Risk factors for transmission in a COVID-19 cluster infection in a high school in the Republic of Korea

Objectives This study aimed to examine the scale, characteristics, risk factors, and modes of transmission in a coronavirus disease 2019 (COVID-19) outbreak at a high school in Seoul, Republic of Korea. Methods An epidemiological survey was conducted of 1,118 confirmed cases and close contacts from a COVID-19 outbreak at an educational facility starting on May 31, 2021. In-depth interviews, online questionnaires, flow evaluations, and CCTV analyses were used to devise infection prevention measures. Behavioral and spatial risk factors were identified, and statistical significance was tested. Results Among 3rd-year students, there were 33 confirmed COVID-19 cases (9.6%). Students who used a study room in the annex building showed a statistically significant 4.3-fold elevation in their relative risk for infection compared to those who did not use the study room. Moreover, CCTV facial recognition analysis confirmed that 17.8% of 3rd-year students did not wear masks and had the lowest percentage of mask-wearers by grade. The air epidemiological survey conducted in the study room in the annex, which met the 3 criteria for a closed space, confirmed that there was only 10% natural ventilation due to the poor ventilation system. Conclusion To prevent and manage the spread of COVID-19 in educational facilities, advance measures that consider the size, operation, and resources of each school are crucial. In addition, various survey methodologies should be used in future studies to quickly analyze a wider range of data that can inform an evidence-based quarantine response

Altered resting-state connectivity in subjects at ultra-high risk for psychosis: an fMRI study

<p>Abstract</p> <p>Background</p> <p>Individuals at ultra-high risk (UHR) for psychosis have self-disturbances and deficits in social cognition and functioning. Midline default network areas, including the medial prefrontal cortex and posterior cingulate cortex, are implicated in self-referential and social cognitive tasks. Thus, the neural substrates within the default mode network (DMN) have the potential to mediate self-referential and social cognitive information processing in UHR subjects.</p> <p>Methods</p> <p>This study utilized functional magnetic resonance imaging (fMRI) to investigate resting-state DMN and task-related network (TRN) functional connectivity in 19 UHR subjects and 20 matched healthy controls. The bilateral posterior cingulate cortex was selected as a seed region, and the intrinsic organization for all subjects was reconstructed on the basis of fMRI time series correlation.</p> <p>Results</p> <p>Default mode areas included the posterior/anterior cingulate cortices, the medial prefrontal cortex, the lateral parietal cortex, and the inferior temporal region. Task-related network areas included the dorsolateral prefrontal cortex, supplementary motor area, the inferior parietal lobule, and middle temporal cortex. Compared to healthy controls, UHR subjects exhibit hyperconnectivity within the default network regions and reduced anti-correlations (or negative correlations nearer to zero) between the posterior cingulate cortex and task-related areas.</p> <p>Conclusions</p> <p>These findings suggest that abnormal resting-state network activity may be related with the clinical features of UHR subjects. Neurodevelopmental and anatomical alterations of cortical midline structure might underlie altered intrinsic networks in UHR subjects.</p

The effect of meditation on brain structure: cortical thickness mapping and diffusion tensor imaging

A convergent line of neuroscientific evidence suggests that meditation alters the functional and structural plasticity of distributed neural processes underlying attention and emotion. The purpose of this study was to examine the brain structural differences between a well-matched sample of long-term meditators and controls. We employed whole-brain cortical thickness analysis based on magnetic resonance imaging, and diffusion tensor imaging to quantify white matter integrity in the brains of 46 experienced meditators compared with 46 matched meditation-naïve volunteers. Meditators, compared with controls, showed significantly greater cortical thickness in the anterior regions of the brain, located in frontal and temporal areas, including the medial prefrontal cortex, superior frontal cortex, temporal pole and the middle and interior temporal cortices. Significantly thinner cortical thickness was found in the posterior regions of the brain, located in the parietal and occipital areas, including the postcentral cortex, inferior parietal cortex, middle occipital cortex and posterior cingulate cortex. Moreover, in the region adjacent to the medial prefrontal cortex, both higher fractional anisotropy values and greater cortical thickness were observed. Our findings suggest that long-term meditators have structural differences in both gray and white matter

