biosensor-for-detection-antibiotic-resistant-staphylococcus

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) ...

prevention-heat-stress-adverse-effects-rats-bacillus-subtilis

Prevention of Heat Stress Adverse Effects in Rats by <em>Bacillus subtilis</em> Strain

This study was designed to evaluate the protective effect of the Bacillus subtilis strain against complications related to heat stress. Thirty-two ...

Auburn University 

Unfolding and subsequent aggregation of proteins is a common phenomenon that is linked to many human disorders. Misfolded hemoglobin is generally manifested in various autoimmune, infectious and inherited diseases. We isolated micrometer and submicrometer particles, termed proteons, from human and animal blood. Proteons lack nucleic acids but contain two major polypeptide populations with homology to the hemoglobin alpha-chain. Proteons form by reversible seeded aggregation of proteins around proteon nucleating centers (PNCs). PNCs are comprised of 1- to 2-nm metallic nanoclusters containing 40-300 atoms. Each milliliter of human blood contained approximately 7 x 10(13) PNCs and approximately 3 x 10(8) proteons. Exposure of isolated blood plasma to elevated temperatures increased the number of proteons. When an aliquot of this heated plasma was introduced into untreated plasma that was subsequently heated, the number of proteons further increased, reaching a maximum after a total of three such iterations. Small concentrations of PNCs were lethal to cultured cancer cells, whereas noncancerous cells were much less affected.

Novel metal clusters isolated from blood are lethal to cancer cells.

Svolgimento e conseguente aggregazione delle proteine &egrave; un fenomeno comune che &egrave; legato a molte patologie umane. Emoglobina malpiegata generalmente si manifesta in varie malattie autoimmuni, infettive ed ereditarie. Abbiamo isolato particelle micrometriche e submicrometriche, definite proteons, da sangue umano e animale. Proteons mancanza di acidi nucleici, ma contengono due popolazioni principali del polipeptide con omologia per la catena alfa dell&#39;emoglobina. Proteons forma di aggregazione reversibile seminato di proteine intorno proteon nucleare centri (PNCs). PNCs sono costituite da 1 - 2 nm nanocluster metallici contenenti atomi di 40-300. Ogni millilitro di sangue umano contiene circa 7 x si PNCs e circa 3 x 10, paragrafo 8 proteons. L&#39;esposizione del plasma sanguigno isolato a temperature elevate ha aumentato il numero di proteons. Quando &egrave; stata introdotta un&#39;aliquota di questo plasma riscaldato nel plasma non trattato che successivamente &egrave; stato riscaldato, il numero di proteons ulteriormente aumentato, raggiungendo un massimo dopo un totale di tre tali iterazioni. Piccole concentrazioni di PNCs erano letale per le cellule tumorali coltivate, mentre le cellule non tumorali molto meno sono state influenzate.

Romanzo cluster metallo isolato dal sangue sono letali per le cellule tumorali.

D&eacute;pliage et suivantes l&#39;agr&eacute;gation des prot&eacute;ines est un ph&eacute;nom&egrave;ne courant qui est li&eacute; &agrave; plusieurs maladies humaines. Forme anormale de l&#39;h&eacute;moglobine se manifeste g&eacute;n&eacute;ralement dans diverses maladies auto-immunes, infectieuses et h&eacute;r&eacute;ditaires. Nous avons isol&eacute; les particules microm&egrave;tre et SUBMICROMETRIQUES, appel&eacute;s proteons, du sang humain et des animaux. Proteons manque d&#39;acides nucl&eacute;iques mais contiennent deux populations de polypeptide majeur avec une homologie avec la cha&icirc;ne alpha de l&#39;h&eacute;moglobine. Proteons forme par une agr&eacute;gation ensemenc&eacute;e r&eacute;versible de prot&eacute;ines autour de carte proteon nucl&eacute;ation centres (PNCs). PNCs sont composent de 1 &agrave; 2 nm nanoagr&eacute;gats m&eacute;tallique contenant des atomes de 40-300. Chaque millilitre de sang humain contenue environ 7 x 10 (13) PNCs et environ 3 x 10 (8) proteons. Exposition d&#39;isol&eacute; le plasma sanguin &agrave; des temp&eacute;ratures &eacute;lev&eacute;es ont augment&eacute; le nombre de proteons. Quand une partie aliquote de ce plasma chauff&eacute;e fut introduite en plasma non trait&eacute; qui est chauff&eacute; par la suite, le nombre de proteons encore augment&eacute;, pour atteindre un maximum apr&egrave;s un total de trois de ces it&eacute;rations. Petites concentrations de PNCs ont &eacute;t&eacute; mortelles pour les cellules canc&eacute;reuses cultiv&eacute;es, alors que les cellules non canc&eacute;reuses sont beaucoup moins affect&eacute;s.

