Glucocerebrosidase (GCase) activity modulation by 2-alkyl trihydroxypiperidines: Inhibition and pharmacological chaperoning

The enzyme glucocerebrosidase (GCase) has become an important therapeutic target due to its involvement in pathological disorders consequent to enzyme deficiency, such as the lysosomal storage Gaucher disease (GD) and the neurological Parkinson disease (PD). Pharmacological chaperones (PCs) are small compounds able to stabilize enzymes when used at sub-inhibitory concentrations, thus rescuing enzyme activity. We report the stereodivergent synthesis of trihydroxypiperidines alkylated at C-2 with both configurations, by means of the stereoselective addition of Grignard reagents to a carbohydrate-derived nitrone in the presence or absence of Lewis acids. All the target compounds behave as good GCase inhibitors, with IC₅₀ in the micromolar range. Moreover, compound 11a behaves as a PC in fibroblasts derived from Gaucher patients bearing the N370/RecNcil mutation and the homozygous L444P mutation, rescuing the activity of the deficient enzyme by up to 1.9- and 1.8-fold, respectively. Rescues of 1.2-1.4-fold were also observed in wild-type fibroblasts, which is important for targeting sporadic forms of PD.

Review and update on drugs related to the development of osteonecrosis of the jaw

Background

Medication-related osteonecrosis of the jaw (MRONJ) is a rare, but serious adverse effect of certain drugs, of which bisphosphonates are the most widely known. This pathology is also associated with other medications such as the biologic antiresorptive agent, denosumab and some antiangiogenics such as sunitinib, bevacizumab or aflibercept. Very recently, new medications have also been associated with osteonecrosis of the jaw (ONJ). The objectives were to update the list of medications associated with ONJ, to analyze the fundamental aspects of this list and to describe the level of evidence available.

Material and Methods

A narrative bibliographic review was made, using the PubMed-MedLine, DOAJ and SCIELO databases. Additional information was obtained through the online Medication Information Centre of the Spanish Agency of Medicines and Medical Devices (AEMPS – CIMA), the websites of the US Food & Drugs Administration (Drugs@FDA) and the European Medicines Agency (EMA).

Results

The latest drugs identified as potential facilitators of this pathology include a number of anti-VEGF based antiangiogenic drugs and anti-TKI and different types of immunomodulators. Neither the level of evidence in this association nor the risk are equal for all these drugs. On the other hand, over the coming years, new drugs will be marketed with similar action mechanisms to those that are recognized as having this adverse effect.

Conclusions

No effective therapy is currently known for the treatment of ONJ. Therefore, in order to prevent new cases of MRONJ, it is essential for all oral healthcare professionals to be fully up-to-date with the etiopathogenic aspects of this pathology and to be aware of those drugs considered to be a risk.

Key words:Osteonecrosis of the jaw, MRONJ, bisphosphonates, antiresorptives, antiangiogenics.

Antibodies to neuronal surface proteins in Tourette Syndrome: Lack of evidence in a European paediatric cohort

In Tourette Syndrome (TS) a role for autoantibodies directed against neuronal proteins has long been suspected, but so far results are still inconsistent. The aim of this study was to look for antibodies to specific or undefined neuronal proteins that could be involved in the aetiology of the disease. Sera from children with Tourette Syndrome or another chronic tic disorder (TS/TD), collected as part of the longitudinal European Multicenter Tics in Children Study, were investigated. Participants included 30 siblings of patients with TS/TD prior to developing tics (preclinical stage) and the same children after the first tic onset (onset), and 158 patients in the chronic phase undergoing an acute relapse (exacerbation). Presence of antibodies binding to rodent brain tissue was assessed by immunohistology on rat brain sections and by immunofluorescent staining of live hippocampal neurons. Live cell-based assays were used to screen for antibodies to NMDAR, CASPR2, LGI1, AMPAR and GABA_AR. Immunohistology indicated evidence of antibodies reactive with brain tissue, binding mainly to the hippocampus, the basal ganglia or the cerebellum in 26/218 (12%), with 8% of the preclinical or onset sera binding to the dentate gyrus/CA3 region or cerebellum. Only two individuals (one pre-clinical, one chronic) had antibodies binding the NMDAR and the binding was only weakly positive. No other specific antibodies were detected. Despite some immunoreactivity towards neuronal antigens on brain tissue, this was not mirrored by antibodies binding to live neurons, suggesting the presence of non-specific antibodies or those that bind non-pathogenic intracellular epitopes. NMDAR or the other neuronal surface antibodies tested were very infrequent in these patients. The evidence for pathogenic antibodies that could be causative of TS is weak.

