The effect of carbodiimide on push-out bond strength of fiber posts and endogenous enzymatic activity.
作者: Uros Josic ; Claudia Mazzitelli ; Tatjana Maravic ; Allegra Comba ; Milena Cadenaro ; Ivana Radovic ; Maicon Sebold ; Gianluca Turco ; Lorenzo Breschi ; Annalisa Mazzoni
To investigate the effect of 0.3 M 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) aqueous solution pretreatment on push-out bond strength (PBS) and matrix-metalloproteinases (MMPs) activity within radicular dentin when different post cementation strategies were employed.
One hundred and twenty monoradicular human teeth were endodontically treated and randomly divided into six groups, depending on the cementation strategy and root dentin pretreatment (n = 20): EAR: cementation with an etch-and-rinse adhesive (LuxaBond Total Etch, DMG) and resin cement (LuxaCore Z Dual, DMG); EAR/EDC: 1 min EDC pretreatment after etching + EAR; SE: cementation with a self-etch primer (Multilink Primer, Ivoclar Vivadent) and corresponding cement (Multilink Automix, Ivoclar Vivadent); SE/EDC: self-etch primer + EDC pretreatment + SE; SA: cementation with a universal self-adhesive cement (RelyX Universal, 3 M); SA/EDC: EDC pretreatment + SA. Slices were submitted to PBS test and interfacial nanoleakage evaluation 24 h after cementation or after thermocycling (40.000 cycles, 5-55 °C). To investigate the effect of EDC on MMPs activity, 4 additional first maxillary premolars per group were processed for in situ zymography analysis. Multivariate ANOVA and post hoc Tukey tests were used to analyze PBS values. The data from in situ zymography were analyzed with Kruskal-Wallis test and Dunn's pairwise multiple comparison procedures (α = 0.05).
The variables "EDC pretreatment", "root region" and "thermocycling" significantly influenced PBS (p < 0.05), while the variable "cementation strategy" had no influence (p > 0.05). Thermocycling significantly reduced PBS in SE and SA groups (p < 0.05). EDC was effective in preserving PBS after artificial aging. EDC pretreatment significantly reduced enzymatic activity at baseline in EAR and SE groups, and in SA group after thermocycling (p < 0.05).
The use of EDC prevents the reduction of bond-strength values after artificial aging and silences endogenous enzymatic activity within radicular dentin when different cementation strategies were employed.
2023-06-08·Journal of biomedical materials research. Part B, Applied biomaterials
Analysis of the adhesive interface of dentine treated with carbodiimide and chitosan before cementation of fiberglass posts with different resin cements.
作者: Helena Cristina de Assis ; Gunther Ricardo Bertolini ; Manoel Damião Sousa-Neto ; Fabiane Carneiro Lopes-Olhê
The objective of this study is to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and chitosan (CHI) on the adhesive interface of resin cements to root dentine. Forty-five upper canines were sectioned, endodontically treated, prepared and divided into three groups according to dentine treatment (distilled water-DW, CHI 0.2% and EDC 0.5) and in three subgroups according to resin cement: RelyX ARC, Panavia F 2.0 or RelyX U200. Slices were obtained, with five slices of each third submitted to the analysis of the adaptation of the adhesive interface through scores and the perimeter with gaps in confocal laser scanning microscopy and one slice of each third later evaluated qualitatively in scanning electron microscopy. The results were analyzed using with Kruskal-Wallis and Spearman correlation tests. There was no difference in adaptation for the different resin cements (p = .438). EDC presented better adaptation when compared to the groups treated with DW and CHI (p < .001), while the CHI and DW presented similar adaptation values (p = .365). No difference was observed in the perimeter referring to the gap areas for the different resin cements (p = .510). EDC showed a lower percentage of perimeters with gaps when compared to CHI (p < .001), with the percentage of perimeter with gaps of teeth treated with CHI being lower than DW (p < .001). A positive correlation coefficient equal to 0.763 was obtained between the perimeter with gaps and the adaptation data of the adhesive interface (p < .001). EDC resulted in better adaptation of the adhesive interface and a lower percentage of perimeters with gaps compared to chitosan.
Controlling the amount of coupling agents on the synthesis of coating antigens to enhance the sensitivity of fluoroquinolone immunodetection.
