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At least 19 recordsLinked to original sources
PubMed1995

Women, ectogenesis and ethical theory.

The nature of two influential theories on the moral status of abortion logically commits them to welcoming the advent of ectogenesis (the gestation of human beings outside the womb) as a solution to the abortion conflict. However, qualitative research into women's response to ectogenesis reveals that both women in favour and women opposed to abortion rights reject the technology on surprisingly similar grounds. The abortion framework which led women to reject ectogenesis as an ethical resolution to unwanted pregnancy is contrasted with the moral framework which shapes formal ethical discussions of abortion. It is argued that the need for ethical relevance requires the views of ethicists to move closer to those of women.

Abortion, Induced↗
PubMed1978

Novel mechanisms of reproduction: preimplantational ectogenesis.

The polarization of attitudes concerning preimplantational ectogenesis, combined with the fact that the field is technically in its infancy, makes likely the passage of much time before the use of ectogenesis becomes widespread either clinically or as a research tool. It is to be hoped that during this interval a properly critical attitude will lead to slow, steady progress while society readjusts some basic philosophic concepts.

Animals↗
PubMed1976

Preimplantational ectogenesis. Science and speculation concerning in vitro fertilization and related procedures.

In recent years, technical advances have made preimplantational ectogenesis (in vitro maturation, fertilization and early embryonic development) more than a theoretical concept. Such procedures hold great promise in medical research. However, despite our newly-acquired skills in tissue culture and microsurgical manipulation, and contrary to many sensational articles in the lay press, it is not likely that preimplantational ectogenesis will soon attain wide clinical use in humans. Adverse societal attitudes, based largely upon moral and ethical dilemmas, will probably combine with still-unresolved technical difficulties to restrict the clinical applications.

Animals↗
PubMed2004

Reproductive ectogenesis: the third era of human reproduction and some moral consequences.

In a well known story Derek Parfit describes a disconnection between two entities that normally (in real life) travel together through space and time, namely your personal identity consisting of both mind and body. Realising the possibility of separation, even if it might never happen in real life, new questions arise that cast doubt on old solutions. In human reproduction, in real life, at present the fetus spends approximately nine months inside the pregnant woman. But, we might envisage other possibilities. Historically, the first era is the normal conception inside the woman, the growth of the fetus in the womb and then, after nine months, birth and the appearance of a new individual. The second era is In Vitro Fertilisation (IVF). The fetus starts outside the woman as a fertilised egg, moves to the body of the woman and spends nine month there, where the body of the woman and the fetus travel together in space-time to separate at birth. In the third era of reproductive ectogenesis, the two never travel together. The fetus spends its gestational time entirely outside the woman's body. We have two entities separated in space-time the whole time. The intimate connection consisting in the fetus being a part of the woman's body is gone. In this paper I will briefly comment on the three eras of human reproduction--and primarily on the relationship between the new individual and the woman--and then spend some time with a fictional story illustrating some moral consequences of the third era. The story is from Pig Pharmaceuticals Limited and how they in the year 2050 report the successful development of pig-related pregnancies with transgenic pigs as surrogate mothers.

Animals↗
PubMed2000

Ethical issues in gestational surrogacy.

The introduction of contraceptive technologies has resulted in the separation of sex and procreation. The introduction of new reproductive technologies (mainly IVF and embryo transfer) has led not only to the separation of procreation and sex, but also to the redefinition of the terms mother and family. For the purpose of this essay, I will distinguish between: 1. the genetic mother--the donor of the egg; 2. the gestational mother--she who bears and gives birth to the baby; 3. the social mother--the woman who raises the child. This essay will deal only with the form of gestational surrogacy in which the genetic parents intend to be the social parents, and the surrogate mother has no genetic relationship to the child she bears and delivers. I will raise questions regarding medical ethical aspects of surrogacy and the obligation(s) of the physician(s) to the parties involved. I will argue that the gestational surrogate is "a womb to rent," that there is great similarity between gestational commercial surrogacy and organ transplant marketing. Furthermore, despite claims to freedom of choice and free marketing, I will claim that gestational surrogacy is a form of prostitution and slavery, exploitation of the poor and needy by those who are better off. The right to be a parent, although not constitutional, is intuitive and deeply rooted. However, the issue remains whether this right overrules all other rights, and at what price to the parties involved. I will finally raise the following provocative question to society: In the interim period between today's limited technology and tomorrow's extra-corporeal gestation technology (ectogenesis), should utilizing females in PVS (persistent vehetative state) for gestational surrogacy be socially acceptable/permissible--provided they have left permission in writing?

Depersonalization↗
PubMed2003

Effect of unsaturated fatty acid on muscarinic current in guinea pig gastric antral circular myocytes.

