After Birth Ebook

Pregnancy Diet Plan

Pregnancy Diet Plan

The first trimester is very important for the mother and the baby. For most women it is common to find out about their pregnancy after they have missed their menstrual cycle. Since, not all women note their menstrual cycle and dates of intercourse, it may cause slight confusion about the exact date of conception. That is why most women find out that they are pregnant only after one month of pregnancy.

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Pregnancy Without Pounds

This proven program will get you through your pregnancy in better shape than most other women in as little as 27 minutes a day and with minimal effort. It contains all the information that I believe will Help you to look and feel like I did barefoot and beautiful! Inside you will learn Exactly how to avoid unwanted pounds, overcome your food cravings, care for your skin, dress to kill and look like one Hot Mama. Ive also put together Fifty simple, yet extremely effective pregnancy-friendly exercises and stretches to keep you and your body looking and feeling Great (includes 3 different fitness programs depending on Your fitness level)!

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Cognitive and Behavioral Differences

Behavioral differences are obvious between the sexes shortly after birth. Newborn boys cry more, respond less to parental comforting, and require more holding than girls. Newborn girls respond more strongly than boys to adult faces and to being held. Boys are somewhat more interested than girls in inanimate nonsocial objects. Boys seem to begin technical problem-solving

Mechanisms Operative in the Developing Brain

Many efforts during the past two decades to develop a suitable animal model for studying FAS met with only limited success. Microencephaly (reduced brain mass) is a characteristic finding in FAE FAS victims, and it was demonstrated that exposure of immature rodents to ethanol in late gestation or during the first two postnatal weeks caused a reduction in brain mass. However, numerous additional animal studies failed to provide an explanation for the reduced brain mass. A modest loss of neurons from the cerebellum was described, but this cannot explain an overall reduction in brain mass, nor can it explain the types of neurobehavioral disturbances observed in FAE FAS victims. The fact that treatment during the neonatal period (the first 2 weeks after birth) caused cerebellar neuronal loss and a reduced brain mass helped to narrow the period of peak vulnerability to the early neonatal period, which in the rodent is a time of rapid brain growth, sometimes called the brain growth spurt...

Major histocompatibility complex antigens

There are also class I-like molecules encoded by genes residing outside the MHC and on different chromosomes. 1) Neonatal Fc receptor (FcRn) first detected in rats and more recently in mice and humans, is involved in the acquisition of passive humoral immunity in young mammals during the first few weeks after birth. FcRn binds immunoglobulin G (IgG) from ingested mother's milk and transports it through gut epithelial cells into the bloodstream by transcytosis. 2) CD1 is a small multigene family, so far detected in several mammals including the mouse, rat and human. These antigens do not show significant polymorphism. CD1 proteins present nonpeptide lipid (mycolic acid) or glycolipid antigens from intracellular mycobacteria such as Mycobacterium leprae and M. tuberculosis to CD8+ a(3 T, CD4 CD8 a(3 T or y5 T cells or T cells within epithelial sheets. 3) Zinc a2-glycoprotein, a zinc-precipitable protein of human plasma, is another oligomorphic MHC-unlinked

Ontogenesis of RBC autoantibody response

Early work showed that neonatal thymectomy of NZB mice failed to prevent the generation of RBC autoantibody, although thymectomy immediately after birth appeared to delay the onset of autoantibody production. It was also established that RBC autoantibody production can be transferred to irradiated non-NZB H-2d recipients with bone marrow cells. Since the anti-RBC plaque-forming response still occurred in chronically T-depleted recipients, it was argued that an intrinsic defect was present in NZB B cells and implied that the RBC autoantibody response was T-independent. Recent work calls these interpretations into question. First, SCID mice repopulated with NZB pre-B cells fail to develop RBC autoantibodies despite that fact that high levels of IgM anti-DNA and low levels of IgG anti-DNA are generated. Secondly, chronic treatment of NZB mice with monoclonal anti-CD4 prevents or considerably delays the generation of RBC autoantibodies. Interestingly, anemia still occurs in...

Endocrinology of ageing

Reduction probably results from reduced stimulation of the liver to produce IGF1 rather than an age-related insensitivity or inability of the liver to respond to circulating GH. The predominant IGF-binding protein (IGFBP) concentration in the blood, IGFBP3, reaches maximum levels at puberty and decreases between 18 and 79 years (Corpas et al 1993). The second most abundant IGFBP, IGFBP2, decreases after birth until puberty, after which it gradually increases again, especially after the age of 60 (Clemmons 1997). At age 80 concentrations are nearly twice as high as in young adults. In agreement with this, our study in subjects aged between 73 and 94 years showed a decrease in serum IGF1 and IGFBP3 levels and an increase in both serum IGFBP1 and IGFBP2 levels.

Competitive Exclusion

Other enteric pathogens, particularly when cultures are administered to animals shortly after birth while the ecology of the gastrointestinal (GI) tract is relatively naive. 1 The mechanism by which CE cultures confer protection is not clearly understood but may involve one or more of the following factors 1) blockage of potential attachment sites 2) production of bacteriocins by endogenous bacterial species 3) maintenance of gut pH by volatile fatty acids and 4) competition for nutrients.

Hepatic Lobar Agenesis

After birth, possibly because of abrupt termination of the oxygenated umbilical venous inflow, the left lobe shrinks considerably so that the fetal lateral segment often comes to be located closer to the midline than the fetal medial segment. However, by convention, the fetal nomenclature for these segments is maintained after birth. The ligamenta teres and venosus lie within fissures that separate the left medial and lateral segments and the caudate lobe. Location of the liver can be abnormal, with one or more segments hypoplastic or absent36-38 (Fig. 2-26). Occasionally, the right rather than the left

The Stem Cell Environment Cytokines and Pluripotency

Genetic studies LIFR-null embryos die shortly after birth, and exhibit reduced bone mass and profound loss of moto-neurons. Embryos homozygous for the gp130 mutation die between 12 and 18 days postcoitum (dpc) because of placen-tal, myocardial, hematological, and neurological disorders. CTFR-deficient mice exhibit perinatal death and display profound motor neuron deficits.

Behavior of Mothers of Precocial Offspring

Fig. 1 Average amount of time spent licking lambs by maternal ewes in a four hour period after the birth of the lamb (lamb born at time zero). Intense licking occurs in the first hour after delivery (ewes spent 38 minutes of the first hour licking the lamb), but ewes are still spending some time licking the lamb four hours after birth. (From C. M. Dwyer, drawn from unpublished data.) (View this art in color at www.dekker.com.) Fig. 1 Average amount of time spent licking lambs by maternal ewes in a four hour period after the birth of the lamb (lamb born at time zero). Intense licking occurs in the first hour after delivery (ewes spent 38 minutes of the first hour licking the lamb), but ewes are still spending some time licking the lamb four hours after birth. (From C. M. Dwyer, drawn from unpublished data.) (View this art in color at www.dekker.com.)

Other dairy products to improve infant health

Infant formulas or so called breast milk substitutes aim to provide an efficient and safe alternative diet for infants of those women who are not able to continue breastfeeding until six months of life. infant formula can be fed directly after birth when breastfeeding is not possible follow-on formulas are designed for children after the sixth month of life. Breast milk substitutes aim to mimic the composition of human breast milk concerning protein, fat and carbohydrate composition. The only carbohydrate of infant formulas is lactose, whereas follow-on formulas contain other carbohydrates, too. Protein sources are mainly bovine whey or casein (in the standard cow's milk based formulas) or soy protein (for infants with lactose intolerance or cow milk protein allergy). The quality parameter for the evaluation of infant diets is the ability to allow normal physical growth as well as optimal neurological and mental development.

Lymphocyte Differentiation

B cell differentiation broadly construed encompasses both the generation of B lymphocytes from precursor or stem cells (i.e. B cell development), as well as their maturation into plasma or memory cells. B cell lymphopoiesis begins in the embryonic yolk sac, switches to the fetal liver, and shortly after birth becomes established in the bone marrow. While B-2 (conventional) B cells are continuously generated in the adult bone marrow, B-l (CD5+) B cells are predominantly produced early in ontogeny in the fetal liver. Early B cell differentiation has been divided into steps or stages based on the status of immunoglobulin gene rearrangements, the expression of cell surface molecules, and the in vitro growth requirements of the developing B cells. One commonly used scheme based on the expression of the cell surface markers B220, CD43, BP-1 and HSA is shown in Table 1. Included in the table are the expression

In Vitro Fertilization and Surrogacy

The birth mother (surrogate) usually signs a contract to allow the adoption of the baby upon birth. However, hormonal changes during pregnancy, especially the increased levels of oxytocin, can produce a variety of behavioral changes, often termed maternal instinct, in the pregnant woman. The woman may have been quite willing to surrender the child upon birth, but she may have become unwilling to do so after birth.

