Differential expression of metastasis-associated cell surface glycoproteins and mRNA in a murine large cell lymphoma

A metastatic variant cell subline of the Abelson virus-transformed murine large lymphoma/lymphosarcoma RAW117 has been selected in vivo ten times for liver colonization. Highly metastatic subline RAW117-H10 forms greater than 200 times as many gross surface liver tumor nodules as the parental line RAW117-P. Analysis of cellular proteins and glycoproteins indicates reduced expression of murine Moloney leukemia virus-associated p15, p30, and gp70, and increased expression of a sialoglycoprotein, gp150, in the highly metastatic H10 cells. Northern analyses of oncogene expression suggested that mRNA of various oncogenes was expressed equally or not expressed in the RAW117 cells of differing metastatic potential. Differential gene expression was examined using a cDNA library of 17,600 clones established from poly A+ mRNA isolated from H10 cells. The cDNA library was screened by the colony hybridization technique using probes made from both RAW117-P and -H10 cells. Approximately 99.5% of these cDNA clones were expressed identically in P and H10 cells. Of the few differentially expressed cDNA clones (approx. 150/17,600), one-half of these were identified as Moloney leukemia virus sequences in a separate probing with a radiolabeled Moloney leukemia virus probe. The remainder of the differentially expressed mRNA detected by colony hybridization of the cDNA library were expressed at higher levels (approx. 1/6) or lower levels (approx. 1/3) in the highly metastatic H10 cells.     

Proliferation and Teratogenicity of Aino Virus in Chick Embryos

Aino virus (AIV; JaNAr 28 strain) 10³ TCID₅₀/0.2 ml was inoculated in the yolk sac of 8-day-old chick embryos. Recovery and titration of the virus from various organs including the central nervous system (CNS) and skeletal muscle were performed at 2, 4, 7, 10 and 13 days after inoculation (PI). AIV was systemically disseminated and proliferated even 2 days PI. The titers of the recovered virus from the CNS and from skeletal muscle was the highest at 4 days PI and declined with time, whereas hydranencephaly, arthrogryposis and cerebellar hypoplasia developed at 7 days PI and gradually progressed until 13 days PI.     

Dynamics of the immune system response in cerebrospinal fluid and blood of SIVmac-infected rhesus monkeys

Paired sera and CSF samples were collected from SIV_mac-infected macaques. Animals infected with SIV_mac251 maintained low gag and high env-specific antibody levels in plasma. Increasing env-specific antibody titers in CSF were associated in one animal with strong intrathecal synthesis. SIV_mac239-infected monkeys revealed high antibody titers of gag and env-specificity, in one animal accompanied by weak intrathecal synthesis of virus-specific antibodies. In all animals, the CD4/CD8 ratio in CSF decreased faster compared to blood.     

Use of VIRAZOLE® to eradicate odontoglossum ringspot virus from in vitro cultures of Cymbidium Sw.

Odontoglossum Ringspot Virus has been eradicated from Cymbidium Sw. through chemotherapy based on incorporation of ribavirin (VIRAZOLE^®) into the in vitro culture medium of protocorms. Applications of the virustatic agent for several consecutive subcultures freed protocorms of the virus. Acclimated plantlets regenerated from those protocorms are healthy as determinated by enzyme-linked immunosorbent assay (ELISA). No resurgence of virus occurred over a period of 5 years. Besides, trueness to type was total at flowering level and the batch grown was perfectly homogeneous.To secure fast and effective eradication of the virus during the consecutive subcultures of protocorms with ribavirin, three factors proved to be of prime importance: accurate isolation of new growths from initial tissues, VIRAZOLE^® concentration and frequency of transplanting in new media.     

Inhibited Long-Distance Movement of Potato Leafroll Virus to Tubers in Potato Genotypes Expressing Combined Resistance to Infection, Virus Multiplication and Accumulation

Plants of two potato clones which, in preliminary greenhouse assessments, showed resistance to multiplication and accumulation of potato leafroll virus (PLRV) were graft or aphid inoculated with the virus and grown in the greenhouse; plants of a moderately susceptible cultivar were used for comparison in all experiments. A high concentration of aphid‐borne inoculum was used to ensure strong infection pressure. Clone M62759 appeared to be highly resistant to PLRV infection, whereas clone PS1706 was more susceptible. Both clones expressed a high level of resistance to virus multiplication, when primary or secondary infection was assayed by enzyme‐linked immunosorbent assay. Moreover, PLRV was detected in only few or none of the progeny plants of clone M62759, which thus strongly inhibited virus transport to tubers. The study on PLRV translocation from aphid‐inoculated shoots to uninoculated shoots sprouted from the same tubers showed that no specific mechanisms are likely to impair PLRV movement through the tubers of the resistant genotypes. These results indicate that three valuable components of the resistance to PLRV are probably closely linked in the genotype, a combination that seems to occur rather rarely in potato clones. Nevertheless, selecting potato genotypes for the complex resistance to PLRV may prove to be a worthwhile part of breeding programmes, provided that the genetic mechanisms governing particular types of resistance are better recognized.     

Applications of DNA shuffling to pharmaceuticals and vaccines

DNA shuffling is a practical process for directed molecular evolution which uses recombination to dramatically accelerate the rate at which one can evolve genes. Single and multigene traits that require many mutations for improved phenotypes can be evolved rapidly. DNA shuffling technology has been significantly enhanced in the past year, extending its range of applications to small molecule pharmaceuticals, pharmaceutical proteins, gene therapy vehicles and transgenes, vaccines and evolved viruses for vaccines, and laboratory animal models.