Interplay between T cell receptor binding kinetics and the level of cognate peptide presented by major histocompatibility complexes governs CD8+ T cell responsiveness.

Through a rational design approach, we generated a panel of HLA-A*0201/NY-ESO-1(157-165)-specific T cell receptors (TCR) with increasing affinities of up to 150-fold from the wild-type TCR. Using these TCR variants which extend just beyond the natural affinity range, along with an extreme supraphysiologic one having 1400-fold enhanced affinity, and a low-binding one, we sought to determine the effect of TCR binding properties along with cognate peptide concentration on CD8(+) T cell responsiveness. Major histocompatibility complexes (MHC) expressed on the surface of various antigen presenting cells were peptide-pulsed and used to stimulate human CD8(+) T cells expressing the different TCR via lentiviral transduction.

Community attitudes to deceased organ donation: a focus group study.

Background: Despite broad community support for organ donation, there is a chronic shortage of donor organs for transplantation. This study elicited community attitudes on deceased organ donation and the current Australian organ donation system.

Methods: Thirteen focus groups with 114 participants aged between 18 and 75 years.

Patient preferences for the allocation of deceased donor kidneys for transplantation: a mixed methods study.

Background: Deceased donor kidneys are a scarce health resource, yet patient preferences for organ allocation are largely unknown. The aim of this study was to determine patient preferences for how kidneys should be allocated for transplantation.

Methods: Patients on dialysis and kidney transplant recipients were purposively selected from two centres in Australia to participate in nominal/focus groups in March 2011.

Orientation of the N-terminal lobe of the myosin regulatory light chain in skeletal muscle fibers.

The orientation of the N-terminal lobe of the myosin regulatory light chain (RLC) in demembranated fibers of rabbit psoas muscle was determined by polarized fluorescence. The native RLC was replaced by a smooth muscle RLC with a bifunctional rhodamine probe attached to its A, B, C, or D helix. Fiber fluorescence data were interpreted using the crystal structure of the head domain of chicken skeletal myosin in the nucleotide-free state.

Mechanics of myosin function in white muscle fibres of the dogfish, Scyliorhinus canicula.

The contractile properties of muscle fibres have been extensively investigated by fast perturbation in sarcomere length to define the mechanical characteristics of myofilaments and myosin heads that underpin refined models of the acto-myosin cycle. Comparison of published data from intact fast-twitch fibres of frog muscle and demembranated fibres from fast muscle of rabbit shows that stiffness of the rabbit myosin head is only ∼62% of that in frog. To clarify if and how much the mechanical characteristics of the filaments and myosin heads vary in muscles of different animals we apply the same high resolution mechanical methods, in combination with X-ray diffraction, to fast-twitch fibres from the dogfish (Scyliorhinus canicula).

Factors that influence the decision to be an organ donor: a systematic review of the qualitative literature.

Background: Transplantation is the treatment of choice for organ failure, but a worldwide shortage of suitable organs exists. We conducted a systematic review of qualitative studies that explored community attitudes towards living and deceased solid organ donation to inform strategies to improve organ donation rates.

Methods: Medline, Embase, PsycINFO and EconLIT were searched.

TCRep 3D: an automated in silico approach to study the structural properties of TCR repertoires.

TCRep 3D is an automated systematic approach for TCR-peptide-MHC class I structure prediction, based on homology and ab initio modeling. It has been considerably generalized from former studies to be applicable to large repertoires of TCR. First, the location of the complementary determining regions of the target sequences are automatically identified by a sequence alignment strategy against a database of TCR Vα and Vβ chains.

Reversible major histocompatibility complex I-peptide multimers containing Ni(2+)-nitrilotriacetic acid peptides and histidine tags improve analysis and sorting of CD8(+) T cells.

MHC-peptide multimers containing biotinylated MHC-peptide complexes bound to phycoerythrin (PE) streptavidin (SA) are widely used for analyzing and sorting antigen-specific T cells. Here we describe alternative T cell-staining reagents that are superior to conventional reagents. They are built on reversible chelate complexes of Ni(2+)-nitrilotriacetic acid (NTA) with oligohistidines.

Nephrologists' perspectives on waitlisting and allocation of deceased donor kidneys for transplant.

Background: Deceased donor kidneys are a scarce resource and there is debate about how to maximize the benefit from each donated kidney while ensuring equity of access to transplants. Allocation of kidneys to waitlisted patients is determined by a computer algorithm, but the decision to waitlist patients or accept the kidneys offered is largely at the discretion of nephrologists. This study aims to elicit nephrologists' perspectives on waitlisting patients for kidney transplant and the allocation of deceased kidneys.

Serpentine fibula polycystic kidney syndrome is part of the phenotypic spectrum of Hajdu-Cheney syndrome.

Serpentine fibula polycystic kidney syndrome (SFPKS; MIM600330) is a rare skeletal dysplasia that has polycystic kidneys and dysmorphic facies as additional defining phenotypic components. The nosological classification of this disease has been debated as the condition shares features common to other skeletal dysplasias such as Melnick Needles syndrome (MNS; MIM309350) and Hajdu-Cheney Syndrome (HCS; MIM102500). Here, two previously reported cases of SFPKS are presented with emphasis on their phenotypic evolution.

Community Preferences for the Allocation & Donation of Organs--the PAraDOx Study.

Background: Transplantation is the treatment of choice for people with severe organ failure. However, demand substantially exceeds supply of suitable organs; consequently many people wait months, or years to receive an organ. Reasons for the chronic shortage of deceased organ donations are unclear; there appears to be no lack of 'in principle' public support for organ donation.

Motion of myosin head domains during activation and force development in skeletal muscle.

