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The Korean Dementia Association (KDA) has been organizing biennial international academic conferences since 2019, with the International Conference of the KDA (IC-KDA) 2023 held in Busan under the theme ‘Beyond Boundaries: Advancing Global Dementia Solutions.’ The conference comprised 6 scientific sessions, 3 plenary lectures, and 4luncheon symposiums, drawing 804 participants from 35 countries. Notably, a Korea– Taiwan Joint Symposium addressed insights into Alzheimer’s disease (AD). Plenary lectures by renowned scholars explored topics such as microbiome-related AD pathogenesis, social cognition in neurodegenerative diseases, and genetic frontotemporal dementia (FTD). On the first day, specific presentations covered subjects like the gut–brain axis and neuroinflammation in dementia, blood-based biomarkers in AD, and updates in AD therapeutics. The second day’s presentations addressed recent issues in clinical neuropsychology, FTD cohort studies, and the pathogenesis of non-AD dementia. The Academic Committee of the KDA compiles lecture summaries to provide comprehensive understanding of the advanced dementia knowledge presented at IC-KDA 2023.
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Background@#The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). @*Methods@#A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. @*Results@#A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = −0.430, P = 0.036), H. influenzae (rs = −0.922, P 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.
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Coinfection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with other respiratory pathogens may complicate diagnosis and treatment. Since the risk of coinfection with SARS-CoV-2 is expected to increase during the influenza epidemic period, it is necessary to study the clinical course of coinfection. To our knowledge, there have been a few cases of coinfection between SARS-CoV-2 and influenza virus in neonates. Here, we report the clinical course of a neonate who was coinfected with the influenza virus and SARS-CoV-2. A 20-day-old boy born with low birth weight presented with a fever. The patient was confirmed as positive with coronavirus disease 2019 (COVID-19) and influenza B by real-time polymerase chain reaction at admission, whereas his mother was only COVID-19 positive at that time. Initial chest x-ray revealed hyperinflation and increased peribronchial markings at the right lower lung bronchus, but slightly decreased lung sounds without crackle or wheezing at admission. We administered empirical antibiotics for neonatal sepsis and oseltamivir for influenza B. On the chest x-ray follow-up, the findings showed improvement. After discharge, the patient showed a stable general condition. Children ineligible for COVID-19 vaccination who are coinfected with SARS-CoV-2 and the influenza virus are more likely to develop severe symptoms. It is necessary to detect coinfections as some can be treated with antibiotics and antivirals in young infants.
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Background@#There is difference in the incidence of multi-system inflammatory syndrome in children (MIS-C) in patients with different variants of severe acute respiratory syndrome coronavirus 2, however, little is known about the epidemiology in Asian countries. We investigated and compared the epidemiology of the MIS-C during omicron-dominant period with that of previous periods in South Korea. @*Methods@#We obtained clinical, epidemiological and laboratory data on MIS-C cases from national MIS-C surveillance in South Korea. We defined pre-delta period as January 2020–May 2021; delta period as June 2021–December 2021; and omicron period as January 2022–April 2022. We describe the clinical characteristics and outcomes of MIS-C patients by period. @*Results@#A total of 91 cases were assessed to be MIS-C cases. Number of MIS-C cases have increased from six cases during pre-delta period to 66 cases during omicron period, while the incidence rate (the number of MIS-C cases per 100,000 cases of reported coronavirus disease 2019) has decreased from 38.5 cases per 100,000 (95% confidence interval [CI], 14.1–83.9) during pre-delta period to 1.6 cases per 100,000 (95% CI, 1.2–2.0) during omicron periods. During pre-delta period, 66.7% and 100% had hypotension and gastrointestinal involvement, respectively; while during omicron period, 12.1% and 6.1% had such clinical manifestations. Fifty percent of pre-delta MIS-C patients were taken intensive care unit (ICU) cares, while 10.6% of patients during omicron periods were in ICUs. @*Conclusion@#Omicron period were associated with less severe clinical manifestation compared to pre-delta and delta periods. Although incidence rate of MIS-C was lower for the omicron period than pre-delta and delta periods, number of patients reported with MIS-C may pose a substantial clinical burden.