作者: Xiangning Han ; Chang Liu ; Xinping Guo ; Jianxin Sui ; Hong Lin ; Xiangfeng Chen ; Limin Cao
There is now increasing demand to improve the sensitivity of various immunoassays for fluoroquinolones (FQs) and other food hazards. In this study, different coating antigens were prepared by adjusting the content of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) to explore its influence on the immunoassay sensitivity of FQs. The results indicated that, unlike traditional assumptions, a reasonable EDC dosage should be addressed to reach the best analytical efficiency, and excessive EDC could enhance the hapten-carrier conjugation but significantly reduce the detection sensitivity. For the FQs investigated, the hapten:EDC:BSA proportion of 20:2.5:50 (Mole ratio:74:34:1) seemed the best for preparation of coating antigens, and the sensitivity could be improved more than 1000 times both for indirect competitive enzyme linked immunosorbent assay ELISA (ic-ELISA) and gold immunochromatography assay (GICA) due to two key factors including coupling-ratios and amide bond groups. Such an improved efficiency was also validated well with different food samples, which indicated the reasonable optimization of EDC in coating antigen synthesis may be widely used as a new, simple and more effective strategy to improve the immunoassay for low molecular targets in medical, environment and food detection filed.
Engineers are developing a cutting-edge process that can reduce energy consumption and cost of water desalination.
Vanderbilt researchers are part of a team that has developed a cutting-edge method that seeks to make the removal of salt from hypersaline industrial wastewater far more energy-efficient and cost-effective.
While desalination through reverse osmosis has made tremendous strides -- allowing for salt removal from seawater for less than a penny per gallon -- it still falls short in eliminating saline in wastewater from industries like mining, oil and gas and power generation and in inland brackish water. The industrial brines are currently injected into deep geological formations or transferred to a evaporation ponds, and both disposal methods are facing more regulatory and environmental challenges.
Zero liquid discharge and minimal liquid discharge, which use engineered treatment systems to eliminate brines or minimize brine volume, are already required in some countries for certain industries, and they are expected to become more widely adopted soon. Current ZLD/MLD treatments typically involve a technology called mechanical vapor compression, which generates heat from electricity to evaporate brines until the salt is all that remains. Because of the high capital and operating costs of MVC, these processes are unaffordable to many users.
Associate professor of civil and environmental engineering and 2023 Chancellor Faculty Fellow Shihong Lin and his team, including researchers from Colorado State University, believe they have an answer to this dilemma.
In a paper featured on the cover of the June 2023 issue of the journal Nature Water, Lin and his colleagues describe a novel brine treatment technology called electrodialytic crystallization that has the potential to reduce the energy consumption and cost of brine crystallization. The fundamental principle of EDC, according to the researchers, is like electrodialysis, a process that has been used in various industries for desalination and brine concentration.
In ED, an electric field is applied to pull ions through ion exchange membranes. By placing different types of IEMs in a certain way, ED can produce streams of deionized water and streams of concentrated brine. With some configuration changes to that process, the researchers say EDC keeps the brine within the integrated system and uses an electric field to induce salt crystallization without using costly evaporation methods.
"The elimination of evaporation is the key to developing potentially energy efficient brine crystallization processes," according to the paper.
One major technical challenge is that when certain ions transport through the IEMs, they drag too much water across and reduce the effectiveness of the process in concentrating the brine stream. This phenomenon, called electro-osmosis, prevents some salts from being crystallized out effectively. The researchers said that better membrane design and optimized operation can potentially address this challenge and make EDC more universally applicable.
Nevertheless, for the salts that EDC can handle, the team performed a preliminary analysis and showed that EDC coupled with reverse osmosis can potentially consume much less energy than MVC for brine crystallization.
Earlier this year, Lin, who is also associate professor of chemical and biomolecular engineering, was awarded a Walter L. Huber Civil Engineering Research Prize by the American Society of Civil Engineers for his contributions to the field of water separation and resource sustainability.
FORT WORTH, Texas--(
)--Alcon (SIX/NYSE: ALC), the global leader in eye care dedicated to helping people see brilliantly, will once again have the largest surgical ophthalmic presence at the American Society of Cataract and Refractive Surgery (ASCRS) 2023 Annual Meeting, taking place May 5-8 in San Diego. The company is proud to have the benefits of its innovations featured in more studies than ever in its history.
