147 research outputs found

    STAT Proteins in Innate Immunity during Sepsis: Lessons from Gene Knockout Mice

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    The innate immune system provides immediate defense against infection and serves as the first line of host defense during infection. In innate immunity, leukocytes such as neutrophils and macrophages recognize and respond to pathogens in a non-specific manner. Therefore, the recruitment and activation of leukocytes are essential in innate immunity, and are governed by a variety of chemical mediators including cytokines. Cytokines are generally divided into 2 types, termed type-1 and type-2 cytokines. Type-1 cytokines are important in local host defense, while type-2 cytokines play a protective role when inflammatory response spreads to the body. These cytokines exert their biological functions through the janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. STAT1/3/4/6 are transcription factors that mediate IFNgamma/IL-10/IL-12/IL-13 cytokine signaling, respectively. Evidence indicates that STAT proteins have a significant impact on innate immunity during sepsis. This review focuses on recent understandings in the regulation of innate immunity by STAT proteins during sepsis and septic shock. The suppressor of cytokine signaling (SOCS) proteins are a family of SH2 domain-containing cytoplasmic proteins that complete a negative feedback loop to attenuate signal transduction from cytokines that act through the JAK/STAT pathway. The participation of SOCS proteins in sepsis is also discussed

    Do Deep Generative Models Know What They Don't Know?

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    A neural network deployed in the wild may be asked to make predictions for inputs that were drawn from a different distribution than that of the training data. A plethora of work has demonstrated that it is easy to find or synthesize inputs for which a neural network is highly confident yet wrong. Generative models are widely viewed to be robust to such mistaken confidence as modeling the density of the input features can be used to detect novel, out-of-distribution inputs. In this paper we challenge this assumption. We find that the density learned by flow-based models, VAEs, and PixelCNNs cannot distinguish images of common objects such as dogs, trucks, and horses (i.e. CIFAR-10) from those of house numbers (i.e. SVHN), assigning a higher likelihood to the latter when the model is trained on the former. Moreover, we find evidence of this phenomenon when pairing several popular image data sets: FashionMNIST vs MNIST, CelebA vs SVHN, ImageNet vs CIFAR-10 / CIFAR-100 / SVHN. To investigate this curious behavior, we focus analysis on flow-based generative models in particular since they are trained and evaluated via the exact marginal likelihood. We find such behavior persists even when we restrict the flows to constant-volume transformations. These transformations admit some theoretical analysis, and we show that the difference in likelihoods can be explained by the location and variances of the data and the model curvature. Our results caution against using the density estimates from deep generative models to identify inputs similar to the training distribution until their behavior for out-of-distribution inputs is better understood.Comment: ICLR 201

    Hybrid Models with Deep and Invertible Features

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    We propose a neural hybrid model consisting of a linear model defined on a set of features computed by a deep, invertible transformation (i.e. a normalizing flow). An attractive property of our model is that both p(features), the density of the features, and p(targets | features), the predictive distribution, can be computed exactly in a single feed-forward pass. We show that our hybrid model, despite the invertibility constraints, achieves similar accuracy to purely predictive models. Moreover the generative component remains a good model of the input features despite the hybrid optimization objective. This offers additional capabilities such as detection of out-of-distribution inputs and enabling semi-supervised learning. The availability of the exact joint density p(targets, features) also allows us to compute many quantities readily, making our hybrid model a useful building block for downstream applications of probabilistic deep learning.Comment: ICML 201

    The chemokine monocyte chemoattractant protein-1/CCL2 is a promoter of breast cancer metastasis

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    Breast cancer is the most prevalent cancer worldwide, and metastasis is the leading cause of death in cancer patients. Human monocyte chemoattractant protein-1 (MCP-1/CCL2) was isolated from the culture supernatants of not only mitogen-activated peripheral blood mononuclear leukocytes but also malignant glioma cells based on its in vitro chemotactic activity toward human monocytes. MCP-1 was subsequently found to be identical to a previously described tumor cell-derived chemotactic factor thought to be responsible for the accumulation of tumor-associated macrophages (TAMs), and it became a candidate target of clinical intervention; however, the role of TAMs in cancer development was still controversial at the time of the discovery of MCP-1. The in vivo role of MCP-1 in cancer progression was first evaluated by examining human cancer tissues, including breast cancers. Positive correlations between the level of MCP-1 production in tumors and the degree of TAM infiltration and cancer progression were established. The contribution of MCP-1 to the growth of primary tumors and metastasis to the lung, bone, and brain was examined in mouse breast cancer models. The results of these studies strongly suggested that MCP-1 is a promoter of breast cancer metastasis to the lung and brain but not bone. Potential mechanisms of MCP-1 production in the breast cancer microenvironment have also been reported. In the present manuscript, we review studies in which the role of MCP-1 in breast cancer development and progression and the mechanisms of its production were examined and attempt to draw a consensus and discuss the potential use of MCP-1 as a biomarker for diagnosis

