Adjustment of the fetal head and adult pelvis in modern humans

In nonhuman anthropoids, the anteroposterior (AP) diameters of the fetus are greater than the transverse (TR) diameters and the AP diameters of the pelvic planes are greater than the TR diameters: during labor, therefore, the fetus moves through the birth canal without changing position or orientation. In modern humans, the fetal head at term is encephalized and the fetal chest is flattened. The maternal pelvic inlet is flattened in an AP direction, the sacral promontory and the ischial spines are prominent. As a result, AP<TR at the inlet, but AP>TR at the midpelvis and outlet. In addition, the birth canal presents a marked sacral curvature in the AP direction. The human fetus successfully negotiates the birth canal because the three crucial fetal adaptations: (1) spheroidicity of the presenting part of the fetal head, which allows it to “roll” in the pelvis; (2) mobility of the head and chest in all directions; and (3) a capacity for cranial molding, which adapts fetal head dimensions to pelvic dimensions. The result is that the human fetal head and chest can perform multiple rotational movements in order to always present the greatest fetal diameters to the greatest pelvic diameters. Monkeys show a limited degree of encephalization and suffer from narrow TR pelvic diameters without any possibility of fetal adaptations as shown by humans. Apes also show some encephalization but, because of wider TR diameters in the pelvis, they achieve an easy delivery with no need of fetal adaptations.     

Radiation and pregnancy

Irradiation during pregnancy may occur either as the result of radioactive pollution of the environment, or during a medical procedure using x-rays or radionuclides. While the former is usually unforeseeable, the latter is known and accepted by both physician and patient.Recent statistics estimate that about one quarter of pregnant women have had a radiographic experience during the pregnancy, either for obstetrical reasons or in the course of medical and dental examinations. The amount of radiation delivered to the fetus is in the range of one rad or less. Radionuclidic procedures may result in fetal radiocontamination, chiefly after placental transfer and fetal uptake. Radioiodine, radioactive calcium and selenomethionine are dangerous for the fetus, since they cross the placenta freely and are taken up by fetal tissues. The labelled proteins, radiocolloids and some mercury compounds remain in the maternal compartment and therefore can affect the fetus only through their gamma radiation at some distance from the fetus.The teratogenic effect, the leukemogenic threshold and the lowered resistance to neonatal infections have been demonstrated after irradiation with doses far higher than those encountered during diagnostic applications of ionizing radiation. Statistical data suggest an increase of susceptibility to leukemia in infancy after intra-uterine irradiation at a diagnostic level. Cytogenic analysis may.... offer valuable data for the establishment of the extent of radiation damage.     

Even if the fetus is not a person,abortion is immoral: The impairment argument

Much of the debate about the ethics of abortion has centered on whether the fetus is a person. In an attempt to sidestep this complex issue, I argue that, even if the fetus is not a person, abortion is immoral. To arrive at this conclusion, I argue that giving a fetus fetal alcohol syndrome is immoral, and that if this is so, then killing the fetus is immoral. Roughly, this is because killing the fetus impairs it more than giving it fetal alcohol syndrome. Since abortion (in most cases) amounts to killing the fetus, this means that abortion (in most cases) is immoral. I defend the premises of this argument against a plethora of objections, concluding that they either do not work, or commit their proponent to a controversial position.     

Cutting edge: regulation of uterine NKT cells by a fetal class I molecule other than CD1

The peri-implantation uterus contains an expanded population of NK1.1(+) V alpha 14(+) TCR(int) (NKT) lymphocytes. Although these cells bear the above features in common with other NKT cells populations in thymus, bone marrow, liver, and spleen, they differ from these other populations in terms of an altered V beta repertoire and absence of a CD4(+) component. In this study, we demonstrate that the uterine population also differs from other NKT cell populations because they recognize a class I/class I-like molecule other than CD1, whereas most previously described V alpha 14(+) NKT cells are CD1-restricted. Moreover, the class I/class I-like molecule leading to the uterine NKT cell expansion may be supplied by the fetus. These data demonstrate a novel mechanism whereby the fetus is capable of modulating the maternal immune system.     

Conflicting perceptions of the fetus: person, patient, 'nobody', commodity?

Different constructions of the fetus lie at the centre of reproductive, abortion and disability politics. Recent developments mean that, within the same hospital, a fetus may be perceived in contrasting and potentially conflicting ways. It is also argued that the status given to the fetus is directly relevant to the status given to pregnant women. During group discussions facilitated by an ethicist, health-care staff highlighted various perceptions of the fetus which included: person; patient; 'nobody'; commodity. Perhaps not surprisingly in view of the current legal situation, staff tended to claim that it is usually the pregnant women who decides how her fetus will be constructed, and the practitioner who responds to this. However, various ways in which practitioners might influence women's perceptions of their fetus are highlighted, as are some ways in which the perceptions of staff might be influenced. This paper illustrates how sensitive health-care staff will need to be if they are indeed to respond to, rather than shape, women's constructions of their fetus.     

