Papers by Julio Luis Erwin Illanes
Journal of Morphology, Sep 1, 1980
It is well established that the capacity for teeth to differentiate “in vitro” depends upon: (a) ... more It is well established that the capacity for teeth to differentiate “in vitro” depends upon: (a) the age of the embryonic rudiments at the time of excision and (b) the number of cells within each tissue type which are capable of differentiating into organ culture. This paper studies ultrastructural aspects of tooth buds grown in vitro from lizard embryos and compares these characteristics with those observed in dental germs grown in situ in older lizard embryos. Moreover, we report the self‐differentiation in vitro dental tissues from adult lizard and compare this phenomenon with the main features of a morphogenetic field. Our results suggest that approximately in the first third of gestation in L. gravenhorsti the dental buds has already acquired the capacity for self‐differentiation in vitro. The ultrastuctural observations show that there are no significant differences between odontoblasts and ameloblasts in situ and in vitro. The tooth from “adult lizards,” isolated by combined microsurgical and enzymatic procedure and cultured in semisolid‐liquid medium were also able to differentiate teeth. This phenomenon implies that self‐differentiation is not rigidly determined, and that in these animals the tooth tissues represents a continuous morphogenetic field throughout the animal's life. This property is intrinsic, resides in the isolated tooth tissues, and is relatively independent of external factors. In addition, these studies indicate that the chick chorio–allantoic membrane and the semisolid‐liquid culture medium supply the majority of the factors required for development of these tissues.
Journal of Morphology, Sep 1, 1981
In this work, we have completed a study of the development of the ovoviviparous lizard Liolaemus ... more In this work, we have completed a study of the development of the ovoviviparous lizard Liolaemus tenuis tenuis. Ovoviviparity in this lizard is a condition in which eggs are retained within the reproductive duct for about 60 days. During this period the phases of segmentation, gastrulation, neurulation, presomitic, and somitic embryos transpire. During the months of December and January the eggs are laid, and at this time the embryos are comparable to stage 27 Liolaemus gravenhorsti lizard embryos, or to stage 29 Calotes versicolor lizard embryos. Differentiation of the facial region occurs between Days 12 and 42 after egg laying. Limbs develop rapidly between the 8th and 23rd days. By 53 days the appendicular skeleton is completely formed. After 36 days the mesonephros begins to degenerate, and its function is gradually taken over by the developing metanephros. Newborn lizards do not possess an egg caruncle. During the period up to hatching, there is a great increase of liquid within the egg, presumably amniotic fluid. Cracks develop in the leathery shell shortly before hatching and are, perhaps, the first sign of the onset of hatching. Increase of liquid in the egg during postlaying development accounts for its increase in weight and change in shape. Weight of the embryo at hatching does not exceed 32% of the total weight of the egg.
Journal of Morphology, Jun 1, 1983
Ultrastructural characteristics of tooth buds of the polyphyodont adult lizards Liolaemus tenuis ... more Ultrastructural characteristics of tooth buds of the polyphyodont adult lizards Liolaemus tenuis and Liolaemus gravenhorsti have been elucidated. Xenoplastic combinations of lizard whole tooth buds and neural crest cells from embryos of the quail Coturnix coturnix japonica have been cultured in vitro. Mesenchymal cells (preodontoblasts) of lizard teeth early develop filopodia that contact the basal lamina. Fragments of quail neural crest isolated by dissection were recombined with isolated lizard tooth buds and cultured for 84 hours in dishes kept in an incubator at 37.8 degrees C in air. Some identifiable quail cells in these recombinants developed a cytoplasmic extension like that of an odontoblastic process. These results suggest that lizard tooth rudiments already determined for tooth development produce some non-species specific transmissible constituents which are capable of inducing quail cranial neural crest cells to express certain dental characteristics (odontoblastogenesis) not expressed in their normal development in vivo.
