RESUMEN
The bilirubin content in the vitreous body of the eye of human fetuses of gestation week 17-31 was measured. During gestation weeks 17-19, the mean bilirubin concentration was 8.67 µmol/liter; then, decreased to 1.37 µmol/liter (gestation weeks 20 to 31). Bilirubin, being an endogenous antioxidant, is probably involved in protection of the retina and lens from LPO processes that intensively develop in retinal neurons and lens fibers.
Asunto(s)
Antioxidantes/metabolismo , Bilirrubina/metabolismo , Cuerpo Vítreo/metabolismo , Feto , Edad Gestacional , Humanos , Cristalino/metabolismo , Nacimiento Prematuro/mortalidad , Retina/metabolismoRESUMEN
A novel one-step procedure is described for synthesizing water soluble biocompatible nanocomposites from maghemite nanoparticles and carboxymethyl cellulose (CMC). The procedure allows the magneto-sensitive nanocomposites with a controlled content of the inorganic phase. The maghemite formation has been proved by X-ray diffraction analysis and Mossbauer spectroscopy. An average diameter of the maghemite nanoparticles is equal to 11nm according to transmission electron microscopy. As shown by FTIR spectroscopy, the nanoparticles bind to the polymer matrix via electrostatic and coordination interactions. The diameter of the nanocomposites in dilute aqueous solutions vary from 50nm at the iron content of 2-4.3wt.% to 140nm at the iron content of 5.2-8.6wt.%. The study of specific magnetization of the nanocomposites vs. applied magnetic field indicates their ferromagnetic properties. The saturation magnetization and coercive force of the sample with the maximum maghemite content (8.6wt.%) are 11.5emu/g and 30.08Oe, respectively. The nanocomposite motion has been shown to be controlled by an external magnetic field. The biocompartible maghemite-CMC nanocomposites seem to be promising for encapsulation and delivery of biologically active compounds.
Asunto(s)
Materiales Biocompatibles/química , Carboximetilcelulosa de Sodio/química , Compuestos Férricos , Nanocompuestos/química , Magnetismo , PolímerosRESUMEN
The content of serum albumin was evaluated in the vitreous body, retina, and lens of human fetuses of 14, 16, 17, 18 and 24 weeks of gestation. Albumin was detected in these tissues. PCR analysis revealed no albumin mRNA in the retina or in the lens, while in fetal liver (control) mRNA for this protein was expressed. These findings suggest that serum albumin is not synthesized by cells of retina and lens, but is captured by them. The presence of serum albumin in human eye tissues suggests its involvement in the metabolism, maintenance of tissue volume, and antioxidant reactions.
Asunto(s)
Feto/metabolismo , Albúmina Sérica/metabolismo , Cuerpo Vítreo/metabolismo , Expresión Génica , Humanos , Hígado/metabolismo , Retina/metabolismo , Albúmina Sérica/genéticaRESUMEN
Triblock copolymers of poly(ethylene oxide) and poly(propylene oxide) (so-called pluronics) were shown to influence the aggregation and fusion of atherogenic low density lipoproteins (atLDL) and be able to inhibit these processes. The character of the influence and the degree of the stabilizing effect depended on the structure, relative hydrophobicity, and concentration of the copolymer. Pluronics L61, P85, and L64 characterized by the hydrophilic-lipophilic balance (HLB) value from 3 to 16 had the greatest ability to suppress the aggregation of atLDL. Pluronic L81 with the higher hydrophobicity (HLB = 2) partially inhibited atLDL aggregation at low concentrations but stimulated it at high concentrations. The influence of pluronics did not have a direct connection with their ability for micelle formation, but it was realized through individual macromolecules. We suppose that effects of pluronics could be due to their interaction with the lipid component of LDL and to a possible influence of these copolymers on the structure and hydrophilic-lipophilic characteristics of lipoproteins.
