Simultaneous PET-MRI: a new approach for functional and morphological imaging

Noninvasive imaging at the molecular level is an emerging field in biomedical research. This paper introduces a new technology synergizing two leading imaging methodologies: positron emission tomography (PET) and magnetic resonance imaging (MRI). Although the value of PET lies in its high-sensitivity tracking of biomarkers in vivo, it lacks resolving morphology. MRI has lower sensitivity, but produces high soft-tissue contrast and provides spectroscopic information and functional MRI (fMRI). We have developed a three-dimensional animal PET scanner that is built into a 7-T MRI. Our evaluations show that both modalities preserve their functionality, even when operated isochronously. With this combined imaging system, we simultaneously acquired functional and morphological PET-MRI data from living mice. PET-MRI provides a powerful tool for studying biology and pathology in preclinical research and has great potential for clinical applications. Combining fMRI and spectroscopy with PET paves the way for a new perspective in molecular imaging.     

Benchmarking the effects of operating system interference on extreme-scale parallel machines

We investigate operating system noise, which we identify as one of the main reasons for a lack of synchronicity in parallel applications. Using a microbenchmark, we measure the noise on several contemporary platforms and find that, even with a general-purpose operating system, noise can be limited if certain precautions are taken. We then inject artificially generated noise into a massively parallel system and measure its influence on the performance of collective operations. Our experiments indicate that on extreme-scale platforms, the performance is correlated with the largest interruption to the application, even if the probability of such an interruption on a single process is extremely small. We demonstrate that synchronizing the noise can significantly reduce its negative influence.

Photometric microplate assay for estimation of the efficacy of paraoxon-inhibited acetylcholinesterase reactivation

Photometric microplate assay was performed for testing of paraoxon-inhibited acetylcholinesterase (AChE) using three reactivators for reactivation purposes: obidoxime, pralidoxime, and HI-6. 3-D graphs (percent of reactivation vs. concentration of reactivator and vs. time of reactivator effecting) were constructed for each reactivator to compare their efficacy. The best results were obtained using obidoxime where reactivation was near to 80%. Suitability of photometric microplates for following of reactivation procedures is discussed.     

Antimicrobial activity screening of some sulfonamide derivatives on some Nocardia species and isolates

Nocardia are aerobic, catalase-positive, Gram-positive microorganisms and typically acid-alcohol fast at some stage of the growth cycle. The genus Nocardia, a member of Mycolata group, is clinically important because it is an opportunistic pathogen. The sulfonamide derivative medicines are prefered to cure infection caused by Nocardia, such as nocardiaosis and mycetoma. Antimicrobial activities of seven sulfonamide derivatives have been investigated against some Nocardia species and isolates using the disk diffusion method on Sensitest agar medium (Oxoid). Thirty-six organisms, which consisted of 10 soil isolates selected from different clusters of Aymen study (2003), six clinical isolates provided by Ege University, Medical School, Microbiology and Clinical Microbiology Department, four reference strains, 15 type strains and a control strain of Staphylococcus aureus ATCC 43300 were tested. The strongest inhibition was observed in the cases of IV [N-(2-hydroxy-4-nitro-phenyl)-4-methyl-benzensulfonamid], V [N-(2-hydroxy-5-nitro-phenyl)-4-methyl-benzensulfonamid] and III [N-(2-Hydroxy-phenyl)-4-methyl-benzenesulfonamide] against Nocardia. Introducing a hydroxyl group into the ortho position on the ring increased the antimicrobial activity. Substitution of the electron withdrawing groups such as a nitro group increased the antimicrobial activity remarkably.     

Diether derivatives of homo- or substituted piperidines as non-imidazole histamine H3 receptor ligands

Synthesis and biological activities of a series of homo- or substituted piperidine unsymmetrical diethers are described. The novel compounds were evaluated for histamine H₃ receptor binding affinities at recombinant human H₃ receptor stably expressed in HEK-293 cells. All diethers showed in vitro affinities in nanomolar concentration range. The most potent compounds are 1-[3-(3-(4-chlorophenoxy)propoxy)propyl]-3-methylpiperidine 11 (K_i = 3.2 nM) and 1-[3-(3-(4-chlorophenoxy)propoxy)propyl]azepane 13 (K_i = 3.5 nM).     

