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http://hdl.handle.net/2115/56843
2024-03-29T09:09:35ZProving that a genome-edited organism is not GMO
http://hdl.handle.net/2115/89196
Title: Proving that a genome-edited organism is not GMO
Authors: Ishii, Megumi; Ishii, Tetsuya
Abstract: A genome-edited agricultural product that is proven to contain no exogenous DNA is not subject to genetically modified organism (GMO) regulations in some countries. However, whether such proof is definitive is often disputed. We discuss the approaches to substantially proving that a genome-edited organism is not GMO, while considering social aspects.2022-04-30T15:00:00ZIshii, MegumiIshii, TetsuyaA genome-edited agricultural product that is proven to contain no exogenous DNA is not subject to genetically modified organism (GMO) regulations in some countries. However, whether such proof is definitive is often disputed. We discuss the approaches to substantially proving that a genome-edited organism is not GMO, while considering social aspects.Shifting to a model of donor conception that entails a communication agreement among the parents, donor, and offspring
http://hdl.handle.net/2115/84766
Title: Shifting to a model of donor conception that entails a communication agreement among the parents, donor, and offspring
Authors: Ishii, Tetsuya; de Miguel Beriain, Iñigo
Abstract: Background Some persons conceived with donor gametes react negatively when they found their birth via donor conception. They request access to information about and seek to communicate with the donor. However, some countries mandate donor anonymity. Other countries allow donor-conceived persons to access donor information, but they can only use this access if their parents have disclosed donor conception to them. We investigated a thorny issue of donor conception: whether donor conception should be shifted from an anonymous basis to a non-anonymous basis. Methods We review the issues and concerns regarding donor conception. We then consider the impact of direct-to-consumer genetic testing on donor conception, as well as the influence of donor conception on offspring’s identity and the potential of different types of donors. To discuss the future policy of donor conception, the policies on the anonymity of gamete donors were investigated using publicly-available documents in 15 countries. Results The aim of mandating donor anonymity is to protect the privacy of the donor and intended parents. However, the diffusion of direct-to-consumer genetic testing may make it impossible to maintain anonymity. Birth via donor conception shapes the offspring’s identity, and the donor may further influence the development of offspring’s identity through communications. It remains important to disclose donor conception to donor-conceived offspring and to provide them with donor information. However, that information might be insufficient for some donor-conceived persons. Here are benefits to having open-identity donors and known donors. Such donors can make an agreement with the parents regarding future communication with the offspring, although both sides should respect privacy. Subsequent counseling for all parties involved can result in better tripartite communication agreements. Conclusions In sum, ethical and practical issues that complicate donor anonymity are driving a shift to non-anonymous donor conception, in which all parties come to a communication agreement. To pave the way for such a donor conception system, transitional measures can be put into place. For countries that already adopted non-anonymous donor conception, ensuring the communication agreements is important to protect the rights of parents, donor, and offspring.2022-03-03T15:00:00ZIshii, Tetsuyade Miguel Beriain, IñigoBackground Some persons conceived with donor gametes react negatively when they found their birth via donor conception. They request access to information about and seek to communicate with the donor. However, some countries mandate donor anonymity. Other countries allow donor-conceived persons to access donor information, but they can only use this access if their parents have disclosed donor conception to them. We investigated a thorny issue of donor conception: whether donor conception should be shifted from an anonymous basis to a non-anonymous basis. Methods We review the issues and concerns regarding donor conception. We then consider the impact of direct-to-consumer genetic testing on donor conception, as well as the influence of donor conception on offspring’s identity and the potential of different types of donors. To discuss the future policy of donor conception, the policies on the anonymity of gamete donors were investigated using publicly-available documents in 15 countries. Results The aim of mandating donor anonymity is to protect the privacy of the donor and intended parents. However, the diffusion of direct-to-consumer genetic testing may make it impossible to maintain anonymity. Birth via donor conception shapes the offspring’s identity, and the donor may further influence the development of offspring’s identity through communications. It remains important to disclose donor conception to donor-conceived offspring and to provide them with donor information. However, that information