Normal embryonic development of human heart is studied with special emphasis to the formation of atrioventricular and ventriculoarterial connections and their significance in congenital heart disease. Twenty nine human embryos and 8 chick embryos are used in this study. Human embryos are analyzed by reconstruction of serial section slides and chick embryos are microdissected and examined by scanning electron microscopy. In the early cardiac development (Streeter horizon 12), bulbo-ventricular fold divided two ventricles first. The atrioventricular canal is incompletely divided and the canal was in contact neither with septum primum nor with ventricular septal crest. Infundibular and truncal septa were not seen. The division of A-V canal was observed during the stages 14-15. Septation of truncus arteriosus (Streeter horizon 15-17) was followed by septation of bulbus cordis (Streeter horizon 16-17). The shortening of mitral-aortic distance and downward left shift of aortic valve occured after the trunco-infundibular septation and finally the secondary interventricular formen closed at the end of seventh week (Streeter horizon 20-21).
Humans ; Chick Embryo ; Animals

No abstract available.
Animals ; Chick Embryo* ; Nicotine*

OBJECTIVETo explore the essential features of the potential distribution of electrocardiac field.

METHODSThe ECGs of 60 hearts of 5-day chick embryos were immersed in normal saline solution or distilled water and their different conductivities were recorded at 5 points at different distances in 4 directions perpendicular to each other. Comparison of the form and amplitude of ECGs was made between every two points with the same distance to the heart in 2 opposite directions to determine the potential distribution of the electrocardiac field of the one-chambered heart.

RESULTSThe ECGs recorded at every 2 points in 2 opposite directions with the same distance to the heart immersed in the same liquid medium were both upper standing, with no significant different between their amplitude of R(r) wave (P > 0.05).

CONCLUSIONThe uniform outward potential distribution of the electrocardiac field might not represent the form of depolarization but that of sphere-like and single-source when the influence of different reference points and thickness of different chamber walls upon mapping of body surface is excluded.

In this study, we report that the treatment of strychinine (STR), an inhibitor of glycine receptor, induced premature onset of programmed cell death (PCD) of developing chick motoneurons (MNs). Treatment of STR on E4 chick embryo increased the apoptosis of MN on E5 when MN PCD does not occur normally. On the other hand, treatment of STR from E3 or E5 for 24 hours did not significantly influence the extent of MN PCD, indicating that the STR effect is developmental stage-specific. However, the expression of glycine receptor isoform was low on E3-4, and other glycine receptor antagonists did not exhibit PCD-promoting activity, suggesting that the STR action on PCD is not related to the glycine receptor activation. Identification of the target molecule for STR action may provide novel mechanism how the onset of developmental PCD is regulated.
Animals ; Apoptosis ; Cell Death ; Chick Embryo ; Glycine ; Hand ; Receptors, Glycine

AIMTo investigate the effect of morphine on fetal movement, heart rate, hatch weight, hatch days and hatch rate.

METHODSMorphine was injected into airspace of eggs and fetal movement, heart rate, hatch weight, hatch days and hatch rates were recorded.

RESULTSHatch days were shorter, hatch rates were lower and some chicks became motor disorder for morphine. Chicks with morphine exposure 20 mg/kg from E 12 to E 16 had highest hatch rate and lowest disable rate. Morphine reduced fetal movement, increased heart rate (P < 0.05).

CONCLUSIONThe development of chick embryo is impaired by morphine exposure and the magnitude of these effects depends on the drug dose and the length of time that the developing organism is exposed to morphine.

To study the relationship between hematopoiesis and primordial germ cells, chick embryos at different developing stages were flatbed and located. After fixed by glutaral, the embryos were PAS and HE stained respectively, dehydrated serially, transparent, mounted, and were observed in situ or in cut sheet condition. The results showed: (1) the cellule amorphous and the disposition in chick embryo of PGCs were coincident no matter stained by PAS or HE staining, and HE staining could disclose the morphologic characteristics more clearly, exactly and completely; (2) genesis of blood island could be observed at the boundary of light and dark region of the extraembryonic blastoderm at about 26 hours; (3) both the blood vessel endothelium cells and free cells of the blood island were differentiated from PGCs. The generating of genuine yolk sac was at about 44 - 48 hours. It is concluded that the initial anatomic site of blood island genesis may be is mesoblast of extraembryonic blastoderm rather than the yolk sac; the blood vessel endothelium cells and the blood cells are generated parallel; the PGCs are the common ancestry of angioblast and HSC.
Animals ; Cell Differentiation ; Cell Movement ; Cells, Cultured ; Chick Embryo ; cytology ; Hematopoietic System ; cytology