Male and female genitalia in some Libyan species of Acrididae (Orthoptera: Acridoidea)

A comparative study of male and female genitalia was carried out in thirty‐seven Libyan species representing twenty genera of the family Acrididae. An attempt has been made to describe and illustrate the different structures, namely, epiphallus, aedeagus, subgenital plate, supra‐anal plate and cerci of the male, and spermatheca, ovipositor, subgenital plate, supra‐anal plate and cerci of the female, in Acridids, with an aim to discover their significance in order to make the identification of genera and species, together with other generic characters, more perfect and convenient. Distinct family characters are shield or bridge‐shaped condition of epiphallus; presence or absence of dorso‐lateral appendices, oval sclerites and lophi on epiphallus; divided, undivided or flexured condition of aedeagus; presence or absence of gonopore process on aedeagus; condition of apical and pre‐apical diverticula of spermatheca; presence or absence of glandular pouches of Cornstock and Kellog on female subgenital plate; and rudimentary or well developed condition of egg‐guide. Stable characters for separating the subfamilies are taken to be presence or absence of ancorae on epiphallus, long or short condition of aedeagal sclerites; elongate, slender or short and broad condition of ovipositor valves: presence or absence of Jannone's organs and setae on posterior margin of female subgenital plate; and shape of diverticula of spermatheca. Useful generic characters are shape of male subgenital plate, supra‐anal plate and cerci, broad or narrow condition of bridge, presence or absence of branch of bridge connecting lophi with bridge of epiphallus; mono‐, bi‐ or tri‐lobate condition of lophi of epiphallus, length and upcurved or downcurved condition of apical valve of aedeagus, shape of posterior margin of female subgenital plate, presence of setae on the whole posterior margin or confined to lateral margins only; and toothed, tuberculate or smooth condition of ovipositor valves, length of the lateral apodeme in relation to the dorsal valves. Specific characters are shape of egg‐guide of female subgenital plate, shape of ovipositor valves and apical tips, shape of male supra‐anal plate and cerci, size of anterior and posterior lobes of lophi of epiphallus, size and shape of ancorae, shape of apical valves of aedeagus; and size of apical and pre‐apical diverticula and presence of protuberance on pre‐apical diverticulum.     

Improved homology-driven computational validation of protein-protein interactions motivated by the evolutionary gene duplication and divergence hypothesis

Background  

Protein-protein interaction (PPI) data sets generated by high-throughput experiments are contaminated by large numbers of erroneous PPIs. Therefore, computational methods for PPI validation are necessary to improve the quality of such data sets. Against the background of the theory that most extant PPIs arose as a consequence of gene duplication, the sensitive search for homologous PPIs, i.e. for PPIs descending from a common ancestral PPI, should be a successful strategy for PPI validation.     

Elevated S100B and Neuron Specific Enolase Levels in Patients with Migraine-without Aura: Evidence for Neurodegeneration?

Although migraine has mainly been considered as a benign disease, there is cumulative evidence of silent changes in the brain, brainstem, or cerebellum and subtle subclinical cerebellar dysfunction. In this study, in order to investigate a possible neuronal and/or glial damage at the cellular level in migraine, we measured and compared serum levels of S100B which is a protein marker of glial damage or activation, and neuron specific enolase (NSE) which is a marker of neuronal damage, in migraine patients and control subjects. Serum levels of S100B and NSE were measured in blood samples from 41 patients with migraine-without aura taken during a migraine attack (ictal) and in the attack-free period between migraine attacks (interictal) and 35 age- and sex-matched controls. Patients with migraine-without aura had significantly higher ictal serum levels of S100B and NSE (P < 0.05, for both) than control subjects; whereas in the interictal phase, there was a significant increment only in S100B levels (P < 0.05) compared to controls. On the other hand, serum levels of S100B and NSE in ictal and interictal blood samples did not differ significantly. The findings of increased ictal serum S100B and NSE levels together with increased interictal levels of S100B suggested that migraine might be associated with glial and/or neuronal damage in the brain and a prolonged disruption of blood–brain barrier. Increased interictal serum levels of S100B might point out to an insidious and slow damaging process in migraine patients.