Bidirectional modulation of TCA cycle metabolites and anaplerosis by metformin and its combination with SGLT2i.

BACKGROUND: Metformin and sodium-glucose-cotransporter-2 inhibitors (SGLT2i) are cornerstone therapies for managing hyperglycemia in diabetes. However, their detailed impacts on metabolic processes, particularly within the citric acid (TCA) cycle and its anaplerotic pathways, remain unclear. This study investigates the tissue-specific metabolic effects of metformin, both as a monotherapy and in combination with SGLT2i, on the TCA cycle and associated anaplerotic reactions in both mice and humans. METHODS: Metformin-specific metabolic changes were initially identified by comparing metformin-treated diabetic mice (MET) with vehicle-treated db/db mice (VG). These findings were then assessed in two human cohorts (KORA and QBB) and a longitudinal KORA study of metformin-naïve patients with Type 2 Diabetes (T2D). We also compared MET with db/db mice on combination therapy (SGLT2i + MET). Metabolic profiling analyzed 716 metabolites from plasma, liver, and kidney tissues post-treatment, using linear regression and Bonferroni correction for statistical analysis, complemented by pathway analyses to explore the pathophysiological implications. RESULTS: Metformin monotherapy significantly upregulated TCA cycle intermediates such as malate, fumarate, and α-ketoglutarate (α-KG) in plasma, and anaplerotic substrates including hepatic glutamate and renal 2-hydroxyglutarate (2-HG) in diabetic mice. Downregulated hepatic taurine was also observed. The addition of SGLT2i, however, reversed these effects, such as downregulating circulating malate and α-KG, and hepatic glutamate and renal 2-HG, but upregulated hepatic taurine. In human T2D patients on metformin therapy, significant systemic alterations in metabolites were observed, including increased malate but decreased citrulline. The bidirectional modulation of TCA cycle intermediates in mice influenced key anaplerotic pathways linked to glutaminolysis, tumorigenesis, immune regulation, and antioxidative responses. CONCLUSION: This study elucidates the specific metabolic consequences of metformin and SGLT2i on the TCA cycle, reflecting potential impacts on the immune system. Metformin shows promise for its anti-inflammatory properties, while the addition of SGLT2i may provide liver protection in conditions like metabolic dysfunction-associated steatotic liver disease (MASLD). These observations underscore the importance of personalized treatment strategies.

Anti-C5 monoclonal antibody treatment showing pathological resolution of complement-mediated atypical hemolytic uremic syndrome: a case report.

BACKGROUND: No reports have shown histological changes before and after anti-C5 monoclonal antibody treatment in patients with atypical hemolytic uremic syndrome (aHUS). Here, we report a rare case of complement-mediated aHUS with a complement factor H (CFH) mutation and anti-CFH antibodies who underwent multiple kidney biopsies. CASE PRESENTATION: A 53-year-old woman developed aHUS with CFH gene mutation [c.3572C > T (p. Ser1191 Leu)] and anti-CFH antibodies. Her father had succumbed to acute kidney injury (AKI) in his 30 s. She exhibited AKI, thrombocytopenia, and hemolytic anemia with schistocytes. After improving the platelet count with one session of plasma exchange, a kidney biopsy was performed one month after the onset of symptoms. Blood vessel thrombosis, obvious endothelial swelling, endocapillary hypercellularity, and subendothelial exudative lesions in the glomeruli and arterioles were detected. Anti-C5 monoclonal antibody treatment with eculizumab immediately improved disease activity. A second biopsy 3 months later revealed marked improvement of endothelial injuries with residual membrane double contours and exudative lesions. A third biopsy at 17 months after gradual improvement of kidney function showed a further decrease of double contours along with alterations of the exudative lesions to fibrous intimal thickening. CONCLUSIONS: This is the first report showing the pathophysiology of aHUS in the kidneys and the efficacy of anti-C5 monoclonal antibody treatment by presenting serial kidney pathological features before and after anti-C5 monoclonal antibody treatment. Since her CFH mutation was considered the most important pathological condition, treatment centered on eculizumab was administered, resulting in a good long-term prognosis. In addition, kidney pathological resolution in aHUS occurred over 1 year after anti-C5 monoclonal antibody treatment.

