The development of jejunum and ileum during the fetal period

OBJECTIVE: In our study, the morphologic structures of the jejunum and ileum sections of small intestine were investigated in human fetuses during the fetal period. MATERIALS AND METHODS: The study was realised on 131 human fetuses (male: 69; female: 62) with ages between 10 and 40 weeks, which have got no external pathology and anomalies. The external sizes of fetuses were measured, and then the structures in the abdominal cavity were determined by the abdominal dissection. The localization of jejunum and ileum, duodenojejunal flexure and ileal orifice points, the measurements of macroscopic diameters, types of the mass of jejunum and ileum and the localization according to the abdominal regions of the mass of jejunum and ileum were determined. Also, the samples of the jejunum and ileum were examined both macroscopically and microscopically. The thickness of tunica serosa, tunica muscularis and tunica mucosa was determined under the light microscope. RESULTS: According to the sexes, gestational ages and groups, the averages and the standard deviations of the all parameters were determined. The correlations between the parameters were determined. The percentage of parameters was compared according to sex and among groups. No differences were found in parameters between sexes (p<0.05). The macroscopic parameters were increased according to the gestational age. The thickness of tunica serosa did not change according to the gestational age. CONCLUSION: It is thought that the data we have will help the evaluation of jejunum and ileum in intrauterine period; we also believe that the data in our study may help in the diagnosis and treatment of anomalies and pathologies in fetal period that belongs to jejunum and ileum.     

Cardiac growth in fetuses of diabetic mothers with good metabolic control

To evaluate cardiac growth in fetuses of those diabetic mothers with good metabolic control, we examined M-mode echocardiographic measurements obtained from 24 fetuses of diabetic mothers (FODM) and compared these with measurements from 31 normal fetuses of similar gestational age. Fetuses were grouped into three gestational periods: 20 to 26 weeks, 27 to 33 weeks, and 34 to 40 weeks. The mothers were believed to have good metabolic control on the basis of mean daily glucose profiles and glycosylated hemoglobin A (HbA1C) values of approximately 110 mg/dl (610 mumol/L) and 7.5%, respectively, before fetal scanning, and estimated fetal weight similar to that of normal fetuses during all three gestational periods. Both FODM and normal fetuses had significant increases in M-mode measurements from period 1 to period 3, but in FODM, cardiac hypertrophy developed by late gestation (period 3). This involved the interventricular septum (6.1 +/- 0.7 vs 4.9 +/- 0.3 mm, p less than 0.05), right ventricular free wall (5.7 +/- 0.8 vs 3.2 +/- 0.3 mm, p less than 0.01), and left ventricular free wall (6.4 +/- 0.6 vs 3.3 +/- 0.4 mm p less than 0.01). The interventricular septum/right ventricular free wall ratio was similar, whereas the interventricular septum/left ventricular free wall ratio in FODM was smaller by period 3 (1.0 +/- 0.1 vs 1.6 +/- 0.1, p less than 0.05). The right ventricular diastolic dimension was similar, but the left ventricular diastolic dimension was significantly smaller in FODM during periods 2 and 3 (8.2 +/- 1.2 vs 12.2 +/- 0.7 mm, p less than 0.05). Strict metabolic control did not prevent FODM from having abnormal cardiac growth. We conclude that good metabolic control results in normal estimated fetal weight but that FODM remain at risk for mild global cardiac hypertrophy and altered diastolic dimensions.     

The effect of adult hemoglobin on red blood cell nitric oxide levels during fetal development

OBJECTIVE: To compare the levels of S-nitrosohemoglobin (HbSNO) at different gestational ages in newborn infants and correlate the levels of HbSNO with HbA and HbF. METHOD: Cord blood samples of 22 newborn infants of different gestational ages (25-41 weeks) were analyzed. The levels of HbF and HbA were determined by HPLC and of HbSNO by chemiluminescence. RESULTS: The level of HbSNO varied from 28.1 to 145.3 nM. There was a significant correlation with gestational age (r(2) = 0.5469, p < 0.0001) and with the relative amount of HbA (r(2) = 0.8144, p < 0.0001). CONCLUSION: The increases in HbSNO in fetal red cells is directly related to the relative amount of HbA.     

