Assessing the Efficiency of the Ability to Intentionally Variate the Power of β<Subscript>2</Subscript> Frequencies in the Frontal Lobes of the Cerebral Cortex

We performed longitudinal examinations by neurofeedback in 17 subjects. The subjects were trained for 12 training seßsions (three weeks) to voluntarily increase the intensity of the ß₂ frequencies in the frontal EEG electrodes of the right (the D scenario) and the left (the S scenario) hemispheres. All the subjects were divided into three groups depending on the training efficacy: a group of subjects that successfully controlled the ß activity in the frontal electrodes of both hemispheres (nine subjects), a group of subjects that successfully controlled this activity only in the right hemisphere (four subjects), and a group of subjects that failed to train during the specified period (four subjects). Analysis of the obtained data showed that the training efficacy depended on the cognitive activity that was focused on achieving the corresponding EEG effects and on the individual personality characteristics.     

Review: Transport of tRNA out of the Nucleus—Direct Channeling to the Ribosome?

Although tRNA was the first substrate whose export from the nuclei of eukaryotic cells had been shown to be carrier-mediated and active, it has only been in the last 2 years that the first mechanistic details of this nucleocytoplasmic transport pathway have begun to emerge. A member of the importin/karyopherin β superfamily, Los1p in yeast and Xpo-t in vertebrates, has been shown to export tRNA in cooperation with the small GTPase Ran (Gsp1p) from the nucleus into the cytoplasm, where tRNA becomes available for translation. However, Los1p is not essential for viability in yeast cells, suggesting that alternative tRNA export pathways exist. Recent results show that aminoacylation and a translation factor are also required for efficient nuclear tRNA export. Thus, protein translation and nuclear export of tRNA appear to be coupled processes.     

Validity of the bereavement exclusion to major depression: does the empirical evidence support the proposal to eliminate the exclusion in DSM-5?

The DSM-IV major depression "bereavement exclusion" (BE), which recognizes that depressive symptoms are sometimes normal in recently bereaved individuals, is proposed for elimination in DSM-5. Evidence cited for the BE's invalidity comes from two 2007 reviews purporting to show that bereavement-related depression is similar to other depression across various validators, and a 2010 review of subsequent research. We examined whether the 2007 and 2010 reviews and subsequent relevant literature support the BE's invalidity. Findings were: a) studies included in the 2007 reviews sampled bereavement-related depression groups most of whom were not BE-excluded, making them irrelevant for evaluating BE validity; b) three subsequent studies cited by the 2010 review as supporting BE elimination did examine BE-excluded cases but were in fact inconclusive; and c) two more recent articles comparing recurrence of BE-excluded and other major depressive disorder cases both support the BE's validity. We conclude that the claimed evidence for the BE's invalidity does not exist. The evidence in fact supports the BE's validity and its retention in DSM-5 to prevent false positive diagnoses. We suggest some improvements to increase validity and mitigate risk of false negatives.     

Ability of Vasconcellea × heilbornii lipase to catalyse the synthesis of alkyl esters from vegetable oils

Lipase-catalysed synthesis of alkyl esters is regarded as a potential alternative to chemical catalysis. Owing to its availability as a waste material from the babaco fruit production, its strong lipolytic activity and its natural immobilization, the dried latex of Vasconcellea × heilbornii appears as a good candidate to produce alkyl esters. The ability and performance of this lipase to catalyse the alcoholysis of sunflower oil with various primary alcohols was evaluated in a solvent-free system. A linear correlation between the final reaction rate and the alcohol polarity was established. For methanolysis, the influence of substrates ratio on final conversion rate was studied at different temperatures. At 30 °C, the lipase was inactivated by shaking in a mixture containing more than 0.5 molar equivalents of methanol; the minimum methanol concentration for enzyme deactivation increased with temperature. Moreover, for a 0.5:1 methanol/TAG molar ratio, conversion rates of 73, 66 and 55% were obtained at 30, 40 and 55 °C respectively, showing that the increase of temperature diminished the final methanolysis conversion rate. These facts were associated to the miscibility of methanol in oil and to the thermodynamic state of the medium. To overcome the inactivation of the lipase by methanol, alcoholysis was carried out by fractionated addition of methanol. In those conditions, Vasconcellea × heilbornii latex could catalyse the conversion of 70% of sunflower TAGs in methyl esters at 30 °C.     