Alcon will showcase product updates that drive efficiencies for ophthalmologists and staff, and host events with surgeons sharing their real-world experiences. Alcon ASCRS event information and registration is available at
“The pace of innovation happening across eye care is extraordinary, and as the industry leader, we are excited to be leading the charge at ASCRS 2023,” said Sergio Duplan, President, North America at Alcon. “As a testament to our commitment to groundbreaking research and innovation, we’re excited to have a significant presence at ASCRS that underscores how our products are changing the lives of patients and surgeons alike.”
Clinical studies continue to demonstrate benefits of Clareon
Collection of intraocular lenses (IOLs).
A study from Micheletti et. al. evaluates a head-to-head comparison of distance and intermediate vision of Clareon monofocal IOL and TECNIS Eyhance* monofocal IOL. The study concludes that Clareon monofocal IOLs provided excellent distance and comparable intermediate vision that was non-inferior to TECNIS Eyhance monofocal IOLs.
Dr. J. Morgan Micheletti will be presenting his full findings on May 6 from 11:09-11:14 a.m., during the “Cataract IOLs-Monofocal/Extended Depth of Focus II session,” Upper Level, Room 4.
Additional data on Alcon IOLs will be presented, including:
Prospective Analysis of PanOptix
Satisfaction and Higher Order Aberrations in Patients with Prior Myopic Laser Vision Correction, Presented by Dr. Brett H. Mueller II (May 6, 9:05-9:10 a.m.)
Evaluation of Refractive Stability and Binocular Visual Acuity in a New Monofocal Hydrophobic Acrylic Intraocular Lens, Presented by Dr. Clayton Blehm (May 6, 1:45-1:50)
Biometer is now connected to NGENUITY
1.5, enabling surgeons to conduct 3D digital image-guided cataract surgery, increasing workflow efficiency and precision.
ARGOS biometry measurements and images can now be imported to NGENUITY 1.5, enabling cataract surgeons to precisely overlay incision location, capsulorhexis, IOL centration and toric alignment.
Now available in the U.S., the open-platform NGENUITY 1.5 offers superior visualization
and includes usability, color, contrast and magnification enhancements.
NGENUITY 1.5 will be featured at Alcon Booth #2111.
Data will be presented at ASCRS demonstrating how surgeons benefit from using ARGOS and NGENUITY in their practices:
Comparison Trial Evaluating Axial Lengths and Predicted Spherical Equivalents of Three Biometers, Presented by Dr. Sam Multack (Electronic Poster)
Comparing Refractive Outcomes of a Swept-Source Optical Coherence Tomography Biometer and an Optical Low Coherence Reflectometry Biometer, Presented by Dr. Clayton G. Blehm (May 6, 3:35-3:40 p.m.)
Development of Phototoxic Maculopathy as a Function of Coaxial Illumination Intensity in Diabetic Patients at the Time of Cataract Surgery, Presented by Lopa S Shah (May 6, 4:20-4:25 p.m.)
New data on the Hydrus
Microstent reinforce significant intraocular pressure (IOP) reduction in glaucoma patients with higher baseline IOP compared to those who receive cataract surgery alone.
Dr. Cathleen McCabe will present these new findings from a randomized, controlled clinical trial on May 6 from 2:27-2:32 p.m. These new findings are derived from the HORIZON 5-year trial results
which had previously demonstrated that the Hydrus Microstent offers long-term glaucoma medication reduction and reduction of IOP.
Surgeons can learn more about the Hydrus Microstent and Alcon pharmaceutical glaucoma products at booth #2111.
Additional data supporting Alcon innovation in cataract glaucoma patients include:
Clinical Outcomes of a Non-Diffractive Extended Depth-of-Focus IOL in Eyes with Glaucoma, Presented by Dr. Tanner J. Ferguson (May 6, 8:00-8:05 a.m.)
Visual Performance of a Trifocal IOL in Subjects with Open-Angle Glaucoma Undergoing Concurrent Minimally Invasive Glaucoma Surgery, Presented by Dr. Steven D. Vold (May 6, 1:50-1:55 p.m.)
Evidence supports that phacoemulsification in cataract
surgery with CENTURION
Vision System with ACTIVE SENTRY
allows surgeons to operate at a more physiological IOP
with excellent anterior chamber stability and surgical efficiency.
A study by Vaishali Vasavada showed that rise of IOP to baseline following occlusion break response was faster with ACTIVE SENTRY handpiece as compared to traditional handpiece when using the CENTURION Vision System.
