Experimental effects of immersion time and water temperature on body condition,burying depth and timing of spawning of the tellinid bivalve <Emphasis Type="Italic">Macoma balthica</Emphasis>

The burying depth of many bivalve molluscs on intertidal mudflats varies throughout the year and differs between places. Many factors are known to influence burying depth on a seasonal or spatial scale, with temperature and tidal regime probably being very important. Burying depth, body condition and gonadal development of Macoma balthica were followed throughout winter and spring in an experiment in which water temperature and immersion time were manipulated. Unexpectedly, relative water temperature, in contrast to the prediction, did not generally affect body condition or burying depth. This was probably a consequence of the exceptionally overall low water temperatures during the experimental winter. Differences in temperature did, however, result in different timing of spawning: M. balthica spawned earlier at higher spring temperatures. Longer immersion times led to higher body condition only late in spring, but led to deeper burying throughout almost the whole period. There was no effect of immersion time on the timing of spawning. We conclude that a longer immersion time leads to deeper burying, independent of body condition. We also conclude that burying behaviour of M. balthica is not determined by the moment of spawning. Electronic Publication     

The role of volatiles in plant communication

Volatiles mediate the interaction of plants with pollinators, herbivores and their natural enemies, other plants and micro‐organisms. With increasing knowledge about these interactions the underlying mechanisms turn out to be increasingly complex. The mechanisms of biosynthesis and perception of volatiles are slowly being uncovered. The increasing scientific knowledge can be used to design and apply volatile‐based agricultural strategies.     

Alternative drying processes for the industrial preservation of lactic acid starter cultures

The preservation of lactic acid starter cultures by alternative drying processes has attracted increasing attention due to the high costs and energy consumption of freezing and freeze drying. This review thus aims to provide a survey regarding the state of knowledge of starter culture production at high levels of viability. The results from numerous studies on various drying processes and lactic acid bacteria are summarized. The alternative drying processes considered, such as spray drying, fluidized bed drying, and vacuum drying, are mainly of industrial interest. The features, advantages, and disadvantages of these drying processes are described. In conclusion, the important factors that need to be considered, standardized, or optimized to achieve high levels of viability include intrinsic tolerance of cultures, growth media and conditions, stress induction, cell harvesting conditions, protective agents, rehydration conditions, enumeration of cells, and storage conditions.     

Prion strain discrimination using luminescent conjugated polymers

The occurrence of multiple strains of prions may reflect conformational variability of PrP(Sc), a disease-associated, aggregated variant of the cellular prion protein, PrP(C). Here we used luminescent conjugated polymers (LCPs), which emit conformation-dependent fluorescence spectra, for characterizing prion strains. LCP reactivity and emission spectra of brain sections discriminated among four immunohistochemically indistinguishable, serially mouse-passaged prion strains derived from sheep scrapie, chronic wasting disease (CWD), bovine spongiform encephalopathy (BSE), and mouse-adapted Rocky Mountain Laboratory scrapie prions. Furthermore, using LCPs we differentiated between field isolates of BSE and bovine amyloidotic spongiform encephalopathy, and identified noncongophilic deposits in prion-infected deer and sheep. We found that fibrils with distinct morphologies generated from chemically identical recombinant PrP yielded unique LCP spectra, suggesting that spectral characteristic differences resulted from distinct supramolecular PrP structures. LCPs may help to detect structural differences among discrete protein aggregates and to link protein conformational features with disease phenotypes.     

A method to enable the investigation of murine bronchial immune cells, their cytokines and mediators

Innovative therapies for severe lung diseases (such as allergic and chronic asthma, chronic obstructive pulmonary disease or any type of lung cancer) require a detailed understanding of the cellular and immune processes in the lung. This protocol details a method to obtain the immune cells of the bronchi as well as the cytokines and mediators produced by these cells for further investigation. The broncho-alveolar lavage fluid (BALF) is taken by injecting physiological solution through the tracheal tube into the murine airways and carefully regained by winding up the connected syringe. After centrifugation, the resulting BALF supernatant can be stored for detection of cytokines or other mediators by enzyme-linked immunosorbent assay or other methods; the resuspended cell pellet can also be used for flow cytometric analyses, to check cell viability and the level of apoptosis, as well as other applications. In addition, CD4+ T cells isolated from wild-type and genetically modified mice alone or along with other immunologically important cells such as T regulatory cells, which can be used to reconstitute immunodeficient mice, may be retrieved from the airways with this method. This protocol can be completed within 35 min.     

Administration of keratinocyte growth factor down-regulates the pulmonary capacity of acetylcholine production

Keratinocyte growth factor protects the lung against various injurious stimuli. The protective mechanisms, however, are not yet fully understood. The aim of this study is to determine the influence of keratinocyte growth factor on the pulmonary capacity to synthesize acetylcholine, a potent regulator of pulmonary functions which is potentially involved in lung damage. Rats were treated twice (days 1 and 2) intratracheally with keratinocyte growth factor and analyzed at day 4. The mRNA expression of choline acetyltransferase - the acetylcholine synthesizing enzyme - was analyzed by real-time RT-PCR in the lung and in isolated alveolar epithelial type II cells. Choline acetyltransferase protein was assessed by immunoblotting and immunohistochemistry. Finally, pulmonary acetylcholine content was assessed biochemically. Keratinocyte growth factor-treatment led to decreased levels of choline acetyltransferase mRNA in the lung and in isolated alveolar epithelial type II cells. Accordingly, pulmonary choline acetyltransferase protein levels were reduced and pulmonary acetylcholine content declined from 2.8 nmol (control) to 0.4 nmol acetylcholine per gram of wet weight. In conclusion, the present data show that the potent regulator of pulmonary functions, acetylcholine, is produced by the major pulmonary target cell of keratinocyte growth factor, that is alveolar epithelial type II cells. Acetylcholine synthesis is down-regulated by keratinocyte growth factor administration which might contribute to lung protection and to harmonize surfactant homeostasis under conditions of keratinocyte growth factor-induced alveolar epithelial type II cell hyperplasia.