Objective comparison of a sit to stand test to the walk test for the identification of unilateral lameness caused by cranial cruciate ligament disease in dogs.

OBJECTIVE: The purpose of this study was to evaluate a sit to stand test with the walk test for the identification of unilateral cranial cruciate ligament rupture in dogs. MATERIALS AND METHODS: Peak vertical force and vertical impulse were measured on a pressure-sensitive walkway, during a sit to stand test and walk test, and in 10 dogs with unilateral cranial cruciate ligament rupture and 18 non-lame dogs. Data collected were used to calculate symmetry indices (SI) of ipsilateral and contralateral hindlimbs (HL), diagonal limb pairs (DLP) and ipsilateral limb pairs (ILP). RESULTS: The symmetry indices of peak vertical force of HL during the walk test and sit to stand test were 100% and 90% sensitive for discriminating lame and non-lame dogs respectively. The symmetry indices of vertical impulse of HLs during the walk test and sit to stand test were 100% and 50% sensitive for discriminating lame and non-lame dogs respectively. Analysis of ipsilateral and diagonal limb pairs did not improve the discrimination in either test. The time taken to collect data from the sit to stand test data was shorter than for the walk test. CLINICAL SIGNIFICANCE: Whilst the sit to stand test required a shorter time for collection of data than the walk test, it did not accurately identify all dogs with lameness associated with CCLR, and thus has relatively limited clinical utility in its tested form.

Quo Vadis Joven. Relatos del abuso de drogas en jóvenes de Guayaquil, Ecuador / Quo Vadis Young. Stories of drug abuse in young people in Guayaquil, Ecuador / Quo Vadis Young. Histórias de abuso de drogas em jovens em Guayaquil, Equador

INTRODUCCIÓN: El uso indebido de drogas es un importante problema de salud pública no solo en el Ecuador, sino también a nivel mundial. OBJETIVO: Interpretar las percepciones de la persona drogodependiente sobre los efectos que produce la droga en su vida personal, familiar, social, y su visión para el futuro. METODOLOGÍA: Investigación cualitativa con análisis interpretativo fenomenológico realizado mediante entrevistas semiestructuradas en muestreo no probabilístico tipo bola de nieve, a 17 sujetos con drogodependencia, en el periodo julio-agosto del 2018, en la ciudad de Guayaquil. RESULTADOS: Los informantes clave, tenían entre 16 a 28 años de edad, estrato social bajo, procedentes de zonas urbano-marginales, en su mayoría de instrucción secundaria incompleta, y con antecedentes de primer contacto con la droga en la adolescencia temprana y en la institución educativa. Se obtuvieron cinco categorías: contexto familiar y el entorno comunitario como factores causales del consumo; discriminación social como castigo a la persona adicta; culpa, soledad y autoestima baja; el tren de la adicción a las drogas destruye a su paso: salud y la vida; y el apoyo familiar y de un Ser Supremo como alternativas para salir de la adicción. CONCLUSIONES: Las causas del consumo de drogas fueron, entre otras: el escape de los problemas de su familia disfuncional y la vulnerabilidad adolescente en su búsqueda de identidad y pertenencia a un grupo. Por otra parte, relataron que se sienten discriminados y castigados por la sociedad, y vislumbran que les espera un futuro de muerte, cárcel, enfermedad e indigencia

INTRODUCTION: The abuse of drugs is an important public health problem not only in Ecuador, but also worldwide. OBJECTIVE: To interpret the perceptions of the drug-dependent person about the effects that the drug produces in their personal, family, social life, and their vision for the future. METHODOLOGY: Qualitative research with phenomenological interpretative analysis performed by semi-structured interviews in non-probabilistic sampling snowball type to 17 subjects with drug dependence in the period July-August 2018 in the city of Guayaquil. RESULTS: The key informants were between 16 and 28 years of age, with low social stratum, from marginal urban areas, mostly incomplete secondary education, and with a history of first contact with the drug in early adolescence and in educational institution. Five categories were obtained: Family context, and the community environment as causal factors of consumption; social discrimination as punishment for the addicted person; guilt, loneliness and low self-esteem; the train of addiction to drugs destroys in its path: health and life; and family support and a Supreme Being as alternatives to get out of addiction. CONCLUSIONS: The causes of drug use were among others: the escape from dysfunctional family problems and adolescent vulnerability in their search for identity and belonging to a group. On the other hand, they reported feeling discriminated against and punished by society, and they foresee that a future of death, prison, sickness and indigence awaiting them

