Effects of the Severity of Stenosis on Clinical Outcomes of Indirect Decompression Using Oblique Lumbar Interbody Fusion.

Background: No consensus has been reached regarding the efficacy of indirect decompression through oblique lumbar interbody fusion (OLIF) in severe lumbar spinal stenosis (LSS). This study investigated the impact of preoperative magnetic resonance imaging (MRI)-based grading of central and foraminal stenosis on OLIF outcomes in LSS patients and identified risk factors for postoperative clinical dissatisfaction. Methods: We retrospectively reviewed LSS patients who underwent OLIF with a minimum 1-year follow-up. Clinical scores obtained preoperatively and at 3, 6, 12, and 24 months postoperatively were analyzed using the substantial clinical benefit (SCB) framework. The severity of central and foraminal stenosis in the initial MRI was assessed through qualitative grading systems. Results: Among the 145 patients, with a mean follow-up of 33.7 months, those with severe central stenosis showed a significantly higher proportion of patients achieving SCB in the visual analog scale for leg pain (94.5% versus 83.1%; p = 0.044) at one year postoperatively than those without. However, those with severe foraminal stenosis showed significantly higher Oswestry Disability Index (ODI) scores (p = 0.024), and lower walking ability scores in the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) (p = 0.004) at one year postoperatively than those without. The presence of a foraminal osteophyte of the superior articular process (SAP) was a significant risk factor responsible for not achieving SCB in ODI and walking ability in JOABPEQ at one year postoperatively (odds ratio: 0.20 and 0.22, respectively). Conclusions: After OLIF, patients with severe central stenosis showed clinical outcomes comparable to those without. The improvement in ODI and walking ability in JOABPEQ was limited in patients with severe foraminal stenosis. Surgeons should consider direct decompression in cases with the presence of foraminal osteophytes of SAP.

Midterm Results of Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Human Immunodeficiency Virus-Infected Patients in South Korea.

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.

Application of codon pair deoptimization for ORF7-induced attenuation of type I porcine reproductive and respiratory syndrome virus without reduced immune responses.

Codon pair deoptimization (CPD) attenuated type I porcine reproductive and respiratory syndrome virus (PRRSV). Infectious clones covering the full genome of a Korean type I PRRSV (E38) were synthesized, and CPD induced nine synonymous mutants of NSP1 (n = 1) and ORF7 (n = 8). In a trial to rescue live viruses from infectious clones, only four clones with mutations at nt 177 downstream of ORF7 were rescued, which showed a substantial decrease in cellular replication ability. The rescue-failed clones had two common mutation sites with a high minimum free energy and significantly modified RNA secondary structure relative to the original virus. In infected pigs, CPD viruses demonstrated significantly lower replication ability and pathogenicity than the original virus. However, immune response level induced by the attenuated viruses and the original virus was similar. This is the first study to demonstrate that type I PRRSV virulence can be attenuated through CPD application to ORF7.

Minimal Dosage of Porcine Circovirus Type 2d Based Virus-like Particles to Induce Stable Protective Immunity against Infection.

In recent years, porcine circovirus type 2d (PCV2d) has achieved a dominant position worldwide. Various PCV2d capsid-based vaccines have been used to alleviate concerns regarding the emergence of the variant. This study aimed to determine the dosage of recombinant PCV2d capsid protein to induce protective efficacy against experimental challenge with a virulent PCV2d strain. Conventional 3-week-old pigs were intramuscularly inoculated with different doses of the protein (60, 20, 10 and 2 µg). Four weeks after vaccination, all pigs were challenged with pathogenic PCV2d (SNU140003), which was isolated from a farm severely experiencing PCV2-associated disease in Korea. Vaccination with greater than 10 µg of the capsid protein caused a significant (p < 0.05) reduction in PCV2d viremia, lymphoid lesions and lymphoid PCV2 antigen levels in vaccinated challenged pigs compared to unvaccinated challenged pigs. The vaccination also resulted in significantly higher (p < 0.05) titers of neutralizing antibodies against PCV2d. However, the pigs vaccinated with 2 µg had significantly lower neutralizing antibody titers than the other vaccinated groups. They showed a similar level of challenged PCV2d in serum and lymphoid lesion score compared to unvaccinated challenged pigs. The difference in efficacy among the vaccinated groups indicates that there may be a baseline dosage to induce sufficient neutralizing antibodies to prevent viral replication in pigs. In conclusion, at least 10 µg dosage of capsid protein is essential for stable protective efficacy against PCV2d in a pig model.

The first assessment to detect Mycoplasma hyopneumoniae by sampling laryngeal swabs to investigate sow stability in South Korea.

