IntraBrain Injector (IBI): A StereotacticGuided Device for Repeated Delivery of Therapeutic Agents Into the Brain Parenchyma

Background@#To deliver therapeutics into the brain, it is imperative to overcome the issue of the blood-brain-barrier (BBB). One of the ways to circumvent the BBB is to administer therapeutics directly into the brain parenchyma. To enhance the treatment efficacy for chronic neurodegenerative disorders, repeated administration to the target location is required. However, this increases the number of operations that must be performed. In this study, we developed the IntraBrain Injector (IBI), a new implantable device to repeatedly deliver therapeutics into the brain parenchyma. @*Methods@#We designed and fabricated IBI with medical grade materials, and evaluated the efficacy and safety of IBI in 9 beagles. The trajectory of IBI to the hippocampus was simulated prior to surgery and the device was implanted using 3D-printed adaptor and surgical guides. Ferumoxytol-labeled mesenchymal stem cells (MSCs) were injected into the hippocampus via IBI, and magnetic resonance images were taken before and after the administration to analyze the accuracy of repeated injection. @*Results@#We compared the planned vs. insertion trajectory of IBI to the hippocampus.With a similarity of 0.990 ± 0.001 (mean ± standard deviation), precise targeting of IBI was confirmed by comparing planned vs. insertion trajectories of IBI. Multiple administrations of ferumoxytol-labeled MSCs into the hippocampus using IBI were both feasible and successful (success rate of 76.7%). Safety of initial IBI implantation, repeated administration of therapeutics, and long-term implantation have all been evaluated in this study. @*Conclusion@#Precise and repeated delivery of therapeutics into the brain parenchyma can be done without performing additional surgeries via IBI implantation.

A Study on Occupational Stress and Coping, Turnover, Knowledge and Practice of Infection Control in Dental Hygienists of COVID-19 / 치위생과학회지

Background@#The importance of infection with COVID-19 is being emphasized in dentistry with high risks such as aerosols. The purpose of this study is to investigate the knowledge and practice of infection control, stress and coping, and turnover of dental hygienists. @*Methods@#Questionnaire was conducted knowledge and practice of infection control, occupational stress and coping, turnover. Survey data was investigated about 149 dental hygienists from February to March 2021 Data were analyzed t-test, ANOVA, Pearson’s correlation using statistical programs of PASW Statistics ver. 21.0. @*Results@#Regarding occupational stress, relationship conflict was higher in the group with less than 2 years of experience (p＜0.05). Job anxiety, organizational system, inadequate compensation, and workplace culture were highly surveyed in the 3 to 5 year of experience. The group with more than 6 years of experience had the highest perception of lack of job autonomy (p＜0.05). The group with higher knowledge of infection control had lower mean inappropriate rewards and stress (p＜0.05). The group with high infection control performance had a lower average in items such as job instability, organizational system, inadequate compensation, workplace culture, and stress. And problem-focused coping ability was found to be high (p＜0.05). Infection control knowledge and performance were positively correlated (r=0.251, p＜0.01), infection control practice and stress were negatively correlated (r=−0.264, p＜0.01), and stress and emotional coping were positively correlated (r=0.367, p＜0.01). Stress was positively correlated with turnover rate (r=0.549, p＜0.01). @*Conclusion@#Infection control training was required to reduce occupational stress. Occupational stress was highly correlated with turnover, a holistic and systemic organizational operation and improvement of the quality of medical care were required to reduce stress.

Effects of Exercise on Cervical Angle and Respiratory Function in Smartphone Users

OBJECTIVES: The aim of this study was to determine whether exercises can change the cervical angle and respiratory function in smartphone users. METHODS: Thirty healthy volunteers were recruited. The subjects were randomly divided into an exercise group and a control group. All participants used a smartphone for 1 hour while maintaining a sitting posture. Then, each group performed their assigned activity. The exercise group performed two types of exercises and the control group maintained routine activities for 20 minutes. To investigate the changes in cervical angle and respiratory function, we measured the craniovertebral angle by using a spirometer. RESULTS: Statistically significant differences were noted in the craniovertebral angle, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, peak expiratory flow, maximal inspiratory pressure, and maximal expiratory pressure of the two groups (p < 0.05). CONCLUSION: Our findings showed that proper exercise could be a good method of improving the cervical angle and respiratory function in smartphone users.

Influence of Unilateral Muscle Fatigue in Knee and Ankle Joint on Balance and Gait in Healthy Adults

PURPOSE: This study was to investigate the effects of unilateral muscle fatigue in knee and ankle joints on balance and gait in healthy adults. METHODS: Exercise inducing muscle fatigue in the knee joint consisted of concentric and eccentric contraction of dominant knee extensors in healthy adults by using the Leg Extension Rehap exercise machine (HUR, Finland). Exercise inducing muscle fatigue in the ankle joint was composed of voluntary contractions and forced contractions of the dominant plantar flexors in healthy adults. Exercises to induce muscle fatigue in the knee and ankle joints were performed until the subject complained of fatigue or pain, the occurrence of muscle fatigue was confirmed by electromyography. We measured static and dynamic balance using the Good Balance system and gait performance by RS-scan. RESULTS: Static and dynamic balance ability and spatial-temporal gait decreased significantly after muscle fatigue in knee and ankle joint. CONCLUSION: These results show that unilateral muscle fatigue of the lower extremities affected postural control and gait. Therefore, therapists and sport trainers should minimize the risks of fall and injuries related to unilateral muscle fatigue.

