Aggresome formation by anti-Ras intracellular scFv fragments. The fate of the antigen-antibody complex.

Diverting the antigen from its normal intracellular location to other compartments in an antibody-mediated way represents a mode of action for intracellular antibodies [Cardinale, A., Lener, M., Messina, S., Cattaneo, A. & Biocca, S. (1998) FEBS Lett., 439, 197-202; Lener, M., Horn, I.R., Cardinale, A., Messina, S., Nielsen, U.B., Rybak, S.M., Hoogenboom, H.R., Cattaneo, A. & Biocca, S. (2000) Eur J Biochem. 267, 1196-205]. In the case of p21Ras, the sequestration of the antigen in aggregated structures in the cytoplasm of transfected cells leads to the inhibition of its biological function. We have further investigated the intracellular fate of the antigen-antibody complex by analyzing the effect of proteasome inhibitors on the formation and the intracellular localization of the aggregates. Overexpression of anti-Ras scFv fragments or inhibition of proteasomes activity leads to the formation of large perinuclear aggresomes formed of ubiquitinated-scFv fragments in which p21Ras is sequestered and degraded in an antibody-mediated way. Disruption of microtubules by nocodazole completely abrogates the accumulation of scFv fragments in a single aggresome and induces the dispersion of these structures in the periphery of the cell. Cotransfection of the GFP-scFv with a myc-tagged ubiquitin and colocalization with specific anti-proteasome antibodies indicate the recruitment of exogenous ubiquitin and proteasomes to the newly formed aggresomes. Taken together these results suggest that the intracellular antigen-antibody complex is naturally addressed to the ubiquitin-proteasome pathway and that the mechanism of ubiquitination does not inhibit the antibody binding properties and the capacity to block the antigen function.     

Comparative effects of trichothecene mycotoxins on bovine platelet function: Acetyl T-2 toxin,a more potent inhibitor than T-2 toxin

The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10^?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.     

Active and passive cation transport and L antigen hertogeneity in low potassium sheep red cells

Several lines of experimental evidence are presented suggesting that the L antigens in low potassium (LK) sheep red cells are associated with separate Na(+)K(+) pump flux is distinct from the action of anti-L(l) on K(+) leak flux, implying that K(+) leak transport sites may not be converted into active pumps by the L antiserum. Treatment of LK red cells with trypsin completely abolished both the stimulation of K(+) pump flux and the enhancement of the rate of ouabain binding brought about by anti- L. That this effect is due to a total destruction of the L(p) determinant associated with the LK pump was evident from the complete failure of anti-L(p) to bind to trypsinized LK red cells. The L(p) antigen can be effectively protected against the trypsin attack by prior incubation with anti-L, indicating that the sites for antibody binding and trypsin action may be closely adjacent at the structural level. Trypsin treatment, however, did not interfere with anti-L(l) reducing ouabain insensitive K(+) leak influx, nor did it prevent binding of anti-L(ly), the hemolytically active L antibody which is probably identical with anti-L(l). The functional independence of the L(p) and L(l) sites was documented by the observation that anti-L(l) still reduced K(+) leak influx in LK cells with experimentally induced high potassium concentrations, at which K(+) pump flux is fully suppressed, whether or not anti-L(p) was binding to the L(p) antigen associated with the LK pump.     

Multiple effects of temperature,photoperiod and food quality on the performance of a pine sawfly

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Endophytic bacteria of Sphagnum mosses as promising objects of agricultural microbiology

Sphagnum mosses serve as a unique habitat for microorganisms, which play an important role both for the host plants and the peatland ecosystems. The aim of the present study was to isolate endophytic bacteria from the tissues of Sphagnum mosses and to screen them for strains promising for further application in agricultural microbiology. About 50 samples of Sphagnum fallax (H. Klinggr.) H. Klinggr. and Sphagnum magellanicum Brid. were collected in the Austrian Alps and the Lenindgrad Region of Russia in 2009–2010. Endophytic bacteria were detected inside the moss plants using fluorescent in situ hybridization (FISH) followed by confocal laser scanning microscopy (CLSM). Altogether, 283 isolates were obtained by cultivation on the nutrient media. Examination of the isolates for the antagonistic activity revealed that more than 50% of them could suppress the growth of phytopathogenic and toxigenic fungi. More than 30% of isolates showed some antagonistic activity against microbial phytopathogens. The isolated strains could colonize crops and promote their growth. Molecular-genetic identification coupled with physiological/biochemical characterization showed that the dominant endophytic groups belonged to the genera Burkholderia, Pseudomonas, Flavobacterium, Serratia and Collimonas. The isolated endophytes were shown to be promising objects for the development of effective growth-promoting and protective microbiological preparations to be used in agriculture.     

Activated zeolite—suitable carriers for microorganisms in anaerobic digestion processes?

Plant cell wall structures represent a barrier in the biodegradation process to produce biogas for combustion and energy production. Consequently, approaches concerning a more efficient de-polymerisation of cellulose and hemicellulose to monomeric sugars are required. Here, we show that natural activated zeolites (i.e. trace metal activated zeolites) represent eminently suitable mineral microhabitats and potential carriers for immobilisation of microorganisms responsible for anaerobic hydrolysis of biopolymers stabilising related bacterial and methanogenic communities. A strategy for comprehensive analysis of immobilised anaerobic populations was developed that includes the visualisation of biofilm formation via scanning electron microscopy and confocal laser scanning microscopy, community and fingerprint analysis as well as enzyme activity and identification analyses. Using SDS polyacrylamide gel electrophoresis, hydrolytical active protein bands were traced by congo red staining. Liquid chromatography/mass spectroscopy revealed cellulolytical endo- and exoglucanase (exocellobiohydrolase) as well as hemicellulolytical xylanase/mannase after proteolytic digestion. Relations to hydrolytic/fermentative zeolite colonisers were obtained by using single-strand conformation polymorphism analysis (SSCP) based on amplification of bacterial and archaeal 16S rRNA fragments. Thereby, dominant colonisers were affiliated to the genera Clostridium, Pseudomonas and Methanoculleus. The specific immobilisation on natural zeolites with functional microbes already colonising naturally during the fermentation offers a strategy to systematically supply the biogas formation process responsive to population dynamics and process requirements.     

