Multi-Epoch VERA Observations of Sagittarius A*: I. Images and Structural Variability

We report the results of multi-epoch observations of Sgr A* with VLBI Exploration of Radio Astrometry (VERA) at 43 GHz, carried out from 2004 to 2008. We detected a time variation of flux at 11 % level and intrinsic size at 19 %. In addition, comparisons with previous Very Long Baseline Array (VLBA) results shows that Sgr A* underwent the flaring event at least longer than 10 days in May 2007. The intrinsic size of Sgr A* remained unchanged within 1 $\sigma$ level from the size before/after the flaring event, indicating that the brightness temperature of Sgr A* was increased. The flaring event occurred within 31 d, which is shorter than the refractive time scale. Moreover it is difficult to explain the increase in the spectral index at the flaring event by the simple interstellar scattering model. Hence, the flaring event is most likely associated with the changes in intrinsic properties of Sgr A*. We considered the origin of the brightness temperature variation, and concluded that the flaring event of Sgr A* could be explained by the continuous heating of electrons, such as a standing shock in accretion flow.Comment: 13 pages, 7 figures, published in Publications of the Astronomical Society of Japan (PASJ

Pulse-Wave Analysis of Optic Nerve Head Circulation Is Significantly Correlated with Kidney Function in Patients with and without Chronic Kidney Disease

Aim. To determine whether there is a significant correlation between the optic nerve head (ONH) circulation determined by laser speckle flowgraphy (LSFG) and kidney function. Materials. Seventy-one subjects were investigated. The estimated glomerular filtration rate (GFR) and serum creatinine, cystatin C, and urinary albumin excretion were measured. The ONH circulation was determined by an analysis of the pulse wave of LSFG, and this parameter was named blowout time (BOT). Chronic kidney disease (CKD) was defined to be present when the estimated GFR was <60 mL/min per 1.73 m2. Pearson’s correlation coefficients were used to determine the relationship between the BOT and the kidney function. We also examined whether there were significant differences in all parameters in patients with and without CKD. Results. BOT was significantly correlated with the level of creatinine (r=-0.24, P=0.04), the estimated GFR (r=0.42, P=0.0003), cystatin C (r=-0.29, P=0.01), and urinary albumin excretion (r=-0.29, P=0.01). The BOT level in subjects with CKD was significantly lower than that in subjects without CKD (P=0.002). Conclusion. BOT in ONH by LSFG can detect the organ damage such as kidney dysfunction, CKD

Cytokine profiles in an extremely preterm infant with congenital syphilis

We report the cytokine profiles of an infant with congenital syphilis as a first case. This female infant was born by vaginal delivery at a gestational age of 27 weeks during her mother's treatment for syphilis. Elevation of T helper (Th)-1 cytokines (interleukin (IL)-2, IL-12) and IL-17, which supports immunological mechanisms of Th-1, was similar to that in cases of syphilis in adults. IL-6 and granulocyte colony-stimulating factor (G-CSF), the synergistic effects of which cause the leukemoid reaction, were also elevated. The levels of interferon-γ and IL-17 in cerebral spinal fluid, which are elevated in neurosyphilis in adults, were slightly elevated

Peripheral platelet phagocytosis in an extremely low birth weight infant: a case report

A 768 g female neonate, born at 25 weeks' gestation, developed sepsis due to methicillin-resistant Staphylococcus epidermidis on day 14. Severe thrombocytopenia was observed, and hemophagocytic macrophages were identified in her peripheral blood smear. Cytokine profiles at the time of onset suggested that an inflammatory cytokine storm had activated lymphocytes and macrophages, leading to platelet phagocytosis. After administration of vancomycin for 14 days and immunoglobulin therapy, she improved without any complications. Considering the results of cytokine profiles, early intervention for infection may have prevented progression to hemophagocytic lymphohistiocytosis and reduced the severity of clinical symptoms