Effect of increased opiate exposure on three years neurodevelopmental outcome in extremely preterm infants

BACKGROUND

International guidelines recommend the use of item based scales for the assessment of pain and sedation. In our previous study, the implementation of the Neonatal Pain Agitation and Sedation Scale (N-PASS), and the associated systematic assessment and treatment of pain and sedation reduced pain and over-sedation in our intervention group, but lead to a significant increase of individual opiate exposure. This increased opiate exposure was not associated with impaired motor and mental development at one year of age. As one-year follow-up is not necessarily representative for future outcomes, we retested our sample at three years of age.

METHODS

Fifty-three patients after (intervention group) and 61 before implementation (control group) of the N-PASS and the Vienna Protocol for the Management of Neonatal Pain and Sedation (VPNPS), were compared for motor, mental and behavioural development at three-years follow-up using the Bayley Scales of Infant Development.

RESULTS

Cumulative opiate exposure was not associated with mental (p = .31) and motor (p = .20) problems when controlling for other important medical conditions, but was associated to lower behavioural scores (p = .007). No statistically significant differences were found with regard to mental (p = .65), psychomotor (p = .12) and behavioural (p = .61) development before and after the implementation of the N-PASS and the VPNPS.

CONCLUSION

Implementing a neonatal pain and sedation protocol increased opiate exposure without affecting neurodevelopmental outcome at three-years of age.

Multimerization of DAB-1 onto Au GNPs affords new potent and selective N-acetylgalactosamine-6-sulfatase (GALNS) inhibitors

Gold glyconanoparticles (Au GNPs) decorated with the natural iminosugar DAB-1 at different densities are reported.

Molecular effect of fenofibrate on PBMC gene transcription related to lipid metabolism in patients with metabolic syndrome

BACKGROUND

Both fasting and postprandial hypertriglyceridaemia are considered independent risk factors for atherosclerosis. Treatment of hypertriglyceridaemia is based on fibrates, which activate the peroxisome proliferator-activated receptor alpha (PPARα). However, the metabolic pathways that activate or inhibit fibrates, and how the postprandial triglyceride levels are modified, have not yet been fully described. Accordingly, the aim of this study was to determine the feasibility of peripheral blood mononuclear cells (PBMC) to study the effects of fenofibrate in patients with the metabolic syndrome.

MATERIALS AND METHODS

A fat overload was given to 50 patients before and after treatment with fenofibrate for 3 months. Anthropometric and biochemical variables as well as gene expression in PBMC were analysed.

RESULTS

After treatment with fenofibrate, we observed a decrease in both baseline and postprandial (3 h after the fat overload) levels of serum triglycerides, cholesterol and uric acid and an increase in HDL cholesterol and apolipoprotein AI levels. After treatment, there was also a rise in PPARα and RXRα expression and changes in genes regulated by PPARα, both baseline and postprandial. Furthermore, in vitro experiments showed that a PPARα agonist changed the expression of genes related with lipid metabolism.

CONCLUSION

Treatment with fenofibrate reduced fasting and postprandial serum triglyceride levels, possibly through a mechanism related with an increase in the expression of RXRα and PPARα, by activating the pathways involved in the uptake and degradation of triglycerides and increasing the synthesis of apolipoprotein. These results suggest that PBMC may be useful for the easy study of fenofibrate actions.

