Many features of the developing nervous system are visible from external observations of intact human embryos. In this study, a photographic atlas from the 4th to the 7th week after ovulation (Carnegie stages 10-18) is provided. The neural folds began to fuse at stage 10, and the rostral and caudal neuropore were closed during stages 11 and 12, respectively. The three primary divisions of the brain were distinguishable before closing of the neural tube. The five secondary brain vesicles were formed during stages 14-15. The development of the cerebellum and cerebrum were first observed at stages 14 and 15, respectively. The mesencephalic flexure was seen at stage 12, and the cervical flexure and pontine flexure at stage 14. After stages 18-19, it became increasingly difficult to identify detailed features of the brain from the surface. Results from this study will help to correlate the characteristic findings of the developing central nervous system of human embryos from stereomicroscopical and light microscopical observations and to locate the exact parts of the developing human brain for other purposes.
Brain/embryology* ; Embryo/anatomy & histology ; Fetal Development ; Human

The mouse eggs in the various stages, of the development prior to implantation were collected and measurements were made on both the largest and smallest diameters of the vitellus, inner and outer surface of the zona pellucida. The various stages of development used were ovarian oocytes (germinal vesiA®e stage), ovulated but unfertilized egg, ovulated and fertilized egg, the 2-cell embryo on the second day of pregnancy, 4-8-cell embryo on the third day of pregnancy and morulablastocyst on the fourth day of pregnancy, A further comparative study on unfertilized and fertilized tubal eggs was made, The time of l2 hours after H.C.G. injection was chosen as the starting point from which to follow the collection of eggs every 3 hours for 24 hours. Since the volume gives a better comparison of size than diameter, the volume of the total eggs, intrazonal cavity, perivitelline space and the various were calculated for the various preimplantation stages of mouse egg. The volume of zona pellucida was also calsulated by subtraction of the volume of the inner zonal cavity from the volume of total egg and compared with the zona pellucida thickness. All calculations were made by computor(CEIR Time-sharing Computor). The diameter and volume of the vitellus in the ovarian oocyte is the largest one of any stage during the preimplantation stages of development, while the total volume of the entire egg as determined from the diameter of outer surface of the zona pellucida of the ovarian cocyte is the smallest one of any stage during development. The diameter and total volume of the entire egg increases from the ovarian oocytes to the first day of pregnancy and then gradually decreases until the third day of pregnancy. An increase in these parameters again takes place on the fourth day of pregnancy. The zona pellucida of the tubal ova is thicker than that of the oocyte, with the zona pellucida of the fertilized egg being definitely thinner when compared with unfertilized eggs. This phenomenon of decreased thickness in fertilized egg may be associated with zona reaction. The perivitelline space between the vitellus and zona pellucida thus formed following ovulation occupied approximately 40 percent of the total volume enclosed by the inner surface of the zona pellucida (intrazonal cavity) in the 1-cell tubal ova. Neither the cause of the rapid accumulation of fluid after ovulation which resulted in the production of the perivitelline space nor the actual time of the formation of the perivitelline space are known. Some possible reasons for the formation or origin of the perivitelline space are discussed. The size and shape of the vitellus undergo compartive reduction during preimplantation stages of development. The possible reason for the reduction of vitelline volume are discussed.
Animal ; Blastocyst ; Embryo/cytology* ; Embryo Implantation ; Embryo and Fetal Development ; Female ; Fertilization ; Mice ; Ovulation ; Ovum/cytology ; Ovum/growth & development ; Temperature ; Time Factors

