166 research outputs found
Genetic diagnosis of inborn errors of immunity using clinical exome sequencing
Inborn errors of immunity (IEI) include a variety of heterogeneous genetic disorders in which defects in the immune system lead to an increased susceptibility to infections and other complications. Accurate, prompt diagnosis of IEI is crucial for treatment plan and prognostication. In this study, clinical utility of clinical exome sequencing (CES) for diagnosis of IEI was evaluated. For 37 Korean patients with suspected symptoms, signs, or laboratory abnormalities associated with IEI, CES that covers 4,894 genes including genes related to IEI was performed. Their clinical diagnosis, clinical characteristics, family history of infection, and laboratory results, as well as detected variants, were reviewed. With CES, genetic diagnosis of IEI was made in 15 out of 37 patients (40.5%). Seventeen pathogenic variants were detected from IEI-related genes, BTK, UNC13D, STAT3, IL2RG, IL10RA, NRAS, SH2D1A, GATA2, TET2, PRF1, and UBA1, of which four variants were previously unreported. Among them, somatic causative variants were identified from GATA2, TET2, and UBA1. In addition, we identified two patients incidentally diagnosed IEI by CES, which was performed to diagnose other diseases of patients with unrecognized IEI. Taken together, these results demonstrate the utility of CES for the diagnosis of IEI, which contributes to accurate diagnosis and proper treatments
Comparison of treatment plans between IMRT with MR-linac and VMAT for lung SABR
Background
The aim of this study was to compare the plan quality of magnetic-resonance image-based intensity modulated radiation therapy (MRI-based-IMRT) with the MRIdian Linac system to that of volumetric modulated arc therapy (VMAT) with the TrueBeam STx system for lung stereotactic ablative radiotherapy (SABR).
Methods
A total of 22 patients with tumors located in the lower lobe were retrospectively selected for the study. For each patient, both the MRI-based-IMRT and VMAT plans were generated using an identical CT image set and identical structures with the exception of the planning target volume (PTV). The PTVs of the MRI-based-IMRT were generated by adding an isotropic margin of 3โmm from the gross tumor volume, whereas those of VMAT were generated by adding an isotropic margin of 5โmm from the internal target volume. For both the MRI-based-IMRT and VMAT, the prescription doses to the PTVs were 60โGy in four fractions.
Results
The average PTV volume of the MRI-based-IMRT was approximately 4-times smaller than that of VMAT (pโ<โย 0.001). The maximum dose to the bronchi for the MRI-based-IMRT was smaller than that for the VMAT (20.4โGy versus 24.2โGy, pโ<โย 0.001). In addition, V40Gy of the rib for the MRI-based-IMRT was smaller than that for the VMAT (1.8โcm3 versus 7.7โcm3, pโ=โ0.008). However, the maximum doses to the skin and spinal cord for the MRI-based-IMRT (33.0โGy and 14.5โGy, respectively) were larger than those for the VMAT (27.8โGy and 11.0โGy, respectively) showing p values of less than 0.02. For the ipsilateral lung, the mean dose, V20Gy, V10Gy, and V5Gy for the MRI-based-IMRT were smaller than those for the VMAT (all with pโ<โย 0.05). For the contralateral lung, V5Gy, V10Gy, D1500cc, and D1000cc for the MRI-based-IMRT were larger than those for the VMAT (all with pโ<โย 0.05). The mean dose and V50% of the whole body for the MRI-based-IMRT were smaller than those for the VMAT (0.9โGy versus 1.2โGy, and 78.7โcm3 versus 103.5โcm3, respectively, all at pโ<โย 0.001).
