Strategies to Enhance Extracellular Vesicle Production

Extracellular vesicles (EVs) are sub-micrometer lipid vesicles secreted from parental cells with their information such as DNA, RNA, and proteins. EVs can deliver their cargo to recipient cells and regulate the signaling pathway of the recipient cells to determine their destiny. Depending on the cargo of EVs, the recipient cells can be changed into abnormal state or be relieved from diseases. Therefore, EVs has been spotlighted as emerging therapeutics in biomedical research. However, slow EV secretion rate is the major limitation for the clinical applications of EVs. EV secretion is highly environmental dependent and can be regulated by various stimulants such as chemicals, oxygen levels, pH, radiation, starvation, and culture methods. To overcome the limitation of low productivity of EVs, EV stimulation methods have been widely studied and applied to massive EV productions. Another strategy is the synthesis of artificial EVs from cells by physical methods such as nitrogen cavitation, extrusion via porous membrane, and sonication. These physical methods disrupt cellular membrane and reassemble the membrane to lipid vesicles containing proteins or drugs. In this review, we will focus on how EV generation can be enhanced and recent advances in large scale EV generation strategies.

Delayed cranial nerve palsy after successful coil embolization in cavernous sinus lesion

Cavernous sinus (CS) lesion is hard to access by surgical approach. With the development of endovascular technique, neurointerventional therapy is an alternative modality for CS lesions. This endovascular technique has been widely used for the past decade, avoiding the risks associated with surgical treatment. However, complications can still arise from coil embolization. Although immediate complication associate with embolic event or mass effect has been well described, but delayed (>1 year from treatment) nerve palsy after coil embolization is rare. We report two cases of delayed cranial nerve palsy after successful endovascular coil embolization in CS lesion.

Strategies to Enhance Extracellular Vesicle Production

Extracellular vesicles (EVs) are sub-micrometer lipid vesicles secreted from parental cells with their information such as DNA, RNA, and proteins. EVs can deliver their cargo to recipient cells and regulate the signaling pathway of the recipient cells to determine their destiny. Depending on the cargo of EVs, the recipient cells can be changed into abnormal state or be relieved from diseases. Therefore, EVs has been spotlighted as emerging therapeutics in biomedical research. However, slow EV secretion rate is the major limitation for the clinical applications of EVs. EV secretion is highly environmental dependent and can be regulated by various stimulants such as chemicals, oxygen levels, pH, radiation, starvation, and culture methods. To overcome the limitation of low productivity of EVs, EV stimulation methods have been widely studied and applied to massive EV productions. Another strategy is the synthesis of artificial EVs from cells by physical methods such as nitrogen cavitation, extrusion via porous membrane, and sonication. These physical methods disrupt cellular membrane and reassemble the membrane to lipid vesicles containing proteins or drugs. In this review, we will focus on how EV generation can be enhanced and recent advances in large scale EV generation strategies.

Delayed cranial nerve palsy after successful coil embolization in cavernous sinus lesion

Cavernous sinus (CS) lesion is hard to access by surgical approach. With the development of endovascular technique, neurointerventional therapy is an alternative modality for CS lesions. This endovascular technique has been widely used for the past decade, avoiding the risks associated with surgical treatment. However, complications can still arise from coil embolization. Although immediate complication associate with embolic event or mass effect has been well described, but delayed (>1 year from treatment) nerve palsy after coil embolization is rare. We report two cases of delayed cranial nerve palsy after successful endovascular coil embolization in CS lesion.

Necessity of introducing postencounter note describing history and physical examination at clinical performance examination in Korea / 한국의학교육

PURPOSE: Information gathering ability had been evaluated mainly via checklists in clinical performance examinations (CPX). But, it is not proved yet if students write the information correctly in postencounter note (PN), although they asked questions or performed physical examinations (PE) about the information when they interacted with standardized patients in CPX. This study addressed the necessity of introducing PN to evaluate the ability in CPX. METHODS: After patient encounters, students were instructed to write the findings of history taking and physical examination that they considered as important information in approaching the patient's problems in PN. PNs were scored using answer keys selected from checklist items, which were considered to be recorded in PN by CPX experts. RESULTS: PNs of six CPX cases from 54 students were analyzed. Correlation coefficients between the key-checklist scores and PN scores of six cases were moderate to high (0.52 to 0.79). However, students frequently neglected some cardinal features of chief complains, pertinent findings of past/social history and PE, and pertinent negative findings of associated symptoms in PNs, which were checked as 'done' in the keys of checklists. CONCLUSION: It is necessary to introduce PN in CPX to evaluate the students' ability of synthesis and integration of patient information.