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Background@#Nonpharmacological interventions (NPIs) reduce the incidence of respiratory infections. After NPIs imposed during the coronavirus disease 2019 pandemic ceased, respiratory infections gradually increased worldwide. However, few studies have been conducted on severe respiratory infections requiring hospitalization in pediatric patients.This study compares epidemiological changes in severe respiratory infections during pre-NPI, NPI, and post-NPI periods in order to evaluate the effect of that NPI on severe respiratory infections in children. @*Methods@#We retrospectively studied data collected at 13 Korean sentinel sites from January 2018 to October 2022 that were lodged in the national Severe Acute Respiratory Infections (SARIs) surveillance database. @*Results@#A total of 9,631 pediatric patients were admitted with SARIs during the pre-NPI period, 579 during the NPI period, and 1,580 during the post-NPI period. During the NPI period, the number of pediatric patients hospitalized with severe respiratory infections decreased dramatically, thus from 72.1 per 1,000 to 6.6 per 1,000. However, after NPIs ceased, the number increased to 22.8 per 1,000. During the post-NPI period, the positive test rate increased to the level noted before the pandemic. @*Conclusion@#Strict NPIs including school and daycare center closures effectively reduced severe respiratory infections requiring hospitalization of children. However, childcare was severely compromised. To prepare for future respiratory infections, there is a need to develop a social consensus on NPIs that are appropriate for children.
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Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been acknowledged as an effective mean of preventing infection and hospitalization.However, the emergence of highly transmissible SARS-CoV-2 variants of concern (VOCs) has led to substantial increase in infections among children and adolescents. Vaccineinduced immunity and longevity have not been well defined in this population. Therefore, we aimed to analyze humoral and cellular immune responses against ancestral and SARSCoV-2 variants after two shots of the BNT162b2 vaccine in healthy adolescents. Although vaccination induced a robust increase of spike-specific binding Abs and neutralizing Abs against the ancestral and SARS-CoV-2 variants, the neutralizing activity against the Omicron variant was significantly low. On the contrary, vaccine-induced memory CD4+ T cells exhibited substantial responses against both ancestral and Omicron spike proteins.Notably, CD4+ T cell responses against both ancestral and Omicron strains were preserved at 3 months after two shots of the BNT162b2 vaccine without waning. Polyfunctionality of vaccine-induced memory T cells was also preserved in response to Omicron spike protein.The present findings characterize the protective immunity of vaccination for adolescents in the era of continuous emergence of variants/subvariants.
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It is challenging to treat ventriculitis with parenteral treatment alone in some cases because of the difficulty involved in maintaining an appropriate level of antibiotics in cerebrospinal fluid (CSF). We report two cases of ventriculitis who did not respond to intravenous (IV) antibiotics but were successfully treated with intraventricular antibiotics using IV agents. The first case was a four-month-old male patient with X-linked hydrocephalus.He showed ventriculitis due to Klebsiella pneumoniae not producing extended-spectrum β-lactamase and susceptible to third-generation cephalosporins and gentamicin, following ventriculoperitoneal (VP) shunt. His condition did not improve during the 47 days of treatment with IV cefotaxime and meropenem. We achieved improvement in clinical presentation and CSF profile after three times of intraventricular gentamicin injection. The patient was discharged from the hospital with antiepileptic drugs. The second case was a six-month-old female patient with a history of neonatal meningitis complicated with hydrocephalus at one month of age, VP shunt at two months of age, followed by a methicillinresistant coagulase-negative staphylococci (CoNS) shunt infection with ventriculitis after the shunt operation. CoNS ventriculitis recurred four weeks later. We failed to treat intractable methicillin-resistant CoNS ventriculitis with IV vancomycin for ten days, and thus intraventricular antimicrobial treatment was considered. Five times of intraventricular vancomycin administration led to improvement in clinical parameters. There were only neurological sequelae of delayed language development but no other major complications. Patients in these two cases responded well to intraventricular antibiotics, with negative CSF culture results, and were successfully treated for ventriculitis without serious complications.