Genetics of Eye Color

Differences in iris color have been attributed to such causes as the temperature of the brain and eyes. Some people have stressed differences between dark-eyed and light-eyed populations and have suggested that eye color is related to general traits such as temperament or intellect. But, toward the middle of the nineteenth century, it had become clear that iris color was due to iris pigment, that this pigment developed soon after birth, and that the final quantity and distribution of the pigment was a hereditary trait.

Explaining Cross Cultural Variation

Homosexual behaviors are rare in societies with monogamous nuclear families where husbands and wives sleep in the same room, and where there is close father-child contact. Homosexuality and transvestism are also rare in societies with the couvade (Carroll, 1978 Munroe, 1980). Although early researchers explained these findings with neo-Freudian theories about sex identities, a more parsimonious explanation might be that they simply reflect a society's attitude toward paternal investments. By spending more time with the children of just one wife, a father automatically devotes more of his resources to his children. And by submitting to couvade taboos around the time of birth he demonstrates to all of society his willingness to assume his paternal responsibilities. In societies with the couvade, fathers are more likely to sleep apart from their wives during the first months or even years after birth. Rather than indicate less paternal investment, this may in fact indicate greater...

Brain Reorganization

Rehabilitation and the developmental learning process have some aspects in common. Both include important elements of inhibition in regard to selective function and precisely coordinated movements. For example, a child learning to write initially demonstrates electromyographic activity in virtually all the muscles related to the hand. As ability increases, muscle activity decreases progressively until there is a minimum of activity, which is coordinated precisely to produce just the muscle action necessary for writing. It then becomes virtually fatigue-free. Following brain damage, coordinated movements are often disturbed. Patients become fatigued when attempting controlled movements rehabilitation is then oriented toward the restoration of precise, fatigue-free movements. Comparably, reflexes that are normal shortly after birth (e.g., Babinski's) are inhibited during maturation and

Cumulative Advantage Doctrine Of See Matthew Effect

The cupboard theory is one of the earliest explanations for the phenomenon of infant attachment. The theory refers to the mother's providing food when her infant is hungry, warmth when it is cold, and dryness when it is wet and uncomfortable. That is, the mother functions virtually as a cupboard of supplies for her infant. Through her association with the infant and giving such needed supplies, the mother herself becomes a positive stimulus (conditioned reinforcer) and, as a result of the association process, the infant clings to her and demonstrates other signs of attachment. A number of experiments conducted on the phenomenon of infant attachment in the monkey, however, indicate unequivocally that the cupboard theory cannot account exclusively for attachment behavior in infants. Rather, the clinging behavior (in the case of the monkeys, clinging to a soft, cuddly form) in infants appears to be an innate response. The American psychologist Harry Harlow (1905-1981)...

Growth Infancy Through Adolescence

After birth, the complex growth process causes the dimensions of bones in the lower limbs to continue to increase until maturity (46). The most accurate data correlating long bone length with chronological age at death originate from radiographic studies of the living. Data on long-bone growth from such studies are provided by Anderson and Green (47) Anderson, Green, and Messner, (48) Anderson, Messner, and Green (49) as well as Francis (50), Ghantus (51), Gindhart (52), Hoffman (53), Maresh (37,38), and Maresh and Deming (39).

Past and Personal History

Relevant past history should concern enquiry about the progress of mother's pregnancy, the circumstances at birth, psychomotor development, diseases during infancy and childhood, neurological sequel consequent to these diseases, and the time interval before the appearance of the symptoms. The place and the conditions during birth should be documented. The psychomotor development must be evaluated according to age specific milestones including but not limiting to sitting, walking, talking etc. A developmental abnormality is probably a sign of central nervous system (CNS) disease. In developing countries obstetrical trauma and perinatal hypoxic-ischemic brain insults are frequent. Multiparity, prematurity, malnutrition, anemia, lack of hygiene and neonatal infections are highly prevalent and may result in many types of cerebral lesions that could result in seizure disorder in later life.19 Of the 1374 patients with epilepsy studied in the community in 9 African countries, mother's...

Risk of Radiation Induced Tumors

Stewart estimated that an in utero irradiation of 10-20 mGy increases the risk of cancer in the child by 1.5-2 (Stewart 1973). Harvey et al. (1985), who studied twin pregnancies subjected or not subjected to diagnostic radiation averaging 1 cGy, evaluated the relative risk at 2.4. However, this risk continues to be debated. It is surprising to note that the risk of radiation-induced cancer is higher when the radiation is received at the end of pregnancy rather than just after birth (Miller 1995). In addition, the tumors observed in children are more of the embryonic type, which does not correspond to tumors known to be radiation-induced.

Gender over the Life Cycle

All phases of Aymara life are explicitly gendered. A baby's gender is its first identity after birth. Even gestation is believed to be different, with boys requiring 8.5-10 months and girls only 7 or 8 months (Buechler & Buechler, 1971, p. 21). The word for baby, wawa, applies to both genders, but the new infant may be described as either a little man or little woman. The child will not receive a formal name until its first haircut as a toddler when the soul is considered to be firmly established in the body. Until then, various gender-appropriate names may be tried out. Neither the soul nor the first haircut and naming ceremonies are differentiated by gender, however.

The genesis of chromosome abnormalities

Enters meiosis produces four spermatozoa the process is continuous, taking 64 days in all. Once past puberty, the male remains fertile into old age. In contrast, the human female is born with a complete set of oogonia - no more develop after birth. The initial stages of the first meiotic division take place early in fetal life but, after synapsis and recombination, each cell enters a period of arrest until after puberty. One egg then matures in each monthly cycle. Ovulation occurs when the oocyte is at metaphase II of meiosis and completion of the second division occurs after fertilization. Although there are several million oogonia at the outset, most are lost before birth and only a few hundred ever mature. Once the egg store is depleted, the menopause begins and the woman becomes infertile.

Way to Test Multistage Models

In the 1960s, the importance of somatic mutations and the nature of stages in progression continued to be debated (Foulds 1969). Several authors developed the idea that cancer arises by the accumulation of genetic mutations to cell lineages. Burch (1963) noted that if a sequence of mutations drives progression, then some individuals may inherit one mutation and obtain the rest after birth by somatic mutation. Burch

Dna Methylation During Normal Development

The essential role of DNA methylation in mammalian development is highlighted by the fact that mutant mice lacking each of the enzymes (generated by gene targeting) are not viable and die either during early embryonic development (Dnmtl and Dnmt3b) or shortly after birth (Dnmt3a). The knockout of Dnmt3l leads to male infertility and the failure to establish imprints in female eggs. Disruption of Dnmt2 did not reveal any obvious effects on genomic DNA methylation. The biological role of Dnmt2 is still elusive however, a possible role in centromere function has been suggested.

Abnormal Dna Methylation Patterns In Clones

These abnormal DNA methylation patterns could result in embryo lethality or phenotypic abnormality. Little is known about the developmental role of dynamic changes in DNA methylation during preimplantation, although recently, the importance of early embryonic methylation patterns in setting up the structural profile of the genome was shown. The failure to establish correct methylation patterns early in development might therefore have far-reaching effects on the chromatin structure. Interestingly, mouse embryos deficient for Dnmt1 and Dnmt3b die around embryonic day 9.5, but Lsh mutant mice die only after birth, despite showing a substantial loss of methylation throughout the genome. This would suggest that, at least for embryogenesis, high levels of DNA methylation are not essential.

Cultural Construction of Gender

The Beng recognize two gender categories, leg (female) and go) (male). In the first few years, the only visual signs of gender difference are that girls nowadays (although not traditionally) have their ears pierced a few days after birth, and baby boys and girls may also wear different necklace and hair styles. Otherwise, all babies wear a variety of jewelry and face and body paints, undistinguished by gender, to prevent disease. Until approximately 5-7 years old, the gender of children is not significantly distinguished by clothes. Boys and girls

Colostrum Composition

The initiation of mammary secretion (lactogenesis) consists of two stages. 1 The first stage takes place before birth and is characterized by accumulation of yellow, viscous, serumlike colostrum in the mammary glands. The second stage of lactogenesis takes place at or shortly after birth and is characterized by active synthesis of lactose in the mammary glands. Different secretory mechanisms of colostrum and milk are reflected in their chemical compositions (Tables 1 and 2).

