Instruct: Given a question, retrieve documents that answer the question.
Query: polycarbonate plastic
The adverse effect of bisphenol-A (BPA) on the male reproductive system observed in animal studies has not been well examined in human populations. BPA is potentially a serious public health problem because of its widely detected presence in the human body. This study was conducted among 427 male workers in regions where high levels of BPA exposure existed. All participants provided urine samples, which were tested for BPA concentration using high-performance liquid chromatography. Male sexual dysfunction was ascertained using standard male sexual function inventories. Male sexual dysfunction was measured in 4 domains using 7 indices. After controlling for potential confounders using linear regression, increasing urine BPA level was associated with worsening male sexual function on a continuous scale. All 7 indices demonstrated this negative linear correlation. Increasing urine BPA level was associated with decreased sexual desire (P < .001), more difficulty having an erection (P < .001), lower ejaculation strength (P < .001), and lower level of overall satisfaction with sex life (P < .01). A similar negative correlation was also observed among participants exposed to BPA from only environmental sources (no occupational exposure to BPA), although the estimates in this group were less stable because of a smaller sample size. Our results reveal a correlation between a biological measure of urine BPA level and declining male sexual function. This finding may enhance the understanding of the BPA effect in human populations, and may have important public health implications given the widespread human exposure to BPA.
Background Obesity, an inflammatory condition linked to cardiovascular disease, is associated with expansion of adipose tissue. Highly prevalent coplanar polychlorinated biphenyls (PCBs) such as 3,3′,4,4′-tetrachlorobiphenyl (PCB-77) accumulate in adipose tissue because of their lipophilicity and increase with obesity. However, the effects of PCBs on adipocytes, obesity, and obesity-associated cardiovascular disease are unknown. Objectives In this study we examined in vitro and in vivo effects of PCB-77 on adipocyte differentiation, proinflammatory adipokines, adipocyte morphology, body weight, serum lipids, and atherosclerosis. Methods PCB-77 or 2,2′,4,4,5,5′-hexachlorobiphenyl (PCB-153) was incubated with 3T3-L1 adipocytes either during differentiation or in mature adipocytes. Concentration-dependent effects of PCB-77 were contrasted with those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). For in vivo studies, we treated C57BL/6 wild-type (WT) or aryl hydrocarbon receptor (AhR)−/− mice with vehicle or PCB-77 (49 mg/kg, by intraperitoneal injection) and examined body weight gain. In separate studies, we injected ApoE−/− mice with vehicle or PCB-77 over a 6-week period and examined body weight, adipocyte size, serum lipids, and atherosclerosis. Results Low concentrations of PCB-77 or TCDD increased adipocyte differentiation, glycerol–3-phosphate dehydrogenase activity, and expression of peroxisome proliferator–activated receptor γ, whereas higher concentrations inhibited adipocyte differentiation. Effects of PCB-77 were abolished by the AhR antagonist α-naphthoflavone. PCB-77 promoted the expression and release of various proinflammatory cytokines from 3T3-L1 adipocytes. Administration of PCB-77 increased body weight gain in WT but not AhR−/− mice. ApoE−/− mice injected with PCB-77 exhibited greater body weight, adipocyte hypertrophy, serum dyslipidemia, and augmented atherosclerosis. Conclusions Our findings suggest that PCB-77 may contribute to the development of obesity and obesity-associated atherosclerosis.
The elimination kinetics of polychlorinated biphenyls (PCBs) in humans is difficult to assess in observational studies, because PCB exposure is never completely abolished. In a community with high dietary PCB exposures from whale blubber, we examined two groups of children with increased body burdens from breast-feeding. Follow-up was from ages 4.5 years to 7.5 years (99 subjects) and 7 to 14 years (101 subjects). The calculations were performed by the use of structural equation models, with adjustment for body weight and dietary blubber intake as the main source of postnatal exposure. As a likely result of background exposures, apparent elimination half-lives were unexpectedly long when based on results from all cohort members. Subjects with exposures above the median and in the highest quartile showed half-lives of about 3-4 years for CB-138, and 4.5-5.5 years for CB-105 and CB-118; 6.5-7.5 years for CB-156, CB-170, and CB-187; and 7-9 years for CB-153 and CB-180. The longest half-lives correspond to elimination of the parent PCB solely with a daily fat excretion rate of 1-2 g, while shorter half-lives assume metabolic break-down.
