• The Korean Journal of Physiology and Pharmacology
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• 제11권3호
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• pp.79-84
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• 2007

Because synaptic refinement of medial nucleus of trapezoid body (MNTB) - lateral superior olive (LSO) synapses is most active during the first postnatal week and the long term depression (LTD) has been suggested as one of its mechanisms, LTD of MNTB-LSO synapses was investigated in neonatal rat brain stem slices with the whole cell voltage clamp technique. In $Mg^{2+}$ free condition, tetanus (10 stimuli at 10 Hz for 2 min) in the current clamp mode induced a robust LTD of isolated D, L-APV-sensitive postsynaptic currents (PSCs) for more than 30 min ($n=6,\;2.4{\pm}0.4%$ of the control), while isolated CNQX-sensitive PSCs were not suppressed ($n=6,\;95.3{\pm}1.6%$). Tetanus also elicited similar LTD in the isolated GABAergic/glycinergic PSCs ($n=6,\;3.6{\pm}0.5%$) and mixed PSCs (GABAergic/glycinergic/glutamatergic) ($n=4,\;2.2{\pm}0.7%$). However, such a strong LTD was not observed in the mixed PSCs when 10 mM EGTA was added in the internal solution (n=10), indicating that postsynaptic $Ca^{2+}$ rise is needed for the strong LTD. This robust LTD might contribute to the active synaptic refinement occurring during the first postnatal week.

• 한국동물위생학회지
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• 제36권2호
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• pp.67-71
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• 2013

Neonatal infection caused by Cronobacter species can result in serious illnesses such as bacteremia, septicemia, meningitis, and death in at-risk infants who are orally fed contaminated reconstituted powdered infant formulas. The objective of this study was to compare the virulence among three Cronobacter species strains by using an animal model for human neonatal Cronobacter species infections. We acquired timed-pregnant ICR mice and all owed them to give birth naturally. On postnatal day 3, each pup was administered orally a total dose of $1{\times}10^7$ CFU Cronobacter species strain 3439, CDC 1123-79, and 3231. Mice were observed twice daily for morbidity and mortality. At postnatal day 10, the remaining pups were euthanized, and brain, liver, and cecum were excised and analyzed for the presence of Cronobacter species. Cronobacter species were isolated from cecum and other tissues in inoculated mice. In the tissues of Cronobacter species infected mice, meningitis and gliosis were detected in the brain. In this study, we identified the virulence among Cronobacter species strains by using a neonatal mice model which was a very effective animal model for human neonatal Cronobacter species infections.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Current Trends in Toxicological Sciences
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• pp.48-64
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• 2002

The primary recognized health risk from common deficiencies in glucose-6-phosphate dehydrogenase (G6PD), a cytoprotective enzyme for oxidative stress, is red blood cell hemolysis. Here we show that litters from untreated pregnant mutant mice with a hereditary G6PD deficiency had increased prenatal (fetal resorptions) and postnatal death. When treated with the anticonvulsant drug phenytoin, a human teratogen that is commonly used in pregnant women and causes embryonic oxidative stress, G6PD-deficient dams had higher embryonic DNA oxidation and more fetal death and birth defects. The reported G6PD gene mutation was confirmed and used to genotype fetal resorptions, which were primarily G6PD deficient. This is the first evidence that G6PD is a developmentally critical cytoprotective enzyme for both endogenous and xenobiotic-initiated embryopathic oxidative stress and DNA damage. G6PD deficiencies accordingly may have a broader biological relevance as important determinants of infertility, in utero and postnatal death, and teratogenesis.-Nicol, C. J., Zielenski, J., Tsui, L.-C., Wells, P. G. An embryoprotective role for glucose-6-phosphate dehydrogenase in developmental oxidative stress and chemical teratogenesis.