Effects Of Colostral Immunoglobulins And Antiinfectious Agents

Immediately after birth. 2 4 weeks postpartum. (Data adapted from Ref. 1.) immediately after birth. 2 4 weeks postpartum. (Data adapted from Ref. 1.) After birth via the gut The ability to absorb macromolecules ceases within the first day or two after birth by a process known as intestinal closure. In some species (e.g., rat, mouse, ferret), intestinal closure is delayed until several weeks after birth. In humans, only the fetal small intestine has the characteristics required for the uptake of intact immuno-globulins. The signals to induce gut closure vary among species and may involve colostral and systemic factors, as well as the maturity of the gut epithelium itself.

Clinical Description

In symptomatic individuals, certain clinical manifestations are common. In women, menorrhagia is frequently reported and there is an increased risk of bleeding after childbirth. 9 Epistaxis may occur, whereas petechiae and bruising are rather unusual. 9 Bleeding can be excessive and frequently manifests postoperatively, in particular after surgical procedures involving tissues with high fibrinolytic activity such as dental extractions, tonsillec-tomies, prostatectomies, or urinary tract operations. For other surgical interventions such as appendectomies, orthopedic operations, cholecystectomies, or hysterectomies, the risk of severe bleeding is less pronounced. 10 Sometimes the first bleeding episode is observed after circumcision. 9 Bleeding can be immediate, 9 but typically, it is protracted or presents as persistent oozing after surgery. 10

Clinical Characteristics

As L. monocytogenes is prevalent in food for human consumption, exposure to this pathogen by the consumption of contaminated food would be considered fairly common. However clinical disease is rare and mainly occurs among the immunocompromised, the pregnant, and the elderly (age > 60 yr). Listeriosis usually manifests itself as meningoencephalitis and or septicemia. In Europe, approx 20 of clinical cases are pregnancy-associated (including neonates within the first 3 wk after birth), and the majority of the rest occur in nonpregnant immunocompromised individuals or in the elderly. The median incubation period is estimated to be 3 wk. Outbreak cases have occurred 3-70 d following a single exposure to an implicated product (13).

Pregnancy and Fetal Growth

Since World War II, the role of maternal nutrition in fetal growth and development has been extensively studied in the context of protein-calorie malnutrition. The role of n-3 fatty acids has only recently come into focus, despite the evidence of its importance having been demonstrated in a series of studies between 1928 and 1930 involving rats and primates. Lipid nutrition during pregnancy and lactation is of special relevance to human development, because brain development in the human takes place during fetal life and in the first 2 years after birth. DHA is found in larger amounts in the gray matter of the brain and in the retinal membranes, where it accounts for 30 or more of the fatty acids in the ethanolamine and serine phos-pholipid. DHA accumulates in the neurons of the brain between weeks 26 and 40 of gestation in humans. with increasing neuromotor activity. The increase in cell size, number, and type requires de novo synthesis of structural lipids, leading to accumulation...

Findings about Morbidity and Mortality

In the 1980s some African clinician-activists from countries that practice those rites documented and brought to the world's attention the accompanying morbidity and mortality. Those pioneering medical studies include the ones conducted in the Sudan by Asma El Dareer (1982), in Sierra Leone by Olayinka Koso-Thomas (1987), and in Somalia by Raquiya Haji Dualeh Abdalla (1982). The death, infection, and disabilities associated with the rites are well established, challenging local beliefs that the rites promote health and well-being. For example, as Koso-Thomas (p. 10) pointed out, stable medical evidence discredits the belief that death could result if, during delivery, the baby's head touches the clitoris, and Abdalla (p.16) pointed to the disutility of regional practices of putting salt into the vagina after childbirth because this induces the narrowing of the vagina to restore the vagina to its former shape and size and make intercourse more pleasurable for the husbands.

Male Genital Alteration in Islam

Depending upon the particular Islamic tradition and which scholars are most influential, male circumcision can be considered either obligatory or strongly recommended. The Prophet Muhammed recommended that circumcision be performed at an early age. In many Muslim cultures, the preferred time is on the seventh day after birth, and that is the common practice among North American Muslims.

Possible influences on fearful behaviour in cats

Another factor that is important in determining feline personality is genetics, and the specific influence on boldness and timidity is something that needs to be taken into consideration. Kittens can be reliably identified from the behaviour of their fathers even when they have never met (Turner et al., 1986) and inheritance of the 'boldness' trait is believed to be an important factor in avoiding problems of fearful behaviour in later life (McCune, 1995). Research has concentrated on the paternal component of this aspect of behaviour, since it is easier to separate genetic and observational influences on kitten behaviour when the torn is not in direct contact with the kittens after birth. However, this does not mean that the queen is insignificant in her contribution to the personality of her offspring, and maternal genetic influences should also be considered.

Hoffding Stepphenomenon

The German philosopher and psychologist Harald Hoffding (1843-1931) advanced the notion that laughter - as an expression of pleasant feelings - is possible at a lower stage of consciousness than is involved in the upper-level of the appreciation of the ridiculous. According to Hoffding's theory of humor laughter, laughter may be aroused, also, by certain physical conditions without being the expression of any emotion (e.g., intense cold may produce laughter as well as shivering). In Hoffding's analysis, smiling does not appear until the fourth week after birth, when it is accompanied by various bleating sounds such sounds - together with the smile - develop later into laughter which is considered originally as an expression of satisfaction. Hoffding's position on laughter approaches Hobbes' humor theory when the former examines how laughter is aroused by the perception of the ludicrous laughter is primarily an expression of pleasure in general, but...

Background to the idiotype network theory

It should be pointed out that not all idiotypic (Id) determinants seem to be equally immunogenic. The dominant idiotopes that are expressed in high amounts in the circulation rarely cause anti-Id responses compared to individual or minor idiotopes. However, experiments carried out with animals in which the expression of cross-reactive idiotypes were suppressed after birth showed that such animals are able to produce anti-Id antibodies subsequent to injection with cross-reactive idiotypes.

Ontogenetic and phyiogenetic significance of the idiotype network

Shown that the injection of idiotype into mice during pregnancy stimulates the generation of idiotype-spe-cific helper cells in neonates, which can expand silent clones to become dominant. Similar results can be obtained with anti-Id antibodies administered after birth. In physiological terms, it is advantangeous for progeny to inherit the immune experience of the mother with an expansion of clones that are specific for common pathogens of a given species. This is particularly important in the period of postnatal life when the concentration of antibodies provided from the mother starts to decline.

Atpase Chromatinremodeling Complexes

The diversity of chromatin-remodeling complexes is likely to be even greater than is currently realized. Numerous SWI2 SNF2-related genes have been identified by reduced stringency hybridization or genome sequencing projects, and some of these genes probably encode orphan catalytic sub-units of complexes that await identification and purification. Some of these putative catalytic subunits have interesting properties, such as the ability to regulate DNA methylation. A targeted mutation of Lsh (lymphoid specific helicase) results in a 50 to 70 reduction in cytosine methylation throughout the genome. Homozygotes die shortly after birth, possibly because of renal failure. (The gene is lymphoid-specific in adults but widely expressed in embryos.) Interestingly, expression and activity of de novo and maintenance DNA methyltransferases are unaffected. Instead, Lshl is expressed during S phase and may facilitate localization of Dnmtl to hemimethylated DNA following replication or protect...

Gender over the Life Cycle Socialization of Boys and Girls

Long, and dress, with boys wearing shorts and shirts, and girls wearing dresses as well as shorts and shirts. Both infant boys and girls are provided with a baki ritual named bagor soon after birth, to introduce them to the spiritual beings. Christian Ifugao may also, or only, have their infant children baptized in a Catholic church or participate in a Protestant dedication ritual. Ifugao conduct a baki ritual when naming their children. One early rite of passage in which only boys participate is the first cutting of their hair, which includes a baki religious ritual and feast (Barton, 1911).

Changes in Foetal Circulation at Birth

At birth, pulmonary vascular resistance falls markedly as the lungs expand and become aerated. This reduces pulmonary arterial pressures and increases blood flow to the left atrium. Umbilical vessels constrict strongly when exposed to trauma, tension, catecholamines, angiotensin and PaO2. These stimuli occur at birth and placental circulation ceases resulting in a rise in systemic vascular resistance and arterial pressure. These changes make left atrial pressure higher than right atrial pressure and tend to close the foramen ovale. The ductus arteriosus closes soon after birth usually within 48 H. The mechanism for this closure has not been completely identified, although a high PaO2 appears to initiate the closure and exposure to a low PaO2 can reverse the closure in the neonate. Prostaglandins maintain the patency of the ductus arteriosus and indomethacin may be successful in closing a patent ductus arteriosus in a neonate.

