BACKGROUND: Plant extracts have been widely used as important therapeutic drugs for many centuries all over the world. There have been many reports that natural products have various kinds of biological activities such as anti-allergy, anti-inflammatory and antimicrobial activities. Recently, the screening for the efficacy and safety of natural products has been extensively performed. OBJECTIVE: This study was carried out to find a beneficial plant extract possessing excellent antioxidative and anti-melanogenic activities. We have found that the leaf of Robinia pseudo-acacia L. has active substances which are involved in those activities. METHODS: To confirm the antioxidative activity of the extract obtained from the leaves of Robinia pseudo-acacia L., scavenging ability of the extract on DPPH free radicals and its inhibitory effects on lipid autoxidation and peroxidation were investigated. In addition, inhibitory effects of the extract on mushroom tyrosinase as well as melanin biosynthesis in cultured B16 melanoma cells were evaluated. RESULTS: The acacia extract showed not only powerful antioxidative activity but also antimelanogenic acitivity as strong as that of arbutin which is a well known inhibitor of melanogenesis. CONCLUSION: These resulis suggest that the extract from the leaves of Robinia pseudo-acacia L. could be used as a 4ghtening and antioxidative agent for the skin.
Acacia ; Agaricales ; Arbutin ; Biological Products ; Free Radicals ; Mass Screening ; Melanins ; Melanoma, Experimental ; Monophenol Monooxygenase ; Plant Extracts ; Plants ; Robinia* ; Skin

The purpose of this study was to compare the corrosion characteristics between implant fixture and two types of abutment screw; gold screw, titanium screw. The anodic polarization behavior, the galvanic corrosion behavior, and the crevice corrosion behavior of prepared samples were investigated using potentiostat and scanning electron microscope. The results were as follows : 1. Anodic polarization behavior of samples: The primary passivation potential of implant fixture was -420mV, implant abutment was -560mV, titanium screw was -370mV and gold screw was -230mV. All samples were shown to have a high corrosion potential and good formation of passive film. The critical passive current density of gold screw was higher than of other samples and the sample of gold screw showed a unstable passive film formation at passive region. 2. Galvanic corrosion behavior of samples: Contact current density between implant fixture and titanium screw showed 8.023x 10-5C/cm2. Contact current density between implant fixture and gold screw showed 5.142x 10-5C/cm2. 3. Crevice corrosion behavior of samples : The crevice corrosion resistance of sample using titanium screw was higher than that of sample using gold screw, and a severe corrosion morphologies were observed at the fixture-screw interface by the scanning electron microscope.
Corrosion* ; Titanium

To evaluate the possible functional role of serum during the process of parturition, 15 serum samples were collected and analyzed for the nickel concentrations in each 3 groups(Group 1 for the period during parturition, Group 2 for the period from delivery of fetus to delivery of placenta, and Group 3 for the period after delivery of placenta) of normal, uncomplicated full term vaginal delivery and one control group composed of healthy unmarried women in 3rd decades of age. Data revealed that average serum nickel concentration of Group 2(26.6 microgram/l) and Group 1(22.2 microgram/l) were significantly higher than that of Control group(13.7 microgram/l), but Group 3's(13.8 microgram/l) was almost same as Control group's. There were significant negative correlation between age and serum nickel concentration in group 2, and a tendency of higher nickel concentration in women who have no previous experiences of pregnancy than who have previous experiences of pregnancy, although it was not significant. These result could be indicative of close causal relationship between serum nickel concentration and the entire process of parturition.
Female ; Fetus ; Humans ; Nickel* ; Parturition ; Placenta ; Pregnancy ; Single Person

No abstract available.
Apolipoproteins* ; Thyroxine*

No abstract available.

BACKGROUND: Nitric Oxide (NO) has been discovered to be an important endothelium-derived relaxing factor. The exogenous inhaled NO may diffuse from the alveoli to pulmonary vascular smooth muscle and produce pulmonary vasodilation, but any NO that diffuses into blood will be inactivated before it can produce systemic effects. To examine the effects of NO on pulmonary and systemic hemodynamics, NO was inhaled by experimental dogs in an attempt to reduce the increase in pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) induced by hypoxia in dogs. METHODS: Eight mongrel dogs were studied while inhaling 1)50% O2 (baseline), 2)12% O2 in N2 (hypoxia), 3)followed by the same hypoxic gas mixture of O2 and N2 containing 20, 40 and 80 ppm of NO, respectively. RESULTS: Breathing at FIO2 0.12 nearly doubled the pulmonary vascular resistance from 173 56dyn sec cm-5 to 407 139dyn sec cm-5 and significantly increased the mean pulmonary artery pressure from 16 3mmHg to 22 4mmHg. After adding 20~80 ppm NO to the inspired gas while maintaining the FIO2 at 0.12, the mean pulmonary artery pressure decreased (p<0.05) to the level when breathing oxygen at FIO2 0.5 while the PaO2 and PaCO2 were unchanged. The pulmonary vascular resistance decreased significantly and the right ventricular stroke work index returned to a level similar to breathing at FIO2 0.5 by addition of NO into the breathing circuit. Pulmonary hypertension resumed within 3~5 minutes of ceasing NO inhalation. In none of our studies did inhaling NO produce systemic hypotension and elevate methemoglobin levels. CONCLUSIONS: Inhalation of 20~80 ppm NO selectively induced pulmonary vasodilation and reversed hypoxic pulmonary vasoconstriction without causing systemic vasodilation and bronchodilation. Methemoglobin and NO2 were within normal limit during the study.
Animals ; Anoxia ; Dogs ; Endothelium-Dependent Relaxing Factors ; Hemodynamics* ; Hypertension, Pulmonary ; Hypotension ; Inhalation* ; Methemoglobin ; Muscle, Smooth, Vascular ; Nitric Oxide* ; Oxygen ; Pulmonary Artery ; Respiration ; Stroke ; Vascular Resistance ; Vasoconstriction* ; Vasodilation

