• Users Online: 100
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts LOGIN

 Table of Contents  
CONFERENCE ABSTRACT
Year : 2016  |  Volume : 1  |  Issue : 1  |  Page : 10-15

AFRH Conference 2015 Abstracts


Date of Web Publication7-Sep-2016

Correspondence Address:
Login to access the Email id

Source of Support: None, Conflict of Interest: None


Rights and PermissionsRights and Permissions

How to cite this article:
. AFRH Conference 2015 Abstracts. Afr J Infertil Assist Concept 2016;1:10-5

How to cite this URL:
. AFRH Conference 2015 Abstracts. Afr J Infertil Assist Concept [serial online] 2016 [cited 2023 Mar 24];1:10-5. Available from: https://www.afrijiac.org/text.asp?2016/1/1/10/189962

Over three and half decades ago, assisted reproduction by way of in vitro fertilization (IVF) produced its first success in the world, and about 10 years later, Sub-Saharan Africa recorded its first. Over the years, assisted reproductive techniques including IVF and embryo transfer have assumed growing importance clinically and economically. They have also offered tangible hope to infertile couples in providing a means of ending their personal tragedy of childlessness.

Unfortunately, while many other countries of the world have developed concrete laws and policies regulating IVF practice, Nigeria has lagged behind in this critical area in spite of the complex existential, ethical, and legal issues that bedevil the intrusion of human agents into the "creation" of persons. A previous attempt at enacting the "Assisted Reproduction Authority Bill, 2012" did not succeed and the ensuing lacuna remains patently undesirable. This lack of specific, directly enforceable, and readily available legal provisions guiding practice has led to unstandardized and incomparable practice methods and voluntary self-regulation, which have left practitioners unattended and made patients vulnerable in the event of harm. Nevertheless, the recent enactment of the National Health Act (2014) has attempted to remedy this deficiency in IVF practice albeit in an unsatisfactory manner.

This paper addressed the specific provisions of the National Health Act (2014), which relate to the manipulation of genetic material in general and reproductive genetic material in particular. It also examined the limits of powers granted to the minister for health and the National Council on Health, which have direct bearing on the regulation of assisted reproductive techniques in Nigeria. Furthermore, it considered the role of statutory regulatory bodies such as the Medical and Dental Council of Nigeria in creating a framework for IVF regulation in the country. Finally, the paper provided relevant recommendations that will address areas of deficiency identified in the act and highlight important lessons that may be learned from the regulatory frameworks of other countries worldwide.

How a bill becomes a law in Nigeria

Alkali Umar Abubakar


National Assembly Clinic, National Assembly Complex Garki, Abuja, Nigeria

The practice of most professions is regulated by law. Laws are made through passage of bills by the legislature. The paper defines a bill and a law. It describes the origins and types of bills and then describes the legislative procedure that a bill has to pass through before it becomes a law in Nigeria. Finally, the paper seeks to describe how nongovernmental organizations (such as the AFRHN) can play a role in getting a bill passed into a law to regulate practice.

Stem cells and gametogenesis

Benedict E. Ekaidem


Fertility Unit, St. Ives Hospital, Lagos, Nigeria

Problems with gamete production constitute one of the leading causes of infertility, a major and growing global problem affecting 13 to 18% of reproductive-age couples. In the past few years, several reports have been published on generating germ cells from stem cells (SCs). SCs exposed to appropriate and specific conditions can differentiate into cell types of all three germ layers (endoderm, ectoderm, and mesoderm) and also into germline cells. This has raised speculations that SCs may have a potential role in reproductive medicine.

This paper presents useful definitions of SCs and gametogenesis in practice, brief SC history, sources and types, as well as the current state of in vitro differentiation to male gametes.

In conclusion, the use of such gametes in assisted reproductive technology remains a "distant prospect."

Genome and epigenome disorders and infertility: From gametes to miscarriage

Moncef Benkhalifa


Department of Reproductive Medicine and Genetics, Regional University Hospital Amiens, France

In reproductive pathology, the contribution of genome and epigenome defects such as chromosomes abnormalities, genes and/or metabolic disorder, and functional biology process misfit is very well documented as a main factor of assisted reproductive technology (ART) cycles failures. General survey showed in somatic genome a higher incidence of chromosomes and genes aberrations in infertile and subfertile couple than neonatal population.

