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PubMed1977

[Study of lysosomal enzymes in chick embryo fibroblasts infected with microorganisms of family Halprowiaceae (Chlamydiaceae)].

It is shown that infection of chick embryo fibroblasts with agents of paratrachoma and meningopneumonia Halprowiaceae (Chlamydiaceae) causes a sharp decrease of the activities of lysosomal enzymes, e.g. acidic alpha-glucosidase, beta-glucuronidase, beta-galactosidase, alpha-mannosidase, acid phosphatase, etc. The activity of cytosol enzymes (neutral alpha-glucosidase, amylo-1,6-glucosidase) does not change, however. A decrease in the activities of lysosomal enzymes in infected fibroblasts occurs some time later after inoculation and is due to a release of lysosomal enzymes from the fibroblasts into the culture medium, without loss of cell integrity. No changes in the activity of lysosomal enzymes in fibroblasts and culture medium is observed in the case of inoculation of cells with a killed agents, as well as after contact of cells with a suspension of normal chick embryo yolk sacs. The release of lysosomal enzymes from halprowiae-infected chick embryo fibroblasts probably occurs by the exocytosis.

Acid Phosphatase↗

PubMed1988

Effects of intermittent hypoxia on structural vascular adaptation in chick embryos.

We explored whether the blood vascular system of the chick embryo adapts its structure to meet the maximum or average oxygen needs of the tissue cells. Chick embryos were grown in continuous 12% oxygen, continuous 16% oxygen, and intermittent 12% oxygen in which the embryos were exposed to 12% oxygen for 4 h each day. Control groups were grown in room air. Measurements of structural vascular resistance (SVR), i.e., the resistance of the maximally dilated vasculature, were used to estimate the whole body vascularity of the 14- or 15-day-old embryos. Continuous exposure to 12% oxygen decreased SVR by 63.1 +/- 1.2 (SE) %, and intermittent exposure to 12% oxygen decreased SVR by 55.6 +/- 0.5% when compared with a 15-day-old normoxic control group. Based on studies with continuous exposure to different levels of low oxygen, it was predicted that exposure to 19.5% oxygen, the average concentration for the intermittent hypoxia group, would decrease SVR by 15.0 +/- 0.3%. These results indicate that intermittent hypoxia at 12% oxygen was approximately 90% as effective as continuous hypoxia at the same level in decreasing SVR and about four times more effective than 19.5% continuous oxygen. Therefore, the results support the hypothesis that the blood vascular system adapts its structure to meet almost entirely the maximum oxygen needs of the tissue cells.

Aerobiosis↗

PubMed1982

Comparative study on glycosaminoglycan-sulfotransferases in rat costal cartilage and chick embryo cartilage.

1. The comparative features of glycosaminoglycan-sulfotransferase system in rat costal cartilage and chick-embryo cartilage were examined. Some different properties of glycosaminoglycan-sulfotransferases in the cartilage of both the animals have been observed. 2. This study shows that rat costal cartilage contains more 4-sulfotransferase than 6-sulfotransferase and that that reverse situation pertains to chick-embryo cartilage, although both the rat and chick-embryo cartilage contain two sulfotransferase species. 3. Our preliminary experiments by use of rat sulfotransferases and chick endogenous acceptor or of chick sulfotransferases and rat sulfotransferases and chick endogenous acceptor or of chick sulfotransferases and rat endogenous acceptor suggest that sulfotransferases in a given tissue play a central role in determining which sites of the N-acetylgalactosamine moiety of chondroitin sulfates occurring in the tissue are sulfated.

Animals↗

PubMed1998

Complete transposition in a chick embryo demonstrated by scanning electron microscopy.

Chick embryos are frequently used as animal models when researching the developing heart. In the past, every attempt to induce complete transposition (the combination of concordant atrioventricular and discordant ventriculo-arterial connections) failed in chicks, suggesting that it might be impossible to develop a chicken model for this malformation. We demonstrate, to the best of our knowledge, the first well-documented case of complete transposition occurring in the chick.

