Myasthenia gravis (MG) is a disease of neuromuscular junction and mainly autoimmune in aetiology. The state of thymus is a critical determinant for the prognosis. In this retrospective review study, we aimed at clarifying the relationship between the mode of clinical presentation of MG and the radiopathological classification of the thymus. We identified patients with MG from the database of our medical center from 1988 – 2017. The patients were classified into two groups according to their clinical presentation: those with a typical presentation with diurnal variation, and those with an atypical presentation of persistent weakness or respiratory failure from the beginning. The underlying thymic state was categorized into six groups: normal, abnormal by imaging (if no operation was performed), hyperplasia, benign thymoma, cortical type thymoma, and malignant thymoma. In total, 227 patients (133 females and 94 males) were included in the analysis, of whom 68% were classified into the typical presentation group. The atypical presentation correlated significantly with thymic categories (p = 0.014) and sex (p = 0.026) but not age at onset (p = 0.232). The atypical presentation was more common in the male patients and in those with thymic carcinoma.

No abstract available.
Disasters*

Purpose: This study examined how students’ academic performance changed after undergoing a transition to online learning during the coronavirus disease 2019 (COVID-19) pandemic, based on the test results of 16 integrated courses conducted in 3 semesters at Hanyang University College of Medicine in Korea. Methods: For the 16 required courses that formed an integrated system-based curriculum running for 3 semesters, the major examinations’ raw scores were collected for each student. Percent-correct scores were used in the subsequent analysis. We used the t-test to compare grades between 2019 and 2020, and the Cohen D was calculated as a measure of effect size. The correlation of scores between courses was calculated using Pearson correlation coefficients. Results: There was a significant decrease in scores in 2020 for 10 courses (62.5%). While most of the integrated system-based curriculum test scores showed strong correlations, with coefficients of 0.6 or higher in both 2019 and 2020, the correlation coefficients were generally higher in 2020. When students were divided into low, middle, and high achievement groups, low-achieving students consistently showed declining test scores in all 3 semesters. Conclusion Our findings suggest that the transition to online classes due to COVID-19 has led to an overall decline in academic performance. This overall decline, which may occur when the curriculum is centered on recorded lectures, needs to be addressed. Further, medical schools need to consider establishing a support system for the academic development of low-achieving students.

The hypervariable short tandem repeat (STR) locus D12S391 was investigated in a Korean population. A total of 14 alleles were detected by size under denaturing conditions in 517 unrelated individuals. To confirm all of the alleles detected in a Korean population, a total of 34 fragments were sequenced. Prior to allele designation, we constructed the allelic ladders containing 11 alleles sequenced in this study. Allele 18 is the most common with a frequency of 0.281 in Koreans, and one variant allele 19.3 which have been confirmed by sequencing, was detected. The observed heterozygosity, the power of discrimination (PD), and the mean exclusion chance (MEC) for the locus D12S391 is 0.781, 0.946 and 0.652, respectively. No deviation from Hardy-Weinberg equilibrium was observed in a Korean population (p=0.557). In the 424 meioses in 105 Korean families confirmed using other 17 STR loci, no mutation was detected in locus D12S391. The STR locus D12S391system is useful both for the analysis identification and parternity.
Alleles ; Discrimination (Psychology) ; Gene Frequency ; Genetics, Population* ; Humans ; Meiosis ; Microsatellite Repeats ; Sequence Analysis

No abstract available.
Disasters*

Purpose: First-year students can form a preconception based on life experiences before entering college and identifying learners’ existing characteristics can be useful foundation data for curriculum development. This study examines what preconceptions freshman students had about medicine before entering medical school. Methods: A total of 110 first-year students were asked about what preconceptions they had about “medicine”. A total of 1,124 data were used in the content analysis method. Results: The results were extracted into 5, and 12 twelve categories. On the theme of “scientific discipline”, the knowledge students had about general health was based on scant expertise and little evidence. Students perceived medicine as Western and scientific, considering Korean traditional medicine as unscientific. Students believed that “medical practice” should be a “disease treatment” and “patient-centered” approach rather than a “social responsibility”. In “the role of the doctor”, students were concerned about the doctor's being financially stable on the positive side, and about the high-intensity workload on the negative side. In “medical education”, students believed that studying medicine would be “hard and difficult” because of the “importance of memorizing” and “extensive study load”. In “specialty stereotype”, students had biases that were mostly concentrated on “psychiatry” and “surgery” Conclusion Perception of “medicine” has been revealed to a varied range of themes, but some have been inaccurate or unrealistic. These prejudices and groundless beliefs have a gap with the learning outcomes that students should achieve in the curriculum, and these preconceptions seem to have been influenced by South Korea’s unique cultural context.

We describe 2 cases in which radiographic evidence of thromboembolic events was obtained during germ cell tumor diagnosis. There was no evidence of coagulation factor abnormalities or contributory procedures or drugs in either patient. We used anticoagulation therapy for thrombolysis in one patient, but in the other, the thromboembolism resolved spontaneously.
Blood Coagulation Factors ; Child ; Germ Cells ; Humans ; Neoplasms, Germ Cell and Embryonal ; Thromboembolism

The prevalence of Epstein-Barr virus(EBV) in the uterine cervix was investigated to define the possible etiologic role in cervical carcinogenesis. The viral genotyping and LMP-1 30bp deletion were also studied. The materials included 169 uterine cervical swabs(152 within normal limits, 12 atypical squamous cells of uncertain significance, 3 low grade intraepithelial lesions, and 2 high grade squamous intraepithelial lesion) and 104 uterine cervical tissues obtained from hysterectomy specimens(32 carcinoma in situ, 9 microinvasive squamous cell carcinomas, 37 invasive squamous cell carcinomas, 7 adenocarcinomas, 7 adenosquamous carcinomas, and 12 cervicitis). EBV detected by PCR for EBNA-1 was positive in 52(56.5%) of 92 invasive and noninvasive cervical carcinomas, and 80(48.8%) of 164 inflammatory or normal cervices. The viruses detected in carcinomas were all type A, and LMP-1 30bp deletion form was more frequent in premalignant and malignant cervical lesions than in nonneoplastic cervices. From the above results, it may be concluded that EBV is one of common viruses detected in uterine cervix of Korean women, and type A virus and LMP-1 30bp deletion form may have a role in cervical carcinogenesis.
Adenocarcinoma ; Carcinogenesis ; Carcinoma in Situ ; Carcinoma, Adenosquamous ; Carcinoma, Squamous Cell ; Cervix Uteri ; Female ; Genotype ; Herpesvirus 4, Human* ; Humans ; Hysterectomy ; Polymerase Chain Reaction ; Prevalence

The artery of Percheron (AOP) is an uncommon variant of the posterior cerebral artery that supplies blood to the paramedian thalamus and rostral midbrain. AOP is often difficult to recognize with intracranial magnetic resonance angiography due to its small size. Although a number of case reports of AOP occlusion have been published, cause of the occlusion is mostly unclear. We experienced a case of AOP occlusion which resulted in bilateral thalamic infarction. It was most likely caused by a microembolism through right-left shunt.

No abstract available.
Airports* ; Disasters*