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Stavroulaki A, Tzatzarakis MN, Karzi V, Katsikantami I, Renieri E, Vakonaki E, Avgenaki M, Alegakis A, Stan M, Kavvalakis M, Rizos AK, Tsatsakis A. Antibiotics in Raw Meat Samples: Estimation of Dietary Exposure and Risk Assessment. Toxics 2022; 10:456. [PMID: 36006135 PMCID: PMC9412356 DOI: 10.3390/toxics10080456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/28/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
The extensive use of antibiotics in livestock farming poses increased concerns for human health as residues of these substances are present in edible tissues. The aim of this study was the determination of the levels of four groups of antibiotics (sulfonamides-SAs, tetracyclines-TCs, streptomycines-STr and quinolones-QNLs) in meat samples (muscles, livers and kidneys from beef, chicken and pork) and the estimation of the dietary exposure to antibiotics from meat consumption and the potential hazard for human health. Fifty-four samples of raw meat were randomly collected in 2018 from the Cretan market, Greece and analyzed both with an enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-mass spectrometry (LC-MS). According to the results derived from the ELISA method, only 2% of the meat samples were free from antibiotics, 2% were detected with 4 antibiotics and the great majority of the samples (87%) were detected with 2 to 3 antibiotics. SAs presented the highest detection frequencies for all samples whereas TCs were not detected in any bovine sample. The highest median concentration was detected for STr in bovine muscles (182.10 μg/kg) followed by QNLs (93.36 μg/kg) in pork kidneys whereas the chicken samples had higher burdens of QNLs compared to the other meat samples. LC-MS analysis showed that oxytetracycline (OTC) was the most common antibiotic in all samples. The highest median concentration of all antibiotics was detected for doxycycline (DOX) (181.73 μg/kg in pork kidney) followed by OTC in bovine liver (74.46 μg/kg). Risk characterization was applied for each of the two methods; The hazard quotients (HQ) did not exceed 0.059 for the ELISA method and 0.113 for the LC-MS method for any group of antibiotics, whereas the total hazard indexes (HI) were 0.078 and 0.021, respectively. The results showed the presence of different groups of antibiotics in meat from the Cretan market and that the health risk to antibiotics is low. A risk assessment analysis conducted for meat consumption and corrected for the aggregated exposure revealed no risk for the consumers.
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Affiliation(s)
- Athina Stavroulaki
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
- Department of Chemistry, University of Crete and Foundation for Research and Technology—Hellas (FORTH-IESL), 70013 Heraklion, Greece
| | | | - Vasiliki Karzi
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Ioanna Katsikantami
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Elisavet Renieri
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Elena Vakonaki
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Maria Avgenaki
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Athanasios Alegakis
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Miriana Stan
- Department of Toxicology, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 200349 Bucharest, Romania
| | - Matthaios Kavvalakis
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
| | - Apostolos K. Rizos
- Department of Chemistry, University of Crete and Foundation for Research and Technology—Hellas (FORTH-IESL), 70013 Heraklion, Greece
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, Medicine School, University of Crete, 70013 Heraklion, Greece
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Karzi V, Tzatzarakis MN, Hatzidaki E, Katsikantami I, Alegakis A, Vakonaki E, Kalogeraki A, Kouvidi E, Xezonaki P, Sifakis S, Rizos AK. Determination of prenatal exposure to parabens and triclosan and estimation of maternal and fetal burden. Toxicol Rep 2021; 8:808-815. [PMID: 33868960 PMCID: PMC8044871 DOI: 10.1016/j.toxrep.2021.03.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Parabens (PBs) and triclosan (TCS) are generally used as antimicrobials mostly in personal care products. Their wide prevalence in daily products raised an acute need for the biomonitoring of these contaminants and the investigation of possible health impacts. MATERIAL AND METHODS In this study we aimed to quantitatively determine PBs and TCS levels in urine and amniotic fluid samples using a liquid chromatography - mass spectrometry system (LC-MS). Ninety nine (99) pregnant women took part in this research. The samples were collected during the amniocentesis in the early second trimester of their pregnancy. Women of all ages, education, household income and profession were selected. The exposure and the burden of pregnant women and their infants were also evaluated. RESULTS The most prevalent compound in urine, among the analyzed, was TCS with 74.7 % positive samples while in amniotic fluid methyl paraben (MePB) with 21.2 % positive samples. MePB was detected at higher concentrations in urine (mean: 378.5 ng/mL) followed by TCS (mean: 55.3 ng/mL), ethyl paraben (EtPB) (mean: 23.2 ng/mL) and butyl paraben (BuPB) (mean: 2.3 ng/mL) while benzyl paraben (BePB) was not detected in any urine sample. Concentrations in amniotic fluid samples were much lower. In particular, the mean concentrations were 6.6 ng/mL for MePB, 9.2 ng/mL for EtPB, 0.4 ng/mL for BuPB, 0.6 ng/mL for BePB and 1.8 ng/mL for TCS. The detected levels of all analytes in urine were correlated with those in amniotic fluid but no statistically significant results arose (p >n0.05). Negative associations were observed between amniotic fluid levels of MePB and maternal age (p = 0.05) while both urinary and amniotic levels of TCS were correlated with maternal BMI (p = 0.04). Somatometric characteristics of the infants showed no statistical significant associations with the detected levels of PBs and TCS. CONCLUSION This study indicated a strong/possible association between exposure of pregnant women to TCS and higher/lower maternal body weight gain during pregnancy. The same trend was observed between amniotic fluid MePB levels and maternal age. However, no statistically significant associations were observed between neonatal somatometric characteristics or health status and PBs and TCS levels.