In ART practice, gametes maturation and competency (genic and epigenetic levels) are mandatory for fertilization, early embryo cleavage, and development success. To assess, select, and predict the best gametes and embryo, cytological, cytogenetic, molecular techniques (karyotype, fluorescence in situ hybridization, polymerase chain reaction, and sequencing) or imaging methods are routinely applied since many years to investigate gametes, embryos quality, and development potential.

For example, in severe male infertility and intracytoplasmic sperm injection failure, the investigation of sperm genome decays (chromosome abnormalities, DNA fragmentation, and/or denaturation) and methylome changes testing can explain the potential contribution of the sperm on fertilization failure and embryo blocking. On parallel oocyte imaging, genome analysis and mitochondria functionality assessment can be helpful to predict metaphase II oocyte maturation, competency, and chromosome nondisjunction risks causing implantation failure and/or early miscarriages.

Preimplantation and prenatal genetic diagnosis is one of the major applications of genomics in ART to diagnose chromosome and genome integrity abnormalities or specific gene disorders to eliminate the worst embryo prior transfer to improve clinical pregnancy, miscarriages reduction, and taking home baby. In reproductive medicine and in vitro fertilization, nanogenomics and omes technologies (genomic, expression, or proteins arrays) will be an important clinical assay for genomics, transcriptomics, and proteomics testing.

The wide range of molecular methods are more and more required for advanced screening and diagnostic for better understanding of reproductive pathology causes to support the best strategy for clinical management.

Legal implications of third-party reproduction: A world view

James Henry Olobo-Lalobo


Paragon Fertility Centre, Kampala, Uganda

The combination of access, availability, and use of third-party sperm, eggs, embryos, and surrogate mothers coupled with the ramification of rights and responsibilities of the collaborators or players poses added complexities to fertility treatment. Given the complexity, a worldwide evaluation of the regulatory framework for third-party reproduction must be grounded on and driven by the need of the patient.

To gain validity, the patient-based evaluation of a particular national assisted reproductive technology (ART) regulation must question whether the regulation promotes the achievement of reproductive rights. Aware, restrictive legislation that stymies the desired and inherent right to create a family is unwanted burden.

The presentation used stakeholder analysis to identify the potential sources of sperm, egg, embryos, and surrogate mothers. Hope or expectation matrix was used to evaluate whether or not the patient's desire to found a family is likely to be achieved through that particular regulation. The key analysis indicators are availability, access, and quality of the third-party services that the patient needs to create a family.

Real case histories of ART regulation from around the globe will be used in the analysis. Input and reaction from the media, doctors, academia, and legal precedence from courts were presented in evidence.

The presentation concluded with how Uganda has used the "the good and the bad" in worldwide regulation as an opportunity to domesticate its ART regulation in support of rights to reproduction, which is enshrined in the Uganda Constitution.

In surrogacy: "Apply and enforce contract law and desist from re-inventing new legal wheels"

James Henry Olobo-Lalobo


Paragon Fertility Centre, Kampala, Uganda

In biblical days and in ancient Rome or classical Greek society, surrogacy was considered as a common sense remedy to childlessness. In contrast, in today's modern world, the legal response to surrogacy ranges from complete prohibition as in Italy, Austria, and Germany to total acceptance in California, Russia, Ukraine, and India.

Prohibitive or restrictive legislation is crippling to the achievement of reproductive rights of affected women. For example, the UK's 1985 Surrogacy Act bans commercial surrogacy and renders surrogacy agreement unenforceable. From a different angle, Thailand's 2015 knee-jerk surrogacy legislation in reaction to the abandonment, by an Australian couple of an abnormal twin, restricts surrogacy agreement between blood relatives only.

The presentation argues that the women who need a surrogate to found a family they would otherwise not have must not be allowed wither or to resort to medical tourism accessible only in countries with favorable legislation. The remedy must lie in contract law, mustn't it? In jurisdictions, the world over the law of contract contains clauses fit for the exchange of goods and services such as surrogacy agreement, doesn't it?