Introduction to the Special Issue <Emphasis Type="Italic">Semiotics of Perception</Emphasis> Being in the World of the Living—Semiotic Perspectives

This special issue on the semiotics of perception originates from two workshops arranged in Tartu, Estonia, in February 2009. We are located at the junction of nature and culture, and of semiotics and phenomenology. Can they be reconciled? More particularly, can subfields such as biosemiotics and ecophenomenology be mutually enriching? The authors of the current special issue believe that they can. Semiotic study of life and the living can emerge as properly informed only if it is capable of incorporating observations made in natural science, philosophy and cultural studies. The semiotic study of nature entails an experiential turn in the study of life processes. Perception is—or should be—at the heart of the life sciences.     

Biotransformation of tolbutamide to 4′-hydroxytolbutamide by the fungus Cunninghamella blakesleeana

The hypoglycemic drug tolbutamide is commonly used as a probe drug to evaluate CYP2C9 enzyme activity in terms of production of 4′-hydroxytolbutamide. In the present study, an initial screening of seven filamentous fungi was carried out to identify which was most competent to transform tolbutamide into 4′-hydroxytolbutamide. From this screening, the fungus Cunninghamella blakesleeana AS 3.910 was selected as a suitable bioconverter. At a concentration of 1.2 mg ml⁻¹, the growing fungus transformed 95.0% of tolbutamide into 4′-hydroxytolbutamide in 96 h. With resting culture, the yield could reach 91.7% and exceeded 91.0% even when the tolbutamide concentration was increased to 4.0 mg ml⁻¹. On scale-up to 3 l buffer containing 12.0 g tolbutamide, 90% of tolbutamide was transformed into 4′-hydroxytolbutamide in 96 h. Work-up of the broth by column chromatography and recrystallization yielded 6.5 g (53.9% recovered) of 4′-hydroxytolbutamide with a purity of more than 99%. These results suggest C. blakesleeana AS 3.910 is a useful biosynthetic tool in the preparation of 4′-hydroxytolbutamide.     

Modification of the structural and functional response of the heart and systemic hemodynamics to the cardioselective β<Subscript>1</Subscript>-blockers in patients with arterial hypertension and adaptation to cold

We investigated the features of the structural and functional organization of the left heart (ventricle—LV, atrium—LA) and the state of systemic hemodynamics at rest and in response to a single dose of cardioselective β₁-blocker (BB) Egilok. We examined the patients with stage II (1–2 degrees) of arterial hypertension (AH); the study was performed in summer and winter in the northern regions of Russia. It was found that the process of adaptation to cold is accompanied by the inhibition of the pacemaker, a decrease in the rate of active diastolic blood filling of the LV and transaortic blood flow in the aortic root (VAo), an increase in the contractility of the LV posterior wall and interventricular septum (IVS). The negative chronotropic cardiac effect in these conditions results in the reduction of heart productivity per minute in 65% of cases. In winter we observed a more pronounced diastolic LV dysfunction and a decrease in the connectivity of active relaxation of LV posterior wall and LA walls with certain structural and functional cardiac parameters. In contrast to summer, in winter period BB causes a decrease in the active relaxation of LA walls and IVS and LA contractility, which leads to a decrease in the blood filling of passive and active LV. At the same time, LV systolic function (ejection fraction, VAo) and the rhythm and the performance of the heart (stroke volume and cardiac output) decreases; the hypotensive effect accompanied by an increase in peripheral vascular resistance is more pronounced. In winter, the effect of BB reduces the correlation between IVS and LV posterior wall contractions, but the feedback rate or passive to active LV diastolic hyperemia and after load increases. We suggest that in winter component “contractile apparatus” retains its the leading role in the organization of intracardiac response to the BB in patients with hypertension; in addition, new dominant components were formed: “contingency of the LV wall contraction with afterload” and “reverse contingency of early and late diastolic LV function.”     

