Dinuclear and tetranuclear group 10 metal complexes constructed from linear tetrasilane comprising both Si-H and Si-Si moieties.

The activation of Si-H bonds and/or Si-Si bonds in organosilicon compounds by transition-metal species plays a crucial role for the production of functional organosilicon compounds. Although group-10-metal species are frequently used to activate Si-H and/or Si-Si bonds, so far, systematic investigation to clarify the preferences of these metal species with respect to the activation of Si-H and/or Si-Si bonds remain elusive. Here, we report that platinum(0) species that bear isocyanide or N-heterocyclic-carbene (NHC) ligands selectively activates the terminal Si-H bonds of the linear tetrasilane Ph2(H)SiSiPh2SiPh2Si(H)Ph2 in a stepwise manner, whereby the Si-Si bonds remain intact. In contrast, analogous palladium(0) species are preferably inserted into the Si-Si bonds of the same linear tetrasilane, whereby the terminal Si-H bonds remain intact. Substitution of the terminal hydride groups in Ph2(H)SiSiPh2SiPh2Si(H)Ph2 with chloride groups leads to the insertion of platinum(0) isocyanide into all Si-Si bonds to afford an unprecedented zig-zag Pt4 cluster.

Serum Uromodulin Is a Possible Auxiliary Diagnostic Tool for Acute Tubular Injury and Acute Interstitial Nephritis: A Case Series.

Recently, the usefulness of serum uromodulin (sUmod) as a novel renal biomarker has been attracting attention. Clinical evidence regarding sUmod measurements has been accumulated by analyzing cross-sectional data. However, little is known about the longitudinal data on sUmod. Therefore, we decided to investigate the variability of sUmod in patients with acute kidney injury due to different causes. High concentrations of sUmod have been observed in patients with acute tubular injury (ATI) and/or acute interstitial nephritis (AIN). sUmod could be used as an auxiliary diagnostic tool for ATI and AIN.

Triangular Palladium Cluster from Activation of the Si-Si Bond in a Disilane with Phosphine Pendants.

A disilane that contains two diphenylphosphino moieties, (Ph2PCH2)Ph2Si-SiPh2(CH2PPh), was readily synthesized from the reaction of ClPh2Si-SiPh2Cl with (tmeda)Li(CH2PPh2). Treatment of the thus-obtained disilane with the palladium(0) precursor [Pd(CNtBu)2]3 led to the exclusive formation of a trinuclear palladium cluster in which three palladium atoms are arranged in a triangular fashion. Single-crystal X-ray diffraction analysis of the obtained triangular cluster revealed that novel silylphosphido chelating ligands were formed via a skeletal rearrangement of the ligand framework.

Serum uromodulin is a novel renal function marker in the Japanese population.

BACKGROUND: Uromodulin, also known as Tamm-Horsfall protein, is the most abundant protein in urine. It has recently been reported that uromodulin exists in a small amount in blood and that its concentration correlates with the estimated glomerular filtration rate (eGFR). METHODS: First, we generated anti-human uromodulin mouse monoclonal antibodies (mAb(s)) and established a specific enzyme-linked immunosorbent assay (ELISA) for uromodulin. We then performed an observational clinical study to determine if there was a correlation between serum uromodulin concentration and estimates of kidney function and whether the serum uromodulin value could be a biomarker in clinical nephrology. The clinical study included 308 patients with and without chronic kidney disease and healthy volunteers. Serum concentrations of creatinine, cystatin C, and uromodulin were measured and correlations were sought between the eGFR calculated from the creatinine and cystatin C levels and the serum uromodulin concentration. RESULTS: There was a good correlation between the serum uromodulin concentration and the eGFR value calculated from the creatinine (r = 0.76) and cystatin C (r = 0.79) levels. The mean serum uromodulin level in the group with an eGFR > 90 mL/min/1.73 m2 calculated using cystatin C was significantly higher than that in the group with an eGFR of 80-89 mL/min/1.73 m2. CONCLUSIONS: The serum uromodulin measurement could be a useful biomarker for identification of patients with early deterioration of kidney function.

Insertion of Ni(0) and Pd(0) precursors into the Si-Si bond of a disilane with two hypercoordinate silicon atoms.

The activation of the silicon-silicon bond in disilane Ph2Si(µ-PzMe2)2SiPh2 (1), which possesses two five-coordinate silicon centers, was achieved by a reaction with Pd(0) or Ni(0) precursors of modest steric demand to afford a dinuclear Pd complex (2) or two types of mononuclear Ni complexes (3 and 4), respectively.

Photochromic Radical Complexes That Show Heterolytic Bond Dissociation.