Investigation of Clinical Features and Association between Vascular Endothelial Injury Markers and Cytomegalovirus Infection Associated with Thrombotic Microangiopathy in Patients with Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: Case-Based Research.

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) can occasionally trigger thrombotic microangiopathy (TMA). Cytomegalovirus (CMV) may be reactivated during intensive immunosuppressive therapy for AAV and cause TMA. Therefore, we aimed to evaluate the clinical features of and the association between vascular endothelial injury markers and TMA due to CMV in patients with AAV. A 61-year-old female was diagnosed with AAV and severe kidney injury. Immunosuppressive therapy gradually improved her symptoms and laboratory findings. However, 2 weeks after induction therapy initiation, she exhibited altered consciousness, a significant decrease in platelet count, and hemolytic anemia, resulting in a TMA diagnosis. Plasma exchange did not improve TMA findings and routine screening test revealed CMV infection. Ganciclovir injection improved the infection and TMA findings. Consequently, we diagnosed her with CMV-induced TMA. Both AAV and CMV may induce severe vascular endothelial injury, potentially leading to TMA development. CMV-induced TMA should be considered when TMA develops during induction therapy against AAV. Moreover, of the three serum markers of vascular injury-serum sulfatides, soluble thrombomodulin, and pentraxin 3-serum sulfatides may be associated with the development of TMA, and a high level of soluble thrombomodulin may be associated with the development of CMV viremia during the clinical course of AAV.

Identification of candidate metabolite biomarkers for metabolic syndrome and its five components in population-based human cohorts.

BACKGROUND: Metabolic Syndrome (MetS) is characterized by risk factors such as abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), hypertension, and hyperglycemia, which contribute to the development of cardiovascular disease and type 2 diabetes. Here, we aim to identify candidate metabolite biomarkers of MetS and its associated risk factors to better understand the complex interplay of underlying signaling pathways. METHODS: We quantified serum samples of the KORA F4 study participants (N = 2815) and analyzed 121 metabolites. Multiple regression models adjusted for clinical and lifestyle covariates were used to identify metabolites that were Bonferroni significantly associated with MetS. These findings were replicated in the SHIP-TREND-0 study (N = 988) and further analyzed for the association of replicated metabolites with the five components of MetS. Database-driven networks of the identified metabolites and their interacting enzymes were also constructed. RESULTS: We identified and replicated 56 MetS-specific metabolites: 13 were positively associated (e.g., Val, Leu/Ile, Phe, and Tyr), and 43 were negatively associated (e.g., Gly, Ser, and 40 lipids). Moreover, the majority (89%) and minority (23%) of MetS-specific metabolites were associated with low HDL-C and hypertension, respectively. One lipid, lysoPC a C18:2, was negatively associated with MetS and all of its five components, indicating that individuals with MetS and each of the risk factors had lower concentrations of lysoPC a C18:2 compared to corresponding controls. Our metabolic networks elucidated these observations by revealing impaired catabolism of branched-chain and aromatic amino acids, as well as accelerated Gly catabolism. CONCLUSION: Our identified candidate metabolite biomarkers are associated with the pathophysiology of MetS and its risk factors. They could facilitate the development of therapeutic strategies to prevent type 2 diabetes and cardiovascular disease. For instance, elevated levels of lysoPC a C18:2 may protect MetS and its five risk components. More in-depth studies are necessary to determine the mechanism of key metabolites in the MetS pathophysiology.

Anti-SARS-CoV-2 IgG antibody titer after BNT162b2 mRNA COVID-19 vaccination in Japanese patients who underwent renal replacement therapy, hemodialysis, peritoneal dialysis, and kidney transplantation.

