Presence of CD3+ and CD79a+ lymphocytes in the pituitary gland of dogs at post-mortem examination

Hypophysitis has been reported occasionally in dogs, with most cases resembling primary lymphocytic hypo-physitis in man. Although it is generally assumed that lymphocytes are not present normally in the canine pi-tuitary gland, few studies have investigated this hypothesis. However, lymphocytes are recognized in thepituitary gland of people and horses without signs of pituitary disease. It is unknown to what degree lympho-cyte infiltration of the pituitary gland might occur as an incidental finding in dogs. The aim of the present studywas to investigate the presence and distribution of lymphocytes in the pituitary gland of dogs without clinicalsuspicion of pituitary disease. Twenty dogs were subjected to routine necropsy examination. Formalin-fixedand paraffin wax-embedded sections of pituitary were stained with haematoxylin and eosin (HE) or subjectedto immunohistochemistry (IHC) using primary antibodies specific for the T-cell marker CD3 and the B-cellmarker CD79a. The number of CD3+ and CD79a+ cells per area unit (CPA) was determined for differentpituitary regions. Two dogs had extensive neoplastic lesions in the pituitary gland and were excluded fromanalysis. In the remaining 18 dogs, occasional scattered CD3+cells were found in the pituitary gland. Therewas a significant difference in CD3+CPA between pituitary regions (P¼0.001). The highest CD3+CPA wasfound in the pars tuberalis (median 41.3 cells/mm2, interquartile range 20.9e50.5 cells/mm2). In six of the 18dogs (33%), CD79a+ cells were detected in small number (median total cell number 0 cells/section, interquar-tile range 0e1.0 cells/section). This study shows that T cell, and fewer B cells, may be found in the pituitarygland of dogs without clinical suspicion of pituitary disease. Regional difference in T-cell density, with the high-est CD3+CPA in the pars tuberalis, may imply regional immunoregulatory functions in the canine pituitarygland

Fermionic Linear Optics Revisited

We provide an alternative view of the efficient classical simulatibility of fermionic linear optics in terms of Slater determinants. We investigate the generic effects of two-mode measurements on the Slater number of fermionic states. We argue that most such measurements are not capable (in conjunction with fermion linear optics) of an efficient exact implementation of universal quantum computation. Our arguments do not apply to the two-mode parity measurement, for which exact quantum computation becomes possible, see quant-ph/0401066.Comment: 16 pages, submitted to the special issue of Foundation of Physics in honor of Asher Peres' 70th birthda

What factors determine placental glucose transfer kinetics?

Introduction: transfer of glucose across the human placenta is directly proportional to maternal glucose concentrations even when these are well above the physiological range. This study investigates the relationship between maternal and fetal glucose concentrations and transfer across the placenta.Methods: transfer of d-glucose, 3H-3-o-methyl-d-glucose (3H-3MG) and 14C-l-glucose across the isolated perfused human placental cotyledon was determined for maternal and fetal arterial d-glucose concentrations between 0 and 20 mmol/l.Results: clearance of 3H-3MG or 14C-l-glucose was not affected by maternal or fetal d-glucose concentrations in either circulation.Discussion: based on the arterial glucose concentrations and the reported KM for GLUT1, the transfer of d-glucose and 3H-3MG would be expected to show signs of saturation as d-glucose concentrations increased but this did not occur. One explanation for this is that incomplete mixing of maternal blood and the rate of diffusion across unstirred layers may lower the effective concentration of glucose at the microvillous membrane and subsequently at the basal membrane. Uncertainties about the affinity of GLUT1 for glucose, both outside and inside the cell, may also contribute to the difference between the predicted and observed kinetics.Conclusion: these factors may therefore help explain why the observed and predicted kinetics differ and they emphasise the importance of understanding the function of transport proteins in their physiological context. The development of a computational model of glucose transfer may improve our understanding of how the determinants of placental glucose transfer interact and function as a syste

Interventions to Improve Transitional Care Between Nursing Homes and Hospitals: A Systematic Review

Transitions between healthcare settings are associated with errors in communication of information and treatment plans for frail older patients, but strategies to improve transitional care are lacking. A systematic review was conducted to identify and evaluate interventions to improve communication of accurate and appropriate medication lists and advance directives for elderly patients who transition between nursing homes and hospitals. MEDLINE, ISI Web, and EBSCO Host (from inception to June 2008) were searched for original, English-language research articles reporting interventions to improve communication of medication lists and advance directives. Five studies ultimately met all inclusion criteria. Two described interventions that enhanced transmission of advance directives, two described interventions that improved communication of medication lists, and one intervention addressed both goals. One study was a randomized controlled trial, whereas the remaining studies used historical or no controls. Study results indicate that a standardized patient transfer form may assist with the communication of advance directives and medication lists and that pharmacist-led review of medication lists may help identify omitted or indicated medications on transfer. Although preliminary evidence supports adoption of these methods to improve transitions between nursing home and hospital, further research is needed to define target populations and outcomes measures for highquality transitional care

Duality covariant quantum field theory on noncommutative Minkowski space

We prove that a scalar quantum field theory defined on noncommutative Minkowski spacetime with noncommuting momentum coordinates is covariant with respect to the UV/IR duality which exchanges coordinates and momenta. The proof is based on suitable resonance expansions of charged noncommutative scalar fields in a background electric field, which yields an effective description of the field theory in terms of a coupled complex two-matrix model. The two independent matrix degrees of freedom ensure unitarity and manifest CT-invariance of the field theory. The formalism describes an analytic continuation of the renormalizable Grosse-Wulkenhaar models to Minkowski signature.Comment: 32 pages; v2: Typos corrected; v3: Further typos corrected - Final version to appear in JHE