Nouveaux clusters m&eacute;talliques isol&eacute;s du sang sont l&eacute;tales pour les cellules canc&eacute;reuses.

Resolution of 90 nm was achieved with a research microscope simply by replacing the standard bright-field condenser with a homebuilt illumination system with a cardioid annular condenser. Diffraction gratings with 100 nm width lines as well as less than 100 nm size features of different-shaped objects were clearly visible on a calibrated microscope test slide. The resolution increase results from a known narrower diffraction pattern in coherent illumination for the annular aperture compared with the circular aperture. This explanation is supported by an excellent accord of calculated and measured diffraction patterns for a 50 nm radius disk.

Resolution of 90 nm (lambda/5) in an optical transmission microscope with an annular condenser.

R&eacute;solution de 90 nm a &eacute;t&eacute; r&eacute;alis&eacute;e avec un microscope de recherche simplement en rempla&ccedil;ant le condensateur lumineux-zone standard d&#39;un syst&egrave;me d&#39;&eacute;clairage de fabrication artisanale avec un condenseur annulaire cardio&iuml;de. R&eacute;seaux de diffraction avec 100 lignes de largeur nm ainsi que moins de 100 nm dimensions caract&eacute;ristiques des objets de formes diff&eacute;rentes ont &eacute;t&eacute; clairement visibles sur un essai de microscope calibr&eacute;. La r&eacute;solution augmente les r&eacute;sultats d&#39;un patron de diffraction plus &eacute;troit connu sous un &eacute;clairage coh&eacute;rent pour l&#39;ouverture annulaire par rapport &agrave; l&#39;ouverture circulaire. Cette explication est prise en charge d&#39;un excellent accord par des patrons de diffraction calcul&eacute;es et mesur&eacute;es pour un disque de rayon 50 nm.

R&eacute;solution de 90 nm (lambda/5) dans un microscope &agrave; transmission optique avec un condenseur annulaire.

Risoluzione di 90 nm &egrave; stato raggiunto con un microscopio di ricerca semplicemente sostituendo il condensatore campo chiaro standard con un sistema di illuminazione di homebuilt con condensatore cardioide anulare. Reticoli di diffrazione con linee di larghezza 100 nm, nonch&eacute; a meno di 100 nm dimensioni caratteristiche di oggetti di forma diversa erano chiaramente visibili su un vetrino da microscopio calibrato test. La risoluzione aumenta i risultati da un pattern di diffrazione pi&ugrave; stretto conosciuto nel campo dell&#39;illuminazione coerente per l&#39;apertura anulare confrontato con l&#39;apertura circolare. Questa spiegazione &egrave; supportata da un eccellente accordo dei pattern di diffrazione misurato e calcolato per un disco di raggio 50 nm.

Risoluzione di 90 nm (lambda/5) in un microscopio a trasmissione ottica con un condensatore anulare.

Staphylococcus aureus (S. aureus)-specific bacteriophage was used as a probe for detection of methicillin-resistant S. aureus (MRSA) in aqueous solution using a novel optical method. Biorecognition phage monolayers transferred to glass substrates using Langmuir-Blodgett (LB) technique were exposed individually to MRSA in solution at logarithmic concentrations ranging from 10(6) to 10(9)cfu/ml, and observed for real-time binding using a CytoViva optical light microscope system. Results indicate that LB monolayers possessed high levels of elasticity (K), measuring 22 and 29 mN/m for 10(9) and 10(11)pfu/ml phage concentrations, respectively. Near-instantaneous MRSA-phage binding produced 33+/-5%, 10+/-1%, 1.1+/-0.1%, and 0.09+/-0.01% coverage of the substrate that directly correlated to a decrease in MRSA concentrations of 10(9), 10(8), 10(7), and 10(6)cfu/ml. The exclusive selectivity of phage monolayers was verified with Salmonella enterica subsp. enterica serovar typhimurium (S. typhimurium) and Bacillus subtilis.

Real-time optical detection of methicillin-resistant Staphylococcus aureus using lytic phage probes.

