Simultaneous Cellular Imaging, Electrical Recording and Stimulation of Hippocampal Activity in Freely Behaving Mice

Hippocampal sharp-wave ripple activity (SWRs) and the associated replay of neural activity patterns are well-known for their role in memory consolidation. This activity has been studied using electrophysiological approaches, as high temporal resolution is required to recognize SWRs in the neuronal signals. However, it has been difficult to analyze the individual contribution of neurons to task-specific SWRs, because it is hard to track neurons across a long time with electrophysiological recording. In this study, we recorded local field potential (LFP) signals in the hippocampal CA1 of freely behaving mice and simultaneously imaged calcium signals in contralateral CA1 to leverage the advantages of both electrophysiological and imaging approaches. We manufactured a custom-designed microdrive array and targeted tetrodes to the left hippocampus CA1 for LFP recording and applied electrical stimulation in the ventral hippocampal commissure (VHC) for closed-loop disruption of SWRs. Neuronal population imaging in the right hippocampal CA1 was performed using a miniature fluorescent microscope (Miniscope) and a genetically encoded calcium indicator. As SWRs show highly synchronized bilateral occurrence, calcium signals of SWR-participating neurons could be identified and tracked in spontaneous or SWR-disrupted conditions. Using this approach, we identified a subpopulation of CA1 neurons showing synchronous calcium elevation to SWRs. Our results showed that SWR-related calcium transients are more disrupted by electrical stimulation than non-SWRrelated calcium transients, validating the capability of the system to detect and disrupt SWRs. Our dual recording method can be used to uncover the dynamic participation of individual neurons in SWRs and replay over extended time windows.

Survey on the Status of Breastfeeding in Korean Medical Institution Workers

Background@#Human breast milk is essential and provides irreplaceable nutrients for early humans. However, breastfeeding is not easy for various reasons in medical institution environments. Therefore, in order to improve the breastfeeding environment, we investigated the difficult reality of breastfeeding through questionnaire responses from medical institution workers. @*Methods@#A survey was conducted among 179 medical institution workers with experience in childbirth within the last five years. The survey results of 175 people were analyzed, with incoherent answers excluded. @*Results@#Of the 175 people surveyed, a total of 108 people (61.7%) worked during the day, and 33 people (18.9%) worked in three shifts. Among 133 mothers who stayed with their babies in the same nursing room, 111 (93.3%) kept breastfeeding for more than a month, but among those who stayed apart, only 10 (71.4%) continued breastfeeding for more than a month (P = 0.024). Ninety-five (88.0%) of daytime workers, 32 (94.1%) two-shift workers, and 33 (100%) three-shift workers continued breastfeeding for more than a month (P = 0.026). Workers in general hospitals tended to breastfeed for significantly longer than those that worked in tertiary hospitals (P = 0.003). A difference was also noted between occupation categories (P = 0.019), but a more significant difference was found in the comparison between nurses and doctors (P = 0.012). Longer breastfeeding periods were noted when mothers worked three shifts (P = 0.037). Depending on the period planned for breastfeeding prior to childbirth, the actual breastfeeding maintenance period after birth showed a significant difference (P = 0.002). Of 112 mothers who responded to the question regarding difficulties in breastfeeding after returning to work, 87 (77.7%) mentioned a lack of time caused by being busy at work, 82 (73.2%) mentioned the need for places and appropriate circumstances. @*Conclusion@#In medical institutions, it is recommended that environmental improvements in medical institutions, the implementation of supporting policies, and the provision of specialized education on breastfeeding are necessary to promote breastfeeding.

Apixaban versus Warfarin in Patients with Chronic Kidney Disease; A Systematic Review and Meta-analysis

