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Hermansky-Pudlak syndrome is an autosomal recessive disease characterized by pigment dilution and prolonged bleeding time. At least 15 mutant mouse strains have been classified as models of Hermansky-Pudlak syndrome. Some of the genes are implicated in intracellular vesicle trafficking: budding, targeting, and secretion. Many of the Hermansky-Pudlak syndrome genes remain uncharacterized and their functions are unknown. Clues to the functions of these genes can be found by analyzing the physiologic and cellular phenotypes. Here we have examined the morphology of the melanosomes in the skin of 10 of the mutant mouse Hermansky-Pudlak syndrome strains by transmission electron microscopy. We demonstrate that the morphologies reflect inhibition of organelle maturation or transfer. The Hermansky-Pudlak syndrome strains are classified into morphologic groups characterized by the step at which melanosome biogenesis or transfer to keratinocytes is inhibited, with the cappuccino strain observed to be blocked at the earliest step and gunmetal blocked at the latest step. We show that all Hermansky-Pudlak syndrome mutant strains except gunmetal have an increase in unpigmented or hypopigmented immature melanosomal forms, leading to the hypopigmented coat colors seen in these strains. In contrast, the hypopigmentation seen in the gunmetal strain is due to the retention of melanosomes in melanocytes, and inefficient transfer into keratinocytes.

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Concentration, distribution, probable sources, and health risks of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in 52 soil samples collected within a radius 50 km from Isfahan metropolis center. Total concentration of PAHs ranged from 57.70 to 11,730.08 μg/kg averaging 2,000.56 μg/kg. Spatial PAH profiles were site-specific and higher concentration of PAHs was observed in the vicinity of industrial zones within Isfahan metropolis. The molecular indices, ring classes, and principal component analysis indicated that the sources of PAHs were both geogenic and pyrogenic. The incremental lifetime cancer risks of exposure to soil PAHs for adults and children living in the study area were 2.3×10(-2) and 2.2×10(-3), respectively. The results suggest that current PAHs levels in Isfahan metropolis soil are highly carcinogenic and may hold a serious health risk for local resident.