179 research outputs found

    The value of 99mTc-MAA SPECT/CT for lung shunt estimation in 90Y radioembolization: a phantom and patient study

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    Abstract Background A major toxicity concern in radioembolization therapy of hepatic malignancies is radiation-induced pneumonitis and sclerosis due to hepatopulmonary shunting of 90Y microspheres. Currently, 99mTc macroaggregated albumin (99mTc-MAA) imaging is used to estimate the lung shunt fraction (LSF) prior to treatment. The aim of this study was to evaluate the accuracy/precision of LSF estimated from 99mTc planar and SPECT/CT phantom imaging, and within this context, to compare the corresponding LSF and lung-absorbed dose values from 99mTc-MAA patient studies. Additionally, LSFs from pre- and post-therapy imaging were compared. Results A liver/lung torso phantom filled with 99mTc to achieve three lung shunt values was scanned by planar and SPECT/CT imaging with repeat acquisitions to assess accuracy and precision. To facilitate processing of patient data, a workflow that relies on SPECT and CT-based auto-contouring to define liver and lung volumes for the LSF calculation was implemented. Planar imaging-based LSF estimates for 40 patients, obtained from their medical records, were retrospectively compared with SPECT/CT imaging-based calculations with attenuation and scatter correction. Additionally, in a subset of 20 patients, the pre-therapy estimates were compared with 90Y PET/CT-based measurements. In the phantom study, improved accuracy in LSF estimation was achieved using SPECT/CT with attenuation and scatter correction (within 13% of the true value) compared with planar imaging (up to 44% overestimation). The results in patients showed a similar trend with planar imaging significantly overestimating LSF compared to SPECT/CT. There was no correlation between lung shunt estimates and the delay between 99mTc-MAA administration and scanning, but off-target extra hepatic uptake tended to be more likely in patients with a longer delay. The mean lung absorbed dose predictions for the 28 patients who underwent therapy was 9.3 Gy (range 1.3–29.4) for planar imaging and 3.2 Gy (range 0.4–13.4) for SPECT/CT. For the patients with post-therapy imaging, the mean LSF from 90Y PET/CT was 1.0%, (range 0.3–2.8). This value was not significantly different from the mean LSF estimate from 99mTc-MAA SPECT/CT (mean 1.0%, range 0.4–1.6; p = 0.968), but was significantly lower than the mean LSF estimate based on planar imaging (mean 4.1%, range 1.2–15.0; p = 0.0002). Conclusions The improved accuracy demonstrated by the phantom study, agreement with 90Y PET/CT in patient studies, and the practicality of using auto-contouring for liver/lung definition suggests that 99mTc-MAA SPECT/CT with scatter and attenuation corrections should be used for lung shunt estimation prior to radioembolization.https://deepblue.lib.umich.edu/bitstream/2027.42/144504/1/13550_2018_Article_402.pd

    Inhibition of HSV-1 by chemoattracted neutrophils: supernatants of corneal epithelial cells (HCE) and macrophages (THP-1) treated with virus components chemoattract neutrophils (PMN), and supernatants of PMN treated with these conditioned media inhibit viral growth

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    The role of PMNs (neutrophils) in corneal herpes was studied using an in vitro system. Human corneal cells (HCE) and macrophages (THP-1) infected with HSV-1 or treated with virus components (DNA or virus immune complexes) released chemokines, which attracted PMNs. Highly reactive oxygen species were detected in PMNs. PMNs inhibited HSV when overlaid onto infected HCE cells (50:1). PMNs incubated with the supernatants of HCE cells treated with virus components released H2O2 and myeloperoxidase. These inhibited virus growth. PMNs released NO and MIG, which may differentiate CD4 T cells to Th1. PMNs participate in innate immune responses, limit virus growth, and initiate immunopathology

    Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study.

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    PurposeOsteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI.MethodsUsing data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves.ResultsIn children, the median z-scores for height in OI types I, III, and IV were -0.66, -6.91, and -2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was -4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P < 0.001), age, bisphosphonate use, and rodding (P < 0.05).ConclusionFrom the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves

    Measuring substance use in the club setting: a feasibility study using biochemical markers

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    <p>Abstract</p> <p>Background</p> <p>During the last few decades the use of club drugs (e.g., cocaine, amphetamines) has been of increased concern in nightlife settings. Traditionally, surveys have been used to estimate the use of club drugs, however, they mostly rely on self-reports which may not be accurate. Recent advances have allowed for readily accessible drug testing methods such as oral fluid drug testing. Nevertheless, research using oral fluid sampling to measure the frequency of drug use in the club environment is scarce. The objective of this study is to evaluate the feasibility of measuring the frequency of alcohol and drug use among Swedish clubbers using breath alcohol and oral fluid drug testing.</p> <p>Method</p> <p>The setting was a 40 hour electronic music dance event (EMDE) on a cruise ship on the Baltic Sea, departing from Sweden, with 875 passengers. Groups of participants at the EMDE were randomly invited to participate. Data were collected with face-to-face and self-administered questionnaires. Further, oral fluid samples were collected to determine illicit drug use, and blood alcohol concentration (BAC) levels were measured using a breath analyzer.</p> <p>Results</p> <p>A total of 422 passengers were asked to participate in the study whereof 21 declined (5.0% refusal rate). Of the 401 study participants (accounting for 45.8% of all attendees), 5 declined oral fluid drug testing. Results show that there was a discrepancy between self-reported and actual drug use as 10.1% of the participants were positive on illicit drug use (amphetamines, ecstasy/MDMA, cannabis, cocaine), while only 3.7% of the participants reported drug use during the last 48 hours. The average BAC level was 0.10% and 23.7% had BAC levels ≥ 0.15%, while 5.9% had levels below the detection limit. The mean BAC levels for the illicit drug users were significantly higher (<it>p </it>= 0.004) than for non-drug users (0.13% vs. 0.10%). Self-reported AUDIT-C scores (using a threshold of ≥ 5 for men and ≥ 4 for women) revealed that 76.0% of the men and 80.7% of the women had risky alcohol consumption patterns.</p> <p>Conclusion</p> <p>This study indicates that it is feasible to conduct breath alcohol and oral fluid drug testing in a Swedish club setting.</p