Accessing 2-substituted piperidine iminosugars by organometallic addition/intramolecular reductive amination: aldehyde vs. nitrone route

A novel dual strategy to build 2-substituted trihydroxypiperidines.

Evidence for a multivalent effect in inhibition of sulfatases involved in lysosomal storage disorders (LSDs)

New targets sensitive to multivalency: synthesis of nonavalent pyrrolidine iminosugars.

From glycals to aminosugars: a challenging test for new stereoselective aminohydroxylation and related methodologies

The most relevant methods to access 1-, 2-, 3-amino or 1,2-diaminosugars starting from unsaturated carbohydrates are concisely reviewed; the given examples illustrate the great challenges offered to several stereoselective strategies.

Management of hypothermia for perinatal asphyxia in Austria - a survey of current practice standards

BACKGROUND

Therapeutic hypothermia (HT) has been shown to reduce the risk of death or disability and increase the rate of survival free of -disability at 18-24 months of age in hypoxic-ischemic encephalopathy (HIE).

OBJECTIVES

The aim of this study was to take a national survey which (a) evaluated the practice of therapeutic HT for perinatal asphyxia in Austria, (b) evaluated the current clinical management of neonatal HIE and (c) evaluated the need for a national perinatal asphyxia and HT registry.

METHODS

In January 2013, a questionnaire was sent out to the clinical heads of all neonatal level-II and level-III units in Austria.

RESULTS

We received replies from all 30 level II and level III units in Austria (response rate 100%). 19 units (63%) answered that they applied HT, 11 units (37%) said they transferred patients for cooling to other units, 3 of those 11 units (27%) said they applied cooling during transport. 25 units (83%) felt the necessity to establish a national registry.

CONCLUSION

The results of this survey show that there is already a high implementation of therapeutic HT in Austria, but there remains a need for information, awareness and training. Problem areas tend to be in the transport of asphyxiated neonates, brain monitoring during cooling and follow-up of affected patients. We believe, that the establishment of national guidelines and a national register could increase awareness for the importance of therapeutic HT in neonatal HIE, thus improve the Austrian management of those infants.

Gold nanoparticles are suitable cores for building tunable iminosugar multivalency

Inhibition in the low micromolar range towards amyloglucosidase.

Blood transfusions using 27 gauge PICC lines: a retrospective clinical study on safety and feasibility

BACKGROUND

Blood transfusions are required by most extremely low birth weight (ELBW) infants, but sometimes an adequate peripheral venous access cannot be achieved. Under these circumstances, we used 27 Gauge (G) peripherally inserted central catheter (PICC) lines that are routinely inserted on the second day of life. Due to their narrow lumen, hemolysis of transfused erythrocytes was a major concern. We therefore performed a retrospective study in ELBW infants to analyze the incidence, safety and feasibility of PRBC transfusions via 27 G PICC lines.

METHODS

ELBW infants admitted from 08/2011-07/2012 were screened for packed red blood cell (PRBC) transfusions. Those applied via 27 G PICC lines were identified. For analysis of transfusion safety (hemolysis), hemoglobin and potassium levels as well as cardiovascular variables (invasive mean arterial blood pressure and heart rate) were evaluated before and after transfusion. For analysis of transfusion feasibility, catheter removal after transfusion and the reason for removal were recorded.

RESULTS

A total of 648 transfusions were applied in 110 ELBW infants. 27 infants (24%) received no transfusion. In 12/83 (14.5%) infants who received PRBCs, transfusions were applied using a 27 G PICC line (38/648, 5.9%). Patients who received PRBCs via the PICC line were smaller at birth (582 g [range 380-752 g] vs. 710 g [430-972 g]; 23+6 [23+1-27+6] vs. 26+0 [23+1-31+4]) and required a higher number of PRBC transfusions (n=13 vs. n=5) overall. Transfusion analysis showed an appropriate increase of blood hemoglobin levels and stable potassium levels as well as cardiovascular parameters. 4/38 of PICC lines were removed within 24 h after transfusion, one due to occlusion (15 h after transfusion).

