The gut-associated lymphoid tissue (GALT) of carp (Cyprinus carpio L.): an immunocytochemical analysis.

The GALT of carp was studied with monoclonal antibodies reacting with carp Ig or carp leukocytes, using (dual) immunofluorescence or immunogold staining on cryosections, cytocentrifuge slides, and cell suspensions of the intestine. The intestinal epithelium contained many Ig-negative lymphoid cells and, in the hindgut, also many large Ig-positive macrophages, which appeared to bind Ig. The lamina propria contained numerous Ig-positive lymphoid cells next to Ig-negative lymphoid cells and granulocytes. Leukocytes isolated from the intestine mainly consisted of Ig-negative lymphoid cells (> 90%). With the methods used, leukocytes were poorly released from the connective tissue. Nevertheless, two types of Ig-containing cells were found: a conventional plasma cell, frequently showing Ig at its surface, and a more common smaller lymphoid cell having a narrow rim of Ig-positive cytoplasm but hardly any Ig on its surface. Many of the Ig-positive lymphoid cells observed in the lamina propria may represent these small Ig-containing cells. Isolated Ig-positive macrophages were frequently associated with B- and T-like cells. Our data strongly suggests an immunological function for the gut of carp, especially for the antigen-transporting hindgut.

Antioxidant capacity of desferrioxamine in biological systems.

The antioxidant capacity of desferrioxamine (DF) was investigated in three biological systems. The addition of DF to rat brain homogenates undergoing autoxidation elicited a concentration dependent inhibition of both oxygen uptake and chemiluminescence, with a median inhibitory concentration (IC50) of 0.52 microM. In this system, Fe3+-induced light emission was completely abolished at a DF/Fe3+ molar ratio of 0.6. In rat erythrocyte suspensions supplemented with t-butyl hydroperoxide, DF lengthened the induction period and decreased the rate of oxygen consumption, with an IC50 of 300 microM. Infusion of increasing concentrations of DF to the perfused rat liver elicited a progressive decrease in the rate of oxygen consumption, with no alterations in the mitochondrial respiration. This DF-sensitive respiration has a maximal value of 200 nmol/g of liver/min, with a half-maximal rate at 120 microM DF. These results indicate that DF behaves as an efficient antioxidant either under basal conditions or in chemically-induced oxidative stress, through Fe3+ chelating and/or free-radical scavenging effects.

Effect of ethanol, acetaldehyde and acetate on the antioxidant-sensitive respiration in the perfused rat liver: influence of fasting and diethylmaleate treatment.

The infusion of 45 mM ethanol or 50 microM acetaldehyde into the perfused rat liver produced comparable and significant antioxidant-sensitive respiratory rates, while marginal responses were obtained with 10 mM acetate. Ethanol-induced antioxidant-sensitive respiration was markedly increased in perfused livers from fasted rats or animals given diethylmaleate which exhibit low hepatic glutathione levels, compared to fed rats. These data point out the significant role of acetaldehyde in ethanol-induced liver oxidative stress, which can be exacerbated by glutathione depletion.

Cáncer bucal: sobrevida / Mouth neoplasm: survival

Se presentan los resultados de sobrevida a cinco años de veintinueve pacientes con carcinoma de células escamosas de la cavidad bucal, analizados con tabla de sobrevida actuarial. La sobrevida fue de 71,8% a cinco años para toda la serie. La mayor letalidad se presentó dentro del primer año consecutivo al tratamiento. Se encontró además una clara tendencia a una mayor sobrevida en los estados menos avanzados

Cáncer intraoral: aspectos clínicos y patológicos / Intraoral cancer: clinical and pathological aspects

El objetivo de esta investigación fue conocer las características clínicas y patológicas del carcinoma intraoral. Se hizo un estudio retrospectivo en 62 pacientes, obteniéndose información útil en 44. Este consistió en el análisis de las características clínicas, patológicas y clasificación T.N.M. (A.J.C.). Hubo 33 hombres y 11 mujeres. La edad osciló entre 36 y 89 años, con un promedio de 60,8 años. Las localizaciones fueron: piso de boca = 24; gíngiva = 12; lengua móvil = 6 y trígono retromolar = 2. Distribución por T: T1=4; T2=17; T3=10 y T4=13: Distribución por N: N0=17; N1=17; N2=6 y N3=4. Hubo 11 pacientes con lesión de tipo exofítico y 33 de tipo infiltrante. Las metástasis regionales se presentaron con mayor frecuencia en los tumores de mayor extensión y en aquéllos menos diferenciados. Las localizaciones más frecuentes fueron el piso de la boca y la gíngiva. No hubo metástasis a distancia en la evaluación inicial

Changes in oxygen consumption induced by t-butyl hydroperoxide in perfused rat liver. Effect of free-radical scavengers.

The addition of t-butyl hydroperoxide to perfused rat liver elicited a biphasic effect on hepatic respiration. A rapid fall in liver oxygen consumption was initially observed, followed by a recovery phase leading to respiratory rates higher than the initial steady-state values of oxygen uptake. This overshoot in hepatic oxygen uptake was abolished by free-radical scavengers such as (+)-cyanidanol-3 or butylated hydroxyanisole at concentrations that did not alter mitochondrial respiration. (+)-Cyanidanol-3 was also able to facilitate the recovery of respiration, the diminution in the calculated rate of hydroperoxide utilization and the decrease in liver GSH content produced by two consecutive pulses of t-butyl hydroperoxide. It is suggested that the t-butyl hydroperoxide-induced overshoot in liver respiration is related to increased utilization of oxygen for lipid peroxidation as a consequence of free radicals produced in the scission of the hydroperoxide by cellular haemoproteins.

Visible chemiluminescence induced by t-butyl hydroperoxide in red blood cell suspensions.

Red blood cells from Wistar rats were exposed to milimolar concentrations of t-butyl hydroperoxide. Extensive hemoglobin oxidation (methemoglobin formation), t-butyl hydroperoxide cleavage (t-butanol formation) and peroxidation (measured by oxygen consumption and thiobarbituric acid reactive substances) was observed. Significant chemiluminescence was emitted by the system. Hemoglobin oxidation and t-butanol production were independent of oxygen pressure and free radical scavengers, however, luminescence was enhanced as oxygen pressure increased and it was reduced by addition of free radical scavengers. The spectral distribution of the light emitted suggests that the luminescence detected is not due to singlet oxygen dimol emission. The results are in agreement with a lipid peroxidative mechanism initiated by t-butoxy radicals produced in the interaction of hemoglobin and t-butyl hydroperoxide.