Asunto(s)
Lipoproteínas LDL/química , Poloxámero/química , Polietilenglicoles/química , Aterosclerosis/sangre , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Lipoproteínas LDL/sangre , Micelas , Relación Estructura-ActividadRESUMEN
AIM: to evaluate and compare the effect of topical superoxide dismutase (SOD), which is an antioxidant enzyme, dexamethasone, and a combination of these on the course of experimental uveitis in rabbits as well as biochemical parameters of aqueous and vitreous humor. MATERIAL AND METHODS: Acute uveitis was induced in 16 rabbits by a double injection (subcutaneous and intravitreal) of normal horse serum. Of them 12 animals, divided into 3 groups of 4 each, received topical SOD, dexamethasone, or both daily for 7 days. The remaining 4 rabbits (8 eyes) were treated with placebo and, thus, constituted the control group. On day 8 the following parameters were measured in aqueous humor: protein concentration, antioxidant activity, SOD activity, α2-macroglobulin level, and leukocyte number. Total protein and albumin levels in vitreous humor were also determined. RESULTS: The effects of SOD and dexamethasone instillations were considered similar in many parameters. However, SOD was associated with a greater increase in antioxidant activity and a greater decrease in aqueous humor leukocytes, while dexamethasone was more effective in decreasing aqueous humor α2-macroglobulin and vitreous humor protein and albumin. The substances had a synergistic effect on iridal edema as well as aqueous humor leukocyte number and α2-macroglobulin level. CONCLUSION. Adding SOD to the complex therapy of uveitis results in lower inflammation intensity and enhanced dexamethasone effect.
Asunto(s)
Humor Acuoso/metabolismo , Dexametasona/administración & dosificación , Superóxido Dismutasa/administración & dosificación , Uveítis/tratamiento farmacológico , Animales , Humor Acuoso/efectos de los fármacos , Fenómenos Bioquímicos/efectos de los fármacos , Modelos Animales de Enfermedad , Quimioterapia Combinada , Depuradores de Radicales Libres/administración & dosificación , Glucocorticoides/administración & dosificación , Instilación de Medicamentos , Conejos , Uveítis/diagnóstico , Cuerpo Vítreo/efectos de los fármacos , Cuerpo Vítreo/metabolismoRESUMEN
In this paper, we analyzed our own results and published data on the expression of regulatory genes encoding transcription factors Pax6/PAX6, Pitx2/PITX2, Fox1/FOXC1, Prox1/PROX1, Oct4/OCT4, Nanog/NANOG, and TGFß2 signaling protein during morphogenesis of the cornea in vertebrates. We considered the results obtained for the cornea of model animals, primarily mice, and human fetal cornea. The main possibility of establishing common mechanisms of eye development in vertebrates in health and disease is comparative studies of eye morphogenesis of humans and animal models.
Asunto(s)
Córnea/embriología , Córnea/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Animales , Córnea/fisiología , Proteínas del Ojo/genética , Factores de Transcripción Forkhead/genética , Proteínas de Homeodominio/genética , Humanos , Ratones , Morfogénesis/genética , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/genética , Proteínas Represoras/genética , Factores de Transcripción/genética , Factor de Crecimiento Transformador beta2/genética , Proteínas Supresoras de Tumor/genética , Vertebrados/genética , Vertebrados/crecimiento & desarrollo , Proteína del Homeodomínio PITX2RESUMEN
The review deals with the role of carotenoids in the formation of the structural and functional differentiation of the macula--the area of the highest visual acuity of the human retina. The review also presents the data on detection of carotenoids (lutein) in the vitreous body of the human eye during its prenatal development and discusses their possible role in the development of the retina, particularly in relation to differentiation of the macular area. Macular dystrophy has been considered till recently as senile pathology. According to modern ophthalmologic observations, the number of cases of appearance of this pathology increases in young humans. Such a shift can be prevented by addition of carotenoids to the diet. This permits a conclusion that the permanent presence of carotenoids in the course of the whole human life is necessary for the formation and retention of structural and functional integrity of the macula.