AIM: The aim of the present study was to investigate the efficacy of Metformin compared with a hypocaloric diet on C-reactive protein (CRP) level and markers of insulin resistance in obese and overweight women with polycystic ovary syndrome (PCOS). MATERIAL AND METHODS: Forty women with body mass index ≥ 27 and PCOS were randomly allocated to receive either Metformin or hypocaloric diet and were assessed before and after a treatment period of 12 weeks. High-sensitivity CRP (hs-CRP) and markers of insulin resistance (IR), homeostasis model assessment-IR, quantitative insulin-sensitivity check index and fasting glucose to insulin ratio were evaluated in each patient. RESULTS: A total of 10 subjects did not complete the trial (three patients in the Metformin group and seven patients in the diet group) and a total of 30 subjects completed the trial (17 subjects in the Metformin group and 13 subjects in the diet group). Serum concentration of hs-CRP significantly decreased in both the Metformin (5.29 ± 2.50 vs 3.81 ± 1.99, P = 0.008) and diet groups (6.08 ± 2.14 vs 4.27 ± 1.60, P = 0.004). There were no significant differences in mean hs-CRP decrement between the two groups. Decrease in hs-CRP levels was significantly correlated with waist circumference in the diet group (r = 0.8, P < 0.001). The effect of a hypocaloric diet with 5-10% weight reduction on markers of insulin resistance (homeostasis model assessment-IR, fasting glucose to insulin ratio, quantitative insulin-sensitivity check index) was better than Metformin therapy (P = 0.001). CONCLUSIONS: Although weight reduction has equal efficacy with Metformin in decreasing serum hs-CRP levels, it was significantly more effective in improving insulin resistance in obese and overweight PCOS women. © 2012 The Authors. Journal of Obstetrics and Gynaecology Research © 2012 Japan Society of Obstetrics and Gynecology.
Respiratory exposure to diacetyl and diacetyl-containing flavorings used in butter-flavored microwave popcorn (BFMP) causes lung disease, including bronchiolitis obliterans (BO), in flavorings and popcorn manufacturing workers. However, there are no published reports of lung disease among BFMP consumers. We present a case series of three BFMP consumers with biopsy-confirmed BO. We review data relating to consumer exposures, estimate case exposures, and compare them to diacetyl-containing flavoring-exposed manufacturing workers with lung disease. These consumer cases' exposure levels are comparable to those that caused disease in workers. We were unable to identify any other exposures or diseases known or suspected to cause BO in these cases. BFMP poses a significant respiratory risk to consumers. Some manufacturers have substituted diacetyl with other alpha-diketones that are likely to pose a similar risk. Simple consumer practices such as cooling the popcorn bag would eliminate the risk of severe lung disease.
Campylobacter spp. are nutritionally fastidious organisms that are sensitive to normal atmospheric oxygen levels and lack homologues of common cold shock genes. At first glance, these bacteria seem ill equipped to persist within food products under processing and storage conditions; however, they survive in numbers sufficient to cause the largest number of foodborne bacterial disease annually. A mechanism proposed to play a role in Campylobacter survival is the addition of polyphosphate-containing marinades during poultry processing. Campylobacter jejuni and Campylobacter coli strains incubated in chicken exudates collected from poultry treated with a marinade demonstrated considerable survival advantages (1 to 4 log CFU/ml) over the same strains incubated in chicken exudate from untreated birds. Polyphosphates, which constitute a large portion of the commercial poultry marinades, were shown to account for a majority of the observed influence of the marinades on Campylobacter survival. When six different food grade polyphosphates (disodium pyrophosphate, tetrasodium pyrophosphate, pentasodium triphosphate, sodium polyphosphate, monosodium phosphate, and trisodium phosphate) were utilized to compare the survival of Campylobacter strains in chicken exudate, significant differences were observed with regard to Campylobacter survival between the different polyphosphates. It was then determined that the addition of polyphosphates to chicken exudate increased the pH of the exudate, with the more sodiated polyphosphates increasing the pH to a greater degree than the less sodiated polyphosphates. It was confirmed that the change in pH mediated by polyphosphates is responsible for the observed increases in Campylobacter survival.
