Glycation of low-density lipoproteins by methylglyoxal and glycolaldehyde gives rise to the in vitro formation of lipid-laden cells

AIMS/HYPOTHESIS

Previous studies have implicated the glycoxidative modification of low-density lipoprotein (LDL) by glucose and aldehydes (apparently comprising both glycation and oxidation), as a causative factor in the elevated levels of atherosclerosis observed in diabetic patients. Such LDL modification can result in unregulated cellular accumulation of lipids. In previous studies we have characterized the formation of glycated, but nonoxidized, LDL by glucose and aldehydes; in this study we examine whether glycation of LDL, in the absence of oxidation, gives rise to lipid accumulation in arterial wall cell types.

METHODS

Glycated LDLs were incubated with macrophage, smooth muscle, or endothelial cells. Lipid loading was assessed by HPLC analysis of cholesterol and individual esters. Oxidation was assessed by cholesterol ester loss and 7-ketocholesterol formation. Cell viability was assessed by lactate dehydrogenase release and cell protein levels.

RESULTS

Glycation of LDL by glycolaldehyde and methylglyoxal, but not glucose (in either the presence or absence of copper ions), resulted in cholesterol and cholesterol ester accumulation in macrophage cells, but not smooth muscle or endothelial cells. The extent of lipid accumulation depends on the degree of glycation, with increasing aldehyde concentration or incubation time, giving rise to greater extents of particle modification and lipid accumulation. Modification of lysine residues appears to be a key determinant of cellular uptake.

CONCLUSIONS/INTERPRETATION

These results are consistent with LDL glycation, in the absence of oxidation, being sufficient for rapid lipid accumulation by macrophage cells. Aldehyde-mediated "carbonyl-stress" may therefore facilitate the formation of lipid-laden (foam) cells in the artery wall.

Fetal programming: the perspective of single and twin pregnancies

Multiple pregnancy is associated with increased risk of adverse consequences for both mother and fetus(es), including increased rates of maternal hypertension and pre-eclampsia, spontaneous abortion, Caesarean delivery, low birthweight, birth prematurity, perinatal mortality, admission to neonatal intensive care and extended length of care, respiratory distress, cerebral palsy, developmental delay, contact with disability services and mortality to age 5 years. Premature birth, which affects 97% of triplets and 53.3% of twins in Australia, is not the sole factor involved. The rate of multiple pregnancy in Australia is 1.7%. This compares to 22.1% for pregnancies resulting from assisted reproduction technology (ART). As a result, 21.8% of babies born from ART are from a multiple pregnancy, in comparison to the USA where the majority of babies born from ART are from a multiple pregnancy. Additionally, the population rate of multiple births is rising due to the more frequent use of ART and continued multi-embryo transfers, which is operating against a background of rising implantation rates within ART clinics. Twins have been of interest from a programming perspective. However, analysis of associations between crude birthweight and subsequent metabolic risk factors or mortality in adulthood from chronic disease indicate that adaptations in pregnancy to support multi-fetal growth are not identical to fetal growth restriction in singleton pregnancies. Indeed, the process of ‘maternal constraint’ is incompletely understood and confounds such comparisons. From a programming perspective, it is a challenge to identify in twin pregnancies the transition from physiological adaptation to pathological growth restriction. Growth disparity between twins has been more illuminating of subtle adverse effects for the smaller of twin pairs in both blood pressure and insulin resistance in adulthood. Interestingly, these effects can be observed in both dizygotic and to a lesser degree in monozygotic twins, which indicates a role for both genetic and environmental factors in these measures. This suggests that, consistent with experimental studies in other species, the relationship between impaired growth in utero and chronic disease in later life is not simply mediated by a common genetic pathway.

