OBJECTIVETo observe the morphological changes during development of the ventricular zone (VZ) and subventricular zone (SVZ) of human fetus and the distribution pattern of neural stem cells in the VA and SVZ.

METHODSHuman fetuses at the gestational ages of 9-11 weeks, 14-16 weeks, 22-24 weeks and 32-36 weeks were collected, and the brain sections of the VZ/SVZ under the frontal lobe were examined for cytoarchitecture and distribution of nestin-positive cells with HE staining, immunohistochemistry or immunofluorescence.

RESULTSThe thickness of VZ underwent no significant changes at the gestational ages of 9-24 weeks (P>0.05) and became obviously thinner at 32 weeks (P<0.05), while the thickness of SVZ increased during 9-24 weeks (P<0.05) without obvious thinning at 32 weeks (P>0.05). VZ was thicker than SVZ at 9-11 weeks but became markedly thinner than SVZ after 14 weeks (P<0.05). The VZ contained denser cells than SVZ and showed a distinct boundary between the VZ and SVZ. Large numbers of nestin-positive cells were detected in the VZ and SVZ, and nestin immunoreactivity was found primarily in the cell processes and occasionally in the soma. Some nestin-positive cells in the SVZ had 1-3 processes. Nestin immunoreactivity in the VZ and SVZ gradually grew weak with development. The cells positive for both nestin and Ki67 were located mainly in the inner zone of the VZ and throughout the SVZ, where some nestin-positive but Ki67-negative cells were also found.

CONCLUSIONThe SVZ fully extends and the neural stem cells in the VZ/SVZ can be morphologically heterogeneous during the development of fetal human brain.

Fetus ; Frontal Lobe ; cytology ; embryology ; metabolism ; Humans ; Nestin ; metabolism ; Neural Stem Cells ; metabolism ; Neurons ; metabolism

OBJECTIVETo explore the role of microtubule-associated protein 2 (MAP-2) and nestin in the development of tongue muscles of human embryos and fetuses.

METHODSPV immunohistochemistry was used to detect the expressions of MAP-2 and nestin proteins in the tongue tissues of human embryos and fetuses at the second, third and fourth months of gestation.

RESULTSMAP-2 and nestin positivity was detected in the tongue muscles of human embryos at 2 to 4 months of gestation. In the embryos at the second month of gestation, no obvious MAP-2 positive cells were found in the tongue muscles; at 3 and 4 months, the number of MAP-2-positive cells in the tongue muscles was 24.14∓8.28 and 15.86∓3.89, with the expression intensity of 109.42∓11.62 and 124.27∓8.73, respectively. At 2, 3 and 4 months of gestation, the number of nestin-positive cells in the tongue muscles was 12.50∓3.17, 19.00∓7.63, and 22.80∓6.91, with expression intensity of 119.99∓24.02, 102.20∓11.76, and 98.24∓10.66, respectively. As the gestational age increased, the number of MAP-2-positive cell number continued to decline following a transient increase but the expression intensity kept increasing; nestin-positive cells increased continuously but the expression intensity kept decreasing in the embryonic or fetal tongue muscles.

CONCLUSIONMAP-2 and nestin proteins are involved in the regulation of the development of tongue muscles in human embryos and fetuses.

Fetus ; metabolism ; Humans ; Microtubule-Associated Proteins ; metabolism ; Nestin ; metabolism ; Tongue ; embryology ; growth & development ; metabolism