INTRODUÇÃO: O abuso de drogas é um grande problema de saúde pública, não apenas no Equador, mas em todo o mundo. Alvo: Interpretar as percepções da pessoa dependente de drogas sobre os efeitos produzidos pela droga em sua vida pessoal, familiar, social e sua visão para o futuro. METODOLOGIA: Pesquisa qualitativa com análise interpretativa fenomenológica realizada por meio de entrevistas semi-estruturadas em amostragem sem probabilística de bolas de neve, para 17 sujeitos com dependência de drogas, no período de julho a agosto de 2018, na cidade de Guayaquil. RESULTADOS: Os informantes chave tinham entre 16 e 28 anos de idade, baixos estratos sociais, de áreas urbanas marginais, principalmente ensino médio incompleto, e com uma história de primeiro em contato com drogas no início da adolescência e na instituição de ensino. Cinco categorias foram obtidas: contexto familiar e o ambiente da comunidade como fatores causais do consumo; discriminação social como punição para a pessoa viciada; culpa, solidão e baixa auto-estima; o trem do tóxico dependência destrói o seu caminho: saúde e vida; e apoio familiar e um Ser Supremo como alternativas para sair do vício. CONCLUSÕES: as causas do uso de drogas foram, entre outros: a fuga de problemas familiares disfuncionais e a vulnerabilidade do adolescente em sua busca por identidade e pertencimento a um grupo. Por outro lado, relataram que se sentem discriminados e punidos pela sociedade, e prevêem que um futuro de morte, prisão, doença e indigência os espera

[Situs inversus of the optic nerve. A case report]. / Situs inversus del nervio optico. A proposito de un caso.

INTRODUCTION: Situs inversus of the optic nerve is a congenital anomaly characterised by the emergence of the vessels in the retina towards the nose rather than in a temporal direction. It is caused by an anomalous insertion of the optic stalks into the optic vesicle that gives rise to dysversion of the head of the optic nerve. It is not an isolated condition and usually appears jointly with tilted disc syndrome and in patients with myopia. It is characterised by the presence of inferior conus atrophy, deficiencies in the temporal visual field, refraction defects and ambliopy. CASE REPORT: A 22 years-old female who attended an ophthalmological examination due to severe frontal headaches accompanied by halos and loss of sharpness in her sight. From the results of the ophthalmetric and ophthalmological examination she was diagnosed as suffering from a condition consistent with this congenital anatomical anomaly. CONCLUSIONS: Situs inversus of the optic nerve is a rare condition that may appear in isolation or accompanied by other pathologies. Application of the visual field test and new diagnostic techniques, such as optical coherence tomography, facilitates the differential diagnosis of this situation. Its prevalence remains unknown, as it is not included in the register of rare diseases. Moreover, the scant number of patients studied and the scarce literature on this anomaly do not allow us to know whether the defects it causes develop over time. It would therefore be important to perform an ophthalmological follow-up of patients with situs inversus of the optic nerve.

TITLE: Situs inversus del nervio optico. A proposito de un caso.Introduccion. El situs inversus del nervio optico es una anomalia congenita caracterizada por la emergencia de los vasos de la retina en direccion nasal en lugar de temporal. Es causado por una anomala insercion del tallo optico en la vesicula optica que da lugar a la variacion de disposicion de la cabeza del nervio optico. No es una condicion aislada y suele aparecer junto con el sindrome del disco inclinado y en pacientes con miopia. Se caracteriza por la presencia de un cono de atrofia inferior, defectos en el campo visual temporal, defectos de refraccion y ambliopia. Caso clinico. Mujer de 22 años, que acude a revision oftalmologica por presentar fuertes cefaleas frontales acompañadas de halos y perdida de nitidez en la vision. Tras un examen optometrico y oftalmologico se llega al juicio clinico de que padece un cuadro compatible con esta anomalia anatomica congenita. Conclusiones. El situs inversus del nervio optico es una condicion rara que puede aparecer aislada o acompañada de otras patologias. La aplicacion de la campimetria y de nuevas tecnicas diagnosticas, como la tomografia de coherencia optica, facilita el diagnostico diferencial de esta situacion. No se conoce su prevalencia, pues no se encuentra en el registro de las enfermedades raras. Ademas, el escaso numero de pacientes estudiados y la exigua bibliografia existente sobre esta anomalia no permiten conocer si los defectos causados progresan en el tiempo, por lo que seria importante realizar un seguimiento oftalmologico de los pacientes con situs inversus del nervio optico.