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Background@#To facilitate evidence-based policy-making on safe reopening of higher education facilities, there is an urgent need to assess baseline profile of coronavirus disease 2019 (COVID-19) incidents within the university/college settings. We aimed to describe the epidemiology of COVID-19 in universities/colleges in Seoul Metropolitan Area during COVID-19 pandemic period. @*Methods@#Among the 38 universities in Seoul, 23 have agreed to participate in the study.Confirmed COVID-19 cases were identified from individual-level case reports submitted to the universities and to the health authorities from February 1, 2020, to June 30, 2021.Through the linkage with the Central Disease Control Headquarters' database, number of secondary infected cases (both within and outside of the campus) were counted. @*Results@#Between February 2020 and June 2021, a total of 827 COVID-19 cases were confirmed and reported in the universities across Seoul Metropolitan City. Generally, the communityassociated cases had peaks preceding the university/college-associated. Of those with the documented clinical parameters, 38.6% of the cases were asymptomatic. Among them, 93% were potentially exposed off-campus, and 87.7% of the cases had not produced the secondary infection cases. @*Conclusion@#In the setting of rigorous infection prevention measures in combination with on- and off- hybrid classes, COVID-19 incidences and outbreaks were limited in university and college campus area across Seoul Metropolitan Area. The evidence around the infection preventive measures in higher education facilities in Seoul Metropolitan Area, suggest insignificant impact on community transmission.
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Purpose@#To determine the usefulness of measuring the tortuosity of retinal arteries using smartphone fundus photographs to quantify plus disease in retinopathy of prematurity (ROP) patients. @*Methods@#Digital fundus photographs were taken with a smartphone of 116 eyes involving 58 premature infants. The tortuosity of retinal arteries named as the tortuosity index (TI) was measured with Image J software. Patients were classified into the treated and control groups and the TIs of the two groups were compared. A receiver operating characteristic curve was constructed and areas under the curve (AUC) were calculated to quantify the diagnostic utility of TI. @*Results@#Fundus photographs of 98 eyes of 50 premature infants were analyzed; 38 eyes of 20 infants were the treated group and 60 eyes of 30 infants were the control group. The TI was 1.231 ± 0.156 in the treated group before treatment, which was significantly larger than 1.062 ± 0.019 in the control group. After treatment of the treated group, the TI was 1.100 ± 0.093, which was significantly smaller than before treatment. The AUC was 0.926, and using a cut-off value of 1.095, the sensitivity and specificity of TIs for requiring treatment were 85.1% and 95.5%, respectively. @*Conclusions@#The tortuosity of retinal arteries was measured by analyzing smartphone fundus photographs to quantify plus disease in ROP patients. This method may be helpful for screening, follow-up, and treatment decisions for ROP patients.
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Purpose@#To compare differences and changes in the parents’ awareness regarding influenza and influenza vaccination for their children according to educational intervention. @*Methods@#This study involved 1,034 parents with children aged 6–59 months, who lived in five areas in northern Seoul and Gyeonggi Province in 2015; the study was conducted using the questionnaire survey method. Survey items included awareness regarding influenza and influenza vaccination for children and future intentions of influenza vaccination and the underlying reasons. The participants were divided into 3 groups and differences according to education (group A: no education, group B: provided education) and the changes before and after education (group C) were analyzed. @*Results@#Differences according to education between groups A and B were seen in the recognition of high-risk of influenza in their children, effectiveness of influenza vaccination, and cost of the influenza vaccine. Changes before and after education in group C were seen in the recognition of high-risk of influenza in their children, safety of influenza vaccination, cost of the influenza vaccine, and negativity toward the influenza vaccine. @*Conclusions@#Educated parents were more aware regarding influenza and influenza vaccination for their children aged 6–59 months.
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Trans-placental neonatal human immunodeficiency virus (HIV) infection is common in Africa; however, it is not yet reported in the Republic of Korea. With the increasing incidence of HIV infection, especially in the reproductive age group, the risk of the vertical transmission of HIV is also increasing. We report the first case of HIV infection acquired in-utero in a newborn in Korea. The baby is growing well with normal development.
