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1.
Journal of Korean Neurosurgical Society ; : 573-581, 2023.
Article in English | WPRIM | ID: wpr-1001282

ABSTRACT

Objective@#: Due to the implementation of vaccinations and the development of therapeutic agents, the coronavirus disease 2019 (COVID-19) pandemic that started at the end of 2019 has entered a new phase. As a result, neurosurgeons should reconsider the way they treat their patients. As the COVID-19 situation prolongs, the change in neurosurgical emergency patients according to the number of confirmed cases is no longer clear. Outpatient treatment by telephone was permitted according to government policy. In addition, visits to caregivers in the intensive care unit were limited. @*Methods@#: The electronic medical records of patients who had been treated over the phone for a month (during April 2020, while the hospital was closing) were reviewed. Meanwhile, according to the limited visits to the intensive care unit, a video meeting was held with the caregivers. After the video meeting, satisfaction was evaluated using a questionnaire. @*Results@#: During April 2020, 1021 patients received non-face-to-face care over the telephone. Among the patients, no critical medical problem occurred due to non-face-to-face care. From July 2021 to December 2021, 321 patients were admitted to the neurosurgical intensive care unit and 107 patients (33.3%) including their caregivers agreed to video visits. Twice a week, advance notice was given that access would be made through a mobile device and the nurse explained to caregivers how to use the mobile device. The time for the video meeting was approximately 20 minutes per patient. Based on the questionnaire, 81 respondents (75.7%) answered that they agreed, and 26 respondents (24.3%) answered that they strongly agreed that was easy to communicate through video meetings. Fifty-two (48.6%) agreed and 55 (51.4%) strongly agreed that they were easy to understand the doctor’s explanation. For overall satisfaction with this video meeting, three respondents (2.8%) gave 4/5 points and 95 respondents (88.8%) gave 5/5 points, and nine (8.4%) gave 3/5 points. Their reason was that there was not enough time. @*Conclusion@#: In situations where patient visits are limited, video meetings through a mobile device can provide sufficient satisfaction to caregivers. Telemedicine will likely become common in the near future. Health care professionals should prepare and respond to these needs and changes. Therefore, establishing a system with institutional support is necessary.

2.
Journal of Korean Neurosurgical Society ; : 726-734, 2023.
Article in English | WPRIM | ID: wpr-1001262

ABSTRACT

Objective@#: Chronic subdural hematoma (CSDH) patients using antithrombotic agents (AT) at high risk for cardiovascular disease are increasing. The authors aimed to analyze the factors influencing outcome by targeting patients using AT and to establish a desirable treatment strategy. @*Methods@#: A retrospective analysis was performed on data from 462 patients who underwent burr hole trephination (BHT) surgery for CSDH at five hospitals from March 2010 to June 2021. Outcomes included incidence of postoperative acute bleeding, recurrence rate, and morbidity or mortality rate. Patients were divided into the following four groups based on their history of AT use : no AT. Only antiplatelet agents (AP), only anticoagulants (AC), both of AP and AC. In addition, a concurrent literature review was conducted alongside our cohort study. @*Results@#: Of 462 patients, 119 (119/462, 25.76%) were using AT. AP prescription did not significantly delay surgery (p=0.318), but AC prescription led to a significant increase in the time interval from admission to operation (p=0.048). After BHT, AP or AC intake significantly increased the period required for an in-dwelling drain (p=0.026 and p=0.037). The use of AC was significantly related to acute bleeding (p=0.044), while the use of AP was not (p=0.808). Use of AP or AC had no significant effect on CSDH recurrence (p=0.517 and p=1.000) or reoperation (p=0.924 and p=1.000). Morbidity was not statistically correlated with use of either AP or AC (p=0.795 and p=0.557, respectively), and there was no significant correlation with mortality for use of these medications (p=0.470 and p=1.000). @*Conclusion@#: Elderly CSDH patients may benefit from maintenance of AT therapy during BHT due to reduced thromboembolic risk. However, the use of AC necessitates individualized due to potential postoperative bleeding. Careful post-operative monitoring could mitigate prognosis and recurrence impacts.

