Search PubMed⌕ Search

Biomedical subjects

D Krüger

Publications and source records attributed to D Krüger.

46 records · Page 3Linked to original sources
PubMed1986

Unusual occurrence of EcoP1 and EcoP15 recognition sites and counterselection of type II methylation and restriction sequences in bacteriophage T7 DNA.

Selected and counterselected oligodeoxynucleotide sequences were identified in the total sequence of bacteriophage T7 DNA using a statistical criterion derived for a probability model of the Markov chain type. All extremely rare tetra- and pentadeoxynucleotides are (or contain) recognition sequences for the Escherichia coli DNA methylases dam or dcm. Most of the 37 hexadeoxynucleotides absent from T7 DNA are recognition sequences for type II modification/restriction enzymes of E. coli or related species. In contrast to most restriction sites counterselected during evolution, the EcoP1 site GGTCT occurs 126 times in the T7 genome, and phage T7 replication is severely repressed in P1-lysogenic host cells. We demonstrate that the frequency of the EcoP1 site is determined by that of the overlapping recognition sites for T7 primase, an essential phage enzyme. The recognition site of a type III enzyme, EcoP15, is also not counterselected. In T7 DNA all 36 EcoP15 sites are arranged in such a manner that the sequence CAGCAG is confined to the H strand, the complementary sequence CTGCTG to the L strand. This "strand bias" is highly significant and, therefore, very probably selected. A functional relation between this strand bias and the refractive behaviour of phage T7 to EcoP15 restriction is suspected.

Base Sequence↗
PubMed1983

[Effect of glucose concentration on spinal anesthesia with bupivacaine 0.5%].

Until recently isobaric agents were relatively seldom employed to produce spinal anaesthesia. Experience with bupivacaine has shown in a prospective study on 60 patients, that complications, especially with high or total spinals, are uncommon with either using hyper- or isobaric agents. Also it has been shown that the height of blockade after using hyperbaric agents can only be crudely controlled by positioning of the patient. 3 ml (15 mg) of 0.5% bupivacaine produces adequate analgesia, and muscle relaxation, rapidly, in the vast majority of patients. The duration of blockade was adequate for longer surgical procedures, and was not affected by varying glucose concentrations in the solutions employed. Also there was no difference in the number of dermatomes blocked. No significant differences could be found between the solutions containing 5 or 8% glucose; however, with the 8% concentration smaller variations were found in regard to the extent of dermatomal blockade. The degree of motor block was identical in all 3 groups. The duration of motor block decreased when using higher concentrations of glucose. It is not clear whether the differing glucose concentrations have an effect on C.S.F. osmolarity, and whether this is clinically relevant. The results show that isobaric spinal anaesthesia is at least as reliable as hyperbaric spinal anaesthesia.

Anesthesia, Spinal↗
PubMed1976

[Results of anti-Rh-immunoprophylaxis in the Berlin-Friedrichshain hospital].

At the beginning the essential facts with a basic signification for the insight into the anti-Rh-immunoprophylaxis (IP) are pointed aut. Then we inform about our own results. During the period--we report on--we carried through the IP nearly 500 times. A sensibilization took place in no case. More than 50 women became pregnant anew, their children were clinically and serologically healthy, no mother proved to have anti-D-antibodies. Herewith our results confirm a full efficiency of the IP. The problem of an immunoprophylactic therapy in already existing anti-D-antibodies is point aut.

Erythroblastosis, Fetal↗
PubMed1975

[Pyrogen testing in vitro using the Limulus test].

The applicability of the Limulus test for the pyrogen test was checked in comparison to the pyrogen test in rabbits. In 6 out of 24 lots of raw materials and drugs pyrogens could be detected by means of the pyrogen test in rabbits. 2 of these 6 lots showed positive reaction in the Limulus test, there were no false positive results. Testing 7 bacterial strains in modified quantity of germs the Limulus test turned out to be more sensitive than the pyrogen test in rabbits. The application of this in vitro test as a complement to the pyrogen test in rabbits for a certain kind of problems is discussed.

Animals↗
PubMed1975

[Immunopreventive management of Rh-positive maltransfusions].

We report on a case of a Rh-positive mis-transfusion in a Rh-negative pregnant woman treated by human-immunoglobulin-G-anti-D (IgG-anti-D). A sensibilization that without a therapy was to be expected with a probability of 75 per cent did not take place. We discuss our observation in connection with information existing hitherto on similar events. Hereby a distinct dependence on an anti-D-dosis becomes evident in order to achieve a reliable immunosuppression in an appointed quantity of erythrocytes. A summarizing of literature at hand results in the fact that a reliable prevention of sensibilization may be achieved by a dosage of 20 microgramme IgG-anti-D each ml of a concentrate of erythrocytes respectively 10 microgramme each ml full blood. This means for a large foetomaternal as well as for false transfusions of adult blood. The dosage in the case, described by us, therefore by 1,9: 1 related to full blood was too low. We acted perfectly consciously as up to date there are no informations on a treatment by anti-D in this way during pregnancy and because an eventually Rh-positive child should not be injured at all. The clinical course after the anti-D-treatment has been examined by numerous authors. It showed even in a therapy by high doses of great quantities of erythrocytes but slight reactions. Severe disorders have not been described hitherto. We therefore ought to treat by sufficiently high doses and as soon as possible in order to allow the organism to contact with the intact antigen as brief as possible. Finally we present a proposition on diagnostics and therapy for the case of a Rh-mis-transfusion respectively a large glut in of foetal blood cells in order to avoid an immunization within the Rh-system.

Adult↗