Partition of Maternal Nutrient Supply Between Maternal and Conceptus Tissues

Soon after birth and is characterized by very high plasma concentrations of growth hormone and low levels of insulin-like growth factor (IGF) I during fetal life. 6 Circulating levels of IGF-II are much higher in the fetus than in the dam, related to the relatively high expression of this growth factor in multiple fetal tissues.

E Gaba Affects Overall Excitability

Outside of the CNS, compromised GABA signaling during development produces cleft palate, a craniofa-cial abnormality in which the roof of the mouth fails to close completely. Animal studies suggest that the barbiturate diazepam, which interacts with GABAA receptors, can cause palatal defects. In addition, mice lacking GAD67 are born with cleft palate and die shortly after birth. The route by which GABA may be associated with cleft palate is not well understood.

Sudden cardiac death in infancy

Sudden death in infancy is usually caused either by infection or by sudden infant death syndrome. A few neonatal or infant deaths are caused by unrecognised congenital cardiovascular malformations, particularly duct dependent abnormalities or obstructive left heart malformations.6 Primary arrhythmias are rare causes of death in infancy but fatal ventricular arrhythmias are described.6 Complete atrioventricular block is usually recognised in utero or soon after birth but may cause death if unrecognised or untreated.w7

The Acting And Perceiving Hand

The importance of the cortical involvement in fine fingertip control can be further appreciated by considering parallels between the ontogenetic development of central neural pathways and that of hand function. The efficacy of the corticomotoneuronal system can be probed using transcranial magnetic stimulation (TMS) of the brain. TMS applied over the hand area of the motor cortex activates muscles of the contralateral hand. During development the latency of this activation, and the stimulation strength required to elicit a response, decreases as the corticomotoneur-onal connections are established. The conduction delays in these motor pathways, as well as in the somatosensory pathways conveying signals from the sensors of the hand, rapidly decrease during the first 2 years after birth and thereafter remain constant at adult values. Responses within the adult latency range appear during the age range in which young children demonstrate important improvements in their ability to grasp...

Choline And Brain Development

Choline availability during embryogenesis and perinatal development are especially important for brain development. There are two sensitive periods in rat brain development during which treatment with choline (about 1 mmol d administered to the mother during a critical period during pregnancy, or 300 mg kg administered subcutaneously 2 wk after after birth) produces long-lasting enhancement of spatial memory that is lifelong (28-36). The first critical period occurs during embryonic d 12-17 (rats give birth on d 21) and the second occurs during postnatal days 16-30. Choline supplementation during these critical periods elicits a major improvement in memory performance at all stages of training on a 12-arm radial maze. The two sensitive periods for memory responsiveness to supplemental cho-line correlate with the formation of cholinergic neurons (neurogenesis prenatal) and with the formation of nerve-nerve connections (synaptogenesis prenatal and postnatal) in the hippocampus and basal...

Persistent pulmonary hypertension of the newborn

Figure 22.1 The upper figure (A) illustrates the rapid reduction in pulmonary arterial wall thickness occurring immediately after birth in the normal lung. This process is profoundly disturbed in persistent pulmonary hypertension of the newborn (PPHN) and an increase in medial thickness eventually leads to pulmonary vascular obstructive disease (PVOD) if the pressure remains high. Insert shows abnormal, hypertensive human peripheral pulmonary artery at three days, stained for yactin. Mechanisms are illustrated in B, C, and D. (B) Confocal and transmission electron microscopy shows, in the left hand panel, the normal porcine peripheral pulmonary artery, and in the right hand panel, the pulmonary hypertensive vessel at three days. Normal remodelling entails reorganisation of the smooth muscle cell actin cytoskeleton which undergoes transient disassembly as the cells thin and elongate to spread around an enlarging lumen. In PPHN larger cells are packed with red actin myofilaments...

Dha Therapy For Patients With Disorders Of Peroxisome Biogenesis

The rationale for DHA therapy in PBD is simple and, at first glance, compelling DHA is important for brain and retinal function, it is deficient in PBD patients, and its level in blood and probably also in brain and retina can be increased by oral DHA administration. A serious limitation is that malformations in brain and other organs develop during fetal life and cannot be remedied by postnatal therapy. Thus, the rationale for therapy is based on the hypothesis that correction of DHA deficiency can remedy secondary ill effects that occur postnatally. Martinez has emphasized that in normal brain, DHA levels increase most rapidly during the perinatal period (Martinez, et al., 1974). Postnatally, brain DHA levels increase at a lower rate from the second month until the second year and level off thereafter (Martinez, 1992). It is postulated therefore that DHA therapy in PBD patients has the greatest chance of success if it is begun during the first 2 yr of life, and preferably shortly...

Studies In Experimental Animals

Jannsen et al. (Janssen, et al., 2000) have conducted studies in the PEX5 - - mouse model of human ZS. These animals show clinical and neuropathological abnormalities similar to those in the human disease, including the characteristic defect in neuronal migration. At birth, levels of DHA in brain were 40 less than in control littermates, but DHA levels in the liver were normal. Because the PEX5-deficient animals are incapable of synthesizing this substance, all of their DHA must have been supplied by the mother. The maternal supply appears sufficient to maintain normal DHA concentrations in the liver, but insufficient to maintain levels in the fetal brain. We have obtained similar results of our studies in the PEX2 - - mouse model of human ZS (Su, et al., 2000). The demonstration of the fetal brain DHA deficit provides the opportunity to determine whether DHA supplementation can ameliorate the neurological deficits. To test this hypothesis the diet of the mothers' of PEX5-1 -mutants...

Cross Cultural Examples of Child Growth

Two volumes by Eveleth and Tanner (1976,1990). Also see Ulijaszek, Johnston, and Preece (1998). There is relatively little difference between individuals cross-culturally in growth before birth, as birth length clusters at 50 cm and mean birth weight ranges from 2.4 kg to 3.4 kg. To be sure, infants born to smaller, undernourished, or ill mothers may be shorter and weigh less than infants born to taller, heavier, or healthier mothers. Indeed, birth weight serves as an indication of the overall health of the infant, and epidemiologists use the mean birth weight of a social group as an indication of its general quality of life. Even so, more variation between individuals and populations develops with time after birth. By adulthood, the range in stature is from 184 cm for young men in the Netherlands (Fredriks et al., 2000) to 145 cm for Efe Pygmy men (Dietz, Marino, Peacock, & Bailey, 1989). In these and other populations, adult women are from 8 cm to 14 cm shorter than men....

Nutritional Programming

We have developed a rodent model of fetal programming using maternal undernutrition throughout pregnancy. On day one of pregnancy animals are randomly assigned to a standard rat diet ad libitum throughout pregnancy (ad libitum (AD) group) or 30 of the AD group intake of the standard diet throughout gestation (undernourished, UN group). After birth, litter size and birth weights are recorded and litter size is adjusted to 8 pups per litter. The number of pups born per litter from UN and AD mothers is identical in this experimental approach it is not affected by maternal undernutrition. The UN offspring are cross-fostered within 24 hours of birth onto AD dams to assure adequate and standardised nutrition from birth until weaning. At birth offspring of UN mothers had fetal and placental weights that were 25 30 lower than offspring of AD mothers. A lack of catch-up growth despite a standard postnatal diet4 was accompanied by a transient reduction in circulating IGF-I and hepatic IGF-I...

The Elusive Cardiac Stem Cell

The adult mammalian heart has long been considered a post-mitotic organ without an endogenous population of stem cells, which instead contain a relatively constant number of myocytes that cease to divide shortly after birth and remain constant into senescence. A long-standing view is that the inability of differentiated cardiac myocytes to reenter the cell cycle may present the ultimate impediment to the heart's regenerative capacity and may be responsible for the drastic effects of acute and chronic myocyte death in the surviving myocardium after infarction.

[2 Phenotype Changes of Fut8 Knockout Mouse Core Fucosylation Is Crucial for the Function of Growth Factor Receptors

Core Fucosylation

Semilethality and growth retardation in Fut8 ' mice. (A) Survival ratio of Fut8 ' (- -, striped bar), Fut8+ (+ -, gray bar) mice after birth. (B) A 16-day-old Fut8 ' pup (- -) with a Fut8+ + litter mate (+ +). Fig. 2. Semilethality and growth retardation in Fut8 ' mice. (A) Survival ratio of Fut8 ' (- -, striped bar), Fut8+ (+ -, gray bar) mice after birth. (B) A 16-day-old Fut8 ' pup (- -) with a Fut8+ + litter mate (+ +).