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Humans , Humans , Infant, Newborn , Africa , HIV Infections , HIV , Incidence , Korea , Republic of KoreaРеферат
PURPOSE: This study was conducted to compare immunogenicities and reactogenicities of the trivalent inactivated subunit influenza vaccine and split influenza vaccine in Korean children and adolescents.METHODS: In total, 202 healthy children aged 36 months to <18 years were enrolled at six hospitals in Korea from October to December 2008. The subjects were vaccinated with either the split or subunit influenza vaccine. The hemagglutinin inhibition antibody titers against the H1N1, H3N2, and B virus strains were measured, and the seroconversion rates, seroprotection rates, and geometric mean titers were calculated. All subjects were observed for local and systemic reactions.RESULTS: Both the split and subunit vaccine groups had similar seroprotection rates against all strains (95.9%, 94.9%, 96.9% vs. 96.0%, 90.9%, and 87.9%). In children aged 36 to <72 months, the seroprotection rates were similar between the two vaccine groups. In children aged 72 months to <18 years, both vaccines showed high seroprotection rates against the H1N1, H3N2, and B strain (98.4%, 98.4%, 98.4% vs. 97.0%, 95.5%, and 91.0%), but showed relatively low seroconversion rates (39.1%, 73.4%, 35.9% vs. 34.3%, 55.2%, and 38.8%). There were more local and systemic reactions in the split vaccine group than in the subunit vaccine group; however, no serious adverse reactions were observed in both groups.CONCLUSIONS: Both the split and subunit vaccines showed acceptable immunogenicity in all age groups. There were no serious adverse events with both vaccines.
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Adolescent , Child , Humans , Hemagglutinins , Herpesvirus 1, Cercopithecine , Influenza Vaccines , Influenza, Human , Korea , Seasons , Seroconversion , Vaccines , Vaccines, SubunitРеферат
The Committee on Infectious Diseases of the Korean Pediatric Society recommended immunization schedule for children and adolescents aged 18 years or younger in the 9th (2018) edition of Immunization guideline. This report provides the revised recommendations made by the committee and summarizes several changes from the 2015 guideline. National immunization program (NIP) launched a human papillomavirus (HPV) immunization for girls aged 12 years in 2016. NIP has also expanded age indication for inactivated influenza vaccine (IIV) to 12 years of age in the 2018-2019 season. Quadrivalent IIVs with a full dose (0.5 mL) are approved for all children of 6 months or older. Recommendations of live attenuated influenza vaccine were removed. For inactivated Japanese encephalitis vaccine, first 2 doses are considered as the primary series. Recommendations for use of newly introduced vaccines (diphtheria-tetanus-acellular pertussis/inactivated poliovirus/Haemophilus influenzae type b, 9-valent HPV, new varicella vaccine, new quadrivalent IIV, and attenuated oral typhoid vaccine) were added. Lastly, monitoring system for adverse events following immunization was updated. Other changes can be found in the 9th edition of Immunization guideline in detail.
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Adolescent , Child , Female , Humans , Infant , Chickenpox Vaccine , Communicable Diseases , Encephalitis, Japanese , Immunization Programs , Immunization Schedule , Immunization , Influenza Vaccines , Influenza, Human , Korea , Seasons , Typhoid Fever , VaccinesРеферат
PURPOSE: Results from a post-marketing study to generate evidence on 1-year antibody persistence and safety following vaccination of infants from South Korea with the quadrivalent meningococcal conjugate vaccine MenACWY-CRM. MATERIALS AND METHODS: In this phase IV, open-label, multi-center study (NCT02446691), 128 infants received MenACWY-CRM at ages 2, 4, 6, and 12 months. One-year antibody persistence following the full vaccination course was evaluated (primary objective) for the four meningococcal serogroups (Men) by serum bactericidal activity assay using human or rabbit complement (hSBA/rSBA). Immune responses at 1-month post-vaccination and safety were also assessed. RESULTS: The percentage of children with hSBA titers ≥8 ranged between 94% (MenA) and 100% (MenY/W) 1-month post-vaccination, and from 39% (MenA) to 89% (MenY) 1-year post-vaccination. At least 99% and 92% of children had rSBA titers ≥8 and ≥128 against each meningococcal serogroup, 1-month post-vaccination. One-year post-vaccination, the percentage of children with rSBA titers ≥8 and ≥128 ranged from 54% (MenC) to 99% (MenA) and from 30% (MenC) to 98% (MenA). Geometric mean titers declined from 1-month to 1-year post-vaccination, when they varied between 6.8 (MenA) and 53.6 (MenW) by hSBA and between 17.2 (MenC) and 2,269.5 (MenA) by rSBA. At least one solicited and unsolicited adverse event was reported for 79% and 66% of children. Of 36 serious adverse events reported, none were vaccination-related. CONCLUSION: Antibody persistence (hSBA/rSBA titers ≥8) was determined in 39%–99% of children 1 year after a 4-dose MenACWY-CRM series during infancy, with an acceptable clinical safety profile.
