A detailed analysis of the spin-crossover reaction of H2S binding to heme and the six-coordinated FeP(Im)-HS- porphyrin complex.

The potential energy surfaces of the H2S binding to iron-porphyrin (FeP) with the imidazole (Im) ligand via intersystem crossings are investigated by using density functional theory. The minimum energy intersystem crossing point (MEISCP) between the quintet and triplet states (MEISCPTQ) for the Fe(II)P(Im)-H2S complex is located at a Fe-S distance of 3.39 Šwith only 1.1 kcal/mol above the quintet state minimum. The second spin-crossover point, where a change from the triplet to the singlet state occurs, comes at a much shorter Fe-S distance of 2.79 Å, and the MEISCPST is located at 3.7 kcal/mol above the triplet state minimum. The nature of the chemical bonding along the Fe-S reaction coordinate from the ground state singlet to the quintet state along the path to the separated species is analyzed. An inspection of the vibrational modes reveals that the largest contribution to the triplet-quintet transition around the quintet and triplet state minimum comes from the symmetric shrinking of the pyrrole units of the porphyrin ring, indicating that the related reaction coordinate plays a main role in the intersystem crossing. The fully optimized structures of the Fe(II)P(Im)-HS- complex corresponding to three different spin multiplicities (M = 1, 3, 5) are characterized by a bent Fe-H-S conformation. The binding of the hydrosulfide anion to Fe(II)P(Im) in the quintet state induces a 0.2 Šdisplacement of the Fe atom out of the nitrogen porphyrin (Npyr) plane. The fully optimized structure of the ground state of Fe(II)P(Im)-HS- agrees well with experimental data for the corresponding heme models.

Correction: Synergistic anti-AML effects of the LSD1 inhibitor T-3775440 and the NEDD8-activating enzyme inhibitor pevonedistat via transdifferentiation and DNA rereplication.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Identification of ABCG2 as an Exporter of Uremic Toxin Indoxyl Sulfate in Mice and as a Crucial Factor Influencing CKD Progression.

Chronic kidney disease (CKD) patients accumulate uremic toxins in the body, potentially require dialysis, and can eventually develop cardiovascular disease. CKD incidence has increased worldwide, and preventing CKD progression is one of the most important goals in clinical treatment. In this study, we conducted a series of in vitro and in vivo experiments and employed a metabolomics approach to investigate CKD. Our results demonstrated that ATP-binding cassette transporter subfamily G member 2 (ABCG2) is a major transporter of the uremic toxin indoxyl sulfate. ABCG2 regulates the pathophysiological excretion of indoxyl sulfate and strongly affects CKD survival rates. Our study is the first to report ABCG2 as a physiological exporter of indoxyl sulfate and identify ABCG2 as a crucial factor influencing CKD progression, consistent with the observed association between ABCG2 function and age of dialysis onset in humans. The above findings provided valuable knowledge on the complex regulatory mechanisms that regulate the transport of uremic toxins in our body and serve as a basis for preventive and individualized treatment of CKD.

Synergistic anti-AML effects of the LSD1 inhibitor T-3775440 and the NEDD8-activating enzyme inhibitor pevonedistat via transdifferentiation and DNA rereplication.

Lysine-specific demethylase 1A (LSD1, KDM1A) specifically demethylates di- and monomethylated histones H3K4 and K9, resulting in context-dependent transcriptional repression or activation. We previously identified an irreversible LSD1 inhibitor T-3775440, which exerts antileukemic activities in a subset of acute myeloid leukemia (AML) cell lines by inducing cell transdifferentiation. The NEDD8-activating enzyme inhibitor pevonedistat (MLN4924, TAK-924) is an investigational drug with antiproliferative activities in AML, and is also reported to induce cell differentiation. We therefore tested the combination of these two agents in AML models. The combination treatment resulted in synergistic growth inhibition of AML cells, accompanied by enhanced transdifferentiation of an erythroid leukemia lineage into granulomonocytic-like lineage cells. In addition, pevonedistat-induced rereplication stress during the S phase was greatly augmented by concomitant treatment with T-3775440, as reflected by the increased induction of apoptosis. We further demonstrated that the combination treatment was markedly effective in subcutaneous tumor xenograft models as well as in a disseminated model of AML, leading to tumor eradication or prolonged survival in T-3775440/pevonedistat cotreated mice. Our findings indicate the therapeutic potential of the combination of LSD1 inhibitors and pevonedistat for the treatment of AML.

