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Biomedical subjects

B H Hyun

Publications and source records attributed to B H Hyun.

At least 19 recordsLinked to original sources
PubMed2006

Corticotropin-releasing factor immunoreactivity increases in the cerebellar climbing fibers in the novel ataxic mutant mouse, pogo.

The ataxic pogo mouse (pogo/pogo) is a novel neurological mutant, which was derived as an inbred strain (KJR/MsKist) from a Korean wild mouse. The pathological manifestations include a difficulty in maintaining a normal posture, the failure of inter-limb coordination and an inability to walk straight. In this study, we examined the distribution of corticotropin-releasing factor (CRF) immunoreactive cerebellar climbing fibres and their projections to tyrosine hydroxylase (TH) immunoreactive Purkinje cells in the cerebellum of the pogo mutant mouse using immunohistochemistry. In the pogo/pogo mouse, a subset of climbing fibres was stained more intensely for CRF than in the control. Moreover, ataxic pogo mouse, neurons of the inferior olivary nucleus projecting climbing fibres were also more intensely stained for CRF than in the control. In the pogo/pogo mouse, TH immunoreactivity was located in the Purkinje cells, whereas no TH expression was found in the control. Double immunostaining for CRF and TH in the pogo/pogo cerebellum revealed that the distribution of TH-immunoreactive Purkinje cells corresponded to terminal fields of CRF-immunoreactive climbing fibres but not to the CRF-immunoreactive mossy fibres. Therefore, we suggest that an increase of CRF level may alter the function of targeted Purkinje cells and that it is related to the ataxic phenotype in the pogo mutant mouse.

Animals↗
PubMed2002

Isolation and phylogeny of endogenous retrovirus HERV-F family in Old World monkeys. Brief report.

A new human endogenous retroviral family (HERV-F) has recently been identified from human chromosome 7q31.1-q31.3 that was identical to the XA34 cDNA clone isolated from a human glioma cDNA library with an ERV-9 env probe. We investigated pol fragments of the HERV-F family from the Old World monkeys (crab-eating monkey, African green monkey, and baboon) and analyzed these with the HERV-F (Hu-XA34). Fifteen pol fragments of the HERV-F family were detected from the Old World monkeys. They showed a high degree of sequence similarity (81-99%) with that of the HERV-F (Hu-XA34). Phylogenetic analysis of pol fragments with those of the human genome distinctively showed five groups, indicating that HERV-F family could be amplified at least five times after the original integration into the monkey genome or represent integration events independently during primate evolution.

Amino Acid Sequence↗
PubMed2002

Evaluation of platelet parameters on the ADVIA 120 as the quality indicator for stored platelets.

In order to investigate the possible use of platelet parameters on the ADVIA 120 hematologic analyzer as the routine quality control indicator for preparation and storage of platelets, platelet parameters, pH and CD62P expression were determined in stored platelet concentrates. Platelet component distribution width (PCDW) was decreased progressively on days 1 and 3 of storage for 5 days when compared with 0 day. PCDW correlated with CD62P expression on unstimulated platelets and the difference in CD62P expression following agonistic stimulation (a measure of functional reserve). Mean platelet component (MPC) was decreased on day 1 of storage. It did not however, show a progressive decrease over storage time and did not correlate with CD62P, although MPC has been known to be a useful screening test for platelet activation. Therefore, PCDW is considered to be a simple, convenient and cost-effective quality indicator for determining the viability and storage lesion of platelets for transfusion.

Blood Preservation↗
PubMed2002

Effect of transfusion of fresh-frozen plasma on recipients' antibodies to hepatitis B surface antigen and hepatitis B surface antigen status in countries where hepatitis B virus is endemic.

