Purpose: Chromosomal instability (CIN) contributes to intercellular genetic heterogeneity and has been implicated in paclitaxel (PTX) resistance in breast cancer. In this study, we explored polo-like kinase 1 (PLK1) as an important regulator of mitotic integrity and as a useful predictive biomarker for PTX resistance in breast cancer. Methods: We performed PTX resistance screening using the human kinome CRISPR/ Cas9 library in breast cancer cells. In vitro cell proliferation and apoptosis assays and in vivo xenograft experiments were performed to determine the effects of PLK1 on breast cancer cells. Immunofluorescence microscopy was used to measure the degree of multipolar cell division. Results: Kinome-wide CRISPR/Cas9 screening identified various kinases involved in PTX resistance in breast cancer cells; among these, PLK1 was chosen for further experiments.PLK1 knockdown inhibited the proliferation of MDA-MB-231 and MDA-MB-468 cells in vitro and in vivo. Moreover, PLK1 silencing sensitized breast cancer cells and mouse xenograft tumor models to PTX cytotoxicity. Silencing of PLK1 induced the formation of multipolar spindles and increased the percentage of multipolar cells. In addition, PLK1 silencing resulted in the downregulation of BubR1 and Mad2 in breast cancer cells. Furthermore, PLK1 upregulation in primary breast cancer was associated with decreased overall patient survival based on the analysis of The Cancer Genome Atlas and Molecular Taxonomy of Breast Cancer International Consortium databases. Conclusion PLK1 plays an important role in PTX resistance by regulating CIN in breast cancer cells. Targeting PLK1 may be an effective treatment strategy for PTX-resistant breast cancers.

Background: To evaluate the effects of isolating coronavirus disease 2019 (COVID-19) patients in general wards, we compared the rates of COVID-19 infection in nurses and nursing assistants working in COVID-19 designated wards and in general wards of our hospital from 1 October 2021 to 21 April 2022. Methods: This study was conducted in a 2,700-bed tertiary care hospital in Seoul, Korea. Designated wards comprised single, negative pressure rooms and a 100% outdoor air system. Results: During the study period, a total of 2,698 nurses and nursing assistants were employed at our hospital, of whom 310 (11%) were working in the designated wards, and the remaining 2,388 (89%) in the general wards, and among whom 1,158 (43%) were diagnosed with COVID-19. The healthcare workers (HCWs) in the designated wards were less frequently diagnosed with COVID-19 than those in the general wards (31% vs. 45%, P < 0.001). During the period before patients with COVID-19 were isolated in general wards, and during the period after these cases were isolated in general ward, HCWs in designated wards were less frequently infected with the virus than those in general wards (7% vs. 11%, P = 0.039; and 23% vs. 33%, P < 0.001, respectively). Conclusion HCWs in designated wards have a lower rate of contracting COVID-19 than those in general wards. A lack of exposure to undiagnosed cases and their caregivers, greater care with social distancing outside the hospital, higher rates of 3-dose vaccinations, and the use of isolation rooms with negative pressure may be associated with this finding.

PURPOSE: Patients often complain of change of defecation pattern and it is necessary to quantify their symptoms. To quantify symptoms, use of questionnaire is ideal, so we adopted a simple and easily writable visual analogue scale for irritable bowel syndrome questionnaire (VAS-IBS). The aim of this study was to develop and validate the Korean version of VAS-IBS questionnaire (Korean VAS-IBS) that can adequately reflect the defecation pattern. METHODS: This study translated English VAS-IBS into Korean using the forward-and-back translation method. Korean VAS-IBS was performed on 30 patients, who visited the outpatient clinic and had no possibility of special defecation pattern. Detailed past medical history and Bristol stool chart was added to the questionnaire. The survey was conducted twice, and the median interval between the 2 surveys was 10 days (8–11 days). Cronbach α for internal consistency reliability and intraclass correlation coefficients for test-retest reliability were analyzed. RESULTS: Korean VAS-IBS achieved acceptable homogeneity with a Cronbach α coefficient of 0.66–0.79 showing adequate internal consistency reliability. In addition, intraclass correlation coefficients showed significant test-retest reliability with 0.46–0.80 except for the question assessing the “perception of psychological wellbeing.” CONCLUSION: The Korean VAS-IBS is a valid and reliable questionnaire for the measurement of the symptoms of defecation pattern changes.
Ambulatory Care Facilities ; Defecation* ; Humans ; Irritable Bowel Syndrome* ; Methods ; Reproducibility of Results ; Translations ; Visual Analog Scale

