Chungbuk National University Research Articles

Risk Factors of Unprovoked Seizures after Acute Symptomatic Seizures in Children

Purpose : Acute symptomatic seizure is defined as a temporary seizure together with acute systemic, metabolic, or toxic insult in association with an acute central nervous system insult. And unprovoked seizure is defined as seizure without provocating factors. We studied the risk factors of unprovoked seizures after acute symptomatic seizure in children. Methods : We retrospectively reviewed the records of one hundred and ten children with acute symptomatic seizures who were admitted to the pediatric department of Chungbuk National University Hospital between January, 1998 and December, 2003. We analyzed overall risk factors of unprovoked seizures after acute symptomatic seizures involving etiology, incidence, type of seizure, duration and neuroimaging. Results : We analyzed records of 110 children with acute symptomatic seizures aged from 1 month to 17 years. 24 children had unprovoked seizures (21.8%) after acute symptomatic seizures. Causes in order of frequency were encephalopathy, central nervous system infection, brain tumor, cerebrovascular disease. The risk of unprovoked seizure was significantly greater for those with status epilepticus (68.4%) than without status epilepticus, with partial seizure (64.7%) than generalized seizure. And the risk of unprovoked seizure was strongly associated with abnormal finding of electroencephalogram (79.1%) and neuroimaging (41.6%). Conclusion : In conclusion, the leading cause of subsequent unprovoked seizure in children with acute symptomatic seizure was encephalopathy and age specific incidence was high in the group aged 24-72 months. The risk for subsequent unprovoked seizure was greater for those with partial seizure, status epilepticus, abnormal finding of neuroimaging and electroencephalography.

A comparison of provoked seizures and febrile seizures associated with minor infections

Purpose : Febrile seizures occur in childhood associated with a febrile illness not caused by infections of the central nervous system. Provoked seizures are identified with seizures in association with infections that do not usually affect the brain such as gastroenteritis, except criteria for other febrile seizures in this study. We studied seizures provoked by minor extracranial infections, to contrast them with febrile and provoked seizures. Methods : We retrospectively studied one hundred and twenty children with provoked and febrile seizures who visited Chungbuk National University hospital from January, 2000 to December, 2004. Among these children, 36 patients were determined as provoked seizures and 84 patients as febrile seizures. We compared the distribution of minor infections between the patients with provoked seizures and those with febrile seizures, and studied risk factors of subsequent unprovoked seizures after febrile and provoked seizures associated with minor infections. Results : We analyzed the records of 120 children aged from 1 month to 15 years. The common etiologies of minor infections were gastroenteritis and respiratory infections. In the group of febrile seizures, there was a significantly greater proportion of patients with respiratory infections (58.3%) and a lesser proportion of those with gastroenteritis (25.0%). But there was a higher incidence of gastroenteritis (50.0%) in the provoked group. Comparing the distribution of etiologies between the patients with provoked seizures and those with febrile seizures seemed a significant difference. But, there were no difference between the provoked seizures and febrile seizures in the risk for subsequent unprovoked seizures. Conclusion : In conclusion, the leading cause except brain involvement is gastroenteritis in patients with provoked seizures, and respiratory infection in those with febrile seizures. Thus we need prompt recognition of, and medical attention given to, seizures associated with minor infections.

