Vorwort

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Abnormal tubulovesicular particles in brains of hamsters with scrapie

Abnormal tubulovesicular particles of an average diameter of 23 nm have been observed in brains of mice with scrapie as well as in other animals with spongiform encephalopathies, but they were thought to be absent from the brains of hamsters with scrapie in which the highest known concentrations of the infectious agent occur. We observed in neuronal processes of hamsters as well as mice clusters of those tubulovesicular structures, most often in postsynaptic terminals. Such particles have now been seen regularly in both experimental and natural scrapie in all species examined as well as in other spongiform encephalopathies.     

Root growth in seedlings of annual pasture species

Summary The mean rate at which roots of 12 annual pasture species penetrated a yellow sand to a depth of 80 to 90 cm varied from 0.8 to 3.2 cm per day.Penetration rate was closely correlated with seed weight until roots reached a depth of about 20 cm. Thereafter rates became progressively less dependent on seed size.Penetration rate varied with time. In six species a minimum rate was reached at a depth of 18 to 24 cm. In two species rhythmic fluctuations in root penetration rate appeared to be associated with the development of new leaves on the shoot.Shading the shoots substantially reduced root penetration rate but the rhythmic fluctuations persisted. These observations are consistent with the hypothesis that the rate of root penetration is determined by the supply of metabolites to the root system.     

Effects of subcutaneous melatonin implants on reproductive seasonality of farmed fallow deer (Dama dama)

A total of 18 fallow does, including pubertal, non-pregnant and pregnant adult does (6 per class), each received a single subcutaneous implant containing 18 mg melatonin on 4 occasions at 29-30-day intervals from 10 November 1986 (approximately 120-day treatment period). A further 18 contemporary does served as herd-mate controls. Two adult fallow bucks were treated the same and were run with the does until 16 March. Thereafter, 1 of 4 control bucks was run with the does until 1 June. Of the 6 pregnant does receiving implants within the last 40 days of their gestation, 4 failed to lactate after parturition in December 1986. The remaining 2 does successfully reared their fawns, as did the 6 contemporary controls. Mean (+/- s.e.m.) dates of first oestrus in 1987 were 27.6 February (+/- 3.0 days) and 22.9 April (+/- 0.8 days) for all treated and all control does respectively (P less than 0.001). Pubertal does were generally later to exhibit first oestrus than were older does within their respective treatment groups. Return oestrus occurred only in 2 pubertal does (1 treated and 1 control) with remaining does conceiving to their first oestrus, as verified by plasma progesterone profiles. However, 5 (28%) of the treated does and 3 (17%) of the control does failed to maintain pregnancy and fawn in 1987. The mean (+/- s.e.m.) 1987 fawning date of the remaining does was 22.4 October (+/- 2.7 days) for the treated group (N = 13) and 13.1 December (+/- 0.8 days) for the control group (N = 15; P less than 0.001). Mean (+/- s.e.m.) gestation length of treated does (238.9 +/- 0.6 days) was significantly longer than that of control does (234.5 +/- 0.4 days; P less than 0.001). Of 13 fawns born to treated does, 4 (31%) died within 24 h of birth (mainly due to hypothermia) whereas all 15 fawns born to control does survived to weaning. Melatonin-treated bucks exhibited a marked advancement of neck muscle hypertrophy during the treatment period and displayed normal rutting activity (e.g. vocalization) in response to early oestrus in the treated does.     

Transverse myelitis following measles vaccination in a rhesus macaque (Macaca mulatta)

A 16-year-old rhesus macaque presented with progressive, ascending quadriparesis following measles vaccination. He was diagnosed with transverse myelitis following MRI, gross necropsy, and histopathology. This is the first report of transverse myelitis in a rhesus macaque following measles vaccination.