Medical Expenses of the Family Members of Brain Dead Organ Donors and National Assistance / 대한이식학회지

BACKGROUND: Analyzing the medical expenses of the family members of brain dead organ donors would be helpful in ascertaining better ways of applying national assistance, which is important for promotion of brain dead organ donation. METHODS: We collected data regarding the medical expenses of 119 brain dead organ donors from January 2009 to December 2013 at a single institution that specializes in organ donation. Donation year, cause of brain death, age, and admission days were deemed factors affecting medical expenses, and these were analyzed. Medical expenses were compared with national assistance (maximum of 1.8 million Korean won [KRW]). RESULTS: Average age of donors was 42.7 years, and, in the older age group, there was a lower average for medical expenses (P=0.025). Brain dead organ donations that were consented to within 2 days after the brain death comprised 41.2%, and medical expenses increased as the consent days were delayed (P<0.001). Average medical expense for donor families was 2,161,297 KRW, and the average national assistance to the families was 577,056 KRW. The medical expenses of 73 donors (61.3%) were below the national assistance maximum; 19 (16.0%) had no charges of their own with other insurance coverage. CONCLUSIONS: National assistance for medical expenses to family members of brain dead organ donors is necessary in Korea, where the rate of brain dead organ donation is very low. As 61% of donors were covered below the maximum assistance amount, there could be additional ways to utilize the remaining budget.

The Factors Associated with the Hypotension Development in Acute Glyphosate-surfactant Herbicide Poisoning

PURPOSE: Recently, glyphosate-surfactant herbicide has been used increasingly because it is known for its low toxicity in mammals. However, some cases presented severe clinical complications including hypotension. Previous studies have shown that hypotension is a predictor of poor outcome and mortality. Therefore, we aimed to identify factors that may be related to hypotension in glyphosate intoxication. METHODS: This retrospective study targeted patients with glyphosate intoxication who were admitted to the emergency department of a single hospital from January 1st, 2004 to November 2014. The data were collected retrospectively from clinical records and laboratory files. Using multivariate logistic analysis, data were analyzed retrospectively for association with hypotension. RESULTS: Of the 245 patients, 63 patients (25.7%) had hypotension. The results of this study showed statistically significant differences in old age, underlying disease, amount of ingestion, GCS (Glasgow coma scale), White blood cell, hemoglobin, total bilirubin, glucose level, pH, bicarbonate, base excess, lactate level, AST (aspartate aminotransferase), creatinine level, saturation, Chest X-ray abnormality, and prolonged QTc (corrected QT interval) between hypotension group and non-hypotension group. By multivariate logistic analysis, GCS, creatinine level, chest X-ray abnormality, and prolonged QTc interval were associated with the cases presenting with hypotension. CONCLUSION: GCS, creatinine level, chest X-ray abnormality, and prolonged QTc interval were significant factors associated with hypotension in patients with glyphosate intoxication.

Molecular Understanding of Osteoclast Differentiation and Physiology

No abstract available.

The Incidence of Cardiac Arrhythmias is Lower in Isoflurane than Enflurane / 대한마취과학회지

BACKGROUND: There is difference between isoflurane and enflurane in the myocardial sensitization to catecholamines, and their actions on the heart. Enflurane reduces cytoplasmic calcium more than isoflurane. The hypothesis could be suggested that these two volatile anesthetics might cause the different incidences and natures of cardiac arrhythmias. METHODS: The anesthesia was induced by the intravenous injection of thiopental(6 mg, kg-1) and pipecuronium(0.1 mg, kg-1). Two groups were randomly allocated to the patients(n=80) in the maintenance: Group I inhaled isoflurane(1~2%), O2(2 L), and N2O(2 L), Group II, enflurane (1.5~2.5%). Continuous electrocardiographic recordings with Holter monitor were made of those undergoing tympanoplasty during anesthesia. The tapes recorded were scanned using analyzer, and we read out ECG complexes on the screen. Results were categorized as induction, maintenance, and emergence, and inferred from unpaired t-test, and X2-test with p<0.05 considered significant. RESULTS: The results were as follows: 1) The total incidence of cardiac arrhythmias was 65.0%. Isoflurane(52.5%) was lower than enflurane(77.5%) in the incidence. 2) During maintenance and emergence, isoflurane was lower than enflurane in the frequency of supraventicular arrhythmias. 3) Ventricular arrhythmias most frequently occurred in induction. 4) The frequency of supraventricular arrhythmias was more than two times that of ventricular ones. The arrhythmias at the AV junction were the most common, and VPC's the second. CONCLUSIONS: Greatest caution should be paid during peri-induction. It could be suggested that compared to enflurane, isoflurane better be administered for those to whom arrhythmias could be harmful.

