Fascin,an actin-bundling protein,modulates colonic epithelial cell invasiveness and differentiation in vitro

In epithelial tissue, cell-matrix and cell-cell adhesive interactions have important roles in the normal organization and stabilization of the cell layer. The malignant conversion of epithelial cells involves alterations in the expression and function of these adhesion systems that enable a switch to a migratory phenotype in tumor invasion and metastasis. Fascin is an actin-crosslinking protein that is found in the core actin bundles of cell-surface spikes and projections that are implicated in cell motility. We demonstrate that fascin is not detectable in normal colonic epithelium, but is dramatically up-regulated in colorectal adenocarcinoma. To test the hypothesis that fascin could participate in tumor invasive behavior, we developed a cell culture model to examine the effect of fascin expression on the adhesive interactions, invasiveness, and differentiation of colonic epithelial cells. We report marked effects on the organization of cell-surface protrusions, actin cytoskeleton, and focal adhesions in the absence of alterations in the protein levels of the major components of these structures. These effects correlate with alterations in cell movements on two-dimensional matrix, and increased invasiveness in three-dimensional matrix. The cells also show increased proliferation and decreased capacity for normal glandular differentiation in collagen gels. We propose that up-regulation of fascin, by promoting the formation of protrusive, actin-based, cell-motility structures, could be a significant component in the acquisition of invasive phenotype in colonic carcinoma.     

Culicoides mohave (Diptera: Ceratopogonidae): new occurrence records and potential role in transmission of hemorrhagic disease

Biting midges of the genus Culicoides are important in the transmission of viral diseases affecting wild and domestic ungulates, including bluetongue (BLU) and epizootic hemorrhagic disease (EHD). The primary known vector for these viruses is C. sonorensis Wirth & Jones, however, it has been speculated that other species of Culicoides may also be involved. One potential candidate is C. mohave, a poorly studied species found in inland desert areas of the southwestern United States. In 2000 and 2001, we collected C. mohave and C. sonorensis at six sites in a previously unsurveyed area in the Sonoran Desert of southwestern Arizona and used PCR to detect nucleic acids associated with BLU and EHD viruses. C. mohave was abundant at two low-elevation sites on the study area, but uncommon or absent elsewhere. C. sonorensis commonly occurred along with C. mohave at one site, but was much less abundant. All C. mohave pools were negative for BLU viral RNA, however, 35% yielded positive results for EHD. All C. sonorensis were negative for both BLU and EHD. Our results suggest that C. mohave is a potential vector of EHD virus in this area, however additional studies are needed to determine its ability to transmit EHD.     

Activity of the enantiomers of 2-amino-5-phosphono-valeric acid as stereospecific antagonists of excitatory aminoacids

The (+) and (?) enantiomers of 2-amino-5-phosphono-valeric acid have been separated and tested as antagonists of aminoacid excitation of neurones in rat cerebral cortex. The compounds were applied by microiontophoresis. The (?)-isomer was about 8–10 times more active than the racemate in blocking responses to N-methyl-d-aspartate, and was better able to distinguish between N-methyl-d-aspartate and glutamate.The results support the concept of a distinct population of receptors for N-methyl-d-aspartate.     

Anti-proliferative effects of phosphodiester oligodeoxynucleotides

The immunostimulatory effects of cytosine-phosphate-guanosine (CpG)-containing oligodeoxynucleotides (ODNs) have been extensively documented. In this paper, we describe the inhibitory effects of ODNs that contain natural phosphodiester backbones (O-ODNs) on the immunostimulation caused by CpG-containing phosphorothioated ODNs (CpG-S). CpG-S stimulation of mouse splenocyte proliferation was reduced by the addition of O-ODNs that contained or lacked the CpG-motif (CpG-containing phosphodiester oligodeoxynucleotide, CpG-O or GpC-O). The total number of cultured splenocytes was up-regulated by CpG-S, whereas repetitive addition of O-ODNs to the cell cultures inhibited this effect. The frequency of T2-like B cells was found to be increased by CpG-S. The culture supernatants of CpG-S-treated splenocytes contained elevated levels of IL-10 and IL-6. However, IL-10 and IL-6 production was down-regulated significantly by the combination of CpG-S and either CpG-O or GpC-O. The O-ODN mediated inhibition of proliferation was less pronounced in IL-10-/- mice. Thus, the O-ODNs, irrespective of CpG content, exerted inhibitory activities on the proliferation of B cells. These anti-proliferative effects appear to be mediated both by the down-regulation of IL-10 production and increased apoptosis.     

Viruses and virus-like particles detected in samples from diseased game birds in Great Britain during 1988

During 1988, 108 samples were received from game birds (78 from pheasants, 28 from partridges and two from quail) for virus isolation or detection; 89 being received during the June to August rearing period. The most common clinical signs resulting in the submissions were death, scour and stunting. Virus or virus-like particles were detected in 51 cases, 43 as a result of direct electron microscopy of gut contents, seven by agar gel precipitin test for the presence of Marble spleen disease antigen and one by isolation, of a rotavirus. Particles observed by electron microscopy were: rotavirus - 15, adenovirus - 1, reovirus - 1, enterovirus - 1, 'fimbriated' virus-like particles - 10, rod-shaped virus-like particles - 19, On three occasions more than one type of particle was seen in the same sample.     