Mouse Models and the DNA Sequence

One of the most notable new advances in research about Down syndrome is the recent production and characterization of mouse models trisomic for significant regions of mouse chromosomes that are homologous to human chromosome 21 (Davisson and Costa, 1999). The genes on human chromosome 21 are found on three mouse chromosomes, 16, 17, and 10. So far, the order of genes in the mouse is the same as the order in the human. This conservation of chromosomal regions has led to attempts to produce mice trisomic for the parts of mouse chromosomes 16, 17, and 10 that are homologous to human chromosome 21. The first of these, trisomy 16 (Ts16) in the mouse, leads to lethality during embryogenesis or shortly after birth. Even so, during embryonic development, these mice show anatomic features that

Development of Microflora

The GI tract is essentially sterile at the time of birth and bacterial colonization begins upon exposure to the environment. Progression of colonization is initially fast, followed by a gradual process of modification over the first few years of life. As the baby passes through the birth canal bifidobacteria and lactobacilli are typically acquired and rapid colonization of mainly enterobacteria occurs. The hospital environment, type of feeding, and type of delivery affect the early colonization of the intestine after birth. Normal vaginal birth permits the transfer of bacteria of the mother as the infant passes through

Treatment Options and Continuing Research

Normally, the production of HbF is turned off shortly after birth. Scientists are trying to determine how to reactivate the gene for HbF so that the bone marrow of people with sickle cell disease can continually produce fetal hemoglobin without the use of medications. Other research focuses on learning how to insert normal beta chains and regulatory genes into stem cells, which are cells that develop into erythrocytes.

Laterality Across The Life Span

During the course of fetal development in humans, certain areas of the right hemisphere seem to develop earlier than homologous areas of the left hemisphere. Various possibilities have been suggested as to the manner in which certain functional asymmetries could arise from the interaction of these maturational asymmetries and changes in the nature of environmental stimulation. One promising idea is that the earlier developing right hemisphere is initially more influenced than the lagging left hemisphere by the impoverished information that the developing brain encounters. This might include nonlinguistic intrau-terine noises, global properties of visual stimuli in newborns, and coarse sensorimotor feedback before and for a few weeks after birth. By being more responsive to these early environmental influences, the right hemisphere may become dominant for perceiving various nonphonetic sounds, for processing global properties of visual stimuli, and for maintaining postural control. In...

The origin of mononuclear phagocytes

During ontogeny, the hematopoietic stem cell - a cell of mesenchymal origin - arises in the yolk sac. In a later stage of gestation, these cells migrate to the fetal liver, where immature mononuclear phagocytes develop hematopoiesis in the liver does not cease until term or the second week after birth, depending on the species. Soon after hematopoiesis begins in the fetal liver, monocytes appear in the circulation only after that does hematopoiesis commence in the bone marrow. Before hematopoiesis commences in the bone marrow, osteoclasts formed by fusion of circulating mononuclear phagocytes (e.g. monocytes or younger cells of this cell line) are found in embryonic bone. The approximate time during gestation, when mononuclear phagocytes appear in hematopoietic organs and in the circulation of mouse and human, is shown in Table 1.

Parental and Other Caretaker Roles

Household's labor force, these women, once they have rested after childbirth (generally 1-3 months), return to labor. Elders in the household will watch over babies and children. An elderly aunt or grandmother may be a primary caregiver, but sometimes an elderly uncle is an important caregiver. Once children become toddlers, older siblings and cousins of either sex often assume their care. Emotional bonds develop between children and caregivers, and at times the bonds of affection are stronger with aunts or uncles than mothers. Children generally refer to all women in the household in the mother's age cohort as emi, and all men as ewu.

Developmental anomalies

As part of a major congenital abnormality of the lower abdominal wall musculature the bladder may open directly onto an incompletely formed abdominal wall so-called ectopia vesicae. Previously the bladder was excised and the ureters diverted into the rectum (uretero-sigmoidostomy). With modern surgical reconstructive techniques it is now possible to close the bladder and repair the abdominal wall a few days after birth.

Fetalneonatal B cells exhibit a restricted antibody repertoire

It has been shown that the fetal neonatal repertoire of available antibody specificities is restricted. The development of antibody specificities during ontogeny proceeds in a temporally dependent and programmed manner. BALB c mice possess B cells capable of responding to the hapten dinitrophenyl and to the carbohydrate antigen (32,6-fructosan by day 1 after birth however, reproducibly, those B cells bearing the T15 idiotype and responsive to the antigen phosphorylcholine are only apparent at 1 week after birth. As a consequence of this pattern of antibody repertoire acquisition, the developing neonate has a more limited spectrum of available B cell specificities which diversifies in a predictable fashion.

Similarities and Differences between Monozygotic Twins

The fertilized egg cell that gives rise to MZ twins begins life with a single set of genes, and so we might predict that every cell that arises from it would be exactly identical. However, small differences between daughter cells may accumulate throughout embryonic development and later in life. The earliest difference may be in the mitochondria each inherits. Mitochondria are the cell's power plants and contain a small amount of DNA. Some of the hundreds of mitochondria in a cell may contain mutations. If the cells that create the two twins carry different mitochondrial genes, even identical twins will be genetically different. Mutations can also accumulate during embryonic development, or after birth, either in the mitochondrial genes or the genes in the nucleus. Such mutations may have a significant effect Some types of cancer are due to mutations accumulated during one's lifetime, often through exposure to environmental chemicals or radiation.

Nutritional regulation of immune function in low birth weight infants and in the elderly

The immune system develops during fetal life and the first few months after birth. If an infant is born preterm or if he or she exhibits growth retardation as a result of a number of environmental factors, including maternal malnutrition or infection, im-munocompetence is reduced. The impact on T lymphocyte numbers and cell-mediated immunity is most discernible. The preterm infant of low birth weight generally recovers its ability to mount immune responses by the age of 3 months. However, the small-for-gestational-age (SGA) infant may continue to show reduced cell-mediated immunity for several months and years. There is a significant difference in the immunocompetence of SGA infants who exhibit a higher level of morbidity and that of infants with lower morbidity. In laboratory animal models of intrauterine malnutrition, immune responses are impaired both in first- and second-generation offspring.

DNA Methylation and Chromatin Remodeling

The first connection between DNA methylation and chromatin remodeling came from studies in Arabidopsis. Mutation of a gene called DDM1 (decrease in DNA methylation) yielded plants with numerous growth defects and a profound loss of genomic 5-methylcytosine. The growth defects and losses of DNA methylation became progressively greater with increasing generations of inbreeding.74 Rather than a DNA methyltransferase, DDMl is a member of the SNF2 family of ATPases. Further evidence of a connection between DNA methylation and chromatin remodeling comes from studies of a human protein called ATRX. The ATRX gene is mutated in a human genetic disease called ATR-X syndrome (a-thalassemia, mental retardation, X-linked).75 ATRX is a member of the CHD subfamily of ATPases and has been shown to associate with transcriptionally inactive heterochromatin and due to its structure, may have a role in chromatin remodeling. ATRX patients also demonstrated DNA methylation defects, although they were far...

Parvovirus Infection And Immunity

Parvoviruses infect many animals including humans, and almost every species has its own parvovirus pathogen. Epidemics in dogs, swine, geese and mink are major practical concerns of veterinarians. Because of the requirement for actively proliferating cells, the developing fetus and the newborn are at highest risk of disease following parvovirus infection. Infection can lead to fetal death, congenital malformations or predominant damage to single organs that may not be manifest until weeks after birth, such as the cerebellar ataxia that follows in utero feline parvovirus infection. Parvovirus infection of young animals can be clinically severe, with manifestations of encephalopathy, hepatitis or myocarditis. Parvoviruses cause a variety of diseases in adult animals, including gastroenteritis in cats, dogs and mink, leukopenia in cats, and immune complex glomerulonephritis in mink persistently infected with Aleutian disease virus.