Effect of hypoxemia on fetal hemoglobin synthesis during late gestation.

This study was carried out to investigate the effect of fetal hypoxemia, as a result of acute intermittent maternal hypoxia, on the switchover from fetal to adult type Hb as well as Hb oxygen affinity and 2,3-diphosphoglycerate levels in the near-term fetus. These experiments were carried out using 10 fetal lambs with gestational ages ranging from 132 to 140 d. After the installation of appropriate fetal catheters, five of the ewes were exposed to an air mixture containing 10% O2 for 90 min/d for 4 consecutive d. Blood samples were withdrawn before the beginning of the hypoxic experiments and between the 5th and 6th d after the first episode of hypoxia. These samples were for the determination of 2,3-diphosphoglycerate concentration, arterial O2 pressure at which Hb is 50% saturated, and Hb type synthesis. Blood gases were monitored during each hypoxic episode. During the hypoxia, fetal arterial O2 pressure decreased from 2.43 +/- 0.36 kPa (18.2 +/- 2.7 mm Hg) to 1.57 +/- 0.17 kPa (11.8 +/- 1.3 mm Hg). These values returned to their initial levels after cessation of the maternal hypoxia. Five control animals of the same gestational age were also followed. During the interval of the study, a decrease of fetal Hb synthesis was noted (71.7 +/- 12.1 to 57.4 +/- 10.2%, p less than 0.001) in the control group. However, the level of fetal Hb synthesis did not significantly change in the hypoxic group (85.1 +/- 11.1 versus 80.6 +/- 18.9%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Are myo-inositol,glucose and zinc concentrations in amniotic fluid of fetuses with spina bifida different from controls?

OBJECTIVE: Associations are reported between myo-inositol, glucose, zinc and the occurrence of spina bifida. To gain more insight into the pathogenesis of spina bifida, the concentrations of myo-inositol, glucose and zinc were determined in amniotic fluids from pregnancies with a spina bifida or unaffected control fetus. METHODS: Amniotic fluids of 27 pregnancies complicated by spina bifida and 49 controls were collected at the Department of Obstetrics and Gynecology of the University Medical Center Nijmegen in the Netherlands. Myo-inositol, glucose and zinc concentrations were determined. By indication, the samples were taken at different gestational ages. Therefore, the data were evaluated using multiple linear regression analysis to adjust for gestational age. RESULTS: Amniocentesis was performed at a more advanced gestational age in the spina bifida group than in controls. In the spina bifida group, amniotic fluid myo-inositol, glucose and zinc concentrations gradually declined throughout pregnancy. At a gestational age of 15 weeks, the estimated mean amniotic fluid glucose and zinc concentrations in the spina bifida group were, respectively, significantly lower (p< or =0.5) and higher (p< or =0.5) compared with the control group. At the same gestational age, the estimated mean myo-inositol concentrations were comparable in both groups. At a gestational age of 38 weeks, the estimated mean myo-inositol, glucose and zinc concentrations were not significantly different in the spina bifida compared with the control group. CONCLUSION: This study may suggest that a derangement in zinc and glucose transfer or metabolism is associated with spina bifida. Since compounds in amniotic fluid are only a very crude marker of the actual fetal condition, studies that focus on the metabolism of these compounds on tissue or even cellular level should be performed to clarify their role in the pathogenesis and future prevention of spina bifida.     