• Child Health Nursing Research
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• 제21권4호
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• pp.339-346
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• 2015

Purpose: This study was performed to explore the weight variations in high-risk term newborns hospitalized during the early postnatal period. Methods: A retrospective explorative study was performed with 64 term newborns who were hospitalized in the NICU after birth. Data on daily weight, birth information, and clinical features such as phototherapy, placements, nutritional status were reviewed through medical records for 14 days of life. General Linear Model, GLM was applied to analyze the weight variation by clinical features of these high-risk term newborns for 14 days of life. Results: Newborns at 40 weeks of gestation showed little weight loss during the few days after birth then steadily gained weight to 7.6% at the 14th day. Infants born at 37-39 gestation showed little weight gain for 14 days though the weight loss itself was not apparent. As well, return to birthweight was not observed in newborns with phototherapy, infants placed on a warmer or infants having gastrointestinal dysfunction for 14 days of life. Conclusion: Even for term newborns, physiologic weight loss may not be warranted even if newborn is born at less than 40 week of gestation, or with high-risk conditions that warrant admission to NICU.

• Child Health Nursing Research
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• 제24권3호
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• pp.345-352
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• 2018

Purpose: The study was conducted to measure stratum corneum hydration (SCH) and pH (SCP) in high-risk newborns in the early postnatal period and to explore the features related to patterns of change in those parameters. Methods: SCH and SCP were measured on the dorsal hand in 99 hospitalized newborns during the first 14 days of life and the results were analyzed using a general linear model. Results: The mean hydration was 42.9% on day 1, which decreased to 34.6% by 2 weeks (F=15.61, p=<.001). An association was observed between SCH and prematurity (F=21.12, p<.001), as well as for their interaction (F=8.11, p<.001). The mean SCP was $6.2{\pm}0.3$ on day 1, and decreased to $5.7{\pm}0.2$ (F=95.75, p<.001), with no association with prematurity. After adjusting for birth weight, SCH was higher in newborns with vaginal delivery (F=9.07, p=.023) and who received phototherapy (F=11.81, p=.011). For SCP, only delivery type had a significant influence (F=6.40, p=.044). Conclusion: This study suggests that SCH is typically in the 30% range during the early postnatal period, and that an acid mantle on the SC surface is very unlikely to form; these findings could be applied to the nursing process for promoting skin integrity in high-risk neonates.

• 한국발생생물학회지:발생과생식
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• 제24권3호
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• pp.167-176
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• 2020

The fat pad defined as the epididymal fat is located at the head part of the epididymis. However, another fat mass is present near the caudal epididymis, named tail epididymal fat. The present research was focused to determine the expression of adipocyte-associated molecules in the mouse tail epididymal fat at different postnatal ages, including 2, 5, 8, and 12 months of age. The quantitative real-time PCR analysis showed continuous increases of expression levels of delta like non-canonical Notch ligand 1, leptin, and resistin as postnatally aged. The transcript level of peroxisome proliferator-activated receptor gamma was the highest at 5 months of age, remaining at a steady level until 12 months of age. Expression levels of fatty acid binding protein 4, leptin, and adiponectin were significantly increased until 8 months of age, persisting the level at 12 months of age. The transcript level of fatty acid synthase was significantly increased at 8 months of age, without a further change of the level at 12 months of age. These findings exhibited the expression of adipocyte-associated genes which were also detected at the ordinary epididymal fat pad. However, expression patterns of these genes in the tail epididymal fat are different with those in the distal and proximal epididymal fat, suggesting distinct characteristics and/or functions of the tail epididymal fat.

• Neonatal Medicine
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• 제28권2호
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• pp.83-88
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• 2021

Treatment guidelines for postnatal cytomegalovirus (pCMV) infection in preterm have not been established yet. Neutropenia, thrombocytopenia, hepatitis, colitis, and sepsis-like disease are among the clinical manifestations, which range from moderate to serious. We present a case of autopsy diagnosed as pCMV infection in a premature infant delivered at gestational age of 24 weeks and 5 days. On the 7th and 14th days of birth, urinary CMV polymerase chain reaction samples were negative, ruling out congenital CMV infection. However, autopsy examination revealed that the patient had disseminated pCMV infection. CMV inclusion bodies were found in the majority of tissues, including the lung, liver, pancreas, breast, kidney, and adrenal gland, but not the placenta. The thymus exhibited significant cortical atrophy and T-cell immunodeficiency, possibly induced by dexamethasone treatment for bronchopulmonary dysplasia or by pCMV infection itself. If dexamethasone treatment is extended or high doses are considered, it may be beneficial to test the CMV infection status to prevent aggravation of infection. This case demonstrates that, despite the low prevalence, pCMV infection should be considered a differential diagnosis in preterm if other conditions or etiology cannot justify clinical deterioration.