3.
Brain Tumor Research and Treatment ; : 216-218, 2023.
Article in English | WPRIM | ID: wpr-999751

ABSTRACT

A 44-year-old female patient who had been diagnosed with breast cancer visited our oncology department. She had developed right-side weakness and mild dysarthria, and MRI revealed a 4-cm cysticenhancing lesion in her left frontal lobe. Her surgery was postponed 48 hours after receiving 5-aminolevulinic acid (5-ALA), because a problem with thyroid function that had not been noticed before was discovered. The main lesion was enhanced on navigation and appeared to be a gross tumor; its 5-ALA uptake was very high. Specimens obtained from this location were histologically confirmed to contain tumor cells. The operation was completed, and removal of all enhancing lesions was confirmed by MRI within 24 hours postoperatively. The pathology report confirmed metastatic ductal carcinoma. The clinical efficacy of 5-ALA was confirmed even 48 hours after administration into a metastatic brain tumor from breast cancer.

4.
Brain Tumor Research and Treatment ; : 123-132, 2023.
Article in English | WPRIM | ID: wpr-999744

ABSTRACT

Background@#During the coronavirus disease 2019 (COVID-19) pandemic, the need for appropriate treatment guidelines for patients with brain tumors was indispensable due to the lack and limitations of medical resources. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has undertaken efforts to develop a guideline that is tailored to the domestic situation and that can be used in similar crisis situations in the future. @*Methods@#The KSNO Guideline Working Group was composed of 22 multidisciplinary experts on neuro-oncology in Korea. In order to reach consensus among the experts, the Delphi method was used to build up the final recommendations. @*Results@#All participating experts completed the series of surveys, and the results of final survey were used to draft the current consensus recommendations. Priority levels of surgery and radiotherapy during crises were proposed using appropriate time window-based criteria for management outcome. The highest priority for surgery is assigned to patients who are life-threatening or have a risk of significant impact on a patient’s prognosis unless immediate intervention is given within 24–48 hours. As for the radiotherapy, patients who are at risk of compromising their overall survival or neurological status within 4–6 weeks are assigned to the highest priority. Curative-intent chemotherapy has the highest priority, followed by neoadjuvant/adjuvant and palliative chemotherapy during a crisis period. Telemedicine should be actively considered as a management tool for brain tumor patients during the mass infection crises such as the COVID-19 pandemic. @*Conclusion@#It is crucial that adequate medical care for patients with brain tumors is maintained and provided, even during times of crisis. This guideline will serve as a valuable resource, assisting in the delivery of treatment to brain tumor patients in the event of any future crisis.

5.
Brain Tumor Research and Treatment ; : 133-139, 2023.
Article in English | WPRIM | ID: wpr-999743

ABSTRACT

Background@#During the coronavirus disease 2019 (COVID-19) pandemic, there was a shortage of medical resources and the need for proper treatment guidelines for brain tumor patients became more pressing. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has undertaken efforts to develop a guideline that is tailored to the domestic situation and that can be used in similar crisis situations in the future. As part II of the guideline, this consensus survey is to suggest management options in specific clinical scenarios during the crisis period. @*Methods@#The KSNO Guideline Working Group consisted of 22 multidisciplinary experts on neuro-oncology in Korea. In order to confirm a consensus reached by the experts, opinions on 5 specific clinical scenarios about the management of brain tumor patients during the crisis period were devised and asked. To build-up the consensus process, Delphi method was employed. @*Results@#The summary of the final consensus from each scenario are as follows. For patients with newly diagnosed astrocytoma with isocitrate dehydrogenase (IDH)-mutant and oligodendroglioma with IDH-mutant/1p19q codeleted, observation was preferred for patients with low-risk, World Health Organization (WHO) grade 2, and Karnofsky Performance Scale (KPS) ≥60, while adjuvant radiotherapy alone was preferred for patients with high-risk, WHO grade 2, and KPS ≥60. For newly diagnosed patients with glioblastoma, the most preferred adjuvant treatment strategy after surgery was radiotherapy plus temozolomide except for patients aged ≥70 years with KPS of 60 and unmethylated MGMT promoters. In patients with symptomatic brain metastasis, the preferred treatment differed according to the number of brain metastasis and performance status. For patients with newly diagnosed atypical meningioma, adjuvant radiation was deferred in patients with older age, poor performance status, complete resection, or low mitotic count. @*Conclusion@#It is imperative that proper medical care for brain tumor patients be sustained and provided, even during the crisis period. The findings of this consensus survey will be a useful reference in determining appropriate treatment options for brain tumor patients in the specific clinical scenarios covered by the survey during the future crisis.