Asunto(s)
Carotenoides/metabolismo , Luteína/metabolismo , Mácula Lútea/metabolismo , Retina/metabolismo , Carotenoides/administración & dosificación , Diferenciación Celular , Dieta , Ojo/crecimiento & desarrollo , Ojo/metabolismo , Femenino , Humanos , Luteína/aislamiento & purificación , Mácula Lútea/crecimiento & desarrollo , Degeneración Macular/etiología , Degeneración Macular/metabolismo , Degeneración Macular/patología , Retina/crecimiento & desarrollo , Retina/patologíaRESUMEN
The content of serum albumin and alpha-fetoprotein in the vitreous body of the eyes of human embryos from the 16th through the 24th week was investigated. It was detected that albumin and alpha-fetoprotein in the vitreous body of human eyes are presented in equal molar concentrations in the 16th week. There is 1.5-fold increased concentration of alpha-fetoprotein in comparison to albumin during the 17th week. Seventeen weeks later, there was a reduction in the concentration of both proteins. It was reported that cyanine dye, used for detection of albumin, does not interact with alpha-fetoprotein.
Asunto(s)
Albúmina Sérica/metabolismo , Cuerpo Vítreo/embriología , Cuerpo Vítreo/metabolismo , alfa-Fetoproteínas/metabolismo , Feto Abortado/metabolismo , Edad Gestacional , Humanos , Albúmina Sérica/análisis , Espectrometría de Fluorescencia , Cuerpo Vítreo/química , alfa-Fetoproteínas/análisisRESUMEN
In this work we focus on the temporal and spatial characteristics of TGFbeta2 expression in various human eye tissues during prenatal development from fetal weeks 8 to 22. We used the complex approach: the analysis of TGFbeta2 gene expression by PCR and the localization of TGFbeta2 protein by immunohistochemistry. TGFbeta2 was detected in all eye tissues. Our results suggest that differential expression pattern of TGFbeta2 in the lens and retina is correlated with the cell type and differentiation state. The data obtained give evidence to the TGFbeta2 contribution to forming of eye tissues of various embryonic origins.
Asunto(s)
Desarrollo Fetal/fisiología , Regulación del Desarrollo de la Expresión Génica/fisiología , Cristalino/embriología , Retina/embriología , Factor de Crecimiento Transformador beta2/biosíntesis , Femenino , Humanos , Cristalino/citología , Masculino , Especificidad de Órganos/fisiología , Retina/citologíaRESUMEN
α-Fetoprotein was detected in human fetal vitreous body and its concentrations on gestation weeks 16-24 were measured. The concentration of α-fetoprotein was maximum during week 17 of pregnancy (17.4 mg/ml), but then decreased and reached 1.42 mg/ml by week 24.
Asunto(s)
Cuerpo Vítreo/embriología , Cuerpo Vítreo/metabolismo , alfa-Fetoproteínas/análisis , Feto Abortado/metabolismo , Femenino , Edad Gestacional , Humanos , EmbarazoRESUMEN
Expression of transforming growth factor-ß2 was detected by PCR in the vitreous body, lens, retina, and ciliary-iris complex of human eye at early stages of fetal development. Immunochemical assay of the corresponding protein in eye tissues revealed a correlation between the localization of transforming growth factor-ß2 and the development of intraocular hyaloid vascular network, its regression, formation of the vitreous body, and development of definite retinal vessels.
Asunto(s)
Ojo/metabolismo , Factor de Crecimiento Transformador beta2/metabolismo , Cuerpo Vítreo/metabolismo , Ojo/embriología , Humanos , Inmunoquímica , Técnicas In Vitro , Reacción en Cadena de la Polimerasa , Retina/metabolismo , Factor de Crecimiento Transformador beta2/genéticaRESUMEN
Noncovalent interactions of intraionic squarylium dyes, derivatives of 3H-indolium, as well as the structurally analogous ionic indodicarbocyanine dye with serum albumins (human, bovine, rat) and, for comparison, with ovalbumin has been studied by spectral and fluorescent methods. The hydrophilic squarylium dye with sulfonate groups was found to interact with albumins more efficiently, which is probably due to the double negative charge on the dye molecule at the expense of the sulfonate groups and the ability to form hydrogen bonds with albumin. The hydrophilic indodicarbocyanine dye without the squarylium group in its structure binds to albumins much more weaker than the structurally analogous squarylium dye. The dyes bind to ovalbumin less efficiently than to serum albumins. Along with the binding of monomeric dye molecules, the aggregation of the dyes on albumins is also observed. The hydrophobic squarylium dye without sulfonate groups tends to form aggregates in aqueous solutions, which partially decompose upon the introduction of albumin into the solution. The hydrophilic squarylium dye with sulfonate groups can be recommended for tests as a spectral-fluorescent probe for serum albumins in extracellular media of living organisms.
