Identification of Francisella tularensis in natural water samples by PCR

Abstract Francisella tularensis , the causative agent of the epizootic disease tularemia in mammals, can be isolated from mud and water. To study the spread and persistence of Francisella tularensis in water, different strategies for pre-treatment of natural water samples prior to identification of the bacterium by polymerase chain reaction (PCR) were evaluated. A method for handling of samples taken from natural waters was developed. Applied on natural water samples amended with F. tularensis , the method rendered identification by PCR reproducible and it resulted in an amplified Francisella -specific product in all samples from natural waters tested. In addition, by employing primers targeting conserved regions of the 16S rDNA the presence of bacteria was demonstrated in all samples investigated. The results presented will, in combination with other techniques that allow identification, improve studies on the epizootiology and epidemiology of the genus Francisella .     

Experiments on adhesive dispersal by wood mouse: seed shadows and dispersal distances of 13 plant species from cultivated areas in southern Sweden

This study on epizoochory offers experimental data on retention times and potential dispersal distances of propagules of 13 plant species that commonly inhabit cultivated areas in the south of Sweden. Wood mouse Apodemus flavicollis was used as dispersal vector. Seven of the investigated species produce fruits that carry obvious hooks, barbs or bristles and for comparison the remaining six species, lacking such features, were also included. Excised fruits that initially carried appendages were used in a complementary comparison. Propagules were applied by hand to the back of the animals, which were which released in enclosures to move about freely. Observations were made continually until the seeds were dropped. The distance covered by the animals while moving was measured and the potential dispersal distances calculated. Small fruits were in general found to be more efficiently transported than large ones, but large propagules carrying appendages sometimes remained in place for considerable periods. The potential dispersal distances ranged up to nearly 30 m. The retention time was significantly enhanced by the presence of dispersal attributes. The behavioural pattern of the animals (grooming, movements) plays a significant part in the successful transportation of propagules. By comparing the result with similar experiments using fallow deer Dama dama and domestic cattle Bos taurus as dispersal vectors it can be stated that mice are surprisingly effective as seed dispersers. Large mammals disperse propagules on a larger scale (<1 km) compared with small mammals, that affect plant distribution more locally (<100 m). We consider adhesive dispersal a most significant component in plant metapopulation dynamics, considerably enhancing the probability of occasional propagules reaching suitable sites in a fragmented landscape.     

Effect of a High-Intensity Exercise Program on Physical Function and Mental Health in Nursing Home Residents with Dementia: An Assessor Blinded Randomized Controlled Trial

Background

Dementia is among the leading causes of functional loss and disability in older adults. Research has demonstrated that nursing home patients without dementia can improve their function in activities of daily living, strength, balance and mental well being by physical exercise. The evidence on effect of physical exercise among nursing home patients with dementia is scarce and ambiguous. Thus, the primary objective of this study was to investigate the effect of a high intensity functional exercise program on the performance of balance in nursing home residents with dementia. The secondary objective was to examine the effect of this exercise on muscle strength, mobility, activities of daily living, quality of life and neuropsychiatric symptoms.

Design and Methods

This single blinded randomized controlled trial was conducted among 170 persons with dementia living in nursing homes. Mean age was 86.7 years (SD = 7.4) and 74% were women. The participants were randomly allocated to an intervention (n = 87) or a control group (n = 83). The intervention consisted of intensive strengthening and balance exercises in small groups twice a week for 12 weeks. The control condition was leisure activities.

Results

The intervention group improved the score on Bergs Balance Scale by 2.9 points, which was significantly more than the control group who improved by 1.2 points (p = 0.02). Having exercised 12 times or more was significantly associated with improved strength after intervention (p<0.05). The level of apathy was lower in the exercise group after the intervention, compared to the control group (p = 0.048).

Conclusion

The results from our study indicate that a high intensity functional exercise program improved balance and muscle strength as well as reduced apathy in nursing home patients with dementia.

Trial Registration

ClinicalTrials.gov NCT02262104     

Spider odors induce stoichiometric changes in fruit fly Drosophila melanogaster

Animal senses and signals are amazingly diverse,and the major modalities by which animals acquire sensory input from their environments are sound,light,vibration,and chemical signals.Insects mainly rely on visual,nociceptive,and olfactory cues to discriminate between rewards and risks.It has been shown that the visual and olfactory cues of predators substantially affect the adult phenotype in Drosophila melanogaster(Krams et al.2016),a prominent animal model for biological research.     