BACKGROUND AND OBJECTIVES: Antibodies to hepatitis B virus (HBV) that are passively acquired through transfusions may lead to confusion and inappropriate clinical decisions. We evaluated the effects of transfusing fresh-frozen plasma (FFP) on serological tests for HBV antibodies in patients without such antibodies. MATERIALS AND METHODS: Tests for HBV surface antigen (HBsAg), and for antibodies to HBV surface antigen (anti-HBs) and HBV core antigen (anti-HBc), were carried out using enzyme immunoassay on the FFP and sera of 50 patients transfused with FFP containing anti-HBs. RESULTS: After FFP transfusion, the incidences of 'false' positivity for anti-HBs and anti-HBc were 64% (32/50) and 100% (seven of seven), respectively, and of 'false' negativity for HBsAg was 18.8% (three of 16) in previously positive patients. The post-transfusion seropositivity for antibodies results from passive transmission, whereas the inability to detect HBsAg is the result of decreased detectable levels. CONCLUSIONS: Laboratory staff and clinicians alike should be cautious in interpreting the results of the HBV marker tests in patients who have recently been transfused, and in obtaining specimens for such studies.

Blood Transfusion↗
PubMed2002

Morphological characteristics of C1 and C2 adrenergic neurone groups in marmoset monkey brainstem by using antibody against phenylethanolamine-N-methyltransferase.

This work describes a mapping study of phenylethanolamine-N-methyltransferase (PNMT) immunoreactive neurones and fibres in the medulla oblongata of the marmoset monkey, Callithrix jacchus. Two groups of PNMT-immunoreactive neurones were found in the marmoset monkey medulla oblongata: a ventrolateral (C1 group) and a dorsomedial PNMT-immunoreactive cells group (C2 group). The PNMT-immunoreactive cells in the ventrolateral group C1 were found to be located around the lateral reticular nucleus. The PNMT-immunoreactive somata within the ventrolateral medulla are round to oval, and mostly multipolar with branched processes. In the dorsomedial group C2, PNMT-immunoreactive cell bodies appeared near the obex. The majority of the dorsomedial PNMT-immunoreactive neurones were observed in the nucleus tractus solitarius; although some were present in the dorsal motor nucleus of the vagus. The PNMT-immunoreactive somata in the dorsomedial medulla were small and round or ovoid. These results provide information upon the adrenergic system in the medulla oblongata of a species that presents a useful model of a small primate brain, the marmoset monkey.

Adrenergic Fibers↗
PubMed2001

Anti-atherogenic effect of citrus flavonoids, naringin and naringenin, associated with hepatic ACAT and aortic VCAM-1 and MCP-1 in high cholesterol-fed rabbits.

The anti-atherogenic effects of the citrus flavonoids, naringin and naringenin, were evaluated in high cholesterol-fed rabbits. At 3 months of age, 30 male New Zealand White (NZW) rabbits were divided into three groups (n = 10 per group). The rabbits were fed a 1% cholesterol diet alone (control group) or a diet supplemented with either 0.1% naringin or 0.05% naringenin for 8 weeks. The plasma lipoprotein levels, total cholesterol, triglyceride, and high-density lipoprotein showed no significant differences in the control and experimental groups. Hepatic acyl-CoA:cholesterol acyltransferase (ACAT) activity was slightly low in naringin (5.0%)- and naringenin (15.0%)-fed rabbits, compared to control group. The aortic fatty streak areas were significantly lower in both the naringin (19.2 +/- 5.6%)- and naringenin (18.1 +/- 6.5%)-supplemented groups than in the control group (60.4 +/- 14.0%). The expression levels of vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemotactic protein-1 (MCP-1), by semiquantitative RT-PCR analysis of the thoracic aorta, were significantly lower in the flavonoids supplemented groups than in the control group. These results suggest that the anti-atherogenic effect of the citrus flavonoids, naringin and naringenin, is involved with a decreased hepatic ACAT activity and with the downregulation of VCAM-1 and MCP-1 gene expression.

Actins↗
PubMed2001

Isolation and phylogeny of new endogenous retroviral sequences belonging to the HERV-F family.

A new human endogenous retroviral family (HERV-F) has been identified from human chromosome 7q31.1-q31.3 that was identical to the XA34 cDNA clone isolated from a human glioma cDNA library with an ERV-9 env probe. We investigated pol gene sequences of the HERV-F family from a human monochromosomal DNA panel and analyzed these with HERV-F. The pol gene sequences of the HERV-F family were detected on chromosomes 3, 6, 7, 10, 11, 14, 19, 20, X, and Y as examined by PCR. Thirty-six pol gene sequences identified from the human chromosomes have a high degree of sequence similarity (80-99%) with that of the HERV-F. Phylogenetic analysis of pol gene sequences distinctively showed four groups, indicating that the HERV-F family could be amplified at least four times after the original integration into the human genome or represent integration events separately during hominid evolution. One clone (HFY-3) on chromosome Y shared 100% sequence identity with a clone (HF19-2) on chromosome 19, and a clone (HF20-6) on chromosome 20 suggests either a recent retrotransposition or a chromosomal translocation. The history of endogenous retroviral sequences may contribute to an understanding of evolutionary change in human genomes.

