Search

Glomerular deposition of IgA1 is a common feature of Henoch-Schönlein purpura nephritis (HSPN) and is indistinguishable from that seen in IgA nephropathy (IgAN). Serum IgA1 is abnormally O-glycosylated in IgA nephropathy, which may contribute to the development of glomerular injury. Abnormal O-glycosylated IgA1 was also detected in HSPN using lectin enzyme-linked immunosorbent assay; however, this method cannot provide the exact structural information of O-glycans. Mass spectrometry is an effective means of quantification of O-glycans, and there is no report to evaluate IgA1 O-glycans in HSPN using mass spectrometry. We investigated O-glycosylation profile in serum IgA1 from 7 HSPN recipients, 26 IgAN recipients, 25 recipients with other kidney diseases (OKDs), and 26 normal healthy donors using mass spectrometry. Of the 14 GalNac-Gal combinations detected using mass spectrometry, the percentage of the only 6GalNAc-2Gal combination was significantly different between HSPN and IgAN. The percentage of GalNAc 3 in HSPN recipients was significantly higher than that in OKDs recipients and healthy donors (P =.0027 and P <.0001, respectively). Inversely, the percentage of GalNAc 5 in HSPN recipients was significantly lower than that in OKDs recipients and healthy donors (P =.0008, P <.0001, respectively). Moreover, the Gal content and the Gal/GalNAc ratio of HSPN recipients were significantly lower than OKDs recipients and healthy donors. Examination of Henoch-Schönlein purpura recipients revealed that the number of GalNAc fell and the Gal attachment to GalNAc was reduced compared to other kidney diseases and healthy donors. The IgA1 O-glycosylation profile of HSPN was very similar to that of IgAN. • This article evaluates IgA1 O-glycosylation profile using mass spectrometry (MALDI–TOF MS). • We compared Henoch-Schönlein purpura nephritis (HSPN) and IgA nephropathy (IgAN). • IgA1 O-glycosylation profiles are common in many respects between HSPN and IgAN. • The amount of GalNAc content in HSPN decreased. • The Gal attachment to GalNAc in HSPN also decreased. [ABSTRACT FROM AUTHOR]

Fe-transferrins/their homologues in ex-vivo mushrooms were identified by ESR spectroscopy at liquid helium temperature, 4 K. The ESR fine-structure signals from Grifola frondosa were analyzed by spectral simulation with a full spin-Hamiltonian approach, determining the spin Hamiltonian parameters of the ferric iron species bound in the biological environment: S  = 5/2, g  = (2.045, 2.01, 2.235), | D | = 0.28 cm −1 , | E / D | = 0.05. The zero-field splitting (ZFS) parameters, D - and E -values, are very close to the reported values, | D|  = 0.25 cm −1 and | E / D | = 0.06, for an Fe-transferrin with oxalate anion, and to | D | = 0.25 cm −1 and | E / D | = 0.04 for one with malonate anion in human sera, suggesting that the Fe 3+ species are from Fe-transferrins or their homologues. Quantum chemical calculations of the ZFS tensors for Fe-transferrins were carried out. Fe-transferrins/homologues have been identified for all the mushrooms under study, suggesting that such Fe 3+ enzymes are widely distributed in mushrooms. [ABSTRACT FROM AUTHOR]

Abstract: C60-based polyanionic high-spin clusters (S =1–3) in their ground state have been prepared by successive chemical reductions of pristine C60 fullerene with potassium in the presence of dicyclohexano-18-crown-6-ether in solution. Intermolecular spin-triplet, quintet, and septet states arising from the C60-based polyanionic molecular clusters have been generated at ambient temperature and identified by CW-ESR and pulse-ESR-based two-dimensional (2D) electron spin transient nutation (2D-ESTN) spectroscopy in organic rigid glasses, for the first time. Intermolecular exchange interactions between mono- and polyanionic C60 fullerenes are ferromagnetic via bridging potassium metal cations. The molecular structures of the polyanionic high-spin C60 clusters in solution have been proposed by a well-established phenomenological spin Hamiltonian approach in terms of the D -tensor-based calculations for the high-spin clusters. The findings of the C60-based high-spin molecular clusters evidence the occurrence of an intramolecular triplet C60 dianion in the ground state. Unequivocal spin identification for molecular high-spin entities by 2D-ESTN spectroscopy and its powerfulness have been illustrated, emphasizing that the 2D-ESTN spectroscopy is useful for mixtures of molecular species with different spin multiplicities, characterized by a small g-anisotropy, for which the powerfulness of advanced high-frequency ESR spectroscopy is hampered. [Copyright &y& Elsevier]