CONCLUSIONS

We conclude that PRBC transfusions via 27 G PICC lines were feasible and performed without signs of hemolysis in ELBW infants. Our findings may help clinicians in the management of ELBW infants requiring transfusions if a peripheral venous access is not achievable.

Safety of blood transfusions using 27 gauge neonatal PICC lines: an in vitro study on hemolysis

Blood transfusions are required by the majority of extremely premature infants. Packed red blood cells (PRBCs) are usually applied via simple peripheral cannulas. In situations where no peripheral venous access is achievable, 27 Gauge (G) neonatal PICC lines - that are ideally exclusively dedicated to application of parenteral nutrition - may represent a useful alternative access for PRBC transfusions. However, transfusion via small scaled catheters may damage PRBCs and lead to hemolysis. We here evaluate whether transfusion of irradiated PRBCs via 27 G PICC lines leads to hemolysis in vitro.Experimental transfusions of gamma-irradiated PRBCs were performed at increasing velocities (2.5, 3.7, 5 ml/h; full force manual push approximating 30 ml/h) via 27 G PICC lines of 20 and 30 cm length. Parameters of hemolysis (lactate dehydrogenase, potassium and free hemoglobin) were measured from the supernatants of transfused PRBCs and the percentage of hemolysis was calculated.Potassium and lactate dehydrogenase after transfusion at increasing velocities did not differ significantly from negative controls. Free hemoglobin levels showed a small but significant increase at the slowest transfusion speed (2.5 ml/h) using the 30 cm 27 G PICC line, with a relative hemolysis of only 0.13%. A manual push (approximating 30 ml/h) showed no significant changes of parameters from baseline.We conclude that transfusion of gamma-irradiated PRBCs using a 27 G neonatal PICC line does not cause clinically relevant hemolysis in vitro. Clinical studies are needed to confirm the feasibility and safety of the approach in vivo.

Endotoxin increase after fat overload is related to postprandial hypertriglyceridemia in morbidly obese patients

The low-grade inflammation observed in obesity has been associated with a high-fat diet, though this relation is not fully understood. Bacterial endotoxin, produced by gut microbiota, may be the linking factor. However, this has not been confirmed in obese patients. To study the relationship between a high-fat diet and bacterial endotoxin, we analyzed postprandial endotoxemia in morbidly obese patients after a fat overload. The endotoxin levels were determined in serum and the chylomicron fraction at baseline and 3 h after a fat overload in 40 morbidly obese patients and their levels related with the degree of insulin resistance and postprandial hypertriglyceridemia. The morbidly obese patients with the highest postprandial hypertriglyceridemia showed a significant increase in lipopolysaccharide (LPS) levels in serum and the chylomicron fraction after the fat overload. Postprandial chylomicron LPS levels correlated positively with the difference between postprandial triglycerides and baseline triglycerides. There were no significant correlations between C-reactive protein (CRP) and LPS levels. The main variables contributing to serum LPS levels after fat overload were baseline and postprandial triglyceride levels but not glucose or insulin resistance. Additionally, superoxide dismutase activity decreased significantly after the fat overload. Postprandial LPS increase after a fat overload is related to postprandial hypertriglyceridemia but not to degree of insulin resistance in morbidly obese patients.

[Bisphosphonate-related osteonecrosis of the jaws. An update]

Bisphosphonates are widely used drugs, primarily for osteoporosis and also in oncology. A drug-induced side effect or complication, which only recently came to light in 2003, is osteonecrosis of the jaw. This study reviews the chemical characteristics of the various bisphosphonates, their possible mechanism of action, relative potency, the commercial products available on the spanish pharmaceutical market and the indications for bisphosphonate treatment. The study also considers osteonecrosis of the jaw with regard to its onset, concept, clinical stages, why this pathology affects the jaws, its risk factors, incidence, the attitude to be adopted by dentists with patients taking bisphosphonates, a quick review of the treatment and the possible prediction of osteonecrosis.