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Affiliation(s)
- Vasiliki Karzi
- Laboratory of Toxicology, Medicine School, University of Crete, Heraklion, Crete, GR-70013, Greece
- Department of Chemistry, University of Crete and Foundation for Research and Technology - Hellas (FORTH-IESL), Heraklion, Crete, GR-71003, Greece
| | - Manolis N. Tzatzarakis
- Laboratory of Toxicology, Medicine School, University of Crete, Heraklion, Crete, GR-70013, Greece
| | - Eleftheria Hatzidaki
- Department of Neonatology & NICU, University Hospital of Heraklion, Crete, GR-71500, Greece
| | - Ioanna Katsikantami
- Laboratory of Toxicology, Medicine School, University of Crete, Heraklion, Crete, GR-70013, Greece
- Department of Chemistry, University of Crete and Foundation for Research and Technology - Hellas (FORTH-IESL), Heraklion, Crete, GR-71003, Greece
| | - Athanasios Alegakis
- Laboratory of Toxicology, Medicine School, University of Crete, Heraklion, Crete, GR-70013, Greece
| | - Elena Vakonaki
- Laboratory of Toxicology, Medicine School, University of Crete, Heraklion, Crete, GR-70013, Greece
| | - Alexandra Kalogeraki
- Department of Pathology-Cytopathology, Medical School, University of Crete, Heraklion, Crete, GR-70013, Greece
| | - Elisavet Kouvidi
- Genesis Genoma Lab, Genetic Diagnosis, Clinical Genetics & Research, Athens, GR-15232, Greece
| | | | - Stavros Sifakis
- Mitera Maternity Hospital, Heraklion, Crete, GR-71201, Greece
| | - Apostolos K. Rizos
- Department of Chemistry, University of Crete and Foundation for Research and Technology - Hellas (FORTH-IESL), Heraklion, Crete, GR-71003, Greece
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Katsikantami I, Tzatzarakis MN, Alegakis AK, Karzi V, Hatzidaki E, Stavroulaki A, Vakonaki E, Xezonaki P, Sifakis S, Rizos AK, Tsatsakis AM. Phthalate metabolites concentrations in amniotic fluid and maternal urine: Cumulative exposure and risk assessment. Toxicol Rep 2020; 7:529-538. [PMID: 32368503 PMCID: PMC7186561 DOI: 10.1016/j.toxrep.2020.04.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/06/2020] [Accepted: 04/15/2020] [Indexed: 11/27/2022] Open
Abstract
Phthalates are used in industry as plasticizers or additives in everyday products and they have been considered as endocrine disrupting chemicals. Maternal exposure during pregnancy has been associated with neonatal exposure, preterm birth and impacts in the reproductive and respiratory systems. The aim of this study is to determine six phthalate metabolites (mono isobutyl phthalate, miBP, mono n-butyl phthalate, mnBP, mono benzyl phthalate, mBzP, mono ethylhexyl phthalate, mEHP, mono 2-ethyl-5-hydroxyhexyl phthalate, mEHHP, mono 2-ethyl-5-oxohexyl-phthalate, mEOHP) in amniotic fluid and urine from 100 pregnant women. Participants answered questionnaires for the use of plastics and cosmetics, dietary habits, health effects, pregnancy problems, health and infant development. Positive amniotic fluid samples ranged from 1% to 21% and urine from 27% to 54%. The median levels for amniotic fluid were 2.3 μg/L - 10.7 μg/L and for urine 4.9 μg/L - 46.7 μg/L. The major results include significant correlations between urinary phthalates indicating their common sources of exposure, the frequent use of deodorant was significantly associated with higher urinary miBP (p = 0.050) and mnBP (p = 0.028) and a weak inverse association was found for the use of make-up products with mBzP (p = 0.053). The frequent use of plastic food containers was significantly associated with urinary mEHP (p = 0.026), and a positive trend was noticed for mEHP in amniotic fluid (p = 0.093). An association although weak was found between urinary mEHP and lower birth length (rs = 0.396, p = 0.062). No other associations were found for infant health problems or development. The daily intake of the total phthalates was calculated 5.4 μg/kg body weight/day which corresponds to hazard index 0.10 and exposure follows the declining trend that has been observed the last decades.
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Key Words
- 2cx-mMHP, mono 2-carboxymethyl-hexyl phthalate
- Amniotic fluid
- BBzP, benzyl butyl phthalate
- DEHP, di 2-ethylhexyl phthalate
- Daily intake
- DiBP, di iso-butyl phthalate
- DiNP, di isononyl phthalate
- DnBP, di n-butyl phthalate
- EDCs, endocrine disrupting chemicals
- EDI, estimated daily intake HQ, hazard quotient
- HI, hazard index
- LC-APCI-MS, liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry
- Phthalate metabolites
- Risk assessment
- Urine
- mBzP, mono benzyl phthalate
- mECPP or 5cx-mEPP, mono 2-ethyl-5-carboxypentyl phthalate
- mEHHP or 5OH-mEHP, mono 2-ethyl-5-hydroxyhexyl phthalate
- mEHP, mono ethylhexyl phthalate
- mEOHP or 5oxo-mEHP, mono 2-ethyl-5-oxohexyl-phthalate
- mEP, mono ethyl phthalate
- miBP, mono iso-butyl phthalate
- mmP, mono methyl phthalate
- mnBP, mono n-butyl phthalate
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Affiliation(s)
- Ioanna Katsikantami
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003, Heraklion, Crete, Greece
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
| | - Manolis N. Tzatzarakis
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
| | - Athanasios K. Alegakis
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
| | - Vasiliki Karzi
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003, Heraklion, Crete, Greece
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
| | - Eleftheria Hatzidaki
- Department of Neonatology & NICU, University Hospital of Heraklion, Crete, Greece
| | - Athina Stavroulaki
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003, Heraklion, Crete, Greece
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
| | - Elena Vakonaki
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
| | | | | | - Apostolos K. Rizos
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003, Heraklion, Crete, Greece
| | - Aristidis M. Tsatsakis
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003, Heraklion, Crete, Greece
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Katsikantami I, Tzatzarakis MN, Karzi V, Stavroulaki A, Xezonaki P, Vakonaki E, Alegakis AK, Sifakis S, Rizos AK, Tsatsakis AM. Biomonitoring of bisphenols A and S and phthalate metabolites in hair from pregnant women in Crete. Sci Total Environ 2020; 712:135651. [PMID: 31810691 DOI: 10.1016/j.scitotenv.2019.135651] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 11/18/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
Phthalates, bisphenols A and S (BPA, BPS) are used as plasticizers and many of them are documented or suspected of being endocrine disruptors. Several studies indicate that exposure during pregnancy may affect the newborn's health and development. The aim of this cross-sectional study is the biomonitoring of seven phthalate metabolites, BPA and BPS in hair from 100 pregnant women in Crete. The most frequently detected compounds were monoethylhexyl phthalate (mEHP) (68%), mono isobutyl phthalate (miBP) (40%), BPA (37%), BPS (34%) and mono-n-butyl phthalate (mnBP) (28%). Phthalate metabolites were detected at medians from 19.5 to 44.4 pg/mg, BPA at 69.9 pg/mg and BPS at 3.5 pg/mg. Significant positive correlations between phthalate metabolites were found which indicated their common sources of exposure. The frequent use of plastics for food storage was strongly associated with mEHP (p = .013) and a weaker association was found for miBP (p = .063). The frequent use of cosmetics during or before pregnancy was associated with levels of phthalate metabolites in hair. More specifically, the use of hair spray before pregnancy was significantly correlated with monobenzyl phthalate (mBzP) (p = .041) and a trend was found for miBP (p = .066). The use of makeup products during pregnancy was strongly associated with miBP (p = .015) and the use of deodorant during pregnancy was inversely associated with mEHP (p = .021). Strong associations came up between mEHP and lower birth weight (Spearman correlation coefficient, r = -0.302, p = .021) and exposure to BPS was associated with increased body mass index of the participants (p = .036). Although data in literature on biomonitoring of the compounds in hair are limited, the findings of this study are promising and in agreement with existing data in hair or urine.
