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At least 73 records · Page 4Linked to original sources
PubMed1985

[3H]Nicotine binding sites in developing fetal brains in rats.

[3H]Nicotine binding sites were examined in developing fetal brains in rats. The fetal brain membranes bound [3H]nicotine with a similar affinity to that of adult brain membranes. This binding was displaced by unlabelled nicotine or carbamylcholine, the inhibition concentrations being approximately the same for fetal and adult brain preparations. alpha-Bungarotoxin had no effect on [3H]nicotine binding to fetal brain membranes as well as to adult brain preparations. The specific [3H]nicotine binding was first detectable on day 16 of gestation and it increased several folds until birth.

Aging↗
PubMed1993

Expression of p68 protein kinase as recognized by the monoclonal antibody TJ4C4 during human fetal development.

In this report we describe the expression of p68, which is believed to be an important regulator of protein synthesis, in various tissues during normal human fetal development. Conventional, formalin-fixed paraffin-embedded sections of normal organs from human fetuses ranging from 9 to 42 weeks of gestation were immunostained with the monoclonal antibody TJ4C4 utilizing a conventional avidin-biotin complex procedure. The expression of p68 could be detected in many cell types arising in most of the tissues examined within the time period of fetal development studied. p68 expression was most frequently seen, and most intensely expressed in respiratory epithelium, urothelium and ependyma. Expression in other tissues was more variable. These data show that there is regulated expression of p68 in a wide variety of tissues during normal fetal development which parallels the known expression of this protein in normal and neoplastic adult tissues.

Antibodies, Monoclonal↗
PubMed1991

Expression of the epitope recognized by the monoclonal antibody 44-3A6 during human fetal development.

In this report we describe the expression of the adenocarcinoma associated antigen recognized by the monoclonal antibody 44-3A6, in various tissues during normal human fetal development. Conventional, formalin-fixed and paraffin-embedded sections of normal organs were examined from fetuses ranging from 9 to 42 weeks of gestation. Immunohistochemical localization of antigen-antibody complexes was accomplished using the avidin-biotin complex (ABC) method using horseradish peroxidase. The monoclonal antibody (MAb) 44-3A6 detects a cell surface 40 kD protein which is frequently expressed by adenocarcinomas and by select normal glandular tissues. Detectable expression of this protein was seen at different time periods during fetal development depending on the tissue. This expression was confined to a relatively small range of cell types and tissues; immunostaining was noted in select epithelial cells of the aerodigestive tract, exocrine pancreas, neural tissues, renal tubules, and transitional urothelium, as well as in other tissues. This immunostaining generally, but not invariably, corresponded with patterns previously reported in benign and/or malignant neoplasms of adult tissues. In most instances, once expression occurred within a tissue, it continued through gestation. These data show that this tumor associated gene product is differentially expressed in a broad range of normal developing human fetal tissues.

Adenocarcinoma↗
PubMed1999

Effect of acute glucose depletion following glucose excess on surfactant phospholipid synthesis in developing fetal lung.