Substance P and calcitonin gene-related peptide intrinsic choroidal neurons in human choroidal whole-mounts.

To determine the presence in the human choroid of substance P (SP)-and calcitonin gene-related peptide (CGRP) positive intrinsic choroidal neurons (ICNs), choroidal whole-mounts were processed for indirect immunofluorescence. An antibody to a component of the neuronal cytoskeleton, neurofilament 200 kDa (NF-200), was combined with antibodies to SP and to CGRP (neuropeptides proper to the sensory nervous system). The human choroid possesses numerous SP(+) and CGRP(+) ICNs. These neurons were observed in the suprachoroid, both in isolation and forming microganglia. For both types of ICNs studied, neurons were more numerous in the temporal than in the nasal regions. In both locations, SP(+) and CGRP(+) ICNs were more abundant in the central choroid (the choroid underneath the macular area of the retina), with cell density diminishing outwards to the choroidal periphery. There were no appreciable differences between the two populations of ICNs studied in terms of size, morphology or immunostaining characteristics. In conclusion, given that peripheral sensory innervation could be involved in the regulation of both choroidal blood flow and vascular architecture, the SP(+) and CGRP(+) ICNs described for the first time in the present work may be involved in these mechanisms of vascular regulation.

Vimentin isoform expression in the human retina characterized with the monoclonal antibody 3CB2.

The antigen recognized by the monoclonal antibody 3CB2 (3CB2-Ag and 3CB2 mAb) is expressed by radial glia and astrocytes in the developing and adult vertebrate central nervous system (CNS) of vertebrates as well as in neural stem cells. Here we identified the 3CB2-Ag as vimentin by proteomic analysis of human glial cell line U-87 extracts (derived from a malignant astrocytoma). Indeed, the 3CB2 mAb recognized three vimentin isoforms in glial cell lines. In the human retina, 3CB2-Ag was expressed in Müller cells, astrocytes, some blood vessels, and cells in the horizontal cell layer, as determined by immunoprecipitation and immunofluorescence. Three populations of astrocytes were distinguishable by double-labeling immunohistochemistry: vimentin+/GFAP+, vimentin-/GFAP+, and vimentin+/GFAP-. Hence, we conclude that 1) the 3CB2-Ag is vimentin; 2) vimentin isoforms are differentially expressed in normal and transformed astrocytes; 3) human retinal astrocytes display molecular heterogeneity; and 4) the 3CB2 mAb is a valuable tool to study vimentin expression and its function in the human retina.

[A comparative study of choroidal innervation in the human and the rabbit (oryctolagus cuniculus)]. / Estudio comparativo de la inervación coroidea en el hombre y en el conejo (oryctolagus cuniculus).

OBJECTIVE: To analyze morphological differences between the choroidal innervation of the human and the rabbit, the latter being a species frequently used as an experimental model of human ocular diseases. METHODS: Twelve human and 12 rabbit choroidal whole mounts were processed using an indirect immunohistochemical technique, peroxidase-anti-peroxidase and antibodies against 200 kD neurofilament. RESULTS: Choroidal nerve fibers were perivascular and intervascular. Perivascular fibers surrounded all arteries forming a network that was more developed in the rabbit. In humans, intervascular fibers were mainly concentrated at the posterior pole where they formed a denser and more highly organized plexus than in the rabbit, which did not exhibit a preferential location for these fibers. Human choroidal ganglion cells were far more numerous than in the rabbit and were concentrated in a circumferential area corresponding to the entrance of the short posterior ciliary arteries of the submacular area. In the rabbit, these cells were restricted to the peripheral choroid. CONCLUSIONS: Some differences were observed between human and rabbit choroidal innervation. The abundance of ganglion cells and their preferential distribution could be necessary to maintain a constant blood flow in the central area of the human choroid. The lack of organization of rabbit choroidal innervation at the posterior pole could be associated with an absence of the macula. These differences, along with peculiarities of retinal vascularization, should be taken into consideration when using the rabbit as an experimental model to study human eye diseases in which regulation of choroidal blood flow is involved.