The oxidative environment and protein damage

Proteins are a major target for oxidants as a result of their abundance in biological systems, and their high rate constants for reaction. Kinetic data for a number of radicals and non-radical oxidants (e.g. singlet oxygen and hypochlorous acid) are consistent with proteins consuming the majority of these species generated within cells. Oxidation can occur at both the protein backbone and on the amino acid side-chains, with the ratio of attack dependent on a number of factors. With some oxidants, damage is limited and specific to certain residues, whereas other species, such as the hydroxyl radical, give rise to widespread, relatively non-specific damage. Some of the major oxidation pathways, and products formed, are reviewed. The latter include reactive species, such as peroxides, which can induce further oxidation and chain reactions (within proteins, and via damage transfer to other molecules) and stable products. Particular emphasis is given to the oxidation of methionine residues, as this species is readily oxidised by a wide range of oxidants. Some side-chain oxidation products, including methionine sulfoxide, can be employed as sensitive, specific, markers of oxidative damage. The product profile can, in some cases, provide valuable information on the species involved; selected examples of this approach are discussed. Most protein damage is non-repairable, and has deleterious consequences on protein structure and function; methionine sulfoxide formation can however be reversed in some circumstances. The major fate of oxidised proteins is catabolism by proteosomal and lysosomal pathways, but some materials appear to be poorly degraded and accumulate within cells. The accumulation of such damaged material may contribute to a range of human pathologies.

Diet during pregnancy, neonatal outcomes and later health

Renewed interest in nutrition during pregnancy has been generated by the hypothesis that adult disease has origins in early life. Animal experiments clearly show that altering maternal diet before and during pregnancy can induce permanent changes in the offspring’s birth size, adult health and lifespan. Among women living in Western societies, cigarette smoking is the most important factor known to reduce fetal growth, followed by low pre-pregnancy weight and low gestational weight gain. Obesity is also associated with pregnancy complications and adverse neonatal outcomes, so inadequate or excessive energy intake is not optimal for the developing fetus. Against a history of inconsistent results, several recent studies suggest that in Western settings the balance of macronutrients in a woman’s diet can influence newborn size. Effects appear to be modest, but this relationship may not encapsulate the full significance for health of the child, as there is emerging evidence of associations with long-term metabolic functioning that are independent of birth size. Consequences of inadequate maternal nutrition, for the offspring, may depend on timing during gestation, reflecting critical windows for fetal development. Where women are not malnourished, changing a woman’s nutritional plane during pregnancy may be detrimental to the unborn baby, and systematic reviews of the literature on dietary supplementation during pregnancy indicate few benefits and possible risks. In view of this, improved diet before pregnancy deserves greater attention.

The correlation between allergic rhinitis and sleep disturbance

Nasal congestion, a common symptom related to allergic rhinitis (AR), often is associated with poor sleep quality, leading to decreased learning ability, decreased productivity at work or school, and a reduced quality of life. The release of inflammatory mediators and activation of inflammatory cells results in nasal congestion, causing disrupted sleep and subsequent daytime somnolence. Therefore it is important to treat AR with medications that improve congestive symptoms without exacerbating sedation. Second-generation antihistamines and anticholinergic drugs are well tolerated but have little effect on congestion and therefore are limited in their ability to reduce AR-associated daytime somnolence. However, intranasal corticosteroids reduce congestion, improve sleep and sleep problems, and reduce daytime sleepiness, fatigue, and inflammation. Recently, montelukast, a leukotriene receptor antagonist, has joined the approved therapies for AR. Montelukast significantly improves both daytime and nighttime symptoms. AR treatment should endeavor to improve daytime and nighttime symptoms, sleep, and productivity, thereby improving quality of life.

