RESUMO
Taurine and zinc exert neurotrophic effects. Zinc modulates Na(+)/Cl(-)-dependent transporters. This study examined the effect of zinc (ZnSO(4)) ex vivo and zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN) in vivo on [(3)H]taurine transport in goldfish retina. The effect of TPEN in vivo on taurine and zinc levels was determined. Isolated cells were incubated in Ringer with zinc (0.1-100 microM). Taurine transport was done with taurine (0.001-1 mM) and 50 nM [(3)H]taurine. Zinc (100 microM) noncompetitively inhibited taurine transport. TPEN was administered intraocularly and retinas extracted 3, 5 and 10 days later. Taurine was determined by HPLC (nmol/mg protein) and zinc by spectrophotometry ICP (mg/mg protein). Taurine and zinc levels decreased at 3 days and increased at 10 days after TPEN administration. At 10 days after intraocular TPEN, taurine transport affinity increased (K (s) = 0.018 +/- 0.006 vs. 0.028 +/- 0.008 mM). Apparently, zinc deficiency affects the taurine-zinc complex and taurine availability. The increased taurine uptake affinity by TPEN was possibly associated with a response to maximize retinal taurine content at low zinc concentration.
Assuntos
Quelantes/química , Retina/metabolismo , Taurina/metabolismo , Zinco/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Etilenodiaminas/química , Carpa Dourada , Cinética , Espectrometria de Fluorescência , Zinco/químicaRESUMO
Taurine and zinc, highly concentrated in the retina, possess similar properties in this structure, such as neuro-protection, membrane stabilization, influencing regeneration, and modulating development, maybe by acting in parallel or as interacting agents. We previously demonstrated that there are some correlations between taurine and zinc levels in hippocampus, dentate gyrus and retina of the developing rat. In the present study we evaluate the possible effects of taurine and zinc on outgrowth from goldfish retinal explants. The optic nerve was crushed 10 days before plating and culturing retinal explants in Leibovitz medium with 10% fetal calf serum and gentamicin. Neurites were measured with SigmaScanPro after 5 days in culture. Taurine (HPLC) and zinc (ICP) concentrations were determined in the retina between 1 and 180 days after crushing the optic nerve. Zinc sulfate (0.01-100 microM), N,N, N',N'-tetrakis (pyridylmethyl) ethylenediamine (TPEN, 0.1-5 nM) and diethylenetriamine penta-acetic acid (DTPA, 10-300 microM), intracellular and extracellular zinc chelators, respectively, were added to the medium. TPEN was also injected intraocular (0.1 nM). Combinations of them were added with taurine (1-16 mM). Taurine concentrations were elevated in the retina 72 h after the crush, but were normalized by 180 days, those of zinc increased at 24 h, preceding the increase of taurine. The axonal transport of [3H]taurine from the optic tectum to the retina was not affected in fish with or without crush of the optic nerve at early periods after the injection, indicating an increase of it post-lesion. Zinc sulfate produced a bell-shaped concentration dependency on in vitro outgrowth, with stimulation at 0.05 microM, and inhibition at higher levels, also increased the effect of 4 mM taurine at 0.02 microM, but diminished it at higher concentrations in the medium. TPEN decreased outgrowth at 1 nM, but not at 0.5 nM, although the simultaneous presence of 4 mM taurine and 0.5 nM TPEN decreased outgrowth respecting the stimulation by taurine alone. The intraocular administration of TPEN decreased outgrowth in vitro, an effect counteracted by the addition of 4 mM taurine to the culture medium. DTPA decreased outgrowth from 10 microM in the medium. The present results indicate that an optimal zinc concentration is necessary for outgrowth of goldfish retinal explants and that, in zinc deficient retina, taurine could stimulate outgrowth. In addition, the observations of variations in tissue concentrations and of the effects of intraocular administration of TPEN indicate that these effects could occur in vivo.