Animals↗

PubMed1997

Changes in protein composition during chick embryo retina development.

Two dimensional gel electrophoresis was employed to analyse the protein composition of chick embryo retina during "in ovo" development in order to individuate some components which are typical of different stages of growth. The study of protein composition of 7-day-old chick embryo retinas revealed the presence of about eighty different soluble components. In four of these proteins the staining intensity decreased during retina development. One of these components, of 35 KD with an isoelectric point of about 5.15, was partially purified by means of preparative isoelectric focusing. Other components, which were absent at day 7 appeared during the second week of development and were clearly visualised at day 16. These results were also compared with those obtained by means of 2DGE performed on liver and brain of chick embryo at day 7 and 16 of development.

Age Factors↗

PubMed1986

Quantification of the initial phases of rapid brain enlargement in the chick embryo.

Rapid brain enlargement requires a hydraulic mechanism in the chick embryo. Such a mechanism involves a closed, fluid-filled system that generates positive pressure. For the chick embryo this study determined when rapid brain enlargement begins, assessed the relative contributions of cavity expansion and tissue growth to overall brain enlargement, and evaluated mathematical models of overall brain enlargement and expansion and growth of the component parts. Three to five embryos were collected at each Hamburger and Hamilton state (11, 12, 14, 16, and 18) and processed for paraffin serial sectioning. Brain growth was determined over a 24-hr period (stages 11-18) by calculating volumes from area measurements of sections of brains from individual embryos by using a computerized image-analysis system. Statistical analysis indicated that a linear model adequately described cavity expansion, and a linear model was rejected for the description of tissue growth and total brain enlargement. At the onset of brain enlargement, the cavity expands faster than the tissue grows; but after 12 hr the reverse is true. Initially (i.e., at stage 11), the cavity accounts for 60% of the total brain volume and tissue for 40%. At stages 12-16, cavity and tissue contribute 50% each. Finally at stage 18, cavity accounts for 55% and tissue for 45%. In order to better distinguish changes in cavity expansion and tissue growth over the 24-hr period studied, this period was divided into four intervals (I-IV). The rates of both cavity expansion and tissue growth increase between intervals I and II, decrease between intervals II and III, and increase between intervals III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1980

[A comparative in vitro culture study of the action of the chick embryo testis and testosterone on different target organs (author's transl)].

This is a survey of previously published data and some new ones. The target organs studied were chick and mouse wolffian ducts and mullerian ducts. The following statements can be made: 1. The anti-mullerian hormone of the chick embryo testis is active on both the avian and mammalian mullerian ducts. Testosterone on the contrary will stimulate them. 2. Testosterone will stimulate both the avian and mammalian wolffian ducts, the chick embryo testis will not. It is concluded that there is no testosterone secretion by the chick embryo testis or in too low a quantity to be effective. Thus, the chick embryo testis and testosterone exert quite different actions on all four target organs studied.

Animals↗

PubMed1996

Method for treating and processing whole chick embryos for autoradiography, immunocytochemistry and other techniques.

A method is presented for in situ treatment of whole chick embryos with drugs and immunocytochemical and fixative reagents that resembles conditions "in ovo." The chick embryo is placed in a "shell-less" culture system where it is contained by an agar ring allowing for treatment in vivo. The conceptus (embryo+membranes) is then mounted on a microporous membrane and inserted into a filter device connected to a three-way stopcock that permits fluids to be changed using syringes. The embryo is then processed in toto or after embedding and sectioning for light or electron microscopy. The proposed handling system decreases technical artifacts and changes in the topographic microanatomy produced by conventional manipulation of chick embryos. This method is useful also for directly observing and recording changes in the embryo during drug treatments and allows processing with dangerous reagents without their direct contact with the operator. It is simple, inexpensive and requires only minimal technical training.

Animals↗

PubMed1978

Development of spontaneous motility in chick embryos supraspinal control.