The presence of elastin layers in the aortic walls of twelve human fetuses was confirmed with scanning electron microscope pictures after hot alkali treatment and histochemical examination. In addition, the number of elastin layers in aortic walls of 5 different segments were compared in fetuses of varying ages. Aldehyde fuchsin stained slides of elastin ascending aortas showed a range between 27 and 55 layers of elastin in fetuses of 8 weeks to 32 weeks. However, in the lower abdominal aortas, elastin layers decreased from 28 to only 3 layers for fetuses of the same age. Furthermore, as elastin layers decreased from ascending aorta to abdominal aorta with the progression of fetal life, similar changes in the elastin lamellae were observed. These results suggest that while aortas grow rapidly in length, the medial elastin thickens slowly, perhaps due to slow development of hydrodynamic forces and pressures. Also the adventitial elastin appears to lose out gradually along the length from ascending aorta to abdominal aorta.
Aorta/*embryology/metabolism/ultrastructure ; Elastin/*metabolism ; Fetus/anatomy & histology/*metabolism/physiology ; Human

Wounds on fetal skin can be repaired without leaving scars until the second trimester, but after this period, skin wounds leave scars as in adults. It's known that certain growth factors such as TGF-beta, and bFGF are present at a very low levels during wound repair in fetal skin. These low levels of growth factors minimize inflammatory response and fibroblast proliferation at the wound site, which in turn inhibit collagen synthesis, and thus, allows scarless wound healing. Recently bone morphogenetic proteins (BMPs), one of the TGF-beta superfamily members, have been studied in the wound healing process. According to several studies, BMPs are related to the differentiation and growth of epithelial and mesenchymal cells, but the precise functions of BMPs and of BMP receptors on skin wound healing have not been elucidated. In this study, we investigated the expression pattern of BMP receptors in fetal skin during the second trimester and in adult skin by immunohistochemical staining and RT-PCR. BMP receptors were detected on the suprabasal epithelial cells and in the hair follicles in adult skin, but were not defected in the fetal skin except for the hair follicles. This was confirmed by confirming mRNA levels of BMP receptors by RT-PCR in both adult and fetal skins. In conclusion, BMPs and BMP receptors seem to be related to fetal and adult wound healing, and low levels of BMPs and BMP receptors during the second trimester seem to contribute to scarless wound healing in the fetus, as is TGF-beta during the second trimester.
Fetus/metabolism ; Human ; Immunohistochemistry ; Receptors, Cell Surface/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Skin/*embryology/*metabolism

OBJECTIVETo study the differences of protein expression levels in the brain cortex of human fetus and adult with proteomics technique, and provide preliminary data on the change of proteins during brain development.

METHODSProteins extracted from human temporal lobes in fetal (3 month and 5 month respectively) and adult (30 years old) brain were separated by two-dimensional gel electrophoresis (2DE). The proteins were then stained with colloidal Coomassie blue to produce a high-resolution map of the proteiome. The differential protein spots were analyzed by PDQuest 7.0 software and 8 spots, which were gradually reduced or gradually increased in brain development process and the protein spots of difference over two-fold in the brain, were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/TOF).

RESULTS(1) On average, 642, 511 and 527 protein spots could be obtained in the temporal lobes of adult, 3 month and 5 month fetus. The matching rate of images was 87%. The basic proteins in adult brain were obviously much more than that in the fetus; (2) There were 172, 171 and 152 singular protein spots in temporal lobes of adult, 3 month and 5 month fetus respectively.(3) Compared with adult, there were 131 and 115 different protein spots in the 3 month and 5 month fetus respectively. There were 60 and 40 protein spots with more than 2 fold difference, among which 24 and 17 were down-regulated, and 36 and 23 were up-regulated respectively. (4) There was different expression in proteins such as serum albumin, triosephosphate isomerase, etc. in the 3 groups. Fatty acid binding protein 7 and unnamed proteins were only highly expressed in the 3 month brain; ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit and transducin beta-1 subunit were up-regulated in adult brain. Serum albumin decreases gradually with brain development. However, ATP synthase, mitochondrial F0 complex, and triosephosphate isomerase increase gradually with brain development.

CONCLUSIONThe proteins of human brain cortex were obviously changed from embryonic stage to adult. The differentially displayed proteins may provide further insight into the understanding of development of human brain.

