Rhizobial polysaccharide-degrading enzymes from roots of legumes

The surface structure and chemistry of symbiotic bacteria from the genus Rhizobium are probably important for the outcome of the infection of legume hosts. Exopolysaccharide, capsular polysaccharide, lipopolysaccharide and a low-molecular-weight polysaccharide were isolated from R. trifolii UTC 110-1 and R. leguminosarum UTC 114-5 and partially characterized. No or only minor differences in sugar composition could be found for the corresponding fractions from the two organisms. A general method to measure low activities of polymer-degrading enzymes was developed, and used to determine enzyme activities in root extracts of Trifolium repens L. cv. Lena and Pisum xativiini L. cv. Little Marvel against the isolated rhizobial polysaccharides. An enzyme preparation from T. repens partially degraded all polysaccharides isolated from its symbiont R. trifolii while polysaccharides from R. leguminosarum , symbiont of P. sativum , were degraded to a much lesser extent. Correspondingly, an enzyme preparation from P. sativum degraded all polysaccharides isolated from both its symbiont R. leguminosarum and its non-symbiont R. trifolii. The amount of symbiont polysaccharides degraded was larger than the amount of polysaccharides degraded from the non-symbiont R. trifolii.     

A Method for Simulating Signal Evolution Using Real Animals

We studied response biases to visual stimulation using a new experimental technique. The subjects (hens, Gallus gallus domesticus) were confronted with several rewarding and non‐rewarding patterns on a computer screen. In contrast with standard discrimination tasks the rewarding patterns were not identical and varied in a dimension differentiating them from the non‐rewarding patterns. The rewarding patterns changed in response to hens' biases in selection of patterns. The aim of the study was to examine the possibility of receivers being a driving force in signal evolution. In one of the experiments a clear‐cut result was obtained. During the course of the experiment the rewarding patterns became gradually more different from the non‐rewarding one, a result expected from theoretical studies of the effect of response bias in signal evolution. A second similar experiment was less conclusive, with ceiling and floor effects influencing the results.     

Shift Work Disorder in a Random Population Sample – Prevalence and Comorbidities

Few studies have investigated the presence of shift work disorder (SWD) in the general community. We addressed many of the limitations in this literature and present new findings. SWD has been treated as an ‘all or none’ construct but we propose the need to consider the ‘severity’ of the disorder. Using random digit dialling, we randomly recruited 1163 participants. Participants completed an extensive battery of scales and questions concerning work, health and individual differences. Three questions based on the criteria from the International Classification for Sleep Disorders were used to categorise participants with SWD (n = 176). In addition, we asked participants whether SWD interfered with aspects of their life and high ratings were used to define severe shift work disorder (SSWD). The prevalence of SWD was 32.1% among night workers and 10.1% in day workers (p<.001). SSWD was present in 9.1% of night workers and 1.3% of day workers (p<.001). Adjusted logistic regression analyses found significant associations between SWD and night work (OR  = 3.35, CI 2.19-5.12), weekly work hours (OR  = 1.02, CI 1.00–1.04), short sleep (≤6 h; OR  = 2.93, CI 1.94–4.41), languidity (OR  = 1.11, CI 1.06–1.16) and resilience (OR  = 0.56, CI 0.43–0.81). Night work, short sleep, languidity, and hypertension were significantly associated with SSWD. Overall, participants with SSWD slept 0.80 h less than other participants (p<.001). Night work, short sleep and languidity were associated with both SWD and SSWD. Day workers with SWD symptoms reported significantly shorter sleep duration, higher levels of languidity and worked longer working hours compared to day workers without SWD.     

Family studies of hereditary hemochromatosis in Denmark and the Faroe Islands

Summary Pedigree studies were performed based on one Faroese and four Danish probands with overt idiopathic hemochromatosis (IH). The study consisted of HLA typing and determination of biochemical iron status indicators (serum transferrin saturation, serum ferritin). In total, 130 persons were evaluated. The screening identified 6 homozygous (h/h) subjects with preclinical IH, 46 heterozygous (h/n), and 8 normal (n/n) subjects, while 39 subjects were classified as normal or heterozygous (n/h?). One family demonstrated both a homozygous x heterozygous as well as a heterozygous x heterozygous mating. Recombination between the HLA region and IH locus occurred possibly in three subjects in three different families. The significance of detailed screening in families with probands with IH is discussed.     

Effects of E2 levuglandins on the contractile activity of the rat uterus

The effects of E2 levuglandins on the contractile activity of rat uterine horns were studied. LGE2, AnLGE2, delta 9-LGE2 and the synthetic epimer, 8-epi-delta 9-LGE2 all induced contractions in a dose-response fashion. AnLGE2 gave decreased responses with increased bath concentrations. Paired comparisons showed potent and selective inhibitory effects of AnLGE2 on the uterotonic activity of prostaglandins. AnLGE2 inhibited the uterotonic activity of PGE2 at a 0.1:1 ratio, of PGD2 at a 1:1 ratio, but did not inhibit the activity of PGF2 alpha. Exposure of spontaneously contracting uteri to high concentrations of AnLGE2, or prolonged exposure to lower concentrations, suppressed contractions.     

Combined perfusion and percolation of embalmed animal bodies for removing formaldehyde

Excess formaldehyde was extracted from embalmed animal cadavers by vascular perfusion or combined perfusion and percolation with 20% ethanol. The perfusion was undertaken through a carotid artery and the percolation through the serous body cavities for 1-2 h. Nineteen goats were perfused once and one goat and three cows were perfused and percolated twice a day for 3 days. The extracted cadavers were stored in 20% ethanol or in a freezer at -20 degrees C. The mean value of the atmospheric concentration of formaldehyde after extraction was 0.27 +/- 0.05 mg/m3 for goats and 0.39 +/- 0.12 mg/m3 for cows.