IMMUNODEFICIENT R2G2 MOUSE STRAIN YIELDS SPLEENS WITH UNUSUAL CYTOARCHITECTURE AND SYMPATHETIC INNERVATION

The nervous system and immune system contact one another through two-way communication in order to establish and preserve homeostasis. The sympathetic neurotransmitter norepinephrine has an impact on how the immune system responds by affecting regional blood flow and activation of adrenergic receptors on leukocytes. Former studies showed that immune cells are capable of releasing nerve growth factor allowing for the establishment and continuation of sympathetic nerves in targeted tissues. From this gathered information, it was hypothesized that sympathetic nerves would prove to be less frequent in spleens from the immunodeficient R2G2 mouse strain (Envigo) when compared to 129P3/J (129) and C57BL/6 (C57) strains. R2G2 mice are an immunodeficient strain that lacks functional T, B, and natural killer cells. Ten to eleven week aged-matched male mice were measured by body weight, spleen weight, and temperature. Spleens were cut and fixed for histological investigation. Sympathetic nerves were labeled by immunostaining tyrosine hydroxylase (TH). Hematoxylin & eosin (H&E) was used to stain spleen sections in order to evaluate cytoarchitecture. Von Willebrand factor (VWF) was used to immunostain for megakaryocytes. R2G2 mice showed slightly higher temperatures and body weights but yielded a significantly smaller spleen weight (R2G2, 38.20 ± 1.48; 129, 65.08 ± 11.71; C57, 81.33 ± 8.38; P\u3c 0.0001, ANOVA). TH stain revealed sympathetic innervation in all strains but location and morphology differed in R2G2 mice compared to controls. Control spleens had nerves which entered white pulp regions of the spleen and were closely related to leukocytes. Fiber profiles in the controls were filamentous with small acute bends. R2G2 differed by having (TH+) nerve fibers more associated with arteries and less localized in the surrounding parenchyma. The fibers were abnormally swollen and held a more granular shape instead of a filamentous shape. The H&E stain showed clear red and white pulp zones in the control spleens with 129 showing more distinct germinal centers than C57. R2G2 H&E sections showed cytoarchitecture with indistinct pulp areas. VWF staining revealed R2G2 mice had an abundant amount of megakaryocytes versus control mice megakaryocyte counts (R2G2, 11.28 ± 3.87 per 20X field; 129, 1.73 ± 0.70; C57, 1.42 ± 0.13; P\u3c 0.0001, ANOVA) and extramedullary hematopoiesis was highly prominent. This evidence supports that leukocytes secrete neurotrophic factors or are vital to establishing normal growth of TH+ nerves toward the white pulp. Leukocytes may not be required for sympathetic innervation of blood vessels in the spleen, however, lack of leukocytes shows TH+ nerve fibers with abnormal morphology in severely immune threatened mice

Loss of Sympathetic Nerves in Spleens From Patients With End Stage Sepsis

The spleen is an important site for central regulation of immune function by noradrenergic sympathetic nerves, but little is known about this major region of neuroimmune communication in humans. Experimental studies using animal models have established that sympathetic innervation of the spleen is essential for cholinergic anti-inflammatory responses evoked by vagal nerve stimulation, and clinical studies are evaluating this approach for treating inflammatory diseases. Most data on sympathetic nerves in spleen derive from rodent studies, and this work has established that remodeling of sympathetic innervation can occur during inflammation. However, little is known about the effects of sepsis on spleen innervation. Our primary goals were to (i) localize noradrenergic nerves in human spleen by immunohistochemistry for tyrosine hydroxylase (TH), a specific noradrenergic marker, (ii) determine if nerves occur in close apposition to leukocytes, and (iii) determine if splenic sympathetic innervation is altered in patients who died from end stage sepsis. Staining for vesicular acetylcholine transporter (VAChT) was done to screen for cholinergic nerves. Archived paraffin tissue blocks were used. Control samples were obtained from trauma patients or patients who died after hemorrhagic stroke. TH + nerves were associated with arteries and arterioles in all control spleens, occurring in bundles or as nerve fibers. Individual TH + nerve fibers entered the perivascular region where some appeared in close apposition to leukocytes. In marked contrast, spleens from half of the septic patients lacked TH + nerves fibers and the average abundance of TH + nerves for the septic group was only 16% of that for the control group (control: 0.272 ± 0.060% area, n = 6; sepsis: 0.043 ± 0.026% area, n = 8; P \u3c 0.005). All spleens lacked cholinergic innervation. Our results provide definitive evidence for the distribution of noradrenergic nerves in normal human spleen and the first evidence for direct sympathetic innervation of leukocytes in human spleen. We also provide the first evidence for marked loss of noradrenergic nerves in patients who died from sepsis. Such nerve loss could impair neuroimmunomodulation and may not be limited to the spleen

