1.A review of mathematical models and strategies for Pandemic Influenza Control.
Seong Sun KIM ; Sang Won LEE ; Bo Youl CHOI
Korean Journal of Epidemiology 2008;30(2):156-167
Despite many countries' current effort to make mathematical models for pandemic influenza (PI) and predict the impact of an outbreak, natural history of PI is remains incomplete, so that any assumption or model is unable to completely predict the impact. Our objective is to review and summarize previous studies on parameters and models of PI, and to make suggestions for the controls in order to decrease the impact of PI. We searched PubMed to retrieve literature about the PI model systematically . Reference lists and review papers on the topic were searched, as well. We found 35 articles that examined the PI model over the period of May 2003 to August 2008. We reviewed modelling methods that were focused on the PI, and their parameters i.e. latent period, and basic reproductive number (R0). Then, we summarized PI controls: antivirals, vaccines, and social distancing. Recent studies showed with mathematical models that Targeted Antiviral Prophylaxis (TAP) is the best strategy for containing PI at the source. In case of an outbreak, quick measures of social distancing, including therapeutic and prophylatic antiviral for cases and closing contacts - school closure, workplace closure, border quarantine, and home isolation - were found to be most effective. We reviewed strengths and weaknesses of models that are adaptable in Korea, and summarized their parameters. It is our hope that these strategies with various interventions give important information for future preparation for and response to PI in Korea.
Antiviral Agents
;
Humans
;
Influenza, Human
;
Korea
;
Models, Theoretical
;
Natural History
;
Pandemics
;
Quarantine
;
Vaccines
2.The Surgical Result of Pituitary Adenoma by Transsphenoidal Approach.
Woo Youl JEON ; Oh Lyong KIM ; Seong Ho KIM ; Jang Ho BAE ; Byung Yon CHOI ; Soo Ho CHO
Journal of Korean Neurosurgical Society 2001;30(11):1278-1283
OBJECTIVE: Transsphenoidal approach(TSA) has been used as useful operative method for pituitary tumor but is still controversal in case of cavernous sinus invasion or severe suprasellar extension. This study was performed to evaluate the surgical result, recurrence, effect of adjuvant treatment, especially in cases of suprasellar extension or cavernous sinus invasion. MATERIAL AND METHODS: We studied 56 cases of surgically treated pituitary adenoma that we were able to follow up, treated by TSA from 1993 to 1998. There were 24 cases of suprasellar extension and 11 cases of cavernous sinus invasion. The medical records and radiological findings were reviewed. Surgical results including hormonal function and recurrence rates were analyzed according to extent of tumor invasion. Mean follow-up period was 19.1 months. RESULTS: Tumors with suprasellar extension were removed totally in 54%, whereas total tumor removal was possible only in 38% with cavernous sinus invasion. Overall of recurrence rate was 14% and recurrence rate was 25% in suprasellar extension and 9% in cavernous sinus invasion. In cases of both suprasellar extension and cavernous sinus invasion, tumors that were treated by TSA and radiation showed recurrence rate of 7%, whereas those treated by surgery alone showed 28% of recurrence. CONCLUSION: Transsphenoidal approach is safe and useful operative method for pituitary adenoma and adjuvant therapy including radiation therapy is effective means to decrease the recurrence in cases of suprasellar extension or cavernous sinus invasion.
Cavernous Sinus
;
Follow-Up Studies
;
Medical Records
;
Pituitary Neoplasms*
;
Recurrence
3.Microsatellite Instability and Its Clinicopathologic Significance in Korean Gastric Cancer Patients.