Postnatal overestimation of gestational age in preterm infants

In a study involving 25 preterm infants, obstetric clinical age (standard gestational age) was determined by history, physical examination, and ultrasonographic evaluation. Postnatally, these infants were then evaluated using the Dubowitz Scoring System (DSS) for gestational age assessment. The DSS, as administered by us, significantly overestimated gestational age compared with the standard gestational age (mean +/- 1 SD: 34.2 +/- 2.9 vs 32.5 +/- 3.9 weeks, respectively) in preterm infants. To illustrate, the gestational ages of 13 newborns (52%) in the total study group were each overestimated by more than two weeks. This percentage increased to 75% among the 16 infants whose gestational ages were less than 34 weeks (by standard gestational age). When the standard gestational age was underestimated by the DSS, this difference never exceeded two weeks. These findings suggest that the present system of postnatal assessment of gestational age in preterm infants needs further investigation.     

人胎脑室下区发育过程中神经干细胞的变化

目的观察人胎脑室下区不同发育时期神经干细胞(NSCs)的变化,为调控自身NSCs治疗神经系统退行性疾病提供实验依据。方法收集胎龄24~28周的水囊引产胎儿30例,采用原位杂交及光镜技术对其脑室下区NSCs的分布、形态以及生长方式进行检测。结果不同胎龄人胎脑室下区均可见Nestin mRNA表达阳性NSCs,NSCs呈星形,有3~6个突起,多个突起形成网丛,细胞散在分布在网丛中,胞核呈圆形,1~4个核仁,细胞染色质疏松。多数NSCs单个存在,可见对称分裂的NestinmRNA表达阳性NSCs和3个NSCs形成的集落样生长方式。不同胎龄Nestin mRNA表达阳性NSCs的分布部位、细胞形态无明显区别,但Nestin mRNA表达阳性NSCs生长方式上存在一定差异。结论不同胎龄人胎脑室下区均存在NSCs,NSCs生长方式随胎龄不同而变化,调控在体NSCs有望成为治疗儿童神经退行性疾病的另一种有效方法。     

国人胚胎及胎儿幽门肌肉神经发育研究

目的 观察正常胚胎及胎儿各期肌肉及神经的发育，作为研究幽门病理状态的基础。方法 标本为３８例胎龄８－３５周的胚胎及胎儿，１例４个月的婴儿。用Ｈ－Ｅ染色法及Ｂｉｅｌｓｃｈｏｗｓｋｙ染色法进行切片染色，对幽门肌、肌间神经节及丛的各期表现进行观察及定量研究。结果采用方差分析进行统计学处理。结果 随胎龄增大，幽门内、外径增加，外径变化更明显的与幽站括约肌的有关；粘膜下层增厚，占各层比例下降，幽门内、外径处     

Thymidine factor in human cord sera and relationship to birth size, gestational age and insulin

Thymidine factor was studied in human cord sera from 44 neonates with gestational ages ranging between 36 and 43 weeks. Thymidine factor was determined by the uptake of 6-3H-thymidine using isolated chick embryo cartilage cells. The thymidine factors increased with gestational age and those of neonates at 40 weeks of gestation were 0.89 +/- 0.17 U/ml (mean +/- SD), but were significantly lower after 42 weeks of gestation. There was no correlation between thymidine factor in cord sera and birth weight or size. There was a positive correlation (p less than 0.02) between insulin level and thymidine factor in cord sera. Our data suggest that somatomedin measured as thymidine factor might not have a major role in fetal growth and insulin might be an important factor in the synthesis of somatomedin by the fetus.     