Changes in spontaneous motility were studied in 11- to 19-day-old chick embryos after acute and chronic decapitation. Chronic decapitation was performed on the 2nd day of incubation, at stage 11--14. Up to the 15th day, acute decapitation merely reduced the frequency of spontaneous movements. In 17-day embryos it was followed by typical spinal shock, with transient complete disappearance of spontaneous movements of the embryo. The duration of spontaneous motor depression was proportional to the age of the embryo. After the 15th day of incubation, spinal decentralization changed continuous to discontinuous motor activity, with spontaneous paroxysms of high amplitude movements followed by long intervals of motor rest. Chronic decapitation was manifested, from the 15th day of incubation, in significant reduction of spontaneous movement frequency and again in discontinuous motility. A microscopic anatomical analysis of the spinal cord of decapitated embryos showed defects of the tracts in the lateral and ventromedial area of the cord and degenerative injury of the motoneurones in the ventral horns. Supraspinal control thus does not begin to act effectively on the spontaneous motility of chick embryos until about the 15th day of incubation. Supraspinal factors modulate both the frequency and the rhythm of spontaneous movements and are evidently also indispensable for normal morphological development of the spinal cord motor apparatus of chick embryos.

Animals↗

PubMed2004

[Establishment of a culture system of chick embryo for mouse tooth germ development].

OBJECTIVE: To establish a new culture system for mouse tooth germs in chick embryo. METHODS: The mandibular first molar germ fragments of 15 embryonic days' Kunming mouse embryo were implanted into the lateral mesenchyme of 4-5 days' chick embryo wing buds in ove. Eggs were reincubated and implanted tissues were examined by histochemistry. RESULTS: The cultured tooth germ development continued from cap stage to latest bell stage. The ameloblast and the odontoblast all differentiated maturely and secreted matrix. CONCLUSION: 4-5 days' wing buds chick embryo could serve as developing the mouse tooth germs and demonstrate well physiological process of differentiation and morphogenesis.

Ameloblasts↗

PubMed1994

Studies of effects of anticancer agents in combination with/without hyperthermia on metastasized human bladder cancer cells in chick embryos using the polymerase chain reaction technique.

Cultivated T24 cells derived from a human bladder cancer were inoculated into the chorioallantoic membrane vein of chick embryos. Hyperthermic treatment was performed following injection of anticancer agents 3 days after the inoculation of the T24 cells. DNA samples were obtained from the livers of the chick embryos, and the polymerase chain reaction technique was used to amplify a DNA fragment specific to the human beta-globin gene. The Southern hybridization method was used to evaluate the inhibitory effects of anticancer agents in combination with/without hyperthermia on T24 cells metastasized to the liver. The hyperthermia exerted an inhibitory effect on the growth of the T24 cells in the livers of the chick embryos, and this was dependent on the thermal dose. The antitumor effects of hyperthermia performed at 42.5 degrees C for 20 min and at 43.0 degrees C for 10 min were evidenced by 69.2% an 82.0% inhibition of the growth of the metastasized T24 cells, respectively, as compared with the growth of untreated T24 cell. Hyperthermia performed at 42.5 degrees C for 10 min alone produced 26.7% tumor growth inhibition, and these conditions for hyperthermia were subsequently used as a criterion for evaluating the effects of its combination with various anticancer agents. Adriamycin (20 micrograms/egg) alone, mitomycin C (10 micrograms/egg) alone, carboplatin (10 micrograms/egg) alone, and cisplatin (10 micrograms/egg) alone produced 13.5%, 58.9%, 27.3%, and 29.1% tumor growth inhibition, respectively. Adriamycin and mitomycin C applied in combination with hyperthermia showed additive inhibitory effects on the growth of the metastasized T24 cells in this chick embryo model.

Animals↗

PubMed1990

Myotome and early neurogenesis in chick embryos.

