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1.
Clin Ter ; 166(1): e1-6, 2015.
Article in Italian | MEDLINE | ID: mdl-25756262

ABSTRACT

AIM: A significant relationship between exposure to cadmium and PAHs from urban air pollution and blood pressure has already been found. The aim of the study is to evaluate if other urban pollutants maintain a similar relationship in outdoor workers. MATERIALS AND METHODS: 349 subjects of both sexes were enrolled in the study; we evaluated values of environmental and biological monitoring of respirable dust, arsenic, lead, benzene, toluene, xylene and we measured blood pressure (BP) in upright and in supine position; to analyze data we used multiple linear regression. Also we valued our results in the light of those we have obtained in previous research. RESULTS: Multiple linear regression showed no significant results that demonstrate a relationship between BP and these pollutants. CONCLUSIONS: The results of our study lead to assume that exposure to urban pollutants studied has not connection with blood pressure, and to retain valid the relationship previously observed for cadmium and PAHs, which seem to be the only pollutants that can affect blood pressure.


Subject(s)
Air Pollutants/adverse effects , Air Pollution/adverse effects , Blood Pressure/drug effects , Occupational Exposure/adverse effects , Urban Population , Environmental Monitoring , Female , Humans , Linear Models , Male
2.
Ann Ig ; 27(1): 16-29, 2015.
Article in English | MEDLINE | ID: mdl-25748502

ABSTRACT

BACKGROUND: Work-related stress is a complex problem requiring a work environment-based assessment. Artists like dancers represent a category of atypical workers potentially at high risk for work-related stress. Aim of our pilot study is to evaluate organizational stress in a population of professional dancers, using the HSE Indicator Tool for Work Related Stress. METHODS: We administered the Italian version of the HSE Indicator Tool to 38 ballet dancers, males and females. The questionnaire evaluates 7 key organizational dimensions: demand, control, managers' support, peer support, relationships, role and change. RESULTS: The standards required-ideal conditions are achieved in none of the above-mentioned dimensions. Change is the only dimension for which results fall between the 20th and the 50th percentile, while for other dimensions results fall below the 20th percentile suggesting the need for immediate corrective action. In male dancers an acceptable situation is highlighted for the dimension "change" compared to female dancers. In both sexes there is a high frequency of subjects complaining of verbal abuse, bullying and harassment. CONCLUSIONS: Despite the small sample size, our pilot study highlights the presence of heightened levels of organizational stress. Preventive measures targeted towards improving communication between managers and dancers and aimed at team building should be implemented.


Subject(s)
Dancing/psychology , Occupational Diseases/epidemiology , Occupational Diseases/psychology , Stress, Psychological/epidemiology , Adolescent , Adult , Female , Humans , Male , Middle Aged , Pilot Projects , Surveys and Questionnaires , Young Adult
3.
Ann Ig ; 26(5): 456-72, 2014.
Article in English | MEDLINE | ID: mdl-25405377

ABSTRACT

BACKGROUND: The aim of this meta-analysis was to evaluate the association between ALS and occupational exposure to physical (ELF-EMF) and chemicals (solvents, heavy metals and pesticides) agents. METHODS: We considered articles published from 1980 up to April 2013; in total, 750 publications were evaluated. The studies had to satisfy the following criteria: 1) cohort or case-control studies; 2) the presence of individual exposures; 3) clinical diagnosis of sporadic ALS or sporadic ALS on the death certificate. We followed the evaluation of quality in two steps. The first step classified studies according to a rating system based on a mix of criteria developed by scientific organizations, especially developed for studies of risk factors for ALS. The ratings obtained range from I (highest) to V (lowest). The data on risk factors derived from studies with Armon ratings of I, II, and III can reach levels of evidence A (established risk factor), B (likely risk factor), or C (possible risk factor). The second step evaluated the exposure and a score from 1 to 4 was assigned to each item; an exposure with a score of 3 or 4 was considered sufficient. Different analyses were performed on ALS and exposure to metals, solvents, pesticides and electromagnetic fields. In our study the heterogeneity was assessed both by χ2-based Q-tests and through the index of inconsistency I² while the measure RR/OR and CI of 95% to estimate the relationship between ALS and the various considered risk factors was employed. RESULTS: The association between exposure to pesticides and ALS as a whole is weak and not significant. With regard to the results of individual studies the following critical synthesis can be reported: 1) the selected studies showed a low level of association between ALS and electromagnetic fields; 2) as regards the solvents, the association with ALS in some studies is combined with a slightly increased risk, particularly in women, and in others a slight but significant linear association is observed; 3) for the metals, in some cases there was a stronger association in women than in men; for individual metals, there was an association especially with chromium and lead; 4) lastly, with regard to the products of agricultural pesticides in general, there was an association with ALS in men but not in women, with a dose-response relationship. CONCLUSIONS: The lack of statistically significant association between occupational exposure and ALS is mainly due to the methodological diversity of the studies and the lack of prospective studies at the workplace.


