Electron microscopy of the paracervical (Frankenhäuser) ganglion of the adult rat

Summary The ultrastructure of the paracervical (Frankenhäuser) ganglion in the rat was studied after immersion or perfusion fixation with glutaraldehyde followed by post-osmification. This ganglion is located at the uterovaginal junction in the vicinity of arteria uterina and contains three neuronal cell types. (1) Principal neurons have a fine structure mainly similar to the ganglion cells of other autonomic ganglia. (2) Small granule-containing cells occur in clusters often close to fenestrated capillaries. They are divided into two subgroups according to the size of their cytoplasmic granules; those containing only small granulated vesicles of 800 to 1400 Å in diameter and those having also large granulated vesicles of 2000 to 3000 Å in diameter. (3) Vacuolated nerve cells are large cells that resemble the principal neurons in their cytoplasmic components, except that they contain one to ten vacuoles with corpuscles of different size and shape. The possible physiological significance of the small, granule-containing cells in the uterine function is discussed.     

Localization of catecholamines and acetylcholinesterase in the terminal nerve fibres of the rabbit myometrium

Summary The autonomic nerves of the myometrium of the rabbit were studied in order to demonstrate simultaneously the adrenergic nature of an axon and the localization of acetylcholinesterase (AChE) in the same axons. The synaptic vesicles of the adrenergic axons and nerve terminals remained partially filled with the electron dense material typical for them after formaldehyde fixation and short incubation time for AChE. AChE stain was localized regularly on the axons which contained agranular synaptic vesicles and also on axons which contained dense cored synaptic vesicles beeing probably adrenergic. The role of AChE on the adrenergic axons is discussed.     

Effect of temperature on the microbiological leaching of sulfide ore material in percolators containing chalcopyrite,pentlandite, sphalerite and pyrrhotite as main minerals

Summary Microbiological leaching of complex sulfide ore material was evaluated in percolators at 4, 10, and 20°C. The onset of leaching was associated with an increase in redox potential and a decrease in pH. Copper from chalcopyrite was leached at a slow rate at each test temperature compared with the leaching of zinc from sphalerite and nickel from pentlandite.     

Frequency alternation and an offbeat rhythm indicate foraging behavior in the echolocating bat, <Emphasis Type="Italic">Saccopteryx bilineata</Emphasis>

The greater sac-winged bat, Saccopteryx bilineata (Emballonuridae), uses two distinct echolocation call sequences: a ‘monotonous’ sequence, where bats emit ~48 kHz calls at a relatively stable rate, and a frequency-alternating sequence, where bats emit calls at ~45 kHz (low-note call) and ~48 kHz (high-note call). The frequencies of these low–high-note pairs remain stable within sequences. In Panama, we recorded echolocation calls from S. bilineata with a multi-microphone array at two sites: one a known roosting site, the other a known foraging site. Our results indicate that this species (1) only produces monotonous sequences in non-foraging contexts and, at times, directly after emitting a feeding buzz and (2) produces frequency-alternating sequences when actively foraging. These latter sequences are also characterized by an unusual, offbeat emission rhythm. We found significant positive relationships between (1) call intensity and call duration and (2) call intensity and distance from clutter. However, these relationships were weaker than those reported for bats from other families. We speculate on how call frequency alternation and an offbeat emission rhythm might reflect a novel strategy for prey detection at the edge of complex habitat in this ancient family of bats.     

Environmental genomics of Late Pleistocene black bears and giant short-faced bears

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Biphasic mini-reactor for characterization of biocatalyst performance

Biphasic reaction media are extending the scope of technical biocatalysis. Thorough investigation of the factors affecting catalyst performance under these conditions is of key importance for the successful implementation of catalytic processes. Here, we present a reactor setup suitable for comprehensive systematic characterization and optimization of biocatalyzed reactions in biphasic systems with distinct phases. It is distinguished by small volumes allowing reproducible experimentation with minimum amounts of solvent and catalyst. The interfacial area is kept constant and independent stirring of both phases is allowed in order to minimize superimposing effects. Evaporation of low-volatile organic solvents is prevented by use of airtight construction. The broad applicability of this mini-reactor is demonstrated with regard to determination of mass transfer, enzyme productivity, and enzyme stability in both batch and continuous mode.     