Comparison of neonatal MRI examinations with and without an MR-compatible incubator: advantages in examination feasibility and clinical decision-making

PURPOSE

To assess the utility of an MRI-compatible incubator (INC) by comparing.

METHODS

In a retrospective study, the clinical and radiological aspects of 129 neonatal MRI examinations during a 3 year period were analyzed. Routine protocols including fast spin-echo T2-weighted (w) sequences, axial T1w, Gradient-echo, diffusion sequences, and 3D T1 gradient-echo sequences were performed routinely, angiography and spectroscopy were added in some cases. Diffusion-tensor imaging was done in 50% of the babies examined in the INC and 26% without INC. Sequences, adapted from fetal MR-protocols were done in infants younger than 32 gestational weeks. Benefit from MR-information with respect to further management was evaluated.

RESULTS

The number of the examinations increased (30-99), while the mean age (43-38, 8 weeks of gestational age) and weight (3308-2766 g) decreased significantly with the use of the MR-compatible incubator. The mean imaging time (34, 43-30, 29 min) decreased, with a mean of one additionally performed sequence in the INC group. All infants received sedatives according to our anaesthetic protocol preceding imaging, but a repeated dose was never necessary (10% without INC) using the INC. Regarding all cases, MR-based changes in clinical management were initiated in 58%, while in 57% of cases the initial ultrasound diagnosis was changed or further specified.

CONCLUSIONS

The use of the INC enables the MR access of unstable infants with suspect CNS problems to the management, of whom is improved by MR information to significantly higher percentage, than without INC.

Assessment of cellular and plasma oxidative stress in SAHS patients before and after continuous positive airway pressure treatment

BACKGROUND

Several indirect techniques have been used for measuring oxidative stress in sleep apnoea-hypopnoea syndrome (SAHS) patients. The purpose of this study was to find out if both, cellular or plasma oxidative stress evaluations, are good estimators to assess oxidative stress in SAHS patients before and after one month's CPAP treatment.

METHODS

The study included 28 SAHS patients requiring CPAP treatment and 15 healthy control subjects. Plasma and serum oxidative stress biomarkers (lipid peroxidation, total antioxidant capacity, and the activities of glutathione peroxidase, glutathione reductase, glutathione s-transferase, catalase and superoxide dismutase) were measured using commercial kits. Cellular oxidative stress biomarkers (mitochondrial membrane potential, intracellular glutathione, superoxide anion, and hydrogen peroxide) were analysed by flow cytometry. The Wilcoxon test for paired samples was used to compare oxidative stress and clinical parameters in patients before and after treatment with CPAP. Relationships in oxidative stress markers between controls and patients were analyzed using the Mann-Whitney U test. The Spearman correlation coefficient was calculated to estimate the linear correlations between variables.

RESULTS

Oxidative stress was notably decreased after CPAP. Before CPAP, SAHS severity positively correlated with hydrogen peroxide levels, while negative correlations were observed between SAHS severity and plasma TAC in patients. Also, plasma glutathione peroxidase activity negatively correlated with cellular superoxide anion, while plasma superoxide dismutase activity positively correlated with intracellular glutathione. After CPAP, plasma TAC and glutathione peroxidase activity negatively correlated with cellular hydrogen peroxide and superoxide anion.

CONCLUSIONS

In conclusion, this study seems to confirm that plasma and cellular assessment reflect, in the same way, the oxidative stress status of the studied patients. Furthermore, plasma total antioxidant capacity as well as cellular hydrogen peroxide levels can be good markers for assessing oxidative stress in SAHS patients.

Anti-oxidized LDL antibody levels are reduced in women with hypertension

BACKGROUND

Previous studies have suggested that hypertension may be associated with increased oxidized low-density lipoprotein (LDL). Increased in vitro oxidizability of LDL or elevated titers of anti-oxidized LDL antibodies have been shown in subjects with essential hypertension. However, the relationship between oxidized LDL and hypertension is equivocal. We examined the association between hypertension and levels of IgG anti-oxidized LDL antibodies in a group of women from the general population.