Estudio comparativo de la inervación coroidea en el hombre y en el conejo (oryctolagus cuniculus) / A comparative study of choroidal innervation in the human and the rabbit (oryctolagus cuniculus)

Objetivo: Analizar las diferencias morfológicas entre la inervación coroidea del hombre y el conejo, especie frecuentemente utilizada como modelo experimental de enfermedades oculares. Método: Se estudiaron montajes planos de coroides (12 humanas y 12 de conejo albino) con la técnica de inmunohistoquímica indirecta de la peroxidasaantiperoxidasa, utilizando un anticuerpo frente al neurofilamento de 200 kD. Resultados: Las fibras nerviosas coroideas pueden ser perivasculares e intervasculares. Las perivasculares rodeaban las arterias formando una red que estaba más desarrollada en la coroides del conejo. En el humano, las fibras intervasculares se concentraban principalmente en el polo posterior donde formaban un plexo más denso y organizado que en el conejo, el cual no tenía una localización preferencial. Las células ganglionares eran más numerosas en el humano, concentrándose en un área circunferencial correspondiente a la entrada de las arterias ciliares cortas posteriores y en el área submacular. En el conejo estas células se situaban sólo en la periferia. Conclusiones: Existen diferencias entre la inervación coroidea humana y del conejo. En el humano, la abundancia de células ganglionares y su distribución, podrían ser necesarias para mantener un flujo sanguíneo constante en el área central de la coroides. La falta de organización nerviosa en el polo posterior del conejo podría estar asociada a la ausencia de mácula. Estas diferencias, junto a las diferencias anatómicas de la vascularización retiniana, deberían ser tenidas en cuenta al utilizar el conejo como modelo experimental para estudiar enfermedades oculares en las que esté implicada la regulación del flujo sanguíneo coroideo

Objective: To analyze morphological differences between the choroidal innervation of the human and the rabbit, the latter being a species frequently used as an experimental model of human ocular diseases. Methods: Twelve human and 12 rabbit choroidal whole mounts were processed using an indirect immunohistochemical technique, peroxidase-anti-peroxidase and antibodies against 200 kD neurofilament. Results: Choroidal nerve fibers were perivascular and intervascular. Perivascular fibers surrounded all arteries forming a network that was more developed in the rabbit. In humans, intervascular fibers were mainly concentrated at the posterior pole where they formed a denser and more highly organized plexus than in the rabbit, which did not exhibit a preferential location for these fibers. Human choroidal ganglion cells were far more numerous than in the rabbit and were concentrated in a circumferential area corresponding to the entrance of the short posterior ciliary arteries of the submacular area. In the rabbit, these cells were restricted to the peripheral choroid. Conclusions: Some differences were observed between human and rabbit choroidal innervation. The abundance of ganglion cells and their preferential distribution could be necessary to maintain a constant blood flow in the central area of the human choroid. The lack of organization of rabbit choroidal innervation at the posterior pole could be associated with an absence of the macula. These differences, along with peculiarities of retinal vascularization, should be taken into consideration when using the rabbit as an experimental model to study human eye diseases in which regulation of choroidal blood flow is involved

[Structural changes of the anterior chamber angle in primary congenital glaucoma with respect to normal development]. / Cambios estructurales del ángulo de la cámara anterior en el glaucoma congénito. Comparación con el desarrollo normal.

PURPOSE: To compare findings of normal angles with those from primary congenital glaucoma in order to clarify the pathogenic mechanisms of the disease and to explain the success of surgical treatment in some of these patients. METHODS: Adult normal eyes from cadavers and fragments of surgical trabeculectomies from patients with primary congenital glaucoma previously treated with goniotomy were studied. Eyes were processed for examination using light microscopy and scanning electron microscopy techniques. RESULTS: The following was evident in congenital glaucoma: 1) high iris insertion; 2) no observable pre-trabecular membrane, but enlarged trabeculae with diminished inter-trabecular spaces; 3) Schlemm's canal (SC) apparently normal, with vacuoles in the wall indicating normal functioning; 4) sectioning of the abnormal trabecular tissue during goniotomy allowed repositioning of the angle structures and hence the appearance of the angular recess. CONCLUSIONS: Anomalies of the trabecular structures in primary congenital glaucoma do not always parallel an abnormal development of the SC and the collector channels. This fact could explain the success of goniotomy in this type of glaucoma.