Subject(s)
Amyotrophic Lateral Sclerosis/etiology , Occupational Diseases/etiology , Occupational Exposure/adverse effects , Amyotrophic Lateral Sclerosis/epidemiology , Electromagnetic Fields/adverse effects , Female , Humans , Male , Metals, Heavy/toxicity , Occupational Diseases/epidemiology , Occupational Diseases/physiopathology , Pesticides/toxicity , Research Design , Risk Factors , Sex Factors , Solvents/toxicity
4.
Clin Ter ; 165(4): e295-303, 2014.
Article in English | MEDLINE | ID: mdl-25203346

ABSTRACT

OBJECTIVES: Everyday outdoor workers are exposed to chemicals including the polycyclic aromatic hydrocarbons (PAHs). The aim of the study is to evaluate the relationship between hydroxypyrene and blood pressure in outdoor workers. MATERIALS AND METHODS: 374 subjects of both sexes entered the study. We evaluated the assay of urinary hydroxypyrene (1-HOP); their blood pressure (BP) was measured in upright position and in the supine position and the correlation between the levels of 1-HOP and BP was assessed using Pearson test and linear multiple regression. RESULTS: The results obtained show that in the total sample the levels of urinary 1-OHP are negatively associated with systolic and diastolic BP in supine position and in upright position. The significance is maintained despite the stratification of the sample according to age; in non-smokers we found a negative relationship between 1-OHP and differential blood pressure, both systolic and diastolic. CONCLUSIONS: The results of the study suggest that occupational exposure to PAHs may be able to significantly influence the blood pressure probably acting on the autonomic nervous system.


Subject(s)
Blood Pressure/physiology , Environmental Monitoring/statistics & numerical data , Occupational Exposure/analysis , Polycyclic Aromatic Hydrocarbons/urine , Adult , Biomarkers/urine , Female , Humans , Italy , Male , Middle Aged , Occupational Exposure/statistics & numerical data , Pyrenes/urine , Urban Population/statistics & numerical data
5.
Clin Ter ; 165(3): e205-12, 2014.
Article in Italian | MEDLINE | ID: mdl-24999575

ABSTRACT

OBJECTIVE: Outdoor workers are daily exposed to urban pollutants. The aim of the study is to evaluate the relationship between the values of environmental monitoring collected by personal dosimetries and changes in blood pressure due to posture in outdoor workers. MATERIALS AND METHODS: 32 subjects of both sexes were enrolled in the study, we evaluated the values of environmental monitoring of breathable dust, nickel, arsenic, cadmium, lead, benzene, toluene, xylene and 16 PAHs. Blood pressure in supine and standing positions was measured in all subjects. RESULTS: The multiple linear regression analysis showed a significant reduction of orthostatic response of diastolic blood pressure in non-smoking outdoor workers occupationally exposed to cadmium. CONCLUSIONS: The results of our study let us to believe that exposure to low doses of urban polluted cadmium may affect the response of diastolic blood pressure to orthostatism, as per a paraphysiological condition of sympathetic down-regulation.