Intravenous immunoglobulin (Ig) therapy is used based on empirical findings for treatment of antibody-mediated rejection (AMR) in cases of renal transplantation, although its therapeutic efficacy has not been proven and the functional mechanism of an administered Ig remains elusive. In this study, the therapeutic effects of an Ig were examined in a preclinical rat renal transplant model of AMR to investigate this mechanism. To establish an AMR renal graft model, skin graft specimens were obtained from Brown-Norway (BN) rats and transplanted to Lewis rats to produce donor-specific antibodies (DSAs), after which kidney transplantation from the Brown-Norway to Lewis rats was performed. AMR model rats were administered the Ig at a dose of 2 g/kg or saline as a control. Survival period, renal graft histopathology, complement factors, and DSA levels were assessed. The survival period of the group administered the Ig was significantly prolonged. Histopathological examinations of renal grafts also showed significant suppression of glomerulitis and peritubular capillaritis in the Ig group, and real-time polymerase chain reaction analysis results demonstrated significantly lower levels of expression of the complement factors C1q and C3. When the Ig was given to rats that underwent skin grafting but not renal transplantation, DSA was decreased after 6 hours and remained lower than the baseline level for at least 7 days. Ig administration suppressed DSA production. The present results showed that suppression of the complement system contributed to effective Ig treatment for AMR. • A preclinical rat renal transplant antibody-mediated rejection model was established. • Immunoglobulin therapy showed activities for controlling complements in the present preclinical rat antibody-mediated rejection model. • Results indicate that immunoglobulin therapy suppresses production of donor-specific antibodies. [ABSTRACT FROM AUTHOR]

Dietary restriction of protein, salt, and energy is recommended to prevent lifestyle related diseases, proteinuria, and graft dysfunction in kidney transplant patients. It is useful if the patients can evaluate meal components by themselves for each meal. A total of 26 maintenance-phase kidney transplant patients were included in the study. The mean age, sex, body mass index, number of years post-transplantation, creatinine clearance, and 24-hour urinary excretion (24 UE) of protein were recorded on a medical chart. Estimated daily protein and salt oral intake were calculated from 24 UE of nitrogen and sodium, respectively. We compared these laboratory results and patients' self-reported dietary intake using a smartphone-based recipe nutrition calculator (SRNC). Estimated daily protein and salt oral intake calculated from 24 UE of nitrogen and sodium were 55.4 ± 12.9 g/d and 8.5 ± 3.1 g/d, respectively. Estimated daily protein and salt oral intake measured by SRNC were 52.4 ± 13.8 g/day and 6.5 ±.9 g/day, respectively. The results of estimated daily protein and salt oral intake measured by SRNC were correlated to those calculated from 24 UE (R2 =.287 and.217, respectively). The results of estimated daily protein and salt oral intake measured by SRNC were correlated to those calculated from 24 UE in maintenance-phase kidney transplant patients. SRNC was useful as a measurement modality to evaluate the adherence to dietary guidance. Dietary therapy for these patients may have the potential to improve kidney graft function and survival. • Self-report by smartphone-based recipe nutrition calculator (SRNC) was evaluated. • Protein and salt intake measured by SRNC were correlated to those from 24-hour urinary excretion. • SRNC was useful to evaluate the adherence to dietary guidance. [ABSTRACT FROM AUTHOR]

• A kidney transplant recipient developed organizing pneumonia after graft loss. • Organizing pneumonia should be identified as cryptogenic or secondary for treatment. • Bronchoscopy is helpful for precise diagnosis in kidney transplant recipients. We present a case of a 68-year-old male patient who underwent ABO-incompatible living kidney transplantation from his wife because of immunoglobulin A nephropathy 13 years ago. Over time, the patient showed a gradual decline in graft function and required reinitiation of hemodialysis because of fluid overload, which led to his admission to our hospital. An arteriovenous fistula was created, and subsequently, hemodialysis therapy was started. Because he had chronic cytomegalovirus retinopathy and thrombotic microangiopathy due to immunosuppressive therapy at admission, mycophenolate mofetil and tacrolimus were discontinued during hemodialysis initiation. Only low-dose prednisolone was continued. One week later, the patient had a fever, and chest computed tomography revealed bilateral pneumonia, which was not improved by antibiotics. The patient was diagnosed with organized pneumonia. After ruling out opportunistic infection, including pneumocystis pneumonia, increased doses of prednisolone resulted in the remission of organizing pneumonia. [ABSTRACT FROM AUTHOR]