Requirements for superoxide-dependent tyrosine hydroperoxide formation in peptides

Superoxide reacts rapidly with other radicals, but these reactions have received little attention in the context of oxidative stress. For tyrosyl radicals, reaction with superoxide is 3-fold faster than dimerization, and forms the addition product tyrosine hydroperoxide. We have explored structural requirements for hydroperoxide formation using tyrosine analogues and di- and tri-peptides. Superoxide and phenoxyl radicals were generated using xanthine oxidase, peroxidase and the respective tyrosine derivative, or by gamma-radiation. Peroxides were measured using FeSO4/Xylenol Orange. Tyrosine and tyramine formed stable hydroperoxides, but N-acetyltyrosine and p-hydroxyphenylacetic acid did not, demonstrating a requirement for a free amino group. Using [14C]tyrosine, the hydroperoxide and dityrosine were formed at a molar ratio of 1.8:1. Studies with pre-formed hydroperoxides, and measurements of substrate losses, indicated that, in the absence of a free amino group, reaction with superoxide resulted primarily in restitution of the parent compound. With dipeptides, hydroperoxides were formed only on N-terminal tyrosines. However, adjacent lysines promoted hydroperoxide formation, as did addition of free lysine or ethanolamine. Results are compatible with a mechanism [d'Alessandro, Bianchi, Fang, Jin, Schuchmann and von Sonntag (2000) J. Chem. Soc. Perkin Trans. II, 1862-1867] in which the phenoxyl radicals react initially with superoxide by addition, and the intermediate formed either releases oxygen to regenerate the parent compound or is converted into a hydroperoxide. Amino groups favour hydroperoxide formation through Michael addition to the tyrosyl ring. These studies indicate that tyrosyl hydroperoxides should be formed in proteins where there is a basic molecular environment. The contribution of these radical reactions to oxidative stress warrants further investigation.

Protein-bound kynurenine is a photosensitizer of oxidative damage

Human lens proteins become progressively modified by tryptophan-derived UV filter compounds in an age-dependent manner. One of these compounds, kynurenine, undergoes deamination at physiological pH, and the product binds covalently to nucleophilic residues in proteins via a Michael addition. Here we demonstrate that after covalent attachment of kynurenine, lens proteins become susceptible to photo-oxidation by wavelengths of light that penetrate the cornea. H2O2 and protein-bound peroxides were found to accumulate in a time-dependent manner after exposure to UV light (lambda > 305-385 nm), with shorter-wavelength light giving more peroxides. Peroxide formation was accompanied by increases in the levels of the protein-bound tyrosine oxidation products dityrosine and 3,4-dihydroxyphenylalanine, species known to be elevated in human cataract lens proteins. Experiments using D2O, which enhances the lifetime of singlet oxygen, and azide, a potent scavenger of this species, are consistent with oxidation being mediated by singlet oxygen. These findings provide a mechanistic explanation for UV light-mediated protein oxidation in cataract lenses, and also rationalize the occurrence of age-related cataract in the nuclear region of the lens, as modification of lens proteins by UV filters occurs primarily in this region.

α-Tropomyosin mutations Asp175Asn and Glu180Gly affect cardiac function in transgenic rats in different ways

To study the mechanisms by which missense mutations in α-tropomyosin cause familial hypertrophic cardiomyopathy, we generated transgenic rats overexpressing α-tropomyosin with one of two disease-causing mutations, Asp175Asn or Glu180Gly, and analyzed phenotypic changes at molecular, morphological, and physiological levels. The transgenic proteins were stably integrated into the sarcomere, as shown by immunohistochemistry using a human-specific anti-α-tropomyosin antibody, ARG1. In transgenic rats with either α-tropomyosin mutation, molecular markers of cardiac hypertrophy were induced. Ca2+sensitivity of cardiac skinned-fiber preparations from animals with mutation Asp175Asn, but not Glu180Gly, was decreased. Furthermore, elevated frequency and amplitude of spontaneous Ca2+waves were detected only in cardiomyocytes from animals with mutation Asp175Asn, suggesting an increase in intracellular Ca2+concentration compensating for the reduced Ca2+sensitivity of isometric force generation. Accordingly, in Langendorff-perfused heart preparations, myocardial contraction and relaxation were accelerated in animals with mutation Asp175Asn. The results allow us to propose a hypothesis of the pathogenetic changes caused by α-tropomyosin mutation Asp175Asn in familial hypertrophic cardiomyopathy on the basis of changes in Ca2+handling as a sensitive mechanism to compensate for alterations in sarcomeric structure.

