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Biomedical subjects

R Müller

Publications and source records attributed to R Müller.

At least 19 recordsLinked to original sources
PubMed1979

[Epidemiology and prognosis of non-A, non-B hepatitis (author's transl)].

The frequency of non-A, non-B hepatitis (n = 325) was determined among all cases (n = 1368) of acute viral hepatitis observed in the Hannover are abetwen 1975 and 1978. Hepatitis A was excluded by demonstration of anti-HAV-IgM, hepatitis B by demonstration of HBs antigen or an isolated occurrence of anti-HBc at the beginning of the disease. Non-A, non-B hepatitis occurred predominantly in adults and showed no seasonal variability. As a consequence of results of followup investigations in 174 hepatitis patients 2 years after the onset of the disease it can be assumed that non-A, non-B hepatitis tends to lead to chronic courses more frequently than hepatitis B.

Adolescent↗
PubMed1979

Studies on the binding of the ribosomal protein complex L7/12-L10 and protein L11 to the 5'-one third of 23S RNA: a functional centre of the 50S subunit.

The RNA binding sites of the protein complex of L7/12 dimers and L10, and of protein L11, occur within the 5'-one third of 23S RNA. Binding of the L7/12-L10 protein complex to the 23S RNA is stimulated by protein L11 and vice-versa. This is the second example to be established of mutual stimulation of RNA binding by two ribosomal proteins or protein complexes, and suggests that this may be an important principle governing ribosomal protein-RNA assembly. When the L7/12-L10 complex is bound to the RNA, L10 becomes strongly resistant to trypsin. Since the L7/12 dimer does not bind specifically to the 23S RNA, this suggests that L10 constitutes a major RNA binding site of the protein complex. Only one of the L7/12 dimers is bound strongly in the (L7/12-L10)-23S RNA complex; the other can dissociate with no concurrent loss of L10.

Escherichia coli↗
PubMed1979

The structure of the RNA binding site of ribosomal proteins S8 and S15.

Proteins S8 and S15 from the 30 S ribosomal subunit of Escherichia coli were bound to 16 S RNA and digested with ribonuclease A. A ribonucleoprotein complex was isolated which contained the two proteins and three noncontiguous RNA subfragments totaling 93 nucleotides, that could be unambiguously located in the 16 S RNA sequence. We present a secondary structural model for the RNA moiety of the binding site complex, in which the two smaller fragments are extensively base-paired, respectively, to the two halves of the large fragment, to form two disconnected duplexes. Each of the two duplexes is interrupted by a small internal loop. This model is supported by (i) minimum energy considerations, (ii) sites of cleavage by ribonuclease A, and (iii) modification by the single strand-specific reagent kethoxal. The effect of protein binding on the topography of the complex is reflected in the kethoxal reactivity of the RNA moiety. In the absence of the proteins, 5 guanines are modified; 4 of these, at positions 663, 732, 733, and 741, are strongly protected from kethoxal when protein S15 is bound.

Base Sequence↗
PubMed1979

Effect of polyenyl phosphatidyl choline on clofibrate-induced increase in LDL cholesterol.

In a double-blind, randomised, cross-over trial clofibrate and a combination of polyenyl phosphatidyl choline (PPC) plus clofibrate were tested in 67 patients with hyperlipoproteinemia. Each treatment lasted for 4 weeks and was separated by a 4 week placebo period. The daily doses were clofibrate 1.2 g and PPC 1.8 g + clofibrate 1.2 g. respectively. The results revealed that polypenyl phosphatidyl choline prevented the elevation of LDL-cholesterol induced by clofibrate treatment, and that the lipid-lowering potency of the combination did not differ significantly from that of clofibrate. Since elevation of LDL-cholesterol is considered to increase the risk of coronary heart disease, the combination appears to offer a therapeutic advantage. Despite the significance of this clinical observation, a final decision may only be obtained from a prospective, long term investigation in patients with coronary heart diseases and hyperlipoproteinemia.

Adult↗
PubMed1979

Kinetic properties of the purified 3-hexulosephosphate synthase from Pseudomonas oleovorans.

The kinetic characteristics of the purified 3-hexulosephosphate synthase from the facultative methylotroph Pseudomonas oleovorans were investigated. It could be demonstrated that the dependence of the reaction rate on the rib(ul)ose-5-phosphate as well as the formaldehyde concentration has a complex shape with the appearence of plateau and trough regions. The shape of the curve is changed in dependence on the fixed level of the second substrate. Multiple forms of the 3-hexulosephosphate synthase were found to be responsible for the generation of the complex kinetic characteristics. By means of ion exchange chromatography it was possible to separate four active enzyme forms with different kinetic characteristics. These forms were also found to be interconvertible. This behaviour of the 3-hexulosephosphate synthase is assumed to have the main regulatory function of the enzyme.

Aldehyde-Lyases↗
PubMed1979

Pentoxifylline -- a biomedical profile.

The therapeutical benefit of pentoxifylline (Trental) in vascular disorders and chronic diseases which provoke disturbances in nutritive microcirculation is reviewed. With its hemorheological activity, pentoxifylline offers a new approach to ameliorate impaired blood flow in affected microvasculature. This statement is given evidence by numerous experimental and clinical data which demonstrate efficacy in various indications, wuch as cerebrovascular insufficiency, senile organic brain syndrome, transient ischemic attacks, cerebral infarctus, ocular and otological circulatory disorders, peripheral angiopathies of arteriosclerotic, diabetic, or inflammatory origin with intermittent claudication, leg ulcers and other disturbances. In vitro and in vivo findings disclose that the efficacy is based on hemorheological effects, such as improving local hyperviscosity, hyperaggregability of red cells or platelets, erythrocyte fluidity and hypercoagulability resulting in a better oxygenation of affected tissues.

Arterial Occlusive Diseases↗
PubMed1979

Cerebrovascular circulatory disorders: new aspects of pathophysiology and therapy.

After reviewing new aspects in the pathophysiology of the poststenotic cerebral ischemia as the cause of the various syndromes of cerebrovascular disorders, therapeutic approaches are discussed. The fatal vicious cycle of the disturbances of the nutritive blood flow within the cerebral microcirculation can be interrupted by means of pentoxifylline. By amelioration of the disturbed flow properties of blood in the microcirculation due to improvement of red cell deformability and inhibition of platelet aggregation, oxygen supply is enhanced and more glucose offered. Membrane permeability and functions of the cells are normalized by the inhibitory action on edematous changes in the brain tissue and by removal of the mechanical obstacles of microcirculation. The disturbed cerebral metabolism is stimulated by enhancement of the energy-rich phosphates in the brain cells. The combined rheological, antiedematous and metabolic effects of pentoxifylline offer a complex therapy of cerebrovascular insufficiency.

Adenosine Triphosphate↗
PubMed1979

[Catamnestic study about the fertility of the man (author's transl)].

Collective investigations of fertility in childless married couples were carried out in 9 andrological health centres of the GDR. Analysis of 1937 spermatograms in comparison to fertility after 1 to 2 years shows: (1) Fertility decreases significantly at sperm density nearly 10 million per ml. (2) Motility below 60 per cent caused reduced fertility. Normal motility is more important than normal density of spermatozoa. (3) Fructose level doesn't correlate to motility or fertility of man.

Cell Count↗