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Pecorini G, Braccini S, Simoni S, Corti A, Parrini G, Puppi D. Additive Manufacturing of Wet-Spun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-Based Scaffolds Loaded with Hydroxyapatite. Macromol Biosci 2024; 24:e2300538. [PMID: 38534197 DOI: 10.1002/mabi.202300538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/20/2024] [Indexed: 03/28/2024]
Abstract
Tissue engineering represents an advanced therapeutic approach for the treatment of bone tissue defects. Polyhydroxyalkanoates are a promising class of natural polymers in this context thanks to their biocompatibility, processing versatility, and mechanical properties. The aim of this study is the development by computer-aided wet-spinning of novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based composite scaffolds for bone engineering. In particular, PHBV scaffolds are loaded with hydroxyapatite (HA), an osteoinductive ceramic, in order to tailor their biological activity and mechanical properties. PHBV blending with poly(lactide-co-glycolide) (PLGA) is also explored to increase the processing properties of the polymeric mixture used for composite scaffold fabrication. Different HA percentages, up to 15% wt., can be loaded into the PHBV or PHBV/PLGA scaffolds without compromising their interconnected porous architecture, as well as the polymer morphological and thermal properties, as demonstrated by scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, HA loading results in increased scaffold compressive stiffness to levels comparable to those of trabecular bone tissue, as well as in higher in vitro MC3T3-E1 cell viability and production of mineralized extracellular matrix, in comparison to what observed for unloaded scaffolds. The observed mechanical and biological properties suggest the suitability of the developed scaffolds for bone engineering.
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Affiliation(s)
- Gianni Pecorini
- BIOLab Research Group, Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM Pisa, Via Moruzzi 13, Pisa, 56124, Italy
| | - Simona Braccini
- BIOLab Research Group, Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM Pisa, Via Moruzzi 13, Pisa, 56124, Italy
| | - Stefano Simoni
- BIOLab Research Group, Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM Pisa, Via Moruzzi 13, Pisa, 56124, Italy
| | - Andrea Corti
- BIOLab Research Group, Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM Pisa, Via Moruzzi 13, Pisa, 56124, Italy
| | | | - Dario Puppi
- BIOLab Research Group, Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM Pisa, Via Moruzzi 13, Pisa, 56124, Italy
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Revealing of sugar utilization systems in Halomonas sp. YLGW01 and application for poly(3-hydroxybutyrate) production with low-cost medium and easy recovery. Int J Biol Macromol 2020; 167:151-159. [PMID: 33249160 DOI: 10.1016/j.ijbiomac.2020.11.163] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Abstract
Poly(3-hydroxybutyrate) (PHB) is a common polyhydroxyalkanoate (PHA) with potential as an alternative for petroleum-based plastics. Previously, we reported a new strain, Halomonas sp. YLGW01, which hyperproduces PHB with 94% yield using fructose. In this study, we examined the PHB production machinery of Halomonas sp. YLGW01 in more detail by deep-genome sequencing, which revealed a 3,453,067-bp genome with 65.1% guanine-cytosine content and 3054 genes. We found two acetyl-CoA acetyltransferases (Acetoacetyl-CoA thiolase, PhaA), one acetoacetyl-CoA reductase (PhaB), two PHB synthases (PhaC1, PhaC2), PHB depolymerase (PhaZ), and Enoyl-CoA hydratase (PhaJ) in the genome, along with two fructose kinases and fructose transporter systems, including the phosphotransferase system (PTS) and ATP-binding transport genes. We then examined the PHB production by Halomonas sp. YLGW01 using high-fructose corn syrup (HFCS) containing fructose, glucose, and sucrose in sea water medium, resulting in 7.95 ± 0.11 g/L PHB (content, 67.39 ± 0.34%). PHB was recovered from Halomonas sp. YLGW01 using different detergents; the use of Tween 20 and SDS yielded micro-sized granules with high purity. Overall, these results reveal the distribution of PHB synthetic genes and the sugar utilization system in Halomonas sp. YLGW01 and suggest a possible method for PHB recovery.