Posterior longitudinal ligament status in cervical spine bilateral facet dislocations

Objective: It is generally accepted that cervical spine bilateral facet dislocation results in complete disruption of the posterior longitudinal ligament. The goal of this study was to evaluate the integrity of numerous spine-stabilizing structures by MRI, and to determine if any associations between injury patterns exist with respect to the posterior longitudinal ligament status. Design: Retrospective case series. Patients: A retrospective review was performed of 30 cervical spine injury subjects with bilateral facet dislocation. Assessment of 1.5T MRI images was carried out for: intervertebral disc disruption, facet fracture, and ligamentous disruption. Statistical analyses were performed to evaluate for associations between various injury patterns and posterior longitudinal ligament status. Results: The frequency of MRI abnormalities was: anterior longitudinal ligament disruption (26.7%), disc herniation or disruption (90%), posterior longitudinal ligament disruption (40%), facet fracture (63.3%) and disruption of the posterior column ligament complex (97%). There were no significant associations between injury to the posterior longitudinal ligament and other structures. Compared to surgical reports, MRI was accurate for determining the status for 24 of 26 ligaments (three of three anterior longitudinal ligament, seven of nine posterior longitudinal ligament, and 14 of 14 posterior column ligament complex) but generated false negatives in two instances (in both MRI showed an intact posterior longitudinal ligament that was torn at surgery). Conclusions: In contradis¬tinction to the existing concept, the posterior longitudinal ligament can remain intact in a substantial propor¬tion of hyperflexion injuries that produce bilateral cervical facet dislocation. Posterior longitudinal ligament integrity is not associated with any other injury pattern related to the anterior longitudinal ligament, intervertebral disc or facet fracture

Scavenger Receptor Class A Plays a Central Role in Mediating Mortality and the Development of the Pro-Inflammatory Phenotype in Polymicrobial Sepsis

Sepsis is a frequent complication in critical illness. The mechanisms that are involved in initiation and propagation of the disease are not well understood. Scavenger receptor A (SRA) is a membrane receptor that binds multiple polyanions such as oxidized LDL and endotoxin. Recent studies suggest that SRA acts as a pattern recognition receptor in the innate immune response. The goal of the present study was to determine the role of SRA in polymicrobial sepsis. SRA deficient (SRA-/-) and C57BL/6JB/6J (WT) male mice were subjected to cecal ligation and puncture (CLP) to induce polymicrobial sepsis. NFκB activity, myeloperoxidase activity, and co-association of SRA with toll like receptor (TLR) 4 and TLR2 was analyzed in the lungs. Spleens were analyzed for apoptosis. Serum cytokines and chemokines were assayed. Blood and peritoneal fluid were cultured for aerobic and anaerobic bacterial burdens. Long term survival was significantly increased in SRA-/- septic mice (53.6% vs. 3.6%, p\u3c0.05) when compared to WT mice. NFκB activity was 45.5% lower in the lungs of SRA-/- septic mice versus WT septic mice (p\u3c0.05). Serum levels of interleukin (IL)-5, IL-6, IL-10 and monocyte chemoattractant protein -1 were significantly lower in septic SRA-/- mice when compared to septic WT mice (p\u3c0.05). We found that SRA immuno-precipitated with TLR4, but not TLR2, in the lungs of WT septic mice. We also found that septic SRA-/- mice had lower bacterial burdens than WT septic mice. SRA deficiency had no effect on pulmonary neutrophil infiltration or splenocyte apoptosis during sepsis. We conclude that SRA plays a pivotal, and previously unknown, role in mediating the pathophysiology of sepsis/septic shock in a murine model of polymicrobial sepsis. Mechanistically, SRA interacts with TLR4 to enhance the development of the pro-inflammatory phenotype and mediate the morbidity and mortality of sepsis/septic shock