6.
Korean Circulation Journal ; : 93-109, 2022.
Article in English | WPRIM | ID: wpr-917381

ABSTRACT

With the recent rapid increase in obesity worldwide, metabolic syndrome (MetS) has gained significant importance. MetS is a cluster of obesity-related cardiovascular risk factors including abdominal obesity, atherogenic dyslipidemia, high blood pressure and impaired glucose tolerance. MetS is highly prevalent and strongly associated with an increased risk of developing diabetes and cardiovascular disease, putting a great burden on human society. Therefore, it is very important to reduce MetS risk, which can improve patients’cardiovascular prognosis. The primary and most effective strategy to control each component of MetS is lifestyle change such as losing body weight, keeping regular exercise, adopting a healthy diet, quitting smoking and alcohol drinking in moderation. Many studies have shown that lifestyle modification has improved all components of MetS, and reduces the incidence of diabetes and cardiovascular disease. Here, the Korean Society of CardioMetabolic Syndrome has summarized specific and practical methods of lifestyle modification in the management of MetS in the healthcare field.

7.
Journal of Korean Neurosurgical Society ; : 130-137, 2022.
Article in English | WPRIM | ID: wpr-915611

ABSTRACT

Objective@#: COVID-19 has spread worldwide since the first case was reported in Wuhan, China, in December 2019. Our institution is a regional trauma and emergency center in the northern Gyeonggi Province. The changing trend of patient care in the emergency room of this hospital likely reflects the overall trend of patients in the area. In the present study, whether changes in the surrounding social environment following the outbreak of COVID-19 changed the incidence of neurosurgical emergency patients and whether differences in practice existed were investigated. @*Methods@#: The overall trend was analyzed from January 2020 which is before the outbreak of COVID-19 to September 2020. To remove bias due to seasonal variation, the previous 2 year's records during the same period were reviewed and compared. Confirmed COVID-19 patients in the northern Gyeonggi Province were identified using data released by the government. And patients who came to the emergency department with head trauma and stroke were identified. @*Results@#: Based on the present study results, the total number of neurosurgery emergency patients decreased over the study period. In the trauma patient group, the number of patients not involved in traffic accidents significantly decreased compared with patients involved in traffic accidents. Among the stroke cases, the rate of ischemic stroke was lower than hemorrhagic stroke, although a statistically significant difference was not observed. Meanwhile, an increase in the risk of mortality associated with trauma or stroke cases was not observed during the COVID-19 outbreak compared with the same time period in the previous year. @*Conclusion@#: Due to the occurrence of COVID-19, non-essential activities have decreased and trauma cases not associated with traffic accidents appeared to decrease. Due to the decrease in overall activity, the number of stroke patients has also decreased. This trend is expected to continue even in the post-COVID-19 era, and accordingly, the results from the present study are relevant especially if the current situation continues.