Asunto(s)
Albúminas/química , Colorantes Fluorescentes/química , Indoles/química , Animales , Bovinos , Pollos , Humanos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Ratas , Espectrometría de FluorescenciaAsunto(s)
Proteínas del Ojo/genética , Ojo/embriología , Ojo/metabolismo , Proteínas de Homeodominio/genética , Factores de Transcripción Paired Box/genética , Proteínas Represoras/genética , Secuencia de Bases , Cartilla de ADN/genética , Proteínas del Ojo/metabolismo , Regulación del Desarrollo de la Expresión Génica , Edad Gestacional , Proteínas de Homeodominio/metabolismo , Humanos , Inmunohistoquímica , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Represoras/metabolismoRESUMEN
The goal of this study was the search for and structure-function analysis of the regulatory genes specific for pluripotent embryonic stem cells (ESCs). This was the first study in which PCR was used to obtain DNA fragments with primers constructed on the basis of OCT4 and NANOG mRNA. cDNA synthesized on mRNA isolated from human embryonic eye in the 9.5th week of development was used as a template in PCR analysis. PCR fragment DNA was sequenced. A comparative analysis of the nucleotide sequences demonstrated their 100% homology with the OCT4-pg1 retrogene and NANOG gene. Expression of the genes of interest was reliably detected in the cornea, crystalline lens, retina, and eye tunics in the 10.5th week of development. The nuclear localization of the products of the NANOG gene and OCT4-pg1 retrogene indicates that these proteins are classified with transcription factors. The role of the OCT4-pg1 retrogene and NANOG gene in self-renewal and differentiation of pluripotent cells in a developing eye is discussed.
Asunto(s)
Células Madre Embrionarias/metabolismo , Proteínas del Ojo/biosíntesis , Ojo/embriología , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas de Homeodominio/biosíntesis , Factor 3 de Transcripción de Unión a Octámeros/biosíntesis , Células Madre Pluripotentes/metabolismo , Diferenciación Celular/fisiología , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células Madre Embrionarias/citología , Ojo/citología , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Humanos , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/genética , Células Madre Pluripotentes/citología , ARN Mensajero/biosíntesis , ARN Mensajero/genéticaRESUMEN
Expression of beta-III tubulin, a marker protein of early neuronal cells, was studied by molecular genetic and immunochemical techniques. The study was performed with human eyes in the 8.5th to 27-28th weeks of prenatal development. Expression of beta-III tubulin was detected immunochemically in the retina and lens fibers in the 8.5 to 22-23 weeks of development. PCR revealed a high level of expression of the gene for beta-III tubulin in the retina of 9.5-week embryos. The level of expression of this gene remained high until the 18th week of prenatal development, slightly decreased to the 24th week, and became negligible in 27- to 28-week embryos. In the 15th to 24th weeks of prenatal development, the level of expression of this gene in the lens was very low and became undetectable in 27- to 28-week embryos. The results of PCR analysis are consistent with immunochemical data.
Asunto(s)
Proteínas del Ojo/biosíntesis , Regulación del Desarrollo de la Expresión Génica/fisiología , Cristalino/embriología , Retina/embriología , Tubulina (Proteína)/biosíntesis , Humanos , Cristalino/citología , Retina/citologíaRESUMEN
The pattern of the PITX2 gene expression was studied in the cornea, lens, retina, iridocorneal complex (ICC), and eye coats of human fetuses at weeks 9.5-22 of intrauterine development. Using the PCR method, PITX2 expression in all these tissues was revealed already at the earliest stage studied (9.5 weeks), being especially strong in the anterior eye complex (the cornea and lens) and weaker in the retina and sclera. The level of PITX2 expression in all eye tissues slightly decreased by week 15, increased to a high level in the ICC on week 18, and further decreased in all tissues by week 22. Using cDNA derived from the whole eyes of 8-, 9-, 10.5-, and 11-week fetuses, the expression of two PITX2 isoforms specific for eye tissues (A and B) was revealed. By means of in situ hybridization, the PITX2 mRNA was localized in the eye tissues of ectodermal and neuroectodermal origin.