background: California children’s exposures to polybrominated diphenyl ether flame retardants (PBDEs) are among the highest worldwide. PBDEs are known endocrine disruptors and neurotoxicants in animals. Objective: Here we investigate the relation of in utero and child PBDE exposure to neurobehavioral development among participants in CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas), a California birth cohort. Methods: We measured PBDEs in maternal prenatal and child serum samples and examined the association of PBDE concentrations with children’s attention, motor functioning, and cognition at 5 (n = 310) and 7 years of age (n = 323). Results: Maternal prenatal PBDE concentrations were associated with impaired attention as measured by a continuous performance task at 5 years and maternal report at 5 and 7 years of age, with poorer fine motor coordination—particularly in the nondominant—at both age points, and with decrements in Verbal and Full-Scale IQ at 7 years. PBDE concentrations in children 7 years of age were significantly or marginally associated with concurrent teacher reports of attention problems and decrements in Processing Speed, Perceptual Reasoning, Verbal Comprehension, and Full-Scale IQ. These associations were not altered by adjustment for birth weight, gestational age, or maternal thyroid hormone levels. Conclusions: Both prenatal and childhood PBDE exposures were associated with poorer attention, fine motor coordination, and cognition in the CHAMACOS cohort of school-age children. This study, the largest to date, contributes to growing evidence suggesting that PBDEs have adverse impacts on child neurobehavioral development.
We studied pregnancy-related changes in serum concentrations of five polychlorinated biphenyls (PCBs, CB 118, CB 138, CB 153, CB 156, CB 180), three hydroxylated PCB metabolites (4-OH-CB107, 4-OH-CB146, 4-OH-CB187), and pentachlorophenol (PCP). Median serum lipid content increased 2-fold between early (weeks 9-13) and late pregnancy (weeks 35-36) (N=10), whereas median PCB levels in serum lipids decreased 20-46%, suggesting a dilution of PCB concentrations in serum lipids. Nevertheless, strong positive intra-individual correlations (Spearman's r=0.61-0.99) were seen for PCBs during the whole study period. Thus, if samples have been collected within the same relative narrow time window during pregnancy, PCB results from one single sampling occasion can be used in assessment of relative differences in body burdens during the whole pregnancy period. Concentrations of OH-PCBs in blood serum tended to decline as pregnancy progressed, although among some women the concentrations increased at the end of pregnancy. Positive intra-individual correlations (r=0.66-0.99) between OH-PCB concentrations were observed during the first and second trimester, whereas correlations with third trimester concentrations were more diverging (r=-0.70-0.85). No decline in PCP concentrations was observed during pregnancy and no significant correlations were found between concentrations at different sampling periods. Our results suggest that for both OH-PCBs and PCP, sampling has to be more specifically timed depending on the time period during pregnancy that is of interest. The differences in patterns of intra- and inter-individual variability of the studied compounds may be due to a combination of factors, including lipid solubility, persistence of the compounds, distribution in blood, metabolic formation, and pregnancy-related changes in body composition and physiological processes. Copyright © 2010 Elsevier Ltd. All rights reserved.
A survey of a broad range of chocolate- and cocoa-containing products marketed in the United States was conducted to provide a more detailed analysis of flavan-3-ol monomers, oligomers, and polymers, which can be grouped into a class of compounds called procyanidins. Samples consisted of the three or four top-selling products within the following six categories: natural cocoa powder, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized for percent fat (% fat), percent nonfat cocoa solids (% NFCS), antioxidant level by ORAC, total polyphenols, epicatechin, catechin, total monomers, and flavan-3-ol oligomers and polymers (procyanidins). On a gram weight basis epicatechin and catechin content of the products follow in decreasing order: cocoa powder > baking chocolate > dark chocolate = baking chips > milk chocolate > chocolate syrup. Analysis of the monomer and oligomer profiles within product categories shows there are two types of profiles: (1) products that have high monomers with decreasing levels of oligomers and (2) products in which the level of dimers is equal to or greater than the monomers. Results show a strong correlation (R(2) = 0.834) of epicatechin to the level of % NFCS and also very good correlations for N = 2-5 oligomers to % NFCS. A weaker correlation was observed for catechin to % NFCS (R(2) = 0.680). Other analyses show a similar high degree of correlation with epicatechin and N = 2-5 oligomers to total polyphenols, with catechin being less well correlated to total polyphenols. A lesser but still good correlation exists between the calculated percent cacao (calcd % cacao) content, a proxy for percent cacao, and these same flavanol measures, with catechin again showing a lesser degree of correlation to calcd % cacao. Principal component analysis (PCA) shows that the products group discretely into five classes: (1) cocoa powder, (2) baking chocolate, (3) dark chocolate and semisweet chips, (4) milk chocolates, and (5) syrup. PCA also shows that most factors group closely together including the antioxidant activity, total polyphenols, and the flavan-3-ol measures with the exception of catechin and % fat in the product, which group separately. Because catechin distribution appears to be different from the other flavan-3-ol measures, an analysis of the epicatechin to catechin ratio was done, indicating there is a >5-fold variation in this measure across the products studied. The cocoa-containing products tested range from cocoa powder with 227.34 +/- 17.23 mg of procyanidins per serving to 25.75 +/- 9.91 mg of procyanidins per serving for chocolate syrup. These results are discussed with respect to other studies on commercial products, the bioavailability of the flavanols, and the possible role of processing on the amount of catechin in products.
