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Biomedical subjects

F Beltran

Publications and source records attributed to F Beltran.

8 recordsLinked to original sources

Lack of virus transmission by the excimer laser plume.

PURPOSE: To test the possibility of pathogenic virus transmission into the operating suite during excimer laser treatment of corneal tissue. Such treatment vaporizes corneal tissue, which may put the surgeon at risk of infection from human immunodeficiency virus, hepatitis virus, or other viruses. We developed a model system to test the possibility of such virus transmission. METHODS: Pseudorabies virus is a porcine enveloped herpesvirus similar in structure and life cycle to human immunodeficiency virus and herpes simplex virus. An excimer laser was used to ablate a virus-infected tissue culture plate while an uninfected tissue culture plate was in an inverted position over the infected plate. Six hundred laser pulses were applied. Pseudorabies virus in the excimer laser plume would, potentially, contact and infect the uninfected cells. The experiment was repeated 20 times with appropriate positive and negative controls. RESULTS: None of the 20 uninfected plates was infected by the laser plume rising from ablation of infected tissue culture plates. Positive and negative controls performed as expected. CONCLUSIONS: Even under conditions designed to maximize the likelihood of virus transmission, the excimer laser ablation plume does not appear capable of transmitting this particular live enveloped virus. Excimer laser ablation of the cornea of a human immunodeficiency virus (HIV)-infected or herpesvirus-infected patient is unlikely to pose a health hazard to the surgeon.

Animals

[Seroepidemiologic study of human cysticerosis in the predominantly indigenous rural Indian population of the State of Chiapas].

The overall proportion of sera with antibodies against cyticercus antigens in 3226 serum samples collected among the Indian rural population in the proximity of San Cristóbal de Las Casas, Chiapas, México is 0.49. The proportion of positive sera varied from 0.4 to 7.6% inversely with the number of inhabitants in the community. The global proportion of positive sera in Chiapas being considerably lower than that expected from the autopsy frequency of brain cysticercosis in México City (1.4-3.6%), it is perhaps indicative of different epidemiologic dynamics in rural and urban areas.

Antibodies

Corneal ectasia as a complication of repeated keratotomy surgery.

BACKGROUND: Staged keratotomy surgery, or "enhancement surgery," may allow a more predictable outcome, but also subjects the patient to additional surgical risks. METHODS: A 39-year-old man underwent astigmatic keratotomy for myopic astigmatism, followed by 12 enhancement procedures for residual astigmatism. RESULTS: These procedures effectively resulted in a double hexagonal keratotomy. The patient's best spectacle-corrected acuity deteriorated to counting fingers. Clinically, a conically-shaped protrusion of the central cornea, Munson's sign, diffuse subepithelial scarring, and central corneal thinning were noted. Penetrating keratoplasty was performed. Histopathologic examination showed central thinning, epithelial edema, disruption of Bowman's layer, marked stromal scarring, and focal areas of endothelial attenuation--findings consistent with keratoconus. CONCLUSION: This case illustrates that multiple keratotomy procedures may result in corneal ectasia in apparently normal eyes and suggests that hexagonal keratotomy may be more likely to cause iatrogenic keratoconus.

Adult