Campylobacter fetus subspecies: Comparative genomics and prediction of potential virulence targets

The genus Campylobacter contains pathogens causing a wide range of diseases, targeting both humans and animals. Among them, the Campylobacter fetus subspecies fetus and venerealis deserve special attention, as they are the etiological agents of human bacterial gastroenteritis and bovine genital campylobacteriosis, respectively. We compare the whole genomes of both subspecies to get insights into genomic architecture, phylogenetic relationships, genome conservation and core virulence factors. Pan-genomic approach was applied to identify the core- and pan-genome for both C. fetus subspecies and members of the genus. The C. fetus subspecies conserved (76%) proteome were then analyzed for their subcellular localization and protein functions in biological processes. Furthermore, with pathogenomic strategies, unique candidate regions in the genomes and several potential core-virulence factors were identified. The potential candidate factors identified for attenuation and/or subunit vaccine development against C. fetus subspecies contain: nucleoside diphosphate kinase (Ndk), type IV secretion systems (T4SS), outer membrane proteins (OMP), substrate binding proteins CjaA and CjaC, surface array proteins, sap gene, and cytolethal distending toxin (CDT). Significantly, many of those genes were found in genomic regions with signals of horizontal gene transfer and, therefore, predicted as putative pathogenicity islands. We found CRISPR loci and dam genes in an island specific for C. fetus subsp. fetus, and T4SS and sap genes in an island specific for C. fetus subsp. venerealis. The genomic variations and potential core and unique virulence factors characterized in this study would lead to better insight into the species virulence and to more efficient use of the candidates for antibiotic, drug and vaccine development.     

A new approach regarding the treatment of preeclampsia and preterm labor

Both preeclampsia and preterm delivery are important complications in pregnancy and are leading causes for maternal and perinatal morbidity and mortality. The underlying molecular mechanisms of both diseases remain unknown, thus treatments (beta2-stimulants and magnesium sulfate) are essentially symptomatic. Both molecules have molecular weights less than 5-8 kDa and cross the placental barrier thus exerting their effects on the fetus. In addition, the fetus produces peptide hormones that are highly vasoactive and uterotonic and increase in response to maternal stress and with continued development. Fetal peptides are also small molecules that inevitably leak across into the maternal circulation. Aminopeptidases such as placental leucine aminopeptidase (P-LAP) and aminopeptidase A (APA) are large molecules that do not cross the placental barrier. We have shown that APA acts as an antihypertensive agent in the pregnant spontaneously hypertensive rat by degrading vasoactive peptides and as a result returns the animal to a normotensive state. We have also noted that P-LAP acts as an anti-uterotonic agent by degrading uterotonic peptides, and as a result prolongs gestation in the pregnant mouse. Thus, P-LAP and APA represent promising agents for the treatment of preeclampsia and preterm labor by degrading bioactive hormones derived from the feto-placental circulation.     

The failure of DNA forensic testing: a case study of the 2009 Australian bushfire disaster

Different constructions of the fetus lie at the centre of reproductive, abortion and disability politics. Recent developments mean that, within the same hospital, a fetus may be perceived in contrasting and potentially conflicting ways. It is also argued that the status given to the fetus is directly relevant to the status given to pregnant women. During group discussions facilitated by an ethicist, health-care staff highlighted various perceptions of the fetus which included: person; patient; 'nobody'; commodity. Perhaps not surprisingly in view of the current legal situation, staff tended to claim that it is usually the pregnant woman who decides how her fetus will be constructed, and the practitioner who responds to this. However, various ways in which practitioners might influence women's perceptions of their fetus are highlighted, as are some ways in which the perceptions of staff might be influenced. This paper illustrates how sensitive health-care staff will need to be if they are indeed to respond to, rather than shape, women's constructions of their fetus.     

A multiplex polymerase chain reaction to detect and differentiate Campylobacter fetus subspecies fetus and Campylobacter fetus -species venerealis: use on UK isolates of C. fetus and other Campylobacter spp