BACKGROUND: Coronavirus disease (COVID-19) vaccination is recommended for patients undergoing renal replacement therapy (RRT), including hemodialysis (HD), peritoneal dialysis (PD), and kidney transplantation (KT). However, the difference in the immune response between RRT patients and healthy individuals after mRNA vaccines remains uncertain. METHODS: This retrospective observational study evaluated the anti-severe-acute-respiratory-syndrome-coronavirus-2 (anti-SARS-CoV-2) IgG antibody acquisition, titers and their changes, normal response rate (reaching titers of healthy individuals), factors associated with a normal response, and effectiveness of booster vaccination in Japanese RRT patients. RESULTS: Most HD and PD patients acquired anti-SARS-CoV-2 IgG antibodies after the second vaccination; however, their antibody titers and normal response rates (62-75%) were low compared with those of healthy subjects. Approximately 62% of KT recipients acquired antibodies, but the normal response rate was low (23%). Anti-SARS-CoV-2 IgG antibody waning occurred in the control, HD, and PD groups, while negative or very low titers remained in KT recipients. Third booster vaccination was effective in most HD and PD patients. However, the effect was mild in KT recipients - only 58% reached a normal response level. Multivariate logistic regression analyses demonstrated that younger age, higher serum albumin level, and RRT other than KT were significantly associated with a normal response after the second vaccination. CONCLUSIONS: RRT patients, particularly KT recipients, exhibited poor vaccine responses. Booster vaccination would be beneficial for HD and PD patients; however, its effect in KT recipients was mild. Further COVID-19 vaccinations using the latest vaccine or alternative procedures should be considered in RRT patients.

Comparison of the factors associated with the short-term prognosis between elderly and non-elderly patients with anti-neutrophil cytoplasmic antibody-associated vasculitis: a retrospective observational study.

OBJECTIVES: The difference in factors associated with the prognosis between elderly and non-elderly patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is uncertain. We aimed to elucidate the clinical factors associated with the short-term prognosis (within 6 months from the start of the treatment) and investigate the differences in the associated factors between elderly and non-elderly individuals. METHODS: We performed a dual centre retrospective observational study of patients newly treated with AAV (eosinophilic granulomatous with polyangiitis was excluded). The primary outcome was all-cause death, and the secondary outcome was end-stage renal disease (ESRD) and infectious complications within 6 months after the start of treatment. We analysed factors associated with these outcomes using logistic regression analyses. RESULTS: Of the 79 patients, patients aged ≥75 years were defined as elderly (n=41), whereas those aged <75 years were de¬fined as non-elderly (n=38). In elderly patients, age was significantly associated with all-cause mortality. In the non-elderly patients, the geriatric nutritional risk index was significantly associated with all-cause death. The estimated glomerular filtration rate (eGFR) before the start of treatment was significantly associated with ESRD in elderly and non-elderly patients. In elderly patients, the Birmingham vasculitis score 3, eGFR, methylprednisolone pulse use, and cyclophosphamide use were significantly associated with infectious complications. Factors other than the serum albumin level were not significantly associated with infectious complications in the non-elderly population. CONCLUSIONS: The factors associated with all-cause death and infectious complications differed between elderly and non-elderly patients. Awareness of these differences may contribute to better management of AAV.

Relationship between glomerular number in fresh kidney biopsy samples and light microscopy samples.

BACKGROUND: On-site evaluation of fresh kidney biopsy (FKB) samples at the time of biopsy is useful to verify that adequate specimens are acquired. However, some cases present poor correlation between glomerular number in FKB samples and light microscopy (LM) samples. We examined the usefulness of such on-site evaluation. METHODS: We conducted a retrospective cross-sectional observational study (n = 129) to assess the correlation between glomerular number in FKB samples and LM samples and the associated factors hindering the evaluation. RESULTS: There was a significant positive correlation between glomerular number in FKB samples and LM samples. The median ratio of glomerular number (LM samples/FKB samples) was 0.74. According to this ratio, cases were divided into three groups: reasonable estimation (65 cases), underestimation (32 cases), and overestimation (32 cases). Comparing the reasonable and underestimation groups, significant differences were detected in the extent of interstitial fibrosis and tubular atrophy (IFTA) and interstitial inflammation. Logistic regression analysis demonstrated that IFTA and interstitial inflammation were significantly associated with the underestimation. Moreover, the cortex length of FKB samples correlated with glomerular number in LM samples regardless of tubulointerstitial lesions. CONCLUSIONS: Glomerular number determined during on-site evaluation can be a reference for the actual number of glomeruli in LM samples. Since tubulointerstitial lesions make it difficult to recognize glomeruli in FKB samples, the possibility of underestimation for cases with possibly severe tubulointerstitial lesions should be considered. In such cases, evaluation of cortex length of FKB samples may substitute for evaluating glomeruli on-site.

Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis Developing Pancreatic Lesion and Diabetes Mellitus: A Case Report and Review of the Literature.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) affects small blood vessels and causes severe systemic organ injury commonly affecting the lungs and kidney. However, gastrointestinal, especially pancreatic, lesions are rare. We report the case of a 67-year-old Japanese man diagnosed with myeloperoxidase (MPO) AAV who developed pancreatic lesions and diabetes mellitus. The patient was admitted to our hospital due to fever, cough, and weight loss. He developed progressive glomerulonephritis, lung nodules, and pancreatic swelling and mass. Additionally, laboratory examination revealed positive MPO-ANCA and elevated glycated hemoglobin A1c, which were suggestive of diabetes mellitus. Renal biopsy revealed necrotizing crescentic glomerulonephritis and vasculitis in the small arteries. Endoscopic ultrasound-guided fine needle aspiration of the pancreas was performed, and histological findings suggested the possibility of pancreatic vasculitis and parenchymal injury. The patient was diagnosed with AAV, which was managed with glucocorticoids. This improved the renal function and pancreatic lesions. Furthermore, blood glucose levels improved despite treatment with glucocorticoids. These findings suggest that AAV-related pancreatic lesions worsened glycemic control. However, glucocorticoid therapy improved vasculitis and pancreatic lesions, which resulted in improved glycemic control.

Microscale pH inhomogeneity in frozen NaCl solutions.

When an aqueous solution freezes at temperatures above the eutectic point, a freeze concentrated solution (FCS) is separated from the ice phase. Reactions of environmental importance often occur in the FCS and, in some cases, are accelerated compared to those in solution conditions. The pH of the FCS is an essential factor governing the thermodynamics and kinetics of the reactions occurring therein. It is known that freezing of aqueous NaCl causes an increase in the FCS pH, which arises from the difference in the partition to the ice phase between Na+ and Cl-. It has also been shown that H+ and other ions show surface-specific behaviors on ice. Although the details are not known, the ice/FCS interface can also affect the behaviors of ions. In this study, the pH distribution in the FCS is evaluated using ratiometric fluorescence microscopy, and the pH inhomogeneity is confirmed for frozen aqueous NaCl. However, interestingly, buffered solutions and frozen aqueous glycerol result in a uniform pH value. The pH in frozen NaCl is always higher near the ice/FCS interface than in the middle of the FCS vein.

Structures of ions accommodated in salty ice Ih crystals.

Frozen aqueous electrolytes are ubiquitous and involved in various phenomena occurring in the natural environment. Although salts are expelled from ice during freezing of aqueous solutions, minor amounts of the constituent ions are accommodated in the crystal lattice of ice. This phenomenon was associated with the generation of the Workman-Reynolds freezing potential. Molecular simulations also confirmed the ion incorporation in the crystal lattice of ice Ih upon freezing of aqueous electrolytes and identified possible local structures of the ions. However, no experimental information is available on the structure of ions accommodated in the crystal lattice of ice Ih. In this work, we use X-ray absorption fine structure (XAFS) to study the local structures of K+ and Cl- accommodated in ice Ih single crystals. Previous molecular simulations predicted that ions are trapped in the hexagonal cavities of the ice structure or replace two water molecules in the crystal lattice. Four possible configurations are considered and optimized by the calculations using ONIOM (QM/QM/QM). The results are evaluated in terms of the agreement between the experimental XAFS spectra and those simulated from the optimized structures. The spectra are most reasonably interpreted by assuming that K+ replaces one water molecule in the ice crystal lattice and is accommodated in a tetrahedral coordination cage. Similarly, Cl- probably adopts the same configuration, because it explains the coordination number better than other structures, such as that assuming the replacement of two water molecules belonging to the same hexagonal planes.

Prevalence of latent tuberculosis infection and its risk factors in Japanese hemodialysis patients.

