Decreased Plaque Formation Research Articles

Bioactive Functional Foods for Cardiovascular Diseases

Cardiovascular Disease (CVD) is a chronic pathological disorder regarded as a serious health concern round the globe. It is a multifactorial disease, with a range of various causative agents, among that dietary factor is considered the most important and may to a large degree determine CVD risk. Unfortunately, it has been less widely investigated. This review outlines the general aspects of CVD, epidemiology, risk factors and emphasizes the use of functional foods for the prevention and treatment of cardiovascular diseases. It highlights the importance of various foods used in daily routine and their activity against CVDs particularly. Recent studies have investigated the consumption of various foods including soybeans, oats, psyllium, flaxseed, garlic, tea, fish, grapes, nuts, fruits, vegetables, chocolate and sterol ester enhanced margarine etc., on CVD patients and their role as a natural/socioeconomic cure over chemical based drugs. Adequate intake of these foods on a constant basis, help in decreasing the risk of cardiovascular disease by several potential mechanisms e.g., lowering blood lipid levels, improving arterial compliance, reducing low-density lipoprotein oxidation, decreasing plaque formation, scavenging free radicals and inhibiting platelet aggregation etc. This review not only emphasizes the dire need of exploring safe functional foods against alarming rise of CVD cases, but also provides future insight in the use of bioactive food components in CVD therapeutics, as they are cost effective and have fewer side effects.

Can immunization with Bacillus Calmette-Guérin (BCG) protect against Alzheimer’s disease?

Alzheimer’s disease (AD) is a neurodegenerative disorder which is the most prevalent cause of dementia in the western world. Currently, it is the most expensive disease in America, costing more than heart diseases and cancer and as the world population is getting older it is expected to become the most expensive medical disorder in the world. AD is characterized by three core pathologies: accumulation of amyloid β (Aβ) plaques, neurofibrillary tangles (NFT) and sustained inflammation. It is now believed that inflammation provides the link between Aβ and NFT. The immune system is therefore, a major player in the pathogenesis of AD. Here we propose that Bacillus Calmette-Guérin (BCG) could affect the incidence of AD.Bacillus Calmette-Guérin (BCG) is a live attenuated Mycobacterium bovis preparation first developed as a vaccine against M. tuberculosis. It has been shown to be moderately effective in preventing tuberculosis, while noted to induce modifications in inflammatory response and to regulate the immune system. Intra-vesical administration of BCG is used successfully in the past four decades to prevent recurrence of non-muscle invasive bladder cancer.In this manuscript we investigate the hypothesis that exposure to BCG decreases the prevalence of AD in elderly population and that this occurs through modulation of the immune system. Our hypothesis is based on several lines of evidence: lower prevalence of AD in countries with high BCG coverage, ability of BCG to ameliorate several conditions involving the immune system like type 1 diabetes mellitus and multiple sclerosis, animal models of AD in which BCG shows therapeutic potential and a plausible molecular mechanism which may be the basis for this hypothesis. Namely, elevated systemic levels of IL-2 (as found when BCG is given intra-vesically) that amplify Treg cells that inhibit AD associated inflammation, decreased plaque formation and restore cognitive function. To test this hypothesis one may study cognition in the large available “natural adult population” exposed to high dose of BCG through the bladder. Bladder cancer survivors not given BCG can serve as control group. This population can be used without adding any medical intervention.

Growth performance, nutrient digestibility, ruminal fermentation, and rumen development of calves during transition from liquid to solid feed: Effects of physical form of starter feed and forage provision