From red to blue to far-red in Lhca4: How does the protein modulate the spectral properties of the pigments?

The first event of photosynthesis is the harvesting of solar energy by a large array of pigments. These pigments are coordinated to proteins that organize them to assure efficient excitation energy transfer. The protein plays an essential role in tuning the spectroscopic properties of the pigments, by determining their site energy and/or by favoring pigment-pigments interactions. Here we investigate how the protein modulates the pigment properties by using a single-point-mutation approach. We monitor changes in the low-energy absorption/emission band of Lhca4, which is well separated from the bulk absorption and thus represents an attractive model system. Moreover, it was recently shown that Lhca4 exists in at least two conformations, a dominating one emitting at 720nm and a second one emitting at 685nm (Kruger et al. PNAS 2011). Here we show that a single amino-acid substitution (from Asn to Gln, which are both chlorophyll-binding residues and only differ for one C-C bond), moves the equilibrium almost completely towards the 685-nm conformation. This indicates that small changes in the protein can have a large effect on the properties of the pigments. We show that His99, which was suggested to coordinate a red-absorbing chlorophyll (Melkozernov and Blankenship, JBC 2003), is not a chlorophyll ligand. We also show that single amino-acid substitutions nearby the chlorophylls allow to tune the emission spectrum of the pigments over a wide range of wavelengths and to modulate the excited-state lifetimes of the complex. These findings are discussed in the light of previously proposed non-photochemical quenching models.     

Deficiency of p110δ Isoform of the Phosphoinositide 3 Kinase Leads to Enhanced Resistance to Leishmania donovani

Background

Visceral leishmaniasis is the most clinically relevant and dangerous form of human leishmaniasis. Most traditional drugs for treatment of leishmaniasis are toxic, possess many adverse reactions and drug resistance is emerging. Therefore, there is urgent need for identification of new therapeutic targets. Recently, we found that mice with an inactivating knock-in mutation in the p110δ isoform of pi3k, (p110δ^d910a) are hyper resistant to L. major, develop minimal cutaneous lesion and rapidly clear their parasite. Here, we investigated whether pi3k signaling also regulates resistance to L. donovani, one of the causative agents of visceral leishmaniasis.

Methodology/Principal Findings

WT and p110δ^D910A mice (on a BALB/c background) were infected with L. donovani. At different time points, parasite burden and granuloma formation were assessed. T and B cell responses in the liver and spleen were determined. In addition, Tregs were expanded in vivo and its impact on resistance was assessed. We found that p110δ^D910A mice had significantly reduced splenomegaly and hepatomegaly and these organs harbored significantly fewer parasites than those of WT mice. Interestingly, infected p110δ^D910A mice liver contains fewer and less organized granulomas than their infected WT counterparts. Cells from p110δ^D910A mice were significantly impaired in their ability to produce cytokines compared to WT mice. The percentage and absolute numbers of Tregs in infected p110δ^D910A mice were lower than those in WT mice throughout the course of infection. In vivo expansion of Tregs in infected p110δ^D910A mice abolished their enhanced resistance to L. donovani infection.

Conclusions/Significance

Our results indicate that the enhanced resistance of p110δ^D910A mice to L. donovani infection is due to impaired activities of Tregs. They further show that resistance to Leishmania in the absence of p110δ signaling is independent of parasite species, suggesting that targeting the PI3K signaling pathway may be useful for treatment of both visceral and cutaneous leishmaniasis.     

