106 research outputs found
Reflex Movements in Patients with Brain Death: A Prospective Study in A Tertiary Medical Center
Reflex movements have been reported to occur in up to 75% of brain-dead patients, but this issue has not been addressed in Korea. The patients admitted to our hospital who met the criteria for brain death were enrolled between March 2003 and February 2005. The frequency and type of reflex movements in these patients were evaluated prospectively using a standardized protocol. Brain death was determined according to the guideline of Korean Medical Association. Of 26 patients who were included, five (19.2%) exhibited reflex movements such as the pronation-extension reflex, abdominal reflex, flexion reflex, the Lazarus sign, and periodic leg movements. This finding suggests that the frequency of spinal reflex movements is not rare and the awareness of these movements may prevent delays in brain-dead diagnosis and misinterpretations
Suction Drain Tip Cultures in Predicting a Surgical Site Infection
Study Design Retrospective study. Purpose This study aimed to evaluate the prognostic value of drain tip culture after spinal surgery with a large number of participants. Overview of Literature The routine culture of suction drain tips that are placed in the surgical site of spinal surgeries has been performed in many institutions to detect surgical site infection (SSI). However, few reports have evaluated drain tip culture as a prognostic for SSI after spinal surgery. Materials and Methods This study retrospectively included 1,415 consecutive patients who underwent spinal surgery between January 2016 and December 2021. Patients diagnosed with infectious diseases were excluded. Prophylactic antibiotics were administered intraoperatively and 24 hours postoperatively. Drains were removed when the volume of postoperative fluid drainage was <50 mL and <100 mL in patients who underwent cervical and thoracic surgery and lumbar surgery in the preceding 24 hours, respectively, and cultures were made. We evaluated the correlation between the results of positive drain tip culture and SSI. Results Positive drain tip cultures were found in 51 cases (3.6%). SSI was identified in 34 cases (2.4%). The most frequently isolated microorganism was methicillin-resistant Staphylococcus epidermidis (61.8%). The sensitivity, specificity, and positive, and negative predictive values of drain tip culture were 50.0%, 97.4%, 32.1%, and 98.8%, respectively. The same bacteria were isolated from the surgical lesion in 16 of 17 SSI cases with a positive drain tip culture, thereby giving a bacteria matching rate between tissue culture and drain tip culture of 94.1%. The number of surgery levels, drain remaining period, and drain tip culture positivity were significantly increased in the SSI group. Conclusions Drain tip cultures might be useful for predicting SSI. Drain tip culture had a high positivity rate in the SSI group, and the coincidence rate for the causative pathogen was high
Knock-down of YME1L1 induces mitochondrial dysfunction during early porcine embryonic development
YME1L1, a mitochondrial metalloproteinase, is an Adenosine triphosphate (ATP)-dependent metalloproteinase and locates in the mitochondrial inner membrane. The protease domain of YME1L1 is oriented towards the mitochondrial intermembrane space, which modulates the mitochondrial GTPase optic atrophy type 1 (OPA1) processing. However, during embryonic development, there is no report yet about the role of YME1L1 on mitochondrial biogenesis and function in pigs. In the current study, the mRNA level of YME1L1 was knocked down by double strand RNA microinjection to the 1-cell stage embryos. The expression patterns of YME1L1 and its related proteins were performed by immunofluorescence and western blotting. To access the biological function of YME1L1, we first counted the preimplantation development rate, diameter, and total cell number of blastocyst on day-7. First, the localization of endogenous YME1L1 was found in the punctate structures of the mitochondria, and the expression level of YME1L1 is highly expressed from the 4-cell stage. Following significant knock-down of YME1L1, blastocyst rate and quality were decreased, and mitochondrial fragmentation was induced. YME1L1 knockdown induced excessive ROS production, lower mitochondrial membrane potential, and lower ATP levels. The OPA1 cleavage induced by YME1L1 knockdown was prevented by double knock-down of YME1L1 and OMA1. Moreover, cytochrome c, a pro-apoptotic signal, was released from the mitochondria after the knock-down of YME1L1. Taken together, these results indicate that YME1L1 is essential for regulating mitochondrial fission, function, and apoptosis during porcine embryo preimplantation development
A Proposal of New Reference System for the Standard Axial, Sagittal, Coronal Planes of Brain Based on the Serially-Sectioned Images