Fifty-two 4-d-old male Holstein dairy calves (41.3±0.41kg of BW) were used in a completely randomized design to evaluate the effects of physical form of starter feed on intake, nutrient digestibility, ruminal fermentation, structural growth, and rumen development. At d 4 of age, individually housed calves were randomly allocated (n=13 per treatment) to 1 of 4 dietary treatments: 1) ground starter feed (Ground; mean particle size of 0.72mm diameter), 2) textured starter feed including steam flaked corn and barley grains (Textured; mean particle size of 3.61mm diameter), 3) pelleted starter feed (Pelleted; mean particle size of 4.53mm diameter), and 4) ground starter feed with 10% chopped alfalfa hay (Ground+AH; mean particle size of 1.02mm diameter). Calves received 4.0L/d of pasteurized milk from d 1 to 46 of study and 1.0L/d from d 47 to 49. Weaning occurred at the end of d 50 and the study lasted for 70 d. During the study (d 1–70), total dry matter (DM) and starter feed intakes, and final BW were greater for calves fed Ground+AH compared with those fed Ground and Pelleted starter feeds. Compared with Pelleted group, calves fed Textured starter feed had greater total DM and starter feed intakes, and final BW with no difference between Ground and Pelleted groups. Feeding Ground+AH starter feed increased average daily gain compared with other groups through the entire of trial. Similarly, feed efficiency was increased and tended to increase in Ground+AH as compared with the Ground and Pelleted groups as well as the Textured group, respectively. Fecal score and skeletal growth measurements were not affected by the dietary treatments. Calves fed Ground+AH starter feed spent more time rumination and had greater rumen pH at d 70 compared with calves fed other starter feeds with no difference in values at d 35. Ruminal NH3N concentration was not different between Ground+AH and Textured groups but was greater for both groups compared with Ground and Pelleted groups. At d 70, total volatile fatty acids concentration and the molar proportion of propionate were greater for calves fed Pelleted- vs. Ground+AH starter feed with no difference across other groups. Empty viscera weights including reticulorumen, omasum, and abomasum were not different between Ground+AH and Textured groups; but Ground+AH starter feed increased viscera weights as compared with the Ground and Pelleted starter feeds which was substantiated with both greater rumen wall thickness and muscularization. Overall, Ground+AH starter feed was able to maintain rumen pH at least by induction of greater time spending rumination and promoted growth performance of calves and also influenced morphometric attributes of the rumen wall which substantiated the effect of alfalfa hay supplementation on macroscopic and microscopic appearances by decreasing plaque formation and increasing muscularization, respectively. These benefits, however, were small when Textured starter feed was provided.

Rebamipide ameliorates atherosclerosis by controlling lipid metabolism and inflammation.

Atherosclerosis is a chronic inflammatory disease caused by the accumulation of excess lipid in the aorta and the severity is regulated by T lymphocytes subsets. Rebamipide has therapeutic activity in collagen induced arthritis (CIA) by controlling the balance between T helper (Th) 17 and regulatory T (Treg) cells. In this study, we aimed to determine whether rebamipide reduces the development of atherosclerosis. To investigate the therapeutic effect of rebamipide, ApoE-KO mice fed a western diet were administered rebamipide orally for 8 weeks. Mice were sacrificed followed by the evaluation of plaque formation in the aorta or immunohistochemistry for IL-17 and Foxp3. Serum was also prepared to determine the pro-inflammatory cytokine levels. The ability of rebamipide to regulate lipid metabolism or inflammation was confirmed ex vivo.ResultsThe oral administration of rebamipide decreased plaque formation in atherosclerotic lesions as well as the markers of metabolic disorder in ApoE-deficient mice with atherosclerosis. Pro-inflammatory cytokines were also suppressed by rebamapide. In addition, the population of Th17 was decreased, whereas Treg was increased in the spleen of rebamipide-treated ApoE deficient mice. Rebamipide also ameliorated the severity of obese arthritis and has the capability to reduce the development of atherosclerosis by controlling the balance between Th17 and Treg cells. Thus, rebamipide could be a therapeutic agent to improve the progression of inflammation in metabolic diseases.

Inhibition of RORα/γ suppresses atherosclerosis via inhibition of both cholesterol absorption and inflammation

ObjectiveCardiovascular diseases (CVDs) are the leading cause of mortality in Western countries. Atherosclerosis is a multi-step inflammatory disease characterized at early stages by accumulation of cholesterol in the arterial wall followed by recruitment of immune cells. We sought to determine if pharmacological suppression of RORα/γ activity is beneficial in treatment of atherosclerosis. MethodsTo identify the role of RORα and RORγ in atherosclerosis, we used the LDL-R−/− mouse model of atherosclerosis placed on a high cholesterol diet treated with SR1001, a RORα/γ inverse agonist, for four weeks. ResultsOur results demonstrate that treatment with the ROR inverse agonist substantially decreases plaque formation in vivo. The mechanism of the anti-atherogenic activity of the inhibition of RORα/γ activity appeared to be due to targeting two distinct pathways. SR1001 treatment reduced plasma low density lipoprotein (LDL) level without affecting high density lipoprotein (HDL) via increasing intestinal cholesterol excretion. Treatment with SR1001 also induced an anti-atherogenic immune profile that was characterized by a reduction in Th17 cells and an increase in Treg and Th2 cells. Our data suggest that RORα and RORγ play a critical role in atherosclerosis development by regulating at least two major pathways important in the pathology of this disease: cholesterol flux and inflammation. ConclusionOur data suggest that pharmacological targeting of RORα/γ may be an effective method for treatment of atherosclerosis offering a distinct mechanism of action relative to statins.

