-associated cardiac, pulmonary, hepatic and renal dysfunction and also reduced CLP-elicited double strand breaks and apoptosis in the liver. BRCA1 gene therapy was associated with lower CLP-evoked cardiac and hepatic superoxide generation that in the liver was in part due to improved reactive oxygen species removal. CLP also elevated mesenteric arteriolar and serum intercellular adhesion molecule-1, both of which were partially abrogated with AdBRCA1 administration. Thioglycollate-challenged AdBRCA1-treated mice displayed reduced peritoneal neutrophil recruitment and dampened cytokine elaboration relative to their Adnull-treated counterparts. Taken together, we report a novel role of BRCA1 gene therapy in limiting systemic inflammation, multiple-organ failure and mortality in experimental sepsis.

A comparison of the assessment and management of cardiometabolic risk in patients with and without type 2 diabetes mellitus in Canadian primary care.

AIM: To investigate the cardiometabolic risk (CMR) assessment and management patterns for individuals with and without type 2 diabetes mellitus (T2DM) in Canadian primary care practices. METHODS: Between April 2011 and March 2012, physicians from 9 primary care teams and 88 traditional non-team practices completed a practice assessment on the management of 2461 patients >40 years old with no clinical evidence of cardiovascular disease and diagnosed with at least one of the following risk factor-T2DM, dyslipidaemia or hypertension. RESULTS: There were 1304 individuals with T2DM and 1157 without. Pharmacotherapy to manage hyperglycaemia, dyslipidaemia and hypertension was widely prescribed. Fifty-eight percent of individuals with T2DM had a glycated haemoglobin (HbA1c) ≤7.0%. Amongst individuals with dyslipidaemia, median low-density lipoprotein cholesterol (LDL-C) was 1.8 mmol/l for those with T2DM and 2.8 mmol/l for those without. Amongst individuals with hypertension, 30% of those with T2DM achieved the <130/80 mmHg target, whereas 60% of those without met the <140/90 mmHg target. The composite glycaemic, LDL-C and blood pressure (BP) target outcome was achieved by 12% of individuals with T2DM. Only 17% of individuals with T2DM and 11% without were advised to increase their physical activity. Dietary modifications were recommended to 32 and 10% of those with and without T2DM, respectively. CONCLUSIONS: Patients at elevated CMR were suboptimally managed in the primary care practices surveyed. There was low attainment of recommended therapeutic glycaemic, lipid and BP targets. Advice on healthy lifestyle changes was infrequently dispensed, representing a missed opportunity to educate patients on the long-term benefits of lifestyle modification.

Poor achievement of guidelines-recommended targets in type 2 diabetes: findings from a contemporary prospective cohort study.

AIMS: To prospectively evaluate diabetes management in the primary care setting and explore factors related to guideline-recommended triple target achievement [blood pressure (BP) ≤ 130/80 mmHg, A1C ≤ 7% and low-density lipoprotein (LDL)-cholesterol < 2.5 mmol/l]. METHODS: Baseline, 6 and 12 month data on clinical and laboratory parameters were measured in 3002 patients with type 2 diabetes enrolled as part of a prospective quality enhancement research initiative in Canada. A generalised estimating equation model was fitted to assess variables associated with triple target achievement. RESULTS: At baseline, 54%, 53% and 64% of patients, respectively, had BP, A1C and LDL-cholesterol at target; all three goals were met by 19% of patients. The percentage of individuals achieving these targets significantly increased during the study [60%, 57%, 76% and 26%, respectively, at the final visit, p < 0.0001 except for A1C, p = 0.27]. A much smaller proportion of patients had adequate control during the entire study period [30%, 39%, 53% and 7%, respectively]. In multivariable analysis, women, patients younger than 65 years and patients of Afro-Canadian origin were less likely to achieve the triple target. DISCUSSION: As part of a quality enhancement research initiative, we observed important improvements in the attainment of guidelines-recommended targets in patients with type 2 diabetes followed for a 12-month period in the primary care setting; however, many individuals still failed to achieve and especially maintain optimal goals for therapy, particularly the triple target. Results of the multivariable analysis reinforce the need to address barriers to improve diabetes care, particularly in more susceptible groups.

Valproic acid induces microglial dysfunction, not apoptosis, in human glial cultures.