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Affiliation(s)
- Ioanna Katsikantami
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003 Heraklion, Crete, Greece; Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece
| | - Manolis N Tzatzarakis
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece.
| | - Vasiliki Karzi
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003 Heraklion, Crete, Greece; Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece
| | - Athina Stavroulaki
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003 Heraklion, Crete, Greece; Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece
| | | | - Elena Vakonaki
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece
| | - Athanasios K Alegakis
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece
| | | | - Apostolos K Rizos
- Department of Chemistry, University of Crete & Foundation for Research and Technology-Hellas (FORTH-IESL), 71003 Heraklion, Crete, Greece.
| | - Aristidis M Tsatsakis
- Laboratory of Toxicology Science and Research, Medical School, University of Crete, 71003 Heraklion, Crete, Greece.
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Tsatsakis A, Stratidakis AK, Goryachaya AV, Tzatzarakis MN, Stivaktakis PD, Docea AO, Berdiaki A, Nikitovic D, Velonia K, Shtilman MI, Rizos AK, Kuskov AN. In vitro blood compatibility and in vitro cytotoxicity of amphiphilic poly-N-vinylpyrrolidone nanoparticles. Food Chem Toxicol 2019; 127:42-52. [PMID: 30836108 DOI: 10.1016/j.fct.2019.02.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 12/11/2022]
Abstract
This study focused on defining the in vitro behavior of amphiphilic poly-N-vinylpyrrolidone (Amph-PVP) nanoparticles toward whole blood, blood plasma and blood cells in order to assess nanoparticle blood compatibility. In addition, possible effects on endothelium cell growth/viability were evaluated. The Amph-PVP nanoparticles were formed via self-assembling in aqueous media and composed of a hydrophobic alkyl core and a hydrophilic PVP outer shell. Their blood compatibility was evaluated by investigating their effect on red blood cells (RBCs) or erythrocytes, white blood cells (WBCs) or leukocytes, platelets (PLTs) and on complement system activation. Our results clearly demonstrate that the Amph-PVP nanoparticles are stable in presence of blood serum, have no significant effects on the function of RBCs, WBCs, PLTs and complement system activation. The Amph-PVP nanoparticles did not show considerable hemolytic or inflammatory effect, neither influence on platelet aggregation, coagulation process, or complement activation at the tested concentration range of 0.05-0.5 mg/ml. The Amph-PVP nanoparticles did not exhibit any significant effect on HMEC-1 microvascular skin endothelial cells' growth in in vitro experiments. The excellent blood compatibility of the Amph-PVP nanoparticles and the lack of effect on endothelium cell growth/viability represent a crucial feature dictating their further study as novel drug delivery systems.
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Affiliation(s)
- A Tsatsakis
- Laboratory of Toxicology, University of Crete, Voutes, Heraklion, 71003, Crete, Greece; Department of Biomaterials, D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation; Department of Technology of Chemical Pharmaceutical and Cosmetic Products, D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation.
| | - A K Stratidakis
- Laboratory of Toxicology, University of Crete, Voutes, Heraklion, 71003, Crete, Greece
| | - A V Goryachaya
- Department of Biomaterials, D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation
| | - M N Tzatzarakis
- Laboratory of Toxicology, University of Crete, Voutes, Heraklion, 71003, Crete, Greece
| | - P D Stivaktakis
- Laboratory of Toxicology, University of Crete, Voutes, Heraklion, 71003, Crete, Greece
| | - A O Docea
- Department of Toxicology, University of Medicine and Pharmacy, Faculty of Pharmacy, Craiova, Romania
| | - Ai Berdiaki
- Laboratory of Anatomy-Histology-Embryology, University of Crete, Voutes, Heraklion, 71003, Crete, Greece
| | - D Nikitovic
- Laboratory of Anatomy-Histology-Embryology, University of Crete, Voutes, Heraklion, 71003, Crete, Greece
| | - K Velonia
- Department of Materials Science and Technology, University of Crete, University Campus Voutes, Heraklion, 71003, Crete, Greece
| | - M I Shtilman
- Department of Biomaterials, D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation
| | - A K Rizos
- Department of Chemistry, University of Crete, Foundation for Research and Technology-Hellas, FORTH-IESL, Heraklion, 71003, Crete, Greece
| | - A N Kuskov
- Department of Biomaterials, D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation; Department of Technology of Chemical Pharmaceutical and Cosmetic Products, D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation.