116 EFFECTS OF EARLY PREGNANCY DIAGNOSIS USING ULTRASONOGRAPHY ON THE SUBSEQUENT EMBRYO AND FETAL LOSS IN DAIRY COWS

Under on-farm condition, pregnancy diagnosis can be rapidly and accurately diagnosed using ultrasound. However, the risk of the incidence of embryo and fetal loss following early pregnancy diagnosis has not been fully determined. This study assessed, using ultrasonography, the incidence of embryo and fetal loss in dairy cows following early pregnancy diagnosis after artificial insemination. A positive pregnancy was the recognition of the vesicle, embryo, or fetus by ultrasonography (Sonoace 600 with 5.0- or 7.5-MHz linear array transducer; Medison Co., Ltd., Seoul, Korea). Pregnancies (n = 702) were divided into three groups according to the number of days pregnant diagnosed: early A group (27 to 40 days, n = 143), early B group (41 to 50 days, n = 172), or standard group (51 to 70 days, n = 387). Following a positive pregnancy diagnosis, embryo or fetal loss included all cows with observed abortions and also cows found open after the positive pregnancy diagnosis. Data were analyzed by chi-square test or Fisher's exact test using an SAS program (SAS Institute, Inc., Cary, NC, USA). The incidence rate of embryo or fetal loss within 7 days after pregnancy diagnosis was 1.4, 0.6, and 0.3% for the early A, early B, and standard groups, respectively (P > 0.05). The incidence rate of the embryo or fetal loss during 8 to 30 days after pregnancy diagnosis was not different (P > 0.05) among the early A (0%), early B (1.2%), and standard groups (1.0%). Furthermore, the cumulative incidence rate of the embryo or fetal loss before calving was not different (P > 0.05) among the early A (9.8%), early B (9.3%), and standard groups (5.9%). In conclusion, early pregnancy diagnosis using ultrasonography does not significantly increase the risk of embryo and fetal loss in dairy cows. This work was supported by the research grant of the Chungbuk National University in 2007.

Clinical and OCT Features in Spontaneously Progressive Idiopathic Choriovitreal Neovascularization

A 47-year-old man presented with blurred vision in the right eye and was diagnosed as having idiopathic subfoveal choroidal neovascularization, which progressed to choriovitreal neovascularization in 2 weeks. Optical coherence tomography imaging revealed a subfoveal choroidal neovascularization breaking through the surface of an intact retina and growing as an epiretinal fibrovascular membrane accompanied by vitreomacular traction. Pars plana vitrectomy and removal of the choriovitreal neovascular membrane were performed.

소아에서 생긴 견갑골 관절와 골절편의 상방 전위에 의한 견관절 충돌 운동 장애 - 증례 보고 -

Abstract — Shoulder Impingement Caused by Superiorly Displaced GlenoidFracture Fragment at a Boy - A Case Report - Kyoung-Il Jeong, M.D. � , Kyoung-Jin Park, M.D.*, Yong-Min Kim, M.D., Dong-Soo Kim, M.D., Eui-Sung Choi, M.D., Hyun-Chul Shon, M.D., Hun-Sik Choi, M.D. � , Gee-Kang Park, M.D. Department of Orthopedic Surgery, Chungbuk National University Cheongju, KoreaDepartment of Orthopedic Surgery, choi Hospital, Cheong Ju, Korea � We experienced a case of impingement caused by a bone fragment which was impacted between acromion andhumeral head in a child. The bone fragment came from antero-inferior glenoid fracture. Satisfactory clinical resultsand stability were obtained by arthroscopic bone fragment removal. In case that bone fragment is located in the uppershoulder joint and results in impingement, We must consider not only greater tubercle fracture but also glenoid frac-ture. Magnetic resonance imaging can assist in the preoperative diagnosis. 관절면을침범한관절와골절은임상적으로흔하지않은골절로알려져있다 5) . 또한골절된골편이상방전위되어견관절의충돌운동장애를일으키는경우는보고된예가없다. 이에저자들은견관절관절와골절후골편이상방전위되어서충돌운동장애를일으킨예에서관절경적제거술로운동범위회복을얻었고불안정성은관찰되지않았기에문헌고찰과함께보고하고자한다.

성인의 만성 Monteggia 골절의 수술적 치료 - 2예 보고 -

Abstract — Surgical Treatment of Neglected Adult Monteggia Fracture - 2 Cases Report - Hyun-Chul Shon, M.D. � , Weon-Yoo Kim, M.D., Sang-Eun Park, M.D., Young-Yul Kim, M.D., Jong-Seoung Yoon, M.D., Jong-Hun Ji, M.D.* Department of Orthopedic Surgery, Chungbuk National University College of Medicine � ,Daejon St. Mary ’ s Hospital, The Catholic University of Korea College of Medicine, Korea Neglected adult Monteggia fracture could induce the pain, instability and malformation of elbow. Especially, com-pared with the chronic Monteggia fracture of child, that of adult is difficult to treat and could concur with valgusinstability and deformity, limitation of range of motion and tardy ulnar nerve palsy. But recently, the chronic Mon-teggia fracture of adult could be treated by the 3.5 mm compression plate (DCP) or 3.5 mm pelvic reconstructionplate, so that the result improved more and more. The treatment of choice of the chronic Monteggia fracture of adultis the corrective osteotomy and reduction of radial head or resection of radial head. We experienced two patients whohad neglected Monteggia fracture over 1 year 6 months and 25 years respectively and we want to report the result ofsurgical treatment of chronic Monteggia fracture of adult.

