Abnormal [ F]NIFENE binding in transgenic 5xFAD mouse model of Alzheimer's disease: In vivo PET/CT imaging studies of α4β2* nicotinic acetylcholinergic receptors and in vitro correlations with Aβ plaques.

Since cholinergic dysfunction has been implicated in Alzheimer's disease (AD), the effects of Aβ plaques on nicotinic acetylcholine receptors (nAChRs) α4β2* subtype were studied using the transgenic 5xFAD mouse model of AD. Using the PET radiotracer [ F]nifene for α4β2* nAChRs, in vitro autoradiography and in vivo PET/CT studies in 5xFAD mice were carried out and compared with wild-type (C57BL/6) mice. Ratios of [ F]nifene binding in brain regions versus cerebellum (CB) in 5xFAD mice brains were for thalamus (TH) = 17, hippocampus-subiculum = 7, frontal cortex (FC) = 5.

Development of [I]IAZA as a New Proteinopathy Imaging Agent for Alzheimer's Disease.

Radioiodinated imaging agents for Aβ amyloid plaque imaging in Alzheimer’s disease (AD) patients have not been actively pursued. Our previous studies employed the “diaza” derivatives [11C]TAZA and [18F]flotaza in order to develop successful positron emission tomography (PET) imaging agents for Aβ plaques. There is a need for radioiodinated imaging agents for Aβ plaques for single photon emission computed tomography (SPECT) and PET imaging.

Obtaining Osmo-resistant Mutants in Nitrogen-Fixing Bacteria Isolated from Saline Soils.

Annually, about, more than 7% of the Earth's land area becomes inappropriate for agriculture subsequently of salinization and desertification. Biofertilizers based on halophilic nitrogen-fixing bacteria can restore saline soils and stimulate plant growth, having a positive effect on germination, development of stems and roots, and fruiting. The aim of this work was to obtain osmo-resistant (Osm-r) nitrogen-fixing mutants isolated from saline soils of Armenia and selection of the best ones.

Overstretching Double-Stranded RNA, Double-Stranded DNA, and RNA-DNA Duplexes.

Using single-molecule force measurements, we compare the overstretching transition of the four types of duplexes composed of DNA or RNA strands. Three of the four extremities of each double helix are attached to two microscopic beads, and a stretching force is applied with a dual-beam optical trapping interferometer. We find that overstretching occurs for all four duplexes with small differences between the plateau forces.

Severe hyponatraemia in elderly hospitalized patients: prevalence, aetiology and outcome.

Background: Hyponatraemia is the commonest electrolyte disorder in the elderly. Data on severe hyponatraemia and the prevalence of cerebral salt wasting syndrome (CSWS) in elderly hospitalized patients are lacking. We studied the incidence, frequency of various aetiologies, outcome and the possible role of CSWS in severe hyponatraemia in elderly medical patients.