Staphylocoque dor&eacute; (Staphylococcus aureus)-bact&eacute;riophage sp&eacute;cifique a &eacute;t&eacute; utilis&eacute; comme une sonde pour la d&eacute;tection de m&eacute;thicilline S. aureus (SARM) en solution aqueuse &agrave; l&#39;aide d&#39;une m&eacute;thode optique originale. Monocouches de phage bioreconnaissance transf&eacute;r&eacute;s &agrave; des substrats de verre &agrave; l&#39;aide de la technique de Langmuir-Blodgett (LB) ont &eacute;t&eacute; expos&eacute;s individuellement au SARM en solution &agrave; logarithmiques concentrations allant de 10 (6) &agrave; 10 (9) UFC/ml et observ&eacute;s pour la liaison en temps r&eacute;el &agrave; l&#39;aide d&#39;un syst&egrave;me de microscopie optique CytoViva. Les r&eacute;sultats indiquent que LB monocouches poss&egrave;dent des niveaux &eacute;lev&eacute;s d&#39;&eacute;lasticit&eacute; (K), 22 et 29 mN/m pour 10 9 et 10 (11) de la mesure des concentrations de phage UFP/ml, respectivement. Liaison quasi instantan&eacute;e de SARM-phage produit 33 +/-5 %, 10 &plusmn; 1 %, 1,1 +/-0,1 % et la couverture de 0.09+/-0.01% du substrat qui directement corr&eacute;l&eacute;e &agrave; une diminution des concentrations de SARM de 10 (9), 10 (8), 10 (7) et 10 (6) UFC/ml. La s&eacute;lectivit&eacute; exclusive de monocouches phage a &eacute;t&eacute; v&eacute;rifi&eacute;e avec Salmonella enterica subsp. enterica serovar typhimurium (Salmonella typhimurium) et de Bacillus subtilis.

Sondes de d&eacute;tection optique en temps r&eacute;el de Staphylococcus aureus m&eacute;thicilline-r&eacute;sistant en utilisant un phage lytique.

Staphylococcus aureus (S. aureus)-specifico batteriofago era usata come una sonda per il rilevamento di meticillino-resistenti Staphylococcus aureus (MRSA) in soluzione acquosa mediante un metodo ottico romanzo. Monostrati di fago Biorecognition trasferiti a substrati di vetro utilizzando la tecnica di Langmuir-Blodgett (LB) esposti singolarmente per MRSA in soluzione a concentrazioni logaritmiche che vanno da 10 a 10 (9) cfu/ml e fu osservate per l&#39;associazione in tempo reale utilizzando un sistema ottico del microscopio CytoViva. I risultati indicano che LB monostrati possedevano alti livelli di elasticit&agrave; (K), 22 e 29 mN/m per arrecavano e 10 (11) di misura concentrazioni dei fagi pfu/ml, rispettivamente. Associazione di MRSA-fago immediato prodotto 33 + 5%, 10 + /-1%, 1,1 + /-0,1% e la copertura 0.09+/-0.01% del substrato che direttamente correlate ad una diminuzione della concentrazione di MRSA di riesami, 10, paragrafo 8, 10 e 10 (6) cfu/ml. La selettivit&agrave; esclusiva di monostrati dei fagi &egrave; stata verificata con Salmonella enterica subsp. enterica sierotipo typhimurium (S. typhimurium) e Bacillus subtilis.

Sonde di rilevamento ottico in tempo reale di Staphylococcus aureus meticillino-resistente utilizzando dei fagi litici.

Zinc metal nanoparticles in picomolar concentrations strongly enhance odorant responses of olfactory sensory neurons. One- to 2-nm metallic particles contain 40-300 zinc metal atoms, which are not in an ionic state. We exposed rat olfactory epithelium to metal nanoparticles and measured odorant responses by electroolfactogram and whole-cell patch clamp. A small amount of zinc nanoparticles added to an odorant or an extracellular/intracellular particle perfusion strongly increases the odorant response in a dose-dependent manner. Zinc nanoparticles alone produce no odor effects. Copper, gold, or silver nanoparticles do not produce effects similar to those of zinc. If zinc nanoparticles are replaced by Zn(+2) ions in the same concentration range, we observed a reduction of the olfactory receptor neuron odorant response. Based on these observations, we hypothesize that zinc nanoparticles are closely located to the interface between the guanine nucleotide-binding protein and the receptor proteins and are involved in transferring signals in the initial events of olfaction. Our results suggest that zinc metal nanoparticles can be used to enhance and sustain the initial olfactory events.

Enhancement of odorant-induced responses in olfactory receptor neurons by zinc nanoparticles.