BACKGROUND: Flow cytometric analysis is the standard method for enumerating CD34+ stem cells in hematopoietic stem cell transplantation. However, it has some limitations such as expensive instrumentation, high reagent costs, and discrepancies between technicians and laboratories. We compared counts of total nucleated cells (TNCs) and CD34+ cells counts obtained from a flow cytometer with a newly-developed image-based microscopic cell counter (ADAM II) to evaluate the possibility of clinical application of the ADAM II.METHODS: We used 18 samples of circulating peripheral blood (PB) and waste tube fractions of peripheral blood stem cells (PBSCs) harvested by apheresis after G-CSF mobilization from adult volunteer donors. We assessed the reproducibility and linearity of the new procedure and compared the numbers of TNCs and viable CD34+ cells determined with the ADAM II and two different flow cytometers (FACSCalibur, FACSCanto II).RESULTS: Numbers of viable CD34+ cells determined with the ADAM II were accurate over the expected range; the intra-assay coefficient of variation was ≤19.8%. Linearity was also satisfactory (R²=0.99). TNC counts obtained with the ADAM II were highly correlated with those obtained with the FACSCalibur (R²>0.9841, P<0.0001) and FACSCanto II (R²>0.9620, P<0.0001), as were the numbers of viable CD34+ cells obtained with the ADAM II and the FACSCalibur and FACSCanto II (R²>0.9911, P<0.0001 and R²>0.9791, P<0.0001), respectively.CONCLUSION: The newly developed image-based microscopic cell counter (ADAM II) appears to be suitable for enumerating TNCs and viable CD34+ cells.
Adult ; Blood Component Removal ; Cell Count ; Granulocyte Colony-Stimulating Factor ; Hematopoietic Stem Cell Transplantation ; Humans ; Methods ; Stem Cells ; Tissue Donors ; Volunteers

OBJECTIVE: To investigate the effects of a shoulder sling on balance in patients with hemiplegia. METHODS: Twenty-seven hemiplegic stroke patients (right 13, left 14) were enrolled in this study. The subjects' movement in their centers of gravity (COGs) during their static and dynamic balance tests was measured with their eyes open in each sling condition-without a sling, with Bobath's axillary support (Bobath sling), and with a simple arm sling. The percent times in quadrant, overall, anterior/posterior, and medial/lateral stability indexes were measured using a posturography platform (Biodex Balance System SD). Functional balance was evaluated using the Berg Balance Scale and the Trunk Impairment Scale. All balance tests were performed with each sling in random order. RESULTS: The COGs of right hemiplegic stroke patients and all hemiplegic stroke patients shifted to, respectively, the right and posterior quadrants during the static balance test without a sling (p<0.05). This weight asymmetry pattern did not improve with either the Bobath or the simple arm sling. There was no significant improvement in any stability index during either the static or the dynamic balance tests in any sling condition. CONCLUSION: The right and posterior deviations of the hemiplegic stroke patients' COGs were maintained during the application of the shoulder slings, and there were no significant effects of the shoulder slings on the patients' balance in the standing still position.
Arm ; Gravitation ; Hemiplegia ; Humans ; Orthotic Devices ; Postural Balance ; Shoulder* ; Stroke*

Myocarditis often occurs due to viral infections and postviral immune-mediated responses. Hypersensitivity myocarditis is a rare form of myocarditis. Numerous drugs can induce myocarditis, which is typically reversible after withdrawal of the causative agent. Here, we report a case of hypersensitivity myocarditis that was probably triggered by amoxicillin and that resolved completely with heart failure management as well as discontinuation of the drug. A 68-year-old woman presented with acute chest pain mimicking acute coronary syndromes, but the coronary angiography was normal. A recent history of taking medications, skin rash, and peripheral eosinophilia suggested a diagnosis of hypersensitivity myocarditis, which was confirmed by cardiac magnetic resonance imaging and endomyocardial biopsy.
Aged ; Amoxicillin/*adverse effects ; Anti-Bacterial Agents/*adverse effects ; *Biopsy ; Drug Hypersensitivity/*diagnosis/drug therapy/etiology/pathology ; Electrocardiography ; Female ; Glucocorticoids/therapeutic use ; Humans ; *Magnetic Resonance Imaging ; Myocarditis/chemically induced/*diagnosis/drug therapy/pathology ; Myocardium/*pathology ; Predictive Value of Tests ; Prednisolone/therapeutic use ; Risk Factors ; Treatment Outcome