Subject(s)
Blood Pressure/drug effects , Cadmium/toxicity , Environmental Pollutants/toxicity , Occupational Exposure/analysis , Posture/physiology , Arsenic/analysis , Benzene/analysis , Cadmium/analysis , Cities , Environmental Monitoring/methods , Environmental Pollutants/analysis , Female , Humans , Linear Models , Male , Metals/analysis , Nickel/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Toluene/analysis
6.
Curr Med Chem ; 21(23): 2702-14, 2014.
Article in English | MEDLINE | ID: mdl-24735357

ABSTRACT

Apoptosis is a highly programmed cell death strictly connected to the pathogenesis of many human diseases, including neoplastic, neurodegenerative or cardiovascular diseases. Mitochondria play a key role in the apoptotic process; their damage activates a series of events which provoke the release of cytochrome c and other pro-apoptotic factors from the mitochondrial intermembrane space, and culminate in cell death. This review provides an overview of the key role played by mitochondria in the activation of the apoptotic process. In particular, the interest is focused on the role played by cardiolipin, a phospholipid deeply involved in the first steps of the process culminating in cell apoptosis. Mitochondrial phospholipids are involved in several cellular functions, such as cell respiration, apoptosis, and autophagy. Therefore, any alteration in the production of phospholipids or in their structural properties causes deep effects on the cell behavior and induces the arising of different pathologies. The present review summarizes the most recent advances in the study of the role that CL, a phospholipid possessing a unique structure, plays in mitochondrial activity, in apoptosis, and in the onset of human diseases.


Subject(s)
Apoptosis , Cardiolipins/metabolism , Mitochondria/metabolism , Animals , Biological Transport , Cardiolipins/chemistry , Cytochromes c/metabolism , Humans
7.
Clin Ter ; 164(2): e139-46, 2013.
Article in English | MEDLINE | ID: mdl-23698217

ABSTRACT

Urban pollution is a current problem, constituting a serious health risk. Many pollutants are present in the urban atmosphere, they are mainly anthropogenic, resulting from the combustion of coal. Several studies have shown the harmful effects of these pollutants, particularly on the respiratory system. Through a library review, we want to explore the effects on the health of general population and of outdoor workers exposed to the products resulting from the combustion of coal, in order to compare them with the estimated effects of the pollutants from the new generation coal plants, certainly less harmful to the environment. In recent years investments in "clean technologies" have resulted in a rapid and significant reduction of all polluting emissions: sulfur dioxide, dust, oxides of nitrogen, ash and gypsum resulting from the desulfurization process. To conclude in the light of the scientific literature we can say that the activation of coal plants based on technologies for the maximum containment and optimal treatment of the production cycle is essential to defend both the environment and the health of the population. Nevertheless it remains necessary to ensure a systematic monitoring of the environment of sanitation and food processing of the population living in the area, with a long-term follow-up.


Subject(s)
Coal/adverse effects , Environment , Environmental Exposure/adverse effects , Power Plants , Environmental Exposure/prevention & control , Humans , Risk Factors
8.
Biomed Chromatogr ; 27(8): 987-93, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23529872

ABSTRACT

In order to monitor biogenic amines in human urine, a method based on field-amplified sample injection combined with capillary electrophoresis and direct UV absorption detection was developed. Dopamine, tyramine, tryptamine, serotonin and epinephrine were effectively separated and identified in human urine samples, and detection limits were 0.072, 0.010, 0.027, 0.010 and 0.120 µmol/L, respectively. Detection limits comparable to laser-induced fluorescence detection or solid phase extraction combined with capillary electrophoresis were achieved. Parameters affecting electrophoretic system detection sensitivity were investigated. Optimal separation conditions were obtained using as background electrolyte a pH 6.5 mixture of 2-(morpholino)ethanesulfonic acid 20 mmol/L and 30 mmol/L phosphate buffer, containing 0.05% hydroxypropylcellulose and 10% v/v methanol. Injections of the sample solution were performed by applying a voltage of 12 kV for 50 s. Recovery and accuracy ranged between 89.4 and 94.9%, and 89 and 112%, respectively. The method was successfully applied on actual urine samples (from a healthy volunteer): target bioamine content was consistent with endogenous levels reported in the literature. The proposed method is simple, fast and inexpensive and can be conveniently employed in work-related stress studies. The affordability and noninvasive sampling of the method allow epidemiological studies on large number of exposed persons to be performed.