Exposure to high glucose and insulin inhibits surfactant synthesis in vitro. We have demonstrated that fetal lung insulin receptor tyrosine kinase (TK) activity is downregulated after culture in high glucose plus insulin, with a resultant decrease in glucose uptake. To see whether relative substrate depletion following substrate excess would further diminish surfactant synthesis, 20-day fetal rat lung explants were initially cultured for 44 hours in media containing 100 mM glucose with or without 0.1 U/mL insulin, followed by a 4-hour pulse in 10 mM glucose +/- insulin or 100 mM glucose +/- insulin, after which the rate of choline incorporation into phosphatidylcholine (PC) or disaturated PC was measured. Choline incorporation was significantly lower after a 4-hour pulse in low glucose (+/- insulin) than under continuing high glucose (+/- insulin) conditions (P < .01). To determine the time required for reversal of TK downregulation in lung explants, insulin receptor TK activity was assayed after 44 hours in high glucose + insulin, followed by an additional 4, 8, 12, or 24 hours in either 10 mM glucose or continued 100 mM glucose + insulin. After 44 hours in 50 mM or 100 mM glucose + insulin, TK activity was significantly decreased (68 +/- 9% and 57 +/- 9% of control; P < .01). When explants cultured in 100 mM glucose + insulin for 44 hours were subsequently placed in 10 mM glucose for an additional 4 or 8 hours, TK activity remained significantly downregulated (70.2 +/- 7.0% and 84.9 +/- 5.5% of control, respectively, P < .05) compared to explants cultured in low glucose throughout. However, after 12 or 24 hours in low glucose, TK activity was no longer significantly different from control values (106.5 +/- 2.1% and 106.0 +/- 19.6%, respectively). Culture of type II cells for 44 hours in 25 mM glucose + insulin, followed by an additional 4 or 24 hours in either low glucose (5.5 mM) + insulin or high glucose (25 mM) + insulin yielded similar results: TK activity was decreased 20-30% by culture in 25 mM glucose + insulin conditions (P < .05) and this downregulation continued for 4 (but not 24) hours after switching to lower glucose conditions (P < .05). Continued receptor downregulation during a period of relative substrate deprivation may adversely affect surfactant synthesis, as in some infants of diabetic mothers who experience hypoglycemia (following intrauterine hyperglycemia) in the immediate postnatal period.

Animals↗
PubMed1988

Antileucoprotease in the developing fetal lung.

The distribution of antileucoprotease in the lungs of 25 fetuses of 9-40 weeks' gestation was studied with monoclonal antibodies and an indirect immunoperoxidase technique. Antileucoprotease was detected from 16 weeks in submucosal glands and collecting ducts in the trachea and main and lobar bronchi: it was also found in the surface epithelium of the trachea at 20 weeks, in main and lobar bronchi at 20 weeks, and in smaller bronchi at 20-25 weeks. Non-ciliated cells containing antileucoprotease were observed in the bronchiolar epithelium at 36 and 40 weeks. The results of this study indicate that antileucoprotease is available from birth. It may therefore form part of the first line of defence of the lung.

Cell Differentiation↗
PubMed1989

Fatty acid biosynthesis in developing fetal lung.

Fatty acids are integral components of glycerolipids and hence of the phosphatidylcholine-rich pulmonary surfactant. There is ample evidence that the lung is able to synthesize fatty acids de novo. Toward the end of gestation as the fetus prepares for life outside the uterus, there is a surge in phosphatidylcholine synthesis. At the same time there is an increase in de novo fatty acid biosynthesis as well as in the activity of fatty acid synthase, the enzyme that catalyzes the final steps in fatty acid synthesis. Glucocorticoids have long been known to accelerate phosphatidylcholine biosynthesis in the fetal lung and they have also been found to stimulate fatty acid biosynthesis and fatty acid synthase activity. In fact, fatty acid synthase is the first, and so far the only, enzyme involved in lipid biosynthesis to be clearly identified as glucocorticoid inducible in fetal lung. De novo fatty acid biosynthesis may have two important roles relating to surfactant production during late fetal life. In addition to providing fatty acids for incorporation into surfactant phospholipids, recent data suggest that fatty acids may also directly regulate phosphatidylcholine biosynthesis by activation of choline-phosphate cytidylyltransferase, an enzyme catalyzing a rate-limiting step in its biosynthetic pathway.

Animals↗
PubMed1987

Evaluation of fetal development and well-being with ultrasonic Doppler fetal actocardiogram.

A new ultrasonic technique for objective, continuous and simple recordings method of fetal movements on CTG chart has been introduced. Fetal activity and heart-rate will be correlated. This allows a differentiation of fetal active and resting states. The duration of the first one was 24 to 150 minutes, that of the last one 10 to 36 minutes. Fetal actogram is useful in the prediction of imminent fetal distress.

Embryonic and Fetal Development↗
PubMed2003

Emergence of oropharyngeal, laryngeal and swallowing activity in the developing fetal upper aerodigestive tract: an ultrasound evaluation.