AIM: To investigate the effect of ectogenesis unsaturated fatty acid on carbachol-induced muscarinic current (ICCh) and its mechanism. METHODS: Using the whole-cell patch-clamp technique, ICCh was recorded in single smooth muscle cell isolated from the antral circular smooth muscles of guinea-pig stomach. RESULTS: Arachidonic acid (AA) was added in external perfusing solution and AA inhibited ICCh to 46 %+/-8 %, 23 %+/-5 %, and 3.8 %+/-0.9 % at 1, 3, and 5 micromol/L. Another unsaturated fatty acid, linoleic acid (LA) also inhibited ICCh in a dose-dependant manner. LA inhibited ICCh to 69 %+/-10 %, 35 %+/-5 %, and 7.4 %+/-1.2 % at 1, 5, and 10 micromol/L, respectively. The same concentration (5 micromol/L) of AA, LA, and oleic acid (OA) suppressed ICCh to 3.8 %+/-0.9 %, 35 %+/-5 %, and 67 %+/-9 %, respectively. The inhibitory potency sequence of these unsaturated fatty acids was AA>LA>OA. After 10-15 min of pretreatment with H-7 (a protein phosphorylation C inhibitor) 100 micromol/L or indomethacin (a cyclooxygenase inhibitor) 10 micromol/L, ICCh was inhibited by 5 micromol/L of AA to 5.5 %+/-0.7 % and 3.0 %+/-1.0 %, respectively. CONCLUSION: The unsaturated fatty acids directly inhibited ICCh, and the inhibitory potency was related to the number of double bonds in fatty acid chain.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2002

[The inhibiting effect of genistein on the growth of human breast cancer cells in vitro].

OBJECTIVE: To study the inhibitig effects of genistein on the growth of human breast cancer cell lines in vitro and its mechanisms. METHORD: Human breast cancer cell lines both MCF-7(positive estrogen receptor, ER+) and MDA-MB-231 (negative estrogen receptor, ER-) were cultured in vitro. The proliferation of cells was measured with MTT methord and the growth curve was drawn with cell count. The estrogen receptor in cells was show with immunohistochemistry. RESULT: Genistein inhibited proliferation of MCF-7 and MDA-MB-231 cell lines and inhibition was dependent on dose within some concentration range, IC50 being 32.5 mumol.L-1 and 46.8 mumol.L-1 respectively. Genisteins antiproliferation of MCF-7 was stimulated by ectogenesis estrogen but proliferation of MDA-MB-231 inhibited by geinstein was not related to estrogen. The positive signs of ER in cellular nuclei of MCF-7 cell line fed with genistein at concentration of 30 mumol.L-1 were significantly weaker than these not fed with genistein. CONCLUSION: Genistein obviously inhibits proliferation of both cell lines of MCF-7 and MDA-MB-231 in vitro and is dependent on dose. Genisteins antiproliferous effect on MCF-7 cell lines is stimulated by estrogen and this effect is related with ER, but genisteins inhibiting proliferation of MDA-MB-231 cell line is not through ER.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Factors affecting the survival of sheep embryos during-freezing and thawing.

The survival of sheep morulae and early blastocysts after deep freezing has been investigated. With a dimethyl sulphoxide concentration of 1.5 M in a phosphate-buffered saline medium, a freezing rate of 1 degreees C/min down to 120 degees C allowed embryos to survival only if rapid thawing (approximately 360 degrees C/min) was employed, whereas with a freezing rate of 0.3 degrees C/min, survival was obtained with both rapid and slow (10 degrees C or 4 degrees C/min) thawing. With even slower freezing (0.1 degrees C/min over intervals between -30 and -60 degrees C) slow thawing was no longer optional but mandatory. With the latter technique survival rates of the order of 80% were obtained. The results of transfer experiments with frozen-thawed sheep and cattle embryos are briefly presented in an Appendix.

Animals↗
PubMed1977

Histochemical evidence of mucosubstances in the metaplastic epidermis and hair follicles produced in vitro in the presence of excess vitamin A.

Pieces of upper lip and lower jaw from 13-day old mouse embryos grown in organ culture with excess vitamin A showed metaplastic changes in epidermis and hair follicles after 7 to 21 days. Changes were less marked in upper lip explants from 15-day old embryos. Areas of keratinizing epidermis showed a much higher incidence of Alcian blue-positive bodies when excess vitamin A was present. Histochemical tests with Alcian blue at critical electrolyte concentrations indicated moderately sulfated acidic mucosubstances in these bodies. Other patches of epidermis were transformed into stratified cuboidal epithelium producing PAS-positive, Alcian blue-negative, mucosubstances. The hair follicles, transformed by vitamin A into glands, developed three types of epithelium with apical granules, luminal borders and occasional goblet cells, all showing mucosubstances. Tests suggest that both metaplastic epidermis and glands secrete either neutral mucosubstances or non-sulfated acidic mucosubstances. Another response to vitamin A was a rapid loss of glycogen, particularly in hair follicles and the epidermal basal layer. It was concluded that excess vitamin A alters not only the morphogenesis but also the distribution and synthesis of polysaccharides in developing skin.

