Use of cardiac troponin T in diagnosis and prognosis of cardiac events in patients on chronic haemodialysis.

Background: Patients undergoing chronic haemodialysis frequently have elevated serum cardiac troponin T (cTnT) levels resulting in difficulty in diagnosing acute coronary syndromes (ACS) in these patients. We sought to determine whether: (i) cTnT concentrations were consistent over time; (ii) intradialytic changes in cTnT levels were due to haemoconcentration; (iii) baseline cTnT levels predicted subsequent mortality or ACS.

Methods: We measured serial pre- and post-dialysis cTnT concentrations in 75 asymptomatic patients undergoing chronic haemodialysis at baseline, and at 48 h, 8 months and 15 months.

Hylamer wear rates and shelf life: a clinical correlation.

We evaluated the performance of 84 Hylamer polyethylene components and zirconia modular femoral heads which were implanted in a single institution over a 5 year period. Patients were followed up for a mean of 6.2 years.

In vitro effects of soy phytoestrogens on rat L6 skeletal muscle cells.

Soy isoflavones display estrogenic activity in humans and animals, and thus are referred to as phytoestrogens. This study was performed to observe the effects of the soy isoflavones genistein, daidzein, and glycitein on cell cultures of rat skeletal muscles. [3H]Thymidine incorporation was used to determine cell proliferation, while protein synthesis and degradation were determined by tracking radiolabeled leucine.

In vivo generation of pathogen-specific Th1 cells in the absence of the IFN-gamma receptor.

The precise mechanisms that govern the commitment of CD4 T cells to become Th1 or Th2 cells in vivo are incompletely understood. Recent experiments demonstrate colocalization of the IFN-gammaR chains with the TCR during activation of naive CD4 T cells, suggesting that association of these molecules may be involved in determining lineage commitment. To test the role of IFN-gamma and its receptor in the generation of Th1 Ag-specific CD4 T cells, we analyzed mice after infection with Listeria monocytogenes or lymphocytic choriomeningitis virus.

Odontoid lateral mass asymmetry: do we over-investigate?

Objectives: This study aimed to evaluate the necessity for further radiological investigation in patients with suspected traumatic rotatory subluxation of the atlanto-axial complex on plain radiography following acute cervical trauma and outline guidelines for assessment of patients with atlanto-axial asymmetry on plain radiography.

Methods: A retrospective review of all patients who had undergone atlanto-axial CT scanning as a result of radiographic C1-C2 asymmetry following cervical spine trauma. The plain x ray and CT images were reviewed retrospectively and correlated with the clinical presentation and outcome.

Primary total hip replacement--a survey of current practice and identifying changing trends.

Primary total hip replacement (THR) surgery is the most commonly performed and successful reconstructive procedure in orthopaedic surgery. We performed a survey of Irish Orthopaedic consultants to elucidate current practices of primary THR in elderly and young patients and identify changing trends. There was an 83% response rate.

Accelerated CD8+ T-cell memory and prime-boost response after dendritic-cell vaccination.

Efficient boosting of memory T-cell numbers to protective levels generally requires a relatively long interval between immunizations. Decreasing this interval could be crucial in biodefense and cancer immunotherapy, in which rapid protective responses are essential. Here, we show that vaccination with peptide-coated dendritic cells (DCs) generated CD8+ T cells with the phenotype and function of memory cells within 4-6 d.

Dynamic regulation of IFN-gamma signaling in antigen-specific CD8+ T cells responding to infection.

IFN-gamma plays a critical role in the CD8(+) T cell response to infection, but when and if this cytokine directly signals CD8(+) T cells during an immune response is unknown. We show that naive Ag-specific CD8(+) T cells receive IFN-gamma signals within 12 h after in vivo infection with Listeria monocytogenes and then become unresponsive to IFN-gamma throughout the ensuing Ag-driven expansion phase. Ag-specific CD8(+) T cells regain partial IFN-gamma responsiveness throughout the contraction phase, whereas the memory pool exhibits uniform, but reduced, responsiveness that is also modulated during the secondary response.