Background@#Patients with chronic kidney disease (CKD) are at a high risk of stroke-related morbidity, mortality, and bleeding. However, the overall risk/benefit of anticoagulant therapy among patients with CKD remains unclear. @*Methods@#The MEDLINE, EMBASE, and CENTRAL databases were comprehensively searched until July 31, 2020, to investigate the safety and efficacy of apixaban in patients with stage 4 or 5 CKD, as compared with warfarin. The primary outcome was an incidence of major bleeding. Secondary outcomes included composite bleeding (major, clinically relevant, and minor bleeding), venous thromboembolism (VTE), stroke, and death. @*Results@#In total, seven studies consisting of 10,816 patients were included. Compared with warfarin, apixaban was associated with a reduced risk of major bleeding (OR 0.49, 95% CI 0.41-0.58). In terms of composite bleeding, apixaban tended to pose a significantly lower risk than warfarin (OR 0.51, 95% CI 0.37-0.71). There was no difference between apixaban and warfarin with respect to the risk of stroke or death (stroke: OR 1.23, 95% CI 0.49-3.12; death: OR 0.73, 95% CI 0.45-1.18). @*Conclusion@#Among patients with stage 4 or 5 CKD, the use of apixaban was associated with a lower risk of bleeding compared to warfarin and was also found to pose no excess risk of thromboembolic events.

Apixaban versus Warfarin in Patients with Chronic Kidney Disease; A Systematic Review and Meta-analysis

Background@#Patients with chronic kidney disease (CKD) are at a high risk of stroke-related morbidity, mortality, and bleeding. However, the overall risk/benefit of anticoagulant therapy among patients with CKD remains unclear. @*Methods@#The MEDLINE, EMBASE, and CENTRAL databases were comprehensively searched until July 31, 2020, to investigate the safety and efficacy of apixaban in patients with stage 4 or 5 CKD, as compared with warfarin. The primary outcome was an incidence of major bleeding. Secondary outcomes included composite bleeding (major, clinically relevant, and minor bleeding), venous thromboembolism (VTE), stroke, and death. @*Results@#In total, seven studies consisting of 10,816 patients were included. Compared with warfarin, apixaban was associated with a reduced risk of major bleeding (OR 0.49, 95% CI 0.41-0.58). In terms of composite bleeding, apixaban tended to pose a significantly lower risk than warfarin (OR 0.51, 95% CI 0.37-0.71). There was no difference between apixaban and warfarin with respect to the risk of stroke or death (stroke: OR 1.23, 95% CI 0.49-3.12; death: OR 0.73, 95% CI 0.45-1.18). @*Conclusion@#Among patients with stage 4 or 5 CKD, the use of apixaban was associated with a lower risk of bleeding compared to warfarin and was also found to pose no excess risk of thromboembolic events.

Comparison of Maternal and Child Health Statistics between South and North Korea

Purpose@#This study aimed to investigate the extent of the difference in health status between South Korea (SK) and North Korea (NK) by comparing indicators relevant to maternal and child health. @*Methods@#The maternal and child health status of SK and NK considering population, birth, and mortality was reviewed using 2 Korean statistics, United Nations Children’s Fund, and United Nations databases from 1950 to 2017. @*Results@#The annual number of total live births in SK had decreased from 1,006,600 in 1970 to 326,900 in 2018, and that in NK had declined from 530,000 in 1970 to 360,000 in 2015. The percentage of children among the total population was higher in NK than in SK, and the decrease in the percentage of children in SK is remarkable, which is related to a low fertility rate in the last few decades. However, the mortality rates related to children were higher in NK than in SK. In 2017, neonatal mortality rates (per 1,000 live births) in SK and NK were 1.5 and 9.0, respectively. The fertile female population of SK and NK in 2015 was 50.2% and 52.0%, respectively, and SK and NK’s aging index (%) in 2017 was 107.3 and 46.1, re spectively. @*Conclusion@#This study shows the different population distributions and maternal and child health statuses between SK and NK, which may have a negative impact on social integration after reunification. Therefore, it is important to understand the indicators of maternal and child health to become the powerbase of effi cient healthcare system integration by minimizing the impact at the beginning of the reunification.

