Effects of ATP reduction on the pattern of force development and myosin light chain phosphorylation in intact arterial smooth muscle

The effect of reduction of ATP content on phosphorylation of the 20 kDa light chain of myosin (MLC) and force development in intact carotid arterial smooth muscle was investigated. With reduction of ATP to 23% of control by treatment with 2-deoxyglucose there was reduction in basal, in peak and 30 min MLC phosphorylation during contraction (P less than 0.001). The rate of force development was reduced, but maximal force was the same as control. By treatment with 50 microM iodoacetate, the resting ATP content was unchanged but fell to 22% after 30 min contraction. Basal MLC phosphorylation was the same as control, but peak (P less than 0.001) and 30 min phosphorylation were lower (P less than 0.005), even though the rate and magnitude of force development were greater. The results indicate that neither rate nor magnitude of force development correlate with MLC phosphorylation. Basal and initial MLC phosphorylation may play a cooperative role in contractile function.     

Bioprocess development for endospore production by Bacillus coagulans using an optimized chemically defined medium

Bacillus coagulans is a promising probiotic, because it combines probiotic properties of Lactobacillus and the ability of Bacillus to form endospores. Due to this hybrid relationship, cultivation of this organism is challenging. As the probiotics market continues to grow, there is a new focus on the production of these microorganisms. In this work, a strain-specific bioprocess for B. coagulans was developed to support growth on one hand and ensure sporulation on the other hand. This circumstance is not trivial, since these two metabolic states are contrary. The developed bioprocess uses a modified chemically defined medium which was further investigated in a one-factor-at-a-time assay after adaptation. A transfer from the shake flask to the bioreactor was successfully demonstrated in the scope of this work. The investigated process parameters included temperature, agitation and pH-control. Especially the pH-control improved the sporulation in the bioreactor when compared to shake flasks. The bioprocess resulted in a sporulation efficiency of 80%–90%. This corresponds to a sevenfold increase in sporulation efficiency due to a transfer to the bioreactor with pH-control. Additionally, a design of experiment (DoE) was conducted to test the robustness of the bioprocess. This experiment validated the beforementioned sporulation efficiency for the developed bioprocess. Afterwards the bioprocess was then scaled up from a 1 L scale to a 10 L bioreactor scale. A comparable sporulation efficiency of 80% as in the small scale was achieved. The developed bioprocess facilitates the upscaling and application to an industrial scale, and can thus help meet the increasing market for probiotics.     

In vitro propagation of Achillea asplenifolia VENT. through multiple shoot regeneration

A method for the micropropagation of Achillea asplenifolia VENT. (Asteraceae) is described. Axillary shoots regenerated from nodal explants of adult plants could be stimulated to multiple shoot formation on the basal medium of Murashige and Skoog (1962), supplemented with different cytokinins. The best proliferation (5.33 shoots per culture), together with a healthy appearance of the cultures, was achieved with N-benzyl-9-(2-tetrahydropyranyl)adenine at a concentration of 1 mg/l. Shoots could be easily rooted on hormone-free MS basal medium and subsequently acclimatized to greenhouse and field conditions with 100% survival rate. DNA-fingerprinting, chromosome counts, the proazulene pattern as well as the essential oil analysis proved the true to type character of the micropropagated plants.Abbreviations 2iP 6-(,-Dimethylallylamino)purine - MS Murashige and Skoog (1962) medium - BAP 6-Benzylaminopurine - GA₃ Gibberellic acid - GC gas chromatography - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - Kin Kinetin - PBA N-Benzyl-9-(2-tetrahydropyranyl)adenine - TLC thin layerchromatography - WPM Lloyd and McCown (1981) woody plant medium - Zea Zeatin     

Monitoring of virus diseases in Austrian grapevine varieties and virus elimination using in vitro thermotherapy

Plant Cell, Tissue and Organ Culture (PCTOC) -     

Post traumatic ocular mycosis due to Penicillium oxalicum.