    A Surgical Instructor Training Course for the Next Generation

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    In 2016, Gunma University Hospital’s Medical Accident Investigation Committee released a report reiterating the necessity of medical education and the need for surgeons to master non-technical skills. We designed a 17-h training course for surgical instructors, designed to teach participants how to sufficiently educate surgeon trainees and encourage their professional identity formation. A post-training survey showed that participants improved their awareness, and their behavioral changes led to favorable team performances. We then began offering a 3-h workshop focusing on the participants’ experiences. We propose that the training course using participant narratives is required and effective to establish surgeons’ self-reflection and professional identity as surgeons

    Notch system in the linkage of innate and adaptive immunity

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142014/1/jlb0059.pd

    Role of CC chemokine CCL6/C10 as a monocyte chemoattractant in a murine acute peritonitis.

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    The aim of this study was to determine the role of CC chemokine CCL6/C10 in acute inflammation. Intraperitoneal injection of thioglycollate increased peritoneal CCL6, which peaked at 4 h and remained elevated at 48 h. Neutralization of CCL6 significantly inhibited the macrophage infiltration (34-48% reduction), but not other cell types, without decreasing the other CC chemokines known to attract monocytes/macrophages. CCL6 was expressed in peripheral eosinophils and elicited macrophages, but not in elicited neutrophils. Peritoneal CCL6 level was not decreased in granulocyte-depleted mice where eosinophil influx was significantly impaired. Thus, CCL6 appears to contribute to the macrophage infiltration that is independent of other CC chemokines. Eosinophils pre-store CCL6, but do not release CCL6 in the peritoneum in this model of inflammation

    Increases in Nonspecific Immunoglobulin E and Eosinophils after H. pylori Eradication

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    Helicobacter pylori infection has been reported to be inversely associated with allergic disorders. We by chance experienced a patient with atrophic gastritis who presented marked elevations of both nonspecific serum immunoglobulin E and eosinophil counts after H. pylori eradication. A 49-year-old Japanese man received eradication of H. pylori using lansoprazole 60 mg/day, amoxicillin 1,500 mg/day, and clarithromycin 400 mg/day for 7 days. Serum immunoglobulin E increased to more than four times its pretreatment level, 306 → 485 → 1,325 U/ml, and peripheral eosinophil counts increased to more than three times, 99 → 139 → 298 per μl. Deducing from the current case, H. pylori eradication might develop allergic disorders in some patients

    Utility of gastric biopsy in diagnosing IgG4‐related gastrointestinal disease

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    The utility of gastric biopsy for diagnosing immunoglobulin (Ig)G4‐related gastrointestinal disease (IgG4‐GID) remains unclear. Bottom‐heavy plasmacytosis (BHP) is a distinct feature of IgG4‐GID. To clarify the feasibility of using gastric biopsies to diagnose BHP in IgG4‐GID, we analyzed the histological features and immunostaining of gastric biopsy specimens from 31 known IgG4‐related disease (IgG4‐RD) patients and we assessed the presence of BHP in 1696 consecutive routine gastric biopsies. Cases with both >10 IgG4‐positive plasma cells per high‐power field and an IgG4/IgG‐positive ratio >40% were defined as IgG4‐high. Ten of the 31 IgG4‐RD patients were concluded to have IgG4‐GID, in which IgG4‐positive plasma cells were notably detected at the deeper part of the mucosa. Six cases displayed BHP whereas the remaining four cases showed transmural infiltration with concomitant Helicobacter pylori‐associated gastritis. In addition to BHP, we identified two unique histologic features for IgG4‐GID: plasmacytic aggregation in the muscularis mucosae and permeative plasmacytic infiltration between fundic glands in the non‐atrophic mucosa. Six of the routine cases (0.35%) displayed BHP, including a case with IgG4‐RD. IgG4‐GID can be suspected by the presence of gastric biopsy specimens with characteristic histological features. Such cases are recommended to undergo further examinations to determine whether IgG4‐RD is present
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