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Biomedical subjects

Joo-Ho Chung

Publications and source records attributed to Joo-Ho Chung.

11 recordsLinked to original sources

Evaluation of a Apo-1/Fas promoter polymorphism in Korean stroke patients.

Apoptosis has been implicated in the pathogenesis of neurodegenerative diseases such as stroke and Alzheimer's disease. Apo-1/Fas gene is one of the mediators of apoptosis in stroke. Mval polymorphism is the first polymorphic marker identified in the Apo-1/Fas gene promoter, which was typed by PCR and followed by Mval digestion and gel electrophoresis. DNA isolated from peripheral blood collected from 91 stroke patients and 103 healthy blood donors was used for genotypes of GG, GA and AA by sequence specific primer PCR. Mval polymorphism was examined based on Fas gene promotor region by restriction fragment length polymorphism (RFLP). The Fas-GG genotype was the least frequent in patients with stroke and healthy controls (P = 0.57). In normal Korean controls the Mval polymorphism GA, AA and GG were 48.6%, 34.9% and 16.5%. In stroke patients were 56.2%, 29.6% and 14.2% respectively. And the allelic frequencies of Mval*2 (G) allele were less frequent than Mval*1 (A) allele in patients with stroke and healthy controls (P = 0.76). In normal Korean controls Mval*1 (A) and Mval*2 (G) alleles were 59.2% and 40.8%. In stroke patients were 57.6% and 42.4%, respectively. Our results, pending confirmation in a larger study, indicate that the Fas genotype may not appear to be a risk factor for stroke in Korean stroke patients.

Adult↗

Acupuncture increases cell proliferation and neuropeptide Y expression in dentate gyrus of streptozotocin-induced diabetic rats.

In this study, effects of acupuncture at Zusanli acupoint on cell proliferation and expression of neuropeptide Y (NPY) in the dentate gyrus (DG) of streptozotocin-induced diabetic rats were investigated. Sprague-Dawley rats were divided into six groups: the control group, the non-diabetic and Zusanli-acupunctured group, the non-diabetic and non-acupoint-acupunctured group, the streptozotocin-induced-diabetes group, the streptozotocin-induced-diabetes and Zusanli-acupunctured group, and the streptozotocin-induced-diabetes and non-acupoint-acupunctured group. In the streptozotocin-induced diabetes group, the mean 5-bromo-2'-deoxyuridine-positive and NPY-positive cell counts in the DG were significantly decreased compared to the control group. Stimulation of the Zusanli resulted in increased cell proliferation and neuropeptide Y levels in the diabetic group. In the present results, it can be suggested that acupuncture may affect cell proliferation in the DG of streptozotocin-induced diabetic rats by regulating neuropeptide Y expression.

Acupuncture↗

Amiodarone induces apoptosis in L-132 human lung epithelial cell line.

To investigate whether amiodarone induces apoptosis in cells of the L-132 human lung epithelial cell line, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, 4,6-diamidino-2-phenylindole staining, DNA fragmentation assay, reverse transcription-polymerase chain reaction, and casapse-3 enzyme assay were performed. Through morphological and biochemical analyses, it was demonstrated that L-132 cells treated with amiodarone exhibit several features of apoptosis. In addition, it was shown that amiodarone increases the mRNA levels of bax and caspase-3. Based on the results, amiodarone appears to activate specific intracellular death-related pathways, including possibly the bax-dependent caspase-3 activation pathway, and thus induce apoptosis in human lung epithelial cells.

Amiodarone↗

Nicotine administration decreases nitric oxide synthase expression in the hypothalamus of food-deprived rats.

Effect of nicotine on nitric oxide synthase (NOS) expression in various hypothalamic regions was investigated in rats via nicotineamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Sprague-Dawley rats were divided into the fed group, the fed and nicotine-treated group, the food-deprived group, and the food-deprived and nicotine-treated group. The fed groups received abundant food and water, while food was withheld from the food-deprived groups for 48 h. The nicotine-treated groups were injected with nicotine. Following food deprivation, enhanced NAPDH-d expression was detected in the paraventricular nucleus, ventromedial hypothalamic nucleus, and lateral hypothalamic area of the hypothalamus. Nicotine administration to the food-deprived rats resulted in decreased NADPH-d positivity. The present results indicate that nicotine administration is effective in limiting the enhancement in NOS expression following food restriction.

Animals↗

Acupuncture enhances cell proliferation in dentate gyrus of maternally-separated rats.

Maternal separation in early life can increase vulnerability to neuropsychiatric disorders over the lifespan. To investigate the effect of acupuncture on cell proliferation in the dentate gyrus (DG), 5-bromo-2'-deoxyuridine (BrdU)-immunohistochemistry was performed in maternally-separated rat pups. Maternal separation, for 7 days from postnatal day 14, induced a significant decrease of BrdU-immunoreactive cells in DG, while acupuncture treatment at acupoint Shenmen (HT7), at the end of the transverse crease of the ulnar wrist, resulted in the significant increase in the number of BrdU-positive cells in DG. However, acupuncture at acupoint ST36, near the knee joint, produced no increase in the number of BrdU-positive cells. These findings indicate that acupuncture at acupoint HT7 appears to stimulate cell proliferation, and we suggested that acupuncture may be useful in the treatment of diseases related to maternal separation.

Acupuncture↗

Decrease of the electroacupuncture-induced analgesic effects in nuclear factor-kappa B1 knockout mice.