Adult ; Cerebral Cortex ; metabolism ; Electrophoresis, Gel, Two-Dimensional ; Fetus ; metabolism ; Humans ; Mass Spectrometry ; Proteins ; metabolism ; Proteomics

OBJECTIVETo investigate the growth and development of brain derived neurophic factor(BDNF)-positive neurons in the frontal lobe of human fetus.

METHODSThe expression of the BDNF-positive neurons in the frontal lobe of human fetus in the 2(nd),3(rd),and 4(th) month of gestation were observed with the streptavidin-biotin-complex/immunoperoxidase(SABC)method.

RESULTSBy the second month of gestation,BDNF-positive neurons were seen in the subventricular layer of the frontal lobe of cerebellum.By the third month of gestation,BDNF-positive neurons in the central layer were in various shapes,with big nucleus,less cytoplasm,and small processes.By the fourth month of gestation,BDNF-positive neurons in the central layer grew larger in size,cytoplasm increased,the BDNF-positive expression was enhanced with deeper dyeing,and the nerve fibers and particles were distributed between neurons;also,the BDNF-positive neurons were seen in the marginal layer of the frontal lobe of cerebrum.

CONCLUSIONBDNF-positive neurons may participate in the early development of the frontal lobe of cerebrum of human fetus.

Brain-Derived Neurotrophic Factor ; metabolism ; Fetus ; metabolism ; Frontal Lobe ; embryology ; Humans ; Neurons ; cytology ; metabolism

OBJECTIVETo observe the expression characteristics of EGFR and FGFR-2 in normal skin from fetal and adult, and attempted to probe the molecule mechanism of fetal scarless healing.

METHODSThe skin samples of fetal and adult were taken from abortive fetus of obstetrics unit and donor site of plastic operation patients in our burn unit, respectively. EGFR and FGFR-2 were used as the biochemical markers for reparative cells. Immunohistochemistry staining technique was employed to determine the expressive levels of different epithelial cells markers.

RESULTSThere were EGFR and FGFR-2 antibody positive cells in normal skin from fetal and adult, but the expressive levels of EGFR and FGFR-2 protein had apparent difference, with the time of fetation increasing, the EGFR and FGFR-2 positive expression rate became stronger gradually. The number of FGFR-2 antibody positive cells found in adult skin was much more than that in fetal skin.

CONCLUSIONThere were the inherent differences of EGFR and FGFR-2 antibody immunohistochemistry staining in cells of adult and fetal skin. which may be an essential facet of fetal scarless healing.

Adult ; Epithelial Cells ; metabolism ; ErbB Receptors ; metabolism ; Female ; Fetus ; metabolism ; Humans ; Immunohistochemistry ; Receptor, ErbB-2 ; metabolism ; Skin ; metabolism ; Wound Healing