Fetal development of the hand, digits and digit ratio (2D:4D)

OBJECTIVE: The purpose of this study was to investigate growth patterns in human hands, digits and digit ratio (2D:4D) during the fetal period. METHODS: The study is carried out on 161 human fetuses (83 males, 78 females) free from external pathology or malformation with ages ranging between 9 and 40 weeks of gestation. Following general external measurements, length and width of the hand, digit lengths separate for each hand was measured, hand index and the ratio of the lengths of the 2nd finger to the 4th finger (2D:4D index) was computed. RESULTS: Means and standard deviations of the parameters with respect to gestational weeks, months and trimesters were calculated. There was a significant correlation between all parameters and gestational age (p<0.001). No significant differences were observed between sexes or sides for any of the parameters (p>0.05). 2D:4D ratio was significantly higher in females compared to males (p<0.05) and mean 2D:4D did not change with gestational age. CONCLUSION: Detailed information of hand and digit parameters related to the fetal period will reveal the extent of biological variations of hand and digit parameters to be used in future studies. We hope that data acquired in this study will facilitate other studies on hand and digit anomalies, pathologies and variations as well as diagnoses and treatments of such conditions conducted in obstetrics, perinatology, forensic medicine and fetal pathology departments.     

New birthweight and head circumference centiles for gestational ages 24 to 42 weeks

Based on 20,713 singleton livebirths at the John Radcliffe Hospital, Oxford, in 1978-1984, we calculated new birthweight and head circumference values for males and females between 24 and 42 weeks of gestation. Among the 803 babies born at or before 34 weeks of gestation, 28% were delivered electively for fetal problems; they were considerably lighter and had smaller heads than infants born after spontaneous preterm labour. As we and others have recommended elsewhere, the electively delivered preterm infants were excluded from the calculation of the new birthweight and head circumference centiles. In our series males were heavier and had larger head circumferences than females at most gestational ages. There were consistent and statistically significant differences in birthweight at all gestational ages from 37 weeks and in head circumference at all gestational ages from 35 weeks.     

Behavioural states in the fetuses of nulliparous women

Behavioural state observations were carried out serially on the fetuses of 14 low risk nulliparae. They were observed serially at 2-weekly intervals between 32 weeks gestational age and delivery at term. Two real-time ultrasound B-scanners were used to visualize fetal body, eye and breathing movements. Fetal heart rate patterns were recorded simultaneously by means of a clinical fetal monitor. States appeared to be present transiently in three fetuses at 34 weeks. States were definitely present in five of 13 fetuses studied at 38 weeks and six of seven observed at 40 weeks. In comparison to the fetuses of low risk multiparae studied earlier, the fetuses in the present study showed a somewhat lower proportion of quiescence (coincidence 1F) and higher percentage of activity (coincidence 2F); however, most of these differences were not statistically significant. In the fetuses which showed states, the distribution and durations of the states at 38 and 40 weeks were not different from those found previously in the fetuses of multiparae. We conclude that the development of behavioural states is generally similar in the fetuses of low risk nulliparae and multiparae, but that states appear at a somewhat later gestational age in the fetuses of nulliparae.     

Glomic Cells and their Peptides in the Carotid Body of the Human Fetus

Carotid bodies from 15 human fetuses of gestational ages 13-19 weeks were examined by light and electron microscopy. They were also labeled with antisera to methionine- and leucine-enkephalins, substance P, and bombesin. At 13 weeks of gestation most fetal glomic cells formed a homogeneous population but a few could be distinguished by light microscopy as rounded, pale fetal chief cells or elongated, darker fetal sustentacular cells, a distinction that became more certain with increasing gestational age Electron microscopy confirmed this distinction, in which fetal chief cells contained dense-core vesicles and were partially enfolded by cytoplasmic extensions of fetal sustentacular cells. Immunoreactivity to methionine- and leucine-enkephalins was found at all gestational ages and was confined largely to fetal chief cells. Immunoreactivity to substance P was less specific, and there was no reaction for bombesin. Thus, by as early as the 13th week of gestation the two principal types of cell of the mature human carotid body begin to become recognizable on paraffin-embedded sections stained with hematoxylin and eosin. Furthermore, fetal chief cells can synthesize the peptides found in the adult.     

