Purpose: We evaluated the incidence and characteristics of Clostridioides difficile infection (CDI) in Korean children. Methods: Medical records of patients aged 2–18 years and diagnosed with CDI at a tertiary hospital between 2009 and 2018 were analyzed. The patients were classified into three CDI groups: community-acquired (CA), community onset-health care facility-associated (COHCFA), and healthcare facility onset (HO). Results: The incidence of CDI increased from 1.00 to 10.01 cases per 10,000 admissions from 2009 to 2018 (P<0.001). As compared to the CA group, the HO group had a higher frequency of operation and malignancy as predisposing factors (40.4% vs. 0.0%, P=0.001; and 27.7% vs. 0.0%, P=0.027, respectively), frequency and number of previous antibiotic use (97.9% vs. 31.3%, P<0.001; and 2 vs. 0, P<0.001, respectively), and median postdiagnosis hospital stay (13 vs. 5 days, P=0.008). The CO-HCFA group had a lower median age and higher frequency of malignancy than the CA group (5 vs. 13 years, P=0.012; and 30.8% vs.0.0%, P=0.030, respectively). As compared to the HO group, the CA group had a higher frequency of abdominal pain and hematochezia (56.3% vs. 10.6%, P=0.001; and 50.0% vs. 10.6%, P=0.002, respectively), inflammatory bowel disease (68.8% vs. 2.1%, P=0.001), and intravenous metronidazole treatment (37.5% vs. 2.1%,P=0.001). Conclusions With the increasing incidence of pediatric CDI, awareness regarding its epidemiology and clinical characteristics is important to manage nosocomial infections.

Purpose: We evaluated the incidence and characteristics of Clostridioides difficile infection (CDI) in Korean children. Methods: Medical records of patients aged 2–18 years and diagnosed with CDI at a tertiary hospital between 2009 and 2018 were analyzed. The patients were classified into three CDI groups: community-acquired (CA), community onset-health care facility-associated (COHCFA), and healthcare facility onset (HO). Results: The incidence of CDI increased from 1.00 to 10.01 cases per 10,000 admissions from 2009 to 2018 (P<0.001). As compared to the CA group, the HO group had a higher frequency of operation and malignancy as predisposing factors (40.4% vs. 0.0%, P=0.001; and 27.7% vs. 0.0%, P=0.027, respectively), frequency and number of previous antibiotic use (97.9% vs. 31.3%, P<0.001; and 2 vs. 0, P<0.001, respectively), and median postdiagnosis hospital stay (13 vs. 5 days, P=0.008). The CO-HCFA group had a lower median age and higher frequency of malignancy than the CA group (5 vs. 13 years, P=0.012; and 30.8% vs.0.0%, P=0.030, respectively). As compared to the HO group, the CA group had a higher frequency of abdominal pain and hematochezia (56.3% vs. 10.6%, P=0.001; and 50.0% vs. 10.6%, P=0.002, respectively), inflammatory bowel disease (68.8% vs. 2.1%, P=0.001), and intravenous metronidazole treatment (37.5% vs. 2.1%,P=0.001). Conclusions With the increasing incidence of pediatric CDI, awareness regarding its epidemiology and clinical characteristics is important to manage nosocomial infections.

Microglia, the resident macrophages in the central nervous system, can rapidly respond to pathological insults. Toll-like receptor 2 (TLR2) is a pattern recognition receptor that plays a fundamental role in pathogen recognition and activation of innate immunity. Although many previous studies have suggested that TLR2 contributes to microglial activation and subsequent pathogenesis following brain tissue injury, it is still unclear whether TLR2 has a role in microglia dynamics in the resting state or in immediate-early reaction to the injury in vivo. By using in vivo two-photon microscopy imaging and Cx3cr1(GFP/+) mouse line, we first monitored the motility of microglial processes (i.e. the rate of extension and retraction) in the somatosensory cortex of living TLR2-KO and WT mice; Microglial processes in TLR2-KO mice show the similar motility to that of WT mice. We further found that microglia rapidly extend their processes to the site of local tissue injury induced by a two-photon laser ablation and that such microglial response to the brain injury was similar between WT and TLR2-KO mice. These results indicate that there are no differences in the behavior of microglial processes between TLR2-KO mice and WT mice when microglia is in the resting state or encounters local injury. Thus, TLR2 might not be essential for immediate-early microglial response to brain tissue injury in vivo.
Animals ; Brain ; Brain Injuries ; Central Nervous System ; Immunity, Innate ; Laser Therapy ; Macrophages ; Mice ; Microglia ; Microscopy ; Somatosensory Cortex ; Toll-Like Receptor 2* ; Toll-Like Receptors*