Ponderal index (fetal weight in grams x 100 / (fetal length in centimeters) 3) (PI) is one of the anthropometric methods used to diagnose impaired fetal growth. Irrespective of the infant's position on the growth-weight-for-gestational age charts, PI is low in malnourished infants and high in obese ones. As fetal growth is affected by ethnicity, geographic location and socioeconomic status, we developed standards for neonatal PI, and assessed the effects of gestational age, sex and maternal parity. Data on 5798 newborns from singleton pregnancies born in the Department of Gynecology and Obstetrics, Split University Hospital, were retrospectively analyzed. Over a 15-month period in 2000/2001, 5596 newborns from 24 to 42 weeks of gestation were born. The other 202 newborns, born from 24 to 34 weeks of gestation in the ten year period, 1990-1999, were added because of the small number of preterm infants; ensuring a minimum of 30 to fill up at least infants in each gestational week. All mothers were of Caucasian origin. Stillbirths and fetuses with congenital malformations were excluded. The 10th, 50th and 90th percentiles, mean values with standard deviation of PI and the 10th, 50th, and 90th percentiles of birth weight and birth length are presented separately at weekly intervals. PI showed linear correlation with gestational age from 24 to 39 weeks, after witch the data plateaued. Sex and parity had no impact on PI in infants born between 24 and 37 weeks. Analysis of variance revealed PI to be significantly higher in female than in male newborns, and in multiparous than in nulliparous infants after 37 weeks of gestation. In conclusion, gestational age is the most important factor of neonatal PI. The effects of sex and parity on PI should only be considered in term neonates.
*Anthropometry ; *Birth Weight ; *Embryo and Fetal Development ; Female ; *Gestational Age ; Human ; Infant, Newborn ; Male ; Pregnancy

The purpose of this study was to measure the level of expression of the inducible heat shock protein70 (Hsp70), the constitutive heat shock protein70 (Hsc70) in the outer nuclear layer and the photoreceptors in the human fetal retina. Fetal eyeballs were selected from fetal autopsy specimens of 12 and 17 to 40 week old fetuses, with no history of congenital anomalies. The retinas had differentiated from neuroblastic cells, into matured sensory retinas, from a gestational age (GA) from 12 to 36 weeks. The Hsp70 and Hsc70 were prominently expressed in the nuclear layers. The Hsc70 was expressed at all GAs and the Hsp70 was expressed from 20 to 33 weeks GA. This period is in accordance with the maturation of the sensory retina. The expression of heat shock protein may be regulated by the development of the fetus, and play an important role in the ocular development.
Embryo and Fetal Development ; Fetus/metabolism ; Heat-Shock Proteins 70/*metabolism ; Human ; Immunohistochemistry ; Retina/*embryology ; Support, Non-U.S. Gov't

OBJECTIVETo observe the effect of Cinnabaris on mouse embryos after pregnant mice were treated by Cinnabaris in different periods of pregnancy.

METHODTwo separate experiments were performed: First, Cinnabaris was orally given into pregnant mice at the doses of 0.08, 0.4, 4.0 g x kg(-1) from D6 to D19 after pregnancy; Second, Cinnabaris was orally given into mice at the same doses mentioned above from D14 prior to pregnancy until D19 after pregnancy. All animals were sacrificed on D 20 of pregnancy by caesarean section. The numbers of survival, dead and absorbed fetuses were calculated and the survival fetus weight was measured. The survival fetuses were treated by two methods: One third survival fetuses were fixed and stained by Bouin solution for organ examination and the remaining two thirds fetuses were stained for skeleton examination.

RESULTNo obvious embryo toxicity was observed in the first experiment at Cinnabaris dose levels of 0.08, 0.4, or 4 g x kg(-1) x d(-1). There was no significant effect on embryonic development and the numbers of the survival, dead and absorbed fetus. No obvious malformations on appearance, organ, and skeleton examination of fetuses were found. The second experiment showed that the rates of abortion and absorbed fetus in 0.4, 4 g x kg(-1) x d(-1) Cinnabaris group were higher but without statistical significance compared with control group. Appearance and organ examination of Cinnabaris groups fetus showed no obvious malformation, but skeleton malformation was found in 0.4, 4 g x kg(-1) x d(-1) groups (the rates of skeleton malformation were 46.7% and 77.8%, respectively).

CONCLUSIONNo obvious embryonic development toxicity was observed when Cinnabaris was orally given in intermediate and late pregnant period, but the embryos in the early stage of pregnancy was more sensitive to Cinnabaris. When Cinnabaris was given prior to pregnancy until the whole period of pregnancy, it may be harmful for the fetuses at above the dose level 0.08 g x kg(-1) x d(-1) (equivalent to 5 times clinical intake dose), both in a dose-dependent manner.