Kinetic analysis of the reactions of hypobromous acid with protein components: implications for cellular damage and use of 3-bromotyrosine as a marker of oxidative stress

Hypohalous acids (HOX, X = Cl, Br) are produced by activated neutrophils, monocytes, eosinophils, and possibly macrophages. These oxidants react readily with biological molecules, with amino acids and proteins being major targets. Elevated levels of halogenated Tyr residues have been detected in proteins isolated from patients with atherosclerosis, asthma, and cystic fibrosis, implicating the production of HOX in these diseases. The quantitative significance of these findings requires knowledge of the kinetics of reaction of HOX with protein targets, and such data have not been previously available for HOBr. In this study, rate constants for reaction of HOBr with protein components have been determined. The second-order rate constants (22 degrees C, pH 7.4) for reaction with protein sites vary by 8 orders of magnitude and decrease in the order Cys > Trp approximately Met approximately His approximately alpha-amino > disulfide > Lys approximately Tyr >> Arg > backbone amides > Gln/Asn. For most residues HOBr reacts 30-100 fold faster than HOCl, though Cys and Met residues are approximately 10-fold less reactive, and ring halogenation of Tyr is approximately 5000-fold faster. Thus, Tyr residues are more, and Cys and Met much less, important targets for HOBr than HOCl. Kinetic models have been developed to predict the targets of HOX attack on proteins and free amino acids. Overall, these results shed light on the mechanisms of cell damage induced by HOX and indicate, for example, that the 3-chloro-Tyr:3-bromo-Tyr ratio does not reflect the relative roles of HOCl and HOBr in disease processes.

Elevated vasoactive intestinal peptide concentrations in patients with irritable bowel syndrome

The aim was to assess the roles of gut hormones and immune dysfunction in irritable bowel. In Study I, rectal mucosal samples examined blindly showed no histological evidence of inflammation in 16 irritable bowel patients compared to 17 healthy controls. The proinflammatory mediators interleukin-1beta and prostaglandin E2 also failed to show evidence of inflammation. Vasoactive intestinal peptide was elevated in irritable bowel (P = 0.01), but substance P, calcitonin gene-related peptide, and somatostatin levels were similar to control values. In Study II, 30 irritable bowel patients had elevated (P = 0.002) plasma concentrations of vasoactive intestinal peptide compared to 30 controls, and peptide levels were unrelated to whether the patient's predominant bowel habit was constipation, diarrhea, or both in alternation. In conclusion, no evidence of inflammation was detected in irritable bowel patients, but elevated vasoactive intestinal peptide concentrations were observed in both studies and might represent a potential diagnostic tool for irritable bowel syndrome.

Efficacy and safety of simvastatin in Asian and non-Asian coronary heart disease patients: a comparison of the GOALLS and STATT studies

BACKGROUND

Asians are thought to be more responsive to the lipid-lowering effects of statins than non-Asians although there are no head-to-head trials that examine this perception.

OBJECTIVE

To compare the results of the GOALLS and STATT studies that used similar titrate-to-goal protocols with 20 mg up to 80 mg simvastatin in Asian and non-Asian coronary heart disease (CHD) patients.