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Park CJ, Barakat R, Ulanov A, Li Z, Lin PC, Chiu K, Zhou S, Perez P, Lee J, Flaws J, Ko CJ. Sanitary pads and diapers contain higher phthalate contents than those in common commercial plastic products. Reprod Toxicol 2019; 84:114-121. [PMID: 30659930 DOI: 10.1016/j.reprotox.2019.01.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 01/11/2019] [Accepted: 01/15/2019] [Indexed: 01/23/2023]
Abstract
Sanitary pads and diapers are made of synthetic plastic materials that can potentially be released while being used. This study measured the amounts of volatile organic compounds (VOCs) (methylene chloride, toluene, and xylene) and phthalates (DBP, DEHP, DEP, and BBP) contained in sanitary pads and diapers. In sanitary pads, 5,900- and 130-fold differences of VOC and phthalate concentrations were seen among the brands. In the diapers, 3- and 63-fold differences of VOC and phthalate concentrations were detected among the brands. VOC concentrations from the sanitary pads and diapers were similar to that of the residential air. However, phthalate concentrations of sanitary pads and diapers were significantly higher than those found in common commercial plastic products. As sanitary pads and diapers are in direct contact with external genitalia for an extended period, there is a probability that a considerable amount of VOCs or phthalates could be absorbed into the reproductive system.
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Affiliation(s)
- Chan Jin Park
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Radwa Barakat
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA; Department of Toxicology, Faculty of Veterinary Medicine, Benha University, Benha, 13518, Egypt
| | - Alexander Ulanov
- Metabolomics Center, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Zhong Li
- Metabolomics Center, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Po-Ching Lin
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Karen Chiu
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Sherry Zhou
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Pablo Perez
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - Jungyeon Lee
- TV Chosun Broadcasting, 33, Sejong-daero 21-gil, Jung-gu, Seoul, 04519, Republic of Korea
| | - Jodi Flaws
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
| | - CheMyong Jay Ko
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA.
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Williams AL, Bates CA, Pace ND, Leonhard MJ, Chang ET, DeSesso JM. Impact of chloroform exposures on reproductive and developmental outcomes: A systematic review of the scientific literature. Birth Defects Res 2018; 110:1267-1313. [PMID: 30350414 DOI: 10.1002/bdr2.1382] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 06/26/2018] [Accepted: 07/27/2018] [Indexed: 12/26/2022]
Abstract
AIMS We assessed the animal and epidemiological data to determine if chloroform exposure causes developmental and/or reproductive toxicity. RESULTS AND DISCUSSION Initial scoping identified developmental toxicity as the primary area of concern. At levels producing maternal toxicity in rats and mice, chloroform caused decrements in fetal weights and associated delays in ossification. In a single mouse inhalation study, exposure to a high concentration of chloroform was associated with small fetuses and increased cleft palate. However, oral exposure of mice to chloroform at a dose 4 times higher was negative for cleft palate; multiple inhalation studies in rats were also negative. Epidemiologic data on low birth weight and small for gestational age were generally equivocal, preventing conclusions from being drawn for humans. The animal data also show evidence of very early (peri-implantation) total litter losses at very high exposure levels. This effect is likely maternally mediated rather than a direct effect on the offspring. Finally, the epidemiologic data indicate a possible association of higher chloroform exposure with lower risk of preterm birth (<37 weeks gestation). CONCLUSIONS The available animal data suggest that exposures lower than those causing maternal toxicity should be without developmental effects in the offspring. Also, most studies in humans rely on group-level geographic exposure data, providing only weak epidemiologic evidence for an association with development outcomes and fail to establish a causal role for chloroform in the induction of adverse developmental outcomes at environmentally relevant concentrations.
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Affiliation(s)
| | | | | | | | | | - John M DeSesso
- Exponent, Inc., Alexandria, Virginia.,Georgetown University School of Medicine, Washington, District of Columbia
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Rivera-Núñez Z, Wright JM, Meyer A. Exposure to disinfectant by-products and the risk of stillbirth in Massachusetts. Occup Environ Med 2018; 75:742-751. [PMID: 30061312 DOI: 10.1136/oemed-2017-104861] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/17/2018] [Accepted: 06/03/2018] [Indexed: 11/03/2022]
Abstract
OBJECTIVES We examined stillbirths in relation to disinfection by-product (DBP) exposures including chloroform, bromodichloromethane (BDCM), dibromochloromethane, bromoform, trichloroacetic acid, dichloroacetic acid (DCAA), monobromoacetic acid and summary DBP measures (trihalomethanes (THM4), haloacetic acids (HAA5), THMBr (brominated trihalomethanes) and DBP9 (sum of THM4 and HAA5)). METHODS We randomly selected 10 controls for each of the 2460 stillbirth cases with complete quarterly 1997-2004 THM4 and HAA5 town-level drinking water data. Adjusted (aORs) were calculated based on weight-averaged second-trimester DBP exposures. RESULTS We detected statistically significant associations for stillbirths and the upper DCAA quartiles (aOR range: 1.50-1.71). We also found positive associations for the upper four HAA5 quintiles and different stillbirth cause of death categories that were examined including unexplained stillbirth (aOR range: 1.24-1.72), compression of umbilical cord (aOR range: 1.08-1.94), prematurity (aOR range: 1.37-2.88), placental separation and haemorrhage (aOR range: 1.44-2.01) and asphyxia/hypoxia (aOR range: 1.52-1.97). Additionally, we found positive associations between stillbirths and chloroform exposure (aOR range: 1.29 - 1.36) and unexplained stillbirths and BDCM exposure (aOR range: 1.51 - 1.78). We saw no evidence of exposure-response relationships for any categorical DBP metrics. CONCLUSIONS Consistent with some previous studies, we found associations between stillbirths and chloroform and unexplained stillbirth and BDCM exposures. These findings strengthen existing evidence of prenatal THM exposures increasing the risk of stillbirth. Additionally, we saw statistically significant associations between DCAA and stillbirth. Future research should examine cause-specific stillbirths in relation to narrower critical windows and additional DBP exposure metrics beyond trihalomethanes and haloacetic acids.