Valproic acid (VPA) is widely used for the treatment of mood disorders and epilepsy, but its mechanism of action is unclear. In vivo and in vitro studies using rodent models have demonstrated that VPA has both neuroprotective and neurotrophic effects. These beneficial effects are, in part, through modulation of glial cell function. Recently, we and others have shown that VPA selectively induces caspase-3 mediated apoptosis in rodent microglial cells. However, the effect of VPA on human microglia has not been tested. In this study, using microglia derived from adult human brains, we demonstrate that VPA does not induce microglial apoptosis as determined by the absence of caspase-3 cleavage. However, VPA does partially decrease the expression of the microglial markers PU.1 and CD45, as well as dramatically reducing microglial phagocytosis. Due to the many roles of microglia in the brain, these VPA-induced alterations in microglial phenotype could potentially have major effects on physiological and pathological actions of these cells.

Penumbral mismatch is underestimated using standard volumetric methods and this is exacerbated with time.

BACKGROUND AND AIMS: The mismatch between perfusion weighted images (PWI) and diffusion weighted images (DWI) using MR is increasingly being applied in patient selection for therapeutic trials. Two approaches to the calculation of the mismatch volume exist--the commonly used volumetric and the more precise co-registration method, the latter of which considers lesion topography. That there are differences in the mismatch volume analysed by each method and that these are time dependent was hypothesised. METHODS: Patients within 48 h of ischaemic stroke onset had baseline MR PWI/DWI mismatch and T2 outcome volumes at 3 months. Volumetric mismatch volume was defined as PWI minus DWI lesion. Co-registration mismatch volume was defined as the PWI defect lesion not overlapped by the co-registered DWI lesion. RESULTS: 72 patients of median age 74.0 years were studied. Median baseline MR was at 5.9 h (IQR 3.0, 20.4 h) after stroke onset. Consistent underestimation of the mismatch volume occurred using the volumetric method (volumetric median 9.3 ml, IQR 0, 63 ml; co-registration median 20.1 ml, IQR 3.2, 69.8 ml; p<0.0001). This difference increased with time from stroke onset (p = 0.006). CONCLUSIONS: Volumetric analysis consistently underestimates the PWI/DWI mismatch volume compared with the more precise co-registration method. This effect increases with time.

Doublecortin expression in the normal and epileptic adult human brain.

Mesial temporal lobe epilepsy (MTLE) is a neurological disorder associated with spontaneous recurrent complex partial seizures and hippocampal sclerosis. Although increased hippocampal neurogenesis has been reported in animal models of MTLE, increased neurogenesis has not been reported in the hippocampus of adult human MTLE cases. Here we showed that cells expressing doublecortin (Dcx), a microtubule-associated protein expressed in migrating neuroblasts, were present in the hippocampus and temporal cortex of the normal and MTLE adult human brain. In particular, increased numbers of Dcx-positive cells were observed in the epileptic compared with the normal temporal cortex. Importantly, 56% of Dcx-expressing cells in the epileptic temporal cortex coexpressed both the proliferative cell marker, proliferating cell nuclear antigen and early neuronal marker, TuJ1, suggesting that they may be newly generated neurons. A subpopulation of Dcx-positive cells in the epileptic temporal cortex also coexpressed the mature neuronal marker, NeuN, suggesting that epilepsy may promote the generation of new neurons in the temporal cortex. This study has identified, for the first time, a novel population of Dcx-positive cells in the adult human temporal cortex that can be upregulated by epilepsy and thus, raises the possibility that these cells may have functional significance in the pathophysiology of epilepsy.

Skin wrinkling for diagnosing small fibre neuropathy: comparison with epidermal nerve density and sympathetic skin response.

OBJECTIVE: To compare simple tests of small nerve fibre function with intraepidermal nerve fibre density (IENFD) in the evaluation of small fibre neuropathy (SFN). METHODS: Patients with idiopathic SFN of the hands were prospectively studied. Evaluation involved clinical examination, nerve conduction studies, sympathetic skin response (SSR) and skin wrinkling stimulated by water and EMLA (eutectic mixture of local anaesthetics). RESULTS: Of 21 patients, 16 (76%) had low IENFD, 15 (71%) impaired water-induced wrinkling, 14 (67%) impaired EMLA-induced wrinkling, and nine (43%) abnormal SSR. CONCLUSIONS: Stimulated skin wrinkling was nearly as sensitive as IENFD in diagnosing SFN, whereas SSR was of less use. Stimulated skin wrinkling is a useful supportive test when IENFD or other tests of small nerve fibre function are not available.

Cellular composition of human glial cultures from adult biopsy brain tissue.