Subject(s)
Biogenic Amines/urine , Electrophoresis, Capillary/methods , Acetonitriles , Biogenic Amines/isolation & purification , Humans , Hydrogen-Ion Concentration , Limit of Detection , Linear Models , Reproducibility of Results
9.
Ann Ig ; 24(5): 429-42, 2012.
Article in English | MEDLINE | ID: mdl-23193899

ABSTRACT

BACKGROUND: Purpose of this study is to evaluate and to compare the excretion of urinary 1-hydroxypyrene (1-OHPu) in traffic policemen (TP) and drivers (D) of a large Italian city and to evaluate the existence and the degree of correlation between airborne exposure to 15 different polycyclic aromatic hydrocarbons (PAHs) and 1-OHPu levels in the examined population. METHODS: 192 male workers, 115 TP and 77 D, were monitored for 1-HOPu. A subgroup of non-smoking workers (subgroup B: 59 TP and 15 D) was also examined and 15 environmental PAHs was monitored through the personal samplings for the measurement of the particulate phase. RESULTS: The 1-OHPu levels and the values of personal airborne exposure to PAHs were significantly higher among non-smoking TP than among non-smoking D (p < 0.05). In subgroup B the levels of environmental exposure to all the 15 PAHs measured in TP and only 6 of 15 PAHs measured in D were significantly correlated with the values of 1-OHPu (p < 0.05). CONCLUSIONS: Our results suggest that the use of 1-OHPu as an indicator of exposure to PAHs is reliable also for what concerns the study of the low-dose work-related exposure in urban outdoor workers.


Subject(s)
Air Pollutants/urine , Environmental Monitoring , Occupational Exposure/adverse effects , Polycyclic Aromatic Hydrocarbons/adverse effects , Pyrenes/urine , Adult , Humans , Italy , Male , Middle Aged , Police , Transportation , Urban Health
10.
Ann Ig ; 24(5): 417-28, 2012.
Article in English | MEDLINE | ID: mdl-23193898

ABSTRACT

BACKGROUND: Cadmium (Cd) is a metal, which induces hypertension in animals. This may not be relevant to the human population because the number of studies is inconsistent. OBJECTIVE: Our aim is to identify an association between levels of blood/urinary cadmium and blood pressure in a group of employees of the municipal police assigned to outdoor activities. MATERIALS AND METHODS: 349 subjects of both sexes were enrolled and sorted on the basis of gender, job function and smoking habit. Blood and urinary cadmium levels and blood pressure readings were collected for each subject. The data were subjected to statistical evaluation. Pearson correlation coefficient between the variables and a linear regression curve was drawn. After eliminating the confounding factors, the multiple linear regression analysis assessed statistical differences. Associations were considered significant at p < 0.05. RESULTS AND CONCLUSIONS: The Pearson correlation showed a positive association between urinary cadmium levels and blood pressure especially for groups of women and non-smokers. The simple and multiple linear regression and t-tests confirmed these associations and underlined the influence cadmium has on diastolic blood pressure, higher than systolic blood pressure. No association was found between blood cadmium and blood pressure. In conclusion, we can say that there is a statistically significant association between urinary cadmium and diastolic blood pressure, supporting the hypothesis that cadmium has a long-term effect on diastolic blood pressure (BP).


