Simulating Problem Difficulty in Arithmetic Cognition Through Dynamic Connectionist Models

The present study aims to investigate similarities between how humans and connectionist models experience difficulty in arithmetic problems. Problem difficulty was operationalized by the number of carries involved in solving a given problem. Problem difficulty was measured in humans by response time, and in models by computational steps. The present study found that both humans and connectionist models experience difficulty similarly when solving binary addition and subtraction. Specifically, both agents found difficulty to be strictly increasing with respect to the number of carries. Another notable similarity is that problem difficulty increases more steeply in subtraction than in addition, for both humans and connectionist models. Further investigation on two model hyperparameters --- confidence threshold and hidden dimension --- shows higher confidence thresholds cause the model to take more computational steps to arrive at the correct answer. Likewise, larger hidden dimensions cause the model to take more computational steps to correctly answer arithmetic problems; however, this effect by hidden dimensions is negligible.Comment: 7 pages; 15 figures; 5 tables; Published in the proceedings of the 17th International Conference on Cognitive Modelling (ICCM 2019

Human Umbilical Cord Blood-Derived Mesenchymal Stem Cell Therapy Promotes Functional Recovery of Contused Rat Spinal Cord through Enhancement of Endogenous Cell Proliferation and Oligogenesis

Numerous studies have shown the benefits of mesenchymal stem cells (MSCs) on the repair of spinal cord injury (SCI) model and on behavioral improvement, but the underlying mechanisms remain unclear. In this study, to investigate possible mechanisms by which MSCs contribute to the alleviation of neurologic deficits, we examined the potential effect of human umbilical cord blood-derived MSCs (hUCB-MSCs) on the endogenous cell proliferation and oligogenesis after SCI. SCI was injured by contusion using a weight-drop impactor and hUCB-MSCs were transplanted into the boundary zone of the injured site. Animals received a daily injection of bromodeoxyuridine (BrdU) for 7 days after treatment to identity newly synthesized cells of ependymal and periependymal cells that immunohistochemically resembled stem/progenitor cells was evident. Behavior analysis revealed that locomotor functions of hUCB-MSCs group were restored significantly and the cavity volume was smaller in the MSCs-transplanted rats compared to the control group. In MSCs-transplanted group, TUNEL-positive cells were decreased and BrdU-positive cells were significantly increased rats compared with control group. In addition, more of BrdU-positive cells expressed neural stem/progenitor cell nestin and oligo-lineage cell such as NG2, CNPase, MBP and glial fibrillary acidic protein typical of astrocytes in the MSC-transplanted rats. Thus, endogenous cell proliferation and oligogenesis contribute to MSC-promoted functional recovery following SCI

Transvaginal Endoscopic Appendectomy

Since Kalloo and colleagues first reported the feasibility and safety of a peroral transgastric approach in the porcine model in 2004, various groups have reported more complex natural orifice transluminal endoscopic surgery (NOTES) procedures, such as the cholecystectomy, splenectomy and liver biopsy, in the porcine model. Natural orifice access to the abdominal cavity, such as transgastric, transvesical, transcolonic, and transvaginal, has been described. Although a novel, minimally invasive approach to the abdominal cavity is a peroral endoscopic transgastric approach, there are still some challenging issues, such as the risk of infection and leakage, and the method of gastric closure. Hybrid-NOTES is an ideal first step in humans. Human hybrid transvaginal access has been used for years by many surgeons for diagnostic and therapeutic purposes. Here, we report a transvaginal flexible endoscopic appendectomy, with a 5-mm umbilical port using ultrasonic scissors in a 74-year-old woman with acute appendicitis

Waldenstrom Macroglobulinemia with CD5+ Expression Presented as Cryoglobulinemic Glomerulonephropathy: A Case Report

Waldenstrom macroglobulinemia (WM) is a B-cell lymphoproliferative disorder associated with bone marrow involvement of lymphoplasmacytic lymphoma (LPL) and an IgM monoclonal gammopathy. Generally B-lymphocytes in LPL do not express CD5 that is important for differential diagnosis of B-cell lymphoproliferative disorders. In WM, various renal diseases and type I cryoglobulinemia are well described separately, but cryoglobulinemic glomerulonephropathy is very rarely reported. A 61-yr-old woman complained of generalized edema, cyanosis of the extremities in cold weather, visual disturbance, and pancytopenia. Bone marrow and renal biopsy showed CD5+ expressing B-cells and cryoglobulinemic glomerulonephropathy. With the diagnosis of WM, she received cyclophosphamide, doxorubicin, vincristine and prednisolone chemotherapy and got complete remission. Here, we report a rare case of WM associated with unusual expression of CD5+ B-lymphocytes and cryoglobulinemic glomerulonephropathy, and emphasize the importance of the clinical features in differentiating CD5+ B-cell lymphoproliferative disorders

Effect of chitinase- 3- like protein 1 on glucose metabolism: In vitro skeletal muscle and human genetic association study