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Child , Humans , Infant , Appointments and Schedules , Complement System Proteins , Korea , Republic of Korea , Serogroup , VaccinationРеферат
The authors regret that one co-author (Kyung-Hyo Kim) was missing in the article.
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BACKGROUND: The titer of influenza vaccine-induced antibodies declines over time, and younger children have lower immunogenicity and shorter duration of immunity. This study aimed to compare persistence of antibody at 6 months after influenza vaccination according to influenza virus strains, vaccine type, antigen dose, and primed status in children aged 6 to 35 months. METHODS: A total 124 healthy children aged 6 to 35 months were enrolled from September to December 2016 at 10 hospitals in Korea and randomly assigned to either a full dose of quadrivalent influenza vaccine or a half dose of trivalent influenza vaccine with Victoria B strain group. Hemagglutination inhibition antibody titers (that measure the seroprotection rates) were assessed for the recommended influenza strains at 6 months post vaccination. RESULTS: The seroprotection rates at 6 months for strains A (H1N1), A (H3N2), B/Yamagata, and B/Victoria were 88.7%, 97.4%, 36.6%, and 27.6%, respectively. The seroprotection rates for A (H1N1), A (H3N2) and B (Victoria) were 91.4%, 98.7% and 27.5% in a full dose of quadrivalent vaccine vs. 83.7%, 94.6% and 27.9% in a half dose trivalent vaccine, respectively. The seroprotection rate for the B (Yamagata) strain was 23.8% in the quadrivalent group and 14.0% in the trivalent group. CONCLUSION: Persistence of antibodies at 6 months was more favorable against the influenza A strains than against the B strains. Persistence of antibodies to additional B strain at 6 months was superior in the quadrivalent vaccine group. The immunity of primed children with different B strains was not superior to that of the unprimed group with another B strain.
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Child , Humans , Antibodies , Hemagglutination , Influenza Vaccines , Influenza, Human , Korea , Orthomyxoviridae , Vaccination , VictoriaРеферат
PURPOSE: This study aimed to evaluate the immunogenicity and safety of a trivalent inactivated influenza vaccine (TIV) among healthy Korean children and adolescents. METHODS: From October to December 2008, 65 healthy patients aged 6 months to 18 years who visited Korea University Ansan Hospital for influenza vaccination were enrolled in this study. We measured the hemagglutinin inhibition antibody titers at baseline and 30 days after vaccinating enrollees with split influenza vaccine and calculated the seroprotection rates, geometric mean titers, and seroconversion rates. Local and systemic adverse events were assessed after vaccination. RESULTS: The seroprotection rates against all three viral strains (A/H1N1, A/H3N2, B) were 87.7%, 89.2%, and 89.2% (≥70%), respectively; seroconversion rates were 44.6%, 73.8%, and 63.1% (≥40%), respectively; and seroconversion factors were 4.5, 8.4, and 10.5 (>2.5), respectively. The TIV immunogenicity was acceptable according to the CPMP (Committee for Proprietary Medicinal Products) criteria. Although 48 patients (73.8%) reported one or more adverse events, no severe adverse events such as anaphylaxis and convulsion were observed. Forty-two patients (64.6%) reported a local skin reaction, including redness (29.2%), pain (43.1%), or swelling (41.5%) of the injected site, and 26 (40.0%) reported a systemic reaction: fatigue (23.1%), myalgia (20.0%), headache (10.8%), arthralgia (10.8%), chills (9.2%), or fever (7.7%). CONCLUSIONS: This study shows that the immunogenicity of the TIV vaccine is acceptable. As there were no serious adverse events aside from local reactions and mild systemic reactions, this vaccine can be safely used among healthy Korean children and adolescents.