MATERIALS AND METHODS

The study included 619 women classified according to their blood pressure values. IgG anti-oxidized LDL antibodies were measured by enzyme-linked immunosorbent assay and the women were classified as being above or below the 50th percentile.

RESULTS

Hypertension was present in 54.3% of the women. These women had significantly lower levels of IgG anti-oxidized LDL antibodies than the normotensive women (0.280 +/- 0.117 vs. 0.336 +/- 0.125, P < 0.001). Both systolic and the diastolic blood pressures showed a significant negative correlation with the levels of IgG anti-oxidized LDL antibodies (r = -0.204, P < 0.001; r = -0.225, P < 0.001, respectively). Women with IgG anti-oxidized LDL antibody levels above the 50th percentile had a lower prevalence of hypertension than those with IgG anti-oxidized LDL antibody levels below the 50th percentile (40.2% vs. 59.8%) (P < 0.001).

CONCLUSIONS

Women with hypertension had lower levels of IgG anti-oxidized LDL antibodies than normotensive women.

Ubiquitin ligase Rsp5p is involved in the gene expression changes during nutrient limitation in Saccharomyces cerevisiae

Rsp5p is an essential ubiquitin ligase involved in many different cellular events, including amino acid transporters degradation, transcription initiation and mRNA export. It plays important role in both stress resistance and adaptation to the change of nutrients. We have found that ubiquitination machinery is necessary for the correct induction of the stress response SPI1 gene at the entry of the stationary phase. SPI1 is a gene whose expression is regulated by the nutritional status of the cell and whose deletion causes hypersensitivity to various stresses, such as heat shock, alkaline stress and oxidative stress. Its regulation is mastered by Rsp5p, as mutations in this gene lead to a lower SPI1 expression. In this process, Rsp5p is helped by several proteins, such as Rsp5p-interacting proteins Bul1p/2p, the ubiquitin conjugating protein Ubc1p and ubiquitin proteases Ubp4p and Ubp16p. Moreover, a mutation in the RSP5 gene has a global effect at the gene expression level when cells enter the stationary phase. Rsp5p particularly controls the levels of the ribosomal proteins mRNAs at this stage. Rsp5p is also necessary for a correct induction of p-bodies under stress conditions, indicating that this protein plays an important role in the post-transcriptional fate of mRNA under nutrient starvation.

Green tea reduces LDL oxidability and improves vascular function

OBJECTIVE

Several different epidemiological studies have examined the association between the consumption of tea and coronary heart disease. Some, though not all, support the view that tea or flavonoids reduce the risk of cardiovascular heart disease. The aim of this study was to determine the short-to medium-term effect of a green tea extract on vascular function and lipid peroxidation as compared with placebo.

METHODS

The study was undertaken with 14 healthy women, none of whom were receiving any medical treatment. Measurements were made of antibodies and immune complexes by ELISA, endothelial dependent vascular function by Doppler ultrasound, and the concentration of oxidized LDL by TBARS.

RESULTS

The mean diameter of the brachial artery following the post-compression hyperaemia phase rose significantly (p < 0.0001) after treatment with green tea extract. Flow-mediated brachial artery vasodilation ranged from 5.68% for the placebo phase to 11.98% after the green tea extract (p = 0.02). The consumption of green tea extract was associated with a significant 37.4% reduction in the concentration of oxidized LDL (TBARS) (p = 0.017). The levels of anti-oxidized LDL IgM antibodies fell significantly after treatment (p = 0.002).

CONCLUSION

This study found that consumption of green tea extract by women for five weeks produced modifications in vascular function and an important decrease in serum oxidizability.

