Histological tests

In many instances, monitoring of an ecosystem has been attempted by the sampling of organisms from a particular environment. Another approach has been the introduction of organisms that can be readily recovered. Upon recovery, these organisms can be measured and subjected to a battery of biochemical, physiological, and histological tests. Lower and Kendall (1990) have published a book of these methods for terrestrial systems. 

Implants in the rabbit corneas exhibited no observable inflammatory characteristics over a period of 6 weeks. Compared to other previously tested polymers, the inertness of these polyanhydrides rivals that of the biocompatible poly(hydroxyethyl methacrylate) and ethylene-vinyl acetate copolymer. Histological examination of the removed corneas also revealed the absence of inflammatory cells (21)... 

Viral vaccines present problems of safety testing far more complex than those experienced with bacterial vaccines. With killed viral vaccines the potential hazards are those due to incomplete virus inactivation and the consequent presence of residual live virus in the preparation. The tests used to detect such live virus consist of the inoculation of susceptible tissue cultures and of susceptible animals. The cultures are examined for cytopathic effects and the animals for symptoms of disease and histological evidence of infection at autopsy. This test is of particular importance in inactivated poliomyelitis vaccine, the vaccine being injected intraspinally into monkeys. At autopsy, sections of brain and spinal cord are examined microscopically for the histological lesions indicative of proliferating poliovirus. 

Dermal exposure of male rabbits to unspecified doses of Cellulube 220 (1-4 hours/day, 4-5 days/week for <46 days) did not elicit histological alterations in the testes (Carpenter et al. 1959). Dermal exposure of male and female rabbits to cyclotriphosphazene at doses < 1,000 mg/kg/day for 6 hours/day, 5 days/week, for 21 days did not affect the reproductive organs (Kinkead et al. 1989c, 1990). No other dermal studies examining reproductive effects in animals were located. This NOAEL value for reproductive effects in rabbits acutely exposed to cyclotriphosphazene hydraulic fluid is recorded in Table 2-8. 

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