BMP-7 Treatment Increases M2 Macrophage Differentiation and Reduces Inflammation and Plaque Formation in Apo E-/- Mice.

Inflammation plays a fundamental role in the inception and development of atherosclerosis (ATH). Mechanisms of inflammation include the infiltration of monocytes into the injured area and subsequent differentiation into either pro-inflammatory M1 macrophages or anti-inflammatory M2 macrophages. We have previously published data suggesting bone morphogenetic protein-7 (BMP-7) enhances M2 macrophage differentiation and anti-inflammatory cytokine secretion in vitro. In this regard, we hypothesized BMP-7 would inhibit plaque formation in an animal model of ATH through monocytic plasticity mediation. ATH was generated in male and female Apo E-/- mice via partial left carotid artery (PLCA) ligation and mice were divided into 3 groups: Sham, PLCA, and PLCA+BMP-7 (200ug/kg; i.v.). Our data suggest that BMP-7 inhibits plaque formation and increases arterial systolic velocity. Furthermore, we report inhibition of monocyte infiltration and a decrease in associated pro-inflammatory cytokines (MCP-1, TNF-α, and IL-6) in the PLCA+BMP-7 mice. In contrast, our data suggest a significant (p<0.05) increase in M2 macrophage populations with consequential enhanced anti-inflammatory cytokine (IL-1RA, IL-10, and Arginase 1) expression following BMP-7 treatment. We have also observed that mechanisms promoting monocyte into M2 macrophage differentiation by BMP-7 involve the upregulation and activation of the BMP-7 receptor (BMP-7RII). In conclusion, we report that BMP-7 has the potential to mediate cellular plasticity and mitigate the inflammatory immune response, which results in decreased plaque formation and improved blood velocity.

Effect of coconut oil in plaque related gingivitis - A preliminary report.

Background:Oil pulling or oil swishing therapy is a traditional procedure in which the practitioners rinse or swish oil in their mouth. It is supposed to cure oral and systemic diseases but the evidence is minimal. Oil pulling with sesame oil and sunflower oil was found to reduce plaque related gingivitis. Coconut oil is an easily available edible oil. It is unique because it contains predominantly medium chain fatty acids of which 45-50 percent is lauric acid. Lauric acid has proven anti inflammatory and antimicrobial effects. No studies have been done on the benefits of oil pulling using coconut oil to date. So a pilot study was planned to assess the effect of coconut oil pulling on plaque induced gingivitis.Materials and Methods:The aim of the study was to evaluate the effect of coconut oil pulling/oil swishing on plaque formation and plaque induced gingivitis. A prospective interventional study was carried out. 60 age matched adolescent boys and girls in the age-group of 16-18 years with plaque induced gingivitis were included in the study and oil pulling was included in their oral hygiene routine. The study period was 30 days. Plaque and gingival indices of the subjects were assessed at baseline days 1,7,15 and 30. The data was analyzed using paired t test.Results:A statistically significant decrease in the plaque and gingival indices was noticed from day 7 and the scores continued to decrease during the period of study.Conclusion:Oil pulling using coconut oil could be an effective adjuvant procedure in decreasing plaque formation and plaque induced gingivitis.

Inhibition of indoleamine 2,3-dioxygenase-mediated tryptophan catabolism accelerates atherosclerosis in hypercholesterolemic mice

Objectives: Tryptophan metabolites downstream of indoleamine 2,3-dioxygenase (IDO), collectively called kynurenines (Kyns), have been established as immune regulators. While we recently showed that the tryptophan metabolite 3-hydroxtanthranilic acid (3-HAA) decreases plaque formation in hypercholesterolemic mice, the role of IDO has never been examined directly in experimental or clinical studies of atherosclerosis. In this study, we used the IDO inhibitor 1-Methyl-DL-tryptophan (1DL-MT) to determine the role of this enzyme and the tryptophan catabolism in atherosclerosis.