Nanoparticules m&eacute;talliques zinc concentrations picomoles am&eacute;liorent fortement odorants r&eacute;ponses des neurones sensoriels olfactifs. 1 &Agrave; 2 nm particules m&eacute;talliques contiennent des atomes de m&eacute;tal zinc 40-300, qui ne sont pas &agrave; l&#39;&eacute;tat ionique. Nous expos&eacute;s &eacute;pith&eacute;lium olfactif rat aux nanoparticules m&eacute;talliques et mesur&eacute; odorisant r&eacute;ponses par &eacute;lectroolfactogrammes et whole-cell patch clamp. Une petite quantit&eacute; de nanoparticules de zinc ajout&eacute; &agrave; une odeur ou une perfusion de particule extracellulaire/intracellulaire augmente fortement la r&eacute;ponse odorant de mani&egrave;re dose-d&eacute;pendante. Nanoparticules de zinc seuls ne produisent aucun effet d&#39;odeur. Nanoparticules de cuivre, or ou argent ne produisent pas d&#39;effets similaires &agrave; ceux de zinc. Si des nanoparticules de zinc sont remplac&eacute;s par des ions de Zn(+2) dans la m&ecirc;me gamme de concentration, nous avons observ&eacute; une r&eacute;duction de la r&eacute;ponse de substance odorante de neurones r&eacute;cepteurs olfactifs. Selon ces observations, nous &eacute;mettons l&#39;hypoth&egrave;se que le zinc nanoparticules sont &eacute;troitement situ&eacute;s &agrave; l&#39;interface entre la prot&eacute;ine de liaison nucl&eacute;otidique de guanine et les prot&eacute;ines r&eacute;ceptrices et sont impliqu&eacute;s dans le transfert de signaux dans les &eacute;v&eacute;nements initiaux de l&#39;olfaction. Nos r&eacute;sultats sugg&egrave;rent que des nanoparticules m&eacute;talliques de zinc peuvent &ecirc;tre utilis&eacute;s pour renforcer et soutenir les &eacute;v&eacute;nements initiaux olfactifs.

Am&eacute;lioration des r&eacute;ponses induites par odorants dans des neurones r&eacute;cepteurs olfactifs de nanoparticules de zinc.

Nanoparticelle metalliche di zinco in concentrazioni picomolar migliorano fortemente odorant risposte dei neuroni sensoriali olfattivi. Particelle metalliche uno - 2 nm contengono atomi metallici zinco 40-300, che non sono in uno stato ionico. Abbiamo esposto epitelio olfattivo del topo di nanoparticelle metalliche e misurato odorant risposte da electroolfactogram e cellule intere patch clamp. Una piccola quantit&agrave; di nanoparticelle di zinco aggiunto una odorant o una perfusione delle particelle extracellulari/intracellulare aumenta fortemente la risposta odorant in modo dose-dipendente. Le nanoparticelle di zinco da solo non producono effetti nessun odore. Le nanoparticelle di argento, oro o rame non producono effetti simili a quelli di zinco. Se le nanoparticelle di zinco vengono sostituite da ioni di Zn(+2) nello stesso intervallo di concentrazione, abbiamo osservato una riduzione della risposta odorant neurone olfattivo del ricevitore. Sulla base di queste osservazioni, si ipotizza che lo zinco nanoparticelle sono strettamente trova all&#39;interfaccia tra la guanina nucleotide-proteina e le proteine del recettore e sono coinvolti nel trasferimento di segnali negli eventi iniziali dell&#39;olfatto. I nostri risultati suggeriscono che le nanoparticelle di metallo di zinco possono essere utilizzate per migliorare e sostenere gli eventi olfattivi iniziali.

Miglioramento delle risposte odorant indotta nei neuroni olfattivi del ricevitore da nanoparticelle di zinco.

Many odorants related to manufactured explosives have low volatilities and are barely detectable as odors. We previously reported that zinc metal nanoparticles increased rat olfactory epithelium responses, measured by electroolfactogram (EOG), to several odorants. Here, we report that nanomolar concentrations of zinc metal nanoparticles strongly enhanced olfactory responses to the explosives related odorants cyclohexanone, methyl benzoate, acetophenone, and eugenol. Rat olfactory epithelium was exposed to metal nanoparticles and odorant responses were quantified by EOG. Zinc nanoparticles added to explosive odorants strongly increased the odorant response in a dose-dependent manner. The enzymatic breakdown of the second messenger cyclic adenosine monophosphate (cAMP) was prevented by adding the membrane-permeable phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX). This caused the olfactory cilia cAMP concentration to increase and generated EOG signals. The EOG responses generated by IBMX were not enhanced by zinc nanoparticles. Based on these observations, we conclude that zinc nanoparticles act at the receptor site and are involved in the initial events of olfaction. Our results suggest that zinc metal nanoparticles can be used to facilitate a canine detection of explosive odorants.