Tae Sung SOHN ; Kwang Soo LEE ; Seong Ho CHOI ; Yong Il KIM ; Youl Hee CHO ; Gu KONG
Journal of the Korean Surgical Society 1999;56(4):539-547
BACKGROUND: Genomic instability has been reported as a novel mechanism of tumorigenesis. Microsatellites are short tandemly repeated nucleotide sequences throughout the human genome. Widespread somatic mutations in these sequences due to the loss or gain of one or more repeated units are termed as microsatellite instabilites (MI). MI have been found to be the result of numerous replication errors due to mutations in mismatched repair genes. Recently, MI have been recognized as the causes of the increased mutation rates of cancer cells. An elevated mutation rate manifested by MI may also affect various genes that are essential for normal cell function and growth, thus contributing to tumor initiation, promotion, and progression. We investigated the frequency of MI in a series of 44 gastric carcinomas in an attempt to clarify the role of these genetic alterations in gastric carcinogenesis and to see whether the cases with MI displayed any clinical significance and morphologic features and/or whether they showed distinctive relations with any clinicopathologic characteristics. METHODS: We analyzed 44 gastric carcinomas and paired samples from non-neoplastic mucosa of Korean patients who had undergone a gastrectomy. The samples were immediately frozen in liquid nitrogen and stored at 70oC until use. High molecular weight DNAs were isolated by standard methods only from cases whose were composed of more than 50% tumor cells. Ten loci of microsatellites were used in this study: D3S1766, D3S1339, D3S1029, D9S162, D9S171, INF-a, D11S925, D11S1818, D11S35, and D11S1284. The MI analysis was performed by Polymerace Chein Reaction (PCR) with 33P-labelled primers. PCR products were separated on 6% polyacrylamide gel containing 7M urea, and autoradiographed. H-E stained sections were used to review the pathologic features. The relationships between MI incidence and clinicopathologic findings were statistically tested. RESULT: Analysis of the 44 cases at the 10 loci of microsatellites allowed us to identify 19 instabilities (43%): 15 cases at 1 locus, 2 cases at 2 loci, and 2 cases at multiple loci. The incidence of MI was remarkably increased in cases with poor differentiation and node metastasis (p=0.067 and p=0.007, respectively). Comparing the histologic type (diffuse vs. intestinal type), the diffuse type of carcinoma had a higher incidence; however, there was no statistical significance (55% vs. 33%, p=0.108). There was no significant correlation between MI and other prognostic variables including location, tumor size, and distant metastasis. CONCLUSIONS: These results confirm that the mutator phenotype plays in a certain role gastric carcinogenesis. The gastric cancers with MI were correlated with the worse prognostic variables of poor differentiation and node metastasis, suggesting that MI appear to be useful as possible indicators of the worst prognosis and represent important genetic alterations associated with tumor progression in gastric carcinogenesis.
Base Sequence
;
Carcinogenesis
;
DNA
;
Gastrectomy
;
Genome, Human
;
Genomic Instability
;
Humans
;
Incidence
;
Microsatellite Instability*
;
Microsatellite Repeats*
;
Molecular Weight
;
Mucous Membrane
;
Mutation Rate
;
Neoplasm Metastasis
;
Nitrogen
;
Phenotype
;
Polymerase Chain Reaction
;
Prognosis
;
Stomach Neoplasms*
;
Urea
4.Traumatic Brain Injury in Children under Age 24 Months: Analysis of Demographic Data, Risk Factors, and Outcomes of Post-traumatic Seizure.
Sang Youl YOON ; Yeon Ju CHOI ; Seong Hyun PARK ; Jeong Hyun HWANG ; Sung Kyoo HWANG
Journal of Korean Neurosurgical Society 2017;60(5):584-590
OBJECTIVE: Traumatic brain injury (TBI) in children under age 24 months has characteristic features because the brain at this age is rapidly growing and sutures are opened. Moreover, children this age are completely dependent on their parents. We analyzed the demographic data and risk factors for outcomes in TBI patients in this age group to elucidate their clinical characteristics. METHODS: We retrospectively reviewed the medical records and radiological films of children under 24 months who were admitted to Kyungpook National University Hospital from January 2004 to December 2013 for TBI. Specifically, we analyzed age, cause of injury, initial Glasgow coma scale (GCS) score, radiological diagnosis, seizure, hydrocephalus, subdural hygroma, and Glasgow outcome scale (GOS) score, and we divided outcomes into good (GOS 4–5) or poor (GOS 1–3). We identified the risk factors for post-traumatic seizure (PTS) and outcomes using univariate and multivariate analyses. RESULTS: The total number of patients was 60, 39 males and 21 females. Most common age group was between 0 to 5 months, and the median age was 6 months. Falls were the most common cause of injury (n=29, 48.3%); among them, 15 were falls from household furniture such as beds and chairs. Ten patients (16.7%) developed PTS, nine in one week; thirty-seven patients (61.7%) had skull fractures. Forty-eight patients had initial GCS scores of 13–15, 8 had scores of 12–8, and 4 had scored 3–7. The diagnoses were as follows: 26 acute subdural hematomas, 8 acute epidural hematomas, 7 focal contusional hemorrhages, 13 subdural hygromas, and 4 traumatic intracerebral hematomas larger than 2 cm in diameter. Among them, two patients underwent craniotomy for hematoma removal. Four patients were victims of child abuse, and all of them had PTS. Fifty-five patients improved to good-to-moderate disability. Child abuse, acute subdural hematoma, and subdural hygroma were risk factors for PTS in univariate analyses. Multivariate analysis found that the salient risk factor for a poor outcome was initial GCS on admission. CONCLUSION: The most common cause of traumatic head injury in individuals aged less than 24 months was falls, especially from household furniture. Child abuse, moderate to severe TBI, acute subdural hematoma, and subdural hygroma were risk factors for PTS. Most of the patients recovered with good outcomes, and the risk factor for a poor outcome was initial mental status.