Identification of Tenrec ecaudatus,a Wild Mammal Introduced to Mayotte Island,as a Reservoir of the Newly Identified Human Pathogenic Leptospira mayottensis

Leptospirosis is a bacterial zoonosis of major concern on tropical islands. Human populations on western Indian Ocean islands are strongly affected by the disease although each archipelago shows contrasting epidemiology. For instance, Mayotte, part of the Comoros Archipelago, differs from the other neighbouring islands by a high diversity of Leptospira species infecting humans that includes Leptospira mayottensis, a species thought to be unique to this island. Using bacterial culture, molecular detection and typing, the present study explored the wild and domestic local mammalian fauna for renal carriage of leptospires and addressed the genetic relationships of the infecting strains with local isolates obtained from acute human cases and with Leptospira strains hosted by mammal species endemic to nearby Madagascar. Tenrec (Tenrec ecaudatus, Family Tenrecidae), a terrestrial mammal introduced from Madagascar, is identified as a reservoir of L. mayottensis. All isolated L. mayottensis sequence types form a monophyletic clade that includes Leptospira strains infecting humans and tenrecs on Mayotte, as well as two other Malagasy endemic tenrecid species of the genus Microgale. The lower diversity of L. mayottensis in tenrecs from Mayotte, compared to that occurring in Madagascar, suggests that L. mayottensis has indeed a Malagasy origin. This study also showed that introduced rats (Rattus rattus) and dogs are probably the main reservoirs of Leptospira borgpetersenii and Leptospira kirschneri, both bacteria being prevalent in local clinical cases. Data emphasize the epidemiological link between the two neighbouring islands and the role of introduced small mammals in shaping the local epidemiology of leptospirosis.     

Reliability and factorial validity of squat and countermovement jump tests

The primary aim of this study was to determine reliability and factorial validity of squat (SJ) and countermovement jump (CMJ) tests. The secondary aim was to compare 3 popular methods for the estimation of vertical jumping height. Physical education students (n = 93) performed 7 explosive power tests: 5 different vertical jumps (Sargent jump, Abalakow's jump with arm swing and without arm swing, SJ, and CMJ) and 2 horizontal jumps (standing long jump and standing triple jump). The greatest reliability among all jumping tests (Cronbach's alpha = 0.97 and 0.98) had SJ and CMJ. The reliability alpha coefficients for other jumps were also high and varied between 0.93 and 0.96. Within-subject variation (CV) in jumping tests ranged between 2.4 and 4.6%, the values being lowest in both horizontal jumps and CMJ. Factor analysis resulted in the extraction of only 1 significant principal component, which explained 66.43% of the variance of all 7 jumping tests. Since all jumping tests had high correlation coefficients with the principal component (r = 0.76-0.87), it was interpreted as the explosive power factor. The CMJ test showed the highest relationship with the explosive power factor (r = 0.87), that is, the greatest factorial validity. Other jumping tests had lower but relatively homogeneous correlation with the explosive power factor extracted. Based on the results of this study, it can be concluded that CMJ and SJ, measured by means of contact mat and digital timer, are the most reliable and valid field tests for the estimation of explosive power of the lower limbs in physically active men.     

Industrial microbiology of solar salt production

Solar salterns can be modeled as giant outdoor chemostats, much like a series of dams on a slow-moving river. Microorganisms and their products play an essential, but sometimes uncharacterized, role in salt production in these ponds, from seawater salinity up through NaCl saturation. They may physically affect the evaporation process and their by-products may chemically modify or bind with dissolved ions. Many solar salt facilities engage microbiologists to establish monitoring programs for analyses of nutrients, standing crop and associated biological variables in the ponds. Other solar salt companies engage microbiologists only when there are “crises” in the ponds that interfere with salt production. Journal of Industrial Microbiology & Biotechnology (2002) 28, 42–47 DOI: 10.1038/sj/jim/7000173 Received 20 May 2001/ Accepted in revised form 13 June 2001     

The effects of whole body vibration on humans: dangerous or advantageous?

The effects of whole body vibration (WBV) have been studied extensively in occupational medicine. In particular, it has been shown that when the body undergoes chronically to whole body vibrations spinal degeneration is likely to be one of the deleterious outcomes. Low back pain has been shown to be the leading major cause of industrial disability in the population under the age of 45 years and has been linked to whole body vibration exposure encountered in some industrial settings. Whole body vibration has been recently purposed as an exercise intervention suggesting its effectiveness in increasing force-generating capacity in lower limbs and low back. It has also been reported to be an effective non-pharmacological intervention for patients with low back pain. Relatively short exposure to whole body vibration has been also shown to increase the serum levels of testosterone and growth hormone. The combined effects on the neuromuscular system and endocrine system seem to suggest its effectiveness as a therapeutic approach for sarcopenia and possibly osteoporosis. Due to the danger of long-term exposure to whole body vibration, it is important to develop safe exercise protocols in order to determine exercise programs for different populations.