Targeted inhibition of ATP‐binding cassette transporter A1 protein degradation promotes reverse cholesterol transport and reduces atherosclerosis in mice (832.15)

Objective ATP‐Bing Cassette Transporter A1 (ABCA1) is a key protein in the rate‐limiting step of reverse cholesterol transport, which maintains plasma HDL levels. Transcriptional regulating ABCA1 promotes HDL generation and RCT is well established, however, little is known about the posttranspcriptional inhibition of ABCA1 degradation on macrophage RCT and atherosclerosis. We therefore investigate whether suppressing ABCA1 degradation would promote RCT and reduce atherosclerosis.Methods and results Pulse‐chase analysis revealed that a small molecular (IMM‐H007) significantly inhibits ABCA1 degradation and facilitates its cell‐surface localization in THP‐1 macrophages. In vitro tests described that IMM‐H007 promote cholesterol efflux via ABCA1‐mediated pathway. Animals fed a western diet containing 1.25% cholesterol with IMM‐H007 treatment showed an increase in circulating HDL levels and enhanced RCT to the plasma, liver, and feces. Additional, elevated hepatic ABCA1 expression and functional HDL were also observed in mice after IMM‐H007 administration. Furthermore, suppressing ABCA1 degradation gave rise to the reduction of plaque size, lipid content and increase markers of plaque stability in apoE‐/‐ mice.Conclusion Our findings reveal that raising HDL levels by inhibiting ABCA1 protein degradation enhances reverse cholesterol transport and decreases plaque formation, suggesting that it is a promising HDL therapeutic strategy to protect against atherosclerotic. IMM‐H007 could be a leading compound for development of drugs for raising HDL quantity and function.

Four-and-a-half LIM domain protein-2 (FHL-2) inhibition reduces atherosclerosis in apolipoprotein E-deficient mice

Background: Four-and-a-half LIM domain protein-2 (FHL-2), a member of the FHL family of proteins, is expressed in vascular endothelial and smooth muscle cells and negatively regulates endothelial cell survival and migration. However, its role in atherogenesis is unknown. Methods and results: To investigate the role of FHL-2 in atherosclerosis, we crossed FHL-2 knockout (FHL-2-/-) with apolipoprotein E-deficient (ApoE-/-) mice, and fed them a high-cholesterol, high-fat diet for 7 weeks. FHL-2-/-ApoE-/- mice displayed significantly less atherosclerotic plaque formation, as assessed by oil red O staining, in the aortic sinus (0.14±0.02 vs. 0.29±0.04 mm2) and aorta (6.9±0.9 vs 10.3±1%), compared with ApoE-/- mice. This was associated with enhanced collagen (16±2 vs 8.6±3%) and smooth muscle cell (4.5±0.8 vs 1.8±0.5%) contents within the plaques in the aortic sinus of FHL-2-/-ApoE-/- mice, as determined by Sirius red and alpha-actin staining, respectively, compared with ApoE-/- mice. These results suggest that absence of FHL-2 promotes smaller and more stable plaques. However, relative monocyte/macrophage content within the atherosclerotic plaques, as determined by MOMA-2 immunostaining, and in spleens, as determined by FACS analysis, was equivalent in both animals groups. Decreased plaque formation in FHL-2-/-ApoE-/- mice was associated with significantly reduced aortic ICAM-1 mRNA levels by 40%. Moreover, FACS analysis of T cells in spleens showed a significant increase in CD4+CD25+Foxp3+ regulatory T cell numbers, in FHL-2-/-ApoE-/- compared with ApoE-/- mice (19.5±1.6 vs. 16.2±2% of CD3+CD4+ cells, respectively). Conclusions: These results suggest that FHL-2 may play an important role in atherogenesis by promoting plaque formation, involving upregulation of adhesion molecule expression and suppression of regulatory T cells.