Subject(s)
Air Pollutants/adverse effects , Blood Pressure , Cadmium/blood , Cadmium/urine , Occupational Exposure/adverse effects , Adult , Female , Humans , Italy , Male , Police , Urban Health
11.
Clin Ter ; 163(4): e201-17, 2012 Jul.
Article in Italian | MEDLINE | ID: mdl-23007827

ABSTRACT

The relationship between stress and new technologies has always been a vexed question. Sociologists and philosophers say technology is a double edged sword, on one hand it increases the potential of human senses, while on the other hand it forces man to adopt rhythms and conditions not natural but artificial, with consequences for his physical and mental health. Modern Cognitive Ergonomic tries to analyze to technology, interacting with mental functions, causes stress and it tries to offer the most appropriate technological solutions for human work. From our analysis it emerges that the old media have an influence on mood causing episodes of insomnia, irritability, anxiety, etc., even if in a way that cannot be completely evaluated. Contrariwise, a controlled use of the web can improve the communication and the interacting abilities in patients with psychosocial distress and low social skills. Nielsen's Heuristics are a great tool to value methods of informatical and media interfaces.


Subject(s)
Communication , Computer Terminals , Internet , Occupational Diseases/etiology , Stress, Psychological/etiology , Technology , Humans
12.
Ann Ig ; 24(4): 325-44, 2012.
Article in English | MEDLINE | ID: mdl-22913176

ABSTRACT

Aim of the study is to evaluate whether occupational exposure to low doses of pollutants present in the air of the city selected for the study could cause alterations in peripheral blood counts in workers of the Municipal Police with outdoor tasks vs workers with indoor tasks. 279 non smoker males were enrolled and divided on the basis of their different kind of task. The dosage of air pollutants was carried out through the use of personal air samplers on a representative group of workers. Data obtained were subject to statistical evaluation consisting of Homogeneity of variance test, ANOVA univariate test with post hoc Bonferroni correction, Jonckheere-Terpstra test and multiple linear regression analysis. The differences were considered statistically significant when p values were lower than 0.05. Mean levels of RBC, HB, MCHC, WBC and neutrophil cells were significantly higher in traffic policemen and police drivers compared to controls (workers with indoor tasks). Mean levels of MCV, MCH and lymphocytes were significantly lower in traffic policemen and police drivers compared to controls. These results were confirmed by Multiple linear regression test and Jonckheere-Terpstra test. The results suggest that prolonged occupational exposure to low doses of traffic pollutants can alter some lines of the hematopoietic system in exposed workers.


Subject(s)
Air Pollutants , Motor Vehicles , Occupational Exposure , Police , Adult , Air Pollutants/analysis , Blood Cell Count , Humans , Italy , Male , Middle Aged , Occupational Exposure/analysis
13.
G Ital Med Lav Ergon ; 34(3 Suppl): 737-9, 2012.
Article in Italian | MEDLINE | ID: mdl-23405765

ABSTRACT

INTRODUCTION: Aim of this study is evaluating alteration of neuro-immune-endocrine parameters in exposed workers and estimating whether urban pollution can modify them. METHODS: Literature research. Different categories of exposed workers were included in the study (7287) and compared with controls (8054). To calculate results Effect Size (ES) and confidence interval were used. RESULTS: A correlation between urban pollution exposition and some neurogenic mediators and metabolites alterations was demonstrated; blood values can be alterated by toxicity of benzene and by xenobiotic metabolites' mechanism; follicle stimulating hormone is significantly increased in exposed versus controls. CONCLUSIONS: High heterogeneity and literature limitations, together with results of this meta analysis, induce to believe that is necessary to deepen the research about urban pollution effects on these parameters.


