Which authorities are alike?

This article describes the first results from the recent revision to The ONS classification of local and health authorities of Great Britain to allow for boundary changes. For each local and health authority of Great Britain as at April 1999 it presents 'most similar' authorities as measured by a selection of 37 socioeconomic and demographic variables from the 1991 Census. These results will assist local and health authorities in identifying other appropriate authorities for comparative studies. A second article, to be published in Population Trends 99, will present the results of the analysis to identify groups of authorities in a hierarchy of new Clusters, Groups and Families for the revised classification.     

Evolution of the genetic code, protein synthesis and nucleic acid replication

A better definition of the structural and thermodynamic determinants of the interaction of nucleic acids with proteins is shedding light on the origin of the genetic code, protein synthesis, and nucleic acid replication. This is also allowing to show a consistent biochemical framework for the appearance of these fundamental synthetic mechanisms. This article reviews recent significant developments in the field, and discusses an integrated model for a biochemically plausible evolution of these fundamental mechanisms of synthesis. This model is based on sequence-specific interactions between abiotically synthesized polynucleotides and polypeptides, and can account for a coordinate evolution of the genetic code, protein synthesis, and nucleic acid replication in living cells.     

Kinesin-II, the heteromeric kinesin

The kinesins constitute a large family of motor proteins which are responsible for the distribution of numerous organelles, vesicles and macromolecular complexes throughout the cell. One class of these molecular motors, kinesin-II, is unique in that these proteins are typically found as heterotrimeric complexes containing two different, though related, kinesin-like motor subunits, and a single nonmotor subunit. The heteromeric nature of these kinesins appears to have resulted in a class of combinatorial kinesins which can 'mix and match' different motor subunits. Another novel feature of these motors is that the activities of several kinesin-II representatives are essential in the assembly of motile and nonmotile cilia, a role not attributed to any other kinesin. This review presents a brief overview of the structure and biological functions of kinesin-II, the heteromeric kinesin.     

Immune responses to DNA vaccines

DNA vaccines, based on plasmid vectors expressing an antigen under the control of a strong promoter, have been shown to induce protective immune responses to a number of pathogens, including viruses, bacteria and parasites. They have also displayed efficacy in treatment or prevention of cancer, allergic diseases and autoimmunity. Immunologically, DNA vaccines induce a full spectrum of immune responses that include cytolytic T cells, T helper cells and antibodies. The immune response to DNA vaccines can be enhanced by genetic engineering of the antigen to facilitate its presentation to B and T cells. Furthermore, the immune response can be modulated by genetic adjuvants in the form of vectors expressing biologically active determinants or by more traditional adjuvants that facilitate uptake of DNA into cells. The ease of genetic manipulation of DNA vaccines invites their use not only as vaccines but also as research tools for immunologists and microbiologists. Received 26 October 1998; received after revision 3 December 1998; accepted 3 December 1998     

The pleiotropic functions of aspirin: mechanisms of action

Recent studies have suggested that aspirin and aspirin-like compounds have a variety of actions in addition to their well-studied ability to inhibit cyclooxygenases. These actions include inhibition of the uncoupling of oxidative phosphorylation, decreases in adenosine triphosphate stores, increases in extracellular adenosine, downregulation of the expression and activity of inducible nitric oxide synthetase, inhibition and/or stimulation of various mitogen-activated protein kinase activities and inhibition of nuclear factor binding κB site (NF-κB) activation. Moreover, aspirin-like compounds have recently been shown to have previously unappreciated clinical and biological effects, some apparently independent of cyclooxygenase. In this review we discuss the various mechanisms of action of aspirin-like compounds and their relevance to clinical disease and therapy. Received 1 February 1999; received after revision 1 April 1999; accepted 7 May 1999     

Ventral neural tube cells differentiate into hepatocytes in the chick embryo

A population of ventral neural tube cells has recently been shown to migrate out of the hind brain neural tube via the vagus nerve and contribute to the developing gastrointestinal tract. Since liver is also innervated by the vagus nerve, we sought to determine if these cells also migrate into the liver. Ventral neural tube cells in the caudal hindbrain of chick embryos were tagged with a replication-deficient retroviral vector containing the LacZ gene on embryonic day 2. Embryos were processed for detection of labeled cells on embryonic day 5 and 11. Labeled cells were seen in the liver on both days and identified as hepatocytes. Previously, it was believed that all hepatocytes develop from the gut endoderm. Results of the present study show an additional source for the formation of liver cells. Received 25 August 1998; received after revision 5 November 1998; accepted 5 November 1998