Why should we switch chest compression providers every 2 minutes during cardiopulmonary resuscitation?

Objective. Tis study was conducted to determine whether trained male rescuers could maintain adequate chest compression depth (CCD) for longer than the current recommended guidelines of 2 minutes. Methods. Forty male medical doctors administered a 5-minute single rescuer cardiopulmonary resuscitation (CPR) to a manikin on the foor with conventional CPR or randomly administered continuous chest compressions (CCC). Te ratio of compression to ventilation was set to 30:2 with mouth-to-mouth technique during conventional CPR. Chest compression data were recorded with an accelerometer device and divided into 1-minute segments for analysis. Results. Although average CCD maintained the recommended depths throughout 5 minutes in conventional CPR, it decreased signifcantly with CCC (1 minute: 55.4 ± 4.5 mm; 2 minutes: 54.2 ± 5.4 mm; 3 minutes: 52.6 ± 5.6 mm; 4 minutes: 51.6 ± 5.5 mm; 5 minutes: 49.9 ± 5.8 mm, p < 0.001). Te average chest compression numbers (ACCN) per minute were maintained over 80/min and have not been changed signifcantly within 5 minutes in the CCC. However, it didn’t reach to the 80/min and decreased signifcantly afer 3minutes compared to the baseline ACCN during frst 1-minute segment in the conventional CPR. Conclusions. Despite the chest compression providers being limited to trained male medical doctors, the average CCD decreased signifcantly within 5minutes with CCC. Although maintaining adequate CCD, ACCN in each minute decreased signifcantly afer 3minutes in the conventional CPR. Terefore, we should rotate chest compression providers every 2minutes regardless of the rescuer’s qualifcations and CPR methods

EFFECTS OF WALKING SPEED AND AGE ON THE DIRECTIONAL STRIDE REGULARJRY AND GAIT VARIABILITY IN TREADMILL WALKING

The purpose of this study was to assess the directional stride regularity (SR) and gait variability (GV) of data from shoe-type inertial measurement unit (IMU) sensors during levelled treadmill walking. The DynaStabtm (IMU based gait analysis system) including Smart Balance' (shoe-type data logger) was used to collect normal gait data from forty-four subjects in their 20s (n=20), 40s (n=13), and 60s (n=ll). Four different walking speeds (3, 4, 5, and 6 km/h, respectively) on a treadmill were applied for one-minute of continuous levelled walking. Only lateral kinematics (mediolateral acceleration and yawing and rolling angular velocities) revealed significant interactions from walking speed and age, demonstrating lower stride regularity and higher gait variability than the anteroposterior and vertical kinematics

Grape seed proanthocyanidin extract inhibits glutamate-induced cell death through inhibition of calcium signals and nitric oxide formation in cultured rat hippocampal neurons

<p>Abstract</p> <p>Background</p> <p>Proanthocyanidin is a polyphenolic bioflavonoid with known antioxidant activity. Some flavonoids have a modulatory effect on [Ca²⁺]_i. Although proanthocyanidin extract from blueberries reportedly affects Ca²⁺buffering capacity, there are no reports on the effects of proanthocyanidin on glutamate-induced [Ca²⁺]_ior cell death. In the present study, the effects of grape seed proanthocyanidin extract (GSPE) on glutamate-induced excitotoxicity was investigated through calcium signals and nitric oxide (NO) in cultured rat hippocampal neurons.</p> <p>Results</p> <p>Pretreatment with GSPE (0.3-10 μg/ml) for 5 min inhibited the [Ca²⁺]_iincrease normally induced by treatment with glutamate (100 μM) for 1 min, in a concentration-dependent manner. Pretreatment with GSPE (6 μg/ml) for 5 min significantly decreased the [Ca²⁺]_iincrease normally induced by two ionotropic glutamate receptor agonists, N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). GSPE further decreased AMPA-induced response in the presence of 1 μM nimodipine. However, GSPE did not affect the 50 mM K⁺-induced increase in [Ca²⁺]_i. GSPE significantly decreased the metabotropic glutamate receptor agonist (<it>RS</it>)-3,5-Dihydroxyphenylglycine-induced increase in [Ca²⁺]_i, but it did not affect caffeine-induced response. GSPE (0.3-6 μg/ml) significantly inhibited synaptically induced [Ca²⁺]_ispikes by 0.1 mM [Mg²⁺]_o. In addition, pretreatment with GSPE (6 μg/ml) for 5 min inhibited 0.1 mM [Mg²⁺]_o- and glutamate-induced formation of NO. Treatment with GSPE (6 μg/ml) significantly inhibited 0.1 mM [Mg²⁺]_o- and oxygen glucose deprivation-induced neuronal cell death.</p> <p>Conclusions</p> <p>All these data suggest that GSPE inhibits 0.1 mM [Mg²⁺]_o- and oxygen glucose deprivation-induced neurotoxicity through inhibition of calcium signals and NO formation in cultured rat hippocampal neurons.</p