Effect of Urban Area Size and Commuting Modes on Physical Activity among working people who took part in health guidance / 体力科学

In the present research, first we evaluated the association between urban area size and commuting modes with physical activity among working people. Then we investigated the longitudinal effects of urban area size and commuting modes on increased physical activity due to health guidance intervention. The subjects were 401 male employees (aged 46.3±7.8) of A corporation, and were split into two groups, metropolitan area group (N=235) and local area group (N=166), based on the population density of place of work. IPAQ-E was used for evaluation of walking environments, and physical activity was assessed using pedometers. The intervention consisted of an exercise-focused health guidance over the course of one year. The cross-sectional study admitted that in comparison with the local area group the metropolitan area group had more than physical activity (p<0.01). Not only the size of urban area but commuting modes were significantly related to the level of daily physical activity (p<0.001). In longitudinal study, regarding the effects of the intervention for the physical activity, the study showed the possibility that urban area size was not directly effective but traffic safety in residential area (p<0.05) and willingness to take a walk (p<0.01) were effective. The cross-sectional study suggested that the size of the urban area and commuting modes had independently an effect on the physical activity of working people. The longitudinal study, on the other hand, suggested that the size of the urban area and commuting modes may not any direct influence on the effects of physical activity intervention.

Fifteen Years After the Gozan-Dong Glass Fiber Outbreak, Incheon in 1995 / 예방의학회지

OBJECTIVES: In 1995, an outbreak survey in Gozan-dong concluded that an association between fiberglass exposure in drinking water and cancer outbreak cannot be established. This study follows the subjects from a study in 1995 using a data linkage method to examine whether an association existed. The authors will address the potential benefits and methodological issues following outbreak surveys using data linkage, particularly when informed consent is absent. METHODS: This is a follow-up study of 697 (30 exposed) individuals out of the original 888 (31 exposed) participants (78.5%) from 1995 to 2007 assessing the cancer outcomes and deaths of these individuals. The National Cancer Registry (KNCR) and death certificate data were linked using the ID numbers of the participants. The standardized incidence ratio (SIR) and standardized mortality ratio (SMR) from cancers were calculated by the KNCR. RESULTS: The SIR values for all cancer or gastrointestinal cancer (GI) occurrences were the lowest in the exposed group (SIR, 0.73; 95% CI, 0.10 to 5.21; 0.00 for GI), while the two control groups (control 1: external, control 2: internal) showed slight increases in their SIR values (SIR, 1.18 and 1.27 for all cancers; 1.62 and 1.46 for GI). All lacked statistical significance. All-cause mortality levels for the three groups showed the same pattern (SMR 0.37, 1.29, and 1.11). CONCLUSIONS: This study did not refute a finding of non-association with a 13-year follow-up. Considering that many outbreak surveys are associated with a small sample size and a cross-sectional design, follow-up studies that utilize data linkage should become standard procedure.

The current status of anesthesiology clerkship in Korea / 대한마취과학회지

BACKGROUND: There had been few regulations or agreements between medical schools how to teach undergraduate medical students during anesthesiology clerkship. We conducted this survey to figure out the current status of the clerkships of medical schools in Korea, and suggest the direction of development. METHODS: The questionnaires about anesthesiology clerkship were sent to chairpersons or clerkship directors of 42 medical schools in Korea by electric mail. The answers were collected by internet system. RESULTS: 33 schools answered the questionnaires. The clerkships were elective in 19 schools, but 26 schools answered that the anesthesiology clerkship should be included in core clerkships. Only a few schools oriented the students about ethical issues and occupational health during clerkship. Most schools evaluated the students by evaluation sheet or written examination. Oral or skill tests were used at only 8 and 5 schools, respectively. CONCLUSIONS: The answers of survey showed that there were many aspects to be improved in anesthesiology clerkship although the responses of students toward the clerkship were positive.

