Antimicrobial Properties of Fucus Vesiculosus and Porphyra Dioica Collected From the Irish Coast.

Various types of algae play an important role in entire ecosystem and has potential role in the continuous search for biologically active compounds with miscellaneous activities, such as antioxidant, antiviral and antimicrobial. The objective of this study was to study the antimicrobial properties of two diverse seaweeds, Fucus vesiculosus and Porphyra dioca. Antimicrobial compounds from both seaweeds could find potential future use in medical or food industries. Water content analysis was performed on both seaweeds and it was determined that high water content around 80% was apparent for both seaweeds, with higher consistency of water content found for Porphyra dioica compared to Fucus vesiculosus. Extraction of active metabolites was performed in diethyl ether, methanol and water; solvents with various polarities at a concentration of 1/100 w/v. Only Porphyra dioica was additionally extracted in ethyl acetate and a methanol:water mixture at concentrations 1/100 w/v and 1/30 w/v, respectively. The seaweed crude extracts were tested against one active pathogenic clinical strain of Methicillin Resistant Staphylococcus aureus (MRSA) WIT-676 obtained from University Hospital Waterford. The effect of various extracts concentrations 1/40, 1/60, 1/80 and 1/100 w/v in methanol was examined using extracts of Fucus vesiculosus followed by antimicrobial screening against the same pathogen to determine the optimal concentration of active metabolites in relation to the screening and which would then require further separation. The highest antimicrobial activity from an extract of Porphyra dioica was found in ethyl acetate and the solvent mixture methanol;water (1:1) compared with Fucus vesiculosus, which exhibited the highest antimicrobial activity in water and methanol extracts. Further analysis for separation of all crude extracts would be required with potential use of those extract in medical area

Recognition of Avirulence Gene AvrLm1 from Hemibiotrophic Ascomycete Leptosphaeria maculans Triggers Salicylic Acid and Ethylene Signaling in Brassica napus

Interaction of a plant with a fungal pathogen is an encounter with hundreds of molecules. In contrast to this, a single molecule often decides between the disease and resistance. In the present article, we describe the defense responses triggered by AvrLm1, an avirulence gene from a hemibiotrophic ascomycete, Leptosphaeria maculans, responsible for an incompatible interaction with Brassica napus. Using multiple hormone quantification and expression analysis of defense-related genes, we investigated signaling events in Rlm1 plants infected with two sister isolates of L. maculans differentiated by the presence or absence of AvrLm1. Infection with the isolate carrying AvrLm1 increased the biosynthesis of salicylic acid (SA) and induced expression of the SA-associated genes ICS1, WRKY70, and PR-1, a feature characteristic of responses to biotrophic pathogens and resistance gene-mediated resistance. In addition to SA-signaling elements, we also observed the induction of ASC2a, HEL, and CHI genes associated with ethylene (ET) signaling. Pharmacological experiments confirmed the positive roles of SA and ET in mediating resistance to L. maculans. The unusual cooperation of SA and ET signaling might be a response to the hemibiotrophic nature of L. maculans. Our results also demonstrate the profound difference between the natural host B. napus and the model plant Arabidopsis in their response to L. maculans infection

Changes in temperature have opposing effects on current amplitude in α7 and α4β2 nicotinic acetylcholine receptors.

We have examined the effect of temperature on the electrophysiological properties of three neuronal nicotinic acetylcholine receptor (NACHR) subtypes: the rapidly desensitizing homomeric α7 nAChR, the more slowly desensitizing heteromeric α4β2 nAChR and on α7 nAChRs containing a transmembrane mutation (L247T) that results in dramatically reduced desensitization. In all cases, the functional properties of receptors expressed in Xenopus oocytes at room temperature (RT; 21°C) were compared to those recorded at either physiological temperature (37°C) or at lower temperature (4°C). Alterations in temperature had dramatically differing effects on the amplitude of whole-cell responses detected with these three nAChR subtypes. Compared to responses at RT, the amplitude of agonist-evoked responses with α4β2 nAChRs was increased at high temperature (125±9%, n = 6, P<0.01) and reduced at low temperature (47±5%, n = 6, P<0.01), whereas the amplitude of α7 responses was reduced at high temperature (27±7%, n = 11, P<0.001) and increased at low temperatures (224±16%, n = 10, P<0.001). In contrast to the effects of temperature on α4β2 and wild type α7 nAChRs, the amplitude of α7 nAChRs containing the L247T mutation was unaffected by changes in temperature. In addition, changes in temperature had little or no effect on current amplitude when α7 nAChRs were activated by the largely non-desensitizing allosteric agonist 4BP-TQS. Despite these differing effects of temperature on the amplitude of agonist-evoked responses in different nAChRs, changes in temperature had a consistent effect on the rate of receptor desensitization on all subtypes examined. In all cases, higher temperature resulted in increased rates of desensitization. Thus, it appears that the differing effects of temperature on the amplitudes of whole-cell responses cannot be explained by temperature-induced changes in receptor desensitization rates

