1,721,037 research outputs found
Rediscovering the Fallopian tube at the time of BRCAmut. Three years experience on tubal sampling protocol applied to all routine cases.
No full textExpression of cellular oncogenes: unrearranged c-myc gene but altered promoter usage in radiation-induced thymoma.
No full textExpression of eleven oncogenes was analyzed in thymomas induced by X-rays in the BALB/c strain of mice. H-, K-, N-ras, c-myc, c-myb, and c-abl genes were consistently expressed in thymomas, as well as in normal, age-matched thymus. Only c-myc transcription appeared to be altered in thymomas: a 1.5-3-fold elevated expression of c-myc was found in 42% of the thymomas tested. An altered ratio of two normal promoters, P1 and P2, of the c-myc gene has also been observed in 6 samples out of 15 tested. In one sample, expression from only the P2 promoter was found. A change in DNA sequence to the 5' side of this promoter was detected in an RNAase cleavage assay; this could have disrupted transcription from the P1 promoter. No other structural alteration has been detected within approximately 1800 bases upstream or 700 bases downstream from the 1st exon including exon 1 of the c-myc gene. With the exception of the one sample described, the results of RNAase cleavage assays, as well as Southern blotting of the c-myc gene, show that the structural alteration of this region of c-myc is not generally associated with radiation-induced thymomas in this strain of mice
Ovarian cancer at the BRCA era: Tube or ovary?Results of tubal sampling protocol applied to all routine cases. III Seminario CientificoCancer: Actualidad, Perspectiva y continuidadCHEMSA Clinica Hospital de Especialidades Medicas Panama (Panama)
No full textCharacterization of polysome-associated RNA from influenza virus-infected cells.
Full text linkVirus-specific polysome-associated RNA (psRNA) and RNA after dissociation of polysomes were analyzed by direct hybridization with unlabeled viral RNA (vRNA) and complementary RNA (cRNA). psRNA after a 30-min pulse with [3H]uridine contained 28% labeled cRNA, 70% host RNA, and no vRNA. After dissociation, psRNA sedimented heterogeneously. Heavy RNA (greater than 60S), ribosomal subunit RNA (rsuRNA, 30-60S), free mRNA (fmRNA, 10-30S), and light RNA (less than 10S) contained 16%, 54%, 70% and 28% cRNA, respectively, but no vRNA. When actinomycin D (AcD) was added at 2 h postinfection, the nature of the psRNA depended on the concentration of AcD and the condition of the labeling. At AcD concentrations of 1 mug or more per ml, no detectable vRNA or cRNA was associated with polysomes. At 0.2 mug of AcD per ml (a concentration that partially inhibited cRNA synthesis) and 2 h of labeling at 2.5 h postinfection, psRNA contained 40% viral-specific RNA, which included both vRNA and cRNA in almost equal amounts. When polysomes were dissociated, however, viral-specific fm RNA from AcD-treated cells contained exclusively cRNA and no detectable vRNA. Increasing amounts of labeled vRNA were present in the heavy region of the gradient (and in the pellet), which also contained varying amounts of cRNA. The labeled vRNA appears to be associated with polysomes in a cesium chloride density gradient (rho = 1.525 g/ml). Although we have ruled out the trivial explanation of viral ribonucleoprotein contamination,the nature of the complex containing both polysomes and vRNA is unknown
Ethiopatogenesis of primary hepatic cancers
No full textOverview of ethiopatoegnetic elements of childhood primary hepatic tumor
TUMORS INDUCED BY MOLONEY MURINE SARCOMA-VIRUS ARE CLONAL IN RATS, NOT CLONAL IN MICE
No full textMoloney murine sarcoma virus (M-MSV) induces rapidly growing tumours in adult mice of most conventional strains. Rats are less susceptible to M-MSV oncogenesis, but the few rhabdomyosarcomas that do develop after viral inoculation of newborn animals closely resemble conventional malignancies: they develop after a long latency, grow progressively, and metastasize to regional lymph nodes and lungs. Southern blot analysis with a v-mos-specific probe of M-MSV-induced tumours in both species demonstrated an oligo-, monoclonal pattern of exogenous v-mos integration only in the rat system, while mouse tumours were not clonal in origin. Furthermore, the same type of analysis of lymph node and lung metastases showed that cell clones already present in the primary rat lesion colonized secondary sites during tumour progression. Apparently, Moloney murine leukemia virus (M-MuLV) was not involved in rhabdomyosarcoma pathogenesis since M-MuLV-specific DNA sequences could not be demonstrated in three of the six rat tumours. Finally, in all mouse tumours, unintegrated linear M-MSV proviruses could be readily detected
Occasional loss of constitutive heterozygosity at 11p15.5 and imprinting relaxation of the IGFII maternal allele in hepatoblastoma.
No full textThe 11p15.5 chromosomal region contains one or more loci involved in congenital developmental abnormalities and in the genesis of embryonal tumors, such as Wilms' tumor, embryonal rhabdomyosarcoma, and hepatoblastoma. In these tumors, a loss of constitutive heterozygosity, selectively involving a specific parental allele, suggests both the presence of onco-suppressor genes and a phenomenon of genomic imprinting. We present evidence that both genetic events could be occasionally involved in hepatoblastoma. In fact, loss of heterozygosity at 11p15.5 could be documented in 3 of 13 patients with hepatoblastoma, and in 2 cases the paternal origin of the residual allele in the tumor was assessed. Moreover, imprinting of the paternal IGFII allele and the maternal H19 allele was confirmed in normal tissues of 5 informative patients. Finally, imprinting relaxation of IGFII was detected in the tumor tissue of 1 patient
Characterization of dualtropic type C retroviruses isolated from spontaneous non-T lymphomas of SJL/J(V+) mice.
No full textEndogenous XC- viruses were isolated from non-T spontaneous lymphomas of SJL/J(v+) mice. These isolates were cloned by limiting dilution procedure and characterized for biological and immunological properties. At the electron microscope these isolates showed typical retrovirus type C morphology. Reverse transcriptase and immunofluorescence assays showed that these viruses were infectious for mouse and heterologous cell lines. Since some of the isolates induced cytopathic foci in mink lung cultures, they had properties similar to those described for other recombinant dualtropic viruses. Using a panel of monoclonal antibodies against gp 70 and p 15 (E) viral proteins, it was observed that the dualtropic XC- viral isolates had an antigenic profile different from that of SJL ecotropic XC+ viru
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