METHODS

GOALLS (N = 198; included non-Asians and Asians) and STATT (N = 133; included Asians only) were both multi-center, open-label 14-week studies in CHD patients with serum low density lipoprotein cholesterol (LDL-C) levels 115 mg/dL-180 mg/dL and triglycerides (TG) levels < or = 400 mg/dL. Simvastatin was titrated from 20 mg/day up to 80 mg/day in order to achieve the National Cholesterol Education Program (NCEP) LDL-C target < or = 100 mg/dL. The primary efficacy variable was the percentage of patients attaining the NCEP LDL-C target at Week 14. Secondary endpoints included proportion of patients achieving the European Society of Cardiology/European Atherosclerosis Society/European Society of Hypertension (European) LDL-C target < or = 115 mg/dL at Week 14 and percentage change in lipid parameters. Safety and tolerability were assessed by monitoring adverse experiences and safety laboratory tests. Fifteen Asian patients were part of the GOALLS cohort and their data were compared separately with results of non-Asians from GOALLS and Asians from the STATT study.

RESULTS

After 14 weeks of simvastatin treatment, 87.1% of GOALLS non-Asians, 85.7% of GOALLS Asians, and 78.2% of STATT patients attained the NCEP LDL-C target. At Week 14, 94.4%, 92.9%, and 91.7% of the GOALLS non-Asians, GOALLS Asians, and STATT patients achieved the European LDL-C target, respectively. The average treatment doses to attain NCEP and European targets were comparable among groups. The percentage reductions in lipid parameters from baseline to week 14 were similar among groups except, changes in high density lipoprotein cholesterol and apolipoprotein A-I favored Asian subjects. There was also a greater reduction in TG in the STATT study, but this was not consistent with TG reductions experienced by Asians in the GOALLS study. In both studies, simvastatin was generally well tolerated by all patients across the dosage range of 20 mg-80 mg. No cases of rhabdomyolysis or myopathy were reported in either study.

CONCLUSIONS

A great majority of CHD patients is able to achieve LDL-C treatment goals (up to 90%) on simvastatin regardless of racial background. Simvastatin treatment at doses of 20 mg-80 mg is well-tolerated in Asian and non-Asian CHD patients. This side-by-side comparison provides evidence that Asian and non-Asian CHD populations respond similarly to comparable doses of simvastatin.

Dietary composition of pregnant women is related to size of the baby at birth

The fetal origins theory of adult disease suggests that term infants who are small for their gestational age have an increased susceptibility to chronic disease in adulthood as a consequence of physiologic adaptations to undernutrition during fetal life. Consistent evidence for an influence of women's dietary composition during pregnancy on growth of their babies is lacking, despite robust effects in animal experiments. We undertook a prospective observational study of 557 women aged 18-41 y, living in Adelaide, South Australia. Diet was assessed in early and late pregnancy using an FFQ. In early pregnancy, medians for energy intake, the proportion of energy derived from protein and from carbohydrate were 9.0 MJ, 17 and 48%, respectively. In late pregnancy the corresponding medians were 9.2 MJ, 16 and 49%. In early pregnancy, the percentage of energy derived from protein was positively associated with birth weight (P = 0.02) and placental weight (P = 0.07), independently of energy intake and weight gain during pregnancy, and after adjustment for potential confounders, including maternal age, parity, and smoking. Effects were stronger among women (n = 429) who had reliable data, based on prespecified criteria including the plausibility of dietary data when referenced against estimated energy expenditure. In addition, for this subgroup, the percentage of energy from carbohydrate in early and late pregnancy was negatively associated with ponderal index of the baby, and a specific effect of protein from dairy sources was identified. These data support the proposition that maternal dietary composition has an effect on fetal growth. Maternal diet in Western societies may therefore be important for the long-term health of the child.

Overexpression of the cell adhesion molecules DDR1, Claudin 3, and Ep-CAM in metaplastic ovarian epithelium and ovarian cancer

PURPOSE

A better understanding of the molecular pathways underlying the development of epithelial ovarian cancer (EOC) is critical to identify ovarian tumor markers for use in diagnostic or therapeutic applications. The aims of this study were to integrate the results from 14 transcript profiling studies of EOC to identify novel biomarkers and to examine their expression in early and late stages of the disease.