Subject(s)
Air Pollutants/blood , Air Pollutants/urine , Occupational Exposure , Humans , Urban Health
14.
Curr Med Chem ; 16(31): 4058-65, 2009.
Article in English | MEDLINE | ID: mdl-19754424

ABSTRACT

Apoptosis is strictly connected to the pathogenesis of many human diseases, including neoplastic, neurodegenerative or cardiovascular diseases. It is a highly programmed cell death which can be activated by various factors. Mitochondria play a key role in the apoptotic process; their damage, which involves permeabilization of the outer mitochondrial membrane, activates a series of events that lead to cell death. Of the two proposed signaling pathways of apoptosis, i.e. the 'extrinsic' and the 'intrinsic' pathway, the latter is assumed to initiate in mitochondria. Its activation involves release of cytochrome c and other pro-apoptotic factors from the mitochondrial intermembrane space. In the cytosol, cytochrome c exerts its pro-apoptotic action. It binds to the apoptosis protease activation factor (APAf-1) and forms a complex indicated as 'apoptosome'. The complex-induced activation of pro-caspase 9 initiates an enzymatic reaction cascade leading to the execution of apoptosis in cells. This review provides an overview of the key role played by mitochondria and cytochrome c in the activation of the apoptotic process.


Subject(s)
Apoptosis/physiology , Cardiovascular Diseases/pathology , Cytochromes c/metabolism , Mitochondria/physiology , Neoplasms/pathology , Neurodegenerative Diseases/pathology , Apoptosis/drug effects , Cardiovascular Diseases/metabolism , Humans , Neoplasms/metabolism , Neurodegenerative Diseases/metabolism
15.
Mini Rev Med Chem ; 8(1): 57-62, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18220985

ABSTRACT

Most proteins fold into their native structure through well defined pathways which involve a limited number of transient intermediates. Intermediates play a relevant role in the folding process; many diseases of genetic nature are in fact coupled with protein misfolding due to formation of stable, inactive intermediate species of the protein. This review deals with a number of diseases associated with protein misfolding and briefly describes the mechanism(s) responsible, at molecular level, for such pathologies. It is also considered the (native <--> molten globule) transition, recently observed for some proteins, in which a native protein converts into a stable compact intermediate state able to carry out distinct physiological functions inside the cell. A non-native compact form of cyt c, for example, appears to have a role in the programmed cell death (apoptosis) after that the protein is released from the mitochondrion, and non-native forms of the same protein appear involved in some of the disorders attributed to amyloid formation.


Subject(s)
Alzheimer Disease/etiology , Neoplasms/etiology , Parkinson Disease/etiology , Protein Folding , Proteins/chemistry , Proteins/metabolism , Humans , Kinetics , Protein Structure, Secondary
16.
Eur J Biochem ; 268(16): 4537-43, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11502215

ABSTRACT

Recombination of two fragments of horse cytochrome c (the heme-containing N-fragment, residues 1-56, and the C-fragment, residues 57-104), which are substantially unstructured at neutral pH, gives rise to a 1:1 fragment complex with a compact conformation, in which the alpha helical structure and the native Met80-Fe(III) axial bond are recovered. With respect to the native protein, the ferric complex shows a less rigid atomic packing and a decreased stability [Delta(DeltaG(o))D = 14.7 kJ.mol(-1)], ascribed to perturbations involving the Trp59 microenvironment and, to a lower extent, the heme pocket region. The redox potential, E1/2 = 234 +/- 5 mV vs. normal hydrogen electrode at 25 degrees C, is close to that of the intact protein, consistent with recovery of the native Met80-heme Fe(III) axial bond. Furthermore, the fragment complex shows reactivity similar to intact cytochrome c, in the reaction with cytochrome c oxidase. We conclude that the absence in the complex of some native cross-links and interlocked packing important for protein rigidity and stability is not as relevant for maintaining the native redox properties of the protein, provided that some structural requirements (i.e. recovering of the native-like alpha helical structure) are fulfilled and coordination of Met80 to the heme-iron is restored.