Asunto(s)
Proteínas del Ojo/biosíntesis , Ojo/embriología , Proteínas de Homeodominio/biosíntesis , Factores de Transcripción/biosíntesis , Humanos , Isoformas de Proteínas/biosíntesis , ARN Mensajero/biosíntesis , Proteína del Homeodomínio PITX2RESUMEN
Whole-body irradiation of mice with gamma-rays at 14 Gy causes DNA single and double strand breaks effectively repaired later. p53 is accumulated during the repair period. There is still some amount of DNA breaks 48-72 hours after the irradiation. Despite p53 accumulation and residual DNA lesions in the cells, mice retina demonstrated no morphological destructive changes or apoptosis signs. Retina resistance to apoptotic signals could derive from efficient repair of radiation-induced lesions in transcriptionally active regions of the genome of differentiated cells.
Asunto(s)
Reparación del ADN , ADN/efectos de la radiación , Rayos gamma/efectos adversos , Tolerancia a Radiación , Retina/efectos de la radiación , Proteína p53 Supresora de Tumor/metabolismo , Animales , Apoptosis , ADN/genética , Daño del ADN , Femenino , Ratones , Ratones Endogámicos A , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Retina/fisiología , Retina/ultraestructura , Irradiación Corporal TotalRESUMEN
Carotenoids were found for the first time in the vitreous body of human eye during the fetal period from week 15 until week 28. Their maximum content was timed to week 16-22. No carotenoids were found the vitreous body of 31-week fetuses, as well as adult humans, which corresponds to the published data. It was shown using HPLC that chromatographic characteristics of these carotenoids correspond to those of lutein and zeaxanthin, characteristic pigments of the retinal yellow macula.
Asunto(s)
Carotenoides/metabolismo , Feto/metabolismo , Cuerpo Vítreo/metabolismo , Adulto , Feto/citología , Edad Gestacional , Humanos , Cuerpo Vítreo/embriologíaRESUMEN
The dynamics of the content albumin and carotenoids in human fetal vitreous body during weeks 16-31 of gestation was studied. The maximum values of total albumin (1.42 mg) and carotenoids (276 ng) during the studied period were recorded on weeks 20-22. Albumin concentration peaked during week 17 (2.11x10(-4) mol/liter) and carotenoids during weeks 16-17 (about 0.045x10(-4) mol/liter) of prenatal development. By week 31, the concentrations and total content of albumin and carotenoids in the vitreous body decreased. The physiological role of the studied components of the vitreous body for prenatal development of human eye is discussed.
Asunto(s)
Albúminas/metabolismo , Carotenoides/metabolismo , Cuerpo Vítreo/embriología , Cuerpo Vítreo/metabolismo , Edad Gestacional , HumanosRESUMEN
Expression of transcription factors PAX6, PROX1, and PITX2 was evaluated in eye tissues after 9.5 and 22.0 weeks of human fetus development using polymerase chain reaction. Pax6, Prox1 and Pitx2 expression has been revealed in the cornea, lens, retina, and eye membranes (total preparation of the pigment epithelium, choroid, and sclera) after 9.5 weeks of prenatal development with the maximum expression of Pax6 gene in all studied tissues. After 22.0 weeks of development, Pax6 expression increased in the retina and lens but decreased in the cornea. Insignificant levels of Pax6 transcription have been detected in the eye membranes. Prox1 expression was apparent in the cornea, lens, retina, and eye membranes after 9.5 weeks. After 22.0 weeks, Prox1 expression increased in the lens and retina, decreased in the cornea, and was undetectable in the eye membranes. High level of Pitx2 expression has been revealed in all studied eye tissues after 9.5 weeks with the lowest transcription level observed in the retina. After 22.0 weeks, Pitx2 expression notably decreased in the lens and cornea and became undetectable in the retina and eye membranes. The differential pattern of Pax6, Prox1 and Pitx2 expression in developing human eye tissues after 9.5 and 22.0 weeks of development agrees with our histological data.