[Oxidative stress and infectious pathology]. / Estrés oxidativo y patología infecciosa.

Pathogenic organism can be considered as pro-oxidant agents because they produce cell death and tissue damage. In addition organism can be eliminated by specific cell defense mechanism which utilize in part, reactive oxygen radicals formed by oxidative stress responses. The cause of the necessarily defense process results in cell damage thereby leading to development of inflammation, a characteristic oxidative stress situation. This fact shows the duality of oxidative stress in infections and inflammation: oxygen free radicals protect against microorganism attack and can produce tissue damage during this protection to trigger inflammation. Iron, a transition metal which participates generating oxygen free radicals, displays also this duality in infection. We suggest also that different infectious pathologies, such as sickle cell anemia/malaria and AIDS, may display in part this duality. In addition, it should be noted that oxidative damage observed in infectious diseases is mostly due the inflammatory response than to the oxidative potential of the pathogenic agent, this last point is exemplified in cases of respiratory distress and in glomerulonephritis. This review analyzes these controversial facts of infectious pathology in relation with oxidative stress.

[Prevalence of Helicobacter pylori in gastric pathology in Aragon]. / Prevalencia del Helicobacter pylori en patología gástrica en Aragón.

The aim of this study was to evaluate the prevalence of Helicobacter pylori in 400 patients referred for upper digestive tract endoscopy. In our area it hasn't developed yet any epidemiologic study about this disease. Helicobacter pylori was observed in 281 of the 400 patients studied (70%). No significant differences by sex were found in the subjects analyzed. There was a rise in the percentage of positivities as age increased. Helicobacter pylori were positive in 74 of the 88 patients with chronic superficial gastritis (84.1%), in 53 of the 65 with chronic atrophic gastritis (81.5%), in 16 of the 25 with chronic atrophic gastritis and intestinal metaplasia (64%), in 49 of the 63 with gastric ulcer (77.8%), in 73 of the 85 with duodenal ulcer (85.9%), in 9 of the 24 patients with gastric carcinoma (37.5%), in 5 of the 19 with stump gastritis (26.3%), where as only a few Helicobacter pylori were found in 2 of the 31 histologically normal subjects (6.5%). These findings support the wiew that Helicobacter pylori may be etiologically related to chronic gastritis and peptic ulceration, even though their precise role still remains to be determined.

[Boerhaave syndrome, as a cause of acute abdomen]. / Síndrome de Boerhaave, como causa de abdomen agudo.

Boerhaave's syndrome, or spontaneous esophageal perforation, is an infrequent entity with an elevated morbidity and mortality. Its clinical manifestations are such that an extensive differential diagnosis with other entities in necessary, but diagnostic delay worsens the prognosis. We present a new case of Boerhaave's syndrome, that debuted as a picture of acute abdomen which led to the realization of an exploratory laparotomy that failed to evidence the esophageal perforation.

[Esophageal ulcer caused by doxycycline]. / Ulcera esofágica por doxiciclina.

We describe a case of esophageal ulcer produced by oral ingestion of a capsule of doxycycline. A review is made of medications that produce esophageal lesions, and the pathogenesis, clinical manifestations, diagnosis and treatment of these lesions. We emphasize the importance of taking these drugs with abundant liquids, in erect position, never before going to bed, to prevent these lesions.