The experience of the labellisation of in vitro fertilization centers in speaking countries by GIERAF

Fiadjoe Moïse Kwasivi, Ernestine Gwetbell, Hervé Leclet


Clinique Biasa, Lomé, Togo

Established in 2009, the main objective of the GIERAF is to promote the treatment of infertility. The GIERAF is present in 12 French-speaking Sub-Saharan African countries.

In 2011, the board of the GIERAF (Inter African Group of Research and Application on Fertility) decided to set up a system of labellisation, a real tool of acknowledgement, a real tool of progress, a real tool of engagement of the centers.

Many arguments are in favor of this:

  • The strong development of assisted reproductive technology (ART) in Sub-Saharan Africa
  • The will to promote quality work
  • The need to used structured and trust worthy processes of managing, ART centers
  • The will to show the professionalism of gynecologists and biologists of GIERAF
  • The need to gain trust of couple in need of ART.


Today, two centers are labellized GIERAF.

Does myomectomy improve in vitro fertilization outcome?

Fiadjoe Moïse Kwasivi


Clinique Biasa, Lomé, Togo

The uterine fibroid is most often found with patients old enough to give birth in Africa, either fertile or not.

From this survey, there arises the main question of the efficient cure of these patients.

  • Does fibroid affect fertility?
  • Does fibroid affect results of assisted reproductive technology?
  • The responsibility of submucous and intracavity myomas is undeniable in the failure of implantation. What is about the number of big fibroid-like we used to see in Africa? Don't they compromise the results of the trials?
  • Does myomectomy improve in vitro fertilization's results?


Evolution of stem cells and their application in modern medical therapeutics in Nigeria

Prosper Ikechukwu Igboeli


M and M Hospital/Bioheart Stem Cell Clinic, Karshi, Abuja, Nigeria

Stem cell therapy has been found to be beneficial in managing several disease states. Since 1998, scientists and investigators have uncovered many sources and different types of stem cells in the human body.

With the birth of Louse Brown in 1978, the first human baby born from in vitro fertilization procedure by Steptoe and Robert Edwards, and "Dolly the Sheep" (1996-2003), the first successful mammalian cloned from a somatic cell, a new era of genetic manipulation and biogenetic engineering became the focus of study for many scientists.

In the early stages of stem cell research and development, many scientists were using discarded and donated embryos for their studies. They cloned monkey, pig, gaur, cattle, cat, rat, etc. These generated a lot of public fury and debate as they considered embryos as potential humans and their use unethical. Many countries then banned embryonic stem cell research based on ethical considerations.

Today, we have better understanding of how the body utilizes the adult mesenchymal stem cells to repair its own damaged tissues and organs. "There are today embryonic, adult, and induced pluripotent stem cells." Virtually, all tissues in the human body possess stem cell capabilities. The most notable are stem cells derived from adipose tissues, bone marrow, muscle, teeth, etc., None of these sources of stem cells have ethical issues or concerns. They have found acceptability in many countries.

Disease states in which stem cell therapy has been found to be beneficial include but not limited to management of alopecia, auto immune diseases, cancer, congestive heart failure, diabetes, erectile dysfunction, degenerative joint diseases, orthopedic conditions, for example, osteoarthritis, rheumatoid arthritis, spinal cord injuries, stroke among many others.

Because of the long-term nature of many of the human conditions needing stem cell therapy, it is always beneficial to harvest the stem cells, to use some at the point of patient presentation, and to process the rest through further cell culture, cell expansion through several passages, and cryopreserved in vials stored in sub-zero temperatures for future use by the patient.

What to do when in vitro fertilization fails: Nursing perspective

Ebele Onwuagbaizu


The Bridge Clinic, Lagos, Nigeria

Childlessness is seen as a curse due to the cultural orientation toward marriage in developing countries such as Nigeria that place emphasis on children as a mark of a successful marriage. This has led to emotional and psychological challenges for the infertile couples such as feelings of vulnerability and diminished self-esteem. Nurses working in infertility clinics offer continued care to the infertile couple and are an important part of every couple's journey through infertility treatment, helping them to manage the emotional and psychological challenges as much as possible.

This continued care of infertile couples requires an intense level of compassion from the nurses working in infertility clinics. To achieve this, nurses maintain contact with the clients from commencement of their treatment to the end of treatment. This level of care is quite significant in managing the emotional requirements of the couple and has indeed been very helpful.