International Journal of Morphology, 2006
RESUMEN: En la última década, la crianza del avestruz en Chile ha ido aumentando sustancialmente,... more RESUMEN: En la última década, la crianza del avestruz en Chile ha ido aumentando sustancialmente, por lo cual se ha hecho necesario incrementar los estudios para mejorar la producción de esta especie. La literatura señala sólo estudios sobre la fisiología y anatomía de esta especie. Nuestro objetivo es aportar al conocimiento de la histología normal de las glándulas anexas al aparato digestivo. Esta investigación se realizó con 6 avestruces clínicamente sanas, de las que se obtuvieron muestras representativas del hígado, pro ventrículo y páncreas. Se realizaron cortes histológicos, los que fueron teñidos y montados para su análisis comparativo bajo microscopio de luz, entre avestruz y gallina. La histología de las glándulas anexas del aparato digestivo es semejante a la descrita en la gallina. Sin embargo, en el hígado los cordones de hepatocitos se disponen en forma radial, tanto alrededor de la vena central como de los espacios porta, característica no observada en otras especies. Con respecto al pro ventrículo, en la mucosa se observan glándulas tubulares simples o ramificadas, semejantes a las glándulas fúndicas de los mamíferos. En la submucosa se observan glándulas túbuloalveolares compuestas con células parietales. El páncreas no presenta diferencias destacables.
International Journal of Morphology, 2018
International Journal of Morphology
Due to the growing interest of the ostrich industry (Struthio camelus var. domesticus) and the sc... more Due to the growing interest of the ostrich industry (Struthio camelus var. domesticus) and the scarce bibliographic material related to morphology of the respiratory system of the ostrich, we carried out a comparative analysis of the laryngotracheal pulmonary segment of this bird. The research was conducted in six clinically healthy ostriches from which representative samples of the laryngotracheal pulmonary segment were obtained. Samples were processed using standard histological technique and a comparative morphological analysis between ostriches and chicken (Gallus gallus) was performed. In the ostrich, the arytenoid cartilage is double and placed in a dorsal and cranial position in relation to the larynx while the cricoid cartilage is single and situated in a ventral and caudal position. Like the chicken, the procricoid cartilage is also present. The trachea exhibits a greater number of rings compared to the chicken. At the syrinx level, the pessulus is made up of a dorso-ventra...
Anatomia, histologia, embryologia, 1995
The teratogenic effect of alcohol on chick embryos has been confirmed by many investigators. Howe... more The teratogenic effect of alcohol on chick embryos has been confirmed by many investigators. However, how this occurs is unknown. The aim of this study was to establish a teratogenic pattern of alcohol effects, on the first stages of development in avians. Fertilized eggs were infused through the air space of the shell on day 0, with ethanol in concentrations of 20%, 40% and 60%. The control group was infused with 0.1 ml of NaCl at 0.9%. At a second stage, the eggs were treated on the 4th day of incubation, using the same method. In both groups the eggs were removed on the 11th day of incubation. The teratological manifestations that appeared more frequently were evisceration, haemorrhagic embryos, oedema, cranial deformities, lack of eyes, and umbilical hernia, showing every embryo a clear reduction in size and body weight.
Revista chilena de pediatría
Anatomia, histologia, embryologia, 1984
Revista chilena de pediatría, 1983
Chimeric chicken organs'with 144 incubation hours, exposed to ultrasound during 10, 20 and 30 min... more Chimeric chicken organs'with 144 incubation hours, exposed to ultrasound during 10, 20 and 30 minutes respectively, at 750 KHz and 6.4 W/cm 2 , were studied. Histologycal findings are described, among them, the presence of necrosis in embrionic tissues irradiated for 20 minutes is remarked. Histograms showed a significant decrease of mitosis in organs exposed by 10 and 20 minutes to ultrasound and an evident increase in those with 30 minutes of irradiation time.