Low Temperature Opacities

Previous computations of low temperature Rosseland and Planck mean opacities from Alexander & Ferguson (1994) are updated and expanded. The new computations include a more complete equation of state with more grain species and updated optical constants. Grains are now explicitly included in thermal equilibrium in the equation of state calculation, which allows for a much wider range of grain compositions to be accurately included than was previously the case. The inclusion of high temperature condensates such as Al$_2$O$_3$ and CaTiO$_3$ significantly affects the total opacity over a narrow range of temperatures before the appearance of the first silicate grains. The new opacity tables are tabulated for temperatures ranging from 30000 K to 500 K with gas densities from 10$^{-4}$ g cm$^{-3}$ to 10$^{-19}$ g cm$^{-3}$. Comparisons with previous Rosseland mean opacity calculations are discussed. At high temperatures, the agreement with OPAL and Opacity Project is quite good. Comparisons at lower temperatures are more divergent as a result of differences in molecular and grain physics included in different calculations. The computation of Planck mean opacities performed with the opacity sampling method are shown to require a very large number of opacity sampling wavelength points; previously published results obtained with fewer wavelength points are shown to be significantly in error. Methods for requesting or obtaining the new tables are provided.Comment: 39 pages with 12 figures. To be published in ApJ, April 200

A Novel Endothelial L-Selectin Ligand Activity in Lymph Node Medulla That Is Regulated by α(1,3)-Fucosyltransferase-IV

Lymphocytes home to peripheral lymph nodes (PLNs) via high endothelial venules (HEVs) in the subcortex and incrementally larger collecting venules in the medulla. HEVs express ligands for L-selectin, which mediates lymphocyte rolling. L-selectin counterreceptors in HEVs are recognized by mAb MECA-79, a surrogate marker for molecularly heterogeneous glycans termed peripheral node addressin. By contrast, we find that medullary venules express L-selectin ligands not recognized by MECA-79. Both L-selectin ligands must be fucosylated by α(1,3)-fucosyltransferase (FucT)-IV or FucT-VII as rolling is absent in FucT-IV+VII−/− mice. Intravital microscopy experiments revealed that MECA-79–reactive ligands depend primarily on FucT-VII, whereas MECA-79–independent medullary L-selectin ligands are regulated by FucT-IV. Expression levels of both enzymes paralleled these anatomical distinctions. The relative mRNA level of FucT-IV was higher in medullary venules than in HEVs, whereas FucT-VII was most prominent in HEVs and weak in medullary venules. Thus, two distinct L-selectin ligands are segmentally confined to contiguous microvascular domains in PLNs. Although MECA-79–reactive species predominate in HEVs, medullary venules express another ligand that is spatially, antigenically, and biosynthetically unique. Physiologic relevance for this novel activity in medullary microvessels is suggested by the finding that L-selectin–dependent T cell homing to PLNs was partly insensitive to MECA-79 inhibition