Endothelin-1 Immunoreactivity and its Association with Intramedullary Hemorrhage and Myelomalacia in Naturally Occurring Disk Extrusion in Dogs.

BACKGROUND: The pathophysiology of ascending/descending myelomalacia (ADMM) after canine intervertebral disk (IVD) extrusion remains poorly understood. Vasoactive molecules might contribute. HYPOTHESIS/OBJECTIVES: To investigate the immunoreactivity of endothelin-1 (ET-1) in the uninjured and injured spinal cord of dogs and its potential association with intramedullary hemorrhage and extension of myelomalacia. ANIMALS: Eleven normal control and 34 dogs with thoracolumbar IVD extrusion. METHODS: Spinal cord tissue of dogs retrospectively selected from our histopathologic database was examined histologically at the level of the extrusion (center) and in segments remote from the center. Endothelin-1 immunoreactivity was examined immunohistochemically and by in situ hybridization. Associations between the immunoreactivity for ET-1 and the severity of intramedullary hemorrhage or the extension of myelomalacia were examined. RESULTS: Endothelin-1 was expressed by astrocytes, macrophages, and neurons and only rarely by endothelial cells in all dogs. At the center, ET-1 immunoreactivity was significantly higher in astrocytes (median score 4.02) and lower in neurons (3.21) than in control dogs (3.0 and 4.54) (P < .001; P = .004) irrespective of the grade of hemorrhage or myelomalacia. In both astrocytes and neurons, there was a higher ET-1 immunoreactivity in spinal cord regions remote from the center (4.58 and 4.15) than in the center itself (P = .013; P = .001). ET-1 mRNA was present in nearly all neurons with variable intensity, but not in astrocytes. CONCLUSION AND CLINICAL IMPORTANCE: Enhanced ET-1 immunoreactivity over multiple spinal cord segments after IVD extrusion might play a role in the pathogenesis of ADMM. More effective quantitative techniques are required.

A DFT and multi-configurational perturbation theory study on O2 binding to a model heme compound via the spin-change barrier.

Dioxygen binding to a model heme compound via intersystem crossing (ISC) was investigated with a multi-state multi-configurational self-consistent field method with second-order perturbation theory (MS-CASPT2) and density functional theory (DFT) calculations. In elongated Fe-O distances, the energy levels of the S0 and T1 states are separated, which decreases the probability of intersystem crossing in these structures. At the DFT(B97D) level of calculation, the Fe-O distances of the S0 and T1 states were 1.91 and 2.92 Å, respectively. The minimum energy intersystem crossing point (MEISCP) was located as a transition state at a Fe-O distance of 2.17 Å with an energy barrier of 1.0 kcal mol(-1) from the T1 minimum. The result was verified with MS-CASPT2 calculations including the spin-orbit interaction which also showed the intersystem crossing point at a Fe-O distance of 2.05 Å. An energy decomposition analysis on the reaction coordinate showed the important contribution of the ring-shrinking mode of the porphyrin ring, indicating that the reaction coordinates which control the relative energy level of the spin-states play a key role in intersystem crossing.

Early optimization of antimicrobial therapy improves clinical outcomes of patients administered agents targeting methicillin-resistant Staphylococcus aureus.

WHAT IS KNOWN AND OBJECTIVE: Antimicrobial stewardship is required to ensure the appropriate use of antimicrobials. However, no reports have been published on clinical outcomes of implementation of antimicrobial stewardship in patients receiving pathogen-specific antibiotics. METHOD: To evaluate the clinical outcomes of patients who received drugs, we conducted a single-centre, retrospective study of the effects of an antimicrobial stewardship programme targeting methicillin-resistant Staphylococcus aureus (MRSA). RESULTS: The time to administer effective antimicrobials was significantly (median number of days, 3 before vs. 0 after, P < 0·001) shortened, and the rate of de-escalation was significantly elevated (47·1% vs. 96·2%, P < 0·001) after implementation of daily review. The 60-day clinical failure associated with Gram-positive bacterial infection was significantly reduced (33·3% vs. 17·6%, P = 0·007) after intervention. WHAT IS NEW AND CONCLUSIONS: Daily review of administration of antimicrobials targeting MRSA was highly effective in improving clinical outcomes by optimizing early antimicrobial therapy.