Fetal plasma leptin concentrations: relationship with different intrauterine growth patterns from 19 weeks to term

The relationship between in utero fetal growth and fetal leptin concentrations was investigated between 19 and 41 wk in 40 normal (appropriate for gestational age, AGA) fetuses, in 25 intrauterine growth-restricted (IUGR) fetuses, and in 18 fetuses from gestational diabetic mothers (GDM), representing different intrauterine growth patterns. Umbilical venous plasma leptin concentrations were determined at the time of either in utero fetal blood sampling or delivery. Plasma leptin was measurable as early as 19 wk of gestation. A significant difference was observed between umbilical venous and arterial plasma leptin concentrations (0.6+/-0.6 ng/mL; p<0.01). In AGA and in IUGR fetuses, significant positive relationships were found between fetal leptin concentrations and both gestational age (p<0.001) and fetal weight (p<0.001). Leptin concentrations were significantly higher in AGA than IUGR only after 34 wk (p<0.05), but leptin per kilogram fetal weight (leptin/kg) was not significantly different. In IUGR with abnormal umbilical arterial Doppler velocimetry and fetal heart rate, leptin/kg significantly higher than in IUGR with normal biophysical and biochemical parameters was found (p<0.05). Both circulating plasma leptin and leptin/kg were significantly higher in GDM than in normal fetuses (p<0.001) and correlated with abdominal fat mass measured by ultrasound. No gender differences were observed in any group of fetuses. These findings indicate a clear relationship between fetal leptin concentrations and fetal fat mass. Data in severe IUGR suggest the presence of increased leptin concentrations associated with in utero signs of fetal distress.     

Areal bone mineral density of the lumbar spine in 80 premature newborns: a prospective and longitudinal study

BACKGROUND: Maximum bone mass accretion in the fetal skeleton is acquired during the third trimester of gestation, and may be compromised in premature newborns. OBJECTIVE: To ascertain the incidence and evolution of osteopenia, a longitudinal study was performed to evaluate areal bone mineral density (aBMD) in the lumbar spine in premature newborns followed during the first 2 years of life. METHODS: aBMD values were assessed in lumbar spine (L2-L4) by DEXA and expressed as grams hydroxyapatite/cm2 in 80 premature newborns, 41 boys and 39 girls, of gestational ages 24.5-35.7 weeks. aBMD values were evaluated at (mean+/-SD) 0.2+/-0.1 years (at discharge from the neonatal unit), 0.9+/-0.2 years and 2.0+/-0.5 years of postnatal age, and compared with those of age- and sex-matched full-term newborns with normal intrauterine and postnatal growth. RESULTS: aBMD values recovered progressively from the first to the third evaluations, and were 0.139+/-0.06 g/cm2 (-2.4+/-1.4 SDS) at 0.2+/-0.1, 0.270+/-0.06 g/cm2 (-1.0+/-1.0 SDS) at 0.9+/-0.2 and 0.410 g/cm2 (-0.08+/-1.0 SDS) at 2.0+/-0.5 years. CONCLUSIONS: Our data show a significant catch-up of aBMD, reaching values similar to those of full-term newborns at the age of 0.2+/-0.5 years, regardless of the gestational age at birth.     

