[Indole cleavage with mebhydroline by sodium periodate--part 2. Mechanism of the dilactam formation]. / Indolspaltung bei Mebhydrolin durch Natriumperiodat-- 2. Mitt. Mechanismus der Dilactam-Bildung.

The gamma-carbolines 1a-d reacted with periodate by loss of one carbon--without available precursors to the eight-membered dilactams 3a-c and the amino acid 9d. As possible intermediates of an indole cleavage alpha-aminoketones as models were examined. While the oxidation of chain-formed 13 afforded only a small amount of C-lost amide 23, the cyclic species 24 and 32 gave rise to considerably higher yields of the corresponding lactams 29 and 36. From the benzazepinone 32 with Hg(II)-EDTA the intermediate product 43, containing all genuine C-atoms, was formed, which could quantitatively cleaved by periodate to the lactam 36 and formic acid. This mechanism can be transferred to the reactions of the gamma-carbolines 1a-d.

Morphometric parameters of peripheral nerves in calves correlated with conduction velocity.

BACKGROUND: Peripheral nerve injuries are the most frequent neurologic disorder in cattle. So far, no physiologic values have been established for the motor nerve conduction velocity (mNCV) in this precocial species. OBJECTIVES: The electrophysiologic and morphometric reference values of peripheral nerves in calves were determined. It was hypothesized that these parameters would correlate to the high degree of maturity in the first days of life in this species compared to other species. ANIMALS: Twenty-six healthy calves were used in this study. METHODS: The mNCV of the radial and the sciatic/common peroneal nerve was measured in all 26 calves. Nerve biopsies from a group of 6 calves were taken to correlate the obtained electrophysiologic data with morphological parameters. RESULTS: The mean mNCV of the radial nerve was 48.3 ± 10.6 m/s, whereas the mean mNCV of the sciatic/peroneal nerve was with 83.8 ± 5.9 m/s significantly faster (P < .0001). The average fiber diameter was 8.40 ± 2.80 µm (range, 1.98-17.90 µm) and the average g-ratio was 0.61 ± 0.04 SD. CONCLUSION AND CLINICAL IMPORTANCE: The established reference values for mNCV in calves correlate well with the evaluated morphometric parameters. Attributable to their comparably fast mNCV and high fiber diameters, juvenile calves appear to be much more mature individuals than other mammals. Electrophysiologic characterization of peripheral nerve injury now is feasible in this species.