BACKGROUND: The majority of active tuberculosis (TB) cases develop from latent tuberculosis infection (LTBI). Since the risk of TB in hemodialysis (HD) patients is particularly high, interferon-gamma release assay (IGRA) for LTBI screening in HD patients is considered important. However, the prevalence and characteristics of LTBI in Japanese HD patients remain obscure. METHODS: We performed an observational cross-sectional study of LTBI using IGRA QFT-3G tests in 118 HD outpatients enrolled at 3 hospitals of varying location and function. RESULTS: Of the 118 patients, 96 were QFT negative, 7 were QFT indeterminate, 14 were QFT positive, and 1 was QFT judgment impossible. No patient had active TB. Confirmed (QFT positive) and possible (QFT positive + indeterminate) LTBI patients totaled 14 (11.9%) and 21 (17.8%), respectively. The LTBI possible group was significantly older and had a significantly higher rate of nephrosclerosis versus the QFT-negative group. The indeterminate group had a significantly longer HD period. The QFT results were not remarkably affected by other clinical data, including hospital characteristics. The possible LTBI rate increased age-dependently, with higher values from 60 years of age. CONCLUSIONS: The prevalence of LTBI is high in Japanese HD patients, especially from the age of 60 years. Older age was a significant risk factor for LTBI, with prediction difficult using other clinical data. Extended HD may mask IGRA results. Therefore, aggressive screening for LTBI is advised in all HD patients regardless of hospital region or type, especially in patients over 60 years of age or newly commencing HD.

Surface-enhanced Raman scattering of DNA bases using frozen silver nanoparticle dispersion as a platform.

Raman spectroscopy is a powerful method to characterize molecules in various media. Although surface-enhanced Raman scattering (SERS) is often employed to compensate for the intrinsically poor sensitivity of Raman spectroscopy, there remain serious tasks, such as simple preparations of SERS substrates, sensitivity control, and reproducible measurements. Here, we propose freezing as an efficient way to overcome these problems in SERS measurements using DNA bases as model targets. Solutes are expelled from ice crystals and concentrated in the liquid phase upon freezing. Silver nanoparticles (AgNPs) are also concentrated in the liquid phase to aggregate with Raman target analytes. The SERS signal intensity is maximized when the AgNP concentration exceeds the critical aggregation value. Freezing allows up to 5000 times enhancements of the SERS signal. Thus, an efficient SERS platform is prepared by simple freezing. The simultaneous detection of four DNA bases effectively eliminates variations of signal intensities and allows the reliable determination of concentration ratios.

Frozen Solution-Mediated Asymmetric Synthesis: Control of Enantiomeric Excess.

Asymmetric List-Mannich reactions were carried out in the frozen state to afford optically active adducts in moderate-to-good chemical yields and enantiomeric excesses (ee). The frozen solution exerts critical control of ee via entropy changes, in sharp contrast to the enthalpy-driven asymmetric reactions typically observed in homogeneous solvents. This study provides new perspectives for asymmetric syntheses and an attractive alternative to conventional media.

Cholesterol Emboli Co-Existing with Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis in a 76-Year-Old Woman.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis injures small vessels and causes severe systemic organ injury. Main target antigens of ANCA are myeloperoxidase and proteinase 3. ANCA strongly associates with the development and progression of the vasculitis. Its manifestations include rapidly progressive glomerulonephritis, interstitial pneumonitis, alveolar hemorrhage, purpura, and neurological disorder. Most patients with ANCA-associated vasculitis in Japan are elderly and have atherosclerotic risk factors. Cholesterol emboli are systemic vascular inflammation triggered by cholesterol crystals. Cholesterol emboli cause kidney dysfunction and ischemia of the intestines, brain, heart, skin, and peripheral nerves. Diabetes mellitus, hypertension, hyperlipidemia, and history of cardiovascular diseases are risk factors of the development of cholesterol emboli. We report a case of ANCA-associated vasculitis coexisting with cholesterol emboli. A 76-year-old woman was diagnosed with ANCA-associated interstitial pneumonitis. She rapidly developed progressive glomerulonephritis, purpura, and peripheral sensory nerve disorder. A kidney biopsy revealed that renal dysfunction was caused by vasculitis of the interlobular arteries and cholesterol emboli. A skin biopsy revealed that purpura was caused by cholesterol emboli. Glucocorticoid and statin therapies were administered. Thereafter, the renal function and other symptoms improved and stabilized. The representative symptoms of ANCA-associated vasculitis and cholesterol emboli are closely similar, and it is difficult to distinguish between these diseases when they coexist. Because the background characteristics of patients with ANCA-associated vasculitis and risk factors of cholesterol emboli overlap, at the time of diagnosing ANCA-associated vasculitis, clinicians should consider the possibility of cholesterol emboli coexistence.