On the covariant quantization of tensionless bosonic strings in AdS spacetime

The covariant quantization of the tensionless free bosonic (open and closed) strings in AdS spaces is obtained. This is done by representing the AdS space as an hyperboloid in a flat auxiliary space and by studying the resulting string constrained hamiltonian system in the tensionless limit. It turns out that the constraint algebra simplifies in the tensionless case in such a way that the closed BRST quantization can be formulated and the theory admits then an explicit covariant quantization scheme. This holds for any value of the dimension of the AdS space.Comment: 1+16 pages; v4 two clarifications adde

Controversies in Osteoporosis Treatment of Nursing Home Residents

Osteoporotic fractures are a common and serious health problem for older adults living in nursing homes (NHs). Risk of fracture increases with age and dementia status, yet gaps in evidence result in controversies around when to start and stop treatment for osteoporosis in NH residents, particularly those who have high fracture risk but have limited life expectancy. In this article, we discuss these areas of controversy. We provide an overview of current guidelines that explicitly address osteoporosis treatment strategies for NH residents, review the evidence for osteoporosis medications in NH residents, and use these sources to suggest practical recommendations for clinical practice and for research. Three published guidelines (from the United States, Canada, and Australia) and several studies provide the current basis for clinical decisions about osteoporosis treatment for NH residents. Practical approaches may include broad use of vitamin D and selective use of osteoporosis medication based on risks, benefits, and goals of care. Clinicians still lack strong evidence to guide treatment of NH residents with advanced dementia, multimorbidity, or severe mobility impairment. Future priorities for research include identifying optimal approaches to risk stratification and prevention strategies for NH residents and evaluating the risk-benefit profile of pharmacologic treatments for osteoporosis NH residents across key clinical strata. In the absence of such evidence, decisions for initiating and continuing treatment should reflect a patient-centered approach that incorporates life expectancy, goals of care, and the potential burden of treatment

A framework for the local information dynamics of distributed computation in complex systems

The nature of distributed computation has often been described in terms of the component operations of universal computation: information storage, transfer and modification. We review the first complete framework that quantifies each of these individual information dynamics on a local scale within a system, and describes the manner in which they interact to create non-trivial computation where "the whole is greater than the sum of the parts". We describe the application of the framework to cellular automata, a simple yet powerful model of distributed computation. This is an important application, because the framework is the first to provide quantitative evidence for several important conjectures about distributed computation in cellular automata: that blinkers embody information storage, particles are information transfer agents, and particle collisions are information modification events. The framework is also shown to contrast the computations conducted by several well-known cellular automata, highlighting the importance of information coherence in complex computation. The results reviewed here provide important quantitative insights into the fundamental nature of distributed computation and the dynamics of complex systems, as well as impetus for the framework to be applied to the analysis and design of other systems.Comment: 44 pages, 8 figure

Superconductors with Magnetic Impurities: Instantons and Sub-gap States

When subject to a weak magnetic impurity potential, the order parameter and quasi-particle energy gap of a bulk singlet superconductor are suppressed. According to the conventional mean-field theory of Abrikosov and Gor'kov, the integrity of the energy gap is maintained up to a critical concentration of magnetic impurities. In this paper, a field theoretic approach is developed to critically analyze the validity of the mean field theory. Using the supersymmetry technique we find a spatially homogeneous saddle-point that reproduces the Abrikosov-Gor'kov theory, and identify instanton contributions to the density of states that render the quasi-particle energy gap soft at any non-zero magnetic impurity concentration. The sub-gap states are associated with supersymmetry broken field configurations of the action. An analysis of fluctuations around these configurations shows how the underlying supersymmetry of the action is restored by zero modes. An estimate of the density of states is given for all dimensionalities. To illustrate the universality of the present scheme we apply the same method to study `gap fluctuations' in a normal quantum dot coupled to a superconducting terminal. Using the same instanton approach, we recover the universal result recently proposed by Vavilov et al. Finally, we emphasize the universality of the present scheme for the description of gap fluctuations in d-dimensional superconducting/normal structures.Comment: 18 pages, 9 eps figure

Using claims data to predict dependency in activities of daily living as a proxy for frailty

Estimating drug effectiveness and safety among older adults in population-based studies using administrative health care claims can be hampered by unmeasured confounding as a result of frailty. A claims-based algorithm that identifies patients likely to be dependent, a proxy for frailty, may improve confounding control. Our objective was to develop an algorithm to predict dependency in activities of daily living (ADL) in a sample of Medicare beneficiaries. Methods: Community-dwelling respondents to the 2006 Medicare Current Beneficiary Survey, >65years old, with Medicare Part A, B, home health, and hospice claims were included. ADL dependency was defined as needing help with bathing, eating, walking, dressing, toileting, or transferring. Potential predictors were demographics, International Classification of Diseases, Ninth Revision Clinical Modification diagnosis/procedure and durable medical equipment codes for frailty-associated conditions. Multivariable logistic regression was used to predict ADL dependency. Cox models estimated hazard ratios for death as a function of observed and predicted ADL dependency. Results: Of 6391 respondents, 57% were female, 88% white, and 38% were ≥80. The prevalence of ADL dependency was 9.5%. Strong predictors of ADL dependency were charges for a home hospital bed (OR=5.44, 95%CI=3.28-9.03) and wheelchair (OR=3.91, 95%CI=2.78-5.51). The c-statistic of the final model was 0.845. Model-predicted ADL dependency of 20% or greater was associated with a hazard ratio for death of 3.19 (95%CI: 2.78, 3.68). Conclusions: An algorithm for predicting ADL dependency using health care claims was developed to measure some aspects of frailty. Accounting for variation in frailty among older adults could lead to more valid conclusions about treatment use, safety, and effectiveness