Chromosomes, Human↗
PubMed2001

Selective left-lobe atrophy by nodularin treatment accompanied by reduced protein phosphatase 1/2A and increased peroxisome proliferation in rat liver.

The effect of nodularin on selective atrophy of left lobes in the liver was investigated in F344 rats. Nodularin was injected for 10 weeks from the third week of initiation with saline or N-nitrosodiethylamine (DEN), grouped as S/N and D/N, respectively. Nodularin significantly decreased weights of left (LL) and caudate (CL) lobes but increased right (RL) and middle (ML) lobes in S/N rats. Activity of protein phosphatases [types 1 (PPI) and 2A (PP2A)] was more severely reduced in S/N than D/N rats; moreover, in LL compared with RL of S/N rats, activity was significantly inhibited by nodularin treatment from week 4, which corresponded to 2 weeks after nodularin injection. However, nodularin significantly induced peroxisomal palmitoyl-CoA oxidase and cytochrome P-450 4A1 expression in S/N compared with D/N rats. An effect of nodularin on apoptosis was evident since expression of Bcl-Xs was clearly induced in LL of S/N rats as opposed to various inductions of Bcl-XL. However, Bcl-XL in RL was persistently induced, with undetectable Bcl-Xs expression. These results demonstrate biochemical evidence of selective atrophy of LL by inhibition of PP1 and PP2A activity, increase of peroxisomal enzymes and induction of Bcl-Xs expression, in contrast to proliferation of RL in rats treated with nodularin alone. However, nodularin endowed DEN-altered hepatocytes with regenerating power and concomitant restoration of phosphatase activity as well as persistent expression of Bcl-XL in D/N rats.

Alkylating Agents↗
PubMed2001

Dietary hematein ameliorates fatty streak lesions in the rabbit by the possible mechanism of reducing VCAM-1 and MCP-1 expression.

Hematein is a compound isolated from Caesalpinia sappan that has been used in oriental medicine as both an analgesic and an anti-inflammatory agent. In this study, we examined the anti-atherogenic potential of hematein using cholesterol-fed New Zealand White (NZW) rabbits. NZW rabbits were divided into a hematein-supplemented (0.05% in diet) group (n=6), a probucol-supplemented (0.25% in diet) group (n=6), and a control group (n=6). After 8 weeks of treatments, the extent of the atherosclerotic lesions was significantly reduced in the hematein-supplemented group and the probucol-supplemented group without changing plasma lipoprotein levels. Hematein and probucol prevented the up-regulation of the vascular cell adhesion molecule-1 (VCAM-1) expression on the descending aorta induced by cholesterol diet. In culture, hematein also significantly inhibited the secretion of soluble VCAM-1 and of monocyte chemotactic protein-1 (MCP-1) respectively induced by tumor necrotic factor alpha (TNF-alpha) and mildly oxidized low density lipoprotein in human umbilical vein endothelial cell (HUVEC) culture. Also, hematein inhibited monocyte adhesion to endothelial cell and the activation of NF-kappaB in HUVECs stimulated with TNF-alpha. The results of the present study suggest that the anti-atherogenic effect of hematein is not related to control of the plasma lipid profile but probably related to the inhibition of VCAM-1 and MCP-1 expression resulting in an amelioration of lesion development in the rabbit.

Animals↗
PubMed2001

Virological properties and nucleotide sequences of Cas-E-type endogenous ecotropic murine leukemia viruses in South Asian wild mice, Mus musculus castaneus.