Hypoxia Fetal Growth and Developmental Origins of Health and Disease

The compelling evidence linking small size at birth with later cardiovascular disease, obtained from epidemiological studies of human populations of more than a dozen countries,1 has clearly renewed and amplified a clinical and scientific interest into the determinants of fetal growth, birth weight and the development of cardiovascular function and dysfunction before and after birth. As early as the 1950s Penrose2 highlighted that an important determinant of birth weight was the quality of the intrauterine environment, being twice as great a determinant of the rate of fetal growth than the maternal or fetal genotype. Studies of birth weights of relatives2 together with strong evidence from animal cross-breeding experiments3'4 have clearly supported this contention. One of the great qualifiers of the fetal environment is the maternal nutritional status during pregnancy. As such, the reciprocal association between low birth weight and increased risk of high blood pressure in adulthood,...

Potential Importance of Phytoestrogens to Human Health Molecular Mechanisms of Action

Phytoestrogens can cause infertility in some animals and thus concerns have been raised over their consumption by human infants. The isoflavones found in a subterranean clover species (in Western Australia) have been identified as the agents responsible for an infertility syndrome in sheep. No reproductive abnormalities have been found in peripubertal rhesus monkeys or in people living in countries where soy consumption is high. Indeed, the finding that dietary isoflavones are excreted into breast milk by soy-consuming mothers suggests that in cultures in which consumption of soy products is the norm, breast-fed infants are exposed to high levels without any adverse effects. Isoflavone exposure soon after birth at a critical developmental period through breast feeding may protect against cancer and may be more important to the observation of lower cancer rates in populations in the Far East than adult dietary exposure to isoflavones. Although some controversy exists as to whether...

Reassuring fetal heart rate patterns

The majority of fetal arrhythmias are benign and spontaneously convert to normal sinus rhythm by 24 hours after birth. Persistent tachyarrhythmias may cause fetal hydrops if present for many hours to days. Persistent bradyarrhythmias are often associated with fetal heart disease (eg, cardiomyopathy related to lupus), but seldom result in hypoxia or acidosis in fetal life.

Apoptosis In The Heart

The adult cardiomyocyte has limited (if any) ability to proliferate. Correspondingly, apoptosis is observed infrequently in adult hearts. In contrast, cardiomyocyte apoptosis plays a critical role in heart formation, such as formation of septa between cardiac chambers and valves. This evidence suggests that defects in apoptosis can result in congenital heart disease. Major foci of apoptosis include zones of fusion of the atrioventricular or bulbar cushions, and both aortic and pulmonary valves in non-myocytes. Myocyte apoptosis also occurs in the interventricular septum and right ventricular wall after birth, during the transition from fetal to adult circulations. The conducting tissue also undergoes apoptosis, and aberrant apoptosis is implicated in congenital heart block and long QT syndrome or the persistence of accessory pathways.

Primordial Germ Cells

In the mouse, PGCs are visible as alkaline phosphatase (AP) positive cells at the base of the allantois at 7.5 to 8.0 days postcoitus (dpc). They begin to associate with the endo-derm that is invaginating to form the hindgut at 8.5 dpc. By 10.5 dpc, PGCs are associated with dorsal mesenteries and are translocated to the genital ridges. The migration of PGCs is caused by both cellular migration and association with moving tissues. Throughout this migration, PGCs expand from approximately 130 cells at 8.5dpc to more than 25,000 at 13.5dpc. Once they arrive at the genital ridge, PGCs continue proliferating until they enter prophase of the first meiotic division. In males, entry into meiosis is inhibited by signals from the developing testis, blocking PGCs at G0 until after birth. In the absence of inhibitory signals, female PGCs undergo oogenesis.

Body Weight Body Composition and Growth

Seasonal stress continues after birth for both mothers and children. In The Gambia lactating women lost on average 0.74 kg month-1, at the same rate of nonlactating women. As shown earlier, during the wet season very young children get less attention and less breast milk from their mothers and their growth is affected. In Taiwan, children born in the hot wet summer season were smaller, but could catch-up in the following 3 months, while those born in the dry season had a larger birth weight but had a slower postnatal growth.

Cell Kinetics of the Enterocyte

After birth, new cells move in the direction of the lumen and mitosis continues for two or three more divisions while each cell remains within the crypt. As the enterocyte emerges out of the crypt, proliferation ceases and the process of differentiation proceeds so that the cell, now passing up the outer surface of the villus, reaches functional maturity with a full capacity of membrane-bound brush border enzymes toward the villus tip. On reaching the tip, enterocytes are sloughed off into the intestinal lumen and digested.

Breast Feeding During Illness

Mothers with hepatitis B can breast-feed their infants if the infant receives the hepatitis B vaccine during the first few days after birth. There is no evidence that hepatitis C is transmitted by breast-feeding. Mothers with chronic hepatitis C are often advised that they can nurse their infants, but they should discuss this with their physician. Other types of infections need to be evaluated by the obstetrician and pediatrician, but nearly all are likely to be safe for breast-feeding.

Advantages Of Markerassisted Selection

Traditional methods of selection can produce very accurate evaluations of genetic merit for traits that are high in heritability (observed or measured value is a good predictor of breeding value) or for individuals that have many progeny with phenotypes recorded. However, many traits of economic importance in livestock are low or moderate (10 40 ) in heritability or can only be measured postmortem, in which case, accurate genetic evaluations are only possible through progeny testing. Other important traits can only be measured late in the productive life of the individual. For these traits, accurate genetic evaluations can only be obtained after the selection decision (to produce progeny) has been made. These are the traits for which MAS is expected to accelerate the rate of genetic improvement1-1'2-1 because the DNA testing component of MAS can be obtained and combined with marker-adjusted estimates of the parents' breeding values anytime after birth. In theory, it is possible to...

Neuropathological Evidence for Neural Injury before Birth in Schizophrenia

However, these data are not conclusive, since some studies have not found evidence for abnormal migration in schizophrenia,4244 and other, more consistent findings such as alterations to neuronal size and synaptic and dendritic organisation may occur later in life, well after birth.5,35 The differences between studies may reflect the methodological difficulties and subde nature of the cytoarchitectural changes.35 Alternatively, it could mean that in many cases the putative in utero insult may occur after mid-gestation, when migration is largely complete.45,46 At this stage there is a marked increase in glial proliferation and if correct this would suggest that we should expect to see a consistent reduction in the amount of white matter.45,46

Congenital dislocation and developmental dysplasia of hip

Previously this condition was known as congenital dislocation of the hip (CDH). However the correct term is developmental dysplasia of hip (DDH) because in many cases the condition is not present at birth but rather develops after birth. Secondly in a majority of cases there is no frank dislocation but a dysplasia (poorly developed acetabulum) leading to instability of the hip joint.

The learning of flavour by the neonate

About eleven weeks after a baby is conceived it has developed an olfactory epithelium (Doty 1992). At this stage the only source of any olfactive stimulus is from the amniotic fluid surrounding the baby, however, this is in contact with the mother's blood and there is considerable evidence that volatile flavour molecules from the mother's diet can reach the baby in utero (Schaal, Marlier el al. 1998, 2000). As the baby grows and its brain develops it experiences more and more olfactive stimuli because it regularly takes amniotic fluid into its lungs which passes over the olfactive epithelium. Especially in the last few months before birth the food eaten by the mother has a strong influence on those flavours which will be preferred by the baby after birth (Menella, Jagnow el al. 2001, Schaal, Soussignan and Marlier 2002) though hardly any courses in prenatal instruction appear to mention this fact to mothers-to-be. After the baby has been born many new sensations become part of its...

Do feeding experiences in early life modify brain structure

The relationship between the emotional content of an eating situation and the flavour of the food has never, to the knowledge of the author, been considered in terms of the direct part it may play in the development of the baby's brain. There are, however, several things which lead to the conclusion that this could be an important and neglected influence on neonatal development. First, we have the well known fact that among all our senses it is only smell which directly influences the amygdala of the brain, the part that is the source of emotions. Second, the human brain is particularly plastic after birth and its growth and neural interconnectivity, especially in relation to the higher cognitive functions, is strongly influenced by sensory stimuli. Third, and most obviously, feeding

Selective Reduction in Multiple Pregnancies

Selective reduction is the process of destroying one or more fetuses with the purpose of reducing the pregnancy, usually to twins. In such a case, selective reduction could be ethically acceptable, because it is aimed at optimizing the quality of life after birth. Even so, those against selective reduction argue that it is ethically wrong and note that it may even, though rarely, result in a loss of the entire pregnancy (2 to 7 percent of cases).