Photochromic materials have been widely used in various research fields because of their variety of photoswitching properties based on various molecular frameworks and bond breaking processes, such as homolysis and heterolysis. However, while a number of photochromic molecular frameworks have been reported so far, there are few reports on photochromic molecular frameworks that show both homolysis and heterolysis depending on the substituents with high durability. The biradicals and zwitterions generated by homolysis and heterolysis have different physical and chemical properties and different potential applications. Therefore, the rational photochromic molecular design to control the bond dissociation in the excited state on demand expands the versatility for photoswitch materials beyond the conventional photochromic molecular frameworks. In this study, we synthesized novel photochromic molecules based on the framework of a radical-dissociation-type photochromic molecule: phenoxyl-imidazolyl radical complex (PIC). While the conventional PIC shows the photoinduced homolysis, the substitution of a strong electron-donating moiety to the phenoxyl moiety enables the bond dissociation process to be switched from homolysis to heterolysis. This study gives a strategy for controlling the bond dissociation process of the excited state of photochromic systems, and the strategy enables us to develop further novel radical and zwitterionic photoswitches.

Efficacy of Semiannual Single Fixed Low-Dose Rituximab Therapy in Steroid-Dependent Minimal Change Nephrotic Syndrome: A Case Series.

The frequency of using rituximab to treat refractory nephrotic syndrome has recently been increasing, and the conventional dose of rituximab used to treat it, 375 mg/m2 body surface area once weekly for 4 weeks, has been modelled on the chemotherapy regimen for B-cell non-Hodgkin's lymphoma. The dose and intervals of rituximab in refractory nephrotic syndrome remain controversial. Clear lymphoma cell hyperplasia is seen in lymphoma patients, but not in nephrotic syndrome patients. Since we thought that it might be possible to reduce the dose of rituximab if only used for the purpose of depleting CD20-positive B cells in nephrotic patients' peripheral blood, we tried semiannually with a single fixed rituximab dose of 100 mg/body, and a complete remission was attained in 3 cases without treatment with prednisolone or cyclosporine. Our report strongly suggests considering appropriate dose and interval of rituximab therapy in the treatment of steroid-dependent nephrotic syndrome.

A case of acetaminophen-induced acute tubulointerstitial nephritis in adult.

We report a case of allergic acute tubulointerstitial nephritis (TIN) induced by acetaminophen in a 48-year-old Japanese man with no past medical history. Two days after receiving the non-steroidal anti-inflammatory drug (NSAID) loxoprofen for left shoulder pain, he developed cold symptoms such as fever and sore throat. He then took a 300 mg dose of acetaminophen three times a day and a 100 mg dose of minocycline hydrochloride twice a day for 7 days. Because there was no improvement in his symptoms, he consulted a local clinic again, where blood tests revealed renal insufficiency, and he was, then, referred to our hospital for evaluation of kidney function. Renal biopsy revealed acute TIN, and Ga-67 scintigraphy showed diffuse uptake in bilateral kidneys. A drug-induced lymphocyte stimulation test (DLST) was positive for acetaminophen and negative for loxoprofen and minocycline. Based on these findings, we made a diagnosis of acetaminophen-induced TIN. We treated the patient with three courses of semi-pulse steroid therapy, after which his fever went down, and his serum creatinine level recovered from 2.09 to 1.43 mg/dL. Although we medical doctors think that therapeutic dose of acetaminophen retains high safety, it is important to keep in mind that acetaminophen can cause allergic acute TIN.

The Improvement of the Outcome of Osmotic Demyelination Syndrome by Plasma Exchange.

A 71-year-old Japanese woman presented with progressive fatigue, lethargy, dysarthria and a gait disorder. Her laboratory data revealed hyponatremia (Na 101 mEq/L), and we started correcting her serum sodium level. Within a few days, she became comatose, bedridden, and was intubated. We diagnosed osmotic demyelination syndrome (ODS) and started performing plasma exchange (PE) on the 39th day of hospitalization. She fully recovered after starting PE, and was discharged on foot unassisted. PE can be a beneficial treatment in patients with chronic ODS.

A case of posterior reversible leukoencephalopathy syndrome caused by fibromuscular dysplasia.

A 23-year-old woman presented with disturbance of consciousness and seizure. Her blood pressure was remarkably high, and brain magnetic resonance imaging (MRI) showed high-intensity T2 signals in the bilateral basal ganglia, corpus callosum, cerebral white matter, and cortex. With the administration of angiotensin II receptor blocker, the symptoms and MRI findings improved, along with normalization of blood pressure, and a diagnosis of posterior reversible leukoencephalopathy syndrome (PRES) was made. Plasma renin activity was high, and the right kidney was severely atrophic. Results from renal and adrenal vein sampling revealed renal vascular hypertension derived from the right renal artery stenosis. The right kidney was then removed by laparoscopic nephrectomy. Pathological examination of the kidney confirmed the diagnosis of fibromuscular dysplasia (FMD). In juvenile-onset encephalitis/encephalopathy, PRES due to FMD should be included in the differential diagnosis.