Cambios estructurales del ángulo de la cámara anterior en el glaucoma congénito. Comparación con el desarrollo normal / Structural changes of the anterior chamber angle in primary congenital glaucoma with respect to normal development

Objetivo: Comparar los hallazgos morfológicosobservados en ángulos normales con los observadosen ángulos de pacientes con glaucoma congénitoprimario, para intentar clarificar los mecanismospatogénicos de esta enfermedad, así como explicarel éxito del tratamiento quirúrgico en alguno deestos pacientes.Métodos: Se utilizaron ojos adultos normales procedentesde cadáveres y fragmentos quirúrgicosprocedentes de trabeculectomías, de pacientes conglaucoma congénito primario que habían sido tratadospreviamente con una goniotomía. Los tejidosfueron procesados para su examen a microscopíaóptica (MO) y microscopía electrónica de barrido(MEB).Resultados: En los glaucomas congénitos encontramos:1) inserción alta del iris; 2) No se observauna membrana pre-trabecular, sino que comparandocon los ángulos normales las trabéculas aparecenensanchadas con disminución de los espacios intertrabeculares; 3) el canal de Schlemm (CS) es aparentementenormal, con vacuolas en su pared queindican un funcionamiento normal del mismo; 4) lasección del tejido trabecular anormal que producela goniotomía, permite el reposicionamiento de lasestructuras del ángulo y por tanto la aparición delreceso angular.Conclusiones: En el glaucoma congénito primariolas anomalías de las estructuras trabeculares nosiempre se acompañan de un desarrollo anómalodel CS y de los canales colectores. Este hechopodría explicar que la goniotomía sea un tratamientocon éxito en estos glaucomas

Purpose: To compare findings of normal angles ;;with those from primary congenital glaucoma in ;;order to clarify the pathogenic mechanisms of the ;;disease and to explain the success of surgical treatment ;;in some of these patients. ;;Methods: Adult normal eyes from cadavers and ;;fragments of surgical trabeculectomies from ;;patients with primary congenital glaucoma previously ;;treated with goniotomy were studied. Eyes ;;were processed for examination using light microscopy ;;and scanning electron microscopy techniques. ;;Results: The following was evident in congenital ;;glaucoma: 1) high iris insertion; 2) no observable pretrabecular ;;membrane, but enlarged trabeculae with ;;diminished inter-trabecular spaces; 3) Schlemm’s ;;canal (SC) apparently normal, with vacuoles in the ;;wall indicating normal functioning; 4) sectioning of ;;the abnormal trabecular tissue during goniotomy allowed ;;repositioning of the angle structures and hence ;;the appearance of the angular recess. Conclusions: Anomalies of the trabecular structures ;;in primary congenital glaucoma do not always ;;parallel an abnormal development of the SC and the ;;collector channels. This fact could explain the success ;;of goniotomy in this type of glaucoma

NPY and TH innervation in human choroidal whole-mounts.

To determine the distribution of NPY and TH human choroidal innervation, choroidal whole-mounts were processed for indirect immunofluorescence. An antibody to a component of the neuronal cytoskeleton, neurofilament 200 kDa (NF-200) was used to identify neurons and axons. A double immunostaining was performed, antibodies against NF-200 being combined with antibodies against neuropeptide Y (NPY) and tyroxine hydroxylase (TH). Fibers containing both NPY and TH were distributed in three plexuses, one in the suprachoroid large-sized vessel layer, and two in the medium-sized vessel layer. Intrinsic choroidal neurons (ICNs) containing NPY and TH were observed in the suprachoroid. The TH(+) ICNs were located in the medium-sized vessel layer. Overall, NPY(+) and TH(+) ICNs were more frequent in the central temporal area, both in isolation and forming microganglia. We also detected small spindle elements intensely immunoreactive to TH(+) and distributed mainly in the suprachoroid from the equator to the periphery. In conclusion, the human choroid contains abundant NPY and TH nerve fibers related to chroroidal vascular structures; it further possesses NPY(+) and TH(+) ICNs which contribute to the choroidal self-regulation persisting after sympathetic denervation. Additionally, these ICNs may at least partially explain why the choroidal blood flow does not respond to the factors that influence systemic vascular control. The preferential location of these cells in the submacular area suggests that dysfunction or degeneration of these cells may be a factor in vascular pathologies found in ocular disease, such as diabetic macular edema or age-related macular degeneration.