Two types of endogenous ecotropic murine leukemia viruses (MuLVs), termed AKV- and Cas-E-type MuLVs, differ in nucleotide sequence and distribution in wild mouse subspecies. In contrast to AKV-type MuLV, Cas-E-type MuLV is not carried by common laboratory mice. Wild mice of Mus musculus (M. m.) castaneus carry multiple copies of Cas-E-type endogenous MuLV, including the Fv-4(r) gene that is a truncated form of integrated MuLV and functions as a host's resistance gene against ecotropic MuLV infection. Our genetic cross experiments showed that only the Fv-4(r) gene was associated with resistance to ecotropic F-MuLV infection. Because the spontaneous expression of infectious virus was not detected in M. m. castaneus, we generated mice that did not carry the Fv-4(r) gene but did carry a single or a few endogenous MuLV loci. In mice not carrying the Fv-4(r) gene, infectious MuLVs were isolated in association with three of six Cas-E-type endogenous MuLV loci. The isolated viruses showed a weak syncytium-forming activity for XC cells, an interfering property of ecotropic MuLV, and a slight antigenic variation. Two genomic DNAs containing endogenous Cas-E-type MuLV were cloned and partially sequenced. All of the Cas-E-type endogenous MuLVs were closely related, hybrid-type viruses with an ecotropic env gene and a xenotropic long terminal repeat. Duplications and a deletion were found in a restricted region of the hypervariable proline-rich region of Env glycoprotein.

Amino Acid Sequence↗
PubMed2001

Infectivity and pathological changes in murine clonorchiasis: comparison in immunocompetent and immunodeficient mice.

The main complications of clonorchiasis are periportal inflammation, biliary hyperplasia, periductal fibrosis, and subsequently the development of biliary tumors in the liver. This study was undertaken to compare the infectivity and histopathologic changes between in immunocompetent FVB/NJ and BALB/cA strains, and immunodeficient severe combined immunodeficient (SCID) and athymic nude mice after the metacercariae of Clonorchis (C.) sinensis were infected. The experiment showed that C. sinensis was very infective in all strains studies, but the status of worm development, infectivity, recovery rate, and morphological changes of livers were very different in each strain. FVB/NJ mice showed more worm recovery than any other strain. Histopathologically the liver of FVB/NJ mice at 4 weeks postinfection showed marked cystic and fibrotic changes, in which C. sinensis was fully developed with ovum production, severe infiltration of inflammatory cells, mostly eosinophils, and high degrees of biliary hyperplasia. In SCID and nude mice, there were few foci of inflammatory cells even at 8 weeks postinfection in periportal areas of the liver, associated with no development into adult worm with ovum production. Fibrosis occurring at 4 weeks postinfection was highly correlated with inflammatory infiltration when each strain was compared. We suggest that massive infiltration of eosinophil and plasma cells caused by the infection might initiate cystic formation and fibrosis. These data demonstrate that the infection of C. sinensis might be related to pathologic consequences of inflammatory cell infiltration, cystic formation and fibrosis which might play a role in the defense mechanism against the parasitism in the liver of each strain. The FVB/NJ mouse model might be very helpful in elucidating the mechanism for human clonorchiasis.

Animals↗
PubMed2001

Induction of immune responses to glycoprotein gD of Aujeszky's disease virus with DNA immunization.

In an attempt to produce a DNA vaccine to prevent Aujeszky's disease, the induction of immune responses against Aujeszky's disease virus (ADV) gD was investigated in mice. The plasmid was constructed by placing ADV gD gene downstream of murine cytomegalovirus immediate early promoter of expression vector pMYK, which was injected twice on the skin of mice by using a gene-gun. All mice showed neutralizing antibodies against ADV gD at 4 weeks after immunization. The induction of cytotoxic T lymphocytes and splenic natural killer cells was also observed at 6 weeks post immunization. These results indicate that ADV gD gene in the form of DNA vaccine may induce specific as well as non-specific immune responses in vivo.

Animals↗
PubMed2000

Abnormalities in cerebellar Purkinje cells in the novel ataxic mutant mouse, pogo.