Sulfonylurea is a Non-competitive Inhibitor of Acetohydroxyacid Synthase from Mycobacterium tuberculosis

Department of Chemistry, Hanyang University, Seoul 133-791, Korea. *E-mail: myyoon@hanyang.ac.kr School of Life Sciences, Chungbuk National University, Cheongju 361-763, Korea Nano Mechatronics Research Center, Korea Electronics Technology Institute, Gyeonggi 463-816, Korea Department of Applied Chemistry, Hanyang University, Ansan 426-791, Korea Department of Chemical Education, Taegu University, Kyungsan 713-714, Korea Received July 5, 2006

The Experience of Web-Based Test in Medical Education

Though web-based tests have many advantages, they do not become the main test form in medical education because of their many technical or operational limitations. We have developed a new web-based test system to overcome these limitations and, ultimately, to replace conventional paper and pencil tests. Methods: We developed a web-based test system using a windows 2000 server, mySQL, visual basic 6.0 and ASP script as developing tools. We applied this system to formal examinations. The system was modified and optimized based on users’ demands and problems identified during testing. Results: Since web-based testing was first administered in 2003 to the third-year students during their clinical practice examinations, it has been used in 51 examinations at the College of Medicine in Chungbuk National University. In 2004, it was used in more than a half of the regular examinations at our medical college. At the beginning, lecturers were reluctant to adopt a new test system because of unfamiliarity and fear of additional workload. Shortly, however, they found that they were able to handle the multimedia contents more easily and obtain much information from results analysis without additional work. Examinees also favored web-based tests in presenting multimedia data but had some difficulties in focusing on the test. Overall, examinees’ preference for web‐based tests was comparable to conventional tests. According to user demand, we improved this test system by verifying question formats and making test analysis. Conclusion: Web-based tests can replace paper and pencil tests in medical education. Improvement of this testing system is expected with serious and continuous concerns from examiners.

DNA Topoisomerases I and II Inhibition and Cytotoxicity of Constituents from the Roots of Rubia cordifolia

College of Pharmacy, Yeungnam University, Gyeongsan 712-749, Korea College of Pharmacy, Catholic University of Daegu, Gyeongsan 712-702, Korea. E-mail: woomh@cu.ac.kr College of Natural Science, Yeungnam University, Gyeongsan 712-749, Korea College of Pharmacy, Chungbuk National University, Cheongju 361-763, Korea College of Life Science, Catholic University of Daegu, Gyeongsan 712-702, Korea Received April 8, 2006

Nrf2 Negatively Regulates Osteoblast Differentiation via Interfering with Runx2-dependent Transcriptional Activation

Nrf2 (nuclear factor E2 p45-related factor 2) is believed to be a transcription factor essential for the regulation of many detoxifying and antioxidative genes in different tissues. In the present study, we investigated the role of Nrf2 in the regulation of osteoblastic differentiation. nrf2 mRNA expression was significantly up-regulated in femur isolated from ovariectomized mice, whereas in situ hybridization analysis revealed that up-regulation of nrf2 mRNA was mainly found in osteoblasts attached on cancellous bone in femur of ovariectomized mice. Expression of Nrf2 protein was also seen in osteoblasts in neonatal mouse tibia and calvaria. In osteoblastic MC3T3-E1 cells stably transfected with nrf2 expression vector, significant inhibition was seen in the maturation-dependent increase in alkaline phosphatase activity as well as the mineralized matrix formation. Stable overexpression of nrf2 significantly impaired Runx2 (runt-related transcription factor 2)-dependent stimulation of osteocalcin promoter activity and recruitment of Runx2 on osteocalcin promoter without affecting the expression of runx2 mRNA. Coimmunoprecipitation and mammalian two-hybrid assay revealed a physical interaction between Runx2 and Nrf2, whereas cellular distribution of endogenous Runx2 was not apparently changed by nrf2 overexpression in MC3T3-E1 cells. Alternatively, Nrf2 bound to antioxidant-responsive element-like-2 sequence of osteocalcin promoter. The inhibition by nrf2 on runx2-dependent osteocalcin promoter activity was partially prevented by the introduction of reporter of deletion mutant for ARE-like-2 sequence of osteocalcin promoter. These data suggest that Nrf2 may negatively regulate cellular differentiation through inhibition of the Runx2-dependent transcriptional activity in osteoblasts.