新生儿脐血Toll样受体变化及其意义

目的观察新生儿脐血单个核细胞（MNC）rrLR4、TLR2mRNA的表达。方法将46例无窒息新生儿及40例窒息新生儿根据胎龄分组,分离脐血MNC,测定其TLR4／2mRNA表达及上清中TNF-α水平。另外将TLR4／2mRNA表达水平与TNF-α水平进行相关分析。结果无窒息新生儿中足月儿TLR4／2mRNA及TNF-O／．水平分别为0．75±0．12、0．63±0．08、2502．6±273．1ng／t,胎龄≥32周但〈37周早产儿分别为0．37±0．04、0．32±0．03、1218．8±145．7ng／t,胎龄〈32周早产儿分别为0．26±0．03、0．20±0．03、811．8±105．2ng／t;窒息新生儿中足月儿TLR4／2mRNA及TNF-α．水平分别为0．58±0．07、0．50±0．06、1946．4±244．2ng／t,胎龄≥32周但〈37周早产儿分别为0．29±0．03、0．26±0．03、970．0±94．3ng／t,胎龄〈32周早产儿分别为0．17±0．02、0．14±0．02、652．6±60．3ng／t;成人TLR4／2mRNA及TNF-α水平分别为2．71±0．75、2．61±0．33、9270．1±1098．3ng／t。早产儿、足月儿TLR4／2mRNA及TNF-α水平均低于成人,胎龄越低,TLR4／2mRNA及TNF-α水平越低。窒息新生儿TLR4／2mRNA及TNF-α的表达水平均低于同胎龄无窒息新生儿（P〈0．01）。TLR4／2mRNA表达水平与TNF-O／．水平呈正相关关系。结论新生儿,特别是早产儿,TLR水平低下,可能是新生儿天然免疫能力低下,容易患败血症等严重感染性疾病的重要原因之一。     

STUDIES ON MATURITY IN NEWBORN INFANTS

Five anthropometric measurements, birth weight, crown-heel length, head circumference, occipito-frontal diameter, and bi-parietal diameter were recorded in a group of 174 newborn infants of various gestational ages. The material was selected to contain a relatively large number of infants with extreme birth weights and/or gestational ages. Head circumference was better correlated to gestational age than were the other four measurements. Birth weight and crown-heel length had the same degree of correlation to gestational age. The two skull diameters showed significantly lower correlations to gestational age. The confidence limits for estimating gestational age on the basis of the mean value for head circumference were ±26.1 days in this material. In SGA infants, crown-heel length and head circumference were not significantly greater than in pre-term infants of the same birth weight.     

Hemoglobin oxygen dissociation (P50) in bronchopulmonary dysplasia.

A study was devised to determine the P50 in infants with bronchopulmonary dysplasia (BPD). Other factors such as red blood cell 2,3-diphosphoglycerate (2,3-DPG) level proportions of adult (HbA) to fetal (HbF) hemoglobins which could affect P50 were also measured. Fourteen infants with clinical and radiological signs of BPD with a mean post-conceptional age of 42.2 +/- 4.7 weeks born at a mean gestational age of 29.3 +/- 2.0 weeks were evaluated. The percentage of HbF determined in 8 infants was 40.1 +/- 20.3% and the mean 2,3-DPG concentrations was 13.1 +/- 2.2 mumol/g Hb. The P50 was 25.1 +/- 2.7 mm Hg (range 18-29.5 mm Hg). When a HbO2 curve was established based on a large volume of blood consisting of adult blood and newborn cord blood mixed to attain a P50 of 25.1 mm Hg, the PaO2 at 90% O2 saturation was 52 mm Hg. Since there can be a wide range in HbO2 in infants with chronic BPD, pulse oximetry remains the most prudent method of monitoring oxygen therapy in BPD infants.     

不同胎龄新生儿身长体重指数研究

目的 制定不同胎龄新生儿身长体重指数,为胎儿宫内发育评价提供参考数据。方法 采用横断面时间段整群抽样实况调查方法,于2005~2006年在深圳宝安区妇幼保健院完成了8 357例不同胎龄新生儿体重、身长、顶臀长、头围、胸围现场测量,用以制定不同胎龄新生儿身长体重指数。结果 计算深圳不同胎龄(孕28~44周)不同性别新生儿身长体重五项指数[克托莱指数(QI)、考浦指数(KI);劳雷尔指数(RI);利比指数(LI);勃洛克指数(PI)],以均数±标准差表示。结果五项身长体重指数都随胎龄增加指数值不断递增,峰值出现在孕41~43周,显示了胎儿胎龄增大人体密度和充实度不断提高。男性QI、KI和PI值高于女性(P结论 不同胎龄新生儿随胎龄增加人体密度和充实度不断提高,男婴充实度比女婴好。