The pogo mouse is a novel neurological mutant, which was discovered, in an inbred strain (KJR/MsKist) derived from a Korean wild mouse. The pathological manifestations include difficulty in maintaining normal posture, failures of interlimb coordination and the inability to walk straight. The ataxia is first apparent from about 2 weeks of age and progresses throughout life. The mutation is inherited as an autosomal recessive trait. In this report, we describe abnormalities in the pogo/pogo cerebellum. Nissl staining shows that the pogo/pogo cerebellum is normal in size and lobulation. Similarly, immunocytochemical staining for a granule cell marker, 10B5, shows no differences in the thickness of the granular layer between pogo/pogo homozygote and pogo/+ heterozygote littermate controls. By using anti-parvalbumin immunocytochemistry, the cells of molecular layer of the pogo/pogo cerebellum also appeared similar in distribution as compared to normal wild type mouse. In anti-neurofilament immunocytochemistry, the basket cells axons of the pogo/pogo cerebellum appeared normal. Purkinje cell abnormalities were identified by using anti-calbindin D immunocytochemistry. In 120-day-old pogo/pogo mutant mice there was a loss of Purkinje cells throughout the cerebellar vermis. Furthermore, the somata and dendrites were extensively vacuolated in the pogo/pogo Purkinje cells and the primary dendrites were frequently swollen. Focal axonal swellings were commonly observed in the Purkinje cell axons of pogo/pogo mutant mice as they traversed the granular layer. These data suggest that the progressive ataxia seen in pogo mice may be due to a failure of normal Purkinje cell activity.

Animals↗
PubMed2000

Abnormal synaptic organization between granule cells and Purkinje cells in the new ataxic mutant mouse, pogo.

The pogo mouse is a new ataxic mutant derived from the Korean wild mouse. The pathological manifestations include difficulty in maintaining normal posture and the inability to walk straight. The ataxia becomes apparent at about 2 weeks of age. Electron microscopic studies of the pogo/pogo homozygous cerebellum, revealed that the ectopic spines emanating from the primary dendrite of Purkinje cells were observed. Major difference between pogo/pogo homozygous and non-affected pogo/+ heterozygous was the synaptic organization of the molecular layer. Parallel fiber varicosities were larger than normal and a single fiber often established synaptic contacts with up to four dendritic spines of a Purkinje cell. This correlation between the presence of altered synaptic organization in the cerebellum and ataxia in pogo/pogo mutant mice warrants further investigation.

Animals↗
PubMed2000

Phylogenetic analysis of retroposon family as exemplified on human chromosome 13: further evidence for recent proliferation.

The retroposon SINE-R.C2 was first identified as a human-specific insertion in the complement C2 gene. In our previous study, SINE-R type retroposons, derived from the endogenous retrovirus HERV-K family, have been found to be hominoid specific. In this report on human chromosome 13, we identified eighteen new SINE-R retroposons resembling those we have previously reported on the sex chromosomes and on chromosomes 7 and 17. Phylogenetic analysis using the neighbor-joining method revealed that four SINE-R retroposons (13-16, 21, 23, 25) on chromosome 13 were closely related to the human-specific retroposon SINE-R.C2, with a high degree of sequence homology (95-97%). Such elements differ from the HERV-K10. LTR sequence from which they are derived in being deleted for the promoter region. Therefore while the evidence adds to the case that some classes of SINE-R element have continued to proliferate in hominid and hominoid evolution and may, as in the case of Fukuyama type muscular dystrophy, be a cause of insertional mutagenesis, they are less likely than the HERV-K10 LTR to have a positive effect on host gene activity.

Chromosomes, Human, Pair 13↗
PubMed2000

Nucleotide sequence and phylogenetic analysis of long terminal repeats of human endogenous retrovirus K family (HERV-K) on human chromosomes.

It has been suggested that human endogenous retroviruses K family (HERV-K) has a role in disease, and solitary long terminal repeats (LTRs) of HERV-K have been potentially capable of affecting the expression of closely located genes. Using the human monochromosomes 8, 9, 17, and 18, with specific PCR primers, we identified thirty-four sequences of new HERV-K LTRs. Those LTR elements were analyzed phylogenetically with the human-specific HERV-K LTRs using neighbor-joining and maximum parsimony methods. Clones HKL8-5, HKL9-5, and HKL9-8 are related by more than 99% homology with the human-specific HERV-K LTRs. The HKL9-5 clone on chromosome 9 was 100% identical with the sequences of human-specific LTR, AC002400, on chromosome 16. The findings suggest that there has been recent proliferation, transposition, or chromosomal translocation of HERV-K LTR elements on human chromosomes.

Chromosomes, Human↗