AIMS: Subspeciation of Campylobacter fetus subsp. fetus (CFF) and Campylobacter fetus subsp. venerealis (CFV) is important for international animal import regulations. Phenotyping can be unreliable, and genotyping by techniques like pulsed field gel electrophoresis is difficult in routine diagnostic laboratories. A PCR subspeciation technique has been reported [Aust Vet J (1997) 75, 827]; we aimed to develop this PCR and investigate its use on UK C. fetus isolates. METHODS AND RESULTS: We augmented the PCR with further primers, and tested 76 isolates of C. fetus and 16 isolates of other Campylobacter spp. PCR failed to correlate well with phenotyping, especially for CFV. We characterized the amplicon of the CFV-specific primers (reported as plasmid derived, but unavailable on the public databases); and predicted a parA gene sequence, anticipated to be plasmid-associated. However, although plasmid isolations from selected CFV isolates demonstrated the presence of several plasmids, there was no correlation between plasmid profile and PCR result. Further, the parA sequence was not detected by PCR in any of the plasmid bands. CONCLUSIONS: This PCR is not suitable for subspeciation of C. fetus in the UK. The results suggest that this is a reflection of the presence of an unusual clone of CFV currently present in cattle in this country. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR cannot substitute for phenotyping of C. fetus isolates in the UK. The reasons for failure of PCR genotyping may reflect local strains and/or plasmid profiles. Further study is required to better elucidate molecular sub-speciation of C. fetus.     

Bioethics for clinicians: 12. Ethical dilemmas that arise in the care of pregnant women: rethinking "maternal-fetal conflicts".

When a pregnant woman makes a decision or acts in a manner that may be detrimental to the health and well-being of her fetus, her physician may be faced with an ethical dilemma. Is the physician''s primary duty to respect the woman''s autonomy, or to promote behaviour that may be in the best interest of the fetus? The controversial concept of "fetal rights" or the "fetus as a patient" contributes to the notion that the pregnant woman and her fetus are potential adversaries. However, Canadian law has upheld women''s right to life, liberty and security of the person and has not recognized fetal rights. If a woman is competent and refuses medical advice, her decision must be respected even if the physician believes that her fetus will suffer as a result. Coercion of the woman is not permissible no matter what appears to be in the best interest of the fetus.     

Against the impairment argument: A reply to Hendricks

In an article of this journal, Perry Hendricks makes a novel argument for the immorality of abortion. According to his impairment argument, abortion is immoral because: (a) it is wrong to impair a fetus to the nth degree, such as causing the fetus to have fetal alcohol syndrome (FAS); (b) it is wrong to impair a fetus to the n+1 degree (to cause the fetus to be more impaired than to have FAS); (c) killing the fetus impairs the fetus to the n+1 degree (causes it to be more impaired than to have FAS); (d) abortion kills the fetus; (e) therefore, abortion is immoral. The impairment argument is a promising account for the wrongness of abortion because it does not rely on the controversial metaphysical premise that a fetus is a person. This article aims to show, that despite some immediate advantages over the rival theories of the immorality of abortion there is a reason to believe that the impairment argument is untenable. That is because there are goods that can be achieved by abortion but that cannot be achieved by impairing the fetus.     

Rights of and duties to non-consenting patients--informed refusal in the developing world

The principle of informed refusal poses a specific problem when it is invoked by a pregnant woman who, in spite of having accepted her pregnancy, refuses the diagnostic and/or therapeutic measures that would ensure the well-being of her endangered fetus. Guidelines issued by professional bodies in the developed world are conflicting: either they allow autonomy and informed consent to be overruled to the benefit of the fetus, or they recommend the full respect of these principles. A number of medical ethicists advocate the overruling of alleged irrational or unreasonable refusal for the benefit of the fetus. The present essay supports the view of fetal rights to health and to life based on the principle that an 'accepted' fetus is a 'third person'. In developing countries, however, the implementation of the latter principle is likely to be in conflict with a 'communitarian' perception of the individual -- in this case, the pregnant woman. Within the scope of the limitations to the right to autonomy of J.S. Mill's 'harm principle', the South African Patients' Charter makes provision for informed refusal. The fact that, in practice, it is not implemented illustrates the well-known difficulty of applying Western bioethical principles in real life in the developing world.     

Congenital toxoplasmosis: An overview of the neurological and ocular manifestations

Toxoplasma gondii is an obligate intracellular parasite which is known to infect one-third of the total world population chronically though it is asymptomatic in immunocompetent patients. However, in an immunocompromised patient or an infected fetus, it may cause devastating effects. The parasite may cross the placenta of an infected pregnant woman and probably infect the fetus congenitally. The severity of the infection depends on the gestational age at which the infection has occurred i.e., if it has occurred in the early phase, the rate of transmission is low but the severity is high if the fetus is infected and if it has occurred in the later phase then transmission rate is higher while the severity would be low. Congenital toxoplasmosis may result in non-specific consequences like abortion, intra-uterine growth restriction, jaundice, hepatosplenomegaly or even intra-uterine death. It may also result in neurological or ocular manifestations like intracranial calcifications, hydrocephalus or retinochoroiditis. The diagnosis may be done by serological screening of anti-Toxoplasma antibodies (IgM and IgG) while PCR of the amniotic fluid or the placenta is the confirmatory test. Acute or chronic infections may be differentiated by IgG avidity tests. The treatment regimens include spiramycin to prevent congenital transmission from an infected mother, pyrimethamine, sulfadoxine and folinic acid to treat the infected fetus, CSF shunting for the treatment of hydrocephalus and a combination of pyrimethamine, azithromycin, and corticosteroids for treating ocular toxoplasmosis.     