EXPERIMENTAL DESIGN

A database incorporating genes identified as being highly up-regulated in each study was constructed. Candidate tumor markers were selected from genes that overlapped between studies and by evidence of surface membrane or secreted expression. The expression patterns of three integral membrane proteins, discoidin domain receptor 1 (DDR1), claudin 3 (CLDN3), and epithelial cell adhesion molecule, all of which are involved in cell adhesion, were evaluated in a cohort of 158 primary EOC using immunohistochemistry.

RESULTS

We confirmed that these genes are highly overexpressed in all histological subtypes of EOC compared with normal ovarian surface epithelium, identifying DDR1 and CLDN3 as new biomarkers of EOC. Furthermore, we determined that these genes are also expressed in ovarian epithelial inclusion cysts, a site of metaplastic changes within the normal ovary, in borderline tumors and in low-grade and stage cancer. A trend toward an association between low CLDN3 expression and poor patient outcome was also observed.

CONCLUSIONS

These results suggest that up-regulation of DDR1, CLDN3, and epithelial cell adhesion molecule are early events in the development of EOC and have potential application in the early detection of disease.

Reduction of cardiovascular events by simvastatin in nondiabetic coronary heart disease patients with and without the metabolic syndrome: subgroup analyses of the Scandinavian Simvastatin Survival Study (4S)

OBJECTIVE

To assess the effect of simvastatin treatment on the risk of cardiovascular events in nondiabetic patients with coronary heart disease (CHD) with and without the metabolic syndrome, as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP-III).

RESEARCH DESIGN AND METHODS

Subgroup analyses were performed on data from 3933 nondiabetic patients with clinically established CHD, serum total cholesterol level 5.5-8.0 mmol/l, and serum triglyceride level <or=2.5 mmol/l who were participating in the Scandinavian Simvastatin Survival Study (4S), a randomized, placebo-controlled trial. End points were total mortality, coronary mortality, major CHD event, myocardial revascularization, any CHD event, stroke, and any atherosclerotic event.

RESULTS

Over the 5.4-year median follow-up period, simvastatin produced similar changes in serum lipid levels in 893 patients with the metabolic syndrome and in 3040 patients without the metabolic syndrome. The relative risks of main end points in simvastatin-treated patients compared with placebo-treated patients with the metabolic syndrome were as follows: total mortality 0.54 (95% CI 0.36-0.82), coronary mortality 0.39 (0.23-0.65), major CHD event 0.59 (0.45-0.77), and any atherosclerotic event 0.69 (0.56-0.84). The corresponding RRs in patients without the metabolic syndrome were 0.72 (0.56-0.91), 0.62 (0.45-0.84), 0.71 (0.61-0.82), and 0.76 (0.68-0.85).

CONCLUSIONS

Nondiabetic CHD patients with or without the metabolic syndrome realize from simvastatin treatment a similar, substantial relative reduction in the risk of cardiovascular events. The absolute benefit may be greater in patients with the metabolic syndrome because they are at a higher absolute risk.

Overweight infertile patients have a higher fecundity than normal-weight women undergoing controlled ovarian hyperstimulation with intrauterine insemination

There is a positive effect of being overweight or obese on the pregnancy rate in women undergoing controlled ovarian hyperstimulation with intrauterine insemination.

EPR spin trapping of protein radicals

Electron paramagnetic resonance (EPR) spin trapping was originally developed to aid the detection of low-molecular-mass radicals formed in chemical systems. It has subsequently found widespread use in biology and medicine for the direct detection of radical species formed during oxidative stress and via enzymatic reactions. Over the last 15 years this technique has also found increasing use in detecting and identifying radicals formed on biological macromolecules as a result of either radical reactions or enzymatic processes. Though the EPR signals that result from the trapping of large, slowly tumbling radicals are often broad and relatively poor in distinctive features, a number of techniques have been developed that allow a wealth of information to be obtained about the nature, site, and reactions of such radicals. This article summarizes recent developments in this area and reviews selected examples of radical formation on proteins.