In vitro and in vivo activity of AS101 against West Nile virus (WNV)

There are currently no effective drugs to treat serious complications caused by WNV infection. The inhibition of WNV by the pluripotent immunomodulator AS101 [ammonium trichloro(dioxyethylene-0-0′)tellurate] was evaluated in vitro and in vivo, and its mechanism was explored. Adding AS101 to Vero cells 1h or 5min before infection increased cell survival from 21% to 84% and decreased plaque formation by 87% and virus yield by 2 logs. Following infection, high titer of WNV remained in the culture supernatants indicating interference with virus cell attachment. The binding of αVβ3 integrin to WNV and of Vero cells to anti-αVβ3 antibody were inhibited by AS101, suggesting that AS101 may block this cellular WNV receptor. Daily treatment of mice with AS101 starting 1 day before lethal infection with WNV resulted in 48% survival. However, treatment beginning 3 days post infection resulted only in 16% survival. Similarly, a single dose of anti-WNV IVIG three days post infection resulted in 16% survival compared to 100% if IVIG was given on the same day of infection or 1 day later. However, when mice received combined treatment with AS101 and IVIG starting 3 days post infection, an additive effect of 33% survival was observed. Our study suggests that AS101 has a potential preventive and therapeutic effect against WNV infection.

Inhibition of Lipoprotein-Associated Phospholipase A2 Ameliorates Inflammation and Decreases Atherosclerotic Plaque Formation in ApoE-Deficient Mice

BackgroundLipoprotein-associated phospholipase A2 (Lp-PLA2) is thought to play modulatory roles in the development of atherosclerosis. Here we evaluated the effects of a specific lp-PLA2 inhibitor on atherosclerosis in ApoE-deficient mice and its associated mechanisms.Methodology/Principal FindingsApoE-deficient mice fed an atherogenic high-fat diet for 17 weeks were divided into two groups. One group was administered the specific lp-PLA2 inhibitor, darapladib (50 mg/kg/day; p.o.) daily for 6 weeks, while the control group was administered saline. We observed no differences in body weight and serum lipids levels between the two groups at the end of the dietary period. Notably, serum lp-PLA2 activity as well as hs-CRP (C-reactive protein) and IL-6 (Interleukin-6) levels were significantly reduced in the darapladib group, compared with the vehicle group, while the serum PAF (platelet-activating factor) levels were similar between the two groups. Furthermore, the plaque area through the arch to the abdominal aorta was reduced in the darapladib group. Another finding of interest was that the macrophage content was decreased while collagen content was increased in atherosclerotic lesions at the aortic sinus in the darapladib group, compared with the vehicle group. Finally, quantitative RT-PCR performed to determine the expression patterns of specific inflammatory genes at atherosclerotic aortas revealed lower expression of MCP-1, VCAM-1 and TNF-α in the darapladib group.Conclusions/SignificanceInhibition of lp-PLA2 by darapladib leads to attenuation of in vivo inflammation and decreased plaque formation in ApoE-deficient mice, supporting an anti-atherogenic role during the progression of atherosclerosis.

Pathophysiology-Based Treatment of Idiopathic Calcium Kidney Stones

Idiopathic calcium oxalate (CaOx) stone-formers (ICSFs) differ from patients who make idiopathic calcium phosphate (CaP) stones (IPSFs). ICSFs, but not IPSFs, form their stones as overgrowths on interstitial apatite plaque; the amount of plaque covering papillary surface is positively correlated with urine calcium excretion and inversely with urine volume. The amount of plaque predicts the number of recurrent stones. The initial crystal overgrowth on plaque is CaP, although the stone is mainly composed of CaOx, meaning that lowering supersaturation (SS) for CaOx and CaP is important for CaOx stone prevention. IPSFs, unlike ICSFs, have apatite crystal deposits in inner medullary collecting ducts, which are associated with interstitial scarring. ICSFs and IPSFs have idiopathic hypercalciuria, which is due to decreased tubule calcium reabsorption, but sites of abnormal reabsorption may differ. Decreased reabsorption in proximal tubules (PTs) delivers more calcium to the thick ascending limb (TAL), where increased calcium reabsorption can load the interstitium, leading to plaque formation. The site of abnormal reabsorption in IPSFs may be the TAL, where an associated defect in bicarbonate reabsorption could produce the higher urine pH characteristic of IPSFs. Preventive treatment with fluid intake, protein and sodium restriction, and thiazide will be effective in ICSFs and IPSFs by decreasing urine calcium concentration and CaOx and CaP SS and may also decrease plaque formation by increased PT calcium reabsorption. Citrate may be detrimental for IPSFs if urine pH rises greatly, increasing CaP SS. Future trials should examine the question of appropriate treatment for IPSFs.

Short-circuiting DCs in atherosclerosis

European researchers have shown that targeting the dendritic cell–derived chemokine CCL17 could decrease plaque formation, pointing to a new strategy to treat inflammation associated with cardiovascular and pulmonary disorders. Carolus Therapeutics has nonexclusively optioned the findings.