Anti-oxidized low-density lipoprotein antibody levels are associated with the development of type 2 diabetes mellitus

BACKGROUND

Anti-oxidized low-density lipoprotein (LDL) antibodies are associated with the oxidative capacity of plasma, but whether they protect or promote diabetes is unknown. We undertook a prospective study to determine the predictive capacity of anti-oxidized LDL antibodies for the onset of type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

We selected 391 non-diabetic women aged 18-65 years. The subjects were classified as being normal (oral glucose test tolerance normal, OGTT-N), or having impaired glucose tolerance (IGT), impaired fasting glucose (IFG) or T2DM according to their baseline glucose levels and after an OGTT. The same subjects were studied six years later. The levels of anti-oxidized LDL antibodies were classified as above or below the 50th percentile.

RESULTS

Of the women who were OGTT-N at the start of the study and who had anti-oxidized LDL antibody levels below the 50th percentile, only 65.1% were still OGTT-N after 6 years versus 79.5% of those who had anti-oxidized LDL antibody levels above the 50th percentile (P = 0.015). Women who had IGT or IFG at the start of the study whose anti-oxidized LDL antibody levels were below the 50th percentile had a relative risk of 9.79 (95% confidence interval, 1.40-68.45) of developing diabetes (P < 0.001). Logistic regression analysis showed that the variables predicting the development of a carbohydrate metabolism disorder in the women after 6 years were body mass index (P < 0.001) and the levels of anti-oxidized LDL antibodies (P = 0.042).

CONCLUSIONS

Levels of anti-oxidized LDL antibodies are independent predictors for the development of T2DM in women.

Fat overload aggravates oxidative stress in patients with the metabolic syndrome

BACKGROUND

Patients with the metabolic syndrome have greater levels of oxidative stress. However, as the response of markers of this stress to a fat overload is unknown, we evaluated certain markers of oxidative stress in these patients.

MATERIAL AND METHODS

The study population comprised 93 subjects (70 men and 23 women): 13 healthy people (controls) with a mean age of 48.81 +/- 9.01 years and 80 patients with the metabolic syndrome (mean age, 43.25 +/- 11.55 years), according to the Adult Treatment Panel III criteria. All the participants were given a 60 g fat overload (Supracal). Three hours later the following biomarkers of oxidative stress were measured: lipid peroxidation products, protein carbonyl groups, reduced glutathione, glutathione peroxidase (GSH-Px), catalase, superoxide dismutase, glutathione reductase (GSH-Road) and glutathione S-transferase. The levels of oxidized glutathione (GSSG) were calculated.

RESULTS

Compared with the controls, the patients showed greater baseline oxidative stress, higher levels of lipid peroxidation products and oxidized glutathione, and lower levels of reduced glutathione, glutathione peroxidase activity, glutathione reductase and glutathione transferase. This stress was more intense after the subjects received a fat overload, more so in the patients who experienced a greater reduction in GSHpx and GSHrd antioxidant activity and a greater increase in the levels of carbonylated proteins and lipoperoxides than the controls.

CONCLUSIONS

Patients with the metabolic syndrome have greater oxidative stress than healthy people. The variation in markers of this stress after a fat overload was even more pronounced in the patients.

The effect of Prestige oil ingestion on the growth and chemical composition of turbot otoliths

Juvenile turbot (Scophthalmus maximus) were kept in captivity and were fed a prepared food contaminated with five different concentrations of seawater-accommodated fuel oil from 2.4+/-0.35 to 48.2+/-2.2 mg g(-1) food, with a control group receiving uncontaminated food. The growth and survival of individually tagged fish (N=202) were measured after a six-week treatment period. The otolith growth rate was measured and otolith composition was determined before and after the treatments using LA-ICPMS. Fish and otolith growth were negatively affected by the fuel oil treatment, and the response decreased with the level of contamination. Otolith growth and element incorporation peaked at mid level exposures and decreased at the highest level. The otolith elemental composition reflected the presence of some elements in the Prestige fuel that may have been incorporated through the diet into the otolith.