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Katsikantami I, Colosio C, Alegakis A, Tzatzarakis MN, Vakonaki E, Rizos AK, Sarigiannis DA, Tsatsakis AM. Estimation of daily intake and risk assessment of organophosphorus pesticides based on biomonitoring data - The internal exposure approach. Food Chem Toxicol 2018; 123:57-71. [PMID: 30352298 DOI: 10.1016/j.fct.2018.10.047] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 12/13/2022]
Abstract
Human exposure to pesticides can be estimated through different approaches. The approach adopted in this study is based on internal dose measures. Studies published during 2001 and 2017 were collected from PubMed and Scopus databases, filtered and organized. The intake of parent compounds is estimated based on the urinary excretion of different OP metabolites applying a mathematical model previously used for similar purposes. Once defined an Estimated Daily Intake (EDI), risk assessment is performed through comparison with specific guideline values and hazard index (HI) is calculated to assess cumulative health risk. The EDI was expressed as malathion, diazinon, parathion, phorate and dimethoate equivalents. Differences in exposure between pregnant women, general population, children and farmers are highlighted and exposures are presented by country and sampling year. Higher exposure to OPs was calculated for farmers, followed by children whereas pregnant women were less exposed. Median HQ values for children ranged between 0.016 and 0.618, for pregnant women 0.005-0.151, for general population 0.008-0.206 and for farmers 0.009-0.979. Combined exposure to dimethoate and phorate was the worst-case scenario. The annual distribution of the urinary DAPs showed that exposure to OPs since 1998 tends to be stable for both children and adults.
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Affiliation(s)
- Ioanna Katsikantami
- Department of Chemistry, University of Crete, Foundation for Research and Technology-Hellas, FORTH-IESL, GR-71003, Heraklion, Crete, Greece; Laboratory of Toxicology, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece
| | - Claudio Colosio
- Department of Occupational and Environmental Health of the University of Milan, International Centre for Rural Health of the University Hospital San Paolo, S. Paolo Hospital Unit, Via San Vigilio 43, 20142 Milan, Italy
| | - Athanasios Alegakis
- Laboratory of Toxicology, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece
| | - Manolis N Tzatzarakis
- Laboratory of Toxicology, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece
| | - Elena Vakonaki
- Laboratory of Toxicology, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece
| | - Apostolos K Rizos
- Department of Chemistry, University of Crete, Foundation for Research and Technology-Hellas, FORTH-IESL, GR-71003, Heraklion, Crete, Greece
| | - Dimosthenis A Sarigiannis
- Environmental Engineering Laboratory, Department of Chemical Engineering, Aristotle University of Thessaloniki, Greece; HERACLES Research Centre on the Exposome and Health, Centre for Interdisciplinary Research and Innovation (KEDEK), Aristotle University of Thessaloniki, Greece; Environmental Health Engineering, Institute for Advanced Study IUSS, Pavia, Italy
| | - Aristides M Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece.
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Tzatzarakis MN, Vakonaki E, Moti S, Alegakis A, Tsitsimpikou C, Tsakiris I, Goumenou M, Nosyrev AE, Rizos AK, Tsatsakis AM. Quantification of 4-Methylimidazole in soft drinks, sauces and vinegars of Greek market using two liquid chromatography techniques. Food Chem Toxicol 2017; 107:565-571. [DOI: 10.1016/j.fct.2017.03.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/08/2017] [Accepted: 03/17/2017] [Indexed: 11/30/2022]
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Tzatzarakis MN, Karzi V, Vakonaki E, Goumenou M, Kavvalakis M, Stivaktakis P, Tsitsimpikou C, Tsakiris I, Rizos AK, Tsatsakis AM. Bisphenol A in soft drinks and canned foods and data evaluation. Food Addit Contam Part B Surveill 2016; 10:85-90. [PMID: 27897085 DOI: 10.1080/19393210.2016.1266522] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Bisphenol A (BPA) is one of the most common industrial chemicals and known to exert endocrine disruption activity. The aim of this study was the quantification of BPA in food stuffs on the Greek market. The applied liquid chromatography-mass spectrometry method was validated for linearity, limit of quantification, accuracy, precision and recovery. About 41.7% of the canned solid phase samples, 25.0% of the canned liquid phase samples and 43.8% of the soft drinks were positive. Mean BPA concentrations (range) were 33.4 ± 4.4 ng/g (4.90 ± 0.64-66.0 ± 8.6 ng/g) in canned solid phase, 2.70 ± 0.08 ng/ml (1.90 ± 0.06-3.50 ± 0.11 ng/ml) in canned liquid phase and 2.30 ± 0.18 ng/ml (0.40 ± 0.03-10.2 ± 0.8 ng/ml) in soft drinks. The results of this study are comparable with those reported in the literature according to which higher concentrations of BPA were detected in the solid fraction of canned food compared to their liquid fraction.
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Affiliation(s)
- Manolis N Tzatzarakis
- a Laboratory of Toxicology, Medical School , University of Crete , Heraklion , Greece
| | - Vasiliki Karzi
- a Laboratory of Toxicology, Medical School , University of Crete , Heraklion , Greece.,b Department of Chemistry , University of Crete and Foundation for Research and Technology-Hellas (FORTH-IESL) , Heraklion , Greece
| | - Elena Vakonaki
- a Laboratory of Toxicology, Medical School , University of Crete , Heraklion , Greece
| | - Marina Goumenou
- c Pesticides Department , European Food Safety Authority , Parma , Italy
| | - Matthaios Kavvalakis
- a Laboratory of Toxicology, Medical School , University of Crete , Heraklion , Greece
| | | | - Christina Tsitsimpikou
- d National Helpdesk for REACH and CLP , General Chemical State Laboratory of Greece , Athens , Greece
| | - Ioannis Tsakiris
- e Department of Agricultural Technology, School of Agriculture Technology, Food Technology and Nutrition , TEI of Western Macedonia , Florina , Greece
| | - Apostolos K Rizos
- b Department of Chemistry , University of Crete and Foundation for Research and Technology-Hellas (FORTH-IESL) , Heraklion , Greece
| | - Aristidis M Tsatsakis
- a Laboratory of Toxicology, Medical School , University of Crete , Heraklion , Greece
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Katsikantami I, Sifakis S, Tzatzarakis MN, Vakonaki E, Kalantzi OI, Tsatsakis AM, Rizos AK. A global assessment of phthalates burden and related links to health effects. Environ Int 2016; 97:212-236. [PMID: 27669632 DOI: 10.1016/j.envint.2016.09.013] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 05/17/2023]
Abstract
Phthalates are ubiquitous environmental contaminants which are used in industry as plasticizers and additives in cosmetics. They are classified as Endocrine Disrupting Chemicals (EDCs) which impair the human endocrine system inducing fertility problems, respiratory diseases, childhood obesity and neuropsychological disorders. The aim of this review is to summarize the current state of knowledge on the toxicity that phthalates pose in humans based on human biomonitoring studies conducted over the last decade. Except for conventional biological matrices (such as urine and serum), amniotic fluid, human milk, semen, saliva, sweat, meconium and human hair are also employed for the estimation of exposure and distribution of pollutants in the human body, although data are not enough yet. Children are highly exposed to phthalates relative to adults and in most studies children's daily intake surpasses the maximum reference dose (RfD) set from US Environmental Protection Agency (US EPA). However, the global trend is that human exposure to phthalates is decreasing annually as a result of the strict regulations applied to phthalates.