Increased urinary Angiotensinogen/Creatinine (AGT/Cr) ratio may be associated with reduced renal function in autosomal dominant polycystic kidney disease patients

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.Background Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary kidney diseases that frequently result in renal failure. In this cross-sectional observational cohort study, we evaluated urinary angiotensinogen (AGT) as a potential biomarker to assess renal function in ADPKD. Methods Urinary AGT was measured in 233 ADPKD patients and its association with estimated glomerular filtration rate (eGFR) and height-adjusted total kidney volume (htTKV) were evaluated. The localization of AGT and other renin-angiotensin system (RAS)-related molecules were identified using immunohistochemistry in human ADPKD tissues. Results Baseline urinary AGT/Cr was negatively correlated with CKD-EPI eGFR (r 2= 0.162, P < 0.001) and positively correlated with htTKV (r2 = 0.107, P < 0.001). Both urinary AGT/Cr and plasma renin activity levels were significantly elevated in hypertensive ADPKD patients. Among hypertensive subjects, urinary AGT/Cr was significantly increased in the advanced CKD stages (III-V) compared to early CKD stages (I-II) (28.6 ± 60.3 vs. 93.2 ± 139.3 μg/g, P < 0.001). Immunohistochemical study showed strong expression of AGT along the cyst-lining epithelial cells as well as the nearby compressed tubular epithelial cells. Conclusions Our results suggested that urinary AGT/Cr may be a valuable biomarker for renal damage in ADPKD since intrarenal ischemic insults induced by cyst growth and subsequent intrarenal RAS activation may play a potential role in the development of hypertension and renal dysfunction in ADPKD

Reduced cortical folding of the anterior cingulate cortex in obsessive-compulsive disorder