might be insufficient for some donor-conceived persons. Here are benefits to having open-identity donors and known donors. Such donors can make an agreement with the parents regarding future communication with the offspring, although both sides should respect privacy. Subsequent counseling for all parties involved can result in better tripartite communication agreements. Conclusions In sum, ethical and practical issues that complicate donor anonymity are driving a shift to non-anonymous donor conception, in which all parties come to a communication agreement. To pave the way for such a donor conception system, transitional measures can be put into place. For countries that already adopted non-anonymous donor conception, ensuring the communication agreements is important to protect the rights of parents, donor, and offspring.Assignment of responsibility for creating persons using germline genome-editing
http://hdl.handle.net/2115/84764
Title: Assignment of responsibility for creating persons using germline genome-editing
Authors: Ishii, Tetsuya
Abstract: The 2018 announcement regarding safe childbirths via germline genome-editing (GGE) with parental consent shocked the world. This minireview examines the predictable risks, burdens, and potential harms of human GGE and explores the question of responsibility for using GGE in human reproduction. Although there is currently no international consensus on proving the absence of harmful off-target mutations in the genome, preclinical GGE study can demonstrate the non-existence under specific conditions. Initially, the clinical application will be limited to small studies without controls. In any case, individuals born via GGE should be followed up for long period. However, such persons can decline follow-up. Due to limited screening, an overlooked off-target mutation may harm the entire body. Some persons suffering such harm might claim damages on the ground that their life is less valuable. However, most jurisdictions will reject such claims. Practitioners are responsible for proving there are no harmful off-target mutations in each GGE case, although the appropriateness of proof is currently difficult to accept. Parents who consented to GGE, as well as practitioners, assume responsibility for the safety of genome-edited offspring; however, the fulfillment of responsibility ultimately depends on the offspring's autonomy. Meanwhile, practitioners and parents may be exempt from some damage claims by offspring harmed by unsafe GGE. The uncertainty of assigning responsibility may underpin GGE's prohibition in light of the unacceptable risks, burdens and potential harms for persons born via GGE; or it may oppositely underpin its permission if an acceptable risk-benefit balance is reached for parents and society2021-05-28T15:00:00ZIshii, TetsuyaThe 2018 announcement regarding safe childbirths via germline genome-editing (GGE) with parental consent shocked the world. This minireview examines the predictable risks, burdens, and potential harms of human GGE and explores the question of responsibility for using GGE in human reproduction. Although there is currently no international consensus on proving the absence of harmful off-target mutations in the genome, preclinical GGE study can demonstrate the non-existence under specific conditions. Initially, the clinical application will be limited to small studies without controls. In any case, individuals born via GGE should be followed up for long period. However, such persons can decline follow-up. Due to limited screening, an overlooked off-target mutation may harm the entire body. Some persons suffering such harm might claim damages on the ground that their life is less valuable. However, most jurisdictions will reject such claims. Practitioners are responsible for proving there are no harmful off-target mutations in each GGE case, although the appropriateness of proof is currently difficult to accept. Parents who consented to GGE, as well as practitioners, assume responsibility for the safety of genome-edited offspring; however, the fulfillment of responsibility ultimately depends on the offspring's autonomy. Meanwhile, practitioners and parents may be exempt from some damage claims by offspring harmed by unsafe GGE. The uncertainty of assigning responsibility may underpin GGE's prohibition in light of the unacceptable risks, burdens and potential harms for persons born via GGE; or it may oppositely underpin its permission if an acceptable risk-benefit balance is reached for parents and societySafety of Germline Genome Editing for Genetically Related "Future" Children as Perceived by Parents
http://hdl.handle.net/2115/76474
Title: Safety of Germline Genome Editing for Genetically Related "Future" Children as Perceived by Parents
Authors: Ishii, Tetsuya; Beriain, Inigo de Miguel