Background: Interleukin (IL)-17 and IL-23 inhibitors have helped achieve clear skin in many patients with psoriasis. However, real-world data to compare short- and long-term efficacy of these biologics in Korean patients are lacking. Objective: To compare short- and long-term efficacy of IL-17A and IL-23 inhibitors in patients with moderateto-severe psoriasis. Methods: We retrospectively evaluated efficacy of IL-17A and IL-23 inhibitors among patients treated at Ajou University Hospital from 2017 to 2022. The specific agents studied were as follows: secukinumab, 32 patients; ixekizumab, four patients; guselkumab, 13 patients; and risankizumab, 31 patients. Patients who were followed up for less than a year or changed biologics were excluded. Results: The rates of psoriasis area and severity index (PASI) 90 achievement of secukinumab were 62.5%, 86.7%, 89.3%, 80.8%, and 70.8% at weeks 16, 40, 88, 112, and 136, respectively. For ixekizumab, the PASI90 achievement rates were 75%, 100%, 75%, and 100% at weeks 16, 40, 64, and 88, respectively. The PASI90 achievement rates of guselkumab were 53.8%, 76.9%, 72.7%, and 77.8% at weeks 20, 44, 68, and 92, respectively. For risankizumab, PASI90 achievement rates were 69.7%, 90.0%, 93.7%, and 100% at weeks 28, 52, 76, and 100, respectively. Before 52 weeks, PASI90 achievement was significantly lower with guselkumab than with secukinumab (hazardratio=0.22). After 52 weeks, PASI90 achievement was significantly higher with risankizumab than with secukinumab (hazard ratio=2.00). Conclusion PASI90 was achieved faster with IL-17A inhibitors than with IL-23 inhibitors. However, IL-23 inhibitors afforded the maintenance of a higher PASI score after 52 weeks.

The primary somatosensory (S1) cortex plays a key role in distinguishing different sensory stimuli. Vibrotactile touch information is conveyed from the periphery to the S1 cortex through three major classes of mechanoreceptors: slowly adapting type 1 (SA1), rapidly adapting (RA), and Pacinian (PC) afferents. It has been a long-standing question whether specific populations in the S1 cortex preserve the peripheral segregation by the afferent submodalities. Here, we investigated whether S1 neurons exhibit specific responses to two distinct vibrotactile stimuli, which excite different types of mechanoreceptors (e.g., SA1 and PC afferents). Using in vivo two-photon microscopy and genetically encoded calcium indicator, GCaMP6s, we recorded calcium activities of S1 L2/3 neurons. At the same time, static (<1 Hz) and dynamic (150 Hz) vibrotactile stimuli, which are known to excite SA1 and PC, respectively, were pseudorandomly applied to the right hind paw in lightly anesthetized mice. We found that most active S1 neurons responded to both static and dynamic stimuli, but more than half of them showed preferred responses to either type of stimulus. Only a small fraction of the active neurons exhibited specific responses to either static or dynamic stimuli. However, the S1 population activity patterns by the two stimuli were markedly distinguished. These results indicate that the vibrotactile inputs driven by excitation of distinct submodalities are converged on the single cells of the S1 cortex, but are well discriminated by population activity patterns composed of neurons that have a weighted preference for each type of stimulus.

Objective: To determine the prognostic value of MRI-based tumor regression grading (mrTRG) in rectal cancer compared withpathological tumor regression grading (pTRG), and to assess the effect of diffusion-weighted imaging (DWI) on interobserveragreement for evaluating mrTRG. Materials and Methods: Between 2007 and 2016, we retrospectively enrolled 321 patients (male:female = 208:113; meanage, 60.2 years) with rectal cancer who underwent both pre-chemoradiotherapy (CRT) and post-CRT MRI. Two radiologistsindependently determined mrTRG using a 5-point grading system with and without DWI in a one-month interval. Two pathologistsgraded pTRG using a 5-point grading system in consensus. Kaplan-Meier estimation and Cox-proportional hazard models wereused for survival analysis. Cohen’s kappa analysis was used to determine interobserver agreement. Results: According to mrTRG on MRI with DWI, there were 6 mrTRG 1, 48 mrTRG 2, 109 mrTRG 3, 152 mrTRG 4, and 6 mrTRG 5.By pTRG, there were 7 pTRG 1, 59 pTRG 2, 180 pTRG 3, 73 pTRG 4, and 2 pTRG 5. A 5-year overall survival (OS) was significantlydifferent according to the 5-point grading mrTRG (p= 0.024) and pTRG (p= 0.038). The 5-year disease-free survival (DFS)was significantly different among the five mrTRG groups (p= 0.039), but not among the five pTRG groups (p= 0.072). OSand DFS were significantly different according to post-CRT MR variables: extramural venous invasion after CRT (hazard ratio= 2.259 for OS, hazard ratio = 5.011 for DFS) and extramesorectal lymph node (hazard ratio = 2.610 for DFS). For mrTRG, kvalue between the two radiologists was 0.309 (fair agreement) without DWI and slightly improved to 0.376 with DWI. Conclusion mrTRG may predict OS and DFS comparably or even better compared to pTRG. The addition of DWI on T2-weightedMRI may improve interobserver agreement on mrTRG.