In vivo effects of sera from Guillain-Barré subgroups: an electrophysiological and histological study on rat nerves.

Serum from 20 patients with Guillain-Barré syndrome (GBS), 10 healthy controls and 10 patients with recent cytomegalovirus, Epstein-Barr virus, or Campylobacter jejuni/coli infections was injected into rat sciatic nerve. The 20 GBS patients consisted of 2 groups of 10 patients with different electrophysiological and clinical disease patterns. The main aim of the study was to investigate possible differences in humoral (auto)-immunity between these subgroups. We found no statistically significant differences in electrophysiological or histological parameters between nerves injected with sera from the 2 GBS groups. The sera of the GBS groups caused significantly more compound muscle action potential reduction at 3 to 5 days postinjection than the healthy control sera. No significant difference in nerve conduction was found between nerves injected with GBS serum and serum of patients with proven infections without GBS. Histological analysis of the same nerves that were studied electrophysiologically showed no significant differences in demyelination or other histological parameters between patients and controls at 5 days postinjection. Based on the findings in this study that sera of GBS groups with important differences in disease pattern and sera of patients with proven infection but without GBS show similar in vivo effects on rat nerves, we suggest it may be more likely that these effects are caused by aspecific serum factors associated with immune-system activation, especially by precedent infections, than by specific disease-related factors such as anti-myelin antibodies.

The shifting of the aortic origin of the brachial arteries in the metamorphosing eel Anguilla anguilla (L.), with remarks on the shifting mechanisms in arterial junctions in general.

In silver eels the arteries supplying the pectoral girdles and fins, arise from a common trunk which branches off from the dorsal aspect of the dorsal aorta, while the origin of this trunk is found at the ventral aspect of the aorta in the leptocephalus larva. The rearrangement of the origin of this trunk is mainly accomplished during metamorphosis, and is related to the rearrangement of the junction of the epibranchial arteries and the aorta. The processes of remodelling the wall of the vessels involved in these rearrangements are discussed against the background of data on similar remodelling, accompanying the rearrangement of arterial junctions during the development of higher vertebrates.

Comparison of the growth of the tunica media of the ascending aorta, aortic isthmus and descending aorta in infants and children.

This study concerns the normal histological growth of the aorta in infants and children. We measured, in post mortem material consisting of 69 hearts and great vessels of infants and children who died from non-vascular diseases, the internal diameters of the ascending aorta, aortic isthmus and descending aorta together with the thickness of the tunica media and the packing density of its elastic fibres. Age range was from 27 weeks of gestational age up to 10 years after birth. The growth of the tunica media of the ascending aorta was, in part, different from that of the aortic isthmus and descending aorta. Notwithstanding an increase in the thickness of the tunica media parallelling, in all three parts of the aorta, an increase in their internal diameters, the packing density of the elastic fibres of the tunica media of the aortic isthmus and of the descending aorta showed no tendency to increase with age. However, the packing density of the elastic fibres of the ascending aorta showed a continuing increase with age parallelling the increase of the internal diameter. This can probably be better explained as a result of functional difference than as a result of different embryological origin.