It is interesting to note that the kind and informative words from a nurse have helped many couples to continue with their treatment and better cope with the complex infertility treatment protocols.

A failed in vitro fertilization (IVF) treatment can be very demanding both for the nurse and for the couple as a lot of emotions are involved. There is need for nurses to realize that they may not always be able to assist couples to achieve their lifelong dream of having a child.

However, it is important to note that the specialized care and emotional support provided by nurses could be the driving force behind a couples' decision to re-experience this process even in the event of a failed IVF treatment.

Many couples undergoing IVF treatment realize this significant contribution from the nurses in their infertility journey even when the treatment fails. This is a significant contribution that needs to be encouraged in all infertility clinics across the country and efforts made to promote and further improve this.

Gamete donation: An overview

Foluke Phillips


George's Memorial Medical Centre, Lagos, Nigeria

Assisted reproduction using donor gamete is of great benefit to infertile couples. Its use and acceptance in infertility treatment are now on the increase; however, this arm of assisted reproductive technology raises a lot of ethical, religious, legal, and safety concerns.

It is therefore glaring that for gamete donation to be used effectively and safely, in-depth consideration and appropriate guidelines must be put in place.

Islamic perspective of assisted reproductive technology

Hadijat Olaide Raji, A. A. G. Jimoh


University of Ilorin Teaching Hospital, Ilorin, Nigeria

Infertility is a pervasive problem with far reaching consequences, particularly in Africa where a large premium is placed on child bearing. Assisted reproductive techniques (ARTs) have greatly improved the chances of conception in couples who would otherwise have remained childless.

Islam encourages procreation and as such infertility has a profound effect on Muslim infertile couples. Examples of couples with infertility exist in the Qur'an and Islam encourages infertile couples to seek treatment within the framework of marriage provided the treatment does not run contrary to laid down Islamic tenets and principles.

With the advent of new medical technologies including ART, various issues arise which will need interpretation by Islamic Law (Sharia). These include the use of donor gametes, surrogacy, use of embryos for stem cell research, etc.

Health-care practitioners are ethically bound to provide necessary information to patients to assist them in making informed choice regarding particular aspects of their care. Nigeria is a multi-ethnic and multi-religious society where people give premium to their religious dictates in taking personal decisions including in health-related issues. As such, knowledge of religious views of these practices may enable us provide more information to our patients.

Areas of concern to Islamic jurists regarding ART include the issue of lineage which could be confused in cases of donor gametes or surrogacy. This presentation espouses further on these issues and discusses the various viewpoints from Islamic schools of thought based on the various sources of Islamic Law which include the Qur'an, Hadith or Sunnah, Ijma (consensus of scholars), Qiyas (reasoning from analogy), and Ijtihad (literary effort/effort of thinking).

Surrogacy in in vitro fertilization

Abiola J. Adewusi


Medical Art Center, Lagos, Nigeria

Surrogacy in in vitro fertilization practice has become a treatment option for couples who otherwise have no hope of having their own genetic offspring because they are medically unfit to do so. There are various reasons why a couple otherwise known as intended parents is unable to carry pregnancy. This presentation elaborates on the different reasons why this line of treatment is necessary and useful to the intended parents. Different recommendations by various professional bodies including the WHO was given on how clinics can go about treating couples, selecting gestational carrier, and the legal implications surrounding the treatment process.

Tips for successful in vitro fertilization

Oladapo Adenrele Ashiru


Medical Art Center and Mart Medicare, Lagos, Nigeria

Since the delivery of Louise Brown in 1978 through the pioneer work of British researchers Robert Edward and Patrick Steptoe in in vitro fertilization, other countries have duplicated the procedure. Starting from Australia (Carl Wood, 1980) to the USA (Howard Jones, 1981) and in Nigeria (Ashiru and Giwa-Osagie, 1983), the technology has become highly improved and the success rate has steadily grown from 10% to 15% in the early 80's and currently, 35%-40%. It has been estimated that 15 years from now, in vitro fertilization (IVF) success rate should approach 90% (Jacque Cohen 2014).