The need for multidisciplinary management of patients with upper thoracic spine fractures caused by high-velocity impact: a review of 32 surgically stabilised cases.

Purpose: To analyse the characteristics of patients who underwent surgery for fractures of the upper thoracic spine (T1-T6) in our institution. The thoracic spine is supported by the rib cage and associated ligaments; therefore, displacement and fracture of the upper thoracic spine in healthy young adults require a great force. The relatively narrow spinal canal around the spinal cord in this area could result in severe neurological deficit should fractures occur.

T cells undergo rapid ON/OFF but not ON/OFF/ON cycling of cytokine production in response to antigen.

Inflammatory cytokines such as IFN-gamma and TNF produced by Ag-stimulated CD4(+) and CD8(+) T cells are important in defense against microbial infection. However, production of these cytokines must be tightly regulated to prevent immunopathology. Previous studies, conducted with BALB/c mice, have suggested that 1) CD8(+) T cells maintain IFN-gamma production but transiently produce TNF in the continued presence of Ag and 2) lymphocytic choriomeningitis virus-specific and in vitro-propagated effector CD8(+) T cells could rapidly cycle IFN-gamma production ON/OFF/ON in response to Ag exposure, removal, and re-exposure.

Percutaneous cementoplasty of acetabular bony metastasis.

The development of malignant lesions in the acetabulum can lead to painful and disabling bone destruction. Lytic metastases of the acetabulum are frequent, causing pathologic fractures, pain and disability. The literature is sparse in relation to the exact indications and technique for this procedure.

Duration of infection and antigen display have minimal influence on the kinetics of the CD4+ T cell response to Listeria monocytogenes infection.

The T cell response to infection consists of clonal expansion of effector cells, followed by contraction to memory levels. It was previously thought that the duration of infection determines the magnitude and kinetics of the T cell response. However, recent analysis revealed that transition between the expansion and contraction phases of the Ag-specific CD8+ T cell response is not affected by experimental manipulation in the duration of infection or Ag display.

Neutrophil involvement in cross-priming CD8+ T cell responses to bacterial antigens.

Substantial CD8(+) T cell responses are generated after infection of mice with recombinant Listeria monocytogenes strains expressing a model epitope (lymphocytic choriomeningitis virus NP(118-126)) in secreted and nonsecreted forms. L. monocytogenes gains access to the cytosol of infected cells, where secreted Ags can be accessed by the endogenous MHC class I presentation pathway.

CD8+ T cell contraction is controlled by early inflammation.

Pathogen-specific CD8(+) T cells expand in number after infection and then their numbers invariably contract by 90-95%, leaving a stable memory cell pool. The chief features of this response are programmed early after infection; however, the factors regulating contraction are mostly undefined. Here we show that antibiotic treatment before Listeria monocytogenes infection induced numbers of protective memory CD8(+) T cells similar to those in control infected mice, by a pathway without contraction.

Anthropometrical analysis of cervical spine injuries.

Unlabelled: To date the principal focus of the mechanism of cervical spine fracture has been directed towards head/neck circumference and vertebral geometric dimensions. However the role of other measurements, including chest circumference and neck length, in a standard cervical fracture population has not yet been studied in detail. Cervical fractures often involve flexion/extension type mechanisms of injury, with the head and cervical spine flexing/extending, using the thorax as an end point of contact.

MHC class Ia-restricted memory T cells inhibit expansion of a nonprotective MHC class Ib (H2-M3)-restricted memory response.

Listeria monocytogenes infection generates major histocompatibility complex (MHC) class Ia-restricted and MHC class Ib-(H2-M3)-restricted effector and memory CD8+ T cells. However, only MHC class Ia-restricted memory cells expand after rechallenge, and it is unknown if MHC class Ib-restricted memory CD8+ T cells generated by vaccination are protective. We show here that H2-M3-restricted memory CD8+ T cells were capable of secondary expansion but, in contrast to primary H2-M3-restricted effector cells, failed to provide protective immunity.