Markers of protein oxidation: different oxidants give rise to variable yields of bound and released carbonyl products

Exposure of proteins to radicals in the presence of O2 gives both side-chain oxidation and backbone fragmentation. These processes can be interrelated, with initial side-chain oxidation giving rise to backbone damage via transfer reactions. We have shown previously that alkoxyl radicals formed on the C-3 carbons of Ala, Val, Leu, and Asp residues undergo beta-scission to give backbone alpha-carbon radicals, with the release of the side- chain as a carbonyl compound. We now show that this is a general mechanism that occurs with a wide range of oxidants. The quantitative significance of this process depends on the extent of oxidation at C-3 compared with other sites. HO*, generated by gamma radiolysis, gave the highest total carbonyl yield, with protein-bound carbonyls predominating over released. In contrast, metal ion/H2O2 systems, gave more released than bound carbonyls, with this ratio modulated by EDTA. This is ascribed to metal ion-protein interactions affecting the sites of initial oxidation. Hypochlorous acid gave low concentrations of released carbonyls, but high yields of protein-bound material. The peroxyl radical generator 2,2'-azobis(2-amidinopropane) hydrochloride, and a peroxynitrite generator, 3-morpholinosydnonimine hydrochloride, gave lower overall carbonyl yields, with released carbonyls predominating over protein-bound species similar to that observed with metal ion/H2O2 systems.

Improving reproductive performance in overweight/obese women with effective weight management

Obesity and overweight are common conditions in the developed countries and they carry many health consequences, including some reproductive disorders. There is a very high prevalence of obese women in the infertile population and many studies have highlighted the link between obesity and infertility. A large proportion of infertile women have polycystic ovary syndrome (PCOS) which is also linked with increased risk of obesity and other metabolic anomalies. The association between obesity and/or PCOS and hyperinsulinaemia, hyper androgenism and abnormal secretion of other hormones, such as leptin, underlies many reproductive disorders observed in this population. It has been demonstrated that weight loss can improve the fertility of obese women through the recovery of spontaneous ovulation, whereas others will have improved response to ovarian stimulation in infertility treatment. Therefore, it is proposed that following the initial assessment of infertility and body mass index or other measurement of obesity, various weight management interventions, including diet, exercise or pharmacotherapeutic approaches, should be considered for overweight and obese infertile women.

Inflammatory responses in allergic rhinitis: traditional approaches and novel treatment strategies

Allergic rhinitis (AR) is associated with decreased learning, performance and productivity at work and school, as well as a reduced quality of life. With a staggering annual economic impact between 6 billion dollars and 8 billion dollars, AR affects 20% of the adult population and up to 40% of children. Effective therapy for allergic rhinitis requires understanding the pathophysiology of the disease, as well as the role of various inflammatory mechanisms. As such, various classes of medication are at the physicians' disposal to treat patients with allergic rhinitis. Among these are second-generation antihistamines and anticholinergic agents, intranasal corticosteroids, and mast cell stabilizers. Recently, montelukast, a leukotriene receptor antagonist, has been added to the modes of therapy approved by the US Food and Drug Administration for allergic rhinitis. For patients refractive to standard pharmacologic intervention, immunotherapy has shown some promising results. As newer strategies emerge, treatment regimens for allergic rhinitis should continue to improve not only daytime symptoms, but also nighttime symptoms and sleep with the fewest possible adverse effects.

