Detection of superoxide anion radical in phospholipid liposomal membrane by fluorescence quenching method using 1,3-diphenylisobenzofuran

AbstractUtilization of a fluorescence dye, 1,3-diphenylisobenzofuran (DPBF) as a detector of superoxide anion radical (O⋅−2) was examined. The fluorescence intensity of DPBF incorporated in phospholipid liposomes consisting of phosphatidylcholine (PC) and phosphatidylserine (PS) is effectively quenched by incubation with xanthine/xanthine oxidase system. On the other hand, xanthine or xanthine oxidase alone did not induce quenching of the DPBF fluorescence in the liposomes. Xanthine/xanthine oxidase-induced fluorescence quenching of DPBF-labeled liposomes was almost completely protected by the addition of superoxide dismutase (SOD, 1 U/ml), but not by heat-denatured SOD (10 min boiling) at the same concentration. On the other hand, catalase (1 U/ml), and hydroxyl radical and singlet oxygen scavengers (10 mM sodium benzoate, 300 mM mannitol, 1 mM tryptophan and 1 mM sodium azide) did not protect xanthine/xanthine oxidase-induced fluorescence quenching of DPBF-labeled liposomes. The concentration dependence profiles of xanthine oxidase on the DPBF fluorescence quenching and O⋅−2 generation showed that there is a good correlation between these parameters. Under the present experimental conditions, approximately 7 μM H2O2/30 min were produced, but the addition of H2O2 (1 mM) to DPBF-labeled liposomes did not quench the dye fluorescence in the liposomes. Temperature dependence profiles of the DPBF fluorescence quenching induced by xanthine/xanthine oxidase treatment and the excimer fluorescence formation of pyrene molecules embedded in the liposomal membrane suggested that the quenching efficiency of the DPBF fluorescence is largely dependent on their lipid dynamics. Based on these results, we proposed the possibility that DPBF fluorescence quenching method is able to be used as a simple method for detecting O⋅−2 inside the membrane lipid layer and that DPBF fluorescence quenching by O⋅−2 is controlled by the physical state of membrane lipids

Osborn Waves: History and Significance

The Osborn wave is a deflection with a dome or hump configuration occurring at the R-ST junction (J point) on the ECG (Fig. 1). In the historical view, different names have been used for this wave in the medical literature, such as “camel-hump sign”, “late delta wave”, “hathook junction”, “hypothermic wave”, “J point wave”, “K wave”, “H wave” and “current of injury”.1 Although there is no definite consensus about terminology of this wave, either “Osborn wave” or “J wave” are the most commonly used names for this wave in the current clinical and experimental cardiology. The Osborn wave can be generally observed in hypothermic patients,1,2,3,4 however, other conditions have been reported to cause Osborn waves, such as hypercalcemia,5 brain injury,6 subarachnoid hemorrhage,7 cardiopulmonary arrest from oversedation,8 vasospastic angina,9 or idiopathic ventricular fibrillation.10,11,12 Our knowledge about the link between the Osborn waves and cardiac arrhythmias remains sparse and the arrhythmogenic potential of the Osborn waves is not fully understood. In this paper, we present a historic review of Osborn waves and discuss their clinical significance in the various clinical settings

Electrical Excitation of the Pulmonary Venous Musculature May Contribute to the Formation of the Last Component of the High Frequency Signal of the P Wave

Pulmonary veins (PVs) have been shown to play an important role in the induction and perpetuation of focal AF. Fifty-one patients with AF, and 24 patients without AF as control subjects, were enrolled in this study. Signal-averaged P-wave recording was performed, and the filtered P wave duration (FPD), the root-mean-square voltage for the last 20, 30 and 40 ms (RMS20, 30, and 40, respectively) were compared. In 7 patients with AF, these parameters were compared before and after the catheter ablation. The FPD was significantly longer and the RMS20 was smaller in the patients with AF than those without AF. Because RMS30 was widely distributed between 2 and 10 µV, the AF group was sub-divided into two groups; Group 1 was comprised of the patients with an RMS30 ≧5.0 µV, and group 2, <5.0 µV. In group 1, short-coupled PACs were more frequently documented on Holter monitoring, and exercise testing more readily induced AF. After successful electrical disconnection between the LA and PVs, each micropotential parameter was significantly attenuated. These results indicate that the high frequency signal amplitude of the last component of the P wave is relatively high in patients with AF triggered by focal repetitive excitations most likely originating from the PVs. That is, attenuation by the LA-PV electrical isolation, and thus the high frequency P signals of the last component, may contain the electrical excitation of the PV musculature

Japanese guidelines for atopic dermatitis 2020.

Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion, which is frequently encountered in clinical practice. Skin barrier dysfunction leads to enhanced skin irritability to non-specific stimuli and epicutaneous sensitization. In the lesion site, a further inflammation-related reduction in skin barrier function, enhanced irritability and scratching-related stimuli deteriorate eczema, leading to vicious cycle of inflammation. The current strategies to treat AD in Japan from the perspective of evidence-based medicine consist of three primary measures: (i) the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice

Admission systolic blood pressure as a prognostic predictor of acute decompensated heart failure: A report from the KCHF registry

[Background] Admission systolic blood pressure has emerged as a predictor of postdischarge outcomes of patients with acute decompensated heart failure; however, its validity in varied clinical conditions of this patient subset is unclear. The aim of this study was to further explore the prognostic value of admission systolic blood pressure in patients with acute decompensated heart failure. [Methods] The Kyoto Congestive Heart Failure (KCHF) registry is a prospective, observational, multicenter cohort study enrolling consecutive patients with acute decompensated heart failure from 19 participating hospitals in Japan. Clinical characteristics at baseline and prognosis were examined by the following value range of admission systolic blood pressure: <100, 100–139, and ≥140 mmHg. The primary outcome measure was defined as all-cause death after discharge. Subgroup analyses were done for prior hospitalization for heart failure, hypertension, left ventricular ejection fraction, and medications at discharge. We excluded patients with acute coronary syndrome or insufficient data. [Results] We analyzed 3564 patients discharged alive out of 3804 patients hospitalized for acute decompensated heart failure. In the entire cohort, lower admission systolic blood pressure was associated with poor outcomes (1-year cumulative incidence of all-cause death: <100 mmHg, 26.8%; 100–139 mmHg, 20.2%; and ≥140 mmHg, 15.1%, p<0.001). The magnitude of the effect of lower admission systolic blood pressure for postdischarge all-cause death was greater in patients with prior hospitalization for heart failure, heart failure with reduced left ventricular ejection fraction, and β-blocker use at discharge than in those without. [Conclusions] Admission systolic blood pressure is useful for postdischarge risk stratification in patients with acute decompensated heart failure. Its magnitude of the effect as a prognostic predictor may differ across clinical conditions of patients

Retroperitoneal abscess complicated with necrotizing fasciitis of the thigh in a patient with sigmoid colon cancer

<p>Abstract</p> <p>Background</p> <p>Necrotizing fasciitis of the thigh due to the colon cancer, especially during chemotherepy, has not been previously reported.</p> <p>Case presentation</p> <p>A 67-year-old man admitted to the hospital was diagnosed with sigmoid colon cancer that had spread to the left psoas muscle. Multiple hepatic metastases were also found, and combination chemotherapy with irinotecan and S-1 was administered. Four months after the initiation of chemotherapy, the patient developed gait disturbance and high fever and was therefore admitted to the emergency department of our hospital. Blood examination revealed generalized inflammation with a high C-reactive protein level. Computed tomography of the abdomen and pelvis showed gas and fluid collection in the retroperitoneum adjacent to the sigmoid colon cancer. The abscess was locally drained under computed tomographic guidance; however, the infection continued to spread and necrotizing fasciitis developed. Consequently, emergent debridement was performed. The patient recovered well, and the primary tumor was resected after remission of the local inflammation.</p> <p>Conclusion</p> <p>Necrotizing fasciitis of the thigh due to the spread of sigmoid colon cancer is unusual, but this fatal complication should be considered during chemotherapy for patients with unresectable colorectal cancer.</p

Artificially Induced Epithelial-Mesenchymal Transition in Surgical Subjects: Its Implications in Clinical and Basic Cancer Research

BACKGROUND: Surgical samples have long been used as important subjects for cancer research. In accordance with an increase of neoadjuvant therapy, biopsy samples have recently become imperative for cancer transcriptome. On the other hand, both biopsy and surgical samples are available for expression profiling for predicting clinical outcome by adjuvant therapy; however, it is still unclear whether surgical sample expression profiles are useful for prediction via biopsy samples, because little has been done about comparative gene expression profiling between the two kinds of samples. METHODOLOGY AND FINDINGS: A total of 166 samples (77 biopsy and 89 surgical) of normal and malignant lesions of the esophagus were analyzed by microarrays. Gene expression profiles were compared between biopsy and surgical samples. Artificially induced epithelial-mesenchymal transition (aiEMT) was found in the surgical samples, and also occurred in mouse esophageal epithelial cell layers under an ischemic condition. Identification of clinically significant subgroups was thought to be disrupted by the disorder of the expression profile through this aiEMT. CONCLUSION AND SIGNIFICANCE: This study will evoke the fundamental misinterpretation including underestimation of the prognostic evaluation power of markers by overestimation of EMT IN past cancer research, and will furnish some advice for the near future as follows: 1) Understanding how long the tissues were under an ischemic condition. 2) Prevalence of biopsy samples for in vivo expression profiling with low biases on basic and clinical research. 3) Checking cancer cell contents and normal- or necrotic-tissue contamination in biopsy samples for prevalence

A Ka-band high power monolithic HEMT VCO using a sub-resonator circuit with phase control architecture

This paper reports on a high output performance of a Ka-band monolithic HEMT Voltage Controlled Oscillator(VCO). This VCO has a sub-resonator in order to avoid reduction in Q-factor of a resonator. Circuit elements of the sub-resonator are optimized to achieve a wide tuning range as well as high output power and low phase noise performances. In addition, an AlGaAs/InGaAs double-hetero struc­ture High Electron Mobility Transistor(HEMT) is employed in the VCO to obtain a high output per­formance. A high output power of 19.4 dBm has been achieved at an oscillation frequency of 36.2 GHz. This performance has been achieved without any buffer amplifiers. A tuning range of more than 2.5 GHz is also obtained with a stable high output power. To our knowledge, this represents the high­est output power of monolithic VCO without any buffer amplifiers