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1.
Elife ; 112022 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-36562467

RESUMEN

Standard models for spatial and episodic memory suggest that the lateral entorhinal cortex (LEC) and medial entorhinal cortex (MEC) send parallel independent inputs to the hippocampus, each carrying different types of information. Here, we evaluate the possibility that information is integrated between divisions of the entorhinal cortex prior to reaching the hippocampus. We demonstrate that, in mice, fan cells in layer 2 (L2) of LEC that receive neocortical inputs, and that project to the hippocampal dentate gyrus, also send axon collaterals to layer 1 (L1) of the MEC. Activation of inputs from fan cells evokes monosynaptic glutamatergic excitation of stellate and pyramidal cells in L2 of the MEC, typically followed by inhibition that contains fast and slow components mediated by GABAA and GABAB receptors, respectively. Inputs from fan cells also directly activate interneurons in L1 and L2 of MEC, with synaptic connections from L1 interneurons accounting for slow feedforward inhibition of L2 principal cell populations. The relative strength of excitation and inhibition following fan cell activation differs substantially between neurons and is largely independent of anatomical location. Our results demonstrate that the LEC, in addition to directly influencing the hippocampus, can activate or inhibit major hippocampal inputs arising from the MEC. Thus, local circuits in the superficial MEC may combine spatial information with sensory and higher order signals from the LEC, providing a substrate for integration of 'what' and 'where' components of episodic memories.


Asunto(s)
Corteza Entorrinal , Hipocampo , Ratones , Animales , Corteza Entorrinal/fisiología , Hipocampo/fisiología , Neuronas/fisiología , Giro Parahipocampal , Ácido gamma-Aminobutírico
2.
Photochem Photobiol ; 98(2): 504-512, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34935147

RESUMEN

In transfusion medicine, bacterial contamination can occur in ex vivo stored blood plasma, and there are continued efforts to improve blood safety and reduce the risk of transfusion-transmitted infections. Visible 405-nm violet-blue light has demonstrated potential for in situ pathogen reduction in ex vivo stored plasma and platelet concentrates. This study investigates the broad-spectrum antibacterial efficacy and compatibility potential of 405-nm light for treatment of blood plasma. Human plasma seeded with bacteria at a range of densities (101 -103 , 104 -106 , 107 -108 CFU mL-1 ) was exposed to 360 J cm-2 405-nm light (1 h at 0.1 W cm-2 ), with this fixed dose selected based on the initial analysis of inactivation kinetics. One-dimensional protein mobility analysis and measurement of advanced oxidation protein products (AOPP) was conducted to evaluate compatibility of the antimicrobial dose with plasma proteins and, identify upper levels at which protein degradation can be detected. Broad-spectrum antibacterial efficacy was observed with a fixed treatment of 360 J cm-2 , with 98.9-100% inactivation achieved across all seeding densities for all organisms, except E. coli, which achieved 95.1-100% inactivation. At this dose (360 J cm-2 ), no signs of protein degradation occurred. Overall, 405-nm light shows promise for broad-spectrum bacterial inactivation in blood plasma, while preserving plasma protein integrity.


Asunto(s)
Escherichia coli , Luz , Antibacterianos/farmacología , Bacterias , Proteínas Sanguíneas , Humanos , Plasma
3.
Dalton Trans ; 39(42): 10105-15, 2010 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-20830404

RESUMEN

The 2,2'-bis(methylene)biphenyl bridged bis(diketonate) (Tol(2)Bob)Ti(IV) fragment is resolved by reaction of the isopropoxide complex with (R)-1,1'-bi-2-naphthol, which selectively forms (S,Δ)-(Tol(2)Bob)Ti(R-BINOL). The binaphtholate ligand can be cleaved from titanium by careful treatment with trifluoromethanesulfonic acid to give (S,Δ)-(Tol(2)Bob)Ti(OTf)(2), which has a half-life toward racemization of at least 34 h at 51 °C. Racemization of the (Tol(2)Bob)Ti(IV) fragment is strongly accelerated under protic conditions, probably due to protonolysis of one of the diketonate ligands. Analogous optically active titanium bis(diketonates) can also be prepared by using an optically active 2,2'-bis(methylene)-1,1'-binaphthyl bridged bis(diketonate) ligand, Tol(2)Bobbinap, prepared from (R)-BINOLH2. Complexation of (R)-Tol(2)BobbinapH(2) with Ti(OiPr)(4) gives only a single diastereomer with the Λ configuration at titanium. The bis(diketonate)titanium(IV) fragment gives rise to characteristic signals in circular dichroism spectra which can be used to identify the configuration at the metal centre.

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