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Affiliation(s)
- Ioanna Katsikantami
- Department of Chemistry, University of Crete, and Foundation for Research and Technology-Hellas, FORTH-IESL, GR-71003 Heraklion, Crete, Greece
| | - Stavros Sifakis
- Department of Obstetrics and Gynecology, University Hospital of Heraklion, GR-71003 Heraklion, Crete, Greece
| | - Manolis N Tzatzarakis
- Center of Toxicology Science and Research, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece
| | - Elena Vakonaki
- Center of Toxicology Science and Research, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece
| | | | - Aristidis M Tsatsakis
- Center of Toxicology Science and Research, Medical School, University of Crete, GR-71003, Heraklion, Crete, Greece.
| | - Apostolos K Rizos
- Department of Chemistry, University of Crete, and Foundation for Research and Technology-Hellas, FORTH-IESL, GR-71003 Heraklion, Crete, Greece
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10
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López de Victoria A, Kieslich CA, Rizos AK, Krambovitis E, Morikis D. Clustering of HIV-1 Subtypes Based on gp120 V3 Loop electrostatic properties. BMC Biophys 2012; 5:3. [PMID: 22313935 PMCID: PMC3295656 DOI: 10.1186/2046-1682-5-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 02/07/2012] [Indexed: 11/10/2022]
Abstract
BACKGROUND The V3 loop of the glycoprotein gp120 of HIV-1 plays an important role in viral entry into cells by utilizing as coreceptor CCR5 or CXCR4, and is implicated in the phenotypic tropisms of HIV viruses. It has been hypothesized that the interaction between the V3 loop and CCR5 or CXCR4 is mediated by electrostatics. We have performed hierarchical clustering analysis of the spatial distributions of electrostatic potentials and charges of V3 loop structures containing consensus sequences of HIV-1 subtypes. RESULTS Although the majority of consensus sequences have a net charge of +3, the spatial distribution of their electrostatic potentials and charges may be a discriminating factor for binding and infectivity. This is demonstrated by the formation of several small subclusters, within major clusters, which indicates common origin but distinct spatial details of electrostatic properties. Some of this information may be present, in a coarse manner, in clustering of sequences, but the spatial details are largely lost. We show the effect of ionic strength on clustering of electrostatic potentials, information that is not present in clustering of charges or sequences. We also make correlations between clustering of electrostatic potentials and net charge, coreceptor selectivity, global prevalence, and geographic distribution. Finally, we interpret coreceptor selectivity based on the N6X7T8|S8X9 sequence glycosylation motif, the specific positive charge location according to the 11/24/25 rule, and the overall charge and electrostatic potential distribution. CONCLUSIONS We propose that in addition to the sequence and the net charge of the V3 loop of each subtype, the spatial distributions of electrostatic potentials and charges may also be important factors for receptor recognition and binding and subsequent viral entry into cells. This implies that the overall electrostatic potential is responsible for long-range recognition of the V3 loop with coreceptors CCR5/CXCR4, whereas the charge distribution contributes to the specific short-range interactions responsible for the formation of the bound complex. We also propose a scheme for coreceptor selectivity based on the sequence glycosylation motif, the 11/24/25 rule, and net charge.
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Affiliation(s)
| | - Chris A Kieslich
- Department of Bioengineering, University of California, Riverside 92521, USA
| | - Apostolos K Rizos
- Department of Chemistry, University of Crete and Foundation for Research and Technology-Hellas, FORTH-IESL, GR-71003, Heraklion, Crete, Greece
| | - Elias Krambovitis
- Department of Veterinary Medicine, University of Thessaly, Karditsa, Greece
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside 92521, USA
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Meng Q, Doetschman DC, Rizos AK, Lee MH, Schulte JT, Spyros A, Kanyi CW. Adsorption of organophosphates into microporous and mesoporous NaX zeolites and subsequent chemistry. Environ Sci Technol 2011; 45:3000-3005. [PMID: 21361286 DOI: 10.1021/es1030678] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Due to the neurotoxicity of organophosphate (OP) pesticides and nerve agents synthesized as military or terror agents, their safe destruction and disposal is of considerable current importance. A representative OP, trimethyl phosphate (TMP), was adsorbed onto NaX zeolite, two mesoporous modifications, and a low-silica X zeolite. The nucleophilic chemical reactions of TMP with the zeolites were investigated by solid-state 13C and 31P nuclear magnetic resonance (NMR) and the solvent extracts by 1H, 13C, and 31P NMR. Nucleophilic substitution and subsequent hydrolysis reaction schemes are proposed. All of the zeolites have similar TMP decomposition yields, supporting the hypothesis that slow or incomplete diffusion of TMP in the microporous zeolite regions limits TMP decomposition.
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Affiliation(s)
- Qingguo Meng
- Department of Chemistry, Binghamton University, State University of New York, Vestal Parkway East, Binghamton, New York 13902-6000, United States.