The present study was undertaken in order to verify the identification of profiles of presumptive growth cones in vivo. The developing spinal nerves of chick embryos were studied by light and electron microscopy. We traced the onset of efferent and afferent innervation of the myotome in 2- to 4-day-old chick embryos in order to be sure that we were examining the growing tips of axons. In the process of studying these growing axons, we were able to observe some unique relationships of neural tube, myotome, and differentiating spinal nerves. The neural tube tightly abuts the myotome in Hamburger and Hamilton's (HH) stage 14 chick embryos and cytoplasmic projections from the myotome directly abut the neural tube. The first ventral roots could be identified in HH stage 15 embryos and dorsal roots in HH stage 16 embryos, both under 2 1/2 days of age. The advancing spinal nerve courses toward the anterior or cranial half of the myotome, and growth cones directly contact the medial wall of the myotome. The spinal nerves continue to abut tightly the myotome during the succeeding day of embryonic life, and growth cones enter the substance of the myotome by 3 days, or HH stage 19 embryos. These dorsolaterally directed axons will form the dorsal ramus of the spinal nerves and the ventral ramus continues to be contiguous with the myotome. Invasion of the myotome by axons (putative innervation), and thus innervation of myotomal cells in the 3-day chick embryos, was a totally unexpected finding. The myotome and its potential derivatives thus have extensive neural contact by 3 days of embryonic life in the chick. These findings document a parallel differentiation of afferent and efferent elements of the nervous system and confirm previous accounts identifying growth cones in an intact organism. These findings suggest that afferent as well as efferent nerves may have critical roles in the differentiation of the mesodermal as well as ectodermal derivatives.

Animals↗

PubMed2005

Propagation of Chandipura virus in chick embryos.

Stocks of three Indian Chandipura virus (CHPV) isolates; one isolate from an adult febrile case in 1965 from Chandipura town, Maharashtra, and two isolates from two pediatric encephalitis cases from Andhra Pradesh, 2003 were inoculated in 10-day-old chick embryos by allantoic route. All three virus isolates replicated in chick embryos showing titre of log 10(12) to log 10(13) EID50. The results demonstrated that chick embryos are susceptible to CHPV and virus grows to high titres in this system. Therefore chick embryos can be used as an alternative host system for cultivation and isolation of CHPV as they are less expensive than laboratory animals and have several other advantages over cell cultures. Also this system can be used for the development of vaccine and diagnostic reagents.

Animals↗

PubMed1989

Histogenetic study of the vestibular ganglion in the developing chick embryo by lectin-horseradish peroxidase methods.

Hatchery eggs of White Leghorn hens were incubated and the vestibular ganglion cells of 3.5- to 6-day-old chick embryos were studied by the lectin-horseradish peroxidase methods (WGA, UEA-1). In the 3.5-day-old chick embryos, the facial-acoustic ganglion mass was recognized close to the otic vesicle. The statoacoustic ganglion reacted to lectins on the rhombencephalic side, indicating that glycoconjugates play a role in the nerve connection between ganglion and rhombencephalon. In the 4-day-old chick embryos, a strong reaction to lectins was observed on the ganglion cell membrane of the geniculate and statoacoustic ganglions, suggesting that glycoconjugates may be related to their differentiation. In 4- and 5-day-old chick embryos, the mesenchymal tissue showed a strong reaction to lectins, suggesting that it plays an important part in the differentiation of the vestibular ganglion.

Animals↗

PubMed1975

Ultrastructure of in vitro aged chick embryo cell cultures in relation to viral infection.

The ultrastructure of young uninfected and infected with herpes simplex virus chick embryo cells was compared with that of aged cells. In contrast to the nuclei of young chick embryo cells 24 hr after infection, the aged chick embryo cells 24 hr after infection presented very expressive blocks of perinuclear chromatin. The nucleoplasm contains forming naked HSV particles. The lesions seen are dilation of the perinuclear cisternae, dilatation of rough endoplasmic reticulum cisternae and formation of multilamellar bodies. The moderate swellings of the mitochondria with violation of cristae arrangement and losing of mitochondrial matrix were observed. In contrast to the cytoplasm of young infected cells no formation of crystal-like arrangement of cytoplasmic ribosome tetrads occurs.