Effects of Isoflurane on Hypoxic Pulmonary Vasocontriction in Human during One Lung Ventilation / 대한마취과학회지

BACKGROUND: AMBU bag is a useful equipment in the cardiopulmonary resuscitation(CPR) and respiratory therapy. The volume delivered during ventilation with AMBU bag may be influenced by many factors. METHOD: We evaluated the effects of ventilation method(one-hand, open-palm, two-hand) and resuscitator's sex on volume in 30 intubated patients under general anesthesia with inhalational anesthetics and muscle relaxants. RESULTS: Mean tidal volume was significantly greater with two-hand method than one-hand and open-palm method in both sex. PaO2 was significantly decreased in all ventilation methods. PaCO2 was also decreased and pH was increased in all methods. CONCLUSION: The results suggest that all ventilation methods with AMBU bag in intubated patients may suitable in the CPR. If airway management by intubation is impossible and mask ventilation, two-hand method may be effective in both resuscitator but open-palm method may not suitable to female resuscitator.

Effects of Isoflurane on Hypoxic Pulmonary Vasocontriction in Human during One Lung Ventilation / 대한마취과학회지

BACKGROUND: AMBU bag is a useful equipment in the cardiopulmonary resuscitation(CPR) and respiratory therapy. The volume delivered during ventilation with AMBU bag may be influenced by many factors. METHOD: We evaluated the effects of ventilation method(one-hand, open-palm, two-hand) and resuscitator's sex on volume in 30 intubated patients under general anesthesia with inhalational anesthetics and muscle relaxants. RESULTS: Mean tidal volume was significantly greater with two-hand method than one-hand and open-palm method in both sex. PaO2 was significantly decreased in all ventilation methods. PaCO2 was also decreased and pH was increased in all methods. CONCLUSION: The results suggest that all ventilation methods with AMBU bag in intubated patients may suitable in the CPR. If airway management by intubation is impossible and mask ventilation, two-hand method may be effective in both resuscitator but open-palm method may not suitable to female resuscitator.

Cardiac Arrhythmias under General Anesthesia Using Enflurane / 대한마취과학회지

The large part of pathophysiology of cardiac arrhythmias has been clarified but still arrhythmias have bothered anesthesiologists. This study was done in order to investigate the incidence and nature of arrhythmias using Holter monitor for complete study during enflurane anesthesia. The patients were randomly allocated to two groups. Group I received succinylcholine 1.5 mg/kg, and Group II vecuronium 0.1 mg/kg, intravenously for intubation. Continuous electrocardiographic recordings on magnetic tape were made in 34 patients undergoing tympanoplasty during general anesthesia (thiopental(5 mg/kg)-muscle relaxants induction, and N2O(50%)-O2-enflurane(1.2%)-pancuronium maintenance). After completion of the recordings, the tapes were scanned to detect changes in rhythm using the analyzer. Complexes were further studied by readouts on standard ECG paper. The results were as follows: 1) The number of patients(n=14) who exhibited arrhythmias during anesthetic maintenance was significantly greater than that(n=4) during induction. 2) The incidence of occurrence of cardiac arrhythmias was 64.7%. There was no difference between two groups. If sinus tachycardia included, the incidence reached at 94.1%. 3) The frequency of supraventricular arrhythmias was more than two times that of ventricular ones. The arrhythmias occuning at the AV junction were the most common, and VPCs the second most common 4) There was no effect on the frequency in arrhythmia occurrence, of age, gender, preoperative ECG findings, intraoperative serum K(+), and intraoperative PaCO2 The discrepancy in the incidence of arrhythmia occurrence between complete and incomplete studies tells that great caution should be paid perioperatively, especially to the patients who have cardiovascular disorders.

Respiratory Effects of Laparoscopic Operation under General Anesthesia / 대한마취과학회지

As laparoscopic operation has become more widely practiced, the full spectrum of effects associated with this technique must be realized. The purpose of this study is to investigate the cardiovascular effects, blood gas changes and especially changes in respiratory variables during laparoscopic operation. We studied 10 patients undergoing elective laparoscopic cholecystectomy (group I) and another 10 patients undergoing elective laparoscopic salpingectomy (group II). In both groups, mean arterial pressure and PaCO2 were increased and pH was decreased. But there was no significant change in PaO2. The changes of respiratory variables in group I were not significant. But in group II, peak airway pressure was increased and compliances significantly decreased (p<0.05) owing to more head-down position. In condusion, patients who are undergoing laparoscopic operatian may require careful monitormg about hemodynamic changes, oxygenation and CO2 retention during anesthetic management.