밝은 장주기 변광성관측을 위한 자동관측시스템 구축

밝은 장주기 변광성들을 효율적으로 관측하기 위하여 충북대학교 교내에 자동관측시스템을 구축하였다. 이 시스템의 구성을 위하여 기존의 Meade사 LX200 40cm 망원경의 구동부를 개선하고, ObsTool II라는 관측프로그램에 의하여 망원경, CCD 카메라, 돔의 제어가 하나의 프로그램으로 가능하도록 구성하였다. ObsTool II는 COM(Common Object Module)을 이용하여 개발한 프로그램으로서 시스템을 구성하는 망원경이나 CCD 카메라의 기종이 바뀌어도 큰 수정 없이 시스템을 재구성할 수 있다. 또한, 이 시스템은 광전측광관측처럼 변광성, 비교성, 검토성 등을 오가는 기능을 가지고 있어 CCD의 시야에 적당한 비교성이 함께 들어오지 않더라도 관측이 가능하다. 이 논문에서 새롭게 구성한 자동관측시스템의 안정성을 검토하기 위하여 W UMa형 변광성 V523 Cas와 자기 격변변광성 TT Ari를 관측하여 그 결과를 제시하면서 본 논문에서 개발한 시스템들의 활용가능성을 토의하였다. An automatic observation system has been constructed at Chungbuk National University for the purpose of monitoring the bright and long period variable stars effectively. We improved the control part of 40cm telescope of the LX200 and developed n observing software ObsTool II so that the telescope, CCD camera and dome can be controlled in one software. ObsTool II is a COM (Common Object Module) based software, which can be easily reprogrammed in case that a new telescope or CCD camera is installed. Because this system has an additional function in which the telescope can switch the variable, comparison, and check stars respectively as like a photoelectric observation, we can observe the variable star even if the CCD view field does not contain the comparison star with the variable star. In order to check the system stability a W UMa type variable V523 Cas and a magnetic cataclysmic variable TT Ari have been observed with the constructed system and the results have been discussed in context with the possibility of a further application of our automatical observation system.

Foreign Body in the Orbit Associated with Blowout Fracture

Department of Otolaryngology, College of Medicine, Chungbuk National University, Cheongju, Korea Correspondence to Dr. Jin, Department of Otolaryngology, Chungbuk National University Hospital, 62 San Gaeshin-dong, Heungdok-gu, Cheongju, Korea, [email protected]

Evidence for the Presence of acis-acting Element in the Coding Region of the Japanese Encephalitis Virus Capsid Protein

Evidence for the Presence of a cis-acting Element in the Coding Region of the Japanese Encephalitis Virus Capsid Protein Sang-Im Yun, Yu-Jeong Choi, Byung-Hak Song, Jeong-Min Kim, Shien-Young Kang and Young-Min Lee Department of Microbiology, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Korea Research Institute of Veterinary Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea

The Use of Complementary and Alternative Medicine in Patients with a Urological Malignancy

From the Department of Urology, Asan Medical Center, University of Ulsan, Seoul, Armed Forces Capital Hospital, Seongnam, Ghil Hospital, Gachon Medical School, Incheon, Pusan National University, Busan, Korea University, Seoul, Chungbuk National University, Cheongju, Yonsei University, Seoul, Yonsei University Wonju College of Medicine, Wonju, Kyung Hee University, Seoul, Samsung Medical Center, Sungkyunkwan University, Seoul, Wonkwang University, Iksan, The Catholic University, Seoul, Ulsan University Hospital, University of Ulsan, Ulsan, Kyungpook National University, Daegu, Korea

The Newly Adopted Integrative Curriculum at Chungbuk National University Medical School

Purpose: Entering a new century in the year 2001, Chungbuk National University Medical School(CNUMS) decided to adopt a fully integrative curriculum. This plan has been executed from 2002 to 2005. we are now at a point to assess this new curriculum and further improve it for the future. Methods: We studied ‘Curricula for Undergraduate’ from Chungbuk National University and ‘The Present Educational Status of Medical College’ the Dean’s Council of Korean Medical College published from 1987 to 2005. Results: All lectures consisted of integrated lectures between the basic and clinical medical sciences. First and second year lectures focused on the horizontal integration of basic and clinical medical sciences, respectively. Also lectures between the first and second years formed longitudinal integration and purposeful repetition. Practical Classes were comprised of essential major clinical medicines and elective clinical medicines. Generally, lectures were reduced to introduce active learning subjects including problem-based learning(PBL), communicational skills, objective structured clinical examination(OSCE)/clinical performance examination(CPX), basic clinical skills, community medicine, and health and society. Conclusion: The curriculum of CNUMS was changed from the traditional department-centered lectures to integrated organ-centered integrated lectures and practical classes. However, further innovation is required on the inside of curriculum.