Downregulation of integrin β4 decreases the ability of airway epithelial cells to present antigens

Airway epithelial cells have been demonstrated to be accessory antigen presentation cells (APC) capable of activating T cells and may play an important role in the development of allergic airway inflammation of asthma. In asthmatic airways, loss of expression of the adhesion molecule integrin β4 (ITGB4) and an increase in Th2 inflammation bias has been observed in our previous study. Given that ITGB4 is engaged in multiple signaling pathways, we studied whether disruption of ITGB4-mediated cell adhesion may contribute to the adaptive immune response of epithelial cells, including their ability to present antigens, induce the activate and differentiate of T cells. We silenced ITGB4 expression in bronchial epithelial cells with an effective siRNA vector and studied the effects of ITGB4 silencing on the antigen presentation ability of airway epithelial cells. T cell proliferation and cytokine production was investigated after co-culturing with ITGB4-silenced epithelial cells. Surface expression of B7 homologs and the major histocompatibility complex (MHC) class II was also detected after ITGB4 was silenced. Our results demonstrated that silencing of ITGB4 resulted in impaired antigen presentation processes and suppressed T cell proliferation. Meanwhile, decrease in Th1 cytokine production and increase in Th17 cytokine production was induced after co-culturing with ITGB4-silenced epithelial cells. Moreover, HLA-DR was decreased and the B7 homologs expression was different after ITGB4 silencing. Overall, this study suggested that downregulation of ITGB4 expression in airway epithelial cells could impair the antigen presentation ability of these cells, which further regulate airway inflammation reaction in allergic asthma.     

TMPRSS4-dependent activation of the epithelial sodium channel requires cleavage of the γ-subunit distal to the furin cleavage site

The epithelial sodium channel (ENaC) is activated by a unique mechanism, whereby inhibitory tracts are released by proteolytic cleavage within the extracellular loops of two of its three homologous subunits. While cleavage by furin within the biosynthetic pathway releases one inhibitory tract from the α-subunit and moderately activates the channel, full activation through release of a second inhibitory tract from the γ-subunit requires cleavage once by furin and then at a distal site by a second protease, such as prostasin, plasmin, or elastase. We now report that coexpression of mouse transmembrane protease serine 4 (TMPRSS4) with mouse ENaC in Xenopus oocytes was associated with a two- to threefold increase in channel activity and production of a unique ～70-kDa carboxyl-terminal fragment of the γ-subunit, similar to the ～70-kDa γ-subunit fragment that we previously observed with prostasin-dependent channel activation. TMPRSS4-dependent channel activation and production of the ～70-kDa fragment were partially blocked by mutation of the prostasin-dependent cleavage site (γRKRK186QQQQ). Complete inhibition of TMPRSS4-dependent activation of ENaC and γ-subunit cleavage was observed when three basic residues between the furin and prostasin cleavage sites were mutated (γK173Q, γK175Q, and γR177Q), in addition to γRKRK186QQQQ. Mutation of the four basic residues associated with the furin cleavage site (γRKRR143QQQQ) also prevented TMPRSS4-dependent channel activation. We conclude that TMPRSS4 primarily activates ENaC by cleaving basic residues within the tract γK173-K186 distal to the furin cleavage site, thereby releasing a previously defined key inhibitory tract encompassing γR158-F168 from the γ-subunit.     

Influence of chronic exposure to low doses of γ-radiation and <Superscript>90</Superscript>Sr on the level of DNA breaks and cell sensitivity to hydrogen peroxide in the mouse spleen

Using comet assay, a statistically significant increase (p < 0.05) in the level of DNA breaks in spleen cells was revealed in male CBA/lac mice exposed to γ-radiation (1.7 mGy/day) or ⁹⁰Sr (150–250 Bq/day) for 210 days. The level of DNA breaks also increased under combined exposure to both γ-radiation and ⁹⁰Sr (p < 0.05), but to a lesser degree than under exposure to each of these factors alone. Upon additional in vitro treatment of spleen cells with hydrogen peroxide, the relative increase in the level of DNA breaks was smaller in cells of irradiated mice than in the control. The ratio of the level of DNA breaks after hydrogen peroxide treatment to that before this treatment in control mice was 4.2 ± 0.9, compared to 1.4 ± 0.6 in γ-irradiated mice, 1.9 ± 0.8 in ⁹⁰Sr-irradiated mice, and 2.3 ± 0.8 in mice exposed to both γ- and ⁹⁰Sr-irradiation.     