An ocular fungal infection in a 33 year-old man is reported. The patient had a traumatic corneal ulcer with subsequent abscess and perforation. Antibiotics were administered at the beginning of the treatment. Two successive conjunctival flaps were performed but were unsuccessful, followed by a corneal transplant with unfavorable outcome and the appearance of endophthalmitis. Material from the vitreous and corneal ulcer margins was obtained and Penicillium oxalicum Currie & Thom was isolated in the Mycology laboratory. Local and systemic antifungal therapy was unsuccessful and the eyeball was enucleated.     

Differential effects of fatty acids on glycolysis and glycogen metabolism in vascular smooth muscle

The effects of fatty acids of different chain lengths on aerobic glycolysis, lactic acid production, glycogen metabolism and contractile function of vascular smooth muscle were investigated. Porcine carotid artery segments were treated with 50 microM iodoacetate and perchloric acid tissue extracts were then analyzed by 31P-NMR spectroscopy to observe the accumulation of phosphorylated glycolytic intermediates so that the activity of the Embden-Myerhof pathway could be tracked under various experimental paradigms. Aerobic glycolysis and lactate production in resting arteries were almost completely inhibited with 0.5 mM octanoate, partially inhibited with 0.5 mM acetate and unaffected by 0.5 mM palmitate. Inhibition of glycolysis by octanoate was not attributable to inhibition of glucose uptake or glucose phosphorylation. Basal glycogen synthesis was unchanged with palmitate and acetate, but was inhibited by 52% with octanoate incubation. The characteristic glycogenolysis which occurs upon isometric contraction with 80 mM KCl in the absence of fatty acid in the medium was not demonstrable in the presence of any of the fatty acids tested. Glycogen sparing was also demonstrable in norepinephrine contractions with octanoate and acetate, but not with palmitate. Additionally, norepinephrine-stimulated isometric contraction was associated with enhanced synthesis of glycogen amounting to 6-times the basal rate in medium containing octanoate. Contractile responses to norepinephrine were attenuated by 20% in media containing fatty acids. Thus, fatty acids significantly alter metabolism and contractility of vascular smooth muscle. Fatty acids of different chain lengths affect smooth muscle differentially; the pattern of substrate utilization during contraction depends on the contractile agonist and the fatty acid present in the medium.     

Tract formation and axon fasciculation of molecularly distinct peripheral neuron subpopulations during leech embryogenesis.

In leech, the central projections of peripheral sensory neurons segregate into specific axonal tracts, which are distinguished by differential expression of surface antigens recognized by the monoclonal antibodies Lan3-2 and Lan4-2. Lan3-2 recognizes an epitope expressed on axons that segregate into three distinct axon fascicles. In contrast, the Lan4-2-positive axons selectively project into only one of the Lan3-2-positive axon tracts. These observations provide evidence for a hierarchy of guidance cues mediating specific pathway formation in this system. Since the Lan3-2 antibody has been shown to perturb this process and since, as shown here, the Lan3-2 and Lan4-2 antigens are closely molecularly interrelated, these antibodies may help define molecules and epitopes mediating neuronal recognition and axonal guidance.     

Movement Patterns Differ between Sexes and Depend on Weather Conditions in the Butterfly <Emphasis Type="Italic">Lycaena tityrus</Emphasis>

Habitat loss and anthropogenic climate change are important threats to biodiversity conservation. Owing to the concomitantly deteriorating habitat quality, individuals are often forced to disperse to new habitats, rendering dispersal an ecologically important process. However, dispersal ability may differ within and among populations, and is further dependent on environmental conditions. We therefore studied sexual differences in and environmental effects on movement patterns in the sooty copper butterfly Lycaena tityrus. As predicted, males were more active and covered longer distances than females, presumably owing to mate location and territorial disputes. Males alighted more often on flowers than females, probably to fuel their high flight activity, while females showed a high affinity to host-plants for egg-laying. Our findings provide a striking example of sex-related differences in animal behavior, as revealed by the use of customary smartphones, which apparently can comprise suitable means to reveal biologically significant behavioural patterns. More problematic than the technical device used seems to be the challenge of following individual butterflies for long enough in the field, such that any extrapolations to dispersal seem difficult.     

The Dfm1 Derlin Is Required for ERAD Retrotranslocation of Integral Membrane Proteins

1. Download high-res image (251KB)
2. Download full-size image