Induction of cytolytic activity and interferon-gamma production in murine natural killer cells by polymyxins B and E

Natural killer (NK) cells are the primary effector cells of the innate immune system and have well-established roles in tumor rejection and resistance to viruses, bacteria and certain parasites. There is a need for more specific immune modulators of NK cell activity that tack the wide-ranging side effects of NK cell-stimulatory interleukins. The polycationic antibiotic polymyxin B (PMB) has been shown to have a unique ability to enhance activities of some immune cells, independent of its antibiotic properties. Here we report that both PMB and its analog potymyxin E (PME) markedly enhanced the activity of NK cells enriched from the murine spleen. Maximal activation of NK cell activity was obtained after 24 h of incubation with PMB at a dose of 300 mu g/ml. PMB nonapeptide, one of the two PMB domains, and PME methanesulfonate, the negatively charged derivative of PME, had little effect on NK cell activity. PMB induced interferon (IFN)-gamma and tumor necrosis factor-a production in NK cells. Proliferation of NK cells in vitro was significantly stimulated by being incubated with PMB. Administration of PMB to mice for 7 consecutive days stimulated splenic NK cell activity and increased NK cell populations in the spleen. These results suggest that the polycationic antibiotics PMB and PME may up-regulate innate and adaptive immune responses by induction of NK cell activity and IFN-gamma production.</p

Influence of nut shell powder content on the tribological properties of recycled polyolefin composites

The purpose of this study is to investigate the influence of nut shell powder (NSP) content on the tribological properties of recycled polyolefin (R-PO) composites. NSP was previously grinded the dried nut shell by crusher machine cryogenically in liquid nitrogen. NSP/R-PO composites with NSP content of 5, 10 and 20 vol.% were prepared in this study. These composites were extruded by a twin screw extruder and injection-molded. Their tribological properties were measured by a reciprocating type sliding wear tester at constant normal load and sliding speed under dry condition. It was found that NSP is effective for reducing the wear resistance of R-PO, and the influence of NSP content on the tribological properties of NSP/R-PO composites does not remarkably appear, but they are improved with the addition of low content such as 5 vol.%. This may be attributed to the change of wear mechanism according to the filling of NSP. © 2016 Author(s).MEXT, Ministry of Education, Culture, Sports, Science, and Technolog

Atomically precise incorporation of BN doped rubicene into graphene nanoribbons

Substituting heteroatoms and non-benzenoid carbons into nanographene structure offers an unique opportunity for atomic engineering of electronic properties. Here we show the bottom-up synthesis of graphene nanoribbons (GNRs) with embedded fused BN-doped rubicene components on a Au(111) surface using on-surface chemistry. Structural and electronic properties of the BN-GNRs are characterized by scanning tunneling microscopy (STM) and atomic force microscopy (AFM) with CO-terminated tips supported by numerical calculations. The periodic incorporation of BN heteroatoms in the GNR leads to an increase of the electronic band gap as compared to its undoped counterpart. This opens avenues for the rational design of semiconducting GNRs with optoelectronic properties.Comment: 18 pages, 4 figure

Magnetic resonance imaging and symptoms in patients with neurosarcoidosis and central diabetes insipidus

Introduction: In the clinical setting, the diagnosis of neurosarcoidosis in patients with central diabetes insipidus (CDI) is typically based both on symptoms (i.e. polydipsia or polyuria) and brain magnetic resonance imaging (MRI) findings (e.g. pituitary abnormality). However, inconsistent changes in the patient’s symptoms and brain MRI findings may occur during the clinical course of the disease. This review was performed to summarise the relationship between symptoms and brain MRI findings in previously reported cases of neurosarcoidosis with CDI. Material and methods: Case studies of patients diagnosed with neurosarcoidosis with CDI were collected via a PubMed search of studies published through 30 June 2018. Results: Thirteen eligible studies were reviewed (20 patients; 12 men, 8 women; mean age 33 years). Polydipsia or polyuria was the first symptom in 13 patients. The mean duration from disease onset to diagnosis was 3.4 months. Brain MRIs showed abnormal findings in the hypothalamus and pituitary for 17 patients. Immunosuppressive drugs were used in 17 patients. For 14 patients, MRI findings improved, while symptoms did not. Conclusion: Patients with both neurosarcoidosis and CDI symptoms often do not improve, despite the fact that brain MRI findings often improve following treatment. More studies involving detailed pathological analyses and longer follow-up periods are necessary