Background: Prospective data regarding persistent organic pollutants (POPs) and risk of type 2 diabetes (T2D) are limited, and the results for individual POPs are not entirely consistent across studies. Objectives: We prospectively examined plasma POP concentrations in relation to incident T2D and summarized existing evidence in a meta-analysis. Methods: Plasma polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and hexachlorobenzene (HCB) concentrations were measured in 1,095 women who were free of diabetes at blood draw in 1989–1990 and participated in two case–control studies in the Nurses’ Health Study. We identified 48 incident T2D cases through 30 June 2008. We conducted a literature search in PubMed and EMBASE through December 2011 to identify prospective studies on POPs in relation to diabetes. We used a fixed-effects model to summarize results. Results: After multivariable adjustment, plasma HCB concentration was positively associated with incident T2D [pooled odds ratio (OR) 3.59 (95% CI: 1.49, 8.64, ptrend = 0.003) comparing extreme tertiles]. Other POPs were not significantly associated with diabetes. After pooling our results with those of six published prospective studies that included 842 diabetes cases in total, we found that HCB and total PCBs both were associated with diabetes: the pooled ORs were 2.00 (95% CI: 1.13, 3.53; I2 = 21.4%, pheterogeneity = 0.28) and 1.70 (95% CI: 1.28, 2.27; I2 = 16.3%, pheterogeneity = 0.30) for HCB and total PCBs, respectively. Conclusions: These findings support an association between POP exposure and the risk of T2D.
Purpose The objective of this study was to formulate and evaluate freeze-dried black raspberry (FBR) ethanol extract (RE) loaded poly(DL-lactic-co-glycolic acid) (PLGA) and poly(DL-lactic acid) (PLA) injectable millicylindrical implants for sustained delivery of chemopreventive FBR anthocyanins (cyanidin-3-sambubioside (CS), cyanidin-3-glucoside (CG) and cyanidin-3-rutinoside (CR)). Methods Identification and quantitation of CS, CG, and CR in RE was performed by mass spectroscopy and HPLC. RE:triacetyl-β-cyclodextrin (TA-β-CD) inclusion complex (IC) was prepared by a kneading method and characterized by X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (NMR) and UV-visible spectroscopy. RE or RE:TA-β-CD IC-loaded PLGA or PLA implants were prepared by a solvent extrusion method. In vitro and in vivo controlled release studies were conducted in phosphate-buffered saline Tween-80 (pH 7.4, 37°C) and after subcutaneous administration in male Sprague-Dawley rats, respectively. Anthocyanins were quantified by HPLC at 520 nm. Results The content of CS, CG, and CR in RE was 0.2, 1.5, and 3.5 wt%, respectively. The chemical stability of anthocyanins in solution was determined to be pH-dependent, and their degradation rate increased with an increase in pH from 2.4 to 7.4. PLGA/PLA millicylindrical implants loaded with 5 or 10 wt% RE exhibited a high initial burst and short release duration of anthocyanins (35–52 and 80–100% CG + CR release after 1 and 14 days, respectively). The cause for rapid anthocyanins release was linked to higher polymer water uptake and porosity associated with the high osmolytic components of large non-anthocyanin fraction of RE. XRD, 1H NMR and UV-visible spectroscopy indicated that the non-anthocyanin fraction molecules of RE formed an IC with TA-β-CD, decreasing the hydrophilicity of RE. Formation of an IC with hydrophobic carrier, TA-β-CD, provided better in vitro/in vivo sustained release of FBR anthocyanins (16–24 and 97–99% CG + CR release, respectively, after 1 and 28 days from 20 wt% RE:TA-β-CD IC/PLA implants) over 1 month, owing to reduced polymer water uptake and porosity. Conclusion PLA injectable millicylindrical implants loaded with RE:TA-β-CD IC are optimal dosage forms for 1-month slow and continuous delivery of chemopreventive FBR anthocyanins.