High interstitial fluid pressure is associated with low tumour penetration of diagnostic monoclonal antibodies applied for molecular imaging purposes

The human epithelial cell adhesion molecule (EpCAM) is highly expressed in a variety of clinical tumour entities. Although an antibody against EpCAM has successfully been used as an adjuvant therapy in colon cancer, this therapy has never gained wide-spread use. We have therefore investigated the possibilities and limitations for EpCAM as possible molecular imaging target using a panel of preclinical cancer models. Twelve human cancer cell lines representing six tumour entities were tested for their EpCAM expression by qPCR, flow cytometry analysis and immunocytochemistry. In addition, EpCAM expression was analyzed in vivo in xenograft models for tumours derived from these cells. Except for melanoma, all cell lines expressed EpCAM mRNA and protein when grown in vitro. Although they exhibited different mRNA levels, all cell lines showed similar EpCAM protein levels upon detection with monoclonal antibodies. When grown in vivo, the EpCAM expression was unaffected compared to in vitro except for the pancreatic carcinoma cell line 5072 which lost its EpCAM expression in vivo. Intravenously applied radio-labelled anti EpCAM MOC31 antibody was enriched in HT29 primary tumour xenografts indicating that EpCAM binding sites are accessible in vivo. However, bound antibody could only be immunohistochemically detected in the vicinity of perfused blood vessels. Investigation of the fine structure of the HT29 tumour blood vessels showed that they were immature and prone for higher fluid flux into the interstitial space. Consistent with this hypothesis, a higher interstitial fluid pressure of about 12 mbar was measured in the HT29 primary tumour via "wick-in-needle" technique which could explain the limited diffusion of the antibody into the tumour observed by immunohistochemistry.     

Rat liver peroxisomes after fibrate treatment. A survey using quantitative mass spectrometry

Fibrates are known to induce peroxisome proliferation and the expression of peroxisomal beta-oxidation enzymes. To analyze fibrate-induced changes of complex metabolic networks, we have compared the proteome of rat liver peroxisomes from control and bezafibrate-treated rats. Highly purified peroxisomes were subfractionated, and the proteins of the matrix, peripheral, and integral membrane subfractions thus obtained were analyzed by matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry after labeling of tryptic peptides with the iTRAQ reagent. By means of this quantitative technique, we were able to identify 134 individual proteins, covering most of the known peroxisomal proteome. Ten predicted new open reading frames were verified by cDNA cloning, and seven of them could be localized to peroxisomes by immunocytochemistry. Moreover, quantitative mass spectrometry substantiated the induction of most of the known peroxisome proliferator-activated receptor alpha-regulated peroxisomal proteins upon treatment with bezafibrate, documenting the suitability of the iTRAQ procedure in larger scale experiments. However, not all proteins reacted to a similar extent but exerted a fibrate-specific induction scheme showing the variability of peroxisome proliferator-activated receptoralpha-transmitted responses to specific ligands. In view of our data, rat hepatic peroxisomes are apparently not specialized to sequester very long chain fatty acids (C22-C26) but rather metabolize preferentially long chain fatty acids (C16-18).     

How does climate warming affect plant‐pollinator interactions?

Climate warming affects the phenology, local abundance and large-scale distribution of plants and pollinators. Despite this, there is still limited knowledge of how elevated temperatures affect plant-pollinator mutualisms and how changed availability of mutualistic partners influences the persistence of interacting species. Here we review the evidence of climate warming effects on plants and pollinators and discuss how their interactions may be affected by increased temperatures. The onset of flowering in plants and first appearance dates of pollinators in several cases appear to advance linearly in response to recent temperature increases. Phenological responses to climate warming may therefore occur at parallel magnitudes in plants and pollinators, although considerable variation in responses across species should be expected. Despite the overall similarities in responses, a few studies have shown that climate warming may generate temporal mismatches among the mutualistic partners. Mismatches in pollination interactions are still rarely explored and their demographic consequences are largely unknown. Studies on multi-species plant-pollinator assemblages indicate that the overall structure of pollination networks probably are robust against perturbations caused by climate warming. We suggest potential ways of studying warming-caused mismatches and their consequences for plant-pollinator interactions, and highlight the strengths and limitations of such approaches.     

Molecular organization of the tear fluid lipid layer

The tear fluid protects the corneal epithelium from drying out as well as from invasion by pathogens. It also provides cell nutrients. Similarly to lung surfactant, it is composed of an aqueous phase covered by a lipid layer. Here we describe the molecular organization of the anterior lipid layer of the tear film. Artificial tear fluid lipid layers (ATFLLs) composed of egg yolk phosphatidylcholine (60 mol %), free fatty acids (20 mol %), cholesteryl oleate (10 mol %), and triglycerides (10 mol %) were deposited on the air-water interface and their physico-chemical behavior was compared to egg-yolk phosphatidylcholine monolayers by using Langmuir-film balance techniques, x-ray diffraction, and imaging techniques as well as in silico molecular level simulations. At low surface pressures, ATFLLs were organized at the air-water interface as heterogeneous monomolecular films. Upon compression the ATFLLs collapsed toward the air phase and formed hemispherelike lipid aggregates. This transition was reversible upon relaxation. These results were confirmed by molecular-level simulations of ATFLL, which further provided molecular-scale insight into the molecular distributions inside and dynamics of the tear film. Similar type of behavior is observed in lung surfactant but the folding takes place toward the aqueous phase. The results provide novel information of the function of lipids in the tear fluid.