Olfactory responses to explosives associated odorants are enhanced by zinc nanoparticles.

Nombreuses substances odorantes des explosifs fabriqu&eacute;s ont des volatilit&eacute;s faibles et sont &agrave; peine d&eacute;tectables, comme les odeurs. Nous avons d&eacute;j&agrave; indiqu&eacute; que le zinc des nanoparticules m&eacute;talliques les r&eacute;ponses de l&#39;&eacute;pith&eacute;lium olfactif rat, mesur&eacute;es par &eacute;lectroolfactogrammes (EOG), est pass&eacute; &agrave; plusieurs substances odorantes. Nous rapportons ici que des concentrations nanomolaires de nanoparticules m&eacute;talliques zinc am&eacute;lior&eacute; fortement olfactifs r&eacute;ponses aux explosifs odorisants connexes cyclohexanone, benzoate de m&eacute;thyle, l&#39;ac&eacute;toph&eacute;none et eug&eacute;nol. &Eacute;pith&eacute;lium olfactif de rat a &eacute;t&eacute; expos&eacute; &agrave; des nanoparticules m&eacute;talliques et odorant r&eacute;ponses ont &eacute;t&eacute; quantifi&eacute;s par EOG. Nanoparticules de zinc ajout&eacute;s &agrave; explosifs odorisants fortement augment&eacute; la r&eacute;ponse de l&#39;odorisant de mani&egrave;re dose-d&eacute;pendante. La d&eacute;gradation enzymatique de la deuxi&egrave;me messager ad&eacute;nosine monophosphate cyclique (AMPc) n&#39;a pas pu en ajoutant la phosphodiest&eacute;rase membrane perm&eacute;able inhibiteur de la 3-isobutyl-1-m&eacute;thylxanthine (IBMX). Cela caus&eacute; les cils olfactifs augmenter la concentration d&#39;AMPc et g&eacute;n&eacute;r&eacute; les signaux EOG. Les r&eacute;ponses de l&#39;EOG g&eacute;n&eacute;r&eacute;es par IBMX n&#39;&eacute;taient pas stimul&eacute;es par des nanoparticules de zinc. Selon ces observations, nous concluons que le zinc nanoparticules agissent sur le site de r&eacute;cepteurs et sont impliqu&eacute;s dans les &eacute;v&eacute;nements initiaux de l&#39;olfaction. Nos r&eacute;sultats sugg&egrave;rent que des nanoparticules m&eacute;talliques de zinc peuvent &ecirc;tre utilis&eacute;s pour faciliter une d&eacute;tection canine d&#39;explosifs odorants.

Olfactifs responses to odorisants explosifs associ&eacute;s sont rehauss&eacute;s par des nanoparticules de zinc.

Molti odorizzazione correlati a esplosivi fabbricati hanno bassa volatilit&agrave; e sono appena rilevabile come gli odori. Abbiamo segnalato in precedenza che lo zinco nanoparticelle metalliche aumentate risposte epitelio olfattivo del ratto, misurate dal electroolfactogram (EOG), di odorizzazione diversi. Qui, segnaliamo che concentrazioni nanomolari di nanoparticelle metalliche di zinco fortemente rafforzata olfattive responses to il cicloesanone correlati odorizzazione esplosivi, benzoato di metile, acetofenone ed eugenolo. Epitelio olfattivo del topo &egrave; stato esposto a nanoparticelle metalliche e odorant risposte sono state quantificate da EOG. Le nanoparticelle di zinco aggiunte all&#39;odorizzazione esplosiva fortemente aumentato la risposta odorant in modo dose-dipendente. Degradazione enzimatica del secondo messaggero ciclico adenosina monofosfato (cAMP) &egrave; stata evitata aggiungendo la membrana permeabile fosfodiesterasi inibitore della 3-isobutil-1-methylxanthine (IBMX). Questo ha causato le ciglia olfattive cAMP concentrazione aumentare e generato segnali EOG. Le risposte EOG generate da IBMX non sono state rafforzate da nanoparticelle di zinco. Sulla base di queste osservazioni, concludiamo che lo zinco nanoparticelle agiscono presso il sito del recettore e sono coinvolti negli eventi iniziali dell&#39;olfatto. I nostri risultati suggeriscono che le nanoparticelle di metallo di zinco possono essere utilizzate per facilitare il rilevamento canino di odorizzazione esplosiva.

