Human neural stem cell transplantation reduces spontaneous recurrent seizures following pilocarpine-induced status epilepticus in adult rats

Transplantation of neural stem cells (NSCs) can replace lost neurons and improve the functional deficits. Cell transplantation strategies have been tried in the epileptic disorder, but the effect of exogenous NSCs is unknown. In this study, we attempted to test the anti-epileptogenic effect of NSCs in adult rats with status epilepticus. Experimental status epilepticus was induced by lithium-pilocarpine injection, and beta galactosidase-encoded human NSCs were transplanted intravenously on the next day of status epilepticus. Spontaneous recurrent seizures were monitored with Racine's seizure severity scale. Immunohistochemistry with anti-beta gal, Tuj-1, NeuN, GFAP, CNPase, GluR2, parvalbumin, and GABA were performed and extracellular field excitatory postsynaptic potentials (fEPSP) were recorded. Human NSCs suppressed spontaneous recurrent seizure formation and transplanted NSCs were differentiated into GABA-immunoreactive interneurons in the damaged hippocampus. Amplitude of fEPSP in the hippocampal CA1 was reduced, which was reversed by picrotoxin. These findings suggest that NSCs could be differentiated into inhibitory interneurons and decrease neuronal excitability, which could prevent spontaneous recurrent seizure formation in adult rats with pilocarpine-induced status epilepticus.     

Diffusion-weighted MRI and 99mTc-HMPAO SPECT in delayed relapsing type of carbon monoxide poisoning: evidence of delayed cytotoxic edema

BACKGROUND: Carbon monoxide (CO) is a common cause of poisoning, and its sequelae include a progressive (25%) and a delayed relapsing form (75%). We report the diffusion-weighted MRI (DWI) findings in the delayed relapsing form of CO poisoning and characterize the types of edema. METHODS: From November 1, 2000 to June 1, 2003, 5 consecutive patients (2 men, 3 women, range of age: 54-67 years), who had the delayed relapsing type of CO poisoning, underwent DWI, conventional MRI, MR angiography and SPECT. CO poisoning was diagnosed by the presence of a typical clinical history, an abnormally increased level of serum carboxyhemoglobin and MRI findings. Apparent diffusion coefficient (ADC) values were measured in all of the abnormal lesions with visual inspection of DWI and T(2)-weighted echo-planar imaging. RESULTS: DWI showed high signal intensities in bilateral periventricular white matter, in the splenium of the corpus callosum, in internal capsules, and brainstem showing moderately decreased ADC values. In the globus pallidus, the ADC values were rather increased with low signal intensities on DWI. Brain SPECT showed decreased perfusion in bilateral white matter and some parts of the cerebral cortex, which correlated well with the DWI findings. CONCLUSIONS: We suggest that prominent, symmetric restricted diffusion can occur in periventricular white matter, brainstem, and corpus callosum after the delayed relapsing type of CO poisoning. Delayed cytotoxic edema can occur in this setting, which provides a new guidance for the pathogenesis of CO poisoning and the differential diagnosis of white matter diseases.     

Autologous cardiomyocyte transplantation using a biodegradable polymer scaffold

BACKGROUND: To achieve a more reliable way of transplanting cardiomyocytes, we conducted an autologous cardiomyocyte transplantation using a biodegradable scaffold, instead of a syringe injection, as a vehicle for transporting cells in an ovine myocardial infarction model. MATERIALS AND METHODS: A myocardial infarction was created in sheep using sequential ligation of the homonymous artery and its diagonal branch. Autologous cardiomyocytes from the right ventricular infundibulum were cultured and seeded onto a biodegradable polymer scaffold. Three months after creating myocardial infarction, the two animals were re-anesthetized and cardiomyocyte-seeded scaffolds were implanted in the infarcted area. The animals were kept alive for a further month, and then sacrificed for postmortem heart examinations. Light microscopic analysis and an immunohistochemical study for myoglobin were performed. RESULTS: On postmortem gross examinations, the polymer scaffolds were visible in the background of well-demarcated thin-walled anteroseptal myocardial infarcts. Microscopic analysis showed abundant myoglobin-stained cells between the fiber strands of the polymer scaffolds. However, there is a possibility that some of these cells might have been giant cells reacting to foreign material. CONCLUSION: The transplantation of cultured autologous cardiomyocytes into an infarct region using a biodegradable scaffold instead of syringe injection provides another promising option for cardiomyocyte transplantation, which warrants further study.     