Conclusions
The MRI-based-IMRT using the MRIdian Linac system could reduce doses to bronchi, rib, ipsilateral lung, and whole body compared to VMAT for lung SABR when the tumor was located in the lower lobe.This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (No. 2017M2A2A7A02020640, 2017M2A2A7A02020641, and 2017M2A2A7A02020643)
Effect of changes in monitor unit rate and energy on dose rate of total marrow irradiation based on Linac volumetric arc therapy
Background
This study set out to evaluate the effect of dose rate on normal tissues (the lung, in particular) and the variation in the treatment efficiency as determined by the monitor unit (MU) and energy applied in Linac-based volumetric arc therapy (VMAT) total marrow irradiation (TMI).
Methods
Linac-based VMAT plans were generated for the TMI for six patients. The planning target volume (PTV) was divided into six sub-volumes, each of which had their own isocenter. To examine the effect of the dose rate and energy, a range of MU rates (40, 60, 80, 100, 300, and 600 MU/min) were selected for 6, 10, and 15 MV. All the plans were verified by portal dosimetry.
Results
The dosimetric parameters for the target and normal tissue were consistent in terms of the energy and MU rate. The beam-on time was changed from 59.6 to 6โmin for 40 and 600 MU/min. When 40 MU/min was set for the lung, the dose rate delivered to the lung was less than 6โcGy/min (that is, 90%), while the beam-on time was approximately 10โmin. The percentage volume of the lung receiving 20โcGy/min was 1.47, 3.94, and 6.22% at 6, 10, and 15 MV, respectively. However, for 600 MU/min, the total lung volume received over 6โcGy/min regardless of the energy, and over 20โcGy/min for 10 and 15 MV (i.e., 54.4% for 6 MV).
Conclusions
In TMI treatment, reducing the dose rate administered to the lung can decrease the incidence of pulmonary toxicity. To reduce the probability of normal tissue complications, the selection of the lowest MU rate is recommended for fields including the lung. To minimize the total treatment time, the maximum MU rate can be applied to other fields.This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (no. 2017M2A2A7A02020641) and the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (no. HA 16C0025)
Evaluation of effectiveness of fault-tolerant techniques in a digital instrumentation and control system with a fault injection experiment
Recently, instrumentation and control (I&C) systems in nuclear power plants have undergone digitalization. Owing to the unique characteristics of digital I&C systems, the reliability analysis of digital systems has become an important element of probabilistic safety assessment (PSA). In a reliability analysis of digital systems, fault-tolerant techniques and their effectiveness must be considered. A fault injection experiment was performed on a safety-critical digital I&C system developed for nuclear power plants to evaluate the effectiveness of fault-tolerant techniques implemented in the target system. A software-implemented fault injection in which faults were injected into the memory area was used based on the assumption that all faults in the target system will be reflected in the faults in the memory. To reduce the number of required fault injection experiments, the memory assigned to the target software was analyzed. In addition, to observe the effect of the fault detection coverage of fault-tolerant techniques, a PSA model was developed. The analysis of the experimental result also can be used to identify weak points of fault-tolerant techniques for capability improvement of fault-tolerant techniques
Efficacy of tetracyclines and fluoroquinolones for the treatment of macrolide-refractory Mycoplasma pneumoniae pneumonia in children: a systematic review and meta-analysis
Abstract
Background
Mycoplasma pneumoniae is a common pathogen that causes community-acquired pneumonia in school-age children. Macrolides are considered a first-line treatment for M. pneumoniae infection in children, but macrolide-refractory M. pneumoniae (MRMP) strains have become more common. In this study, we assessed the efficacy of tetracyclines and fluoroquinolones in MRMP treatment in children through a systematic review and meta-analysis.
Methods
Two reviewers individually searched 10 electronic databases (Medline/Pubmed, Embase, the Cochrane Library, and core Korean, Chinese, and Japanese journals) for papers published from January 1, 1990 to March 8, 2018. The following data for each treatment group were extracted from the selected studies: intervention (tetracyclines and fluoroquinolones/comparator), patient characteristics (age and sex), and outcomes (fever duration, hospital stay length, treatment success rate, and defervescence rates 24, 48, and 72ย h after starting treatment).