Accidental Falls
;
Brain
;
Brain Injuries*
;
Child Abuse
;
Child*
;
Contusions
;
Craniocerebral Trauma
;
Craniotomy
;
Demography
;
Diagnosis
;
Family Characteristics
;
Female
;
Glasgow Coma Scale
;
Glasgow Outcome Scale
;
Gyeongsangbuk-do
;
Hematoma
;
Hematoma, Subdural, Acute
;
Hemorrhage
;
Humans
;
Hydrocephalus
;
Infant
;
Interior Design and Furnishings
;
Male
;
Medical Records
;
Multivariate Analysis
;
Parents
;
Retrospective Studies
;
Risk Factors*
;
Seizures*
;
Skull Fractures
;
Subdural Effusion
;
Sutures
5.Subdural Hygroma Following Pterional Approach for Cerebral Aneurysmal Surgery.
Chan Youl PARK ; Byung Yon CHOI ; Seong Ho KIM ; Jang Ho BAE ; Oh Lyong KIM ; Soo Ho CHO
Journal of Korean Neurosurgical Society 1996;25(8):1602-1606
The occurrence of subdural hygroma following pterional approach for intracranial aneurysm at Yeungnam University from March 1994 to December 1994 was studied with regard to the patients age, location of aneurysm, preoperative ventricular dilatation, operation time, cortex color, CSF flow, opening degree of Liliequist membrane, dissection degree of sylvian fissure, postoperative intradural air amount and day for mannitol infusion using chi-square test. The following results and conclusions were obtained: 1) Subdural hygroma was observed in 28 of 53 patients(52.8%). 2) The patient's age was significantly related to the occurance of subdural hygroma(p<0.05). 3) CSF flow through the basal cistern was significantly related to the occurrence of subdural hygroma(p<0.05). 4) In cases of good CSF flow, degree of Lilieqist membrane opening was significantly related to the occurrence of subdural hygroma(p<0.05). Preserving of Liliequist membrane will minimize the occurrence of subdural hygroma.
Aneurysm
;
Dilatation
;
Humans
;
Intracranial Aneurysm*
;
Mannitol
;
Membranes
;
Subdural Effusion*
6.GDC Embolization of Wide-necked Cerebral Aneurysms Using Balloon-Assisted Technique.
Seong Ho PARK ; Seung Kug BAIK ; Dong Youl RHEE ; Sun Mi BAIK ; Han Yong CHOI ; Bong Gi KIM
Journal of the Korean Radiological Society 1999;41(2):221-227
PURPOSE: The main factor limiting endovascular treatment of intracranial aneurysms is the shape of the a-neurysmal sac, especially the width of the neck. We describe an early experience and technical aspects of treating wide-necked cerebral aneurysm using a Guglielmi detachable coil (GDC) and simultaneous application of a temporary balloon. MATERIALS AND METHODS: Four cases of unruptured wide-necked cerebral aneurysm were treated with GDC, with simultaneous application of a temporary balloon. Patients were aged between 29 and 49 years. On admission, clinical presentation was subarachnoid hemorrhage (SAH) in all cases. Hunt and Hess grade was II in two cases, III in one case, and traumatic SAH in one case. In all patients angiography revealed an asymptomatic a-neurysm after rupture of another aneurysm or traumatic SAH. The aneurysms were occluded with GDC-10, and a Cirrus balloon occlusion system was used simultaneously. All procedures were performed under endo-tracheal general anesthesia and systemic heparinization. RESULTS: All cases were treated successfully, without parent artery compromise. The occlusion rate at the end of the procedure was total in three cases and subtotal in one. In one case a heparin-related hematoma occurred during post-procedural treatment and the patient eventually expired. One patient underwent follow-up angiography after 6 months, and the coil was not changed. CONCLUSION: An aneurysm may not be completely occluded, but with regard to coil compaction and parent artery preservation, the technique is an attractive alternative.