Animals↗
PubMed2003

Aerobic biological treatment of synthetic municipal wastewater in membrane-coupled bioreactors.

Membrane-coupled bioreactors (MBRs) offer many benefits compared to conventional biological wastewater treatment systems; however, their performance characteristics are poorly understood. Laboratory-scale MBRs were used to study bacterial adaptations in physiology and community structure. MBRs were fed a mixture of starch, gelatin, and polyoxyethylene-sorbitan monooleate to simulate the polysaccharide, protein, and lipid components of municipal wastewater. Physiological adaptations were detected by measuring ectoenzyme activity while structural dynamics were studied by denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments. As cell biomass accumulated in the MBRs, pollutant removal efficiency initially improved and then stabilized with respect to effluent concentrations of chemical oxygen demand, protein, and carbohydrate. Comparison of the MBR effluent to filtered reactor fluid indicated that a portion of the observed pollutant removal was due to filtration by the membrane rather than microbial activity. The rates of ectoenzyme-mediated polysaccharide (alpha-glucosidase) and protein (leucine aminopeptidase) hydrolysis became relatively constant once pollutant removal efficiency stabilized. However, the maximum rate of lipid hydrolysis (heptanoate esterase) concomitantly increased more than 10-fold. Similarly, alpha-glucosidase and leucine aminopeptidase ectoenzyme affinities were relatively constant, while the heptanoate esterase affinity increased more than 30-fold. Community analysis revealed that a substantial community shift occurred within the first 7 days of operation. A Flavobacterium-like bacterial population dominated the community (>50% of total band intensity) and continued to do so for the remainder of the experiment.

Adaptation, Physiological↗
PubMed1988

Investigation of the tissue specificity of the lethal yellow (Ay) gene in mouse embryos.

The tissue specificity of the lethal yellow mutant was investigated by separation of blastocyst tissues. Embryos from experimental (Ay/ae X Ay/ae) and control (ae/ae X Ay/ae) crosses of the AG/CamPa inbred strain were recovered at 3.5 days post coitum, cultured for 24 hours, and then mechanically dissected into the component tissues of the blastocyst, the inner cell mass (ICM), and trophectoderm. These fragments were then cultured separately, with or without a feeder layer of inactivated fibroblasts, for an additional 3-5 days. Comparisons between experimental and control crosses indicated that the lethal Ay/Ay embryos were among the blastocysts successfully dissected but that both the ICM and trophectoderm from lethal embryos failed to develop further in vitro, either with or without feeders. With retrospective identification of the lethal embryos, it was found that at 4.5 days, after 1 day of culture, they had formed morphologically normal blastocysts but were frequently more fragile upon dissection and had smaller ICMs. Although none had hatched from the zona pellucida, some had ruptured it and were halfway out. With culture, lethal ICMs showed no development, and lethal trophectoderm usually attached but showed very limited outgrowth. Thus, no rescue of lethal tissue was shown with dissection and in vitro culture, and results are consistent with the gene affecting both tissues of the late blastocyst.

Animals↗
PubMed1976

Studies on the generation of B lymphocytes in the mouse embryo.

Using an organ culture technique, the development of B lymphocytes has been studied in a number of isolated embryonic hemopoietic tissues. Developing B lymphocytes were identified by cytoplasmic and surface immunofluorescence using purified class-specific antibodies and a Fab anti-immunoglobulin reagent. In fetal liver cultures these cells were further characterized for Fc and complement receptors and for the presence of mouse-specific B lymphocyte antigen. The results indicate that B lymphocytes develop independently in fetal liver and in fetal spleen; they do not develop in cultures of yolk sac and thymus. In conclusion, it is likely that B lymphocyte maturation in mammals is multifocal and is not dependent upon gastrointestinal influences as suggested previously.

Animals↗
PubMed1979

In vitro development of core cells of the inner cell mass of the mouse blastocyst: effects of conditioned medium.

Blastocysts submitted to two rounds of immunosurgery give rise to cores of presumptive ectoderm cells, many of which do not survive for more than 48 hours when cultured individually. Precoating of the culture plates with conditioned medium (CM) from PYS-2 cells increases the incidence with which cores regenerate an outer layer. This procedure also improves the survival frequency of the cores, but only for a limited period of time. The small number of cores which survive for two weeks or more, either in uncoated or CM-coated plates, give rise to any array of cell types, including giant cells resembling trophoblast.

Animals↗