Functional evidence of decreased tumorigenicity associated with monochromosome transfer of chromosome 14 in esophageal cancer and the mapping of tumor-suppressive regions to 14q32

Despite the abundant evidence of high allelic loss of chromosome arm 14q in human cancers, tumor-suppressor genes mapped to this chromosome have yet to be identified. To narrow the search for candidate genes, we performed monochromosome transfer of chromosome 14 into an esophageal carcinoma cell line, SLMT-1 S1. Statistically significant suppression of the tumorigenic potential of microcell hybrids containing the transferred chromosome 14 provided functional evidence that tumor-suppressive regions of chromosome 14 are essential for esophageal cancer. Tumor segregants emerging in nude mice during the tumorigenicity assay were analyzed by detailed PCR-microsatellite typing to identify critical nonrandomly eliminated regions (CRs). A 680-kb CR mapped to 14q32.13 and an approximately 2.2-Mb CR mapped to 14q32.33 were delineated. Dual-color BAC FISH analysis of microcell hybrids and tumor segregants verified the selective loss of the 14q32.13 region. In contrast, similar transfers of an intact chromosome 11 into SLMT-1 S1 did not significantly suppress tumor formation. These functional complementation studies showing the correlation of tumorigenic potential with critical regions of chromosome 14 validated the importance of the 14q32 region in tumor suppression in esophageal cancer. The present study also paved the path for further identification of novel tumor-suppressor genes that are relevant to the molecular pathogenesis of esophageal cancer.     

Characterisation of avian paramyxoviruses of serotype PMV-3 isolated from commercial turkeys in Great Britain

Avian paramyxoviruses isolated from turkeys in 1981 and 1982 were shown by haemagglutination inhibition tests and structural polypeptide analysis to be similar viruses of PMV-3 serotype but more closely related to PMV-3/turkey/Wisconsin/68 than to PMV-3/parakeet/Netherlands/ 449/75 or PMV-3/parakeet/England/l-83/82.     

Combined segregation and linkage analysis of inflammatory bowel disease in the IBD1 region using severity to characterise Crohn's disease and ulcerative colitis. On behalf of the GISC

Inflammatory bowel disease (IBD) is a chronic relapsing disorder affecting the gastro-intestinal tract and is subdivided into two main subtypes: Crohn's disease (CD) and ulcerative colitis (UC). Although the aetiology of IBD is unknown, a strong genetic susceptibility is suggested and different candidate regions have been identified for both CD and UC. The IBD1 region on chromosome 16 has been confirmed to be important for susceptibility to CD, whereas conflicting evidence has been obtained for UC. We performed a combined linkage and segregation analysis in the identified IBD1 region on a sample of 82 extended families with IBD using a parametric method implemented in the computer program COMDS. This approach allows simultaneous evaluation of linkage while estimating the mode of inheritance and to include severity of the trait to characterise the CD and UC phenotypes. Our results are consistent with the presence of a major gene in the IBD1 region close to D16S408 involved in both UC and CD. Furthermore, our data support evidence that a single mutation in the gene leads more frequently to UC, whereas inheritance of two mutant alleles results in the more severe CD. In our study the IBD1 locus was found to have a major role in IBD predisposition in the Italian population.     

Immunohistochemistry of a spontaneous murine ovarian teratoma with neuroepithelial differentiation. Neuron-associated beta-tubulin as a marker for primitive neuroepithelium

Spontaneous ovarian teratomas develop in a large proportion of female LT strain mice. These tumors display a large neuroectodermal component with morphologic differentiation ranging from primitive neuroepithelium (medulloepithelial and ependymoblastic rosettes) to mature neurons, and provide a useful system for the study of various asynchronous stages of neuroepithelial differentiation. The aim of this study was to assess the expression of various cytoskeletal proteins in conjunction with other differentiation-related antigens in these tumors. We found that the medulloepithelial rosettes reacted with only two anti-beta-tubulin monoclonal antibodies. One of these (TU27) recognizes an epitope common to all of the mammalian beta-tubulin isotypes. The other monoclonal antibody (TUJ1) recognizes an epitope unique to class III beta-tubulin isotypes (neuronal-associated). Whereas immunoreactivity in the ependymoblastic rosettes was limited to TU27, differentiating polar neuroblasts reacted with both TU27 and TUJ1 and expressed neuron-specific enolase, synaptophysin, and the 68 kilodalton subunit of neurofilament protein. In well-differentiated foci, mature neurons were positive for all three neurofilament protein subunits (68, 168 and 200 kilodaltons), microtubule-associated-protein 2, synaptophysin, and neuron-specific-enolase, and reacted with both TU27 and TUJ1. By contrast, glial elements expressed glial fibrillary acidic and S-100 proteins, Leu-7 and TU27 but not TUJ1. Myelin basic protein and myelin-associated glycoprotein reactivity was found in the neuropile of these mature areas. The neuroepithelial components were negative for retinal S-antigen and cytokeratin. The expression of the class III beta-tubulin isotype by medulloepithelial rosettes suggests that this isotype may be one of the earliest markers to signal neuronal commitment in primitive neuroepithelium.     

Circumsporozoite protein of the human malaria parasite Plasmodium ovale identified with monoclonal antibodies.

Monoclonal antibodies (MAbs) have been produced against Plasmodium ovale sporozoites and used to characterize the circumsporozoite (CS) protein. Six MAbs were produced, and all were species specific. By using Western blot (immunoblot) analysis, three polypeptides were detected: a predominant 51,000-Mr polypeptide and two presumed precursor 57,000- and 67,000-Mr molecules. The presence of a repeating epitope in the CS protein of P. ovale was demonstrated by using one of the MAbs in a single-antibody two-site enzyme immunoassay. Three MAbs recognized epitopes on the surfaces of sporozoites; the presence of at least one other epitope within the CS protein, but not on the surfaces of P. ovale sporozoites, was also demonstrated.