8.
Korean Journal of Dental Materials ; (4): 37-52, 2022.
Article in English | WPRIM | ID: wpr-938490

ABSTRACT

The objective of the present study was to investigate the effects of heat treatment (HT) time on the optical properties, mechanical properties, and microstructure of lithium disilicate (Li 2 Si 2 O 5) glass-ceramic blocks. Samples were prepared by cutting lithium disilicate glass-ceramic blocks – Amber® Mill Prototype (AMP) and IPS e.max CAD (IEC) – into a disc shape (diameter of 12 mm and thickness of 1.2 mm) and evenly polishing the surface. Each sample was heat treated according to the manufacturer’s manual and HT holding time was set to 15, 30, 45, and 60 minutes according to different groups. The samples were tested by color difference analysis using a spectrophotometer. X-ray diffraction analysis, HR FE-SEM observation, Vickers hardness test, fracture toughness test, and biaxial flexural strength test were carried out. The acicular crystals of lithium disilicate became coarser and less transparent with increasing HT time. The results for color difference (ΔE * ) compared to VITA A2 standard shade showed that the difference was significantly higher in the AMP groups than the IEC groups (P<0.05). Translucency parameter (TP) values were significantly higher in the AMP groups than the IEC groups (P<0.05). The AMP30 group showed the highest TP value, while all other experimental groups showed the tendency of decrease in TP value with increase in HT time. Moreover, increase in TP value was associated with decrease in contrast ratio. When fracture toughness was measured by indentation fracture method, both AMP and IEC groups showed similar results with 1.77 MPa·m 1/2 after HT for 15 minutes. However, as HT time increased, the IEC groups showed significantly higher values than the AMP groups (P<0.05). X-ray diffraction analysis results showed that quartz (SiO 2) and cristobalite (SiO 2) peaks were observed together with the lithium disilicate (Li 2Si 2O 5) peak in the AMP groups, whereas a lithium phosphate (Li 3PO 4) peak was observed together with the lithium disilicate (Li 2Si 2O 5) peak in the IEC groups. With respect to biaxial flexural strength in the AMP groups, the AMP15 group (HT for 15 minutes) showed the highest value of (524.09±89.95) MPa, whereas the AMP60 group (HT for 60 minutes) showed the lowest value of (446.56±76.75) MPa, with a significant difference between the two groups (P<0.05). In the IEC groups, IEC30 group showed the highest value of (668.51±158.57) MPa and the IEC45 group showed the lowest value of (517.37±129.52) MPa, with a significant difference between the two groups (P<0.05). Within the limitations of the present study, it is concluded that if increased strength is required when fabricating restorations using lithium disilicate glass-ceramic, then changing the HT time could be considered as long as such change does not significantly alter the color tone.

9.
Journal of the Korean Society of Emergency Medicine ; : 233-238, 2022.
Article in Korean | WPRIM | ID: wpr-938362

ABSTRACT

Objective@#Emergency cricothyroidotomy is an infrequently performed procedure and post-procedural complications may result from attempting to pass a device with a large external diameter through the cricothyroid membrane. This study aimed to determine the maximum height of the cricothyroid membrane according to the patient’ s sex and age based on cervical-spine computed tomography (C-spine CT) in the emergency department (ED) and determine the appropriate endotracheal tube (ETT) size. @*Methods@#A retrospective analysis of patients was conducted from May 2014 to April 2020 in the ED. The data were obtained from medical records. Electronic calipers were used to measure the maximum height of the cricothyroid membrane in C-spine CT by an emergency physician and an emergency medicine resident. @*Results@#Six hundred and sixty-four patients were included in the study. The mean height of the cricothyroid membrane was 10.11±2.24 mm in males (n=351) and 8.90±1.84 mm in females (n=313) (P<0.001). In males, the cricothyroid membrane height showed significant variance between the ≥75-year-old and the 25-34-year-old groups (9.26±2.40 mm vs. 11.80±2.36 mm) (P<0.001). The tube size of the cricothyroidotomy equipment was suitable for more than 72.1% of patients when applied with an ETT (internal diameter ≤6.0 mm). @*Conclusion@#This study showed that the height of the cricothyroid membrane differed according to sex and also age in males. It may thus be necessary to consider anatomical differences according to sex and age when selecting the appropriate tube size to reduce complications during emergency cricothyroidotomy.