Animals ; Drugs, Chinese Herbal ; toxicity ; Embryo, Mammalian ; Embryonic Development ; drug effects ; Female ; Fetal Development ; drug effects ; Mice ; Mice, Inbred ICR ; Models, Animal ; Pregnancy

The crown-rump length(CRL) remains the most accurate parameter used for gestational dating. We aimed to establish the early fetal growth with CRL range in Korean women. The CRL of 48 singleton pregnancies which resulted from in vitro fertilization and e mbryo transfer(IVF-ET) at SNUH were assessed two to six times in the first trimester by trans-vaginal ultrasonography. All women included in this study went on to deliver norma l infa-nts at 37 completed weeks or after weighing over 2.5 kg. And we also studied the r elationship between CRL(in millimeters) and gestational age(in days), and found that the fo llowing second-order polynomial might be applied either to expect CRL using the menstr ual gestational age, or to estimate gestational age using measured CRL(r2=0.980, p=0.000 1). CRL=0.0175(GA)2-1.049(GA)+19.17 GA=7.5593(CRL-3.45)1/2+29.97 Finally we compared our data with some of published articles which assessed CRL in spontaneous and induced pregnancies. In conclusion, this study establish the early fetal growth with CRL range in Korean women on the basis of exact ovulation timing using high resolution transvaginal ultrasonography. And these data will be of great use in the evaluation of fetal growth in the first trimester.
Crown-Rump Length* ; Embryo Transfer* ; Embryonic Structures* ; Female ; Fertilization in Vitro* ; Fetal Development ; Gestational Age ; Humans ; Ovulation ; Pregnancy ; Pregnancy Trimester, First* ; Ultrasonography

Skeletogenesis occurs through either intramembranous or endochondral ossification. In addition, some parts of the skeletal components maintain their cartilaginous characteristics throughout life without mineralization. Runx2 is known to be a pivotal transcription factor for all skeletogenic processes. In this study, we examined the expression patterns of two major isoforms of Runx2 in early skeletogenesis. During intramembranous bone formation, Runx2-type I (Runx2-I) was widely expressed in osteoprogenitor cells and active osteoblasts, while Runx2-type II (Runx2-II) expression was stringently restricted to cells lining mineralized bones. Cells in permanent cartilage expressed collagen type II (Col-II) but never expressed Runx2 or Col-X. These permanent cartilages were well circumscribed by Runx2-I positive cells, in which Runx2-II was negative. In endochondral bone formation, Runx2 expression temporarily disappeared in Col-II-positive proliferating chondrocytes, but a secondary surge of Runx2-I expression occurred in the prehypertrophic zone before the mineralization of cartilage. Collectively, both Runx2 isoforms showed very similar expression patterns in active bone forming areas; however, Runx2-I has an exclusive role in the early commitment stage of intramembranous or endochondral bone forming processes or in cells surrounding permanent cartilage.
Animals ; *Bone Development ; Cartilage/cytology/growth & development/metabolism ; Embryo and Fetal Development/genetics ; *Gene Expression Profiling ; *Gene Expression Regulation, Developmental ; In Situ Hybridization ; Mice ; Mice, Inbred ICR ; Protein Isoforms/genetics/metabolism ; Time Factors ; Transcription Factors/*genetics/metabolism

Recurrent pregnancy loss (RPL) is a common complication in obstetrics, affecting about 5% of women of childbearing age. An increase in the number of abortions results in escalation in the risk of miscarriage. Although concentrated research has identified numerous causes for RPL, about 50% of them remain unexplained. Pregnancy is a complex process, comprising fertilization, implantation, organ and tissue differentiation, and fetal growth, which is effectively controlled by a number of both maternal and fetal factors. An example is the immune response, in which T cells and natural killer cells participate, and inflammation mediated by tumor necrosis factor or colony-stimulating factor, which hinders embryo implantation. Furthermore, vitamin D affects glucose metabolism and inhibits embryonic development, whereas microRNA has a negative effect on the gene expression of embryo implantation and development. This review examines the causes of RPL from multiple perspectives, and focuses on the numerous factors that may result in RPL.
Abortion, Habitual ; Abortion, Spontaneous ; Colony-Stimulating Factors ; Embryo Implantation ; Embryonic Development ; Female ; Fertilization ; Fetal Development ; Gene Expression ; Glucose ; Humans ; Inflammation ; Killer Cells, Natural ; Metabolism ; MicroRNAs ; Obstetrics ; Pregnancy ; Proteomics ; T-Lymphocytes ; Tumor Necrosis Factor-alpha ; Vitamin D

