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.     

A design study for a 'spiral staircase' ionization chamber for the quality control of electron beams

In order to verify that the energies of electron beams used for external beam therapy remain constant, IPEM 81 recommends a constancy check based on the ratio of ionization chamber measurements at two depths along the central axis. Such measurements for a range of electron energies can be a time consuming process. The purpose of this study was to design a device that would use several ion chambers simultaneously to measure electron depth dose curves, and hence the electron energy. A design was developed for a device consisting of ten independent ionization chambers, shaped and arranged in a solid phantom like the steps of a spiral staircase, the axis of the staircase being coincident with the axis of the electron beam. Measurements were carried out to test the design of individual chambers and to optimize the radius of the spiral and both the depth intervals and the lateral spacing between adjacent chambers. For ranges of electron energy from 6-12 MeV and 12-20 MeV the radii of the spirals needed were found to be 36.5 mm and 30.9 mm, the angular separations between edges of the chambers were 52 degrees and 30 degrees and chamber depths were found to be 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 mm and 20, 40, 45, 50, 55, 60, 65, 70, 75, 80 mm, respectively.     

Cytogenetic and loss of heterozygosity studies in ependymomas, pilocytic astrocytomas, and oligodendrogliomas.

Cytogenetic and/or loss of heterozygosity studies were performed on 13 ependymomas, 11 pilocytic astrocytomas, and 18 oligodendrogliomas. Loss of chromosome 22 was the most frequent genetic abnormality among the ependymomas. We found no consistent genetic abnormality in pilocytic astrocytomas. The most common genetic abnormality in oligodendrogliomas was loss of a portion of chromosome 19. Each informative oligodendroglioma had loss of alleles mapped to the long arm (q) of chromosome 19. One oligodendroglioma had an apparent homozygous deletion of the D19S8 locus. Our results, when combined with those in the literature, indicate that chromosomes 9, 11, and 22 may harbor genes important for the pathogenesis of ependymomas and that 19q probably harbors a gene important for the pathogenesis of oligodendrogliomas.     

Female phenotype and multiple abnormalities in sibs with a Y chromosome and partial X chromosome duplication: H--Y antigen and Xg blood group findings.

A mentally retarded female child with multiple congenital abnormalities had an abnormal X chromosome and a Y chromosome; the karyotype was interpreted as 46,dup(X)(p21 leads to pter)Y. Prenatal chromosome studies in a later pregnancy indicated the same chromosomal abnormality in the fetus. The fetus and proband had normal female genitalia and ovarian tissue. H--Y antigen was virtually absent in both sibs, a finding consistent with the view that testis-determining genes of the Y chromosome may be suppressed by regulatory elements of the X. The abnormal X chromosome was present in the mother, the maternal grandmother, and a female sib: all were phenotypically normal and showed the karyotype 46,Xdup(X)(p21 leads to pter) with non-random inactivation of the abnormal X. Anomalous segregation of the Xga allele suggests that the Xg locus was involved in the inactivation process or that crossing-over at meiosis occurred.     

In vitro and in vivo immunolabeling of sporozoites,schizonts, and sexual stages ofEimeria acervulina andE. tenella by a species-and stage-cross-reactive monoclonal antibody

A cross-reactive monoclonal antibody (mAb), designated 1205, was used to study redistribution, parasitophorous vacuole (PV) incorporation, and in situ antigen production during the intracellular parasite development ofEimeria acervulina andE. tenella. Western-blot analysis of sporozoite preparations showed that the mAb recognized antigenic bands at 55 and 80 kDa. Indirect immunofluorescent antibody (IFA) labeling of sporozoites produced an internal dot pattern. Immunogold electron microscopy (IM) showed labeling of dense granules within sporozoites. The IFA pattern changed to a general-internal label in immature schizonts followed by a surface-tip pattern in mature merozoites both in vitro and in vivo. IM of the asexual stages revealed the same labeling pattern for the in vivo development of both species, and labeling of rhoptries was seen. In vitro, the PV membrane together with amorphous material within the PV was labeled by IFA during schizont development forE. tenella. No IM labeling of either the PV membrane or material within the PV was observed. Sexual stages seen in vivo for both species had the general-internal IFA pattern.     

Phase I and pharmacokinetic study of tiazofurin (TCAR,NSC 286193) administered by continuous infusion

Summary Tiazofurin (2--D-ribofuranosylthiazole-4-carboxamide, TCAR) is a synthetic C-nucleoside that demonstrated significant in vivo activity against a variety of animal tumors as well as in vitro activity against human tumor-derived cell lines. Thirteen patients were treated with TCAR administered as a 5-day continuous infusion in this Phase I trial. Seventeen complete cycles were administered in three dose levels ranging from 550 to 1450 mg/M². Dose-limiting toxicities were myelosuppression and neurotoxicity including severe lethargy. Other toxicities including superficial skin peeling, myalgias, and tearing were seen at all doses. One patient had chest pain on day 4 resulting in stopping the drug, however, there was no evidence of cardiac or pericardial disease. Uric acid levels rose within one day in the absence of allopurinol treatment. There were no treatment related deaths. HPLC measurement of drug levels demonstrated steady-state plasma levels during the infusion, and a half-life following the infusion of 7.7 ± 0.6 hours. Minor abnormalities in renal function were associated with dramatic changes in pharmacokinetics and toxicity. No clinical responses were observed in this trial.Abbreviations TCAR Tiazofurin - HPLC High performance liquid chromatography - IMPD Inosine monophosphate dehydrogenase - WBC white blood cell - CPK creatine phosphokinase - C_ss steady-state concentration     

Osteopetrosis: MR characteristics at 1.5 T

Four patients with proved osteopetrosis (three with the infantile malignant form and one with the benign form) were examined with magnetic resonance imaging at 1.5 T. All patients were studied in the coronal and sagittal planes using both short and long repetition time/echo time sequences. The infantile malignant form was characterized by a complete lack of signal from the marrow alternating with a signal intensity equivalent to that of the intervertebral disks, resulting in a "stepladder" appearance. In the benign form or after successful marrow transplantation in the infantile malignant form, intermediate or high signal intensity in the vertebrae was noted, suggesting the presence of some marrow elements.