Background: Anterior cingulate cortex (ACC) abnormalities have been implicated consistently in the pathophysiology of obsessive-compulsive disorder (OCD), yet it remains unclear whether these abnormalities originated during early neurodevelopment. In this study, we examined the ACC sulcal/gyral patterns to investigate whether neurodevelopmental anomalies of the ACC were present in patients with OCD. We hypothesized that patients with OCD would show reduced cortical folding of the ACC compared with controls. Methods: We used magnetic resonance imaging (MRI) of 169 healthy volunteers and 110 patients with OCD to examine the paracingulate sulcus and cingulate sulcus. We assessed cortical folding patterns according to established classification criteria and constructed 3 categories of paracingulate sulcus morphology according to its presence and anteroposterior extent: "prominent," "present" and "absent." We classified the cingulate sulcus as "interrupted" or "continuous" according to the interruptions in its course. In addition, we evaluated ACC sulcal asymmetry based on interhemispheric comparisons of paracingulate sulcus morphology. Results: Analyses revealed that patients with OCD were significantly less likely than controls to show a well-developed left paracingulate sulcus: 50.0% of patients and 65.1% of controls showed a "prominent" or "present" paracingulate sulcus in the left hemisphere. However, there were no differences in regard to cingulate sulcus continuity, and patients also showed the same leftward ACC sulcal asymmetry as controls. Limitations: Our study was limited by the fact that we obtained the MRI scans from 2 different scanners, and we did not calculate cerebral fissurization as our study was restricted to 1 specific brain region. Moreover, patients and controls differed significantly in terms of sex ratio and IQ, although we controlled these variables as covariates. Conclusion: Our findings imply a subtle deviation in the early neurodevelopment of the ACC in patients with OCD, but the extent to which these anomalies contributed to the pathogenesis of OCD remains unclear. Further studies that link the ACC morphologic anomalies to the pathophysiology of OCD are recommended.This work was supported by Cognitive Neuroscience Program of the Korean Ministry of Science and Technology (M10644020003-08N4402-00310).Jung MH, 2009, PROG NEURO-PSYCHOPH, V33, P605, DOI 10.1016/j.pnpbp.2009.02.017Whittle S, 2009, PSYCHIAT RES-NEUROIM, V172, P68, DOI 10.1016/j.pscychresns.2008.06.005Gu BM, 2008, BRAIN, V131, P155, DOI 10.1093/brain/awm277Fornito A, 2007, ACTA PSYCHIAT SCAND, V116, P467, DOI 10.1111/j.1600-0447.2007.01069.xShin YW, 2007, HUM BRAIN MAPP, V28, P1128, DOI 10.1002/hbm.20338Huster RJ, 2007, NEUROIMAGE, V34, P888, DOI 10.1016/j.neuroimage.2006.10.023De Geus F, 2007, PSYCHIAT CLIN NEUROS, V61, P45, DOI 10.1111/j.1440-1819.2007.01609.xFornito A, 2006, SCHIZOPHR RES, V88, P192, DOI 10.1016/j.schres.2006.06.034Jang JH, 2006, AM J PSYCHIAT, V163, P1202Kim YY, 2006, BRAIN TOPOGR, V18, P201, DOI 10.1007/s10548-006-0269-2Klimkeit EI, 2006, CORTEX, V42, P113Valente AA, 2005, BIOL PSYCHIAT, V58, P479, DOI 10.1016/j.biopsych.2005.04.021Rosenberg DR, 2004, J AM ACAD CHILD PSY, V43, P1146, DOI 10.1097/01.chi.0000132812.44664.2dFornito A, 2004, CEREB CORTEX, V14, P424, DOI 10.1093/cercor/bhh004Shin YW, 2004, PSYCHIAT CLIN NEUROS, V58, P16Yucel M, 2003, BRIT J PSYCHIAT, V182, P518Yucel M, 2002, BIOL PSYCHIAT, V52, P15Lyoo IK, 2001, J CLIN PSYCHIAT, V62, P637Allman JM, 2001, ANN NY ACAD SCI, V935, P107Yucel M, 2001, CEREB CORTEX, V11, P17Bradshaw JL, 2000, BRAIN LANG, V73, P297Bush G, 2000, TRENDS COGN SCI, V4, P215Penalva J, 2000, BIOSENS BIOELECTRON, V15, P99Lohmann G, 1999, CEREB CORTEX, V9, P754Magnotta VA, 1999, CEREB CORTEX, V9, P151Tibbo P, 1999, J PSYCHIATR NEUROSCI, V24, P15Rosenberg DR, 1998, BIOL PSYCHIAT, V43, P623Purcell R, 1998, BIOL PSYCHIAT, V43, P348SAXENA S, 1998, BRIT J PSYCHIAT S, V35, P26FIRST MB, 1998, STRUCTURED CLIN INTESIEGEL S, 1998, NONPARAMETRIC STAT BRauch SL, 1997, J NEUROPSYCH CLIN N, V9, P568Bartley AJ, 1997, BRAIN, V120, P257VanEssen DC, 1997, NATURE, V385, P313Paus T, 1996, CEREB CORTEX, V6, P207FIRST MB, 1996, STRUCTURED CLIN INTEVOGT BA, 1995, J COMP NEUROL, V359, P490DEVINSKY O, 1995, BRAIN, V118, P279ARMSTRONG E, 1995, CEREB CORTEX, V5, P56PAULS DL, 1995, AM J PSYCHIAT, V152, P76KIM JS, 1995, KOREAN J CLIN PSYCHO, V14, P111*AM PSYCH ASS, 1994, DIAGN STAT MAN MENTBAXTER LR, 1992, ARCH GEN PSYCHIAT, V49, P681HUANG CC, 1991, BRAIN DEV-JPN, V13, P27WELKER W, 1990, CEREBRAL CORTEX B, V8, P3DIXON WJ, 1990, BMDP STAT SOFTWARE MHOLLANDER E, 1990, ARCH GEN PSYCHIAT, V47, P27CROW TJ, 1989, ARCH GEN PSYCHIAT, V46, P1145GOODMAN WK, 1989, ARCH GEN PSYCHIAT, V46, P1006GOODMAN WK, 1989, ARCH GEN PSYCHIAT, V46, P1012SWEDO SE, 1989, ARCH GEN PSYCHIAT, V46, P518RAKIC P, 1988, SCIENCE, V241, P170BEAR D, 1986, ARCH NEUROL-CHICAGO, V43, P598GESCHWIND N, 1985, ARCH NEUROL-CHICAGO, V42, P521FLORHENRY P, 1983, CEREBRAL BASIS PSYCH, P301CHI JG, 1977, ANN NEUROL, V1, P86ANNETT M, 1970, BRIT J PSYCHOL, V61, P303CRICHTONBROWNE J, 1879, BRAIN, V2, P42