Evidence of effectiveness of a fracture liaison service to reduce the re-fracture rate.

SUMMARY: We assessed the ability of a fracture liaison service (FLS) to directly reduce re-fracture risk. Having a FLS is associated with a ∼40% reduction in the 3-year risk of major bone and ∼30% of any bone re-fracture. The number needed to treat to prevent a re-fracture is 20. INTRODUCTION: FLS have been promoted as the most effective interventions for secondary fracture prevention, and while there is evidence of increased rate of investigation and treatment at institutions with a FLS, only a few studies have considered fracture outcomes directly. We therefore sought to evaluate the ability of our FLS to reduce re-fracture risk. METHODS: Historical cohort study of all patients ≥50 years presenting over a 6-month period with a minimal trauma fracture (MTF) to the emergency departments of a tertiary hospital with a FLS, and one without a FLS. Baseline characteristics, mortality and MTFs over a 3-year follow-up were recorded. RESULTS: Five hundred fifteen patients at the FLS hospital and 416 patients at the non-FLS hospital were studied. Over 3 years, 63/515 (12%) patients at the FLS hospital and 70/416 (17%) at the non-FLS hospital had a MTF. All patients were analysed in an intention-to-treat analysis regardless of whether they were seen in the FLS follow-up clinic. Statistical analysis using Cox proportional hazard models in the presence of a competing risk of death from any cause was used. After adjustment for baseline characteristics, there was a ∼30% reduction in rate of any re-fracture at the FLS hospital (hazard ratio (HR) 0.67, confidence interval (CI) 0.47-0.95, p value 0.025) and a ∼40% reduction in major re-fractures (hip, spine, femur, pelvis or humerus) (HR 0.59, CI 0.39-0.90, p value 0.013). CONCLUSIONS: We found a ∼30% reduction in any re-fractures and a ∼40% reduction in major re-fractures at the FLS hospital compared with a similar non-FLS hospital. The number of patients needed to treat to prevent one new fracture over 3 years is 20.

Anti-platelet effects of chalcones from Angelica keiskei Koidzumi (Ashitaba) in vivo.

Angelica keiskei Koidzumi (Ashitaba) is a traditional folk medicine that is also regarded in Japan as a health food with potential antithrombotic properties. The ability of the major chalcones, xanthoangelol (XA) and 4-hydroxyderricin (4-HD) extracted from Ashitaba roots to inhibit platelet aggregation activity in vitro was recently determined. However, the anti-platelet activities of Ashitaba chalcones in vivo have remained unclear. The present study examines the anti-platelet effects of Ashitaba exudate and its constituent chalcones using mouse tail-bleeding models that reflect platelet aggregation in vivo. Ashitaba exudate and the major chalcone subtype XA, suppressed the lipopolysaccharide (LPS)-induced shortening of mouse tail bleeding. However, trace amounts of other Ashitaba chalcone subtypes including xanthoangelols B (XB), D (XD), E (XE) and F (XF) did not affect tail bleeding. These results suggest that the major chalcone subtype in Ashitaba, XA, has anti-platelet-activities in vivo.

Thyroid signaling in immune organs and cells of the teleost fish rainbow trout (Oncorhynchus mykiss).

Thyroid hormones are involved in modulating the immune system in mammals. In contrast, there is no information on the role played by these hormones in the immune system of teleost fish. Here we provide initial evidence for the presence of active thyroid signaling in immune organs and cells of teleosts. We demonstrate that immune organs (head kidney and spleen) and isolated leukocytes (from head kidney and peripheral blood) of the rainbow trout (Oncorhynchus mykiss) express both thyroid receptor α (THRA) and ß (THRB). Absolute mRNA levels of THRA were significantly higher than those of THRB. THRA showed higher expression in immune organs and isolated immune cells compared to the reference organ, liver, while THRB showed the opposite. In vivo exposure of trout to triiodothryronine (T3) or the anti-thyroid agent propylthiouracil (PTU) altered THR expression in immune organs and cells. Effect of T3 and PTU over the relative expression of selected marker genes of immune cell subpopulations was also studied. Treatments changed the relative expression of markers of cytotoxic, helper and total T cells (cd4, cd8a, trb), B lymphocytes (mIgM) and macrophages (csf1r). These findings suggest that the immune system of rainbow trout is responsive to thyroid hormones.

