• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.393-399
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• 2023

Objective : Chiari II malformation (CM II) is still the main cause of severe morbidity and mortality in children with open neural tube defects (ONTDs). The goal of this study was to validate a CM II model in late-stage chick embryos with surgically induced ONTDs. Methods : To make the chick embryo model of ONTD, their neural tubes were opened for a length of 5-6 somites at the thoracic level in Hamburger and Hamilton stage 18 chick embryos (n=150). They were reincubated in ovo up to a total age of 17-21 days. A total of 19 embryos survived and were assigned to either the postoperative day (POD) 14-15 group (n=6) or the POD 17-18 group (n=13). Magnetic resonance imaging (MRI) and histopathologic findings of embryo heads with spinal ONTDs were compared with age-matched normal chick embryos. Results : The chick embryos with ONTDs demonstrated definite and constant structural changes, such as downward displacement of the cerebellum to just above the foramen magnum and narrow and small cerebrospinal fluid spaces in the crowded small posterior fossa. These morphologic features were more prominent in the POD 17-18 group than in the POD 14-15 group. Conclusion : This is the first description of CM II with spinal ONTD in a late-stage chick embryo model with MRI and histopathological analysis. The morphological changes of the posterior fossa in this study mimic those of CM II associated with spinal ONTD in humans. This model will facilitate investigation of the pathogenesis of CM II.

• Mycobiology
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• v.51 no.6
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• pp.452-462
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• 2023

Opportunistic infections due to Cryptococcus neoformans and C. gattii species complexes continue to rise unabated among HIV/AIDS patients, despite improved antifungal therapies. Here, we collected a total of 20 environmental and 25 presumptive clinical cryptococcal isolates from cerebrospinal fluid (CSF) samples of 175 patients enrolled in an ongoing clinical trial Ambition 1 Project (Botswana-Harvard Partnership). Identity confirmation of the isolates was done using MALDI-TOF MS and PCR. We describe the diversity of the isolates by PCR fingerprinting and sequencing (Oxford Nanopore Technology) of the intergenic spacer region. Mating types of the isolates were determined by amplification of the MAT locus. We report an unusual prevalence of 42.1% of C. neoformans × C. deneoformans hybrids Serotype AD (n = 16), followed by 39.5% of C. neoformans Serotype A (n = 15), 5.3% of C. deneoformans, Serotype D (n = 2), 7.9% of C. gattii (n = 3), and 5.3% of C. tetragattii (n = 2) in 38 representative isolates that have been characterized. Mating type-specific PCR performed on 38 representative environmental and clinical isolates revealed that 16 (42.1%) were MATa/MAT𝛼 hybrids, 17 (44.7%) were MAT𝛼, and five (13.2%) possessed MATa mating type. We used conventional and NGS platforms to demonstrate a potential link between environmental and clinical isolates and lay a foundation to further describe mating patterns/history in Botswana.

• IMMUNE NETWORK
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• v.24 no.2
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• pp.18.1-18.12
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• 2024

Acute necrotizing encephalopathy (ANE) is a rare but deadly complication with an unclear pathogenesis. We aimed to elucidate the immune characteristics of H1N1 influenza virus-associated ANE (IANE) and provide a potential therapeutic approach for IANE. Seven pediatric cases from a concentrated outbreak of H1N1 influenza were included in this study. The patients' CD4⁺ T cells from peripheral blood decreased sharply in number but highly expressed Eomesodermin (Eomes), CD69 and PD-1, companied with extremely high levels of IL-6, IL-8 in the cerebrospinal fluid and plasma. Patient 2, who showed high fever and seizures and was admitted to the hospital very early in the disease course, received intravenous tocilizumab and subsequently showed a reduction in temperature and a stable conscious state 24 h later. In conclusion, a proinflammatory cytokine storm associated with activated CD4⁺ T cells may cause severe brain pathology in IANE. Tocilizumab may be helpful in treating IANE.