Abstract: The social acceptability of germline genome editing (GGE) depends on its perceived safety, as well as respect for reproductive autonomy. However, it is doubtful that prospective parents sufficiently understand the risks of GGE. In the future, the use of GGE in specific situations seems plausible, as it offers couples potential means to safeguard genetically related future children from a serious disease and overcome infertility due to a gene mutation. Should GGE fail, however, some couples may be obliged to abort affected fetuses, or give birth to adversely affected children, which would be a tragedy. Some children might develop diseases later in life due to overlooked off-target mutations. Compounding this, some parents are unlikely to inform their offspring about the details of conception, hampering necessary follow-up. Prospective parents, scientists and policy makers should carefully discuss the safety implications of GGE for genetically related future children.2019-11-30T15:00:00ZIshii, TetsuyaBeriain, Inigo de MiguelThe social acceptability of germline genome editing (GGE) depends on its perceived safety, as well as respect for reproductive autonomy. However, it is doubtful that prospective parents sufficiently understand the risks of GGE. In the future, the use of GGE in specific situations seems plausible, as it offers couples potential means to safeguard genetically related future children from a serious disease and overcome infertility due to a gene mutation. Should GGE fail, however, some couples may be obliged to abort affected fetuses, or give birth to adversely affected children, which would be a tragedy. Some children might develop diseases later in life due to overlooked off-target mutations. Compounding this, some parents are unlikely to inform their offspring about the details of conception, hampering necessary follow-up. Prospective parents, scientists and policy makers should carefully discuss the safety implications of GGE for genetically related future children.Mitochondrial replacement techniques and Mexico's rule of law : on the legality of the first maternal spindle transfer case
http://hdl.handle.net/2115/68152
Title: Mitochondrial replacement techniques and Mexico's rule of law : on the legality of the first maternal spindle transfer case
Authors: Ishii, Tetsuya2017-05-08T15:00:00ZIshii, Tetsuya断層画像再構成の基礎 : フィルタ補正逆投影法と逐次近似法
http://hdl.handle.net/2115/65123
Title: 断層画像再構成の基礎 : フィルタ補正逆投影法と逐次近似法
Authors: 久保, 直樹2017-04-13T15:00:00Z久保, 直樹Germ line genome editing in clinics: the approaches, objectives and global society
http://hdl.handle.net/2115/65116
Title: Germ line genome editing in clinics: the approaches, objectives and global society
Authors: Ishii, Tetsuya
Abstract: Genome editing allows for the versatile genetic modification of somatic cells, germ cells and embryos. In particular, CRISPR/ Cas9 is worldwide used in biomedical research. Although the first report on Cas9-mediated gene modification in human embryos focused on the prevention of a genetic disease in offspring, it raised profound ethical and social concerns over the safety of subsequent generations and the potential misuse of genome editing for human enhancement. The present article considers germ line genome editing approaches from various clinical and ethical viewpoints and explores its objectives. The risks and benefits of the following three likely objectives are assessed: the prevention of monogenic diseases, personalized assisted reproductive technology (ART) and genetic enhancement. Although genetic enhancement should be avoided, the international regulatory landscape suggests the inevitability of this misuse at ART centers. Under these circumstances, possible regulatory responses and the potential roles of public dialogue are discussed.2016-12-31T15:00:00ZIshii, TetsuyaGenome editing allows for the versatile genetic modification of somatic cells, germ cells and embryos. In particular, CRISPR/ Cas9 is worldwide used in biomedical research. Although the first report on Cas9-mediated gene modification in human embryos focused on the prevention of a genetic disease in offspring, it raised profound ethical and social concerns over the safety of subsequent generations and the potential misuse of genome editing for human enhancement. The present article considers germ line genome editing approaches from various clinical and ethical viewpoints and explores its objectives. The risks and benefits of the following three likely objectives are assessed: the prevention of monogenic diseases, personalized assisted reproductive technology (ART) and genetic enhancement. Although genetic enhancement should be avoided, the international regulatory landscape suggests the inevitability of this misuse at ART centers. Under these circumstances, possible regulatory responses and the potential roles of public dialogue are discussed.Consumer acceptance of food crops developed by genome editing
http://hdl.handle.net/2115/64971
Title: Consumer acceptance of food crops developed by genome editing
Authors: Ishii, Tetsuya; Araki, Motoko