Assuntos
Retina/efeitos dos fármacos , Taurina/farmacologia , Zinco/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Carpa Dourada , Nervo Óptico/química , Ratos , Retina/crescimento & desenvolvimento , Espectrometria de Fluorescência , Taurina/análise , Zinco/análiseRESUMO
Describir la clínica, imagenología y el tratamiento de esta patología poco frecuente. Servicio de Cirugía III. Hospital Universitario de Caracas. Reporte de un caso clínico y revisión de la literatura. El término mielolipoma suprarrenal fue acuñado por Oberling 1929 para denominar a una variedad de tumores benignos formados por tejido adiposo maduro y tejido meiloide hematopoyético originados en el estroma suprarrenal. Su incidencia en autopsia oscila entre 0.3 y el 0.4 por ciento(²), la misma aumenta en los pacientes obesos(²³) y es más frecuente en la 4ta a 6ta década de la vida. Dentro de los estudios diagnósticos está la resonancia magnética en donde las áreas lipomatosas muestran intensidad aumentada en T1 y moderada hiperdensidad en T2. El tratamiento recomendado cuando son mayores de 5 cm. es quirúrgico
Assuntos
Adulto , Humanos , Feminino , Glândulas Suprarrenais , Adrenalectomia , Administração de Caso , Mielolipoma , Neoplasias , Cirurgia Geral , Medicina , VenezuelaRESUMO
Taurine and zinc possess neurotrophic and neuroprotective properties, and they have been demonstrated to interact in the central nervous system (CNS). The aim of this work was to determine taurine, hypotaurine, and zinc levels during postnatal development and any possible significant correlation between them in selective areas of the CNS with differential taurine level regulation and intrinsic capacity to proliferate. Taurine and hypotaurine content (nM/region) and concentration (nM/mg protein) and total zinc levels were determined in the retina, hippocampus, and dentate gyrus of the rat at postnatal days 5, 10, 15, 20, 30, and 50. Taurine and hypotaurine increased during development in the retina without significant correlation between them. In the hippocampus there was a progressive decrease, and in the dentate gyrus there was an initial increase and a posterior decrease of taurine and hypotaurine levels. Correlation between the two amino acids was observed at P10, P15, and P50 for the hippocampus and at P15, P30, and P50 for the dentate gyrus. The variations in total zinc levels followed a biphasic behavior, with an early decrease and later increase. Significant and positive correlation of zinc and taurine was only observed in the hippocampus at P30 and P50 and negative in the dentate gyrus at P30. No significant correlation was obtained for the retina. The maintenance of taurine levels in specific CNS areas does not seem to be related to the availability of the precursor, hypotaurine, which might have a role by itself. There are critical postnatal periods during which there is a preservation of taurine, hypotaurine, or zinc levels. It seems that these requirements could be related to zinc-taurine interactions.
Assuntos
Giro Denteado/metabolismo , Hipocampo/metabolismo , Retina/metabolismo , Taurina/análogos & derivados , Taurina/metabolismo , Zinco/metabolismo , Animais , Ratos , Ratos Sprague-DawleyRESUMO
Rorte de un primer caso realizado en el Hospital Universitario de Caracas, de un paciente masculino de 46 años de edad, con neoplasia intra epitelial de lato grado en fundus gástrico, a quién se le realiazó gastrectomía total con reconstrucción asófago-yeyuno anatomosis en "Y" de Roux término - lateral por laparoscopia
Assuntos
Adulto , Masculino , Humanos , Anastomose em-Y de Roux , Esôfago/patologia , Neoplasias Esofágicas , Gastrectomia , Jejuno , Laparoscopia , Cirurgia Geral , Medicina , VenezuelaRESUMO
Se presentaron los casos de pacientes con diagnóstico de cáncer gástrico de trece años de cirugía, a los cuales se les realizó gastrectomía total con esófago-yeyuno anastomosis término-lateral en Y Roux con el uso de máquina autosuturadora, como técnica simplificada, segura y efectiva en el manejo de esta patología. Entre 1991 y 2004 se operaron 13 casos. Diez pacientes maculinos (76,9 por ciento) y tres pacientes femeninos (23,1 por ciento), con una edad promedio de 65,07 años. Diez (10) pacientes presentaron adenocarcinoma gástrico (ADC) del tercio superior (76,92 por ciento), uno (1) del tercio medio (7,69 por ciento). La mortalidad en el postoperatorio tardío ocurrió en dos pacientes (15,38 pacientes) por complicaciones respiratorias. La sobrevida esciló entre 22 días y 13 años, siendo en promedio de 24,13 meses. La sobrevida a los 2 años fue de 46,15 por ciento y de 7,69 por ciento a los 5 años