We investigated the effect of chitinase- 3- like protein 1 (CHI3L1) on glucose metabolism and its underlying mechanisms in skeletal muscle cells, and evaluated whether the observed effects are relevant in humans. CHI3L1 was associated with increased glucose uptake in skeletal muscles in an AMP- activated protein kinase (AMPK)- dependent manner, and with increased intracellular calcium levels via PAR2. The improvement in glucose metabolism observed in an intraperitoneal glucose tolerance test on male C57BL/6J mice supported this association. Inhibition of the CaMKK was associated with suppression of CHI3L1- mediated glucose uptake. Additionally, CHI3L1 was found to influence glucose uptake through the PI3K/AKT pathway. Results suggested that CHI3L1 stimulated the phosphorylation of AS160 and p38 MAPK downstream of AMPK and AKT, and the resultant GLUT4 translocation. In primary myoblast cells, stimulation of AMPK and AKT was observed in response to CHI3L1, underscoring the biological relevance of CHI3L1. CHI3L1 levels were elevated in cells under conditions that mimic exercise in vitro and in exercised mice in vivo, indicating that CHI3L1 is secreted during muscle contraction. Finally, similar associations between CHI3L1 and metabolic parameters were observed in humans alongside genotype associations between CHI3L1 and diabetes at the population level. CHI3L1 may be a potential therapeutic target for the treatment of diabetes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162777/2/fsb220907.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162777/1/fsb220907_am.pd

Performance of the tuberculin skin test and interferon-γ release assay for detection of tuberculosis infection in immunocompromised patients in a BCG-vaccinated population

<p>Abstract</p> <p>Background</p> <p>Interferon-γ release assay (IGRA) may improve diagnostic accuracy for latent tuberculosis infection (LTBI). This study compared the performance of the tuberculin skin test (TST) with that of IGRA for the diagnosis of LTBI in immunocompromised patients in an intermediate TB burden country where BCG vaccination is mandatory.</p> <p>Methods</p> <p>We conducted a retrospective observational study of patients given the TST and an IGRA, the QuantiFERON-TB Gold In-Tube (QFT-IT), at Severance Hospital, a tertiary hospital in South Korea, from December 2006 to May 2009.</p> <p>Results</p> <p>Of 211 patients who underwent TST and QFT-IT testing, 117 (55%) were classified as immunocompromised. Significantly fewer immunocompromised than immunocompetent patients had positive TST results (10.3% vs. 27.7%, p 0.001), whereas the percentage of positive QFT-IT results was comparable for both groups (21.4% vs. 25.5%). However, indeterminate QFT-IT results were more frequent in immunocompromised than immunocompetent patients (21.4% vs. 9.6%, p 0.021). Agreement between the TST and QFT-IT was fair for the immunocompromised group (κ = 0.38), but moderate agreement was observed for the immunocompetent group (κ = 0.57). Indeterminate QFT-IT results were associated with anaemia, lymphocytopenia, hypoproteinemia, and hypoalbuminemia.</p> <p>Conclusion</p> <p>In immunocompromised patients, the QFT-IT may be more sensitive than the TST for detection of LTBI, but it resulted in a considerable proportion of indeterminate results. Therefore, both tests may maximise the efficacy of screening for LTBI in immunocompromised patients.</p

Non-specific Defensive Factors of the Pacific Oyster Crassostrea gigas against Infection with Marteilioides chungmuensis: A Flow-Cytometric Study

In order to assess changes in the activity of immunecompetency present in Crassostrea gigas infected with Marteilioides chungmuensis (Protozoa), the total hemocyte counts (THC), hemocyte populations, hemocyte viability, and phagocytosis rate were measured in oysters using flow cytometry. THC were increased significantly in oysters infected with M. chungmuensis relative to the healthy appearing oysters (HAO) (P<0.05). Among the total hemocyte composition, granulocyte levels were significantly increased in infected oysters as compared with HAO (P<0.05). In addition, the hyalinocyte was reduced significantly (P<0.05). The hemocyte viability did not differ between infected oysters and HAO. However, the phagocytosis rate was significantly higher in infected oysters relative to HAO (P<0.05). The measurement of alterations in the activity of immunecompetency in oysters, which was conducted via flow cytometry in this study, might be a useful biomarker of the defense system for evaluating the effects of ovarian parasites of C. gigas

Trans-Differentiation of Neural Stem Cells: A Therapeutic Mechanism Against the Radiation Induced Brain Damage

Radiation therapy is an indispensable therapeutic modality for various brain diseases. Though endogenous neural stem cells (NSCs) would provide regenerative potential, many patients nevertheless suffer from radiation-induced brain damage. Accordingly, we tested beneficial effects of exogenous NSC supplementation using in vivo mouse models that received whole brain irradiation. Systemic supplementation of primarily cultured mouse fetal NSCs inhibited radiation-induced brain atrophy and thereby preserved brain functions such as short-term memory. Transplanted NSCs migrated to the irradiated brain and differentiated into neurons, astrocytes, or oligodendrocytes. In addition, neurotrophic factors such as NGF were significantly increased in the brain by NSCs, indicating that both paracrine and replacement effects could be the therapeutic mechanisms of NSCs. Interestingly, NSCs also differentiated into brain endothelial cells, which was accompanied by the restoration the cerebral blood flow that was reduced from the irradiation. Inhibition of the VEGF signaling reduced the migration and trans-differentiation of NSCs. Therefore, trans-differentiation of NSCs into brain endothelial cells by the VEGF signaling and the consequential restoration of the cerebral blood flow would also be one of the therapeutic mechanisms of NSCs. In summary, our data demonstrate that exogenous NSC supplementation could prevent radiation-induced functional loss of the brain. Therefore, successful combination of brain radiation therapy and NSC supplementation would provide a highly promising therapeutic option for patients with various brain diseases