Intestinal tract, which produces more than fifty kinds of gut peptides, is regarded as the largest endocrine organ. With regard to the gut peptides, a number of studies were focused on their structure, function and the roles in some diseases. The changes in output or distribution of gut peptides in the intestinal tract during development have been largely unknown. This study was aimed to investigate the changes of somatostatin (SST) and somatostatin receptor 2 (SSTR2) in small intestinal and hepatic tissues during the development of macaque. The tissue samples of small intestine, liver or blood samples from peripheral and portal vein of 4 macaques in 6-month fetus, 2-day neonate, 45-day neonate and adult were obtained after anesthetization. The concentrations of SST in blood or tissues of macaques were measured by radioimmunoassay. The distributions of SST in small intestinal or hepatic tissues were visualized by immunohistochemical staining. The expression of SSTR2 was detected by in situ hybridization. SST concentration of intestinal tissue in 6-month-old macaque was (27.3+/-16.6) ng /mg protein and light positive staining of SST was localized in mucosal crypts but negative in muscle layer. The intestinal concentration of SST increased gradually with macaque development and reached to the peak [(120.1+/-35.3) ng /mg protein] in adult. It was significantly higher than that in fetus (P<0.01). Strong positive staining of SST was found in both mucosal crypts and myenteric nerve plexus of adult animal. SSTR2 was obviously expressed in intestinal epithelium of fetus but its expression was greatly reduced in epithelium and was shifted to mucosal crypts when grown to adult. Negative staining of SSTR2 in muscle layer of fetal or neonatal macaque turned to be positive in myenteric nerve plexus of adult. The levels of SST or SSTR2 in liver decreased gradually during development. SST concentrations of small intestinal tissue kept significantly higher than those of hepatic tissues in the macaque developing stages. SST levels of portal vein were also maintained significantly higher than those of peripheral blood in the macaque developing stages. In conclusion, the level of SST and expression of SSTR2 in mucosal crypt increased gradually with macaque development. SST from intestinal tract was quickly degraded in portal vein before entering into liver. SST positive myenteric nerve plexus was visualized only in mature macaque.
Animals ; Animals, Newborn ; Fetus ; Intestine, Small ; metabolism ; Liver ; metabolism ; Macaca mulatta ; growth & development ; metabolism ; Male ; Receptors, Somatostatin ; metabolism ; Somatostatin ; metabolism

OBJECTIVETo investigate the growth and development of nerve growth factor (NGF)-positive neurons in the cerebellum of midanaphase human fetus.

METHODSThe expression of the NGF-positive neurons in the cerebrum of human fetus was observed by immunohistochemical methods, and the integral absorbance (IA) was detected.

RESULTSBy the 3rd to 4th month of gestation, neurons was seen in the ependymal, central, and marginal plate of cerebellum; the nucleus was oval and the neurons had short and small processes. By the 5th to 7th month of gestation, the number of NGF-positive neurons increased, the expressions enhanced, the nucleus was round-, oval-, or fusiform-shaped, the neurons grew larger in size, and the Purkinje cells showed NGF-positive expression. By the 8th to 10th month of gestation, the NGF-positive expression was enhanced with deeper dying, the body of Purkinje cells grew larger gradually, and the number of NGF-positive neurons in the granular cell layer and molecular layer increased. IA of the cerebellar cortical neurons of the 3rd, 4th, 5th, 6th, 7th, and 8th month of gestation showed an increasing trend, and significant difference was observed (P < 0. 05).

CONCLUSIONNGF-positive neurons in the cerebellum play an important role for differentiation, proliferation, migration, and growth of neurons in the cerebellum.

Cerebellum ; cytology ; metabolism ; Fetus ; cytology ; metabolism ; Humans ; Nerve Growth Factor ; metabolism ; Neurons ; cytology ; metabolism ; Purkinje Cells ; metabolism

OBJECTIVETo investigate the role of microtubule-associated protein 2 (MAP-2) and nestin in gastric development in human embryos and fetuses.

METHODSImmunohistochemistry was used to detect the expressions of MAP-2 and nestin proteins in the gastric cardia, pyloric and gastric tissues of human embryos and fetuses during the second, third and fourth month of development.

RESULTSIn the second to fourth months of gestation, MAP-2 and nestin expressions were detected in the neural cells and neural fibers of the intermuscular nerve plexus and submucosal plexus in the gastric cardia, pyloric and gastric tissues. As the gestational age increased, the number of MAP-2- and nestin-positive cells and the expression intensity all increased in the myenteric plexus, but MAP-2 and nestin expressions were negative in the glandular and mucosal tissues of human embryonic and fetal gastric cardia, pylorus or gastric walls.

CONCLUSIONMAP-2 and nestin participate in the regulation of the development of gastric tissues in human embryos.

Fetus ; metabolism ; Humans ; Intermediate Filament Proteins ; metabolism ; Microtubule-Associated Proteins ; metabolism ; Nerve Tissue Proteins ; metabolism ; Nestin ; Stomach ; embryology ; metabolism