Caveolin-1 (CAV-1) is a molecule associated with endothelial cell dysfunction in chronic antibody-mediated rejection (CAMR) and considered to be a novel biomarker of CAMR. For immunohistochemical staining to reveal CAV-1 expression, most studies have used immunofluorescent stained frozen specimens, whereas formalin-fixed tissues have not been utilized. In the present study, we examined CAV-1 expression in specimens from CAMR patients using an immunoenzymatic technique with formalin-fixed tissues. Eleven patients diagnosed with CAMR based on findings of transplanted renal biopsy samples were enrolled. Those biopsy specimens were formalin fixed and stained with CAV-1 using an immunoenzymatic method. Dye extent was evaluated by classifying that in peritubular capillaries (PTC) and glomerular capillaries (GBM) in 3 steps. We then compared the Banff scores for peritubular capillaritis (ptc), glomerulopathy (cg), and C4d using those results. CAV-1 expression was confirmed in vascular endothelium (PTC, GBM), while it was poor in epithelial cells. A Banff score for ptc and cg of 3 points was seen in 3 and 4 cases, of 2 points was seen in 1 and 4 cases, of 1 point was seen in 7 and 3 cases, and of 0 points was seen in 0 and 0 cases, respectively. In PTC, C4d and CAV-1 scores of 3 points were seen in 0 and 9 cases, of 2 points were seen in 2 and 2 cases, of 1 point was seen in 5 and 0 cases, and of 0 points were seen in 4 and 0 cases, respectively. As for GBM, C4d and CAV-1 scores of 3 points were seen in 8 and 7 cases, of 2 points were seen in 2 and 4 cases, of 1 point was seen in 0 and 0 cases, and of 0 points were seen 1 and 0 cases, respectively. CAV-1 expression in PTC had a score ≥2 in all cases, indicating that an adequate level of staining of formalin-fixed tissue was attained with the present immunoenzymatic technique. These results suggest that CAV-1 expression examined by the present method may be useful for identifying endothelial dysfunction. • Immunoenzymatic staining revealed CAV-1 in formalin-fixed renal grafts with CAMR. • CAV-1 showed a good level of expression in GC and PTC in CAMR. • CAV-1 staining showed better expression in PTC in CAMR than C4d staining. [ABSTRACT FROM AUTHOR]

A carboxylate group of D1-Glu-189 in photosystem II has been proposed to serve as a direct ligand for the manganese cluster. Here we constructed a mutant that eliminates the carboxylate by replacing D1-GIu-189 with Gin in the cyanobacterium Synechocystis sp. PCC 6803, and we examined the resulting effects on the structural and functional properties of the oxygen-evolving complex (OEC) in photosystem II. The E189Q mutant grew photoautotrophically, and isolated photosystem II core particles evolved oxygen at ∼70% of the rate of control wild-type particles. The E189Q OEC showed typical S2 state electron spin resonance signals, and the spin center distance between the S2 state manganese cluster and the YD (D2-Tyr-160), detected by electron-electron double resonance spectroscopy, was not affected by this mutation. However, the redox potential of the E189Q OEC was considerably lower than that of the control OEC, as revealed by the elevated peak temperature of the S2 state thermoluminescence bands. The mutation resulted in specific changes to bands ascribed to the putative carboxylate ligands for the manganese cluster and to a few carbonyl bands in mid-frequency (1800 to 1100 cm-1) S2/S1 Fourier transform infrared difference spectrum. Notably, the low frequency (650 to 350 cm-1) S2/S1 Fourier transform infrared difference spectrum was also uniquely changed by this mutation in the frequencies for the manganese cluster core vibrations. These results suggested that the carboxylate group of D1-Glu-189 ligates the manganese ion, which is influenced by the redox change of the oxidizable manganese ion upon the S1 to S2 transition. [ABSTRACT FROM AUTHOR]

The C-terminal alanine 344 (Ala-344) in the D1 protein of photosystem II is conserved in all of the organisms performing oxygenic photosynthesis. A free α-COO- of Ala-344 has been proposed to be responsible for ligating the Mn cluster. Here, we constructed a mutant having D1 in which D1-Ala-344 was replaced with glycine (Gly) in cyanobacterium Synechocystis sp. PCC 6803. The effects of this minimal change in the side group from methyl to hydrogen on the properties of the oxygenevolving complex were comprehensively investigated using purified core particles. The mutant grew photoautotrophically, and little change was observed in the protein composition of the oxygen-evolving core particles. The Gly-substituted oxygen-evolving complex showed small but normal S2 multiline and enhanced g = 4.1 electron spin resonance signals and S2-state thermoluminescence bands with slightly elevated peak temperature. The Gly substitution resulted in distinct but relatively small changes in a few bands arising from the putative carboxylate ligand for the Mn cluster in the mid-frequency (1800-1000 cm-1) S2/S1 Fourier trans- form infrared difference spectrum. In contrast, the low frequency (670-350 cm-1) S2/S1 Fourier transform infra- red difference spectrum was markedly changed by the substitution. The results indicate that the internal structure of the Mn cluster and/or the interaction between the Mn cluster and its ligand are considerably altered by a simple change in the side group, from methyl to hydrogen, at the C-terminal of the D1 protein. [ABSTRACT FROM AUTHOR]