The developing fetal upper aerodigestive system provides the structural support for respiratory and ingestive functions necessary to sustain life at birth. This study investigated prenatal development of upper aerodigestive anatomy and the association of emerging functions as predictors of postnatal feeding skills. Biometric measures of oral, lingual, pharyngeal and laryngeal structures were obtained in fetuses 15-38 weeks gestational age using a four-plane sonographic technique. Accompanying ingestive behaviors were tallied across development. The data from 62 healthy controls were compared to seven cases at risk for postnatal feeding and swallowing dysfunction (Type II Arnold Chiari Malformation, trisomy 18, polyhydramnios, intrauterine growth restriction, Brachmann-de Lange Syndrome). Significant (p<0.001) linear regressions occurred in pharyngeal and lingual growth across gestation while ingestive behavior such as suckling emerged in a sequence of basic to complex movement patterns. Jaw and lip movements progressed from simple mouth opening to repetitive open-close movements important for postnatal suckling. Lingual movements increased in complexity from simple forward thrusting and cupping to anterior-posterior motions necessary for successful suckling at term. Laryngeal movements varied from shallow flutter-like movements along the lumen to more complex and complete adduction-abduction patterns. Fetal swallowing primarily occurred in the presence of concomitant oral-facial stimulatory activity. Significant variations (p<0.01) in the form and function of the ingestive system occurred in comparisons of gestational age-matched controls to at-risk cases. We postulate that prenatal developmental indices of emerging aerodigestive skills may guide postnatal decisions for feeding readiness and, ultimately, advance the care of the premature, medically fragile neonate.

Adult↗
PubMed2002

[Impact on environmental factors on the reproductive system and fetal development].

A literature review discusses the effect of selected environmental factors on women reproductive system, fetal development and growth. According to recent reports, 2-3% of newborns have congenital malformations. These malformations are caused by interaction of genetic and environmental factors. Exposure of paternal or maternal organisms to environmental hazards may damage germ cells or interfere fetal development, resulting in malformation of various organ systems. Since environmental hazards exposures are complex, it is difficult to establish the primary effect of single factor. Factors, that are known to increase the risk of congenital malformations, preterm delivery or spontaneous abortion, are classified into five groups--psychological, social, biological, physical and chemical factors. The governments of most counties recognize the effect of hazardous environmental factors on public health as global problem. World Health Organization encourages researches, aimed at evaluation of various environmental factors impact on health of pregnant women and their offsprings.

Abnormalities, Drug-Induced↗
PubMed1986

Thymocyte subpopulations during early fetal development in sheep.

Phenotypic analysis of thymocytes during fetal development may identify subpopulations which are either absent or difficult to detect in postnatal thymus. A panel of monoclonal antibodies specific for sheep lymphocyte antigens (SBU-T1, -T4, -T8, -T6) was used to identify thymocyte subpopulations in postnatal and fetal sheep. Thymuses were analyzed by two-color immunofluorescence and flow cytometry or by immunohistology. Two-color immunofluorescent staining of postnatal sheep thymus with anti-SBU-T4 and anti-SBU-T8 revealed four relatively distinct subpopulations with particular localizations: a) SBU-T4-T8-, predominantly outer cortex (12%); b) SBU-T4+T8+, inner cortex (74%); c) SBU-T4+T8-, medulla (10%), and d) SBU-T4-T8+, medulla (4%). One- and two-color immunofluorescent analysis of cells from early fetal thymuses demonstrated the appearance of SBU-T8+ cells well before SBU-T4+ cells. Immunohistologic staining of fetal sheep thymus at various stages of gestation (term = 150 days) revealed that lymphoid cells and MHC class II-positive dendritic cells first appeared at 35 days, at which stage the thymic epithelium was weakly positive for class I MHC antigens but negative for class II MHC antigens. The earliest lymphocyte antigens detectable on fetal sheep thymocytes were SBU-LCA and SBU-T1. By 40 days, the antigens SBU-T6, SBU-T4, and SBU-T8 were detectable on a small number of thymocytes; SBU-T8 preceded SBU-T4, and the number of SBU-T8+ thymocytes always exceeded the number of SBU-T4+ thymocytes throughout early gestation. At 50 days, a thymic medulla appeared and thereafter grew rapidly in size. Immunoperoxidase staining of serial sections of the fetal neck revealed cortical-type thymocytes outside the thymus from 40 days onward, before the appearance of a thymic medulla. However, by 60 days, only medullary-type thymocytes were observed either extrathymically or within the interlobular septa of the thymus, indicating that only thymocytes with a medullary phenotype leave the thymus from this stage of gestation.

