A novel approach using transcomplementing adenoviral vectors for gene therapy of adrenocortical cancer.

Current therapies for adrenocortical carcinomas do not improve the life expectancy of patients. In this study, we tested whether a gene-transfer therapy based upon a suicide gene/prodrug system would be effective in an animal model of the disease. We employed E4- and E1A/B-depleted, herpes simplex virus-thymidine kinase-expressing adenoviral mutants that transcomplement each other within tumor cells, hereby improving transgene delivery and efficacy by viral replication in situ. Transcomplementation of vectors increased the fraction of transduced of tumor cells. This increase was accompanied by greater tumor volume reduction compared to non-transcomplementing approaches. Survival time improved with non-replicating vectors plus GCV compared to controls. However, transcomplementation/replication of vectors led to a further significant increment in anti-tumor activity and survival time (p < 0.02). In treated animals, we observed a high number of apoptotic nuclei both adjacent to and distant from injection sites and sites of viral oncolysis. Ultrastructural analyses exhibited nuclear inclusion bodies characteristic of virus production in situ, and provided further evidence that this therapy induced apoptotic cell death within tumor cells. We conclude that the efficacy of suicide gene therapy is significantly amplified by viral replication and, in combination with GCV, significantly reduces tumor burden and increases survival time.     

The brain glutamate system in liver failure

Liver failure results in significant alterations of the brain glutamate system. Ammonia and the astrocyte play major roles in such alterations, which affect several components of the brain glutamate system, namely its synthesis, intercellular transport (uptake and release), and function. In addition to the neurological symptoms of hepatic encephalopathy, modified glutamatergic regulation may contribute to other cerebral complications of liver failure, such as brain edema, intracranial hypertension and changes in cerebral blood flow. A better understanding of the cause and precise nature of the alterations of the brain glutamate system in liver failure could lead to new therapeutic avenues for the cerebral complications of liver disease.     

Identification and molecular characterisation of a fibrinogen binding protein from <Emphasis Type="Italic">Streptococcus iniae</Emphasis>.

Background  

Binding of serum components by surface M-related proteins, encoded by the emm genes, in streptococci constitutes a major virulence factor in this important group of organisms. The present study demonstrates fibrinogen binding by S. iniae, a Lancefield non-typeable pathogen causing devastating fish losses in the aquaculture industry and an opportunistic pathogen of humans, and identifies the proteins involved and their encoding genes.     

Variations in airborne pollen in central and south-western Spain in relation to the distribution of potential sources

The present study seeks to compare daily and hourly airborne pollen concentrations at eight different stations in Castilla-La Mancha (central Spain) and Extremadura (south-western Spain) and assess pollen distribution sources. Sampling stations were located 69–440 km apart in a straight line in Albacete, Toledo, Talavera de la Reina and Ciudad Real in Castilla-La Mancha, and in Badajoz, Plasencia, Santa Amalia and Zafra in Extremadura. Airborne pollen was collected using Hirst-type volumetric spore traps. Quercus was the most abundant pollen type at all stations except for Ciudad Real, where Olea pollen predominated. Comparisons of daily data between pairs of stations revealed statistically significant positive correlations in all cases for Poaceae and Olea. Comparisons of hourly data between stations indicated greater differences than daily data. Analysis of correlation coefficients and straight-line distances between stations revealed a strong negative correlation. Analysis of total airborne pollen data for the eight sampling stations suggests that airborne pollen concentrations decrease from west to east and from south to north, partly reflecting dominant wind patterns. A clear correlation was observed between airborne pollen concentrations and the surface area covered by olive crops in a 50 km radius around the sampling stations.     

Practical considerations for pharmaceutical antibody production in different crop systems

The potential of plant cells to produce functional recombinantantibodies has been demonstrated in a number of different plant systems. Wepresent a comparative study of a well-defined target protein, a single chain Fvantibody, in different transgenic crop species and cultured tissues. The effectof different regulatory elements and signals for subcellular targeting areconsidered. Practical considerations for the choice of a particular cropsystem,such as yield, storage, distribution and containment properties are discussed.     

Kinetics of messenger accumulation coding for IFN gamma, related to modifications in the poly(A) RNA population of activated human lymphocytes.

Exposure of human lymphocytes to a mitogen induces the appearance of newly synthesized RNAs and proteins. This study describes the changes in overall synthesis as measured by pulse labelling of PHA treated lymphocytes as well as a qualitative analysis of the protein synthetic patterns "in vivo" and "in vitro". Both the levels of RNA and protein synthesis increase drastically in PHA stimulated cells, while cultures incubated without mitogen remained at background levels. The low translational activity in control cells is not due to the absence of messengers since the extracted RNAs clearly direct the synthesis of high molecular weight proteins when translated "in vitro". A number of qualitative differences are seen in the "in vitro" translation of RNA extracted from induced and non-induced lymphocytes, although the apparent protein synthetic pattern "in vivo" remains identical. The secretion of IFN- gamma is one of the newly expressed functions in stimulated lymphocytes and therefore has been studied more detailed in a time-course of the messenger level compared to the secreted activity of the medium. A specific probe was used to quantitate in Northern blot's the accumulation of mRNA coding for IFN- gamma.     

Evolution at the tip and base of the X chromosome in an African population of Drosophila melanogaster

Hitchhiking effects of advantageous mutations have been invoked to explain reduced polymorphism in regions of low crossing-over in Drosophila. Besides reducing DNA heterozygosity, hitchhiking effects should produce strong linkage disequilibrium and a frequency spectrum skewed toward an excess of rare polymorphisms (compared to the neutral expectation). We measured DNA polymorphism in a Zimbabwe population of D. melanogaster at three loci, yellow, achaete, and suppressor of forked, located in regions of reduced crossing-over. Similar to previously published surveys of these genomic regions in other populations, we observed low levels of nucleotide variability. However, the frequency spectrum was compatible with a neutral model, and there was abundant evidence for recombination in the history of the yellow and ac genes. Thus, some aspects of the data cannot be accounted for by a simple hitchhiking model. An alternative hypothesis, background selection, might be compatible with the observed patterns of linkage disequilibrium and the frequency spectrum. However, this model cannot account for the observed reduction in nucleotide heterozygosity. Thus, there is currently no satisfactory theoretical model for the data from the tip and base of the X chromosome in D. melanogaster.      

Natural killer cells in meningiomas.

A monoclonal antibody against the surface marker IOT-10 of natural killer (NK) cells was used to investigate the presence of these cells in a series of twenty intracranial meningiomas. In all of these tumours, IOT-10 positive NK cells were found in small numbers, mainly distributed among the tumor cells. Two recurrent tumors showed a relatively high number of immunostained cells. The data obtained in the present study suggest that a NK-cell-mediated immunological response can occur in meningioma tissue.     

Phylogenetic relationships inSecale (Poaceae): An isozymatic study

The genetic frequencies of 9 isozyme loci have been estimated in 23 samples of 4 species ofSecale by means of starch gel electrophoresis. The populations ofS. silvestre andS. vavilovii were monomorphic and uniform within each species, those ofS. montanum andS. cereale were polymorphic for most of the isozyme loci. On the basis of isozyme patterns as well as allelic and genotypic frequencies of isozyme loci,S. silvestre can be distinguished fromS. vavilovii, and both fromS. cereale andS. montanum; but there is no clear differentiation between the two latter species. Clusters constructed from genetic distances separateS. silvestre andS. vavilovii, whereasS. cereale andS. montanum were grouped together. The isozymatic data presented here, along with cytogenetic and life habit data, agree with the generally admitted existence of 4 species inSecale, and support the relationships suggested byKhush & Stebbins (1961).