육계 도축 시 전기 실신 시간이 육질에 미치는 영향

H. S. Chae*, C. N. Ahn*, Y. M. Yoo*, J. S. Ham*, S. G. Jeong*, J. M. Lee* and Y. I. Choi**National Livestock Research Institute, RDA*,Dept. of Animal Science, Chungbuk National University**ABSTRACTThis study was investigated the effect of the length of stunning time on pH, water holdingcapacity(WHC), cooking loss(CL), meat color and incidence rate of blood spot in broiler carcass.One-hundred and forty broiler chickens were slaughtered by three different length of stunning times(5 sec.,8 sec., 11 sec.) with the same electrical frequency(255Hz) and 50 voltage in a commercial abattoir. TheWBS values and cooking loss of breast muscle were increased with increasing the stunning time, whileWHC of breast muscle were decreased. Lightness(L* value) and yellowness(b* value) scores of leg muscleand skin stunned with 50V, 255Hz, 8 sec, 11 sec. were higher than those of broilers stunned with 50V,255Hz, 5sec(P<0.05). But, there was no significant difference in color on breast and wing muscle. Insubjective evaluation, frequence of the first grade had a trend of being increased by extending the stunningtime. There was only a few cases of PSE chicken with 0.02%, while blood spot was observed at thehighest rate for the 5 sec. treatment. TBARS indicated that a longer length of stunning resulted in ahigher rate of fat oxidation. This experiment demonstrated that the length of stunning time has asignificant effect on meat quality and its stability during chiller storage.(Keywords : Broiler, Stunning time, Meat quality)

Adsorption of Microcystin LR by Activated Carbon Fibers

Blooms of toxic microorganisms are commonly found in freshwater in several areas of the world. Freshwater poisonings are mainly caused by species of cyanobacteria, also known as blue-green algae. They develop in eutrophic water wherever proper conditions for their growth are found, including a mild wind, a water temperature between 15 and 30 C, a neutral or alkaline pH and a rather high level of mineral nutrients. As a consequence of the extended use of nitrates and phosphates, blooms occur more and more frequently. There is a risk that these blooms contaminate water supplies that are used as recreational areas or as drinking water reservoirs. This is a serious water quality problem because many of the cyanobaterial species are able to produce potent toxins. The most frequently reported toxins are hepatotoxins. They are classified as microcystins and nodularins, the former representing the largest group. All microcystins have a common cyclic heptapeptide structure consisting of (-DAla-L-X-D-MeAsp-L-Z-Adda-D-Glu-Mdha), where MeAsp stands for erythro-β-methylaspartic acid, Mdha for Nmethyldehydroalanine, Adda for 3-amino-9-methoxy-2,6,8trimethyl-10-phenyldeca-4,6-dienoic acid, and X and Z for the variable amino acids that give its name to the molecule. For example, microcystin LR has X = Leusine and Z = Arginine, microcystin RR has X = Arginine and Z = Arginine. Microcystins can be synthesized by various genera of cyanobacteria such as Microcystis, Oscillatoria, Anabaena or Nostoc. They have been responsible for the poisoning of fish, birds, wild and domestic animals in many countries. Adverse effects on human health have also been recognized. Recent researches have actually shown that microcystins act as type 1, 2A and 3 protein phosphatase inhibitors, as well as tumor promoters when present in nanomolar concentrations. Nowadays, WHO guidelines have been established for the monitoring of microcystins in water. Maximal values of 0.1 μg/L in drinking water for a long term exposure or 1 μg/L for a short term exposure have been proposed on the basis of laboratory experiments of toxicity on mice and pigs. Blooms of blue-green algae, which have been increasing in recent years, have the potential to cause problems for the water supply industry. Recent occurrences of toxic algal blooms have highlighted the potential risk of toxins entering drinking water supplies, and posing a threat to public health. This necessitates a need for research to determine the effectiveness of different water treatment processes for removing algal toxins. At present, slow sand filtration has shown some potential to remove toxins by biodegradation. However, not all types of toxin were successfully removed. The limited amount of work on ozonation has shown that it is an effective process for removing toxins, even with relatively low ozone doses. Ozonation does produce by-products, but these have been shown to be non-toxic. Activated carbon adsorption has been shown to be capable of effectively removing different toxins. With powdered activated carbon (PAC), high PAC doses were generally required. However, most of the tests were conducted with higher toxin concentrations than would probably be found in raw waters. Granular activated carbon (GAC) can effectively remove toxins, but the studies have not fully assessed the most suitable GAC. In addition, the PAC doses required may be impractical to dose at a treatment works. For GAC adsorption to be effective, contact times of more than 15 minutes should be considered, assuming that microcystin does not biodegrade on the GAC. Activated Carbon Fiber (ACF) is a recently developed adsorbent which has more superior adsorbing capacity to active carbons. Recently, Chungbuk National University (Chungju, South Korea) has developed a manufacturing process of ACF by using various precursors of fabrics, cottons, viscous rayons and mixed fabrics etc. ACF made by fabrics and cottons has never been used to remove microcystins in water sample. There is no published data available that has investigated water treatment processes using ACF made by fabrics and cottons, In this study we aimed to obtain basic data on the adsorption of the toxic peptide, microcystin LR to the ACF that was prepared in Chungbuk National University. Our future goal would be to identify and develop ACF treatment processes suitable for removal of algal toxins and to provide a basis for estimating potential water treatment usage.

