[Giant retroperitoneal liposarcoma]. / Liposarcoma retroperitoneal gigante.

Liposarcoma is a malignant tumor that has an embryologic origin from mesodermal tissue depending on fatty tissue. Although liposarcoma is only 0.1% of all human neoplasms, it is the most common histology subtype of retroperitoneal soft tissue sarcomas. This tumor grows slowly. Diffuse abdominal pain is its most frequent symptom and abdominal mass is the most common sign. Aggressive surgical treatment is basic to get a complete resection and a local disease control. This objective is difficult because of the large tumor size it gets in the retroperitoneal location and the multiorgan involvement that require the resection of a high percentage of contiguous organs. We report a case of a giant retroperitoneal liposarcoma presenting like continuous left hemiabdominal pain because of the visceral compression. The right kidney was involved and suffering from renal vessel enlargement without renal function. There is a high probability of microscopic residual disease and a good follow-up of the patients is necessary as well as an adjuvant radiation therapy in some cases.

Fístula apendicocutánea: complicación tardía de la apendicitis aguda / Appendical-cutaneous fistula: a late complication of acute appendicitis

Los cuadros de dolor abdominal en la población infectada por el virus de la inmunodeficiencia humana (VIH) son frecuentes, debido a las enfermedades asociadas a este virus, por lo que a menudo se producen errores y retrasos en el diagnóstico y tratamiento de la apendicitis aguda, incrementándose la tasa de complicaciones. En este trabajo se describe un caso de fístula apendicocutánea en un paciente infectado por el VIH al que no se le diagnosticó una apendicitis aguda (AU)

Estudio de la eritropoyetina sérica en pacientes con cáncer colorrectal / Serum erythropoietin response in patients with colorectal cancer

Introducción. Los pacientes con tumores sólidos avanzados desarrollan frecuentemente anemia. El mecanismo más importante en la patogenia de la anemia es el descenso de la eritropoyesis. Ésta puede ser debida a un descenso de la síntesis de eritropoyetina, una menor actividad de ésta sobre la médula ósea o una respuesta disminuida de la médula ósea a la eritropoyetina. El objetivo de este estudio es analizar la tasa de eritropoyetina en pacientes con cáncer colorrectal poco avanzado, comparándola con un grupo control. Pacientes y métodos. Hemos estudiado a 20 pacientes con cáncer colorrectal, que fueron diagnosticados por estudio radiológico y/o endoscópico con biopsia, y a un grupo control de 20 sujetos sanos. Tras el diagnóstico se determinaron los siguientes parámetros séricos: hemoglobina, hematócrito, hematíes y eritropoyetina. El análisis estadístico se realizó con el test de la t de Student y las correlaciones entre las variables con el test de Pearson (r). Resultados. Los parámetros hematológicos fueron inferiores en el grupo del cáncer colorrectal, aunque se hallaban dentro de la normalidad. La tasa de eritropoyetina en este grupo se encontraba significativamente aumentada (p < 0,01), existiendo una correlación entre la eritropoyetina y la hemoglobina (r = 0,59; p < 0,01), y entre la eritropoyetina y el hematócri-to (r = 0,61; p < 0,01).Conclusiones. Las concentraciones de eritropoyetina están muy elevadas en los pacientes con cáncer colorrectal, a pesar de no presentar una anemia evidente, pudiendo deberse este incremento a otras causas (factores tumorales, citocinas, etc.) (AU)

Effect of 4-aminopyridine and 3,4-diaminopyridine on guinea-pig isolated ileum.

1. 4-Aminopyridine and 3,4-diaminopyridine produced concentration-dependent contraction on guinea-pig isolated ileum incubated in Tyrode solution. The EC30 values were 1.14 x 10(-4) and 1.39 x 10(-4) M, respectively. 2. Calcium channel blockers such as verapamil, diltiazem, nifedipine, flunarizine, and lanthanum chloride antagonized the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 3. Diazoxide and atropine sulphate behaved similarly as antagonists of the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 4. It is concluded that the aminopyridines exert their effects through the release of acetylcholine from parasympathetic nerve terminals.

The role of the neurotransmitters acetylcholine and noradrenaline in the pathogenesis of stress ulcers.

1. Adrenergic and cholinergic mechanisms seem to be involved in the pathogenesis of stress ulcers. 2. In this study, gastric ulcers were induced in rats by immobilization and cold. Prior intraperitoneal administration of both anticholinergic (atropine) as well as alpha-blocking medication (phenoxybenzamine) produced a very significant decrease in stress ulcers. 3. Additionally, using the technique of continuous intravenous perfusion in rats, acetylcholine was shown to have a gastric ulcerogenic effect, in contrast to noradrenaline. 4. It is concluded that acetylcholine is the peripheral mediator in stress ulcers, while noradrenaline intervenes at the encephalic level in stress ulcer pathogenesis.

Effects of antidepressants on alcohol-induced gastric mucosal injury in rats.

The purpose of the present report is to study the effects of antidepressants such as trimipramine, amitriptyline, maprotiline and mianserin on severe gastric mucosal lesions produced by ethanol in comparison with cimetidine (H2-antihistamine) and dexchlorepheniramine (H2-antihistamine). The percentage of macroscopic mucosal lesions caused by alcohol affects 15% of the mucosal area. But pretreated with cimetidine the affected area was 9.18%, with dexchlorepheniramine 5.01%, with trimipramine 14.46%, with amitripytline 7.94%, with maprotiline 3.8%, and with mianserin 4.07%. Microscopic evaluation reveals that ethanol produces destruction of glandular cells and injures medial and basal layers. All drugs used previously to ethanol produce a decrease of microscopical lesions. A direct relation was found between micro and macroscopical lesions in rats treated with maprotiline, mianserin and dexchlorepheniramine.