Anesthesia, General
;
Aneurysm
;
Angiography
;
Arteries
;
Balloon Occlusion
;
Follow-Up Studies
;
Hematoma
;
Heparin
;
Humans
;
Intracranial Aneurysm*
;
Neck
;
Parents
;
Rupture
;
Subarachnoid Hemorrhage
7.Prevalence of Congenital Heart Disease from the Elementary Student Heart Disease Screening Program.
Hong Jue LEE ; Myoung Hee KIM ; Jo Won JUNG ; Seong Ho KIM ; Bo Youl CHOI
Korean Journal of Preventive Medicine 2001;34(4):427-436
OBJECTIVE: To estimate the prevalence of congenital heart disease from the 1998 student heart disease screening program. METHODS: The heart disease screening program for elementary students was conducted in Kyonggi-do, in 1998. The subjects of the present study comprised the 40,402 students who attended the schools in the catchment area of a collaborative university hospital and who participated in the primary examination. The congenital heart disease (CHD) patients were initially identified through a questionnaire about prior medical history, and further through diagnostic tests & medical examinations in the secondary & the tertiary examinations. Certain assumptions were used in the estimation of the number of CHD cases among non-participants of the secondary & tertiary examinations. The overall prevalence of CHD was estimated by adding the CHD detection rates of the participants and the estimated prevalence of the non-participants. RESULTS: Among the 40,402 primary participants, 1,655 were referred further, of whom 79.1% (1,309) participated in the secondary examination. Of these, 121 were referred to the tertiary examination, with a participation rate at this last stage of 80.2%. The positive predictive value (PPV) of the screening tools was the highest when the results of both EKG and the questionnaire were positive. Because 85.9% of the detected cases had a past history of CHD, PPV was higher when the selection criteria in the questionnaire included past CHD history than when it didnt. The CHD detection rate among the participants was 1.76 cases/1,000 and the presumed number of cases among the non-participants was 31; giving an estimated final CHD prevalence of 2.52 cases/1,000 (95% CI : 2.06-3.06). Among the identified cases of CHD, VSD (52.8%) was the most common, followed by PDA (9.7%), TOF (9.7%) & PS (9.7%). CONCLUSION: Because the characteristics of the non-participants differed from those of the participants, the estimation of prevalence was influenced by the participation rate. Of the detected cases, 85.9% had a past history of diagnosis or operation for CHD. These findings suggested that the prevalence estimated in this study may be an underestimation of the actual condition. Therefore, a birth cohort study is required in order to more accurately estimate the prevalence and the effects of the program.
Cohort Studies
;
Diagnosis
;
Diagnostic Tests, Routine
;
Electrocardiography
;
Gyeonggi-do
;
Heart Defects, Congenital*
;
Heart Diseases*
;
Heart*
;
Humans
;
Mass Screening*
;
Parturition
;
Patient Selection
;
Prevalence*
;
Questionnaires
8.An Outbreak of Gastroenteritis Caused by Norovirus-Contaminated Groundwater at a Waterpark in Korea.
Seong Joon KOH ; Han Gil CHO ; Bo Hyun KIM ; Bo Youl CHOI
Journal of Korean Medical Science 2011;26(1):28-32
In January 2008, an outbreak of acute gastroenteritis at a waterpark was reported to the Bundang-gu Public Health Center in Seongnam, Korea. To determine the etiological agent and mode of transmission, a retrospective cohort study was done using structured questionnaires and stool samples from patients who had current gastrointestinal symptoms and three food handlers were tested. A total of 67 (31.0%) students and teachers developed acute gastroenteritis. No food items were associated with an increased risk of the illness. Norovirus was detected in 3 stool specimens collected from 6 patients who had severe diarrhea using semi-nested RT-PCR. All the specimens contained the genogroup I strains of the norovirus. Norovirus was also detected in the groundwater samples from the waterpark. In the nucleotide sequencing analysis, all the genogroup I noroviruses from the patients and groundwater samples were identified as the norovirus genotype I-4 strain. They were indistinguishable by DNA sequencing with a 97% homology. We conclude the outbreak of acute gastroenteritis caused by the norovirus was closely related to the contaminated groundwater.