A direct contact between astrocyte and vitreous body is possible in the rabbit eye due to discontinuities in the basement membrane of the retinal inner limiting membrane.

Different from most mammalian species, the optic nerve of the rabbit eye is initially formed inside the retina where myelination of the axons of the ganglion cells starts and vascularization occurs. Astrocytes are confined to these regions. The aforementioned nerve fibers known as medullated nerve fibers form two bundles that may be identified with the naked eye. The blood vessels run on the inner surface of these nerve fiber bundles (epivascularization) and, accordingly, the accompanying astrocytes lie mostly facing the vitreous body from which they are separated only by the inner limiting membrane of the retina. The arrangement of the astrocytes around blood vessels leads to the formation of structures known as glial tufts. Fragments (N = 3) or whole pieces (N = 3) of the medullated nerve fiber region of three-month-old male rabbits (Orictolagus cuniculus) were fixed in glutaraldehyde followed by osmium tetroxide, and their thin sections were examined with a transmission electron microscope. Randomly located discontinuities (up to a few micrometers long) of the basement membrane of the inner limiting membrane of the retina were observed in the glial tufts. As a consequence, a direct contact between the astrocyte plasma membrane and vitreous elements was demonstrated, making possible functional interactions such as macromolecular exchanges between this glial cell type and the components of the vitreous body.

A direct contact between astrocyte and vitreous body is possible in the rabbit eye due to discontinuities in the basement membrane of the retinal inner limiting membrane

Different from most mammalian species, the optic nerve of the rabbit eye is initially formed inside the retina where myelination of the axons of the ganglion cells starts and vascularization occurs. Astrocytes are confined to these regions. The aforementioned nerve fibers known as medullated nerve fibers form two bundles that may be identified with the naked eye. The blood vessels run on the inner surface of these nerve fiber bundles (epivascularization) and, accordingly, the accompanying astrocytes lie mostly facing the vitreous body from which they are separated only by the inner limiting membrane of the retina. The arrangement of the astrocytes around blood vessels leads to the formation of structures known as glial tufts. Fragments (N = 3) or whole pieces (N = 3) of the medullated nerve fiber region of three-month-old male rabbits (Orictolagus cuniculus) were fixed in glutaraldehyde followed by osmium tetroxide, and their thin sections were examined with a transmission electron microscope. Randomly located discontinuities (up to a few micrometers long) of the basement membrane of the inner limiting membrane of the retina were observed in the glial tufts. As a consequence, a direct contact between the astrocyte plasma membrane and vitreous elements was demonstrated, making possible functional interactions such as macromolecular exchanges between this glial cell type and the components of the vitreous body

Análisis cuantitativo de la expresión KI67 en lesiones melanocíticasbenignas y malignas / Quantitative analysis of ki67 expression in benign and malignant melanocytic lesions

- Propósito: La búsqueda de marcadores celulares en el diagnóstico y pronóstico las lesiones melanocíticas es uno de los actuales retos de la dermatología. El objetivo de este trabajo ha sido la cuantificación de la expresión ki67 en nevus melanocíticos (clinicamente atípicos) y en melanomas malignos, y su correlación con los factores pronósticos y la supervivencia.- Material y métodos: Se han estudiado 30 melanomas malignos en fase de crecimiento vertical (MM), 30 nevus melanocíticos (NM) (20 intradérmicos y 10 compuestos) y 30 biopsias cutáneas sanas (BCS). La expresión del antígeno ki67 fue demostrada por histoinmunoquímica. Posteriormente se realizó un estudio cuantitativo mediante el programa de análisis de imagen Qwin colour RGB. Finalmente, se estudió el número de núcleos marcados y el análisis estadístico de los resultados. - Resultados: En BCS y en NM el número de núcleos ki67 era, respectivamente, 12.56 ñ 8.79 y 21.48 ñ 11.49. Los núcleos ki67 positivos en los MM mostraba un número de 234.54 ñ 52.67. El análisis estadístico demostró diferencias significativas entre las lesiones pigmentadas benignas y malignas. También, el número de núcleos ki67 en los MM se correlacionó significativamente con el espesor (Breslow), la presencia de ulceración y del nivel de infiltración (Clark) del tumor. El número de núcleos ki67 positivos estaba correlacionado con la supervivencia total y con el periodo libre de enfermedad. - Conclusiones: Estos resultados sugieren que la expresión ki67, especialmente su cuantificación, es un claro indicador diagnóstico y puede tener interés como parámetro pronóstico en los MM: el antígeno ki67 es indicador de mal pronóstico. Esta técnica sería de interés en la valoración oncológica del melanoma maligno (AU)