To investigate the involvement of nuclear factor kappa B1 (NF-kappaB1; p50/p105) in electroacupuncture (EA)-induced analgesia, 2 and 100 Hz EA stimulations were applied at acupoint ST36 (Zusanli) in NF-kappaB1 knockout mice. EA was performed for 30 min and tail-flick latencies (TFLs) were evaluated every 15 min for 1 h. Wild-type mice displayed a 63.3% increase in TFLs compared to baseline after 2 Hz EA, whereas NF-kappaB1+/- mice exhibited a 41.8% increase and NF-kappaB1-/- mice showed only a 3.9% increase of TFLs. The TFLs of 100 Hz EA showed similar trends: a 72.6% increase of TFLs in wild-type, a 38.6% increase in NF-kappaB1+/- and a 9.3% increase in NF-kappaB1-/- mice. The present findings suggest that NF-kappaB1 may play a crucial role in both low and high frequency EA-induced analgesic effects.

Analgesia↗

Modulation of tianeptine on ion currents induced by inhibitory neurotransmitters in acutely dissociated dorsal raphe neurons of Sprague-Dawley rats.

Classical antidepressant therapy has mainly used selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs), but tianeptine appears to possess effects on 5-hydroxytryptamine (5-HT, serotonin) levels in the synaptic cleft contradictory to those of SSRIs. The mechanism behind its antidepressant effects is still unclear. The effect of tianeptine on the electrophysiological characteristics of neurons in the dorsal raphe, where serotonergic neurons mainly originate from, were investigated by the patch-clamp method in the present study. Tianeptine was shown to inhibit the ion currents induced by the inhibitory neurotransmitters GABA and glycine as well as the inwardly rectifying K(+) current induced by 5-HT and 8-hydroxy-2 (di-n-propylamino) tetraline hydrobromide (8-OH-DPAT), a 5-HT(1A) agonist. Tianeptine, however, exerted no effect on the ion current induced by the excitatory neurotransmitter glutamate. These results indicate that tianeptine has an inhibitory effect on ion currents evoked by GABA, glycine, and inwardly rectifying K(+) current induced by 5-HT in the dorsal raphe. This action may increase the excitability of serotonergic neurons of the dorsal raphe.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

Melatonin suppresses NO-induced apoptosis via induction of Bcl-2 expression in PGT-beta immortalized pineal cells.

In the present study, we investigated whether melatonin would prevent nitric oxide (NO)-induced apoptotic death of PGT-beta immortalized pineal cells. To examine the protective effect of melatonin, cytotoxicity assay, DNA fragmentation analysis, caspase-3 activity assay, and Western blotting for caspase-3 and poly(ADP-ribose) polymerase (PARP) were performed. Treatment of cells with S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, was shown to induce apoptotic cell death in a dose-dependent manner, and pretreatment with melatonin (0.1 mm) attenuated the occurrence of NO-induced apoptotic cell death. DNA fragmentation in response to NO was also arrested by melatonin. Caspase-3 activity induced by NO was decreased with melatonin treatment. Furthermore, the active fragments of caspase-3 and PARP were almost completely absent following exposure to melatonin. To elucidate the protective mechanisms of action of melatonin, Western blot analyses for Bcl-2 expression and cytochrome c release were carried out. Pretreatment with melatonin (0.1 mm) induced the expression of Bcl-2 and suppressed the release of cytochrome c into the cytosol, thereby arresting NO-induced apoptotic cell death. These results suggest that the antiapoptotic effect of melatonin is associated with induction of Bcl-2 expression in PGT-beta cells, which in turn blocks caspase-3 activation and inhibits cytochrome c release into the cytosol.

Animals↗

Acupuncture stimulation of the vision-related acupoint (Bl-67) increases c-Fos expression in the visual cortex of binocularly deprived rat pups.

Our previous study with functional magnetic resonance imaging (MRI) demonstrated that acupuncture stimulation of the vision-related acupoint, B1-67, activates the visual cortex of the human brain. As a further study on the effect of B1-67 acupuncture stimulation on the visual cortex, we examined c-Fos expression in binocularly deprived rat pups. Binocular deprivation significantly reduced the number of c-Fos-positive cells in the primary visual cortex, compared with that of normal control rat pups. Interestingly, acupuncture stimulation of B1-67 resulted in a significant increase in the number of c-Fos-positive cells in the primary visual cortex, while acupuncture stimulation of other acupoints less important for visual function had no significant effect on c-Fos expression in the primary visual cortex. The results suggest the possibility of vision-related acupoint (B1-67) having an influence over the activity of the primary visual cortex.

Acupuncture Points↗

Protective effects of Wuyaoshunqisan against H2O2-induced apoptosis on hippocampal cell line HiB5.

Oxidative stress has been implicated in the pathogenesis of different neurodegenerative disorders. To investigate the protective effects of Wuyaoshunqisan against H2O2-induced apoptosis in the central nervous system, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) method, flow cytometric analysis, and the DNA fragmentation assay were performed on cells of the hippocampal cell line HiB5. Through the morphological and biochemical analyses, it was shown that HiB5 cells treated with H2O2 exhibit classical apoptotic features, while the occurrence of such changes is reduced in cells pre-treated with Wuyaoshunqisan prior to H2O2 exposure.

Animals↗

Effects of Puerariae radix on cell proliferation and nitric oxide synthase expression in dentate gyrus of alcohol-intoxicated Sprague-Dawley rats.

Traditionally, Puerariae radix had been used for the treatment of alcohol-related problems. In this study, effects of Puerariae radix on cell proliferation and nitric oxide synthase expression in the dentate gyrus of alcohol-intoxicated Sprague-Dawley rats were investigated via 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Alcohol administration was shown to inhibit the numbers of both BrdU-positive and NADPH-d-positive cells, while Puerariae radix treatment was shown to increase those numbers. It is possible that nitric oxide, which might play an important role in the regulation of cell proliferation, is a major target of the toxic effects of alcohol.

Alcoholic Intoxication↗