The full study will be presented on Sunday, May 7 at 1:45 pm.
Additional data on CENTURION with ACTIVE SENTRY include:
Improved Surgical Times Using Active Sentry™ Hand Piece on the Centurion™ Cataract System, a Randomized Controlled Trial, Presented by Julio Echegoyen, MD, ABO (On-Demand Electronic Poster, May 5, 8:05-8:10 p.m.)
Surge and Capsule Dynamics during Phacoemulsification using an Adjustable Compliance Mechanical Eye Model, Presented by Dr. Jaime Zacharias (May 7, 4:45-4:50 p.m.)
Evaluation of Early Changes of the Anterior Vitreous Interface after Cataract Surgery, Using Low-Pressure Settings Determined by OCT, Presented by Hugo A. Scarfone, MD; Emilia Carolina C. Rodriguez, MD (May 6, 8:05-8:10 a.m.)
Additional educational opportunities and experiences for surgeons will be available at the Alcon booth #2111. For information on Alcon events and news at ASCRS, please visit
IOLs and Delivery Systems
The family of Clareon
intraocular lenses (IOLs) includes the Clareon
Aspheric Hydrophobic Acrylic and Clareon
Aspheric Toric IOLs, the Clareon
Trifocal Hydrophobic IOL, Clareon PanOptix
Toric, Clareon Vivity
Extended Vision Hydrophobic Posterior Chamber IOL and Clareon
Toric IOLs. Each of these IOLs is indicated for visual correction of aphakia in adult patients following cataract surgery. In addition, the Clareon
Toric IOLs are indicated to correct pre-existing corneal astigmatism at the time of cataract surgery. The Clareon
lens mitigates the effects of presbyopia by providing improved intermediate and near visual acuity while maintaining comparable distance visual acuity with a reduced need for eyeglasses, compared to a monofocal IOL. The Clareon
lens mitigates the effects of presbyopia by providing an extended depth of focus. Compared to an aspheric monofocal IOL, the lens provides improved intermediate and near visual acuity while maintaining comparable distance visual acuity. All of these IOLs are intended for placement in the capsular bag. Careful preoperative evaluation and sound clinical judgment should be used by the surgeon to decide the risk/benefit ratio before implanting any IOL in a patient with any of the conditions described in the Directions for Use that accompany each IOL. Prior to surgery, physicians should provide prospective patients with a copy of the Patient Information Brochure available from Alcon, informing them of possible risks and benefits associated with these IOLs. Reference the Directions for Use labelling for each IOL for a complete listing of indications, warnings and precautions.
Biometer with Image Guidance
is a non-invasive, non-contact biometer based on Swept-Source Optical Coherence Tomography (SS-OCT). The device is intended to acquire ocular measurements as well as perform calculations to determine the appropriate intraocular lens (IOL) power and type for implantation during intraocular lens placement. Please refer to the ARGOS
User Manual for a complete description of proper use and maintenance, optical and technical specifications, as well as a complete list of warnings and precautions.
3D Visualization System
3D Visualization System consists of a 3D stereoscopic, high-definition digital video camera and workstation to provide magnified stereoscopic images of objects during micro-surgery. It acts as an adjunct to the surgical microscope during surgery displaying real-time images or images from recordings. Please refer to the User Manual for a complete list of appropriate uses, warnings and precautions.
Roughly the size of an eyelash, the Hydrus
Microstent is a next-generation MIGS device designed to reduce eye pressure by reestablishing flow through Schlemm's canal, the eye's natural outflow pathway. When placed in the canal during minimally invasive microsurgery, the device restores the flow of fluid in the eye, using a Tri-Modal
mechanism of action: the Hydrus
Microstent dilates and scaffolds Schlemm's canal to augment outflow of aqueous humor from the anterior chamber. It maintains an opening through the trabecular meshwork from the anterior chamber into Schlemm's canal. Its length spans approximately 90 degrees of the canal to provide consistent access to multiple fluid collector channels in the eye. Approved by the FDA in August 2018 for use in conjunction with cataract surgery, the Hydrus
Microstent is one of the most rigorously researched and thoroughly studied MIGS devices.