Physiological Functions of atRA

The many RAR knockouts illustrate the physiological functions of vitamin A. Disruption of the RARa gene, the RAR with the most widespread, if not ubiquitous, expression in the embryo and adult, does not cause embryonic lethality but reduces the homozygous null population by 60 within 12-24 h after birth and by 90 within 2 months. The RARa null mice that survive 4 or 5 months have severe germinal epithelium degeneration and are sterile. RAR 3 gene null mice are fertile and viable and show no immediate signs of morphological abnormalities. Nevertheless, complementary data show that RAR,3 may mediate the antiproliferative function of atRA and as such may serve as a tumor suppressor. Moreover, RAR 3 null mice have virtually no hippocampal long-term potentiation or long-term depression, the forms of synaptic plasticity that provide a mechanism of short-term spatial learning and memory. This phenomenon can be reproduced by vitamin A depletion. RAR7 null mice have an 86 incidence of skeletal...

Acquisition of passively transferred immunity

In all higher vertebrates mechanisms have evolved to ensure that passive immune protection is provided to the neonate to assist in control of microbial challenge after birth until the endogenous immune mechanisms of the newborn animal have achieved sufficient functional maturity. The extent to which this occurs before or after birth differs vastly between species, an adaptation which is related to the type of placen-tation (Table 2). Ungulates obtain no immunoglobulin prenatally from the maternal circulation and are born agammaglobulinemic, but large quantities of maternal IgG are selectively transported into the mammary gland just prior to parturition and are ingested and absorbed intact into the circulation by the suckling neonate. The intestine in newborn ruminants is consequently adapted for large-scale uptake of intact immunoglobulin across the gut into the neonatal circulation in the first 24-28 hours of life, during which time the large, palely staining vacuolated cells of the...

Appetitive movements of face mouth and tongue

Lastly, from the very first day after birth, the mother's general body odour (gathered on clothing) stimulates oro-lingual responses in newborns more efficiently than another mother's odour (Sullivan and Toubas 1998). Oral movements can thus be highly selective, and can express neonatal motivation to explore and orally grasp the offered stimulus. The hypothesis that these oral movements anticipate feeding is suggested by the comparison of responses to different odours in the tested newborns, before and after nursing (see below).

Sensitivity of early olfactory detection

Research referred to in the first section indicates that olfactory discrimination capacity improves with postnatal age. Self et al. (1972) analysed the evolution of olfactory reactivity over the three first days after birth in terms of variations in respiratory rhythm and various behavioural indices. To that aim, she exposed newborns to constant, supra-liminal artificial odorants selected on the basis of their presumed lack of trigeminal elements (extracts of aniseed, Asa foetida, lavender and valerian) and to control stimulations (dry and humid blanks). As early as the first day after birth, over two-thirds of infants were capable of detecting most of these odorants. The percentage of subjects reactive to Asa foetida, lavender, or valerian, tends to increase between days 1 and 3. Is this increased reactivity connected with improved sensitivity of the olfactory system, or with functional changes in the effectors on which the detection indices are based

The discriminative power of early olfaction

The first study is based on electroencephalographic responses in sleeping infants. A former study indicated that the odours of coffee, citral, vanillin and pyridine, do not cause any significant alteration in the EEG of infants aged less than 6 days repeatable variations were reported only on infants between 6 and 90 days old (Fusari and Pardelli 1962). This negative result for the newborn period is surprising given highly discriminative behavioural findings presented above. A comparable discordance between behavioural and electrophysiological indices has been noted in human adults (Perbellini and Scolari, 1966) and in young animals. So, for example, even though no spontaneous electric activity has been detected in the olfactory bulb of newborn rats before 4 days (Salas et al. 1969), they rely exclusively on olfactory indices in heading for and localizing the nipple from the first postnatal hours. This incoherence between different levels of functional analysis should probably be put...

Memory and plasticity of olfactory function in early life 1841 Early postnatal shaping of odour preferences

Also, monitoring, between postnatal days 1 and 5, of the development of relative attraction towards two odour substrata, to which the infants were exposed just before or just after birth (amniotic fluid and milk), confirms the importance of repeated exposure in establishing infant discrimination and hedonic aptitudes. During days 1 to 3, the infants did not respond to the two stimulations in differential ways, indicating equal sensory and or motivational treatment of them (Marlier el al. 1997). However, with increasing age and nursing experience, they displayed an enhanced attraction for the milk odour compared to amniotic fluid odour, and this differentiation was significantly apparent after day 3. Progressively divergent responses towards the two odours can be explained by two mechanisms. The first phase (days 1-3 with 0-12 feeds) seems to reflect newborn preference for an odour acquired in the womb, as well as equivalent sensory and or hedonic responses to milk and amniotic odours....

Olfactory preferences established independently of postnatal experience

Other points specific to our own species support the hypothesis that nasal chemosensory detection does function in the foetus. Maturation of the chemo-receptor system is sufficiently advanced at the end of gestation to make the processing of chemical information possible (Schaal et al. 1995c, 2005). Chemical analysis has revealed the presence of numerous potentially odorous components in amniotic fluid (Schaal 2005). Lastly, fetal brain aptitude in detecting intra-uterine sensory information and in proving capable of retaining it after birth has been demonstrated in audition (DeCasper and Spence 1986, Granier-Deferre et al. 2005). For obvious ethical reasons, the human foetus is not accessible for experimentation. Accordingly, a posteriori approaches have to be devised to examine the aptitude of the foetal brain to memorise odours. These approaches examined responses of newborns to prenatal odours. It was first proven that newborns remain attracted to the odour of amniotic fluid...

Conclusions and future trends

In humans, as in other mammals, nasal chemoreception is already functional before birth and it can then contribute to the behavioural and physiological adjustments necessary to adaptive transitions in the postnatal period (cf. Schaal 2005). Chemosensory systems are comprehensive in nature, i.e. they can detect a large spectrum of odorants and flavorants, and are open to early influences, as attested by the variety of stimuli influencing behaviour and the variety of rewarding means and contexts which can boost up learning processes. However, some findings suggest that olfactory learning in early life may be paralleled with cognitive mechanisms that are more or less pre-functional. Certain odorants, often carried in homospecific milk, have particular reactogenic properties which are revealed in the absence of any prolonged exposure after birth. Such inborn predispositions may result either from sensory images shaped by pre-birth interaction between olfactory neurons and the environment,...

Src Family of Protein Tyrosine Kinases

The unique functions of Src were revealed when P. Soriano knocked out the mouse src gene. Surprisingly, considering the profound effects of activated v-src on vertebrate cells, absence of src had remarkably mild effects on development in utero. However, some defects were detected after birth. Teeth failed to erupt through the gum, and the cranium grew to form a domed shape. Both of these phenotypes are due to increased bone density, attributable to altered osteoclasts, the macro-phage-related blood cells that resorb and remodel bone. Detailed studies of src mutant osteoclasts indicate that they differentiate normally but have a reduced ability to form specialized adhesion contacts through which they stick to bone and initiate bone resorption. However, blood platelets and neurons, where Src is highly expressed, are not noticeably altered in src mutant mice.

Components of Parenteral Nutrition

Preterm infants often require more glucose than the term infant secondary to the higher brain to body weight ratio and the need for additional energy for central nervous system energy requirements. Measurements of glucose utilization in the preterm infant range from 6 to 10 mgkg1 min1 .033-0.055 mmol kg1 min1). Glycogen stores are very limited in the preterm infant therefore, it requires a large and continuous source of glucose. This should be initiated at a rate of 6mgkg_1 min1 (0.033 mmol kg1 min1) and can be advanced 1-2 mg kg1 min1 (0.0055-0.011 mmol kg1 min1) each day to an optimum of 12-14 mg kg1 min1 (0.066-0.78 mmol kg1 min1) as long as the infant does not become hyperglycemic. Above this rate, glucose is not used for energy but rather fat deposition. This is an inefficient process that can result in increased energy expenditure and carbon dioxide production.

Evolving Concepts of Regeneration

The limited restorative capacity of the adult mammalian heart has been attributed to the loss of cardiomyocyte versatility soon after birth. Emerging concepts of regeneration as an evolutionary variable are dramatically illustrated by the relatively robust proliferative capacity of the injured heart in other vertebrate species. The dramatic regeneration of urodele amphibian limb and lens extends to their robust repair of injured myocardium. Unlike their mammalian counterparts, adult

Mohair Biology and Characteristics

Mohair fibers are produced by cell division in primary (P) and secondary (S) follicles in the skin of Angora goats (Fig. 1). The two types of follicles are distinguished by their accessory structures. The P follicles each have a sebaceous gland, a sudoriferous (sweat) gland, and an arrector pili muscle. The S follicles have only a sebaceous gland. Some S follicles produce more than one fiber. The central P follicles are first observed on the fetal head about 40 days into pregnancy and spread across the body over the next 20 days. During this time, two more P follicles (laterals) appear on either side of the central P follicle, thus forming a trio group. After 80 days of pregnancy, S follicles associated with each trio group begin to emerge, forming a follicle group. At birth (day 149), all P follicles are fully formed and are actively producing fiber, whereas only a small but quite variable proportion of the S follicles are producing fibers. Twelve weeks after birth, most of the...

