Potential dependence of the ionic structure at the ionic liquid/water interface studied using MD simulation.

The structure at the electrochemical liquid/liquid interface between water (W) and trioctylmethylammonium bis(nonafluorobutanesulfonyl)amide, a hydrophobic ionic liquid (IL), was studied using molecular dynamics (MD) simulation in which the interfacial potential difference was controlled. On the IL side of the IL/W interface, ionic multilayers were found in the number density distribution of IL ions whereas monolayer-thick charge accumulation was found in the charge density distribution. This suggests that the potential screening is completed within the first ionic layer and the effect of overlayers on the potential is marginal. The W side of the interface showed the diffuse electric double layer as expected, and unexpectedly unveiled a density depletion layer, indicating that the IL surface is hydrophobic enough to be repelled by water. The IL ions in the first ionic layer showed anisotropic orientation even at the potential of zero charge, in which the polar moieties were oriented to the W side and the non-polar moieties preferred parallel orientation to the interface. When an electric field is applied across the interface so that the IL ions are more accumulated, the non-polar moieties changed the parallel preference to more oriented to the IL side due to the dipolar nature of the IL ions. The ionic orientations at the IL/W interface were compared with those at other two IL interfaces, the vacuum and graphene interfaces of the IL. The parallel preference of the non-polar moieties was similar at the IL/graphene interface but different from the perpendicular orientation toward the vacuum side at the IL/vacuum interface. The comparison suggests that water behaves like a wall that repels IL ions like a solid electrode.

Influenza Virus Infection Induces Host Pyruvate Kinase M Which Interacts with Viral RNA-Dependent RNA Polymerase.

Influenza virus RNA-dependent RNA polymerase (RdRp) is a heterotrimer of three viral proteins, PB1, PB2, and PA and is involved in both transcription and replication of the negative strand of the viral RNA (vRNA) genome. RdRp is multifunctional, possessing RNA polymerase, cap binding, and endonuclease activities. The enzyme synthesizes three different RNAs, complementary RNA (cRNA) and messenger RNA (mRNA) from vRNA, and vRNA from cRNA. To synthesize these three RNAs, RdRp requires conversion of its function by host factor. Here, we performed yeast two-hybrid screening to identify the relevant host factor, revealing that pyruvate kinase M2 (PKM2) interacted with the PA subunit of influenza virus RdRp. PKM2 is one of two enzymes (PKM1 and PKM2) produced by alternative splicing of the pyruvate kinase M (PKM) pre-mRNA. We determined the interacting regions in both PKM2 and PA, the expression level of PKM by western blotting at different time points after viral infection, and the effects of transfection of siRNA targeting PKM on influenza virus replication. The results demonstrated that the C-terminal region of PKM2 interacted with the C-terminus of the PA subunit, that the expression level of PKM2 increased with influenza virus infection time, and that this enzyme is essential for influenza virus multiplication. Moreover, isoelectric focusing of uninfected and influenza virus infected cell extracts, followed by gradient gel electrophoresis to separate the PKM1 and PKM2 isoforms and western blotting indicated that PKM2 became more acidic after influenza infection. The decreased pH of PKM2 may have been due to phosphorylation, and phosphorylated PKM2 is active as a pyruvate kinase and protein kinase; therefore, it is possible that PKM2 may transfer a phosphate group to PA and consequently transform the function of RdRp from transcriptase to replicase.

Evaluation of recurrent nerve paralysis due to thoracic aortic aneurysm and aneurysm repair.

OBJECTIVES: We sought to clarify the relationship between the outcome of recurrent laryngeal nerve paralysis with the characteristics of the thoracic aortic aneurysm and the surgical procedure used in each patient. METHODS: Nine patients who developed recurrent nerve paralysis (nonsurgical paralysis) due to a thoracic aortic aneurysm alone and 14 patients who underwent artificial vessel replacement for thoracic aortic aneurysm and developed recurrent nerve paralysis postoperatively (surgical paralysis) were evaluated. RESULTS: In the patients with nonsurgical paralysis, the aneurysms were similar in size to those of other patients who underwent surgery of the thoracic aorta and were invariably located near the aortic arch. Aneurysm shape was not associated with nerve paralysis. Surgical paralysis was alleviated in two patients. Surgical paralysis was observed in 9% of those who underwent surgery of the thoracic aorta. Vocal cord mobility recovered in 4 of the 11 patients with surgical paralysis who underwent follow-up. Symptoms were alleviated by rehabilitation in many patients who did not recover vocal cord mobility. The positions of the artificial vessel anastomoses are thought to be closely related to the outcome of paralysis. CONCLUSION: Recurrent nerve paralysis reduced not only the patient's quality of life but also survival by leading to disorders including aspiration pneumonia. Therefore, early rehabilitation should be performed, and surgical treatment should be considered, if necessary, for patients with recurrent nerve paralysis.

Involuntary expiratory phonation as a dose-related consequence of L-dopa therapy in a patient with Parkinson's disease.

We report a case of involuntary phonation caused by abnormal vocal cord movements during expiration in a patient with Parkinson's disease. A 60-year-old woman had been treated for parkinsonism at the outpatient clinic of the Department of Neurology since August 1999. She began to groan involuntarily in the daytime in September 2001. She could not eat well while groaning. Stridor was not noted during sleep at night. Endoscopic examination of the larynx revealed insufficient abduction of the bilateral vocal cords, although the glottis was not so small as to cause stridor during inspiration. During expiration, however, the vocal cords adducted, resulting in the involuntary production of voice. Electromyography showed an increase in the activity of the thyroarytenoid and lateral cricoarytenoid muscles. This muscle activity was further enhanced during inspiration. The involuntary phonation disappeared when the patient's dose of L-dopa was decreased, although she had a decrease in her systemic mobility as well. When the dose of L-dopa was increased to the therapeutic level, involuntary phonation recurred, and her voluntary systemic activity improved. In the present case, it was considered that excessive dopaminergic denervation occurred in the nerve innervating the laryngeal adductors. Involuntary voice appeared to be produced by hypertonus of the laryngeal adductors because of a lowering in the threshold level for L-dopa, even though the drug was administered at the usual dose.

[Localization of senescence marker protein-30 (SMP30) in the mouse submandibular gland and histological findings in the SMP30 knock-out mouse].

Senescence marker protein-30 (SMP30), which has a molecular mass of 30 kDa, is strongly expressed during maturation and decreases with aging in the liver and kidney. SMP30 is suspected of being closely related to cell functions, especially intracellular Ca2+ homeostasis, in differentiated tissues of the liver and kidney. We produced an antibody against SMP30 to study the localization of SMP30 in the submandibular gland of normal mice using an enzyme-labeled antibody. The submandibular gland was also observed under transmission electron microscopy in newly created SMP30-knockout mice compared to normal mice. SMP30 was found to be widely distributed in acinic cells of ductal and peripheral areas of the submandibular gland. Degenerative mitochondria tended to be abundantly observed in cells with SMP30, although marked changes were not noted in SMP30-knockout mice.