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Biomedical subjects

G Stetter

Publications and source records attributed to G Stetter.

At least 19 recordsLinked to original sources
PubMed1992

[Iotrolan versus iopamidol. A controlled double-blind study with lumbar myelography].

Within the frame work of lumbar myelography, 158 patients were entered in a double-blind study in order to test a dimeric contrast medium (iotrolan) against a monomeric one (iopamidol), both of them non-ionic. A three-step scheme was applied to evaluate the X-ray pictures with respect to contrast quality. Particular attention was paid to the visibility of details, i.e. the nerve root and its course, as well as to how well it could be distinguished in the nerve root sheath. On the basis of a high level of significance (P less than 0.05), comparison of the two contrast media showed no difference in contrast quality. Sixty-nine percent of the examinations using iotrolan resulted in excellent contrast quality, whereas the corresponding very good results using iopamidol lay at 76%. Twenty-nine percent of the patients examined with iotrolan and 27% of those examined with iopamidol showed side effects. Headache occurred most frequently, followed by nausea, dizziness and neck pain. Sixty percent of the patients suffering from postmyelographic reactions reported delayed headache, which occurred most often with iotrolan rather than iopamidol. As for manifestation of other postmyelographic side effects, there were no significant differences (P less than 0.05, Fischer's test) between the two groups of contrast media.

Adult↗
PubMed1991

A new DNA binding assay to study subclasses of SV40 large T antigen binding to individual binding sites on the SV40 DNA.

SV40 large T antigen interacts specifically with three different sequences, termed sites I, II or III, within the control region of the SV40 DNA to regulate transcription as well as the initiation and progress of SV40 DNA replication. We have biotinylated three different DNAs containing either site I, II or III and immobilized these constructs on a streptavidin agarose matrix. All three immobilized DNAs were shown to bind T antigen from a total cell extract of SV40 infected monkey cells although with different affinities. Pulse chase experiments revealed that newly synthesized T antigen bound efficiently to all three binding sites whereas mature T antigen bound only to site I and site III DNA. The analysis of non-binding and DNA-bound T antigen on sucrose density gradients showed that only low molecular weight forms of T antigen were bound to all three immobilized DNAs. However, incubation of T antigen in the total cell extract with site I DNA resulted in high molecular weight forms of T antigen, indicating that the presence of site I DNA influences the quaternary structure of T antigen which might result in a detachment from the DNA.

Animals↗
PubMed1989

Complex interaction of SV40 large T antigen with the control region on the SV40 DNA.

SV40 large T antigen interacts specifically with three different DNA sequences within the SV40 control region namely site I, II and III, in order to regulate the viral DNA replication and the stimulation of late, or repression of early viral transcription. We define three different plasmids, containing either site I alone, site II with SV40 specific flanking sequences or both sites I and II with additional neighbouring sequences which were used to study the interaction of T antigen with each of its binding sites. We found that binding of T antigen to site II reduced binding of T antigen to site I as opposed to the interaction of T antigen with site I alone. These results were supported by our findings that T antigen from an SV40 temperature-sensitive mutant, tsA58, which is heat-sensitive for binding to site II, exhibited the same binding affinity for site I as for the DNA fragment containing both binding sites. Thus, binding of T antigen to binding site II seems to interfere with binding to site I, thereby influencing the regulatory functions of T antigen in the repression of early viral gene transcription.

Animals↗
PubMed1988

SV40 T-antigen binding to site II is functionally separated from binding to site I.

During lytic infection SV40 T antigen binds specifically to three different regions of the SV40 DNA to initiate viral DNA replication and to regulate early and late transcription. We have used the recently described plasmids pKB1, containing a 23-bp oligonucleotide coding for site I, pdl1085 containing sites II and III together with SV40 specific flanking sequences, and as a control pATC, a plasmid which contains all three binding sites (D. Müller et al. (1987), Virology 161, 81-91) to analyze the differential binding of T antigen to these individual binding sites in the course of an SV40 infection. We found that shortly after infection the amount of bound DNA increased with the concentration of T antigen reaching a steady-state level at about 20 hr after infection. In comparison to binding at site I, binding to site II appeared with a delay of about 8-9 hr corresponding to the onset of viral DNA replication. The correlation between binding of T antigen to site II and the SV40 DNA replication could be further corroborated by using T antigen from the heat-sensitive mutant tsA58 which completely failed to bind to site II at nonpermissive temperature but exhibited a residual binding to site I. This reduced binding to site I proved insufficient for the proper functioning of autorepression. Our results support the hypothesis that distinctly different subclasses of T-antigen binding to site I or site II may exist.

Antigens, Polyomavirus Transforming↗
PubMed1986

[Imaging of cecal tumors using computer tomography].

Although contrast enema of the colon and endoscopy remain the preferential diagnostic methods in tumour of the caecum, computed tomography can accurately determine the extent of extraluminar tumour growth and hence help to arrive preoperatively at the appropriate therapeutic concept. Adenocarcinomas are morphologically distinctly different, due to focal thickenings of the colon wall, from the diffuse wall thickenings associated with malignant lymphomas, or from inflammatory conglomerate tumours. Computed tomography of the caecal region is a noninvasive examination method that can speed up diagnosis especially in elderly patients with elongated colon and stool incontinence.

Adenocarcinoma↗
PubMed1985

[Inflammatory changes in shoulder arthrography].

Arthrography of the shoulder joint in so-called periarthritis humeroscapularis often shows nodular contrast defects, irregular defects in the bursa and contrast-filling of irregular lymphatics; these are characteristic signs of a synovitis. Arthrography can provide an exact diagnosis, not only in suspected post-traumatic rotator cuff, tears, but also in other painful conditions that limit movement. It is superior to CT in demonstrating inflammatory changes.

Arthrography↗