Five-year follow-up of a case of lipoprotein glomerulopathy with APOE Kyoto mutation.

We report the case of a 34-year-old Japanese male with lipoprotein glomerulopathy (LPG). Renal biopsy showed LPG, and followed by a genetic analysis revealed a mutation in apolipoprotein E gene (APOE Kyoto; Arg25Cys). We started treatment with probucol, bezafibrate, losartan, and allopurinol. Urinary protein decreased in response to treatment but has remained at about 1.27 ± 0.71 g/gCr, and a repeat biopsy which was performed 1 year after the first biopsy showed no clear evidence of pathological remission and complication of other glomerular disease. After 5 years of follow-up after the start of treatment, renal function has almost maintained without apparent deterioration. Interestingly, the course of the urinary protein level closely paralleled his triglyceride and cholesterol levels in a long-term. This observation suggests the importance of tight control of lipid profiles as a means of renoprotection in LPG patient.

IgG4-related tubulointerstitial nephritis and lymphadenopathy after therapy for malignant lymphoma.

We report a middle-aged Japanese man who had a past history of malignant lymphoma with tubulointerstitial nephritis (TIN) presenting a high serum immunoglobulin G4 (IgG4) concentration and bilateral kidney enlargement and swelling of many lymph nodes. Although lymph node biopsy was not evident of a recurrence of lymphoma, kidney biopsy showed prominent infiltration of IgG4-positive plasma cells in a tubulointerstitial lesion but not in glomeruli. We made a diagnosis of IgG4-related TIN and lymphadenopathy; administration of oral prednisolone improved his physical and laboratory parameters. This is the first report of a case of IgG4-related TIN and lymphadenopathy after therapy for malignant lymphoma.

EphA1 interacts with integrin-linked kinase and regulates cell morphology and motility.

The Eph-ephrin receptor-ligand system is implicated in cell behavior and morphology. EphA1 is the founding member of the Eph receptors, but little is known about its function. Here, we show that activation of EphA1 kinase inhibits cell spreading and migration in a RhoA-ROCK-dependent manner. We also describe a novel interaction between EphA1 and integrin-linked kinase (ILK), a mediator of interactions between integrin and the actin cytoskeleton. The C-terminal sterile alpha motif (SAM) domain of EphA1 is required and the ankyrin region of ILK is sufficient for the interaction between EphA1 and ILK. The interaction is independent of EphA1 kinase activity but dependent on stimulation of the EphA1 ligand ephrin-A1. Activation of EphA1 kinase resulted in a decrease of ILK activity. Finally, we demonstrated that expression of a kinase-active form of ILK (S343D) rescued the EphA1-mediated spreading defect, and attenuated RhoA activation. These results suggest that EphA1 regulates cell morphology and motility through the ILK-RhoA-ROCK pathway.

Fibronectin type I repeat is a nonactivating ligand for EphA1 and inhibits ATF3-dependent angiogenesis.

ATF3 stimulated promoter activity of EphA1 by 3.4-fold in ATF3-dependent angiogenesis in vitro. Although tyrosine kinase activation of EphA1 was dispensable, binding of EphA1 to fibronectin through its type I repeat played an essential role in the angiogenesis. Recombinant proteins containing fibronectin 10th to 12th type I repeat (I 10-12) but not I 12 could inhibit the angiogenesis in vitro by competitively targeting EphA1 with the full-length fibronectin. However, I 12 acquired a higher affinity toward EphA2 with K(d) 18 nm and inhibited vascular endothelial growth factor-dependent angiogenic invasion in a Matrigel plug assay.

Ligand-independent activation of vascular endothelial growth factor receptor 1 by low-density lipoprotein.

Elevated serum low-density lipoprotein (LDL) is a risk factor for atherosclerotic disorders. However, prominent atherosclerosis, which has been observed in LDL receptor (LDLR)-knockout mice, has diminished the significance of LDLR as a cause of atherosclerosis, while elaborate studies have focused on the receptors for denatured LDL. Here we report that native LDL (nLDL) activates vascular endothelial growth factor (VEGF) receptor 1 (VEGFR1) but not VEGFR2 through LDLR and is as potent as VEGF in macrophage migration. Binding and co-endocytosis of VEGFR1 and LDLR were enhanced by nLDL, which is concomitant with ubiquitination-mediated degradation of VEGFR1. We propose that LDLR-mediated use of VEGFR1 by nLDL could be a potential therapeutic target in atherosclerotic disorders.