Results
Eight studies involving 537 participants were included. Fever duration and hospital stay length were shorter in the tetracycline group than in the macrolide group (weighted mean difference [WMD]โ=โโย 1.45, 95% confidence interval [CI]: โย 2.55 to โย 0.36, Pโ=โ0.009; and WMDโ=โโย 3.33, 95% CI: โย 4.32 to โย 2.35, Pโ<โ0.00001, respectively). The therapeutic efficacy was significantly higher in the tetracycline group than in the macrolide group (odds ratio [OR]: 8.80, 95% CI: 3.12โ24.82). With regard to defervescence rate, patients in the tetracycline group showed significant improvement compared to those in the macrolide group (defervescence rate after 24ย h, OR: 5.34, 95% CI: 1.81โ15.75; after 48ย h, OR 18.37, 95% CI: 8.87โ38.03; and after 72ย h, OR: 40.77, 95% CI: 6.15โ270.12). There were no differences in fever improvement within 24ย h in patients in the fluoroquinolone group compared to those in the macrolide group (OR: 1.11, 95% CI: 0.25โ5.00), although the defervescence rate was higher after 48ย h in the fluoroquinolone group (OR: 2.78, 95% CI: 1.41โ5.51).
Conclusion
Tetracyclines may shorten fever duration and hospital stay length in patients with MRMP infection. Fluoroquinolones may achieve defervescence within 48ย h in patients with MRMP infection. However, these results should be carefully interpreted as only a small number of studies were included, and they were heterogeneous.This study was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (Grant number: HI16C2300)
Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas
Background/AimsThe efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.MethodsAmong patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.ResultsOverall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.ConclusionsCautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy
Radiosensitization with combined use of olaparib and PI-103 in triple-negative breast cancer
This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited.Abstract
Background
Triple-negative breast cancer (TNBC) shows aggressive clinical behavior, but the treatment options are limited due to lack of a specific target. TNBC shares many clinical and pathological similarities with BRCA-deficient breast cancer, for which poly(ADP-ribose) polymerase (PARP) inhibitor is effective, but PARP inhibitor alone failed to show clinical effects in patients with sporadic TNBC. Radiation induces DNA double-strand breaks, and the phosphoinositide 3-kinase (PI3K) signaling pathway has been known to regulate steady-state levels of homologous recombination. A recent preclinical study showed that PI3K inhibition impairs BRCA1/2 expression and sensitizes BRCA-proficient TNBC to PARP inhibition. Therefore, we assessed the radiosensitizing effect, and the underlying mechanism of combination treatment with PARP inhibitor olaparib and PI3K inhibitor PI-103 in BRCA-proficient TNBC cells.
Methods
MDA-MB-435S cells were divided into four treatment groups, irradiation (IR) alone, olaparib plus IR, PI-103 plus IR, and olaparib plus PI-103 plus IR. Cells were exposed to the drugs for 2ย hours prior to irradiation, and the cell survival curve was obtained using a clonogenic assay. Western blotting and immunofluorescent detection of ฮณH2AX foci were performed. Xenograft and bioluminescence imaging were carried out to assess in vivo radiosensitivity.
Results
Combined use of olaparib and PI-103 enhanced radiation-induced death of MDA-MB-435S (sensitizer enhancement ratio[SER]0.05,1.7) and MDA-MB-231-BR (SER0.05,2.1) cells and significantly reduced tumor volume in a xenograft models (Pโ<โ0.001). Treatment with PI-103 showed persistent ฮณH2AX foci, indicating delayed repair of DNA strand breaks. PI-103 alone increased levels of poly(ADP-ribose) and phosphorylated extracellular signal-regulated kinase, and downregulated BRCA1.