Effects of Case Type and Standardized Patient Gender on Student Performance in a Clinical Performance Examination / 한국의학교육

PURPOSE: The purpose of this study is to assess the effects of case type and gender of standardized patient on student performance in a clinical performance examination(CPX). METHODS: During 2005, an eight-station CPX was administered to fourth-year students from 4 medical schools. A total of 306 students, of which 206(67%) were male, participated in the exam. Station checklists, scored by the SPs, consisted of history taking(Hx), physical examination(PE), information sharing(IS), clinical courtesy(CC) and patient-physician interaction(PPI). A measurement of students' perceived difficulty was obtained through student questionnaires. The difference of CPX scores between male and female students were studied using Mann-Whitney's U. RESULTS: Across the gender-neutral cases, female students scored better in Hx in 2 cases. In PE, IS and CC, the only difference seen was with CC in 1 case(female students scored higher). In PPI, female students performed better than male students in all female SP cases and one male SP case, but, there was a significant student gender-SP gender interaction when averaging all cases. For the gender sensitive case, there was no significant difference in all checklist categories in the male case when student gender was considered. In the female case, female students performed better than male students only in PPI. Student questionnaires revealed that there was no significant difference in perceived difficulty between male and female students. RESULTS: The standardized patients' ratings in gender sensitive cases are not affected by the gender of standardized patients and students, except in PPI with a female case where female students performed better than male students.

The Effect of Fentanyl and Remifentanil on Postoperative Nausea and Vomiting, and Pain after Gynecologic Laparoscopic Ovarian Cyst Enucleation by Balanced Anesthesia with Sevoflurane / 대한마취과학회지

BACKGROUND: Opioids are known to increase the incidence of postoperative nausea and vomiting (PONV). Remifentanil is an ultrashort-acting opioid with a potent analgesic effect and is useful for rapid emergence. This study compared the effect of remifentanil on the incidence and severity of PONV and postoperative pain with that of fentanyl in patients undergoing laparoscopic surgery, which is normally associated with a high incidence of PONV. METHODS: Forty-four adult female patients, who were scheduled for laparoscopic ovarian cyst enucleation, were randomly assigned to either the remifentanil or fentanyl group. Anesthesia was induced with propofol after injecting fentanyl 2 microgram/kg or remifentnail 1 microgram/kg and was maintained with sevoflurane. Remifentanil and fentanyl was infused continuously in the range of 0.2-0.5 microgram/kg/min and 0.03-0.05 microgram/kg/min, respectively. Ketorolac 0.5 mg/kg was injected 30 min before the end of surgery. The incidence and severity of PONV and pain were recorded upon arrival at the recovery room and 2, 6, 12 and 24 hours thereafter. RESULTS: The incidence and severity of PONV and pain were significantly higher in the remifentanil group upon arrival at the recovery room than in the fentanyl group. The incidence and severity of PONV and pain at the other measurement times were similar. CONCLUSIONS: Despite the ultrashort action duration of the remifentanil, the incidence and severity of PONV and postoperative pain immediately after awakening was higher in the remifentanil group undergoing laparoscopic ovarian cyst enucleation than in the fentanyl group. However, there were no significant differences after two hours in the recovery phase.

The Effects of Information Sharing between Students on Results of Clinical Performance Examination / 한국의학교육

PURPOSE: This study was designed to investigate the effects of information sharing between students on results of clinical performance examination (CPX). METHODS: 143 third-year students, who completed their core clinical clerkship, were randomly assigned to one day of a 3-day, 6 station CPX. Station checklists, scored by the SP(s), consisted of history taking, physical examination, information sharing, clinical courtesy and patient-physician interaction. We compared the CPX station scores, CPX domain scores, self assessment scores and GPA of the three groups tested on different days with ANOVA, and analyzed the differences in CPX scores, after controlling for GPA, with ANCOVA. The correlations among the CPX total and domain scores, self assessment and the GPA of the 3rd year students were calculated. Data regarding information sharing between students and self-assessment were obtained through student questionnaires. RESULTS: CPX total scores, self assessment scores and GPA of 3rd year students from day-2 were significantly higher than scores from day-1 or day-3. Checklist analysis showed that PE, CC and PPI scores were significantly higher on day-2, but Hx and IS scores were not significantly different. Results from questionnaires showed that 43% of students shared evaluation information. And CPX total scores had little correlation with self assessment scores. GPA of 3rd year students showed a similar pattern with the CPX totalscore. CONCLUSION: There is information sharing occurring between students during clinical performance examinations. Although there are significant differences in CPXscores for the treatment group, it seemed that CPX scores are not affected by information sharing between students. Reliability of information sharing from other students is low. The generalization of this study should be interpreted carefully.