Sectional anatomy of human brain is useful to examine the diseased brain as well as normal brain. However, intracerebral reference points for the axial, sagittal, and coronal planes of brain have not been standardized in anatomical sections or radiological images. We made 2,343 serially-sectioned images of a cadaver head with 0.1 mm intervals, 0.1 mm pixel size, and 48 bit color and obtained axial, sagittal, and coronal images based on the proposed reference system. This reference system consists of one principal reference point and two ancillary reference points. The two ancillary reference points are the anterior commissure and the posterior commissure. And the principal reference point is the midpoint of two ancillary reference points. It resides in the center of whole brain. From the principal reference point, Cartesian coordinate of x, y, z could be made to be the standard axial, sagittal, and coronal planes
An elevated likelihood of stroke, ischemic heart disease, or heart failure in individuals with gout: a longitudinal follow-up study utilizing the National Health Information database in Korea
ObjectiveAccumulating evidence from other countries indicates potential associations between gout and cardiovascular diseases; however, the associations of gout with cardiovascular diseases, particularly stroke, ischemic heart disease, and heart failure, remain ambiguous in the Korean population. We hypothesized that individuals with gout are at a higher likelihood of stroke, ischemic heart disease, or heart failure. This study expands upon previous research by ensuring a comparable baseline between patient and control groups and analyzing 16 years of data derived from an extensive healthcare database.MethodsWe selected 22,480 patients with gout and 22,480 control individuals from the Korean National Health Insurance Service-Health Screening Cohort database (2002β2019), and matched them at a 1:1 ratio according to sex, age, income, and residence. A Cox proportional hazard model with weighted overlap was employed to examine the relationship between gout and the risk of stroke, ischemic heart disease, or heart failure after adjustment for several covariates.ResultsThe incidences of stroke, ischemic heart disease, or heart failure in participants with gout were slightly higher than those in controls (stroke: 9.84 vs. 8.41 per 1000 person-years; ischemic heart disease: 9.77 vs. 7.15 per 1000 person-years; heart failure: 2.47 vs. 1.46 per 1000 person-years). After adjustment, the gout group had an 11% (95% confidence interval [CI] = 1.04β1.19), 28% (95% CI = 1.19β1.37), or 64% (95% CI = 1.41β1.91) higher likelihood of experiencing stroke, ischemic heart disease, or heart failure, respectively, than the control group.ConclusionThe present findings suggest that individuals with gout in the Korean population, particularly those aged β₯ 60 years, were more likely to have stroke, ischemic heart disease, or heart failure
An Essential Regulatory Role of Downstream of Kinase-1 in the Ovalbumin-Induced Murine Model of Asthma
The downstream of kinase (DOK)-1 is involved in the protein tyrosine kinase (PTK) pathway in mast cells, but the role of DOK-1 in the pathogenesis of asthma has not been defined. In this study, we have demonstrated a novel regulatory role of DOK-1 in airway inflammation and physiologic responses in a murine model of asthma using lentiviral vector containing DOK-1 cDNA or DOK-1-specific ShRNA. The OVA-induced inflammatory cells, airway hyperresponsiveness, Th2 cytokine expression, and mucus response were significantly reduced in DOK-1 overexpressing mice compared to OVA-challenged control mice. The transgenic introduction of DOK-1 significantly stimulated the activation and expression of STAT-4 and T-bet, while impressively inhibiting the activation and expression of STAT-6 and GATA-3 in airway epithelial cells. On the other hand, DOK-1 knockdown mice enhanced STAT-6 expression and its nuclear translocation compared to OVA-challenged control mice. When viewed in combination, our studies demonstrate DOK-1 regulates allergen-induced Th2 immune responses by selective stimulation and inhibition of STAT-4 and STAT-6 signaling pathways, respectively. These studies provide a novel insight on the regulatory role of DOK-1 in allergen-induced Th2 inflammation and airway responses, which has therapeutic potential for asthma and other allergic diseases
Long-term efficacy, safety and immunogenicity in patients with rheumatoid arthritis continuing on an etanercept biosimilar (LBEC0101) or switching from reference etanercept to LBEC0101: an open-label extension of a phase III multicentre, randomised, double-blind, parallel-group study
Background
To evaluate the long-term efficacy, safety and immunogenicity of continuing LBEC0101; the etanercept (ETN) biosimilar; or switching from the ETN reference product (RP) to LBEC0101 in patients with rheumatoid arthritis (RA).