BACKGROUND: Plaque rupture and/or erosion is the leading cause of cardiovascular events; however, the process is not well understood. Although certain morphologic characteristics have been associated with ruptured plaques, these observations are of static histological images and not of the dynamics of plaque rupture. To elucidate the process of plaque rupture, we investigated the transformation of cholesterol from liquid to solid crystal to determine whether growing crystals are capable of injuring the plaque cap. HYPOTHESIS: We hypothesized that during cholesterol crystallization the spatial configuration rapidly changes, causing forceful expansion of sharp-edged crystals that can damage the plaque cap. METHODS: Two experiments were performed in vitro: first, cholesterol powder was melted in graduated cylinders and allowed to crystallize at room temperature. Volume changes from liquid to solid state were measured and timed. Second, thin biological membranes (20-40 microm) were put in the path of growing crystals to determine damage during crystallization. RESULTS: As cholesterol crystallized, the peak volume increased rapidly by up to 45% over 3 min and sharp-tipped crystals cut through and tore membranes. The amount of cholesterol and peak level of crystal growth correlated directly (r = 0.98; p < 0.01), as did the amount of cholesterol and rate of crystal growth (r = 0.99; p < 0.01). CONCLUSIONS: These observations suggest that crystallization of supersaturated cholesterol in atherosclerotic plaques can induce cap rupture and/or erosion. This novel insight may help in the development of therapeutic strategies that can alter cholesterol crystallization and prevent acute cardiovascular events.
Background Inoxitol hexakisphosphate (IP6) has been found to have an important role in biomineralization and a direct effect inhibiting mineralization of osteoblasts in vitro without impairing extracellular matrix production and expression of alkaline phosphatase. IP6 has been proposed to exhibit similar effects to those of bisphosphonates on bone resorption, however, its direct effect on osteoclasts (OCL) is presently unknown. Methodology/Principal Findings The aim of the present study was to investigate the effect of IP6 on the RAW 264.7 monocyte/macrophage mouse cell line and on human primary osteoclasts. On one hand, we show that IP6 decreases the osteoclastogenesis in RAW 264.7 cells induced by RANKL, without affecting cell proliferation or cell viability. The number of TRAP positive cells and mRNA levels of osteoclast markers such as TRAP, calcitonin receptor, cathepsin K and MMP-9 was decreased by IP6 on RANKL-treated cells. On the contrary, when giving IP6 to mature osteoclasts after RANKL treatment, a significant increase of bone resorption activity and TRAP mRNA levels was found. On the other hand, we show that 1 µM of IP6 inhibits osteoclastogenesis of human peripheral blood mononuclear cells (PBMNC) and their resorption activity both, when given to undifferentiated and to mature osteoclasts. Conclusions/Significance Our results demonstrate that IP6 inhibits osteoclastogenesis on human PBMNC and on the RAW264.7 cell line. Thus, IP6 may represent a novel type of selective inhibitor of osteoclasts and prove useful for the treatment of osteoporosis.
Interest in the biological activities of cocoa polyphenols is increasing steadily. In fact, the high polyphenol content of cocoa, coupled with its widespread presence in many food items, render this food of particular interest from the nutritional and "pharmacological" viewpoints. This paper summarizes the new findings and developments regarding the effects of cocoa and chocolate consumption on human health as presented at the International Conference "Chocolate, Lifestyle, and Health" (Milan, Italy, March 2, 2007) regarding the effects of cocoa and chocolate consumption on human health.
Punctal and canalicular plugs are widely used for both temporary and permanent occlusion of the lacrimal puncta in dry eyes. There are many designs and materials available on the market. While their efficacy in improving dry eye symptoms is widely proven, the gamut of complications associated with these devices have never been subject to a general review, although there are numerous case series in the literature associated with one particular device. This review aims to examine the track record of a variety of plugs currently in use, to review the management of complications, and propose strategies for both the prevention of these complications and their treatment.