Expresión de los AgNORs en melanomas malignos: análisis comparativo entre lesiones melánicas benignas y malignas de piel / Evaluation of the AgNORs technique in malignant melanomas: comparative analysis between benignant and malignant melanocytic lesions of the skin

Propósito: Valoración de los AgNORs, especialmente el número de partículas por núcleo en nevus melanocíticos y en melanomas malignos, y su correlación con los factores pronósticos y la supervivencia. Pacientes y métodos: Se han estudiado 29 casos de melanoma maligno en fase de crecimiento vertical (MMFCV), 30 nevus melanocíticos (NM) (20 intradérmicos y 10 compuestos) y 30 biopsias cutáneas sanas. Resultados: En piel normal y en NM el número de partículas de AgNORs por célula era, respectivamente, 1.22ñ0.41 y 1.35ñ0.54 (menos 3 por núcleo). Los AgNORs estaban bien definidos, pequeños e independientes. Los AgNORs por núcleo en los MMFCV mostraba un número de 8.02ñ 5.31 y su morfología estaba mal definida, mayor tamaño y tendencia a confluir. El número de AgNORs en los MMFCV depende significativamente del espesor (Breslow) y del número de mitosis, pero resulta independiente del nivel infiltrante (Clark) del tumor. El número de AgNORs estaba correlacionado con la supervivencia teórica pero era independiente de la supervivencia real. Conclusiones: Estos resultados sugieren que los AgNORs, especialmente su número y morfología, son un claro indicador diagnóstico y pueden tener interés como parámetro pronóstico en los MMFCV, siendo además una técnica rápida, barata y asequible, por lo cual debe incorporarse a la rutina oncológica del melanoma maligno (AU)

Changes of astrocytes in retinal ageing and age-related macular degeneration.

Most studies of age-related macular degeneration (AMD) have focused on the outer retina but little has been done on the involvement of astrocytes in this disease. We examined normal (young and old) and pathological (AMD) human retinas for the presence of changes in morphology and distribution of the astrocytes. Electron microscopy and inmunohistochemical techniques (anti-GFAP) were used for this study. Astrocytes in the ageing group showed: (1) higher GFAP immunoreactivity and more cytoplasmic organelles and glial filaments than astrocytes from younger retinas; (2) lipofucsin deposits; (3) a significantly smaller number of cells in the honeycomb astroglial plexus in the ganglion cell layer than in the younger group; and (4) Spaces with no GFAP reactivity in the nerve fiber layer. Changes observed in the AMD group were: (1) the basal membrane of the retinal capillaries was considerably thicker than in normal old individuals; (2) There were numerous non-functional capillaries; (3) There were hypertrophic astrocytes that phagocytosed dead ganglion cells; and (4) There were glial membranes constituted by astrocytes and Müller cells located between the vitreous humour and internal limiting membrane. These observations suggested that the extensive retinal ischaemia that can occur with AMD, together with the loss of astroglial cells accompanying normal ageing, could cause the death of the ganglion cells which cannot be protected from oxidative damage. Extensive ischaemia could cause the astrocytes to migrate to the vitreous humour where there is a metabolic reserve.

A practical method for the radioisotope labeling of rabbit astrocytes with (3)H-thymidine.

A practical method for the radioisotope labeling aimed at the study of the proliferative behavior of astrocytes was described. It consisted in injecting 20 microCi of (3)H-thymidine into the vitreous body and tracing by autoradiography labeled astrocytes located both inside and outside the retina, e.g. optic nerve and neighboring parts of the central nervous system. The paraffin sections were immunostained for glial fibrillary acidic protein (GFAP) previous to autoradiographic processing. The semiquantitative analysis of labeled astrocytes was carried out on autoradiographs of semithin sections of rabbits killed as early as 6 h and as late as 3 months after the single intravitreal injection of (3)H-thymidine. Compared with the technique of labeling astrocytes by systemic administration (single injection or continuous infusion) of (3)H-thymidine into small animals, the method described herein has the following outstanding features: (i) it is much more economical in terms of the amount of labeled precursor used per animal; (ii) the labeling of the astrocytes is obtained as early as 6 h and remains up to 3 months after injection; (iii) the immunolabeling of the astrocytes is compatible with autoradiography; (iv) it is less risky to the experimental animal and to the environment; (v) it can be used in animals much larger than rats or mice.