Morbidity and Mortality of Very Low Birth Weight Infants with Congenital Heart Disease

Background and Objectives@#This study aimed to provide morbidity and mortality information on very low birth weight (VLBW) infants with congenital heart disease (CHD-VLBWs). @*Methods@#The study used a 10-year cohort of VLBW infants from a single institution. CHD was classified according to International Classification of Diseases, Version 9, Clinical Modification. Mortality and neonatal outcomes were assessed by comparing the CHD-VLBWs with gestational age- and birth weight-matched controls. @*Results@#The prevalence of CHD-VLBWs was 7.5% (79/1,050), mean gestational age was 31.1±3.2 weeks, and mean birth weight was 1,126.2±268.3 g; 50.6% of the infants were small for the gestational age. The CHD-VLBWs more commonly had bronchopulmonary dysplasia (BPD), and the longer they were exposed to oxygen, the more frequently they developed BPD. Those with cyanotic heart disease developed severe BPD more frequently. Necrotizing enterocolitis (NEC) occurred frequently in the CHD-VLBWs and was not associated with their feeding patterns. CHD-VLBWs had a higher mortality rate; prematurity-related diseases were the leading cause of death before surgery, while heart-related problems were the leading cause of death after surgery. We found no significant difference in mortality from prematurity-related disease between the CHD-VLBWs and controls. In the subgroup analysis of CHD, the cyanotic CHD group had a higher incidence of BPD and higher mortality rate than the acyanotic CHD group. @*Conclusions@#CHD-VLBWs showed higher BPD, NEC, and mortality rates than those without CHD. There was also a higher incidence of BPD and mortality in VLBW infants with cyanotic CHD than in those with acyanotic CHD.

Campomelic Dysplasia with Sex Reversal Harboring a Novel Frameshift Mutation

Campomelic dysplasia (CD) is a rare genetic disease characterized by skeletal dysplasia that also affects several other organ systems. CD is caused by a SOX9 mutation. We here report a case of CD with a 46, XY karyotype and female external genitalia. This child was born with a weight of 3.12 kg after 37 weeks of gestation. She exhibited a number of characteristic features including a small thoracic cage, bowing of both femurs, clubbed feet, hypoplastic scapula, 11 pairs of ribs, a bell-shaped narrow thorax, micrognathia, macroglossia, a cleft palate, a flattened nasal bridge, and low set ears. She experienced additional distress because of the presence of a tracheal ring and because she had tracheomalacia. CD was diagnosed through nucleotide sequence analysis. A frameshift mutation, c.235delC (p.Gln79Argfs*31), was identified in the SOX9 gene that has not previously been reported.

Campomelic Dysplasia with Sex Reversal Harboring a Novel Frameshift Mutation

Campomelic dysplasia (CD) is a rare genetic disease characterized by skeletal dysplasia that also affects several other organ systems. CD is caused by a SOX9 mutation. We here report a case of CD with a 46, XY karyotype and female external genitalia. This child was born with a weight of 3.12 kg after 37 weeks of gestation. She exhibited a number of characteristic features including a small thoracic cage, bowing of both femurs, clubbed feet, hypoplastic scapula, 11 pairs of ribs, a bell-shaped narrow thorax, micrognathia, macroglossia, a cleft palate, a flattened nasal bridge, and low set ears. She experienced additional distress because of the presence of a tracheal ring and because she had tracheomalacia. CD was diagnosed through nucleotide sequence analysis. A frameshift mutation, c.235delC (p.Gln79Argfs*31), was identified in the SOX9 gene that has not previously been reported.

History of Pulmonary Surfactant Replacement Therapy for Neonatal Respiratory Distress Syndrome in Korea

Neonatal respiratory distress syndrome (RDS) is a disease that is unique to newborn infants. It is caused by a deficiency of pulmonary surfactant (PS), which is usually ready to be activated around the perinatal period. Until RDS was more clearly understood, it was not known why premature infants died from respiratory failure, although pathology revealed hyaline membranes in the alveoli. Surprisingly, the era of PS replacement therapy began only relatively recently. The first clinical trial investigating neonatal RDS was conducted in 1980. Since then, newborn survival has improved dramatically, which has led to significant advances in the field of neonatology. The present comprehensive review addresses PS, from its discovery to the application of artificial PS in newborns with RDS. It also reviews the history of PS in Korea, including its introduction, various commercial products, present and past research, newborn registries, and health insurance issues. Finally, it describes the inception of the Korean Society of Neonatology and future directions of research and treatment.