Plants contain numerous polyphenols, which have been shown to reduce inflammation and hereby to increase resistance to disease. Examples of such polyphenols are isothiocyanates in cabbage and broccoli, epigallocatechin in green tee, capsaicin in chili peppers, chalones, rutin and naringenin in apples, resveratrol in red wine and fresh peanuts and curcumin/curcuminoids in turmeric. Most diseases are maintained by a sustained discreet but obvious increased systemic inflammation. Many studies suggest that the effect of treatment can be improved by a combination of restriction in intake of proinflammatory molecules such as advanced glycation end products (AGE), advanced lipoperoxidation end products (ALE), and rich supply of antiinflammatory molecules such as plant polyphenols. To the polyphenols with a bulk of experimental documentation belong the curcuminoid family and especially its main ingredient, curcumin. This review summarizes the present knowledge about these turmericderived ingredients, which have proven to be strong antioxidants and inhibitors of cyclooxigenase-2 (COX-2), lipoxygenase (LOX) and nuclear factor kappa B (NF-kappaB) but also AGE. A plethora of clinical effects are reported in various experimental diseases, but clinical studies in humans are few. It is suggested that supply of polyphenols and particularly curcuminoids might be value as complement to pharmaceutical treatment, but also prebiotic treatment, in conditions proven to be rather therapy-resistant such as Crohn's, long-stayed patients in intensive care units, but also in conditions such as cancer, liver cirrhosis, chronic renal disease, chronic obstructive lung disease, diabetes and Alzheimer's disease.
The effects exerted by three mixtures of Polychlorinated Biphenyls (PCBs) were evaluated on human fetal corpora cavernosa cells, as a model for male external genitalia development. The three mixtures feature congeners grouped according to potentially shared modes of action: one dioxin-like (DL) (Mix2) and two non dioxin-like (NDL) mixtures featuring congeners defined as estrogenic (Mix1) and highly persistent-cytochrome P-450 inducers (Mix3). Congeners concentrations used were derived from human internal exposure data. Toxicogenomic analysis revealed that all mixtures modulated critical genes involved in genitourinary development, however displaying three different expression profiles. The DL Mix2 modulated actin-related, cell-cell and epithelial-mesenchymal communication morphogenetic processes; Mix1 modulated smooth muscle function genes, whereas Mix3 mainly modulated genes involved in cell metabolism (e.g., steroid and lipid synthesis) and growth. Our data indicate that fetal exposure to environmentally relevant PCB levels modulates several patterns of genitourinary programming; moreover, NDL congener groups may have specific modes of action. Copyright © 2011 Elsevier Inc. All rights reserved.
Various pesticides are being used to destabilize, perturb, or inhibit crucial biochemical and physiological targets related to metabolism, growth, development, nervous communication, or behavior in pestiferous organisms. Chitin is an eukaryotic extracellular aminosugar biopolymer, massively produced by most fungal systems and by invertebrates, notably arthropods. Being an integral supportive component in fungal cell wall, insect cuticle, and nematode egg shell, chitin has been considered as a selective target for pesticide action. Throughout the elaborate processes of chitin formation and deposition, only the polymerization events associated with the cell membrane compartment are so far available for chemical interference. Currently, the actinomycetes-derived nucleoside peptide fungicides such as the polyoxins and the insecticidal benzoylaryl ureas have reached commercial pesticide status. The polyoxins and other structurally-related antibiotics like nikkomycins are strong competitive inhibitors of the polymerizing enzyme chitin synthase. The exact biochemical lesion inflicted by the benzoylaryl ureas is still elusive, but a post-polymerization event, such as translocation of chitin chains across the cell membrane, is suggested. Hydrolytic degradation of the chitin polymer is essential for hyphal growth, branching, and septum formation in fungal systems as well as for the normal molting of arthropods. Recently, insect chitinase activity was strongly and specifically suppressed by allosamidin, an actimomycetes-derived metabolite. In part, the defense mechanism in plants against invasion of pathogens is associated with induced chitinases. Chitin, chitosan, and their oligomers are able to act as elicitors which induce enhanced levels of chitinases in various plants. Lectins which bind to N-acetyl-D-glucosamine strongly interfere with fungal and insect chitin synthases. Plant lectins with similar properties may be involved in plant-pathogen interaction inter alia by suppressing fungal invasion.