Vision System with ACTIVE SENTRY
Vision System with ACTIVE SENTRY
is indicated for emulsification, separation, irrigation, and aspiration of cataracts, residual cortical material and lens epithelial cells, vitreous aspiration and cutting associated with anterior vitrectomy, bipolar coagulation, and intraocular lens injection. Appropriate use of CENTURION
Vision System parameters and accessories is important for successful procedures. Please refer to the CENTURION
Operator’s Manual for a complete description of proper use and maintenance, as well as a complete list of contraindications, warnings and precautions.
Alcon helps people see brilliantly. As the global leader in eye care with a heritage spanning over 75 years, we offer the broadest portfolio of products to enhance sight and improve people’s lives. Our Surgical and Vision Care products touch the lives of more than 260 million people in over 140 countries each year living with conditions like cataracts, glaucoma, retinal diseases and refractive errors. Our more than 25,000 associates are enhancing the quality of life through innovative products, partnerships with Eye Care Professionals and programs that advance access to quality eye care. Learn more at
* Trademarks are the property of their respective owners.
** Compared to analog microscopes, including the Leica Proveo 8 and Zeiss OPMI LUMERA® 700 scopes.
† Specified performance was achieved at maximum system magnification with an aperture setting of 30% open and viewing distance of 1.2 meters.
Alcon Data on File.
Micheletti JM, Duncan N, Hall B. Head-to-Head Comparison of Intermediate Vision of Two Monofocal Intraocular Lenses. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
1.5 3D Visualization System User Manual.
Berquet F, Henry A, Barbe C, et al. Comparing heads-up versus binocular microscope visualization systems in anterior and posterior segment surgeries: a retrospective study. Ophthalmologica. 2020;243(5):347-354.
Alcon Data on File.
Mouro-Coelho N, Nascimento J, Henriques J, Medeiros MD. Three-dimensional display systems in ophthalmic surgery – a review. European Ophthalmic Review. 2019;13(1):31-36.
Tamaoki A, Kojima T, Hasegawa A, et al. Clinical evaluation of a new swept-source optical coherence biometer that uses individual refractive indices to measure axial length in cataract patients. Ophthalmic Res. 2019;19:1-13.
Shammas HJ, Ortiz S, Shammas MC, et al. Biometry measurements using a new large-coherence-length swept-source optical coherence tomographer. J Cataract Refract Surg. 2016;42:50-61.
Mueller BH, Saenz B, Parkhurst GD, Welburn KR. Prospective Analysis of Panoptix Satisfaction and Higher Order Aberrations in Patients with Prior Myopic Laser Vision Correction. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Blehm Clayton G. Evaluation of Refractive Stability and Binocular Visual Acuity in a New Monofocal Hydrophobic Acrylic Intraocular Lens. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Multack Sam. Comparison Trial Evaluating Axial Lengths and Predicted Spherical Equivalents of Three Biometers. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Blehm Clayton G. Comparing Refractive Outcomes of a Swept-Source Optical Coherence Tomography Biometer and an Optical Low Coherence Reflectometry Biometer. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Lopa SS, Rosenberg E. Development of Phototoxic Maculopathy as a Function of Coaxial Illumination Intensity in Diabetic Patients at the Time of Cataract Surgery. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
McCabe Cathleen M. Increase in High Level IOP Reduction with a Schlemm’s Canal Microstent: Outcomes from a Randomized, Controlled Clinical Trial. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Ferguson TJ, Wilson CW, Shafer BM, Berdahl JP, et al. Clinical Outcomes of a Non-Diffractive Extended Depth-of-Focus IOL in Eyes with Glaucoma. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Vold SD, McFarland MR. Visual Performance of a Trifocal IOL in Subjects with Open-Angle Glaucoma Undergoing Concurrent Minimally Invasive Glaucoma Surgery. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Vasavada V, et. al. Comparison of Intraoperative Performance, Intraocular Pressure and Postoperative Outcomes during Cataract Surgery with Three Fluidic Systems. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Echegoyen Julio. Improved Surgical Times Utilizing Fluidic Analysis at the Eye Level, A Randomized Controlled Trial. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Zacharias J, Berthet N, Orellana D. Surge and Capsule Dynamics during Phacoemulsification using an Adjustable Compliance Mechanical Eye Mode. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
Scarfone HA, Rodriguez Emilia CC. Evaluation of Early Changes of the Anterior Vitreous Interface After Cataract Surgery, Using Low-Pressure Settings Determined By OCT. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting; May 5-8, 2023; San Diego, CA, USA.