Validity of the Korean Developmental Screening Test for very-low-birth-weight infants / 소아과

PURPOSE: The importance of the neurodevelopmental outcomes of very-low-birth-weight (VLBW) infants has been emphasized as their mortality rate has markedly improved. This study aimed to assess the validity of the Korean Developmental Screening Test (K-DST), a developmental screening tool approved by the Korean Society of Pediatrics, for the timely diagnosis of neurodevelopmental delay in VLBW infants. METHODS: Subjects included VLBW infants enrolled in the Korean Neonatal Network database between January 2012 and December 2014. The collected data were analyzed for sensitivity, specificity, positive predictive value, and negative predictive value (NPV) in the K-DST compared to those in the Bayley Scales of Infant Development-II for VLBW infants. RESULTS: A total of 173 patients were enrolled. Their mean gestational age and mean birth weight were 27.5±2.8 weeks and 980.5±272.1 g, respectively. The frequency of failed psychomotor developmental index (PDI) <85 was similar to that in at least one domain of K-DST <1 standard deviation. Failure in more than one K-DST domain compared with a mental developmental index (MDI) <85 showed a sensitivity and NPV of 73.2% and 75.0%, respectively. Failure in more than one K-DST domain compared with PDI <85 showed a sensitivity and NPV of 60.3% and 71.6%, respectively. Each K-DST domain had a stronger correlation with predicting a failing MDI <85 than a failing PDI <85 (P<0.05). CONCLUSION: K-DST could be a useful screening tool for predicting mental developmental delay in VLBW infants and referring them for neurodevelopmental assessments.

Chronic Placental Inflammation as a Risk Factor of Severe Retinopathy of Prematurity

BACKGROUND: Chronic placental inflammation (CPI) has been implicated in the pathogenesis of diseases in premature infants, whereas retinopathy of prematurity (ROP) is a major complication primarily affecting preterm and very low-birth-weight (VLBW) infants. This study aims to investigate the association between CPI and ROP in VLBW infants. METHODS: We performed a retrospective review of clinical records of VLBW infants born between 2013 and 2016. Placental pathology findings including CPI cases were analyzed using logistic regression to study infants’ morbidities and other clinical characteristics. RESULTS: A total of 402 infants with a mean (standard deviation) gestational age of 28.5 (2.8) weeks and birth weight of 1,027.2 (304.4) g were included. The incidence of ROP was 24.1%. CPI was found in 90 infants (22.4%), among which 28.9% (26 of 90) developed ROP, and 21.1% (19 of 90) underwent laser photocoagulation. Lower gestational age, lower birth weight, longer duration of oxygen supply, and presence of CPI were associated with the development of ROP. After adjustment for gestational age, birth weight, sex, duration of oxygen supply, and other overlapping placental pathology, CPI was associated with the odds for type 1 ROP that required laser photocoagulation (adjusted odds ratio, 2.739; 95% confidence interval, 1.112 to 6.749; p = .029). CONCLUSIONS: CPI was associated with severe ROP requiring treatment with laser photocoagulation in VLBW infants.

High Remission Rate of Chronic Immune Thrombocytopenia in Children: Result of 20-Year Follow-Up

PURPOSE: This study examined the outcomes of children with chronic immune thrombocytopenia (ITP). MATERIALS AND METHODS: We retrospectively analyzed the medical records of all patients diagnosed with ITP from January 1992 to December 2011 at our institution. RESULTS: A total of 128 patients (64%) satisfied the criteria for newly diagnosed ITP, 31 (15%) for persistent ITP, and 41 (21%) for chronic ITP. The median age at diagnosis was 4.5 years (range, 1 month to 18 years). The median platelet count at diagnosis was 32x109/L. A comparison of the initial treatment data from 2001 to 2011 with those from 1992 to 2000 showed that the number of bone marrow examinations decreased, whereas observation increased. Chronic ITP presented at an older age than newly diagnosed and persistent ITP (6.6 years vs. 3.8 years vs. 4.1 years, respectively); however, the difference did not reach statistical significance (p=0.17). The probability of complete remission of chronic ITP was 50% and 76% at 2 and 5 years after diagnosis, respectively. Patients aged <1 year at diagnosis had a significantly better prognosis than did older patients (hazard ratio, 3.86; p=0.02). CONCLUSION: Children with chronic ITP showed a high remission rate after long-term follow-up. This study suggests that invasive treatments such as splenectomy in children with chronic ITP can be delayed for 4 to 5 years if thrombocytopenia and therapeutic medication do not affect the quality of life.