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Kuskov AN, Voskresenskaya AA, Goryachaya AV, Shtilman MI, Spandidos DA, Rizos AK, Tsatsakis AM. Amphiphilic poly-N-vinylpyrrolidone nanoparticles as carriers for non-steroidal anti-inflammatory drugs: characterization and in vitro controlled release of indomethacin. Int J Mol Med 2010; 26:85-94. [PMID: 20514426 DOI: 10.3892/ijmm_00000438] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Novel amphiphilic poly-N-vinylpyrrolidone derivatives with different molecular weight of hydrophilic PVP fragment and one secondary di-n-alkyl terminal hydrophobic fragment of different length were synthesized to compare their inclination for formation of nano-scaled micelle-like aggregates in aqueous media with previously studied primary n-alkyl terminated poly-N-vinylpyrrolidones. The behavior of amphiphilies in water solutions was studied and critical aggregation concentration values for prepared polymer samples were determined by fluorescence spectroscopy and compared with those for primary n-alkyl derivatives. Polymeric micelle-like particles with or without encapsulated drug were prepared using dialysis or solvent evaporation techniques. Indomethacin was incorporated into hydrophobic inner core of these nanoparticles as a typical model drug. Dynamic light-scattering studies determined that the average size of particles formed was from 90 nm up to 600 nm with monodisperse size distribution and the nanoparticle size slightly increased with the amount of indomethacin encapsulated into inner core of the particles. In vitro release experiments carried out at different medium pH values using indomethacin-loaded nanoparticles exhibited slow and steady drug release into the medium.
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Affiliation(s)
- A N Kuskov
- D.I. Mendeleyev University of Chemical Technology, Moscow 125047, Russia
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13
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Galanakis PA, Kandias NG, Rizos AK, Morikis D, Krambovitis E, Spyroulias GA. NMR evidence of charge-dependent interaction between various PND V3 and CCR5 N-terminal peptides. Biopolymers 2009; 92:94-109. [PMID: 19117029 DOI: 10.1002/bip.21127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The third variable (V3) loop is an important region of glycoprotein 120 (gp120) for many biological processes, as it contains the highly conserved GPGR sequence and it represents the binding site for human immunodeficiency virus 1 (HIV-1) antibodies and for CCR5 and CXCR4 host cell coreceptors. The interaction of the principal neutralizing determinant (PND) V3 with the chemokine receptor CCR5 N-terminal region has been reported to be crucial for HIV-1 infection. The goal of this study is to characterize the solution structures of three HIV-1 gp120 V3 subtype B peptides and their interaction with a nonsulfated N-terminal CCR5 peptide. NMR titration experiments revealed that the CCR5Nt-PND V3 interaction is dependent on the number of the positively charged V3 residues, which is in agreement with the observation that increase in positive charge in the V3 sequence correlates with the augmentation of the interaction. As expected for free peptides in solution, the peptides representing the PND V3 region of gp120 exhibit conformational flexibility, but they also exhibit a large number of NOEs which allowed convergence to a dominant conformation. The PND V3 peptides retain the U-turn conformation observed in the crystal structures of gp120 complexes independently of CCR5 presence. The interaction of different regions of the CCR5Nt peptide is gradually increasing proportionally to the positive charge increase in the V3 peptides. The data demonstrate that the PND V3 and CCR5Nt peptide sequences have propensities for interaction even in the absence of sulfated tyrosines and that their binding and selectivity is determined by simple electrostatic attraction mechanisms.
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Affiliation(s)
- Petros A Galanakis
- Department of Pharmacy, University of Patras, Panepistimioupoli-Rion, Patras, Greece
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Kantzilakis K, Aivaliotis M, Kotakis C, Krasanakis F, Rizos AK, Kotzabasis K, Tsiotis G. A comparative approach towards thylakoid membrane proteome analysis of unicellular green alga Scenedesmus obliquus. Biochimica et Biophysica Acta (BBA) - Biomembranes 2007; 1768:2271-9. [PMID: 17574204 DOI: 10.1016/j.bbamem.2007.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 04/21/2007] [Accepted: 04/24/2007] [Indexed: 12/29/2022]
Abstract
The chlorophyll (Chl)-containing membrane protein complexes from the green alga Scenedesmus obliquus have been isolated from the thylakoid membranes by solubilization with dodecyl-beta-maltoside and fractionation using a sucrose density gradient. The Chl-containing protein fractions were characterized by absorption spectroscopy, tricine SDS PAGE, BN-PAGE, and dynamic light scattering (DLS). BN-PAGE showed the presence of seven protein complexes with molecular weights in the range of 68, 118, 157, 320, 494, 828 and 955 kDa, respectively. Furthermore, light scattering reveals the simultaneous presence of particles of different sizes in the 3-4 nm and 6.0-7.5 nm range, respectively. The smaller size is related to the hydrodynamic radius of the trimer Light Harvesting Complex (LHCII), whereas the larger size is associated with the presence of photosystem I and photosystem II reaction centers. Additionally, functional information regarding protein-protein interactions was deconvoluted using coupling 2-D BN-PAGE, MALDI-TOF MS and a detailed mapping of S. obliquus photosynthetic proteome of the solubilized thylakoid membranes is therefore presented.
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Affiliation(s)
- Konstantinos Kantzilakis
- Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, 71003 Voutes Heraklion, Greece
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15
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Rizos AK, Baritaki S, Tsikalas I, Doetschman DC, Spandidos DA, Krambovitis E. Biophysical characterization of V3-lipopeptide liposomes influencing HIV-1 infectivity. Biochem Biophys Res Commun 2007; 355:963-9. [PMID: 17331474 DOI: 10.1016/j.bbrc.2007.02.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Accepted: 02/10/2007] [Indexed: 11/23/2022]
Abstract
The V3-loop of the HIV-1 gp120 alters host cell immune function and modulates infectivity. We investigated biophysical parameters of liposome constructs with embedded lipopeptides from the principle neutralizing domain of the V3-loop and their influence on viral infectivity. Dynamic light scattering measurements showed liposome supramolecular structures with hydrodynamic radius of the order of 900 and 1300nm for plain and V3-lipopeptide liposomes. Electron paramagnetic resonance measurements showed almost identical local microenvironment. The difference in liposome hydrodynamic radius was attributed to the fluctuating ionic environment of the V3-lipopeptide liposomes. In vitro HIV-1 infectivity assays showed that plain liposomes reduced virus production in all cell cultures, probably due to the hydrophobic nature of the aggregates. Liposomes carrying V3-lipopeptides with different cationic potentials restored and even enhanced infectivity (p<0.05). These results highlight the need for elucidation of the involvement of lipid bilayers as dynamic components in supramolecular structures and in HIV-1 fusion mechanisms.