Muscle contraction is driven by a change in the structure of the head domain of myosin, the "working stroke" that pulls the actin filaments toward the midpoint of the myosin filaments. This movement of the myosin heads can be measured very precisely in intact muscle cells by X-ray interference, but until now this technique has not been applied to physiological activation and force generation following electrical stimulation of muscle cells. By using this approach, we show that the long axes of the myosin head domains are roughly parallel to the filaments in resting muscle, with their center of mass offset by approximately 7 nm from the C terminus of the head domain.

Clinical management of achondroplasia.

Achondroplasia, one of the skeletal dysplasias and the commonest form of disproportionate short stature, has a different developmental and growth profile compared to average stature children. In addition, a specific group of complications occur more frequently in children with achondroplasia. These include common but usually relatively minor complications such as recurrent otitis media, and rarer but more severe problems such as cervicomedullary compression.

Two novel COL2A1 mutations associated with a Legg-Calvé-Perthes disease-like presentation.

Background: Abnormal development and growth of the capital femoral epiphysis and acetabulum are associated with a wide variety of underlying etiologies, one of which is Legg-Calvé-Perthes disease.

Case Description: We report the cases of two children who presented with abnormal development of both hips and in whom novel mutations in the COL2A1 gene were found. These cases illustrate the importance of identifying individuals with a type II collagen abnormality, as it informs management, allows investigation for other complications, and provides the opportunity for accurate genetic counseling and consideration of other family members who might be at risk.

Mutations in NOTCH2 cause Hajdu-Cheney syndrome, a disorder of severe and progressive bone loss.

We used an exome-sequencing strategy and identified an allelic series of NOTCH2 mutations in Hajdu-Cheney syndrome, an autosomal dominant multisystem disorder characterized by severe and progressive bone loss. The Hajdu-Cheney syndrome mutations are predicted to lead to the premature truncation of NOTCH2 with either disruption or loss of the C-terminal proline-glutamate-serine-threonine-rich proteolytic recognition sequence, the absence of which has previously been shown to increase Notch signaling.

Infantile onset myofibrillar myopathy due to recessive CRYAB mutations.

Mutations in the αB-crystallin (CRYAB) gene, encoding a small heat shock protein with chaperone function, are a rare cause of myofibrillar myopathy with autosomal-dominant inheritance, late-onset and moderate severity. We report a female infant presenting from 4 months with profound muscle stiffness, persistent creatine kinase elevation and electromyography characterized by spontaneous electrical activity and pseudomyotonic discharges. Muscle biopsy suggested a myofibrillar myopathy and genetic testing revealed homozygosity for the CRYAB mutation c.

Opinions on the content and effects of the Caring for Australasians with Renal Impairment (CARI) Guidelines: a survey of renal nurses and comparison with the opinions of nephrologists in Australasia.

Aim: Renal nurses in Australia and New Zealand are critical to the care of patients with chronic kidney disease (CKD), especially those on dialysis. We aimed to obtain the opinions of renal nurses in Australia and New Zealand on the Caring for Australasians with Renal Impairment (CARI) Guidelines.

Methods: A self-administered survey was distributed to all members of the professional organisation for renal nurses (Renal Society of Australasia) in 2006.

Evidence for a TCR affinity threshold delimiting maximal CD8 T cell function.

Protective adaptive immune responses rely on TCR-mediated recognition of Ag-derived peptides presented by self-MHC molecules. However, self-Ag (tumor)-specific TCRs are often of too low affinity to achieve best functionality. To precisely assess the relationship between TCR-peptide-MHC binding parameters and T cell function, we tested a panel of sequence-optimized HLA-A(*)0201/NY-ESO-1(157-165)-specific TCR variants with affinities lying within physiological boundaries to preserve antigenic specificity and avoid cross-reactivity, as well as two outliers (i.

MM-GBSA binding free energy decomposition and T cell receptor engineering.

Recognition by the T-cell receptor (TCR) of immunogenic peptides (p) presented by class I major histocompatibility complexes (MHC) is the key event in the immune response against virus infected cells or tumor cells. The major determinant of T cell activation is the affinity of the TCR for the peptide-MHC complex, though kinetic parameters are also important. A study of the 2C TCR/SIYR/H-2Kb system using a binding free energy decomposition (BFED) based on the MM-GBSA approach had been performed to assess the performance of the approach on this system.

Time-lapse FRET microscopy using fluorescence anisotropy.

We present recent data on dynamic imaging of Rac1 activity in live T-cells. Förster resonance energy transfer between enhanced green and monomeric red fluorescent protein pairs which form part of a biosensor molecule provides a metric of this activity. Microscopy is performed using a multi-functional high-content screening instrument using fluorescence anisotropy to provide a means of monitoring protein-protein activity with high temporal resolution.

Nephrologists' perspectives on the effect of guidelines on clinical practice: a semistructured interview study.

Background: A consistent gap exists between evidence-based guideline recommendations and clinical practice across all medical disciplines, including nephrology. This study aims to explore nephrologists' perspectives on guidelines and elicit their perspectives on the effects of guidelines on clinical decisions.

Methods: Semistructured face-to-face interviews were undertaken with 19 nephrologists from a variety of clinical settings across Australia.

Exploring peptide mimics for the production of antibodies against discontinuous protein epitopes.

Peptide "mimics" (mimotopes) of linear protein epitopes and carbohydrate epitopes have been successfully used as immunogens to elicit cross-reactive antibodies against their cognate epitopes; however, immunogenic mimicry has been difficult to achieve for discontinuous protein epitopes. To explore this, we developed from phage-displayed peptide libraries optimized peptide mimics for three well-characterized discontinuous epitopes on hen egg lysozyme and horse cytochrome c. The peptides competed with their cognate antigens for antibody binding, displayed affinities in the nM range, and shared critical binding residues with their native epitopes.