Isolation and characterization of root-associated bacteria from agricultural crops in the Kavango region of Namibia

Root-associated bacteria can have beneficial effects on their host plants. Microbial products can promote and stimulate plant growth or lead to bioprotection against pathogens. This study aimed to isolate putatively beneficial bacteria from traditional cereals grown by subsistence farmers in the Kavango of Namibia. Bacteria were isolated from surface-sterilized roots of Pennisetum glaucum, Sorghum bicolor, and Zea mays, and subjected to phenotypic and phylogenetic analyses. A total of 44 root-associated bacterial strains were isolated. From 33 distinct isolates, 22 belonged to Firmicutes and Actinobacteria, while 11 were Proteobacteria. Eleven novel phylotypes were among the isolates. Features known to contribute to plant growth-promotion and biocontrol were tested in vitro and revealed promising candidates with multiple beneficial characteristics. This is the first report on the characterization of native isolates associated with important agriculture crops in the Kavango region of Namibia. Such isolates have the potential for application as inoculants adapted to poor soils and local crops. Desiccation-tolerant or sporulating Gram-positive bacteria are of particular interest for this region, which is characterized by a long dry season.     

Continuous flow augments reactivity of rabbit carotid artery by reducing bioavailability of NO despite an increase in release of EDHF

Experiments were designed to investigate the influence of steady flow and pressure on endothelial function in the rabbit carotid artery. Increases and decreases in isometric force were compared in static rings and perfused (5 or 50 ml/min) segments of the same arteries in the presence and absence of endothelium. The alpha(1)-adrenoceptor agonist phenylephrine and the muscarinic agonist acetylcholine were applied as vasoconstrictor and vasodilator stimuli, respectively. Continuous flow (5 and 50 ml/min) reduced the cGMP content and shifted the concentration-response curve to phenylephrine to the left compared with nonperfused static rings. Removal of the endothelium abolished the differences in cGMP content and the sensitivity to phenylephrine between static rings and perfused segments. No difference in sensitivity to phenylephrine was observed in tissues treated with N(omega)-nitro-l-arginine methyl ester (l-NAME). Acetylcholine-evoked relaxations were increased in perfused segments. l-NAME nearly abolished the acetylcholine-evoked relaxation in static rings, whereas about one-half of the relaxation remained in segments exposed to flow. This remnant relaxation was blocked by inhibition of endothelial small- and intermediate-conductance calcium-activated potassium channels by apamin plus 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34). These experiments demonstrate that continuous flow increases the constriction evoked by alpha(1)-adrenergic activation in the rabbit carotid artery through a reduced influence of basally released endothelial NO and, furthermore, that luminal flow unmasks an ability of the endothelium to release a non-NO, noncyclooxygenase vasodilator, presumably endothelium-derived hyperpolarizing factor.     

Immune activation in advanced cancer patients treated with recombinant IL-21: multianalyte profiling of serum proteins

Purpose  Recombinant interleukin-21 (rIL-21) is an immune stimulating cytokine recently tested in two Phase 1 trials for immune responsive cancers. A secondary objective of these trials was to characterize pharmacodynamic responses to rIL-21 in patients. Here, we report the effects of systemic rIL-21 on serum markers of immune stimulation. Experimental design  Recombinant IL-21 was administered by intravenous bolus injection at dose levels from 1 to 100 μg/kg using two distinct treatment regimens: thrice weekly (‘3/w’) for 6 weeks; or once daily for five consecutive days followed by nine dose-free days (‘5 + 9’). In the absence of dose limiting toxicity, additional cycles of dosing were initiated immediately following the nine dose-free days. An array of 70 different proteins was profiled in subject serum samples from several time points during the course of the study. Hierarchical clustering analysis was performed on a normalized subset of these data. Results  Systemic administration of rIL-21 affected the serum levels of several cytokines, chemokines, acute-phase proteins and cell adhesion proteins. The magnitude and duration of response were dose dependent for a subset of these biomarkers. The 5 + 9 dosing regimen generally produced cyclic changes that were of greater magnitude, as compared to a more chronic stimulation with the 3/w dosing regimen. Despite these differences, rIL-21 effects on many analytes were similar between regimens when averaged over the time of treatment. Based on similar temporal, between-subject and dose response changes, groups of analytes were identified that exhibited distinct components of the rIL-21-mediated immune activation. Biomarkers indicative of lymphocyte activation (increased IL-16, decreased RANTES), acute phase response (increased CRP, ferritin), myeloid activation (increased MDC, MIP-1 alpha), and leukocyte chemotaxis/trafficking (increased sCAMs, MCP-1) were strongly modulated in subjects treated with rIL-21. Conclusions  Administration of rIL-21 resulted in activation of multiple cell types and immune response pathways. The changes observed in serum proteins were consistent with coincident processes of lymphoid and myeloid cell activation and trafficking, and acute phase response. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.