Subject(s)
Cytochrome c Group/chemistry , Animals , Circular Dichroism , Cytochrome c Group/metabolism , Enzyme Stability , Horses , Oxidation-Reduction
17.
Free Radic Res ; 35(6): 953-66, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11811546

ABSTRACT

In the present study, the antioxidant activity, the interaction with reactive oxygen species and the redox potential of cyanidin-3-O-beta-glucopyranoside (C-3-G), the main anthocyanin present in juice of pigmented oranges, were evaluated in detail. C-3-G effects on low density lipoproteins (LDL) oxidation induced by 40 microM Cu at a pH of 7.4 were compared with those of resveratrol and ascorbic acid, two other natural antioxidants. All cyanidin-3-O-beta-glucopyranoside concentrations used (1, 2, 5, 10, 20, 50, 100 and 200 microM) inhibited malondialdehyde (MDA) generation (an index of lipid peroxidation), the inhibition being significantly higher than that obtained with equal concentrations of resveratrol and ascorbic acid (IC50 = 6.5 microM for C-3-G, 34 microM for resveratrol and 212 microM for ascorbic acid). Experiments of LDL oxidation performed at a pH of 5.0 or 6.0 showed that C-3-G antioxidant activity is not influenced by pH variations between 5.0 and 7.4. This suggests that metal chelation, exerted by C-3-G through the eventual dissociation of its phenolic groups, plays a minor role in its protective mechanism. The presence of C-3-G produced significantly higher protective effects of pigmented orange juice (obtained from Moro cultivar) with respect to blond orange juice, when tested on copper-induced LDL oxidation. The evaluation of the direct interaction with reactive oxygen species (H2O2, -O2, OH*), demonstrated that C-3-G is quickly oxidized by these compounds and it is, therefore, a highly efficient oxygen free radical scavenger. The powerful C-3-G antioxidant activity is in excellent agreement with the very negative redox potential (-405 mV), determined through direct current cyclic voltammetry measurements. On the basis of these results, C-3-G should be considered as one of the most effective antioxidants that can be assumed with dietary plants; therefore, pigmented oranges represent a very relevant C-3-G source because of the high content of this anthocyanin in their juice.


Subject(s)
Anthocyanins/pharmacology , Antioxidants/pharmacology , Anthocyanins/metabolism , Antioxidants/metabolism , Beverages , Chromatography, High Pressure Liquid , Citrus/chemistry , Dose-Response Relationship, Drug , Electrochemistry , Humans , Hydrogen Peroxide/pharmacology , Hydrogen-Ion Concentration , Lipoproteins, LDL/metabolism , Oxidation-Reduction/drug effects , Reactive Oxygen Species/metabolism , Time Factors
18.
Arch Biochem Biophys ; 379(2): 331-6, 2000 Jul 15.
Article in English | MEDLINE | ID: mdl-10898952

ABSTRACT

The structural and redox properties of a heme-containing fragment (1-56 residues) of cytochrome c have been investigated by spectroscopic (circular dichroism, electronic absorption, and EPR) and voltammetric techniques. The results indicate that the N-fragment lacks ordered secondary structure and has two histidines axially bound to the heme-iron (the native His18 and a misligated His26 or His33). Despite the absence of ordered secondary structure, the peptide chain shields the heme group from solvent, as shown by (i) the pK(a) of protonation of the nonnative histidine ligand (5.18 +/- 0.05), lower than that of the bis-histidine guanidine-unfolded cytochrome c (5.58 +/- 0.05), and (ii) the redox potential, E(o) = 0 +/- 5 mV versus NHE, close to that of bis-histidine cytochrome c mutants but less negative than that of bis-histidine complexes of microperoxidase with short peptides. The electroactive N-fragment may be taken as a "minichrome c" model, with interesting potential for application to biosensor technology; further, the system provides useful information for a deeper understanding of cytochrome c folding and structural/functional organization.


Subject(s)
Cytochrome c Group/chemistry , Cytochrome c Group/metabolism , Histidine/metabolism , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Animals , Circular Dichroism , Electron Spin Resonance Spectroscopy , Histidine/chemistry , Horses , Hydrogen-Ion Concentration , Iron/metabolism , Ligands , Models, Molecular , Myocardium/enzymology , Oxidation-Reduction , Protein Denaturation , Protein Folding , Protein Structure, Secondary , Spectrophotometry, Ultraviolet
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