10.
Korean Journal of Neurotrauma ; : 329-324, 2022.
Article in English | WPRIM | ID: wpr-969002

ABSTRACT

A lesion in the medial longitudinal fasciculus (MLF) causes internuclear ophthalmoplegia (INO). Many intracranial lesions, such as multiple sclerosis or vascular disorders may be associated with INO; however, INO is a rare complication of minor head injury. The mechanism underlying injury to the MLF may be shear force on the brain stem during head trauma. The shear force can tear or stretch the fibers of the MLF and can also lead to compromise or rupture of the perforating branches of the basilar artery. We present an unusual case of unilateral INO after minor head injury in a patient with a small site of hemorrhage in the midline of the pontomesencephalic junction, confirmed by brain magnetic resonance imaging using susceptibility-weighted imaging.

11.
Korean Journal of Neurotrauma ; : 3-11, 2022.
Article in English | WPRIM | ID: wpr-968976

ABSTRACT

The Neurotrauma Clinical Practice Guidelines Committee of the Korean Neurotraumatology Society (KNTS-NCPGC) is developing clinical guidelines for neurotrauma in line with the capabilities of the Korean Neurotraumatology Society, which is leading pioneering development in the field of neurosurgery. From the mid-1990s, the KNTS-NCPGC has been working to develop guidelines and disseminate evidence-based medicine, including the development of Korean guidelines for the management of severe head injuries and active participation in the Clinical Practice Guidelines Committee of the Korean Academy of Medical Sciences. The KNTS-NCPGC strives to write and inherit the will of the society through the development of clinical practice guidelines, which are one of the outcomes representing professionalism and public interest and can be expressed in terms of “trust” and “best.” In this review, the history and achievements of KNTS-NCPGC, the status of the ongoing development of guidelines, and the perspectives of the committee are covered.

12.
Korean Journal of Neurotrauma ; : 12-21, 2022.
Article in English | WPRIM | ID: wpr-968974

ABSTRACT

Chronic subdural hematoma (CSDH), which generally occurs in elderly patients, is a frequently diagnosed condition in neurosurgical departments. Computed tomography (CT) and magnetic resonance imaging (MRI) are the most preferred diagnostic modalities for CSDH assessment. With early diagnosis and adequate management, CSDH may show favorable prognosis in majority of the patients; however, recurrence after surgery can occur in a significant number of patients. The recently increasing number of CSDH studies could reveal the prognostic factors affecting CSDH recurrence. Particularly, radiological characteristics regarding the internal architecture of CSDH are considered closely associated with recurrence in surgically treated CSDH patients. In this literature review, we evaluated the various diagnostic modalities of CSDH and its radiological characteristics on CT and MRI. Furthermore, we summarized the prognostic factors of recurrence for the hematoma type based on the radiological findings.

13.
The Korean Journal of Orthodontics ; : 412-419, 2022.
Article in English | WPRIM | ID: wpr-968763

ABSTRACT

Objective@#This study evaluated the effect of cyclic pre-calcification treatment on the improvement of bioactivity and osseointegration of Ti-6Al-4V miniscrews. @*Methods@#The experimental groups were: an untreated group (UT), an anodized and heat-treated group (AH), and an anodized treatment followed by cyclic pre-calcification treatment group (ASPH). A bioactive material with calcium phosphate was coated on the mini-screws, and its effects on bioactivity and osseointegration were evaluated in in vitro and in vivo tests of following implantation in the rat tibia. @*Results@#As a result of immersing the ASPH group in simulated body fluid for 2 days, protrusions appearing in the initial stage of hydroxyapatite precipitation were observed. On the 3rd day, the protrusions became denser, other protrusions overlapped and grew on it, and the calcium and phosphorus concentrations increased. The removal torque values increased significantly in the following order: UT group (2.08 ± 0.67 N·cm), AH group (4.10 ± 0.72 N·cm), and ASPH group (6.58 ± 0.66 N·cm) with the ASPH group showing the highest value (p < 0.05). In the ASPH group, new bone was observed that was connected to the threads, and it was confirmed that a bony bridge connected to the adjacent bone was formed. @*Conclusions@#In conclusion, it was found that the surface treatment method used in the ASPH group improved the bioactivity and osseointegration of Ti-6Al-4V orthodontic miniscrews.