Lymphoid tumors of the orbit are rare, and sometimes it is not possible either clinically or histologically to differentiate between lymphoid tumor and pseudolymphoma. Some authors assert that the degree of cytologic differentiation appears to be the single most important factor for determining the prognosis of patients with orbital lymphoid lesions. However, the cytomorphologic basis is not so helpful to diagnose and classify our case, which shows some discrepancy between pathological findings and clinical and radiological findings. At first we misdiagnosed our case as orbital malignant lymphoma on the basis of cytomorphology and immunohistochemical study. But no responce to local intensive radiotherapy and the follow up study of the patient suggest orbital pseudolymphoma.
Follow-Up Studies

BACKGROUND/AIMS: It is difficult to clinically distinguish infants with Hirschsprung disease (HD) from those with other causes of intestinal obstruction. Therefore, reliable and safe diagnostic procedures are particularly necessary in infants with early onset symptoms. The purpose of this study was to assess the accuracy of anorectal manometry in the diagnosis of HD in infancy. METHODS: Forty five infants who were suspected of having HD, at Seoul National University Children's Hospital, from May 1999 to July 2002, were enrolled in this study. The diagnostic accuracy of recto-anal inhibitory reflex (RAIR) and transition zone was evaluated. RESULTS: Final diagnosis of HD was made in 18 cases. The presence of transition zone was proved to be very specific (100%), but sensitivity was very low (39%). The sensitivity and specificity of anorectal manometry were 100% and 93% in total 45 infants. However the sensitivity and specificity of this test were 100% in infants older than 3 months. CONCLUSIONS: It could be stated that the diagnostic accuracy of the RAIR is a highly valid diagnostic value for HD in young infancy. It is particularly helpful when clinical and radiological findings are inconclusive.
Diagnosis* ; Hirschsprung Disease* ; Humans ; Infant ; Intestinal Obstruction ; Manometry ; Reflex* ; Sensitivity and Specificity ; Seoul

Twenty-six renal allograft biopsies which showed acute rejection and had renal capsule and medulla in the same specimen were selected in order to compare the severity of acute rejection between superficial cortex, deep cortex and medulla. Disregarding the mid cortical region, the superficial cortex was considered as being one-third of the distance from the renal capsule to the medulla and the deep cortex as being that one-third of the cortex which was adjacent to the medulla. Using semiquantitative histologic analysis the following parameters were compared in superficial cortex, deep cortex, and medulla: interstitial inflammation, edema, tubulitis, and acute tubulointerstitial rejection grade. Also, the presence of lymphocyte activation and polymorphonuclear leukocytes was evaluated. Significantly greater histologic changes of acute rejection were found in the deep cortex vs. superficial cortex for the following parameters: interstitial inflammation(P=0.013), edema (P= 0.023) and tubulointerstitial rejection grade(P=0.016). These findings support the view that biopsies in which deep cortex is not included may result in underestimation of the severity of renal allograft rejection.
Allografts* ; Biopsy* ; Edema ; Graft Rejection ; Inflammation ; Kidney Transplantation ; Lymphocyte Activation ; Neutrophils

The purpose of this study is to present the results of the clerkship evaluation by the students using questionnaire, to discuss the problems revealed in performing the evaluation, and to find out the ways to improve the evaluation. In 2000, the evaluation has been conducted by the Department of Radiology, Seoul National University College of Medicine. The questionnaires filled-up by 97 junior students who completed the clerkship schedule of 2 weeks were analyzed in this study. The questionnaire consisted of 28 structured items with 5-grade scale each, the contents of which included the amount and level of the overall clerkship course and those of 5 subtypes of the clerkship(self-learning, student conference, student seminar, on-site clerkship, and small group discussion with faculty). In small group discussion, enthusiasm of each faculty, delivery effect, and difficulty of the contents were also evaluated. As a result, the most items were assessed to be slightly better than average(3 or 4 point of 5 scale). It was found that the small group discussion was most favored, whereas the student seminar was least favored. Faculty activity was also scored to be better than average. There were no significant differences among all faculty activity. The limitation of this study is failure of assessing the validity and reliability of the student response. In order to improve the evaluation, we should consider following four subjects: First, all the items are carefully developed to enhance the validity and reliability of the evaluation. Second, students should be fully informed of the objects of the evaluation before it is carried out. Third, teaching support facilities for the faculty are needed. Finally, an organization which takes complete charge of the instruction evaluation must be established.
Appointments and Schedules ; Humans ; Reproducibility of Results ; Seoul ; Surveys and Questionnaires