[Application of confocal microscopy in the study of the relationships between astrocytes and blood vessels in the retina]. / Aplicación de la microscopia confocal al estudio de las relaciones vaso-gliales en la retina.

OBJECTIVE: To study the rabbit retina astrocytes by using immunofluorescence techniques together with the confocal microscopy. MATERIAL AND METHODS: The rabbit retinas were processed with an anti-glial fibrillary acidic protein (anti-GFAP) for astrocyte detection and with propidium lobide for nuclear staining. RESULTS: Confocal microscopy allows for three-dimensional reconstruction of astroglial cells, the performance of double staining procedures with superposition of images corresponding to each chromogen, the exchange of observation axes for each slide and finally the performance of serial optic sections that indicate the exact cell location and their relationship with adjacent structures, eliminating the background signals. CONCLUSIONS: The confocal microscopy provides detailed information about tridimensional morphology and the location of the astrocytes in the rabbit retina. The astrocytes associated with the nerve fiber bundles are located in the nerve fiber layer. The type III perivascular astrocytes are located between the intravitreous capillaries close to the internal limiting membrane of the retina. The type I perivascular astrocytes are found in the retinal face of the intravitreal capillaries, these being the neurons which are the most distant from the retina.

Aplicación de la microscopia confocal al estudio de las relaciones vaso-gliales en la retina / Application of confocal microscopy in the study of the relationships between astrocytes and blood vessels in the retina

Objetivo: Se pretende estudiar los astrocitos de la retina del conejo utilizando técnicas inmunohistoquímicas de fluorescencia asociadas a la microscopia confocal. Material y métodos: Se analizan mediante microscopia confocal retinas de conejo teñidas con anti-GFAP. para el marcaje de los astrocitos, y con ioduro de propidio para marcaje de los núcleos Resultados: El empleo del microscopio confocal permite la reconstrucción tridimensional de las células astrogliales, la realización de dobles marcajes superponiendo las imágenes obtenidas con cada uno de ellos, el cambio de los ejes de observación y toma de imágenes de la preparación, y por último la realización de series de secciones ópticas que nos indican la localización exacta de las células y sus relaciones con las estructuras adyacentes, eliminando las señales de fondo. Conclusión: El estudio de la retina del conejo con microscopia confocal proporciona una información detallada de la morfología tridimensional y de la localización de los astrocitos. Los astrocitos acompañantes de axones se localizan en el espesor de la capa de fibras del nervio óptico. Los astrocitos perivasculares tipo III se sitúan en el humor vítreo en la proximidad de la membrana limitante interna de la retina. Los astrocitos perivasculares tipo I se encuentran en la cara retiniana de los vasos intravítreos siendo la célula nerviosa más alejada de la retina (AU)

Immunohistochemistry in association with scanning electron microscopy for the morphological characterization and location of astrocytes of the rabbit retina.

The purpose of the present investigation was to establish a method for the morphological characterization and location of the several types of astrocytes in the rabbit retina. Whole retinas were incubated with unlabeled antibody to glial fibrillary acidic protein (GFAP) and, afterwards, treated with secondary antibody labeled according to the requirements for the visualization of the antigen-antibody reaction either with the confocal or transmission electron microscope. Specimens treated similarly to the latter were osmium enhanced and analyzed with scanning electron microscopy (SEM). The different immunohistochemical approaches led to the conclusion that the cells selectively visualized with the SEM are astrocytes. The higher resolution and depth of focus of this instrument allowed a better morphological characterization and a more precise location of the astrocytes in the several levels of the inner portion of the rabbit retina. The method described herein, in which pre-embedding immunohistochemistry for GFAP on rabbit retinas was associated with osmium enhancement and examination with SEM, proved to be reliable and efficient for the morphological characterization and location of astrocytes.