Researchers have long debated the adverse effects of exposure to polychlorinated biphenyls (PCBs) on children versus the benefits of breastfeeding. In this article, the authors provide an overview of the known health effects of PCBs in children and examine the level of evidence regarding the risk of postnatal exposure via breastfeeding. The major source of PCBs is environmental, with over 90% of human exposure through the food chain. PCB exposure in infants is predominantly via breast milk, but limited evidence exists of significant toxicity associated with this mode of transmission. Breastfeeding should, therefore, continue to be encouraged on the basis of evidence of the benefits derived from human milk coupled with inconclusive proof that lactational PCB exposure has major detrimental effects on the overall health and development of infants.
In the late 1960s the first scientific studies on contamination in Antarctica demonstrated the presence of pollutants in Antarctic ecosystems. Many Persistent Organic Pollutants (POPs) are transported globally from the areas in which they are produced and released into the environment in remote areas, including Antarctica. Here we report results obtained concerning the accumulation of polybrominated diphenyl ethers (PBDEs), mono- and non-ortho-polychlorobiphenyls (PCBs), polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in the tissues of two species of Antarctic fish (Chionodraco hamatus and Trematomus bernacchii). The 2,3,7,8-TCDD toxic equivalents (TEQs) were also calculated to evaluate the potential risk of these compounds for the two species. In general, POP levels were higher in the tissues of T. bernacchii than in C. hamatus and the highest concentrations were found in the liver of both species. The PBDE levels varied from 160.5 pg g(-1) wet wt in C. hamatus muscle to 789.9 pg g(-1) wet wt in T. bernacchii liver and were lower than the levels of PCBs. PCBs were the main organochlorine compounds detected and their concentrations ranged from 0.3 ng g(-1) wet wt in C. hamatus muscle to 15.1 ng g(-1) wet wt in T. bernacchii liver. TEQ concentrations resulted higher in C. hamatus than in T. bernacchii and were due mainly to PCDDs. The presence of PBDEs and organochlorine pollutants in the tissues of Antarctic organisms confirms their global transport and distribution.
Objectives Polyphenols, natural compounds found in plant-based foods, possess special properties that can battle oxidative stress and stimulate the activation of molecules that aid in synaptic plasticity, a process that underlies cognitive function. Unlike many traditional treatments, polyphenols affect a broad range of mechanisms in the brain that can assist in the maintenance of cognitive and mental health, as well as the recovery from neurodegenerative diseases. Examining the molecular basis underlying the link between food intake and brain function has presented the exciting possibility of using diet as a viable method to battle cognitive and psychiatric disorders. Methods We will discuss the molecular systems that link polyphenols, the gut, and the brain, as well as introduce published human and animal studies demonstrating the effects of polyphenol consumption on brain plasticity and cognition. Results By influencing cellular energy metabolism and modulating the signaling pathways of molecules involved with brain plasticity, dietary factors – formerly recognized for just their effects on bodily systems – have emerged as affecters of the brain. Conclusion Thus, the consumption of diets enriched with polyphenols may present the potential of dietary manipulation as a non-invasive, natural, and inexpensive therapeutic means to support a healthy brain.
Background: There is increasing interest in the potential effects of polybrominated diphenyl ethers (PBDEs) on children’s neuropsychological development, but only a few small studies have evaluated such effects. Objectives: Our goal was to examine the association between PBDE concentrations in colostrum and infant neuropsychological development and to assess the influence of other persistent organic pollutants (POPs) on such association. Methods: We measured concentrations of PBDEs and other POPs in colostrum samples of 290 women recruited in a Spanish birth cohort. We tested children for mental and psychomotor development with the Bayley Scales of Infant Development at 12–18 months of age. We analyzed the sum of the seven most common PBDE congeners (BDEs 47, 99, 100, 153, 154, 183, 209) and each congener separately. Results: Increasing Σ7PBDEs concentrations showed an association of borderline statistical significance with decreasing mental development scores (β per log ng/g lipid = –2.25; 95% CI: –4.75, 0.26). BDE-209, the congener present in highest concentrations, appeared to be the main congener responsible for this association (β = –2.40, 95% CI: –4.79, –0.01). There was little evidence for an association with psychomotor development. After adjustment for other POPs, the BDE-209 association with mental development score became slightly weaker (β = –2.10, 95% CI: –4.66, 0.46). Conclusions: Our findings suggest an association between increasing PBDE concentrations in colostrum and a worse infant mental development, particularly for BDE-209, but require confirmation in larger studies. The association, if causal, may be due to unmeasured BDE-209 metabolites, including OH-PBDEs (hydroxylated PBDEs), which are more toxic, more stable, and more likely to cross the placenta and to easily reach the brain than BDE-209.