• Journal of Genetic Medicine
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• 제17권2호
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• pp.83-88
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• 2020

Silver-Russell syndrome (SRS) is a rare genetic disorder characterized by intrauterine growth restriction, poor postnatal growth, relative macrocephaly, a triangular face, body asymmetry, and feeding difficulties. It is primarily diagnosed according to a clinical scoring system; however, the clinical diagnosis is confirmed with molecular testing, and the disease is stratified into the specific molecular subtypes. SRS is a genetically heterogeneous condition. The major molecular changes are hypomethylation of imprinting control region 1 in 11p15.5 and maternal uniparental disomy of chromosome 7 (UPD(7)mat). Therefore, first-line molecular testing should include methylation-specific approaches for these regions. Here, we report an extremely low birth weight (ELBW) infant with intrauterine growth retardation, postnatal growth retardation, and dysmorphic facial appearance-characteristics consistent with the clinical diagnostic criteria of SRS. Methylation-specific molecular genetic analysis revealed UPD(7)mat, while the loss of heterozygosity was not detected on chromosomal microarray analysis. We present a case of SRS with suspected uniparental heterodisomy of chromosome 7 in an ELBW infant.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 1996년도 제19회정기학술대회(The 19th Symposium of the Korean Society of Environmental Toxicology)
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• pp.25-41
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• 1996

KWON, O. S. SCHMUED, L. C. and LSIKKER, W. JR. Neurotoxiciligy. objectives of this study were to test the hypothesis that fumonisin $B_1$ ($FB_1$) alters sphinganine (Sa) levels and myelin synthesis in the central nervous system of developing rats. $FB_1$ (subcutaneous, 0. 4 or 0. 8 mg/kg/day) from postnatal days (PND) 3 to PND 12 resulted in a significantly increased in the brain of rats given 0. 8 mg $FB_1$/kg/day. To confirm the effect of limited nutrition on changes in the Sa levels and myelinogenesis, rats given 0.8mg $FB_1$/kg/day or treated by limited nutrition (temporary removal from dam during postnatal period) were compared to those in saline controls. Sa levels and Sa/So ratios were compared to those in saline in the 0.8 $FB_1$-treated, 3'-phosphohydrolase (CNP) activities were decreased significantly in both nutritionally limited and $FB_1$-exposed rats. These data indicate that sphingolipid metabolism in the central nervous system of develiping rats is vulnerable to $FB_1$ exposure. The hypomyelination associated with $FB_1$-treatment may be mediated by limited nutrition.

• Journal of Interdisciplinary Genomics
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• 제5권2호
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• pp.18-23
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• 2023

Conventional evaluation method for identifying the organic cause of short stature has a low detection rate. If an infant who is small for gestational age manifests postnatal growth deterioration, triangular face, relative macrocephaly, and protruding forehead, a genetic testing of IGF2, H19, GRB10, MEST, CDKN1, CUL7, OBSL1, and CCDC9 should be considered to determine the presence of Silver-Russell syndrome and 3-M syndrome. If a short patient with prenatal growth failure also exhibits postnatal growth failure, microcephaly, low IGF-1 levels, sensorineural deafness, or impaired intellectual development, genetic testing of IGF1 and IGFALS should be conducted. Furthermore, genetic testing of GH1, GHRHR, HESX1, SOX3, PROP1, POU1F1, and LHX3 should be considered if patients with isolated growth hormone deficiency have short stature below -3 standard deviation score, barely detectable serum growth hormone concentration, and other deficiencies of anterior pituitary hormone. In short patients with height SDS <-3 and high growth hormone levels, genetic testing should be considered to identify GHR mutations. Lastly, when severe short patients (height z score <-3) exhibit high levels of prolactin and recurrent pulmonary infection, genetic testing should be conducted to identify STAT5B mutations.