Pro-oxidant properties of ascorbate have been studied with uses of brain tissues and neuronal cells. Here we address potential mechanism of ascorbate coupling with glutamate to generate oxidative stress, and the role which oxidized ascorbate (dehydroascorbate) transport plays in oxidative neuronal injury. Ascorbate in neurones can be depleted by adding glutamate in culture medium since endogenous ascorbate can be exchanged with glutamate, which enhances ascorbate/ dehydroascorbate transport by depleting ascorbate in the neurons with the glutamate-heteroexchange. However, ascorbate is known readily being oxidized to dehydroascorbate in the medium. Glutamate enhanced the dehydroascorbate uptake by cells via a glucose transporter (GLUT) from extracellular region, and cytosolic dehydroascorbate enhanced lipid peroxide production and reduced glutathione (GSH) concentrations. Iso-ascorbate, the epimer of ascorbate was ineffective in generating the oxidative stress. These observations support the current concept that the high rates of dehydroascorbate transport via a GLUT after the release of ascorbate by glutamate leads to peroxidation, the role of glutamate on ascorbate/ dehydroascorbate recycling being critical to induce neuronal death via an oxidative stress in the brain injury.
Animals ; Ascorbic Acid/analogs & derivatives/pharmacology ; Biological Transport/drug effects ; Cerebral Cortex/*drug effects/*metabolism ; Cytochalasin B/pharmacology ; Dehydroascorbic Acid/*metabolism ; Glutamic Acid/*pharmacology ; Glutathione/metabolism ; In Vitro ; Lipid Peroxidation/*drug effects ; Male ; Oxidation-Reduction/drug effects ; Oxidative Stress/drug effects ; Rats ; Rats, Sprague-Dawley ; Thiobarbituric Acid Reactive Substances/metabolism

We evaluated the effect of the pregnane X receptor agonist, pregnenolone 16 alpha-carbonitrile (PCN) on the expression levels of plasma monoamine transporter (PMAT) in the intestine. Male C57/BL6 mice were divided into two 2 groups: mice in the PCN group (n=3) were administered PCN once a day for 4 days, while those in the control group (n=3) received the same volume of vehicle once a day for 4 days. After the mice were killed 24 h after administration of the last dose of PCN or vehicle, and the expression levels of PMAT in the intestine tissues were isolated and measured the expression level of PMAT using immunohistochemical and western blotting analyses. The expression level of PMAT expression levels in the small intestine increased after PCN treatment. These results suggest that the induction of PMAT may play a clinically significant role by increasing intestinal absorption of PMAT substrates such as metformin.
Animals ; Blotting, Western ; Cell Membrane* ; Humans ; Intestinal Absorption ; Intestine, Small ; Intestines ; Male ; Metformin ; Mice ; Plasma ; Pregnenolone Carbonitrile

No abstract available.
Polyps*

No abstract available.
Epinephrine* ; Tonsillectomy*

No abstract available.
Cholesteatoma* ; Otitis Media* ; Otitis* ; Temporal Bone*

PURPOSE: The Purposes of this study are to identify the circulating etiologic viruses of acute lower respiratory tract infection in children and to understand the relation with clinical diagnosis. METHODS: We obtained a total of 418 nasopharyngeal aspirates from children admitted for their acute lower respiratory tract infections at three tertiary hospitals in Seoul from September 2008 to March 2009. We performed multiplex RT-PCR to identify 14 etiologic viruses and analyzed their emerging patterns and clinical features. RESULTS: Average age of patients was 16.4 months old and the ratio of male to female was 1.36. Viruses were detected in 56.2% of a total of 418 samples. Respiratory syncytial virus (35%) was the most frequently detected and followed by human rhinovirus (22%), human bocavirus, adenovirus, human metapneumovirus, parainfluenza virus, influenza virus and human coronavirus. Co-infection reached 21.9% of positive patients. CONCLUSION: When we manage the patients with acute lower respiratory infectious diseases, we should remind the role of various viral pathogens, which might be circulating by seasons and by local areas.
Adenoviruses, Human ; Child ; Coinfection ; Communicable Diseases ; Coronavirus ; Female ; Human bocavirus ; Humans ; Male ; Metapneumovirus ; Orthomyxoviridae ; Paramyxoviridae Infections ; Respiratory Syncytial Viruses ; Respiratory System ; Respiratory Tract Infections ; Rhinovirus ; Seasons ; Tertiary Care Centers ; Viruses

Purpose: To compare the visual outcomes and corneal aberrations between wavefront-optimized (WFO) and corneal wavefront-guided (WFG) photorefractive keratectomy (PRK) in low to moderate myopia. Methods: Twenty-seven eyes treated with WFO and 29 eyes treated with WFG PRK using a Schwind Amaris 750S Excimer laser were included after 6 months of postoperative follow-up. Uncorrected distance visual acuity, corrected distance visual acuity, refractive errors, corneal higher-order aberrations (HOA) and corneal thickness obtained using a Scheimpflug system, and central ablation depth and volume were evaluated during the preoperative period and again at the postoperative 6-month visits. Results: Postoperatively, uncorrected distance visual acuity, corrected distance visual acuity, manifest spherical equivalent, and refractive astigmatism were improved in both groups, and there was no statistically significant difference between the two groups. There was no significant difference in safety, efficacy, or predictability of the refractive outcome. Postoperative total corneal HOA root mean square (RMS), coma RMS, and spherical aberration were significantly increased in both groups. Among these, only spherical aberration showed a significant difference between the two groups, with greater increase in the WFO group at 6 months postoperatively. The changes in corneal HOA RMS and spherical aberration were smaller in the WFG group, and this benefit was marked in eyes with high HOA RMS (≥0.4 μm) and spherical aberration (≥0.2 μm). Even though ablation volume in the WFG group was much larger than that of the WFO group, there was no significant difference in postoperative central and peripheral corneal thickness between the two groups. Conclusions Both WFO and WFG PRK using a Schwind Amaris 750S laser for low to moderate myopia were safe and effective at improving visual and refractive outcomes. However, WFG PRK induced fewer spherical aberrations than WFO PRK and may be more advantageous for eyes with high HOA root mean square or spherical aberration.