BACKGROUND: Xenobiotic organochlorine pesticides (OCPs) are a major environmental problem because of their historic widespread use, pronounced persistence against chemical and biological degradation, and bioaccumulation in the food chain. Pesticide use is prevalent in the production of edible bamboo shoots, which are exported widely from China. To evaluate the quality of Chinese bamboo shoots we determined the residual content of some OCPs in shoot samples. RESULTS: Three types of OCPs-hexachlorocyclohexane (HCH), 1,1,1-trichlor-2,2-bis(p-chlorophenyl)ethane (DDT) and pentachloronitrobenzene (PCNB)-were detected in bamboo shoots from Zhejiang province, China. Detection rates were 100%, 100% and 75% for HCH, DDT and PCNB, respectively. However, the average residue concentration did not exceed the maximum residue limit for pesticides detected in food in China (50 µg kg(-1) ). In terms of residue concentrations of the pesticides, 82.14% of the bamboo shoot samples could be classified as safe. CONCLUSION: While all sampled bamboo shoots contained OCP, most (82.14%) were safe for consumption. 2010 Society of Chemical Industry.
Obesity remains a major public health challenge, and its prevalence is dramatically increasing. Diet and exercise are typically recommended to prevent and manage obesity; however, the results are often conflicting. Polyphenols, a class of phytochemicals that have been shown to reduce the risk factors for diabetes type II and cardiovascular diseases, are recently suggested as complementary agents in the management of obesity through several mechanisms such as decreasing fat absorption and/or fat synthesis. Dark chocolate, a high source of polyphenols, and flavanols in particular, has lately received attention for its possible role in modulating obesity because of its potential effect on fat and carbohydrate metabolism, as well as on satiety. This outcome was investigated in animal models of obesity, cell cultures and few human observational and clinical studies. The research undertaken to date has shown promising results, with the possible implication of cocoa/dark chocolate in the modulation of obesity and body weight through several mechanisms including decreasing the expression of genes involved in fatty acid synthesis, reducing the digestion and absorption of fats and carbohydrates and increasing satiety. Copyright © 2013 John Wiley & Sons, Ltd.
BACKGROUND: Some evidence has suggested that a diet with a higher ratio of protein to carbohydrates has metabolic advantages in the treatment of polycystic ovary syndrome (PCOS). OBJECTIVE: The objective of this study was to compare the effect of a high-protein (HP) diet to a standard-protein (SP) diet in women with PCOS. DESIGN: A controlled, 6-mo trial was conducted in 57 PCOS women. The women were assigned through rank minimization to one of the following 2 diets without caloric restriction: an HP diet (>40% of energy from protein and 30% of energy from fat) or an SP diet (<15% of energy from protein and 30% of energy from fat). The women received monthly dietary counseling. At baseline and 3 and 6 mo, anthropometric measurements were performed, and blood samples were collected. RESULTS: Seven women dropped out because of pregnancy, 23 women dropped out because of other reasons, and 27 women completed the study. The HP diet produced a greater weight loss (mean: 4.4 kg; 95% CI: 0.3, 8.6 kg) and body fat loss (mean: 4.3 kg; 95% CI: 0.9, 7.6 kg) than the SP diet after 6 mo. Waist circumference was reduced more by the HP diet than by the SP diet. The HP diet produced greater decreases in glucose than did the SP diet, which persisted after adjustment for weight changes. There were no differences in testosterone, sex hormone-binding globulin, and blood lipids between the groups after 6 mo. However, adjustment for weight changes led to significantly lower testosterone concentrations in the SP-diet group than in the HP-diet group. CONCLUSION: Replacement of carbohydrates with protein in ad libitum diets improves weight loss and improves glucose metabolism by an effect that seems to be independent of the weight loss and, thus, seems to offer an improved dietary treatment of PCOS women.