Real-time estimation of tongue movement based on suprahyoid muscle activity.

In this study, we introduce a real-time method for tongue movement estimation based on the analysis of the surface electromyography (EMG) signals from the suprahyoid muscles, which usual function is to open the mouth and to control the position of the hyoid, the base of the tongue. Nine surface electrodes were affixed to the underside of the jaw and their signals were processed via multi-channel EMG system. The features of the EMG signals were extracted by using a root mean square (RMS) method. The dimension of the variables was reduced additionally from 108 to 10 by applying the Principal Component Analysis (PCA). The feature quantities of the reduced dimension set were associated with the tongue movements by using an artificial neural network. Results showed that the proposed method allows precise estimation of the tongue movements. For the test data set, the identification rate was greater than 97 % and the response time was less than 0.7 s. The proposed method could be implemented to facilitate novel approaches for alternative communication and control of assistive technology for supporting the independent living of people with severe quadriplegia.

Suitability of polymers as screw post materials in primary teeth: an in vitro study.

AIM: Primary teeth undergo physiological root resorption during the transition to permanent dentition. The aim of this study was to assess the potential use of screw posts in core build-up for primary teeth while adequately retaining the crown restoration and allowing smooth physiological root resorption. METHODS: To determine whether biodegradable polymers such as polyglycolic acid (PGA) and poly-L-lactic acid (PLLA) were appropriate as post materials, bending strength test and bending elastic modulus test were performed according to ISO standards. The prepared screw posts were immersed in 0.01 mol/L phosphate-buffered saline at 37 degrees Celsius, and changes due to hydrolysis were observed. Results In the bending strength test and bending elastic modulus test, PGA and PLLA showed similar values to composite resins used for core build-up. Although both showed adequate hydrolysis, the hydrolysis rate of PGA was higher than that of PLLA. CONCLUSION: PGA and PLLA may be suitable as biodegradable screw posts for primary teeth because they have appropriate strength and hydrolysis ability.

Identification of ABCG2 dysfunction as a major factor contributing to gout.

The ATP-binding cassette, subfamily G, member 2 gene ABCG2/BCRP locates in a gout-susceptibility locus (MIM 138900) on chromosome 4q. Recent genome-wide association studies also showed that the ABCG2 gene relates to serum uric acid levels and gout. Since ABCG2 is also known as a transporter of nucleotide analogs that are structurally similar to urate, and is an exporter that has common polymorphic reduced functionality variants, ABCG2 could be a urate secretion transporter and a gene causing gout. To find candidate mutations in ABCG2, we performed a mutation analysis of the ABCG2 gene in 90 Japanese patients with hyperuricemia and found six non-synonymous mutations. Among the variants, ATP-dependent urate transport was reduced or eliminated in five variants, and two out of the five variants (Q126X and Q141K) were frequently detected in patients. Haplotype frequency analysis revealed that there is no simultaneous presence of Q126X and Q141K in one haplotype. As Q126X and Q141K are a nonfunctional and half-functional haplotype, respectively, their genotype combinations are divided into four estimated functional groups. The association study with 161 male gout patients and 865 male controls showed that all of those who had dysfunctional ABCG2 had an increased risk of gout, and that a remarkable risk was observed in those with ≤1/4 function (OR, 25.8; 95% CI, 10.3-64.6; p = 3.39 × 10(-21)). In 2,150 Japanese individuals, the frequency of those with dysfunctional ABCG2 was more than 50%. Our function-based clinicogenetic analysis identified the combinations of dysfunctional variants of ABCG2 as a major contributing factor in Japanese patients with gout.

Pathogenic GLUT9 mutations causing renal hypouricemia type 2 (RHUC2).