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Affiliation(s)
- Apostolos K Rizos
- Department of Chemistry and Foundation for Research and Technology-Hellas (FORTH-IESL), University of Crete, P.O. Box 2208, Heraklion 71003, Greece.
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Morikis D, Rizos AK, Spandidos DA, Krambovitis E. Electrostatic modeling of peptides derived from the V3-loop of HIV-1 gp120: implications of the interaction with chemokine receptor CCR5. Int J Mol Med 2007; 19:343-51. [PMID: 17273779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
Infection of CD4+ T cells by macrophage-tropic HIV-1 strains involves interaction of viral gp120 with the host cell chemokine receptor CCR5. The principle neutralizing determinant (PND) of the V3-loop of the HIV-1 gp120 was investigated for its interaction with CCR5 by computational modeling methods at atomic resolution and electrostatic calculations to complement experimental findings. The study focused on the recognition step and examined possible peptide-peptide interactions between various PND-derived peptides from the V3-loop and the N-terminal (Nt) domain of CCR5. These recognition interactions are possible because of the complementary character of the spatial distribution of the predominantly positive electrostatic potentials of the PND-derived peptides and the predominantly negative electrostatic potential of the CCR5Nt domain. The CCR5Nt appears more amenable to interaction with the V3 peptides, than the other CCR5 extracellular domains (ECL), because of its length and the domination of its negative electrostatic potential. On the contrary, ECL2 possesses a predominantly positive electrostatic potential. There are positive patches in Nt and negative patches in ECL2, which, following the non-specific recognition of the V3-loop by CCR5 and with the expected local structural rearrangements to facilitate specific binding, may be contributing to the stabilization of the complex. A sequential two-step specific binding, involving different extracellular domains, is conceivable. Although the electrostatic potentials may play a role in a V3-CCR5 interaction, a more specific model cannot be derived in the absence of a three-dimensional structure of a gp120/CD4/CCR5 complex.
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Affiliation(s)
- Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
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17
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Rizos AK, Spandidos DA, Krambovitis E. Light scattering characterization of synthetic MUC-1 peptides and their behavior in dilute solution. Int J Mol Med 2003; 12:559-63. [PMID: 12964034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Human epithelial mucin, MUC-1 is frequently expressed in adenocarcinoma. The sequentially-repeating nature of the core protein 20 a.a. polypeptide chain on the surface of malignant cells makes it a potential target for immunotherapy. Addressing the physicochemical role of these peptide tandem repeats (VNTR) in the structure of MUC-1 we have been prompted to use dynamic light scattering as an experimental tool to investigate peptide polymer size and dynamics directly in solution. We synthesized oligomeric VNTR peptides (monomer, trimer and pentamer) and studied their free behavior in aqueous solution. Our results revealed the simultaneous presence of three different relaxation modes corresponding to three different sizes. The small size is related to the expected hydrodynamic radius of the individual peptides, whereas the large size is associated with the presence of higher order peptide aggregates. The appearance of a third mode in the monomeric and trimeric MUC-1 reveals an actual peptide interaction.
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Affiliation(s)
- Apostolos K Rizos
- Department of Chemistry, University of Crete, Knossou Avenue, Heraklion 71409, Greece.
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18
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Aivaliotis M, Samolis P, Neofotistou E, Remigy H, Rizos AK, Tsiotis G. Molecular size determination of a membrane protein in surfactants by light scattering. Biochim Biophys Acta 2003; 1615:69-76. [PMID: 12948588 DOI: 10.1016/s0005-2736(03)00208-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular size of an outer surface protein from the photosynthetic bacterium Chlorobium tepidum was studied by dynamic light scattering (DLS) and HPLC gel filtration. For that purpose, the membrane protein was isolated and studied in four different nonionic surfactants, namely t-octylphenoxypolyethenoxyethanol (Triton X-100), (methyl-6-O-(N)-heptyl-carbamoyl)-alpha-D-glucopyranoside (Hecameg), dodecyl-beta-D-maltoside (DDM) and n-octyl-oligo-oxyethylene (Octyl-POE). The protein was isolated by solubilization of the membranes with Triton X-100. The final purification step was a gel filtration, which was also used for surfactant exchange. Light scattering reveals the simultaneous presence of particles of different sizes in the 3-6 and 20-110 nm range, respectively. The smaller size is related to the hydrodynamic radius of the individual protein/surfactant complexes, whereas the larger size is associated with the presence of complex aggregates.
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Affiliation(s)
- Michalis Aivaliotis
- Division of Biochemistry, Department of Chemistry, University of Crete, Heralilion, Greece
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19
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Baritaki S, Tzanakakis GN, Alifragis J, Zafiropoulos A, Tashmukhamedov RI, Tsatsakis A, Shtilman MI, Rizos AK, Krambovitis E. Light scattering and in vitro biocompatibility studies of poly (vinyl pyrrolidone) derivatives with amino-acid-dependent groups. J Biomed Mater Res 2003; 63:830-7. [PMID: 12418031 DOI: 10.1002/jbm.10409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Two poly (vinyl pyrrolidone) (PVP) families with amino-acid residues (glycine, beta-alanine, gamma-aminobutiric acid and epsilon-aminocaproic acid) on the base of the co-polymer N-vinyl pyrrolidone and allyl-glycidyl ether (VP-AGE) and on the base of epoxidized PVP (EPVP) were synthesized. Static and dynamic light scattering measurements of these PVP derivatives in water showed that their structure/ behavior were similar to that of PVP. The bioreactivity was also similar to that of PVP. Further investigation of the immunoreactive properties of the derivatives in in vitro proliferation assays with fresh normal human peripheral blood lymphocytes and monocytes led to the determination of a costimulatory profile for each derivative in terms of polyclonal stimulation, specific antigen presentation, and immunoglobulin secretion. This profile allows the selection of an appropriate derivative as a carrier that would suit the immunoreactivity needs of the immobilized ligand.
