The use of a genetically engineered herpes simplex virus (R7020) with ionizing radiation for experimental hepatoma

The herpes simplex virus (HSV) recombinant virus R7020 is an attenuated virus designed as a candidate for immunization against both HSV-1 and HSV-2 infections. It was extensively tested in an experimental animal system and in a healthy human adult population without significant untoward effects. We report on the use of R7020 with ionizing radiation as an oncolytic agent for hepatomas. Two hepatoma cell lines were studied, Hep3B and Huh7. R7020 replicated to higher titers in Hep3B cells than in Huh7 cells. Tissue culture studies correlated with hepatoma xenograft responses to R7020. R7020 was more effective in mediating Hep3B tumor xenograft regression compared with Huh7. Ionizing radiation combined with R7020 also showed differential results in antitumor efficacy between the two cell lines in tumor xenografts. Ionizing radiation enhanced the replication of R7020 in Hep3B xenografts. Moreover, the combination of ionizing radiation and virus caused a greater regression of xenograft volume than either R7020 or radiation alone. Ionizing radiation had no effect on the replication of R7020 virus in Huh7 xenografts. These results indicate that a regimen involving infection with an appropriate herpesvirus such as R7020 in combination with ionizing radiation can be highly effective in eradicating certain tumor xenografts.

Azarcón por empacho--another cause of lead toxicity

A new source of toxic lead ingestion has been identified roentgenologically in Mexican-American children and adults. Azarcón is an orange powder that contains 86% to 95% lead tetroxide (Pb3O4). At least three children have been treated with this substance by folk healers for relief of abdominal symptoms. Other Hispanic medical folklores may include this toxic "remedy."

Isovalericacidemia: a case report

Aminoacidopathies are rare metabolic defects that frequently present shortly after birth or in early infancy with vomiting, dehydration, ketoacidosis, and a peculiar body odor. If not recognized early, these can result in developmental retardation and/or death. A case of isovalericacidemia is reported to emphasize the importance of metabolic screening when an infant presents with the above-mentioned symptoms along with an anion gap greater than 20 mEq/liter. In our patient, a metabolic disorder was suggested by the clinical presentation and was confirmed by measuring elevated levels of biproducts. The infant was given a low-leucine diet and has developed normally since then.