Roles of Conserved Ectodomain Cysteines of the Rat P2X4 Purinoreceptor in Agonist Binding and Channel Gating

Mammalian P2X receptors contain 10 conserved cysteine residues in their ectodomains, which form five disulfide bonds (SS1-5). Here, we analyzed the relevance of these disulfide pairs in rat P2X4 receptor function by replacing one or both cysteines with alanine or threonine, expressing receptors in HEK293 cells and studying their responsiveness to ATP in the absence and presence of ivermectin, an allostenic modulator of these channels. Response to ATP was not altered when both cysteines forming the SS3 bond (C132-C159) were replaced with threonines. Replacement of SS1 (C116-C165), SS2 (C126-C149) and SS4 (C217-C227), but not SS5 (C261-C270), cysteine pairs with threonines resulted in decreased sensitivity to ATP and faster deactivation times. The maximum current amplitude was reduced in SS2, SS4 and SS5 double mutants and could be partially rescued by ivermectin in SS2 and SS5 double mutants. This response pattern was also observed in numerous single residue mutants, but receptor function was not affected when the 217 cysteine was replaced with threonine or arginine or when the 261 cysteine was replaced with alanine. These results suggest that the SS1, SS2 and SS4 bonds contribute substantially to the structure of the ligand binding pocket, while the SS5 bond located towards the transmembrane domain contributes to receptor gating

Highly conserved tyrosine 37 stabilizes desensitized states and restricts calcium permeability of ATP-gated P2X3 receptor

Tyrosine 37 in the first transmembrane (TM1) domain is highly conserved in ATP-gated P2X receptors suggesting its fundamental role. We tested whether Y37 contributes to the desensitization of P2X3 receptors, which is currently not well understood. By combining electrophysiological, imaging and modeling approaches, we studied desensitization of various Y37 P2X3 mutants and potential partners of Y37. Unlike the membrane current of the WT receptor, which desensitized in seconds, Y37A mutant current did not fully desensitize even after minutes-long applications of β,γ-meATP, α,β-meATP, ATP or 2MeS-ATP. The fractional calcium current was enhanced in the Y37A mutant. Y37F did not rescue the native P2X3 phenotype indicating a role for the hydroxyl group of Y37 for the WT receptor. Homology modeling indicated I318 or I319 in TM2 as potential partners for Y37 in the receptor closed state. We tested this hypothesis by creating a permanent interaction between the two residues via disulfide bond. Whereas single Y37C, I318C and I319C mutants were functional, the double mutants Y37C-I318C and Y37C-I319C were non-functional. Using a cyclic model of receptor operation, we suggest that the conserved tyrosine 37 links TM1 to TM2 of adjacent subunit to stabilize desensitized states and restricts calcium permeability through the ion channel. © 2011 International Society for Neurochemistry

Correlation of RET somatic mutations with clinicopathological features in sporadic medullary thyroid carcinomas

Screening of REarranged during Transfection (RET) gene mutations has been carried out in different series of sporadic medullary thyroid carcinomas (MTC). RET-positive tumours seem to be associated to a worse clinical outcome. However, the correlation between the type of RET mutation and the patients' clinicopathological data has not been evaluated yet

Utjecaj radne okoline u pogonu miješanja stočne hrane na bolesti organa za disanje

