Peptidoglycan-Targeted [F]3,3,3-Trifluoro-d-alanine Tracer for Imaging Bacterial Infection.

Imaging is increasingly used to detect and monitor bacterial infection. Both anatomic (X-rays, computed tomography, ultrasound, and MRI) and nuclear medicine ([In]-WBC SPECT, [F]FDG PET) techniques are used in clinical practice but lack specificity for the causative microorganisms themselves. To meet this challenge, many groups have developed imaging methods that target pathogen-specific metabolism, including PET tracers integrated into the bacterial cell wall.

The effects of plastic additives on swimming activity and startle response in marine amphipod Echinogammarus marinus.

Plastic additives are widely used in plastic production and are found in the environment owing to their widespread applications. Among these additives, N-butyl benzenesulfonamide (NBBS) and triphenyl phosphate (TPHP) are under international watchlist for evaluation, with limited studies on amphipods. Di-ethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP) are banned in some countries and categorised as substances of very high concern.

Evaluation of precopulatory pairing behaviour and male fertility in a marine amphipod exposed to plastic additives.

Plastics contain a mixture of chemical additives that can leach into the environment and potentially cause harmful effects on reproduction and the endocrine system. Two of these chemicals, N-butyl benzenesulfonamide (NBBS) and triphenyl phosphate (TPHP), are among the top 30 organic chemicals detected in surface and groundwater and are currently placed on international watchlist for evaluation. Although bans have been placed on legacy pollutants such as diethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP), their persistence remains a concern.

Retrospective fractional dose reduction in Tc-99m cardiac perfusion SPECT/CT patients: A human and model observer study.

Background: In the ongoing efforts to reduce cardiac perfusion dose (injected radioactivity) for conventional SPECT/CT systems, we performed a human observer study to confirm our clinical model observer findings that iterative reconstruction employing OSEM (ordered-subset expectation-maximization) at 25% of the full dose (quarter-dose) has a similar performance for detection of hybrid cardiac perfusion defects as FBP at full dose.

Methods: One hundred and sixty-six patients, who underwent routine rest-stress Tc-99m sestamibi cardiac perfusion SPECT/CT imaging and clinically read as normally perfused, were included in the study. Ground truth was established by the normal read and the insertion of hybrid defects.

Development of a Rapid Point-of-Use DNA Test for the Screening of Genuity® Roundup Ready 2 Yield® Soybean in Seed Samples.

Testing for the presence of genetically modified material in seed samples is of critical importance for all stakeholders in the agricultural industry, including growers, seed manufacturers, and regulatory bodies. While rapid antibody-based testing for the transgenic protein has fulfilled this need in the past, the introduction of new variants of a given transgene demands new diagnostic regimen that allows distinguishing different traits at the nucleic acid level. Although such molecular tests can be performed by PCR in the laboratory, their requirement for expensive equipment and sophisticated operation have prevented its uptake in point-of-use applications.

Cross-subtype detection of HIV-1 using reverse transcription and recombinase polymerase amplification.

A low complexity diagnostic test that rapidly and reliably detects HIV infection in infants at the point of care could facilitate early treatment, improving outcomes. However, many infant HIV diagnostics can only be performed in laboratory settings. Recombinase polymerase amplification (RPA) is an isothermal amplification technology that can rapidly amplify proviral DNA from multiple subtypes of HIV-1 in under twenty minutes without complex equipment.

Multicenter evaluation of stress-first myocardial perfusion image triage by nuclear technologists and automated quantification.

Background: A stress-first myocardial perfusion imaging (MPI) protocol saves time, is cost effective, and decreases radiation exposure. A limitation of this protocol is the requirement for physician review of the stress images to determine the need for rest images. This hurdle could be eliminated if an experienced technologist and/or automated computer quantification could make this determination.

Non-instrumented incubation of a recombinase polymerase amplification assay for the rapid and sensitive detection of proviral HIV-1 DNA.

Sensitive diagnostic tests for infectious diseases often employ nucleic acid amplification technologies (NAATs). However, most NAAT assays, including many isothermal amplification methods, require power-dependent instrumentation for incubation. For use in low resource settings (LRS), diagnostics that do not require consistent electricity supply would be ideal.

Rapid detection of HIV-1 proviral DNA for early infant diagnosis using recombinase polymerase amplification.

Early diagnosis and treatment of human immunodeficiency virus type 1 (HIV-1) infection in infants can greatly reduce mortality rates. However, current infant HIV-1 diagnostics cannot reliably be performed at the point of care, often delaying treatment and compromising its efficacy. Recombinase polymerase amplification (RPA) is a novel technology that is ideal for an HIV-1 diagnostic, as it amplifies target DNA in <20 min at a constant temperature, without the need for complex thermocycling equipment.

Peptide-major histocompatibility complex dimensions control proximal kinase-phosphatase balance during T cell activation.

T cell antigen recognition requires binding of the T cell receptor (TCR) to a complex between peptide antigen and major histocompatibility complex molecules (pMHC), and this recognition occurs at the interface between the T cell and the antigen-presenting cell. The TCR and pMHC molecules are small compared with other abundant cell surface molecules, and it has been suggested that small size is functionally important. We show here that elongation of both mouse and human MHC class I molecules abrogates T cell antigen recognition as measured by cytokine production and target cell killing.

A single-chain H-2Db molecule presenting an influenza virus nucleoprotein epitope shows enhanced ability at stimulating CD8+ T cell responses in vivo.

We have generated a construct encoding a single-chain H-2D(b) mouse MHC class I molecule in which an influenza virus nucleoprotein (NP) epitope, amino acid sequence ASNENMDAM, is fused to mouse beta(2)-microglobulin and the D(b) H chain via flexible linker sequences. This single-chain trimer (SCT) was efficiently expressed at the cell surface independently of TAP and endogenous beta(2)-microglobulin, and it was recognized directly and efficiently by specific T cells in vitro. A recombinant vaccinia virus encoding the D(b) NP SCT primed a CD8(+) T cell response in C57BL/6 mice 4-fold greater than an equivalent virus expressing the NP epitope as a minigene, as shown by tetramer staining, whether or not the minigene was directed into the endoplasmic reticulum by a signal sequence.

Glucose transporter-2 (GLUT2) promoter mediated transgenic insulin production reduces hyperglycemia in diabetic mice.

Insulin production afforded by hepatic gene therapy (HGT) retains promise as a potential treatment for type 1 diabetes, but successful approaches have been limited. We employed a novel and previously untested promoter for this purpose, glucose transporter-2 (GLUT2) to drive insulin production via delivery by recombinant adeno-associated virus (rAAV). In vitro, the GLUT2 promoter was capable of robust glucose-responsive expression in transduced HepG2 human hepatoma cells.

Surface mu heavy chain signals down-regulation of the V(D)J-recombinase machinery in the absence of surrogate light chain components.

Early B cell development is characterized by stepwise, ordered rearrangement of the immunoglobulin (Ig) heavy (HC) and light (LC) chain genes. Only one of the two alleles of these genes is used to produce a receptor, a phenomenon referred to as allelic exclusion. It has been suggested that pre-B cell receptor (pre-BCR) signals are responsible for down-regulation of the VDJH-recombinase machinery (Rag1, Rag2, and terminal deoxynucleotidyl transferase [TdT]), thereby preventing further rearrangement on the second HC allele.