Phaeohyphomycosis in a snow leopard (Uncia uncia) due to Cladophialophora bantiana.

Phaeohyphomycosis caused by Cladophialophora bantiana was diagnosed in a 5-month-old snow leopard with spastic paralysis of the hind legs and inability to defaecate or urinate. At post-mortem examination, a greenish soft mass resembling an abscess was found on one side of the epidural space at the fourth lumbar vertebral body. Histological examination revealed a purulent meningitis with myelomalacia. Dematiaceous fungal hyphae, present within the inflammatory infiltrate, were identified as C. bantiana by culture and sequence analysis of the 18S ribosomal RNA gene. This neurotropic fungus rarely affects organs other than the brain in human beings and cats, and has been reported only occasionally in Europe. The case described suggests that phaeohyphomycosis due to C. bantiana infection may be recognized more frequently in the future and the possible involvement of organs other than the brain should be borne in mind.

Alveolar echinococcosis in the zoological garden Basle.

Alveolar echinococcosis (AE) is a rare, but potentially severe zoonotic disease caused by Echinococcus (E.) multilocularis. Recent findings indicated an increasing importance of AE for non-human primates living in regions endemic for E. multilocularis. The death of five cynomolgus monkeys (Macaca fascicularis) and a lowland gorilla (Gorilla g. gorilla) due to AE raised concern about the incidence of this parasite in the Basle Zoo. Consequently, a project was initiated to investigate the prevalence amongst an affected group of cynomolgus monkeys, as well as in foxes and mice. Three out of 46 monkeys were seropositive for E. multilocularis antigen. In two of these monkeys and in another three animals, which were seronegative, structures compatible with metacestodal cysts were observed using ultrasonography. Seven out of 35 free roaming foxes caught at the zoo were positive for an intestinal E. multilocularis copro-antigen ELISA, four of them shed taeniid eggs simultaneously. No lesions compatible with AE were present in 50 necropsied mice from the zoo area. These results indicate that the fox population is a potential source to introduce E. multilocularis and may thus represent a risk for the zoo animals.

Immunohistochemical study of retinol-binding protein in livers of polar bears (Thalarctos maritimus).

Liver tumors of unknown cause have frequently been described in polar bears. Concurrent decrease of vitamin A levels and chronic liver disease are associated with hepatic carcinogenesis in humans. More than 90% of the body's vitamin A is stored in the liver, where it is bound to an intracellular retinol-binding protein (RBP). Therefore, in this retrospective study, RBP was assessed by immunohistochemistry in liver sections of 11 polar bears. Two of these polar bears had hepatocellular carcinoma, four showed other chronic liver changes, and five had normal livers. In normal livers, the cytoplasm stained diffusely positive with intensely staining cytoplasmic granules. RBP staining was evaluated and the abundance of diffuse cytoplasmic staining and intracytoplasmic large granules was determined. All cases with pathologic liver changes had markedly decreased staining intensities for RBP compared with normal livers. The findings of this study suggest that in polar bears, as in humans, vitamin A metabolism may play a role in hepatic carcinogenesis.

New aspects of the tolerance of retinol in humans.

A review is given of the evaluation of 517 cases of acute vitamin A intoxication and chronic hypervitaminosis A. Whereas acute vitamin A intoxication has lost numerical importance during the past 15 years, chronic hypervitaminosis-A, especially that caused by self-medication, has provoked world-wide discussion concerning the safety of retinol intake. Evaluation of the 132 cases of chronic hypervitaminosis-A showed that approximately one quarter cannot be considered as genuine cases, whereas the rest is divided almost equally between vitamin A prescription and self-medication. A significant positive correlation could be shown between the dose administered and the duration of treatment. Moreover, with comparable doses the symptoms of chronic hypervitaminosis-A appear significantly earlier (by a factor of 6) after emulsified or equivalent preparations than after oily emulsions because of their better absorbability. As soon as the liver vitamin A storage capacity is exhausted, hypervitaminosis-A symptoms appear and the liver vitamin A concentration is at least 10-fold the normal. The calculated vitamin A concentration in the liver of the individual cases of hypervitaminosis-A is highly correlated with the daily intake of vitamin A per kg of body-weight and its duration.