Biomedical subjects
Publications and source records attributed to G Wurm.
Thermal lumbar sympathectomy has been the method of choice since the 'eighties in the treatment of reflex dystrophy. We are using this method since January 1990. First results are presented and critically analysed. 15 patients who underwent thermal lumbar sympathectomy were examined and interviewed 1 year after treatment. 7 patients reported persisting pain relief, while the remaining 8 did not.
We studied the effects of 37 flavonoids on prostaglandin endoperoxide synthase (EC 1.14.99.1) purified from sheep vesicular glands. Nonplanar flavans were more potent inhibitors than planar flavones and flavonols (IC50 values were, e.g., 40 mumol/l for catechin and epicatechin, 110 mumol/l for galangin, 490 mumol/l for quercetin and 450 mumol/l for kaempherol). Different inhibition mechanisms were observed, i.e. uncompetitive inhibition for nonplanar flavonoids and competitive or noncompetitive inhibition for planar flavonoids. Potent inhibitors in the group of flavones were substances with an o-dihydroxy structure in the B ring and in the group of flavonol substances with two hydroxyl groups in position 5 and 7 of the A ring. None of the flavanones studied caused significant inhibition, except for the flavanone-3-ol, silibinin (silybin), which caused potent inhibition with an IC50 of 120 mumol/l. Several flavonoids, which were able to inhibit the prostaglandin endoperoxide synthase at higher concentrations, were also able to stimulate the enzyme at lower concentrations. These results indicate that the flavonoids should be divided into two groups according to their capacity to inhibit the prostaglandin endoperoxide synthase, represented by planar and nonplanar substances as in each group a close correlation between structure and inhibitory activity was observed.
The stimulating or inhibiting influences of 33 phenolic compounds on the prostaglandin synthetase of rat renal medulla were tested. Dihydroxyphenylcarbonic acids clearly proved to be activators of the prostaglandin synthetase. Dimethoxyphenylcarbonic acids were ineffective. Aminoethylphenols as well as p-substituted monohydroxybenzenes with a carbonic acid side chain were clear stimulators in contrast to their alkyl derivatives which are pronounced inhibitors. Among the tested bioflavonoids (+)-cyanidanol-3 and morin were inhibitors of the prostaglandin synthesis. Flavonoids with polar substitution in 3,5,7-position such as rutin on the other hand showed activating properties.
The passive cutaneous anaphylaxis (PCA) activities of a number of new A- and B-ring carboxyflavone and carboxyflavonol derivatives with planar and without planar orientation of the B-ring--synthesized in relation to baicalein and 2-carboxyxanthone derivatives as antianaphylactic prototypes--are recorded. From the investigated compounds A-ring carboxylic acids are more active than B-ring carboxy derivatives and flavonols are less active than flavones. Problems resulting from the correlation of the PCA activity of a number of chromone derivatives with the substitution of the 3-position are discussed.
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