This press release contains “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as: “anticipate,” “intend,” “commitment,” “look forward,” “maintain,” “plan,” “goal,” “seek,” “believe,” “project,” “estimate,” “expect,” “strategy,” “future,” “likely,” “may,” “should,” “will” and similar references to future periods.
Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based only on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, and other future conditions. Because forward-looking statements relate to the future, they are subject to inherent uncertainties and risks that are difficult to predict. Some of these factors are discussed in our filings with the United States Securities and Exchange Commission, including our Form 20-F. Should one or more of these uncertainties or risks materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those anticipated. Therefore, you should not rely on any of these forward-looking statements.
Forward-looking statements in this press release speak only as of the date of its filing, and we assume no obligation to update forward-looking statements as a result of new information, future events or otherwise.
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Fathers exposed to chemicals in plastics can affect the metabolic health of their offspring for two generations, a mouse study reports.
Fathers exposed to chemicals in plastics can affect the metabolic health of their offspring for two generations, a University of California, Riverside, mouse study reports.
Plastics, which are now ubiquitous, contain endocrine disrupting chemicals, or EDCs, that have been linked to increased risk of many chronic diseases; parental exposure to EDCs, for example, has been shown to cause metabolic disorders, including obesity and diabetes, in the offspring.
Most studies have focused on the impact of maternal EDC exposure on the offspring's health. The current study, published in the journal Environment International, focused on the effects of paternal EDC exposure.
Led by Changcheng Zhou, a professor of biomedical sciences in the School of Medicine, the researchers investigated the impact of paternal exposure to a phthalate called dicyclohexyl phthalate, or DCHP, on the metabolic health of first generation (F1) and second generation (F2) offspring in mice. Phthalates are chemicals used to make plastics more durable.
The researchers found that paternal DCHP exposure for four weeks led to high insulin resistance and impaired insulin signaling in F1 offspring. The same effect, but weaker, was seen in F2 offspring.
"We found paternal exposure to endocrine disrupting phthalates may have intergenerational and transgenerational adverse effects on the metabolic health of their offspring," Zhou said. "To the best of our knowledge, our study is the first to demonstrate this."
In the case of paternal exposure in the study, intergenerational effects are changes that occur due to direct exposure to a stressor, such as exposure to DCHP of fathers (F0 generation) and his developing sperm (F1 generation). Transgenerational effects are changes passed down to offspring that are not directly exposed to the stressor (for example, F2 generation).
Zhou's team focused on sperm, specifically, its small-RNA molecules that are responsible for passing information down generations. The researchers used "PANDORA-seq method," an innovative method that showed DCHP exposure can lead to small-RNA changes in sperm. These changes are undetected by traditional RNA-sequencing methods, which lack the comprehensive overview of the small-RNA pro PANDORA-seq provides.
The study used only F1 males to breed with unexposed female mice to generate F2 offspring. The team found that paternal DCHP exposure induced metabolic disorders, such as impaired glucose tolerance, in both male and female F1 offspring, but these disorders were seen only in female F2 offspring. The study did not examine F3 offspring.
"This suggests that paternal DCHP exposure can lead to sex-specific transgenerational effects on the metabolic health of their progenies," Zhou said. "At this time, we do not know why the disorders are not seen in male F2 offspring."
Zhou stressed that the impact of exposure to DCHP on human health is not well understood, even though DCHP is widely used in a variety of plastic products and has been detected in food, water, and indoor particulate matter. DCHP has also been found in human urinary and blood samples. Indeed, the U.S. Environmental Protection Agency recently designated DCHP as one of 20 high-priority substances for risk evaluation.
"It's best to minimize our use of plastic products," Zhou said. "This can also help reduce plastic pollution, one of our most pressing environmental issues."
Zhou, whose earlier mouse study showed exposure to DCHP leads to increased plasma cholesterol levels, was joined in the current study by Jingwei Liu, Junchao Shi, Rebecca Hernandez, Xiuchun Li, Pranav Konchadi, Yuma Miyake, and Qi Chen of UCR; and Tong Zhou of University of Nevada, Reno School of Medicine.
The study was partially supported by grants from the National Institutes of Health and American Heart Association. Hernandez was supported by a National Institutes of Health training grant and an American Heart Association predoctoral fellowship.