In order to determine the adjuvant effects of the chicken IL-2 (ChIL-2) on new generation vaccines, ChIL-2 gene was amplified from ConA-stimulated chicken spleen cells by RT-PCR and was directionally inserted into fowlpox virus (FPV) transferring vector p1175 under the control of FPV early/late promoter (PE/L), resulting in recombinant transferring vector p1175IL2. Then the p1175IL2 plasmid was transfected into chicken embryo fibroblasts (CEF) pre-infected with wild type FPV to generate recombinant fowlpox virus expressing ChIL-2 (rFPV-IL2). By selection of blue plaques on the CEF, overlaid with agar containing X-gal, rFPV-IL2 was obtained and purified. The supernatant from CEF monolayer infected with rFPV-IL2 (M.O.I2.0) after 72 hours was detected for the production of ChIL-2 by XTT/PMS colorimetric assay. About 3.6 x 10(5) u/mL of specific ChIL-2 activity was determined. The results show that rFPV-IL2 can express ChIL-2 effectively. rFPV-IL2 provides us with an effective tool for studying avian immunology as well as a potential vaccine-enhancing agent.
Animals ; Chick Embryo ; Chickens ; Fowlpox virus ; genetics ; Interleukin-2 ; genetics ; pharmacology ; Recombinant Proteins ; biosynthesis ; pharmacology

OBJECTIVE: To investigate a re-closure capacity and chronological changes of re-closure, the histologic findings are observed after skin graft on surgically induced spinal open neural tube defect(ONTD) in chick embryos. METHODS: Embryos were divided into two groups: graft and control. In the embryos of the graft, a skin fragment from another chick embryo of embryonic day 7 was grafted on the ONTD immediately after neural tube incision. Embryos were re-incubated in ovo, up to postoperative days(PODs) 3, 5, 7, 10 and sacrificed. Rate of re-closure was compared according to the group of the embryo and the observation time point. Serial changes in histological appearance were observed to investigate whether the re-closured ONTDs regain normal shape. Statistical analysis was performed using the SAS and x2 test. RESULTS: On PODs 3, 5, 7, and 10, re-closure rates of the graft were 87, 60, 53 and 88%, and those of the control were 13, 0, 0 and 20%, respectively. They showed more frequent re-closure of ONTDs by the skin allograft in the graft than control. There was no statistical difference between the closure rates of adjacent POD subgroups. Some embryos of the closed groups revealed complete closure of the neural tube and there was no difference from the normal neural tube. CONCLUSION: Skin graft on the surgically induced ONTD in the embryonic period has a protective effect on the spinal cord. It is suggested that the prenatal skin graft on the lesions of fetal myelomeningocele might prevent repeated spinal cord damage.
Allografts ; Animals ; Chick Embryo* ; Embryonic Structures ; Meningomyelocele ; Neural Tube Defects* ; Neural Tube* ; Skin* ; Spinal Cord ; Transplants*

LG1 strain of avian influenza virus H9N2 was passaged continuously for 40 generations in chicken embryos with anti-LG1 maternal antibodies in 4 parallel experiments, of which 3 experiments had a stable mutation of "G" to "A" at #99 of the neuraminidase gene(NA)from the 20th passage resulting in a change of Met to Ile and 2 had a stable mutation of "A" to "G" at #473 of the NA gene from the 30th passage resulting in a change of Asn to Ser which occurred in the 50th passage of another experiment. Eighty continuous passages in chicken embryos without antibody did not have the same mutation, indicating that the mutations of the 2 positions were associated with selective pressure of antibodies. Analysis of the ratios of nonsynonium (NS) vs synonium (S) mutations of nucleic acids demonstrated that NS/S of 4 parallel experiments with antibodies was 4.6 (32/7) compared with 2.0 (16/8) of the 2 experiments without antibodies and this significant difference implied the selective pressure of antibodies.
Animals ; Antibodies, Viral ; immunology ; Chick Embryo ; Influenza A Virus, H9N2 Subtype ; genetics ; immunology ; Mutation ; Neuraminidase ; genetics

Twenty-four isolates of Newcastle disease virus (NDV) prevailing during 1997 -- 2005 in China were collected. These isolates were purified by CEF plaque assay and replicated in SPF chicken embryos. The hemagglutinin-neuraminidase (HN) genes of these viruses were cloned and sequenced. The HN gene sequences of thirty-six NDV reference strains in GenBank were also used in this study. The amino acid homologing of these viruses were compared and analyzed. The correlations among different fragments of HN gene were also analyzed. The results indicated that the homology of Chinese field NDV strains was 94.4%-99.4%, but 86.9%-89% compared with LaSota and Clone30, 87.9%-89.9% to F48E9, and 87.2%-96.2% to foreign NDV strains. There had the nearest distances among Chinese NDV isolates as compared with that of the LaSota, Clone30 and F48E9 by the phylogenetic tree. However, the distances of seven foreign NDV isolates were very close to Chinese NDV isolates as compared with these of the other foreign NDV isolates. We also found that all the Chinese field isolates were devoid of glycosylation site in position 538 -- 540. There were good correlations between different length amino acid fragments and the genomes of HN, especially the 5'-terminus first 80aa.
Animals ; Chick Embryo ; Chickens ; China ; HN Protein ; genetics ; Newcastle disease virus ; classification ; genetics ; Phylogeny