Safety and Efficacy of Single-Stage versus 2-Stage Spinal Fusion via Posterior Instrumentation and Anterior Thoracoscopy: A Retrospective Matched-Pair Cohort Study with 247 Consecutive Patients.

Objective: Posterior-anterior spondylodesis is often used to stabilize the spine in various pathologies. The anterior procedure is often performed via thoracoscopy. It is unclear whether the anterior procedure should be performed immediately after posterior instrumentation or after the patient has convalesced.

The rat as a model to evaluate the gastric irritation potential of alkaline products.

Animal models historically used to assess the acute gastric irritation potential of accidental ingestion of consumer products include the dog, pig, rabbit, and cat. In looking at alternative methods that are of shorter duration and more cost-effective, the rat is being evaluated as a potential model. Acute gastric irritation is known to increase as the reserve alkalinity of the formulation increases.

Spontaneous corneal dystrophy and generalized basement membrane changes in Fischer-344 rats.

Groups of young, sexually mature Fischer-344 rats (n = 25/sex) obtained from commercial breeders were examined ophthalmologically and histopathologically to determine the prevalence and severity of corneal basement membrane lesions (corneal dystrophy) and basement membrane changes in select nonocular tissues. Results disclosed a high incidence of corneal basement membrane dystrophy in rats of both sexes from all breeders; however, severity levels were significantly increased in rats obtained from one breeder when compared to others. Furthermore, rats that displayed the most advanced corneal lesions also exhibited more severe basement membrane changes in other organs, especially renal tubules and vascular internal laminae.

Comparison of the up-and-down method and the fixed-dose procedure for acute oral toxicity testing.

The acute oral toxicity data for 10 compounds, generated by using two alternative methods in rats, the up-and-down method and the fixed-dose procedure, were compared with those obtained from the classical LD50 test. In this evaluation, both alternative methods offered a reduction in animal use, while providing adequate information to rank the compounds according to the EEC classification for acute oral toxicity. In addition to the ranking, these alternative methods also provided useful information on signs of toxicity and gross autopsy findings, although the results varied depending on the method used.

Human and rabbit eye responses to chemical insult.

Groups of eight human volunteers and eight albino rabbits, under controlled laboratory conditions, were exposed in one eye without subsequent rinsing to the same concentrations and volumes of four prototype consumer products: fabric softener, shampoo, hand soap, and laundry detergent. Dose volume was 0.10 or 0.