Animals↗
PubMed1992

Fetal development of the pyloric muscle.

The fetal development of the pyloric muscle was studied in five human embryos (crown-rump length 5 to 31 mm) and in ten fetuses aged 3 to 9 months. Samples of pyloric muscle were obtained during operation for pyloric stenosis in two infants aged six weeks. Anatomo-radiologic, morphologic and immunohistochemical studies were made on this material, from which it emerged that the pylorus is identifiable by means of specific markers from the 40th day. Its two-layered muscular structure is described in detail. The mechanism of sphincteric function is reviewed. This study assumes clinical importance in the context of the etiopathogenesis of hypertrophic stenosis of the pylorus.

Humans↗
PubMed1981

Congenital neuroblastoma, neuroblastoma in situ, and the normal fetal development of the adrenal.

In normal fetal development nodular collections of neuroblast cells were found in the adrenal glands from 7 wk gestation; there nodules increased in size and number, and in all specimens from fetuses of 14-18 wk gestation, aggregates of nodules closely resembling neuroblastoma in situ could be found. From about 12 wk gestation the large neuroblast nodules appear to split into smaller nodules and differentiation into chromaffin cells takes place. The mean nuclear size of neuroblasts at all stages of development studied was 4.25 +/- 0.84 mu, statistically significantly less than the mean nuclear size of the cells measured in 7 neonatal neuroblastomas. Measurement of nuclear size may be a way of distinguishing a true potentially malignant neuroblastoma in situ from a normal benign residual neuroblast nodule.

Adrenal Gland Neoplasms↗
PubMed2005

Maternal ghrelin plays an important role in rat fetal development during pregnancy.

Ghrelin, an acylated peptide serving as an endogenous ligand for GH secretagogue receptor (GHS-R), was originally isolated from rat and human stomach. In this study, we report the critical role of maternal ghrelin in fetal development. High levels of ghrelin receptor (GHS-R) mRNA were detected in various peripheral fetal tissues beginning at embryonic d 14 and lasting until birth. Fetal GHS-R expression was also confirmed in fetal tissues by immunohistochemistry. Autoradiography revealed that both des-acyl ghrelin and acyl ghrelin bind to fetal tissues. Chronic treatment of mothers with ghrelin resulted in a significant increase in birth weight in comparison to newborns from saline-treated mothers. Even when maternal food intake after ghrelin treatment was restricted through paired feeding, significant stimulation of fetal development still occurred. Conversely, active immunization of mothers against ghrelin decreased fetal body weight during pregnancy. A single ghrelin injection into the mother increased circulating ghrelin levels in the fetus within 5 min of injection, suggesting that maternal ghrelin transits easily to the fetal circulation. High levels of des-acyl ghrelin were detected in fetal blood and amniotic fluid. Both acylated and des-acyl ghrelin increased [3H]thymidine and 5-bromo-2'-deoxyuridine incorporation of cultured fetal skin cells in a dose-dependent manner, and calcium-imaging analysis revealed that acyl and des-acyl ghrelin increased the Ca2+ influx in discrete cultured fetal skin cells, respectively. These results indicate that maternal ghrelin regulates fetal development during the late stages of pregnancy.

Amniotic Fluid↗
PubMed2004

Effects of prenatal exposure to the environmental pollutant 2-bromopropane on embryo-fetal development in rats.