Risposte olfattive di odorizzazione esplosivi associati sono arricchite da nanoparticelle di zinco.

Discrimination of methicillin resistant (MRSA) and sensitive (MSSA) strains of Staphylococcus aureus, was achieved by the specially selected lytic bacteriophage with a wide host range of S. aureus strains and a penicillin-binding protein (PBP 2a) specific antibody. A quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to analyze bacteria-phage interactions. The lytic phages were transformed into phage spheroids by exposure to water-chloroform interface. Phage spheroid monolayers were transferred onto QCM-D sensors by Langmuir-Blodgett (LB) technique. Biosensors were tested in the flow mode with bacterial water suspensions, while collecting frequency and energy dissipation changes. Bacteria-spheroid interactions resulted in decreased resonance frequency and an increase in dissipation energy for both MRSA and MSSA strains. Following the bacterial binding, these sensors were further exposed to a flow of the penicillin-binding protein (PBP 2a) specific antibody conjugated latex beads. Sensors tested with MRSA responded to PBP 2a antibody beads; while sensors examined with MSSA gave no response. This experimental difference establishes an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains. Both free and immobilized bacteriophages strongly inhibit bacterial growth on solid/air interfaces and in water suspensions. After lytic phages are transformed into spheroids, they retain their strong lytic activity and demonstrate high bacterial capture efficiency. The phage and phage spheroids can be used for screening and disinfection of antibiotic resistant bacteria. Other applications may include use on biosensors, bacteriophage therapy, and antimicrobial surfaces.

Detection and identification of methicillin resistant and sensitive strains of Staphylococcus aureus using tandem measurements.

Discrimination de r&eacute;sistant &agrave; la m&eacute;thicilline (SARM) et des souches sensibles (MSSA) de Staphylococcus aureus, a &eacute;t&eacute; atteint par le bact&eacute;riophage lytique sp&eacute;cialement s&eacute;lectionn&eacute; avec une gamme de S. aureus souches de gamme d&#39;h&ocirc;tes et un anticorps sp&eacute;cifique de la p&eacute;nicilline-liaison prot&eacute;ique (PBP 2 a). Une microbalance &agrave; cristal de quartz avec dissipation surveillance (QCM-D) a &eacute;t&eacute; utilis&eacute;e pour analyser les interactions bact&eacute;riophages-bact&eacute;ries. Les phages lytiques sont transform&eacute;es en sph&eacute;ro&iuml;des phage par l&#39;exposition &agrave; l&#39;interface eau-chloroforme. Monocouches sph&eacute;ro&iuml;de phage ont &eacute;t&eacute; transf&eacute;r&eacute;s sur des capteurs de QCM-D par la technique de Langmuir-Blodgett (LB). Biocapteurs ont &eacute;t&eacute; test&eacute;s sous le mode avec des suspensions bact&eacute;riennes de l&#39;eau, tout en collectant des changements de dissipation de fr&eacute;quence et de l&#39;&eacute;nergie. Interactions bact&eacute;ries-sph&eacute;ro&iuml;de a abouti &agrave; la fr&eacute;quence de r&eacute;sonance une diminution et une augmentation de l&#39;&eacute;nergie de dissipation pour les souches de SARM et de MSSA. Suite &agrave; la liaison bact&eacute;rienne, ces capteurs ont &eacute;t&eacute; davantage expos&eacute;s &agrave; un flux des prot&eacute;ine se liant &agrave; la p&eacute;nicilline (PBP 2 a) anticorps sp&eacute;cifique conjugu&eacute; billes de latex. Capteurs test&eacute; par SARM a r&eacute;pondu aux perles d&#39;anticorps PBP 2 a ; pendant l&#39;examen de capteurs avec MSSA a donn&eacute; aucune r&eacute;ponse. Cette diff&eacute;rence exp&eacute;rimentale &eacute;tablit une discrimination sans ambigu&iuml;t&eacute; entre r&eacute;sistants &agrave; la m&eacute;thicilline et sensibles S. aureus souches. Les bact&eacute;riophages libres et immobilis&eacute;es inhibent fortement la croissance bact&eacute;rienne sur des interfaces solide/air et dans des suspensions de l&#39;eau. Apr&egrave;s que les phages lytiques sont transform&eacute;s en sph&eacute;ro&iuml;des, ils conservent leur forte activit&eacute; lytique et d&eacute;montrent l&#39;efficacit&eacute; de captage bact&eacute;rienne &eacute;lev&eacute;e. Le phage et sph&eacute;ro&iuml;des phage peuvent &ecirc;tre utilis&eacute;s pour le d&eacute;pistage et la d&eacute;sinfection de bact&eacute;ries r&eacute;sistantes aux antibiotiques. Autres applications peuvent inclure l&#39;utilisation sur surfaces antimicrobiennes, th&eacute;rapie bact&eacute;riophage et biocapteurs.