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Affiliation(s)
| | - J Michael Wright
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Cincinnati, Ohio, USA
| | - Amy Meyer
- Oak Ridge Institute of Science and Education Research, Oak Ridge, Tennessee, USA
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Tenori L, Santucci C, Meoni G, Morrocchi V, Matteucci G, Luchinat C. NMR metabolomic fingerprinting distinguishes milk from different farms. Food Res Int 2018; 113:131-139. [PMID: 30195505 DOI: 10.1016/j.foodres.2018.06.066] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 11/25/2022]
Abstract
A fast and reproducible protocol for milk Nuclear Magnetic Resonance (NMR) metabolomic fingerprinting was developed, allowing for an accurate discrimination among milk samples from large-scale distribution, as well as among milk sample from different farms located in the same restricted geographical area. Seasonal variations in milk composition and correlations with cows' nutritional patterns are also assessed, underlining relationships between feeding and metabolites. The most important difference was related to the use of silage feeding. This finding is relevant to assess the suitability of milk for different dairy products. A prominent example is parmesan cheese, the preparation protocol of which excludes milk from silage-fed cows.
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Affiliation(s)
- Leonardo Tenori
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, 50134 Florence, Italy; Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Claudio Santucci
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Gaia Meoni
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Valentina Morrocchi
- Cooperlatte s.c.a., via Togliatti 24, 50032, Borgo San Lorenzo, Florence, Italy
| | - Giacomo Matteucci
- Cooperlatte s.c.a., via Togliatti 24, 50032, Borgo San Lorenzo, Florence, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy; Giotto Biotech s.r.l., via Madonna del Piano 6, 50019 Sesto Fiorentino, Florence, Italy.
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Teixidó E, Piqué E, Gonzalez-Linares J, Llobet JM, Gómez-Catalán J. Developmental effects and genotoxicity of 10 water disinfection by-products in zebrafish. JOURNAL OF WATER AND HEALTH 2015; 13:54-66. [PMID: 25719465 DOI: 10.2166/wh.2014.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Disinfection by-products are contaminants produced during drinking water disinfection. Several DBPs have been implicated in a variety of toxic effects, mainly carcinogenic and genotoxic effects. Moreover, DBPs exposure has also been associated with an increased risk of developmental effects. In this study, the developmental toxicity and genotoxicity of 10 DBPs (four trihalomethanes [THMs], five haloacetic acids [HAAs] and sodium bromate) in the zebrafish embryo model were evaluated. Embryos exposed for 72 hours were observed for different endpoints such as growth, hatching success, malformations and lethality. THMs exposure resulted in adverse developmental effects and a significant reduced tail length. Two HAAs, tribromoacetic acid and dichloroacetic acid, along with sodium bromate were found to cause a significant increase in malformation rate. Chloroform, chlorodibromomethane and sodium bromate produced a weak induction of DNA damage to whole embryos. However, developmental effects occurred at a range of concentrations (20-100 μg/mL) several orders of magnitude above the levels that can be attained in fetal blood in humans exposed to chlorinated water. In conclusion, the teratogenic and genotoxic activity observed by some DBPs in zebrafish reinforce the view that there is a weak capacity of disinfection products to cause developmental effects at environmentally relevant concentrations.