14.
Korean Journal of Dental Materials ; (4): 213-232, 2022.
Article in English | WPRIM | ID: wpr-968026

ABSTRACT

Gelatin methacryloyl 3d mesh mimics the natural extracellular matrix which allow loading as promising drug delivery systems.However, insufficient mechanical and degradation properties remain the biggest obstacle for this material application. In this study, a modified hydrogel with natural phytochemical was developed to improve the antibacterial effect by the addition of ginger extract, a natural spicy used in traditional medicine. GelMA hydrogels with ginger extract were fabricated and their chemical and morphological characteristics were analyzed by Fourier transformer infrared spectroscopy and scanning electron microscopy, structural characteristic were evaluated by compressive test and surface wettability analysis. S. mutans, S. aureus and P. gingivalis were used to confirm the antibacterial effect of the modified hydrogels. The FT-IR spectra of the hydrogels modified with ginger presented an increase in intensity of some peaks in comparison with the 10% GelMA hydrogel. The pores of ginger-modified hydrogels decreased it size which affected the hydrogels physical properties, decreasing the compressive modulus and increasing the durability, swelling ratio and, hydrophobicity of the surface. The ginger-modified hydrogels exhibited excellent antibacterial properties against S. mutans and S. aureus at high concentrations of ginger extract, while P. gingivalis presented a higher sensitivity at all tested concentrations. Hence, this study concludes that ginger-modified GelMA hydrogels presented better antibacterial effect, durability over time and, swelling stability.

15.
Journal of Korean Neurosurgical Society ; : 255-268, 2022.
Article in English | WPRIM | ID: wpr-926027

ABSTRACT

Objective@#: Chronic subdural hematoma (CSDH) is a common disease in neurosurgical departments, but optimal perioperative management guidelines have not yet been established. We aimed to assess the current clinical management and outcomes for CSDH patients and identify prognostic factors for CSDH recurrence. @*Methods@#: We enrolled a total of 293 consecutive patients with CSDH who underwent burr hole craniostomy at seven institutions in 2018. Clinical and surgery-related characteristics and surgical outcomes were analyzed. The cohort included 208 men and 85 women. @*Results@#: The median patient age was 75 years. Antithrombotic agents were prescribed to 105 patients. History of head trauma was identified in 59% of patients. Two hundred twenty-seven of 293 patients (77.5%) had unilateral hematoma and 46.1% had a homogenous hematoma type. About 70% of patients underwent surgery under general anesthesia, and 74.7% underwent a single burr hole craniostomy surgery. Recurrence requiring surgery was observed in 17 of 293 patients (5.8%), with a median of 32 days to recurrence. The postoperative complication rate was 4.1%. In multivariate analysis, factors associated with CSDH recurrence were separated hematoma type (odds ratio, 3.906; p=0.017) and patient who underwent surgery under general anesthesia had less recurrence (odds ratio, 0.277; p=0.017). @*Conclusion@#: This is the first retrospective multicenter generalized cohort pilot study in the Republic of Korea as a first step towards the development of Korean clinical practice guidelines for CSDH. The type of hematoma and anesthesia was associated with CSDH recurrence. Although the detailed surgical method differs depending on the institution, the surgical treatment of CSDH was effective. Further studies may establish appropriate management guidelines to minimize CSDH recurrence.