Detection of brown dwarf-like objects in the core of NGC3603

We use near-infrared data obtained with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope to identify objects having the colors of brown dwarfs (BDs) in the field of the massive galactic cluster NGC 3603. These are identified through use of a combination of narrow and medium band filters spanning the J and H bands, and which are particularly sensitive to the presence of the 1.3-1.5{\mu}m H2O molecular band - unique to BDs. We provide a calibration of the relationship between effective temperature and color for both field stars and for BDs. This photometric method provides effective temperatures for BDs to an accuracy of {\pm}350K relative to spectroscopic techniques. This accuracy is shown to be not significantly affected by either stellar surface gravity or uncertainties in the interstellar extinction. We identify nine objects having effective temperature between 1700 and 2200 K, typical of BDs, observed J-band magnitudes in the range 19.5-21.5, and that are strongly clustered towards the luminous core of NGC 3603. However, if these are located at the distance of the cluster, they are far too luminous to be normal BDs. We argue that it is unlikely that these objects are either artifacts of our dataset, normal field BDs/M-type giants or extra-galactic contaminants and, therefore, might represent a new class of stars having the effective temperatures of BDs but with luminosities of more massive stars. We explore the interesting scenario in which these objects would be normal stars that have recently tidally ingested a Hot Jupiter, the remnants of which are providing a short-lived extended photosphere to the central star. In this case, we would expect them to show the signature of fast rotation.Comment: 26 Pages, 8 Figures, Accepted for publication on Ap

Aptamer-based multiplexed proteomic technology for biomarker discovery

Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine

Health equity issues at the local level: Socio-geography, access, and health outcomes in the service area of the Hôpital Albert Schweitzer-Haiti

<p>Abstract</p> <p>Background</p> <p>Although health equity issues at regional, national and international levels are receiving increasing attention, health equity issues at the local level have been virtually overlooked. Here, we describe here a comprehensive equity assessment carried out by the Hôpital Albert Schweitzer-Haiti (HAS) in 2003. HAS has been operating health and development programs in the Artibonite Valley of Haiti for 50 years.</p> <p>Methods</p> <p>We reviewed all available information arising from a comprehensive evaluation of the programs of HAS carried out in 1999 and 2000. As part of this evaluation, two demographic and health surveys were carried out. We carried out exit interviews with clients receiving primary health care, observations within health facilities, interviews with households related to quality of care, and focus group discussions with community-based health workers. A special study was carried out in 2003 to assess factors determining the use of prenatal care services. Finally, selected findings were obtained from the HAS information system.</p> <p>Results</p> <p>We found markedly reduced access to health services in the peripheral mountainous areas compared to the central plains. The quality of services was more deficient and the coverage of key services was lower in the mountains. Finally, health status, as measured by under-five mortality rates and levels of childhood malnutrition, was also worse in the mountains.</p> <p>Conclusion</p> <p>These findings indicate that local health programs need to give attention to monitoring the health status as well as the quality and coverage of basic services among marginalized groups within the program service area. Health inequities will not be overcome until such monitoring occurs and leaders of health programs ensure that inequities identified are addressed in the local programming of activities. It is quite likely that, within relatively small geographic areas in resource-poor settings around the world, similar, if not even greater, levels of health inequities exist. These inequities need to be measured and addressed in order for health programs to achieve equity and maximum improvement in health status within the population.</p

Reminiscence groups for people with dementia and their family carers: pragmatic eight-centre randomised trial of joint reminiscence and maintenance versus usual treatment: a protocol

The growing number of people with dementia, and the increasing cost of care, provides a major incentive to develop and test methods of supporting them in the community for longer. Most attention has been given to pharmacological interventions, but there is increasing recognition that psychosocial interventions may be equally effective, even preferable where medication has negative side-effects. Reminiscence groups, run by professionals and volunteers, which use photographs, recordings and other objects to trigger personal memories are probably the most popular therapeutic approach to working with people with dementia, but there is little evidence for their effectiveness and cost-effectiveness. The recent inclusion of family carers in groups with people with dementia, notably in our own pilot studies, has generated informal evidence that this joint approach improves relationships between people with dementia and their carers, and benefits both