Abstract: One of the major problems regarding consumer acceptance of genetically modified organisms (GMOs) is the possibility that their transgenes could have adverse effects on the environment and/or human health. Genome editing, represented by the CRISPR/Cas9 system, can efficiently achieve transgene-free gene modifications and is anticipated to generate a wide spectrum of plants. However, the public attitude against GMOs suggests that people will initially be unlikely to accept these plants. We herein explored the bottlenecks of consumer acceptance of transgene-free food crops developed by genome editing and made some recommendations. People should not pursue a zero-risk bias regarding such crops. Developers are encouraged to produce cultivars with a trait that would satisfy consumer needs. Moreover, they should carefully investigate off-target mutations in resultant plants and initially refrain from agricultural use of multiplex genome editing for better risk-benefit communication. The government must consider their regulatory status and establish appropriate regulations if necessary. The government also should foster communication between the public and developers. If people are informed of the benefits of genome editing-mediated plant breeding and trust in the relevant regulations, and if careful risk-benefit communication and sincere considerations for the right to know approach are guaranteed, then such transgene-free crops could gradually be integrated into society.2016-06-30T15:00:00ZIshii, TetsuyaAraki, MotokoOne of the major problems regarding consumer acceptance of genetically modified organisms (GMOs) is the possibility that their transgenes could have adverse effects on the environment and/or human health. Genome editing, represented by the CRISPR/Cas9 system, can efficiently achieve transgene-free gene modifications and is anticipated to generate a wide spectrum of plants. However, the public attitude against GMOs suggests that people will initially be unlikely to accept these plants. We herein explored the bottlenecks of consumer acceptance of transgene-free food crops developed by genome editing and made some recommendations. People should not pursue a zero-risk bias regarding such crops. Developers are encouraged to produce cultivars with a trait that would satisfy consumer needs. Moreover, they should carefully investigate off-target mutations in resultant plants and initially refrain from agricultural use of multiplex genome editing for better risk-benefit communication. The government must consider their regulatory status and establish appropriate regulations if necessary. The government also should foster communication between the public and developers. If people are informed of the benefits of genome editing-mediated plant breeding and trust in the relevant regulations, and if careful risk-benefit communication and sincere considerations for the right to know approach are guaranteed, then such transgene-free crops could gradually be integrated into society.障害を防止し安全を確保することを見据えた画像技術
http://hdl.handle.net/2115/64806
Title: 障害を防止し安全を確保することを見据えた画像技術
Authors: 久保, 直樹2015-09-30T15:00:00Z久保, 直樹Collimator for Variable Sensitivity and Spatial Resolution Without the Need for Exchange
http://hdl.handle.net/2115/64691
Title: Collimator for Variable Sensitivity and Spatial Resolution Without the Need for Exchange
Authors: Kubo, Naoki; Tsuchiya, Katsutoshi; Shiga, Tohru; Kojima, Shinichi; Suzuki, Atsuro; Ueno, Yuichiro; Kobashi, Keiji; Tamaki, Nagara
Abstract: A new design of collimator is proposed that has variable sensitivity and spatial resolution, eliminating the need for exchanging collimators in a gamma camera. Using Monte Carlo simulations, the present article evaluates the shielding of undesirable gamma rays in a parallel-hole collimator. It consists of a number of layers of rectangular holes. These layers consist of alternately stacked fixed and movable collimators. In high-resolution mode, the movable collimators are shifted by half the aperture pitch along the diagonal direction. The first collimator (type A) has 50 layers with fixed thicknesses of 1.2 mm. The second collimator (type B) has 25 layers with a thickness of 1.0 mm on the object side and 25 layers with a thickness of 1.4 mm on the opposite side. The third collimator (type C) has 20 layers with non-uniform thicknesses. The ratios of the maximum artificial peak to the main-peak are calculated for point-source responses. The ratios for types A, B, and C collimators are 0.78, 0.08, and 0.03, respectively. The same performance for shielding undesirable gamma rays is achieved in the type C collimator as for a conventional collimator.2014-08-07T15:00:00ZKubo, NaokiTsuchiya, KatsutoshiShiga, TohruKojima, ShinichiSuzuki, AtsuroUeno, YuichiroKobashi, KeijiTamaki, NagaraA new design of collimator is proposed that has variable sensitivity and spatial resolution, eliminating the need for exchanging collimators in a gamma camera. Using Monte Carlo simulations, the present article evaluates the shielding of undesirable gamma rays in a parallel-hole collimator. It consists of a number of layers of rectangular holes. These layers consist of alternately stacked fixed and movable collimators. In high-resolution mode, the movable collimators are shifted by half the aperture pitch along the diagonal direction. The first collimator (type A) has 50 layers with fixed thicknesses of 1.2 mm. The second collimator (type B) has 25 layers with a thickness of 1.0 mm on the object side and 25 layers with a thickness of 1.4 mm on the opposite side. The third collimator (type C) has 20 layers with non-uniform thicknesses. The ratios of the maximum artificial peak to the main-peak are calculated for point-source responses. The ratios for types A, B, and C collimators are 0.78, 0.08, and 0.03, respectively. The same performance for shielding undesirable gamma rays is achieved in the type C collimator as for a conventional collimator.