Some aspects of amino acid metabolism in the rat fetus

• 1.1. In spite of an eventual catabolic phase during the last third of pregnancy, nitrogen retention seems to increase in pregnant rats. Furthermore, the high uterine blood flow and the high placental transfer of amino acids maintains an adequate nutrient supply to the fetuses.
• 2.2. The terminal rat fetus has a high circulating plasma amino acid level, as well as an increased free amino acid tissue pool when compared to its mother's.
• 3.3. In the rat fetus the development of enzymatic capabilities shows a sudden emergence (also denomined clustering) in late fetal life. In a general trend, the activities of enzymes related with amino acid metabolism are not well developed during rat fetal life.
• 4.4. The rate of amino nitrogen excertion in rat fetus is low, mainly due to the low development of urea cycle enzyme activities.
• 5.5. The rates of protein synthesis in many tissues are high in the rat fetus and they show a progressive decrease until delivery. On the other hand, the rates of protein breakdown are also higher during fetal life than in the adult.

     

11β—羟基类固醇脱氢酶

现已发现两型１１β－羟基因固醇脱氢酶（１１β－ＨＳＤ）：１１β－ＨＳＤ１为氧化还原酶,催化皮质醇与其代谢产物之间的相互转化;１１β－ＨＳＤ２则为专一氧化酶,只催化皮质醇的失活。１１β－ＨＳＤ１在体内分布广泛,功能目前沿不清楚。１１β－ＨＳＤ２主要存在于盐皮质激素靶器官,肾脏１１β－ＨＳＤ２通过降解糖皮质激素保护盐皮质激素受体的特异性,肾脏此酶的缺乏,可以导致严重高血压。胎盘１１β－ＨＳＤ２通过降解     

Development of the mucosa and differentiation of the lymphocytes of the vermiform appendix of the human fetus

One hundred and twenty-two appendices have been obtained from 12-30-week-old human fetuses and studied histologically (90) and immune-morphologically (32). Lymphoid follicles in the organ appear on the 17th week. Character of the epithelial and the reticular tissue structure in the area of the cupola including the lymphoid follicle have been studied. T- and B-lymphocytes have been stated to be present in the appendix of a 17-week-old fetus. As the fetus is further developing, the number of lymphocytes in the appendix increases: the amount of T-lymphocytes is practically constant, and that of B-lymphocytes increases. Direction of the lymphocytes migration out of the follicle is demonstrated. The lymphoid formations of the appendix are necessary for certain local protective reactions and already in the fetus they begin to participate in the general system of the organism's immunogenesis.     

What's in a Name? Death before birth

The medical, legal, and lay communities utilize a range of words to describe a pregnancy that does not result in live birth. These terms, including abortion, miscarriage, and stillbirth, are more than just words: they carry with them a range of meanings and social consequences. This paper explores the complex implications embodied in the language used to designate fetal death and describes how they simultaneously, and paradoxically, establish conflicting subject positions for mother and fetus. It also examines the statutory regulations that affirm the problematic terms in a manner that may leave grieving families without ritual outlets for the expression of their loss. This paper draws on specific examples from Aotearoa New Zealand, while recognizing similarities across Western cultures.     

Blunt abdominal trauma in pregnancy.

Two cases are presented in which the effects of blunt trauma to a pregnant woman''s abdomen were apparently minor but resulted in fetal death. Blunt trauma may result in serious injury to the fetus or the placenta. Three-point restraint systems should be worn by pregnant women travelling in automobiles to minimize the risks to mother and fetus. Awareness of the potential for injury in these circumstances is essential to reduce the risks to the fetus.     

Correlations between pregnancy pathology, study of the placenta, antenatal echography and examination of the product of conception in a series of 175 congenital malformations

In order to verify the hypothesis that during pregnancy in a woman without peculiar history, signs could be discovered when the fetus is malformed we have reviewed the files of 175 women who had a malformed child and of 300 controls. All of these women had at least one clinical examination and one ultrasonographic examination during pregnancy. Two clinical symptoms were more often discovered in the mother of the malformed fetus (p less than 0.001): decrease of fetal movements and small for date fetus. The placenta is never abnormal in the mother with normal fetus. Placenta is abnormal in 31% of the mother with malformed fetus but the abnormalities are not specific. Ultrasonographic examinations allowed more often the discovery of a malformation when hydramnios (p less than 0.001) or fetal hypotrophy (p less than 0.01) or an anomaly of the morphology of the fetus is discovered. Accuracy of prenatal diagnostic is considered for the different categories of congenital malformations.