Renal hypouricemia (MIM 220150) is an inherited disorder characterized by low serum uric acid levels and has severe complications such as exercise-induced acute renal failure and urolithiasis. We have previously reported that URAT1/SLC22A12 encodes a renal urate-anion exchanger and that its mutations cause renal hypouricemia type 1 (RHUC1). With the large health-examination database of the Japan Maritime Self-Defense Force, we found two missense mutations (R198C and R380W) of GLUT9/SLC2A9 in hypouricemia patients. R198C and R380W occur in highly conserved amino acid motifs in the "sugar transport proteins signatures" that are observed in GLUT family transporters. The corresponding mutations in GLUT1 (R153C and R333W) are known to cause GLUT1 deficiency syndrome because arginine residues in this motif are reportedly important as the determinants of the membrane topology of human GLUT1. Therefore, on the basis of membrane topology, the same may be true of GLUT9. GLUT9 mutants showed markedly reduced urate transport in oocyte expression studies, which would be the result of the loss of positive charges in those conserved amino acid motifs. Together with previous reports on GLUT9 localization, our findings suggest that these GLUT9 mutations cause renal hypouricemia type 2 (RHUC2) by their decreased urate reabsorption on both sides of the renal proximal tubule cells. However, a previously reported GLUT9 mutation, P412R, was unlikely to be pathogenic. These findings also enable us to propose a physiological model of the renal urate reabsorption via GLUT9 and URAT1 and can lead to a promising therapeutic target for gout and related cardiovascular diseases.

Pharmacokinetics and metabolism of N-[N-[3-(3-hydroxy-4-methoxyphenyl) propyl]-α-aspartyl]-L-phenylalanine 1-methyl ester, monohydrate (advantame) in the rat, dog, and man.

The pharmacokinetics and metabolism of advantame were evaluated in rats, dogs, and humans. The oral pharmacokinetic studies using (14)C-advantame showed that advantame undergoes rapid but incomplete absorption, with an oral bioavailability of total radioactivity in the range of 4-23%. Data indicated that absorption was mainly as ANS9801-acid (de-esterified advantame), which was formed in the gastrointestinal tract as a result of the hydrolysis of the methyl ester group of the parent compound. In the dog, plasma ANS9801-acid was present largely in the form of an unidentified conjugate. Advantame (chiefly in the form of metabolites) was mainly excreted in the feces in rats, dogs, and humans (>80% in each species), with urinary excretion representing a minor route. The predominant metabolite of (14)C-advantame detected in the feces and the urine of rats, dogs, and humans was ANS9801-acid, with lower amounts of 3-[3-hydroxy-4-methoxyphenyl]-1-propylamine (termed HU-1) or N-(3-(3-hydroxy-4-methoxy phenyl))propyl-L-aspartic acid (termed HF-1) present, as well as other minor metabolites and areas of indistinct radioactivity. ANS9801-acid, HU-1, and HF-1 were detected and identified in the urine of rats, humans, and dogs, while ANS9801-acid and HF-1 were identified in the feces of humans and dogs. In the feces of rats, in addition to ANS9801-acid, other additional metabolites were detected, including demethylated ANS9801-acid (designated as RF-1) and another unidentified metabolite (designated as RF-2). Overall, the data show generally similar pharmacokinetics of advantame and ANS9801-acid in animals and in humans and close similarity with neotame. Metabolites of advantame that occur in humans are also found in the 2 species utilized in the toxicology studies, and the metabolism studies support the interpretation of safety data from studies conducted in rats and dogs.

A novel mutation in the C-terminal region of RUNX2/CBFA1 distal to the DNA-binding runt domain in a Japanese patient with cleidocranial dysplasia.

Cleidocranial dysplasia (CCD) is an autosomal dominant inherited skeletal disease with high penetrance and variable expressivity. Although many mutations in RUNX2/CBFA1, an osteoblast-specific transcription factor, have been identified as causes of CCD, it is unclear whether these mutation genotypes relate to various symptoms. Heterogeneous mutations of RUNX2/CBFA1 result in disease characterized by abnormal skeletal genesis and dental disorders. There are few reports describing the relation between detailed orofacial pathology and the RUNX2/CBFA1 genotype. The case of a Japanese patient with severe orofacial dysplasia who was clinically thought to have CCD is described here. The authors performed mutation analysis on the RUNX2/CBFA1 gene and identified a novel frameshift mutation (722delT), which produces a mutant RUNX2/CBFA1 with a truncating C-terminus distal to the runt domain.

