J. Armando Guevara

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Bacterial adherence to cerebrospinal fluid (CSF) shunts was analyzed in vivo and in vitro. Scanning electron micrographs (SEM's) of catheters removed from pediatric patients with shunts infected by Staphylococcus aureus or Klebsiella pneumoniae revealed numerous bacterial cells and microcolonies, leukocytes, and erythrocytes attached to the CSF catheters'(More)
Valve-regulated systems, used for the treatment of hydrocephalus, were studied with the scanning electron microscope. The study was performed on unused systems of shunt replaced after different pathologies and on systems removed due to cerebrospinal fluid infection. Defects in the material, such as holes and protrusions, were systematically found in new(More)
UNLABELLED Fourteen children and 3 adults with cystic craniopharyngiomas were treated with intracavitary 90Y, by the procedure described by Backlund. Their ages ranged from 2 to 65 years and postoperative follow-up ranged from 6 to 40 months. Leksell's stereotactic technique was employed to determine coordinates by CAT. Cyst volume was quantified both(More)
Single hydatid cysts of the brain are rarely seen by pediatric neurosurgeons who do not reside in certain countries, i.e. Australia, Uruguay, and Argentina. It is, however, of considerable importance that every pediatric neurosurgeon be aware of the manner of diagnosis of this condition and surgical management of these patients. Out of 35 cases of(More)
Boars fed on ration of 200 ppm Zn methionate showed a significant increase (P < 0.001) in sperm DNA fragmentation when compared to animals fed on non-supplemented and rations containing 150 ppm Zn methionate. There was a positive correlation (R2 = 0.207; P = 0.002) between % sperm DNA fragmentation (SDF) and the concentration of Zn in spermatozoa. Increased(More)