Adult
;
Caliciviridae Infections/*epidemiology/*virology
;
Child
;
Cohort Studies
;
*Disease Outbreaks
;
Feces/virology
;
Female
;
Fresh Water/*virology
;
Gastroenteritis/*epidemiology/*virology
;
Genotype
;
Humans
;
Male
;
Norovirus/classification/genetics/*isolation & purification
;
Phylogeny
;
Republic of Korea
;
Retrospective Studies
;
Reverse Transcriptase Polymerase Chain Reaction
;
Sequence Analysis, RNA
9.An Outbreak of Gastroenteritis Caused by Norovirus-Contaminated Groundwater at a Waterpark in Korea.
Seong Joon KOH ; Han Gil CHO ; Bo Hyun KIM ; Bo Youl CHOI
Journal of Korean Medical Science 2011;26(1):28-32
In January 2008, an outbreak of acute gastroenteritis at a waterpark was reported to the Bundang-gu Public Health Center in Seongnam, Korea. To determine the etiological agent and mode of transmission, a retrospective cohort study was done using structured questionnaires and stool samples from patients who had current gastrointestinal symptoms and three food handlers were tested. A total of 67 (31.0%) students and teachers developed acute gastroenteritis. No food items were associated with an increased risk of the illness. Norovirus was detected in 3 stool specimens collected from 6 patients who had severe diarrhea using semi-nested RT-PCR. All the specimens contained the genogroup I strains of the norovirus. Norovirus was also detected in the groundwater samples from the waterpark. In the nucleotide sequencing analysis, all the genogroup I noroviruses from the patients and groundwater samples were identified as the norovirus genotype I-4 strain. They were indistinguishable by DNA sequencing with a 97% homology. We conclude the outbreak of acute gastroenteritis caused by the norovirus was closely related to the contaminated groundwater.
Adult
;
Caliciviridae Infections/*epidemiology/*virology
;
Child
;
Cohort Studies
;
*Disease Outbreaks
;
Feces/virology
;
Female
;
Fresh Water/*virology
;
Gastroenteritis/*epidemiology/*virology
;
Genotype
;
Humans
;
Male
;
Norovirus/classification/genetics/*isolation & purification
;
Phylogeny
;
Republic of Korea
;
Retrospective Studies
;
Reverse Transcriptase Polymerase Chain Reaction
;
Sequence Analysis, RNA
10.Current status of education for disaster medicine in Korean medical schools
Jong-Young PARK ; Jae-Hyug WOO ; Jea Yeon CHOI ; Jin Seong CHO ; Yong Su LIM ; Sung Youl HYUN
Journal of the Korean Society of Emergency Medicine 2020;31(5):504-510
Objective:
Doctors or public health doctors at the nearest institution to a disaster scene often have to treat the casualties at the scene. Therefore, disaster medical education is necessary for medical students and doctors, but such education is not properly implemented. This study investigated the status of disaster medical education in Korean medical schools and the professors' thoughts on the appropriateness and necessity of disaster medical education.
Methods:
A survey was conducted on working-level professors in charge of student education in emergency medicine in 40 medical schools. The survey asked the professors the current status of disaster medical education at each school and the professors' thoughts on the appropriateness and necessity of disaster medical education.
Results:
Thirty-seven professors (92.5%) responded to the survey. Twenty-seven schools (73.0%) had a regular curriculum of disaster medicine. Disaster drills were conducted at 34 training hospitals (91.9%), while students of 10 schools (29.4%) were officially participating in the drill. Of the responders, 31 (83.8%) responded that disaster medicine is necessary for clinicians. Thirty-seven professors (100%) thought disaster medical education was necessary for medical students, and 20 (54.1%) of them responded that their schools did not provide adequate disaster medical education.
Conclusion
Many schools did not have a proper course on disaster medical education. Disaster medical education is necessary for medical students, but such education is not properly implemented.