The differences in human cumulative irritation responses to positive and negative irritant controls from three geographical locations.

A retrospective analysis was conducted to evaluate whether studies from three geographically diverse locations have similar response profiles to the positive and negative controls in a standard 14-day cumulative irritation study (1). The positive irritant control (0.1% sodium lauryl sulfate, SLS) and the negative control (0.9% sodium chloride, saline) data from seventeen 14-day cumulative irritation studies were reviewed. The studies were compiled from three locations representing dry/hot, humid/hot, and dry/cold environments (Scottsdale, Arizona; St. Petersburg, Florida; and Winnipeg, Manitoba, respectively). Irritation scores were generated by trained skin graders from a total of 442 subjects studied between 1999 and 2005. Cumulative irritation scores were reviewed and compared between study locations. The irritation scores for the positive and negative controls were not significantly different between locations. Temperature and relative humidity (RH) variation did not correlate significantly with overall irritation. However, the dryer climate (i.e., negative or low dew point) had a tendency to induce a higher overall irritation level for both positive and negative controls.

A practical UV source to induce Herpes simplex labialis lesions in the clinic.

BACKGROUND: Ultraviolet (UV) sources have been used to clinically induce herpes simplex lesions in the lips of susceptible individuals. METHODS: This study reports the optimization of a UV source for studies involving multiple clinical laboratory sites and subsequent clinical UV induction of cold sore lesions. We describe novel adaptations of a commercially available broadband UV phototherapy lamp that facilitate determination of individual's minimal erythemal dose (MED) and expose the lips with minimal risk of viral transmission to or between the volunteers and technicians. CLINICAL RESULTS: The source performed well in a clinical setting, with 171 of 386 subjects (44%) developing lesions, an induction rate similar to spectrally similar UV sources. CONCLUSIONS: The advantages of consistent and reproducible exposure geometry, additional UV shielding and biological hygiene achieved by our method significantly enhance the execution of UV-induced herpes simplex labialis studies.

Prevalence and airborne spore levels of Stachybotrys spp. in 200 houses with water incursions in Houston, Texas.

Two hundred homes with a history of water incursion were sampled for fungi to determine the prevalence and airborne spore levels of Stachybotrys spp. Sampling methods included room air, surface, and wall cavity air sampling. Stachybotrys spp. were detected with at least one of the methods in 58.5% of the houses tested, but only 9.6% of the room air samples contained Stachybotrys spores. Aerosolization of Stachybotrys spores was correlated with both wall cavity and surface contamination. However, after adjustment for the surface effect, Stachybotrys spores detected in wall cavities were not a significant factor contributing to spores detected in room air samples. We conclude that Stachybotrys spp. are commonly found on water-damaged building materials. In addition, the observations made in this study suggest that the impact on the living space air is low if the fungal spores are contained within a wall cavity.