Capillary electrophoresis: the promise and the practice.

The field of capillary electrophoresis has undergone rapid development over the past 10 years. Many advances have been made, but there are still some problems that must be addressed before the technique can reach its full potential.     

Immunospecific inhibition of nerve conduction by T lymphocytes reactive to basic protein of myelin

Experimental autoimmune encephalomyelitis (EAE) induced by immunization to the basic protein of central nervous system myelin (BP) is a paralytic disease in which T lymphocytes attack the individual's own central nervous system. As the target is in white matter, EAE has been considered an experimental model of some aspects of human disease such as multiple sclerosis. To investigate whether autoimmune T lymphocytes could produce paralysis, we studied the effects on the electrophysiology of isolated nerves produced by T-lymphocyte lines reactive specifically to BP or other antigens. We now report that propagation of action potentials evoked by electrical stimulation was blocked by incubating optic nerves with specific anti-BP T cells. This blockade could be reversed for up to two hours by removing the anti-BP line cells from the optic nerve. The anti-BP line cells had no effect on conduction along allogeneic optic nerves or syngeneic peripheral nerves. This indicates that disruption of the function of myelin in neuroimmunological disease may result from an immunologically specific interaction between autoimmune T lymphocytes and myelin antigens.     

Septation and fragmentation inOedogonium mitochondria as different and independent effects of dimethyl sulfoxide (DMSO) treatment

Summary Oedogonium cardiacum Wittrock, a filamentous green alga, was treated with DMSO. The substance induced active swelling and fragmentation of mitochondria at both 5 and 7.5%. Septa were observed at 7.5% only and were not identical with the fragmentation sites. Thus it is concluded that internal partition by septa is not a prerequisite for mitochondrial fragmentation or division.Acknowledgment. This work was supported by the Österreichische Nationalbank, Jubiläumsfondsprojekt No. 1927.     

On the use of ordered sets in problems of comparison and consensus of classifications

Ordered set theory provides efficient tools for the problems of comparison and consensus of classifications Here, an overview of results obtained by the ordinal approach is presented Latticial or semilatticial structures of the main sets of classification models are described Many results on partitions are adaptable to dendrograms; many results on n-trees hold in any median semilattice and thus have counterparts on ordered trees and Buneman (phylogenetic) trees For the comparison of classifications, the semimodularity of the ordinal structures involved yields computable least-move metrics based on weighted or unweighted elementary transformations In the unweighted case, these metrics have simple characteristic properties For the consensus of classifications, the constructive, axiomatic, and optimization approaches are considered Natural consensus rules (majoritary, oligarchic, ) have adequate ordinal formalizations A unified presentation of Arrow-like characterization results is given In the cases of n-trees, ordered trees and Buneman trees, the majority rule is a significant example where the three approaches convergeThe authors would like to thank the anonymous referees for helpful suggestions on the first draft of this paper, and W H E Day for his comments and his significant improvements of style     

Viral transduction of c-myc gene in naturally occurring feline leukaemias

Feline leukaemia virus (FeLV) is epidemiologically associated with induction of the majority of lymphoid tumours of the domestic cat. However, about one-third of these tumours are devoid of exogenous virus or show evidence of virus integration only after tumour outgrowth. To help define the genetic mechanisms of feline lymphomagenesis we have explored here the possibility that cellular oncogenes (c-onc genes) are rearranged in tumour cell DNA. Of 16 FeLV-positive T-cell tumours among 31 naturally occurring lymphomas, 2 showed evidence of recombinant FeLV proviruses containing myc oncogene sequences. One of the two produced a transmissible myc-containing FeLV. In both cases c-myc and its surrounding DNA appeared unaltered. We believe that the association of myc with FeLV may result in its activation and play a part in the development of a significant fraction of cat T-cell lymphomas. Our findings contrast with studies of experimental induction of chicken lymphoma, in which myc activation occurs by retrovirus promoter insertion near c-myc (refs 3-5), rather than by incorporation into virus.     

Circadian rhythm of bile secretion in the rat.

In rats the bile flow and the estimated bile acid independant flow (BAIF) were significantly lower at 17.00 h than at 08.00 and 24.00 h. The decrease in BAIF paralleled the decrease in liver weight. Bile acid excretion was not different.     

Structure-dependent,selective localization of chlorinated xenobiotics in the cerebellum and other brain structures

Summary Remarkable regional distribution patterns of some chlorinated xenobiotics in the CNS are described.We thank Dr Åke Bergman, Wallenberg Laboratory, University of Stockholm, Stockholm, for the synthesis of compounds IV and V. The studies were supported by the Swedish Work Environment Fund (grants nos 73/169 and 74/181) and by the Research Committee of the National Swedish Environment Protection Board (grant no. 7-27/79).