Impact of chronic kidney dysfunction on serum Sulfatides and its metabolic pathway in mice.

Serum sulfatides are critical glycosphingolipids that are present in lipoproteins and exert anticoagulant effects. A previous study reported decreased levels of serum sulfatides in hemodialysis patients and suggested an association with cardiovascular disease. However, the mechanism of changes in serum sulfatides in chronic kidney dysfunction has not been well investigated. The current study examined whether a chronic kidney disease (CKD) state could decrease serum sulfatide levels using 5/6 nephrectomy (5/6NCKD) mice, an established CKD murine model, and studied the mechanisms contributing to diminished sulfatides. 5/6NCKD mice and sham operation control mice were sacrificed at the 4th or 12th postoperative week (POW) for measurement of serum sulfatide levels. Hepatic sulfatide content, which is the origin of serum sulfatides, and the expression of sulfatide metabolic enzymes in liver tissue were assessed as well. The 5/6NCKD mice developed CKD and showed increased serum creatinine and indoxyl sulfate. The serum levels and hepatic amounts of sulfatides were significantly decreased in 5/6NCKD mice at both 4 and 12 POW, while the degradative enzymes of sulfatides arylsulfatase A and galactosylceramidase were significantly increased. In a Hepa1-6 murine liver cell line, indoxyl sulfate addition caused intracellular levels of sulfatides to decrease and degradative enzymes of sulfatides to increase in a manner comparable to the changes in 5/6NCKD mice liver tissue. In conclusion, chronic kidney dysfunction causes degradation of sulfatides in the liver to decrease serum sulfatide levels. One explanation of these results is that indoxyl sulfate, a uremic toxin, accelerates the degradation of sulfatides in liver tissue.

Peroxisome proliferator-activated receptor α attenuates high-cholesterol diet-induced toxicity and pro-thrombotic effects in mice.

Peroxisome proliferator-activated receptor α (PPARα) is involved in the regulation of fatty acid and cholesterol metabolism. A high-cholesterol (HC) diet increases the risk of developing cardiovascular diseases (CVD); however, it is unclear whether the toxic effects of cholesterol involve changes in thrombotic factor expression, and whether PPARα is necessary for such effects. To investigate this possibility, we fed a HC diet to wild-type (WT) and Ppara-null mice and measured cholesterol and triglyceride contents, liver histology, serum/plasma levels of coagulation factors, hepatic expression of the coagulation factors, liver/serum sulfatide levels, hepatic sulfatide metabolism, hepatic expression of lipid transporters, and hepatic oxidative stress and its relating enzymes. In Ppara-null mice, the HC diet caused triglyceride accumulation and exacerbated inflammation and oxidative stress in liver, increased levels of coagulation factors, including tissue factor, plasminogen activator inhibitor-1 and carboxypeptidase B2 in blood and liver, and decreased levels of anti-thrombotic sulfatides in serum and liver. These changes were much less marked in WT mice. These findings imply that cholesterol overload exerts its toxic effects at least in part by enhancing thrombosis, secondary to abnormal hepatic lipid metabolism, inflammation, and oxidative stress. Moreover, we reveal for the first time that PPARα can attenuate these toxic effects by transcriptional regulation of coagulation factors and sulfatides, in addition to its known effects of controlling lipid homeostasis and suppressing inflammation and oxidative stress. Therapies aimed at activating PPARα might prevent HC diet-induced CVD through modulating various pro- and anti-thrombotic factors.

Multiple MicroRNA Quantification Based on Acoustic Levitation of Single Microspheres after One-Pot Sandwich Interparticle Hybridizations.

We propose a scheme for the sensitive quantification of multiple microRNAs (miRNAs) on the basis of the levitation coordinate change (Δ z) of single microparticles of different sizes in a coupled acoustic-gravitational (CAG) field. This field transduces the density change of a microparticle into Δ z, which can be measured with high precision. The density of a microparticle is induced by the binding of gold nanoparticles (AuNPs) on it through the sandwich DNA hybridization with miRNA. Different probe DNAs are anchored onto microparticles of different sizes, which are clearly distinguishable on a microscopic view. The target miRNAs are captured by these particles having complementary nucleotide sequences and then entrap reporter-anchored AuNPs. Thus, the densities of the microparticles are modified according to the concentration of individual target miRNAs. The interparticle hybridizations for multiple target miRNAs are conducted in one-pot reactions before the levitation of the microparticles is measured in the CAG field. This principle is successfully applied to the quantification of miR-21 and miR-122 in the total RNA extracted from liver cancer tissues.

