1.Polishing characteristics of polyetherketoneketone on Candida albicans adhesion
Hyunyoung KIM ; Jonghyuk LEE ; Sung-Hoon LEE ; Dongheon BAEK
The Journal of Korean Academy of Prosthodontics 2020;58(3):207-216
Purpose:
To compare the polishing characteristics and their influence on Candida albicans adhesion to the recently introduced polyetherketoneketone (PEKK) and the conventional polymethylmethacrylate (PMMA) denture resin material.
Materials and methods:
Specimens from PEKK (Group E) and PMMA (Group M) were made in dimensions of 8 mm in diameter and 2 mm in thickness. The specimens were further divided into sub-groups according to the extent of polishing (ER, MR: rough; EP, MP: polished, N = 12 each). The specimens were polished using polishing machine and SiC foil. ER and MR group specimens were polished with 600 grit SiC foil only. EP and MP groups were further polished with 800, 1,000, 1,200 grit SiC foils sequentially. To measure the surface roughness values (Sa) of specimens, atomic force microscope (AFM) was used and scanning electron microscope (SEM) observation under 1,000, and 20,000 magnifications was performed to investigate surface topography. The polished specimens were soaked in C. albicans suspension for 2 hours with shaking to promote adhesion. The attached C. albicans were detached from the surface with 10 times of pipetting. The suspension of detached C. albicans was performed by serial dilution to 103 times, and the diluted suspensions were inoculated on Sabouraud dextrose agar plates using spread plate method. After incubating the plate for 48 hours, colony forming unit (CFU)/plate of C. albicans was counted. Statistical analysis was performed using one-way ANOVA and Tukey HSD test to confirm significant difference between the groups (α=.05).
Results:
Average Sa value was significantly higher in MR group compared to other groups (P<.05), meaning that additional polishing steps reduced surface roughness effectively only in the PMMA specimens. There was no significant difference in Sa values between MP and EP groups. In SEM images, PEKK specimens showed numerous spikes of abraded material protruding from the surface and this phenomenon was more significant in EP group. The mean CFU/plate value was the highest in EP group and this was significant when it was compared to MP group (P<.05) which was the lowest.
Conclusion
Polishing PEKK using serial SiC abrasive foil may result in higher adhesion of C. albicans. In clinic, this should be considered carefully.
2.Midterm Results of Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Human Immunodeficiency Virus-Infected Patients in South Korea
Jonghyuk BAEK ; Hong Seok KIM ; Nam Joong KIM ; Jeong Joon YOO
Clinics in Orthopedic Surgery 2023;15(3):367-372
Background:
Studies have reported that osteonecrosis of the femoral head (ONFH) is more prevalent in patients with human immunodeficiency virus (HIV). Total hip arthroplasty (THA) is considered reasonable management of ONFH. However, only scarce data exist on the outcomes of THA for HIV-infected patients in South Korea. The purpose of this study was to evaluate the midterm results of HIV-positive patients who underwent THA for ONFH.
Methods:
We performed a retrospective review of HIV-infected patients with ONFH who underwent THA in our institution from 2005 to 2021. Twenty-two hips in 15 patients underwent THAs with cementless implants. The clinical and radiographic evaluation was performed at each follow-up, and any complication was recorded.
Results:
The mean follow-up period was 5.2 years (range, 1.0–16.0 years). The mean age of the HIV infected patients with osteonecrosis at the time of surgery was 44.7 ± 11.6 years. ONFH occurred 9.8 ± 3.7 years after the initial diagnosis of HIV infection.The average modified Harris hip score improved from 58.3 ± 14.8 to 95.2 ± 11.3 at the latest follow-up. Surgical complications such as infection, nerve injury, or dislocation were not present. The radiographic evidence of stable fixation by bone ingrowth without migration was seen in all implants.
Conclusions
Our data suggest that THA is a safe and valid option of treatment for ONFH in well-controlled HIV-infected patients in Korea. Further large-scale nationwide studies are warranted.
3.Prognostic significance of programmed cell death-ligand 1 expression on immune cells and epithelialmesenchymal transition expression in patients with hepatocellular carcinoma
Hae Il JUNG ; Hyein AHN ; Mee-Hye OH ; JongHyuk YUN ; Hyunyong LEE ; Sang Ho BAE ; Yung Kil KIM ; Sung Yong KIM ; Moo-Jun BAEK ; Moon-Soo LEE
Annals of Surgical Treatment and Research 2023;105(5):297-309
Purpose:
Immune checkpoint inhibitors (ICIs) have been shown significant oncological improvements in several cancers.However, ICIs are still in their infancy in hepatocellular carcinoma (HCC). Programmed cell death-ligand 1 (PD-L1), tumorinfiltrating lymphocytes (TILs), and epithelial-mesenchymal transition (EMT) have been known as prognostic factors in HCC. Therefore, we have focused on identifying the molecular mechanisms between each marker to evaluate a predictive role.
Methods:
Formalin-fixed paraffin-embedded samples were obtained from 166 patients with HCC who underwent surgery. The expression of PD-L1 and TILs and EMT marker were evaluated by immunohistochemical analysis.
Results:
The multivariate analysis showed that TIL expression (hazard ratio [HR], 0.483; 95% confidence interval [CI], 0.269–0.866; P = 0.015) were independent prognostic factors for overall survival. The prognostic factors for disease-free survival were EMT marker expression (HR, 1.565; 95% CI, 1.019–2.403; P = 0.005). Patients with high expression of TILs had significantly better survival compared to patients with low expression (P = 0.023). Patients who were TIL+/EMT– showed a significantly better prognosis than those who were TIL–/EMT+ (P = 0.049).
Conclusion
This study demonstrates that PD-L1 expression of TILs is closely associated with EMT marker expression in HCC. Clinical investigations using anti–PD-1/PD-L1 inhibitors in patients with EMT-associated PD-L1 upregulation are warranted.