The Use of Rituximab with Immune Tolerance Induction Therapy for Hemophilia A with Inhibitors / 임상소아혈액종양

Inhibitor development is one of the major adverse events associated with increased morbidity and mortality in patients with congenital hemophilia. Recent treatment for them is immune tolerance induction (ITI), which involves the administration of high doses of factor concentrates over a prolonged period, sometimes combined with immunosuppressive agents. We report a case of inhibitor elimination with Rituximab, and high-dose factor VIII concentrates in a 5-year-old boy with hemophilia A. The patient improved clinically, with fewer bleeding episodes. However, he continued to have low immunoglobulin levels, which led to recurrent infections. After an infusion of intravenous immunoglobulin, inhibitor titers increased rapidly and his ITI was deemed a failure. In conclusion, even though it failed in the present study, Rituximab may be an alternative adjuvant therapy to eliminate the inhibitor in patients with hemophilia. The appropriate schedule and long-term side effects need further investigation.

The Use of Rituximab with Immune Tolerance Induction Therapy for Hemophilia A with Inhibitors / 임상소아혈액종양

Inhibitor development is one of the major adverse events associated with increased morbidity and mortality in patients with congenital hemophilia. Recent treatment for them is immune tolerance induction (ITI), which involves the administration of high doses of factor concentrates over a prolonged period, sometimes combined with immunosuppressive agents. We report a case of inhibitor elimination with Rituximab, and high-dose factor VIII concentrates in a 5-year-old boy with hemophilia A. The patient improved clinically, with fewer bleeding episodes. However, he continued to have low immunoglobulin levels, which led to recurrent infections. After an infusion of intravenous immunoglobulin, inhibitor titers increased rapidly and his ITI was deemed a failure. In conclusion, even though it failed in the present study, Rituximab may be an alternative adjuvant therapy to eliminate the inhibitor in patients with hemophilia. The appropriate schedule and long-term side effects need further investigation.

Preclinical studies for pharmacokinetics and biodistribution of Ad-stTRAIL, an adenovirus delivering secretable trimeric TRAIL for gene therapy

Malignant glioma is the most frequent type in brain tumors. The prognosis of this tumor has not been significantly improved for the past decades and the average survival of patients is less than one year. Thus, an effective novel therapy is urgently needed. TNF-related apoptosis inducing ligand (TRAIL), known to have tumor cell-specific killing activity, has been investigated as a novel therapeutic for cancers. We have developed Ad-stTRAIL, an adenovirus delivering secretable trimeric TRAIL for gene therapy and demonstrated the potential to treat malignant gliomas. Currently, this Ad-stTRAIL gene therapy is under phase I clinical trial for malignant gliomas. Here, we report preclinical studies for Ad-stTRAIL carried out using rats. We delivered Ad-stTRAIL intracranially and determined its pharmacokinetics and biodistribution. Most Ad-stTRAIL remained in the delivered site and the relatively low number of viral genomes was detected in the opposite site of brain and cerebrospinal fluid. Similarly, only small portion of the viral particles injected was found in the blood plasma and major organs and tissues, probably due to the brain-blood barrier. Multiple administrations did not lead to accumulation of Ad-stTRAIL at the injection site and organs. Repeated delivery of Ad-stTRAIL did not show any serious side effects. Our data indicate that intracranially delivered Ad-stTRAIL is a safe approach, demonstrating the potential as a novel therapy for treating gliomas.

Preclinical studies for pharmacokinetics and biodistribution of Ad-stTRAIL, an adenovirus delivering secretable trimeric TRAIL for gene therapy