Protocols that have improved IVF outcomes include techniques in controlled ovarian stimulation, ultrasound-guided oocyte aspiration, and embryo transfer. New and current trends in embryo culture, biopsy, and vitrification for preimplantation genetic diagnosis (PGD) also play a major role. This presentation highlights the rationale and evidence supporting the use of adjuncts to stimulations such as metformin, low-dose aspirin, growth hormone, letrozole, and DHEA.

Theater and laboratory practices such as transvaginal oocyte aspiration with heated aspiration tubing and optimal culture conditions such as strict temperature control, pH, and CO 2 concentration essential for generating high-quality embryos were also explained. The technique of ultrasound embryo transfer is critical to the success of IVF. The method of embryo transfer, the importance of mock embryo transfer, and the aspects of window of implantation now being determined with endometrial receptor array (ERA) were discussed.

Embryo biopsy technique has evolved from polar body to blastomeres biopsy and the current trends indicate that trophectoderm biopsy reduces the incidence of no result while also providing more DNA for analysis.

Vitrification is the popular method of choice for cryopreservation of oocytes and embryos. The process and advantages (especially for PGD and ovarian hyperstimulation syndrome patients) were also highlighted.

AFRH conference program outline: September 23-25, Lagos 2015

September 23


Preconference workshop on intrauterine insemination

September 24

Safety tips: Dr. Kehinde Bamgbopa

Session 1: Chairman: Prof. Osato Giwa-Osagie/Co-Chairman: Dr. Benedict Ekaidem

Training and educational status of embryologists - Dr. Bryan Woodward

Effect of sperm selection techniques on in vitro fertilization outcome - Dr. Akinwunmi Akinsanya

Trouble-shooting in vitro fertilization failures: Laboratory perspectives - Mr. Femi Olaifa

Keynote address 1: Setting up a voluntary licensing authority in Nigeria - Prof. Cooke

Keynote address 2: Legal implications of third-party reproduction: A world view - Dr. James Henry Olobo-Lalobo

Session 2: Chairman: Dr. Moise Fiadjoe/Co-Chairman: Mrs. Abiola J. Adewusi

Guidelines and regulations of assisted reproductive technology practice in the USA - Dr. Fidelis Akagbosu

National health bill and its implications for in vitro fertilization practice - Dr. Abegboyega Ogunwale

How to get a bill passed in Nigeria - Dr. Umar Alkali

Market forces versus regulation in in vitro fertilization - Dr. Enejo Abdu (MDCN)

Session 3: Chairman: Prof. John Ikimalo/Dr. Faye Iketubosin/Co-Chairman: Dr. Ikenna Emeka

Low cost in vitro fertilization: Myth or reality - Prof. Osato Giwa-Osagie

Tips for successful in vitro fertilization: From stimulation to ovum pick-up to embryo transfer - Prof. Oladapo Adenrele Ashiru

Stem cells and its applications in in vitro fertilization - Dr. Prosper Ikechukwu Igboeli

The experience of the labialization in French-speaking countries - Dr. Moise Fiadjoe (GIERAF)

Session 4: Industry sponsored presentations: Chairman: Dr. Adewunmi Adeyemi-Bero/Co-Chairman: Mrs. Bobo Kayode

New technologies in assisted reproductive technology -Dr. Manish Banker (NOVA in vitro fertilization India)

  • Jusoto Scientific Ltd. Presentation
  • Alpha Pharmacy Presentation
  • Astra Zeneca Presentation
  • Access Bank Presentation
  • AFRH AGM.


September 25

Safety tips: Dr. Kehinde Bamgbopa

Session 5: Chairman: Prof. Brian Adinma/Co-Chairman: Dr. Ibrahim Wada

Christian perspectives of in vitro fertilization in Nigeria - Dr. Abu Humphrey Alasa

Islamic perspectives of in vitro fertilization in Nigeria - Dr. Hadijat Olaide Raji (University of Ilorin)

Religious, cultural and social perspectives of in vitro fertilization in Nigeria - Dr. Obajimi (University of Ibadan)

IFFS/AFS mini-seminar

Address by AFS President: Prof. Oladapo Adenrele Ashiru

Address by IFFS President Prof. Joe Leigh Simpson

Session 6: Chairman: Prof. Oladapo Adenrele Ashiru/Co-Chairman: Mrs. Rose Ogeche

Improving in vitro fertilization success: Advanced techniques for embryo selection - Prof. Nicholas Zeck