2-Bromopropane (2-BP), a halogenated propane analogue, is a substitute for chlorofluorocarbones. The present study was carried out to investigate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure on gestational days (GD) 6 through 19 in Sprague-Dawley rats. The test chemical was administered subcutaneously to pregnant rats at dose levels of 0, 250, 500, and 1000 mg/kg per day. All dams were subjected to caesarean section on GD 20 and their fetuses were examined for external, visceral and skeletal abnormalities. In the 1000 mg/kg group, maternal toxicity included an increase in the incidence of abnormal clinical signs, a suppression in the body weight and body weight gain, and a decrease in the food intake. Developmental toxicity included an increase in the fetal deaths, a decrease in the litter size, and a reduction in the fetal body weight. In addition, an increase in the incidence of fetal external, visceral, and skeletal abnormalities was seen. In the 500 mg/kg group, minimal developmental toxicity including decreased fetal body weight and increased fetal ossification delay was observed. There were no adverse effects on either pregnant dams or embryo-fetal development in the 250 mg/kg group. These findings suggest that a 14-day subcutaneous dose of 2-BP is embryotoxic and teratogenic at a maternally toxic dose (i.e., 1000 mg/kg per day) and is minimally embryotoxic at a nonmaternally toxic dose (i.e., 500 mg/kg per day) in Sprague-Dawley rats. In the present experimental conditions, the no-observed-adverse-effect level (NOAEL) of 2-BP is considered to be 500 mg/kg per day for dams and 250 mg/kg per day for embryo-fetal development.

Abnormalities, Drug-Induced↗
PubMed1998

Fetal development of the white line (Zona alba) of the equine hoof.

The fetal development of the white line (Zona alba) in the equine hoof is described. Its specific structure of lamellar and interlamellar horn, which in turn is composed of cap and terminal horn, is formed in the second half of the hoof's fetal development. In equine fetuses with a crown-rump length of less than 550 mm, the hoof capsule lacks a 'characteristic' white line since no borders between stratum medium, stratum internum and sole horn are discernible. In the hoof of an equine fetus with a crown-rump length of 550 mm, a narrow white line has taken shape. Its shallow lamellae are arranged like arcades. Between the horn lamellae lie the polyhedral cells of the interlamellar horn. Up until birth, the height of the horn lamellae and, therefore, the width of the white line increases significantly. In the white line of the hoof of newborn foals, the terminal horn contains horn tubules with a characteristic architecture.

Animals↗
PubMed1996

Identification of five embryonic hemoglobins of rat and ontogeny of their constituent globins during fetal development.

Hemoglobins of rats switch from an embryonic to an adult type during fetal development. However, very little is known about the structures and molecular species of hemoglobins occurring in the fetal life of rats. In the present study we isolated five embryonic hemoglobins, designated E1, E2, E3, E4, and E5, from the blood of rat fetuses on day 14 of gestation by ion exchange chromatography. Reverse-phase high performance liquid chromatography revealed that these hemoglobins each consist of two kinds of globins: E1(11 alpha:epsilon 1), E2(1 alpha: epsilon 1), E3(zetta: epsilon 1), E4(1 alpha: epsilon 3), and E5(zetta: epsilon 3), respectively. The complete amino acid sequences of the zetta, epsilon 1, and epsilon 3 globins were determined. The zetta globin showed characteristic features common in alpha-type embryonic globins of known species in that the N-terminus is blocked and the amino acid at position 38 is Gln. epsilon 1 and epsilon 3 are beta-type embryonic globins, sharing 73.7% amino acid homology. Interestingly, they are more similar to the corresponding mouse beta-type embryonic globins, y and z, respectively, than to each other, implying that these globins have evolved orthologously from common ancestral proteins. It was also shown that the zetta, epsilon 1, and epsilon 3 globins are almost completely replaced by the adult type alpha and beta globins in the blood of rat fetuses by day 18 of gestation.

Amino Acid Sequence↗