Malignant glioma is the most frequent type in brain tumors. The prognosis of this tumor has not been significantly improved for the past decades and the average survival of patients is less than one year. Thus, an effective novel therapy is urgently needed. TNF-related apoptosis inducing ligand (TRAIL), known to have tumor cell-specific killing activity, has been investigated as a novel therapeutic for cancers. We have developed Ad-stTRAIL, an adenovirus delivering secretable trimeric TRAIL for gene therapy and demonstrated the potential to treat malignant gliomas. Currently, this Ad-stTRAIL gene therapy is under phase I clinical trial for malignant gliomas. Here, we report preclinical studies for Ad-stTRAIL carried out using rats. We delivered Ad-stTRAIL intracranially and determined its pharmacokinetics and biodistribution. Most Ad-stTRAIL remained in the delivered site and the relatively low number of viral genomes was detected in the opposite site of brain and cerebrospinal fluid. Similarly, only small portion of the viral particles injected was found in the blood plasma and major organs and tissues, probably due to the brain-blood barrier. Multiple administrations did not lead to accumulation of Ad-stTRAIL at the injection site and organs. Repeated delivery of Ad-stTRAIL did not show any serious side effects. Our data indicate that intracranially delivered Ad-stTRAIL is a safe approach, demonstrating the potential as a novel therapy for treating gliomas.

Increased in vivo immunological potency of HB-110, a novel therapeutic HBV DNA vaccine, by electroporation

Pulse-induced permeabilization of cellular membranes, generally referred to as electroporation (EP), has been used for years as a tool to increase macromolecule uptake in tissues, including nucleic acids, for gene therapeutic applications, and this technique has been shown to result in improved immunogenicity. In this study, we assessed the utility of EP as a tool to improve the efficacy of HB-110, a novel therapeutic DNA vaccine against chronic hepatitis B, now in phase 1 of clinical study in South Korea. The potency of HB-110 in mice was shown to be improved by EP. The rapid onset of antigen expression and higher magnitude of humoral and cellular responses in electric pulse-treated mice revealed that EP may enable a substantial reduction in the dosage of DNA vaccine required to elicit a response similar in magnitude to that achievable via conventional administration. This study also showed that EP-based vaccination at 4-week-intervals elicited a cellular immune response which was about two-fold higher than the response elicited by conventional vaccination at 2-week intervals. These results may provide a rationale to reduce the clinical dose and increase the interval between the doses in the multidose vaccination schedule. Electric pulsing also elicited a more balanced immune response against four antigens expressed by HB-110: S, preS, Core, and Pol.

Cardiac expression profiles of the naked DNA vectors encoding vascular endothelial growth factor and basic fibroblast growth factor

We investigated expression profiles and biological effects of the naked DNA vectors in the heart. To this end, naked DNA vector was injected into the apex of the beating rat heart after thorocotomy. When the expression of LacZ reporter was examined by reverse transcription-PCR and histochemical staining for b-galactosidase, LacZ expression was detected only in the heart, suggesting limited dissemination of the injected vector in vivo. Even within the heart, LacZ expression was limited to the injection area (apex). Similar observations were made with other transgenes such as VEGF and basic fibroblast growth factor (bFGF), where 77% and 69% of the total transgene exprssion were detected in the heart segments containing the apex. Although VEGF and bFGF expressions were detected until 2 weeks after DNA injection, the highest levels of VEGF and bFGF were observed on day 5 and day 1, respectively. The optimal doses of the vectors were 10 mg and 25 mg for the VEGF and bFGF vectors, respectively. Interestingly, injection of bFGF vector led to 50% increase in the level of endogenous murine VEGF expression. Consistent with this finding, the number of vessels that stained positive for alpha-smooth muscle actin was increased in the bFGF vector-injected heart. These results suggest that simple injection of naked DNA vector may be sufficient to induce significant angiogenesis in the myocardium and that naked DNA gene therapy may be a feasible approach for the treatment of ischemic heart disease.

Overexpression and Purification of p24 and gp41 Proteins of Human Immunodeficiency Virus Type 1 in E. coli

Synthetic genes encoding the gag p24 and the part of the envelope protein gp41 of the human immunodeficiency virus (HIV-1) were cloned and overexpressed as fusion proteins in Escherichia coli, using an expression vector carrying 77 promoter and the poly-histidine leader sequence. The overexpressed p24 fusion protein was purified by centrifugation, Ni-affinity chromatography and CM-sepharose chromatography The overexpressed gp41 fusion protein was purified by centrifugation, C4 chromatography and DEAE-sepharose chromatography. The purified fusion proteins showed a high level of purity and immunoreactivity in SDS-polyacrylamide gel electrophoresis and western blot analysis. These results suggest that this prokaryotic expression-purification method is suitable for obtaining a large amount of the viral antigen which may be useful for screening of antibodies to HIV-1 in human blood samples.