Pathology & Oncology Research, 2002
International Journal of Morphology, 2014
Journal of Experimental Zoology, 1987
The developmental processes related to odontogenesis are similar in all vertebrates and they occu... more The developmental processes related to odontogenesis are similar in all vertebrates and they occur during embryogenesis. The dental papilla can exercises directive morphogenetic role on epithelia of different phylogenetic origin. In our laboratory we have previously shown that cultured heterologous tissue recombinations between adult lizards dental papillae and quail epithelia were capable of producing odontogenesis and amelogenesis. Employing sodium dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) according to Laemmli ('70, Nature, 227:680-685.) and two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) (O'Farrell, '75, J. Biol. Chem., 250:4007-4021.), we have examined the distribution of soluble proteins with respect to isoelectric point and molecular weight of dental papillae isolated from tooth germs at bell stage of adult lizard LioZuemus tenuis tenuis (polyphyodont species) and dog fetuses Cunis fumiZiuris (diphyodont species). A comparison was also made with dental pulps from adult dogs. Some dental papillae from lizard tooth at bell stage were recombined with quail ectoderm and cultured in explant for 8 days. Furthermore, the histological analysis of dental papillae from lizard and dog fetus showed that dental papillae from both species contain preodontoblast cells, scarce extracellular matrix, and some blood vessels. Dental pulp from adult dogs is composed of odontoblast and fibroblast cells, extracellular matrix, collagen, blood vessels, etc. The control heterologous recombinants after the culture period differentiated chimeric tooth structures, showing that the dental papillae were capable of producing developmental instructions. The electrophoretic study of the supernatants showed differences and similarities. Under SDS-PAGE the presence of one band of an approximate molecular weight of 49.000 daltons was disclosed, which seems to be unique to dental papilla from adult lizards and dog fetuses. Under 2-D PAGE protein patterns from adult lizard and dog fetuses disclosed also two protein spots with an approximate molecular weight of 49.000 daltons and isoelectric point of pH ranges between 6 and 7.5. Apparently these spots are unique to both patterns and would have some significance in odontogenesis.
International Journal of Morphology, 2007
Análisis Macroscópico y Microscópico del Desarrollo Embrionario y Fetal en el Gato (Felis catus),... more Análisis Macroscópico y Microscópico del Desarrollo Embrionario y Fetal en el Gato (Felis catus), en Relación con el Desarrollo de la Vesícula Coriónica y de la Placenta Macroscopic and Microscopic Analysis of the Embryonic and Fetal Growth in the Cat (Felis catus), in Relation to Chorionic Vesicle and Placental Development
Journal of Morphology, 1999
Using tartrate-resistant acid phosphatase (TRAP), we examined the cytodifferentiation of odontocl... more Using tartrate-resistant acid phosphatase (TRAP), we examined the cytodifferentiation of odontoclast cells in resorbing areas of dental tissues during the replacement of teeth in a polyphyodont lizard, Liolaemus gravenhorsti. We also report, by means of Lectin-HRP histochemistry, the distribution pattern of some specific sugar residues of TRAPase-positive cells. For detection of TRAPase activity, the azo dye-coupling technique was used. Lectin binding sites were demonstrated by means of specific HRP-lectins. The process of tooth resorption was divided into four stages: 1) preresorption-the wall of the dental pulp is covered with an odontoblast layer, and no TRAP-positive cells are in the dental pulp; 2) early resorption-TRAP-positive multinucleate odontoclasts are present on the dental wall, but the rest of the pulp surface is still covered with an odontoblast layer; 3) later resorption-the entire surface of the pulp chamber is lined with multinucleate odontoclasts; and 4) final resorption-the tooth has been totally resorbed. Odontoclasts are usually detached from the resorbed surface, and show signs of degeneration. Of the six lectins used, PNA, ECA, and UEA-1 bind to multinucleated but not mononuclear cells. All the remaining lectins, BS-1, RCA(120), and LTA showed no binding to any cells of the teeth. The significance of saccharidic moieties such as acetyl-galactosamine, acetyl-glucosamine, and fucose sugar residues is difficult to ascertain. Perhaps these oligosaccharides might be borne on molecules associated with odontoclastic resorption or associated with multinucleation of odontoclasts after attachment to the dentine surface.
Journal of Morphology, 1986
In this study we examined the possible inductive role of the dental papilla from polyphyodont liz... more In this study we examined the possible inductive role of the dental papilla from polyphyodont lizard tooth germs. Flank skin sheets of quail ectoderm enzymatically separated from dermal tissue were recombined with lizard tooth papillae and placed on semisolid medium and cultured for 2 days. Subsequently, the recombinants were removed and placed on the chorioallantoic membrane of chick hosts and incubated for 6 days. After this period of 8 days in explant, control tissues differentiated according to their own phenotypes. Lizard dental papilla alone differentiated as fibroblasts. Quail flank skin ectoderm differentiated into epithelial sheets. Intact lizard tooth buds developed into teeth with dentine and incipient enamel. In the best experimental recombinants, advanced and relatively well-constructed teeth were observed, with clear indications of hard tissue deposition in association with quail epithelium. The results show that mesenchyme of the adult lizard dental papilla and embryonic quail ectoderm of heterotopic origin are capable of carrying out the complex sequence of morphogenetic interactions involved in normal odontogenesis.