    IL-33-mediated protection against experimental cerebral malaria is linked to induction of Type 2 innate lymphoid cells, M2 macrophages and regulatory T cells

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    Author Summary Cerebral malaria (CM) caused by the parasite Plasmodium sp . is a fatal disease, especially in children. Currently there is no effective treatment. We report here our investigation on the role of a recently discovered cytokine IL-33, in treating experimental cerebral malaria (ECM) in the susceptible C57BL/6 mice. IL-33 protects the mice against ECM. The protection is accompanied by a reduction of Th1 response and the enhancement of type 2 cytokine response. We also found that IL-33 mediates its protective effect by inducing a population of type 2 innate lymphoid cells (ILC2), which then polarize macrophages to alternatively-activated phenotypes (M2). M2 in turn expand regulatory T cells (Tregs) which suppress the deleterious Th1 response. Our report therefore reveals hitherto unrecognised mechanisms of the regulation of ECM and provide a novel function of IL-33

    IL-12p35 induces expansion of IL-10 and IL-35-expressing regulatory B cells and ameliorates autoimmune disease

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    We thank Dr. Haohua Qian and Yichao Li (Visual function core, NEI, NIH) for technical assistance with OCT; Phyllis Silver (NEI, NIH) for EAU scoring of the eyes; Rashid Mahdi. M.J.M. for technical assistance with western blot analyses and Rafael Villasmil (NEI FLOW Cytometry Core facility) for assistance with FACS analysis.Peer reviewedPublisher PD

    Importance of TLR2 on Hepatic Immune and Non-Immune Cells to Attenuate the Strong Inflammatory Liver Response During Trypanosoma cruzi Acute Infection

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    Trypanosoma cruzi, an obligate intracellular protozoan, is the etiological agent of Chagas Disease that represents an important public health burden in Latin America. The infection with this parasite can lead to severe complications in cardiac, liver and gastrointestinal tissue depending on the strain of parasite and host genetics. Recently, we reported a fatal liver injury in T. cruzi infected B6 mice. However, the local immune response against this parasite is poorly understood. This work highlights some of the molecular and cellular mechanisms involved in liver pathology during the acute phase of infection. Using two mouse strains with different genetic backgrounds and responses to infection, B6 and BALB/c, we found that infected B6 mice develop a strong pro-inflammatory environment associated with high TLR9 expression. Conversely, infected BALB/c mice showed a more balanced inflammatory response in liver. Moreover, higher TLR2 and TLR4 expression were found only in hepatocytes from BALB/c. These data emphasize the importance of an adequate integration of signalling between immune and non-immune cells to define the outcome of infection. In addition, the pre-treatment with TLR2-agonist reverts the strong pro-inflammatory environment in T. cruzi infected B6 mice. These results could be useful in the understanding and design of novel immune strategies in controlling liver pathologies

    The Myeloid Receptor PILRβ Mediates the Balance of Inflammatory Responses through Regulation of IL-27 Production

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    Paired immunoglobulin-like receptors beta, PILRβ, and alpha, PILRα, are related to the Siglec family of receptors and are expressed primarily on cells of the myeloid lineage. PILRβ is a DAP12 binding partner expressed on both human and mouse myeloid cells. The potential ligand, CD99, is found on many cell types, such as epithelial cells where it plays a role in migration of immune cells to sites of inflammation. Pilrb deficient mice were challenged with the parasite Toxoplasma gondii in two different models of infection induced inflammation; one involving the establishment of chronic encephalitis and a second mimicking inflammatory bowel disease in order to understand the potential role of this receptor in persistent inflammatory responses. It was found that in the absence of activating signals from PILRβ, antigen-presenting cells (APCs) produced increased amounts of IL-27, p28 and promoted IL-10 production in effector T cells. The sustained production of IL-27 led ultimately to enhanced survival after challenge due to dampened immune pathology in the gut. Similar protection was also observed in the CNS during chronic T. gondii infection after i.p. challenge again providing evidence that PILRβ is important for regulating aberrant inflammatory responses

    Regulatory T cells and their role in rheumatic diseases: a potential target for novel therapeutic development

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    Regulatory T cells have an important role in limiting immune reactions and are essential regulators of self-tolerance. Among them, CD4+CD25high regulatory T cells are the best-described subset. In this article, we summarize current knowledge on the phenotype, function, and development of CD4+CD25high regulatory T cells. We also review the literature on the role of these T cells in rheumatic diseases and discuss the potential for their use in immunotherapy
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