Decreased levels of uric acid after oral glucose challenge is associated with triacylglycerol levels and degree of insulin resistance

Hyperuricaemia is one of the components of metabolic syndrome. Both oxidative stress and hyperinsulinism are important variables in the genesis of this syndrome and have a close association with uric acid (UA). We evaluated the effect of an oral glucose challenge on UA concentrations. The study included 656 persons aged 18 to 65 years. Glycaemia, insulin, UA and plasma proteins were measured at baseline and 120 min after an oral glucose tolerance test (OGTT). The baseline sample also included measurements of total cholesterol, triacylglycerol (TAG) and HDL-cholesterol. Insulin resistance was calculated with the homeostasis model assessment. UA levels were significantly lower after the OGTT (281·93 (sd92·19)v. 267·48 (sd90·40) μmol/l;P < 0·0001). Subjects with a drop in UA concentrations >40·86 μmol/l (>75th percentile) had higher plasma TAG levels (P = 0·0001), baseline insulin (P = 0·02) and greater insulin resistance (P = 0·034). Women with a difference in plasma concentrations of UA above the 75th percentile had higher baseline insulin levels (P = 0·019), concentration of plasma TAG (P = 0·0001) and a greater insulin resistance index (P = 0·029), whereas the only significant difference in men was the level of TAG. Multiple regression analysis showed that the basal TAG levels, insulin at 120 min, glycaemia at 120 min and waist:hip ratio significantly predicted the variance in the UA difference (r20·077). Levels of UA were significantly lower after the OGTT and the individuals with the greatest decrease in UA levels are those who have greater insulin resistance and higher TAG levels.

Pharmacokinetics and Pharmacodynamics of the Dual FII/FX Inhibitor BIBT 986 in Endotoxin-induced Coagulation

BIBT986 is a dual inhibitor of factors Xa and IIa. The aim of this study was to compare with placebo the effect of three doses of BIBT986 on coagulation, platelet activation, and inflammation. This was a prospective, randomized, double-blind, placebo-controlled, parallel-group dose escalation trial in 48 healthy male volunteers. Participants received one of three doses of BIBT986 or placebo intravenously together with a bolus infusion of 2 ng/kg lipopolysaccharide (LPS). BIBT986 dose-dependently changed global coagulation parameters and in vivo markers of thrombin generation and action: BIBT986 doses, which prolonged activated partial thromboplastin time by 100%, completely suppressed the LPS-induced increases in prothrombin fragment, thrombin-antithrombin complexes, and D-dimer, which were 6.1-, 14.5, and 3.5-fold in the placebo group, respectively. BIBT986 did not influence inflammation, fibrinolysis, or platelet activation. Therefore, BIBT986 is a potent anticoagulant in the human endotoxemia model.

Monounsaturatedn-9 fatty acids and adipocyte lipolysis in rats

To investigate the role of the monounsaturatedn-9 fatty acids (MUFA) in the lipolytic activity of adipocytes, a study was carried out in which an increase in MUFA was produced in the tissues by two different methods; by the dietary enrichment of oleic acid or by producing an essential fatty acid deficiency syndrome. For this, forty-five male Sprague–Dawley rats were fed with a normal-energy diet and were subdivided into three groups. The diets varied in the type of dietary fat; palmitic acid, olive oil, or soyabean oil+palmitic acid. At the end of the study measurements were taken of weight, plasma leptin, tissue concentration of fatty acids, fat-cell size in the epididymal and the omental adipose tissues, adipocyte lipolytic activity of both tissues after stimulation with adrenaline, and the capacity of insulin to inhibit lipolysis. The baseline and adrenaline-stimulated lipolytic activity were greater and the anti-lipolytic capacity of insulin lower in the animals undergoing an increase in MUFA in the tissues (palmitic-acid and olive-oil diets). The area under the curve of glycerol, used as an indicator of lipolytic activity, was positively correlated with the concentration of MUFA and negatively with polyunsaturated fatty acids in the adipose tissues. It is concluded that an increase in tissue MUFA, however obtained, induces an increase in lipolytic activity.