Animals↗

PubMed1978

Histological study of muscular hypoplasia in the crooked neck dwarf mutant (cn/cn) chick embryo.

Tibiotarsal segments of 12-day chick embryos homozygous for the crooked neck dwarf gene (cn/cn) were examined histologically following routine methods of preparation. The myogenic mass fails to divide into separate muscle bundles during the early stages of differentiation. Myoblasts and myotubes are observed, although the proportion favors the mononucleate cell population. Multinucleate myotubes are often wavy in appearance and many contain eosinophilic cytoplasmic inclusions. The entire tissue mass of mutants appears more compacted than in control limbs. Poor organization of muscle appears related to the lack of a suitable connective tissue system. Epimysia, perimysia, and subcutaneous connective tissue fail to develop properly. Tendons are poorly developed or absent. Comparisons between mutant and control embryos show no differences in peripheral innervation. Nerve fascicles penetrate deeply into the developing muscle of both species. The distribution of vascular elements is seemingly normal also. Skeletal muscle of cn/cn embryos is capable of differentiating to the myotube stage, after which it undergoes cellular degeneration without achieving a functional state. Comparisons of this mutant with alleged chemical phenocopies show important differences.

Animals↗

PubMed2000

Hepatocyte growth factor/scatter factor is a neurotrophic survival factor for lumbar but not for other somatic motoneurons in the chick embryo.

Hepatocyte growth factor/scatter factor (HGF/SF) is expressed in the developing limb muscles of the chick embryo during the period of spinal motoneuron (MN) programmed cell death, and its receptor c-met is expressed in lumbar MNs during this same period. Although cultured motoneurons from brachial, thoracic, and lumbar segments are all rescued from cell death by chick embryo muscle extract (CMX) as well as by other specific trophic agents, HGF/SF only promotes the survival of lumbar MNs. Similarly, treatment of embryos in ovo with exogenous HGF/SF rescues lumbar but not other somatic MNs from cell death. Blocking antibodies to HGF/SF (anti-HGF) reduce the effects of CMX on MN survival in vitro and decrease the number of lumbar MNs in vivo. The expression of c-met on MNs in vivo is regulated by a limb-derived trophic signal distinct from HGF/SF. HGF/SF is a potent, select, and physiologically relevant survival factor for a subpopulation of developing spinal MNs in the lumbar segments of the chick embryo.

Animals↗

PubMed1990

Prenatal oxidative stress: I. Malondialdehyde in hypoxic and hyperoxic chick embryos.

Evidence suggests a positive correlation between metabolic rate (VO2), or ambient oxygen (O2) tension, and the rate of formation of free radicals from O2. We have previously demonstrated that the rates of growth, VO2, protein and DNA accumulation, and the activity of cytochrome oxidase (a key mitochondrial respiratory enzyme), are increased significantly by exposing the chick embryo to 72 h of hyperoxia (60% O2) late in incubation. To test the hypothesis that the chick embryo responds to a prenatal alteration in O2 availability in such a way as to protect its tissues from oxidative damage, we have used the thiobarbituric acid assay to estimate lipid peroxidation (a major form of free radical damage) in selected organs from chick embryos exposed to altered O2 availability. We found significantly higher concentrations of malondialdehyde (MDA, a secondary product of lipid peroxidation) in liver than in chorioallantoic membrane, brain, or heart. However, embryos exposed to brief (72 h) hypoxia (15% O2) or hyperoxia (60% O2) late in incubation, or 48 h of such exposure followed by 24 h of incubation in pure O2, exhibited no significant difference in MDA levels compared to normoxic (21% O2) controls in any of the tissues examined. We conclude that the increase in aerobic metabolism induced in the chick embryo by 3 days of hyperoxia is not accompanied by an increase in lipid peroxidation. We postulate that the chick embryo adapts to hyperoxia in such a way as to escape additional free radical damage, perhaps by increasing the capacity of its antioxidant defenses to compensate for a potential increase in the rate of free radical generation.

Animals↗