The Axonal Myelin Sheath

As cells that myelinate CNS axons, oligodendro-cytes line up along axons in tracts or diffuse white matter as interfascicular glia. In human fetal and postnatal development, tracts are myelinated and thus become fully functional at different times. Motor nerve roots are well-myelinated by birth, but optic nerves and sensory roots lag behind until the 3rd and 4th months after birth, respectively. The corticospinal tracts require 1 year to achieve full myelination, whereas cerebral commissural fibers requuire up to 10 years. This staggered ensheathment has important functional correlates for the developing individual when she or he can move, see, begin to walk, perform directed movements, and so on. One intracortical plexus is not completely myelinated until middle age the stripe of Kaes-Bechterew in layer IIIa (Fig. 8, right panel). Neuropathologist Paul Yakovlev called it ''the wisdom stripe.''

Determining Viability

Delivery of premature infants who are at the limits of viability is not an uncommon occurrence in the emergency department. Under these circumstances, the first priority of the physician caring for the infant is to determine whether resuscitation is justified. An infant born at a gestational age of less than 24 weeks, weighing less than 500 g, who has gelatinous skin and fused eyes should not, except under unusual circumstances, be resuscitated. By contrast, infants born at greater than 24 weeks are likely to have a relatively good outcome and should be supported aggressively after birth. The decision to initiate support must be made immediately. If the decision is not clear, proceed with resuscitation.

Physiological Cross Species and Evolutionary Perspective

Two hormones are involved in breast-feeding prolactin, which promotes milk production, and oxytocin, which enables the milk to move from the mammary glands into the infant's mouth. When an infant suckles, a signal is sent from the breast to the pituitary gland, which, in turn, stimulates the release of prolactin and oxytocin. Oxytocin is also involved in uterine repair after birth and in suppression of ovulation during the period of intense nursing, thus delaying the start of another pregnancy. Certainly the most important contribution of breastfeeding is nutritional, but breast milk also contains antibodies from the mother that protect the nursing infant from a number of pathogens to which it is exposed in the first few weeks of life. Also, as noted above, highly frequent nursing, especially when coupled with low caloric intake in the mother, usually leads to inhibition of ovulation in the first few months of nursing (Ellison, 2001). A longer birth interval is associated with lower...

Brain Lipids during Development

Days after birth in the pig brain, and during the first 8 or 9 months after birth in the human brain (Fig. 4). Moreover, the cells that multiply just before the peak cholesterol synthesis are almost all oligodendroglia, the cells that form myelin around the central neuronal axons. The same sequence of cell (oligodendroglial) multiplication and peak cholesterol accumulation is also seen in the brain of nonmammalian species such as the catfish. Gangliosides are most concentrated in the brain compared to the rest of the body. Within the brain, the concentration in the gray matter is several times higher than that in white matter. Within the gray matter, these lipids are most concentrated in the axon terminals and dendrites, the structures that constitute most of the synaptic interconnections. As mentioned previously, gangliosides are thus considered label lipids for synaptogenesis. Based on ganglioside measurement, it has been shown that the period of most rapid synaptogenesis in the...

Initiation and Maintenance of Breast Feeding

As noted above, breast-feeding a child is a somewhat predictable part of the life course for most women. That does not mean that initiation of nursing is routine and easy. Most populations also have cultural rules that women must follow during pregnancy to prepare for and ensure successful breast-feeding. These may include specific foods to eat or avoid, the wearing of special clothing and amulets, and other prescribed or restricted behaviors. Following birth, cultural practices relating to breast-feeding a child may include avoiding sexual relations, food restrictions, and performing ritual acts. Dana Raphael describes the tradition of the doula, a family member or friend whose primary role is to assist a new mother in breast-feeding her child (Raphael, 1973). Although the word itself is Greek and describes a person who assists women after childbirth (mothering the mother), the practice is found throughout the world, evidence that breast-feeding is not something that comes easily to...

Normal Physiology and Function

In the CNS, oligodendrocytes are responsible for the synthesis and maintenance of the myelin that surrounds the axons of neighboring neurons. The purpose of the myelin sheath is to allow saltatory propagation of nerve impulses along the length of the axon, resulting in a faster and more efficient neural impulse than in uninsulated nerve fibers. The exact cellular mechanisms responsible for the process of myelination are unclear. In humans, oligodendrocytes emerge several days or weeks before they actually start to synthesize myelin, and myelination takes place principally within the first year after birth. Recent studies have shown that initiation of myelination may be partially dependent on the activity of protein kinase C (PKC), a family of phospholipid-dependent enzymes ubiquitously present in the CNS. Not only do myelin-associated proteins appear to be excellent substrates for PKC-mediated phosphorylation but PKC activity also increases gradually after birth, coinciding with the...

Pancreatic Stem Cells

After birth, the growth of the pancreas continues but slows significantly around 1 month of age in the mouse and rat. However, even in old animals there is a measurable rate of cell birth in all pancreatic compartments. In the b-cell compartment, where most studies have been done, the replication rate falls from 5 in 4-week-old animals to 0.1 in mice older than 3 months. Embryonic-type progenitors (based on expression patterns) are not seen in the normal adult animal (with the possible exception of rare islet cells generated from neurogenin3+ progenitors). The most comprehensive effort in this direction was carried out by Finegood et al., who studied b-cell dynamics throughout the lifespan of the rat. Their results imply a significant contribution of progenitor cells to the b-cell mass in the first weeks after birth and then a shift to tissue maintenance by slow replication of b-cells. In addition, significant b-cell neogenesis was deduced in a similar...

The US Human Embryo Research Panel

In developing its position and recommendations, the panel focused on two distinct sources of guidance viewpoints on the moral status of the early human embryo, and ethical standards governing research involving human subjects. It considered a wide range of possible views on the moral status of the embryo, from the position that full human personhood is attained at fertilization, to the argument that personhood requires self-consciousness and is not attained until after birth. In the end, all nineteen members of the panel agreed to the following statement

Other possible models in the evolution of heart diseases and limitations of the studies

In Europe there are more than 20 large longitudinal studies in which the main focus has been or is to study prenatal or early life factors in relation to adult disease risk. Many of them are historical cohort studies, or data collection has started after birth retrospectively at various points of life. The most important historical cohort studies, from the point of view of the fetal origin hypothesis, are the Hertfordshire,4 14 Preston,12 21 and Sheffield8 studies, as well as the Helsinki27 and Uppsala28 cohort studies.

Gender Assignment of Newborns and Children

The gender assignment of John Joan has received a great deal of attention (Colapinto, 1997). In 1966 a physician burned the penis of boy beyond repair during a circumcision that involved an electrocautery needle. Fearful of what the boy's life would be like, his parents took him Johns Hopkins University for evaluation. The psychologist John Money proposed gender reassignment from male to female on the assumption that the loss of the penis was so damaging that it would be better for the child to be raised as female he also believed that gender identity can be shaped after birth. With the consent of the parents, in 1967 physicians removed the boy's testicles at the age of 22 months, repositioned the urethra, and induced a preliminary vaginal cleft. The parents selected a girl's name and began to treat and raise the child as female (Colapinto, 2000). Some commentators believe that that failure provides evidence that gender assignments do not work, but that conclusion is not fully...

Medicinal Hygiene And Wound Infection

It was not until the mid to late 1800s that even the most basic practices of hygiene were applied to medical procedures. In a Paris hospital between 1861 and 1864,1226 of 9886 pregnant women died a few days after childbirth. The deaths were attributed to puerperal fever. The situation was similar the world over. In Boston in 1843, Oliver Wendall Holmes taught that germs on physicians' and midwives' hands caused puerperal fever (4). Other doctors largely dismissed his ideas. Ignaz Semmelweiss taught the same hygienic concepts in Vienna (11). He realized the dangers of many of the current practices including that of medical students performing post mortem dissections and then assisting in childbirth without so much as breaking to wash their hands. He instituted a strict rule requiring doctors, midwives, and medical students to hand wash in a chloride of lime solution prior to examining expectant women. Mortality fell from 18 to 1 . In 1861 he published The Cause and Prevention of...