1.Inhibition of Pacemaker Activity of Interstitial Cells of Cajal by Hydrogen Peroxide via Activating ATP-sensitive K(+) Channels.
Seok CHOI ; Shankar Prasad PARAJULI ; Hyeon Sook CHEONG ; Dilli Parasad PAUDYAL ; Cheol Ho YEUM ; Pyung Jin YOON ; Jae Yeoul JUN
The Korean Journal of Physiology and Pharmacology 2007;11(1):15-20
To investigate whether hydrogen peroxide (H2O2) affects intestinal motility, pacemaker currents and membrane potential were recorded in cultured interstitial cells of Cajal (ICC) from murine small intestine by using a whole-cell patch clamp. In whole cell patch technique at 30 degress C, ICC generated spontaneous pacemaker potential under current clamp mode (I=0) and inward currents (pacemaker currents) under voltage clamp mode at a holding potential of -70 mV. When ICC were treated with H2O2 in ICC, H2O2 hyperpolarized the membrane potential under currents clamp mode and decreased both the frequency and amplitude of pacemaker currents and increased the resting currents in outward direction under voltage clamp mode. Also, H2O2 inhibited the pacemaker currents in a dose-dependent manner. Because the properties of H2O2 action on pacemaker currents were same as the effects of pinacidil (ATP-sensitive K+ channels opener), we tested the effects of glibenclamide (ATP-sensitive K+ channels blocker) on H2O2 action in ICC, and found that the effects of H2O2 on pacemaker currents were blocked by co- or pre-treatment of glibenclamide. These results suggest that H2O2 inhibits pacemaker currents of ICC by activating ATP-sensitive K(+) channels.
Gastrointestinal Motility
;
Glyburide
;
Hydrogen Peroxide*
;
Hydrogen*
;
Interstitial Cells of Cajal*
;
Intestine, Small
;
Membrane Potentials
;
Pinacidil
2.Clinical characteristics of cerebral palsy following preterm or term birth; 10 years' experience.
Young Ah KOO ; Dong Seok CHOI ; Suk Joo CHOI ; Soo Young OH ; Yun Sil CHANG ; Won Soon PARK ; Hyeon Sook KIM ; Cheong Rae ROH ; Jong Hwa KIM
Korean Journal of Obstetrics and Gynecology 2006;49(12):2543-2549
OBJECTIVE: To investigate the perinatal and clinical characteristics of cerebral palsy (CP) following preterm or term birth. METHODS: A total of 75 infants born and diagnosed as CP in our hospital from October 1994 to December 2004 were recruited retrospectively. Their maternal and perinatal outcomes and the type, involved lesion and severity of CP were analyzed. RESULTS: The incidence of CP was 0.23%, which showed decreasing pattern according to advancing gestational age at birth. CP was more frequent (6.7-times) in multifetal pregnancy. Male to female ratio was 1.5: 1. After excluding five infants with major congenital anomalies, 55 (79%) infants were born before 37 weeks' gestation (preterm CP) and 15 (21%) infants were born beyond 37 weeks' gestation (term CP). Eighty-six percent of preterm CP had significant neonatal morbidities, but only 6 out of 15 infants in term CP had significant perinatal events including hypoxic ischemic encephalopathy, meconium aspiration syndrome, and seizure of unknown origin. The most common type of preterm CP was spastic (95%), whereas the types of term CP were more diverse; spastic in 67%, athetoid in 20%, dystonic in 7%, and hypotonic in 7%. Regarding the involved lesions, the most common type was diplegic in preterm CP and quadriplegic in term CP. CONCLUSION: In contrast to preterm CP, term CP had significantly less perinatal risk factors, and their type and involved lesion showed more diverse patterns. These findings may implicate that more heterogenous etiologies are involved in pathogenesis of term CP.
Cerebral Palsy*
;
Female
;
Gestational Age
;
Humans
;
Hypoxia-Ischemia, Brain
;
Incidence
;
Infant
;
Infant, Newborn
;
Male
;
Meconium Aspiration Syndrome
;
Muscle Spasticity
;
Parturition
;
Pregnancy
;
Premature Birth
;
Retrospective Studies
;
Risk Factors
;
Seizures
;
Term Birth*
3.Magnetic resonance evaluation of human mesenchymal stem cells in corpus cavernosa of rats and rabbits.
Yun-Seob SONG ; Ja-Hyeon KU ; Eun-Seop SONG ; Jung-Hoon KIM ; Jin-Suck JEON ; Kong-Hee LEE ; Sook-Ja KIM ; Hee-Jeong CHEONG ; Ik-Sung LIM ; Dongho CHOI ; Jong-Ho WON
Asian Journal of Andrology 2007;9(3):361-367
AIMTo investigate whether the biological process of superparamagnetic iron oxide (SPIO)-labeled human mesenchymal stem cells (hMSCs) may be monitored non-invasively by using in vivo magnetic resonance (MR) imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits.
METHODSThe labeling efficiency and viability of SPIO-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period.
RESULTShMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than 1 X 10 (5) concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections.
CONCLUSIONSPIO-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated non-invasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.
Animals ; Cell Survival ; Contrast Media ; administration & dosage ; Dextrans ; Ferrosoferric Oxide ; Humans ; Iron ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; Male ; Mesenchymal Stem Cell Transplantation ; methods ; Oxides ; Penis ; pathology ; Rabbits ; Rats ; Staining and Labeling ; methods