Prevention of Type 2 diabetes mellitus. A review of the evidence and its application in a UK setting

Abstract Type 2 Diabetes mellitus (T2DM) is a complex metabolic, multifactorial disease, which affects the quality, quantity and style of life. People with T2DM have a life expectancy that can be shortened by as much as 15 years, with up to 75% dying of macrovascular complications. To reduce the impact of T2DM in the 21st century, we need an approach that not only optimally treats the person with established diabetes but also prevents diabetes from occurring in the first place. The best evidence for prevention of diabetes is for interventions that target individuals at highest risk. Targeting patients who have impaired glucose tolerance with lifestyle changes including physical activity and dietary factors has been shown to be effective in the Chinese, North American and Finnish populations. In order for such lifestyle interventions to be successful in other populations, they need to be culturally sensitive, individualized and sustained. Some pharmacological agents including metformin and acarbose have also been shown to be effective, although the profile of those who respond is different. There continues to be a need to develop and evaluate interventions that target communities and populations at risk in a UK setting.

The retina: oxidative stress and diabetes

A prominent and early feature of the retinopathy of diabetes mellitus is a diffuse increase in vascular permeability. As the disease develops, the development of frank macular oedema may result in vision loss. That reactive oxygen species production is likely to be elevated in the retina, and that certain regions of the retina are enriched in substrates for lipid peroxidation, may create an environment susceptible to oxidative damage. This may be more so in the diabetic retina, where hyperglycaemia may lead to elevated oxidant production by a number of mechanisms, including the production of oxidants by vascular endothelium and leukocytes. There is substantial evidence from animal and clinical studies for both impaired antioxidant defences and increased oxidative damage in the retinae of diabetic subjects that have been, in the case of animal studies, reversible with antioxidant supplementation. Whether oxidative damage has a causative role in the pathology of diabetic retinopathy, and thus whether antioxidants can prevent or correct any retinal damage, has not been established, nor has the specific nature of any damaging species been characterised.

What is the most relevant standard of success in assisted reproduction?: Assessing the BESST index for reproduction treatment

It has been proposed that use of performance indicators for assisted reproduction treatment (ART) should be revised to better reflect the burden of treatment endured by a couple, and to place greater emphasis on the desired outcome of healthy babies. Recently, the BESST (birth emphasizing a successful singleton at term) score as a routine measurement for use in ART has been suggested. We applied the BESST index to a sample of ART patients and found that the BESST score was sensitive to the effects of patient age and extremes in the number of embryos transferred. However, the statistical properties of the index placed great weight on the effective implantation rate, which when applied to a time series in which implantation rates were improving, showed BESST scores to increase simultaneously with multiple pregnancy rates. This limits the completeness of the summary score as an expression of benefits compared to risks. A modified BESST index, not including cycles of initiated treatment as a denominator, indicated that the ART births contained a substantially lower proportion of BESST babies when compared to the entire population of births.

Direct detection and quantification of transition metal ions in human atherosclerotic plaques: evidence for the presence of elevated levels of iron and copper

OBJECTIVE

The involvement of transition metals in atherosclerosis is controversial. Some epidemiological studies have reported a relationship between iron (Fe) and cardiovascular disease, whereas others have not. Experimental studies have reported elevated levels of iron and copper (Cu) in diseased human arteries but have often used methods that release metal ions from proteins.

METHODS AND RESULTS

In this study, we have used the minimally invasive technique of electron paramagnetic resonance (EPR) spectroscopy and inductively coupled plasma mass spectroscopy (ICPMS) to quantify iron and copper in ex vivo healthy human arteries and carotid lesions. The EPR spectra detected are characteristic of nonheme Fe(III) complexes. Statistically elevated levels of iron were detected in the intima of lesions compared with healthy controls (0.370 versus 0.022 nmol/mg tissue for EPR, 0.525 versus 0.168 nmol/mg tissue by ICPMS, P<0.05 in each cases). Elevated levels of copper were also detected (7.51 versus 2.01 pmol/mg tissue, lesion versus healthy control, respectively, P<0.05). Iron levels did not correlate with the gender or age of the donor, or tissue protein or calcium levels, but cholesterol levels correlated positively with iron accumulation, as measured by EPR.

CONCLUSIONS

These data support the hypothesis that iron accumulates in human lesions and may contribute to disease progression.