D&eacute;tection et identification des souches sensibles et r&eacute;sistantes &agrave; la m&eacute;thicilline de Staphylococcus aureus en utilisant des mesures en tandem.

Discriminazione di meticillino-resistente (MRSA) e sensibile (MSSA) ceppi di Staphylococcus aureus, fu raggiunto da batteriofago litico appositamente selezionato con un host vasta gamma di S. aureus ceppi e un anticorpo specifico penicillina-binding protein di (PBP 2a). Una microbilancia al quarzo cristallo con dissipazione di monitoraggio (QCM-D) &egrave; stato impiegato per analizzare le interazioni dei fagi batteri. I fagi litici furono trasformati in sferoidi fago da esposizione all&#39;interfaccia acqua-cloroformio. Monostrati sferoide dei fagi sono stati trasferiti su sensori QCM-D da tecnica di Langmuir-Blodgett (LB). Biosensori sono stati testati in modalit&agrave; flusso con sospensioni batteriche dell&#39;acqua, mentre la raccolta modifiche di dissipazione di energia e frequenza. Interazioni batteri-sferoide portato a frequenza di risonanza &egrave; diminuito e un aumento di energia di dissipazione per i ceppi MRSA sia MSSA. Seguendo l&#39;associazione batterica, questi sensori sono stati ulteriormente esposti ad un flusso di penicillina-binding protein (PBP 2a) specifico anticorpo coniugato con lattice perline. Sensori testati con MRSA ha risposto alle perle di PBP 2a dell&#39;anticorpo; mentre sensori esaminati con MSSA ha dato alcuna risposta. Questa differenza sperimentale stabilisce una discriminazione univoca tra i ceppi meticillino resistente e sensibile S. aureus. Entrambi gratuiti e immobilizzati batteriofagi fortemente inibiscono la crescita batterica su interfacce solido/aria e nelle sospensioni di acqua. Dopo fagi litici vengono trasformati in sferoidi, essi conservano la loro forte attivit&agrave; litico e dimostrare acquisizione batterica ad alta efficienza. Il fago e sferoidi fago possono essere utilizzati per lo screening e la disinfezione dei batteri resistenti agli antibiotici. Altre applicazioni possono includere utilizzo su superfici antimicrobiche, terapia del batteriofago e biosensori.

Rilevazione e l&#39;identificazione dei ceppi meticillino resistenti e sensibili di Staphylococcus aureus utilizzando misurazioni tandem.

The images of human erythrocytes and vesicles were analyzed by a light microscopy system with spatial resolution of better than 90 nm. The samples were observed in an aqueous environment and required no freezing, dehydration, staining, shadowing, marking, or any other manipulation. Temperature elevation resulted in significant concentration increase of structurally transformed erythrocytes (echinocytes) and vesicles in the blood. The process of vesicle separation from spiculated erythrocytes was video recorded in real time. At a temperature of 37°C, mean vesicle concentrations and diameters were found to be 1.50 ± 0.35 × 10(6) vesicles per microliter and 0.365 ± 0.065 μm, respectively. The vesicle concentration increased approximately threefold as the temperature increased from 37 to 40°C. It was estimated that 80% of all vesicles found in the blood are smaller than 0.4 μm. Accurate account of vesicle numbers and dimensions suggest that 86% of the lost erythrocyte material is lost not by vesiculation but by another, as yet, unknown mechanism.

Microscopic evaluation of vesicles shed by erythrocytes at elevated temperatures.

The default mode network (DMN) in humans has been extensively studied using seed-based correlation analysis (SCA) and independent component analysis (ICA). While DMN has been observed in monkeys as well, there are conflicting reports on whether they exist in rodents. Dogs are higher mammals than rodents, but cognitively not as advanced as monkeys and humans. Therefore, they are an interesting species in the evolutionary hierarchy for probing the comparative functions of the DMN across species. In this study, we sought to know whether the DMN, and consequently its functions such as self-referential processing, are exclusive to humans/monkeys or can we also observe the DMN in animals such as dogs. To address this issue, resting state functional MRI data from the brains of lightly sedated dogs and unconstrained and fully awake dogs were acquired, and ICA and SCA were performed for identifying the DMN. Since anesthesia can alter resting state networks, confirming our results in awake dogs was essential. Awake dog imaging was accomplished by training the dogs to keep their head still using reinforcement behavioral adaptation techniques. We found that the anterior (such as anterior cingulate and medial frontal) and posterior regions (such as posterior cingulate) of the DMN were dissociated in both awake and anesthetized dogs.

