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Biomedical subjects

H Ibelgaufts

Publications and source records attributed to H Ibelgaufts.

7 recordsLinked to original sources
PubMed1994

Interferon response pathways--a paradigm for cytokine signalling?

Considerable progress has been made in the past few years elucidating the molecular mechanisms of cytokine signalling. The interferons (IFNs) have provided a singular system allowing the detailed characterization of a specific cytokine signalling pathway. Studies on the IFN signal transduction pathway have identified protein tyrosine kinases (PTKs) that phosphorylate signal transducers (STATs) which then bind to DNA promoter sequences and activate gene transcription. Related work has shown that JAKs and STATs are also activated in response to a variety of the cytokines. Thus the novel type of signal transduction pathway identified for the IFNs promises to be more widely utilized than anticipated.

Animals↗
PubMed1982

Adenovirus-related RNA sequences in human neurogenic tumours.

Thirty two human tumours, mainly neurogenic, have been investigated for the presence of adenovirus-related RNA sequences. 3H-labelled tumour virus DNA probes derived from human adenoviruses types 2 and 12, bovine adenovirus type 3, and avian adenovirus CELO were hybridized in-situ on tumour kryostat sections under conditions that detect complementary RNA. Tumour virus-related RNA was detected in 62% of all tumours tested, but was not detectable in normal human brain tissues. Expression of tumour virus-related RNA was found in 2/4 astrocytomas, 2/4 metastatic brain carcinomas, 2/2 glioblastomas, 1/1 melanoma, 5/7 meningiomas, 4/4 neurinomas, 1/2 oligodendrogliomas, and 1/1 rhabdomyosarcoma. The presence of adenovirus-related RNA in the majority of human neurogenic tumours may reflect a viral involvement in the pathogenesis of these tumours.

Adenoviridae↗
PubMed1982

Papovavirus-related RNA sequences in human neurogenic tumours.

Thirty-two human brain tumours were investigated for the presence of papovavirus-related RNA sequences. Radiolabelled viral DNAs isolated from SV40, BKV, HDV, and BPV were hybridized in-situ on to tumour kryostat sections under conditions that detect complementary RNA. SV40-related RNA was detectable in 34% of all tumours tested but was not found in normal human brain tissue. SV40-positive tumours included 1/1 angiofibroma, 1/4 astrocytomas, 2/4 metastatic brain tumours, 1/1 melanoma, 3/7 meningiomas, 2/4 neurinomas, 1/2 oligodendrogliomas. Bovine papilloma virus-, BKV-, and HDV-related RNAs were absent from all tissues tested. The presence of SV40-related nucleic acids in a large number of human neurogenic tumours may reflect a viral involvement in the etiology of these tumours.

Astrocytoma↗
PubMed1980

Adenovirus type 12-induced rat tumor cells of neuroepithelial origin: persistence and expression of the viral genome.

Four cell lines derived from adenovirus type 12-induced rat brain tumors were studied. The polyploid cells displayed neuroepithelial characteristics and were transplantable into syngeneic rats and nude mice. In tissue culture the cells grew in monolayers and multilayers. A very high saturation density was reached, and the cells plated in agar and were easily agglutinated with low concentrations of concanavalin A. Between 2 and 11 copies of the viral genome per diploid cellular genome were detected by reassociation kinetics analysis in the different lines. The patterns of distribution of viral DNA sequences in these lines, as revealed by blot analysis, suggest colinear integration of the intact viral genome into the cellular DNA. The patterns of integration were stable after more than 15 months of prolonged tissue culture and after animal reimplantation. Integration patterns were identical in three of the tumor lines and different in another line. Viral sequences were transcribed. The extent of homology found toward adenovirus type 12 DNA in polyadenylated polysome-associated mRNA isolated from the tumor lines suggests that the early and some of the late genes of adenovirus type 12 DNA are transcribed in these tumor cells. Infectious virus was not rescuable from these lines.

Adenoviruses, Human↗
PubMed1980

Viruses as tools for studies on the molecular biology of mammalian cells.

1. Multiple copies of intact adenovirus type 12 (Ad12) DNA are integrated into the DNA of Ad12-transformed hamster and Ad12-induced rat brain tumor cells. Free viral DNA is not present in the Ad12-transformed lines investigated. 2. Only few sites of integration are found in Al2-transformed hamster and Ad12-induced rat brain tumor cells. Integration may have occurred into repetitive cellular sequences at selective sites. These sites may be different in different cell lines, however, none of these sites has been analyzed in sufficient detail. 3. Three lines of Ad12-induced rat brain tumor cells exhibit identical patterns of integration. These lines have been derived from three brain tumors in one animal and may have evolved from the same transformed cell. 4. In Ad12-induced rat brain tumor cells early and late segments of the viral genome are expressed as polysome-associated messenger RNA. 5. In human cells productively infected with adenovirus type 2 (Ad2), a large number of viral genome copies are linked to cellular DNA early postinfection. There are only a few sites of recombination (illegitimate?) which probably lie in repetitive cellular DNA sequences. The functional significance of this frequent recombination is unknown.

Adenoviridae↗