A new neutral radical ligand, 5,8-di-tert-butyl-2-(4′,6′-dimethylpyrimidine-2′-yl)-1,3-diazaphenalenyl (2), has been designed on the basis of 1,3-diazaphenalenyl system. As a study for the metal complexes of coordinated neutral radical 6, we have synthesized the metal complex coordinated diazaphenalene 3 by a combination of CoCl2 with 1,3-diazaphenalene 4. The 1,3-diazaphenalene of the metal complex 3 in the crystal was planar and nearly coplanar with the pyrimidine ring, giving the first study on the structurally characterized metal complex based on the azaphenalene system. Preliminary magnetic susceptibility measurements have revealed that 3 is a spin-quartet in the ground state. [Copyright &y& Elsevier]

1,3-Diazaphenalenyl is a typical example of the isoelectronic mode of heteroatomic modification for phenalenyl. Recently, we have designed and isolated 2,5,8-tri-tert-butyl-1,3-diazaphenalenyl (6) as the first example of stable azaphenalenyl. For further elucidation of the electronic and solid-state structures of 6, 15N atoms incorporated 1,3-diazaphenalenyl 7 was designed. New nitration reaction by K15NO3 of 2,7-di-tert-butylnaphthalene has enabled us to accomplish effective introduction of 15N atoms and synthesis of 7. The spin structure of 1,3-(15N2)diazaphenalenyl 7 was unequivocally determined by the ratio of the hfcc for 14N and 15N (A14N/A15N=0.292/0.409=0.714), which was equal to the ratio of each gyromagnetic ratio (γ14N/γ15N=0.713). Under an air atmosphere, the radical 7 decomposes slowly, but most of it remains unchanged for weeks. By comparing the spin densities of 7 with those of parent phenalenyl radical 2, it appears that the spin densities of the 1- and 3-positions decrease appreciably, while those of the 4-, 6-, 7-, and 9-positions increase. The radical 7 forms the syn-dimer with gable structure in the crystal, and the dimer stacks in a columnar structure motif. [Copyright &y& Elsevier]

A 6-oxophenalenoxyl system is found to be the first example of the molecular system with redox-based spin diversity nature. To generalize this nature, we focus on the 3-oxophenalenoxyl system as a topological isomer of 6-oxophenalenoxyl system. The radical dianion derivative 3 which is the redox state in the 3-oxophenalenoxyl system was successfully generated by the reduction of the corresponding hydroxyphenalenone 5 with potassium mirror. Our ESR/ENDOR/TRIPLE measurements and DFT calculation of 3 demonstrated that the 3-oxophenalenoxyl system has also redox-based spin diversity nature. In addition, for the elucidation of the interplay between spin and charge fluctuation in 3, we discuss a VB approach derived from MO calculations. [Copyright &y& Elsevier]

An idea of molecular topology for spin alignment in π-electron networks, which has been widely accepted in high-spin chemistry, can be expanded to monoradical π-systems. In this paper, we describe the importance of the topology of π-electron network for elucidating spin structures in the monoradical systems. An oxophenalenoxyl is a phenalenyl-based neutral monoradical and has many topological isomers depending on the positions of introduced two oxygen atoms. We have focused on a series of α, α-type of oxophenalenoxyls, 3-, 4-, 6- and 9-oxophenalenoxyl systems with two oxygen substituents at α-positions on the phenalenyl skeleton. Our experimental studies have demonstrated that the spin-delocalized nature of the oxophenalenoxyl systems extremely depends on the topological symmetry of the introduced two oxygen atoms. The π-spin density distributions have been calculated by density functional theory, supporting the topology-dependent spin diversity nature inherent in a series of oxophenalenoxyl systems. [Copyright &y& Elsevier]

Highlights from the article: Logistic regression analyses revealed that eGFR at biopsy and transplantation vintage were associated with the presence of ci [Odds ratio 0.48 (95%CI 0.32-0.71) per 10 mL/min/1.73 m[b]; and 1.17 (1.05-1.30) per 10 years, respectively]. Proteinuria reflects FSGS lesion and tubular atrophy. While transplantation vintage was associated with interstitial fibrosis, it was donor age that affects the prevalence of FSGS-like lesion in long-term graft.