Use of intercellular washing fluid to investigate the secreted proteome of the rice–<Emphasis Type="Italic">Magnaporthe</Emphasis> interaction

Early interactions between invading penetration hyphae of the pathogenic fungus Magnaporthe oryzae and rice cells occur at the apoplast, the free diffusional space outside the plasma membrane of leaves. After initial colonization, intercellular hyphae are again in intimate contact with the rice apoplast. While several studies have looked at proteomics in rice–Magnaporthe interactions, none have focused on apoplast localized proteins. We adjusted a protocol for intercellular washing fluids (IWF) to rice leaves infected with Magnaporthe oryzae for proteomic analysis. In our IWF extract, we identified several proteins associated with compatible or incompatible pathogen interactions. Three DUF26 domain proteins were identified as changing in abundance 12 h after inoculation, confirming DUF26 domain-containing proteins are among early, pathogen stress-responsive proteins induced by infection with Magnaporthe oryzae. A Magnaporthe cyclophilin, previously identified as a virulence factor was also identified in the intercellular washing fluid.     

Does the response of the intestinal epithelium to keratinocyte growth factor vary according to the method of administration?

BACKGROUND: Keratinocyte growth factor (KGF) is a potent mitogen and may be of value for the treatment of conditions such as short bowel syndrome and chemotherapy-induced mucositis. However the most efficacious route and method of administration is unclear. METHODS: Rats maintained by total parenteral nutrition (TPN) were given KGF (1 mg/kg/rat/day, i.v.) infused continuously or as a once-daily injection. The same dose was also given s.c. to chow-fed rats. Changes in gut growth were assessed by measurement of wet weight, proliferation (vincristine induced metaphase arrest) and crypt branching index. Changes in gut hormone profile were also determined to examine if any trophic effects were mediated via this mechanism. RESULTS: KGF caused a 70-100% increase in wet weight of the stomach, small and large intestine of TPN-fed rats (P < 0.01) with no significant differences seen between the two methods of administration. The increase in metaphase counts was greatest in the stomach (about seven-fold P < 0.01), but was less pronounced in the distal small intestine and colon (about 50% increase). The trophic effect of KGF was much less prominent in orally-fed rats. Crypt branching index was significantly reduced by KGF in the proximal small intestine of TPN, but not orally-fed rats. Plasma gastrin, PYY, total glucagon, enteroglucagon and GLP-1 all increased by two-three-fold (all P < 0.01) in response to KGF whereas insulin levels fell by about 25% in the TPN group. CONCLUSIONS: The mitogenic action of KGF occurred predominantly in the stomach and proximal small intestine. Its efficacy was less pronounced in orally-fed animals, suggesting KGF may be of greatest benefit in conditions associated with lowered intestinal proliferation. Clinical trials of KGF can probably use single daily i.v. injections without reduction in efficacy.     

Identification of sorting motifs of AtβFruct4 for trafficking from the ER to the vacuole through the Golgi and PVC

Although much is known about the molecular mechanisms involved in transporting soluble proteins to the central vacuole, the mechanisms governing the trafficking of membrane proteins remain largely unknown. In this study, we investigated the mechanism involved in targeting the membrane protein, AtβFructosidase 4 (AtβFruct4), to the central vacuole in protoplasts. AtβFruct4 as a green fluorescent protein (GFP) fusion protein was transported as a membrane protein during transit from the endoplasmic reticulum (ER) through the Golgi apparatus and the prevacuolar compartment (PVC). The N-terminal cytosolic domain of AtβFruct4 was sufficient for transport from the ER to the central vacuole and contained sequence motifs required for trafficking. The sequence motifs, LL and PI, were found to be critical for ER exit, while the EEE and LCPYTRL sequence motifs played roles in trafficking primarily from the trans Golgi network (TGN) to the PVC and from the PVC to the central vacuole, respectively. In addition, actin filaments and AtRabF2a, a Rab GTPase, played critical roles in vacuolar trafficking at the TGN and PVC, respectively. On the basis of these results, we propose that the vacuolar trafficking of AtβFruct4 depends on multiple sequence motifs located at the N-terminal cytoplasmic domain that function as exit and/or sorting signals in different stages during the trafficking process.     

Translational biomaterials — the journey from the bench to the market — think ‘product’

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