Most cases of gas gangrene caused by Clostridium species begin with trauma-related injuries but in rare cases, spontaneous gas gangrene (SGG) can occur when patients have conditions such as advanced malignancy, diabetes, or immunosuppression. Clostridium perfringens, a rare cause of SGG, exists as normal flora of skin and intestines of human. Adequate antibiotics with surgical debridement of infected tissue is the only curative therapeutic management. Mortality rate among adults is reported range of 67-100% and majority of deaths are occurred within 24 hours of onset. We experienced a case of SGG on the trunk, buttock and thigh in a neutropenic patient with acute lymphoblastic leukemia. His clinical course was rapid and fatal during pre-engraftment neutropenic period of allogeneic stem cell transplantation.
Adult ; Anti-Bacterial Agents ; Buttocks ; Clostridium ; Clostridium perfringens* ; Debridement ; Gas Gangrene* ; Humans ; Immunosuppression ; Intestines ; Mortality ; Neutropenia* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Skin ; Stem Cell Transplantation* ; Thigh

Myeloid sarcoma is a solid, extramedullary tumor comprising of immature myeloid cells. It may occur in any organ; however, the invasion of peripheral nervous system is rare. Herein, we report the case of myeloid sarcoma on the brachial plexus. A 37-year-old woman with acute myelogenous leukemia achieved complete remission after chemotherapy. One year later, she presented right shoulder pain, progressive weakness in the right upper extremity and hypesthesia. Based on magnetic resonance images (MRI) and electrophysiologic study, a provisional diagnosis of brachial plexus neuritis was done and hence steroid pulse therapy was carried out. Three months later the patient presented epigastric pain. After upper gastrointestinal endoscopy, myeloid sarcoma of gastrointestinal tract was confirmed pathologically. Moreover, 18-fluoride fluorodeoxyglucose positron emission tomography showed a fusiform shaped mass lesion at the brachial plexus overlapping with previous high signal lesion on the MRI. Therefore, we concluded the final diagnosis as brachial plexopathy due to myeloid sarcoma.
Brachial Plexus ; Brachial Plexus Neuritis ; Brachial Plexus Neuropathies ; Endoscopy, Gastrointestinal ; Female ; Gastrointestinal Tract ; Humans ; Hypesthesia ; Leukemia, Myeloid, Acute ; Magnetic Resonance Spectroscopy ; Myeloid Cells ; Peripheral Blood Stem Cell Transplantation ; Peripheral Nervous System ; Positron-Emission Tomography ; Sarcoma, Myeloid ; Shoulder Pain ; Upper Extremity

Linezolid is an antibiotic in the oxazolidinone family that works as a bacterial protein synthesis inhibitor. It is used for the treatment of Gram-positive, multidrug-resistant bacteria. Adverse effects of linezolid include bone marrow suppression, peripheral or optic neuropathy, and, less commonly, lactic acidosis. Lactic acidosis usually occurs as a result of cardiopulmonary failure or sepsis, but it is sometimes caused by drugs, such as linezolid, and treatment of such lactic acidosis involves cessation of the drug. We report a case of lactic acidosis caused by the use of linezolid for the treatment of persistent methicillin-resistant Staphylococcus aureus bacteremia, which occurred after endoscopic sclerotherapy of gastic varices.
Acetamides ; Acidosis, Lactic ; Bacteremia ; Bacteria ; Bacterial Proteins ; Bone Marrow ; Humans ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Optic Nerve Diseases ; Oxazolidinones ; Sclerotherapy ; Sepsis ; Varicose Veins ; Linezolid