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Adolescent , Child , Humans , Anaphylaxis , Arthralgia , Chills , Fatigue , Fever , Headache , Hemagglutinins , Influenza Vaccines , Influenza, Human , Korea , Myalgia , Seizures , Seroconversion , Skin , VaccinationРеферат
The pathological features of Alzheimer's disease are senile plaques which are aggregates of β-amyloid peptides and neurofibrillary tangles in the brain. Neurofibrillary tangles are aggregates of hyperphosphorylated tau proteins, and these induce various other neurodegenerative diseases, such as progressive supranuclear palsy, corticobasal degeneration, frontotemporal lobar degeneration, frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), and chronic traumatic encephalopathy. In the case of Alzheimer's disease, the measurement of neurofibrillary tangles associated with cognitive decline is suitable for differential diagnosis, disease progression assessment, and to monitor the effects of therapeutic treatment. This review discusses considerations for the development of tau ligands for imaging and summarizes the results of the first-in-human and preclinical studies of the tau tracers that have been developed thus far. The development of tau ligands for imaging studies will be helpful for differential diagnosis and for the development of therapeutic treatments for tauopathies including Alzheimer's disease.
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The pathological features of Alzheimer's disease are senile plaques which are aggregates of β-amyloid peptides and neurofibrillary tangles in the brain. Neurofibrillary tangles are aggregates of hyperphosphorylated tau proteins, and these induce various other neurodegenerative diseases, such as progressive supranuclear palsy, corticobasal degeneration, frontotemporal lobar degeneration, frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), and chronic traumatic encephalopathy. In the case of Alzheimer's disease, the measurement of neurofibrillary tangles associated with cognitive decline is suitable for differential diagnosis, disease progression assessment, and to monitor the effects of therapeutic treatment. This review discusses considerations for the development of tau ligands for imaging and summarizes the results of the first-in-human and preclinical studies of the tau tracers that have been developed thus far. The development of tau ligands for imaging studies will be helpful for differential diagnosis and for the development of therapeutic treatments for tauopathies including Alzheimer's disease.
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Alzheimer Disease , Brain , Brain Injury, Chronic , Chromosomes, Human, Pair 17 , Diagnosis, Differential , Disease Progression , Frontotemporal Dementia , Frontotemporal Lobar Degeneration , Ligands , Neurodegenerative Diseases , Neurofibrillary Tangles , Parkinsonian Disorders , Peptides , Plaque, Amyloid , Supranuclear Palsy, Progressive , tau Proteins , TauopathiesРеферат
BACKGROUND: Invasive bacterial infections in apparently immunocompetent children were retrospectively analyzed to figure causative bacterial organisms in Korea. METHODS: A total of 947 cases from 25 university hospitals were identified from 2006 to 2010 as a continuance of a previous 10-year period study from 1996 to 2005. RESULTS: Escherichia coli (41.3%), Streptococcus agalactiae (27.7%), and Staphylococcus aureus (27.1%) were the most common pathogens in infants < 3 months of age. S. agalactiae was the most prevalent cause of meningitis and pneumonia and E. coli was the major cause of bacteremia without localizing signs in this group. In children 3 to 59 months of age, Streptococcus pneumoniae (54.2%), S. aureus (20.5%), and Salmonella spp. (14.4%) were the most common pathogens. S. pneumoniae was the leading cause of pneumonia (86.0%), meningitis (65.0%), and bacteremia without localizing signs (49.0%) in this group. In children ≥ 5 years of age, S. aureus (62.8%) was the predominant pathogen, followed by Salmonella species (12.4%) and S. pneumoniae (11.5%). Salmonella species (43.0%) was the most common cause of bacteremia without localizing signs in this group. The relative proportion of S. aureus increased significantly over the 15-year period (1996–2010) in children ≥ 3 months of age (P < 0.001), while that of Haemophilus influenzae decreased significantly in both < 3 months of age group (P = 0.036) and ≥ 3 months of age groups (P < 0.001). CONCLUSION: S. agalactiae, E. coli, S. pneumoniae, and S. aureus are common etiologic agents of invasive bacterial infections in Korean children.