The Effects of 1‐Nitropyrene on Oxidative DNA Damage and Expression of DNA Repair Enzymes

Nitropyrenes (NPs) present in diesel and gasoline emissions are mutagenic and carcinogenic in experimental animals. Nitro-reduction of 1-NP causes oxidative stress. It is unclear whether 8-hydroxydeoxyguanosine (8-OH-dG) is produced from 1-NP and whether it contributes to the carcinogenic activity of 1-NP. In this study, we measured the level of reactive oxygen species (ROS) in cultured human lung epithelial cells after exposure to 1-NP and the intracellular level of 8-OH-dG and expression level of the 8-OH-dG repair enzymes. As results, 1-NP induced the generation of 8-OH-dG via ROS, but 8-OH-dG repair enzymes prevented an increase of 8-OH-dG formation in cellular DNA of the A549 cell line below 250 microM of 1-NP. These data suggest that 1-NP can induce oxidative DNA damage by generation of ROS, which may play a role in the carcinogenesis induced by 1-NP. These data also suggest that individuals with impaired DNA repair enzymes might be more susceptible to lung cancer induced by 1-NP.

양송이 즙-금 전극을 이용한 페놀의 전기화학적 정량

Mushroom-juice Based Gold Electrode for the Determination of Phenols Hyoshik Kwon*, Eunhwa Jin, Kil-Joong Yoon, and Yongnam Pak School of Science Education, Chungbuk National University, Cheongju 361-763, Korea Division of Applied Sciences, Chongju University, Cheongju 360-764, Korea Department of Chemistry Education, Korea National University of Education, Chungbuk 363-791, Korea (Received November 9, 2004)

Face recognition using a fuzzy fisherface classifier

In this study, we are concerned with face recognition using fuzzy fisherface approach and its fuzzy set based augmentation. The well-known fisherface method is relatively insensitive to substantial variations in light direction, face pose, and facial expression. This is accomplished by using both principal component analysis and Fisher's linear discriminant analysis. What makes most of the methods of face recognition (including the fisherface approach) similar is an assumption about the same level of typicality (relevance) of each face to the corresponding class (category). We propose to incorporate a gradual level of assignment to class being regarded as a membership grade with anticipation that such discrimination helps improve classification results. More specifically, when operating on feature vectors resulting from the PCA transformation we complete a Fuzzy K-nearest neighbor class assignment that produces the corresponding degrees of class membership. The comprehensive experiments completed on ORL, Yale, and CNU (Chungbuk National University) face databases show improved classification rates and reduced sensitivity to variations between face images caused by changes in illumination and viewing directions. The performance is compared vis-à-vis other commonly used methods, such as eigenface and fisherface.