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Plant Source Foods
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
The gymnosperms are non-flowering or seed-producing plants such as Cycas, Pinus, Ginkgo in which ovules are not enclosed by any ovary wall; hence they are called naked-seeded plants. In angiosperms or flowering plants, the male sex organs (stamen) and female sex organs (pistil) are borne in a same flower. The anther produces pollen grains (male gametophyte). The pistil consists of an ovary enclosing one to many ovules. Within the ovule is the female gametophyte or embryo sac which contains the egg cell. The angiosperms are divided into two classes: the monocotyledons or monocots (seed with a single cotyledon or one embryonic leaf) and the dicotyledons or dicots (seed having two cotyledons or two embryonic leaves) (2). They range in size from tiny, aquatic Wolffia to tall trees of Eucalyptus (over 100 m). Plants provide us with food, fodder, fuel, medicines, and several other commercially important products (2).
Midwifery and obstetrics
Published in Roy Palmer, Diana Wetherill, Medicine for Lawyers, 2020
Beverley Gordon, Gareth Thomas
Multiple pregnancy carries its own specific problems. There is an increased risk of maternal complications of pregnancy, and a risk of twin-to-twin transfusion in utero when the pregnancy has arisen from one egg cell, as well as a series of added risks to the second twin during labour and delivery.
Reproductive Choice and Advancing Technologies
Published in Robert M. Veatch, Laura K. Guidry-Grimes, The Basics of Bioethics, 2019
Robert M. Veatch, Laura K. Guidry-Grimes
As the complexity of these relations increases, the moral issues also increase. For one, the question of compensation to motivate a surrogate’s assistance arises. Sperm donors have always been paid, raising the issue of why women who provide an egg cell or a womb for gestation should not also be compensated. Some argue that there are significant differences in the time, burden, and risk involved, but it is not clear whether that implies that payment would be more or less justified. Presently, markets to pay surrogates who provide a womb (or a womb plus an egg, as Mary Beth Whitehead did) are considered highly suspect and actually prohibited in some jurisdictions. Excluding compensation is believed to make the decision to participate, particularly by poor women, less coercive, but it also raises questions about fairness for women who accept a considerable burden for the benefit of others.
The effects of metformin treatment on the ovaries and uterus of offspring
Published in Gynecological Endocrinology, 2021
Bülent Ayas, Seda Kırmızıkan, Adem Kocaman, Bahattin Avcı
Metformin reduces steroid synthesis through AMPK activation, aromatase activity, and inhibition of LH and FSH receptor formation in granulosa cells [32–37]. As a result of this reduction, the number of granulosa cells and estradiol release is expected to be decreased. This effect was observed in our study. The estradiol level decreased in the experimental groups compared to the control group and also this decrease was found statistically significant in the Metformin 200 group (p < .05). A similar effect was also observed in the tertiary follicle volume. Metformin 200 showed a significant decrease compared to the control group (p < .05). It has been suggested that this might be related to the gonadotropin receptors which are affected during the formation and development of follicles in the over-reserve of rat offspring [35]. Also, it is well known that all egg cells are produced before birth and do not proliferate during the life of female humans. For that reason, metformin exposure during the intrauterine period might change the function of egg cells. In this study, the oocyte number was compared between the groups and there was no significant difference found (p > .05). This result assumes that the low-dose metformin may not show any toxic effect on the formation and the development of oocyte during the intrauterine period. However, the optimal concentration range of metformin for maintaining pregnancy is unclear because metformin has the potential to harm the offspring while getting therapeutic benefit from it [26].
A case of placental hydatid changes in third trimester of pregnancy
Published in Journal of Obstetrics and Gynaecology, 2020
Bai Yun, Zhao Xiang-Zhai, Guo Zhao-Jun, Pang Yi-Cun, Wang Jian
We searched published articles on ‘placental chimaera’ and found two cases with similar genotypes; however, the clinical manifestations were different. Zhang et al. (2000) reported a patient with a 20–week pregnancy who was diagnosed with foetal heart failure and severe preeclampsia. The foetus was a diploid (46XX) female, while the genotype of the vesicular part of the placenta was the same diploid and triploid chimaera, as in our case. The non-vesicular part of the placenta was triploid. The serum HCG of this patient was higher (311837 IU/L) than in our case, and serum AFP was not measured. The authors speculate that the principle of karyotype formation may be such that a whole set of haploid chromosomes are lost from triploid embryos and diploid cells develop into foetuses, but how this whole set of chromosomes is lost is hard to explain. Another possible explanation is that the embryo would be the product of fertilisation between a pack of egg cells containing polar nuclei and sperm. When the embryo precursor forms a placenta, the pentaploid divides into diploid and triploid sets of chromosomes.
Aluminum reproductive toxicity: a summary and interpretation of scientific reports
Published in Critical Reviews in Toxicology, 2020
The development of an oocyte begins as a primordial germ cell. Early in embryonic development these cells migrate into the future site of the ovaries, undergo meiotic cell division, and multiply, resulting in primary oocytes (primordial follicle) within the ovary. Their development is arrested until puberty, when follicle stimulating hormone (FSH) produced by the pituitary gland stimulates some to begin to mature, developing through follicle stages (primary, secondary, and if fertilized tertiary (Graafian) follicles), in the process of folliculogenesis. Most die (atresia) during these stages. During the resumption of cell division, the oocyte’s nucleus (germinal vesicle) breaks down and the first polar body (that forms concomitantly during oocyte division) is extruded. Follicle cells secrete and release estrogen that feeds back to the pituitary gland to decrease FSH release and increase luteinizing hormone (LH) release. This causes the follicle to rupture, resulting in release of the egg (ovulation), that migrates into the fallopian tubes where it can be fertilized by sperm. The ruptured follicle forms a corpus luteum, a transitory endocrine organ that secretes estrogen and progesterone. The latter feeds back to the pituitary gland to decrease LH release. The fertilized oocyte forms a mature egg cell (ovum). When the oocyte and sperm chromosomes combine, it becomes a zygote, which divides as it migrates into the uterus, creating the pregnant (gravid) state.