Deficient anti-listerial immunity in the absence of perforin can be restored by increasing memory CD8+ T cell numbers.

Compared with wild-type (WT) mice, Listeria monocytogenes (LM)-vaccinated perforin-deficient (PKO) mice have elevated levels of CD8(+) T cell memory, but exhibit reduced levels of protection against virulent LM. In this study, Ag-specific CD8(+) T cells from LM-vaccinated WT and PKO mice were used in adoptive transfer assays to determine the contribution of perforin-dependent cytolysis in protective immunity to LM. Perforin deficiency resulted in an approximately 5-fold reduction in the per-cell protective capacity of Ag-specific memory CD8(+) T cells that was not caused by differences in memory cell quality as measured by CD62L/CD27 expression, TCR repertoire use, functional avidity, differences in expansion of Ag-specific cells upon infection, or maintenance of memory levels over time.

Outcome after single technique ankle arthrodesis in patients with rheumatoid arthritis.

The established treatment for severe rheumatoid arthritis in the ankle is arthrodesis. Numerous reports in the literature describe outcomes in patients with degenerative and posttraumatic arthrosis and rheumatoid disease. This has led to results that are difficult to interpret.

The effect of leg length discrepancy on foot loading patterns and contact times.

The effect of a simulated leg length discrepancy on foot loading patterns and gait cycle times in normal individuals was investigated. Thirty feet of 15 normal volunteers were evaluated. Leg length discrepancy was simulated using flexible polyurethane soles.

Regulation of CD8+ T cells undergoing primary and secondary responses to infection in the same host.

Naive Ag-specific CD8(+) T cells expand, contract, and become memory cells after infection and/or vaccination. Memory CD8(+) T cells provide faster, more effective secondary responses against repeated exposure to the same pathogen. Using an adoptive transfer system with low numbers of trackable nontransgenic memory CD8(+) T cells, we showed that secondary responses can be comprised of both primary (naive) and secondary (memory) CD8(+) T cells after bacterial (Listeria monocytogenes) and/or viral (lymphocytic choriomeningitis virus) infections.

Viral infection results in massive CD8+ T cell expansion and mortality in vaccinated perforin-deficient mice.

Perforin-mediated cytotoxicity is essential for clearance of primary LCMV infection. BALB/c-perforin-deficient (PKO) mice survived LCMV infection by deleting NP(118)-specific CD8(+) T cells whereas vaccination of PKO mice with Listeria expressing NP(118) generated a stable memory CD8(+) T cell population. However, >85% of vaccinated BALB/c-PKO mice died after LCMV infection.

Recognition of progressive atlanto-occipital dislocation (by a changing neurologic status and clinical deformity).

We present a case of progressive atlanto-occipital dislocation, recognized by a new onset of positive neurologic findings. We discuss the anatomic relationship of the lower four cranial nerves to the foramen magnum and the atlanto-occipital joint. The importance of careful assessment of the cranial nerves prior to choosing a treatment algorithm is emphasized.

Quantitation of CD8+ T cell expansion, memory, and protective immunity after immunization with peptide-coated dendritic cells.

Dendritic cells (DCs) are potent APCs for naive CD8(+) T cells and are being investigated as vaccine delivery vehicles. In this study, we examine the CD8(+) T cell response to defined peptides from Listeria monocytogenes (LM), lymphocytic choriomeningitis virus, and murine CMV coated singly and in combination onto mature bone marrow-derived DCs (BMDCs). We show that immunization of mice with 2 x 10(5) mature BMDCs coated with multiple MHC class I peptides generates a significant Ag-specific CD8(+) T cell response in both the spleen and nonlymphoid organs.