Altered cellular membrane fluidity levels and lipid peroxidation during experimental pancreas transplantation.

Although the pathogenesis of ischemia reperfusion (IR) injury is based on complex mechanisms, free radicals play a central role. We evaluated membrane fluidity and lipid peroxidation during pancreas transplantation (PT) performed in 12 pigs (six donors and six recipients). Fluidity was measured by fluorescence spectroscopy, and malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations were used as an index of lipid oxidation. Pancreatic tissues were collected as follows: (A) donor, immediately before vascular clamping; (B) graft, following perfusion lavage with University of Wisconsin preservation fluid; (C) graft, after 16 h of cold ischemia; and (D) recipient, 30 min vascular postreperfusion. Fluidity and MDA and 4-HDA concentrations were similar in cases A, B, and C. However, there was significant membrane rigidity and increased lipid peroxidation after reperfusion (D). These findings suggest that reperfusion exaggerates oxidative damage and may account for the rigidity in the membranes of allografts during PT.

Acute exercise increases plasma total antioxidant status and antioxidant enzyme activities in untrained men.

Antioxidant defences are essential for cellular redox regulation. Since free-radical production may be enhanced by physical activity, herein, we evaluated the effect of acute exercise on total antioxidant status (TAS) and the plasma activities of catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase and its possible relation to oxidative stress resulting from exercise. Healthy untrained male subjects (n = 34) performed three cycloergometric tests, including maximal and submaximal episodes. Venous blood samples were collected before and immediately after each different exercise. TAS and enzyme activities were assessed by spectrophotometry. An increase of the antioxidant enzyme activities in plasma was detected after both maximal and submaximal exercise periods. Moreover, under our experimental conditions, exercise also led to an augmentation of TAS levels. These findings are consistent with the idea that acute exercise may play a beneficial role because of its ability to increase antioxidant defense mechanisms through a redox sensitive pathway.

In vivo hepatic oxidative stress because of carbon tetrachloride toxicity: protection by melatonin and pinoline.

The protective in vivo effects of melatonin or pinoline on carbon tetrachloride (CCl(4))-induced oxidative damage were investigated in liver of rats and compared to rats injected only with CCl(4) (5 mL/kg body weight). Hepatic cell membrane fluidity, monitored using fluorescence spectroscopy, exhibited a significant decrease in animals exposed to CCl(4) compared to control rats. Increases in lipid and protein oxidation, as assessed by concentrations of malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA), and protein carbonylation, respectively, were also seen in hepatic homogenates of animals exposed to CCl(4). The administration of melatonin (10 mg/kg body weight) or pinoline injected 30 min before and 1 hr after CCl(4), fully prevented membrane rigidity and protein oxidation. However, treatment with melatonin was more effective in terms of reducing lipid peroxidation than pinoline, as the increases in MDA+4-HDA levels because of CCl(4) were reduced by 93.4% and 34.4% for melatonin or pinoline, respectively. Livers from CCl(4)-injected rats showed several histopathological alterations; above all, there were signs of necrosis and ballooning degeneration. The concurrent administration of melatonin or pinoline reduced the severity of these morphological changes. On the basis of the biochemical and histopathological findings, we conclude that both melatonin and pinoline were highly effective in protecting the liver against oxidative damage and membrane rigidity because of CCl(4). Therefore, these indoles may be useful as cotreatments for patients with hepatic intoxication induced by CCl(4).

Maxillomandibular osteomyelitis in osteopetrosis. Report of a case and review of the literature.

INTRODUCTION: Osteopetrosis is a rare hereditary group of bony displasias. They range from a devastating metabolic disease (including severe malignant infantile osteopetrosis) to other conditions with a more benign phenotype (autosomal dominant osteopetrosis I and II). CASE REPORT: Several case reports have been published of infectious complications affecting the mandible but maxillary affectation is quite rare. We present the case of a 23-year-old woman with a malignant recessive form of osteopetrosis complicated by repeated episodes of osteomyelitis (caused by actinomyces) of the mandible and maxilla.

Fístula arteriovenosa postraumática: tratamiento endovascular. Revisión de la literatura y presentación de un caso clínico / Endovascular treatment of a post-traumatic arterio-venous fistula: presentation of a clinical case and literature review

Las fístulas arteriovenosas en la cabeza y el cuello son entidades poco frecuentes. La mayoría es secundaria a heridas penetrantes por arma blanca. Se describe el tratamiento exitoso mediante cirugía endovascular de una fístula postraumática tras una herida penetrante entre la arteria maxilar interna izquierda y la vena yugular externa. A través de este caso clínico y la revisión de la literatura se ilustran las causas, manifestaciones, estudio radiológico y tratamiento de una fístula postraumática entre la arteria maxilar interna y la vena yugular externa. A través de este caso clínico se demuestra la utilidad de los procedimientos endovasculares en el tratamiento de estas complicaciones(AU)

Traumatic arteriovenous fistulas of the head and neck region are uncommon. The majority are due to penetration of blunt injury. We describe a successful endovascular treatment of a posttraumatic fistula between the left maxillary artery and the external jugular vein due to a penetration injury. This case and a review of the literature illustrate the causes, manifestations, image studies and treatment for a posttraumatic fistula between the maxillary artery and the external jugular vein. This case demonstrate the utility of endovascular treatment of head and neck injuries complications(AU)

Absceso crónico submaseterino secundario a cordal incluido / Chronic submasseter secondary abscess of impacted wisdom tooth

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Quiste nasoalveolar bilateral / Bilateral nasoalveolar cyst

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Carcinoma cutáneo de células de Merkel. Presentación de un caso y revisión de la literatura / Cutaneous Merkel cell carcinoma. Case report and literature review

El carcinoma de células de Merkel, constituye una variedad infrecuentede cáncer cutáneo, de origen neuroendocrino, que clásicamentese describe, como la malignidad cutánea de peor pronóstico. Se originaa partir de las células de Merkel o receptores cutáneos de presión. Presentaun patrón infiltrativo dermo-linfático así como extensión linfática nodal ydiseminación hematógena. Presenta numerosas similitudes con el carcinomapulmonar de células pequeñas, con una sensibilidad intrínseca a laquimio-radioterapia y un gran potencial metastático. Los mejores resultadosse obtienen cuando se combina un diagnóstico precoz y el tratamientocombinado con cirugía- radio y quimioterapia. La principal dificultad quepresentan estos tumores es la avanzada edad de la población en que sepresentan y la localización de los mismos, que en ocasiones limitan lasopciones terapéuticas disponibles. Presentamos un caso de carcinoma decélulas de Merkel facial, tratado con cirugía y radioterapia. Se realiza unarevisión de la literatura (AU)

Merkel-cell carcinoma is a rare skin cancer ofneuroendocrine origin, which has been described as the mostaggressive skin malignancy. The tumor arises from the Merkel cells,or skin pressure receptors. It has an infiltrative growth pattern andspreads by the lymphatic vessels and blood. It is similar to small celllung carcinoma, with an intrinsic sensitivity to chemo-radiotherapyand a remarkable tendency to metastasize. The best treatmentoutcomes are obtained with early diagnosis and a combination ofsurgery, chemotherapy, and radiotherapy. A clinical case of Merkelcell carcinoma of the face treated with surgery and radiotherapy isreported and the literature is reviewed (AU)

Efecto protector de 5-metoxi-indolaminas pineales en la oxidación de sinaptosomas mediada por radicales libres / No disponible

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Peorxidación lipídica en pacientes afectos de tumores del sistema nervioso central / No disponible

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Efecto protector de la melatonina frente a la toxicidad de la mitomicina C / No disponible

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