Sex-Dependent Attenuation of Plaque Growth After Treatment With Bone Marrow Mononuclear Cells

There are clinically relevant differences in symptomatology, risk stratification, and efficacy of therapies between men and women with coronary artery disease. Sex-based differences in plaque attenuation after administration of bone marrow mononuclear cells (BMNCs) are unknown. Forty-five male and 57 female apolipoprotein-E knockout (apoE(-/-)) mice were fed a high-fat diet. At 14 weeks of age, animals received 4 biweekly intravenous sex-matched (males, n=11; females, n=13) or -mismatched (males, n=12; females, n=14) BMNCs obtained from C57BL6/J mice. The rest of the apoE(-/-) mice were vehicle treated (males, n=13; females, n=20) or were age-matched untreated controls (males, n=9; females, n=10). Aortic plaque burden, progenitor cell profiles in bone marrow (BM) and 22 circulating cytokines/chemokines were examined 1 week following the final injection. Only female BMNCs infused into male apoE(-/-) recipients significantly decreased plaque formation (P<0.001). This reparative response univariately correlated with increased CD34(+) (P=0.02), CD45(+) (P=0.0001), and AC133(+)/CD34(+) (P=0.001) cell percentages in the BM of recipients but not with total serum cholesterol or percentage of BM-CD31(+)/CD45(low) cells. In a multivariate analysis, BM-AC133(+)/CD34(+) and BM-CD45(+) percentage counts correlated with a lower plaque burden (P<0.05). Increased granulocyte colony-stimulating factor levels highly correlated with plaque attenuation (r=-0.86, P=0.0004). In untreated apoE(-/-) mice of either sex, BM-AC133(+)/CD34(+) cells rose initially and then fell as plaque accumulated; however, BM-AC133(+)/CD34(+) percentages were higher in females at all times (P<or=0.01). We have demonstrated an atheroprotective effect of female-derived BMNCs administered to male atherosclerotic apoE(-/-) mice; this reparative response correlated with the upregulation of BM-AC133(+)/CD34(+) and CD45(+) cells and of circulating granulocyte colony-stimulating factor. Atherosclerotic female apoE(-/-) mice did not exhibit atheroprotection after BMNCs of either sex. Our findings may have implications for clinical cell therapy trials for coronary artery disease. Further exploration of sex-based differences in atheroprotection and vascular repair is warranted.

Glatiramer acetate fights against Alzheimer’s disease by inducing dendritic-like microglia expressing insulin-like growth factor 1

Alzheimer's disease (AD) is characterized by plaque formation, neuronal loss, and cognitive decline. The functions of the local and systemic immune response in this disease are still controversial. Using AD double-transgenic (APP/PS1) mice, we show that a T cell-based vaccination with glatiramer acetate, given according to a specific regimen, resulted in decreased plaque formation and induction of neurogenesis. It also reduced cognitive decline, assessed by performance in a Morris water maze. The vaccination apparently exerted its effect by causing a phenotype switch in brain microglia to dendritic-like (CD11c) cells producing insulin-like growth factor 1. In vitro findings showed that microglia activated by aggregated beta-amyloid, and characterized as CD11b(+)/CD11c(-)/MHC class II(-)/TNF-alpha(+) cells, impeded neurogenesis from adult neural stem/progenitor cells, whereas CD11b(+)/CD11c(+)/MHC class II(+)/TNF-alpha(-) microglia, a phenotype induced by IL-4, counteracted the adverse beta-amyloid-induced effect. These results suggest that dendritic-like microglia, by facilitating the necessary adjustment, might contribute significantly to the brain's resistance to AD and argue against the use of antiinflammatory drugs.

Chlorhexidine digluconate induces mitotic recombination in diploid cells of Aspergillus nidulans