Anterior-posterior dissociation of the default mode network in dogs.

We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology.

Functional MRI of the olfactory system in conscious dogs.

In the 1960s Bong Han Kim discovered and characterized a new vascular system. He was able to differentiate it clearly from vascular blood and lymph systems by the use of a variety of methods, which were available to him in the mid-20th century. He gave detailed characterization of the system and created comprehensive diagrams and photographs in his publications. He demonstrated that this system is composed of nodes and vessels, and it was responsible for tissue regeneration. However, he did not disclose in detail his methods. Consequently, his results are relatively obscure from the vantage point of contemporary scientists. The stains that Kim used had been perfected and had been in use for more than 100 years. Therefore, the names of the stains were directed to the explicit protocols for the usage with the particular cells or molecules. Traditionally, it was not normally necessary to describe the method used unless it is significantly deviated from the original method. In this present work, we have been able to disclose staining methods used by Kim.

Primo-Vascular System as Presented by Bong Han Kim.

Using noninvasive in vivo functional magnetic resonance imaging (fMRI), we demonstrate that the enhancement of odorant response of olfactory receptor neurons by zinc nanoparticles leads to increase in activity in olfaction-related and higher order areas of the dog brain. To study conscious dogs, we employed behavioral training and optical motion tracking for reducing head motion artifacts. We obtained brain activation maps from dogs in both anesthetized state and fully conscious and unrestrained state. The enhancement effect of zinc nanoparticles was higher in conscious dogs with more activation in higher order areas as compared with anesthetized dogs. In conscious dogs, voxels in the olfactory bulb and hippocampus showed higher activity to odorants mixed with zinc nanoparticles as compared with pure odorants, odorants mixed with gold nanoparticles as well as zinc nanoparticles alone. These regions have been implicated in odor intensity processing in other species including humans. If the enhancement effect of zinc nanoparticles observed in vivo are confirmed by future behavioral studies, zinc nanoparticles may provide a way for enhancing the olfactory sensitivity of canines for detection of target substances such as explosives and contraband substances at very low concentrations, which would otherwise go undetected.

Enhancement of Odor-Induced Activity in the Canine Brain by Zinc Nanoparticles: A Functional MRI Study in Fully Unrestrained Conscious Dogs.

Small metal nanoparticles obtained from animal blood were observed to be toxic to cultured cancer cells, whereas noncancerous cells were much less affected. In this work, engineered zinc and copper metal nanoparticles were produced from bulk metal rods by an underwater high-voltage discharge method. The metal nanoparticles were characterized by atomic force microscopy and X-ray photoelectron spectroscopy. The metal nanoparticles, with estimated diameters of 1 nm-2 nm, were determined to be more than 85% nonoxidized. A cell viability assay and high-resolution light microscopy showed that exposure of RG2, cultured rat brain glioma cancer cells, to the zinc and copper nanoparticles resulted in cell morphological changes, including decreased cell adherence, shrinking/rounding, nuclear condensation, and budding from cell bodies. The metal-induced cell injuries were similar to the effects of staurosporine, an active apoptotic reagent. The viability experiments conducted for zinc and copper yielded values of dissociation constants of 0.22±0.08 nmol/L (standard error [SE]) and 0.12±0.02 nmol/L (SE), respectively. The noncancerous astrocytes were not affected at the same conditions. Because metal nanoparticles were lethal to the cancer cells at sub-nanomolar concentrations, they are potentially important as nanomedicine.

Oleg Pustovyy

Department of Anatomy,
Physiology and Pharmacology,
College of Veterinary Medicine,
Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine

Auburn University

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Prevention of Heat Stress Adverse Effects in Rats by Bacillus subtilis Strain

Oleg Pustovyy

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Anatomy,Physiology and Pharmacology,College of Veterinary Medicine,Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine

Auburn University

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Prevention of Heat Stress Adverse Effects in Rats by Bacillus subtilis Strain

Department of Anatomy,
Physiology and Pharmacology,
College of Veterinary Medicine,
Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine