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Biomedical subjects

E Valdivia

Publications and source records attributed to E Valdivia.

79 records · Page 5Linked to original sources
PubMedDate not supplied

Antagonistic action of the bacterium Bacillus licheniformis M-4 toward the amoeba Naegleria fowleri.

Free-living amoebae belonging to the species Naegleria fowleri are known to be the etiological agents for a form of fulminant meningoencephalitis that is generally fatal (primary amoebic meningoencephalitis). In a broad bacterial screening from soil and water we have isolated three strains (M-4, D-13 and A-12) belonging to the species Bacillus licheniformis that have remarkable amoebicidal activity against Naegleria sp. and also against different Gram-positive and Gram-negative bacteria. Physical-chemical characteristics, partial purification and biological activities of a substance produced by the M-4 strain have been investigated. This substance (m-4) is stable at high temperature (up to 100 degrees C) and extremes of pH (2.5-9.5) and also at -20 degrees C for months. Its production is greatly influenced by oxygenation of the cultures and is probably related to the sporulation process of the bacterium. Scanning electron microscope observations reveal that amoebae are lysed after a few minutes contact with m-4.

Amebicides↗
PubMedDate not supplied

Lipoblastoma presenting as a mesenteric mass in an infant.

PURPOSE: This article describes an infant with a large abdominal mass and hypertension. PATIENT AND METHODS: A 5-month-old infant girl with diarrhea of 1 week's duration and a large right-sided abdominal mass was brought for treatment. Computed tomography of the abdomen revealed a large, generally homogeneous, hypodense mass, which compressed the right kidney, resulting in dilatation of the right renal collecting system. At surgery, the mass was adherent anteriorly to the transverse colon and attached by a stalk to the mesentery near the origin of the right colic artery. RESULTS: Examination of the mass showed an encapsulated lipoblastoma. Cytogenetic analysis revealed a 46,XX karyotype with a reciprocal translocation between chromosome 2 and chromosome 8 with breakpoints at q23 and q11.2, respectively. CONCLUSION: Lipoblastoma is a rapidly growing but benign tumor, which can cause severe medical problems by compressing major organs. Cytogenetic analysis can reveal translocations involving chromosome 8 band q11.2, which appears to be a specific chromosome marker for lipoblastoma.

Abdominal Neoplasms↗