16.
Korean Journal of Legal Medicine ; : 14-21, 2021.
Article in Korean | WPRIM | ID: wpr-917823

ABSTRACT

Numerous methods for human body fluid identification using microbiological markers specific to different human body parts are well-established in forensic science. However, method for vaginal fluid screening have not been standardized yet. Therefore, in this study, a real-time polymerase chain reaction based assay for vaginal fluid identification was devised using bacteria residing in human vagina. This method employed three markers, namely Lactobacillus iners, Lactobacillus crispatus, and Bacteroides fragilis. L. iners and L. crispatus were chosen due to their high abundance in the vagina, whereas B. fragilis resides in the rectum. To examine the suitability of the new method for forensic microbial applications, a study of the distribution of vaginal flora in 143 Korean women was performed, along with characterization of the specificity, and performance of the new assay. Additionally, a casework study based on 130, 21, 20 and 17 DNA samples collected from the vagina, anus, saliva, blood, respectively, was carried out. L. iners (80.4%) and L. crispatus (55.2%) were detected with high abundance in the vagina of Korean women. The specificity of these markers was verified using microbial DNA from 23 species. This method could detect at least 1,000 copies/µL of microorganisms for all markers, thereby highlighting its robust sensitivity for vaginal fluid identification. The casework study confirmed these findings, with 89.2% (116/130) detection of vaginal fluid-derived DNA samples, and no false positives identified from the other sources studied. In conclusion, the developed method is expected to be efficient for preliminary microbiological analysis of vaginal samples in forensics.

17.
Korean Journal of Dental Materials ; (4): 229-244, 2021.
Article in English | WPRIM | ID: wpr-917593

ABSTRACT

Surface treatment was conducted to reduce dissolution of Mg mesh and to improve bioactivity in physiological environment. Mg mesh was immersed in 40 wt% hydrofluoric (HF) solution for 2 hours to form a protective coating layer. Then, hydrothermal treatment was performed in a mixed solution of Ca(NO3)2·4H2O and Na2HPO 4 at 90 ℃ for 30 minutes, and cyclic precalcification treatment was conducted by soaking in each 0.06 M NH 4H 2PO4 solution and 0.011 M Ca(OH)2 solution in turn at 90 ℃. Immersion test was performed in simulated body fluid (SBF) to investigate solubility and bioactivity. Release characteristics were investigated after loading ibandronate to suppress initial bone resorption. Bone regeneration ability was evaluated through micro-CT analysis and conforming inflammatory cytokines levels in blood. Fine granular calcium phosphate-based materials were precipitated as clusters on the surface treated in cyclic precalcification. Agglomerated calcium phosphate precipitates on the surface were observed after SBF immersion. pH in SBF during immersion increased slowly in hydrothermal treatment and cyclic precalcification groups compared to pure Mg group. Release of ibandronate occurred over 6 days in cyclic precalcification treatment group (CP-H1). IL-1β and IL-6 were significantly lower than those of untreated group in all test groups except for the group (CP-H4) that was heat-treated at 400 ℃ after pretreatment with circulating calcification. As a result of micro-CT analysis, the new bone volume and density were significantly higher in the CP-H1 group. It was concluded that cyclic precalcification treatment after formation of fluorine protective layer on Mg mesh could retard the dissolution and enhanced bone regeneration ability.

18.
Korean Journal of Dental Materials ; (4): 245-254, 2021.
Article in English | WPRIM | ID: wpr-917592

ABSTRACT

This study was performed to evaluate the effect of cyclic precalcification treatment on the improvement of bioactivity of Ti-6Al-4V mini-screws. The cutted plate-shaped specimens of 10 mm × 10 mm dimensions, and a mini-screw with a diameter of 1.6 mm × 6.0 mm in length were used. Anodic oxidation treatment was carried out in a glycerol electrolyte solution containing 20 wt% H2O and 1.5 wt% NH 4F. Voltage of 20 V with current density of 20 mA/cm2 was applied for 1 hour to form a nanotube TiO2 layer. Afterwards, to improve the bioactivity, specimens were immersed in 0.5 vol% silica aqueous solution at 37 ℃ for 5 minutes, and then cyclic precalcification treatment with 0.05 M NH 4H2PO4and 0.01 M Ca(OH)2 solution at 90 ℃ was repeated with 20 times. Based on surface treatment the experimental groups were divided into three groups, namely untreated group (UT), anodized and heat-treated group (AH), and anodized, silica-treated, cyclic precalcified and heat-treated group (ASPH). There were TiO2 nanotubes completely self-aligned and formed in a dense structure on the surface after anodic oxidation treatment. A fine granular cluster layer of hydroxyapatite and octacalcium phosphate were formed on the surface after the cyclic precalcification treatment. As a result of immersion test in the simulated body fluid (SBF), bioactivity was confirmed to be improved by the precipitation of protrusions appearing at the initial stage of formation of hydroxyapatite.