BACKGROUND: Mycoplasma hyopneumoniae (M. hyopneumoniae), a representative pathogen causing swine enzootic pneumonia, generally infects piglets vertically. However, it is difficult to ascertain the M. hyopneumoniae infection state of sows due to limited detection methods. This report investigated sow herd stability by applying nested PCR to laryngeal swabs of suckling pigs, which is reportedly the most sensitive method. RESULTS: M. hyopneumoniae was detected in 14 farms (63.6%) and 127 piglets (6.5%). The prevalence of sows likely to transmit M. hyopneumoniae in herds (11.1%) was calculated. In addition, there was a significant difference in detection rates among farms depending on herd size, gilt replacement rate, acclimation method, and antibiotic usage, suggesting various parameters that influence sow stability. CONCLUSIONS: The results demonstrated that laryngeal swabs from suckling pigs have provided useful information regarding vertical transmission from sows in South Korean farm conditions. This result demonstrated that farms with larger herd sizes, higher gilt replacement rates, and a practice of naturally exposing gilts for acclimation had higher detection rates in weaning piglets, indicating an unstable sow infection state.

Postoperative Longitudinal Outcomes in Patients with Residual Disc Fragments after Percutaneous Endoscopic Lumbar Discectomy.

BACKGROUND: Residual disc fragments are observed on immediate postoperative magnetic resonance imaging (MRI) in 2.8-15% of patients after percutaneous endoscopic lumbar discectomy (PELD). Considering the known postoperative longitudinal outcomes in patients with residual disc tissue, a 'watchful waiting' strategy may be preferable to immediate re-operation in patients with asymptomatic residual disc material. OBJECTIVES: The aim of the present study was to compare the longitudinal clinical outcomes between PELD patients in whom the complete removal of disc fragments was achieved (complete group) and those in whom residual disc fragments were observed on postoperative MRI (residual group). STUDY DESIGN: Retrospective nested case-control study. METHODS: A total of 225 patients were included (complete group, n=187 and residual group, n=38). Clinical assessments were performed using the visual analog pain score for the leg (VAS-L, x/10) and back (VAS-B, x/10) and the Korean version of the Oswestry Disability Index (K-ODI, x/45). A linear mixed-effects model was used to analyze changes during the first 24 postoperative months. RESULTS: One month after surgery, significant improvements in the VAS-L, VAS-B and K-ODI values were observed and were maintained during the first 24 postoperative months. No differences in these changes were noted between the groups. Early re-operation (during the first 3 postoperative months) was performed in 3 patients in the residual group (7.9%) and in 4 patients in the complete group (2.1%) (P = 0.10). LIMITATIONS: First, the study design was retrospective. Moreover, the number of patients was relatively small and therefore insufficient to achieve robust statistical power. Second, we did not explore the radiological outcomes in patients with asymptomatic residual disc material because follow-up MRI was only obtained to document symptom recurrence. CONCLUSION: When residual disc tissue is observed in asymptomatic patients, a 'watchful waiting' strategy may be preferable to immediate re-operation. However, an increased early re-operation rate is expected for patients with residual disc tissue. KEY WORDS: Discectomy, endoscopes, longitudinal studies, patient-reported outcome, percutaneous, reoperation, spine, residual disc.

Bacterial Overexpression and Denaturing Purification of VPS34-Binding Domain of Beclin 1.

As a scaffolding subunit of the PIK3C3/VPS34 complex, Beclin 1 recruits a variety of proteins to class III phosphatidylinositol-3-kinase (VPS34), resulting in the formation of a distinct PIK3C3/VPS34 complex with a specific function. Therefore, the investigation of a number of Beclin 1 domains required for the protein-protein interactions will provide important clues to understand the PIK3C3/VPS34 complex, of which Beclin1-VPS34 interaction is the core unit. In the present study, we have designed a bacterial overexpression system for the Beclin 1 domain corresponding to VPS34 binding (Vps34-BD) and set up the denaturing purification protocol due to the massive aggregation of Vps34-BD in Escherichia coli. The expression and purification conditions determined in this study successfully provided soluble and functional Vps34-BD.

Development of in vitro PIK3C3/VPS34 complex protein assay for autophagy-specific inhibitor screening.

Autophagy is an important catabolic program to respond to a variety of cellular stresses by forming a double membrane vesicle, autophagosome. Autophagy plays key roles in various cellular functions. Accordingly, dysregulation of autophagy is closely associated with diseases such as diabetes, neurodegenerative diseases, cardiomyopathy, and cancer. In this sense, autophagy is emerging as an important therapeutic target for disease control. Among the autophagy machineries, PIK3C3/VPS34 complex functions as an autophagy-triggering kinase to recruit the subsequent autophagy protein machineries on the phagophore membrane. Accumulating evidence showing that inhibition of PIK3C3/VPS34 complex successfully inhibits autophagy makes the complex an attractive target for developing autophagy inhibitors. However, one concern about PIK3C3/VPS34 complex is that many different PIK3C3/VPS34 complexes have distinct cellular functions. In this study, we have developed an in vitro PIK3C3/VPS34 complex monitoring assay for autophagy inhibitor screening in a high-throughput assay format instead of targeting the catalytic activity of the PIK3C3/VPS34 complex, which shuts down all PIK3C3/VPS34 complexes. We performed in vitro reconstitution of an essential autophagy-promoting PIK3C3/VPS34 complex, Vps34-Beclin1-ATG14L complex, in a microwell plate (96-well format) and successfully monitored the complex formation in many different conditions. This PIK3C3/VPS34 complex protein assay would provide a reliable tool for the screening of autophagy-specific inhibitors.