Clinical use of alumina-toughened zirconia abutments for implant-supported restoration: prospective cohort study of survival analysis

Objectives The aim of this prospective cohort study was to compute the long-term clinical survival and complication rates of alumina-toughened zirconia abutments used for implant-supported restorations and to evaluate the effects of several clinical variables on these rates. Material and methods From May 1998 to September 2010, 213 patients aged 18years or older were recruited. The patients received 611 external hex implants and 328 implant-supported fixed restorations using alumina-toughened zirconia abutments. During the follow-up, each restoration was coded as a dental event, which included loosening or fracture of abutment screws, and abutment fracture. From the coded data, the effects of the investigated clinical variablesrestored area (anterior/posterior), number of prosthodontic units (one/two units or over), prosthesis type (single-unit/multiunit without pontic/multiunit with pontic), implant system, and patient genderon the survival of the abutments were evaluated. Survival analysis using KaplanMeier method and Cox proportional hazard model was applied. The 5-year survival and complication rates of the abutments were assessed. Results The number of prosthodontic units and the type of prosthesis had a significant association with complication rates (P<0.05). KaplanMeier survival analysis estimated that the cumulative 5-year complication rate of the abutments used in single restorations was 19.7%. Multiunit-fixed dental prostheses without and with pontics had complication rates of 3.9% and 3.8%, respectively. The 5-year survival rate of the abutments was more than 95%, regardless of the type of prosthesis. Conclusions Alumina-toughened zirconia abutments are likely to exhibit excellent long-term survival in clinical use for fixed restorations. Single tooth replacement with the abutment at the molar region may require special care and extra attention.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000030821/3SEQ:3PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000030821ADJUST_YN:YEMP_ID:A076080DEPT_CD:861CITE_RATE:2.514FILENAME:2013 05월 coir 24(5),2013,517-522.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:YCONFIRM:

Physicochemical, Biological, and Antibacterial Properties of Four Bioactive Calcium Silicate-Based Cements

Calcium silicate-based cement (CSC) is a pharmaceutical agent that is widely used in dentistry. This bioactive material is used for vital pulp treatment due to its excellent biocompatibility, sealing ability, and antibacterial activity. Its drawbacks include a long setting time and poor maneuverability. Hence, the clinical properties of CSC have recently been improved to decrease its setting time. Despite the widespread clinical usage of CSC, there is no research comparing recently developed CSCs. Therefore, the purpose of this study is to compare the physicochemical, biological, and antibacterial properties of four commercial CSCs: two powder–liquid mix types (RetroMTA® [RETM]; Endocem® MTA Zr [ECZR]) and two premixed types (Well-Root™ PT [WRPT]; Endocem® MTA premixed [ECPR]). Each sample was prepared using circular Teflon molds, and tests were conducted after 24 h of setting. The premixed CSCs exhibited a more uniform and less rough surface, higher flowability, and lower film thickness than the powder–liquid mix CSCs. In the pH test, all CSCs showed values between 11.5 and 12.5. In the biological test, cells exposed to ECZR at a concentration of 25% showed greater cell viability, but none of the samples showed a significant difference at low concentration (p &gt; 0.05). Alkaline phosphatase staining revealed that cells exposed to ECZR underwent more odontoblast differentiation than the cells exposed to the other materials; however, no significant difference was observed at a concentration of 12.5% (p &gt; 0.05). In the antibacterial test, the premixed CSCs showed better results than the powder–liquid mix CSCs, and ECPR yielded the best results, followed by WRPT. In conclusion, the premixed CSCs showed improved physical properties, and of the premixed types, ECPR exhibited the highest antibacterial properties. For biological properties, none of these materials showed significant differences at 12.5% dilution. Therefore, ECPR may be a promising material with high antibacterial activity among the four CSCs, but further investigation is needed for clinical situations