Assuntos
Masculino , Humanos , Feminino , Anastomose em-Y de Roux , Esofagostomia , Gastrectomia , Neoplasias Gástricas , Jejunostomia , Gastroenterologia , VenezuelaRESUMO
A chronic methanol (MeOH) intoxication scheme (2 g/kg/day ip for 2 weeks) was carried out in Sprague-Dawley rats, previously depleted of folates with methotrexate (MTX). beta-Alanine (beta-Ala), 5%, was also administered to some animals in the drinking water. Amino acids were determined in plasma, retina, optic nerve, hippocampus and posterior cortex by HPLC with fluorescence detection and monoamines in retina, hippocampus and posterior cortex by electrochemical detection. Beta-Ala administration reduced taurine (Tau) levels in plasma, hippocampus and posterior cortex, but not in retina and optic nerve. Aspartate (Asp) concentration in the optic nerve was increased in MTX-MeOH treated animals, and the administration of beta-Ala did not modify this elevation. The association of beta-Ala with MTX-MeOH produced an increase of threonine, and a decrease of 5-hydroxytryptamine (5-HT) in the retina without modifying 5-hydroxyindoleacetic acid, whereas in the hippocampus an elevation of asparagine was observed. We conclude that, in the retina, beta-Ala in combination with MTX-MeOH increased serotonin and decreased dopamine (DA) turnover rate, and resulted in changes in the amino acid balance, that could affect glycinergic activity. On the other hand, in the hippocampus, Asp metabolism could be affected by Tau depletion with beta-Ala.
Assuntos
Aminoácidos/análise , Monoaminas Biogênicas/análise , Encéfalo/efeitos dos fármacos , Metanol/toxicidade , Retina/efeitos dos fármacos , Taurina/deficiência , Aminoácidos/sangue , Animais , Asparagina/análise , Química Encefálica , Córtex Cerebral/química , Cromatografia Líquida de Alta Pressão , Dopamina/análise , Ingestão de Líquidos , Deficiência de Ácido Fólico/induzido quimicamente , Hipocampo/química , Ácido Hidroxi-Indolacético/análise , Masculino , Metanol/administração & dosagem , Metotrexato/administração & dosagem , Nervo Óptico/química , Nervo Óptico/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Retina/química , Serotonina/análise , Taurina/análise , Taurina/fisiologia , Treonina/análise , beta-Alanina/administração & dosagemRESUMO
The clinical and electroretinographic features of chronic methanol intoxication are scarce, and neurotransmitter studies have not been conducted. In addition, most of the studies in the field include results after acute administration. In the present work, a chronic methanol intoxication scheme (2 g/kg/day ip for 2 weeks) was carried out in Sprague-Dawley rats previously depleted of folates with methotrexate. Taurine (2%) in drinking water was also administered in two groups of animals. Blood formate levels were increased in methotrexate-methanol-treated animals with respect to controls (0.98 +/- 0.09 and 0.30 +/- 0.03 mM, respectively). Amino acids and monoamines were determined in plasma and in retina, optic nerve, hippocampus, and posterior cortex by HPLC with fluorescence or electrochemical detection. The main finding was an increased aspartate content in the optic nerve in methotrexate methanol-treated animals. Methanol alone increased glutamate, aspartate, glutamine, taurine, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid levels in the hippocampus and 5-hydroxytryptamine in the retina. Taurine administration had no significant effect on changes induced by methanol treatment. We concluded that chronic methanol administration produced accumulation of aspartate, an excitotoxic amino acid, in the optic nerve. These findings contribute to the understanding of methanol neurotoxicity and might indicate a relationship between chronic methanol consumption and the development of optic neuropathies.