Frequency and Nature of Spontaneous Age-Related Eye Lesions Observed in a 2-Year Inhalation Toxicity Study in Rats

Abstract

A group of 160 Wistar rats (both sexes) from a larger chronic inhalation toxicity study was monitored at baseline and after 1 and 2 years with a photo-slitlamp microscope and a direct ophthalmoscope to record spontaneous age-related eye lesions and treatment-related eye lesions over a period of 24 months. A second group from the same study was monitored at the start and after 5 months of a 6-month posttreatment period immediately following the inhalation period. Rats were nose-only exposed for 6 h/day, 7 days/week, for 2 years to low (3 µg/l) or high (10 µg/l) total particulate matter concentrations of room-aged cigarette sidestream smoke (RASS) or diesel engine exhaust (DEE). Control animals were exposed to filtered fresh air. All ophthalmological examinations were performed in mydriasis, and relevant observations were documented on color slide film. At baseline, all animals with eye lesions were excluded from the study. After 1 year, only minor lesions were found: retrolental opacities (14%) and a few cases of corneal dryness with reddish lid margins. After 2 years, 23% of the animals had unilateral or bilateral retrolental opacities, but the most frequent eye lesions were posterior subcapsular cataracts (PSC, 32%). Water clefts and spokes were found in 11% of the lenses and mature cataracts in 6%. All other eye lesions observed were much less frequent. There were a few cases of glaucoma, corneal dryness and stromal neovascularization. The frequency and type of lesion in animals monitored from the start of the posttreatment period was comparable to what was seen after 2 years. Toward the end of this period the frequency of mature cataracts went up to 9% and that of (secondary) glaucomas to 5%. None of the eye lesions observed showed any association in frequency or severity of expression to the treatment, either RASS or DEE, or to the sex of the animals. In comparison to the (limited) literature data available, far fewer corneal lesions were found in this study, but PSCs and mature cataracts were more frequent. Strain differences may influence these parameters. This study provided valuable information on the nature and frequency of spontaneous age-related eye lesions (0–56%, depending on the tissue) in long-term toxicity studies in Wistar rats.

Prevalence and Risk Factors of Asthma among Adolescents and Their Parents in Al-Ain (United Arab Emirates)

“…increased exposure to pollen due to anti-desertification projects). So far, family history and sensitization to house-dust mites, pollen and other airborne allergens [15,16,17] have been identified as possible risk factors for asthma. Interestingly, a high prevalence of vitamin D deficiency in women, reportedly related to asthma in offspring [18,19], has also been found among Emirati women of child-bearing age [20].…”

Diesel Exhaust Particles Selectively Induce Both Proinflammatory Cytokines and Mucin Production in Cornea and Conjunctiva Human Cell Lines

“…[7][8][9][10] However, few studies have shown the effects of DEP on the ocular mucosa. [11][12][13] Inhabitants of cities are exposed to high levels of air pollutants, including DEP, and often present irritation, burning, foreign body sensation, hyperemia, and itching in the eye. 14 They also show a reduced time of rupture of the tear film and slight damage to the surface layer of the cornea.…”

Date Palm Pollen Allergoid: Characterization of Its Chemical-Physical and Immunological Properties

“…Pollen from members of the Arecaceae (Palmaceae), in particular the date palm ( P. dactylifera L.), can cause allergic symptoms, especially among people living in Middle Eastern, North African and some Mediterranean countries, as well as in India [1,2,3,4,5,6,7,8,9,10,11]. Previous papers evidenced the presence of several allergens in DP pollen extract, the more clinically relevant being those at 14, 25, 28–30, 37–40, 55–70 and 90–100 kDa [12, 16, 17].…”

“…The importance of date palm (DP, Phoenix dactylifera ) pollen and pollen from other members of the palm family as potent inhalant allergens has been reported from different areas of the world where these palms grow [1,2,3,4,5,6,7,8,9,10,11]. The intense influx of immigration from these countries to Italy where there is an abundance of autochthonous palm tree species, such as the European fan palm (EFP, Chamaerops humilis ), could in the near future increase the risk for sensitized migrating people of developing allergic symptoms.…”

“…According to recent estimates, the prevalence of palm pollen allergy ranges from 13% in the United Arab Emirates to over 44% in India and Saudi Arabia [3, 9, 10]. The existence of date palm cultivars which are differentially allergenic can create problems [12,13,14], making it difficult to devise precise in vitro and in vivo diagnosis, a factor which in turn creates gross underestimates of the real incidence of this kind of allergy [15].…”