real world efficacy and safety of nebivolol in korean patients with hypertension from the benefit korea study

Objective:The efficacy and safety of nebivolol in patients with hypertension is well established, but its effect in Asian patients with essential hypertension in the real world has not been studied.Methods:Adult South Korean patients with essential hypertension, with or without comorbidities, were

Enhancement of radiation response in human cervical cancer cells in vitro and in vivo by arsenic trioxide (As2O3)

AbstractArsenic trioxide (As2O3) inhibits cell growth and induces apoptosis in certain types of cancer cells including acute promyelocytic leukemia, prostate and ovarian carcinomas, but its effect on response of tumor cells to ionizing radiation has never been explored before. Here we demonstrate that As2O3 can sensitize human cervical cancer cells to ionizing radiation both in vitro and in vivo. As2O3 in combination with ionizing radiation have a synergistic effect in decreasing clonogenic survival and in the regression of established human cervical tumor xenografts. Pretreatment of the cells with As2O3 also synergistically enhanced radiation-induced apoptosis. Apoptosis of the cells by combined treatment of As2O3 and radiation was associated with reactive oxygen species generation and loss of mitochondrial membrane potential, resulting in the activation of caspase-9 and caspase-3. The combined treatment also resulted in an increased G2/M cell cycle distribution at the concentration of As2O3 which did not alter cell cycle when applied alone. These results indicate that As2O3 can synergistically enhance radiosensitivity of human cervix carcinoma cells in vitro and in vivo, suggesting a potential clinical applicability of combination treatment of As2O3 and ionizing radiation in cancer therapies

Direct measurement of mechanical vibrations of the 4-rod RFQ at the HLI

In this paper, we present a new haptic interface, called active skin , which is configured with a tactile sensor and a tactile stimulator in single haptic cell, and multiple haptic cells are embedded in a dielectric elastomer. The active skin generates a wide variety of haptic feel in response to the touch by synchronizing the sensor and the stimulator. In this paper, the design of the haptic cell is derived via iterative analysis and design procedures. A fabrication method dedicated to the proposed device is investigated and a controller to drive multiple haptic cells is developed. In addition, several experiments are performed to evaluate the performance of the active skin

Segmented tomographic evaluation of structural degradation of carbon support in proton exchange membrane fuel cells

The variation of the three-dimensional (3D) structure of the membrane electrode of a fuel cell during proton exchange cycling involves the corrosion/compaction of the carbon support. The increasing degradation of the carbon structure continuously reduces the electrocatalytic performance of proton exchange membrane fuel cells (PEM-FCs). This phenomenon can be explained by performing 3D tomographic analysis at the nanoscale. However, conventional tomographic approaches which present limited experimental feasibility, cannot perform such evaluation and have not provided sufficient structural information with statistical significance thus far. Therefore, a reliable methodology is required for the 3D geometrical evaluation of the carbon structure. Here, we propose a segmented tomographic approach which employs pore network analysis that enables the visualization of the geometrical parameters corresponding to the porous carbon structure at a high resolution. This approach can be utilized to evaluate the 3D structural degradation of the porous carbon structure after cycling in terms of local surface area, pore size distribution, and their 3D networking. These geometrical parameters of the carbon body were demonstrated to be substantially reduced owing to the cycling-induced degradation. This information enables a deeper understanding of the degradation phenomenon of carbon supports and can contribute to the development of stable PEM-FC electrodes. (C) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press