Parthenogenetic activation of rat oocytes and their development (in vitro)

The present study was performed to determine suitable methods for parthenogenetic activation and subsequent development of rat oocytes in vitro. In the first series of experiments, the ability of electrical pulses, strontium, ethanol and ionomycin to activate Sprague-Dawley (SD) rat oocytes was examined. The synergistic effect of strontium and cycloheximide or puromycin was also examined in the second series of experiments. In the third series of experiments, the development of F1 hybrid (SD x Dark Agouti) parthenotes activated with different concentrations of strontium (10-0.08 mM) was compared with that of SD parthenotes. The effect of the timing of activation (10 min and 2, 4 and 6 h after cervical dislocation) was also assessed in a fourth series of experiments. The oocytes activated by strontium showed higher pronuclear formation and cleavage rates than those in the other groups (P < 0.05). Higher blastocyst development was obtained from parthenotes activated by strontium and strontium-cycloheximide compared with the strontium-puromycin group (P < 0.01). However, the total cell number of blastocysts from the strontium-cycloheximide activation group was higher than that of other groups (P < 0.05). With strontium (2.5-10 mM) treatment, 40.9% of blastocysts were obtained from F1 hybrid oocytes, whereas 22.9% were obtained from SD (P < 0.01). The oocytes activated 10 min or 2 h following cervical dislocation showed higher blastocyst development than those of the 4 and 6 h groups (P < 0.01). These results suggest that strontium-cycloheximide produces the highest parthenogenetic activation rate in the rat and that oocytes must be activated by 2 h after cervical dislocation.     

Biphasic changes in the Ser-9 phosphorylation of glycogen synthase kinase-3beta after electroconvulsive shock in the rat brain

BACKGROUND: Glycogen synthase kinase-3beta (GSK-3beta) plays important roles in intracellular signaling pathways. Phosphorylation at Ser-9 reduces the activity of GSK-3beta, while phosphorylation at Tyr-216 enhances its activity. Mood stabilizing agents increase the phosphorylation of GSK-3beta at Ser-9, and hence inhibit its activity. This property has been considered to be related to the therapeutic action of these drugs. The effect of electroconvulsive shock (ECS), an effective mood stabilizing treatment, on the phosphorylation of GSK-3beta is not known yet. METHODS: In this study, the effect of ECS on the phosphorylation of GSK-3beta was examined in the rat frontal cortex, hippocampus, and cerebellum by Western blot analysis using antibodies specific for Ser-9 or Tyr-216 phosphorylated GSK-3beta. RESULTS: In all regions, the phosphorylation of GSK-3beta at Ser-9 was decreased immediately after ECS, but then increased above basal level within 10 min and maintained at an increased level for more than 30 min. Meanwhile, the phosphorylation at Tyr-216 of GSK-3beta did not show any significant changes after ECS. CONCLUSIONS: These results showed that ECS could induce biphasic changes in the Ser-9 phosphorylation of GSK-3beta in the rat brain, suggesting some similarities, as well as differences, in the actions of mood stabilizers and ECS in the signal transduction mechanisms of the brain.     

Videostrobokymographic analysis of benign vocal fold lesions

OBJECTIVES: Videostrobokymography (VSK) has recently been introduced. The aim of this study was to analyze vibratory patterns and objective parameters in various benign vocal fold lesions using VSK and to examine the efficacy of VSK in clinical applications. MATERIAL AND METHODS: Using VSK, we analyzed the vibration patterns of normal vocal folds, various benign lesions such as nodules, polyps, cysts and Reinke's edema and cases of unilateral vocal fold paralysis. We also calculated the objective parameters open quotient and asymmetric index and compared them with their mean values in normal controls. RESULTS: In nodules, polyps and cysts, the open quotient at the site of the lesion was similar to the mean value in the normal controls; however, on the other parts of the vocal folds, it was much larger than the normal mean value. In Reinke's edema, irregular and asymmetric vibrations were observed. The posterior area of the vocal folds showed larger open quotients than the anterior area. In unilateral vocal fold paralysis, irregular vocal fold vibration and incomplete closure of the vocal folds were documented. Much larger asymmetric indices were calculated for unilateral vocal fold paralysis than in normal controls or for other lesions. The asymmetric index may be a good quantitative parameter of vibration in patients with vocal fold paralysis. CONCLUSION: This study demonstrated that VSK could generate clear quantitative documentation of fine vibrations of vocal folds in many different types of benign lesion. VSK has the potential to be an effective tool for the quantitative analysis of vibratory patterns of vocal folds in clinical settings.     

Facial anthropometric dimensions of Koreans and their associations with fit of quarter-mask respirators

Past studies on respirator fit or performance have mostly been done for Whites or male subjects, and little attention has been paid to minorities and Asians. To fill this gap, this study was designed to provide facial anthropometric data for Koreans and to analyze the association between facial dimensions and respirator fit factors for three brands of quarter-mask respirators, two domestic and one imported brand, using a Portacount 8020. A total of 110 university student subjects, 70 males and 40 females volunteered for participation in the study. The results of this study showed that Korean males and females have different facial dimensions as compared with those of White males and females. Unexpectedly, the imported respirator performed better than the domestic respirators. Males were found to achieve better respirator fit than females regardless of respirator brands tested. The regression analysis found no common prognostic variables with the three respirator brands studied. A stepwise logistic regression analysis was conducted to find predictive facial dimensions with respirator fits. Some facial dimensions were found to be statistically significant, but these dimensions are different from the traditionally recommended facial dimensions of face length and lip width for quarter mask. To improve respirator fit for Koreans, these different facial characteristics need to be considered in the design of quarter mask respirators.