• Journal of Korean Neurosurgical Society
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• v.67 no.4
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• pp.467-476
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• 2024

Objective : To evaluate the usefulness of a cranial implantable chemoport, the H-port, as an alternative to the Ommaya reservoir for intraventricular chemotherapy/cerebrospinal fluid (CSF) access in patients with leptomeningeal metastasis (LM). Methods : One hundred fifty-two consecutive patients with a diagnosis of LM and who underwent H-port installation between 2015 and 2021 were evaluated. Adverse events associated with installation and intraventricular chemotherapy, and the rate of increased intracranial pressure (ICP) control via the port were evaluated for safety and efficacy. These indices were compared with published data of Ommaya (n=89), from our institution. Results : Time-to-install and installation-related complications of intracranial hemorrhage (n=2) and catheter malposition (n=5) were not significantly different between the two groups. Intraventricular chemotherapy-related complications of CSF leakage occurred more frequently in the Ommaya than in the H-port group (13/89 vs. 3/152, respectively, p<0.001). Intracranial hemorrhage during chemotherapy occurred only in the Ommaya group (n=4). The CSF infection rate was not statistically different between groups (14/152 vs. 12/89, respectively). The ICP control rate according to reservoir type revealed a significantly higher ICP control rate with the H-port (40/67), compared with the Ommaya result (12/58, p<0.001). Analyzing the ICP control rate based on the CSF drainage method, continuous extraventricular drainage (implemented only with the H-port), found a significantly higher ICP control rate than with intermittent CSF drainage (33/40 vs. 6/56, respectively, p<0.0001). Conclusion : The H-port for intraventricular chemotherapy in patients with LM was superior for ICP control; it had equal or lower complication rates than the Ommaya reservoir.

• The Journal of Internal Korean Medicine
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• v.44 no.6
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• pp.1279-1293
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• 2023

A 67-year-old female patient diagnosed with acute transverse myelitis visited our hospital in February 2023. Consultation papers indicated that she was diagnosed with acute transverse myelitis and that she complained of quadriparesis and numbness in both hands and feet. However, her spine magnetic resonance imaging (MRI) did not clearly indicate that she suffered from acute transverse myelitis. She was then sent to a high-level hospital and diagnosed with Guillain-Barre Syndrome through electromyography, cerebrospinal fluid test, and spine MRI. On March 2023, she visited our hospital again, still complaining about weakness in both hands and inability to walk. She was treated with Korean medicine, including acupuncture, electroacupuncture, pharmacopuncture, and herbal medicine such as Yanggyeoksanhwatang and Sipimijihwang-tanggami. After three months, she was discharged on cane walking. The manual muscle test (MMT) grade of her upper limbs increased from 3-/3-/3-/3- (shoulder/elbow/wrist/fingers) to 4/4/4/3+, and the MMT grade of her lower limbs increased from 2/2/2/2 (pelvis/knee/ankle/feet) to 4/4/4-/4-. Her numbness in both feet disappeared, and her numbness in both hands decreased from a numeric rating scale of 7 to 2. No adverse events were reported during treatment. This case implies the therapeutic potential of Korean medicine for Guillain-Barre Syndrome, especially for those who had delayed diagnosis and missed the opportunity to get plasma exchange.

• Molecules and Cells
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• v.46 no.12
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• pp.746-756
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• 2023

A recent study revealed that the loss of Deup1 expression does not affect either centriole amplification or multicilia formation. Therefore, the deuterosome per se is not a platform for amplification of centrioles. In this study, we examine whether gain-of-function of Deup1 affects the development of multiciliated ependymal cells. Our time-lapse study reveals that deuterosomes with an average diameter of 300 nm have two different fates during ependymal differentiation. In the first instance, deuterosomes are scattered and gradually disappear as cells become multiciliated. In the second instance, deuterosomes self-organize into a larger aggregate, called a deuterosome cluster (DC). Unlike scattered deuterosomes, DCs possess centriole components primarily within their large structure. A characteristic of DC-containing cells is that they tend to become primary ciliated rather than multiciliated. Our in utero electroporation study shows that DCs in ependymal tissue are mostly observed at early postnatal stages, but are scarce at late postnatal stages, suggesting the presence of DC antagonists within the differentiating cells. Importantly, from our bead flow assay, ectopic expression of Deup1 significantly impairs cerebrospinal fluid flow. Furthermore, we show that expression of mouse Deup1 in Xenopus embryos has an inhibitory effect on differentiation of multiciliated cells in the epidermis. Taken together, we conclude that the DC formation of Deup1 in multiciliated cells inhibits production of multiple centrioles.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.5
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• pp.413-422
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• 2024

Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg²⁺ concentration ([Mg²⁺]_o)-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg²⁺-free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg²⁺]_o-induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity. U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca²⁺-ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP₃ receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not. MPEP significantly decreased low [Mg²⁺]_o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg²⁺]_o-induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca²⁺ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1592-1598
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• 2024