Long-term blockade of L/N-type Ca(2+) channels by cilnidipine ameliorates repolarization abnormality of the canine hypertrophied heart.

BACKGROUND AND PURPOSE: The heart of the canine model of chronic atrioventricular block is known to have a ventricular electrical remodelling, which mimics the pathophysiology of long QT syndrome. Using this model, we explored a new pharmacological therapeutic strategy for the prevention of cardiac sudden death. EXPERIMENTAL APPROACH: The L-type Ca(2+) channel blocker amlodipine (2.5 mg.day(-1)), L/N-type Ca(2+) channel blocker cilnidipine (5 mg.day(-1)), or the angiotensin II receptor blocker candesartan (12 mg.day(-1)) was administered orally to the dogs with chronic atrioventricular block for 4 weeks. Electropharmacological assessments with the monophasic action potential (MAP) recordings and blood sample analyses were performed before and 4 weeks after the start of drug administration. KEY RESULTS: Amlodipine and cilnidipine decreased the blood pressure, while candesartan hardly affected it. The QT interval, MAP duration and beat-to-beat variability of the ventricular repolarization period were shortened only in the cilnidipine group, but such effects were not observed in the amlodipine or candesartan group. Plasma concentrations of adrenaline, angiotensin II and aldosterone decreased in the cilnidipine group. In contrast, plasma concentrations of angiotensin II and aldosterone were elevated in the amlodipine group, whereas in the candesartan group an increase in plasma levels of angiotensin II and a decrease in noradrenaline and adrenaline concentrations were observed. CONCLUSIONS AND IMPLICATIONS: Long-term blockade of L/N-type Ca(2+) channels ameliorated the ventricular electrical remodelling in the hypertrophied heart which causes the prolongation of the QT interval. This could provide a novel therapeutic strategy for the treatment of cardiovascular diseases.

Isolation and development of microsatellite markers for the Japanese dormouse, Glirulus japonicus.

Eight microsatellite markers were developed for the Japanese dormouse (Glirulus japonicus), a natural monument and near-threatened species in Japan. The markers amplify in individuals from all of the mitochondrial lineages detected in a previous study. Numerous polymorphisms were detected in specimens from a local population in central Honshu (11-21 alleles per locus; n = 31) and from the entire distribution range of the species (19-41 alleles per locus; n = 152). These microsatellites will be useful in conservation genetic studies of G. japonicus.

Behaviour of bone marrow osteoblast-like cells on mineral trioxide aggregate: morphology and expression of type I collagen and bone-related protein mRNAs.

AIM: To investigate the in vitro behaviour of rat bone marrow cells (RBM) on mineral trioxide aggregate (MTA) (ProRoot, MTA Root Canal Repair Material; Dentsply Tulsa, Tulsa, OK, USA) compared with intermediate restorative materials (IRM) (Dentsply Caulk, Milford, DE, USA). METHODOLOGY: RBM were obtained from rat femur and were primary cultured and then subcultured. Cells were then seeded on three dishes of each material, and cultured for 3 days, after which they were evaluated morphologically using scanning (SEM) and transmission (TEM) electron microscopy. Furthermore, the calcium released from hydrated material, the cell proliferation ratio and alkaline phosphatase (ALP) activity were analysed, and the expression of type I collagen and bone-related protein mRNAs were evaluated. The data were averaged and analysed via one-way analysis of variance (anova) and were then compared by the Scheffe's test. RESULTS: SEM showed that RBM attached to MTA and had a flattened appearance without nuclear protrusions and microspikes. TEM showed that the cells attached in the same manner as the control group, but gaps larger than 2 microm were frequently seen. The calcium released from hydrated MTA was about 130 ppm after 3 days of immersion in saline. The ALP activity was similar to the control group. Cell proliferation and expression of type I collagen mRNA was significantly lower, while the expression of osteopontin mRNA was significantly higher than the control group at the third day of culture. In IRM groups, a few rounded cells were observed on the material but no living cells were seen. CONCLUSIONS: MTA is a material of low toxicity which does not inhibit cell growth, but does suppress the differentiation of osteoblast-like cells.