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Affiliation(s)
- Elisabet Teixidó
- GRET-CERETOX and Toxicology Unit, Public Health Department, School of Pharmacy, University of Barcelona. Av. Joan XXIII s/n, E-08028, Barcelona, Spain E-mail:
| | - Esther Piqué
- GRET-CERETOX and Toxicology Unit, Public Health Department, School of Pharmacy, University of Barcelona. Av. Joan XXIII s/n, E-08028, Barcelona, Spain E-mail:
| | - Javier Gonzalez-Linares
- GRET-CERETOX and Experimental Toxicology and Ecotoxicology Unit, Barcelona Science Park. Baldiri i Reixac 10-12, E-08028, Barcelona, Spain
| | - Joan M Llobet
- GRET-CERETOX and Toxicology Unit, Public Health Department, School of Pharmacy, University of Barcelona. Av. Joan XXIII s/n, E-08028, Barcelona, Spain E-mail:
| | - Jesús Gómez-Catalán
- GRET-CERETOX and Toxicology Unit, Public Health Department, School of Pharmacy, University of Barcelona. Av. Joan XXIII s/n, E-08028, Barcelona, Spain E-mail:
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Hwang BF, Jaakkola JJK. Risk of stillbirth in the relation to water disinfection by-products: a population-based case-control study in Taiwan. PLoS One 2012; 7:e33949. [PMID: 22457804 PMCID: PMC3311556 DOI: 10.1371/journal.pone.0033949] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 02/20/2012] [Indexed: 12/03/2022] Open
Abstract
Background Few epidemiological studies that have assessed the relation between water disinfection by-products (DBPs) and the risk of stillbirth provide inconsistent results. The objective was to assess the relation between exposure to water disinfection by-products and the risk of stillbirth. Methods We conducted a population-based case-control study of 3,289 cases of stillbirth and a random sample of 32,890 control subjects from 396,049 Taiwanese newborns in 2001–2003 using information from the Birth Registry and Waterworks Registry in Taiwan. We compared the risk of stillbirth in four disinfection by-product exposure categories based on the levels of total trihalomethanes (TTHMs) representing high (TTHMs 20+ µg/L), medium (TTHMs 10–19 µg/L), low exposure (TTHMs 5–9 µg/L), and 0–4 µg/L as the reference category. In addition, we conducted a meta-analysis of the results from the present and 5 previous studies focusing on stillbirth. Findings In logistic regression analysis adjusting for gender, maternal age, plurality, conception of season and population density of the municipality where the mother lived during pregnancy, the odds ratio (OR) for stillbirth was 1.10 (95% CI 1.00–1.21) for medium exposure and 1.06 (95% 0.96–1.17) for high exposure compared to reference category. In the meta-analysis, the summary odds ratio for stillbirth (1.11, 95% CI: 1.03, 1.19) was consistently elevated. Conclusions The present study is consistent with the hypothesis that the risk of stillbirth is related to prenatal exposure to disinfection by-products. This finding on stillbirth is consistent with previous epidemiologic studies, which strengthens the weight of evidence.
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Affiliation(s)
- Bing-Fang Hwang
- Department and Graduate Institute of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan, Republic of China.
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Colman J, Rice GE, Wright JM, Hunter ES, Teuschler LK, Lipscomb JC, Hertzberg RC, Simmons JE, Fransen M, Osier M, Narotsky MG. Identification of developmentally toxic drinking water disinfection byproducts and evaluation of data relevant to mode of action. Toxicol Appl Pharmacol 2011; 254:100-26. [DOI: 10.1016/j.taap.2011.02.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 04/22/2010] [Accepted: 04/22/2010] [Indexed: 12/26/2022]
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Hwang BF, Jaakkola JJK, Guo HR. Water disinfection by-products and the risk of specific birth defects: a population-based cross-sectional study in Taiwan. Environ Health 2008; 7:23. [PMID: 18518952 PMCID: PMC2467412 DOI: 10.1186/1476-069x-7-23] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 06/02/2008] [Indexed: 05/21/2023]
Abstract
BACKGROUND Recent findings suggest that exposure to disinfection by-products may increase the risk of birth defects. Previous studies have focused mainly on birth defects in general or groups of defects. The objective of the present study was to assess the effect of water disinfection by-products on the risk of most common specific birth defects. METHODS We conducted a population-based cross-sectional study of 396,049 Taiwanese births in 2001-2003 using information from the Birth Registry and Waterworks Registry. We compared the risk of eleven most common specific defects in four disinfection by-product exposure categories based on the levels of total trihalomethanes (TTHMs) representing high (TTHMs 20+ microg/L), medium (TTHMs 10-19 microg/L), low exposure (TTHMs 5-9 microg/L), and 0-4 microg/L as the reference category. In addition, we conducted a meta-analysis of the results from the present and previous studies focusing on the same birth defects. RESULTS In multivariate logistic regression analysis the risk of ventricular septal defects (adjusted odds ratio 1.81, 95% confidence interval: 0.98 3.35), cleft palate (1.56. 95% CI: 1.00, 2.41), and anencephalus (1.96, 95% CI: 0.94, 4.07) were elevated in the high exposure compared to the reference category. In the meta-analysis, the summary odds ratio for ventricular septal defects (1.59, 95% CI: 1.21, 2.07) was consistently elevated. CONCLUSION The present study suggests that prenatal exposure to disinfection by-products increases the risk of ventricular septal defects, cleft palate, and anencephalus. The evidence on ventricular septal defects is consistent in the three available studies.