Zeptomole Detection Scheme Based on Levitation Coordinate Measurements of a Single Microparticle in a Coupled Acoustic-Gravitational Field.

We present a novel analytical principle in which an analyte (according to its concentration) induces a change in the density of a microparticle, which is measured as a vertical coordinate in a coupled acoustic-gravitational (CAG) field. The density change is caused by the binding of gold nanoparticles (AuNP's) on a polystyrene (PS) microparticle through avidin-biotin association. The density of a 10-µm PS particle increases by 2% when 500 100-nm AuNP's are bound to the PS. The CAG can detect this density change as a 5-10 µm shift of the levitation coordinate of the PS. This approach, which allows us to detect 700 AuNP's bound to a PS particle, is utilized to detect biotin in solution. Biotin is detectable at a picomolar level. The reaction kinetics plays a significant role in the entire process. The kinetic aspects are also quantitatively discussed based on the levitation behavior of the PS particles in the CAG field.

Growth and Morphology of Liquid Phase in Frozen Aqueous NaCl Probed by Voltammetry and Simulations.

Cyclic voltammograms (CVs) of Fe(CN)64- are measured using a microelectrode in frozen aqueous NaCl solutions to obtain morphological information on the liquid phase developed on the electrode surface. CVs in frozen solutions feature the radial diffusion similar to that measured in bulk solution in some cases but the linear diffusion in other cases. The former suggests the sufficient growth of the liquid phase, whereas the latter implies the diffusion paths in particular directions are hindered. Two parameters, i. e. a ratio of the maximum current to the steady-state current (R) and current amplification (ramp ), are extracted from CVs and compared with those of simulated ones. CV simulations are carried out for four geometrical models. From the relationship between ramp and R, the FCS developed on the electrode surface can be regarded as a thin layer developed in the direction parallel to the electrode surface or a cylinder running in the direction away from the electrode. Since solutes are concentrated in this liquid phase, highly sensitive voltammetric analysis would be possible if the growth of the FCS were successfully managed. The liquid phase morphology on the electrode, which cannot be probed by other methods, is useful information for designing such highly sensitive voltammetric analyses.

Onset of Takotsubo Syndrome during the Clinical Course of Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis: A Case Report.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic vasculitis resulting in severe organ injuries. ANCA is a disease-labeled antibody of AAV, and myeloperoxidase (MPO) and proteinase 3 are the main targeted antigens of ANCA. Takotsubo syndrome, a transient cardiac dysfunction caused by emotional or physical stress, is characterized by ST-segment elevation and negative T waves in electrocardiogram, transient left ventricular asynergy, and absence of obstructive coronary disease. To the best of our knowledge, only two cases of coexistence of AAV and takotsubo syndrome have been reported. Herein, we report the case of AAV complicated with takotsubo syndrome. A 78-year-old Japanese woman presented with severe renal dysfunction, which was diagnosed as MPO-ANCA-associated systemic vasculitis. Despite the treatment with cyclophosphamide and glucocorticoid, the patient presented with severe respiratory failure due to alveolar hemorrhage and heart failure. Electrocardiography indicated newly developed T wave inversions. Echocardiography demonstrated severe left ventricular dysfunction with hypokinesis of the apical area. Moreover, coronary angiography revealed no noticeable stenotic or obstructive lesions. These findings indicate the onset of takotsubo syndrome. After immunosuppressive therapy, systemic vasculitis and takotsubo syndrome were improved. Although a coexisting case of AAV and takotsubo syndrome is rare, we have to consider the possible complication of takotsubo syndrome in case of presenting acute heart failure. Considering the present case and the previously reported coexisting cases of takotsubo syndrome and AAV, we propose that female sex, initiation of glucocorticoid therapy, and high titer of MPO-ANCA are potential risk factors of developing takotsubo syndrome.