19.
The Korean Journal of Internal Medicine ; : 898-905, 2021.
Article in English | WPRIM | ID: wpr-903683

ABSTRACT

Background/Aims@#Beta-blockers (BBs) have been shown to improve clinical outcomes in heart failure (HF) patients. We evaluated the prescribing status of BBs in patients with HF with reduced ejection fraction (HFrEF) at discharge according to the presence or not of bradycardia, and its effect on prognosis. @*Methods@#Study data were obtained from a multicenter cohort of 3,200 patients hospitalized for HF. Patients were classified into four groups according to the presence of bradycardia and use of BBs at discharge. The primary outcome was the incidence of all-cause death during follow-up. @*Results@#Of 1,584 patients with HFrEF, 281 patients died during follow-up (median 523 days, mean 578.5 ± 429.7 days). In patients with bradycardia, the all-cause death rate did not significantly differ according to the use of BBs, but in those patients without bradycardia, the incidence of all-cause death was significantly lower in the BBs group than the no BBs group. Among these four groups, patients with heart rate (HR) ≥ 60 beats/min with no BBs group had the lowest cumulative death-free survival rate. In addition, HR ≥ 60 beats/min with BBs use was independently associated with a 31% reduced risk of all-cause death in patients with HFrEF. @*Conclusions@#BBs had a beneficial effect on clinical prognosis only in those HFrEF patients without bradycardia. Therefore, BBs should be given by clinicians to HF patients without bradycardia to improve their clinical outcomes.

20.
Korean Journal of Dental Materials ; (4): 159-174, 2021.
Article in English | WPRIM | ID: wpr-901915

ABSTRACT

Ginger has been used worldwide in traditional medicine. It has been reported that phenolic compounds such as gingerol and shogaol in ginger have beneficial cellular effect and antibacterial effect. The purpose of this study was to investigate the effect of gingerol and shogaol on the cytocompatibility for the osteoblastic cells and antibacterial activity against oral microorganisms. Chemical structures of gingerol and shogaol were determined by Fourier transform infrared (FT-IR). Thermal and pH stability was analyzed by UPLC assay. Streptococcus mutans, and Porphyromonas gingivalis were used to confirm the antibacterial effect of the ginger compounds and MC3T3-E1 cells were used to identify biocompatibility test. Cell viability and bacterial growth was determined by water-soluble tetrazolium salt (WST-8) colorimetric assay. Cellular morphology was identified with optical microscope after crystal violet staining. Cell differentiation and oxidative stress were evaluated by Alkaline phosphatase (ALP) assay and hydrogen peroxide colorimetric assay. The chemical bonding related with hydroxyl groups, carbonyl groups and aromatic ring was identified in all ginger compounds. Gingerol and shogaol presented good stability at acid and neutral pH at room temperature. All compounds showed better antibacterial effect against Porphyromonas gingivalis than Streptococcus mutans. 10-gingerol and all shogaol groups below 10-6 M presented suitable cytocompatibility for osteoblastic cells compared to control group. All groups showed similar Oxidative stress to control group, and ALP activity in all groups below 10-6 M was not statistically significant compared to control. Hence, this study concludes that shogaol groups presented better antibacterial effect and suitable cytocompatibility than gingerol groups.

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