Selective termination can be used to preserve normal fetus from the other fetus with chromosomal, structural abnormality in multifetal pregnancy. This case is about twin pregnant patient who had undergone in vitro fertilization and embryo transfer. In 18 weeks of gestation, we found that one of the fetus had cranical encephalocele and was in concern for the termination by using ultrasound guided intrcardiac injection of 2.5 ml of potassium chloride solution. After performing this procedure the other healthy female newborn was naturally delivered at 38 weeks gestation with weight of 2.8 kg.
Embryo Transfer* ; Embryonic Structures* ; Encephalocele* ; Female ; Fertilization in Vitro* ; Fetus ; Humans ; Infant, Newborn ; Potassium Chloride ; Pregnancy ; Pregnancy Trimester, Second* ; Pregnancy* ; Pregnancy, Twin ; Twins, Dizygotic* ; Ultrasonography

The observation that ascorbate known to retain pro-oxidant properties induces cell death in a number of immortal cell lines, led us to examine its mechanism and whether it is involved in oxidative stress injury in such asocorbate-enriched tissue cells as hepatocytes. In rat liver homogenates, higher concentrations (1 and 3 mM) of ascorbate suppressed lipid peroxide productions but lower concentrations (0.1 and 0.3 mM) did not. In contrast to the homogenate, ascorbate increased lipid peroxide production in liver slices in a concentration dependant manner. Iso-ascorbate, the epimer of ascorbate did not cause an increase the oxidative stress in liver slices. This differential effect between homogenates and liver slices implies that cellular integrity is required for ascorbate to induce oxidative stress. Wortmannin, an inhibitor of the GLUT (glucose transporter) thought to transport dehydroascorbate into cells, inhibited [14C]- ascorbate uptake and suppressed oxidative stress in liver slices. Wortmannin suppressed that [14C]- ascorbate uptake by GLUT following oxidation to [14C]dehydroascorbate. Taken together, these observations support our hypothesis that ascorbate is oxidized to dehydroascorbate by molecular oxygen in solution (i.e., plasma and culture medium) which is then carried into hepatocytes (via a GLUT) where it is reduced back to ascorbate causing oxidative stress.
Androstadienes/pharmacology ; Animals ; Ascorbic Acid/*metabolism/*pharmacology ; Biological Transport ; Edetic Acid/pharmacology ; Glutathione/*metabolism ; In Vitro ; Liver/*drug effects/*metabolism ; Male ; Oxidation-Reduction/drug effects ; Oxidative Stress/*drug effects ; Rats ; Rats, Sprague-Dawley ; Thiobarbituric Acid Reactive Substances/metabolism ; Time Factors

Anemia is a common clinical feature in chronic renal failure(CRF) patients. The primary cause of anemia in CRF is a deficiency of erythropoietin which is normally produced in the kidney. Erythropoietin therapy for correcting anemia has greatly increased the well-being of CRF patients and decreased cardiac morbidity. In Korea approximately 40% of CRF population on maintenance dialysis are using recombinant human erythropoietin(rhEPO). Commercially available rhEPO used in Korea is imported from abroad. Recently LG Chemical Co., produced rhEPO. In this study we evaluated the effect of LG-rhEPO on anemia in 5/6 nephrectomized rats. A total of 23 normal male Sprague-Dawley rats were used. A two-stage 5/6 nephrectomy was performed under ether anesthesia in 15 rats(group 1), additional 4 rats underwent sham operation(group 2). 4 normal rats served as normal control(group 3). rhEPO was injected subcutaneously 8 weeks after surgery. To evaluate the dose effect of rhEPO 250 IU/kg/day was injected in 2 rats, 500IU/kg/day in 4 rats, and 1000 IU/kg/day in 4 rats in group 1. To exclude the effect of LG-rhEPO vehicle, PBS, the same amount of PBS was injected in 4 rats in group 1. One rat each in groups 2 and 3 received rhEPO 250 IU/kg/day, 500 IU/kg/day, 1000 IU/kg /day, and PBS. rhEPO or PBS were injected daily in the first week, every other day in the second week and twice a week in the third week. Body weight and hematocrit level were observed weekly for the initial 8 weeks of observation period and then every other day for 3 weeks of injection and 1 week after discontinuation of injection, and BUN level every week during the study period. Body weight progressively increased in 3 groups. BUN level increased 1 week after 5/6 nephrectomy in group 1 and was stable in group 2 and 3. Hct level was significantly lower after 2 weeks of nephrectomy in group 1. Hct decreased transiently for the first week after sham operation and then returned to the baseline value in group 2. No significant change in Hct level was observed in group 3. After injection of rhEPO, Hct level increased significantly at 2 days in all 3 groups. Hct level increased significanly at 2 days in all 3 groups. Hct did not change in 3 groups with PBS injecion. In conclusion LG-rhEPO is effective in correcting anemia in animal model of CRF. A further study to evaluate the effect rhEPO on anemia in CRF patients and longterm consequences are required.
Anemia* ; Anesthesia ; Animals ; Body Weight ; Dialysis ; Erythropoietin ; Ether ; Hematocrit ; Humans ; Kidney ; Korea ; Male ; Models, Animal ; Nephrectomy ; Rats* ; Rats, Sprague-Dawley