Biological Research, 2002
In this study, we showed the effect of the betamethasone, sulindac and quinacrine alone or combin... more In this study, we showed the effect of the betamethasone, sulindac and quinacrine alone or combined, on the inflammatory angiogenesis promoted by polyurethane sponge on mice. The main finding reported here is that the formation of new blood vessels was strongly inhibited by low concentration of betamethasone, sulindac or quinacrine, whether alone or in combination. It is known that steroidal anti-inflammatory drugs inhibit the enzymes required for the production of prostaglandins through a nuclear glucocorticoid receptor (GR) mediated mechanism. This mechanism may occur in endothelial cells as well. Considering that activity of cyclo-oxigenases 1 and 2 is inhibited by sulindac, and that these enzymes are located in the stromal tissue, we propose that the anti-angiogenic effect of these agents may occur via inhibition of both COX isoforms. On the other hand, quinacrine inhibited PLA2 activity, and we propose here that the anti-angiogenic effect occurs via inhibition of the enzyme PLA2. The potentiated effect of the association of betamethasone, sulindac and quinacrine may have some therapeutic benefit in the control of pathological angiogenesis. Further studies are required to validate these propositions.
Biological Research, 2001
Tumor growth is the result of combined cell proliferation overwhelming cell death and neoangiogen... more Tumor growth is the result of combined cell proliferation overwhelming cell death and neoangiogenesis. This report shows CAM angiogenesis promoted by TA3 tumor supernatant with or without low dosis of betamethasone (Minimal antiangiogenic concentration: beta-MAAC). Methylcellulose discs instilled with 10 microliters of beta-MAAC (0.08 microgram/ml), 10 microliters of tumor supernatant (TA3ts), 5 microliters beta-MAAC + 5 microliters TA3ts, and 10 microliters of PBS as control were implanted in host chick eggs. On day 12, the grafts were removed, photographed and fixed. Sections were stained in parallel, one and three with hematoxylin-eosin, and section two by the Tunel method. The number of vessels was evaluated in a microscopic field of the CAM (2250 micron 2). The results show that beta-MAAC produced a significant inhibition of neovascularization in comparison to that observed in controls (P < 0.0025; Student t-Test). Discs instilled with TA3ts produced an intense stimulation of angiogenesis in contrast, when discs were instilled with 5 microliters of beta-MAAC + 5 microliters of TA3ts the angiogenesis was significantly inhibited (P < 0.001). The results show that effective antiangiogenic doses of betamethasone are in the range of 10(-7) M, (probably a genomic mediated action) and that this effect of low concentration may have clinical applications.
Biological Research, 2000
The structural diversity of the many oligosaccharide chains of surface glycoconjugates renders th... more The structural diversity of the many oligosaccharide chains of surface glycoconjugates renders them likely candidates for modulators of cell-interactions, cellular movements, differentiation, and cellular recognition. A selection of different lectins was used to investigate the appearance of cellular distribution and changes in sugar residues during tooth development in the polyphyodont lizard, Liolaemus gravenhorsti. Lectins from three groups were used: (1) N-acetylgalactosamine specificity: BS-1, PNA, RCA-120; (2) N-acetylglucosamine specificity: ECA; and (3) fucose specificity: UEA 1 and LTA.. Digital images were processed using Scion Image. Grayscale graphics in each image were obtained. The lectins used showed a strong, wide distribution of the L-fucose and N-acetylgalactosamine at the cell surface and in the cytoplasm of multinucleate odontoclast cell, while mononuclear odontoclast cells showed no binding, suggesting some roles that the residues sugar might play in the resorption of dentine or with multinucleation of odontoclast after the attachment to the dentine surface in this polyphyodont species. Further studies must be planned to determine the specific identities of these glycoconjugates,and to elucidate the roles played by these sugar residues in the complex processes related to odontogenesis in polyphyodont species.
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Papers by Julio Luis Erwin Illanes