Mesenchymal Stem Cells Transfer Mitochondria to the Cells with Virtually No Mitochondrial Function but Not with Pathogenic mtDNA Mutations

It has been reported that human mesenchymal stem cells (MSCs) can transfer mitochondria to the cells with severely compromised mitochondrial function. We tested whether the reported intercellular mitochondrial transfer could be replicated in different types of cells or under different experimental conditions, and tried to elucidate possible mechanism. Using biochemical selection methods, we found exponentially growing cells in restrictive media (uridine− and bromodeoxyuridine [BrdU]+) during the coculture of MSCs (uridine-independent and BrdU-sensitive) and 143B-derived cells with severe mitochondrial dysfunction induced by either long-term ethidium bromide treatment or short-term rhodamine 6G (R6G) treatment (uridine-dependent but BrdU-resistant). The exponentially growing cells had nuclear DNA fingerprint patterns identical to 143B, and a sequence of mitochondrial DNA (mtDNA) identical to the MSCs. Since R6G causes rapid and irreversible damage to mitochondria without the removal of mtDNA, the mitochondrial function appears to be restored through a direct transfer of mitochondria rather than mtDNA alone. Conditioned media, which were prepared by treating mtDNA-less 143B ρ0 cells under uridine-free condition, induced increased chemotaxis in MSC, which was also supported by transcriptome analysis. Cytochalasin B, an inhibitor of chemotaxis and cytoskeletal assembly, blocked mitochondrial transfer phenomenon in the above condition. However, we could not find any evidence of mitochondrial transfer to the cells harboring human pathogenic mtDNA mutations (A3243G mutation or 4,977 bp deletion). Thus, the mitochondrial transfer is limited to the condition of a near total absence of mitochondrial function. Elucidation of the mechanism of mitochondrial transfer will help us create a potential cell therapy-based mitochondrial restoration or mitochondrial gene therapy for human diseases caused by mitochondrial dysfunction

Clinical outcomes of balloon-occluded retrograde transvenous obliteration for the treatment of gastric variceal hemorrhage in Korean patients with liver cirrhosis: a retrospective multicenter study

Background/AimsThis study evaluated the clinical outcomes of balloon-occluded retrograde transvenous obliteration (BRTO) for the treatment of hemorrhage from gastric varices (GV) in Korean patients with liver cirrhosis (LC).MethodsWe retrospectively analyzed data from 183 LC patients who underwent BRTO for GV bleeding in 6 university-based hospitals between January 2001 and December 2010.ResultsOf the 183 enrolled patients, 49 patients had Child-Pugh (CP) class A LC, 105 had CP class B, and 30 had CP class C at the time of BRTO. BRTO was successfully performed in 177 patients (96.7%). Procedure-related complications (e.g., pulmonary thromboembolism and renal infarction) occurred in eight patients (4.4%). Among 151 patients who underwent follow-up examinations of GV, 79 patients (52.3%) achieved eradication of GV, and 110 patients (72.8%) exhibited marked shrinkage of the treated GV to grade 0 or I. Meanwhile, new-appearance or aggravation of esophageal varices (EV) occurred in 54 out of 136 patients who underwent follow-up endoscopy (41.2%). During the 36.0±29.2 months (mean±SD) of follow-up, 39 patients rebled (hemorrhage from GV in 7, EV in 18, nonvariceal origin in 4, and unknown in 10 patients). The estimated 3-year rebleeding-free rate was 74.8%, and multivariate analysis showed that CP class C was associated with rebleeding (odds ratio, 2.404; 95% confidence-interval, 1.013-5.704; P=0.047).ConclusionsBRTO can be performed safely and effectively for the treatment of GV bleeding. However, aggravation of EV or bleeding from EV is not uncommon after BRTO; thus, periodic endoscopy to follow-up of EV with or without prophylactic treatment might be necessary in LC patients undergoing BRTO