Die Staubmenge in 42 Futtermischungsbetrieben überschreitet die tschechoslowakische Maximalarbeitskonzentration 6 mal bis 85 mal. In 485 Staubproben aus diesen Futtermischungsbetrieben wurden zahlreiche Schimmel-und Hefeorganismen am häufigsten Aspergillus sp. (45,3%,), Mucor sp. (28,9%), Rhizopus sp. (36,9%), Penicillium sp, (25,3%) festgestellt. Bei 17 5 untersuchten Männern, von denen 144 vor ihrer Arbeit im Mischungsbetrieb als Müller, in der Pflanzenproduktion oder unter dem Risiko des anorganischen Staubes gearbeitet hatten, wurden Bronchitiden, Bronchitiden mit Emphysem sowie Lungenemphysem an 33%, und zwar vorwiegend bei vorher staubexponierten Männern, und bei 13% der Frauen von 105 Untersuchten, und zwar überwiegend bei 54 vorher staubexponierten Frauen festgestellt. Bei den Männern wurde kein statistischer Unterschied zwischen dem Vorkommen und Umfang der bronchitischen Änderungen zwischen den Räuchern und Nichträuchern festgestellt (ausgewertet nach den Symptomen mittels des modifizierten Fletscher - Fragebogens). Bei Frauen mit vorherigen Staubexposition bestand ein statistischer Unterschied im Vorkommen der Beschwerden gegenüber den Frauen ohne vorherige Staubexposition. Weder bei Frauen noch bei Männern wurde ein höheres Vorkommen allergischer Erkrankungen in den Anamnesen festgestellt. Die an Bronchitis leidenden Männer mit vorheriger Staubanamnese wiesen zu 33% vor der Arbeit in den Mischungsräumen durchgemachte Pneumonien in der Anamnese gegenüber 0,9% .der Männer ohne Bronchitis auf. Bei den Männern wurden statistisch nachweisbar mehr Schimmelpilze Aspergillus sp. (8,5% gegenüber 1,9% Kontrollgruppe) und Penicillium sp. (8,5% gegenüber 6,9_%) im Sputum als bei der aus 310 Männern ohne.Količina prašine u 42 pogona za pripremu miješane stočne hrane prelazi čehoslovačku maksimalno dopuštenu koncentraciju za 6 do 85 puta. U 485 ispitivanja prašine iz tih pogona ustanovljene su brojne plijesni i gljivice, najčešće Aspergillus sp. (45,3%). Mucor sp. (28,9%), Rhizopus sp. (36,9%), Penicillium sp. (25,3%). Kod 175 pregledanih muškaraca, od kojih su 144 prije uposlenja u pogonu miješanja stočne hrane bili uposleni kao mlinari, u proizvodnji biljnih produkata ili u ekspoziciji anorganskoj prašini, ustanovljene su bronhitide, bronhitide s emfizemom kao i plućni emfizem kod 33%, i to pretežno kod muškaraca koji su prethodno bili eksponirani prašini te kod 13% žena od 105 pregledanih i to opet pretežno kod onih 54 koje su bile prethodno u ekspoziciji prašini. Nije bilo statistički značajne razlike u incidenciji u stupnju bronhitičnih promjena između pušača i nepušača kad se bronhitis ocjenjivao po simptomima upotrebom modificiranog Fletscherova anketnog upitnika. Kod žena koje su već i prethodno bile eksponirane prašini postojala je statistički značajna razlika u pojavi smetnja u usporedbi sa ženama koje nisu prothodno bile eksponirane prašini, ni kod žena ni kod muškaraca nije u anamnezi bilo učestale pojave alergijskih bolesti. Muškarci koji su bolovali od bnonhitisa a prethodno su bili eksponirani prašini imali su prije nastupa posla u pogonu miješanja do 33% preboljelih pneumonija u anamnezi prema samo 0,9% muškaraca bez bronhitisa. Kod muškaraca je statistički dokazano više prisustva gljivica Aspergillus sp. (8,5% prema 1,9% u kontnolnoj grupi) i Penicillium sp. (8,5% prema 6,9% iz sputuma 310 muškaraca od kojih se sastojala kontrolna grupa bez ekspozicije organskim praši nama) što govori za masivnu inhalaciju tih spona. Sinantropne gljivice kao što su Candida albicans, češće su nađene kod pušača koji boluju od bronhitisa (39,4%) nego kod nepušača koji boluju od te bolesti, i to sa 23,6%. Pojava bronhitida u pogonu miješanja bila je jednaka po učestalosti pojavu te bolesti u poljoprivredi. Bolesti u ovim pogonima se mogu spriječiti potpunim mehaniziranjem radnog procesa. Temeljno poboljšanje su već preuzeli projektanti čehoslovačkog poduzeća »Che-pos«

Electrophysiological characterization of α7 nAChRs expressed in <i>Xenopus</i> oocytes in response to 4BP-TQS.

<p>A) A bar chart illustrates responses (mean ± SEM) from α7 nAChRs expressed in <i>Xenopus</i> oocytes in response to a maximal (10 µM) concentration of the allosteric agonist 4BP-TQS at room temperature (RT; 21°C), higher temperature (37°C) and lower temperature (4°C). Data are means of 5–22 responses, each from a different oocyte, in which responses obtained at either 4°C or 37°C are normalized to responses obtained from the same oocyte at RT. B) Representative traces illustrating responses obtained at RT (upper trace) and 4°C (lower trace) from a single oocyte. C) Representative traces illustrating responses obtained at RT (upper trace) and 37°C (lower trace) from a single oocyte.</p

Amplitude and desensitization of nAChR responses examined at different temperatures.

†, ††<p>Data for desensitization of all receptor and agonist combinations (with the exception of wild-type α7, activated by ACh) are expressed as the percentage of decay from the peak response in 5 seconds. Due to the rapid rate of desensitization for wild-type α7 activated by ACh, these values are expressed as the time required for the response to decay to 50% of the peak response.</p><p>Data are means ± SEM. Significant differences to responses recorded at RT are indicated (* = <i>P</i><0.05, ** = <i>P</i><0.01, *** = <i>P</i><0.001).</p