Genotype V (GV) Japanese encephalitis virus (JEV) has been predominantly reported in the Republic of Korea (ROK) since 2010. GV JEV exhibits higher virulence and distinct antigenicity compared to other genotypes, which results in reduced efficacy of existing vaccines. Research on GV JEV is essential to minimize its clinical impact, but the only available clinical strain in the ROK is K15P38, isolated from the cerebrospinal fluid of a patient in 2015. We obtained this virus from National Culture Collection for Pathogens (NCCP) and isolated a variant forming small plaques during our research. We identified that this variant has one amino acid substitution each in the PrM and NS5 proteins compared to the reported K15P38. Additionally, we confirmed that this virus exhibits delayed propagation in vitro and an attenuated phenotype in mice. The isolation of this variant is a critical reference for researchers intending to study K15P38 obtained from NCCP, and the mutations in the small plaque-forming virus are expected to be useful for studying the pathology of GV JEV.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.48-54
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• 2005

Purpose : The pathologic mechanisms of central nervous system(CNS) injuries in human meningitis are not yet completely understood. Recent studies indicate that the host inflammatory responses are as important in brain damage as the infecting organisms and toxins. There have been some reports on the relationship of nitric oxide(NO), macrophage inflammatory protein-$1{\alpha}$(MIP-$1{\alpha}$), and lactoferrin in bacterial meningitis, but few reports in aseptic meningitis. Thus, we investigated the concentrations of NO, MIP-$1{\alpha}$ and lactoferrin in cerebrospinal fluid(CSF) and serum of patients with aseptic meningitis and control subjects and evaluated their relationship with other parameters of meningitis. Methods : CSF and blood were obtained from 25 subjects with aseptic meningitis and 15 control subjects. After centrifugation, supernatants were stored at $-70^{\circ}C$ and we assayed the concentrations of NO, MIP-$1{\alpha}$ and lactoferrin with the ELISA method. There were no patients with neurologic sequelae after being recovered from aseptic meningitis. Results : Concentrations of CSF and serum NO, MIP-$1{\alpha}$ were not increased in aseptic meningitis subjects compared to control subjects. Concentration of CSF lactoferrin was significantly elevated in patients with aseptic meningitis and concentration of serum lactoferrin was significantly decreased in patients with aseptic meningitis compared with those in control subjects(P<0.05). CSF lactoferrin level was positively correlated with CSF WBC counts($r_s=0.449$, P=0.007), especially with neutrophil counts($r_s=0.574$, P<0.001) and CSF protein level($r_s=0.508$, P=0.002). Conclusion : Lactoferrin plays an important role in aseptic meningitis and may be released from neutrophils recruited from blood to the CSF through breakdown of blood-brain barrier. NO and MIP-$1{\alpha}$ may not be important factors in the pathogenesis of aseptic meningitis without neurologic sequelae.

• Clinical and Experimental Pediatrics
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• v.46 no.6
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• pp.548-553
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• 2003

Purpose : Matrix metalloproteinase(MMP)-9 is known to breakdown the blood-brain barrier by degrading the extracellular matrix of the subendothelial basement membrane in meningitis. Tissue inhibitor of metalloproteinase(TIMP)-1, a known inhibitor of MMP-9, has been postulated to inhibit the proteolytic activity of MMP-9 by bindng to MMP-9, but their interaction has not been fully understood yet. So far, there have been some reports on the relationship of MMP-9 and TIMP-1 in bacterial meningitis, but few reports in viral meningitis. Furthermore, there has been no report on this in Korea. We investigated the concentrations of MMP-9 and TIMP-1 in cerebrospinal fluid (CSF) and serum of patients with viral meningitis and control subjects, and evaluated their relationship with other clinical parameters of meningitis. Methods : CSF and blood were obtained from 25 subjects with viral meningitis and 14 control subjects. After centrifugation, supernatants were stored at $-20^{\circ}C$ and we assayed concentrations of MMP-9 and TIMP-1 by the sandwich ELISA method. Results : Concentrations of CSF MMP-9 and TIMP-1 were significantly elevated in patients with viral meningitis, when compared with those in control subjects. Their serum levels showed no differences between the two groups. MMP-9 levels were closely correlated with TIMP-1 levels in the CSF($r_s=0.42$, P<0.05). CSF MMP-9/TIMP-1 ratios were significantly higher in patients with viral meningitis than those in the control subjects(P<0.05). Both CSF MMP-9 and TIMP-1 levels positively correlated with CSF total leukocyte counts($r_s=0.43$, P<0.05, $r_s=0.48$, P<0.05). TIMP-1 levels positively correlated with total protein concentrations in the CSF($r_s=0.43$, P<0.05). Conclusion : MMP-9 and TIMP-1 may play an important role in the breakdown and maintenance of BBB in viral meningitis, respectively.