Microglia and astrocytes play vital roles in normal human brain function and in neurological disorders. To study their physiological and pathological roles it is desirable to establish in vitro systems that are derived from the adult human brain. Although several groups have successfully cultured cells from the human brain, the composition of these cultures remains controversial. Using morphological criteria, immunocytochemical analysis and a BrdU incorporation assay we demonstrate the presence of poorly proliferative microglia and astrocytes in cultures derived from epilepsy biopsy tissue. In addition, we characterized a third cell type as fibronectin and prolyl 4-hydroxylase immunopositive fibroblast-like cells, which are highly proliferative and become the predominant cell type after successive sub-culturing. Therefore, although cultures from adult human brain tissue provide an excellent resource for studying human glial cells, careful consideration must be given to their cellular composition when performing studies using these methods.

Bickerstaff's brainstem encephalitis: can it recur?

Bickerstaff's brain-stem encephalitis is usually a monophasic post-viral inflammatory illness characterized by progressive ophthalmoplegia, ataxia and disturbance of consciousness (or hyper-reflexia). Since the clinical spectrum of Bickerstaff encephalitis may overlap with the Miller-Fisher and Guillain-Barré syndromes, the presence of anti- GQ1b antibodies and abnormal brain MRI can help to support its diagnosis. However, absence of anti-GQ1b antibodies and normal MRI do not exclude the diagnosis, which remains based on clinical criteria and exclusion of other etiologies. We report a case of recurrent Bickerstaff's brainstem encephalitis with no identifiable antecedent illness, and overlapping features of Miller Fisher and Guillain-Barré syndromes, in the presence of negative anti-GQ1b antibodies and repeatedly normal MRI of the brain.

The NORSE (new-onset refractory status epilepticus) syndrome: defining a disease entity.

INTRODUCTION: To characterise a homogeneous group of patients with new-onset refractory status epilepticus (NORSE syndrome). MATERIALS AND METHODS: This is a descriptive, semiprospective review of all cases of NORSE syndrome seen between 2000 and 2004 at a tertiary care public hospital in Singapore. A review of the literature was performed to identify possible additional similar cases for comparison. RESULTS: Seven patients with NORSE syndrome were identified. Characterising features were female gender, young age, previous good health, cerebrospinal fluid pleocytosis (in 4), antecedent febrile illness (in 5), extraordinarily prolonged status epilepticus (average 32 days), failure of extensive investigations to reveal an underlying cause, catastrophic outcome as well as temporal lobe and leptomeningeal abnormality on brain magnetic resonance imaging. A review of the literature identified 12 similar patients, comprising both adults and children. CONCLUSIONS: Based on our patients and those described in the literature, we characterise the NORSE syndrome. Increased recognition of this clinical entity is needed to help delineate the underlying aetiology of this unique severe illness.

Acute impairment of relaxation by low levels of testosterone in porcine coronary arteries.

OBJECTIVES: While there are many suggested reasons for the marked gender bias in cardiovascular events, much of the available data indicate that circulating estrogens are cardioprotective. The possibility that endogenous androgens may be detrimental to the cardiovascular system has received relatively less attention. We investigated the short-term modulatory effects of various concentrations of testosterone on vascular function in isolated porcine coronary artery rings. RESULTS: The higher concentrations (> 1 microM) of testosterone relaxed U46619-contracted coronary artery rings in an endothelium-independent manner. This direct effect was insensitive to the testosterone receptor antagonists, flutamide and cyproterone acetate. Short-term exposure (20 min) to low levels of testosterone (1-100 nM), which were ineffective on their own on vascular function, significantly diminished relaxation to bradykinin and calcium ionophore A23187 but not those produced by levcromakalim and sodium nitroprusside. The inhibitory effect observed with 1 nM testosterone was only partially reversed by flutamide and cyproterone acetate and unaltered in the presence of actinomycin D and cycloheximide. CONCLUSIONS: These results demonstrate that acute treatment with testosterone, at concentrations that have no effect on their own, reduces vasorelaxation. Furthermore, they suggest that this modulatory action may be in part independent of the classical testosterone receptor since it was not completely sensitive to the anti-androgens and was not inhibited by the transcriptional and translational inhibitors. These findings support the postulation that testosterone may have unfavorable influences on vascular function.

Short-term exposure to physiological levels of 17 beta-estradiol enhances endothelium-independent relaxation in porcine coronary artery.