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Affiliation(s)
- Stavroula Baritaki
- Department of Applied Biochemistry & Immunology, Institute of Molecular Biology & Biotechnology, Vassilika Vouton, 71110 Heraklion, Crete, Greece
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Torchilin VP, Levchenko TS, Whiteman KR, Yaroslavov AA, Tsatsakis AM, Rizos AK, Michailova EV, Shtilman MI. Amphiphilic poly-N-vinylpyrrolidones: synthesis, properties and liposome surface modification. Biomaterials 2001; 22:3035-44. [PMID: 11575478 DOI: 10.1016/s0142-9612(01)00050-3] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Certain amphiphilic water-soluble polymers including amphiphilic derivatives of polyvinyl pyrrolidone (PVP) were found to be efficient steric protectors for liposomes in vivo. In this study, we have tried to develop synthetic pathways for preparing amphiphilic PVP and to investigate the influence of the hydrophilic/hydrophobic blocks on some properties of resulting polymers and polymer-coated liposomes. To prepare amphiphilic PVP with the end stearyl (S) or palmityl (P) residues, amino- and carboxy-terminated PVP derivatives were first synthesized by the free-radical polymerization of vinyl pyrrolidone in the presence of amino- or carboxy-mercaptans as chain transfer agents, and then modified by interaction of amino-PVP with stearoyl chloride or palmitoyl chloride, or by dicyclohexyl carbodiimide coupling of stearylamine with carboxy-PVP. ESR-spectra of the hydrophobic spin-probe, nitroxyl radical N-oxyl-2-hexyl-2-(10-methoxycarbonyl)decyl-4,4'-dimethyl oxazoline, in the presence of amphiphilic PVP demonstrated good accessibility of terminal P- and S-groups for the interaction with other hydrophobic ligands. Spontaneous micellization and low CMC values (in a low micromolar range) were found for amphiphilic PVP derivatives using the pyrene method. In general, S-PVP forms more stable micelles than P-PVP (at similar MW, CMC values for S-PVP are lower than for P-PVP). It was found that amphiphilic PVP incorporated into negatively charged liposomes effectively prevents polycation(poly-ethylpyridinium-4-vinylchloride)-induced liposome aggregation, completely abolishing it at ca. 10 mol% polymer content in liposomes. Additionally, the liposome-incorporated PVP prevents the fluorescence quenching of the membrane-incorporated hydrophobic fluorescent label [N-(4-fluoresceinthiocarbamoyl)dipalmitoyl-PE] by the free polycation. PVP-modified liposomes were loaded with a self-quenching concentration of carboxyfluorescein, and their destabilization in the presence of mouse serum was investigated following the release of free dye. Amphiphilic PVP with MW between 1,500 and 8,000 provides good steric protection for liposomes. The degree of this protection depends on both polymer concentration and molecular size of the PVP block.
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Affiliation(s)
- V P Torchilin
- Department of Pharmaceutical Sciences, Bouve College of Health Sciences, Northeastern University, Boston, MA 02115, USA.
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Rizos AK, Alifragis J, Ngai KL, Heitjans P. Near constant loss in glassy and crystalline LiAlSi[sub 2]O[sub 6] from conductivity relaxation measurements. J Chem Phys 2001. [DOI: 10.1063/1.1331299] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Rizos AK, Petihakis L, Ngai KL, Wu J, Yee AF. A Dielectric Relaxation Study of the γ-Relaxation in Tetramethylbisphenol A Polycarbonate Plasticized by Tris(2-ethylhexyl) Phosphate. Macromolecules 1999. [DOI: 10.1021/ma980204o] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - K. L. Ngai
- Naval Research Laboratory, Washington, DC 20375-5320
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Affiliation(s)
- Apostolos K. Rizos
- Department of Chemistry, University of Crete, and Foundation for Research & Technology-Hellas, P.O. Box 1527, Heraklion 71110, Greece
| | - K. L. Ngai
- Naval Research Laboratory, Washington, D.C. 20375-5320
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Ngai KL, Rizos AK. Parameterless explanation of the non-Arrhenius conductivity in glassy fast ionic conductors. Phys Rev Lett 1996; 76:1296-1299. [PMID: 10061685 DOI: 10.1103/physrevlett.76.1296] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Rizos AK, Fytas G, Semenov AN. Concentration fluctuation effects on chain orientation dynamics of polymer blends in the critical region. J Chem Phys 1995. [DOI: 10.1063/1.469130] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rizos AK, Ngai KL. Anomalous reduction of solvent friction in chlorinated biphenyl solutions of 1,2-polybutadiene. Phys Rev B Condens Matter 1992; 46:8126-8131. [PMID: 10002569 DOI: 10.1103/physrevb.46.8126] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Bangcharoenpaurpong O, Rizos AK, Champion PM, Jollie D, Sligar SG. Resonance Raman detection of bound dioxygen in cytochrome P-450cam. J Biol Chem 1986; 261:8089-92. [PMID: 3722145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We have used resonance Raman spectroscopy and isotopic labeling techniques to unambiguously assign the dioxygen stretching frequency (vo-o) in the substrate-bound oxygenated complex of cytochrome P-450cam. The frequency found for Vo-o in the P-450cam system (1140 cm-1) is in remarkable agreement with recent studies of thiolate heme model compounds. The general features of the oxy-P-450cam Raman spectra are tabulated and comparisons are made with the oxy complexes of hemoglobin, myoglobin, and various model compounds. Most of the results are qualitatively explained by consideration of electron donation into the pi g (O2)/d pi (M) orbitals of the oxygenated complex (M = Fe or Co). It is also noted that the effect of the "extra" electron in the nitrogen base Co(II) oxy complexes, in some ways, parallels the effect of the lone pair electrons of thiolate in the oxy-P-450cam complex. This is evidenced by the enhanced resonance Raman activity of vo-o in both the Co(II) and P-450 systems as well as by the similarity of the vo-o frequencies.
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