Chlorhexidine digluconate (1,1'-hexamethylene-bis[(5-p-clorophenyl)-biguanide]) is a bisbiguanidine antiseptic, used to decrease plaque formation and to control periodontal diseases. The determination of the frequency of mitotic crossing-over constitutes a very important method for detecting carcinogenic agents. The recombinogenic potential of chlorhexidine digluconate was evaluated on Aspergillus nidulans by the production of cells homozygous for the following nutritional markers: riboA1, pabaA124, biA1, methA17 and pyroA4. A. nidulans was exposed to three concentrations of chlorhexidine digluconate (1, 5, and 10 microM). Inhibition of colony development, conidiophore morphological alteration (cytotoxic effect), and the recombinogenic effect, indicated by homozygotization index (HI) values higher than 2.0, were observed for all concentrations of chlorhexidine digluconate. A homozygous pyro+//pyro+ diploid strain and a diploid homozygous for the recessive w gene were isolated from UT448//A757 diploid treated with chlorhexidine digluconate, emphasazing its recombinogenic potential. Although, beneficial effects of chlorhexidine, as an antiseptic agent, are reported in the literature, our results revealed that chlorhexidine digluconate, at less levels lowered those used clinically, caused toxic and recombinogenic effects on diploid A. nidulans strain.

Novel actions of thiazolidinediones on vascular function and exercise capacity

The endothelium is the first line of defense for maintaining normal vascular function in the vessel wall; however, the endothelium is sensitive to metabolic stress. In patients with insulin resistance or type 2 diabetes mellitus, a set of metabolic insults—namely high plasma levels of glucose and free fatty acids, increased inflammation, dyslipidemia, and hypertension—cause endothelial dysfunction and a transition from an antiatherogenic endothelium to a proatherogenic endothelium. Disruption of endothelial function leads to activation of platelets and macrophages, increased thrombotic potential, transition of macrophages to foam cells, stimulation of cytokine secretion, and proliferation of vascular smooth muscle cells. Insulin-sensitizing agents, such as the thiazolidinediones (TZDs), improve flow-mediated vasodilation, decrease macrophage and smooth muscle cell activation, proliferation, and migration, and decrease plaque formation. The TZDs exert multifaceted effects on the vasculature by regulating the expression of transcription factors and orchestrating whole-gene programs that restore vascular physiology to the healthy state. Exercise training and increased levels of habitual physical activity have therapeutic benefit in terms of both preventing and treating insulin resistance and diabetes. However, this benefit of exercise training and increased physical activity is complicated by the fact that individuals with insulin resistance or type 2 diabetes have decreased maximal exercise capacity or maximal oxygen consumption and have slower oxygen uptake kinetics at the beginning of exercise. Both of these abnormalities contribute to the decreased levels of habitual physical activity observed in patients with diabetes. Preliminary data suggest that TZDs improve measures of cardiac function and exercise capacity, and investigators are assessing the impact of treatment with rosiglitazone on exercise capacity in an ongoing clinical trial.

Functional foods and cardiovascular disease

Functional foods are foods that, by virtue of physiologically active food components, provide health benefits beyond basic nutrition. Many functional foods have been found to be potentially beneficial in the prevention and treatment of cardiovascular disease, the leading cause of mortality in the United States. These foods include soybeans, oats, psyllium, flaxseed, garlic, tea, fish, grapes, nuts, and stanol- and sterol ester enhanced margarine. When eaten in adequate amounts on a consistent basis, these foods may aid in decreasing the risk of cardiovascular disease by several potential mechanisms: lowering blood lipid levels, improving arterial compliance, reducing low-density lipoprotein oxidation, decreasing plaque formation, scavenging free radicals, and inhibiting platelet aggregation.

Butadiene-induced Intrastrand DNA Cross-links: A Possible Role in Deletion Mutagenesis

To initiate studies designed to identify the mutagenic spectrum associated with butadiene diepoxide-induced N(2)-N(2) guanine intrastrand cross-links, site specifically adducted oligodeoxynucleotides were synthesized in which the adducted bases were centrally located within the context of the human ras 12 codon. The two stereospecifically modified DNAs and the corresponding unmodified DNA were ligated into a single-stranded M13mp7L2 vector and transfected into Escherichia coli. Both stereoisomeric forms (R, R and S,S) of the DNA cross-links resulted in very severely decreased plaque-forming ability, along with an increased mutagenic frequency for both single base substitutions and deletions compared with unadducted DNAs, with the S,S stereoisomer being the most mutagenic. Consistent with decreased plaque formation, in vitro replication of DNA templates containing the cross-links by the three major E. coli polymerases revealed replication blockage by both stereoisomeric forms of the cross-links. The same DNAs that were used for replication studies were also assembled into duplex DNAs and tested as substrates for the initiation of nucleotide excision repair by the E. coli UvrABC complex. UvrABC incised linear substrates containing these intrastrand cross-links with low efficiency, suggesting that these lesions may be inefficiently repaired by the nucleotide excision repair system.