Depression and anxiety in different thyroid function states.

Previous studies on hypothyroid subjects have indicated serious psychiatric symptoms affecting the patients' quality of life. The present prospective cross-sectional study's aim was to examine these symptoms in thyroid patients with different functional states. A total of 254 patients (age: 56 +/- 14 years [mean +/- standard deviation], 181 female, 73 male) referred to a hospital for radioiodine treatment of hyperthyroidism or for follow-up of differentiated thyroid cancer, respectively, were included. All patients underwent the twelve-item general health questionnaire, which is an instrument for detecting mood disturbances. Euthyroid and hyperthyroid patients did not differ significantly in their general health questionnaire score (11 +/- 5 vs. 11 +/- 7), nor did subclinical hyperthyroid (11 +/- 6) or subclinical hypothyroid subjects (12 +/- 5). In contrast, hypothyroid patients showed a significantly higher mean score (17 +/- 7, p < 0.001, ANOVA). Binary logistic regression revealed that hypothyroidism increases age and gender-adjusted risk for critical mood deterioration by seven-fold. Thus, hypothyroidism represents a widely underestimated functional condition that may severely affect mental health.     

Mimicking a Honeybee Queen?Vespa affinis indosinensis Pérez 1910 Hunts Drones of Apis cerana F. 1793

Hornets (Vespa affinis) flying in a drone congregation area attracted drones of Apis cerana. The drones followed the hornet and were ‘manoeuvred’ towards a leaf or a tree. The hornet then rushed at one of the drones. Many attempts by the hornet to catch a drone were unsuccessful and all drones fled. After failing, the hornet returned to centre of the drone congregation area and repeated the behaviour. Only after successfully seizing of a drone did the hornet leave the drone congregation area carrying its prey. In a two-choice test in the centre of the drone congregation area, free-flying A. cerana drones preferred a hornet model to a live A. cerana queen. V. affinis apparently ‘exploits’ the intraspecific communication between queen and drones of A. cerana. Hunting of drones in the drone congregation area by V. affinis may be an example of predatory mimicry.     

The enzymatic malonylation of 1-aminocyclopropane-1-carboxylic acid in homogenates of mung-bean hypocotyls

Homogenates of hypocotyls of light-grown mung-bean (Vigna radiata (L.) Wilczek) seedlings catalyzed the formation of 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC) from the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and malonyl-coenzyme A. Apparent K_m values for ACC and malonyl-CoA were found to be 0.17 mM and 0.25 mM, respectively. Free coenzyme A was an uncompetitive inhibitor with respect to malonyl-CoA (apparent K_i=0.3 mM). Only malonyl-CoA served as an effective acyl donor in the reaction. The d-enantiomers of unpolar amino acids inhibited the malonylation of ACC. Inhibition by d-phenylalanine was competitive with respect to ACC (apparent K_i=1.2 mM). d-Phenylalanine and d-alanine were malonylated by the preparation, and their malonylation was inhibited by ACC. When hypocotyl segments were administered ACC in the presence of certain unpolar d-amino acids, the malonylation of ACC was inhibited while the production of ethylene was enhanced. Thus, a close-relationship appears to exist between the malonylation of ACC and d-amino acids. The cis- as well as the trans-diastereoisomers of 2-methyl- or 2-ethyl-substituted ACC were potent inhibitors of the malonyltransferase. Treatment of hypocotyl segments with indole-3-acetic acid or CdCl₂ greatly increased their content of ACC and MACC, as well as their release of ethylene, but had little, or no, effect on their extractable ACC-malonylating activity.Abbreviations ACC 1-aminocyclopropane-1-carboxylic acid - MACC 1-(malonylamino)-cyclopropane-1-carboxylic acid Dedicated to Professor Dr. Hubert Ziegler on the occasion of his 60th birthday     

Germacranolides from Melampodium americanum and Melampodium pilosum

Chemical analysis of Melampodium americanum yielded, besides the known melampodinin A, four new melampolides, melampodinin B, melampodinin C, 9-des     

On the turnover of polyamines spermidine and spermine in mouse brain and other organs

The apparent biological half-lives of spermidine and spermine in mouse brain and other organs were determined by measurement of the specific radioactivities of these compounds over long periods of time. The endogenous polyamine pools were labeled by repeated intraperitoneal injections of [1,4-¹⁴C]putrescine·2HCl, [2-¹⁴C]d,l-methionine, [2-³H]l-methionine, andS-adenosyl-[2-³H]l-methionine. Repeated injections were given to ensure labeling of both fast and slow polyamine pools. It was shown that the two parts of the polyamine molecules which derive from ornithine and methionine have significantly different life spans, especially in the brain. Actual turnover rates of polyamines could not be determined because of the active interconversion between spermine and spermidine, and between spermidine and putrescine. The observed reutilization of putrescine originating from spermidine degradation for spermidine biosynthesis, and the analogous reutilization of spermidine in spermine biosynthesis is discussed with respect to its physiological significance and its relationship to cellular organization.     

Regulatory interrelations between GABA and polyamines. I. Brain GABA levels and polyamine metabolism

Elevation of brain GABA levels by GABA-T inhibition is accompanied by a decrease ofS-adenosylmethionine decarboxylase activity. This is followed by an increase of ornithine decarboxylase activity and a severalfold increase of brain putrescine levels. Spermidine and spermine levels are not significantly affected under these conditions. These unexpected findings support a regulatory interaction between GABA and polyamine metabolism.     

The estimation of phenylalanine ammonia-lyase (PAL)-activity in intact cells of higher plant tissue

From cell cultures of Haplopappus gracilis, an enzyme, catalyzing the glucosylation of cyanidin at the 3 position using uridine diphosphate-D-glucose (UDPG) as glucosyl-donor, has been isolated and purified 50-fold. The enzyme was not specific for cyanidin alone, but also glucosylated other anthocyanidins and flavonols in position 3. However, apigenin, luteolin, naringenin and dihydroquercetin were not glucosylated. The reaction has an optimum pH of approximately 8, and the apparent K _m values for UDPG and cyanidin were 0.5 and 0.33 mM respectively. The enzyme reaction is strongly inhibited by cyanidin (above 0.25 mM).