Methods
This multicentre, single-arm, open-label extension study enrolled patients who had completed a 52-week randomised, double-blind, parallel phase III trial of LBEC0101 vs ETN-RP. Patients treated with ETN-RP during the randomised controlled trial switched to LBEC0101; those treated with LBEC0101 continued to receive LBEC0101 in this study. LBEC0101 (50βmg) was administered subcutaneously once per week for 48βweeks with a stable dose of methotrexate. Efficacy, safety and immunogenicity of LBEC0101 were assessed up to week 100.
Results
A total of 148 patients entered this extension study (70 in the maintenance group and 78 in the switch group). The 28-joint disease activity scores (DAS28)-erythrocyte sedimentation rate (ESR) were maintained in both groups from week 52 to week 100 (from 3.068 to 3.103 in the maintenance group vs. from 3.161 to 3.079 in the switch group). ACR response rates at week 100 for the maintenance vs. switch groups were 79.7% vs. 83.3% for ACR20, 65.2% vs. 66.7% for ACR50 and 44.9% vs. 42.3% for ACR70. The incidence of adverse events and the proportion of patients with newly developed antidrug antibodies were similar in the maintenance and switch groups (70.0% and 70.5%, 1.4% and 1.3%, respectively).
Conclusions
Administration of LBEC0101 showed sustained efficacy and acceptable safety in patients with RA after continued therapy or after switching from ETN-RP to LBEC0101.
Trial registration
ClinicalTrials.gov, NCT02715908. Registered 22 March 2016.This extension study was funded by LG Chem, Ltd. (formerly, LG Life Sciences, Ltd), Mochida Pharmaceutical Co., Ltd. and Korea Health Industry Development Institute
Performance Improvement of DTC-SVM of PMSM with Compensation for the Dead Time Effect and Power Switch Loss Based on Extended Kalman Filter
Two algorithms have been extensively studied for motor control: Field Oriented Control (FOC) and Direct Torque Control (DTC). Both control algorithms use a Voltage Source Inverter (VSI) to drive a Permanent Magnet Synchronous Motor (PMSM). To prevent short-arm short-circuit accidents when driving PMSM using VSI, a dead time is used to turn off the TOP and BOTTOM switches of each arm at the same time. However, this dead-time technique causes an unexpected pole voltage to be applied to the PMSM on the VSI output voltage, causing distortion and resulting in control nonlinearity. The disturbance voltage that causes nonlinearity is difficult to measure directly with the sensor. Therefore, this paper analyzes the nonlinearity of the controller due to the distorted voltage caused by the dead time during PMSM operation using the DTC algorithm and predicts the distorted output voltage using the extended Kalman Filter (EKF) to improve control stability. As a result, The algorithm proposed in this paper has verified the improvement of torque ripple and stator flux ripple through experiments and simulations
Field-free control of exchange bias by spin Hall currents
A trilayer structure consisting of ferromagnetic alloy CoFeB/antiferromagnetic IrMn/heavy metal Pt layers was prepared, and the manipulation of its exchange bias effect was achieved without applying an external magnetic field. Spin polarized current, generated by the spin Hall effect of the electrical current through the Pt layer, was shown to be able to control the spin alignment state in the neighboring antiferromagnetic material as well as the corresponding exchange bias effect in the ferromagnet coupled to the antiferromagnet. The results demonstrated stable and reliable switching of the spin structure in antiferromagnets, providing a useful route to all-electrical manipulation of antiferromagnetic states without a need for the bulky global application of the external magnetic field. Therefore, with the results presented in the present work, precise control of magnetism including both ferromagnets and antiferromagnets on submicron to nanometer length scales can be expected
- β¦