OBJECTIVES: While alterations in cholesterol and lipoprotein profiles partly account for menopause being a risk factor for coronary heart disease, recent studies have suggested that 17 beta-estradiol may have vascular effects. Our aims were to study the short-term effects of 17 beta-estradiol on vascular function in isolated porcine coronary artery rings. Concomitantly, we sought to determine if physiological concentrations of 17 beta-estradiol could acutely potentiate relaxation RESULTS: 17 alpha- and 17 beta-estradiol at pharmacological (> 1 microM) concentrations produced relaxation in U46619-pre-contracted porcine coronary artery rings. Relaxation evoked by 17 beta-estradiol was not reversed by the estrogen receptor antagonists tamoxifen and ICI 182780. Following 20 min exposure to a physiological concentration of 17 beta-estradiol (1 nM), which on its own had no effect, relaxation elicited by cromakalim, levcromakalim and sodium nitroprusside, but not bradykinin or calcium ionophore A23187, were significantly enhanced. This potentiating action was also insensitive to tamoxifen and ICI 182780. Our data provide evidence for an acute indirect relaxant action of 17 beta-estradiol and suggest that it may be via a tamoxifen- and ICI 182780-insensitive estrogen receptor. While this response was only observed at pharmacological concentrations, the potentiation of cromakalim, levcromakalim and sodium nitroprusside relaxation was evident in the presence of a physiological concentration (1 nM) of 17 beta-estradiol. CONCLUSIONS: These results demonstrate that short-term exposure to 17 beta-estradiol, at concentrations that have no effect on their own, can enhance vasorelaxation. These vascular effects may partly account for some of the acute effects of 17 beta-estradiol on blood flow.

Assessment of intracranial collaterals on CT angiography in anterior circulation acute ischemic stroke.

BACKGROUND AND PURPOSE: Intracranial collaterals influence the prognosis of patients treated with intravenous tissue plasminogen activator in acute anterior circulation ischemic stroke. We compared the methods of scoring collaterals on pre-tPA brain CT angiography for predicting functional outcomes in acute anterior circulation ischemic stroke. MATERIALS AND METHODS: Two hundred consecutive patients with acute anterior circulation ischemic stroke treated with IV-tPA during 2010-2012 were included. Two independent neuroradiologists evaluated intracranial collaterals by using the Miteff system, Maas system, the modified Tan scale, and the Alberta Stroke Program Early CT Score 20-point methodology. Good and extremely poor outcomes at 3 months were defined by modified Rankin Scale scores of 0-1 and 5-6 points, respectively. RESULTS: Factors associated with good outcome on univariable analysis were younger age, female sex, hypertension, diabetes mellitus, atrial fibrillation, small infarct core (ASPECTS ≥8), vessel recanalization, lower pre-tPA NIHSS scores, and good collaterals according to Tan methodology, ASPECTS methodology, and Miteff methodology. On multivariable logistic regression, only lower NIHSS scores (OR, 1.186 per point; 95% CI, 1.079-1.302; P = .001), recanalization (OR, 5.599; 95% CI, 1.560-20.010; P = .008), and good collaterals by the Miteff method (OR, 3.341; 95% CI, 1.203-5.099; P = .014) were independent predictors of good outcome. Poor collaterals by the Miteff system (OR, 2.592; 95% CI, 1.113-6.038; P = .027), Maas system (OR, 2.580; 95% CI, 1.075-6.187; P = .034), and ASPECTS method ≤5 points (OR, 2.685; 95% CI, 1.156-6.237; P = .022) were independent predictors of extremely poor outcomes. CONCLUSIONS: Only the Miteff scoring system for intracranial collaterals is reliable for predicting favorable outcome in thrombolyzed acute anterior circulation ischemic stroke. However, poor outcomes can be predicted by most of the existing methods of scoring intracranial collaterals.

Low concentrations of 17beta-estradiol reduce oxidative modification of low-density lipoproteins in the presence of vitamin C and vitamin E.

Micromolar concentrations of estradiol are required to inhibit the oxidation of low-density lipoproteins (LDL) in vitro. Recent evidence suggests that estradiol must be modified before it can become an effective antioxidant at physiological levels. Our aim was to determine other possible conditions under which low concentrations of 17beta-estradiol can reduce LDL oxidation. LDL susceptibility to oxidation was monitored by measurements of conjugated diene formation. High levels of 17beta-estradiol reduced oxidative modification of LDL. Vitamin C and vitamin E also increased LDL resistance to Cu2+-mediated oxidation. More importantly, 10 nM 17beta-estradiol, which on its own had no effect, exhibited significant antioxidant actions in the presence of either vitamins C or E. In conclusion, supraphysiological concentrations of 17beta-estradiol are required to exert antioxidant effects directly in vitro. However, in the presence of vitamins C and E, concentrations of 17beta-estradiol close to physiological levels can also protect LDL from oxidation.