Genome and epigenome disorders and infertility: From gametes to miscarriage - Prof. Moncef Benkhalifa

Anonymity and gamete donation: Disclosure issues - Dr. Valentine Akande

Session 7: Chairman: Dr. Richard Ajayi/Co-Chairman: Mr. Femi Olaifa

Setting up the embryology lab for HIV-positive patients - Dr. Bryan Woodward

Does myomectomy improve in vitro fertilization outcome? - Dr. Fiadjoe Moïse Kwasivi

Surrogacy in in vitro fertilization - Mrs. Abiola J. Adewusi

In surrogacy: "Apply and enforce contract law and desist from re-inventing new legal wheels" - Dr. James Henry Olobo-Lalobo

Session 8: Chairman: Dr. Abayomi Ajayi/Co-Chairman: Dr. Tayo Abiara

Ethics of donor compensation - Dr. Jude Okohue

When in vitro fertilization fails: Nursing perspectives - Ms. Ebele Onwuagbaizu

Management of in vitro fertilization failures - Dr. Ibrahim Wada

Gametes donor program - Ms. Foluke Philips

Session 9: Chairman: Dr. Jude Okohue/Co-Chairman: Ms. Foluke Philips

Consenting in in vitro fertilization - Dr. Ben Ekaidem

Efficacy of low-cost in vitro fertilization - Dr. Louis Alekwe

Preimplantation genetic diagnosis (PGD) - Ms. Adedamilola Atiba (Nordica Lagos)

Parallel Sessions Program: Abstracts Presentation

Session 10:
Chairman: Dr. Alekwe/Co-Chairman: Dr. Kehinde Bamgbopa/Mr. Oluwatosin Ogunyemi

Comparing sex ratio at birth following cleavage stage embryo transfer and blastocyst transfer - J. C. Onyeike and L. C. Okorie

A review of patients with severe oligospermia undergoing in vitro fertilization: Its effect on treatment outcome and sex ratio of offspring - O. E. Ogunyemi

Trend in sperm quality metrics in a fertility clinic in Nigeria from 2009 to 2012 - Lateef Akinola et al.

Sperm bank scheme and surrogacy institution: Willingness and utilization of assisted reproductive technology among women of reproductive-age group in Ilorin, Nigeria - A. A. G. Jimoh et al.

Session 11: Chairman: Dr. Adeniyi Adewunmi/Co-Chairman: Ms. Akemini Umana

The profile of clients seeking assisted conception at Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria - Dr. A. A. Adewunmi et al.

Semenology update in assisted reproductive technology - Abimbola Nanna

New insights into the mechanisms underlying chlamydia trachomatis infection induced female infertility by Ajonuma Louis C. Department of Physiology, (Lasucom), Ikeja, Lagos, Nigeria

Experience with the Bonanno catheter in the management of ovarian hyperstimulation syndrome from in vitro fertilization-et cycles - J. E. Okohue, V. K. Oriji, J. I. Ikimalo

Session 12: Chairman: Dr. Gabriel Igberase/Co-Chairman: Dr. O. Makewu

Pregnancy outcome after trophectoderm biopsy: Retrospective study - Ogbeche Rose, Umana Akemini, Iloabachie Ebele, Oladimeji Moruf, Osumah Jumoke, Oladapo Adenrele Ashiru

Biophysical profile of infertile women with endometriosis - Dr. Abayomi Ajayi et al.

Age-specific anti-Mullerian hormone levels in young women in Lagos, Nigeria - O. Ogunro, O. Adeyemi-Bero

Assessment of anxiety levels of infertile women undergoing in vitro fertilization program at Nordica Fertility Center Lagos, Nigeria - Dr. Abayomi Ajayi et al.

Audit: Outpatient hysteroscopic procedures (April 2013 to February 2015) - L. A. Akinola, A. Akinyemi, O. Makewu, O. Moses, Oladapo Adenrele Ashiru

Advanced abdominal pregnancy following in vitro fertilization and embryo transfer: A case report - Osato Giwa-Osagie et al.




 

Top
 
 
  Search
 
Similar in PUBMED
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article

 Article Access Statistics
    Viewed5298    
    Printed408    
    Emailed0    
    PDF Downloaded452    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]