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Affiliation(s)
- Bing-Fang Hwang
- Department and Graduate Institute of Occupational Safety and Health, College of Public Health, China Medical University, No.91 Hsueh-Shih Road, Taichung 40402, Taiwan, ROC
- Department of Occupational and Environmental Medicine, National Chung Kung University, No. 138 Sheng-Li Road, Tainan 70428, Taiwan, ROC
- Department of Health Care Administration, Diwan College of Management, No. 87-1 Nan-Shih Li, Tainan 72153, Taiwan, ROC
| | - Jouni JK Jaakkola
- The Institute of Occupational and Environmental Medicine, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - How-Ran Guo
- Department of Occupational and Environmental Medicine, National Chung Kung University, No. 138 Sheng-Li Road, Tainan 70428, Taiwan, ROC
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Náprstková I, Radochová B, Novotná B, Jirkovská M, Janácek J, Kubínová L. Quantitative analysis of embryonic kidney impairment by confocal microscopy and stereology: effect of 1,2-dibromoethane in the chick mesonephros. Br Poult Sci 2007; 46:661-7. [PMID: 16428107 DOI: 10.1080/00071660500394064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
1. Chick embryos in ovo were treated with a teratogenic dose of 1,2-dibromoethane (DBE) on embryonic day (ED) 3. On ED 6 and 10, histological sections of whole embryos were prepared for confocal microscopy. In parallel, mesonephroi of 10-d-old embryos were dissected for in situ staining with acridine orange (AO), a fluorescence probe for lysosomes. 2. DBE impaired differentiation of renal vessels which manifested as a delay in rearrangement of primitive renal vascular architecture on ED 6 and a significant reduction of the mesonephric vascularisation on ED 10. This was accompanied by delayed functional maturation of embryonic kidney, as suggested by staining with AO. 3. Renal vessels appeared to be more susceptible to DBE than tubules. Unequal growth of these renal components might be a cause of DBE-induced spatial disorganisation of tubular apparatus. 4. Nephrotoxic effects of DBE during the embryonic period are associated primarily with damage to the renal blood supply. 5. Confocal microscopy, stereological methods and three-dimensional reconstruction of developing tissues are useful tools to investigate pathogenic processes during embryonic development.
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Affiliation(s)
- I Náprstková
- Institute of Physiology, Academy of Sciences of the Czech Republic
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Synergistic utilization of dichloroethylene as sole carbon source by bacterial consortia isolated from contaminated sites in Africa. BIOTECHNOL BIOPROC E 2006. [DOI: 10.1007/bf02932031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Olaniran AO, Pillay D, Pillay B. Haloalkane and haloacid dehalogenases from aerobic bacterial isolates indigenous to contaminated sites in Africa demonstrate diverse substrate specificities. CHEMOSPHERE 2004; 55:27-33. [PMID: 14720543 DOI: 10.1016/j.chemosphere.2003.10.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Five bacteria were isolated from contaminated sites in Nigeria and South Africa using the culture enrichment technique. They were subjected to standard cultural, biochemical and microbiological techniques and identified to be species of Bacillus, Burkholderia, Corynebacterium, Micrococcus and Pseudomonas. Axenic cultures of the bacterial isolates utilized 1,2-dichloroethane (1,2-DCE) as the sole carbon source up to a final substrate concentration of 10 mM. Their mean generation time in 1,2-DCE ranged significantly (P<0.05) from 9.77 to 15.72 h with the maximum chloride release ranging between 59% and 86%. All the bacterial isolates produced two different dehalogenases, viz. one which is heat labile and specific for halogenated alkanes with optimum activity at a pH of 7.5 and the other which is more heat stable with a higher pH optimum of 9.0 and specific for halogenated alkanoic acids. However, the two enzyme types when tested demonstrated wide substrate specificities. It is therefore adjudged that these organisms may play a vital role in the bioremediation of sites polluted with chlorinated hydrocarbons.
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Affiliation(s)
- A O Olaniran
- Department of Microbiology, University of Durban-Westville, P. Bag X54001, Durban 4000, South Africa.
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