Conclusions
Combined use of olaparib and PI-103 enhanced radiation-induced cell death in BRCA-proficient MDA-MB-435S and MDA-MB-231-BR cells and xenografts. TNBC patients have high incidences of locoregional relapse and distant metastasis, and radiation therapy targets both locoregional control and treatment of distant recurrences such as brain metastasis or other oligometastasis. Targeting of the PI3K signaling pathway combined with PARP inhibition maybe a feasible approach to enhance effects of radiation in BRCA-proficient TNBC
Toll-like receptor 2 downregulation and cytokine dysregulation predict mortality in patients with Staphylococcus aureus bacteremia
Background
Staphylococcus aureus bacteremia (SAB) presents heterogeneously, owing to the differences in underlying host conditions and immune responses. Although Toll-like receptor 2 (TLR2) is important in recognizing S. aureus, its function during S. aureus infection remains controversial. We aimed to examine the association of TLR2 expression and associated cytokine responses with clinical SAB outcomes.
Methods
Patients from a prospective SAB cohort at two tertiary-care medical centers were enrolled. Blood was sampled at several timepoints (โค5 d, 6โ9 d, 10โ13 d, 14โ19 d, andโโฅโ20 d) after SAB onset. TLR2 mRNA levels were determined via real-time PCR and serum tumor necrosis factor [TNF]-ฮฑ, interleukin [IL]-6, and IL-10 levels were analyzed with multiplex-high-sensitivity electrochemiluminescent ELISA.
Results
TLR2 levels varied among 59 SAB patients. On days 2โ5, TLR2 levels were significantly higher in SAB survivors than in healthy controls (pโ=โ0.040) and slightly but not significantly higher than non-survivors (pโ=โ0.120), and SAB patients dying within 7 d had lower TLR2 levels than survivors (Pโ=โ0.077) although statistically insignificant. IL-6 and IL-10 levels were significantly higher in non-survivors than in survivors on days 2โ5 post-bacteremia (Pโ=โ0.010 and Pโ=โ0.021, respectively), and those dying within 7 d of SAB (nโ=โ3) displayed significantly higher IL-10/TNF-ฮฑ ratios than the survivors did (Pโ=โ0.007).
Conclusion
TLR2 downregulation and IL-6 and IL-10 concentrations suggestive of immune dysregulation during early bacteremia may be associated with mortality from SAB. TLR2 expression levels and associated cytokine reactions during early-phase SAB may be potential prognostic factors in SAB, although larger studies are warranted.This study was supported by a research grant (13โ2014-002) from Seoul National University Bundang Hospital (Seongnam, South Korea). The funder had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript
Neural Dynamics of Olfactory Perception: Low- and High-Frequency Modulations of Local Field Potential Spectra in Mice Revealed by an Oddball Stimulus
Recent brain connectome studies have evidenced distinct and overlapping brain regions involved in processing olfactory perception. However, neural correlates of hypo- or anosmia in olfactory disorder patients are poorly known. Furthermore, the bottom-up and top-down processing of olfactory perception have not been well-documented, resulting in difficulty in locating the disease foci of olfactory disorder patients. The primary aim of this study is to characterize the bottom-up process of the neural dynamics across peripheral and central brain regions in anesthetized mice. We particularly focused on the neural oscillations of local field potential (LFP) in olfactory epithelium (OE), olfactory blub (OB), prefrontal cortex (PFC), and hippocampus (HC) during an olfactory oddball paradigm in urethane anesthetized mice. Odorant presentations evoked neural oscillations across slow and fast frequency bands including delta (1โ4 Hz), theta (6โ10 Hz), beta (15โ30 Hz), low gamma (30โ50 Hz), and high gamma (70โ100 Hz) in both peripheral and central nervous systems, and the increases were more prominent in the infrequently presented odorant. During 5 s odorant exposures, the oscillatory responses in power were persistent in OE, OB, and PFC, whereas neural oscillations of HC increased only for short time at stimulus onset. These oscillatory responses in power were insignificant in both peripheral and central regions of the ZnSO4-treated anosmia model. These results suggest that olfactory stimulation induce LFP oscillations both in the peripheral and central nervous systems and suggest the possibility of linkage of LFP oscillations in the brain to the oscillations in the peripheral olfactory system
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