Astrocytes are ubiquitous in the brain and have multiple functions. It is becoming clear that they play an important role in monitoring the neuromicroenvironment, information processing, and signaling in the central nervous system (CNS) in normal conditions and that they respond to CNS injuries. During the development of the CNS, astrocytes play a key role as a substrate for neuronal migration and axonal growth. To identify genes that could participate in astrocyte maturation, we used the differential display reverse transcription-PCR (DDRT-PCR) method. Human fetal astrocytes were cultured and total RNAs were isolated at intervals of 5 days for 50 days. Using 24 primer combinations, we identified a set of 18 candidate cDNAs deriving from the excised DDRT-PCR bands. DNA sequencing revealed 16 genes that have been described already. We found that RTP, TG, hTM-alpha, SPARC, TRIP7, and RPL7 genes were expressed increasingly, while HMGCR, RPL27a, NACA, NPM, and TARBP2 genes were expressed decreasingly, according to their culture stages. We also found two unidentified genes, A3 and C8, which were expressed differently in culture stages; the former was expressed decreasingly and the latter increasingly. These two genes were found in the same amount in genomic DNA from various human cells such as astrocytes, astrocytoma, trophoblasts and lymphocytes. The A3 gene was found only in human genomic DNA, but not in rat (ATr5), mouse (RAW264.7), or monkey (Vero) cells, whereas the C8 gene was found in human genomic DNA and monkey cells, but not in rat or mouse cells. We analysed these two genes for identification. There was > 92% nucleotide sequence identity between the A3 gene (3, 626 bp) and the Homo sapiens general transcription factor 3 (GTF3), and > 96% nucleotide sequence identity between the C8 gene (2, 401 bp) and the transmembrane receptor Unc5h2. These findings suggest that these two genes may participate in some functional roles within the cells.
Animals ; Astrocytes/*physiology ; Cell Aging/genetics ; Cells, Cultured ; Cercopithecus aethiops ; Embryo and Fetal Development ; Fetus/*physiology ; *Gene Expression ; Gene Expression Profiling ; Human ; Mice ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Support, Non-U.S. Gov't ; Vero Cells

In this study, we examined the effects of a two-step culture system, which involves the use of different culture media for early cleavage and later stage embryos, on the in vitro development of bovine embryos. We also investigated the effect of glucose, phosphate and citrate on the in vitro early developmental period of bovine embryos in a two-step culture system. Moreover, the supplementation of different protein sources (BSA-V, BSA-FAF and FBS) during IVC did not affect the frequency of blastocyst development. Using two-step culture, embryos were cultured in protein-free media for an initial 5 days. This was then followed by the same culture media or an FBS supplemented media. The developmental rates of blastocysts in the FBS containing group were significantly higher than in the replaced with no serum containing group. Embryos cultured in mSOF supplemented with 1.5 mM glucose plus 1.2 mM phosphate were significantly inhibited. The inhibition of developmental competence by glucose plus phosphate was consistent with the existence of 0.5 mM sodium citrate. This study indicates that a two-step culture system, which applies different conditions for early cleavage embryos, i.e., serum-free media, vs. later stage embryos, with serum containing media, may be effective for in vitro production systems. In addition, the developmental competence of bovine embryos was depressed in the presence of glucose plus phosphate as compared to either alone or the absence of both. Therefore, the avoidance of this negative effect should allow more optimal conditions to be developed for in vitro production.
Animals ; Blastocyst/drug effects/metabolism ; Cattle/*embryology ; Citric Acid/pharmacology ; Culture Media/*chemistry ; Culture Techniques/*methods ; Ectogenesis/drug effects ; Embryo/*drug effects/embryology/metabolism ; Embryonic and Fetal Development/drug effects ; *Energy Metabolism ; Female ; Fertilization in Vitro ; Glucose/pharmacology ; Male ; Phosphates/pharmacology ; Proteins/*pharmacology ; Zygote/drug effects/metabolism